diff --git a/include/swift/ABI/ObjectFile.h b/include/swift/ABI/ObjectFile.h
index 2158215c4862f..fddf9c7e064e2 100644
--- a/include/swift/ABI/ObjectFile.h
+++ b/include/swift/ABI/ObjectFile.h
@@ -83,7 +83,7 @@ class SwiftObjectFileFormatELF : public SwiftObjectFileFormat {
   }
 };
 
-/// Responsible for providing the COFF reflection section identifiers
+/// Responsible for providing the COFF reflection section identifiers.
 class SwiftObjectFileFormatCOFF : public SwiftObjectFileFormat {
 public:
   llvm::StringRef getSectionName(ReflectionSectionKind section) override {
@@ -101,5 +101,28 @@ class SwiftObjectFileFormatCOFF : public SwiftObjectFileFormat {
     return sectionName.starts_with(".sw5");
   }
 };
+
+/// Responsible for providing the WebAssembly reflection section identifiers.
+/// WebAssembly binaries store all reflection metadata in the DATA
+/// section. There are symbols for each reflection section kind in the "name"
+/// section that point to the corresponding offset inside DATA.
+class SwiftObjectFileFormatWasm : public SwiftObjectFileFormat {
+public:
+  llvm::StringRef getSectionName(ReflectionSectionKind section) override {
+    switch (section) {
+#define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF)                           \
+  case KIND:                                                                   \
+    return ELF;
+#include "llvm/BinaryFormat/Swift.def"
+#undef HANDLE_SWIFT_SECTION
+    }
+    llvm_unreachable("Section  not found.");
+  }
+
+  bool sectionContainsReflectionData(llvm::StringRef sectionName) override {
+    return sectionName.starts_with("swift5_");
+  }
+};
+
 } // namespace swift
 #endif // SWIFT_ABI_OBJECTFILE_H
diff --git a/include/swift/AST/Attr.h b/include/swift/AST/Attr.h
index 3d010447b27f3..2aeb34da2b65c 100644
--- a/include/swift/AST/Attr.h
+++ b/include/swift/AST/Attr.h
@@ -1098,7 +1098,7 @@ class ObjCAttr final : public DeclAttribute,
     unsigned length = 2;
     if (auto name = getName())
       length += name->getNumSelectorPieces();
-    return {getTrailingObjects<SourceLoc>(), length};
+    return getTrailingObjects(length);
   }
 
   /// Retrieve the trailing location information.
@@ -1107,7 +1107,7 @@ class ObjCAttr final : public DeclAttribute,
     unsigned length = 2;
     if (auto name = getName())
       length += name->getNumSelectorPieces();
-    return {getTrailingObjects<SourceLoc>(), length};
+    return getTrailingObjects(length);
   }
 
 public:
@@ -1283,14 +1283,14 @@ class DynamicReplacementAttr final
   MutableArrayRef<SourceLoc> getTrailingLocations() {
     assert(Bits.DynamicReplacementAttr.HasTrailingLocationInfo);
     unsigned length = 2;
-    return {getTrailingObjects<SourceLoc>(), length};
+    return getTrailingObjects(length);
   }
 
   /// Retrieve the trailing location information.
   ArrayRef<SourceLoc> getTrailingLocations() const {
     assert(Bits.DynamicReplacementAttr.HasTrailingLocationInfo);
     unsigned length = 2; // lParens, rParens
-    return {getTrailingObjects<SourceLoc>(), length};
+    return getTrailingObjects(length);
   }
 
 public:
@@ -1480,8 +1480,7 @@ class SPIAccessControlAttr final : public DeclAttribute,
   /// Note: A single SPI name per attribute is currently supported but this
   /// may change with the syntax change.
   ArrayRef<Identifier> getSPIGroups() const {
-    return { this->template getTrailingObjects<Identifier>(),
-             numSPIGroups };
+    return getTrailingObjects(numSPIGroups);
   }
 
   static bool classof(const DeclAttribute *DA) {
@@ -2059,11 +2058,11 @@ class StorageRestrictionsAttr final
   unsigned getNumAccessesProperties() const { return NumAccesses; }
 
   ArrayRef<Identifier> getInitializesNames() const {
-    return {getTrailingObjects<Identifier>(), NumInitializes};
+    return getTrailingObjects(NumInitializes);
   }
 
   ArrayRef<Identifier> getAccessesNames() const {
-    return {getTrailingObjects<Identifier>() + NumInitializes, NumAccesses};
+    return {getTrailingObjects() + NumInitializes, NumAccesses};
   }
 
   ArrayRef<VarDecl *> getInitializesProperties(AccessorDecl *attachedTo) const;
@@ -2562,10 +2561,10 @@ class DifferentiableAttr final
   /// The parsed differentiability parameters, i.e. the list of parameters
   /// specified in 'wrt:'.
   ArrayRef<ParsedAutoDiffParameter> getParsedParameters() const {
-    return {getTrailingObjects<ParsedAutoDiffParameter>(), NumParsedParameters};
+    return getTrailingObjects(NumParsedParameters);
   }
   MutableArrayRef<ParsedAutoDiffParameter> getParsedParameters() {
-    return {getTrailingObjects<ParsedAutoDiffParameter>(), NumParsedParameters};
+    return getTrailingObjects(NumParsedParameters);
   }
   size_t numTrailingObjects(OverloadToken<ParsedAutoDiffParameter>) const {
     return NumParsedParameters;
@@ -2747,10 +2746,10 @@ class DerivativeAttr final
   /// The parsed differentiability parameters, i.e. the list of parameters
   /// specified in 'wrt:'.
   ArrayRef<ParsedAutoDiffParameter> getParsedParameters() const {
-    return {getTrailingObjects<ParsedAutoDiffParameter>(), NumParsedParameters};
+    return getTrailingObjects(NumParsedParameters);
   }
   MutableArrayRef<ParsedAutoDiffParameter> getParsedParameters() {
-    return {getTrailingObjects<ParsedAutoDiffParameter>(), NumParsedParameters};
+    return getTrailingObjects(NumParsedParameters);
   }
   size_t numTrailingObjects(OverloadToken<ParsedAutoDiffParameter>) const {
     return NumParsedParameters;
@@ -2838,10 +2837,10 @@ class TransposeAttr final
   /// The parsed linearity parameters, i.e. the list of parameters specified in
   /// 'wrt:'.
   ArrayRef<ParsedAutoDiffParameter> getParsedParameters() const {
-    return {getTrailingObjects<ParsedAutoDiffParameter>(), NumParsedParameters};
+    return getTrailingObjects(NumParsedParameters);
   }
   MutableArrayRef<ParsedAutoDiffParameter> getParsedParameters() {
-    return {getTrailingObjects<ParsedAutoDiffParameter>(), NumParsedParameters};
+    return getTrailingObjects(NumParsedParameters);
   }
   size_t numTrailingObjects(OverloadToken<ParsedAutoDiffParameter>) const {
     return NumParsedParameters;
@@ -3492,8 +3491,8 @@ class AllowFeatureSuppressionAttr final
   bool getInverted() const { return Bits.AllowFeatureSuppressionAttr.Inverted; }
 
   ArrayRef<Identifier> getSuppressedFeatures() const {
-    return {getTrailingObjects<Identifier>(),
-            static_cast<size_t>(Bits.AllowFeatureSuppressionAttr.NumFeatures)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.AllowFeatureSuppressionAttr.NumFeatures));
   }
 
   static bool classof(const DeclAttribute *DA) {
diff --git a/include/swift/AST/AvailabilityContextStorage.h b/include/swift/AST/AvailabilityContextStorage.h
index a110d8ccdce1d..beae4a6df6ba1 100644
--- a/include/swift/AST/AvailabilityContextStorage.h
+++ b/include/swift/AST/AvailabilityContextStorage.h
@@ -82,7 +82,7 @@ class AvailabilityContext::Storage final
                             const ASTContext &ctx);
 
   llvm::ArrayRef<DomainInfo> getDomainInfos() const {
-    return llvm::ArrayRef(getTrailingObjects<DomainInfo>(), domainInfoCount);
+    return getTrailingObjects(domainInfoCount);
   }
 
   llvm::SmallVector<DomainInfo, 4> copyDomainInfos() const {
diff --git a/include/swift/AST/Builtins.h b/include/swift/AST/Builtins.h
index 799fd3514feec..213a61ff50a70 100644
--- a/include/swift/AST/Builtins.h
+++ b/include/swift/AST/Builtins.h
@@ -121,12 +121,13 @@ class BuiltinInfo {
 
 /// The information identifying the llvm intrinsic - its id and types.
 class IntrinsicInfo {
-  mutable llvm::AttributeList Attrs =
-      llvm::DenseMapInfo<llvm::AttributeList>::getEmptyKey();
+  mutable llvm::AttributeSet FnAttrs =
+      llvm::DenseMapInfo<llvm::AttributeSet>::getEmptyKey();
+
 public:
   llvm::Intrinsic::ID ID;
   SmallVector<Type, 4> Types;
-  const llvm::AttributeList &getOrCreateAttributes(ASTContext &Ctx) const;
+  const llvm::AttributeSet &getOrCreateFnAttributes(ASTContext &Ctx) const;
 };
 
 /// Turn a string like "release" into the LLVM enum.
diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
index 89a203f3708ac..09c780101eece 100644
--- a/include/swift/AST/Decl.h
+++ b/include/swift/AST/Decl.h
@@ -1777,8 +1777,8 @@ class ImportDecl final : public Decl,
   ///          path will include 'Foo'. This return value is always owned by \c ImportDecl
   ///          (which is owned by the AST context), so it can be persisted.
   ImportPath getImportPath() const {
-    return ImportPath({ getTrailingObjects<ImportPath::Element>(),
-                        static_cast<size_t>(Bits.ImportDecl.NumPathElements) });
+    return ImportPath(getTrailingObjects(
+        static_cast<size_t>(Bits.ImportDecl.NumPathElements)));
   }
 
   /// Retrieves the import path, replacing any module aliases with real names.
@@ -2824,7 +2824,7 @@ class PatternBindingDecl final : public Decl,
 private:
   MutableArrayRef<PatternBindingEntry> getMutablePatternList() {
     // Pattern entries are tail allocated.
-    return {getTrailingObjects<PatternBindingEntry>(), getNumPatternEntries()};
+    return getTrailingObjects(getNumPatternEntries());
   }
 };
   
@@ -3676,10 +3676,7 @@ class OpaqueTypeDecl final :
   /// Retrieve the buffer containing the opaque return type
   /// representations that correspond to the opaque generic parameters.
   ArrayRef<TypeRepr *> getOpaqueReturnTypeReprs() const {
-    return {
-      getTrailingObjects<TypeRepr *>(),
-      getNumOpaqueReturnTypeReprs()
-    };
+    return getTrailingObjects(getNumOpaqueReturnTypeReprs());
   }
 
   /// Should the underlying type be visible to clients outside of the module?
@@ -3745,13 +3742,12 @@ class OpaqueTypeDecl final :
           Substitutions(substitutions) {
       assert(!availabilityQueries.empty());
       std::uninitialized_copy(availabilityQueries.begin(),
-                              availabilityQueries.end(),
-                              getTrailingObjects<AvailabilityQuery>());
+                              availabilityQueries.end(), getTrailingObjects());
     }
 
   public:
     ArrayRef<AvailabilityQuery> getAvailabilityQueries() const {
-      return {getTrailingObjects<AvailabilityQuery>(), NumAvailabilityQueries};
+      return getTrailingObjects(NumAvailabilityQueries);
     }
 
     SubstitutionMap getSubstitutions() const { return Substitutions; }
@@ -5945,7 +5941,7 @@ class AbstractStorageDecl : public ValueDecl {
     inline AccessorDecl *getAccessor(AccessorKind kind) const;
 
     ArrayRef<AccessorDecl *> getAllAccessors() const {
-      return { getTrailingObjects<AccessorDecl*>(), NumAccessors };
+      return getTrailingObjects(NumAccessors);
     }
 
     void addOpaqueAccessor(AccessorDecl *accessor);
@@ -5954,7 +5950,7 @@ class AbstractStorageDecl : public ValueDecl {
 
   private:
     MutableArrayRef<AccessorDecl *> getAccessorsBuffer() {
-      return { getTrailingObjects<AccessorDecl*>(), NumAccessors };
+      return getTrailingObjects(NumAccessors);
     }
 
     bool registerAccessor(AccessorDecl *accessor, AccessorIndex index);
@@ -8807,7 +8803,7 @@ class EnumCaseDecl final : public Decl,
   {
     Bits.EnumCaseDecl.NumElements = Elements.size();
     std::uninitialized_copy(Elements.begin(), Elements.end(),
-                            getTrailingObjects<EnumElementDecl *>());
+                            getTrailingObjects());
   }
   SourceLoc getLocFromSource() const { return CaseLoc; }
 
@@ -8818,8 +8814,8 @@ class EnumCaseDecl final : public Decl,
   
   /// Get the list of elements declared in this case.
   ArrayRef<EnumElementDecl *> getElements() const {
-    return {getTrailingObjects<EnumElementDecl *>(),
-            static_cast<size_t>(Bits.EnumCaseDecl.NumElements)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.EnumCaseDecl.NumElements));
   }
   SourceRange getSourceRange() const;
 
diff --git a/include/swift/AST/Expr.h b/include/swift/AST/Expr.h
index ae80a3f70a27b..08980a8f85989 100644
--- a/include/swift/AST/Expr.h
+++ b/include/swift/AST/Expr.h
@@ -154,12 +154,12 @@ class alignas(8) Expr : public ASTAllocated<Expr> {
     Implicit : 1
   );
 
-  SWIFT_INLINE_BITFIELD_FULL(CollectionExpr, Expr, 64-NumExprBits,
+  SWIFT_INLINE_BITFIELD_FULL(CollectionExpr, Expr, 64-NumberOfExprBits,
     /// True if the type of this collection expr was inferred by the collection
     /// fallback type, like [Any].
     IsTypeDefaulted : 1,
     /// Number of comma source locations.
-    NumCommas : 32 - 1 - NumExprBits,
+    NumCommas : 32 - 1 - NumberOfExprBits,
     /// Number of entries in the collection. If this is a DictionaryExpr,
     /// each entry is a Tuple with the key and value pair.
     NumSubExprs : 32
@@ -256,8 +256,8 @@ class alignas(8) Expr : public ASTAllocated<Expr> {
     LitKind : 3
   );
 
-  SWIFT_INLINE_BITFIELD(AbstractClosureExpr, Expr, (16-NumExprBits)+16,
-    : 16 - NumExprBits, // Align and leave room for subclasses
+  SWIFT_INLINE_BITFIELD(AbstractClosureExpr, Expr, (16-NumberOfExprBits)+16,
+    : 16 - NumberOfExprBits, // Align and leave room for subclasses
     Discriminator : 16
   );
 
@@ -3293,8 +3293,7 @@ class DestructureTupleExpr final : public ImplicitConversionExpr,
       DstExpr(dstExpr) {
     Bits.DestructureTupleExpr.NumElements = destructuredElements.size();
     std::uninitialized_copy(destructuredElements.begin(),
-                            destructuredElements.end(),
-                            getTrailingObjects<OpaqueValueExpr *>());
+                            destructuredElements.end(), getTrailingObjects());
   }
 
 public:
@@ -3306,8 +3305,8 @@ class DestructureTupleExpr final : public ImplicitConversionExpr,
          Expr *srcExpr, Expr *dstExpr, Type ty);
 
   ArrayRef<OpaqueValueExpr *> getDestructuredElements() const {
-    return {getTrailingObjects<OpaqueValueExpr *>(),
-            static_cast<size_t>(Bits.DestructureTupleExpr.NumElements)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.DestructureTupleExpr.NumElements));
   }
 
   Expr *getResultExpr() const {
@@ -3712,7 +3711,7 @@ class UnresolvedSpecializeExpr final : public Expr,
       SubExpr(SubExpr), LAngleLoc(LAngleLoc), RAngleLoc(RAngleLoc) {
     Bits.UnresolvedSpecializeExpr.NumUnresolvedParams = UnresolvedParams.size();
     std::uninitialized_copy(UnresolvedParams.begin(), UnresolvedParams.end(),
-                            getTrailingObjects<TypeRepr *>());
+                            getTrailingObjects());
   }
 
 public:
@@ -3726,8 +3725,8 @@ class UnresolvedSpecializeExpr final : public Expr,
   /// Retrieve the list of type parameters. These parameters have not yet
   /// been bound to archetypes of the entity to be specialized.
   ArrayRef<TypeRepr *> getUnresolvedParams() const {
-    return {getTrailingObjects<TypeRepr *>(),
-            static_cast<size_t>(Bits.UnresolvedSpecializeExpr.NumUnresolvedParams)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.UnresolvedSpecializeExpr.NumUnresolvedParams));
   }
   
   SourceLoc getLoc() const { return LAngleLoc; }
@@ -3984,7 +3983,7 @@ class SequenceExpr final : public Expr,
     Bits.SequenceExpr.NumElements = elements.size();
     assert(Bits.SequenceExpr.NumElements > 0 && "zero-length sequence!");
     std::uninitialized_copy(elements.begin(), elements.end(),
-                            getTrailingObjects<Expr*>());
+                            getTrailingObjects());
   }
 
 public:
@@ -4000,11 +3999,13 @@ class SequenceExpr final : public Expr,
   unsigned getNumElements() const { return Bits.SequenceExpr.NumElements; }
 
   MutableArrayRef<Expr*> getElements() {
-    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.SequenceExpr.NumElements)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.SequenceExpr.NumElements));
   }
 
   ArrayRef<Expr*> getElements() const {
-    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.SequenceExpr.NumElements)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.SequenceExpr.NumElements));
   }
 
   Expr *getElement(unsigned i) const {
@@ -4641,7 +4642,7 @@ class CaptureListExpr final : public Expr,
     assert(closureBody);
     Bits.CaptureListExpr.NumCaptures = captureList.size();
     std::uninitialized_copy(captureList.begin(), captureList.end(),
-                            getTrailingObjects<CaptureListEntry>());
+                            getTrailingObjects());
   }
 
 public:
@@ -4650,8 +4651,8 @@ class CaptureListExpr final : public Expr,
                                  AbstractClosureExpr *closureBody);
 
   ArrayRef<CaptureListEntry> getCaptureList() {
-    return {getTrailingObjects<CaptureListEntry>(),
-            static_cast<size_t>(Bits.CaptureListExpr.NumCaptures)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.CaptureListExpr.NumCaptures));
   }
   AbstractClosureExpr *getClosureBody() { return closureBody; }
   const AbstractClosureExpr *getClosureBody() const { return closureBody; }
@@ -6591,7 +6592,7 @@ class TypeJoinExpr final : public Expr,
   }
 
   MutableArrayRef<Expr *> getMutableElements() {
-    return { getTrailingObjects<Expr *>(), getNumElements() };
+    return getTrailingObjects(getNumElements());
   }
 
   TypeJoinExpr(llvm::PointerUnion<DeclRefExpr *, TypeBase *> result,
@@ -6634,7 +6635,7 @@ class TypeJoinExpr final : public Expr,
   }
 
   ArrayRef<Expr *> getElements() const {
-    return { getTrailingObjects<Expr *>(), getNumElements() };
+    return getTrailingObjects(getNumElements());
   }
 
   Expr *getElement(unsigned i) const {
diff --git a/include/swift/AST/GenericParamList.h b/include/swift/AST/GenericParamList.h
index fc3ebe33941cf..3c29a0793a453 100644
--- a/include/swift/AST/GenericParamList.h
+++ b/include/swift/AST/GenericParamList.h
@@ -277,11 +277,11 @@ class GenericParamList final :
                                   SourceLoc RAngleLoc);
 
   MutableArrayRef<GenericTypeParamDecl *> getParams() {
-    return {getTrailingObjects<GenericTypeParamDecl *>(), NumParams};
+    return getTrailingObjects(NumParams);
   }
 
   ArrayRef<GenericTypeParamDecl *> getParams() const {
-    return {getTrailingObjects<GenericTypeParamDecl *>(), NumParams};
+    return getTrailingObjects(NumParams);
   }
 
   using iterator = GenericTypeParamDecl **;
@@ -387,12 +387,12 @@ class alignas(RequirementRepr) TrailingWhereClause final :
 
   /// Retrieve the set of requirements.
   MutableArrayRef<RequirementRepr> getRequirements() {
-    return {getTrailingObjects<RequirementRepr>(), NumRequirements};
+    return getTrailingObjects(NumRequirements);
   }
 
   /// Retrieve the set of requirements.
   ArrayRef<RequirementRepr> getRequirements() const {
-    return {getTrailingObjects<RequirementRepr>(), NumRequirements};
+    return getTrailingObjects(NumRequirements);
   }
 
   /// Compute the source range containing this trailing where clause.
diff --git a/include/swift/AST/IRGenOptions.h b/include/swift/AST/IRGenOptions.h
index 6de88bebc3793..eddbc98292bb3 100644
--- a/include/swift/AST/IRGenOptions.h
+++ b/include/swift/AST/IRGenOptions.h
@@ -29,9 +29,9 @@
 #include "llvm/IR/CallingConv.h"
 // FIXME: This include is just for llvm::SanitizerCoverageOptions. We should
 // split the header upstream so we don't include so much.
-#include "llvm/Transforms/Instrumentation.h"
-#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/VersionTuple.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/Instrumentation.h"
 #include <optional>
 #include <string>
 #include <tuple>
diff --git a/include/swift/AST/Identifier.h b/include/swift/AST/Identifier.h
index 7efec38a97bab..814e995871c44 100644
--- a/include/swift/AST/Identifier.h
+++ b/include/swift/AST/Identifier.h
@@ -518,10 +518,10 @@ class DeclName {
         : BaseName(BaseName), NumArgs(NumArgs) { }
     
     ArrayRef<Identifier> getArgumentNames() const {
-      return {getTrailingObjects<Identifier>(), NumArgs};
+      return getTrailingObjects(NumArgs);
     }
     MutableArrayRef<Identifier> getArgumentNames() {
-      return {getTrailingObjects<Identifier>(), NumArgs};
+      return getTrailingObjects(NumArgs);
     }
 
     /// Uniquing for the ASTContext.
diff --git a/include/swift/AST/ImportCache.h b/include/swift/AST/ImportCache.h
index 7c573d94b5ef8..8c9059f14d5fe 100644
--- a/include/swift/AST/ImportCache.h
+++ b/include/swift/AST/ImportCache.h
@@ -87,25 +87,20 @@ class ImportSet final :
   }
 
   ArrayRef<ImportedModule> getTopLevelImports() const {
-    return {getTrailingObjects<ImportedModule>(),
-            NumTopLevelImports};
+    return getTrailingObjects(NumTopLevelImports);
   }
 
   ArrayRef<ImportedModule> getTransitiveImports() const {
-    return {getTrailingObjects<ImportedModule>() +
-              NumTopLevelImports,
-            NumTransitiveImports};
+    return {getTrailingObjects() + NumTopLevelImports, NumTransitiveImports};
   }
 
   ArrayRef<ImportedModule> getTransitiveSwiftOnlyImports() const {
-    return {getTrailingObjects<ImportedModule>() +
-              NumTopLevelImports + NumTransitiveImports,
+    return {getTrailingObjects() + NumTopLevelImports + NumTransitiveImports,
             NumTransitiveSwiftOnlyImports};
   }
 
   ArrayRef<ImportedModule> getAllImports() const {
-      return {getTrailingObjects<ImportedModule>(),
-              NumTopLevelImports + NumTransitiveImports};
+    return getTrailingObjects(NumTopLevelImports + NumTransitiveImports);
   }
 
   SWIFT_DEBUG_DUMP;
diff --git a/include/swift/AST/LifetimeDependence.h b/include/swift/AST/LifetimeDependence.h
index 6ecfe99d27564..7b501920d6cc0 100644
--- a/include/swift/AST/LifetimeDependence.h
+++ b/include/swift/AST/LifetimeDependence.h
@@ -160,7 +160,7 @@ class LifetimeEntry final
       : startLoc(startLoc), endLoc(endLoc), numSources(sources.size()),
         targetDescriptor(targetDescriptor) {
     std::uninitialized_copy(sources.begin(), sources.end(),
-                            getTrailingObjects<LifetimeDescriptor>());
+                            getTrailingObjects());
   }
 
   size_t numTrailingObjects(OverloadToken<LifetimeDescriptor>) const {
@@ -179,7 +179,7 @@ class LifetimeEntry final
   SourceLoc getEndLoc() const { return endLoc; }
 
   ArrayRef<LifetimeDescriptor> getSources() const {
-    return {getTrailingObjects<LifetimeDescriptor>(), numSources};
+    return getTrailingObjects(numSources);
   }
 
   std::optional<LifetimeDescriptor> getTargetDescriptor() const {
diff --git a/include/swift/AST/ParameterList.h b/include/swift/AST/ParameterList.h
index 344db0c3f045d..0ed8c758d5a6f 100644
--- a/include/swift/AST/ParameterList.h
+++ b/include/swift/AST/ParameterList.h
@@ -87,10 +87,10 @@ class alignas(ParamDecl *) ParameterList final :
   ParamDecl *back() const { return getArray().back(); }
 
   MutableArrayRef<ParamDecl*> getArray() {
-    return {getTrailingObjects<ParamDecl*>(), numParameters};
+    return getTrailingObjects(numParameters);
   }
   ArrayRef<ParamDecl*> getArray() const {
-    return {getTrailingObjects<ParamDecl*>(), numParameters};
+    return getTrailingObjects(numParameters);
   }
 
   size_t size() const {
diff --git a/include/swift/AST/Pattern.h b/include/swift/AST/Pattern.h
index 1351f3ef4e40a..dc2a836ed0bc5 100644
--- a/include/swift/AST/Pattern.h
+++ b/include/swift/AST/Pattern.h
@@ -349,10 +349,10 @@ class TuplePattern final : public Pattern,
   }
 
   MutableArrayRef<TuplePatternElt> getElements() {
-    return {getTrailingObjects<TuplePatternElt>(), getNumElements()};
+    return getTrailingObjects(getNumElements());
   }
   ArrayRef<TuplePatternElt> getElements() const {
-    return {getTrailingObjects<TuplePatternElt>(), getNumElements()};
+    return getTrailingObjects(getNumElements());
   }
 
   const TuplePatternElt &getElement(unsigned i) const {return getElements()[i];}
diff --git a/include/swift/AST/SILLayout.h b/include/swift/AST/SILLayout.h
index 1b5267bd7b33d..63c486e579263 100644
--- a/include/swift/AST/SILLayout.h
+++ b/include/swift/AST/SILLayout.h
@@ -141,10 +141,8 @@ class SILLayout final : public llvm::FoldingSetNode,
   }
   
   /// Get the fields inside the layout.
-  ArrayRef<SILField> getFields() const {
-    return llvm::ArrayRef(getTrailingObjects<SILField>(), NumFields);
-  }
-  
+  ArrayRef<SILField> getFields() const { return getTrailingObjects(NumFields); }
+
   /// Produce a profile of this layout, for use in a folding set.
   static void Profile(llvm::FoldingSetNodeID &id,
                       CanGenericSignature Generics,
diff --git a/include/swift/AST/Stmt.h b/include/swift/AST/Stmt.h
index 933b2c5c07411..50238fef5fc39 100644
--- a/include/swift/AST/Stmt.h
+++ b/include/swift/AST/Stmt.h
@@ -215,12 +215,12 @@ class BraceStmt final : public Stmt,
 
   /// The elements contained within the BraceStmt.
   MutableArrayRef<ASTNode> getElements() {
-    return {getTrailingObjects<ASTNode>(), static_cast<size_t>(Bits.BraceStmt.NumElements)};
+    return getTrailingObjects(static_cast<size_t>(Bits.BraceStmt.NumElements));
   }
 
   /// The elements contained within the BraceStmt (const version).
   ArrayRef<ASTNode> getElements() const {
-    return {getTrailingObjects<ASTNode>(), static_cast<size_t>(Bits.BraceStmt.NumElements)};
+    return getTrailingObjects(static_cast<size_t>(Bits.BraceStmt.NumElements));
   }
 
   ASTNode findAsyncNode();
@@ -337,10 +337,10 @@ class YieldStmt final
   SourceLoc getEndLoc() const;
 
   ArrayRef<Expr*> getYields() const {
-    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.YieldStmt.NumYields)};
+    return getTrailingObjects(static_cast<size_t>(Bits.YieldStmt.NumYields));
   }
   MutableArrayRef<Expr*> getMutableYields() {
-    return {getTrailingObjects<Expr*>(), static_cast<size_t>(Bits.YieldStmt.NumYields)};
+    return getTrailingObjects(static_cast<size_t>(Bits.YieldStmt.NumYields));
   }
   
   static bool classof(const Stmt *S) { return S->getKind() == StmtKind::Yield; }
@@ -505,7 +505,7 @@ class alignas(8) PoundAvailableInfo final :
     Flags.isInvalid = false;
     Flags.isUnavailability = isUnavailability;
     std::uninitialized_copy(queries.begin(), queries.end(),
-                            getTrailingObjects<AvailabilitySpec *>());
+                            getTrailingObjects());
   }
 
 public:
@@ -519,7 +519,7 @@ class alignas(8) PoundAvailableInfo final :
   void setInvalid() { Flags.isInvalid = true; }
 
   ArrayRef<AvailabilitySpec *> getQueries() const {
-    return llvm::ArrayRef(getTrailingObjects<AvailabilitySpec *>(), NumQueries);
+    return getTrailingObjects(NumQueries);
   }
 
   /// Returns an iterator for the statement's type-checked availability specs.
@@ -1431,8 +1431,7 @@ class SwitchStmt final : public LabeledStmt,
 
   /// Get the list of case clauses.
   ArrayRef<CaseStmt *> getCases() const {
-    return {getTrailingObjects<CaseStmt *>(),
-            static_cast<size_t>(Bits.SwitchStmt.CaseCount)};
+    return getTrailingObjects(static_cast<size_t>(Bits.SwitchStmt.CaseCount));
   }
 
   /// Retrieve the complete set of branches for this switch statement.
@@ -1472,7 +1471,7 @@ class DoCatchStmt final
         Body(body) {
     Bits.DoCatchStmt.NumCatches = catches.size();
     std::uninitialized_copy(catches.begin(), catches.end(),
-                            getTrailingObjects<CaseStmt *>());
+                            getTrailingObjects());
     for (auto *catchStmt : getCatches())
       catchStmt->setParentStmt(this);
   }
@@ -1506,10 +1505,10 @@ class DoCatchStmt final
   void setBody(Stmt *s) { Body = s; }
 
   ArrayRef<CaseStmt *> getCatches() const {
-    return {getTrailingObjects<CaseStmt *>(), static_cast<size_t>(Bits.DoCatchStmt.NumCatches)};
+    return getTrailingObjects(static_cast<size_t>(Bits.DoCatchStmt.NumCatches));
   }
   MutableArrayRef<CaseStmt *> getMutableCatches() {
-    return {getTrailingObjects<CaseStmt *>(), static_cast<size_t>(Bits.DoCatchStmt.NumCatches)};
+    return getTrailingObjects(static_cast<size_t>(Bits.DoCatchStmt.NumCatches));
   }
 
   /// Retrieve the complete set of branches for this do-catch statement.
diff --git a/include/swift/AST/TypeRepr.h b/include/swift/AST/TypeRepr.h
index 89a2b69c1ba52..13c37817aec13 100644
--- a/include/swift/AST/TypeRepr.h
+++ b/include/swift/AST/TypeRepr.h
@@ -266,9 +266,7 @@ class AttributedTypeRepr final
       : TypeRepr(TypeReprKind::Attributed), Ty(Ty) {
     assert(!attrs.empty());
     Bits.AttributedTypeRepr.NumAttributes = attrs.size();
-    std::uninitialized_copy(attrs.begin(), attrs.end(),
-                            getTrailingObjects<TypeOrCustomAttr>());
-
+    std::uninitialized_copy(attrs.begin(), attrs.end(), getTrailingObjects());
   }
 
   friend TrailingObjects;
@@ -279,8 +277,7 @@ class AttributedTypeRepr final
                                     TypeRepr *ty);
 
   ArrayRef<TypeOrCustomAttr> getAttrs() const {
-    return llvm::ArrayRef(getTrailingObjects<TypeOrCustomAttr>(),
-                          Bits.AttributedTypeRepr.NumAttributes);
+    return getTrailingObjects(Bits.AttributedTypeRepr.NumAttributes);
   }
 
   TypeAttribute *get(TypeAttrKind kind) const;
@@ -870,12 +867,10 @@ class PackTypeRepr final
   SourceRange getBracesRange() const { return BraceLocs; }
 
   MutableArrayRef<TypeRepr*> getMutableElements() {
-    return llvm::MutableArrayRef(getTrailingObjects<TypeRepr *>(),
-                                 Bits.PackTypeRepr.NumElements);
+    return getTrailingObjects(Bits.PackTypeRepr.NumElements);
   }
   ArrayRef<TypeRepr*> getElements() const {
-    return llvm::ArrayRef(getTrailingObjects<TypeRepr *>(),
-                          Bits.PackTypeRepr.NumElements);
+    return getTrailingObjects(Bits.PackTypeRepr.NumElements);
   }
 
   static bool classof(const TypeRepr *T) {
@@ -958,8 +953,8 @@ class TupleTypeRepr final : public TypeRepr,
   }
 
   ArrayRef<TupleTypeReprElement> getElements() const {
-    return { getTrailingObjects<TupleTypeReprElement>(),
-             static_cast<size_t>(Bits.TupleTypeRepr.NumElements) };
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.TupleTypeRepr.NumElements));
   }
 
   void getElementTypes(SmallVectorImpl<TypeRepr *> &Types) const {
@@ -1040,13 +1035,13 @@ class CompositionTypeRepr final : public TypeRepr,
       : TypeRepr(TypeReprKind::Composition), FirstTypeLoc(FirstTypeLoc),
         CompositionRange(CompositionRange) {
     Bits.CompositionTypeRepr.NumTypes = Types.size();
-    std::uninitialized_copy(Types.begin(), Types.end(),
-                            getTrailingObjects<TypeRepr*>());
+    std::uninitialized_copy(Types.begin(), Types.end(), getTrailingObjects());
   }
 
 public:
   ArrayRef<TypeRepr *> getTypes() const {
-    return {getTrailingObjects<TypeRepr*>(), static_cast<size_t>(Bits.CompositionTypeRepr.NumTypes)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.CompositionTypeRepr.NumTypes));
   }
   SourceLoc getSourceLoc() const { return FirstTypeLoc; }
   SourceRange getCompositionRange() const { return CompositionRange; }
diff --git a/include/swift/AST/Types.h b/include/swift/AST/Types.h
index 6b257866dc283..da0996d628cd6 100644
--- a/include/swift/AST/Types.h
+++ b/include/swift/AST/Types.h
@@ -2345,8 +2345,7 @@ class TypeAliasType final
   /// Retrieve the parent of this type as written, e.g., the part that was
   /// written before ".", if provided.
   Type getParent() const {
-    return Bits.TypeAliasType.HasParent ? *getTrailingObjects<Type>()
-                                        : Type();
+    return Bits.TypeAliasType.HasParent ? *getTrailingObjects() : Type();
   }
 
   /// Retrieve the substitution map applied to the declaration's underlying
@@ -2361,10 +2360,9 @@ class TypeAliasType final
   /// arguments that are directly applied to the typealias declaration
   /// this type references.
   ArrayRef<Type> getDirectGenericArgs() const {
-    return ArrayRef<Type>(
-        getTrailingObjects<Type>() +
-        (Bits.TypeAliasType.HasParent ? 1 : 0),
-        Bits.TypeAliasType.GenericArgCount);
+    return ArrayRef<Type>(getTrailingObjects() +
+                              (Bits.TypeAliasType.HasParent ? 1 : 0),
+                          Bits.TypeAliasType.GenericArgCount);
   }
 
   SmallVector<Type, 2> getExpandedGenericArgs();
@@ -2755,16 +2753,16 @@ class TupleType final : public TypeBase, public llvm::FoldingSetNode,
 
   /// getElements - Return the elements of this tuple.
   ArrayRef<TupleTypeElt> getElements() const {
-    return {getTrailingObjects<TupleTypeElt>(), getNumElements()};
+    return getTrailingObjects(getNumElements());
   }
 
   const TupleTypeElt &getElement(unsigned i) const {
-    return getTrailingObjects<TupleTypeElt>()[i];
+    return getTrailingObjects()[i];
   }
 
   /// getElementType - Return the type of the specified element.
   Type getElementType(unsigned ElementNo) const {
-    return getTrailingObjects<TupleTypeElt>()[ElementNo].getType();
+    return getTrailingObjects()[ElementNo].getType();
   }
 
   TupleEltTypeArrayRef getElementTypes() const {
@@ -2794,7 +2792,7 @@ class TupleType final : public TypeBase, public llvm::FoldingSetNode,
       : TypeBase(TypeKind::Tuple, CanCtx, properties) {
     Bits.TupleType.Count = elements.size();
     std::uninitialized_copy(elements.begin(), elements.end(),
-                            getTrailingObjects<TupleTypeElt>());
+                            getTrailingObjects());
   }
 };
 BEGIN_CAN_TYPE_WRAPPER(TupleType, Type)
@@ -6231,7 +6229,7 @@ class SILPackType final : public TypeBase, public llvm::FoldingSetNode,
       : TypeBase(TypeKind::SILPack, &ctx, properties) {
     Bits.SILPackType.Count = elements.size();
     Bits.SILPackType.ElementIsAddress = info.ElementIsAddress;
-    memcpy(getTrailingObjects<CanType>(), elements.data(),
+    memcpy(getTrailingObjects(), elements.data(),
            elements.size() * sizeof(CanType));
   }
 
@@ -6253,13 +6251,13 @@ class SILPackType final : public TypeBase, public llvm::FoldingSetNode,
 
   /// Retrieves the type of the elements in the pack.
   ArrayRef<CanType> getElementTypes() const {
-    return {getTrailingObjects<CanType>(), getNumElements()};
+    return getTrailingObjects(getNumElements());
   }
 
   /// Returns the type of the element at the given \p index.
   /// This is a lowered SIL type.
   CanType getElementType(unsigned index) const {
-    return getTrailingObjects<CanType>()[index];
+    return getTrailingObjects()[index];
   }
 
   SILType getSILElementType(unsigned index) const; // in SILType.h
@@ -6554,7 +6552,8 @@ class ProtocolCompositionType final : public TypeBase,
   /// a protocol composition type; you also have to look at
   /// hasExplicitAnyObject().
   ArrayRef<Type> getMembers() const {
-    return {getTrailingObjects<Type>(), static_cast<size_t>(Bits.ProtocolCompositionType.Count)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.ProtocolCompositionType.Count));
   }
 
   InvertibleProtocolSet getInverses() const { return Inverses; }
@@ -6602,7 +6601,7 @@ class ProtocolCompositionType final : public TypeBase,
     Bits.ProtocolCompositionType.HasExplicitAnyObject = hasExplicitAnyObject;
     Bits.ProtocolCompositionType.Count = members.size();
     std::uninitialized_copy(members.begin(), members.end(),
-                            getTrailingObjects<Type>());
+                            getTrailingObjects());
   }
 };
 BEGIN_CAN_TYPE_WRAPPER(ProtocolCompositionType, Type)
@@ -6651,8 +6650,8 @@ class ParameterizedProtocolType final : public TypeBase,
   }
 
   ArrayRef<Type> getArgs() const {
-    return {getTrailingObjects<Type>(),
-            static_cast<size_t>(Bits.ParameterizedProtocolType.ArgCount)};
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.ParameterizedProtocolType.ArgCount));
   }
 
   bool requiresClass() const {
@@ -7733,8 +7732,7 @@ class ErrorUnionType final
                  RecursiveTypeProperties properties) 
         : TypeBase(TypeKind::ErrorUnion, /*Context=*/ctx, properties) {
     Bits.ErrorUnionType.NumTerms = terms.size();
-    std::uninitialized_copy(terms.begin(), terms.end(),
-                            getTrailingObjects<Type>());
+    std::uninitialized_copy(terms.begin(), terms.end(), getTrailingObjects());
   }
 
 public:
@@ -7742,7 +7740,8 @@ class ErrorUnionType final
   static Type get(const ASTContext &ctx, ArrayRef<Type> terms);
 
   ArrayRef<Type> getTerms() const {
-    return { getTrailingObjects<Type>(), static_cast<size_t>(Bits.ErrorUnionType.NumTerms) };
+    return getTrailingObjects(
+        static_cast<size_t>(Bits.ErrorUnionType.NumTerms));
   };
 
   // Support for FoldingSet.
@@ -7834,12 +7833,12 @@ class PackType final : public TypeBase, public llvm::FoldingSetNode,
 
   /// Retrieves the type of the elements in the pack.
   ArrayRef<Type> getElementTypes() const {
-    return {getTrailingObjects<Type>(), getNumElements()};
+    return getTrailingObjects(getNumElements());
   }
 
   /// Returns the type of the element at the given \p index.
   Type getElementType(unsigned index) const {
-    return getTrailingObjects<Type>()[index];
+    return getTrailingObjects()[index];
   }
 
   bool containsPackExpansionType() const;
@@ -7865,7 +7864,7 @@ class PackType final : public TypeBase, public llvm::FoldingSetNode,
      : TypeBase(TypeKind::Pack, CanCtx, properties) {
      Bits.PackType.Count = elements.size();
      std::uninitialized_copy(elements.begin(), elements.end(),
-                             getTrailingObjects<Type>());
+                             getTrailingObjects());
   }
 };
 BEGIN_CAN_TYPE_WRAPPER(PackType, Type)
@@ -8353,11 +8352,11 @@ inline ParameterTypeFlags ParameterTypeFlags::fromParameterType(
 
 inline const Type *BoundGenericType::getTrailingObjectsPointer() const {
   if (auto ty = dyn_cast<BoundGenericStructType>(this))
-    return ty->getTrailingObjects<Type>();
+    return ty->getTrailingObjects();
   if (auto ty = dyn_cast<BoundGenericEnumType>(this))
-    return ty->getTrailingObjects<Type>();
+    return ty->getTrailingObjects();
   if (auto ty = dyn_cast<BoundGenericClassType>(this))
-    return ty->getTrailingObjects<Type>();
+    return ty->getTrailingObjects();
   llvm_unreachable("Unhandled BoundGenericType!");
 }
 
diff --git a/include/swift/Basic/EncodedSequence.h b/include/swift/Basic/EncodedSequence.h
index 8b041731d5de3..81b5bc5ad32ec 100644
--- a/include/swift/Basic/EncodedSequence.h
+++ b/include/swift/Basic/EncodedSequence.h
@@ -102,14 +102,12 @@ class EncodedSequenceBase {
     }
 
