diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
diff --git a/clang/include/clang/Sema/SemaBase.h b/clang/include/clang/Sema/SemaBase.h
@@ -146,7 +146,7 @@ class SemaBase {
     ///   if (SemaDiagnosticBuilder(...) << foo << bar)
     ///     return ExprError();
     ///
-    /// But see CUDADiagIfDeviceCode() and CUDADiagIfHostCode() -- you probably
+    /// But see DiagIfDeviceCode() and DiagIfHostCode() -- you probably
     /// want to use these instead of creating a SemaDiagnosticBuilder yourself.
     operator bool() const { return isImmediate(); }
 

diff --git a/clang/include/clang/Sema/SemaCUDA.h b/clang/include/clang/Sema/SemaCUDA.h
@@ -0,0 +1,304 @@
+//===----- SemaCUDA.h ----- Semantic Analysis for CUDA constructs ---------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares semantic analysis for CUDA constructs.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SEMA_SEMACUDA_H
+#define LLVM_CLANG_SEMA_SEMACUDA_H
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/Redeclarable.h"
+#include "clang/Basic/Cuda.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Sema/Lookup.h"
+#include "clang/Sema/Ownership.h"
+#include "clang/Sema/ParsedAttr.h"
+#include "clang/Sema/Scope.h"
+#include "clang/Sema/ScopeInfo.h"
+#include "clang/Sema/SemaBase.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include <string>
+
+namespace clang {
+
+enum class CUDAFunctionTarget;
+
+class SemaCUDA : public SemaBase {
+public:
+  SemaCUDA(Sema &S);
+
+  /// Increments our count of the number of times we've seen a pragma forcing
+  /// functions to be __host__ __device__.  So long as this count is greater
+  /// than zero, all functions encountered will be __host__ __device__.
+  void PushForceHostDevice();
+
+  /// Decrements our count of the number of times we've seen a pragma forcing
+  /// functions to be __host__ __device__.  Returns false if the count is 0
+  /// before incrementing, so you can emit an error.
+  bool PopForceHostDevice();
+
+  ExprResult ActOnExecConfigExpr(Scope *S, SourceLocation LLLLoc,
+                                 MultiExprArg ExecConfig,
+                                 SourceLocation GGGLoc);
+
+  /// A pair of a canonical FunctionDecl and a SourceLocation.  When used as the
+  /// key in a hashtable, both the FD and location are hashed.
+  struct FunctionDeclAndLoc {
+    CanonicalDeclPtr<const FunctionDecl> FD;
+    SourceLocation Loc;
+  };
+
+  /// FunctionDecls and SourceLocations for which CheckCall has emitted a
+  /// (maybe deferred) "bad call" diagnostic.  We use this to avoid emitting the
+  /// same deferred diag twice.
+  llvm::DenseSet<FunctionDeclAndLoc> LocsWithCUDACallDiags;
+
+  /// An inverse call graph, mapping known-emitted functions to one of their
+  /// known-emitted callers (plus the location of the call).
+  ///
+  /// Functions that we can tell a priori must be emitted aren't added to this
+  /// map.
+  llvm::DenseMap</* Callee = */ CanonicalDeclPtr<const FunctionDecl>,
+                 /* Caller = */ FunctionDeclAndLoc>
+      DeviceKnownEmittedFns;
+
+  /// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
+  /// context is "used as device code".
+  ///
+  /// - If CurContext is a __host__ function, does not emit any diagnostics
+  ///   unless \p EmitOnBothSides is true.
+  /// - If CurContext is a __device__ or __global__ function, emits the
+  ///   diagnostics immediately.
+  /// - If CurContext is a __host__ __device__ function and we are compiling for
+  ///   the device, creates a diagnostic which is emitted if and when we realize
+  ///   that the function will be codegen'ed.
+  ///
+  /// Example usage:
+  ///
+  ///  // Variable-length arrays are not allowed in CUDA device code.
+  ///  if (DiagIfDeviceCode(Loc, diag::err_cuda_vla) << CurrentTarget())
+  ///    return ExprError();
+  ///  // Otherwise, continue parsing as normal.
+  SemaDiagnosticBuilder DiagIfDeviceCode(SourceLocation Loc, unsigned DiagID);
+
+  /// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
+  /// context is "used as host code".
+  ///
+  /// Same as DiagIfDeviceCode, with "host" and "device" switched.
+  SemaDiagnosticBuilder DiagIfHostCode(SourceLocation Loc, unsigned DiagID);
+
+  /// Determines whether the given function is a CUDA device/host/kernel/etc.
+  /// function.
+  ///
+  /// Use this rather than examining the function's attributes yourself -- you
+  /// will get it wrong.  Returns CUDAFunctionTarget::Host if D is null.
+  CUDAFunctionTarget IdentifyTarget(const FunctionDecl *D,
+                                    bool IgnoreImplicitHDAttr = false);
+  CUDAFunctionTarget IdentifyTarget(const ParsedAttributesView &Attrs);
+
+  enum CUDAVariableTarget {
+    CVT_Device,  /// Emitted on device side with a shadow variable on host side
+    CVT_Host,    /// Emitted on host side only
+    CVT_Both,    /// Emitted on both sides with different addresses
+    CVT_Unified, /// Emitted as a unified address, e.g. managed variables
+  };
+  /// Determines whether the given variable is emitted on host or device side.
+  CUDAVariableTarget IdentifyTarget(const VarDecl *D);
+
+  /// Defines kinds of CUDA global host/device context where a function may be
+  /// called.
+  enum CUDATargetContextKind {
+    CTCK_Unknown,       /// Unknown context
+    CTCK_InitGlobalVar, /// Function called during global variable
+                        /// initialization
+  };
+
+  /// Define the current global CUDA host/device context where a function may be
+  /// called. Only used when a function is called outside of any functions.
+  struct CUDATargetContext {
+    CUDAFunctionTarget Target = CUDAFunctionTarget::HostDevice;
+    CUDATargetContextKind Kind = CTCK_Unknown;
+    Decl *D = nullptr;
+  } CurCUDATargetCtx;
+
+  struct CUDATargetContextRAII {
+    SemaCUDA &S;
+    SemaCUDA::CUDATargetContext SavedCtx;
+    CUDATargetContextRAII(SemaCUDA &S_, SemaCUDA::CUDATargetContextKind K,
+                          Decl *D);
+    ~CUDATargetContextRAII() { S.CurCUDATargetCtx = SavedCtx; }
+  };
+
+  /// Gets the CUDA target for the current context.
+  CUDAFunctionTarget CurrentTarget() {
+    return IdentifyTarget(dyn_cast<FunctionDecl>(SemaRef.CurContext));
+  }
+
+  static bool isImplicitHostDeviceFunction(const FunctionDecl *D);
+
+  // CUDA function call preference. Must be ordered numerically from
+  // worst to best.
+  enum CUDAFunctionPreference {
+    CFP_Never,      // Invalid caller/callee combination.
+    CFP_WrongSide,  // Calls from host-device to host or device
+                    // function that do not match current compilation
+                    // mode.
+    CFP_HostDevice, // Any calls to host/device functions.
+    CFP_SameSide,   // Calls from host-device to host or device
+                    // function matching current compilation mode.
+    CFP_Native,     // host-to-host or device-to-device calls.
+  };
+
+  /// Identifies relative preference of a given Caller/Callee
+  /// combination, based on their host/device attributes.
+  /// \param Caller function which needs address of \p Callee.
+  ///               nullptr in case of global context.
+  /// \param Callee target function
+  ///
+  /// \returns preference value for particular Caller/Callee combination.
+  CUDAFunctionPreference IdentifyPreference(const FunctionDecl *Caller,
+                                            const FunctionDecl *Callee);
+
+  /// Determines whether Caller may invoke Callee, based on their CUDA
+  /// host/device attributes.  Returns false if the call is not allowed.
+  ///
+  /// Note: Will return true for CFP_WrongSide calls.  These may appear in
+  /// semantically correct CUDA programs, but only if they're never codegen'ed.
+  bool IsAllowedCall(const FunctionDecl *Caller, const FunctionDecl *Callee) {
+    return IdentifyPreference(Caller, Callee) != CFP_Never;
+  }
+
+  /// May add implicit CUDAHostAttr and CUDADeviceAttr attributes to FD,
+  /// depending on FD and the current compilation settings.
+  void maybeAddHostDeviceAttrs(FunctionDecl *FD, const LookupResult &Previous);
+
+  /// May add implicit CUDAConstantAttr attribute to VD, depending on VD
+  /// and current compilation settings.
+  void MaybeAddConstantAttr(VarDecl *VD);
+
+  /// Check whether we're allowed to call Callee from the current context.
+  ///
+  /// - If the call is never allowed in a semantically-correct program
+  ///   (CFP_Never), emits an error and returns false.
+  ///
+  /// - If the call is allowed in semantically-correct programs, but only if
+  ///   it's never codegen'ed (CFP_WrongSide), creates a deferred diagnostic to
+  ///   be emitted if and when the caller is codegen'ed, and returns true.
+  ///
+  ///   Will only create deferred diagnostics for a given SourceLocation once,
+  ///   so you can safely call this multiple times without generating duplicate
+  ///   deferred errors.
+  ///
+  /// - Otherwise, returns true without emitting any diagnostics.
+  bool CheckCall(SourceLocation Loc, FunctionDecl *Callee);
+
+  void CheckLambdaCapture(CXXMethodDecl *D, const sema::Capture &Capture);
+
+  /// Set __device__ or __host__ __device__ attributes on the given lambda
+  /// operator() method.
+  ///
+  /// CUDA lambdas by default is host device function unless it has explicit
+  /// host or device attribute.
+  void SetLambdaAttrs(CXXMethodDecl *Method);
+
+  /// Record \p FD if it is a CUDA/HIP implicit host device function used on
+  /// device side in device compilation.
+  void RecordImplicitHostDeviceFuncUsedByDevice(const FunctionDecl *FD);
+
+  /// Finds a function in \p Matches with highest calling priority
+  /// from \p Caller context and erases all functions with lower
+  /// calling priority.
+  void EraseUnwantedMatches(
+      const FunctionDecl *Caller,
+      llvm::SmallVectorImpl<std::pair<DeclAccessPair, FunctionDecl *>>
+          &Matches);
+
+  /// Given a implicit special member, infer its CUDA target from the
+  /// calls it needs to make to underlying base/field special members.
+  /// \param ClassDecl the class for which the member is being created.
+  /// \param CSM the kind of special member.
+  /// \param MemberDecl the special member itself.
+  /// \param ConstRHS true if this is a copy operation with a const object on
+  ///        its RHS.
+  /// \param Diagnose true if this call should emit diagnostics.
+  /// \return true if there was an error inferring.
+  /// The result of this call is implicit CUDA target attribute(s) attached to
+  /// the member declaration.
+  bool inferTargetForImplicitSpecialMember(CXXRecordDecl *ClassDecl,
+                                           CXXSpecialMemberKind CSM,
+                                           CXXMethodDecl *MemberDecl,
+                                           bool ConstRHS, bool Diagnose);
+
+  /// \return true if \p CD can be considered empty according to CUDA
+  /// (E.2.3.1 in CUDA 7.5 Programming guide).
+  bool isEmptyConstructor(SourceLocation Loc, CXXConstructorDecl *CD);
+  bool isEmptyDestructor(SourceLocation Loc, CXXDestructorDecl *CD);
+
+  // \brief Checks that initializers of \p Var satisfy CUDA restrictions. In
+  // case of error emits appropriate diagnostic and invalidates \p Var.
+  //
+  // \details CUDA allows only empty constructors as initializers for global
+  // variables (see E.2.3.1, CUDA 7.5). The same restriction also applies to all
+  // __shared__ variables whether they are local or not (they all are implicitly
+  // static in CUDA). One exception is that CUDA allows constant initializers
+  // for __constant__ and __device__ variables.
+  void checkAllowedInitializer(VarDecl *VD);
+
+  /// Check whether NewFD is a valid overload for CUDA. Emits
+  /// diagnostics and invalidates NewFD if not.
+  void checkTargetOverload(FunctionDecl *NewFD, const LookupResult &Previous);
+  /// Copies target attributes from the template TD to the function FD.
+  void inheritTargetAttrs(FunctionDecl *FD, const FunctionTemplateDecl &TD);
+
+  /// Returns the name of the launch configuration function.  This is the name
+  /// of the function that will be called to configure kernel call, with the
+  /// parameters specified via <<<>>>.
+  std::string getConfigureFuncName() const;
+
+private:
+  unsigned ForceHostDeviceDepth = 0;
+
+  friend class ASTReader;
+  friend class ASTWriter;
+};
+
+} // namespace clang
+
+namespace llvm {
+// Hash a FunctionDeclAndLoc by looking at both its FunctionDecl and its
+// SourceLocation.
+template <> struct DenseMapInfo<clang::SemaCUDA::FunctionDeclAndLoc> {
+  using FunctionDeclAndLoc = clang::SemaCUDA::FunctionDeclAndLoc;
+  using FDBaseInfo =
+      DenseMapInfo<clang::CanonicalDeclPtr<const clang::FunctionDecl>>;
+
+  static FunctionDeclAndLoc getEmptyKey() {
+    return {FDBaseInfo::getEmptyKey(), clang::SourceLocation()};
+  }
+
+  static FunctionDeclAndLoc getTombstoneKey() {
+    return {FDBaseInfo::getTombstoneKey(), clang::SourceLocation()};
+  }
+
+  static unsigned getHashValue(const FunctionDeclAndLoc &FDL) {
+    return hash_combine(FDBaseInfo::getHashValue(FDL.FD),
+                        FDL.Loc.getHashValue());
+  }
+
+  static bool isEqual(const FunctionDeclAndLoc &LHS,
+                      const FunctionDeclAndLoc &RHS) {
+    return LHS.FD == RHS.FD && LHS.Loc == RHS.Loc;
+  }
+};
+} // namespace llvm
+
+#endif // LLVM_CLANG_SEMA_SEMACUDA_H
diff --git a/clang/include/clang/Sema/SemaHLSL.h b/clang/include/clang/Sema/SemaHLSL.h
@@ -13,23 +13,42 @@
 #ifndef LLVM_CLANG_SEMA_SEMAHLSL_H
 #define LLVM_CLANG_SEMA_SEMAHLSL_H
 
+#include "clang/AST/Attr.h"
+#include "clang/AST/Decl.h"
 #include "clang/AST/DeclBase.h"
 #include "clang/AST/Expr.h"
+#include "clang/Basic/AttributeCommonInfo.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/SemaBase.h"
+#include <initializer_list>
 
 namespace clang {
 
 class SemaHLSL : public SemaBase {
 public:
   SemaHLSL(Sema &S);
 
-  Decl *ActOnStartHLSLBuffer(Scope *BufferScope, bool CBuffer,
-                             SourceLocation KwLoc, IdentifierInfo *Ident,
-                             SourceLocation IdentLoc, SourceLocation LBrace);
-  void ActOnFinishHLSLBuffer(Decl *Dcl, SourceLocation RBrace);
+  Decl *ActOnStartBuffer(Scope *BufferScope, bool CBuffer, SourceLocation KwLoc,
+                         IdentifierInfo *Ident, SourceLocation IdentLoc,
+                         SourceLocation LBrace);
+  void ActOnFinishBuffer(Decl *Dcl, SourceLocation RBrace);
+  HLSLNumThreadsAttr *mergeNumThreadsAttr(Decl *D,
+                                          const AttributeCommonInfo &AL, int X,
+                                          int Y, int Z);
+  HLSLShaderAttr *mergeShaderAttr(Decl *D, const AttributeCommonInfo &AL,
+                                  HLSLShaderAttr::ShaderType ShaderType);
+  HLSLParamModifierAttr *
+  mergeParamModifierAttr(Decl *D, const AttributeCommonInfo &AL,
+                         HLSLParamModifierAttr::Spelling Spelling);
+  void ActOnTopLevelFunction(FunctionDecl *FD);
+  void CheckEntryPoint(FunctionDecl *FD);
+  void CheckSemanticAnnotation(FunctionDecl *EntryPoint, const Decl *Param,
+                               const HLSLAnnotationAttr *AnnotationAttr);
+  void DiagnoseAttrStageMismatch(
+      const Attr *A, HLSLShaderAttr::ShaderType Stage,
+      std::initializer_list<HLSLShaderAttr::ShaderType> AllowedStages);
 };
 
 } // namespace clang

diff --git a/clang/include/clang/Sema/SemaOpenACC.h b/clang/include/clang/Sema/SemaOpenACC.h
@@ -40,7 +40,11 @@ class SemaOpenACC : public SemaBase {
       OpenACCDefaultClauseKind DefaultClauseKind;
     };
 
-    std::variant<DefaultDetails> Details;
+    struct ConditionDetails {
+      Expr *ConditionExpr;
+    };
+
+    std::variant<DefaultDetails, ConditionDetails> Details;
 
   public:
     OpenACCParsedClause(OpenACCDirectiveKind DirKind,
@@ -63,6 +67,16 @@ class SemaOpenACC : public SemaBase {
       return std::get<DefaultDetails>(Details).DefaultClauseKind;
     }
 
+    const Expr *getConditionExpr() const {
+      return const_cast<OpenACCParsedClause *>(this)->getConditionExpr();
+    }
+
+    Expr *getConditionExpr() {
+      assert(ClauseKind == OpenACCClauseKind::If &&
+             "Parsed clause kind does not have a condition expr");
+      return std::get<ConditionDetails>(Details).ConditionExpr;
+    }
+
     void setLParenLoc(SourceLocation EndLoc) { LParenLoc = EndLoc; }
     void setEndLoc(SourceLocation EndLoc) { ClauseRange.setEnd(EndLoc); }
 
@@ -71,6 +85,18 @@ class SemaOpenACC : public SemaBase {
              "Parsed clause is not a default clause");
       Details = DefaultDetails{DefKind};
     }
+
+    void setConditionDetails(Expr *ConditionExpr) {
+      assert(ClauseKind == OpenACCClauseKind::If &&
+             "Parsed clause kind does not have a condition expr");
+      // In C++ we can count on this being a 'bool', but in C this gets left as
+      // some sort of scalar that codegen will have to take care of converting.
+      assert((!ConditionExpr || ConditionExpr->isInstantiationDependent() ||
+              ConditionExpr->getType()->isScalarType()) &&
+             "Condition expression type not scalar/dependent");
+
+      Details = ConditionDetails{ConditionExpr};
+    }
   };
 
   SemaOpenACC(Sema &S);

diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -698,6 +698,10 @@ enum ASTRecordTypes {
   /// Record code for an unterminated \#pragma clang assume_nonnull begin
   /// recorded in a preamble.
   PP_ASSUME_NONNULL_LOC = 67,
+
+  /// Record code for lexical and visible block for delayed namespace in
+  /// reduced BMI.
+  DELAYED_NAMESPACE_LEXICAL_VISIBLE_RECORD = 68,
 };
 
 /// Record types used within a source manager block.

diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
@@ -517,6 +517,20 @@ class ASTReader
   /// in the chain.
   DeclUpdateOffsetsMap DeclUpdateOffsets;
 
+  using DelayedNamespaceOffsetMapTy = llvm::DenseMap<
+      serialization::DeclID,
+      std::pair</*LexicalOffset*/ uint64_t, /*VisibleOffset*/ uint64_t>>;
+
+  /// Mapping from global declaration IDs to the lexical and visible block
+  /// offset for delayed namespace in reduced BMI.
+  ///
+  /// We can't use the existing DeclUpdate mechanism since the DeclUpdate
+  /// may only be applied in an outer most read. However, we need to know
+  /// whether or not a DeclContext has external storage during the recursive
+  /// reading. So we need to apply the offset immediately after we read the
+  /// namespace as if it is not delayed.
+  DelayedNamespaceOffsetMapTy DelayedNamespaceOffsetMap;
+
   struct PendingUpdateRecord {
     Decl *D;
     serialization::GlobalDeclID ID;
@@ -859,7 +873,7 @@ class ASTReader
 
   /// Our current depth in #pragma cuda force_host_device begin/end
   /// macros.
-  unsigned ForceCUDAHostDeviceDepth = 0;
+  unsigned ForceHostDeviceDepth = 0;
 
   /// The IDs of the declarations Sema stores directly.
   ///

diff --git a/clang/include/clang/Serialization/ASTWriter.h b/clang/include/clang/Serialization/ASTWriter.h
@@ -201,6 +201,16 @@ class ASTWriter : public ASTDeserializationListener,
   /// The declarations and types to emit.
   std::queue<DeclOrType> DeclTypesToEmit;
 
+  /// The delayed namespace to emit. Only meaningful for reduced BMI.
+  ///
+  /// In reduced BMI, we want to elide the unreachable declarations in
+  /// the global module fragment. However, in ASTWriterDecl, when we see
+  /// a namespace, all the declarations in the namespace would be emitted.
+  /// So the optimization become meaningless. To solve the issue, we
+  /// delay recording all the declarations until we emit all the declarations.
+  /// Then we can safely record the reached declarations only.
+  llvm::SmallVector<NamespaceDecl *, 16> DelayedNamespace;
+
   /// The first ID number we can use for our own declarations.
   serialization::DeclID FirstDeclID = serialization::NUM_PREDEF_DECL_IDS;
 
@@ -529,7 +539,8 @@ class ASTWriter : public ASTDeserializationListener,
   void WriteType(QualType T);
 
   bool isLookupResultExternal(StoredDeclsList &Result, DeclContext *DC);
-  bool isLookupResultEntirelyExternal(StoredDeclsList &Result, DeclContext *DC);
+  bool isLookupResultEntirelyExternalOrUnreachable(StoredDeclsList &Result,
+                                                   DeclContext *DC);
 
   void GenerateNameLookupTable(const DeclContext *DC,
                                llvm::SmallVectorImpl<char> &LookupTable);
@@ -704,6 +715,15 @@ class ASTWriter : public ASTDeserializationListener,
   /// declaration.
   serialization::DeclID getDeclID(const Decl *D);
 
+  /// Whether or not the declaration got emitted. If not, it wouldn't be
+  /// emitted.
+  ///
+  /// This may only be called after we've done the job to write the
+  /// declarations (marked by DoneWritingDeclsAndTypes).
+  ///
+  /// A declaration may only be omitted in reduced BMI.
+  bool wasDeclEmitted(const Decl *D) const;
+
   unsigned getAnonymousDeclarationNumber(const NamedDecl *D);
 
   /// Add a string to the given record.
@@ -798,6 +818,10 @@ class ASTWriter : public ASTDeserializationListener,
     return WritingModule && WritingModule->isNamedModule();
   }
 
+  bool isGeneratingReducedBMI() const { return GeneratingReducedBMI; }
+
+  bool getDoneWritingDeclsAndTypes() const { return DoneWritingDeclsAndTypes; }
+
 private:
   // ASTDeserializationListener implementation
   void ReaderInitialized(ASTReader *Reader) override;

diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
@@ -142,6 +142,8 @@ class CachedFileSystemEntry {
   CachedFileContents *Contents;
 };
 
+using CachedRealPath = llvm::ErrorOr<std::string>;
+
 /// This class is a shared cache, that caches the 'stat' and 'open' calls to the
 /// underlying real file system, and the scanned preprocessor directives of
 /// files.
@@ -154,9 +156,11 @@ class DependencyScanningFilesystemSharedCache {
     /// The mutex that needs to be locked before mutation of any member.
     mutable std::mutex CacheLock;
 
-    /// Map from filenames to cached entries.
-    llvm::StringMap<const CachedFileSystemEntry *, llvm::BumpPtrAllocator>
-        EntriesByFilename;
+    /// Map from filenames to cached entries and real paths.
+    llvm::StringMap<
+        std::pair<const CachedFileSystemEntry *, const CachedRealPath *>,
+        llvm::BumpPtrAllocator>
+        CacheByFilename;
 
     /// Map from unique IDs to cached entries.
     llvm::DenseMap<llvm::sys::fs::UniqueID, const CachedFileSystemEntry *>
@@ -168,6 +172,9 @@ class DependencyScanningFilesystemSharedCache {
     /// The backing storage for cached contents.
     llvm::SpecificBumpPtrAllocator<CachedFileContents> ContentsStorage;
 
+    /// The backing storage for cached real paths.
+    llvm::SpecificBumpPtrAllocator<CachedRealPath> RealPathStorage;
+
     /// Returns entry associated with the filename or nullptr if none is found.
     const CachedFileSystemEntry *findEntryByFilename(StringRef Filename) const;
 
@@ -194,6 +201,17 @@ class DependencyScanningFilesystemSharedCache {
     const CachedFileSystemEntry &
     getOrInsertEntryForFilename(StringRef Filename,
                                 const CachedFileSystemEntry &Entry);
+
+    /// Returns the real path associated with the filename or nullptr if none is
+    /// found.
+    const CachedRealPath *findRealPathByFilename(StringRef Filename) const;
+
+    /// Returns the real path associated with the filename if there is some.
+    /// Otherwise, constructs new one with the given one, associates it with the
+    /// filename and returns the result.
+    const CachedRealPath &
+    getOrEmplaceRealPathForFilename(StringRef Filename,
+                                    llvm::ErrorOr<StringRef> RealPath);
   };
 
   DependencyScanningFilesystemSharedCache();
@@ -210,14 +228,17 @@ class DependencyScanningFilesystemSharedCache {
 /// This class is a local cache, that caches the 'stat' and 'open' calls to the
 /// underlying real file system.
 class DependencyScanningFilesystemLocalCache {
-  llvm::StringMap<const CachedFileSystemEntry *, llvm::BumpPtrAllocator> Cache;
+  llvm::StringMap<
+      std::pair<const CachedFileSystemEntry *, const CachedRealPath *>,
+      llvm::BumpPtrAllocator>
+      Cache;
 
 public:
   /// Returns entry associated with the filename or nullptr if none is found.
   const CachedFileSystemEntry *findEntryByFilename(StringRef Filename) const {
     assert(llvm::sys::path::is_absolute_gnu(Filename));
     auto It = Cache.find(Filename);
-    return It == Cache.end() ? nullptr : It->getValue();
+    return It == Cache.end() ? nullptr : It->getValue().first;
   }
 