     MutableArrayRef<Chunk> chunkStorage() {
-      return {getTrailingObjects<Chunk>(), Capacity};
+      return getTrailingObjects(Capacity);
     }
     ArrayRef<Chunk> chunkStorage() const {
-      return {getTrailingObjects<Chunk>(), Capacity};
-    }
-    ArrayRef<Chunk> chunks() const {
-      return {getTrailingObjects<Chunk>(), Size};
+      return getTrailingObjects(Capacity);
     }
+    ArrayRef<Chunk> chunks() const { return getTrailingObjects(Size); }
   };
   OutOfLineStorage *getOutOfLineStorage() {
     assert(hasOutOfLineStorage());
diff --git a/include/swift/Basic/InlineBitfield.h b/include/swift/Basic/InlineBitfield.h
index b41ae018d4edf..1378115aee012 100644
--- a/include/swift/Basic/InlineBitfield.h
+++ b/include/swift/Basic/InlineBitfield.h
@@ -41,7 +41,7 @@ namespace swift {
     uint64_t : 64 - (C); /* Better code gen */ \
   } T; \
   LLVM_PACKED_END \
-  enum { Num##T##Bits = (C) }; \
+  enum { NumberOf##T##Bits = (C) }; \
   static_assert(sizeof(T##Bitfield) <= 8, "Bitfield overflow")
 
 /// Define an bitfield for type 'T' with parent class 'U' and 'C' bits used.
@@ -49,11 +49,11 @@ namespace swift {
   LLVM_PACKED_START \
   class T##Bitfield { \
     friend class T; \
-    uint64_t : Num##U##Bits, __VA_ARGS__; \
-    uint64_t : 64 - (Num##U##Bits + (HC) + (C)); /* Better code gen */ \
+    uint64_t : NumberOf##U##Bits, __VA_ARGS__; \
+    uint64_t : 64 - (NumberOf##U##Bits + (HC) + (C)); /* Better code gen */ \
   } T; \
   LLVM_PACKED_END \
-  enum { Num##T##Bits = Num##U##Bits + (C) }; \
+  enum { NumberOf##T##Bits = NumberOf##U##Bits + (C) }; \
   static_assert(sizeof(T##Bitfield) <= 8, "Bitfield overflow")
 
 #define SWIFT_INLINE_BITFIELD(T, U, C, ...) \
@@ -75,8 +75,8 @@ namespace swift {
   LLVM_PACKED_START \
   class T##Bitfield { \
     friend class T; \
-    enum { NumPadBits = 64 - (Num##U##Bits + (C)) }; \
-    uint64_t : Num##U##Bits, __VA_ARGS__; \
+    enum { NumPadBits = 64 - (NumberOf##U##Bits + (C)) }; \
+    uint64_t : NumberOf##U##Bits, __VA_ARGS__; \
   } T; \
   LLVM_PACKED_END \
   static_assert(sizeof(T##Bitfield) <= 8, "Bitfield overflow")
@@ -101,15 +101,15 @@ namespace swift {
   class T##Bitfield {                                                          \
     template <typename TTy>                                                    \
     friend class T;                                                            \
-    enum { NumPadBits = 64 - (Num##U##Bits + (C)) };                           \
-    uint64_t : Num##U##Bits, __VA_ARGS__;                                      \
+    enum { NumPadBits = 64 - (NumberOf##U##Bits + (C)) };                      \
+    uint64_t : NumberOf##U##Bits, __VA_ARGS__;                                 \
   } T;                                                                         \
   LLVM_PACKED_END                                                              \
   static_assert(sizeof(T##Bitfield) <= 8, "Bitfield overflow")
 
 /// Define an empty bitfield for type 'T'.
 #define SWIFT_INLINE_BITFIELD_EMPTY(T, U) \
-  enum { Num##T##Bits = Num##U##Bits }
+  enum { NumberOf##T##Bits = NumberOf##U##Bits }
 
 // XXX/HACK: templated max() doesn't seem to work in a bitfield size context.
 constexpr unsigned bitmax(unsigned a, unsigned b) {
diff --git a/include/swift/Basic/OwnedString.h b/include/swift/Basic/OwnedString.h
index 109eb003e6819..c37370d18c052 100644
--- a/include/swift/Basic/OwnedString.h
+++ b/include/swift/Basic/OwnedString.h
@@ -35,8 +35,7 @@ class OwnedString {
   class TextOwner final : public llvm::ThreadSafeRefCountedBase<TextOwner>,
                           public llvm::TrailingObjects<TextOwner, char> {
     TextOwner(StringRef Text) {
-      std::uninitialized_copy(Text.begin(), Text.end(),
-                              getTrailingObjects<char>());
+      std::uninitialized_copy(Text.begin(), Text.end(), getTrailingObjects());
     }
 
   public:
@@ -50,7 +49,7 @@ class OwnedString {
     /// data.
     void operator delete(void *p) { ::operator delete(p); }
 
-    const char *getText() const { return getTrailingObjects<char>(); }
+    const char *getText() const { return getTrailingObjects(); }
   };
 
   /// The text this owned string represents
diff --git a/include/swift/ClangImporter/SwiftAbstractBasicReader.h b/include/swift/ClangImporter/SwiftAbstractBasicReader.h
index b5063c1c43493..8e31db659d2c1 100644
--- a/include/swift/ClangImporter/SwiftAbstractBasicReader.h
+++ b/include/swift/ClangImporter/SwiftAbstractBasicReader.h
@@ -64,6 +64,11 @@ class DataStreamBasicReader
     return uint32_t(asImpl().readUInt64());
   }
 
+  clang::UnsignedOrNone readUnsignedOrNone() {
+    return clang::UnsignedOrNone::fromInternalRepresentation(
+        unsigned(asImpl().readUInt64()));
+  }
+
   clang::Selector readSelector() {
     uint64_t numArgsPlusOne = asImpl().readUInt64();
 
diff --git a/include/swift/ClangImporter/SwiftAbstractBasicWriter.h b/include/swift/ClangImporter/SwiftAbstractBasicWriter.h
index be8e2bf3c0e57..f636cba5907ba 100644
--- a/include/swift/ClangImporter/SwiftAbstractBasicWriter.h
+++ b/include/swift/ClangImporter/SwiftAbstractBasicWriter.h
@@ -61,6 +61,10 @@ class DataStreamBasicWriter
     asImpl().writeUInt64(uint64_t(value));
   }
 
+  void writeUnsignedOrNone(clang::UnsignedOrNone value) {
+    asImpl().writeUInt64(uint64_t(value.toInternalRepresentation()));
+  }
+
   void writeSelector(clang::Selector selector) {
     if (selector.isNull()) {
       asImpl().writeUInt64(0);
diff --git a/include/swift/IDE/CodeCompletionString.h b/include/swift/IDE/CodeCompletionString.h
index 858d11090872e..0cedbae77cb9e 100644
--- a/include/swift/IDE/CodeCompletionString.h
+++ b/include/swift/IDE/CodeCompletionString.h
@@ -347,9 +347,7 @@ class alignas(detail::CodeCompletionStringChunk) CodeCompletionString final
   static CodeCompletionString *create(llvm::BumpPtrAllocator &Allocator,
                                       ArrayRef<Chunk> Chunks);
 
-  ArrayRef<Chunk> getChunks() const {
-    return {getTrailingObjects<Chunk>(), NumChunks};
-  }
+  ArrayRef<Chunk> getChunks() const { return getTrailingObjects(NumChunks); }
 
   StringRef getFirstTextChunk(bool includeLeadingPunctuation = false) const;
   std::optional<unsigned>
diff --git a/include/swift/Markup/AST.h b/include/swift/Markup/AST.h
index c48e8fa624989..d1cfbb813053c 100644
--- a/include/swift/Markup/AST.h
+++ b/include/swift/Markup/AST.h
@@ -112,11 +112,11 @@ class Document final : public MarkupASTNode,
                           ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -136,11 +136,11 @@ class BlockQuote final : public MarkupASTNode,
   static BlockQuote *create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -162,17 +162,16 @@ class List final : public MarkupASTNode,
                       bool IsOrdered);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   void setChildren(ArrayRef<MarkupASTNode *> NewChildren) {
     assert(NewChildren.size() <= NumChildren);
-    std::copy(NewChildren.begin(), NewChildren.end(),
-              getTrailingObjects<MarkupASTNode *>());
+    std::copy(NewChildren.begin(), NewChildren.end(), getTrailingObjects());
     NumChildren = NewChildren.size();
   }
 
@@ -197,11 +196,11 @@ class Item final : public MarkupASTNode,
   static Item *create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -265,11 +264,11 @@ class Paragraph final : public MarkupASTNode,
                            ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -291,11 +290,11 @@ class Header final : public MarkupASTNode,
                         ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   unsigned getLevel() const {
@@ -482,11 +481,11 @@ class Emphasis final : public InlineContent,
                           ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -506,11 +505,11 @@ class Strong final : public InlineContent,
                         ArrayRef<MarkupASTNode *> Children);
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -536,11 +535,11 @@ class Link final : public InlineContent,
   StringRef getDestination() const { return Destination; }
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -577,11 +576,11 @@ class Image final : public InlineContent,
   }
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -607,11 +606,11 @@ class InlineAttributes final : public InlineContent, private llvm::TrailingObjec
   StringRef getAttributes() const { return Attributes; }
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -678,11 +677,11 @@ class ParamField final : public PrivateExtension,
   }
 
   ArrayRef<MarkupASTNode *> getChildren() {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   ArrayRef<const MarkupASTNode *> getChildren() const {
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren};
+    return getTrailingObjects(NumChildren);
   }
 
   static bool classof(const MarkupASTNode *N) {
@@ -703,11 +702,11 @@ public: \
   static Id *create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children); \
 \
   ArrayRef<MarkupASTNode *> getChildren() { \
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren}; \
+    return getTrailingObjects(NumChildren); \
   } \
 \
   ArrayRef<const MarkupASTNode *> getChildren() const { \
-    return {getTrailingObjects<MarkupASTNode *>(), NumChildren}; \
+    return getTrailingObjects(NumChildren); \
   } \
 \
   static bool classof(const MarkupASTNode *N) { \
diff --git a/include/swift/Migrator/FixitApplyDiagnosticConsumer.h b/include/swift/Migrator/FixitApplyDiagnosticConsumer.h
index 4937a881b827d..ce5aebf58f5e9 100644
--- a/include/swift/Migrator/FixitApplyDiagnosticConsumer.h
+++ b/include/swift/Migrator/FixitApplyDiagnosticConsumer.h
@@ -21,7 +21,7 @@
 #include "swift/Migrator/FixitFilter.h"
 #include "swift/Migrator/Migrator.h"
 #include "swift/Migrator/Replacement.h"
-#include "clang/Rewrite/Core/RewriteBuffer.h"
+#include "llvm/ADT/RewriteBuffer.h"
 #include "llvm/ADT/SmallSet.h"
 
 namespace swift {
@@ -37,7 +37,7 @@ struct Replacement;
 
 class FixitApplyDiagnosticConsumer final
   : public DiagnosticConsumer, public FixitFilter {
-  clang::RewriteBuffer RewriteBuf;
+  llvm::RewriteBuffer RewriteBuf;
 
   /// The entire text of the input file.
   const StringRef Text;
diff --git a/include/swift/Migrator/RewriteBufferEditsReceiver.h b/include/swift/Migrator/RewriteBufferEditsReceiver.h
index 91c86d893bc6d..e9366ead711f5 100644
--- a/include/swift/Migrator/RewriteBufferEditsReceiver.h
+++ b/include/swift/Migrator/RewriteBufferEditsReceiver.h
@@ -16,7 +16,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Edit/EditsReceiver.h"
-#include "clang/Rewrite/Core/RewriteBuffer.h"
+#include "llvm/ADT/RewriteBuffer.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -26,12 +26,13 @@ namespace swift {
 namespace migrator {
 
 /// An EditsReceiver that collects edits from an EditedSource and directly
-/// applies it to a clang::RewriteBuffer.
+/// applies it to a llvm::RewriteBuffer.
 class RewriteBufferEditsReceiver final : public clang::edit::EditsReceiver {
   const clang::SourceManager &ClangSourceManager;
   const clang::FileID InputFileID;
   const StringRef InputText;
-  clang::RewriteBuffer RewriteBuf;
+  llvm::RewriteBuffer RewriteBuf;
+
 public:
   RewriteBufferEditsReceiver(const clang::SourceManager &ClangSourceManager,
                              const clang::FileID InputFileID,
diff --git a/include/swift/Option/SanitizerOptions.h b/include/swift/Option/SanitizerOptions.h
index faa394f39b072..ab7f3bbdb8776 100644
--- a/include/swift/Option/SanitizerOptions.h
+++ b/include/swift/Option/SanitizerOptions.h
@@ -20,7 +20,7 @@
 #include "llvm/Option/ArgList.h"
 // FIXME: This include is just for llvm::SanitizerCoverageOptions. We should
 // split the header upstream so we don't include so much.
-#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/Transforms/Utils/Instrumentation.h"
 
 namespace swift {
 class DiagnosticEngine;
diff --git a/include/swift/RemoteInspection/ReflectionContext.h b/include/swift/RemoteInspection/ReflectionContext.h
index ac475a82930e4..329878e6356bb 100644
--- a/include/swift/RemoteInspection/ReflectionContext.h
+++ b/include/swift/RemoteInspection/ReflectionContext.h
@@ -18,13 +18,14 @@
 #ifndef SWIFT_REFLECTION_REFLECTIONCONTEXT_H
 #define SWIFT_REFLECTION_REFLECTIONCONTEXT_H
 
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/BinaryFormat/COFF.h"
-#include "llvm/BinaryFormat/MachO.h"
 #include "llvm/BinaryFormat/ELF.h"
+#include "llvm/BinaryFormat/MachO.h"
+#include "llvm/BinaryFormat/Wasm.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/Memory.h"
-#include "llvm/ADT/STLExtras.h"
 
 #include "swift/ABI/Enum.h"
 #include "swift/ABI/ObjectFile.h"
@@ -40,6 +41,8 @@
 #include "swift/RemoteInspection/TypeRefBuilder.h"
 #include "swift/Basic/Unreachable.h"
 
+#include <cstdint>
+#include <map>
 #include <set>
 #include <utility>
 #include <vector>
@@ -72,6 +75,11 @@
 #define HAS_DISPATCH_LOCK_IS_LOCKED 1
 #endif
 
+#define DEBUG_TYPE "reflection"
+#ifdef SWIFT_RUNTIME
+#undef LLVM_DEBUG
+#define LLVM_DEBUG(IGNORE)
+#endif
 namespace {
 
 template <unsigned PointerSize> struct MachOTraits;
@@ -799,6 +807,297 @@ class ReflectionContext
     }
   }
 
+  /// Parses metadata information from a WebAssembly image.
+  ///
+  ///
+  /// \param[in] ImageStart
+  ///     A remote address pointing to the start of the image in the running
+  ///     process.
+  ///
+  /// \param[in] FileBuffer
+  ///     A buffer which contains the contents of the image's file
+  ///     in disk. If missing, all the information will be read using the
+  ///     instance's memory reader.
+  ///
+  /// \return The newly added reflection info ID if successful, \b std::nullopt
+  ///     otherwise.
+  std::optional<uint32_t>
+  readWasm(RemoteAddress ImageStart,
+           std::optional<llvm::sys::MemoryBlock> FileBuffer,
+           llvm::SmallVector<llvm::StringRef, 1> PotentialModuleNames) {
+    /// A WASM data segment. The reflection metadata "sections" are DATA
+    /// segments.
+    struct Segment {
+      RemoteAddress remoteAddr;
+      uint64_t offset;
+      uint64_t size;
+    };
+    std::map<std::string, Segment> sections;
+    std::vector<Segment> segments;
+    auto &reader = getReader();
+    RemoteAddress cursor = ImageStart;
+    cursor += sizeof(llvm::wasm::WasmMagic) + sizeof(llvm::wasm::WasmVersion);
+
+    /// Decode one byte and move the cursor.
+    auto decodeU8 = [&reader, &cursor](uint8_t &b) -> bool {
+      if (!reader.readInteger(cursor, 1, &b))
+        return false;
+      cursor += 1;
+      return true;
+    };
+
+    /// Decode 32-bit ULEB constants.
+    auto decodeULEB32 = [&](uint32_t &val) -> bool {
+      uint64_t result = 0;
+      uint8_t b;
+      for (uint8_t n = 0; n < 5; ++n) {
+        if (!decodeU8(b))
+          return false;
+        result |= (b & ~(1 << 7)) << 7 * n;
+        if ((b & (1 << 7)) == 0)
+          break;
+      }
+      if (result > std::numeric_limits<uint32_t>::max())
+        return false;
+      memcpy(&val, &result, 4);
+      return true;
+    };
+
+    /// Decode a string.
+    auto decodeString = [&](std::string &str) -> bool {
+      uint32_t len;
+      if (!decodeULEB32(len))
+        return false;
+      auto chars = reader.readBytes(cursor, len);
+      if (!chars)
+        return false;
+      str = std::string((const char *)chars.get(), len);
+      cursor += len;
+      chars.release();
+      return true;
+    };
+
+    /// Decode one section header.
+    auto decodeSection = [&]() -> bool {
+      uint8_t sectionID;
+      if (!decodeU8(sectionID))
+        return false;
+
+      if (sectionID > llvm::wasm::WASM_SEC_LAST_KNOWN)
+        return false;
+
+      uint32_t payloadLen;
+      if (!decodeULEB32(payloadLen))
+        return false;
+      RemoteAddress payloadStart = cursor;
+      std::string sectName;
+      if (sectionID == llvm::wasm::WASM_SEC_CUSTOM) {
+        if (!decodeString(sectName))
+          return false;
+        RemoteAddress sectionStart = cursor;
+        sections.insert(
+            {sectName, {cursor, 0, payloadLen - (sectionStart - cursor)}});
+      } else {
+        sectName = llvm::wasm::sectionTypeToString(sectionID);
+        sections.insert({sectName, {cursor, 0, payloadLen}});
+      }
+      LLVM_DEBUG(llvm::dbgs()
+                 << "section " << sectName << " size=" << payloadLen << "\n");
+
+      cursor = payloadStart + payloadLen;
+      return true;
+    };
+
+    // Decode the DATA segments.
+    auto decodeData = [&](uint64_t sectLength) -> bool {
+      RemoteAddress start = cursor;
+      RemoteAddress end = start + sectLength;
+      uint32_t count;
+
+      auto decodeActiveSegmentOffset = [&]() -> std::optional<uint32_t> {
+        uint32_t offset = 0;
+        while (true) {
+          uint8_t b;
+          if (!decodeU8(b))
+            return {};
+
+          if (b == llvm::wasm::WASM_OPCODE_I32_CONST) {
+            if (!decodeULEB32(offset)) // FIXME: Actually an SLEB.
+              return {};
+          } else if (b == llvm::wasm::WASM_OPCODE_END) {
+            break;
+          } else {
+            // Unhandled opcode.
+            return {};
+          }
+        }
+        return offset;
+      };
+
+      if (!decodeULEB32(count))
+        return false;
+      // Parse the segment header.
+      for (uint32_t i = 0; i < count && cursor < end; ++i) {
+        uint32_t flags;
+        uint32_t offset = 0;
+        if (!decodeULEB32(flags))
+          return false;
+        if ((flags & 2) == 2) {
+          uint32_t memidx;
+          if (!decodeULEB32(memidx))
+            return false;
+        }
+        if ((flags & 1) == 0) {
+          auto offsOrErr = decodeActiveSegmentOffset();
+          if (!offsOrErr)
+            return false;
+          offset = *offsOrErr;
+        }
+        uint32_t size;
+        if (!decodeULEB32(size))
+          return false;
+        LLVM_DEBUG(llvm::dbgs()
+                   << "Segment[" << i << "]: flags=" << flags
+                   << " offset=" << offset << " size=" << size << "\n");
+        segments.push_back({cursor, offset, size});
+        cursor += size;
+      }
+      return true;
+    };
+    // Decode the NAMES table pointing to the DATA segments.
+    auto decodeNames = [&](uint64_t sectLength) -> bool {
+      RemoteAddress start = cursor;
+      RemoteAddress end = start + sectLength;
+      while (cursor < end) {
+        uint8_t type;
+        if (!decodeU8(type))
+          return false;
+        uint32_t len;
+        if (!decodeULEB32(len))
+          return false;
+        if (type == llvm::wasm::WASM_NAMES_DATA_SEGMENT) {
+          uint32_t count;
+          if (!decodeULEB32(count))
+            return false;
+          for (uint32_t i = 0; i < count; ++i) {
+            uint32_t idx;
+            if (!decodeULEB32(idx))
+              return false;
+            std::string sectName;
+            if (!decodeString(sectName))
+              return false;
+            if (idx >= segments.size())
+              return false;
+            LLVM_DEBUG(llvm::dbgs() << sectName << ": " << idx << "\n");
+            sections.insert({sectName, segments[idx]});
+          }
+        }
+        cursor += len;
+      }
+      return true;
+    };
+    // Decode the LINK section of object files.
+    auto decodeLinking = [&](RemoteAddress dataStart,
+                             uint64_t sectLength) -> bool {
+      RemoteAddress start = cursor;
+      RemoteAddress end = start + sectLength;
+
+      uint32_t version;
+      if (!decodeULEB32(version) || version != 2)
+        return false;
+      while (cursor < end) {
+        uint8_t type;
+        if (!decodeU8(type))
+          return false;
+        uint32_t len;
+        if (!decodeULEB32(len))
+          return false;
+        if (type == llvm::wasm::WASM_SEGMENT_INFO) {
+          uint32_t count;
+          if (!decodeULEB32(count))
+            return false;
+          for (uint32_t idx = 0; idx < count; ++idx) {
+            std::string sectName;
+            if (!decodeString(sectName))
+              return false;
+            uint32_t align;
+            if (!decodeULEB32(align))
+              return false;
+            uint32_t flags;
+            if (!decodeULEB32(flags))
+              return false;
+            LLVM_DEBUG(llvm::dbgs() << sectName << ": " << idx << "\n");
+            sections.insert({sectName, segments[idx]});
+          }
+        }
+        cursor += len;
+      }
+      return true;
+    };
+
+    while (decodeSection()) {
+    };
+    auto dataSect = sections.find("DATA");
+    if (dataSect == sections.end())
+      return false;
+
+    auto [dataStart, _, dataLength] = dataSect->second;
+    cursor = dataStart;
+    if (!decodeData(dataLength))
+      return false;
+
+    auto nameSect = sections.find("name");
+    if (nameSect != sections.end()) {
+      cursor = nameSect->second.remoteAddr;
+      if (!decodeNames(nameSect->second.size))
+        return false;
+    } else {
+      // This may be an object file?
+      auto linkingSect = sections.find("linking");
+      if (linkingSect == sections.end())
+        return false;
+      cursor = linkingSect->second.remoteAddr;
+      if (!decodeLinking(dataStart, linkingSect->second.size))
+        return false;
+    }
+
+    // Find reflection sections within the data section segments.
+    auto lookup =
+        [&](const std::string &name) -> std::pair<RemoteRef<void>, uint64_t> {
+      auto sectionIt = sections.find(name);
+      if (sectionIt == sections.end())
+        return {{}, 0};
+      auto &section = sectionIt->second;
+      RemoteAddress mappedSectionStart(0 + section.offset,
+                                       RemoteAddress::DefaultAddressSpace);
+      auto secBuf = reader.readBytes(section.remoteAddr, section.size);
+      auto secContents = RemoteRef<void>(mappedSectionStart, secBuf.get());
+      savedBuffers.push_back(std::move(secBuf));
+      LLVM_DEBUG(llvm::dbgs() << name << " @ " << section.offset << "\n");
+      return {secContents, section.size};
+    };
+
+    auto FieldMdSec = lookup("swift5_fieldmd");
+    auto AssocTySec = lookup("swift5_assocty");
+    auto BuiltinTySec = lookup("swift5_builtin");
+    auto CaptureSec = lookup("swift5_capture");
+    auto TypeRefMdSec = lookup("swift5_typeref");
+    auto ReflStrMdSec = lookup("swift5_reflstr");
+    auto ConformMdSec = lookup("swift5_protocol_conformances");
+    auto MPEnumMdSec = lookup("swift5_mpenum");
+
+    ReflectionInfo info = {{FieldMdSec.first, FieldMdSec.second},
+                           {AssocTySec.first, AssocTySec.second},
+                           {BuiltinTySec.first, BuiltinTySec.second},
+                           {CaptureSec.first, CaptureSec.second},
+                           {TypeRefMdSec.first, TypeRefMdSec.second},
+                           {ReflStrMdSec.first, ReflStrMdSec.second},
+                           {ConformMdSec.first, ConformMdSec.second},
+                           {MPEnumMdSec.first, MPEnumMdSec.second},
+                           PotentialModuleNames};
+    return addReflectionInfo(info);
+  }
+
   /// On success returns the ID of the newly registered Reflection Info.
   std::optional<uint32_t>
   addImage(RemoteAddress ImageStart,
@@ -827,7 +1126,6 @@ class ReflectionContext
       return readPECOFF(ImageStart, PotentialModuleNames);
     }
 
-
     // ELF.
     if (MagicBytes[0] == llvm::ELF::ElfMagic[0]
         && MagicBytes[1] == llvm::ELF::ElfMagic[1]
@@ -837,6 +1135,14 @@ class ReflectionContext
                      PotentialModuleNames);
     }
 
+    // WASM.
+    if (MagicBytes[0] == llvm::wasm::WasmMagic[0] &&
+        MagicBytes[1] == llvm::wasm::WasmMagic[1] &&
+        MagicBytes[2] == llvm::wasm::WasmMagic[2] &&
+        MagicBytes[3] == llvm::wasm::WasmMagic[3]) {
+      return readWasm(ImageStart, std::optional<llvm::sys::MemoryBlock>(),
+                      PotentialModuleNames);
+    }
     // We don't recognize the format.
     return std::nullopt;
   }
diff --git a/include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/Wasm.h b/include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/Wasm.h
new file mode 100644
index 0000000000000..7c6e6494500bf
--- /dev/null
+++ b/include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/Wasm.h
@@ -0,0 +1,581 @@
+//===- Wasm.h - Wasm object file format -------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines manifest constants for the wasm object file format.
+// See: https://github.com/WebAssembly/design/blob/main/BinaryEncoding.md
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BINARYFORMAT_WASM_H
+#define LLVM_BINARYFORMAT_WASM_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Compiler.h"
+#include <optional>
+
+namespace llvm {
+namespace wasm {
+
+// Object file magic string.
+const char WasmMagic[] = {'\0', 'a', 's', 'm'};
+// Wasm binary format version
+const uint32_t WasmVersion = 0x1;
+// Wasm linking metadata version
+const uint32_t WasmMetadataVersion = 0x2;
+// Wasm uses a 64k page size by default (but the custom-page-sizes proposal
+// allows changing it)
+const uint32_t WasmDefaultPageSize = 65536;
+
+enum : unsigned {
+  WASM_SEC_CUSTOM = 0,     // Custom / User-defined section
+  WASM_SEC_TYPE = 1,       // Function signature declarations
+  WASM_SEC_IMPORT = 2,     // Import declarations
+  WASM_SEC_FUNCTION = 3,   // Function declarations
+  WASM_SEC_TABLE = 4,      // Indirect function table and other tables
+  WASM_SEC_MEMORY = 5,     // Memory attributes
+  WASM_SEC_GLOBAL = 6,     // Global declarations
+  WASM_SEC_EXPORT = 7,     // Exports
+  WASM_SEC_START = 8,      // Start function declaration
+  WASM_SEC_ELEM = 9,       // Elements section
+  WASM_SEC_CODE = 10,      // Function bodies (code)
+  WASM_SEC_DATA = 11,      // Data segments
+  WASM_SEC_DATACOUNT = 12, // Data segment count
+  WASM_SEC_TAG = 13,       // Tag declarations
+  WASM_SEC_LAST_KNOWN = WASM_SEC_TAG,
+};
+
+// Type immediate encodings used in various contexts.
+enum : unsigned {
+  WASM_TYPE_I32 = 0x7F,
+  WASM_TYPE_I64 = 0x7E,
+  WASM_TYPE_F32 = 0x7D,
+  WASM_TYPE_F64 = 0x7C,
+  WASM_TYPE_V128 = 0x7B,
+  WASM_TYPE_NULLFUNCREF = 0x73,
+  WASM_TYPE_NULLEXTERNREF = 0x72,
+  WASM_TYPE_NULLEXNREF = 0x74,
+  WASM_TYPE_NULLREF = 0x71,
+  WASM_TYPE_FUNCREF = 0x70,
+  WASM_TYPE_EXTERNREF = 0x6F,
+  WASM_TYPE_EXNREF = 0x69,
+  WASM_TYPE_ANYREF = 0x6E,
+  WASM_TYPE_EQREF = 0x6D,
+  WASM_TYPE_I31REF = 0x6C,
+  WASM_TYPE_STRUCTREF = 0x6B,
+  WASM_TYPE_ARRAYREF = 0x6A,
+  WASM_TYPE_NONNULLABLE = 0x64,
+  WASM_TYPE_NULLABLE = 0x63,
+  WASM_TYPE_FUNC = 0x60,
+  WASM_TYPE_ARRAY = 0x5E,
+  WASM_TYPE_STRUCT = 0x5F,
+  WASM_TYPE_SUB = 0x50,
+  WASM_TYPE_SUB_FINAL = 0x4F,
+  WASM_TYPE_REC = 0x4E,
+  WASM_TYPE_NORESULT = 0x40, // for blocks with no result values
+};
+
+// Kinds of externals (for imports and exports).
+enum : unsigned {
+  WASM_EXTERNAL_FUNCTION = 0x0,
+  WASM_EXTERNAL_TABLE = 0x1,
+  WASM_EXTERNAL_MEMORY = 0x2,
+  WASM_EXTERNAL_GLOBAL = 0x3,
+  WASM_EXTERNAL_TAG = 0x4,
+};
+
+// Opcodes used in initializer expressions.
+enum : unsigned {
+  WASM_OPCODE_END = 0x0b,
+  WASM_OPCODE_CALL = 0x10,
+  WASM_OPCODE_LOCAL_GET = 0x20,
+  WASM_OPCODE_LOCAL_SET = 0x21,
+  WASM_OPCODE_LOCAL_TEE = 0x22,
+  WASM_OPCODE_GLOBAL_GET = 0x23,
+  WASM_OPCODE_GLOBAL_SET = 0x24,
+  WASM_OPCODE_I32_STORE = 0x36,
+  WASM_OPCODE_I64_STORE = 0x37,
+  WASM_OPCODE_I32_CONST = 0x41,
+  WASM_OPCODE_I64_CONST = 0x42,
+  WASM_OPCODE_F32_CONST = 0x43,
+  WASM_OPCODE_F64_CONST = 0x44,
+  WASM_OPCODE_I32_ADD = 0x6a,
+  WASM_OPCODE_I32_SUB = 0x6b,
+  WASM_OPCODE_I32_MUL = 0x6c,
+  WASM_OPCODE_I64_ADD = 0x7c,
+  WASM_OPCODE_I64_SUB = 0x7d,
+  WASM_OPCODE_I64_MUL = 0x7e,
+  WASM_OPCODE_REF_NULL = 0xd0,
+  WASM_OPCODE_REF_FUNC = 0xd2,
+  WASM_OPCODE_GC_PREFIX = 0xfb,
+};
+
+// Opcodes in the GC-prefixed space (0xfb)
+enum : unsigned {
+  WASM_OPCODE_STRUCT_NEW = 0x00,
+  WASM_OPCODE_STRUCT_NEW_DEFAULT = 0x01,
+  WASM_OPCODE_ARRAY_NEW = 0x06,
+  WASM_OPCODE_ARRAY_NEW_DEFAULT = 0x07,
+  WASM_OPCODE_ARRAY_NEW_FIXED = 0x08,
+  WASM_OPCODE_REF_I31 = 0x1c,
+  // any.convert_extern and extern.convert_any don't seem to be supported by
+  // Binaryen.
+};
+
+// Opcodes used in synthetic functions.
+enum : unsigned {
+  WASM_OPCODE_BLOCK = 0x02,
+  WASM_OPCODE_BR = 0x0c,
+  WASM_OPCODE_BR_TABLE = 0x0e,
+  WASM_OPCODE_RETURN = 0x0f,
+  WASM_OPCODE_DROP = 0x1a,
+  WASM_OPCODE_MISC_PREFIX = 0xfc,
+  WASM_OPCODE_MEMORY_INIT = 0x08,
+  WASM_OPCODE_MEMORY_FILL = 0x0b,
+  WASM_OPCODE_DATA_DROP = 0x09,
+  WASM_OPCODE_ATOMICS_PREFIX = 0xfe,
+  WASM_OPCODE_ATOMIC_NOTIFY = 0x00,
+  WASM_OPCODE_I32_ATOMIC_WAIT = 0x01,
+  WASM_OPCODE_I32_ATOMIC_STORE = 0x17,
+  WASM_OPCODE_I32_RMW_CMPXCHG = 0x48,
+};
+
+// Sub-opcodes for catch clauses in a try_table instruction
+enum : unsigned {
+  WASM_OPCODE_CATCH = 0x00,
+  WASM_OPCODE_CATCH_REF = 0x01,
+  WASM_OPCODE_CATCH_ALL = 0x02,
+  WASM_OPCODE_CATCH_ALL_REF = 0x03,
+};
+
+enum : unsigned {
+  WASM_LIMITS_FLAG_NONE = 0x0,
+  WASM_LIMITS_FLAG_HAS_MAX = 0x1,
+  WASM_LIMITS_FLAG_IS_SHARED = 0x2,
+  WASM_LIMITS_FLAG_IS_64 = 0x4,
+  WASM_LIMITS_FLAG_HAS_PAGE_SIZE = 0x8,
+};
+
+enum : unsigned {
+  WASM_DATA_SEGMENT_IS_PASSIVE = 0x01,
+  WASM_DATA_SEGMENT_HAS_MEMINDEX = 0x02,
+};
+
+enum : unsigned {
+  WASM_ELEM_SEGMENT_IS_PASSIVE = 0x01,
+  WASM_ELEM_SEGMENT_IS_DECLARATIVE = 0x02,   // if passive == 1
+  WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER = 0x02, // if passive == 0
+  WASM_ELEM_SEGMENT_HAS_INIT_EXPRS = 0x04,
+};
+const unsigned WASM_ELEM_SEGMENT_MASK_HAS_ELEM_DESC = 0x3;
+
+// Feature policy prefixes used in the custom "target_features" section
+enum : uint8_t {
+  WASM_FEATURE_PREFIX_USED = '+',
+  WASM_FEATURE_PREFIX_DISALLOWED = '-',
+};
+
+// Kind codes used in the custom "name" section
+enum : unsigned {
+  WASM_NAMES_MODULE = 0,
+  WASM_NAMES_FUNCTION = 1,
+  WASM_NAMES_LOCAL = 2,
+  WASM_NAMES_GLOBAL = 7,
+  WASM_NAMES_DATA_SEGMENT = 9,
+};
+
+// Kind codes used in the custom "linking" section
+enum : unsigned {
+  WASM_SEGMENT_INFO = 0x5,
+  WASM_INIT_FUNCS = 0x6,
+  WASM_COMDAT_INFO = 0x7,
+  WASM_SYMBOL_TABLE = 0x8,
+};
+
+// Kind codes used in the custom "dylink" section
+enum : unsigned {
+  WASM_DYLINK_MEM_INFO = 0x1,
+  WASM_DYLINK_NEEDED = 0x2,
+  WASM_DYLINK_EXPORT_INFO = 0x3,
+  WASM_DYLINK_IMPORT_INFO = 0x4,
+  WASM_DYLINK_RUNTIME_PATH = 0x5,
+};
+
+// Kind codes used in the custom "linking" section in the WASM_COMDAT_INFO
+enum : unsigned {
+  WASM_COMDAT_DATA = 0x0,
+  WASM_COMDAT_FUNCTION = 0x1,
+  // GLOBAL, TAG, and TABLE are in here but LLVM doesn't use them yet.
+  WASM_COMDAT_SECTION = 0x5,
+};
+
+// Kind codes used in the custom "linking" section in the WASM_SYMBOL_TABLE
+enum WasmSymbolType : unsigned {
+  WASM_SYMBOL_TYPE_FUNCTION = 0x0,
+  WASM_SYMBOL_TYPE_DATA = 0x1,
+  WASM_SYMBOL_TYPE_GLOBAL = 0x2,
+  WASM_SYMBOL_TYPE_SECTION = 0x3,
+  WASM_SYMBOL_TYPE_TAG = 0x4,
+  WASM_SYMBOL_TYPE_TABLE = 0x5,
+};
+
+enum WasmSegmentFlag : unsigned {
+  WASM_SEG_FLAG_STRINGS = 0x1,
+  WASM_SEG_FLAG_TLS = 0x2,
+  WASM_SEG_FLAG_RETAIN = 0x4,
+};
+
+// Kinds of tag attributes.
+enum WasmTagAttribute : uint8_t {
+  WASM_TAG_ATTRIBUTE_EXCEPTION = 0x0,
+};
+
+const unsigned WASM_SYMBOL_BINDING_MASK = 0x3;
+const unsigned WASM_SYMBOL_VISIBILITY_MASK = 0xc;
+
+const unsigned WASM_SYMBOL_BINDING_GLOBAL = 0x0;
+const unsigned WASM_SYMBOL_BINDING_WEAK = 0x1;
+const unsigned WASM_SYMBOL_BINDING_LOCAL = 0x2;
+const unsigned WASM_SYMBOL_VISIBILITY_DEFAULT = 0x0;
+const unsigned WASM_SYMBOL_VISIBILITY_HIDDEN = 0x4;
+const unsigned WASM_SYMBOL_UNDEFINED = 0x10;
+const unsigned WASM_SYMBOL_EXPORTED = 0x20;
+const unsigned WASM_SYMBOL_EXPLICIT_NAME = 0x40;
+const unsigned WASM_SYMBOL_NO_STRIP = 0x80;
+const unsigned WASM_SYMBOL_TLS = 0x100;
+const unsigned WASM_SYMBOL_ABSOLUTE = 0x200;
+
+#define WASM_RELOC(name, value) name = value,
+
+enum WasmRelocType : unsigned {
+#include "WasmRelocs.def"
+};
+
+#undef WASM_RELOC
+
+struct WasmObjectHeader {
+  StringRef Magic;
+  uint32_t Version;
+};
+
+// Subset of types that a value can have
+enum class ValType {
+  I32 = WASM_TYPE_I32,
+  I64 = WASM_TYPE_I64,
+  F32 = WASM_TYPE_F32,
+  F64 = WASM_TYPE_F64,
+  V128 = WASM_TYPE_V128,
+  FUNCREF = WASM_TYPE_FUNCREF,
+  EXTERNREF = WASM_TYPE_EXTERNREF,
+  EXNREF = WASM_TYPE_EXNREF,
+  // Unmodeled value types include ref types with heap types other than
+  // func, extern or exn, and type-specialized funcrefs
+  OTHERREF = 0xff,
+};
+
+struct WasmDylinkImportInfo {
+  StringRef Module;
+  StringRef Field;
+  uint32_t Flags;
+};
+
+struct WasmDylinkExportInfo {
+  StringRef Name;
+  uint32_t Flags;
+};
+
+struct WasmDylinkInfo {
+  uint32_t MemorySize;           // Memory size in bytes
+  uint32_t MemoryAlignment;      // P2 alignment of memory
+  uint32_t TableSize;            // Table size in elements
+  uint32_t TableAlignment;       // P2 alignment of table
+  std::vector<StringRef> Needed; // Shared library dependencies
+  std::vector<WasmDylinkImportInfo> ImportInfo;
+  std::vector<WasmDylinkExportInfo> ExportInfo;
+  std::vector<StringRef> RuntimePath;
+};
+
+struct WasmProducerInfo {
+  std::vector<std::pair<std::string, std::string>> Languages;
+  std::vector<std::pair<std::string, std::string>> Tools;
+  std::vector<std::pair<std::string, std::string>> SDKs;
+};
+
+struct WasmFeatureEntry {
+  uint8_t Prefix;
+  std::string Name;
+};
+
+struct WasmExport {
+  StringRef Name;
+  uint8_t Kind;
+  uint32_t Index;
+};
+
+struct WasmLimits {
+  uint8_t Flags;
+  uint64_t Minimum;
+  uint64_t Maximum;
+  uint32_t PageSize;
+};
+
+struct WasmTableType {
+  ValType ElemType;
+  WasmLimits Limits;
+};
+
+struct WasmTable {
+  uint32_t Index;
+  WasmTableType Type;
+  StringRef SymbolName; // from the "linking" section
+};
+
+struct WasmInitExprMVP {
+  uint8_t Opcode;
+  union {
+    int32_t Int32;
+    int64_t Int64;
+    uint32_t Float32;
+    uint64_t Float64;
+    uint32_t Global;
+  } Value;
+};
+
+// Extended-const init exprs and exprs with GC types are not explicitly
+// modeled, but the raw body of the expr is attached.
+struct WasmInitExpr {
+  uint8_t Extended; // Set to non-zero if extended const is used (i.e. more than
+                    // one instruction)
+  WasmInitExprMVP Inst;
+  ArrayRef<uint8_t> Body;
+};
+
+struct WasmGlobalType {
+  uint8_t Type; // TODO: make this a ValType?
+  bool Mutable;
+};
+
+struct WasmGlobal {
+  uint32_t Index;
+  WasmGlobalType Type;
+  WasmInitExpr InitExpr;
+  StringRef SymbolName; // from the "linking" section
+  uint32_t Offset; // Offset of the definition in the binary's Global section
+  uint32_t Size;   // Size of the definition in the binary's Global section
+};
+
+struct WasmTag {
+  uint32_t Index;
+  uint32_t SigIndex;
+  StringRef SymbolName; // from the "linking" section
+};
+
+struct WasmImport {
+  StringRef Module;
+  StringRef Field;
+  uint8_t Kind;
+  union {
+    uint32_t SigIndex;
+    WasmGlobalType Global;
+    WasmTableType Table;
+    WasmLimits Memory;
+  };
+};
+
+struct WasmLocalDecl {
+  uint8_t Type;
+  uint32_t Count;
+};
+
+struct WasmFunction {
+  uint32_t Index;
+  uint32_t SigIndex;
+  std::vector<WasmLocalDecl> Locals;
+  ArrayRef<uint8_t> Body;
+  uint32_t CodeSectionOffset;
+  uint32_t Size;
+  uint32_t CodeOffset;                 // start of Locals and Body
+  std::optional<StringRef> ExportName; // from the "export" section
+  StringRef SymbolName;                // from the "linking" section
+  StringRef DebugName;                 // from the "name" section
+  uint32_t Comdat;                     // from the "comdat info" section
+};
+
+struct WasmDataSegment {
+  uint32_t InitFlags;
+  // Present if InitFlags & WASM_DATA_SEGMENT_HAS_MEMINDEX.
+  uint32_t MemoryIndex;
+  // Present if InitFlags & WASM_DATA_SEGMENT_IS_PASSIVE == 0.
+  WasmInitExpr Offset;
+
+  ArrayRef<uint8_t> Content;
+  StringRef Name; // from the "segment info" section
+  uint32_t Alignment;
+  uint32_t LinkingFlags;
+  uint32_t Comdat; // from the "comdat info" section
+};
+
+// 3 different element segment modes are encodable. This class is currently
+// only used during decoding (see WasmElemSegment below).
+enum class ElemSegmentMode { Active, Passive, Declarative };
+
+// Represents a Wasm element segment, with some limitations compared the spec:
+// 1) Does not model passive or declarative segments (Segment will end up with
+// an Offset field of i32.const 0)
+// 2) Does not model init exprs (Segment will get an empty Functions list)
+// 3) Does not model types other than basic funcref/externref/exnref (see
+// ValType)
+struct WasmElemSegment {
+  uint32_t Flags;
+  uint32_t TableNumber;
+  ValType ElemKind;
+  WasmInitExpr Offset;
+  std::vector<uint32_t> Functions;
+};
+
+// Represents the location of a Wasm data symbol within a WasmDataSegment, as
+// the index of the segment, and the offset and size within the segment.
+struct WasmDataReference {
+  uint32_t Segment;
+  uint64_t Offset;
+  uint64_t Size;
+};
+
+struct WasmRelocation {
+  uint8_t Type;    // The type of the relocation.
+  uint32_t Index;  // Index into either symbol or type index space.
+  uint64_t Offset; // Offset from the start of the section.
+  int64_t Addend;  // A value to add to the symbol.
+
+  WasmRelocType getType() const { return static_cast<WasmRelocType>(Type); }
+};
+
+struct WasmInitFunc {
+  uint32_t Priority;
+  uint32_t Symbol;
+};
+
+struct WasmSymbolInfo {
+  StringRef Name;
+  uint8_t Kind;
+  uint32_t Flags;
+  // For undefined symbols the module of the import
+  std::optional<StringRef> ImportModule;
+  // For undefined symbols the name of the import
+  std::optional<StringRef> ImportName;
+  // For symbols to be exported from the final module
+  std::optional<StringRef> ExportName;
+  union {
+    // For function, table, or global symbols, the index in function, table, or
+    // global index space.
+    uint32_t ElementIndex;
+    // For a data symbols, the address of the data relative to segment.
+    WasmDataReference DataRef;
+  };
+};
+
+enum class NameType {
+  FUNCTION,
+  GLOBAL,
+  DATA_SEGMENT,
+};
+
+struct WasmDebugName {
+  NameType Type;
+  uint32_t Index;
+  StringRef Name;
+};
+
+// Info from the linking metadata section of a wasm object file.
+struct WasmLinkingData {
+  uint32_t Version;
+  std::vector<WasmInitFunc> InitFunctions;
+  std::vector<StringRef> Comdats;
+  // The linking section also contains a symbol table. This info (represented
+  // in a WasmSymbolInfo struct) is stored inside the WasmSymbol object instead
+  // of in this structure; this allows vectors of WasmSymbols and
+  // WasmLinkingDatas to be reallocated.
+};
+
+struct WasmSignature {
+  SmallVector<ValType, 1> Returns;
+  SmallVector<ValType, 4> Params;
+  // LLVM can parse types other than functions encoded in the type section,
+  // but does not actually model them. Instead a placeholder signature is
+  // created in the Object's signature list.
+  enum { Function, Tag, Placeholder } Kind = Function;
+  // Support empty and tombstone instances, needed by DenseMap.
+  enum { Plain, Empty, Tombstone } State = Plain;
+
+  WasmSignature(SmallVector<ValType, 1> &&InReturns,
+                SmallVector<ValType, 4> &&InParams)
+      : Returns(InReturns), Params(InParams) {}
+  WasmSignature() = default;
+};
+
+// Useful comparison operators
+inline bool operator==(const WasmSignature &LHS, const WasmSignature &RHS) {
+  return LHS.State == RHS.State && LHS.Returns == RHS.Returns &&
+         LHS.Params == RHS.Params;
+}
+
+inline bool operator!=(const WasmSignature &LHS, const WasmSignature &RHS) {
+  return !(LHS == RHS);
+}
+
+inline bool operator==(const WasmGlobalType &LHS, const WasmGlobalType &RHS) {
+  return LHS.Type == RHS.Type && LHS.Mutable == RHS.Mutable;
+}
+
+inline bool operator!=(const WasmGlobalType &LHS, const WasmGlobalType &RHS) {
+  return !(LHS == RHS);
+}
+
+inline bool operator==(const WasmLimits &LHS, const WasmLimits &RHS) {
+  return LHS.Flags == RHS.Flags && LHS.Minimum == RHS.Minimum &&
+         (LHS.Flags & WASM_LIMITS_FLAG_HAS_MAX ? LHS.Maximum == RHS.Maximum
+                                               : true) &&
+         (LHS.Flags & WASM_LIMITS_FLAG_HAS_PAGE_SIZE
+              ? LHS.PageSize == RHS.PageSize
+              : true);
+}
+
+inline bool operator==(const WasmTableType &LHS, const WasmTableType &RHS) {
+  return LHS.ElemType == RHS.ElemType && LHS.Limits == RHS.Limits;
+}
+
+inline llvm::StringRef sectionTypeToString(uint32_t type) {
+#define ECase(X)                                                               \
+  case wasm::WASM_SEC_##X:                                                     \
+    return #X;
+  switch (type) {
+    ECase(CUSTOM);
+    ECase(TYPE);
+    ECase(IMPORT);
+    ECase(FUNCTION);
+    ECase(TABLE);
+    ECase(MEMORY);
+    ECase(GLOBAL);
+    ECase(EXPORT);
+    ECase(START);
+    ECase(ELEM);
+    ECase(CODE);
+    ECase(DATA);
+    ECase(DATACOUNT);
+    ECase(TAG);
+  default:
+    llvm_unreachable("unknown section type");
+  }
+#undef ECase
+}
+
+} // end namespace wasm
+} // end namespace llvm
+
+#endif
diff --git a/include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/WasmRelocs.def b/include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/WasmRelocs.def
new file mode 100644
index 0000000000000..6f5a946b1c63d
--- /dev/null
+++ b/include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/WasmRelocs.def
@@ -0,0 +1,31 @@
+#ifndef WASM_RELOC
+#error "WASM_RELOC must be defined"
+#endif
+
+WASM_RELOC(R_WASM_FUNCTION_INDEX_LEB,      0)
+WASM_RELOC(R_WASM_TABLE_INDEX_SLEB,        1)
+WASM_RELOC(R_WASM_TABLE_INDEX_I32,         2)
+WASM_RELOC(R_WASM_MEMORY_ADDR_LEB,         3)
+WASM_RELOC(R_WASM_MEMORY_ADDR_SLEB,        4)
+WASM_RELOC(R_WASM_MEMORY_ADDR_I32,         5)
+WASM_RELOC(R_WASM_TYPE_INDEX_LEB,          6)
+WASM_RELOC(R_WASM_GLOBAL_INDEX_LEB,        7)
+WASM_RELOC(R_WASM_FUNCTION_OFFSET_I32,     8)
+WASM_RELOC(R_WASM_SECTION_OFFSET_I32,      9)
+WASM_RELOC(R_WASM_TAG_INDEX_LEB,          10)
+WASM_RELOC(R_WASM_MEMORY_ADDR_REL_SLEB,   11)
+WASM_RELOC(R_WASM_TABLE_INDEX_REL_SLEB,   12)
+WASM_RELOC(R_WASM_GLOBAL_INDEX_I32,       13)
+WASM_RELOC(R_WASM_MEMORY_ADDR_LEB64,      14)
+WASM_RELOC(R_WASM_MEMORY_ADDR_SLEB64,     15)
+WASM_RELOC(R_WASM_MEMORY_ADDR_I64,        16)
+WASM_RELOC(R_WASM_MEMORY_ADDR_REL_SLEB64, 17)
+WASM_RELOC(R_WASM_TABLE_INDEX_SLEB64,     18)
+WASM_RELOC(R_WASM_TABLE_INDEX_I64,        19)
+WASM_RELOC(R_WASM_TABLE_NUMBER_LEB,       20)
+WASM_RELOC(R_WASM_MEMORY_ADDR_TLS_SLEB,   21)
+WASM_RELOC(R_WASM_FUNCTION_OFFSET_I64,    22)
+WASM_RELOC(R_WASM_MEMORY_ADDR_LOCREL_I32, 23)
+WASM_RELOC(R_WASM_TABLE_INDEX_REL_SLEB64, 24)
+WASM_RELOC(R_WASM_MEMORY_ADDR_TLS_SLEB64, 25)
+WASM_RELOC(R_WASM_FUNCTION_INDEX_I32,     26)
diff --git a/include/swift/SIL/MemAccessUtils.h b/include/swift/SIL/MemAccessUtils.h
index 41a42f10275bd..955a55ff3039c 100644
--- a/include/swift/SIL/MemAccessUtils.h
+++ b/include/swift/SIL/MemAccessUtils.h
@@ -383,12 +383,12 @@ class AccessRepresentation {
     // Define bits for use in AccessStorageAnalysis. Each identified storage
     // object is mapped to one instance of this subclass.
     SWIFT_INLINE_BITFIELD_FULL(StorageAccessInfo, AccessRepresentation,
-                               64 - NumAccessRepresentationBits,
+                               64 - NumberOfAccessRepresentationBits,
                                accessKind : NumSILAccessKindBits,
                                noNestedConflict : 1,
-                               storageIndex : 64 - (NumAccessRepresentationBits
-                                                    + NumSILAccessKindBits
-                                                    + 1));
+                               storageIndex : 64 -
+                                   (NumberOfAccessRepresentationBits +
+                                    NumSILAccessKindBits + 1));
 