   /// Associates the given entry with the filename and returns the given entry
@@ -226,9 +247,40 @@ class DependencyScanningFilesystemLocalCache {
   insertEntryForFilename(StringRef Filename,
                          const CachedFileSystemEntry &Entry) {
     assert(llvm::sys::path::is_absolute_gnu(Filename));
-    const auto *InsertedEntry = Cache.insert({Filename, &Entry}).first->second;
-    assert(InsertedEntry == &Entry && "entry already present");
-    return *InsertedEntry;
+    auto [It, Inserted] = Cache.insert({Filename, {&Entry, nullptr}});
+    auto &[CachedEntry, CachedRealPath] = It->getValue();
+    if (!Inserted) {
+      // The file is already present in the local cache. If we got here, it only
+      // contains the real path. Let's make sure the entry is populated too.
+      assert((!CachedEntry && CachedRealPath) && "entry already present");
+      CachedEntry = &Entry;
+    }
+    return *CachedEntry;
+  }
+
+  /// Returns real path associated with the filename or nullptr if none is
+  /// found.
+  const CachedRealPath *findRealPathByFilename(StringRef Filename) const {
+    assert(llvm::sys::path::is_absolute_gnu(Filename));
+    auto It = Cache.find(Filename);
+    return It == Cache.end() ? nullptr : It->getValue().second;
+  }
+
+  /// Associates the given real path with the filename and returns the given
+  /// entry pointer (for convenience).
+  const CachedRealPath &
+  insertRealPathForFilename(StringRef Filename,
+                            const CachedRealPath &RealPath) {
+    assert(llvm::sys::path::is_absolute_gnu(Filename));
+    auto [It, Inserted] = Cache.insert({Filename, {nullptr, &RealPath}});
+    auto &[CachedEntry, CachedRealPath] = It->getValue();
+    if (!Inserted) {
+      // The file is already present in the local cache. If we got here, it only
+      // contains the entry. Let's make sure the real path is populated too.
+      assert((!CachedRealPath && CachedEntry) && "real path already present");
+      CachedRealPath = &RealPath;
+    }
+    return *CachedRealPath;
   }
 };
 
@@ -296,6 +348,9 @@ class DependencyScanningWorkerFilesystem
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
   openFileForRead(const Twine &Path) override;
 
+  std::error_code getRealPath(const Twine &Path,
+                              SmallVectorImpl<char> &Output) override;
+
   std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
 
   /// Returns entry for the given filename.
@@ -310,6 +365,10 @@ class DependencyScanningWorkerFilesystem
   /// false if not (i.e. this entry is not a file or its scan fails).
   bool ensureDirectiveTokensArePopulated(EntryRef Entry);
 
+  /// Check whether \p Path exists. By default checks cached result of \c
+  /// status(), and falls back on FS if unable to do so.
+  bool exists(const Twine &Path) override;
+
 private:
   /// For a filename that's not yet associated with any entry in the caches,
   /// uses the underlying filesystem to either look up the entry based in the
@@ -402,6 +461,10 @@ class DependencyScanningWorkerFilesystem
   llvm::ErrorOr<std::string> WorkingDirForCacheLookup;
 
   void updateWorkingDirForCacheLookup();
+
+  llvm::ErrorOr<StringRef>
+  tryGetFilenameForLookup(StringRef OriginalFilename,
+                          llvm::SmallVectorImpl<char> &PathBuf) const;
 };
 
 } // end namespace dependencies

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
@@ -799,7 +799,7 @@ ASTContext::getCanonicalTemplateTemplateParmDecl(
 
   TemplateTemplateParmDecl *CanonTTP = TemplateTemplateParmDecl::Create(
       *this, getTranslationUnitDecl(), SourceLocation(), TTP->getDepth(),
-      TTP->getPosition(), TTP->isParameterPack(), nullptr,
+      TTP->getPosition(), TTP->isParameterPack(), nullptr, /*Typename=*/false,
       TemplateParameterList::Create(*this, SourceLocation(), SourceLocation(),
                                     CanonParams, SourceLocation(),
                                     /*RequiresClause=*/nullptr));

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
@@ -3947,6 +3947,14 @@ ExpectedDecl ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
     // decl and its redeclarations may be required.
   }
 
+  StringLiteral *Msg = D->getDeletedMessage();
+  if (Msg) {
+    auto Imported = import(Msg);
+    if (!Imported)
+      return Imported.takeError();
+    Msg = *Imported;
+  }
+
   ToFunction->setQualifierInfo(ToQualifierLoc);
   ToFunction->setAccess(D->getAccess());
   ToFunction->setLexicalDeclContext(LexicalDC);
@@ -3961,6 +3969,11 @@ ExpectedDecl ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
   ToFunction->setRangeEnd(ToEndLoc);
   ToFunction->setDefaultLoc(ToDefaultLoc);
 
+  if (Msg)
+    ToFunction->setDefaultedOrDeletedInfo(
+        FunctionDecl::DefaultedOrDeletedFunctionInfo::Create(
+            Importer.getToContext(), {}, Msg));
+
   // Set the parameters.
   for (auto *Param : Parameters) {
     Param->setOwningFunction(ToFunction);
@@ -5952,7 +5965,8 @@ ASTNodeImporter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
           ToD, D, Importer.getToContext(),
           Importer.getToContext().getTranslationUnitDecl(), *LocationOrErr,
           D->getDepth(), D->getPosition(), D->isParameterPack(),
-          (*NameOrErr).getAsIdentifierInfo(), *TemplateParamsOrErr))
+          (*NameOrErr).getAsIdentifierInfo(), D->wasDeclaredWithTypename(),
+          *TemplateParamsOrErr))
     return ToD;
 
   if (D->hasDefaultArgument()) {

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
@@ -3058,7 +3058,7 @@ FunctionDecl::FunctionDecl(Kind DK, ASTContext &C, DeclContext *DC,
   FunctionDeclBits.IsTrivialForCall = false;
   FunctionDeclBits.IsDefaulted = false;
   FunctionDeclBits.IsExplicitlyDefaulted = false;
-  FunctionDeclBits.HasDefaultedFunctionInfo = false;
+  FunctionDeclBits.HasDefaultedOrDeletedInfo = false;
   FunctionDeclBits.IsIneligibleOrNotSelected = false;
   FunctionDeclBits.HasImplicitReturnZero = false;
   FunctionDeclBits.IsLateTemplateParsed = false;
@@ -3092,30 +3092,65 @@ bool FunctionDecl::isVariadic() const {
   return false;
 }
 
-FunctionDecl::DefaultedFunctionInfo *
-FunctionDecl::DefaultedFunctionInfo::Create(ASTContext &Context,
-                                            ArrayRef<DeclAccessPair> Lookups) {
-  DefaultedFunctionInfo *Info = new (Context.Allocate(
-      totalSizeToAlloc<DeclAccessPair>(Lookups.size()),
-      std::max(alignof(DefaultedFunctionInfo), alignof(DeclAccessPair))))
-      DefaultedFunctionInfo;
+FunctionDecl::DefaultedOrDeletedFunctionInfo *
+FunctionDecl::DefaultedOrDeletedFunctionInfo::Create(
+    ASTContext &Context, ArrayRef<DeclAccessPair> Lookups,
+    StringLiteral *DeletedMessage) {
+  static constexpr size_t Alignment =
+      std::max({alignof(DefaultedOrDeletedFunctionInfo),
+                alignof(DeclAccessPair), alignof(StringLiteral *)});
+  size_t Size = totalSizeToAlloc<DeclAccessPair, StringLiteral *>(
+      Lookups.size(), DeletedMessage != nullptr);
+
+  DefaultedOrDeletedFunctionInfo *Info =
+      new (Context.Allocate(Size, Alignment)) DefaultedOrDeletedFunctionInfo;
   Info->NumLookups = Lookups.size();
+  Info->HasDeletedMessage = DeletedMessage != nullptr;
+
   std::uninitialized_copy(Lookups.begin(), Lookups.end(),
                           Info->getTrailingObjects<DeclAccessPair>());
+  if (DeletedMessage)
+    *Info->getTrailingObjects<StringLiteral *>() = DeletedMessage;
   return Info;
 }
 
-void FunctionDecl::setDefaultedFunctionInfo(DefaultedFunctionInfo *Info) {
-  assert(!FunctionDeclBits.HasDefaultedFunctionInfo && "already have this");
+void FunctionDecl::setDefaultedOrDeletedInfo(
+    DefaultedOrDeletedFunctionInfo *Info) {
+  assert(!FunctionDeclBits.HasDefaultedOrDeletedInfo && "already have this");
   assert(!Body && "can't replace function body with defaulted function info");
 
-  FunctionDeclBits.HasDefaultedFunctionInfo = true;
-  DefaultedInfo = Info;
+  FunctionDeclBits.HasDefaultedOrDeletedInfo = true;
+  DefaultedOrDeletedInfo = Info;
+}
+
+void FunctionDecl::setDeletedAsWritten(bool D, StringLiteral *Message) {
+  FunctionDeclBits.IsDeleted = D;
+
+  if (Message) {
+    assert(isDeletedAsWritten() && "Function must be deleted");
+    if (FunctionDeclBits.HasDefaultedOrDeletedInfo)
+      DefaultedOrDeletedInfo->setDeletedMessage(Message);
+    else
+      setDefaultedOrDeletedInfo(DefaultedOrDeletedFunctionInfo::Create(
+          getASTContext(), /*Lookups=*/{}, Message));
+  }
+}
+
+void FunctionDecl::DefaultedOrDeletedFunctionInfo::setDeletedMessage(
+    StringLiteral *Message) {
+  // We should never get here with the DefaultedOrDeletedInfo populated, but
+  // no space allocated for the deleted message, since that would require
+  // recreating this, but setDefaultedOrDeletedInfo() disallows overwriting
+  // an already existing DefaultedOrDeletedFunctionInfo.
+  assert(HasDeletedMessage &&
+         "No space to store a delete message in this DefaultedOrDeletedInfo");
+  *getTrailingObjects<StringLiteral *>() = Message;
 }
 
-FunctionDecl::DefaultedFunctionInfo *
-FunctionDecl::getDefaultedFunctionInfo() const {
-  return FunctionDeclBits.HasDefaultedFunctionInfo ? DefaultedInfo : nullptr;
+FunctionDecl::DefaultedOrDeletedFunctionInfo *
+FunctionDecl::getDefalutedOrDeletedInfo() const {
+  return FunctionDeclBits.HasDefaultedOrDeletedInfo ? DefaultedOrDeletedInfo
+                                                    : nullptr;
 }
 
 bool FunctionDecl::hasBody(const FunctionDecl *&Definition) const {
@@ -3202,7 +3237,7 @@ Stmt *FunctionDecl::getBody(const FunctionDecl *&Definition) const {
   if (!hasBody(Definition))
     return nullptr;
 
-  assert(!Definition->FunctionDeclBits.HasDefaultedFunctionInfo &&
+  assert(!Definition->FunctionDeclBits.HasDefaultedOrDeletedInfo &&
          "definition should not have a body");
   if (Definition->Body)
     return Definition->Body.get(getASTContext().getExternalSource());
@@ -3211,7 +3246,7 @@ Stmt *FunctionDecl::getBody(const FunctionDecl *&Definition) const {
 }
 
 void FunctionDecl::setBody(Stmt *B) {
-  FunctionDeclBits.HasDefaultedFunctionInfo = false;
+  FunctionDeclBits.HasDefaultedOrDeletedInfo = false;
   Body = LazyDeclStmtPtr(B);
   if (B)
     EndRangeLoc = B->getEndLoc();

diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp
@@ -822,9 +822,14 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
 
   if (D->isPureVirtual())
     Out << " = 0";
-  else if (D->isDeletedAsWritten())
+  else if (D->isDeletedAsWritten()) {
     Out << " = delete";
-  else if (D->isExplicitlyDefaulted())
+    if (const StringLiteral *M = D->getDeletedMessage()) {
+      Out << "(";
+      M->outputString(Out);
+      Out << ")";
+    }
+  } else if (D->isExplicitlyDefaulted())
     Out << " = default";
   else if (D->doesThisDeclarationHaveABody()) {
     if (!Policy.TerseOutput) {
@@ -1218,7 +1223,10 @@ void DeclPrinter::VisitTemplateDecl(const TemplateDecl *D) {
 
   if (const TemplateTemplateParmDecl *TTP =
         dyn_cast<TemplateTemplateParmDecl>(D)) {
-    Out << "class";
+    if (TTP->wasDeclaredWithTypename())
+      Out << "typename";
+    else
+      Out << "class";
 
     if (TTP->isParameterPack())
       Out << " ...";

diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
@@ -805,10 +805,10 @@ void TemplateTemplateParmDecl::anchor() {}
 
 TemplateTemplateParmDecl::TemplateTemplateParmDecl(
     DeclContext *DC, SourceLocation L, unsigned D, unsigned P,
-    IdentifierInfo *Id, TemplateParameterList *Params,
+    IdentifierInfo *Id, bool Typename, TemplateParameterList *Params,
     ArrayRef<TemplateParameterList *> Expansions)
     : TemplateDecl(TemplateTemplateParm, DC, L, Id, Params),
-      TemplateParmPosition(D, P), ParameterPack(true),
+      TemplateParmPosition(D, P), Typename(Typename), ParameterPack(true),
       ExpandedParameterPack(true), NumExpandedParams(Expansions.size()) {
   if (!Expansions.empty())
     std::uninitialized_copy(Expansions.begin(), Expansions.end(),
@@ -819,26 +819,26 @@ TemplateTemplateParmDecl *
 TemplateTemplateParmDecl::Create(const ASTContext &C, DeclContext *DC,
                                  SourceLocation L, unsigned D, unsigned P,
                                  bool ParameterPack, IdentifierInfo *Id,
-                                 TemplateParameterList *Params) {
+                                 bool Typename, TemplateParameterList *Params) {
   return new (C, DC) TemplateTemplateParmDecl(DC, L, D, P, ParameterPack, Id,
-                                              Params);
+                                              Typename, Params);
 }
 
 TemplateTemplateParmDecl *
 TemplateTemplateParmDecl::Create(const ASTContext &C, DeclContext *DC,
                                  SourceLocation L, unsigned D, unsigned P,
-                                 IdentifierInfo *Id,
+                                 IdentifierInfo *Id, bool Typename,
                                  TemplateParameterList *Params,
                                  ArrayRef<TemplateParameterList *> Expansions) {
   return new (C, DC,
               additionalSizeToAlloc<TemplateParameterList *>(Expansions.size()))
-      TemplateTemplateParmDecl(DC, L, D, P, Id, Params, Expansions);
+      TemplateTemplateParmDecl(DC, L, D, P, Id, Typename, Params, Expansions);
 }
 
 TemplateTemplateParmDecl *
 TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
   return new (C, ID) TemplateTemplateParmDecl(nullptr, SourceLocation(), 0, 0,
-                                              false, nullptr, nullptr);
+                                              false, nullptr, false, nullptr);
 }
 
 TemplateTemplateParmDecl *
@@ -847,7 +847,7 @@ TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID,
   auto *TTP =
       new (C, ID, additionalSizeToAlloc<TemplateParameterList *>(NumExpansions))
           TemplateTemplateParmDecl(nullptr, SourceLocation(), 0, 0, nullptr,
-                                   nullptr, std::nullopt);
+                                   false, nullptr, std::nullopt);
   TTP->NumExpandedParams = NumExpansions;
   return TTP;
 }
@@ -1469,7 +1469,7 @@ createMakeIntegerSeqParameterList(const ASTContext &C, DeclContext *DC) {
   // template <typename T, ...Ints> class IntSeq
   auto *TemplateTemplateParm = TemplateTemplateParmDecl::Create(
       C, DC, SourceLocation(), /*Depth=*/0, /*Position=*/0,
-      /*ParameterPack=*/false, /*Id=*/nullptr, TPL);
+      /*ParameterPack=*/false, /*Id=*/nullptr, /*Typename=*/false, TPL);
   TemplateTemplateParm->setImplicit(true);
 
   // typename T

diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -2778,26 +2778,34 @@ bool ByteCodeExprGen<Emitter>::visitVarDecl(const VarDecl *VD) {
   std::optional<PrimType> VarT = classify(VD->getType());
 
   if (Context::shouldBeGloballyIndexed(VD)) {
-    // We've already seen and initialized this global.
-    if (P.getGlobal(VD))
-      return true;
-
-    std::optional<unsigned> GlobalIndex = P.createGlobal(VD, Init);
-
-    if (!GlobalIndex)
-      return false;
-
-    if (Init) {
+    auto initGlobal = [&](unsigned GlobalIndex) -> bool {
+      assert(Init);
       DeclScope<Emitter> LocalScope(this, VD);
 
       if (VarT) {
         if (!this->visit(Init))
           return false;
-        return this->emitInitGlobal(*VarT, *GlobalIndex, VD);
+        return this->emitInitGlobal(*VarT, GlobalIndex, VD);
       }
-      return this->visitGlobalInitializer(Init, *GlobalIndex);
+      return this->visitGlobalInitializer(Init, GlobalIndex);
+    };
+
+    // We've already seen and initialized this global.
+    if (std::optional<unsigned> GlobalIndex = P.getGlobal(VD)) {
+      if (P.getPtrGlobal(*GlobalIndex).isInitialized())
+        return true;
+
+      // The previous attempt at initialization might've been unsuccessful,
+      // so let's try this one.
+      return Init && initGlobal(*GlobalIndex);
     }
-    return true;
+
+    std::optional<unsigned> GlobalIndex = P.createGlobal(VD, Init);
+
+    if (!GlobalIndex)
+      return false;
+
+    return !Init || initGlobal(*GlobalIndex);
   } else {
     VariableScope<Emitter> LocalScope(this);
     if (VarT) {

diff --git a/clang/lib/AST/Interp/FunctionPointer.h b/clang/lib/AST/Interp/FunctionPointer.h
@@ -20,31 +20,45 @@ namespace interp {
 class FunctionPointer final {
 private:
   const Function *Func;
+  bool Valid;
 
 public:
-  // FIXME: We might want to track the fact that the Function pointer
-  // has been created from an integer and is most likely garbage anyway.
-  FunctionPointer(uintptr_t IntVal = 0, const Descriptor *Desc = nullptr)
-      : Func(reinterpret_cast<const Function *>(IntVal)) {}
+  FunctionPointer(const Function *Func) : Func(Func), Valid(true) {
+    assert(Func);
+  }
 
-  FunctionPointer(const Function *Func) : Func(Func) { assert(Func); }
+  FunctionPointer(uintptr_t IntVal = 0, const Descriptor *Desc = nullptr)
+      : Func(reinterpret_cast<const Function *>(IntVal)), Valid(false) {}
 
   const Function *getFunction() const { return Func; }
   bool isZero() const { return !Func; }
+  bool isWeak() const {
+    if (!Func || !Valid)
+      return false;
+
+    return Func->getDecl()->isWeak();
+  }
 
   APValue toAPValue() const {
     if (!Func)
       return APValue(static_cast<Expr *>(nullptr), CharUnits::Zero(), {},
                      /*OnePastTheEnd=*/false, /*IsNull=*/true);
 
+    if (!Valid)
+      return APValue(static_cast<Expr *>(nullptr),
+                     CharUnits::fromQuantity(getIntegerRepresentation()), {},
+                     /*OnePastTheEnd=*/false, /*IsNull=*/false);
+
     return APValue(Func->getDecl(), CharUnits::Zero(), {},
                    /*OnePastTheEnd=*/false, /*IsNull=*/false);
   }
 
   void print(llvm::raw_ostream &OS) const {
     OS << "FnPtr(";
-    if (Func)
+    if (Func && Valid)
       OS << Func->getName();
+    else if (Func)
+      OS << reinterpret_cast<uintptr_t>(Func);
     else
       OS << "nullptr";
     OS << ")";

diff --git a/clang/lib/AST/Interp/Interp.cpp b/clang/lib/AST/Interp/Interp.cpp
@@ -56,22 +56,65 @@ static bool Jf(InterpState &S, CodePtr &PC, int32_t Offset) {
   return true;
 }
 
+static void diagnoseMissingInitializer(InterpState &S, CodePtr OpPC,
+                                       const ValueDecl *VD) {
+  const SourceInfo &E = S.Current->getSource(OpPC);
+  S.FFDiag(E, diag::note_constexpr_var_init_unknown, 1) << VD;
+  S.Note(VD->getLocation(), diag::note_declared_at) << VD->getSourceRange();
+}
+
+static void diagnoseNonConstVariable(InterpState &S, CodePtr OpPC,
+                                     const ValueDecl *VD);
+static bool diagnoseUnknownDecl(InterpState &S, CodePtr OpPC,
+                                const ValueDecl *D) {
+  const SourceInfo &E = S.Current->getSource(OpPC);
+
+  if (isa<ParmVarDecl>(D)) {
+    if (S.getLangOpts().CPlusPlus11) {
+      S.FFDiag(E, diag::note_constexpr_function_param_value_unknown) << D;
+      S.Note(D->getLocation(), diag::note_declared_at) << D->getSourceRange();
+    } else {
+      S.FFDiag(E);
+    }
+  } else if (const auto *VD = dyn_cast<VarDecl>(D)) {
+    if (!VD->getType().isConstQualified()) {
+      diagnoseNonConstVariable(S, OpPC, VD);
+      return false;
+    }
+
+    // const, but no initializer.
+    if (!VD->getAnyInitializer()) {
+      diagnoseMissingInitializer(S, OpPC, VD);
+      return false;
+    }
+  }
+  return false;
+}
+
 static void diagnoseNonConstVariable(InterpState &S, CodePtr OpPC,
                                      const ValueDecl *VD) {
   if (!S.getLangOpts().CPlusPlus)
     return;
 
   const SourceInfo &Loc = S.Current->getSource(OpPC);
+  if (const auto *VarD = dyn_cast<VarDecl>(VD);
+      VarD && VarD->getType().isConstQualified() &&
+      !VarD->getAnyInitializer()) {
+    diagnoseMissingInitializer(S, OpPC, VD);
+    return;
+  }
 
-  if (VD->getType()->isIntegralOrEnumerationType())
+  if (VD->getType()->isIntegralOrEnumerationType()) {
     S.FFDiag(Loc, diag::note_constexpr_ltor_non_const_int, 1) << VD;
-  else
-    S.FFDiag(Loc,
-             S.getLangOpts().CPlusPlus11
-                 ? diag::note_constexpr_ltor_non_constexpr
-                 : diag::note_constexpr_ltor_non_integral,
-             1)
-        << VD << VD->getType();
+    S.Note(VD->getLocation(), diag::note_declared_at);
+    return;
+  }
+
+  S.FFDiag(Loc,
+           S.getLangOpts().CPlusPlus11 ? diag::note_constexpr_ltor_non_constexpr
+                                       : diag::note_constexpr_ltor_non_integral,
+           1)
+      << VD << VD->getType();
   S.Note(VD->getLocation(), diag::note_declared_at);
 }
 
@@ -202,6 +245,9 @@ bool CheckExtern(InterpState &S, CodePtr OpPC, const Pointer &Ptr) {
   if (!Ptr.isExtern())
     return true;
 
+  if (Ptr.isInitialized())
+    return true;
+
   if (!S.checkingPotentialConstantExpression() && S.getLangOpts().CPlusPlus) {
     const auto *VD = Ptr.getDeclDesc()->asValueDecl();
     diagnoseNonConstVariable(S, OpPC, VD);
@@ -369,9 +415,15 @@ bool CheckInitialized(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
   if (const auto *VD = Ptr.getDeclDesc()->asVarDecl();
       VD && VD->hasGlobalStorage()) {
     const SourceInfo &Loc = S.Current->getSource(OpPC);
-    S.FFDiag(Loc, diag::note_constexpr_var_init_non_constant, 1) << VD;
-    S.Note(VD->getLocation(), diag::note_declared_at);
+    if (VD->getAnyInitializer()) {
+      S.FFDiag(Loc, diag::note_constexpr_var_init_non_constant, 1) << VD;
+      S.Note(VD->getLocation(), diag::note_declared_at);
+    } else {
+      diagnoseMissingInitializer(S, OpPC, VD);
+    }
+    return false;
   }
+
   if (!S.checkingPotentialConstantExpression()) {
     S.FFDiag(S.Current->getSource(OpPC), diag::note_constexpr_access_uninit)
         << AK << /*uninitialized=*/true << S.Current->getRange(OpPC);
@@ -598,33 +650,6 @@ bool CheckFloatResult(InterpState &S, CodePtr OpPC, const Floating &Result,
   return true;
 }
 
-static bool diagnoseUnknownDecl(InterpState &S, CodePtr OpPC,
-                                const ValueDecl *D) {
-  const SourceInfo &E = S.Current->getSource(OpPC);
-
-  if (isa<ParmVarDecl>(D)) {
-    if (S.getLangOpts().CPlusPlus11) {
-      S.FFDiag(E, diag::note_constexpr_function_param_value_unknown) << D;
-      S.Note(D->getLocation(), diag::note_declared_at) << D->getSourceRange();
-    } else {
-      S.FFDiag(E);
-    }
-  } else if (const auto *VD = dyn_cast<VarDecl>(D)) {
-    if (!VD->getType().isConstQualified()) {
-      diagnoseNonConstVariable(S, OpPC, VD);
-      return false;
-    }
-
-    // const, but no initializer.
-    if (!VD->getAnyInitializer()) {
-      S.FFDiag(E, diag::note_constexpr_var_init_unknown, 1) << VD;
-      S.Note(VD->getLocation(), diag::note_declared_at) << VD->getSourceRange();
-      return false;
-    }
-  }
-  return false;
-}
-
 /// We aleady know the given DeclRefExpr is invalid for some reason,
 /// now figure out why and print appropriate diagnostics.
 bool CheckDeclRef(InterpState &S, CodePtr OpPC, const DeclRefExpr *DR) {

diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h
@@ -758,7 +758,7 @@ inline bool CmpHelperEQ<FunctionPointer>(InterpState &S, CodePtr OpPC,
 
   // We cannot compare against weak declarations at compile time.
   for (const auto &FP : {LHS, RHS}) {
-    if (!FP.isZero() && FP.getFunction()->getDecl()->isWeak()) {
+    if (FP.isWeak()) {
       const SourceInfo &Loc = S.Current->getSource(OpPC);
       S.FFDiag(Loc, diag::note_constexpr_pointer_weak_comparison)
           << FP.toDiagnosticString(S.getCtx());

diff --git a/clang/lib/AST/Interp/InterpState.h b/clang/lib/AST/Interp/InterpState.h
@@ -89,7 +89,11 @@ class InterpState final : public State, public SourceMapper {
 