     // Define bits for use in the AccessEnforcementOpts pass. Each begin_access
     // in the function is mapped to one instance of this subclass.  Reserve a
@@ -398,13 +398,11 @@ class AccessRepresentation {
     //
     // `AccessRepresentation` refers to the AccessRepresentationBitfield defined
     // above, setting aside enough bits for common data.
-    SWIFT_INLINE_BITFIELD_FULL(AccessEnforcementOptsInfo,
-                               AccessRepresentation,
-                               64 - NumAccessRepresentationBits,
-                               seenNestedConflict : 1,
-                               seenIdenticalStorage : 1,
-                               beginAccessIndex :
-                                 62 - NumAccessRepresentationBits);
+    SWIFT_INLINE_BITFIELD_FULL(AccessEnforcementOptsInfo, AccessRepresentation,
+                               64 - NumberOfAccessRepresentationBits,
+                               seenNestedConflict : 1, seenIdenticalStorage : 1,
+                               beginAccessIndex : 62 -
+                                   NumberOfAccessRepresentationBits);
 
     // Define data flow bits for use in the AccessEnforcementDom pass. Each
     // begin_access in the function is mapped to one instance of this subclass.
diff --git a/include/swift/SIL/SILConstants.h b/include/swift/SIL/SILConstants.h
index 9c829ac42322a..51cc6e3b495e9 100644
--- a/include/swift/SIL/SILConstants.h
+++ b/include/swift/SIL/SILConstants.h
@@ -737,7 +737,7 @@ struct SymbolicClosure final
                                  SymbolicValueAllocator &allocator);
 
   ArrayRef<SymbolicClosureArgument> getCaptures() const {
-    return {getTrailingObjects<SymbolicClosureArgument>(), numCaptures};
+    return getTrailingObjects(numCaptures);
   }
 
   // This is used by the llvm::TrailingObjects base class.
diff --git a/include/swift/SIL/SILInstruction.h b/include/swift/SIL/SILInstruction.h
index f246b9cb1f9ce..40618b7b580c6 100644
--- a/include/swift/SIL/SILInstruction.h
+++ b/include/swift/SIL/SILInstruction.h
@@ -1737,7 +1737,7 @@ class InstructionBaseWithTrailingOperands
 
   // Destruct tail allocated objects.
   ~InstructionBaseWithTrailingOperands() {
-    Operand *Operands = TrailingObjects::template getTrailingObjects<Operand>();
+    Operand *Operands = this->template getTrailingObjectsNonStrict<Operand>();
     auto end = sharedUInt32().InstructionBaseWithTrailingOperands.numOperands;
     for (unsigned i = 0; i < end; ++i) {
       Operands[i].~Operand();
@@ -1750,13 +1750,13 @@ class InstructionBaseWithTrailingOperands
   }
 
   ArrayRef<Operand> getAllOperands() const {
-    return {TrailingObjects::template getTrailingObjects<Operand>(),
-            sharedUInt32().InstructionBaseWithTrailingOperands.numOperands};
+    return this->template getTrailingObjectsNonStrict<Operand>(
+        sharedUInt32().InstructionBaseWithTrailingOperands.numOperands);
   }
 
   MutableArrayRef<Operand> getAllOperands() {
-    return {TrailingObjects::template getTrailingObjects<Operand>(),
-            sharedUInt32().InstructionBaseWithTrailingOperands.numOperands};
+    return this->template getTrailingObjectsNonStrict<Operand>(
+        sharedUInt32().InstructionBaseWithTrailingOperands.numOperands);
   }
 };
 
@@ -2839,13 +2839,13 @@ class ApplyInstBase<Impl, Base, false> : public Base {
   ///   - the formal arguments
   ///   - the type-dependency arguments
   MutableArrayRef<Operand> getAllOperands() {
-    return { asImpl().template getTrailingObjects<Operand>(),
-             getNumAllOperands() };
+    return asImpl().template getTrailingObjectsNonStrict<Operand>(
+        getNumAllOperands());
   }
 
   ArrayRef<Operand> getAllOperands() const {
-    return { asImpl().template getTrailingObjects<Operand>(),
-             getNumAllOperands() };
+    return asImpl().template getTrailingObjectsNonStrict<Operand>(
+        getNumAllOperands());
   }
 
   /// Check whether the given operand index is a call-argument index
@@ -4337,7 +4337,7 @@ class IncrementProfilerCounterInst final
 
   /// The PGO function name for the function in which the counter resides.
   StringRef getPGOFuncName() const {
-    return StringRef(getTrailingObjects<char>(), PGOFuncNameLength);
+    return StringRef(getTrailingObjects(), PGOFuncNameLength);
   }
 
   /// The total number of counters within the function.
@@ -4560,7 +4560,7 @@ class StringLiteralInst final
 public:
   /// getValue - Return the string data for the literal, in UTF-8.
   StringRef getValue() const {
-    return {getTrailingObjects<char>(), sharedUInt32().StringLiteralInst.length};
+    return {getTrailingObjects(), sharedUInt32().StringLiteralInst.length};
   }
 
   /// getEncoding - Return the desired encoding of the text.
@@ -5620,7 +5620,7 @@ class SpecifyTestInst final
   void setValueForName(StringRef name, SILValue value) { values[name] = value; }
   llvm::StringMap<SILValue> const &getValues() { return values; }
   StringRef getArgumentsSpecification() const {
-    return StringRef(getTrailingObjects<char>(), ArgumentsSpecificationLength);
+    return StringRef(getTrailingObjects(), ArgumentsSpecificationLength);
   }
 
   ArrayRef<Operand> getAllOperands() const { return {}; }
@@ -9884,9 +9884,7 @@ class CondFailInst final
                               StringRef Message, SILModule &M);
 
 public:
-  StringRef getMessage() const {
-    return {getTrailingObjects<char>(), MessageSize};
-  }
+  StringRef getMessage() const { return {getTrailingObjects(), MessageSize}; }
 };
 
 //===----------------------------------------------------------------------===//
diff --git a/include/swift/SIL/SILVTable.h b/include/swift/SIL/SILVTable.h
index 0285c87e332c0..21ad8294bbc77 100644
--- a/include/swift/SIL/SILVTable.h
+++ b/include/swift/SIL/SILVTable.h
@@ -173,15 +173,13 @@ class SILVTable final : public SILAllocated<SILVTable>,
   }
 
   /// Return all of the method entries.
-  ArrayRef<Entry> getEntries() const {
-    return {getTrailingObjects<SILVTableEntry>(), NumEntries};
-  }
+  ArrayRef<Entry> getEntries() const { return getTrailingObjects(NumEntries); }
 
   /// Return all of the method entries mutably.
   /// If you do modify entries, make sure to invoke `updateVTableCache` to update the
   /// SILModule's cache entry.
   MutableArrayRef<Entry> getMutableEntries() {
-    return {getTrailingObjects<SILVTableEntry>(), NumEntries};
+    return getTrailingObjects(NumEntries);
   }
                           
   void updateVTableCache(const Entry &entry);
diff --git a/include/swift/SILOptimizer/Analysis/Analysis.h b/include/swift/SILOptimizer/Analysis/Analysis.h
index 3a3afbd75b8db..deed38a88d6e5 100644
--- a/include/swift/SILOptimizer/Analysis/Analysis.h
+++ b/include/swift/SILOptimizer/Analysis/Analysis.h
@@ -233,19 +233,19 @@ class FunctionAnalysisBase : public SILAnalysis {
     // Check that the analysis can handle this function.
     verifyFunction(f);
 
-    auto &it = storage.FindAndConstruct(f);
-    if (!it.second)
-      it.second = newFunctionAnalysis(f);
-    return it.second.get();
+    auto &value = storage[f];
+    if (!value)
+      value = newFunctionAnalysis(f);
+    return value.get();
   }
 
   virtual void forcePrecompute(SILFunction *f) override {
     // Check that the analysis can handle this function.
     verifyFunction(f);
 
-    auto &it = storage.FindAndConstruct(f);
-    if (!it.second)
-      it.second = newFunctionAnalysis(f);
+    auto &value = storage[f];
+    if (!value)
+      value = newFunctionAnalysis(f);
   }
 
   /// Invalidate all information in this analysis.
diff --git a/include/swift/SILOptimizer/Utils/PartitionUtils.h b/include/swift/SILOptimizer/Utils/PartitionUtils.h
index db5008bfbf1f8..8c4d56280bd30 100644
--- a/include/swift/SILOptimizer/Utils/PartitionUtils.h
+++ b/include/swift/SILOptimizer/Utils/PartitionUtils.h
@@ -282,7 +282,7 @@ class IsolationHistory::Node final
 
   /// Access the tail allocated buffer of additional element arguments.
   MutableArrayRef<Element> getAdditionalElementArgs() {
-    return {getTrailingObjects<Element>(), numAdditionalElements};
+    return getTrailingObjects(numAdditionalElements);
   }
 
   Node(Kind kind, Node *parent)
diff --git a/include/swift/Sema/CSFix.h b/include/swift/Sema/CSFix.h
index c6e5be5319005..dbfff2be4ea47 100644
--- a/include/swift/Sema/CSFix.h
+++ b/include/swift/Sema/CSFix.h
@@ -663,7 +663,7 @@ class RelabelArguments final
   std::string getName() const override { return "re-label argument(s)"; }
 
   ArrayRef<Identifier> getLabels() const {
-    return {getTrailingObjects<Identifier>(), NumLabels};
+    return getTrailingObjects(NumLabels);
   }
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
@@ -680,7 +680,7 @@ class RelabelArguments final
 
 private:
   MutableArrayRef<Identifier> getLabelsBuffer() {
-    return {getTrailingObjects<Identifier>(), NumLabels};
+    return getTrailingObjects(NumLabels);
   }
 };
 
@@ -1201,7 +1201,7 @@ class GenericArgumentsMismatch final
   }
 
   ArrayRef<unsigned> getMismatches() const {
-    return {getTrailingObjects<unsigned>(), NumMismatches};
+    return getTrailingObjects(NumMismatches);
   }
 
   bool coalesceAndDiagnose(const Solution &solution,
@@ -1224,7 +1224,7 @@ class GenericArgumentsMismatch final
                 bool asNote = false) const;
 
   MutableArrayRef<unsigned> getMismatchesBuf() {
-    return {getTrailingObjects<unsigned>(), NumMismatches};
+    return getTrailingObjects(NumMismatches);
   }
 };
 
@@ -1794,7 +1794,7 @@ class AddMissingArguments final
   std::string getName() const override { return "synthesize missing argument(s)"; }
 
   ArrayRef<SynthesizedArg> getSynthesizedArguments() const {
-    return {getTrailingObjects<SynthesizedArg>(), NumSynthesized};
+    return getTrailingObjects(NumSynthesized);
   }
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
@@ -1813,7 +1813,7 @@ class AddMissingArguments final
 
 private:
   MutableArrayRef<SynthesizedArg> getSynthesizedArgumentsBuf() {
-    return {getTrailingObjects<SynthesizedArg>(), NumSynthesized};
+    return getTrailingObjects(NumSynthesized);
   }
 };
 
@@ -1842,7 +1842,7 @@ class RemoveExtraneousArguments final
   std::string getName() const override { return "remove extraneous argument(s)"; }
 
   ArrayRef<IndexedParam> getExtraArguments() const {
-    return {getTrailingObjects<IndexedParam>(), NumExtraneous};
+    return getTrailingObjects(NumExtraneous);
   }
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
@@ -1870,7 +1870,7 @@ class RemoveExtraneousArguments final
 
 private:
   MutableArrayRef<IndexedParam> getExtraArgumentsBuf() {
-    return {getTrailingObjects<IndexedParam>(), NumExtraneous};
+    return getTrailingObjects(NumExtraneous);
   }
 };
 
@@ -2274,7 +2274,7 @@ class CollectionElementContextualMismatch final
   }
 
   ArrayRef<Expr *> getElements() const {
-    return {getTrailingObjects<Expr *>(), NumElements};
+    return getTrailingObjects(NumElements);
   }
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
@@ -2289,7 +2289,7 @@ class CollectionElementContextualMismatch final
 
 private:
   MutableArrayRef<Expr *> getElementBuffer() {
-    return {getTrailingObjects<Expr *>(), NumElements};
+    return getTrailingObjects(NumElements);
   }
 };
 
@@ -3528,14 +3528,14 @@ class RenameConflictingPatternVariables final
   }
 
   MutableArrayRef<VarDecl *> getConflictingBuffer() {
-    return {getTrailingObjects<VarDecl *>(), NumConflicts};
+    return getTrailingObjects(NumConflicts);
   }
 
 public:
   std::string getName() const override { return "rename pattern variables"; }
 
   ArrayRef<VarDecl *> getConflictingVars() const {
-    return {getTrailingObjects<VarDecl *>(), NumConflicts};
+    return getTrailingObjects(NumConflicts);
   }
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
diff --git a/include/swift/Sema/PreparedOverload.h b/include/swift/Sema/PreparedOverload.h
index 0d678214a6126..de316eb988b1d 100644
--- a/include/swift/Sema/PreparedOverload.h
+++ b/include/swift/Sema/PreparedOverload.h
@@ -171,7 +171,7 @@ class PreparedOverload final :
     : OpenedType(openedType), ThrownErrorType(thrownErrorType),
       Count(changes.size()) {
     std::uninitialized_copy(changes.begin(), changes.end(),
-                            getTrailingObjects<Change>());
+                            getTrailingObjects());
   }
 
   Type getOpenedType() const {
@@ -182,9 +182,7 @@ class PreparedOverload final :
     return ThrownErrorType;
   }
 
-  ArrayRef<Change> getChanges() const {
-    return ArrayRef<Change>(getTrailingObjects<Change>(), Count);
-  }
+  ArrayRef<Change> getChanges() const { return getTrailingObjects(Count); }
 };
 
 struct PreparedOverloadBuilder {
diff --git a/include/swift/StaticMirror/ObjectFileContext.h b/include/swift/StaticMirror/ObjectFileContext.h
index 927418cf5b7c7..5b53b3670aa82 100644
--- a/include/swift/StaticMirror/ObjectFileContext.h
+++ b/include/swift/StaticMirror/ObjectFileContext.h
@@ -57,6 +57,8 @@ class Image {
 
   void scanCOFF(const llvm::object::COFFObjectFile *O);
 
+  void scanWasm(const llvm::object::WasmObjectFile *O);
+
   bool isMachOWithPtrAuth() const;
 
 public:
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 4a1d8b9be6db0..a3ed0a899d5c8 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2518,8 +2518,7 @@ void OverriddenDeclsRequest::cacheResult(
 
   // Record the overrides in the context.
   auto &ctx = decl->getASTContext();
-  auto overriddenCopy =
-    ctx.AllocateCopy(value.operator ArrayRef<ValueDecl *>());
+  auto overriddenCopy = ctx.AllocateCopy(ArrayRef<ValueDecl *>(value));
   (void)ctx.getImpl().Overrides.insert({decl, overriddenCopy});
 }
 
@@ -3473,7 +3472,7 @@ TypeAliasType::TypeAliasType(TypeAliasDecl *typealias, Type parent,
   // Record the parent (or absence of a parent).
   if (parent) {
     Bits.TypeAliasType.HasParent = true;
-    *getTrailingObjects<Type>() = parent;
+    *getTrailingObjects() = parent;
   } else {
     Bits.TypeAliasType.HasParent = false;
   }
@@ -3486,8 +3485,7 @@ TypeAliasType::TypeAliasType(TypeAliasDecl *typealias, Type parent,
     ASSERT(params->size() == count);
     Bits.TypeAliasType.GenericArgCount = count;
     std::uninitialized_copy(genericArgs.begin(), genericArgs.end(),
-                            getTrailingObjects<Type>() +
-                            (parent ? 1 : 0));
+                            getTrailingObjects() + (parent ? 1 : 0));
   } else {
     ASSERT(params == nullptr);
     Bits.TypeAliasType.GenericArgCount = 0;
@@ -5919,9 +5917,8 @@ const AvailabilityContext::Storage *AvailabilityContext::Storage::get(
       ctx.Allocate(storageToAlloc, alignof(AvailabilityContext::Storage));
   auto *newNode = ::new (mem) AvailabilityContext::Storage(
       platformRange, isDeprecated, domainInfos.size());
-  std::uninitialized_copy(
-      domainInfos.begin(), domainInfos.end(),
-      newNode->getTrailingObjects<AvailabilityContext::DomainInfo>());
+  std::uninitialized_copy(domainInfos.begin(), domainInfos.end(),
+                          newNode->getTrailingObjects());
   foldingSet.InsertNode(newNode, insertPos);
 
   return newNode;
diff --git a/lib/AST/Attr.cpp b/lib/AST/Attr.cpp
index ee971084a0b04..63ade446016e7 100644
--- a/lib/AST/Attr.cpp
+++ b/lib/AST/Attr.cpp
@@ -2724,7 +2724,7 @@ SPIAccessControlAttr::SPIAccessControlAttr(SourceLoc atLoc, SourceRange range,
                     /*Implicit=*/false),
       numSPIGroups(spiGroups.size()) {
   std::uninitialized_copy(spiGroups.begin(), spiGroups.end(),
-                          getTrailingObjects<Identifier>());
+                          getTrailingObjects());
 }
 
 SPIAccessControlAttr *
@@ -2762,8 +2762,7 @@ DifferentiableAttr::DifferentiableAttr(bool implicit, SourceLoc atLoc,
   assert((diffKind != DifferentiabilityKind::Normal &&
           diffKind != DifferentiabilityKind::Forward) &&
          "'Normal' and 'Forward' are not supported");
-  std::copy(params.begin(), params.end(),
-            getTrailingObjects<ParsedAutoDiffParameter>());
+  std::copy(params.begin(), params.end(), getTrailingObjects());
 }
 
 DifferentiableAttr::DifferentiableAttr(Decl *original, bool implicit,
@@ -2865,8 +2864,7 @@ DerivativeAttr::DerivativeAttr(bool implicit, SourceLoc atLoc,
     : DeclAttribute(DeclAttrKind::Derivative, atLoc, baseRange, implicit),
       BaseTypeRepr(baseTypeRepr), OriginalFunctionName(std::move(originalName)),
       NumParsedParameters(params.size()) {
-  std::copy(params.begin(), params.end(),
-            getTrailingObjects<ParsedAutoDiffParameter>());
+  std::copy(params.begin(), params.end(), getTrailingObjects());
 }
 
 DerivativeAttr::DerivativeAttr(bool implicit, SourceLoc atLoc,
@@ -2932,8 +2930,7 @@ TransposeAttr::TransposeAttr(bool implicit, SourceLoc atLoc,
     : DeclAttribute(DeclAttrKind::Transpose, atLoc, baseRange, implicit),
       BaseTypeRepr(baseTypeRepr), OriginalFunctionName(std::move(originalName)),
       NumParsedParameters(params.size()) {
-  std::uninitialized_copy(params.begin(), params.end(),
-                          getTrailingObjects<ParsedAutoDiffParameter>());
+  std::uninitialized_copy(params.begin(), params.end(), getTrailingObjects());
 }
 
 TransposeAttr::TransposeAttr(bool implicit, SourceLoc atLoc,
@@ -2971,9 +2968,9 @@ StorageRestrictionsAttr::StorageRestrictionsAttr(
     : DeclAttribute(DeclAttrKind::StorageRestrictions, AtLoc, Range, Implicit),
       NumInitializes(initializes.size()), NumAccesses(accesses.size()) {
   std::uninitialized_copy(initializes.begin(), initializes.end(),
-                          getTrailingObjects<Identifier>());
+                          getTrailingObjects());
   std::uninitialized_copy(accesses.begin(), accesses.end(),
-                          getTrailingObjects<Identifier>() + NumInitializes);
+                          getTrailingObjects() + NumInitializes);
 }
 
 StorageRestrictionsAttr *
@@ -3233,7 +3230,7 @@ AllowFeatureSuppressionAttr::AllowFeatureSuppressionAttr(
   Bits.AllowFeatureSuppressionAttr.Inverted = inverted;
   Bits.AllowFeatureSuppressionAttr.NumFeatures = features.size();
   std::uninitialized_copy(features.begin(), features.end(),
-                          getTrailingObjects<Identifier>());
+                          getTrailingObjects());
 }
 
 AllowFeatureSuppressionAttr *AllowFeatureSuppressionAttr::create(
diff --git a/lib/AST/Builtins.cpp b/lib/AST/Builtins.cpp
index 6778477c96966..b2d5dd8af304f 100644
--- a/lib/AST/Builtins.cpp
+++ b/lib/AST/Builtins.cpp
@@ -49,13 +49,14 @@ bool BuiltinInfo::isReadNone() const {
   return strchr(BuiltinExtraInfo[(unsigned)ID].Attributes, 'n') != nullptr;
 }
 
-const llvm::AttributeList &
-IntrinsicInfo::getOrCreateAttributes(ASTContext &Ctx) const {
-  using DenseMapInfo = llvm::DenseMapInfo<llvm::AttributeList>;
-  if (DenseMapInfo::isEqual(Attrs, DenseMapInfo::getEmptyKey())) {
-    Attrs = llvm::Intrinsic::getAttributes(Ctx.getIntrinsicScratchContext(), ID);
+const llvm::AttributeSet &
+IntrinsicInfo::getOrCreateFnAttributes(ASTContext &Ctx) const {
+  using DenseMapInfo = llvm::DenseMapInfo<llvm::AttributeSet>;
+  if (DenseMapInfo::isEqual(FnAttrs, DenseMapInfo::getEmptyKey())) {
+    FnAttrs =
+        llvm::Intrinsic::getFnAttributes(Ctx.getIntrinsicScratchContext(), ID);
   }
-  return Attrs;
+  return FnAttrs;
 }
 
 Type swift::getBuiltinType(ASTContext &Context, StringRef Name) {
@@ -2427,18 +2428,6 @@ bool swift::canBuiltinBeOverloadedForType(BuiltinValueKind ID, Type Ty) {
   return isBuiltinTypeOverloaded(Ty, OverloadedBuiltinKinds[unsigned(ID)]);
 }
 
-/// Table of string intrinsic names indexed by enum value.
-static const char *const IntrinsicNameTable[] = {
-    "not_intrinsic",
-#define GET_INTRINSIC_NAME_TABLE
-#include "llvm/IR/IntrinsicImpl.inc"
-#undef GET_INTRINSIC_NAME_TABLE
-};
-
-#define GET_INTRINSIC_TARGET_DATA
-#include "llvm/IR/IntrinsicImpl.inc"
-#undef GET_INTRINSIC_TARGET_DATA
-
 llvm::Intrinsic::ID swift::getLLVMIntrinsicID(StringRef InName) {
   using namespace llvm;
 
@@ -2454,10 +2443,8 @@ llvm::Intrinsic::ID swift::getLLVMIntrinsicID(StringRef InName) {
     NameS.push_back(C == '_' ? '.' : C);
 
   const char *Name = NameS.c_str();
-  ArrayRef<const char *> NameTable(&IntrinsicNameTable[1],
-                                   TargetInfos[1].Offset);
-  int Idx = Intrinsic::lookupLLVMIntrinsicByName(NameTable, Name);
-  return static_cast<Intrinsic::ID>(Idx + 1);
+
+  return Intrinsic::lookupIntrinsicID(Name);
 }
 
 llvm::Intrinsic::ID
@@ -2543,7 +2530,6 @@ Type IntrinsicTypeDecoder::decodeImmediate() {
   case IITDescriptor::Metadata:
   case IITDescriptor::ExtendArgument:
   case IITDescriptor::TruncArgument:
-  case IITDescriptor::HalfVecArgument:
   case IITDescriptor::VarArg:
   case IITDescriptor::Token:
   case IITDescriptor::VecOfAnyPtrsToElt:
@@ -2552,6 +2538,7 @@ Type IntrinsicTypeDecoder::decodeImmediate() {
   case IITDescriptor::Subdivide4Argument:
   case IITDescriptor::PPCQuad:
   case IITDescriptor::AArch64Svcount:
+  case IITDescriptor::OneNthEltsVecArgument:
     // These types cannot be expressed in swift yet.
     return Type();
 
@@ -2649,8 +2636,8 @@ getSwiftFunctionTypeForIntrinsic(llvm::Intrinsic::ID ID,
   // Translate LLVM function attributes to Swift function attributes.
   IntrinsicInfo II;
   II.ID = ID;
-  auto attrs = II.getOrCreateAttributes(Context);
-  if (attrs.hasFnAttr(llvm::Attribute::NoReturn)) {
+  auto &attrs = II.getOrCreateFnAttributes(Context);
+  if (attrs.hasAttribute(llvm::Attribute::NoReturn)) {
     ResultTy = Context.getNeverType();
     if (!ResultTy)
       return false;
diff --git a/lib/AST/ClangTypeConverter.cpp b/lib/AST/ClangTypeConverter.cpp
index efa8a0e8e9122..464a595942de1 100644
--- a/lib/AST/ClangTypeConverter.cpp
+++ b/lib/AST/ClangTypeConverter.cpp
@@ -71,7 +71,7 @@ getClangBuiltinTypeFromKind(const clang::ASTContext &context,
 #define SVE_TYPE(Name, Id, SingletonId)                                        \
   case clang::BuiltinType::Id:                                                 \
     return context.SingletonId;
-#include "clang/Basic/AArch64SVEACLETypes.def"
+#include "clang/Basic/AArch64ACLETypes.def"
 #define PPC_VECTOR_TYPE(Name, Id, Size)                                        \
   case clang::BuiltinType::Id:                                                 \
     return context.Id##Ty;
@@ -84,10 +84,14 @@ getClangBuiltinTypeFromKind(const clang::ASTContext &context,
   case clang::BuiltinType::Id:                                                 \
     return context.SingletonId;
 #include "clang/Basic/WebAssemblyReferenceTypes.def"
-#define AMDGPU_TYPE(Name, Id, SingletonId)                                     \
+#define AMDGPU_TYPE(Name, Id, SingletonId, Width, Align)                       \
   case clang::BuiltinType::Id:                                                 \
     return context.SingletonId;
 #include "clang/Basic/AMDGPUTypes.def"
+#define HLSL_INTANGIBLE_TYPE(Name, Id, SingletonId)                            \
+  case clang::BuiltinType::Id:                                                 \
+    return context.SingletonId;
+#include "clang/Basic/HLSLIntangibleTypes.def"
   }
 
   // Not a valid BuiltinType.
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index fff6a6e2a26a8..e5bfc0fdeb988 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1731,8 +1731,7 @@ ImportDecl::ImportDecl(DeclContext *DC, SourceLoc ImportLoc, ImportKind K,
   assert(Bits.ImportDecl.NumPathElements == Path.size() && "Truncation error");
   Bits.ImportDecl.ImportKind = static_cast<unsigned>(K);
   assert(getImportKind() == K && "not enough bits for ImportKind");
-  std::uninitialized_copy(Path.begin(), Path.end(),
-                          getTrailingObjects<ImportPath::Element>());
+  std::uninitialized_copy(Path.begin(), Path.end(), getTrailingObjects());
 }
 
 ImportKind ImportDecl::getBestImportKind(const ValueDecl *VD) {
@@ -2334,7 +2333,7 @@ PatternBindingDecl::create(ASTContext &Ctx, SourceLoc StaticLoc,
                                           PatternList.size(), Parent);
   // Set up the patterns.
   std::uninitialized_copy(PatternList.begin(), PatternList.end(),
-                          PBD->getTrailingObjects<PatternBindingEntry>());
+                          PBD->getTrailingObjects());
 
   for (auto idx : range(PBD->getNumPatternEntries())) {
     auto *initContext = PBD->getInitContext(idx);
@@ -10761,9 +10760,8 @@ OpaqueTypeDecl::OpaqueTypeDecl(ValueDecl *NamingDecl,
   assert(OpaqueReturnTypeReprs.empty() ||
          OpaqueReturnTypeReprs.size() ==
             OpaqueInterfaceGenericSignature.getInnermostGenericParams().size());
-  std::uninitialized_copy(
-      OpaqueReturnTypeReprs.begin(), OpaqueReturnTypeReprs.end(),
-      getTrailingObjects<TypeRepr *>());
+  std::uninitialized_copy(OpaqueReturnTypeReprs.begin(),
+                          OpaqueReturnTypeReprs.end(), getTrailingObjects());
 }
 
 OpaqueTypeDecl *OpaqueTypeDecl::get(
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index a8f3f57f8eefc..881e269d348c0 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2915,7 +2915,7 @@ TypeJoinExpr::TypeJoinExpr(llvm::PointerUnion<DeclRefExpr *, TypeBase *> result,
   Bits.TypeJoinExpr.NumElements = elements.size();
   // Copy elements.
   std::uninitialized_copy(elements.begin(), elements.end(),
-                          getTrailingObjects<Expr *>());
+                          getTrailingObjects());
 }
 
 TypeJoinExpr *TypeJoinExpr::createImpl(
diff --git a/lib/AST/GenericParamList.cpp b/lib/AST/GenericParamList.cpp
index 7ca5ffbb42f36..3dbfe884992d5 100644
--- a/lib/AST/GenericParamList.cpp
+++ b/lib/AST/GenericParamList.cpp
@@ -39,8 +39,7 @@ GenericParamList::GenericParamList(SourceLoc LAngleLoc,
     WhereLoc(WhereLoc), Requirements(Requirements),
     OuterParameters(nullptr)
 {
-  std::uninitialized_copy(Params.begin(), Params.end(),
-                          getTrailingObjects<GenericTypeParamDecl *>());
+  std::uninitialized_copy(Params.begin(), Params.end(), getTrailingObjects());
 }
 
 GenericParamList *
@@ -123,7 +122,7 @@ TrailingWhereClause::TrailingWhereClause(
     NumRequirements(requirements.size())
 {
   std::uninitialized_copy(requirements.begin(), requirements.end(),
-                          getTrailingObjects<RequirementRepr>());
+                          getTrailingObjects());
 }
 
 TrailingWhereClause *TrailingWhereClause::create(
diff --git a/lib/AST/ImportCache.cpp b/lib/AST/ImportCache.cpp
index 0567151a37dac..3a8db740179c9 100644
--- a/lib/AST/ImportCache.cpp
+++ b/lib/AST/ImportCache.cpp
@@ -35,7 +35,7 @@ ImportSet::ImportSet(bool hasHeaderImportModule,
     NumTopLevelImports(topLevelImports.size()),
     NumTransitiveImports(transitiveImports.size()),
     NumTransitiveSwiftOnlyImports(transitiveSwiftOnlyImports.size()) {
-  auto buffer = getTrailingObjects<ImportedModule>();
+  auto *buffer = getTrailingObjects();
   std::uninitialized_copy(topLevelImports.begin(), topLevelImports.end(),
                           buffer);
   std::uninitialized_copy(transitiveImports.begin(), transitiveImports.end(),
diff --git a/lib/AST/PackConformance.cpp b/lib/AST/PackConformance.cpp
index c6d3bdfec01c3..e2f6250b1e71d 100644
--- a/lib/AST/PackConformance.cpp
+++ b/lib/AST/PackConformance.cpp
@@ -48,7 +48,7 @@ PackConformance::PackConformance(PackType *conformingType,
 
   assert(ConformingType->getNumElements() == conformances.size());
   std::uninitialized_copy(conformances.begin(), conformances.end(),
-                          getTrailingObjects<ProtocolConformanceRef>());
+                          getTrailingObjects());
 }
 
 size_t PackConformance::numTrailingObjects(
@@ -63,8 +63,7 @@ bool PackConformance::isInvalid() const {
 