   /// Delegates source mapping to the mapper.
   SourceInfo getSource(const Function *F, CodePtr PC) const override {
-    return M ? M->getSource(F, PC) : F->getSource(PC);
+    if (M)
+      return M->getSource(F, PC);
+
+    assert(F && "Function cannot be null");
+    return F->getSource(PC);
   }
 
   Context &getContext() const { return Ctx; }

diff --git a/clang/lib/AST/Interp/Program.cpp b/clang/lib/AST/Interp/Program.cpp
@@ -177,7 +177,7 @@ std::optional<unsigned> Program::createGlobal(const ValueDecl *VD,
   bool IsStatic, IsExtern;
   if (const auto *Var = dyn_cast<VarDecl>(VD)) {
     IsStatic = Context::shouldBeGloballyIndexed(VD);
-    IsExtern = !Var->getAnyInitializer();
+    IsExtern = Var->hasExternalStorage();
   } else if (isa<UnnamedGlobalConstantDecl, MSGuidDecl>(VD)) {
     IsStatic = true;
     IsExtern = false;

diff --git a/clang/lib/AST/JSONNodeDumper.cpp b/clang/lib/AST/JSONNodeDumper.cpp
@@ -975,6 +975,9 @@ void JSONNodeDumper::VisitFunctionDecl(const FunctionDecl *FD) {
   if (FD->isDefaulted())
     JOS.attribute("explicitlyDefaulted",
                   FD->isDeleted() ? "deleted" : "default");
+
+  if (StringLiteral *Msg = FD->getDeletedMessage())
+    JOS.attribute("deletedMessage", Msg->getString());
 }
 
 void JSONNodeDumper::VisitEnumDecl(const EnumDecl *ED) {
@@ -1576,6 +1579,14 @@ void JSONNodeDumper::VisitMaterializeTemporaryExpr(
   attributeOnlyIfTrue("boundToLValueRef", MTE->isBoundToLvalueReference());
 }
 
+void JSONNodeDumper::VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *Node) {
+  attributeOnlyIfTrue("hasRewrittenInit", Node->hasRewrittenInit());
+}
+
+void JSONNodeDumper::VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *Node) {
+  attributeOnlyIfTrue("hasRewrittenInit", Node->hasRewrittenInit());
+}
+
 void JSONNodeDumper::VisitCXXDependentScopeMemberExpr(
     const CXXDependentScopeMemberExpr *DSME) {
   JOS.attribute("isArrow", DSME->isArrow());

diff --git a/clang/lib/AST/ODRHash.cpp b/clang/lib/AST/ODRHash.cpp
@@ -696,6 +696,12 @@ void ODRHash::AddFunctionDecl(const FunctionDecl *Function,
   AddBoolean(Function->isDeletedAsWritten());
   AddBoolean(Function->isExplicitlyDefaulted());
 
+  StringLiteral *DeletedMessage = Function->getDeletedMessage();
+  AddBoolean(DeletedMessage);
+
+  if (DeletedMessage)
+    ID.AddString(DeletedMessage->getBytes());
+
   AddDecl(Function);
 
   AddQualType(Function->getReturnType());

diff --git a/clang/lib/AST/OpenACCClause.cpp b/clang/lib/AST/OpenACCClause.cpp
@@ -13,6 +13,7 @@
 
 #include "clang/AST/OpenACCClause.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/Expr.h"
 
 using namespace clang;
 
@@ -27,10 +28,47 @@ OpenACCDefaultClause *OpenACCDefaultClause::Create(const ASTContext &C,
   return new (Mem) OpenACCDefaultClause(K, BeginLoc, LParenLoc, EndLoc);
 }
 
+OpenACCIfClause *OpenACCIfClause::Create(const ASTContext &C,
+                                         SourceLocation BeginLoc,
+                                         SourceLocation LParenLoc,
+                                         Expr *ConditionExpr,
+                                         SourceLocation EndLoc) {
+  void *Mem = C.Allocate(sizeof(OpenACCIfClause), alignof(OpenACCIfClause));
+  return new (Mem) OpenACCIfClause(BeginLoc, LParenLoc, ConditionExpr, EndLoc);
+}
+
+OpenACCIfClause::OpenACCIfClause(SourceLocation BeginLoc,
+                                 SourceLocation LParenLoc, Expr *ConditionExpr,
+                                 SourceLocation EndLoc)
+    : OpenACCClauseWithCondition(OpenACCClauseKind::If, BeginLoc, LParenLoc,
+                                 ConditionExpr, EndLoc) {
+  assert(ConditionExpr && "if clause requires condition expr");
+  assert((ConditionExpr->isInstantiationDependent() ||
+          ConditionExpr->getType()->isScalarType()) &&
+         "Condition expression type not scalar/dependent");
+}
+
+OpenACCClause::child_range OpenACCClause::children() {
+  switch (getClauseKind()) {
+  default:
+    assert(false && "Clause children function not implemented");
+    break;
+#define VISIT_CLAUSE(CLAUSE_NAME)                                              \
+  case OpenACCClauseKind::CLAUSE_NAME:                                         \
+    return cast<OpenACC##CLAUSE_NAME##Clause>(this)->children();
+
+#include "clang/Basic/OpenACCClauses.def"
+  }
+  return child_range(child_iterator(), child_iterator());
+}
+
 //===----------------------------------------------------------------------===//
 //  OpenACC clauses printing methods
 //===----------------------------------------------------------------------===//
-void OpenACCClausePrinter::VisitOpenACCDefaultClause(
-    const OpenACCDefaultClause &C) {
+void OpenACCClausePrinter::VisitDefaultClause(const OpenACCDefaultClause &C) {
   OS << "default(" << C.getDefaultClauseKind() << ")";
 }
+
+void OpenACCClausePrinter::VisitIfClause(const OpenACCIfClause &C) {
+  OS << "if(" << C.getConditionExpr() << ")";
+}
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
@@ -2445,9 +2445,10 @@ void StmtProfiler::VisitTemplateArgument(const TemplateArgument &Arg) {
 namespace {
 class OpenACCClauseProfiler
     : public OpenACCClauseVisitor<OpenACCClauseProfiler> {
+  StmtProfiler &Profiler;
 
 public:
-  OpenACCClauseProfiler() = default;
+  OpenACCClauseProfiler(StmtProfiler &P) : Profiler(P) {}
 
   void VisitOpenACCClauseList(ArrayRef<const OpenACCClause *> Clauses) {
     for (const OpenACCClause *Clause : Clauses) {
@@ -2456,20 +2457,30 @@ class OpenACCClauseProfiler
       Visit(Clause);
     }
   }
-  void VisitOpenACCDefaultClause(const OpenACCDefaultClause &Clause);
+
+#define VISIT_CLAUSE(CLAUSE_NAME)                                              \
+  void Visit##CLAUSE_NAME##Clause(const OpenACC##CLAUSE_NAME##Clause &Clause);
+
+#include "clang/Basic/OpenACCClauses.def"
 };
 
 /// Nothing to do here, there are no sub-statements.
-void OpenACCClauseProfiler::VisitOpenACCDefaultClause(
+void OpenACCClauseProfiler::VisitDefaultClause(
     const OpenACCDefaultClause &Clause) {}
+
+void OpenACCClauseProfiler::VisitIfClause(const OpenACCIfClause &Clause) {
+  assert(Clause.hasConditionExpr() &&
+         "if clause requires a valid condition expr");
+  Profiler.VisitStmt(Clause.getConditionExpr());
+}
 } // namespace
 
 void StmtProfiler::VisitOpenACCComputeConstruct(
     const OpenACCComputeConstruct *S) {
   // VisitStmt handles children, so the AssociatedStmt is handled.
   VisitStmt(S);
 
-  OpenACCClauseProfiler P;
+  OpenACCClauseProfiler P{*this};
   P.VisitOpenACCClauseList(S->clauses());
 }
 

diff --git a/clang/lib/AST/TextNodeDumper.cpp b/clang/lib/AST/TextNodeDumper.cpp
@@ -397,6 +397,11 @@ void TextNodeDumper::Visit(const OpenACCClause *C) {
     case OpenACCClauseKind::Default:
       OS << '(' << cast<OpenACCDefaultClause>(C)->getDefaultClauseKind() << ')';
       break;
+    case OpenACCClauseKind::If:
+      // The condition expression will be printed as a part of the 'children',
+      // but print 'clause' here so it is clear what is happening from the dump.
+      OS << " clause";
+      break;
     default:
       // Nothing to do here.
       break;
@@ -1450,23 +1455,13 @@ void TextNodeDumper::VisitExpressionTraitExpr(const ExpressionTraitExpr *Node) {
 }
 
 void TextNodeDumper::VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *Node) {
-  if (Node->hasRewrittenInit()) {
+  if (Node->hasRewrittenInit())
     OS << " has rewritten init";
-    AddChild([=] {
-      ColorScope Color(OS, ShowColors, StmtColor);
-      Visit(Node->getExpr());
-    });
-  }
 }
 
 void TextNodeDumper::VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *Node) {
-  if (Node->hasRewrittenInit()) {
+  if (Node->hasRewrittenInit())
     OS << " has rewritten init";
-    AddChild([=] {
-      ColorScope Color(OS, ShowColors, StmtColor);
-      Visit(Node->getExpr());
-    });
-  }
 }
 
 void TextNodeDumper::VisitMaterializeTemporaryExpr(
@@ -1966,6 +1961,9 @@ void TextNodeDumper::VisitFunctionDecl(const FunctionDecl *D) {
   if (D->isTrivial())
     OS << " trivial";
 
+  if (const StringLiteral *M = D->getDeletedMessage())
+    AddChild("delete message", [=] { Visit(M); });
+
   if (D->isIneligibleOrNotSelected())
     OS << (isa<CXXDestructorDecl>(D) ? " not_selected" : " ineligible");
 

diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
@@ -638,9 +638,10 @@ const Stmt *ExprMutationAnalyzer::findFunctionArgMutation(const Expr *Exp) {
       if (!RefType->getPointeeType().getQualifiers() &&
           RefType->getPointeeType()->getAs<TemplateTypeParmType>()) {
         std::unique_ptr<FunctionParmMutationAnalyzer> &Analyzer =
-            FuncParmAnalyzer[Func];
+            CrossAnalysisCache->FuncParmAnalyzer[Func];
         if (!Analyzer)
-          Analyzer.reset(new FunctionParmMutationAnalyzer(*Func, Context));
+          Analyzer.reset(new FunctionParmMutationAnalyzer(*Func, Context,
+                                                          CrossAnalysisCache));
         if (Analyzer->findMutation(Parm))
           return Exp;
         continue;
@@ -653,13 +654,15 @@ const Stmt *ExprMutationAnalyzer::findFunctionArgMutation(const Expr *Exp) {
 }
 
 FunctionParmMutationAnalyzer::FunctionParmMutationAnalyzer(
-    const FunctionDecl &Func, ASTContext &Context)
-    : BodyAnalyzer(*Func.getBody(), Context) {
+    const FunctionDecl &Func, ASTContext &Context,
+    std::shared_ptr<ExprMutationAnalyzer::Cache> CrossAnalysisCache)
+    : BodyAnalyzer(*Func.getBody(), Context, CrossAnalysisCache) {
   if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(&Func)) {
     // CXXCtorInitializer might also mutate Param but they're not part of
     // function body, check them eagerly here since they're typically trivial.
     for (const CXXCtorInitializer *Init : Ctor->inits()) {
-      ExprMutationAnalyzer InitAnalyzer(*Init->getInit(), Context);
+      ExprMutationAnalyzer InitAnalyzer(*Init->getInit(), Context,
+                                        CrossAnalysisCache);
       for (const ParmVarDecl *Parm : Ctor->parameters()) {
         if (Results.contains(Parm))
           continue;
@@ -675,11 +678,14 @@ FunctionParmMutationAnalyzer::findMutation(const ParmVarDecl *Parm) {
   const auto Memoized = Results.find(Parm);
   if (Memoized != Results.end())
     return Memoized->second;
-
+  // To handle call A -> call B -> call A. Assume parameters of A is not mutated
+  // before analyzing parameters of A. Then when analyzing the second "call A",
+  // FunctionParmMutationAnalyzer can use this memoized value to avoid infinite
+  // recursion.
+  Results[Parm] = nullptr;
   if (const Stmt *S = BodyAnalyzer.findMutation(Parm))
     return Results[Parm] = S;
-
-  return Results[Parm] = nullptr;
+  return Results[Parm];
 }
 
 } // namespace clang
diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
@@ -305,6 +305,10 @@ bool Module::directlyUses(const Module *Requested) {
   if (Requested->fullModuleNameIs({"_Builtin_stddef", "max_align_t"}) ||
       Requested->fullModuleNameIs({"_Builtin_stddef_wint_t"}))
     return true;
+  // Darwin is allowed is to use our builtin 'ptrauth.h' and its accompanying
+  // module.
+  if (!Requested->Parent && Requested->Name == "ptrauth")
+    return true;
 
   if (NoUndeclaredIncludes)
     UndeclaredUses.insert(Requested);

diff --git a/clang/lib/CIR/CMakeLists.txt b/clang/lib/CIR/CMakeLists.txt
diff --git a/clang/lib/CMakeLists.txt b/clang/lib/CMakeLists.txt
@@ -31,3 +31,7 @@ if(CLANG_INCLUDE_TESTS)
 endif()
 add_subdirectory(Interpreter)
 add_subdirectory(Support)
+
+if(CLANG_ENABLE_CIR)
+  add_subdirectory(CIR)
+endif()
diff --git a/clang/lib/CodeGen/CGAtomic.cpp b/clang/lib/CodeGen/CGAtomic.cpp
@@ -1806,7 +1806,11 @@ void AtomicInfo::EmitAtomicUpdateOp(
                                              /*NumReservedValues=*/2);
   PHI->addIncoming(OldVal, CurBB);
   Address NewAtomicAddr = CreateTempAlloca();
-  Address NewAtomicIntAddr = castToAtomicIntPointer(NewAtomicAddr);
+  Address NewAtomicIntAddr =
+      shouldCastToInt(NewAtomicAddr.getElementType(), /*CmpXchg=*/true)
+          ? castToAtomicIntPointer(NewAtomicAddr)
+          : NewAtomicAddr;
+
   if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) ||
       requiresMemSetZero(getAtomicAddress().getElementType())) {
     CGF.Builder.CreateStore(PHI, NewAtomicIntAddr);

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -18194,7 +18194,8 @@ Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
     Value *Op0 = EmitScalarExpr(E->getArg(0));
     return Builder.CreateIntrinsic(
         /*ReturnType=*/llvm::Type::getInt1Ty(getLLVMContext()),
-        Intrinsic::dx_any, ArrayRef<Value *>{Op0}, nullptr, "dx.any");
+        CGM.getHLSLRuntime().getAnyIntrinsic(), ArrayRef<Value *>{Op0}, nullptr,
+        "hlsl.any");
   }
   case Builtin::BI__builtin_hlsl_elementwise_clamp: {
     Value *OpX = EmitScalarExpr(E->getArg(0));
@@ -18303,9 +18304,16 @@ Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
     Value *Op0 = EmitScalarExpr(E->getArg(0));
     if (!E->getArg(0)->getType()->hasFloatingRepresentation())
       llvm_unreachable("rcp operand must have a float representation");
-    return Builder.CreateIntrinsic(
-        /*ReturnType=*/Op0->getType(), Intrinsic::dx_rcp,
-        ArrayRef<Value *>{Op0}, nullptr, "dx.rcp");
+    llvm::Type *Ty = Op0->getType();
+    llvm::Type *EltTy = Ty->getScalarType();
+    Constant *One =
+        Ty->isVectorTy()
+            ? ConstantVector::getSplat(
+                  ElementCount::getFixed(
+                      dyn_cast<FixedVectorType>(Ty)->getNumElements()),
+                  ConstantFP::get(EltTy, 1.0))
+            : ConstantFP::get(EltTy, 1.0);
+    return Builder.CreateFDiv(One, Op0, "hlsl.rcp");
   }
   case Builtin::BI__builtin_hlsl_elementwise_rsqrt: {
     Value *Op0 = EmitScalarExpr(E->getArg(0));

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
@@ -4124,7 +4124,8 @@ static bool isProvablyNull(llvm::Value *addr) {
 }
 
 static bool isProvablyNonNull(Address Addr, CodeGenFunction &CGF) {
-  return llvm::isKnownNonZero(Addr.getBasePointer(), CGF.CGM.getDataLayout());
+  return llvm::isKnownNonZero(Addr.getBasePointer(), /*Depth=*/0,
+                              CGF.CGM.getDataLayout());
 }
 
 /// Emit the actual writing-back of a writeback.

diff --git a/clang/lib/CodeGen/CGHLSLRuntime.h b/clang/lib/CodeGen/CGHLSLRuntime.h
@@ -73,6 +73,7 @@ class CGHLSLRuntime {
   //===----------------------------------------------------------------------===//
 
   GENERATE_HLSL_INTRINSIC_FUNCTION(All, all)
+  GENERATE_HLSL_INTRINSIC_FUNCTION(Any, any)
   GENERATE_HLSL_INTRINSIC_FUNCTION(ThreadId, thread_id)
 
   //===----------------------------------------------------------------------===//

diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -25,8 +25,11 @@
 #include "clang/CodeGen/ModuleBuilder.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/MultiplexConsumer.h"
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Serialization/ASTWriter.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
@@ -1003,6 +1006,12 @@ CodeGenerator *CodeGenAction::getCodeGenerator() const {
   return BEConsumer->getCodeGenerator();
 }
 
+bool CodeGenAction::BeginSourceFileAction(CompilerInstance &CI) {
+  if (CI.getFrontendOpts().GenReducedBMI)
+    CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
+  return true;
+}
+
 static std::unique_ptr<raw_pwrite_stream>
 GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
   switch (Action) {
@@ -1061,6 +1070,16 @@ CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
     CI.getPreprocessor().addPPCallbacks(std::move(Callbacks));
   }
 
+  if (CI.getFrontendOpts().GenReducedBMI &&
+      !CI.getFrontendOpts().ModuleOutputPath.empty()) {
+    std::vector<std::unique_ptr<ASTConsumer>> Consumers(2);
+    Consumers[0] = std::make_unique<ReducedBMIGenerator>(
+        CI.getPreprocessor(), CI.getModuleCache(),
+        CI.getFrontendOpts().ModuleOutputPath);
+    Consumers[1] = std::move(Result);
+    return std::make_unique<MultiplexConsumer>(std::move(Consumers));
+  }
+
   return std::move(Result);
 }
 

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2635,7 +2635,7 @@ void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
         addUsedGlobal(F);
       if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
         if (!D->getAttr<SectionAttr>())
-          F->addFnAttr("implicit-section-name", SA->getName());
+          F->setSection(SA->getName());
 
       llvm::AttrBuilder Attrs(F->getContext());
       if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
@@ -3952,7 +3952,8 @@ bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
   // behavior may break ABI compatibility of the current unit.
   if (const Module *M = F->getOwningModule();
       M && M->getTopLevelModule()->isNamedModule() &&
-      getContext().getCurrentNamedModule() != M->getTopLevelModule())
+      getContext().getCurrentNamedModule() != M->getTopLevelModule() &&
+      !F->hasAttr<AlwaysInlineAttr>())
     return false;
 
   if (F->hasAttr<NoInlineAttr>())

diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
@@ -4756,6 +4756,14 @@ Action *Driver::ConstructPhaseAction(
     if (Args.hasArg(options::OPT_extract_api))
       return C.MakeAction<ExtractAPIJobAction>(Input, types::TY_API_INFO);
 
+    // With 'fexperimental-modules-reduced-bmi', we don't want to run the
+    // precompile phase unless the user specified '--precompile'. In the case
+    // the '--precompile' flag is enabled, we will try to emit the reduced BMI
+    // as a by product in GenerateModuleInterfaceAction.
+    if (Args.hasArg(options::OPT_modules_reduced_bmi) &&
+        !Args.getLastArg(options::OPT__precompile))
+      return Input;
+
     types::ID OutputTy = getPrecompiledType(Input->getType());
     assert(OutputTy != types::TY_INVALID &&
            "Cannot precompile this input type!");
@@ -5916,8 +5924,10 @@ const char *Driver::GetNamedOutputPath(Compilation &C, const JobAction &JA,
   // If we're emitting a module output with the specified option
   // `-fmodule-output`.
   if (!AtTopLevel && isa<PrecompileJobAction>(JA) &&
-      JA.getType() == types::TY_ModuleFile && SpecifiedModuleOutput)
+      JA.getType() == types::TY_ModuleFile && SpecifiedModuleOutput) {
+    assert(!C.getArgs().hasArg(options::OPT_modules_reduced_bmi));
     return GetModuleOutputPath(C, JA, BaseInput);
+  }
 
   // Output to a temporary file?
   if ((!AtTopLevel && !isSaveTempsEnabled() &&

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
@@ -796,7 +796,13 @@ ToolChain::getTargetSubDirPath(StringRef BaseDir) const {
 std::optional<std::string> ToolChain::getRuntimePath() const {
   SmallString<128> P(D.ResourceDir);
   llvm::sys::path::append(P, "lib");
-  return getTargetSubDirPath(P);
+  if (auto Ret = getTargetSubDirPath(P))
+    return Ret;
+  // Darwin does not use per-target runtime directory.
+  if (Triple.isOSDarwin())
+    return {};
+  llvm::sys::path::append(P, Triple.str());
+  return std::string(P);
 }
 
 std::optional<std::string> ToolChain::getStdlibPath() const {

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4045,6 +4045,24 @@ static bool RenderModulesOptions(Compilation &C, const Driver &D,
   // module fragment.
   CmdArgs.push_back("-fskip-odr-check-in-gmf");
 
+  if (Args.hasArg(options::OPT_modules_reduced_bmi) &&
+      (Input.getType() == driver::types::TY_CXXModule ||
+       Input.getType() == driver::types::TY_PP_CXXModule)) {
+    CmdArgs.push_back("-fexperimental-modules-reduced-bmi");
+
+    if (Args.hasArg(options::OPT_fmodule_output_EQ))
+      Args.AddLastArg(CmdArgs, options::OPT_fmodule_output_EQ);
+    else
+      CmdArgs.push_back(Args.MakeArgString(
+          "-fmodule-output=" +
+          getCXX20NamedModuleOutputPath(Args, Input.getBaseInput())));
+  }
+
+  // Noop if we see '-fexperimental-modules-reduced-bmi' with other translation
+  // units than module units. This is more user friendly to allow end uers to
+  // enable this feature without asking for help from build systems.
+  Args.ClaimAllArgs(options::OPT_modules_reduced_bmi);
+
   // We need to include the case the input file is a module file here.
   // Since the default compilation model for C++ module interface unit will
   // create temporary module file and compile the temporary module file

diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -114,6 +114,7 @@ static bool useFramePointerForTargetByDefault(const llvm::opt::ArgList &Args,
   case llvm::Triple::csky:
   case llvm::Triple::loongarch32:
   case llvm::Triple::loongarch64:
+  case llvm::Triple::m68k:
     return !clang::driver::tools::areOptimizationsEnabled(Args);
   default:
     break;

diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -786,6 +786,10 @@ void Flang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
+  // Pass the path to compiler resource files.
+  CmdArgs.push_back("-resource-dir");
+  CmdArgs.push_back(D.ResourceDir.c_str());
+
   // Offloading related options
   addOffloadOptions(C, Inputs, JA, Args, CmdArgs);
 

diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -244,8 +244,9 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
       // Android ARM uses max-page-size=4096 to reduce VMA usage.
       ExtraOpts.push_back("-z");
       ExtraOpts.push_back("max-page-size=4096");
-    } else if (Triple.isAArch64()) {
+    } else if (Triple.isAArch64() || Triple.getArch() == llvm::Triple::x86_64) {
       // Android AArch64 uses max-page-size=16384 to support 4k/16k page sizes.
+      // Android emulates a 16k page size for app testing on x86_64 machines.
       ExtraOpts.push_back("-z");
       ExtraOpts.push_back("max-page-size=16384");
     }

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
@@ -684,7 +684,13 @@ void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
         // arguments to function calls. We do this by ensuring that either all
         // arguments (including any lambdas) go on the same line as the function
         // call, or we break before the first argument.
-        auto PrevNonComment = Current.getPreviousNonComment();
+        const auto *Prev = Current.Previous;
+        if (!Prev)
+          return false;
+        // For example, `/*Newline=*/false`.
+        if (Prev->is(TT_BlockComment) && Current.SpacesRequiredBefore == 0)
+          return false;
+        const auto *PrevNonComment = Current.getPreviousNonComment();
         if (!PrevNonComment || PrevNonComment->isNot(tok::l_paren))
           return false;
         if (Current.isOneOf(tok::comment, tok::l_paren, TT_LambdaLSquare))

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
@@ -3891,7 +3891,11 @@ static FormatStyle::LanguageKind getLanguageByFileName(StringRef FileName) {
       FileName.ends_with_insensitive(".protodevel")) {
     return FormatStyle::LK_Proto;
   }
-  if (FileName.ends_with_insensitive(".textpb") ||
+  // txtpb is the canonical extension, and textproto is the legacy canonical
+  // extension
+  // https://protobuf.dev/reference/protobuf/textformat-spec/#text-format-files
+  if (FileName.ends_with_insensitive(".txtpb") ||
+      FileName.ends_with_insensitive(".textpb") ||
       FileName.ends_with_insensitive(".pb.txt") ||
       FileName.ends_with_insensitive(".textproto") ||
       FileName.ends_with_insensitive(".asciipb")) {

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
@@ -281,6 +281,13 @@ GenerateModuleInterfaceAction::CreateASTConsumer(CompilerInstance &CI,
   if (Consumers.empty())
     return nullptr;
 
+  if (CI.getFrontendOpts().GenReducedBMI &&
+      !CI.getFrontendOpts().ModuleOutputPath.empty()) {
+    Consumers.push_back(std::make_unique<ReducedBMIGenerator>(
+        CI.getPreprocessor(), CI.getModuleCache(),
+        CI.getFrontendOpts().ModuleOutputPath));
+  }
+
   return std::make_unique<MultiplexConsumer>(std::move(Consumers));
 }
 

diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -747,6 +747,9 @@ static void InitializeCPlusPlusFeatureTestMacros(const LangOptions &LangOpts,
   Builder.defineMacro("__cpp_named_character_escapes", "202207L");
   Builder.defineMacro("__cpp_placeholder_variables", "202306L");
 