 ArrayRef<ProtocolConformanceRef>
 PackConformance::getPatternConformances() const {
-  return {getTrailingObjects<ProtocolConformanceRef>(),
-          ConformingType->getNumElements()};
+  return getTrailingObjects(ConformingType->getNumElements());
 }
 
 bool PackConformance::isCanonical() const {
diff --git a/lib/AST/Pattern.cpp b/lib/AST/Pattern.cpp
index 53ed6442ec106..94a2fc40be5c3 100644
--- a/lib/AST/Pattern.cpp
+++ b/lib/AST/Pattern.cpp
@@ -466,7 +466,7 @@ TuplePattern *TuplePattern::create(ASTContext &C, SourceLoc lp,
                             alignof(TuplePattern));
   TuplePattern *pattern = ::new (buffer) TuplePattern(lp, n, rp);
   std::uninitialized_copy(elts.begin(), elts.end(),
-                          pattern->getTrailingObjects<TuplePatternElt>());
+                          pattern->getTrailingObjects());
   return pattern;
 }
 
diff --git a/lib/AST/RequirementMachine/ApplyInverses.cpp b/lib/AST/RequirementMachine/ApplyInverses.cpp
index a37726b7c4a48..bed9797a7ec3d 100644
--- a/lib/AST/RequirementMachine/ApplyInverses.cpp
+++ b/lib/AST/RequirementMachine/ApplyInverses.cpp
@@ -212,7 +212,7 @@ void swift::rewriting::applyInverses(
       continue;
     }
 
-    auto state = inverses.getOrInsertDefault(representativeSubject);
+    auto &state = inverses[representativeSubject];
 
     // Check if this inverse has already been seen.
     auto inverseKind = inverse.getKind();
diff --git a/lib/AST/RequirementMachine/Term.cpp b/lib/AST/RequirementMachine/Term.cpp
index 5455fb348fa56..62cd07e6bd201 100644
--- a/lib/AST/RequirementMachine/Term.cpp
+++ b/lib/AST/RequirementMachine/Term.cpp
@@ -39,13 +39,9 @@ struct Term::Storage final
     return Size;
   }
 
-  MutableArrayRef<Symbol> getElements() {
-    return {getTrailingObjects<Symbol>(), Size};
-  }
+  MutableArrayRef<Symbol> getElements() { return getTrailingObjects(Size); }
 
-  ArrayRef<Symbol> getElements() const {
-    return {getTrailingObjects<Symbol>(), Size};
-  }
+  ArrayRef<Symbol> getElements() const { return getTrailingObjects(Size); }
 
   void Profile(llvm::FoldingSetNodeID &id) const;
 };
diff --git a/lib/AST/SILLayout.cpp b/lib/AST/SILLayout.cpp
index 2a4599b7baf6d..efcf5ac734934 100644
--- a/lib/AST/SILLayout.cpp
+++ b/lib/AST/SILLayout.cpp
@@ -82,7 +82,7 @@ SILLayout::SILLayout(CanGenericSignature Sig,
 #ifndef NDEBUG
   verifyFields(Sig, Fields);
 #endif
-  auto FieldsMem = getTrailingObjects<SILField>();
+  auto *FieldsMem = getTrailingObjects();
   for (unsigned i : indices(Fields)) {
     new (FieldsMem + i) SILField(Fields[i]);
   }
diff --git a/lib/AST/Stmt.cpp b/lib/AST/Stmt.cpp
index 68e5dcd8e38af..95529d2af8216 100644
--- a/lib/AST/Stmt.cpp
+++ b/lib/AST/Stmt.cpp
@@ -184,8 +184,7 @@ BraceStmt::BraceStmt(SourceLoc lbloc, ArrayRef<ASTNode> elts, SourceLoc rbloc,
     : Stmt(StmtKind::Brace, getDefaultImplicitFlag(implicit, lbloc)),
       LBLoc(lbloc), RBLoc(rbloc) {
   Bits.BraceStmt.NumElements = elts.size();
-  std::uninitialized_copy(elts.begin(), elts.end(),
-                          getTrailingObjects<ASTNode>());
+  std::uninitialized_copy(elts.begin(), elts.end(), getTrailingObjects());
 
 #ifndef NDEBUG
   for (auto elt : elts)
@@ -998,7 +997,7 @@ SwitchStmt *SwitchStmt::create(LabeledStmtInfo LabelInfo, SourceLoc SwitchLoc,
                                                EndLoc);
 
   std::uninitialized_copy(Cases.begin(), Cases.end(),
-                          theSwitch->getTrailingObjects<CaseStmt *>());
+                          theSwitch->getTrailingObjects());
   for (auto *caseStmt : theSwitch->getCases())
     caseStmt->setParentStmt(theSwitch);
 
diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index ba6a64f87c442..6f5ba55d4637a 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -3651,7 +3651,7 @@ bool TypeBase::matchesFunctionType(Type other, TypeMatchOptions matchMode,
 /// return the field index, otherwise return -1.
 int TupleType::getNamedElementId(Identifier I) const {
   for (unsigned i = 0, e = Bits.TupleType.Count; i != e; ++i) {
-    if (getTrailingObjects<TupleTypeElt>()[i].getName() == I)
+    if (getTrailingObjects()[i].getName() == I)
       return i;
   }
 
@@ -3987,7 +3987,7 @@ ParameterizedProtocolType::ParameterizedProtocolType(
   assert(args.size() > 0);
   Bits.ParameterizedProtocolType.ArgCount = args.size();
   for (unsigned i : indices(args))
-    getTrailingObjects<Type>()[i] = args[i];
+    getTrailingObjects()[i] = args[i];
 }
 
 void ParameterizedProtocolType::Profile(llvm::FoldingSetNodeID &ID,
diff --git a/lib/AST/TypeRepr.cpp b/lib/AST/TypeRepr.cpp
index c19587b38aa02..f614e2dc98d8c 100644
--- a/lib/AST/TypeRepr.cpp
+++ b/lib/AST/TypeRepr.cpp
@@ -525,7 +525,7 @@ TupleTypeRepr::TupleTypeRepr(ArrayRef<TupleTypeReprElement> Elements,
   Bits.TupleTypeRepr.NumElements = Elements.size();
 
   std::uninitialized_copy(Elements.begin(), Elements.end(),
-                          getTrailingObjects<TupleTypeReprElement>());
+                          getTrailingObjects());
 }
 
 TupleTypeRepr *TupleTypeRepr::create(const ASTContext &C,
@@ -682,7 +682,7 @@ PackTypeRepr::PackTypeRepr(SourceLoc keywordLoc, SourceRange braceLocs,
   : TypeRepr(TypeReprKind::Pack),
     KeywordLoc(keywordLoc), BraceLocs(braceLocs) {
   Bits.PackTypeRepr.NumElements = elements.size();
-  memcpy(getTrailingObjects<TypeRepr*>(), elements.data(),
+  memcpy(getTrailingObjects(), elements.data(),
          elements.size() * sizeof(TypeRepr*));
 }
 
diff --git a/lib/Basic/Platform.cpp b/lib/Basic/Platform.cpp
index 8060efeab0d36..8906bce54be32 100644
--- a/lib/Basic/Platform.cpp
+++ b/lib/Basic/Platform.cpp
@@ -282,6 +282,7 @@ StringRef swift::getPlatformNameForTriple(const llvm::Triple &triple) {
     return "none";
   case llvm::Triple::UEFI:
   case llvm::Triple::LiteOS:
+  case llvm::Triple::Managarm:
     llvm_unreachable("unsupported OS");
   }
   llvm_unreachable("unsupported OS");
diff --git a/lib/Basic/TargetInfo.cpp b/lib/Basic/TargetInfo.cpp
index 0a80a98d6b0de..36e1512d1d103 100644
--- a/lib/Basic/TargetInfo.cpp
+++ b/lib/Basic/TargetInfo.cpp
@@ -145,13 +145,13 @@ void printTripleInfo(const CompilerInvocation &invocation,
   out << "    \"arch\": \"" << swift::getMajorArchitectureName(triple)
       << "\",\n";
 
-  clang::DiagnosticsEngine DE{new clang::DiagnosticIDs(),
-                              new clang::DiagnosticOptions(),
+  clang::DiagnosticOptions diagOpts;
+  clang::DiagnosticsEngine DE{new clang::DiagnosticIDs(), diagOpts,
                               new clang::IgnoringDiagConsumer()};
-  std::shared_ptr<clang::TargetOptions> TO =
-      std::make_shared<clang::TargetOptions>();
-  TO->Triple = triple.str();
-  clang::TargetInfo *TI = clang::TargetInfo::CreateTargetInfo(DE, TO);
+
+  clang::TargetOptions targetOpts;
+  targetOpts.Triple = triple.str();
+  clang::TargetInfo *TI = clang::TargetInfo::CreateTargetInfo(DE, targetOpts);
   out << "    \"pointerWidthInBits\": "
       << TI->getPointerWidth(clang::LangAS::Default) << ",\n";
   out << "    \"pointerWidthInBytes\": "
diff --git a/lib/ClangImporter/ClangAdapter.cpp b/lib/ClangImporter/ClangAdapter.cpp
index f832a5af21f05..363425226914e 100644
--- a/lib/ClangImporter/ClangAdapter.cpp
+++ b/lib/ClangImporter/ClangAdapter.cpp
@@ -428,7 +428,7 @@ OmissionTypeName importer::getClangTypeNameForOmission(clang::ASTContext &ctx,
 
     // ARM SVE builtin types that don't have Swift equivalents.
 #define SVE_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
-#include "clang/Basic/AArch64SVEACLETypes.def"
+#include "clang/Basic/AArch64ACLETypes.def"
       return OmissionTypeName();
 
     // PPC MMA builtin types that don't have Swift equivalents.
@@ -450,6 +450,11 @@ OmissionTypeName importer::getClangTypeNameForOmission(clang::ASTContext &ctx,
 #define AMDGPU_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
 #include "clang/Basic/AMDGPUTypes.def"
       return OmissionTypeName();
+
+    // HLSL intangible builtin types that don't have Swift equivalents.
+#define HLSL_INTANGIBLE_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
+#include "clang/Basic/HLSLIntangibleTypes.def"
+      return OmissionTypeName();
     }
   }
 
diff --git a/lib/ClangImporter/ClangDiagnosticConsumer.cpp b/lib/ClangImporter/ClangDiagnosticConsumer.cpp
index 910e46fa8ef8d..185165cca43b7 100644
--- a/lib/ClangImporter/ClangDiagnosticConsumer.cpp
+++ b/lib/ClangImporter/ClangDiagnosticConsumer.cpp
@@ -34,10 +34,8 @@ namespace {
 
   public:
     ClangDiagRenderer(const clang::LangOptions &langOpts,
-                      clang::DiagnosticOptions *diagOpts,
-                      decltype(callback) fn)
-       : DiagnosticNoteRenderer(langOpts, diagOpts),
-         callback(fn) {}
+                      clang::DiagnosticOptions &diagOpts, decltype(callback) fn)
+        : DiagnosticNoteRenderer(langOpts, diagOpts), callback(fn) {}
 
   private:
     /// Is this a diagnostic that doesn't do the user any good to show if it
@@ -107,10 +105,9 @@ namespace {
 
 ClangDiagnosticConsumer::ClangDiagnosticConsumer(
     ClangImporter::Implementation &impl,
-    clang::DiagnosticOptions &clangDiagOptions,
-    bool dumpToStderr)
-  : TextDiagnosticPrinter(llvm::errs(), &clangDiagOptions),
-    ImporterImpl(impl), DumpToStderr(dumpToStderr) {}
+    clang::DiagnosticOptions &clangDiagOptions, bool dumpToStderr)
+    : TextDiagnosticPrinter(llvm::errs(), clangDiagOptions), ImporterImpl(impl),
+      DumpToStderr(dumpToStderr) {}
 
 void ClangDiagnosticConsumer::HandleDiagnostic(
     clang::DiagnosticsEngine::Level clangDiagLevel,
@@ -179,7 +176,7 @@ void ClangDiagnosticConsumer::HandleDiagnostic(
     assert(clangDiag.hasSourceManager());
     auto clangCI = ImporterImpl.getClangInstance();
     ClangDiagRenderer renderer(clangCI->getLangOpts(),
-                               &clangCI->getDiagnosticOpts(), emitDiag);
+                               clangCI->getDiagnosticOpts(), emitDiag);
     clang::FullSourceLoc clangDiagLoc(clangDiag.getLocation(),
                                       clangDiag.getSourceManager());
     renderer.emitDiagnostic(clangDiagLoc, clangDiagLevel, message,
diff --git a/lib/ClangImporter/ClangImporter.cpp b/lib/ClangImporter/ClangImporter.cpp
index cbaf9a0bc67e3..8f5648145d350 100644
--- a/lib/ClangImporter/ClangImporter.cpp
+++ b/lib/ClangImporter/ClangImporter.cpp
@@ -329,7 +329,7 @@ class BridgingPPTracker : public clang::PPCallbacks {
       return;
     SmallVector<clang::SourceLocation, 4> IdLocs;
     for (auto &P : Path)
-      IdLocs.push_back(P.second);
+      IdLocs.push_back(P.getLoc());
     handleImport(ImportLoc, IdLocs, Imported);
   }
 
@@ -862,6 +862,10 @@ importer::addCommonInvocationArguments(
     invocationArgStrs.push_back("-mcx16");
   }
 
+  // REPL and LLDB unconditionally want debug info in pcm files.
+  if (importerOpts.DebuggerSupport)
+    invocationArgStrs.push_back("-g");
+
   if (triple.isOSDarwin()) {
     if (auto variantTriple = ctx.LangOpts.TargetVariant) {
       // Passing the -target-variant along to clang causes clang's
@@ -985,10 +989,8 @@ bool ClangImporter::canReadPCH(StringRef PCHFilename) {
   // FIXME: The following attempts to do an initial ReadAST invocation to verify
   // the PCH, without causing trouble for the existing CompilerInstance.
   // Look into combining creating the ASTReader along with verification + update
-  // if necessary, so that we can create and use one ASTReader in the common case
-  // when there is no need for update.
-  clang::CompilerInstance CI(Impl.Instance->getPCHContainerOperations(),
-                             &Impl.Instance->getModuleCache());
+  // if necessary, so that we can create and use one ASTReader in the common
+  // case when there is no need for update.
   auto invocation =
       std::make_shared<clang::CompilerInvocation>(*Impl.Invocation);
   invocation->getPreprocessorOpts().DisablePCHOrModuleValidation =
@@ -1003,10 +1005,13 @@ bool ClangImporter::canReadPCH(StringRef PCHFilename) {
   // will try to free it.
   invocation->getPreprocessorOpts().RemappedFileBuffers.clear();
 
-  CI.setInvocation(std::move(invocation));
+  clang::DiagnosticOptions diagOpts;
+  clang::CompilerInstance CI(std::move(invocation),
+                             Impl.Instance->getPCHContainerOperations(),
+                             &Impl.Instance->getModuleCache());
   CI.setTarget(&Impl.Instance->getTarget());
-  CI.setDiagnostics(
-      &*clang::CompilerInstance::createDiagnostics(new clang::DiagnosticOptions()));
+  CI.setDiagnostics(&*clang::CompilerInstance::createDiagnostics(
+      Impl.Instance->getVirtualFileSystem(), diagOpts));
 
   // Note: Reusing the file manager is safe; this is a component that's already
   // reused when building PCM files for the module cache.
@@ -1146,6 +1151,8 @@ ClangImporter::getClangDriverArguments(ASTContext &ctx, bool ignoreClangTarget)
 std::optional<std::vector<std::string>> ClangImporter::getClangCC1Arguments(
     ASTContext &ctx, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
     bool ignoreClangTarget) {
+  ASSERT(VFS && "Expected non-null file system");
+
   std::unique_ptr<clang::CompilerInvocation> CI;
 
   // Set up a temporary diagnostic client to report errors from parsing the
@@ -1156,13 +1163,11 @@ std::optional<std::vector<std::string>> ClangImporter::getClangCC1Arguments(
   //
   // The long-term client for Clang diagnostics is set up afterwards, after the
   // clang::CompilerInstance is created.
-  llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> tempDiagOpts{
-      new clang::DiagnosticOptions};
-  auto *tempDiagClient =
-      new ClangDiagnosticConsumer(Impl, *tempDiagOpts,
-                                  ctx.ClangImporterOpts.DumpClangDiagnostics);
+  clang::DiagnosticOptions tempDiagOpts;
+  auto *tempDiagClient = new ClangDiagnosticConsumer(
+      Impl, tempDiagOpts, ctx.ClangImporterOpts.DumpClangDiagnostics);
   auto clangDiags = clang::CompilerInstance::createDiagnostics(
-      tempDiagOpts.get(), tempDiagClient,
+      *VFS, tempDiagOpts, tempDiagClient,
       /*owned*/ true);
 
   // If using direct cc1 module build, use extra args to setup ClangImporter.
@@ -1246,9 +1251,7 @@ std::optional<std::vector<std::string>> ClangImporter::getClangCC1Arguments(
   // to missing files and report the error that clang would throw manually.
   // rdar://77516546 is tracking that the clang importer should be more
   // resilient and provide a module even if there were building it.
-  auto TempVFS = clang::createVFSFromCompilerInvocation(
-      *CI, *clangDiags,
-      VFS ? VFS : Impl.SwiftContext.SourceMgr.getFileSystem());
+  auto TempVFS = clang::createVFSFromCompilerInvocation(*CI, *clangDiags, VFS);
 
   std::vector<std::string> FilteredModuleMapFiles;
   for (auto ModuleMapFile : CI->getFrontendOpts().ModuleMapFiles) {
@@ -1284,10 +1287,10 @@ std::unique_ptr<clang::CompilerInvocation> ClangImporter::createClangInvocation(
   // option here is either generated by dependency scanner or just round tripped
   // from `getClangCC1Arguments` so we don't expect it to fail. Use a simple
   // printing diagnostics consumer for debugging any unexpected error.
-  auto diagOpts = llvm::makeIntrusiveRefCnt<clang::DiagnosticOptions>();
+  clang::DiagnosticOptions diagOpts;
   clang::DiagnosticsEngine clangDiags(
       new clang::DiagnosticIDs(), diagOpts,
-      new clang::TextDiagnosticPrinter(llvm::errs(), diagOpts.get()));
+      new clang::TextDiagnosticPrinter(llvm::errs(), diagOpts));
 
   // Finally, use the CC1 command-line and the diagnostic engine
   // to instantiate our Invocation.
@@ -1374,6 +1377,9 @@ std::unique_ptr<ClangImporter> ClangImporter::create(
     // The Clang modules produced by ClangImporter are always embedded in an
     // ObjectFilePCHContainer and contain -gmodules debug info.
     importer->Impl.Invocation->getCodeGenOpts().DebugTypeExtRefs = true;
+    if (importerOpts.DebuggerSupport)
+      importer->Impl.Invocation->getCodeGenOpts().setDebugInfo(
+          llvm::codegenoptions::FullDebugInfo);
 
     auto PCHContainerOperations =
       std::make_shared<clang::PCHContainerOperations>();
@@ -1381,12 +1387,10 @@ std::unique_ptr<ClangImporter> ClangImporter::create(
         std::make_unique<clang::ObjectFilePCHContainerWriter>());
     PCHContainerOperations->registerReader(
         std::make_unique<clang::ObjectFilePCHContainerReader>());
-    importer->Impl.Instance.reset(
-        new clang::CompilerInstance(std::move(PCHContainerOperations)));
+    importer->Impl.Instance.reset(new clang::CompilerInstance(
+        importer->Impl.Invocation, std::move(PCHContainerOperations)));
   }
   auto &instance = *importer->Impl.Instance;
-  instance.setInvocation(importer->Impl.Invocation);
-
   if (tracker)
     instance.addDependencyCollector(tracker->getClangCollector());
 
@@ -1396,7 +1400,7 @@ std::unique_ptr<ClangImporter> ClangImporter::create(
     auto actualDiagClient = std::make_unique<ClangDiagnosticConsumer>(
         importer->Impl, instance.getDiagnosticOpts(),
         importerOpts.DumpClangDiagnostics);
-    instance.createDiagnostics(actualDiagClient.release());
+    instance.createDiagnostics(*VFS, actualDiagClient.release());
   }
 
   // Set up the file manager.
@@ -1430,22 +1434,12 @@ std::unique_ptr<ClangImporter> ClangImporter::create(
         importer.get(), importerOpts, VFS, *swiftTargetClangArgs);
     if (!swiftTargetClangInvocation)
       return nullptr;
-    auto targetInfo = clang::TargetInfo::CreateTargetInfo(
-        clangDiags, swiftTargetClangInvocation->TargetOpts);
-    // Ensure the target info has configured target-specific defines
-    std::string defineBuffer;
-    llvm::raw_string_ostream predefines(defineBuffer);
-    clang::MacroBuilder builder(predefines);
-    targetInfo->getTargetDefines(instance.getLangOpts(), builder);
-    importer->Impl.setSwiftTargetInfo(targetInfo);
-    importer->Impl.setSwiftCodeGenOptions(new clang::CodeGenOptions(
-        swiftTargetClangInvocation->getCodeGenOpts()));
+
+    importer->Impl.configureOptionsForCodeGen(clangDiags,
+                                              swiftTargetClangInvocation.get());
   } else {
-    // Just use the existing Invocation's directly
-    importer->Impl.setSwiftTargetInfo(clang::TargetInfo::CreateTargetInfo(
-        clangDiags, importer->Impl.Invocation->TargetOpts));
-    importer->Impl.setSwiftCodeGenOptions(
-        new clang::CodeGenOptions(importer->Impl.Invocation->getCodeGenOpts()));
+    // Set using the existing invocation.
+    importer->Impl.configureOptionsForCodeGen(clangDiags);
   }
 
   // Create the associated action.
@@ -1462,9 +1456,8 @@ std::unique_ptr<ClangImporter> ClangImporter::create(
   // things here.
 
   // Create the target instance.
-  instance.setTarget(
-    clang::TargetInfo::CreateTargetInfo(clangDiags,
-                                        instance.getInvocation().TargetOpts));
+  instance.setTarget(clang::TargetInfo::CreateTargetInfo(
+      clangDiags, instance.getInvocation().getTargetOpts()));
   if (!instance.hasTarget())
     return nullptr;
 
@@ -1472,7 +1465,8 @@ std::unique_ptr<ClangImporter> ClangImporter::create(
   //
   // FIXME: We shouldn't need to do this, the target should be immutable once
   // created. This complexity should be lifted elsewhere.
-  instance.getTarget().adjust(clangDiags, instance.getLangOpts());
+  instance.getTarget().adjust(clangDiags, instance.getLangOpts(),
+                              /*AuxTarget=*/nullptr);
 
   if (importerOpts.Mode == ClangImporterOptions::Modes::EmbedBitcode)
     return importer;
@@ -1792,7 +1786,7 @@ bool ClangImporter::importHeader(StringRef header, ModuleDecl *adapter,
   // serialized preprocessed contents when debugger support is on.
   if (!Impl.SwiftContext.ClangImporterOpts.PreferSerializedBridgingHeader ||
       cachedContents.empty()) {
-    auto headerFile = fileManager.getFile(header, /*OpenFile=*/true);
+    auto headerFile = fileManager.getOptionalFileRef(header, /*OpenFile=*/true);
     // Prefer importing the header directly if the header content matches by
     // checking size and mod time. This allows correct import if some no-modular
     // headers are already imported into clang importer. If mod time is zero,
@@ -1800,9 +1794,9 @@ bool ClangImporter::importHeader(StringRef header, ModuleDecl *adapter,
     // verify.  LLDB prefers the serialized bridging header because, in an
     // explicit modules project, LLDB might not know all the search paths needed
     // to imported the on disk header.
-    if (headerFile && (*headerFile)->getSize() == expectedSize &&
+    if (headerFile && headerFile->getSize() == expectedSize &&
         (expectedModTime == 0 ||
-         (*headerFile)->getModificationTime() == expectedModTime)) {
+         headerFile->getModificationTime() == expectedModTime)) {
       return importBridgingHeader(header, adapter, diagLoc, false, true);
     }
   }
@@ -1829,7 +1823,7 @@ bool ClangImporter::importBridgingHeader(StringRef header, ModuleDecl *adapter,
   }
 
   clang::FileManager &fileManager = Impl.Instance->getFileManager();
-  auto headerFile = fileManager.getFile(header, /*OpenFile=*/true);
+  auto headerFile = fileManager.getOptionalFileRef(header, /*OpenFile=*/true);
   if (!headerFile) {
     Impl.diagnose(diagLoc, diag::bridging_header_missing, header);
     return true;
@@ -1922,13 +1916,13 @@ std::string ClangImporter::getBridgingHeaderContents(
 
   invocation->getPreprocessorOpts().resetNonModularOptions();
 
-  clang::CompilerInstance rewriteInstance(
-    Impl.Instance->getPCHContainerOperations(),
-    &Impl.Instance->getModuleCache());
-  rewriteInstance.setInvocation(invocation);
-  rewriteInstance.createDiagnostics(new clang::IgnoringDiagConsumer);
-
   clang::FileManager &fileManager = Impl.Instance->getFileManager();
+
+  clang::CompilerInstance rewriteInstance(
+      std::move(invocation), Impl.Instance->getPCHContainerOperations(),
+      &Impl.Instance->getModuleCache());
+  rewriteInstance.createDiagnostics(fileManager.getVirtualFileSystem(),
+                                    new clang::IgnoringDiagConsumer);
   rewriteInstance.setFileManager(&fileManager);
   rewriteInstance.createSourceManager(fileManager);
   rewriteInstance.setTarget(&Impl.Instance->getTarget());
@@ -1978,9 +1972,9 @@ std::string ClangImporter::getBridgingHeaderContents(
     return "";
   }
 
-  if (auto fileInfo = fileManager.getFile(headerPath)) {
-    fileSize = (*fileInfo)->getSize();
-    fileModTime = (*fileInfo)->getModificationTime();
+  if (auto fileInfo = fileManager.getOptionalFileRef(headerPath)) {
+    fileSize = fileInfo->getSize();
+    fileModTime = fileInfo->getModificationTime();
   }
   return result;
 }
@@ -2027,14 +2021,14 @@ ClangImporter::cloneCompilerInstanceForPrecompiling() {
   // Share the CASOption and the underlying CAS.
   invocation->setCASOption(Impl.Invocation->getCASOptsPtr());
 
+  clang::FileManager &fileManager = Impl.Instance->getFileManager();
+
   auto clonedInstance = std::make_unique<clang::CompilerInstance>(
-    Impl.Instance->getPCHContainerOperations(),
-    &Impl.Instance->getModuleCache());
-  clonedInstance->setInvocation(std::move(invocation));
-  clonedInstance->createDiagnostics(&Impl.Instance->getDiagnosticClient(),
+      std::move(invocation), Impl.Instance->getPCHContainerOperations(),
+      &Impl.Instance->getModuleCache());
+  clonedInstance->createDiagnostics(fileManager.getVirtualFileSystem(),
+                                    &Impl.Instance->getDiagnosticClient(),
                                     /*ShouldOwnClient=*/false);
-
-  clang::FileManager &fileManager = Impl.Instance->getFileManager();
   clonedInstance->setFileManager(&fileManager);
   clonedInstance->createSourceManager(fileManager);
   clonedInstance->setTarget(&Impl.Instance->getTarget());
@@ -2320,17 +2314,15 @@ ModuleDecl *ClangImporter::Implementation::loadModuleClang(
   auto realModuleName = SwiftContext.getRealModuleName(path.front().Item).str();
 
   // Convert the Swift import path over to a Clang import path.
-  SmallVector<std::pair<clang::IdentifierInfo *, clang::SourceLocation>, 4>
-      clangPath;
+  SmallVector<clang::IdentifierLoc, 4> clangPath;
   bool isTopModuleComponent = true;
   for (auto component : path) {
     StringRef item = isTopModuleComponent? realModuleName:
                                            component.Item.str();
     isTopModuleComponent = false;
 
-    clangPath.emplace_back(
-        getClangPreprocessor().getIdentifierInfo(item),
-        exportSourceLoc(component.Loc));
+    clangPath.emplace_back(exportSourceLoc(component.Loc),
+                           getClangPreprocessor().getIdentifierInfo(item));
   }
 
   auto &diagEngine = Instance->getDiagnostics();
@@ -2340,14 +2332,13 @@ ModuleDecl *ClangImporter::Implementation::loadModuleClang(
   auto loadModule = [&](clang::ModuleIdPath path,
                         clang::Module::NameVisibilityKind visibility)
       -> clang::ModuleLoadResult {
-    auto importRAII =
-        diagClient.handleImport(clangPath.front().first, diagEngine,
-                                importLoc);
+    auto importRAII = diagClient.handleImport(
+        clangPath.front().getIdentifierInfo(), diagEngine, importLoc);
 
     std::string preservedIndexStorePathOption;
     auto &clangFEOpts = Instance->getFrontendOpts();
     if (!clangFEOpts.IndexStorePath.empty()) {
-      StringRef moduleName = path[0].first->getName();
+      StringRef moduleName = path[0].getIdentifierInfo()->getName();
       // Ignore the SwiftShims module for the index data.
       if (moduleName == SwiftContext.SwiftShimsModuleName.str()) {
         preservedIndexStorePathOption = clangFEOpts.IndexStorePath;
@@ -4237,7 +4228,7 @@ clang::TargetInfo &ClangImporter::getModuleAvailabilityTarget() const {
 }
 
 clang::TargetInfo &ClangImporter::getTargetInfo() const {
-  return *Impl.getSwiftTargetInfo();
+  return Impl.getCodeGenTargetInfo();
 }
 
 clang::ASTContext &ClangImporter::getClangASTContext() const {
@@ -4270,7 +4261,7 @@ clang::Sema &ClangImporter::getClangSema() const {
 }
 
 clang::CodeGenOptions &ClangImporter::getCodeGenOpts() const {
-  return *Impl.getSwiftCodeGenOptions();
+  return Impl.getCodeGenOptions();
 }
 
 std::string ClangImporter::getClangModuleHash() const {
@@ -4286,8 +4277,8 @@ ClangImporter::getSwiftExplicitModuleDirectCC1Args() const {
   });
 
   clang::CompilerInvocation instance;
-  clang::DiagnosticsEngine clangDiags(new clang::DiagnosticIDs(),
-                                      new clang::DiagnosticOptions(),
+  clang::DiagnosticOptions diagOpts;
+  clang::DiagnosticsEngine clangDiags(new clang::DiagnosticIDs(), diagOpts,
                                       new clang::IgnoringDiagConsumer());
   bool success = clang::CompilerInvocation::CreateFromArgs(instance, clangArgs,
                                                            clangDiags);
@@ -4717,6 +4708,37 @@ void ClangImporter::Implementation::getMangledName(
   }
 }
 
+void ClangImporter::Implementation::configureOptionsForCodeGen(
+    clang::DiagnosticsEngine &Diags, clang::CompilerInvocation *CI) {
+  clang::TargetInfo *targetInfo = nullptr;
+  if (CI) {
+    TargetOpts.reset(new clang::TargetOptions(std::move(CI->getTargetOpts())));
+    CodeGenOpts.reset(
+        new clang::CodeGenOptions(std::move(CI->getCodeGenOpts())));
+    targetInfo = clang::TargetInfo::CreateTargetInfo(Diags, *TargetOpts);
+
+    // Ensure the target info has configured target-specific defines
+    std::string defineBuffer;
+    llvm::raw_string_ostream predefines(defineBuffer);
+    clang::MacroBuilder builder(predefines);
+    targetInfo->getTargetDefines(Instance->getLangOpts(), builder);
+  } else {
+    targetInfo =
+        clang::TargetInfo::CreateTargetInfo(Diags, Invocation->getTargetOpts());
+  }
+
+  CodeGenTargetInfo.reset(targetInfo);
+}
+
+clang::CodeGenOptions &
+ClangImporter::Implementation::getCodeGenOptions() const {
+  if (CodeGenOpts) {
+    return *CodeGenOpts.get();
+  }
+
+  return Invocation->getCodeGenOpts();
+}
+
 // ---------------------------------------------------------------------------
 // Swift lookup tables
 // ---------------------------------------------------------------------------
@@ -7301,7 +7323,8 @@ ClangImporter::instantiateCXXClassTemplate(
     ctsd = clang::ClassTemplateSpecializationDecl::Create(
         decl->getASTContext(), decl->getTemplatedDecl()->getTagKind(),
         decl->getDeclContext(), decl->getTemplatedDecl()->getBeginLoc(),
-        decl->getLocation(), decl, arguments, nullptr);
+        decl->getLocation(), decl, arguments, /*StrictPackMatch*/ false,
+        nullptr);
     decl->AddSpecialization(ctsd, InsertPos);
   }
 
diff --git a/lib/ClangImporter/ClangIncludePaths.cpp b/lib/ClangImporter/ClangIncludePaths.cpp
index 4eb9548656465..13fb11e164f96 100644
--- a/lib/ClangImporter/ClangIncludePaths.cpp
+++ b/lib/ClangImporter/ClangIncludePaths.cpp
@@ -127,9 +127,13 @@ std::pair<clang::driver::Driver,
 ClangImporter::createClangDriver(
     const LangOptions &LangOpts, const ClangImporterOptions &ClangImporterOpts,
     llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> vfs) {
+
+  auto diagVFS = vfs ? vfs : llvm::vfs::getRealFileSystem();
+
+  clang::DiagnosticOptions diagOpts;
   auto *silentDiagConsumer = new clang::DiagnosticConsumer();
   auto clangDiags = clang::CompilerInstance::createDiagnostics(
-      new clang::DiagnosticOptions(), silentDiagConsumer);
+      *diagVFS, diagOpts, silentDiagConsumer);
   clang::driver::Driver clangDriver(ClangImporterOpts.clangPath,
                                     LangOpts.Target.str(), *clangDiags,
                                     "clang LLVM compiler", vfs);
diff --git a/lib/ClangImporter/ClangModuleDependencyScanner.cpp b/lib/ClangImporter/ClangModuleDependencyScanner.cpp
index 6eb7e99d9ac76..7051051cf29bb 100644
--- a/lib/ClangImporter/ClangModuleDependencyScanner.cpp
+++ b/lib/ClangImporter/ClangModuleDependencyScanner.cpp
@@ -106,8 +106,8 @@ void ClangImporter::getBridgingHeaderOptions(
   // Round-trip clang args to canonicalize and clear the options that swift
   // compiler doesn't need.
   clang::CompilerInvocation depsInvocation;
-  clang::DiagnosticsEngine clangDiags(new clang::DiagnosticIDs(),
-                                      new clang::DiagnosticOptions(),
+  clang::DiagnosticOptions diagOpts;
+  clang::DiagnosticsEngine clangDiags(new clang::DiagnosticIDs(), diagOpts,
                                       new clang::IgnoringDiagConsumer());
 
   llvm::SmallVector<const char *> clangArgs;
diff --git a/lib/ClangImporter/ImportDecl.cpp b/lib/ClangImporter/ImportDecl.cpp
index a2f5c792560d8..e08e84653f2ed 100644
--- a/lib/ClangImporter/ImportDecl.cpp
+++ b/lib/ClangImporter/ImportDecl.cpp
@@ -399,6 +399,7 @@ getSwiftStdlibType(const clang::TypedefNameDecl *D,
       case clang::TargetInfo::PNaClABIBuiltinVaList:
       case clang::TargetInfo::SystemZBuiltinVaList:
       case clang::TargetInfo::X86_64ABIBuiltinVaList:
+      case clang::TargetInfo::XtensaABIBuiltinVaList:
         return std::make_pair(Type(), "");
     }
     break;
@@ -3300,7 +3301,7 @@ namespace {
             decl->getLocation(),
             const_cast<clang::ClassTemplateSpecializationDecl *>(decl),
             clang::TemplateSpecializationKind::TSK_ImplicitInstantiation,
-            /*Complain*/ false);
+            /*Complain*/ false, /*PrimaryStrictPackMatch*/ false);
         // If the template can't be instantiated, bail.
         if (notInstantiated)
           return nullptr;
@@ -4273,14 +4274,14 @@ namespace {
             for (auto param : attr->params()) {
               // FIXME: Swift assumes no escaping to globals. We should diagnose
               // this.
-              if (param == clang::LifetimeCaptureByAttr::GLOBAL ||
-                  param == clang::LifetimeCaptureByAttr::UNKNOWN ||
-                  param == clang::LifetimeCaptureByAttr::INVALID)
+              if (param == clang::LifetimeCaptureByAttr::Global ||
+                  param == clang::LifetimeCaptureByAttr::Unknown ||
+                  param == clang::LifetimeCaptureByAttr::Invalid)
                 continue;
 
               paramHasAnnotation[idx] = true;
               if (isa<clang::CXXMethodDecl>(decl) &&
-                  param == clang::LifetimeCaptureByAttr::THIS) {
+                  param == clang::LifetimeCaptureByAttr::This) {
                 auto [it, inserted] = inheritedArgDependences.try_emplace(
                     result->getSelfIndex(), SmallBitVector(dependencyVecSize));
                 it->second[idx] = true;
diff --git a/lib/ClangImporter/ImportMacro.cpp b/lib/ClangImporter/ImportMacro.cpp
index ada666b6b8612..db511fa3d372b 100644
--- a/lib/ClangImporter/ImportMacro.cpp
+++ b/lib/ClangImporter/ImportMacro.cpp
@@ -621,7 +621,7 @@ static ValueDecl *importMacro(ClangImporter::Implementation &impl,
       clang::LookupResult R(S, {{tok.getIdentifierInfo()}, {}},
                             clang::Sema::LookupAnyName);
       if (S.LookupName(R, S.TUScope))
-        if (R.getResultKind() == clang::LookupResult::LookupResultKind::Found)
+        if (R.getResultKind() == clang::LookupResultKind::Found)
           if (const auto *VD = dyn_cast<clang::ValueDecl>(R.getFoundDecl()))
             return importDeclAlias(impl, DC, VD, name);
     }
diff --git a/lib/ClangImporter/ImportType.cpp b/lib/ClangImporter/ImportType.cpp
index 91de6cf22ee6e..037568715be21 100644
--- a/lib/ClangImporter/ImportType.cpp
+++ b/lib/ClangImporter/ImportType.cpp
@@ -347,7 +347,7 @@ namespace {
 
       // ARM SVE builtin types that don't have Swift equivalents.
 #define SVE_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
-#include "clang/Basic/AArch64SVEACLETypes.def"
+#include "clang/Basic/AArch64ACLETypes.def"
         return Type();
 
       // PPC SVE builtin types that don't have Swift equivalents.
@@ -365,10 +365,15 @@ namespace {
         return Type();
 
       // AMDGPU builtin types that don't have Swift equivalents.
-#define AMDGPU_TYPE(Name, Id, SingletonId) case clang::BuiltinType::Id:
+#define AMDGPU_TYPE(Name, Id, SingletonId, Width, Align)                       \
+      case clang::BuiltinType::Id:
 #include "clang/Basic/AMDGPUTypes.def"
         return Type();
 
+      // HLSL intangible builtin types that don't have Swift equivalents.
+#define HLSL_INTANGIBLE_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
+#include "clang/Basic/HLSLIntangibleTypes.def"
+        return Type();
       }
 
       llvm_unreachable("Invalid BuiltinType.");
@@ -414,6 +419,26 @@ namespace {
       return Type();
     }
 
+    ImportResult VisitHLSLAttributedResourceType(
+        const clang::HLSLAttributedResourceType *type) {
+      Impl.addImportDiagnostic(
+          type,
+          Diagnostic(diag::unsupported_builtin_type, type->getTypeClassName()),
+          clang::SourceLocation());
+      // FIXME: (?) HLSL types are not supported in Swift.
+      return Type();
+    }
+
+    ImportResult
+    VisitHLSLInlineSpirvType(const clang::HLSLInlineSpirvType *type) {
+      Impl.addImportDiagnostic(
+          type,
+          Diagnostic(diag::unsupported_builtin_type, type->getTypeClassName()),
+          clang::SourceLocation());
+      // FIXME: (?) HLSL types are not supported in Swift.
+      return Type();
+    }
+
     ImportResult
     VisitCountAttributedType(const clang::CountAttributedType *type) {
       return Visit(type->desugar());
diff --git a/lib/ClangImporter/ImporterImpl.h b/lib/ClangImporter/ImporterImpl.h
index c409b20305fbc..ed4c18dd1ca7a 100644
--- a/lib/ClangImporter/ImporterImpl.h
+++ b/lib/ClangImporter/ImporterImpl.h
@@ -641,22 +641,22 @@ class LLVM_LIBRARY_VISIBILITY ClangImporter::Implementation
   /// corresponding to the instantiating Swift compilation's triple. These are
   /// to be used by all IRGen/CodeGen clients of `ClangImporter`.
   std::unique_ptr<clang::TargetInfo> CodeGenTargetInfo;
+  /// - Important: Do not access directly. This field exists only to make sure
+  ///   we own the target options stored in `CodeGenTargetInfo` because
+  ///   `clang::TargetOptions` no longer co-owns them:
+  ///   https://github.com/llvm/llvm-project/pull/106271.
+  std::unique_ptr<clang::TargetOptions> TargetOpts;
   std::unique_ptr<clang::CodeGenOptions> CodeGenOpts;
 
-public:
-  void setSwiftTargetInfo(clang::TargetInfo *SwiftTargetInfo) {
-    CodeGenTargetInfo.reset(SwiftTargetInfo);
-  }
-  clang::TargetInfo *getSwiftTargetInfo() const {
-    return CodeGenTargetInfo.get();
-  }
+  /// Sets the target & code generation options for use by IRGen/CodeGen
+  /// clients of `ClangImporter`. If `CI` is null, the data is drawn from the
+  /// importer's invocation.
+  void configureOptionsForCodeGen(clang::DiagnosticsEngine &Diags,
+                                  clang::CompilerInvocation *CI = nullptr);
 
-  void setSwiftCodeGenOptions(clang::CodeGenOptions *SwiftCodeGenOpts) {
-    CodeGenOpts.reset(SwiftCodeGenOpts);
-  }
-  clang::CodeGenOptions *getSwiftCodeGenOptions() const {
-    return CodeGenOpts.get();
-  }
+  clang::TargetInfo &getCodeGenTargetInfo() const { return *CodeGenTargetInfo; }
+
+  clang::CodeGenOptions &getCodeGenOptions() const;
 
 private:
   /// Generation number that is used for crude versioning.
diff --git a/lib/ClangImporter/Serializability.cpp b/lib/ClangImporter/Serializability.cpp
index b57c47dce21c9..4802ea506f3d3 100644
--- a/lib/ClangImporter/Serializability.cpp
+++ b/lib/ClangImporter/Serializability.cpp
@@ -330,6 +330,9 @@ namespace {
     void writeTypeCoupledDeclRefInfo(clang::TypeCoupledDeclRefInfo info) {
       llvm_unreachable("TypeCoupledDeclRefInfo shouldn't be reached from swift");
     }
+    void writeHLSLSpirvOperand(clang::SpirvOperand) {
+      llvm_unreachable("SpirvOperand shouldn't be reached from swift");
+    }
   };
 }
 
diff --git a/lib/ClangImporter/SwiftDeclSynthesizer.cpp b/lib/ClangImporter/SwiftDeclSynthesizer.cpp
index 1f310fe3086d8..1059413ada45e 100644
--- a/lib/ClangImporter/SwiftDeclSynthesizer.cpp
+++ b/lib/ClangImporter/SwiftDeclSynthesizer.cpp
@@ -2628,11 +2628,12 @@ SwiftDeclSynthesizer::synthesizeStaticFactoryForCXXForeignRef(
 
   clang::FunctionDecl *operatorNew = nullptr;
   clang::FunctionDecl *operatorDelete = nullptr;
-  bool passAlignment = false;
+  clang::ImplicitAllocationParameters IAP(clang::AlignedAllocationMode::No);
   clang::Sema::SFINAETrap trap(clangSema);
   bool findingAllocFuncFailed = clangSema.FindAllocationFunctions(
-      cxxRecordDeclLoc, clang::SourceRange(), clang::Sema::AFS_Both,
-      clang::Sema::AFS_Both, cxxRecordTy, /*IsArray=*/false, passAlignment,
+      cxxRecordDeclLoc, clang::SourceRange(),
+      clang::AllocationFunctionScope::Both,
+      clang::AllocationFunctionScope::Both, cxxRecordTy, /*IsArray=*/false, IAP,
       clang::MultiExprArg(), operatorNew, operatorDelete,
       /*Diagnose=*/false);
   if (trap.hasErrorOccurred() || findingAllocFuncFailed || !operatorNew ||
diff --git a/lib/ClangImporter/SwiftLookupTable.cpp b/lib/ClangImporter/SwiftLookupTable.cpp
index a203c00dfe618..235e9531d7af0 100644
--- a/lib/ClangImporter/SwiftLookupTable.cpp
+++ b/lib/ClangImporter/SwiftLookupTable.cpp
@@ -1136,7 +1136,8 @@ namespace {
       ids = StoredSingleEntry::forSerializedDecl(
                                  astWriter.getDeclID(decl).getRawValue());
     } else if (auto *macro = mappedEntry.dyn_cast<clang::MacroInfo *>()) {
-      ids = StoredSingleEntry::forSerializedMacro(astWriter.getMacroID(macro));
+      ids = StoredSingleEntry::forSerializedMacro(
+          astWriter.getMacroRef(macro, /*Name=*/nullptr));
     } else {
       auto *moduleMacro = cast<clang::ModuleMacro *>(mappedEntry);
       StoredSingleEntry::SerializationID nameID =
diff --git a/lib/Demangling/NodePrinter.cpp b/lib/Demangling/NodePrinter.cpp
index db8f4956cb9a2..8885f9a8494df 100644
--- a/lib/Demangling/NodePrinter.cpp
+++ b/lib/Demangling/NodePrinter.cpp
@@ -2371,14 +2371,28 @@ NodePointer NodePrinter::print(NodePointer Node, unsigned depth,
       Printer << "merged ";
     }
     return nullptr;
-  case Node::Kind::TypeSymbolicReference:
+  case Node::Kind::TypeSymbolicReference: {
     Printer << "type symbolic reference 0x";
-    Printer.writeHex(Node->getIndex());
+    if (Node->hasRemoteAddress()) {
+      auto ra = Node->getRemoteAddress();
+      Printer.writeHex(ra.first);
+      Printer << " (" << ra.second << ")";
+    } else if (Node->hasIndex()) {
+      Printer.writeHex(Node->getIndex());
+    }
     return nullptr;
-  case Node::Kind::OpaqueTypeDescriptorSymbolicReference:
+  }
+  case Node::Kind::OpaqueTypeDescriptorSymbolicReference: {
     Printer << "opaque type symbolic reference 0x";
-    Printer.writeHex(Node->getIndex());
+    if (Node->hasRemoteAddress()) {
+      auto ra = Node->getRemoteAddress();
+      Printer.writeHex(ra.first);
+      Printer << " (" << ra.second << ")";
+    } else if (Node->hasIndex()) {
+      Printer.writeHex(Node->getIndex());
+    }
     return nullptr;
+  }
   case Node::Kind::DistributedThunk:
     if (!Options.ShortenThunk) {
       Printer << "distributed thunk ";
diff --git a/lib/DependencyScan/ModuleDependencyScanner.cpp b/lib/DependencyScan/ModuleDependencyScanner.cpp
index 0db8bc41eb60d..d6dcd926b79f2 100644
--- a/lib/DependencyScan/ModuleDependencyScanner.cpp
+++ b/lib/DependencyScan/ModuleDependencyScanner.cpp
@@ -1915,7 +1915,7 @@ ModuleDependencyInfo ModuleDependencyScanner::bridgeClangModuleDependency(
 
   // CASFileSystemRootID.
   std::string RootID = clangModuleDep.CASFileSystemRootID
-                           ? clangModuleDep.CASFileSystemRootID->toString()
+                           ? clangModuleDep.CASFileSystemRootID.value()
                            : "";
 
   std::string IncludeTree =
diff --git a/lib/DriverTool/swift_cache_tool_main.cpp b/lib/DriverTool/swift_cache_tool_main.cpp
index 7fc902e4483d2..d32519b0928a9 100644
--- a/lib/DriverTool/swift_cache_tool_main.cpp
+++ b/lib/DriverTool/swift_cache_tool_main.cpp
@@ -65,12 +65,13 @@ enum ID {
 #undef OPTION
 };
 
-#define PREFIX(NAME, VALUE)                                                    \
-  constexpr llvm::StringLiteral NAME##_init[] = VALUE;                         \
-  constexpr llvm::ArrayRef<llvm::StringLiteral> NAME(                          \
-      NAME##_init, std::size(NAME##_init) - 1);
+#define OPTTABLE_STR_TABLE_CODE
 #include "SwiftCacheToolOptions.inc"
-#undef PREFIX
+#undef OPTTABLE_STR_TABLE_CODE
+
+#define OPTTABLE_PREFIXES_TABLE_CODE
+#include "SwiftCacheToolOptions.inc"
+#undef OPTTABLE_PREFIXES_TABLE_CODE
 
 static const OptTable::Info InfoTable[] = {
 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
@@ -80,7 +81,8 @@ static const OptTable::Info InfoTable[] = {
 
 class CacheToolOptTable : public llvm::opt::GenericOptTable {
 public:
-  CacheToolOptTable() : GenericOptTable(InfoTable) {}
+  CacheToolOptTable()
+      : GenericOptTable(OptionStrTable, OptionPrefixesTable, InfoTable) {}
 };
 
 class SwiftCacheToolInvocation {
diff --git a/lib/DriverTool/swift_llvm_opt_main.cpp b/lib/DriverTool/swift_llvm_opt_main.cpp
index 00b97178dee56..6620418f3ddc9 100644
--- a/lib/DriverTool/swift_llvm_opt_main.cpp
+++ b/lib/DriverTool/swift_llvm_opt_main.cpp
@@ -135,7 +135,7 @@ getTargetMachine(llvm::Triple TheTriple, StringRef CPUStr,
   }
 
   return TheTarget->createTargetMachine(
-      TheTriple.getTriple(), CPUStr, FeaturesStr, targetOptions,
+      TheTriple, CPUStr, FeaturesStr, targetOptions,
       std::optional<llvm::Reloc::Model>(llvm::codegen::getExplicitRelocModel()),
       llvm::codegen::getExplicitCodeModel(), GetCodeGenOptLevel(options));
 }
@@ -174,7 +174,8 @@ int swift_llvm_opt_main(ArrayRef<const char *> argv, void *MainAddr) {
 
   // If we are supposed to override the target triple, do so now.
   if (!options.TargetTriple.empty())
-    M->setTargetTriple(llvm::Triple::normalize(options.TargetTriple));
+    M->setTargetTriple(
+        llvm::Triple(llvm::Triple::normalize(options.TargetTriple)));
 
   // Figure out what stream we are supposed to write to...
   std::unique_ptr<llvm::ToolOutputFile> Out;
diff --git a/lib/Frontend/ModuleInterfaceLoader.cpp b/lib/Frontend/ModuleInterfaceLoader.cpp
index 0902ea421ba02..27c3b70862dbb 100644
--- a/lib/Frontend/ModuleInterfaceLoader.cpp
+++ b/lib/Frontend/ModuleInterfaceLoader.cpp
@@ -2058,6 +2058,17 @@ InterfaceSubContextDelegateImpl::InterfaceSubContextDelegateImpl(
     GenericArgs.push_back("-enable-experimental-feature");
     GenericArgs.push_back("Embedded");
   }
+
+  if (langOpts.DebuggerSupport) {
+    if (clangImporterOpts.DirectClangCC1ModuleBuild) {
+      subClangImporterOpts.ExtraArgs.push_back("-dwarf-ext-refs");
+      subClangImporterOpts.ExtraArgs.push_back("-fmodule-format=obj");
+        subClangImporterOpts.ExtraArgs.push_back("-debug-info-kind=standalone");
+    } else {
+      subClangImporterOpts.ExtraArgs.push_back("-gmodules");
+      subClangImporterOpts.ExtraArgs.push_back("-g");
+    }
+  }
 }
 
 /// Calculate an output filename in \p genericSubInvocation's cache path that
diff --git a/lib/IDE/CodeCompletionString.cpp b/lib/IDE/CodeCompletionString.cpp
index cc7d57bcc6108..6479b3a1e87df 100644
--- a/lib/IDE/CodeCompletionString.cpp
+++ b/lib/IDE/CodeCompletionString.cpp
@@ -18,8 +18,7 @@ using namespace swift;
 using namespace swift::ide;
 
 CodeCompletionString::CodeCompletionString(ArrayRef<Chunk> Chunks) {
-  std::uninitialized_copy(Chunks.begin(), Chunks.end(),
-                          getTrailingObjects<Chunk>());
+  std::uninitialized_copy(Chunks.begin(), Chunks.end(), getTrailingObjects());
   NumChunks = Chunks.size();
 }
 
diff --git a/lib/IDE/Utils.cpp b/lib/IDE/Utils.cpp
index 2d33d32ab0e2b..9e6721b5f9c5d 100644
--- a/lib/IDE/Utils.cpp
+++ b/lib/IDE/Utils.cpp
@@ -20,7 +20,7 @@
 #include "swift/Parse/Parser.h"
 #include "swift/Subsystems.h"
 #include "clang/AST/ASTContext.h"
-#include "clang/Rewrite/Core/RewriteBuffer.h"
+#include "llvm/ADT/RewriteBuffer.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -782,11 +782,11 @@ accept(SourceManager &SM, RegionType Type, ArrayRef<Replacement> Replacements) {
 namespace {
 class ClangFileRewriterHelper {
   unsigned InterestedId;
-  clang::RewriteBuffer RewriteBuf;
+  llvm::RewriteBuffer RewriteBuf;
   bool HasChange;
   llvm::raw_ostream &OS;
 
-  void removeCommentLines(clang::RewriteBuffer &Buffer, StringRef Input,
+  void removeCommentLines(llvm::RewriteBuffer &Buffer, StringRef Input,
                           StringRef LineHeader) {
     size_t Pos = 0;
     while (true) {
diff --git a/lib/IDETool/CompilerInvocation.cpp b/lib/IDETool/CompilerInvocation.cpp
index 278d579b6dd2f..1e1dfa05ace27 100644
--- a/lib/IDETool/CompilerInvocation.cpp
+++ b/lib/IDETool/CompilerInvocation.cpp
@@ -267,13 +267,12 @@ bool ide::initCompilerInvocation(
 bool ide::initInvocationByClangArguments(ArrayRef<const char *> ArgList,
                                          CompilerInvocation &Invok,
                                          std::string &Error) {
-  llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> DiagOpts{
-    new clang::DiagnosticOptions()
-  };
+  const auto VFS = llvm::vfs::getRealFileSystem();
 
   clang::TextDiagnosticBuffer DiagBuf;
+  clang::DiagnosticOptions DiagOpts;
   llvm::IntrusiveRefCntPtr<clang::DiagnosticsEngine> ClangDiags =
-      clang::CompilerInstance::createDiagnostics(DiagOpts.get(), &DiagBuf,
+      clang::CompilerInstance::createDiagnostics(*VFS, DiagOpts, &DiagBuf,
                                                  /*ShouldOwnClient=*/false);
 
   // Clang expects this to be like an actual command line. So we need to pass in
@@ -351,7 +350,7 @@ bool ide::initInvocationByClangArguments(ArrayRef<const char *> ArgList,
 
   if (!PPOpts.ImplicitPCHInclude.empty()) {
     clang::FileSystemOptions FileSysOpts;
-    clang::FileManager FileMgr(FileSysOpts);
+    clang::FileManager FileMgr(FileSysOpts, VFS);
     auto PCHContainerOperations =
         std::make_shared<clang::PCHContainerOperations>();
     std::string HeaderFile = clang::ASTReader::getOriginalSourceFile(
diff --git a/lib/IRGen/CallEmission.h b/lib/IRGen/CallEmission.h
index 89ac2baa265f7..e6c6ac8b36ebd 100644
--- a/lib/IRGen/CallEmission.h
+++ b/lib/IRGen/CallEmission.h
@@ -152,11 +152,12 @@ class CallEmission {
                        WitnessMetadata *witnessMetadata);
   virtual Address getCalleeErrorSlot(SILType errorType, bool isCalleeAsync) = 0;
 
-  void addFnAttribute(llvm::Attribute::AttrKind Attr);
+  void addFnAttribute(llvm::Attribute::AttrKind kind);
 
   void setIndirectReturnAddress(Address addr) { indirectReturnAddress = addr; }
 
-  void addParamAttribute(unsigned ParamIndex, llvm::Attribute::AttrKind Attr);
+  void addParamAttribute(unsigned paramIndex, llvm::Attribute::AttrKind kind);
+  void addParamAttribute(unsigned paramIndex, llvm::Attribute attr);
 
   void emitToMemory(Address addr, const LoadableTypeInfo &substResultTI,
                     bool isOutlined);
diff --git a/lib/IRGen/GenBuiltin.cpp b/lib/IRGen/GenBuiltin.cpp
index 21bba9a29f133..b2d38181012da 100644
--- a/lib/IRGen/GenBuiltin.cpp
+++ b/lib/IRGen/GenBuiltin.cpp
@@ -446,9 +446,9 @@ void irgen::emitBuiltinCall(IRGenFunction &IGF, const BuiltinInfo &Builtin,
     SmallVector<llvm::Type*, 4> ArgTys;
     for (auto T : IInfo.Types)
       ArgTys.push_back(IGF.IGM.getStorageTypeForLowered(T->getCanonicalType()));
-      
-    auto F = llvm::Intrinsic::getDeclaration(&IGF.IGM.Module,
-                                             (llvm::Intrinsic::ID)IID, ArgTys);
+
+    auto F = llvm::Intrinsic::getOrInsertDeclaration(
+        &IGF.IGM.Module, (llvm::Intrinsic::ID)IID, ArgTys);
     llvm::FunctionType *FT = F->getFunctionType();
     SmallVector<llvm::Value*, 8> IRArgs;
     for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
@@ -514,7 +514,7 @@ void irgen::emitBuiltinCall(IRGenFunction &IGF, const BuiltinInfo &Builtin,
     SmallVector<llvm::Type *, 2> ArgTys;                                       \
     auto opType = Builtin.Types[0]->getCanonicalType();                        \
     ArgTys.push_back(IGF.IGM.getStorageTypeForLowered(opType));                \
-    auto F = llvm::Intrinsic::getDeclaration(                                  \
+    auto F = llvm::Intrinsic::getOrInsertDeclaration(                          \
         &IGF.IGM.Module, getLLVMIntrinsicIDForBuiltinWithOverflow(Builtin.ID), \
         ArgTys);                                                               \
     SmallVector<llvm::Value *, 2> IRArgs;                                      \
diff --git a/lib/IRGen/GenCall.cpp b/lib/IRGen/GenCall.cpp
index 6e622da2773d7..301251919cf6e 100644
--- a/lib/IRGen/GenCall.cpp
+++ b/lib/IRGen/GenCall.cpp
@@ -317,7 +317,7 @@ static void addIndirectValueParameterAttributes(IRGenModule &IGM,
   // Bitwise takable value types are guaranteed not to capture
   // a pointer into itself.
   if (!addressable && ti.isBitwiseTakable(ResilienceExpansion::Maximal))
-    b.addAttribute(llvm::Attribute::NoCapture);
+    b.addCapturesAttr(llvm::CaptureInfo::none());
   // The parameter must reference dereferenceable memory of the type.
   addDereferenceableAttributeToBuilder(IGM, b, ti);
 
@@ -330,7 +330,7 @@ static void addPackParameterAttributes(IRGenModule &IGM,
                                        unsigned argIndex) {
   llvm::AttrBuilder b(IGM.getLLVMContext());
   // Pack parameter pointers can't alias.
-  // Note: they are not marked `nocapture` as one
+  // Note: they are not marked `captures(none)` as one
   // pack parameter could be a value type (e.g. a C++ type)
   // that captures its own pointer in itself.
   b.addAttribute(llvm::Attribute::NoAlias);
@@ -357,7 +357,7 @@ static void addInoutParameterAttributes(IRGenModule &IGM, SILType paramSILType,
   // Bitwise takable value types are guaranteed not to capture
   // a pointer into itself.
   if (!addressable && ti.isBitwiseTakable(ResilienceExpansion::Maximal))
-    b.addAttribute(llvm::Attribute::NoCapture);
+    b.addCapturesAttr(llvm::CaptureInfo::none());
   // The inout must reference dereferenceable memory of the type.
   addDereferenceableAttributeToBuilder(IGM, b, ti);
 
@@ -411,7 +411,7 @@ static void addIndirectResultAttributes(IRGenModule &IGM,
   // Bitwise takable value types are guaranteed not to capture
   // a pointer into itself.
   if (typeInfo.isBitwiseTakable(ResilienceExpansion::Maximal))
-    b.addAttribute(llvm::Attribute::NoCapture);
+    b.addCapturesAttr(llvm::CaptureInfo::none());
   if (allowSRet) {
     assert(storageType);
     b.addStructRetAttr(storageType);
@@ -530,7 +530,7 @@ void IRGenModule::addSwiftErrorAttributes(llvm::AttributeList &attrs,
   // The error result should not be aliased, captured, or pointed at invalid
   // addresses regardless.
   b.addAttribute(llvm::Attribute::NoAlias);
-  b.addAttribute(llvm::Attribute::NoCapture);
+  b.addCapturesAttr(llvm::CaptureInfo::none());
   b.addDereferenceableAttr(getPointerSize().getValue());
 
   attrs = attrs.addParamAttributes(this->getLLVMContext(), argIndex, b);
@@ -1211,6 +1211,8 @@ namespace {
       }
 
       case clang::Type::ArrayParameter:
+      case clang::Type::HLSLAttributedResource:
+      case clang::Type::HLSLInlineSpirv:
         llvm_unreachable("HLSL type in ABI lowering");
 
 
@@ -1319,7 +1321,7 @@ namespace {
 
       // We should never see ARM SVE types at all.
 #define SVE_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
-#include "clang/Basic/AArch64SVEACLETypes.def"
+#include "clang/Basic/AArch64ACLETypes.def"
         llvm_unreachable("ARM SVE type in ABI lowering");
 
       // We should never see PPC MMA types at all.
@@ -1341,6 +1343,11 @@ namespace {
 #include "clang/Basic/AMDGPUTypes.def"
         llvm_unreachable("AMDGPU type in ABI lowering");
 
+      // We should never see HLSL intangible types at all.
+#define HLSL_INTANGIBLE_TYPE(Name, Id, ...) case clang::BuiltinType::Id:
+#include "clang/Basic/HLSLIntangibleTypes.def"
+        llvm_unreachable("HLSL intangible type in ABI lowering");
+
       // Handle all the integer types as opaque values.
 #define BUILTIN_TYPE(Id, SingletonId)
 #define SIGNED_TYPE(Id, SingletonId) \
@@ -1682,6 +1689,9 @@ void SignatureExpansion::expandExternalSignatureTypes() {
                                     paramTI.getStorageType(), paramTI);
         break;
       }
+      case clang::ParameterABI::HLSLOut:
+      case clang::ParameterABI::HLSLInOut:
+        llvm_unreachable("not implemented");
       }
 
       // If the coercion type is a struct which can be flattened, we need to
@@ -2846,7 +2856,9 @@ class SyncCallEmission final : public CallEmission {
         }
       }
       Args[--LastArgWritten] = errorResultSlot.getAddress();
-      addParamAttribute(LastArgWritten, llvm::Attribute::NoCapture);
+      addParamAttribute(LastArgWritten, llvm::Attribute::getWithCaptureInfo(
+                                            IGF.IGM.getLLVMContext(),
+                                            llvm::CaptureInfo::none()));
       IGF.IGM.addSwiftErrorAttributes(CurCallee.getMutableAttributes(),
                                       LastArgWritten);
 
@@ -5555,14 +5567,20 @@ void CallEmission::setArgs(Explosion &adjusted, bool isOutlined,
   }
 }
 
-void CallEmission::addFnAttribute(llvm::Attribute::AttrKind attr) {
+void CallEmission::addFnAttribute(llvm::Attribute::AttrKind kind) {
   assert(state == State::Emitting);
   auto &attrs = CurCallee.getMutableAttributes();
-  attrs = attrs.addFnAttribute(IGF.IGM.getLLVMContext(), attr);
+  attrs = attrs.addFnAttribute(IGF.IGM.getLLVMContext(), kind);
+}
+
+void CallEmission::addParamAttribute(unsigned paramIndex,
+                                     llvm::Attribute::AttrKind kind) {
+  addParamAttribute(paramIndex,
+                    llvm::Attribute::get(IGF.IGM.getLLVMContext(), kind));
 }
 
 void CallEmission::addParamAttribute(unsigned paramIndex,
-                                     llvm::Attribute::AttrKind attr) {
+                                     llvm::Attribute attr) {
   assert(state == State::Emitting);
   auto &attrs = CurCallee.getMutableAttributes();
   attrs = attrs.addParamAttribute(IGF.IGM.getLLVMContext(), paramIndex, attr);
diff --git a/lib/IRGen/GenDecl.cpp b/lib/IRGen/GenDecl.cpp
index 558255905517f..f54133e4ca5ef 100644
--- a/lib/IRGen/GenDecl.cpp
+++ b/lib/IRGen/GenDecl.cpp
@@ -5996,9 +5996,8 @@ void IRGenModule::emitExtension(ExtensionDecl *ext) {
 Address IRGenFunction::createAlloca(llvm::Type *type,
                                     Alignment alignment,
                                     const llvm::Twine &name) {
-  llvm::AllocaInst *alloca =
-      new llvm::AllocaInst(type, IGM.DataLayout.getAllocaAddrSpace(), name,
-                           AllocaIP);
+  llvm::AllocaInst *alloca = new llvm::AllocaInst(
+      type, IGM.DataLayout.getAllocaAddrSpace(), name, AllocaIP->getIterator());
   alloca->setAlignment(llvm::MaybeAlign(alignment.getValue()).valueOrOne());
   return Address(alloca, type, alignment);
 }
@@ -6008,9 +6007,10 @@ Address IRGenFunction::createAlloca(llvm::Type *type,
                                     llvm::Value *ArraySize,
                                     Alignment alignment,
                                     const llvm::Twine &name) {
-  llvm::AllocaInst *alloca = new llvm::AllocaInst(
-      type, IGM.DataLayout.getAllocaAddrSpace(), ArraySize,
-      llvm::MaybeAlign(alignment.getValue()).valueOrOne(), name, AllocaIP);
+  llvm::AllocaInst *alloca =
+      new llvm::AllocaInst(type, IGM.DataLayout.getAllocaAddrSpace(), ArraySize,
+                           llvm::MaybeAlign(alignment.getValue()).valueOrOne(),
+                           name, AllocaIP->getIterator());
   return Address(alloca, type, alignment);
 }
 
diff --git a/lib/IRGen/GenExistential.cpp b/lib/IRGen/GenExistential.cpp
index 5e0d4af15359d..1c39124ce0e60 100644
--- a/lib/IRGen/GenExistential.cpp
+++ b/lib/IRGen/GenExistential.cpp
@@ -149,7 +149,7 @@ namespace {
         : Base(std::forward<As>(args)...),
           NumStoredProtocols(protocols.size()) {
       std::uninitialized_copy(protocols.begin(), protocols.end(),
-          this->template getTrailingObjects<const ProtocolDecl *>());
+                              this->getTrailingObjects());
     }
 
   public:
@@ -180,8 +180,7 @@ namespace {
     /// type are not know to implement any protocols, although we do
     /// still know how to manipulate them.
     ArrayRef<const ProtocolDecl *> getStoredProtocols() const {
-      return {this->template getTrailingObjects<const ProtocolDecl *>(),
-              NumStoredProtocols};
+      return this->getTrailingObjects(NumStoredProtocols);
     }
 
     /// Given the address of an existential object, find the witness
diff --git a/lib/IRGen/GenPointerAuth.cpp b/lib/IRGen/GenPointerAuth.cpp
index 9d094032747be..b28db161be422 100644
--- a/lib/IRGen/GenPointerAuth.cpp
+++ b/lib/IRGen/GenPointerAuth.cpp
@@ -26,6 +26,7 @@
 #include "swift/SIL/TypeLowering.h"
 #include "clang/CodeGen/CodeGenABITypes.h"
 #include "llvm/ADT/APInt.h"
+#include "llvm/Support/SipHash.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace swift;
@@ -324,16 +325,10 @@ PointerAuthInfo::getOtherDiscriminator(IRGenModule &IGM,
   llvm_unreachable("bad kind");
 }
 
-static llvm::ConstantInt *getDiscriminatorForHash(IRGenModule &IGM,
-                                                  uint64_t rawHash) {
-  uint16_t reducedHash = (rawHash % 0xFFFF) + 1;
-  return llvm::ConstantInt::get(IGM.Int64Ty, reducedHash);
-}
-
 static llvm::ConstantInt *getDiscriminatorForString(IRGenModule &IGM,
                                                     StringRef string) {
-  uint64_t rawHash = clang::CodeGen::computeStableStringHash(string);
-  return getDiscriminatorForHash(IGM, rawHash);
+  return llvm::ConstantInt::get(IGM.Int64Ty,
+                                llvm::getPointerAuthStableSipHash(string));
 }
 
 static std::string mangle(AssociatedTypeDecl *assocType) {
@@ -570,7 +565,8 @@ static void hashStringForFunctionType(IRGenModule &IGM, CanSILFunctionType type,
   }
 }
 
-static uint64_t getTypeHash(IRGenModule &IGM, CanSILFunctionType type) {
+static llvm::ConstantInt *getTypeDiscriminator(IRGenModule &IGM,
+                                               CanSILFunctionType type) {
   // The hash we need to do here ignores:
   //   - thickness, so that we can promote thin-to-thick without rehashing;
   //   - error results, so that we can promote nonthrowing-to-throwing
@@ -590,10 +586,11 @@ static uint64_t getTypeHash(IRGenModule &IGM, CanSILFunctionType type) {
   hashStringForFunctionType(
       IGM, type, Out,
       genericSig.getCanonicalSignature().getGenericEnvironment());
-  return clang::CodeGen::computeStableStringHash(Out.str());
+  return getDiscriminatorForString(IGM, Out.str());
 }
 
-static uint64_t getYieldTypesHash(IRGenModule &IGM, CanSILFunctionType type) {
+static llvm::ConstantInt *
+getCoroutineYieldTypesDiscriminator(IRGenModule &IGM, CanSILFunctionType type) {
   SmallString<32> buffer;
   llvm::raw_svector_ostream out(buffer);
   auto genericSig = type->getInvocationGenericSignature();
@@ -629,7 +626,7 @@ static uint64_t getYieldTypesHash(IRGenModule &IGM, CanSILFunctionType type) {
     out << ":";
   }
 
-  return clang::CodeGen::computeStableStringHash(out.str());  
+  return getDiscriminatorForString(IGM, out.str());
 }
 
 llvm::ConstantInt *
@@ -649,8 +646,7 @@ PointerAuthEntity::getTypeDiscriminator(IRGenModule &IGM) const {
       llvm::ConstantInt *&cache = IGM.getPointerAuthCaches().Types[fnType];
       if (cache) return cache;
 
-      auto hash = getTypeHash(IGM, fnType);
-      cache = getDiscriminatorForHash(IGM, hash);
+      cache = ::getTypeDiscriminator(IGM, fnType);
       return cache;
     }
     
@@ -667,15 +663,6 @@ PointerAuthEntity::getTypeDiscriminator(IRGenModule &IGM) const {
     llvm_unreachable("invalid representation");
   };
 
-  auto getCoroutineYieldTypesDiscriminator = [&](CanSILFunctionType fnType) {
-    llvm::ConstantInt *&cache = IGM.getPointerAuthCaches().Types[fnType];
-    if (cache) return cache;
-
-    auto hash = getYieldTypesHash(IGM, fnType);
-    cache = getDiscriminatorForHash(IGM, hash);
-    return cache;
-  };
-
   switch (StoredKind) {
   case Kind::None:
   case Kind::Special:
@@ -687,7 +674,13 @@ PointerAuthEntity::getTypeDiscriminator(IRGenModule &IGM) const {
 
   case Kind::CoroutineYieldTypes: {
     auto fnType = Storage.get<CanSILFunctionType>(StoredKind);
-    return getCoroutineYieldTypesDiscriminator(fnType);
+
+    llvm::ConstantInt *&cache = IGM.getPointerAuthCaches().Types[fnType];
+    if (cache)
+      return cache;
+
+    cache = getCoroutineYieldTypesDiscriminator(IGM, fnType);
+    return cache;
   }
 
   case Kind::CanSILFunctionType: {
diff --git a/lib/IRGen/GenRecord.h b/lib/IRGen/GenRecord.h
index 65acff49edccf..2aaf5df5c879c 100644
--- a/lib/IRGen/GenRecord.h
+++ b/lib/IRGen/GenRecord.h
@@ -138,7 +138,7 @@ class RecordTypeInfoImpl : public Base,
         NumFields(fields.size()),
         AreFieldsABIAccessible(fieldsABIAccessible) {
     std::uninitialized_copy(fields.begin(), fields.end(),
-                            this->template getTrailingObjects<FieldImpl>());
+                            this->getTrailingObjects());
   }
 
   void fillWithZerosIfSensitive(IRGenFunction &IGF, Address address, SILType T) const {
@@ -169,7 +169,7 @@ class RecordTypeInfoImpl : public Base,
   }
 
   ArrayRef<FieldImpl> getFields() const {
-    return {this->template getTrailingObjects<FieldImpl>(), NumFields};
+    return this->getTrailingObjects(NumFields);
   }
 
   /// The standard schema is just all the fields jumbled together.
diff --git a/lib/IRGen/GenStruct.cpp b/lib/IRGen/GenStruct.cpp
index 6816689777e03..d870143d153ea 100644
--- a/lib/IRGen/GenStruct.cpp
+++ b/lib/IRGen/GenStruct.cpp
@@ -657,7 +657,7 @@ namespace {
             });
 
         bool hasRequiresClause =
-            copyConstructor->getTrailingRequiresClause() != nullptr;
+            !copyConstructor->getTrailingRequiresClause().isNull();
 
         if (hasRequiresClause || hasCopyableIfAttr) {
           ctx.Diags.diagnose(copyConstructorLoc, diag::maybe_missing_annotation,
@@ -1468,7 +1468,7 @@ class ClangRecordLowering {
         // Collect all of the following bitfields.
         unsigned bitStart =
           layout.getFieldOffset(clangField->getFieldIndex());
-        unsigned bitEnd = bitStart + clangField->getBitWidthValue(ClangContext);
+        unsigned bitEnd = bitStart + clangField->getBitWidthValue();
 
         while (cfi != cfe && (*cfi)->isBitField()) {
           clangField = *cfi++;
@@ -1484,7 +1484,7 @@ class ClangRecordLowering {
             bitStart = nextStart;
           }
 
-          bitEnd = nextStart + clangField->getBitWidthValue(ClangContext);
+          bitEnd = nextStart + clangField->getBitWidthValue();
         }
 
         addOpaqueBitField(bitStart, bitEnd);
diff --git a/lib/IRGen/IRBuilder.h b/lib/IRGen/IRBuilder.h
index 0770691fc2485..99a506888479b 100644
--- a/lib/IRGen/IRBuilder.h
+++ b/lib/IRGen/IRBuilder.h
@@ -139,11 +139,11 @@ class IRBuilder : public IRBuilderBase {
 
   using IRBuilderBase::CreateOr;
   llvm::Value *CreateOr(llvm::Value *LHS, llvm::Value *RHS,
-                        const Twine &Name = "") {
+                        const Twine &Name = "", bool IsDisjoint = false) {
     if (auto *RC = dyn_cast<llvm::Constant>(RHS))
       if (RC->isNullValue())
         return LHS;  // LHS | 0 -> LHS
-    return IRBuilderBase::CreateOr(LHS, RHS, Name);
+    return IRBuilderBase::CreateOr(LHS, RHS, Name, IsDisjoint);
   }
   llvm::Value *CreateOr(llvm::Value *LHS, const APInt &RHS,
                         const Twine &Name = "") {
@@ -311,8 +311,8 @@ class IRBuilder : public IRBuilderBase {
   // FunctionPointer.
 
   bool isTrapIntrinsic(llvm::Value *Callee) {
-    return Callee ==
-           llvm::Intrinsic::getDeclaration(getModule(), llvm::Intrinsic::trap);
+    return Callee == llvm::Intrinsic::getOrInsertDeclaration(
+                         getModule(), llvm::Intrinsic::trap);
   }
   bool isTrapIntrinsic(llvm::Intrinsic::ID intrinsicID) {
     return intrinsicID == llvm::Intrinsic::trap;
@@ -382,7 +382,7 @@ class IRBuilder : public IRBuilderBase {
                                       const Twine &name = "") {
     assert(!isTrapIntrinsic(intrinsicID) && "Use CreateNonMergeableTrap");
     auto intrinsicFn =
-      llvm::Intrinsic::getDeclaration(getModule(), intrinsicID);
+        llvm::Intrinsic::getOrInsertDeclaration(getModule(), intrinsicID);
     return CreateCallWithoutDbgLoc(
         cast<llvm::FunctionType>(intrinsicFn->getValueType()), intrinsicFn,
         args, name);
@@ -394,8 +394,8 @@ class IRBuilder : public IRBuilderBase {
                                       ArrayRef<llvm::Value *> args,
                                       const Twine &name = "") {
     assert(!isTrapIntrinsic(intrinsicID) && "Use CreateNonMergeableTrap");
-    auto intrinsicFn =
-      llvm::Intrinsic::getDeclaration(getModule(), intrinsicID, typeArgs);
+    auto intrinsicFn = llvm::Intrinsic::getOrInsertDeclaration(
+        getModule(), intrinsicID, typeArgs);
     return CreateCallWithoutDbgLoc(
         cast<llvm::FunctionType>(intrinsicFn->getValueType()), intrinsicFn,
         args, name);
diff --git a/lib/IRGen/IRGen.cpp b/lib/IRGen/IRGen.cpp
index d70df477ef61c..2566667e69027 100644
--- a/lib/IRGen/IRGen.cpp
+++ b/lib/IRGen/IRGen.cpp
@@ -88,7 +88,6 @@
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
-#include "llvm/Transforms/Instrumentation.h"
 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
@@ -96,6 +95,7 @@
 #include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Scalar/DCE.h"
+#include "llvm/Transforms/Utils/Instrumentation.h"
 
 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
 #include "llvm/IR/DiagnosticInfo.h"
@@ -135,6 +135,9 @@ swift::getIRTargetOptions(const IRGenOptions &Opts, ASTContext &Ctx) {
   // FIXME: We should do this entirely through Clang, for consistency.
   TargetOptions TargetOpts;
 
+  // Linker support for this is not widespread enough.
+  TargetOpts.SupportIndirectSymViaGOTPCRel_AArch64_ELF = false;
+
   // Explicitly request debugger tuning for LLDB which is the default
   // on Darwin platforms but not on others.
   TargetOpts.DebuggerTuning = llvm::DebuggerKind::LLDB;
@@ -345,7 +348,8 @@ void swift::performLLVMOptimizations(const IRGenOptions &Opts,
             FPM.addPass(SwiftARCOptPass());
         });
     PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
-                                          OptimizationLevel Level) {
+                                           OptimizationLevel Level,
+                                           llvm::ThinOrFullLTOPhase) {
       if (Level != OptimizationLevel::O0)
         MPM.addPass(createModuleToFunctionPassAdaptor(SwiftARCContractPass()));
       if (Level == OptimizationLevel::O0)
@@ -360,7 +364,8 @@ void swift::performLLVMOptimizations(const IRGenOptions &Opts,
 
   if (Opts.Sanitizers & SanitizerKind::Address) {
     PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
-                                           OptimizationLevel Level) {
+                                           OptimizationLevel Level,
+                                           llvm::ThinOrFullLTOPhase) {
       AddressSanitizerOptions ASOpts;
       ASOpts.CompileKernel = false;
       ASOpts.Recover = bool(Opts.SanitizersWithRecoveryInstrumentation &
@@ -379,17 +384,19 @@ void swift::performLLVMOptimizations(const IRGenOptions &Opts,
   }
 
   if (Opts.Sanitizers & SanitizerKind::Thread) {
-    PB.registerOptimizerLastEPCallback(
-        [&](ModulePassManager &MPM, OptimizationLevel Level) {
-          MPM.addPass(ModuleThreadSanitizerPass());
-          MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
-        });
+    PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
+                                           OptimizationLevel Level,
+                                           llvm::ThinOrFullLTOPhase) {
+      MPM.addPass(ModuleThreadSanitizerPass());
+      MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
+    });
   }
 
   if (Opts.SanitizeCoverage.CoverageType !=
       llvm::SanitizerCoverageOptions::SCK_None) {
     PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
-                                           OptimizationLevel Level) {
+                                           OptimizationLevel Level,
+                                           llvm::ThinOrFullLTOPhase) {
       std::vector<std::string> allowlistFiles;
       std::vector<std::string> ignorelistFiles;
       MPM.addPass(SanitizerCoveragePass(Opts.SanitizeCoverage,
@@ -398,14 +405,15 @@ void swift::performLLVMOptimizations(const IRGenOptions &Opts,
   }
 
   if (RunSwiftSpecificLLVMOptzns && !Opts.DisableLLVMMergeFunctions) {
-    PB.registerOptimizerLastEPCallback(
-        [&](ModulePassManager &MPM, OptimizationLevel Level) {
-          if (Level != OptimizationLevel::O0) {
-            const PointerAuthSchema &schema = Opts.PointerAuth.FunctionPointers;
-            unsigned key = (schema.isEnabled() ? schema.getKey() : 0);
-            MPM.addPass(SwiftMergeFunctionsPass(schema.isEnabled(), key));
-          }
-        });
+    PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
+                                           OptimizationLevel Level,
+                                           llvm::ThinOrFullLTOPhase) {
+      if (Level != OptimizationLevel::O0) {
+        const PointerAuthSchema &schema = Opts.PointerAuth.FunctionPointers;
+        unsigned key = (schema.isEnabled() ? schema.getKey() : 0);
+        MPM.addPass(SwiftMergeFunctionsPass(schema.isEnabled(), key));
+      }
+    });
   }
 
   if (Opts.GenerateProfile) {
@@ -427,7 +435,13 @@ void swift::performLLVMOptimizations(const IRGenOptions &Opts,
   bool isThinLTO = Opts.LLVMLTOKind  == IRGenLLVMLTOKind::Thin;
   bool isFullLTO = Opts.LLVMLTOKind  == IRGenLLVMLTOKind::Full;
   if (!Opts.shouldOptimize() || Opts.DisableLLVMOptzns) {
-    MPM = PB.buildO0DefaultPipeline(level, isFullLTO || isThinLTO);
+    auto phase = llvm::ThinOrFullLTOPhase::None;
+    if (isFullLTO) {
+      phase = llvm::ThinOrFullLTOPhase::FullLTOPreLink;
+    } else if (isThinLTO) {
+      phase = llvm::ThinOrFullLTOPhase::ThinLTOPreLink;
+    }
+    MPM = PB.buildO0DefaultPipeline(level, phase);
   } else if (isThinLTO) {
     MPM = PB.buildThinLTOPreLinkDefaultPipeline(level);
   } else if (isFullLTO) {
@@ -1047,7 +1061,7 @@ swift::createTargetMachine(const IRGenOptions &Opts, ASTContext &Ctx) {
 
   // Create a target machine.
   llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
-      EffectiveTriple.str(), CPU, targetFeatures, TargetOpts, Reloc::PIC_,
+      EffectiveTriple, CPU, targetFeatures, TargetOpts, Reloc::PIC_,
       cmodel, OptLevel);
   if (!TargetMachine) {
     Ctx.Diags.diagnose(SourceLoc(), diag::no_llvm_target,
@@ -1148,8 +1162,8 @@ static void embedBitcode(llvm::Module *M, const IRGenOptions &Opts)
 static void initLLVMModule(IRGenModule &IGM, SILModule &SIL, std::optional<unsigned> idx = {}) {
   auto *Module = IGM.getModule();
   assert(Module && "Expected llvm:Module for IR generation!");
-  
-  Module->setTargetTriple(IGM.Triple.str());
+
+  Module->setTargetTriple(IGM.Triple);
 
   if (IGM.Context.LangOpts.SDKVersion) {
     if (Module->getSDKVersion().empty())
diff --git a/lib/IRGen/IRGenDebugInfo.cpp b/lib/IRGen/IRGenDebugInfo.cpp
index 0ede779f729e6..a79c30268bfa8 100644
--- a/lib/IRGen/IRGenDebugInfo.cpp
+++ b/lib/IRGen/IRGenDebugInfo.cpp
@@ -1951,7 +1951,8 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
           nullptr, PtrSize, 0,
           /* DWARFAddressSpace */ std::nullopt, MangledName);
 
-      return DBuilder.createObjectPointerType(PTy);
+      // FIXME: Set DIFlagObjectPointer and make sure it is only set for `self`.
+      return PTy;
     }
     case TypeKind::BuiltinExecutor: {
       return createDoublePointerSizedStruct(
@@ -3684,16 +3685,16 @@ struct DbgIntrinsicEmitter {
   PointerUnion<llvm::BasicBlock *, llvm::Instruction *> InsertPt;
   irgen::IRBuilder &IRBuilder;
   llvm::DIBuilder &DIBuilder;
-  AddrDbgInstrKind ForceDbgDeclare;
+  AddrDbgInstrKind ForceDbgDeclareOrCoro;
 