+  // C++26 features supported in earlier language modes.
+  Builder.defineMacro("__cpp_deleted_function", "202403L");
+
   if (LangOpts.Char8)
     Builder.defineMacro("__cpp_char8_t", "202207L");
   Builder.defineMacro("__cpp_impl_destroying_delete", "201806L");

diff --git a/clang/lib/Headers/CMakeLists.txt b/clang/lib/Headers/CMakeLists.txt
@@ -437,14 +437,14 @@ foreach( f ${generated_files} )
 endforeach( f )
 
 function(add_header_target target_name file_list)
-  add_custom_target(${target_name} DEPENDS ${file_list})
+  add_library(${target_name} INTERFACE ${file_list})
   set_target_properties(${target_name} PROPERTIES
     FOLDER "Misc"
     RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
 endfunction()
 
 # The catch-all clang-resource-headers target
-add_custom_target("clang-resource-headers" ALL DEPENDS ${out_files})
+add_library(clang-resource-headers INTERFACE ${out_files})
 set_target_properties("clang-resource-headers" PROPERTIES
   FOLDER "Misc"
   RUNTIME_OUTPUT_DIRECTORY "${output_dir}")
@@ -501,6 +501,10 @@ add_header_target("windows-resource-headers" ${windows_only_files})
 add_header_target("utility-resource-headers" ${utility_files})
 
 get_clang_resource_dir(header_install_dir SUBDIR include)
+target_include_directories(clang-resource-headers INTERFACE
+  $<BUILD_INTERFACE:${output_dir}>
+  $<INSTALL_INTERFACE:${header_install_dir}>)
+set_property(GLOBAL APPEND PROPERTY CLANG_EXPORTS clang-resource-headers)
 
 #############################################################
 # Install rules for the catch-all clang-resource-headers target

diff --git a/clang/lib/InstallAPI/DylibVerifier.cpp b/clang/lib/InstallAPI/DylibVerifier.cpp
@@ -176,7 +176,13 @@ void DylibVerifier::addSymbol(const Record *R, SymbolContext &SymCtx,
 
 bool DylibVerifier::shouldIgnoreObsolete(const Record *R, SymbolContext &SymCtx,
                                          const Record *DR) {
-  return SymCtx.FA->Avail.isObsoleted();
+  if (!SymCtx.FA->Avail.isObsoleted())
+    return false;
+
+  if (Zippered)
+    DeferredZipperedSymbols[SymCtx.SymbolName].emplace_back(ZipperedDeclSource{
+        SymCtx.FA, &Ctx.Diag->getSourceManager(), Ctx.Target});
+  return true;
 }
 
 bool DylibVerifier::shouldIgnoreReexport(const Record *R,
@@ -195,6 +201,28 @@ bool DylibVerifier::shouldIgnoreReexport(const Record *R,
   return false;
 }
 
+bool DylibVerifier::shouldIgnoreInternalZipperedSymbol(
+    const Record *R, const SymbolContext &SymCtx) const {
+  if (!Zippered)
+    return false;
+
+  return Exports->findSymbol(SymCtx.Kind, SymCtx.SymbolName,
+                             SymCtx.ObjCIFKind) != nullptr;
+}
+
+bool DylibVerifier::shouldIgnoreZipperedAvailability(const Record *R,
+                                                     SymbolContext &SymCtx) {
+  if (!(Zippered && SymCtx.FA->Avail.isUnavailable()))
+    return false;
+
+  // Collect source location incase there is an exported symbol to diagnose
+  // during `verifyRemainingSymbols`.
+  DeferredZipperedSymbols[SymCtx.SymbolName].emplace_back(
+      ZipperedDeclSource{SymCtx.FA, SourceManagers.back().get(), Ctx.Target});
+
+  return true;
+}
+
 bool DylibVerifier::compareObjCInterfaceSymbols(const Record *R,
                                                 SymbolContext &SymCtx,
                                                 const ObjCInterfaceRecord *DR) {
@@ -294,6 +322,9 @@ DylibVerifier::Result DylibVerifier::compareVisibility(const Record *R,
     if (shouldIgnorePrivateExternAttr(SymCtx.FA->D))
       return Result::Ignore;
 
+    if (shouldIgnoreInternalZipperedSymbol(R, SymCtx))
+      return Result::Ignore;
+
     unsigned ID;
     Result Outcome;
     if (Mode == VerificationMode::ErrorsAndWarnings) {
@@ -321,6 +352,9 @@ DylibVerifier::Result DylibVerifier::compareAvailability(const Record *R,
   if (!SymCtx.FA->Avail.isUnavailable())
     return Result::Valid;
 
+  if (shouldIgnoreZipperedAvailability(R, SymCtx))
+    return Result::Ignore;
+
   const bool IsDeclAvailable = SymCtx.FA->Avail.isUnavailable();
 
   switch (Mode) {
@@ -588,13 +622,58 @@ void DylibVerifier::visitSymbolInDylib(const Record &R, SymbolContext &SymCtx) {
     }
   }
 
+  const bool IsLinkerSymbol = SymbolName.starts_with("$ld$");
+
+  if (R.isVerified()) {
+    // Check for unavailable symbols.
+    // This should only occur in the zippered case where we ignored
+    // availability until all headers have been parsed.
+    auto It = DeferredZipperedSymbols.find(SymCtx.SymbolName);
+    if (It == DeferredZipperedSymbols.end()) {
+      updateState(Result::Valid);
+      return;
+    }
+
+    ZipperedDeclSources Locs;
+    for (const ZipperedDeclSource &ZSource : It->second) {
+      if (ZSource.FA->Avail.isObsoleted()) {
+        updateState(Result::Ignore);
+        return;
+      }
+      if (ZSource.T.Arch != Ctx.Target.Arch)
+        continue;
+      Locs.emplace_back(ZSource);
+    }
+    assert(Locs.size() == 2 && "Expected two decls for zippered symbol");
+
+    // Print violating declarations per platform.
+    for (const ZipperedDeclSource &ZSource : Locs) {
+      unsigned DiagID = 0;
+      if (Mode == VerificationMode::Pedantic || IsLinkerSymbol) {
+        updateState(Result::Invalid);
+        DiagID = diag::err_header_availability_mismatch;
+      } else if (Mode == VerificationMode::ErrorsAndWarnings) {
+        updateState(Result::Ignore);
+        DiagID = diag::warn_header_availability_mismatch;
+      } else {
+        updateState(Result::Ignore);
+        return;
+      }
+      // Bypass emitDiag banner and print the target everytime.
+      Ctx.Diag->setSourceManager(ZSource.SrcMgr);
+      Ctx.Diag->Report(diag::warn_target) << getTargetTripleName(ZSource.T);
+      Ctx.Diag->Report(ZSource.FA->Loc, DiagID)
+          << getAnnotatedName(&R, SymCtx) << ZSource.FA->Avail.isUnavailable()
+          << ZSource.FA->Avail.isUnavailable();
+    }
+    return;
+  }
+
   if (shouldIgnoreCpp(SymbolName, R.isWeakDefined())) {
     updateState(Result::Valid);
     return;
   }
 
-  const bool IsLinkerSymbol = SymbolName.starts_with("$ld$");
-
   // All checks at this point classify as some kind of violation.
   // The different verification modes dictate whether they are reported to the
   // user.
@@ -647,8 +726,6 @@ void DylibVerifier::visitSymbolInDylib(const Record &R, SymbolContext &SymCtx) {
 }
 
 void DylibVerifier::visitGlobal(const GlobalRecord &R) {
-  if (R.isVerified())
-    return;
   SymbolContext SymCtx;
   SimpleSymbol Sym = parseSymbol(R.getName());
   SymCtx.SymbolName = Sym.Name;
@@ -658,8 +735,6 @@ void DylibVerifier::visitGlobal(const GlobalRecord &R) {
 
 void DylibVerifier::visitObjCIVar(const ObjCIVarRecord &R,
                                   const StringRef Super) {
-  if (R.isVerified())
-    return;
   SymbolContext SymCtx;
   SymCtx.SymbolName = ObjCIVarRecord::createScopedName(Super, R.getName());
   SymCtx.Kind = EncodeKind::ObjectiveCInstanceVariable;
@@ -679,8 +754,6 @@ void DylibVerifier::accumulateSrcLocForDylibSymbols() {
 }
 
 void DylibVerifier::visitObjCInterface(const ObjCInterfaceRecord &R) {
-  if (R.isVerified())
-    return;
   SymbolContext SymCtx;
   SymCtx.SymbolName = R.getName();
   SymCtx.ObjCIFKind = assignObjCIFSymbolKind(&R);
@@ -713,9 +786,12 @@ DylibVerifier::Result DylibVerifier::verifyRemainingSymbols() {
 
   DWARFContext DWARFInfo;
   DWARFCtx = &DWARFInfo;
-  Ctx.DiscoveredFirstError = false;
-  Ctx.PrintArch = true;
+  Ctx.Target = Target(Architecture::AK_unknown, PlatformType::PLATFORM_UNKNOWN);
   for (std::shared_ptr<RecordsSlice> Slice : Dylib) {
+    if (Ctx.Target.Arch == Slice->getTarget().Arch)
+      continue;
+    Ctx.DiscoveredFirstError = false;
+    Ctx.PrintArch = true;
     Ctx.Target = Slice->getTarget();
     Ctx.DylibSlice = Slice.get();
     Slice->visit(*this);

diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
@@ -946,9 +946,13 @@ OptionalFileEntryRef HeaderSearch::LookupFile(
       // If we have no includer, that means we're processing a #include
       // from a module build. We should treat this as a system header if we're
       // building a [system] module.
-      bool IncluderIsSystemHeader =
-          Includer ? getFileInfo(*Includer).DirInfo != SrcMgr::C_User :
-          BuildSystemModule;
+      bool IncluderIsSystemHeader = [&]() {
+        if (!Includer)
+          return BuildSystemModule;
+        const HeaderFileInfo *HFI = getExistingFileInfo(*Includer);
+        assert(HFI && "includer without file info");
+        return HFI->DirInfo != SrcMgr::C_User;
+      }();
       if (OptionalFileEntryRef FE = getFileAndSuggestModule(
               TmpDir, IncludeLoc, IncluderAndDir.second, IncluderIsSystemHeader,
               RequestingModule, SuggestedModule)) {
@@ -963,10 +967,11 @@ OptionalFileEntryRef HeaderSearch::LookupFile(
         // Note that we only use one of FromHFI/ToHFI at once, due to potential
         // reallocation of the underlying vector potentially making the first
         // reference binding dangling.
-        HeaderFileInfo &FromHFI = getFileInfo(*Includer);
-        unsigned DirInfo = FromHFI.DirInfo;
-        bool IndexHeaderMapHeader = FromHFI.IndexHeaderMapHeader;
-        StringRef Framework = FromHFI.Framework;
+        const HeaderFileInfo *FromHFI = getExistingFileInfo(*Includer);
+        assert(FromHFI && "includer without file info");
+        unsigned DirInfo = FromHFI->DirInfo;
+        bool IndexHeaderMapHeader = FromHFI->IndexHeaderMapHeader;
+        StringRef Framework = FromHFI->Framework;
 
         HeaderFileInfo &ToHFI = getFileInfo(*FE);
         ToHFI.DirInfo = DirInfo;
@@ -1153,10 +1158,12 @@ OptionalFileEntryRef HeaderSearch::LookupFile(
   // "Foo" is the name of the framework in which the including header was found.
   if (!Includers.empty() && Includers.front().first && !isAngled &&
       !Filename.contains('/')) {
-    HeaderFileInfo &IncludingHFI = getFileInfo(*Includers.front().first);
-    if (IncludingHFI.IndexHeaderMapHeader) {
+    const HeaderFileInfo *IncludingHFI =
+        getExistingFileInfo(*Includers.front().first);
+    assert(IncludingHFI && "includer without file info");
+    if (IncludingHFI->IndexHeaderMapHeader) {
       SmallString<128> ScratchFilename;
-      ScratchFilename += IncludingHFI.Framework;
+      ScratchFilename += IncludingHFI->Framework;
       ScratchFilename += '/';
       ScratchFilename += Filename;
 
@@ -1286,11 +1293,11 @@ OptionalFileEntryRef HeaderSearch::LookupSubframeworkHeader(
   }
 
   // This file is a system header or C++ unfriendly if the old file is.
-  //
-  // Note that the temporary 'DirInfo' is required here, as either call to
-  // getFileInfo could resize the vector and we don't want to rely on order
-  // of evaluation.
-  unsigned DirInfo = getFileInfo(ContextFileEnt).DirInfo;
+  const HeaderFileInfo *ContextHFI = getExistingFileInfo(ContextFileEnt);
+  assert(ContextHFI && "context file without file info");
+  // Note that the temporary 'DirInfo' is required here, as the call to
+  // getFileInfo could resize the vector and might invalidate 'ContextHFI'.
+  unsigned DirInfo = ContextHFI->DirInfo;
   getFileInfo(*File).DirInfo = DirInfo;
 