   /// Initialize the emitter and initialize the emitter to assume that it is
   /// going to insert an llvm.dbg.declare or an llvm.dbg.addr either at the
   /// current "generalized insertion point" of the IRBuilder. The "generalized
   /// insertion point" is
   DbgIntrinsicEmitter(irgen::IRBuilder &IRBuilder, llvm::DIBuilder &DIBuilder,
-                      AddrDbgInstrKind ForceDebugDeclare)
+                      AddrDbgInstrKind AddrDInstrKind)
       : InsertPt(), IRBuilder(IRBuilder), DIBuilder(DIBuilder),
-        ForceDbgDeclare(ForceDebugDeclare) {
+        ForceDbgDeclareOrCoro(AddrDInstrKind) {
     auto *ParentBB = IRBuilder.GetInsertBlock();
     auto InsertBefore = IRBuilder.GetInsertPoint();
 
@@ -3720,19 +3721,29 @@ struct DbgIntrinsicEmitter {
                           llvm::DIExpression *Expr,
                           const llvm::DILocation *DL,
                           llvm::Instruction *InsertBefore) {
-    if (ForceDbgDeclare == AddrDbgInstrKind::DbgDeclare)
-      return DIBuilder.insertDeclare(Addr, VarInfo, Expr, DL, InsertBefore);
+    if (ForceDbgDeclareOrCoro == AddrDbgInstrKind::DbgDeclare)
+      return DIBuilder.insertDeclare(Addr, VarInfo, Expr, DL,
+                                     InsertBefore->getIterator());
+
+    if (ForceDbgDeclareOrCoro == AddrDbgInstrKind::DbgCoroFrameEntry)
+      return DIBuilder.insertCoroFrameEntry(Addr, VarInfo, Expr, DL,
+                                            InsertBefore->getIterator());
+
     Expr = llvm::DIExpression::append(Expr, llvm::dwarf::DW_OP_deref);
     return DIBuilder.insertDbgValueIntrinsic(Addr, VarInfo, Expr, DL,
-                                            InsertBefore);
+                                             InsertBefore->getIterator());
   }
 
   llvm::DbgInstPtr insert(llvm::Value *Addr, llvm::DILocalVariable *VarInfo,
                           llvm::DIExpression *Expr,
                           const llvm::DILocation *DL,
                           llvm::BasicBlock *Block) {
-    if (ForceDbgDeclare == AddrDbgInstrKind::DbgDeclare)
+    if (ForceDbgDeclareOrCoro == AddrDbgInstrKind::DbgDeclare)
       return DIBuilder.insertDeclare(Addr, VarInfo, Expr, DL, Block);
+
+    if (ForceDbgDeclareOrCoro == AddrDbgInstrKind::DbgCoroFrameEntry)
+      return DIBuilder.insertCoroFrameEntry(Addr, VarInfo, Expr, DL, Block);
+
     Expr = llvm::DIExpression::append(Expr, llvm::dwarf::DW_OP_deref);
     return DIBuilder.insertDbgValueIntrinsic(Addr, VarInfo, Expr, DL, Block);
   }
@@ -3792,13 +3803,17 @@ void IRGenDebugInfoImpl::emitDbgIntrinsic(
   if (optimized && (!InCoroContext || !Var->isParameter()))
     AddrDInstKind = AddrDbgInstrKind::DbgValueDeref;
 
+  if (InCoroContext && AddrDInstKind != AddrDbgInstrKind::DbgValueDeref)
+    AddrDInstKind = AddrDbgInstrKind::DbgCoroFrameEntry;
+
   DbgIntrinsicEmitter inserter{Builder, DBuilder, AddrDInstKind};
 
   // If we have a single alloca...
   if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Storage)) {
     auto InsertBefore = Builder.GetInsertPoint();
 
-    if (AddrDInstKind == AddrDbgInstrKind::DbgDeclare) {
+    if (AddrDInstKind == AddrDbgInstrKind::DbgDeclare ||
+        AddrDInstKind == AddrDbgInstrKind::DbgCoroFrameEntry) {
       ParentBlock = Alloca->getParent();
       InsertBefore = std::next(Alloca->getIterator());
     }
@@ -3825,7 +3840,8 @@ void IRGenDebugInfoImpl::emitDbgIntrinsic(
     // splitter that in split coroutines we always create debug info for values
     // in the coroutine context by creating a llvm.dbg.declare for the variable
     // in the entry block of each funclet.
-    if (AddrDInstKind == AddrDbgInstrKind::DbgDeclare) {
+    if (AddrDInstKind == AddrDbgInstrKind::DbgDeclare ||
+        AddrDInstKind == AddrDbgInstrKind::DbgCoroFrameEntry) {
       // Function arguments in async functions are emitted without a shadow copy
       // (that would interfere with coroutine splitting) but with a
       // llvm.dbg.declare to give CoroSplit.cpp license to emit a shadow copy
@@ -3868,19 +3884,23 @@ void IRGenDebugInfoImpl::emitDbgIntrinsic(
   }
 
   // Insert a dbg.value at the current insertion point.
-  if (isa<llvm::Argument>(Storage) && !Var->getArg() &&
-      ParentBlock->getFirstNonPHIOrDbg())
-    // SelectionDAGISel only generates debug info for a dbg.value
-    // that is associated with a llvm::Argument if either its !DIVariable
-    // is marked as argument or there is no non-debug intrinsic instruction
-    // before it. So In the case of associating a llvm::Argument with a
-    // non-argument debug variable -- usually via a !DIExpression -- we
-    // need to make sure that dbg.value is before any non-phi / no-dbg
-    // instruction.
-    DBuilder.insertDbgValueIntrinsic(Storage, Var, Expr, DL,
-                                     ParentBlock->getFirstNonPHIOrDbg());
-  else
-    DBuilder.insertDbgValueIntrinsic(Storage, Var, Expr, DL, ParentBlock);
+  if (isa<llvm::Argument>(Storage) && !Var->getArg()) {
+    const auto InsertPt = ParentBlock->getFirstNonPHIOrDbg();
+    if (InsertPt != ParentBlock->end()) {
+      // SelectionDAGISel only generates debug info for a dbg.value
+      // that is associated with a llvm::Argument if either its !DIVariable
+      // is marked as argument or there is no non-debug intrinsic instruction
+      // before it. So In the case of associating a llvm::Argument with a
+      // non-argument debug variable -- usually via a !DIExpression -- we
+      // need to make sure that dbg.value is before any non-phi / no-dbg
+      // instruction.
+      DBuilder.insertDbgValueIntrinsic(Storage, Var, Expr, DL, InsertPt);
+
+      return;
+    }
+  }
+
+  DBuilder.insertDbgValueIntrinsic(Storage, Var, Expr, DL, ParentBlock->end());
 }
 
 void IRGenDebugInfoImpl::emitGlobalVariableDeclaration(
diff --git a/lib/IRGen/IRGenDebugInfo.h b/lib/IRGen/IRGenDebugInfo.h
index 4007bf3178a25..364f357deb3a3 100644
--- a/lib/IRGen/IRGenDebugInfo.h
+++ b/lib/IRGen/IRGenDebugInfo.h
@@ -50,9 +50,10 @@ enum ArtificialKind : bool { RealValue = false, ArtificialValue = true };
 /// instead of dbg.value + op_deref. By default, we now emit dbg.value instead of
 /// dbg.declare for normal variables. This is not true for metadata which
 /// truly are function wide and should be llvm.dbg.declare.
-enum class AddrDbgInstrKind : bool {
+enum class AddrDbgInstrKind : uint8_t {
   DbgDeclare,
   DbgValueDeref,
+  DbgCoroFrameEntry,
 };
 
 /// Helper object that keeps track of the current CompileUnit, File,
diff --git a/lib/IRGen/IRGenFunction.cpp b/lib/IRGen/IRGenFunction.cpp
index e4ec6b07fe44b..34606f3353a9a 100644
--- a/lib/IRGen/IRGenFunction.cpp
+++ b/lib/IRGen/IRGenFunction.cpp
@@ -524,8 +524,8 @@ llvm::CallInst *IRBuilder::CreateNonMergeableTrap(IRGenModule &IGM,
   }
 
   // Emit the trap instruction.
-  llvm::Function *trapIntrinsic =
-      llvm::Intrinsic::getDeclaration(&IGM.Module, llvm::Intrinsic::trap);
+  llvm::Function *trapIntrinsic = llvm::Intrinsic::getOrInsertDeclaration(
+      &IGM.Module, llvm::Intrinsic::trap);
   if (EnableTrapDebugInfo && IGM.DebugInfo && !failureMsg.empty()) {
     IGM.DebugInfo->addFailureMessageToCurrentLoc(*this, failureMsg);
   }
diff --git a/lib/IRGen/IRGenModule.cpp b/lib/IRGen/IRGenModule.cpp
index b13893ff833d2..9ba09c542f9b8 100644
--- a/lib/IRGen/IRGenModule.cpp
+++ b/lib/IRGen/IRGenModule.cpp
@@ -2419,7 +2419,7 @@ bool swift::writeEmptyOutputFilesFor(
     auto *clangImporter = static_cast<ClangImporter *>(
       Context.getClangModuleLoader());
     llvmModule->setTargetTriple(
-      clangImporter->getTargetInfo().getTargetOpts().Triple);
+        llvm::Triple(clangImporter->getTargetInfo().getTargetOpts().Triple));
 
     // Add LLVM module flags.
     auto &clangASTContext = clangImporter->getClangASTContext();
diff --git a/lib/IRGen/IRGenSIL.cpp b/lib/IRGen/IRGenSIL.cpp
index adc1a267e061a..a8ca6585964b1 100644
--- a/lib/IRGen/IRGenSIL.cpp
+++ b/lib/IRGen/IRGenSIL.cpp
@@ -823,7 +823,7 @@ class IRGenSILFunction :
           if (DVI->getParent() == BB)
             IGM.DebugInfo->getBuilder().insertDbgValueIntrinsic(
                 DVI->getValue(), DVI->getVariable(), DVI->getExpression(),
-                DVI->getDebugLoc(), &*CurBB->getFirstInsertionPt());
+                DVI->getDebugLoc(), CurBB->getFirstInsertionPt());
       }
     }
   }
@@ -907,7 +907,7 @@ class IRGenSILFunction :
 
       llvm::Instruction *Cloned = Orig->clone();
       Cloned->setOperand(0, Inner);
-      Cloned->insertBefore(Orig);
+      Cloned->insertBefore(Orig->getIterator());
       return static_cast<llvm::Value *>(Cloned);
     };
     if (auto *LdInst = dyn_cast<llvm::LoadInst>(Storage))
@@ -5747,7 +5747,7 @@ static Address isSafeForMemCpyPeephole(const TypeInfo &TI, SILArgument *arg,
     return Address();
   }
 
-  lifetimeBegin->moveBefore(load);
+  lifetimeBegin->moveBefore(load->getIterator());
 
   // Set insertPt to the first load such that we are within the lifetime of the
   // alloca marked by the lifetime intrinsic.
diff --git a/lib/IRGen/ProtocolInfo.h b/lib/IRGen/ProtocolInfo.h
index 8c4180cb549c1..a1c3fa9819bc6 100644
--- a/lib/IRGen/ProtocolInfo.h
+++ b/lib/IRGen/ProtocolInfo.h
@@ -222,8 +222,7 @@ class ProtocolInfo final :
 
   ProtocolInfo(ArrayRef<WitnessTableEntry> table, ProtocolInfoKind kind)
       : NumTableEntries(table.size()), Kind(kind) {
-    std::uninitialized_copy(table.begin(), table.end(),
-                            getTrailingObjects<WitnessTableEntry>());
+    std::uninitialized_copy(table.begin(), table.end(), getTrailingObjects());
   }
 
   static std::unique_ptr<ProtocolInfo> create(ArrayRef<WitnessTableEntry> table,
@@ -249,7 +248,7 @@ class ProtocolInfo final :
   /// The addresses of the entries in this array can be passed to
   /// getBaseWitnessIndex/getNonBaseWitnessIndex, below.
   ArrayRef<WitnessTableEntry> getWitnessEntries() const {
-    return {getTrailingObjects<WitnessTableEntry>(), NumTableEntries};
+    return getTrailingObjects(NumTableEntries);
   }
 
   /// Given the address of a witness entry from this PI for a base protocol
diff --git a/lib/Immediate/SwiftMaterializationUnit.cpp b/lib/Immediate/SwiftMaterializationUnit.cpp
index 7203a8ab141c8..0465188f2b270 100644
--- a/lib/Immediate/SwiftMaterializationUnit.cpp
+++ b/lib/Immediate/SwiftMaterializationUnit.cpp
@@ -197,11 +197,11 @@ renameFunctionBodies(llvm::orc::MaterializationResponsibility &MR,
       if (!Sym->hasName() || !Sym->isCallable())
         continue;
 
-      if (ToRename.count(Sym->getName())) {
-        // FIXME: Get rid of the temporary when Swift's llvm-project is
-        // updated to LLVM 17.
-        auto NewName = G.allocateCString(Twine(mangle(Sym->getName())));
-        Sym->setName({NewName.data(), NewName.size() - 1});
+      const StringRef Name = *Sym->getName();
+
+      if (ToRename.count(Name)) {
+        auto NewName = G.intern(mangle(Name));
+        Sym->setName(NewName);
       }
     }
   }
diff --git a/lib/LLVMPasses/ARCEntryPointBuilder.h b/lib/LLVMPasses/ARCEntryPointBuilder.h
index 9e92f3f2349de..8f069e7a3f097 100644
--- a/lib/LLVMPasses/ARCEntryPointBuilder.h
+++ b/lib/LLVMPasses/ARCEntryPointBuilder.h
@@ -251,11 +251,16 @@ class ARCEntryPointBuilder {
 
     auto *ObjectPtrTy = PtrTy;
     auto &M = getModule();
-    auto AttrList = AttributeList::get(M.getContext(), 1, Attribute::NoCapture);
-    AttrList = AttrList.addFnAttribute(M.getContext(), Attribute::NoUnwind);
+    auto &C = M.getContext();
+
+    AttributeList AttrList;
+    AttrList = AttrList.addFnAttribute(C, Attribute::NoUnwind);
+    AttrList = AttrList.addParamAttribute(
+        C, 0, Attribute::getWithCaptureInfo(C, llvm::CaptureInfo::none()));
+
     CheckUnowned = cast<llvm::Function>(
         M.getOrInsertFunction("swift_checkUnowned", AttrList,
-                              Type::getVoidTy(M.getContext()), ObjectPtrTy)
+                              Type::getVoidTy(C), ObjectPtrTy)
             .getCallee());
     if (llvm::Triple(M.getTargetTriple()).isOSBinFormatCOFF() &&
         !llvm::Triple(M.getTargetTriple()).isOSCygMing())
diff --git a/lib/LLVMPasses/LLVMARCOpts.cpp b/lib/LLVMPasses/LLVMARCOpts.cpp
index e66650b1bfb1b..16d9d2874ff3c 100644
--- a/lib/LLVMPasses/LLVMARCOpts.cpp
+++ b/lib/LLVMPasses/LLVMARCOpts.cpp
@@ -398,7 +398,7 @@ static bool performLocalReleaseMotion(CallInst &Release, BasicBlock &BB,
   // there) move the release to the top of the block.
   // TODO: This is where we'd plug in some global algorithms someday.
   if (&*BBI != &Release) {
-    Release.moveBefore(&*BBI);
+    Release.moveBefore(BBI);
     return true;
   }
 
@@ -520,7 +520,7 @@ static bool performLocalRetainMotion(CallInst &Retain, BasicBlock &BB,
   // If we were able to move the retain down, move it now.
   // TODO: This is where we'd plug in some global algorithms someday.
   if (MadeProgress) {
-    Retain.moveBefore(&*BBI);
+    Retain.moveBefore(BBI);
     return true;
   }
 
diff --git a/lib/LLVMPasses/LLVMMergeFunctions.cpp b/lib/LLVMPasses/LLVMMergeFunctions.cpp
index cc4d99e523a4b..89a58962a1637 100644
--- a/lib/LLVMPasses/LLVMMergeFunctions.cpp
+++ b/lib/LLVMPasses/LLVMMergeFunctions.cpp
@@ -30,7 +30,6 @@
 
 #include "swift/Basic/Assertions.h"
 #include "swift/LLVMPasses/Passes.h"
-#include "clang/AST/StableHash.h"
 #include "clang/Basic/PointerAuthOptions.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/FoldingSet.h"
@@ -55,6 +54,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/SipHash.h"
 #include "llvm/TargetParser/Triple.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/Utils/FunctionComparator.h"
@@ -258,7 +258,7 @@ class SwiftMergeFunctions {
     FunctionEntry *First;
 
     /// A very cheap hash, used to early exit if functions do not match.
-    llvm::IRHash Hash;
+    llvm::stable_hash Hash;
 
   public:
     // Note the hash is recalculated potentially multiple times, but it is cheap.
@@ -416,9 +416,10 @@ class SwiftMergeFunctions {
         if (auto *GO = dyn_cast<GlobalObject>(value))
           concatenatedCalleeNames += GO->getName();
       }
-      uint64_t rawHash = clang::getStableStringHash(concatenatedCalleeNames);
+      uint64_t hash =
+          llvm::getPointerAuthStableSipHash(concatenatedCalleeNames);
       IntegerType *discrTy = Type::getInt64Ty(Context);
-      discriminator = ConstantInt::get(discrTy, (rawHash % 0xFFFF) + 1);
+      discriminator = ConstantInt::get(discrTy, hash);
     }
   };
 
@@ -713,7 +714,7 @@ bool SwiftMergeFunctions::runOnModule(Module &M) {
 
   // All functions in the module, ordered by hash. Functions with a unique
   // hash value are easily eliminated.
-  std::vector<std::pair<IRHash, Function *>> HashedFuncs;
+  std::vector<std::pair<stable_hash, Function *>> HashedFuncs;
 
   for (Function &Func : M) {
     if (isEligibleFunction(&Func)) {
@@ -721,10 +722,11 @@ bool SwiftMergeFunctions::runOnModule(Module &M) {
     }
   }
 
-  std::stable_sort(
-      HashedFuncs.begin(), HashedFuncs.end(),
-      [](const std::pair<IRHash, Function *> &a,
-         const std::pair<IRHash, Function *> &b) { return a.first < b.first; });
+  std::stable_sort(HashedFuncs.begin(), HashedFuncs.end(),
+                   [](const std::pair<stable_hash, Function *> &a,
+                      const std::pair<stable_hash, Function *> &b) {
+                     return a.first < b.first;
+                   });
 
   std::vector<FunctionEntry> FuncEntryStorage;
   FuncEntryStorage.reserve(HashedFuncs.size());
@@ -1044,8 +1046,9 @@ void SwiftMergeFunctions::replaceCallWithAddedPtrAuth(CallInst *origCall,
     copiedArgs.push_back(op);
   }
 
-  auto *newCall = CallInst::Create(origCall->getFunctionType(),
-    newCallee, copiedArgs, bundles, origCall->getName(), origCall);
+  auto *newCall =
+      CallInst::Create(origCall->getFunctionType(), newCallee, copiedArgs,
+                       bundles, origCall->getName(), origCall->getIterator());
   newCall->setAttributes(origCall->getAttributes());
   newCall->setTailCallKind(origCall->getTailCallKind());
   newCall->setCallingConv(origCall->getCallingConv());
@@ -1079,7 +1082,6 @@ void SwiftMergeFunctions::mergeWithParams(const FunctionInfos &FInfos,
   Function *NewFunction = Function::Create(funcType,
                                            FirstF->getLinkage(),
                                            FirstF->getName() + "Tm");
-  NewFunction->setIsNewDbgInfoFormat(FirstF->IsNewDbgInfoFormat);
   NewFunction->copyAttributesFrom(FirstF);
   // NOTE: this function is not externally available, do ensure that we reset
   // the DLL storage
diff --git a/lib/Markup/AST.cpp b/lib/Markup/AST.cpp
index 2c94e1d49306e..92994f9ccc181 100644
--- a/lib/Markup/AST.cpp
+++ b/lib/Markup/AST.cpp
@@ -25,7 +25,7 @@ using namespace markup;
 Document::Document(ArrayRef<MarkupASTNode*> Children)
     : MarkupASTNode(ASTNodeKind::Document), NumChildren(Children.size()) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Document *Document::create(MarkupContext &MC,
@@ -38,7 +38,7 @@ Document *Document::create(MarkupContext &MC,
 BlockQuote::BlockQuote(ArrayRef<MarkupASTNode*> Children)
     : MarkupASTNode(ASTNodeKind::BlockQuote), NumChildren(Children.size()) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 BlockQuote *BlockQuote::create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children) {
@@ -72,7 +72,7 @@ List::List(ArrayRef<MarkupASTNode *> Children, bool IsOrdered)
     : MarkupASTNode(ASTNodeKind::List), NumChildren(Children.size()),
       Ordered(IsOrdered) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 List *List::create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children,
@@ -85,7 +85,7 @@ List *List::create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children,
 Item::Item(ArrayRef<MarkupASTNode*> Children)
     : MarkupASTNode(ASTNodeKind::Item), NumChildren(Children.size()) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Item *Item::create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children) {
@@ -98,7 +98,7 @@ Link::Link(StringRef Destination, ArrayRef<MarkupASTNode *> Children)
     : InlineContent(ASTNodeKind::Link), NumChildren(Children.size()),
       Destination(Destination) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Link *Link::create(MarkupContext &MC, StringRef Destination,
@@ -114,7 +114,7 @@ Image::Image(StringRef Destination, std::optional<StringRef> Title,
     : InlineContent(ASTNodeKind::Image), NumChildren(Children.size()),
       Destination(Destination), Title(Title) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Image *Image::create(MarkupContext &MC, StringRef Destination,
@@ -133,7 +133,7 @@ Header::Header(unsigned Level, ArrayRef<MarkupASTNode *> Children)
     : MarkupASTNode(ASTNodeKind::Header), NumChildren(Children.size()),
       Level(Level) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Header *Header::create(MarkupContext &MC, unsigned Level,
@@ -147,7 +147,7 @@ Paragraph::Paragraph(ArrayRef<MarkupASTNode *> Children)
     : MarkupASTNode(ASTNodeKind::Paragraph),
       NumChildren(Children.size()) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Paragraph *Paragraph::create(MarkupContext &MC,
@@ -158,7 +158,8 @@ Paragraph *Paragraph::create(MarkupContext &MC,
 }
 
 InlineAttributes::InlineAttributes(StringRef Attributes, ArrayRef<MarkupASTNode *> Children) : InlineContent(ASTNodeKind::InlineAttributes), NumChildren(Children.size()), Attributes(Attributes) {
-  std::uninitialized_copy(Children.begin(), Children.end(), getTrailingObjects<MarkupASTNode *>());
+  std::uninitialized_copy(Children.begin(), Children.end(),
+                          getTrailingObjects());
 }
 
 InlineAttributes *InlineAttributes::create(MarkupContext &MC, StringRef Attributes, ArrayRef<MarkupASTNode *> Children) {
@@ -190,7 +191,7 @@ LineBreak *LineBreak::create(MarkupContext &MC) {
 Emphasis::Emphasis(ArrayRef<MarkupASTNode *> Children)
     : InlineContent(ASTNodeKind::Emphasis), NumChildren(Children.size()) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Emphasis *Emphasis::create(MarkupContext &MC,
@@ -203,7 +204,7 @@ Emphasis *Emphasis::create(MarkupContext &MC,
 Strong::Strong(ArrayRef<MarkupASTNode *> Children)
     : InlineContent(ASTNodeKind::Strong), NumChildren(Children.size()) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 Strong *Strong::create(MarkupContext &MC,
@@ -217,7 +218,7 @@ ParamField::ParamField(StringRef Name, ArrayRef<MarkupASTNode *> Children)
     : PrivateExtension(ASTNodeKind::ParamField), NumChildren(Children.size()),
       Name(Name), Parts(std::nullopt) {
   std::uninitialized_copy(Children.begin(), Children.end(),
-                          getTrailingObjects<MarkupASTNode *>());
+                          getTrailingObjects());
 }
 
 ParamField *ParamField::create(MarkupContext &MC, StringRef Name,
@@ -237,7 +238,7 @@ Id *Id::create(MarkupContext &MC, ArrayRef<MarkupASTNode *> Children) { \
 Id::Id(ArrayRef<MarkupASTNode *> Children) \
     : PrivateExtension(ASTNodeKind::Id), NumChildren(Children.size()) { \
   std::uninitialized_copy(Children.begin(), Children.end(), \
-                          getTrailingObjects<MarkupASTNode *>()); \
+                          getTrailingObjects()); \
 }
 #include "swift/Markup/SimpleFields.def"
 
diff --git a/lib/Migrator/APIDiffMigratorPass.cpp b/lib/Migrator/APIDiffMigratorPass.cpp
index 6052aaaa66b09..17ce0e7916f7e 100644
--- a/lib/Migrator/APIDiffMigratorPass.cpp
+++ b/lib/Migrator/APIDiffMigratorPass.cpp
@@ -29,7 +29,7 @@
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Edit/EditedSource.h"
-#include "clang/Rewrite/Core/RewriteBuffer.h"
+#include "llvm/ADT/RewriteBuffer.h"
 #include "llvm/Support/FileSystem.h"
 
 using namespace swift;
diff --git a/lib/Migrator/Migrator.cpp b/lib/Migrator/Migrator.cpp
index 7549d14200480..857e30eb3dead 100644
--- a/lib/Migrator/Migrator.cpp
+++ b/lib/Migrator/Migrator.cpp
@@ -21,7 +21,7 @@
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Edit/EditedSource.h"
-#include "clang/Rewrite/Core/RewriteBuffer.h"
+#include "llvm/ADT/RewriteBuffer.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 
@@ -191,11 +191,11 @@ bool Migrator::performSyntacticPasses(SyntacticPassOptions Opts) {
   llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> DummyClangDiagIDs {
     new clang::DiagnosticIDs()
   };
-  auto ClangDiags =
-    std::make_unique<clang::DiagnosticsEngine>(DummyClangDiagIDs,
-                                                new clang::DiagnosticOptions,
-                                                new clang::DiagnosticConsumer(),
-                                                /*ShouldOwnClient=*/true);
+
+  clang::DiagnosticOptions diagOpts;
+  auto ClangDiags = std::make_unique<clang::DiagnosticsEngine>(
+      DummyClangDiagIDs, diagOpts, new clang::DiagnosticConsumer(),
+      /*ShouldOwnClient=*/true);
 
   clang::SourceManager ClangSourceManager { *ClangDiags, ClangFileManager };
   clang::LangOptions ClangLangOpts;
diff --git a/lib/Option/Options.cpp b/lib/Option/Options.cpp
index 6a159de3150ba..5a334e131bcc1 100644
--- a/lib/Option/Options.cpp
+++ b/lib/Option/Options.cpp
@@ -16,15 +16,16 @@
 #include "llvm/Option/OptTable.h"
 #include "llvm/Option/Option.h"
 
-using namespace swift::options;
-using namespace llvm::opt;
+#define OPTTABLE_STR_TABLE_CODE
+#include "swift/Option/Options.inc"
+#undef OPTTABLE_STR_TABLE_CODE
 
-#define PREFIX(NAME, VALUE)                                                    \
-  constexpr llvm::StringLiteral NAME##_init[] = VALUE;                         \
-  constexpr llvm::ArrayRef<llvm::StringLiteral> NAME(                          \
-      NAME##_init, std::size(NAME##_init) - 1);
+#define OPTTABLE_PREFIXES_TABLE_CODE
 #include "swift/Option/Options.inc"
-#undef PREFIX
+#undef OPTTABLE_PREFIXES_TABLE_CODE
+
+using namespace swift::options;
+using namespace llvm::opt;
 
 static const llvm::opt::GenericOptTable::Info InfoTable[] = {
 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
@@ -36,7 +37,8 @@ namespace {
 
 class SwiftOptTable : public llvm::opt::GenericOptTable {
 public:
-  SwiftOptTable() : GenericOptTable(InfoTable) {}
+  SwiftOptTable()
+      : GenericOptTable(OptionStrTable, OptionPrefixesTable, InfoTable) {}
 };
 
 } // end anonymous namespace
diff --git a/lib/PrintAsClang/_SwiftStdlibCxxOverlay.h b/lib/PrintAsClang/_SwiftStdlibCxxOverlay.h
index a29ec356cb9e8..885bbb3773ad8 100644
--- a/lib/PrintAsClang/_SwiftStdlibCxxOverlay.h
+++ b/lib/PrintAsClang/_SwiftStdlibCxxOverlay.h
@@ -171,8 +171,13 @@ struct SymbolicP {
 } __attribute__((packed));
 
 SWIFT_INLINE_THUNK const void *_Nullable getErrorMetadata() {
+// We do not care about these symbols being duplicated across multiple shared
+// libraries for now.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunique-object-duplication"
   static SymbolicP errorSymbol;
   static int *_Nonnull got_ss5ErrorMp = &$ss5ErrorMp;
+#pragma clang diagnostic pop
   errorSymbol._1 = 2;
   errorSymbol._2 =
       static_cast<uint32_t>(reinterpret_cast<uintptr_t>(&got_ss5ErrorMp) -
diff --git a/lib/SIL/IR/SILConstants.cpp b/lib/SIL/IR/SILConstants.cpp
index 3996a1c3694c4..7005fd7e2965b 100644
--- a/lib/SIL/IR/SILConstants.cpp
+++ b/lib/SIL/IR/SILConstants.cpp
@@ -455,7 +455,7 @@ struct AggregateSymbolicValue final
     auto *aggregate =
         ::new (rawMem) AggregateSymbolicValue(aggregateType, members.size());
     std::uninitialized_copy(members.begin(), members.end(),
-                            aggregate->getTrailingObjects<SymbolicValue>());
+                            aggregate->getTrailingObjects());
     return aggregate;
   }
 
@@ -464,7 +464,7 @@ struct AggregateSymbolicValue final
 
   /// Return the symbolic values of members.
   ArrayRef<SymbolicValue> getMemberValues() const {
-    return {getTrailingObjects<SymbolicValue>(), numElements};
+    return getTrailingObjects(numElements);
   }
 
   // This is used by the llvm::TrailingObjects base class.
@@ -531,12 +531,12 @@ struct alignas(SourceLoc) UnknownSymbolicValue final
     auto value = ::new (rawMem) UnknownSymbolicValue(
         node, reason, static_cast<unsigned>(elements.size()));
     std::uninitialized_copy(elements.begin(), elements.end(),
-                            value->getTrailingObjects<SourceLoc>());
+                            value->getTrailingObjects());
     return value;
   }
 
   ArrayRef<SourceLoc> getCallStack() const {
-    return {getTrailingObjects<SourceLoc>(), callStackSize};
+    return getTrailingObjects(callStackSize);
   }
 
   // This is used by the llvm::TrailingObjects base class.
@@ -657,14 +657,14 @@ struct DerivedAddressValue final
     auto dav =
         ::new (rawMem) DerivedAddressValue(memoryObject, elements.size());
     std::uninitialized_copy(elements.begin(), elements.end(),
-                            dav->getTrailingObjects<unsigned>());
+                            dav->getTrailingObjects());
     return dav;
   }
 
   /// Return the access path for this derived address, which is an array of
   /// indices drilling into the memory object.
   ArrayRef<unsigned> getElements() const {
-    return {getTrailingObjects<unsigned>(), numElements};
+    return getTrailingObjects(numElements);
   }
 
   // This is used by the llvm::TrailingObjects base class.
@@ -749,13 +749,13 @@ struct SymbolicArrayStorage final
     auto *storage =
         ::new (rawMem) SymbolicArrayStorage(elementType, elements.size());
     std::uninitialized_copy(elements.begin(), elements.end(),
-                            storage->getTrailingObjects<SymbolicValue>());
+                            storage->getTrailingObjects());
     return storage;
   }
 
   /// Return the stored elements.
   ArrayRef<SymbolicValue> getElements() const {
-    return {getTrailingObjects<SymbolicValue>(), numElements};
+    return getTrailingObjects(numElements);
   }
 
   // This is used by the llvm::TrailingObjects base class.
@@ -872,9 +872,8 @@ SymbolicClosure *SymbolicClosure::create(SILFunction *target,
   //  Placement initialize the object.
   auto closure = ::new (rawMem) SymbolicClosure(
       target, args.size(), substMap, closureInst, hasNonConstantCapture);
-  std::uninitialized_copy(
-      args.begin(), args.end(),
-      closure->getTrailingObjects<SymbolicClosureArgument>());
+  std::uninitialized_copy(args.begin(), args.end(),
+                          closure->getTrailingObjects());
   return closure;
 }
 
diff --git a/lib/SIL/IR/SILInstruction.cpp b/lib/SIL/IR/SILInstruction.cpp
index 9c0d392ae5f42..137c57371e0e5 100644
--- a/lib/SIL/IR/SILInstruction.cpp
+++ b/lib/SIL/IR/SILInstruction.cpp
@@ -1026,15 +1026,15 @@ MemoryBehavior SILInstruction::getMemoryBehavior() const {
     // Handle LLVM intrinsic functions.
     const IntrinsicInfo &IInfo = BI->getIntrinsicInfo();
     if (IInfo.ID != llvm::Intrinsic::not_intrinsic) {
-      auto IAttrs = IInfo.getOrCreateAttributes(getModule().getASTContext());
+      auto &IAttrs = IInfo.getOrCreateFnAttributes(getModule().getASTContext());
       auto MemEffects = IAttrs.getMemoryEffects();
       // Read-only.
       if (MemEffects.onlyReadsMemory() &&
-          IAttrs.hasFnAttr(llvm::Attribute::NoUnwind))
+          IAttrs.hasAttribute(llvm::Attribute::NoUnwind))
         return MemoryBehavior::MayRead;
       // Read-none?
       return MemEffects.doesNotAccessMemory() &&
-                     IAttrs.hasFnAttr(llvm::Attribute::NoUnwind)
+                     IAttrs.hasAttribute(llvm::Attribute::NoUnwind)
                  ? MemoryBehavior::None
                  : MemoryBehavior::MayHaveSideEffects;
     }
diff --git a/lib/SIL/IR/SILInstructions.cpp b/lib/SIL/IR/SILInstructions.cpp
index 19892dafade05..06c61cc97af17 100644
--- a/lib/SIL/IR/SILInstructions.cpp
+++ b/lib/SIL/IR/SILInstructions.cpp
@@ -539,7 +539,7 @@ IncrementProfilerCounterInst *IncrementProfilerCounterInst::create(
       Loc, CounterIdx, PGOFuncNameLength, NumCounters, PGOFuncHash);
 
   std::uninitialized_copy(PGOFuncName.begin(), PGOFuncName.end(),
-                          Inst->getTrailingObjects<char>());
+                          Inst->getTrailingObjects());
   return Inst;
 }
 
@@ -554,7 +554,7 @@ SpecifyTestInst *SpecifyTestInst::create(SILDebugLocation Loc,
       ::new (Buffer) SpecifyTestInst(Loc, ArgumentsSpecificationLength);
   std::uninitialized_copy(ArgumentsSpecification.begin(),
                           ArgumentsSpecification.end(),
-                          Inst->getTrailingObjects<char>());
+                          Inst->getTrailingObjects());
   return Inst;
 }
 
@@ -1121,7 +1121,7 @@ IntegerLiteralInst::IntegerLiteralInst(SILDebugLocation Loc, SILType Ty,
     : InstructionBase(Loc, Ty) {
   sharedUInt32().IntegerLiteralInst.numBits = Value.getBitWidth();
   std::uninitialized_copy_n(Value.getRawData(), Value.getNumWords(),
-                            getTrailingObjects<llvm::APInt::WordType>());
+                            getTrailingObjects());
 }
 
 IntegerLiteralInst *IntegerLiteralInst::create(SILDebugLocation Loc,
@@ -1182,8 +1182,7 @@ IntegerLiteralInst *IntegerLiteralInst::create(IntegerLiteralExpr *E,
 /// getValue - Return the APInt for the underlying integer literal.
 APInt IntegerLiteralInst::getValue() const {
   auto numBits = sharedUInt32().IntegerLiteralInst.numBits;
-  return APInt(numBits, {getTrailingObjects<llvm::APInt::WordType>(),
-                         getWordsForBitWidth(numBits)});
+  return APInt(numBits, getTrailingObjects(getWordsForBitWidth(numBits)));
 }
 
 FloatLiteralInst::FloatLiteralInst(SILDebugLocation Loc, SILType Ty,
@@ -1191,7 +1190,7 @@ FloatLiteralInst::FloatLiteralInst(SILDebugLocation Loc, SILType Ty,
     : InstructionBase(Loc, Ty) {
   sharedUInt32().FloatLiteralInst.numBits = Bits.getBitWidth();
   std::uninitialized_copy_n(Bits.getRawData(), Bits.getNumWords(),
-                            getTrailingObjects<llvm::APInt::WordType>());
+                            getTrailingObjects());
 }
 
 FloatLiteralInst *FloatLiteralInst::create(SILDebugLocation Loc, SILType Ty,
@@ -1222,8 +1221,7 @@ FloatLiteralInst *FloatLiteralInst::create(FloatLiteralExpr *E,
 
 APInt FloatLiteralInst::getBits() const {
   auto numBits = sharedUInt32().FloatLiteralInst.numBits;
-  return APInt(numBits, {getTrailingObjects<llvm::APInt::WordType>(),
-                         getWordsForBitWidth(numBits)});
+  return APInt(numBits, getTrailingObjects(getWordsForBitWidth(numBits)));
 }
 
 APFloat FloatLiteralInst::getValue() const {
@@ -1236,7 +1234,7 @@ StringLiteralInst::StringLiteralInst(SILDebugLocation Loc, StringRef Text,
     : InstructionBase(Loc, Ty) {
   sharedUInt8().StringLiteralInst.encoding = uint8_t(encoding);
   sharedUInt32().StringLiteralInst.length = Text.size();
-  memcpy(getTrailingObjects<char>(), Text.data(), Text.size());
+  memcpy(getTrailingObjects(), Text.data(), Text.size());
 
   // It is undefined behavior to feed ill-formed UTF-8 into `Swift.String`;
   // however, the compiler creates string literals in many places, so there's a
@@ -1262,7 +1260,7 @@ CondFailInst::CondFailInst(SILDebugLocation DebugLoc, SILValue Operand,
                            StringRef Message)
       : UnaryInstructionBase(DebugLoc, Operand),
         MessageSize(Message.size()) {
-  memcpy(getTrailingObjects<char>(), Message.data(), Message.size());
+  memcpy(getTrailingObjects(), Message.data(), Message.size());
 }
 
 CondFailInst *CondFailInst::create(SILDebugLocation DebugLoc, SILValue Operand,
@@ -3073,14 +3071,14 @@ KeyPathPattern::KeyPathPattern(CanGenericSignature signature,
     Signature(signature), RootType(rootType), ValueType(valueType),
     ObjCString(objcString)
 {
-  auto *componentsBuf = getTrailingObjects<KeyPathPatternComponent>();
+  auto *componentsBuf = getTrailingObjects();
   std::uninitialized_copy(components.begin(), components.end(),
                           componentsBuf);
 }
 
 ArrayRef<KeyPathPatternComponent>
 KeyPathPattern::getComponents() const {
-  return {getTrailingObjects<KeyPathPatternComponent>(), NumComponents};
+  return getTrailingObjects(NumComponents);
 }
 
 void KeyPathPattern::Profile(llvm::FoldingSetNodeID &ID,
@@ -3184,7 +3182,7 @@ KeyPathInst::KeyPathInst(SILDebugLocation Loc,
     Substitutions(Subs.getCanonical())
 {
   assert(allOperands.size() >= numPatternOperands);
-  auto *operandsBuf = getTrailingObjects<Operand>();
+  auto *operandsBuf = getTrailingObjects();
   for (unsigned i = 0; i < allOperands.size(); ++i) {
     ::new ((void*)&operandsBuf[i]) Operand(this, allOperands[i]);
   }
@@ -3197,7 +3195,7 @@ KeyPathInst::KeyPathInst(SILDebugLocation Loc,
 
 MutableArrayRef<Operand>
 KeyPathInst::getAllOperands() {
-  return {getTrailingObjects<Operand>(), numPatternOperands + numTypeDependentOperands};
+  return getTrailingObjects(numPatternOperands + numTypeDependentOperands);
 }
 
 KeyPathInst::~KeyPathInst() {
diff --git a/lib/SIL/IR/SILModule.cpp b/lib/SIL/IR/SILModule.cpp
index df0f588565155..ff87beb0d1b8d 100644
--- a/lib/SIL/IR/SILModule.cpp
+++ b/lib/SIL/IR/SILModule.cpp
@@ -888,8 +888,8 @@ void SILModule::notifyMovedInstruction(SILInstruction *inst,
 bool SILModule::isNoReturnBuiltinOrIntrinsic(Identifier Name) {
   const auto &IntrinsicInfo = getIntrinsicInfo(Name);
   if (IntrinsicInfo.ID != llvm::Intrinsic::not_intrinsic) {
-    return IntrinsicInfo.getOrCreateAttributes(getASTContext())
-        .hasFnAttr(llvm::Attribute::NoReturn);
+    return IntrinsicInfo.getOrCreateFnAttributes(getASTContext())
+        .hasAttribute(llvm::Attribute::NoReturn);
   }
   const auto &BuiltinInfo = getBuiltinInfo(Name);
   switch (BuiltinInfo.ID) {
diff --git a/lib/SIL/IR/SILVTable.cpp b/lib/SIL/IR/SILVTable.cpp
index c62e6d4764d00..241e127fb3ba8 100644
--- a/lib/SIL/IR/SILVTable.cpp
+++ b/lib/SIL/IR/SILVTable.cpp
@@ -95,8 +95,7 @@ SILVTable::SILVTable(ClassDecl *c, SILType classType,
                      SerializedKind_t serialized, ArrayRef<Entry> entries)
     : Class(c), classType(classType), SerializedKind(serialized),
       NumEntries(entries.size()) {
-  std::uninitialized_copy(entries.begin(), entries.end(),
-                          getTrailingObjects<Entry>());
+  std::uninitialized_copy(entries.begin(), entries.end(), getTrailingObjects());
 
   // Bump the reference count of functions referenced by this table.
   for (const Entry &entry : getEntries()) {
diff --git a/lib/SILOptimizer/Analysis/ARCAnalysis.cpp b/lib/SILOptimizer/Analysis/ARCAnalysis.cpp
index 4740b4b3090f4..702029bac29d3 100644
--- a/lib/SILOptimizer/Analysis/ARCAnalysis.cpp
+++ b/lib/SILOptimizer/Analysis/ARCAnalysis.cpp
@@ -104,7 +104,7 @@ static bool canApplyOfBuiltinUseNonTrivialValues(BuiltinInst *BInst) {
 
   auto &II = BInst->getIntrinsicInfo();
   if (II.ID != llvm::Intrinsic::not_intrinsic) {
-    auto attrs = II.getOrCreateAttributes(F->getASTContext());
+    auto &attrs = II.getOrCreateFnAttributes(F->getASTContext());
     if (attrs.getMemoryEffects().doesNotAccessMemory()) {
       for (auto &Op : BInst->getAllOperands()) {
         if (!Op.get()->getType().isTrivial(*F)) {
diff --git a/lib/SILOptimizer/Analysis/ColdBlockInfo.cpp b/lib/SILOptimizer/Analysis/ColdBlockInfo.cpp
index f42fe7b60d449..9fde5f1ea0431 100644
--- a/lib/SILOptimizer/Analysis/ColdBlockInfo.cpp
+++ b/lib/SILOptimizer/Analysis/ColdBlockInfo.cpp
@@ -441,7 +441,7 @@ bool ColdBlockInfo::isCold(const SILBasicBlock *BB) const {
 }
 
 void ColdBlockInfo::resetToCold(const SILBasicBlock *BB) {
-  auto &entry = EnergyMap.getOrInsertDefault(BB);
+  auto &entry = EnergyMap[BB];
   if (isColdEnergy(entry))
     return;
 
@@ -451,7 +451,7 @@ void ColdBlockInfo::resetToCold(const SILBasicBlock *BB) {
 }
 
 void ColdBlockInfo::set(const SILBasicBlock *BB, State::Temperature temp) {
-  auto &entry = EnergyMap.getOrInsertDefault(BB);
+  auto &entry = EnergyMap[BB];
   if (entry.contains(temp))
     return;
 
diff --git a/lib/Serialization/Deserialization.cpp b/lib/Serialization/Deserialization.cpp
index 4646e9b0c5ef8..703cabb4c970e 100644
--- a/lib/Serialization/Deserialization.cpp
+++ b/lib/Serialization/Deserialization.cpp
@@ -8489,7 +8489,8 @@ class SwiftToClangBasicReader :
     bool isRegularKeywordAttribute = readBool();
 
     clang::AttributeCommonInfo info(
-        name, scopeName, {rangeStart, rangeEnd}, scopeLoc, parsedKind,
+        name, clang::AttributeScopeInfo(scopeName, scopeLoc),
+        {rangeStart, rangeEnd}, parsedKind,
         {syntax, spellingListIndex, /*IsAlignas=*/false,
          isRegularKeywordAttribute});
 
@@ -8518,6 +8519,9 @@ class SwiftToClangBasicReader :
   clang::TypeCoupledDeclRefInfo readTypeCoupledDeclRefInfo() {
     llvm_unreachable("TypeCoupledDeclRefInfo shouldn't be reached from swift");
   }
+  clang::SpirvOperand readHLSLSpirvOperand() {
+    llvm_unreachable("SpirvOperand shouldn't be reached from swift");
+  }
 };
 
 } // end anonymous namespace
@@ -8773,7 +8777,7 @@ class LazyConformanceLoaderInfo final
 
   LazyConformanceLoaderInfo(ArrayRef<uint64_t> ids)
     : NumConformances(ids.size()) {
-    auto buffer = getTrailingObjects<ProtocolConformanceID>();
+    auto *buffer = getTrailingObjects();
     for (unsigned i = 0, e = ids.size(); i != e; ++i)
       buffer[i] = ProtocolConformanceID(ids[i]);
   }
@@ -8791,8 +8795,7 @@ class LazyConformanceLoaderInfo final
 
   ArrayRef<ProtocolConformanceID> claim() {
     // TODO: free the memory here (if it's not used in multiple places?)
-    return llvm::ArrayRef(getTrailingObjects<ProtocolConformanceID>(),
-                          NumConformances);
+    return getTrailingObjects(NumConformances);
   }
 };
 } // end anonymous namespace
diff --git a/lib/Serialization/Serialization.cpp b/lib/Serialization/Serialization.cpp
index a53aee6299c4d..413d7efe3adca 100644
--- a/lib/Serialization/Serialization.cpp
+++ b/lib/Serialization/Serialization.cpp
@@ -6317,6 +6317,9 @@ class ClangToSwiftBasicWriter :
   void writeTypeCoupledDeclRefInfo(clang::TypeCoupledDeclRefInfo info) {
     llvm_unreachable("TypeCoupledDeclRefInfo shouldn't be reached from swift");
   }
+  void writeHLSLSpirvOperand(clang::SpirvOperand) {
+    llvm_unreachable("SpirvOperand shouldn't be reached from swift");
+  }
 };
 
 }
diff --git a/lib/StaticMirror/ObjectFileContext.cpp b/lib/StaticMirror/ObjectFileContext.cpp
index 4ad8d5c3ce3e5..ed8239ebb183d 100644
--- a/lib/StaticMirror/ObjectFileContext.cpp
+++ b/lib/StaticMirror/ObjectFileContext.cpp
@@ -29,6 +29,7 @@
 #include "llvm/Object/ELFTypes.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/Object/RelocationResolver.h"
+#include "llvm/Object/Wasm.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/StringSaver.h"
 
@@ -266,6 +267,38 @@ void Image::scanCOFF(const llvm::object::COFFObjectFile *O) {
   Segments.push_back({HeaderAddress, O->getData()});
 }
 
+void Image::scanWasm(const llvm::object::WasmObjectFile *O) {
+  HeaderAddress = 0;
+
+  auto resolver = getRelocationResolver(*O);
+  auto resolverSupports = resolver.first;
+  auto resolve = resolver.second;
+
+  if (!resolverSupports || !resolve)
+    return;
+
+  for (auto SectionRef : O->sections()) {
+    auto Section = O->getWasmSection(SectionRef);
+    for (auto &r : Section.Relocations) {
+      auto sym = O->symbol_begin();
+      for (unsigned i = 0; sym != O->symbol_end() && i < r.Index; ++i)
+        ++sym;
+      if (sym == O->symbol_end())
+        continue;
+      auto &wsym = O->getWasmSymbol(*sym);
+      if (!resolverSupports(r.Type)) {
+        llvm::errs() << "Unsupported +" << r.Offset << " " << wsym.Info.Name
+                     << " +" << r.Addend << "\n";
+        continue;
+      }
+      uint64_t offset = resolve(r.Type, r.Offset, 0, 0, r.Addend);
+      DynamicRelocations.insert({r.Offset, {wsym.Info.Name, offset}});
+    }
+  }
+
+  Segments.push_back({HeaderAddress, O->getData()});
+}
+
 bool Image::isMachOWithPtrAuth() const {
   auto macho = dyn_cast<llvm::object::MachOObjectFile>(O);
   if (!macho)
@@ -286,6 +319,8 @@ Image::Image(const llvm::object::ObjectFile *O) : O(O) {
     scanELF(elf);
   } else if (auto coff = dyn_cast<llvm::object::COFFObjectFile>(O)) {
     scanCOFF(coff);
+  } else if (auto wasm = dyn_cast<llvm::object::WasmObjectFile>(O)) {
+    scanWasm(wasm);
   } else {
     fputs("unsupported image format\n", stderr);
     abort();
diff --git a/test/CAS/debug_info_pcm.swift b/test/CAS/debug_info_pcm.swift
new file mode 100644
index 0000000000000..2bd1f56b8eb43
--- /dev/null
+++ b/test/CAS/debug_info_pcm.swift
@@ -0,0 +1,43 @@
+// REQUIRES: OS=macosx
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+
+// RUN: %target-swift-frontend -scan-dependencies -module-name Test -module-cache-path %t/clang-module-cache -O \
+// RUN:   -disable-implicit-string-processing-module-import -disable-implicit-concurrency-module-import \
+// RUN:   %t/test.swift -o %t/deps.json -cache-compile-job -cas-path %t/cas -I %t/include
+
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:SwiftShims > %t/shim.cmd
+// RUN: %swift_frontend_plain @%t/shim.cmd
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:B > %t/B.cmd
+// RUN: %swift_frontend_plain @%t/B.cmd
+// RUN: %{python} %S/Inputs/BuildCommandExtractor.py %t/deps.json clang:A > %t/A.cmd
+// RUN: %swift_frontend_plain @%t/A.cmd
+// RUN: %{python} %S/Inputs/SwiftDepsExtractor.py %t/deps.json clang:A modulePath > %t/A.path
+
+// RUN: dwarfdump --debug-info @%t/A.path | %FileCheck %s
+
+// CHECK: DW_AT_GNU_dwo_name
+// CHECK-SAME: BUILD_DIR
+
+//--- test.swift
+import A
+
+//--- include/a.h
+#include "b.h"
+struct A {
+  int a;
+};
+
+//--- include/b.h
+void b(void);
+
+//--- include/module.modulemap
+module A {
+  header "a.h"
+  export *
+}
+
+module B {
+  header "b.h"
+  export *
+}
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 34eaf125dfc02..98fdb1942b5fe 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -135,7 +135,8 @@ function(get_test_dependencies SDK result_var_name)
       llvm-strings
       llvm-readtapi
       not
-      split-file)
+      split-file
+      yaml2obj)
   endif()
 
   if(("${SDK}" STREQUAL "IOS") OR
diff --git a/test/ClangImporter/broken-modules.swift b/test/ClangImporter/broken-modules.swift
index 7ca1bda9e8ca6..288d59791787b 100644
--- a/test/ClangImporter/broken-modules.swift
+++ b/test/ClangImporter/broken-modules.swift
@@ -1,6 +1,6 @@
 // RUN: not %target-swift-frontend -typecheck %s -I %S/Inputs/custom-modules/ -enable-objc-interop -show-diagnostics-after-fatal -D MISSING_FROM_MODULE -o /dev/null 2>&1 | %FileCheck -check-prefix CHECK-MODULE-MAP %s
 // RUN: not %target-swift-frontend -typecheck %s -I %S/Inputs/custom-modules/ -enable-objc-interop -show-diagnostics-after-fatal -o /dev/null 2>&1 | %FileCheck -check-prefix CHECK -check-prefix CHECK-DIRECT %s
-// RUN: not %target-swift-frontend -typecheck %s -I %S/Inputs/custom-modules/ -enable-objc-interop -show-diagnostics-after-fatal -D INDIRECT -o /dev/null 2>&1 | %FileCheck -check-prefix CHECK -check-prefix CHECK-INDIRECT %s
+// RUN: not %target-swift-frontend -typecheck %s -I %S/Inputs/custom-modules/ -I %S/Inputs/custom-modules/more-custom-modules -enable-objc-interop -show-diagnostics-after-fatal -D INDIRECT -o /dev/null 2>&1 | %FileCheck -check-prefix CHECK -check-prefix CHECK-INDIRECT %s
 
 // FIXME: not every test here depends on Objective-C syntax, this test can be split.
 
diff --git a/test/DebugInfo/EagerTypeMetadata.swift b/test/DebugInfo/EagerTypeMetadata.swift
index 1f53cb5cae90e..e216d788fc7de 100644
--- a/test/DebugInfo/EagerTypeMetadata.swift
+++ b/test/DebugInfo/EagerTypeMetadata.swift
@@ -13,6 +13,6 @@ public class C<T>
 }
 // CHECK: !DIDerivedType(tag: DW_TAG_typedef, name: "T",
 // CHECK-SAME:           baseType: ![[PTRTY:[0-9]+]]
-// CHECK: ![[PTRTY]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "$sBpD", baseType: null, size: {{64|32}}, flags: DIFlagArtificial | DIFlagObjectPointer)
+// CHECK: ![[PTRTY]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "$sBpD", baseType: null, size: {{64|32}})
 // CHECK: ![[LOC]] = !DILocation(line: 0,
 
diff --git a/test/DebugInfo/Imports.swift b/test/DebugInfo/Imports.swift
index ce98458c03040..d79a5fe62a37c 100644
--- a/test/DebugInfo/Imports.swift
+++ b/test/DebugInfo/Imports.swift
@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-frontend -emit-module-path %t/basic.swiftmodule %S/basic.swift
+// RUN: %target-swift-frontend -emit-module-path %t/advanced.swiftmodule %S/advanced.swift
 
 // RUN: %target-swift-frontend -emit-ir -module-name Foo %s -I %t -g -o - | %FileCheck %s
 // RUN: %target-swift-frontend -c -module-name Foo %s -I %t -g -o %t.o
@@ -10,13 +10,13 @@
 // CHECK-DAG: ![[THISFILE]] = !DIFile(filename: "{{.*}}test{{/|\\\\}}DebugInfo{{/|\\\\}}Imports.swift",
 // CHECK-DAG: ![[SWIFTMODULE:[0-9]+]] = !DIModule({{.*}}, name: "Swift"
 // CHECK-DAG: !DIImportedEntity(tag: DW_TAG_imported_module, scope: ![[THISFILE]], entity: ![[SWIFTMODULE]]
-// CHECK-DAG: ![[BASICMODULE:[0-9]+]] = !DIModule({{.*}}, name: "basic"
+// CHECK-DAG: ![[BASICMODULE:[0-9]+]] = !DIModule({{.*}}, name: "advanced"
 // CHECK-DAG: !DIImportedEntity(tag: DW_TAG_imported_module, scope: ![[THISFILE]], entity: ![[BASICMODULE]]
-import basic
+import advanced
 import typealias Swift.Optional
 
 func markUsed<T>(_ t: T) {}
-markUsed(basic.foo(1, 2))
+markUsed(advanced.foo(1, 2))
 
 // DWARF: .debug_info
 // DWARF: DW_TAG_module
@@ -26,7 +26,7 @@ markUsed(basic.foo(1, 2))
 // DWARF:   DW_AT_name ("Swift")
 // DWARF:   DW_AT_LLVM_include_path
 // DWARF: DW_TAG_module
-// DWARF:   DW_AT_name ("basic")
+// DWARF:   DW_AT_name ("advanced")
 
 // DWARF-NOT: "Swift.Optional"
 
diff --git a/test/DebugInfo/ParseableInterfaceImports.swift b/test/DebugInfo/ParseableInterfaceImports.swift
index e05c0533a8411..1a13c2543d56c 100644
--- a/test/DebugInfo/ParseableInterfaceImports.swift
+++ b/test/DebugInfo/ParseableInterfaceImports.swift
@@ -1,23 +1,23 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-frontend-typecheck %S/basic.swift \
-// RUN:    -emit-module-interface-path %t/basic.swiftinterface
+// RUN: %target-swift-frontend-typecheck %S/advanced.swift \
+// RUN:    -emit-module-interface-path %t/advanced.swiftinterface
 // RUN: %target-swift-frontend -emit-ir -module-name Foo %s -I %t -g -o - \
 // RUN:    | %FileCheck %s
 // RUN: %target-swift-frontend -emit-ir -module-name Foo %s -I %t -g -o - \
 // RUN:    -sdk %t | %FileCheck %s --check-prefix=SDK
 
-import basic
+import advanced
 
-// CHECK: !DIModule(scope: null, name: "basic",
+// CHECK: !DIModule(scope: null, name: "advanced",
 // CHECK-SAME:      includePath: "
-// CHECK-SAME:      basic.swiftinterface"
+// CHECK-SAME:      advanced.swiftinterface"
 
 // Even if the module interface is in the SDK, we still return the path
 // to the swiftinterface.
-// SDK:   !DIModule(scope: null, name: "basic",
+// SDK:   !DIModule(scope: null, name: "advanced",
 // SDK-SAME:        includePath: "
-// SDK-SAME:        basic{{.*}}.swiftinterface"
+// SDK-SAME:        advanced{{.*}}.swiftinterface"
 
 func markUsed<T>(_ t: T) {}
-markUsed(basic.foo(1, 2))
+markUsed(advanced.foo(1, 2))
 
diff --git a/test/DebugInfo/advanced.swift b/test/DebugInfo/advanced.swift
new file mode 100644
index 0000000000000..7fe50b54106b1
--- /dev/null
+++ b/test/DebugInfo/advanced.swift
@@ -0,0 +1,81 @@
+// A (no longer) basic test for debug info.
+// --------------------------------------------------------------------
+// Verify that we don't emit any type info with -gline-tables-only.
+// RUN: %target-swift-frontend %s -emit-ir -gline-tables-only -o - \
+// RUN:   | %FileCheck %s --check-prefix CHECK-LINETABLES
+// CHECK: !dbg
+// CHECK-LINETABLES-NOT: DI{{.*}}Variable
+// CHECK-LINETABLES-NOT: DW_TAG_structure_type
+// CHECK-LINETABLES-NOT: DIBasicType
+// --------------------------------------------------------------------
+// Now check that we do generate line+scope info with -g.
+// RUN: %target-swift-frontend %/s -emit-ir -g -o - \
+// RUN:   | %FileCheck %s --check-prefixes CHECK,DWARF-CHECK
+// --------------------------------------------------------------------
+// Currently -gdwarf-types should give the same results as -g.
+// RUN: %target-swift-frontend  %/s -emit-ir -gdwarf-types -o - \
+// RUN:   | %FileCheck %s --check-prefixes CHECK,DWARF-CHECK
+// --------------------------------------------------------------------
+// Verify that -g -debug-info-format=dwarf gives the same results as -g.
+// RUN: %target-swift-frontend %/s -emit-ir -g -debug-info-format=dwarf -o - \
+// RUN:   | %FileCheck %s --check-prefixes CHECK,DWARF-CHECK
+// --------------------------------------------------------------------
+// RUN: %target-swift-frontend %/s -emit-ir -g -debug-info-format=codeview -o - \
+// RUN:   | %FileCheck %s --check-prefixes CHECK,CV-CHECK
+// --------------------------------------------------------------------
+//
+// CHECK: foo
+// CHECK-DAG: ret{{.*}}, !dbg ![[RET:[0-9]+]]
+// CHECK-DAG: ![[FOO:[0-9]+]] = distinct !DISubprogram(name: "foo",{{.*}} line: [[@LINE+2]],{{.*}} type: ![[FOOTYPE:[0-9]+]]
+public
+func foo(_ a: Int64, _ b: Int64) -> Int64 {
+     var a = a
+     var b = b
+     // CHECK-DAG: ![[ALOC:.*]] = !DILocation(line: [[@LINE-3]],{{.*}} scope: ![[FOO]])
+     // Check that a is the first and b is the second argument.
+     // CHECK-DAG: store i64 %0, ptr [[AADDR:.*]], align
+     // CHECK-DAG: store i64 %1, ptr [[BADDR:.*]], align
+     // CHECK-DAG: [[AVAL:%.*]] = getelementptr inbounds {{.*}}, [[AMEM:.*]], i32 0, i32 0
+     // CHECK-DAG: [[BVAL:%.*]] = getelementptr inbounds {{.*}}, [[BMEM:.*]], i32 0, i32 0
+     // CHECK-DAG: #dbg_declare(ptr [[AADDR]], ![[AARG:.*]], !DIExpression(), ![[ALOC]]
+     // CHECK-DAG: #dbg_declare(ptr [[BADDR]], ![[BARG:.*]], !DIExpression()
+     // CHECK-DAG: ![[AARG]] = !DILocalVariable(name: "a", arg: 1
+     // CHECK-DAG: ![[BARG]] = !DILocalVariable(name: "b", arg: 2
+     if b != 0 {
+       // CHECK-DAG: !DILexicalBlock({{.*}} line: [[@LINE-1]]
+       // Transparent inlined multiply:
+       // CHECK-DAG: smul{{.*}}, !dbg ![[MUL:[0-9]+]]
+       // CHECK-DAG: [[MUL]] = !DILocation(line: [[@LINE+1]],
+       return a*b
+     } else {
+       // CHECK-DAG: ![[PARENT:[0-9]+]] = distinct !DILexicalBlock({{.*}} line: [[@LINE-1]]
+       // CHECK-DAG: ![[VARSCOPE:[0-9]+]] = distinct !DILexicalBlock({{.*}} line: [[@LINE+1]]
+       var c: Int64 = 42
+       // CHECK-DAG: ![[CONDITION:[0-9]+]] = distinct !DILexicalBlock(scope: ![[VARSCOPE]], {{.*}}, line: [[@LINE+1]]
+       if a == 0 {
+         // CHECK-DAG: !DILexicalBlock(scope: ![[CONDITION]], {{.*}}, line: [[@LINE-1]]
+         // What about a nested scope?
+         return 0
+       }
+       return c
+     }
+}
+
+// CHECK-DAG: ![[MAINFILE:[0-9]+]] = !DIFile(filename: "{{.*}}DebugInfo/advanced.swift", directory: "{{.*}}")
+// CHECK-DAG: !DICompileUnit(language: DW_LANG_Swift, file: ![[MAINFILE]],{{.*}} producer: "{{.*}}Swift version{{.*}},{{.*}}
+// CHECK-DAG: !DISubprogram(name: "main", {{.*}}file: ![[MAINFILE]],
+
+// Function type for foo.
+// CHECK-DAG: ![[FOOTYPE]] = !DISubroutineType(types: ![[PARAMTYPES:[0-9]+]])
+// CHECK-DAG: ![[INT64:.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Int64", {{.*}}, identifier: "$ss5Int64VD")
+// CHECK-DAG: ![[PARAMTYPES]] = !{![[INT64]], ![[INT64]], ![[INT64]]}
+// Import of the main module with the implicit name.
+// CHECK-DAG: !DIImportedEntity(tag: DW_TAG_imported_module, scope: ![[MAINFILE]], entity: ![[MAINMODULE:[0-9]+]], file: ![[MAINFILE]])
+// CHECK-DAG: ![[MAINMODULE]] = !DIModule({{.*}}, name: "advanced"
+
+// DWARF Version
+// DWARF-CHECK-DAG:  i32 7, !"Dwarf Version", i32 4}
+// CV-CHECK-DAG: i32 2, !"CodeView", i32 1}
+
+// Debug Info Version
+// CHECK-DAG:  i32 2, !"Debug Info Version", i32
diff --git a/test/DebugInfo/basic.swift b/test/DebugInfo/basic.swift
index ca64ef87f9bf2..8f2ff92818b67 100644
--- a/test/DebugInfo/basic.swift
+++ b/test/DebugInfo/basic.swift
@@ -1,6 +1,8 @@
-// A (no longer) basic test for debug info.
+// A basic test for debug info.
+// UNSUPPORTED: OS=windows-msvc
 // --------------------------------------------------------------------
-// Verify that we don't emit any debug info by default.
+// Verify that we don't emit any debug info by default. This test has a
+// specific Windows implementation in debug_basic_windows.swift.
 // RUN: %target-swift-frontend %s -emit-ir -o - \
 // RUN:   | %FileCheck %s --check-prefix NDEBUG
 // NDEBUG: source_filename
@@ -10,83 +12,7 @@
 // Verify that we don't emit any debug info with -gnone.
 // RUN: %target-swift-frontend %s -emit-ir -gnone -o - \
 // RUN:   | %FileCheck %s --check-prefix NDEBUG
-// --------------------------------------------------------------------
-// Verify that we don't emit any type info with -gline-tables-only.
-// RUN: %target-swift-frontend %s -emit-ir -gline-tables-only -o - \
-// RUN:   | %FileCheck %s --check-prefix CHECK-LINETABLES
-// CHECK: !dbg
-// CHECK-LINETABLES-NOT: DI{{.*}}Variable
-// CHECK-LINETABLES-NOT: DW_TAG_structure_type
-// CHECK-LINETABLES-NOT: DIBasicType
-// --------------------------------------------------------------------
-// Now check that we do generate line+scope info with -g.
-// RUN: %target-swift-frontend %/s -emit-ir -g -o - \
-// RUN:   | %FileCheck %s --check-prefixes CHECK,DWARF-CHECK
-// --------------------------------------------------------------------
-// Currently -gdwarf-types should give the same results as -g.
-// RUN: %target-swift-frontend  %/s -emit-ir -gdwarf-types -o - \
-// RUN:   | %FileCheck %s --check-prefixes CHECK,DWARF-CHECK
-// --------------------------------------------------------------------
-// Verify that -g -debug-info-format=dwarf gives the same results as -g.
-// RUN: %target-swift-frontend %/s -emit-ir -g -debug-info-format=dwarf -o - \
-// RUN:   | %FileCheck %s --check-prefixes CHECK,DWARF-CHECK
-// --------------------------------------------------------------------
-// RUN: %target-swift-frontend %/s -emit-ir -g -debug-info-format=codeview -o - \
-// RUN:   | %FileCheck %s --check-prefixes CHECK,CV-CHECK
-// --------------------------------------------------------------------
-//
-// CHECK: foo
-// CHECK-DAG: ret{{.*}}, !dbg ![[RET:[0-9]+]]
-// CHECK-DAG: ![[FOO:[0-9]+]] = distinct !DISubprogram(name: "foo",{{.*}} line: [[@LINE+2]],{{.*}} type: ![[FOOTYPE:[0-9]+]]
-public
-func foo(_ a: Int64, _ b: Int64) -> Int64 {
-     var a = a
-     var b = b
-     // CHECK-DAG: ![[ALOC:.*]] = !DILocation(line: [[@LINE-3]],{{.*}} scope: ![[FOO]])
-     // Check that a is the first and b is the second argument.
-     // CHECK-DAG: store i64 %0, ptr [[AADDR:.*]], align
-     // CHECK-DAG: store i64 %1, ptr [[BADDR:.*]], align
-     // CHECK-DAG: [[AVAL:%.*]] = getelementptr inbounds {{.*}}, [[AMEM:.*]], i32 0, i32 0
-     // CHECK-DAG: [[BVAL:%.*]] = getelementptr inbounds {{.*}}, [[BMEM:.*]], i32 0, i32 0
-     // CHECK-DAG: #dbg_declare(ptr [[AADDR]], ![[AARG:.*]], !DIExpression(), ![[ALOC]]
-     // CHECK-DAG: #dbg_declare(ptr [[BADDR]], ![[BARG:.*]], !DIExpression()
-     // CHECK-DAG: ![[AARG]] = !DILocalVariable(name: "a", arg: 1
-     // CHECK-DAG: ![[BARG]] = !DILocalVariable(name: "b", arg: 2
-     if b != 0 {
-       // CHECK-DAG: !DILexicalBlock({{.*}} line: [[@LINE-1]]
-       // Transparent inlined multiply:
-       // CHECK-DAG: smul{{.*}}, !dbg ![[MUL:[0-9]+]]
-       // CHECK-DAG: [[MUL]] = !DILocation(line: [[@LINE+1]],
-       return a*b
-     } else {
-       // CHECK-DAG: ![[PARENT:[0-9]+]] = distinct !DILexicalBlock({{.*}} line: [[@LINE-1]]
-       // CHECK-DAG: ![[VARSCOPE:[0-9]+]] = distinct !DILexicalBlock({{.*}} line: [[@LINE+1]]
-       var c: Int64 = 42
-       // CHECK-DAG: ![[CONDITION:[0-9]+]] = distinct !DILexicalBlock(scope: ![[VARSCOPE]], {{.*}}, line: [[@LINE+1]]
-       if a == 0 {
-         // CHECK-DAG: !DILexicalBlock(scope: ![[CONDITION]], {{.*}}, line: [[@LINE-1]]
-         // What about a nested scope?
-         return 0
-       }
-       return c
-     }
-}
-
-// CHECK-DAG: ![[MAINFILE:[0-9]+]] = !DIFile(filename: "{{.*}}DebugInfo/basic.swift", directory: "{{.*}}")
-// CHECK-DAG: !DICompileUnit(language: DW_LANG_Swift, file: ![[MAINFILE]],{{.*}} producer: "{{.*}}Swift version{{.*}},{{.*}}
-// CHECK-DAG: !DISubprogram(name: "main", {{.*}}file: ![[MAINFILE]],
-
-// Function type for foo.
-// CHECK-DAG: ![[FOOTYPE]] = !DISubroutineType(types: ![[PARAMTYPES:[0-9]+]])
-// CHECK-DAG: ![[INT64:.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Int64", {{.*}}, identifier: "$ss5Int64VD")
-// CHECK-DAG: ![[PARAMTYPES]] = !{![[INT64]], ![[INT64]], ![[INT64]]}
-// Import of the main module with the implicit name.
-// CHECK-DAG: !DIImportedEntity(tag: DW_TAG_imported_module, scope: ![[MAINFILE]], entity: ![[MAINMODULE:[0-9]+]], file: ![[MAINFILE]])
-// CHECK-DAG: ![[MAINMODULE]] = !DIModule({{.*}}, name: "basic"
-
-// DWARF Version
-// DWARF-CHECK-DAG:  i32 7, !"Dwarf Version", i32 4}
-// CV-CHECK-DAG: i32 2, !"CodeView", i32 1}
-
-// Debug Info Version
-// CHECK-DAG:  i32 2, !"Debug Info Version", i32
+public func foo() -> Int {
+  let bar = 1
+  return bar
+}
\ No newline at end of file
diff --git a/test/DebugInfo/basic_windows.swift b/test/DebugInfo/basic_windows.swift
new file mode 100644
index 0000000000000..e2195b08a1c12
--- /dev/null
+++ b/test/DebugInfo/basic_windows.swift
@@ -0,0 +1,17 @@
+// A basic test for debug info.
+// REQUIRES: OS=windows-msvc
+// --------------------------------------------------------------------
+// Verify that, by default, we exactly emit 1 DICompileUnit entry without dwoId.
+// On Windows, we always emit minimal DebugInfo to match MSVC's behavior:
+// See https://github.com/llvm/llvm-project/pull/142970 for more details.
+// RUN: %target-swift-frontend %s -emit-ir -o - \
+// RUN:   | %FileCheck %s --check-prefix NDEBUG
+// NDEBUG: source_filename
+// NDEBUG: !DICompileUnit(
+// NDEBUG-NOT: dwoId:
+// NDEBUG-SAME: )
+// NDEBUG-NOT: !DICompileUnit(
+public func foo() -> Int {
+  let bar = 1
+  return bar
+}
diff --git a/test/IRGen/annotated_cond_fail.swift b/test/IRGen/annotated_cond_fail.swift
index bb754384aa3c9..ef50e578426da 100644
--- a/test/IRGen/annotated_cond_fail.swift
+++ b/test/IRGen/annotated_cond_fail.swift
@@ -19,7 +19,7 @@ public func test(_ a: [Int], _ i: Int) -> Int {
 
 // CHECK:  [[SIZE_ADDR:%.*]] = getelementptr
 // CHECK:  [[SIZE:%.*]] = load i64, ptr [[SIZE_ADDR]]
-// CHECK:  [[C1:%.*]] = icmp ult i64 [[IDX]], [[SIZE]]
+// CHECK:  [[C1:%.*]] = icmp samesign ult i64 [[IDX]], [[SIZE]]
 // CHECK:  br i1 [[C1]], {{.*}}!annotation ![[ARRAY_INDEX_OUT_OF_BOUNDS]]
 
 
diff --git a/test/IRGen/argument_attrs.sil b/test/IRGen/argument_attrs.sil
index ee82eb7eb4ddb..4e2a98d6b732f 100644
--- a/test/IRGen/argument_attrs.sil
+++ b/test/IRGen/argument_attrs.sil
@@ -4,49 +4,49 @@ import Builtin
 
 struct Huge { var x, y, z, w, a, b, c, d, e, f: Builtin.Int32 }
 
-// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @arguments_in_def(ptr nocapture dereferenceable(4) %0, ptr noalias nocapture dereferenceable(4) %1, ptr noalias nocapture dereferenceable(4) %2, ptr noalias nocapture dereferenceable(40) %3, ptr noalias %4, ptr noalias nocapture %5, ptr %T)
+// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @arguments_in_def(ptr captures(none) dereferenceable(4) %0, ptr noalias captures(none) dereferenceable(4) %1, ptr noalias captures(none) dereferenceable(4) %2, ptr noalias captures(none) dereferenceable(40) %3, ptr noalias %4, ptr noalias captures(none) %5, ptr %T)
 sil @arguments_in_def : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> () {
 entry(%1 : $*Builtin.Int32, %2 : $*Builtin.Int32, %3 : $*Builtin.Int32, %4 : $Huge, %5 : $*T, %6 : $*()):
-  // CHECK: call swiftcc void @arguments_in_decl(ptr nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias nocapture {{%.*}}, ptr %T)
+  // CHECK: call swiftcc void @arguments_in_decl(ptr captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias captures(none) {{%.*}}, ptr %T)
   %f = function_ref @arguments_in_decl : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> ()
   %x = apply %f<T>(%1, %2, %3, %4, %5, %6) : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> ()
-  // CHECK: call swiftcc void @arguments_in_def(ptr nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias nocapture {{%.*}}, ptr %T)
+  // CHECK: call swiftcc void @arguments_in_def(ptr captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias captures(none) {{%.*}}, ptr %T)
   %g = function_ref @arguments_in_def : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> ()
   %y = apply %g<T>(%1, %2, %3, %4, %5, %6) : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> ()
   return undef : $()
 }
 
-// CHECK-LABEL: declare{{( dllimport)?}} swiftcc void @arguments_in_decl(ptr nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(40), ptr noalias, ptr noalias nocapture, ptr)
+// CHECK-LABEL: declare{{( dllimport)?}} swiftcc void @arguments_in_decl(ptr captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(40), ptr noalias, ptr noalias captures(none), ptr)
 sil @arguments_in_decl : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> ()
 
-// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @arguments_in_def_out(ptr noalias nocapture sret({{.*}}) %0, ptr nocapture dereferenceable(4) %1, ptr noalias nocapture dereferenceable(4) %2, ptr noalias nocapture dereferenceable(4) %3, ptr noalias nocapture dereferenceable(40) %4, ptr noalias %5, ptr noalias nocapture %6, ptr %T)
+// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @arguments_in_def_out(ptr noalias sret({{.*}}) captures(none) %0, ptr captures(none) dereferenceable(4) %1, ptr noalias captures(none) dereferenceable(4) %2, ptr noalias captures(none) dereferenceable(4) %3, ptr noalias captures(none) dereferenceable(40) %4, ptr noalias %5, ptr noalias captures(none) %6, ptr %T)
 sil @arguments_in_def_out : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> @out Builtin.Int32 {
 entry(%0 : $*Builtin.Int32, %1 : $*Builtin.Int32, %2 : $*Builtin.Int32, %3 : $*Builtin.Int32, %4 : $Huge, %5 : $*T, %6 : $*()):
-  // CHECK: call swiftcc void @arguments_in_decl_out(ptr noalias nocapture sret({{.*}}) {{%.*}}, ptr nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias nocapture {{%.*}}, ptr {{%.*}})
+  // CHECK: call swiftcc void @arguments_in_decl_out(ptr noalias sret({{.*}}) captures(none) {{%.*}}, ptr captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias captures(none) {{%.*}}, ptr {{%.*}})
   %f = function_ref @arguments_in_decl_out : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> @out Builtin.Int32
   %x = apply %f<T>(%0, %1, %2, %3, %4, %5, %6) : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> @out Builtin.Int32
-  // CHECK: call swiftcc void @arguments_in_def_out(ptr noalias nocapture sret({{.*}}) {{%.*}}, ptr nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias nocapture {{%.*}}, ptr {{%.*}})
+  // CHECK: call swiftcc void @arguments_in_def_out(ptr noalias sret({{.*}}) captures(none) {{%.*}}, ptr captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias captures(none) {{%.*}}, ptr {{%.*}})
   %g = function_ref @arguments_in_def_out : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> @out Builtin.Int32
   %y = apply %g<T>(%0, %1, %2, %3, %4, %5, %6) : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> @out Builtin.Int32
   return undef : $()
 }
 
-// CHECK-LABEL: declare{{( dllimport)?}} swiftcc void @arguments_in_decl_out(ptr noalias nocapture sret({{.*}}), ptr nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(40), ptr noalias, ptr noalias nocapture, ptr)
+// CHECK-LABEL: declare{{( dllimport)?}} swiftcc void @arguments_in_decl_out(ptr noalias sret({{.*}}) captures(none), ptr captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(40), ptr noalias, ptr noalias captures(none), ptr)
 sil @arguments_in_decl_out : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> @out Builtin.Int32
 
-// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @arguments_in_def_huge_ret(ptr noalias nocapture sret({{.*}}V) %0, ptr nocapture dereferenceable(4) %1, ptr noalias nocapture dereferenceable(4) %2, ptr noalias nocapture dereferenceable(4) %3, ptr noalias nocapture dereferenceable(40) %4, ptr noalias %5, ptr noalias nocapture %6, ptr %T)
+// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @arguments_in_def_huge_ret(ptr noalias sret({{.*}}V) captures(none) %0, ptr captures(none) dereferenceable(4) %1, ptr noalias captures(none) dereferenceable(4) %2, ptr noalias captures(none) dereferenceable(4) %3, ptr noalias captures(none) dereferenceable(40) %4, ptr noalias %5, ptr noalias captures(none) %6, ptr %T)
 sil @arguments_in_def_huge_ret : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> Huge {
 entry(%1 : $*Builtin.Int32, %2 : $*Builtin.Int32, %3 : $*Builtin.Int32, %4 : $Huge, %5 : $*T, %6 : $*()):
   %f = function_ref @arguments_in_decl_huge_ret : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> Huge
-  // CHECK: call swiftcc void @arguments_in_decl_huge_ret(ptr noalias nocapture sret({{.*}}) {{%.*}}, ptr nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias nocapture {{%.*}}, ptr {{%.*}})
+  // CHECK: call swiftcc void @arguments_in_decl_huge_ret(ptr noalias sret({{.*}}) captures(none) {{%.*}}, ptr captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias captures(none) {{%.*}}, ptr {{%.*}})
   %x = apply %f<T>(%1, %2, %3, %4, %5, %6) : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> Huge
-  // CHECK: call swiftcc void @arguments_in_def_huge_ret(ptr noalias nocapture sret({{.*}}) {{%.*}}, ptr nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(4) {{%.*}}, ptr noalias nocapture dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias nocapture {{%.*}}, ptr {{%.*}})
+  // CHECK: call swiftcc void @arguments_in_def_huge_ret(ptr noalias sret({{.*}}) captures(none) {{%.*}}, ptr captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(4) {{%.*}}, ptr noalias captures(none) dereferenceable(40) {{%.*}}, ptr noalias {{%.*}}, ptr noalias captures(none) {{%.*}}, ptr {{%.*}})
   %g = function_ref @arguments_in_def_huge_ret : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> Huge
   %y = apply %g<T>(%1, %2, %3, %4, %5, %6) : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> Huge
   return %y : $Huge
 }
 
-// CHECK-LABEL: declare{{( dllimport)?}} swiftcc void @arguments_in_decl_huge_ret(ptr noalias nocapture sret({{.*}}), ptr nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(4), ptr noalias nocapture dereferenceable(40), ptr noalias, ptr noalias nocapture, ptr)
+// CHECK-LABEL: declare{{( dllimport)?}} swiftcc void @arguments_in_decl_huge_ret(ptr noalias sret({{.*}}) captures(none), ptr captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(4), ptr noalias captures(none) dereferenceable(40), ptr noalias, ptr noalias captures(none), ptr)
 sil @arguments_in_decl_huge_ret : $@convention(thin) <T> (@inout Builtin.Int32, @in Builtin.Int32, @in_guaranteed Builtin.Int32, Huge, @in T, @in ()) -> Huge
 
 
diff --git a/test/IRGen/integer-comparison.swift b/test/IRGen/integer-comparison.swift
index ac7d4677ce13a..d5052c461cf4c 100644
--- a/test/IRGen/integer-comparison.swift
+++ b/test/IRGen/integer-comparison.swift
@@ -4,11 +4,11 @@
 func f(_ x: Int, _ y: UInt32) -> Bool { x < y }
 // CHECK-LABEL: define {{.*}} @"$s4main1fySbSi_s6UInt32VtF"(i64 %0, i32 %1)
 // CHECK: %2 = zext i32 %1 to i64
-// CHECK-NEXT: %3 = icmp sgt i64 %2, %0
+// CHECK-NEXT: %3 = icmp slt i64 %0, %2
 // CHECK-NEXT: ret i1 %3
 
 func g(_ x: UInt32, _ y: Int) -> Bool { x < y }
 // CHECK-LABEL: define {{.*}} @"$s4main1gySbs6UInt32V_SitF"(i32 %0, i64 %1)
 // CHECK: %2 = zext i32 %0 to i64
-// CHECK-NEXT: %3 = icmp slt i64 %2, %1
+// CHECK-NEXT: %3 = icmp sgt i64 %1, %2
 // CHECK-NEXT: ret i1 %3
diff --git a/test/Interop/C/swiftify-import/Inputs/TransitiveModules/module.modulemap b/test/Interop/C/swiftify-import/Inputs/TransitiveModules/module.modulemap
deleted file mode 100644
index 7c3b96f1111b9..0000000000000
--- a/test/Interop/C/swiftify-import/Inputs/TransitiveModules/module.modulemap
+++ /dev/null
@@ -1,24 +0,0 @@
-module ModuleA {
-    header "module-a.h"
-    export *
-}
-module ModuleB {
-    header "module-b.h"
-}
-module ModuleOuter {
-    module ModuleC {
-        header "module-c.h"
-        export *
-    }
-    explicit module ModuleD {
-         header "module-d.h"
-         export *
-    }
-}
-module ModuleDeep {
-    module ModuleDeepNested {
-        module ModuleDeepNestedNested {
-            header "module-e.h"
-        }
-    }
-}
diff --git a/test/Interop/C/swiftify-import/Inputs/counted-by-lifetimebound.h b/test/Interop/C/swiftify-import/Inputs/counted-by-lifetimebound.h
index 574bcccd0d57f..6a5bbf2ee5534 100644
--- a/test/Interop/C/swiftify-import/Inputs/counted-by-lifetimebound.h
+++ b/test/Interop/C/swiftify-import/Inputs/counted-by-lifetimebound.h
@@ -1,23 +1,24 @@
 #pragma once
 
 #define __counted_by(x) __attribute__((__counted_by__(x)))
+#define __counted_by_or_null(x) __attribute__((__counted_by_or_null__(x)))
 #define __lifetimebound __attribute__((lifetimebound))
 
-int * __counted_by(len) simple(int len, int len2, int * __counted_by(len2) __lifetimebound p);
+int * __counted_by(len) simple(int len, int len2, int * p __counted_by(len2) __lifetimebound);
 
-int * __counted_by(len) shared(int len, int * __counted_by(len) __lifetimebound p);
+int * __counted_by(len) shared(int len, int * p __counted_by(len) __lifetimebound);
 
-int * __counted_by(len - offset) complexExpr(int len, int offset, int len2, int * __counted_by(len2) __lifetimebound p);
+int * __counted_by(len - offset) complexExpr(int len, int offset, int len2, int * p __counted_by(len2) __lifetimebound);
 
-int * __counted_by(len) _Null_unspecified nullUnspecified(int len, int len2, int * __counted_by(len2) __lifetimebound _Null_unspecified p);
+int * __counted_by(len) _Null_unspecified nullUnspecified(int len, int len2, int * _Null_unspecified p __counted_by(len2) __lifetimebound);
 
-int * __counted_by(len) _Nonnull nonnull(int len, int len2, int * __counted_by(len2) __lifetimebound _Nonnull p);
+int * __counted_by(len) _Nonnull nonnull(int len, int len2, int * _Nonnull p __counted_by(len2) __lifetimebound);
 
-int * __counted_by(len) _Nullable nullable(int len, int len2, int * __counted_by(len2) __lifetimebound _Nullable p);
+int * __counted_by(len) _Nullable nullable(int len, int len2, int * _Nullable p __counted_by(len2) __lifetimebound);
 
 typedef struct foo opaque_t;
-opaque_t * __counted_by(len) opaque(int len, int len2, opaque_t * __counted_by(len2) __lifetimebound p);
+opaque_t * __counted_by(len) opaque(int len, int len2, opaque_t * p __counted_by(len2) __lifetimebound);
 
-int * __counted_by(len) noncountedLifetime(int len, int * __lifetimebound p);
+int * __counted_by(len) noncountedLifetime(int len, int * p __lifetimebound);
 
-int * __counted_by(13) _Nullable constant(int * __counted_by(13) __lifetimebound _Nullable p);
+int * __counted_by(13) _Nullable constant(int * _Nullable p __counted_by_or_null(13) __lifetimebound);
diff --git a/test/Interop/C/swiftify-import/Inputs/module.modulemap b/test/Interop/C/swiftify-import/Inputs/module.modulemap
index 93416d69a4a97..29c1c6b295413 100644
--- a/test/Interop/C/swiftify-import/Inputs/module.modulemap
+++ b/test/Interop/C/swiftify-import/Inputs/module.modulemap
@@ -33,3 +33,29 @@ module ClangIncludesModule {
 module ClangIncludesNoExportModule {
     header "clang-includes.h"
 }
+
+// TransitiveModules/
+module ModuleA {
+    header "TransitiveModules/module-a.h"
+    export *
+}
+module ModuleB {
+    header "TransitiveModules/module-b.h"
+}
+module ModuleOuter {
+    module ModuleC {
+        header "TransitiveModules/module-c.h"
+        export *
+    }
+    explicit module ModuleD {
+         header "TransitiveModules/module-d.h"
+         export *
+    }
+}
+module ModuleDeep {
+    module ModuleDeepNested {
+        module ModuleDeepNestedNested {
+            header "TransitiveModules/module-e.h"
+        }
+    }
+}
diff --git a/test/Interop/C/swiftify-import/Inputs/sized-by-lifetimebound.h b/test/Interop/C/swiftify-import/Inputs/sized-by-lifetimebound.h
index e158071e9c954..e66f2fa1ee80c 100644
--- a/test/Interop/C/swiftify-import/Inputs/sized-by-lifetimebound.h
+++ b/test/Interop/C/swiftify-import/Inputs/sized-by-lifetimebound.h
@@ -7,25 +7,25 @@
 #endif
 #define __lifetimebound __attribute__((lifetimebound))
 
-const void * __sized_by(len) simple(int len, int len2, const void * __sized_by(len2) __lifetimebound p);
+const void * __sized_by(len) simple(int len, int len2, const void * p __sized_by(len2) __lifetimebound);
 
-const void * __sized_by(len) shared(int len, const void * __sized_by(len) __lifetimebound p);
+const void * __sized_by(len) shared(int len, const void * p __sized_by(len) __lifetimebound);
 
-const void * __sized_by(len - offset) complexExpr(int len, int offset, int len2, const void * __sized_by(len2) __lifetimebound p);
+const void * __sized_by(len - offset) complexExpr(int len, int offset, int len2, const void * p __sized_by(len2) __lifetimebound);
 
-const void * __sized_by(len) _Null_unspecified nullUnspecified(int len, int len2, const void * __sized_by(len2) __lifetimebound _Null_unspecified p);
+const void * __sized_by(len) _Null_unspecified nullUnspecified(int len, int len2, const void * _Null_unspecified p __sized_by(len2) __lifetimebound);
 
-const void * __sized_by(len) _Nonnull nonnull(int len, int len2, const void * __sized_by(len2) __lifetimebound _Nonnull p);
+const void * __sized_by(len) _Nonnull nonnull(int len, int len2, const void * _Nonnull p __sized_by(len2) __lifetimebound);
 
-const void * __sized_by(len) _Nullable nullable(int len, int len2, const void * __sized_by(len2) __lifetimebound _Nullable p);
+const void * __sized_by(len) _Nullable nullable(int len, int len2, const void * _Nullable p __sized_by(len2) __lifetimebound);
 
 typedef struct foo opaque_t;
-opaque_t * __sized_by(len) opaque(int len, int len2, opaque_t * __sized_by(len2) __lifetimebound p);
+opaque_t * __sized_by(len) opaque(int len, int len2, opaque_t * p __sized_by(len2) __lifetimebound);
 
-const void * __sized_by(len) nonsizedLifetime(int len, const void * __lifetimebound p);
+const void * __sized_by(len) nonsizedLifetime(int len, const void * p __lifetimebound);
 
-uint8_t *__sized_by(size)  bytesized(int size, const uint8_t *__sized_by(size) __lifetimebound);
+uint8_t *__sized_by(size)  bytesized(int size, const uint8_t * p __sized_by(size) __lifetimebound);
 
-char *__sized_by(size) charsized(char *__sized_by(size) __lifetimebound, int size);
+char *__sized_by(size) charsized(char * p __sized_by(size) __lifetimebound, int size);
 
-const uint16_t *__sized_by(size)  doublebytesized(uint16_t *__sized_by(size) __lifetimebound, int size);
+const uint16_t *__sized_by(size)  doublebytesized(uint16_t * p __sized_by(size) __lifetimebound, int size);
diff --git a/test/Interop/C/swiftify-import/clang-includes-aliasing-imports.swift b/test/Interop/C/swiftify-import/clang-includes-aliasing-imports.swift
index 6e4419de54413..13588c6d76abd 100644
--- a/test/Interop/C/swiftify-import/clang-includes-aliasing-imports.swift
+++ b/test/Interop/C/swiftify-import/clang-includes-aliasing-imports.swift
@@ -6,8 +6,8 @@
 // RUN: %target-swift-frontend -dump-source-file-imports -emit-module -plugin-path %swift-plugin-dir -o %t/ClangIncludesExplicit.swiftmodule -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/test.swift 2>&1 | %FileCheck %s --check-prefix DUMP
 // RUN: %target-swift-frontend -dump-source-file-imports -emit-module -plugin-path %swift-plugin-dir -o %t/ClangIncludesExplicit.swiftmodule -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/test.swift -cxx-interoperability-mode=default 2>&1 | %FileCheck %s --check-prefix DUMP --check-prefix DUMP-CXX
 
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-A1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-A2 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-A1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-A2 --implicit-check-not=import --match-full-lines
 
 //--- test.swift
 import A1
diff --git a/test/Interop/C/swiftify-import/clang-includes-indirect-explicit-modules.swift b/test/Interop/C/swiftify-import/clang-includes-indirect-explicit-modules.swift
index e6131d7cee542..35a934ec4d2a8 100644
--- a/test/Interop/C/swiftify-import/clang-includes-indirect-explicit-modules.swift
+++ b/test/Interop/C/swiftify-import/clang-includes-indirect-explicit-modules.swift
@@ -6,10 +6,10 @@
 // RUN: %target-swift-frontend -dump-source-file-imports -emit-module -plugin-path %swift-plugin-dir -o %t/ClangIncludesExplicit.swiftmodule -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/test.swift 2>&1 | %FileCheck %s --check-prefix DUMP
 // RUN: %target-swift-frontend -dump-source-file-imports -emit-module -plugin-path %swift-plugin-dir -o %t/ClangIncludesExplicit.swiftmodule -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/test.swift -cxx-interoperability-mode=default 2>&1 | %FileCheck %s --check-prefix DUMP --check-prefix DUMP-CXX
 
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1.C1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-C1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1.C1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-C1 --implicit-check-not=import --match-full-lines
 
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B2 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B2 --implicit-check-not=import --match-full-lines
 
 //--- test.swift
 import A1.B1
diff --git a/test/Interop/C/swiftify-import/clang-includes-redundant-imports.swift b/test/Interop/C/swiftify-import/clang-includes-redundant-imports.swift
index 34fec7dfc97e2..0ea13db6ee4c4 100644
--- a/test/Interop/C/swiftify-import/clang-includes-redundant-imports.swift
+++ b/test/Interop/C/swiftify-import/clang-includes-redundant-imports.swift
@@ -6,17 +6,17 @@
 // RUN: %target-swift-frontend -dump-source-file-imports -emit-module -plugin-path %swift-plugin-dir -o %t/ClangIncludesExplicit.swiftmodule -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/test.swift 2>&1 | %FileCheck %s --check-prefix DUMP
 // RUN: %target-swift-frontend -dump-source-file-imports -emit-module -plugin-path %swift-plugin-dir -o %t/ClangIncludesExplicit.swiftmodule -I %t/Inputs -enable-experimental-feature SafeInteropWrappers %t/test.swift -cxx-interoperability-mode=default 2>&1 | %FileCheck %s --check-prefix DUMP --check-prefix DUMP-CXX
 
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-A1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1.C1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-C1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1.C1.D1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-D1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.E1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-E1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.E1.F1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-F1 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.E1.G1 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-G1 --implicit-check-not=import --match-full-lines
-
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B2 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2.C2 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-C2 --implicit-check-not=import --match-full-lines
-// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2.C2.D2 -plugin-path %swift-plugin-dir -I %t -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-D2 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-A1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1.C1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-C1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.B1.C1.D1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-D1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.E1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-E1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.E1.F1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-F1 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A1.E1.G1 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-G1 --implicit-check-not=import --match-full-lines
+
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-B2 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2.C2 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-C2 --implicit-check-not=import --match-full-lines
+// RUN: %target-swift-ide-test -print-module -module-print-hidden -module-to-print=A2.B2.C2.D2 -plugin-path %swift-plugin-dir -I %t/Inputs -source-filename=x -enable-experimental-feature SafeInteropWrappers | %FileCheck %s --check-prefix CHECK-D2 --implicit-check-not=import --match-full-lines
 
 //--- test.swift
 import A1
diff --git a/test/Interop/C/swiftify-import/sized-by-lifetimebound.swift b/test/Interop/C/swiftify-import/sized-by-lifetimebound.swift
index 27250d41af53b..83ae29fd82920 100644
--- a/test/Interop/C/swiftify-import/sized-by-lifetimebound.swift
+++ b/test/Interop/C/swiftify-import/sized-by-lifetimebound.swift
@@ -13,14 +13,14 @@ import SizedByLifetimeboundClang
 
 // CHECK:      /// This is an auto-generated wrapper for safer interop
 // CHECK-NEXT: @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *)
-// CHECK-NEXT: @_lifetime(copy _bytesized_param1)
-// CHECK-NEXT: @_alwaysEmitIntoClient @_disfavoredOverload public func bytesized(_ _bytesized_param1: RawSpan) -> MutableRawSpan
+// CHECK-NEXT: @_lifetime(copy p)
+// CHECK-NEXT: @_alwaysEmitIntoClient @_disfavoredOverload public func bytesized(_ p: RawSpan) -> MutableRawSpan
 
 // CHECK-NEXT: /// This is an auto-generated wrapper for safer interop
 // CHECK-NEXT: @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *)
-// CHECK-NEXT: @_lifetime(copy _charsized_param0)
-// CHECK-NEXT: @_lifetime(_charsized_param0: copy _charsized_param0)
-// CHECK-NEXT: @_alwaysEmitIntoClient @_disfavoredOverload public func charsized(_ _charsized_param0: inout MutableRawSpan) -> MutableRawSpan
+// CHECK-NEXT: @_lifetime(copy p)
+// CHECK-NEXT: @_lifetime(p: copy p)
+// CHECK-NEXT: @_alwaysEmitIntoClient @_disfavoredOverload public func charsized(_ p: inout MutableRawSpan) -> MutableRawSpan
 
 // CHECK-NEXT: /// This is an auto-generated wrapper for safer interop
 // CHECK-NEXT: @available(visionOS 1.0, tvOS 12.2, watchOS 5.2, iOS 12.2, macOS 10.14.4, *)
diff --git a/test/Interop/Cxx/stdlib/msvcprt-module-interface.swift b/test/Interop/Cxx/stdlib/msvcprt-module-interface.swift
index 63dd1a39e515c..3fbd3be898749 100644
--- a/test/Interop/Cxx/stdlib/msvcprt-module-interface.swift
+++ b/test/Interop/Cxx/stdlib/msvcprt-module-interface.swift
@@ -15,8 +15,9 @@
 // CHECK-STRING:   struct basic_string<CChar, std.char_traits<CChar>, std.allocator<CChar>> : CxxRandomAccessCollection {
 // CHECK-STRING:     typealias value_type = CChar
 // CHECK-STRING:   }
-// CHECK-STRING:   struct basic_string<CWideChar, std.char_traits<CWideChar>, std.allocator<CWideChar>> : CxxRandomAccessCollection {
-// CHECK-STRING:     typealias value_type = CWideChar
+// CHECK-STRING:   struct basic_string<CChar16, std.char_traits<CChar16>, std.allocator<CChar16>> : CxxRandomAccessCollection {
+// CHECK-STRING:     typealias value_type = UInt16
+// FIXME: why the value type is different from CChar16?
 // CHECK-STRING:   }
 // CHECK-STRING:   typealias string = std.basic_string<CChar, std.char_traits<CChar>, std.allocator<CChar>>
 // CHECK-STRING:   typealias wstring = std.basic_string<CWideChar, std.char_traits<CWideChar>, std.allocator<CWideChar>>
diff --git a/test/LLVMPasses/allocation-deletion.ll b/test/LLVMPasses/allocation-deletion.ll
index 81d9b181dc576..3dc2ebb2ad3f7 100644
--- a/test/LLVMPasses/allocation-deletion.ll
+++ b/test/LLVMPasses/allocation-deletion.ll
@@ -7,7 +7,7 @@ target triple = "x86_64-apple-macosx10.9"
 %swift.heapmetadata = type { ptr, ptr }
 
 declare ptr @swift_allocObject(ptr , i64, i64) nounwind
-declare void @swift_release(ptr nocapture)
+declare void @swift_release(ptr captures(none))
 declare void @swift_retain(ptr ) nounwind
 declare { i64, i64, i64 } @swift_retainAndReturnThree(ptr , i64, i64 , i64 )
 
@@ -36,7 +36,7 @@ entry:
 ; trivial_alloc_eliminate1 - Show that we can eliminate an allocation with a
 ; trivial destructor.
 @trivial_dtor_metadata = internal constant %swift.heapmetadata { ptr @trivial_dtor, ptr null }
-define internal i64 @trivial_dtor(ptr nocapture) nounwind readonly {
+define internal i64 @trivial_dtor(ptr captures(none)) nounwind readonly {
 entry:
   %1 = getelementptr inbounds %swift.refcounted, ptr %0, i64 1
   %length = load i64, ptr %1, align 8
@@ -59,7 +59,7 @@ entry:
 ; trivial_alloc_eliminate2 - Show that we can eliminate an allocation with a
 ; destructor that does a retain on the 'self' object.
 @trivial_dtor_metadata2 = internal constant %swift.heapmetadata { ptr @trivial_dtor2, ptr null }
-define internal i64 @trivial_dtor2(ptr nocapture %this) nounwind readonly {
+define internal i64 @trivial_dtor2(ptr captures(none) %this) nounwind readonly {
 entry:
   %0 = getelementptr inbounds %swift.refcounted, ptr %this, i64 1, i32 0
   store ptr inttoptr (i64 4 to ptr), ptr %0, align 8
diff --git a/test/LLVMPasses/basic.ll b/test/LLVMPasses/basic.ll
index be8b54b3e16dc..f53e1f9fc66a1 100644
--- a/test/LLVMPasses/basic.ll
+++ b/test/LLVMPasses/basic.ll
@@ -16,7 +16,7 @@ declare void @swift_unknownObjectRelease(ptr)
 declare ptr @llvm.objc.retain(ptr)
 declare void @llvm.objc.release(ptr)
 declare ptr @swift_allocObject(ptr , i64, i64) nounwind
-declare void @swift_release(ptr nocapture)
+declare void @swift_release(ptr captures(none))
 declare ptr @swift_retain(ptr returned) nounwind
 declare ptr @swift_bridgeObjectRetain(ptr)
 declare void @swift_bridgeObjectRelease(ptr)
diff --git a/test/LLVMPasses/contract.ll b/test/LLVMPasses/contract.ll
index d5081e5c9e3f9..23c05a02096b3 100644
--- a/test/LLVMPasses/contract.ll
+++ b/test/LLVMPasses/contract.ll
@@ -10,9 +10,9 @@ target triple = "x86_64-apple-macosx10.9"
 declare ptr @swift_allocObject(ptr , i64, i64) nounwind
 declare ptr @swift_bridgeObjectRetain(ptr)
 declare void @swift_bridgeObjectRelease(ptr )
-declare void @swift_release(ptr nocapture)
+declare void @swift_release(ptr captures(none))
 declare ptr @swift_retain(ptr ) nounwind
-declare void @swift_unknownObjectRelease(ptr nocapture)
+declare void @swift_unknownObjectRelease(ptr captures(none))
 declare ptr @swift_unknownObjectRetain(ptr ) nounwind
 declare void @__swift_fixLifetime(ptr)
 declare void @noread_user(ptr) readnone
diff --git a/test/LLVMPasses/crash.ll b/test/LLVMPasses/crash.ll
index 020ce65262495..1aa748c1a9254 100644
--- a/test/LLVMPasses/crash.ll
+++ b/test/LLVMPasses/crash.ll
@@ -8,7 +8,7 @@ target triple = "x86_64-apple-macosx10.9"
 
 declare { ptr, i64, ptr } @_Tsop1pFT3lhsNs6String3rhsS__S_(ptr, i64, ptr, ptr, i64, ptr)
 declare { ptr, i64, ptr } @_TNs6String24convertFromStringLiteralFT3valp_S_(ptr)
-declare void @swift_release(ptr nocapture)
+declare void @swift_release(ptr captures(none))
 
 
 @0 = private unnamed_addr constant [3 x i8] c"So\00"
diff --git a/test/LLVMPasses/disable_llvm_optzns.ll b/test/LLVMPasses/disable_llvm_optzns.ll
index e71f22ae88a5f..c0a4ba020c4bd 100644
--- a/test/LLVMPasses/disable_llvm_optzns.ll
+++ b/test/LLVMPasses/disable_llvm_optzns.ll
@@ -16,7 +16,7 @@ declare void @swift_unknownObjectRelease(ptr)
 declare ptr @llvm.objc.retain(ptr)
 declare void @llvm.objc.release(ptr)
 declare ptr @swift_allocObject(ptr , i64, i64) nounwind
-declare void @swift_release(ptr nocapture)
+declare void @swift_release(ptr captures(none))
 declare ptr @swift_retain(ptr returned) nounwind
 declare ptr @swift_bridgeObjectRetain(ptr)
 declare void @swift_bridgeObjectRelease(ptr)
diff --git a/test/LLVMPasses/missing_runtime_declarations.ll b/test/LLVMPasses/missing_runtime_declarations.ll
index 3b5c20414afc0..f20263bc8472f 100644
--- a/test/LLVMPasses/missing_runtime_declarations.ll
+++ b/test/LLVMPasses/missing_runtime_declarations.ll
@@ -3,11 +3,11 @@
 target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-apple-macosx10.9"
 
-; CHECK: declare void @swift_bridgeObjectRelease(ptr nocapture)
+; CHECK: declare void @swift_bridgeObjectRelease(ptr captures(none))
 
 %a = type opaque
-declare void @swift_bridgeObjectRelease(ptr nocapture)
-declare ptr @swift_bridgeObjectRetain(ptr nocapture)
+declare void @swift_bridgeObjectRelease(ptr captures(none))
+declare ptr @swift_bridgeObjectRetain(ptr captures(none))
 
 ; CHECK-LABEL: define void @testcase1(ptr %0) {
 ; CHECK: entry:
diff --git a/test/LLVMPasses/release_motion_landingpad.ll b/test/LLVMPasses/release_motion_landingpad.ll
index 3a3c5ae4045f9..f6bee19d82dc5 100644
--- a/test/LLVMPasses/release_motion_landingpad.ll
+++ b/test/LLVMPasses/release_motion_landingpad.ll
@@ -3,7 +3,7 @@
 target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-apple-macosx10.9"
 
-declare void @swift_release(ptr nocapture)
+declare void @swift_release(ptr captures(none))
 declare void @swift_retain(ptr) nounwind
 declare ptr @_Znwm(i64)
 declare i32 @__gxx_personality_v0(...)
diff --git a/test/Reflection/Inputs/wasm.yaml b/test/Reflection/Inputs/wasm.yaml
new file mode 100644
index 0000000000000..4a5338b309acf
--- /dev/null
+++ b/test/Reflection/Inputs/wasm.yaml
@@ -0,0 +1,443 @@
+--- !WASM
+FileHeader:
+  Version:         0x1
+Sections:
+  - Type:            TYPE
+    Signatures:
+      - Index:           0
+        ParamTypes:
+          - I32
+          - I32
+        ReturnTypes:
+          - I32
+      - Index:           1
+        ParamTypes:
+          - I32
+        ReturnTypes:     []
+      - Index:           2
+        ParamTypes:      []
+        ReturnTypes:     []
+      - Index:           3
+        ParamTypes:
+          - I32
+          - I32
+        ReturnTypes:     []
+      - Index:           4
+        ParamTypes:
+          - I32
+          - I32
+          - I32
+          - I32
+        ReturnTypes:     []
+      - Index:           5
+        ParamTypes:
+          - I32
+        ReturnTypes:
+          - I32
+      - Index:           6
+        ParamTypes:
+          - I32
+          - I32
+          - I32
+        ReturnTypes:
+          - I32
+      - Index:           7
+        ParamTypes:      []
+        ReturnTypes:
+          - I32
+  - Type:            IMPORT
+    Imports:
+      - Module:          wasi_snapshot_preview1
+        Field:           args_get
+        Kind:            FUNCTION
+        SigIndex:        0
+      - Module:          wasi_snapshot_preview1
+        Field:           args_sizes_get
+        Kind:            FUNCTION
+        SigIndex:        0
+      - Module:          wasi_snapshot_preview1
+        Field:           proc_exit
+        Kind:            FUNCTION
+        SigIndex:        1
+  - Type:            FUNCTION
+    FunctionTypes:   [ 2, 1, 2, 2, 0, 3, 4, 4, 5, 5, 6, 1, 1, 0, 1, 7, 
+                       0, 0, 1, 2, 5, 2, 2, 6 ]
+  - Type:            TABLE
+    Tables:
+      - Index:           0
+        ElemType:        FUNCREF
+        Limits:
+          Flags:           [ HAS_MAX ]
+          Minimum:         0x4
+          Maximum:         0x4
+  - Type:            MEMORY
+    Memories:
+      - Minimum:         0x2
+  - Type:            GLOBAL
+    Globals:
+      - Index:           0
+        Type:            I32
+        Mutable:         true
+        InitExpr:
+          Opcode:          I32_CONST
+          Value:           70624
+      - Index:           1
+        Type:            I32
+        Mutable:         false
+        InitExpr:
+          Opcode:          I32_CONST
+          Value:           0
+  - Type:            EXPORT
+    Exports:
+      - Name:            memory
+        Kind:            MEMORY
+        Index:           0
+      - Name:            _start
+        Kind:            FUNCTION
+        Index:           5
+  - Type:            ELEM
+    Segments:
+      - Offset:
+          Opcode:          I32_CONST
+          Value:           1
+        Functions:       [ 9, 10, 7 ]
+  - Type:            CODE
+    Functions:
+      - Index:           3
+        Locals:          []
+        Body:            10060B
+      - Index:           4
+        Locals:          []
+        Body:            000B
+      - Index:           5
+        Locals:
+          - Type:            I32
+            Count:           1
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+        Locals:          []
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+        Body:            0F0B
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+        Locals:
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+        Body:            024020024121490D00200020012002FC0B0020000F0B02402002450D00200020013A0000200020026A2203417F6A20013A000020024103490D00200020013A0002200020013A00012003417D6A20013A00002003417E6A20013A000020024107490D00200020013A00032003417C6A20013A000020024109490D002000410020006B41037122046A2205200141FF017141818284086C22033602002005200220046B413C7122016A2202417C6A200336020020014109490D002005200336020820052003360204200241786A2003360200200241746A200336020020014119490D002005200336021820052003360214200520033602102005200336020C200241706A20033602002002416C6A2003360200200241686A2003360200200241646A20033602002001200541047141187222026B22014120490D002003AD4281808080107E2106200520026A2102034020022006370318200220063703102002200637030820022006370300200241206A2102200141606A2201411F4B0D000B0B20000B
+  - Type:            DATA
+    Segments:
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+        InitFlags:       0
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+          Opcode:          I32_CONST
+          Value:           4096
+        Content:         10000000480000008000000000000000430001005C0000006400000000000000010000005A0000000700000000000000510000003C000000480000000100000094000000000000000200000051000000200000002E0000000200000088000000010000000200000073696D706C6500000000000000000000F0FFFFFF50004100540053000300
+      - SectionOffset:   148
+        InitFlags:       0
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+          Opcode:          I32_CONST
+          Value:           4232
+        Content:         001000001D110000000000000010000000020000301000000000000000100000000200004C10000000000000
+      - SectionOffset:   198
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4276
+        Content:         5CFFFFFF
+      - SectionOffset:   208
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4280
+        Content:         48FFFFFF
+      - SectionOffset:   218
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4284
+        Content:         74FFFFFF8CFFFFFF
+      - SectionOffset:   232
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4292
+        Content:         640000000000000004000C0000000000620000000000000000000C00000000003E0000000000000000000C0001000000000000003E0000001E000000
+      - SectionOffset:   298
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4352
+        Content:         ''
+      - SectionOffset:   304
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4352
+        Content:         '220000002400000001000000080000000800000008000000'
+      - SectionOffset:   334
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4376
+        Content:         ''
+      - SectionOffset:   340
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4376
+        Content:         '41007400'
+      - SectionOffset:   350
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4380
+        Content:         426933325F000129FFFFFF0024733673696D706C65315050000001F9FEFFFF00
+      - SectionOffset:   388
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         ''
+      - SectionOffset:   394
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         ''
+      - SectionOffset:   400
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         ''
+      - SectionOffset:   406
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         ''
+      - SectionOffset:   412
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         ''
+      - SectionOffset:   418
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         ''
+      - SectionOffset:   424
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4412
+        Content:         '0300000000000000'
+      - SectionOffset:   438
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4420
+        Content:         F94D3CBDE6014046B3FF38670353FD4E
+  - Type:            CUSTOM
+    Name:            .swift1_autolink_entries
+    Payload:         ''
+  - Type:            CUSTOM
+    Name:            name
+    FunctionNames:
+      - Index:           0
+        Name:            __imported_wasi_snapshot_preview1_args_get
+      - Index:           1
+        Name:            __imported_wasi_snapshot_preview1_args_sizes_get
+      - Index:           2
+        Name:            __imported_wasi_snapshot_preview1_proc_exit
+      - Index:           3
+        Name:            __wasm_call_ctors
+      - Index:           4
+        Name:            'signature_mismatch:swift_addNewDSOImage'
+      - Index:           5
+        Name:            _start
+      - Index:           6
+        Name:            'swift_image_constructor()'
+      - Index:           7
+        Name:            main
+      - Index:           8
+        Name:            '$s6simple1SV1tAA1TVvg'
+      - Index:           9
+        Name:            '$s6simple1TVMa'
+      - Index:           10
+        Name:            '$s6simple1SVMa'
+      - Index:           11
+        Name:            malloc
+      - Index:           12
+        Name:            dlmalloc
+      - Index:           13
+        Name:            prepend_alloc
+      - Index:           14
+        Name:            free
+      - Index:           15
+        Name:            dlfree
+      - Index:           16
+        Name:            calloc
+      - Index:           17
+        Name:            _Exit
+      - Index:           18
+        Name:            __main_void
+      - Index:           19
+        Name:            __wasi_args_get
+      - Index:           20
+        Name:            __wasi_args_sizes_get
+      - Index:           21
+        Name:            __wasi_proc_exit
+      - Index:           22
+        Name:            abort
+      - Index:           23
+        Name:            sbrk
+      - Index:           24
+        Name:            dummy
+      - Index:           25
+        Name:            __wasm_call_dtors
+      - Index:           26
+        Name:            memset
+    GlobalNames:
+      - Index:           0
+        Name:            __stack_pointer
+      - Index:           1
+        Name:            GOT.data.internal.__memory_base
+    DataSegmentNames:
+      - Index:           0
+        Name:            .rodata
+      - Index:           1
+        Name:            .data
+      - Index:           2
+        Name:            swift5_protocols
+      - Index:           3
+        Name:            swift5_protocol_conformances
+      - Index:           4
+        Name:            swift5_type_metadata
+      - Index:           5
+        Name:            swift5_fieldmd
+      - Index:           6
+        Name:            swift5_builtin
+      - Index:           7
+        Name:            swift5_assocty
+      - Index:           8
+        Name:            swift5_capture
+      - Index:           9
+        Name:            swift5_reflstr
+      - Index:           10
+        Name:            swift5_typeref
+      - Index:           11
+        Name:            swift5_mpenum
+      - Index:           12
+        Name:            swift5_replace
+      - Index:           13
+        Name:            swift5_replac2
+      - Index:           14
+        Name:            swift5_accessible_functions
+      - Index:           15
+        Name:            swift5_runtime_attributes
+      - Index:           16
+        Name:            swift5_tests
+      - Index:           17
+        Name:            swift5_entry
+      - Index:           18
+        Name:            .swift_modhash
+  - Type:            CUSTOM
+    Name:            producers
+    Languages:
+      - Name:            C_plus_plus_14
+        Version:         ''
+    Tools:
+      - Name:            clang
+        Version:         '17.0.0 (https://github.com/swiftlang/llvm-project.git b9d3d72e441c70ab8c463d615e36db1df685151b)'
+  - Type:            CUSTOM
+    Name:            target_features
+    Features:
+      - Prefix:          USED
+        Name:            bulk-memory
+      - Prefix:          USED
+        Name:            multivalue
+      - Prefix:          USED
+        Name:            mutable-globals
+      - Prefix:          USED
+        Name:            reference-types
+      - Prefix:          USED
+        Name:            sign-ext
+...
diff --git a/test/Reflection/wasm.test b/test/Reflection/wasm.test
new file mode 100644
index 0000000000000..98c904795dcc6
--- /dev/null
+++ b/test/Reflection/wasm.test
@@ -0,0 +1,28 @@
+# RUN: %yaml2obj %S/Inputs/wasm.yaml -o %t.wasm
+# RUN: %target-swift-reflection-dump --arch=wasi --no-objc-interop %t.wasm | %FileCheck %s
+#
+# CHECK: FIELDS
+# CHECK: t:
+# CHECK: ASSOCIATED TYPES
+# CHECK: -  : simple.P
+# CHECK: typealias A = Builtin.Int32
+# CHECK: Builtin.Int32
+# CHECK: (builtin Builtin.Int32)
+#
+# simple.swift
+# protocol P { associatedtype A }
+# struct T {}
+# struct S : P {
+#   typealias A = Builtin.Int32
+#   let t: T
+# }
+# sys.c
+# void swift_addNewDSOImage() {}
+#
+# compiled for -target wasm32-unknown-wasip1
+# obj2yaml simple.o -o simple.o.yaml
+# (replace UNDEFINED symbol with a definition)
+# obj2yaml simple.o.yaml -o simple-mod.o
+# swiftc simple-mod.o sys.o -o simple.wasm
+# yaml2obj simple.wasm -o simple-mod.o
+#
diff --git a/test/lit.cfg b/test/lit.cfg
index 8cac70321fcce..54f36dab837c7 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -347,6 +347,7 @@ config.llvm_dis = inferSwiftBinary('llvm-dis')
 config.llvm_nm = inferSwiftBinary('llvm-nm')
 config.llvm_readtapi = inferSwiftBinary('llvm-readtapi')
 config.llvm_size = inferSwiftBinary('llvm-size')
+config.yaml2obj = inferSwiftBinary('yaml2obj')
 config.sourcekitd_test = inferSwiftBinary('sourcekitd-test')
 config.complete_test = inferSwiftBinary('complete-test')
 config.swift_api_digester = inferSwiftBinary('swift-api-digester')
@@ -747,6 +748,7 @@ config.substitutions.append( ('%llvm-dis', config.llvm_dis) )
 config.substitutions.append( ('%llvm-nm', config.llvm_nm) )
 config.substitutions.append( ('%llvm-readtapi', config.llvm_readtapi) )
 config.substitutions.append( ('%llvm-size', config.llvm_size) )
+config.substitutions.append( ('%yaml2obj', config.yaml2obj) )
 config.substitutions.append( ('%swift-demangle-yamldump', config.swift_demangle_yamldump) )
 config.substitutions.append( ('%swift-demangle', config.swift_demangle) )
 config.substitutions.append( ('%Benchmark_O', config.benchmark_o) )
diff --git a/tools/SourceKit/lib/Support/ImmutableTextBuffer.cpp b/tools/SourceKit/lib/Support/ImmutableTextBuffer.cpp
index 81a4623b1a93b..0ebf2619ba200 100644
--- a/tools/SourceKit/lib/Support/ImmutableTextBuffer.cpp
+++ b/tools/SourceKit/lib/Support/ImmutableTextBuffer.cpp
@@ -11,13 +11,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "SourceKit/Support/ImmutableTextBuffer.h"
-#include "clang/Rewrite/Core/RewriteRope.h"
+#include "llvm/ADT/RewriteRope.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
 
 using namespace SourceKit;
 using namespace llvm;
-using clang::RewriteRope;
+using llvm::RewriteRope;
 
 void ImmutableTextUpdate::anchor() {}
 
diff --git a/tools/SourceKit/tools/sourcekitd-test/TestOptions.cpp b/tools/SourceKit/tools/sourcekitd-test/TestOptions.cpp
index 39d06a12a279f..f17962bfce1eb 100644
--- a/tools/SourceKit/tools/sourcekitd-test/TestOptions.cpp
+++ b/tools/SourceKit/tools/sourcekitd-test/TestOptions.cpp
@@ -35,13 +35,13 @@ enum Opt {
 #undef OPTION
 };
 
-// Create prefix string literals used in Options.td.
-#define PREFIX(NAME, VALUE)                                                    \
-  constexpr llvm::StringLiteral NAME##_init[] = VALUE;                         \
-  constexpr llvm::ArrayRef<llvm::StringLiteral> NAME(                          \
-      NAME##_init, std::size(NAME##_init) - 1);
+#define OPTTABLE_STR_TABLE_CODE
 #include "Options.inc"
-#undef PREFIX
+#undef OPTTABLE_STR_TABLE_CODE
+
+#define OPTTABLE_PREFIXES_TABLE_CODE
+#include "Options.inc"
+#undef OPTTABLE_PREFIXES_TABLE_CODE
 
 // Create table mapping all options defined in Options.td.
 static const llvm::opt::OptTable::Info InfoTable[] = {
@@ -53,7 +53,8 @@ static const llvm::opt::OptTable::Info InfoTable[] = {
 // Create OptTable class for parsing actual command line arguments
 class TestOptTable : public llvm::opt::GenericOptTable {
 public:
-  TestOptTable() : GenericOptTable(InfoTable) {}
+  TestOptTable()
+      : GenericOptTable(OptionStrTable, OptionPrefixesTable, InfoTable) {}
 };
 
 } // end anonymous namespace
diff --git a/tools/swift-ide-test/swift-ide-test.cpp b/tools/swift-ide-test/swift-ide-test.cpp
index dba714047b1dc..1361ec48e8ea4 100644
--- a/tools/swift-ide-test/swift-ide-test.cpp
+++ b/tools/swift-ide-test/swift-ide-test.cpp
@@ -55,7 +55,7 @@
 #include "swift/Markup/Markup.h"
 #include "swift/Parse/ParseVersion.h"
 #include "swift/Sema/IDETypeChecking.h"
-#include "clang/Rewrite/Core/RewriteBuffer.h"
+#include "llvm/ADT/RewriteBuffer.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/CommandLine.h"
@@ -2273,7 +2273,7 @@ static int doDumpImporterLookupTables(const CompilerInvocation &InitInvok,
 class StructureAnnotator : public ide::SyntaxModelWalker {
   SourceManager &SM;
   unsigned BufferID;
-  clang::RewriteBuffer RewriteBuf;
+  llvm::RewriteBuffer RewriteBuf;
   std::vector<SyntaxStructureNode> NodeStack;
   CharSourceRange LastPoppedNodeRange;
 
diff --git a/tools/swift-reflection-dump/swift-reflection-dump.cpp b/tools/swift-reflection-dump/swift-reflection-dump.cpp
index dba4352311f20..100af2eb203c7 100644
--- a/tools/swift-reflection-dump/swift-reflection-dump.cpp
+++ b/tools/swift-reflection-dump/swift-reflection-dump.cpp
@@ -79,11 +79,13 @@ static llvm::cl::opt<std::string>
                  llvm::cl::desc("Architecture to inspect in the binary"),
                  llvm::cl::Required);
 
-#if SWIFT_OBJC_INTEROP
 static llvm::cl::opt<bool> DisableObjCInterop(
     "no-objc-interop",
-    llvm::cl::desc("Disable Objective-C interoperability support"));
+    llvm::cl::desc("Disable Objective-C interoperability support"
+#if SWIFT_OBJC_INTEROP
+                   " (not supported)"
 #endif
+                   ));
 } // end namespace options
 
 static int doDumpReflectionSections(ArrayRef<std::string> BinaryFilenames,
diff --git a/utils/build.ps1 b/utils/build.ps1
index bc2d8ba443fb0..5cf7ae145932f 100644
--- a/utils/build.ps1
+++ b/utils/build.ps1
@@ -2041,7 +2041,7 @@ function Build-BuildTools([Hashtable] $Platform) {
     -Platform $Platform `
     -UseMSVCCompilers $(if ($UseHostToolchain) { @("ASM_MASM", "C", "CXX") } else { @("") }) `
     -UsePinnedCompilers $(if ($UseHostToolchain) { @("") } else { @("ASM", "C", "CXX") }) `
-    -BuildTargets llvm-tblgen,clang-tblgen,clang-pseudo-gen,clang-tidy-confusable-chars-gen,lldb-tblgen,llvm-config,swift-def-to-strings-converter,swift-serialize-diagnostics,swift-compatibility-symbols `
+    -BuildTargets llvm-tblgen,clang-tblgen,clang-tidy-confusable-chars-gen,lldb-tblgen,llvm-config,swift-def-to-strings-converter,swift-serialize-diagnostics,swift-compatibility-symbols `
     -Defines @{
       CMAKE_CROSSCOMPILING = "NO";
       CLANG_ENABLE_LIBXML2 = "NO";
diff --git a/utils/build_swift/build_swift/defaults.py b/utils/build_swift/build_swift/defaults.py
index 25ce03135ef4f..07d0fbc228b6f 100644
--- a/utils/build_swift/build_swift/defaults.py
+++ b/utils/build_swift/build_swift/defaults.py
@@ -48,7 +48,7 @@
 
 COMPILER_VENDOR = 'none'
 SWIFT_USER_VISIBLE_VERSION = Version('6.3')
-CLANG_USER_VISIBLE_VERSION = Version('17.0.0')
+CLANG_USER_VISIBLE_VERSION = Version('21.0.0')
 SWIFT_ANALYZE_CODE_COVERAGE = 'false'
 
 DARWIN_XCRUN_TOOLCHAIN = 'default'
diff --git a/utils/swift_build_support/swift_build_support/products/llvm.py b/utils/swift_build_support/swift_build_support/products/llvm.py
index 15a9a236f4167..7b484a4b71588 100644
--- a/utils/swift_build_support/swift_build_support/products/llvm.py
+++ b/utils/swift_build_support/swift_build_support/products/llvm.py
@@ -446,8 +446,6 @@ def build(self, host_target):
                                                 'clang-tidy-confusable-chars-gen')
             llvm_cmake_options.define('CLANG_TIDY_CONFUSABLE_CHARS_GEN',
                                       confusable_chars_gen)
-            pseudo_gen = os.path.join(host_build_dir, 'bin', 'clang-pseudo-gen')
-            llvm_cmake_options.define('CLANG_PSEUDO_GEN', pseudo_gen)
             llvm = os.path.join(host_build_dir, 'llvm')
             llvm_cmake_options.define('LLVM_NATIVE_BUILD', llvm)
 
diff --git a/utils/update_checkout/update-checkout-config.json b/utils/update_checkout/update-checkout-config.json
index 8e920661871f1..838fe3286e031 100644
--- a/utils/update_checkout/update-checkout-config.json
+++ b/utils/update_checkout/update-checkout-config.json
@@ -129,10 +129,10 @@
     "default-branch-scheme": "main",
     "branch-schemes": {
         "main": {
-            "aliases": ["swift/main", "main", "stable/20240723"],
+            "aliases": ["swift/main", "main", "stable/21.x"],
             "repos": {
-                "llvm-project": "stable/20240723",
-                "swift-llvm-bindings": "stable/20240723",
+                "llvm-project": "stable/21.x",
+                "swift-llvm-bindings": "stable/21.x",
                 "swift": "main",
                 "cmark": "gfm",
                 "llbuild": "main",
@@ -557,7 +557,7 @@
             }
         },
         "rebranch": {
-            "aliases": ["rebranch", "stable/21.x", "llvm.org/main"],
+            "aliases": ["rebranch", "llvm.org/main"],
             "repos": {
                 "llvm-project": "stable/21.x",
                 "swift-llvm-bindings": "stable/21.x",