   FrameworkName.pop_back(); // remove the trailing '/'
@@ -1348,8 +1355,6 @@ static void mergeHeaderFileInfo(HeaderFileInfo &HFI,
     HFI.Framework = OtherHFI.Framework;
 }
 
-/// getFileInfo - Return the HeaderFileInfo structure for the specified
-/// FileEntry.
 HeaderFileInfo &HeaderSearch::getFileInfo(FileEntryRef FE) {
   if (FE.getUID() >= FileInfo.size())
     FileInfo.resize(FE.getUID() + 1);
@@ -1366,27 +1371,20 @@ HeaderFileInfo &HeaderSearch::getFileInfo(FileEntryRef FE) {
   }
 
   HFI->IsValid = true;
-  // We have local information about this header file, so it's no longer
-  // strictly external.
+  // We assume the caller has local information about this header file, so it's
+  // no longer strictly external.
   HFI->External = false;
   return *HFI;
 }
 
-const HeaderFileInfo *
-HeaderSearch::getExistingFileInfo(FileEntryRef FE, bool WantExternal) const {
-  // If we have an external source, ensure we have the latest information.
-  // FIXME: Use a generation count to check whether this is really up to date.
+const HeaderFileInfo *HeaderSearch::getExistingFileInfo(FileEntryRef FE) const {
   HeaderFileInfo *HFI;
   if (ExternalSource) {
-    if (FE.getUID() >= FileInfo.size()) {
-      if (!WantExternal)
-        return nullptr;
+    if (FE.getUID() >= FileInfo.size())
       FileInfo.resize(FE.getUID() + 1);
-    }
 
     HFI = &FileInfo[FE.getUID()];
-    if (!WantExternal && (!HFI->IsValid || HFI->External))
-      return nullptr;
+    // FIXME: Use a generation count to check whether this is really up to date.
     if (!HFI->Resolved) {
       auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
       if (ExternalHFI.IsValid) {
@@ -1395,16 +1393,25 @@ HeaderSearch::getExistingFileInfo(FileEntryRef FE, bool WantExternal) const {
           mergeHeaderFileInfo(*HFI, ExternalHFI);
       }
     }
-  } else if (FE.getUID() >= FileInfo.size()) {
-    return nullptr;
-  } else {
+  } else if (FE.getUID() < FileInfo.size()) {
     HFI = &FileInfo[FE.getUID()];
+  } else {
+    HFI = nullptr;
   }
 
-  if (!HFI->IsValid || (HFI->External && !WantExternal))
-    return nullptr;
+  return (HFI && HFI->IsValid) ? HFI : nullptr;
+}
+
+const HeaderFileInfo *
+HeaderSearch::getExistingLocalFileInfo(FileEntryRef FE) const {
+  HeaderFileInfo *HFI;
+  if (FE.getUID() < FileInfo.size()) {
+    HFI = &FileInfo[FE.getUID()];
+  } else {
+    HFI = nullptr;
+  }
 
-  return HFI;
+  return (HFI && HFI->IsValid && !HFI->External) ? HFI : nullptr;
 }
 
 bool HeaderSearch::isFileMultipleIncludeGuarded(FileEntryRef File) const {

diff --git a/clang/lib/Parse/ParseCXXInlineMethods.cpp b/clang/lib/Parse/ParseCXXInlineMethods.cpp
@@ -20,6 +20,49 @@
 
 using namespace clang;
 
+/// Parse the optional ("message") part of a deleted-function-body.
+StringLiteral *Parser::ParseCXXDeletedFunctionMessage() {
+  if (!Tok.is(tok::l_paren))
+    return nullptr;
+  StringLiteral *Message = nullptr;
+  BalancedDelimiterTracker BT{*this, tok::l_paren};
+  BT.consumeOpen();
+
+  if (isTokenStringLiteral()) {
+    ExprResult Res = ParseUnevaluatedStringLiteralExpression();
+    if (Res.isUsable()) {
+      Message = Res.getAs<StringLiteral>();
+      Diag(Message->getBeginLoc(), getLangOpts().CPlusPlus26
+                                       ? diag::warn_cxx23_delete_with_message
+                                       : diag::ext_delete_with_message)
+          << Message->getSourceRange();
+    }
+  } else {
+    Diag(Tok.getLocation(), diag::err_expected_string_literal)
+        << /*Source='in'*/ 0 << "'delete'";
+    SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
+  }
+
+  BT.consumeClose();
+  return Message;
+}
+
+/// If we've encountered '= delete' in a context where it is ill-formed, such
+/// as in the declaration of a non-function, also skip the ("message") part if
+/// it is present to avoid issuing further diagnostics.
+void Parser::SkipDeletedFunctionBody() {
+  if (!Tok.is(tok::l_paren))
+    return;
+
+  BalancedDelimiterTracker BT{*this, tok::l_paren};
+  BT.consumeOpen();
+
+  // Just skip to the end of the current declaration.
+  SkipUntil(tok::r_paren, tok::comma, StopAtSemi | StopBeforeMatch);
+  if (Tok.is(tok::r_paren))
+    BT.consumeClose();
+}
+
 /// ParseCXXInlineMethodDef - We parsed and verified that the specified
 /// Declarator is a well formed C++ inline method definition. Now lex its body
 /// and store its tokens for parsing after the C++ class is complete.
@@ -70,7 +113,8 @@ NamedDecl *Parser::ParseCXXInlineMethodDef(
                       ? diag::warn_cxx98_compat_defaulted_deleted_function
                       : diag::ext_defaulted_deleted_function)
         << 1 /* deleted */;
-      Actions.SetDeclDeleted(FnD, KWLoc);
+      StringLiteral *Message = ParseCXXDeletedFunctionMessage();
+      Actions.SetDeclDeleted(FnD, KWLoc, Message);
       Delete = true;
       if (auto *DeclAsFunction = dyn_cast<FunctionDecl>(FnD)) {
         DeclAsFunction->setRangeEnd(KWEndLoc);

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
@@ -26,6 +26,7 @@
 #include "clang/Sema/Lookup.h"
 #include "clang/Sema/ParsedTemplate.h"
 #include "clang/Sema/Scope.h"
+#include "clang/Sema/SemaCUDA.h"
 #include "clang/Sema/SemaDiagnostic.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallString.h"
@@ -2664,7 +2665,8 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
     }
   }
 
-  Sema::CUDATargetContextRAII X(Actions, Sema::CTCK_InitGlobalVar, ThisDecl);
+  SemaCUDA::CUDATargetContextRAII X(Actions.CUDA(),
+                                    SemaCUDA::CTCK_InitGlobalVar, ThisDecl);
   switch (TheInitKind) {
   // Parse declarator '=' initializer.
   case InitKind::Equal: {
@@ -2676,6 +2678,7 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
           << 1 /* delete */;
       else
         Diag(ConsumeToken(), diag::err_deleted_non_function);
+      SkipDeletedFunctionBody();
     } else if (Tok.is(tok::kw_default)) {
       if (D.isFunctionDeclarator())
         Diag(ConsumeToken(), diag::err_default_delete_in_multiple_declaration)

diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -3397,6 +3397,7 @@ ExprResult Parser::ParseCXXMemberInitializer(Decl *D, bool IsFunction,
               << 1 /* delete */;
         else
           Diag(ConsumeToken(), diag::err_deleted_non_function);
+        SkipDeletedFunctionBody();
         return ExprError();
       }
     } else if (Tok.is(tok::kw_default)) {

diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
@@ -30,6 +30,7 @@
 #include "clang/Sema/EnterExpressionEvaluationContext.h"
 #include "clang/Sema/ParsedTemplate.h"
 #include "clang/Sema/Scope.h"
+#include "clang/Sema/SemaCUDA.h"
 #include "clang/Sema/SemaSYCL.h"
 #include "clang/Sema/TypoCorrection.h"
 #include "llvm/ADT/SmallVector.h"
@@ -2129,10 +2130,8 @@ Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
         }
 
         if (!LHS.isInvalid()) {
-          ExprResult ECResult = Actions.ActOnCUDAExecConfigExpr(getCurScope(),
-                                    OpenLoc,
-                                    ExecConfigExprs,
-                                    CloseLoc);
+          ExprResult ECResult = Actions.CUDA().ActOnExecConfigExpr(
+              getCurScope(), OpenLoc, ExecConfigExprs, CloseLoc);
           if (ECResult.isInvalid())
             LHS = ExprError();
           else

diff --git a/clang/lib/Parse/ParseHLSL.cpp b/clang/lib/Parse/ParseHLSL.cpp
@@ -72,9 +72,9 @@ Decl *Parser::ParseHLSLBuffer(SourceLocation &DeclEnd) {
     return nullptr;
   }
 
-  Decl *D = Actions.HLSL().ActOnStartHLSLBuffer(
-      getCurScope(), IsCBuffer, BufferLoc, Identifier, IdentifierLoc,
-      T.getOpenLocation());
+  Decl *D = Actions.HLSL().ActOnStartBuffer(getCurScope(), IsCBuffer, BufferLoc,
+                                            Identifier, IdentifierLoc,
+                                            T.getOpenLocation());
 
   while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
     // FIXME: support attribute on constants inside cbuffer/tbuffer.
@@ -88,15 +88,15 @@ Decl *Parser::ParseHLSLBuffer(SourceLocation &DeclEnd) {
       T.skipToEnd();
       DeclEnd = T.getCloseLocation();
       BufferScope.Exit();
-      Actions.HLSL().ActOnFinishHLSLBuffer(D, DeclEnd);
+      Actions.HLSL().ActOnFinishBuffer(D, DeclEnd);
       return nullptr;
     }
   }
 
   T.consumeClose();
   DeclEnd = T.getCloseLocation();
   BufferScope.Exit();
-  Actions.HLSL().ActOnFinishHLSLBuffer(D, DeclEnd);
+  Actions.HLSL().ActOnFinishBuffer(D, DeclEnd);
 
   Actions.ProcessDeclAttributeList(Actions.CurScope, D, Attrs);
   return D;

diff --git a/clang/lib/Parse/ParseOpenACC.cpp b/clang/lib/Parse/ParseOpenACC.cpp
@@ -535,14 +535,6 @@ bool ClauseHasRequiredParens(OpenACCDirectiveKind DirKind,
   return getClauseParensKind(DirKind, Kind) == ClauseParensKind::Required;
 }
 
-ExprResult ParseOpenACCConditionalExpr(Parser &P) {
-  // FIXME: It isn't clear if the spec saying 'condition' means the same as
-  // it does in an if/while/etc (See ParseCXXCondition), however as it was
-  // written with Fortran/C in mind, we're going to assume it just means an
-  // 'expression evaluating to boolean'.
-  return P.getActions().CorrectDelayedTyposInExpr(P.ParseExpression());
-}
-
 // Skip until we see the end of pragma token, but don't consume it. This is us
 // just giving up on the rest of the pragma so we can continue executing. We
 // have to do this because 'SkipUntil' considers paren balancing, which isn't
@@ -595,6 +587,23 @@ Parser::OpenACCClauseParseResult Parser::OpenACCSuccess(OpenACCClause *Clause) {
   return {Clause, OpenACCParseCanContinue::Can};
 }
 
+ExprResult Parser::ParseOpenACCConditionExpr() {
+  // FIXME: It isn't clear if the spec saying 'condition' means the same as
+  // it does in an if/while/etc (See ParseCXXCondition), however as it was
+  // written with Fortran/C in mind, we're going to assume it just means an
+  // 'expression evaluating to boolean'.
+  ExprResult ER = getActions().CorrectDelayedTyposInExpr(ParseExpression());
+
+  if (!ER.isUsable())
+    return ER;
+
+  Sema::ConditionResult R =
+      getActions().ActOnCondition(getCurScope(), ER.get()->getExprLoc(),
+                                  ER.get(), Sema::ConditionKind::Boolean);
+
+  return R.isInvalid() ? ExprError() : R.get().second;
+}
+
 // OpenACC 3.3, section 1.7:
 // To simplify the specification and convey appropriate constraint information,
 // a pqr-list is a comma-separated list of pdr items. The one exception is a
@@ -842,12 +851,15 @@ Parser::OpenACCClauseParseResult Parser::ParseOpenACCClauseParams(
       break;
     }
     case OpenACCClauseKind::If: {
-      ExprResult CondExpr = ParseOpenACCConditionalExpr(*this);
+      ExprResult CondExpr = ParseOpenACCConditionExpr();
+      ParsedClause.setConditionDetails(CondExpr.isUsable() ? CondExpr.get()
+                                                           : nullptr);
 
       if (CondExpr.isInvalid()) {
         Parens.skipToEnd();
         return OpenACCCanContinue();
       }
+
       break;
     }
     case OpenACCClauseKind::CopyIn:
@@ -964,7 +976,7 @@ Parser::OpenACCClauseParseResult Parser::ParseOpenACCClauseParams(
       switch (ClauseKind) {
       case OpenACCClauseKind::Self: {
         assert(DirKind != OpenACCDirectiveKind::Update);
-        ExprResult CondExpr = ParseOpenACCConditionalExpr(*this);
+        ExprResult CondExpr = ParseOpenACCConditionExpr();
 
         if (CondExpr.isInvalid()) {
           Parens.skipToEnd();

diff --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
@@ -21,6 +21,7 @@
 #include "clang/Parse/RAIIObjectsForParser.h"
 #include "clang/Sema/EnterExpressionEvaluationContext.h"
 #include "clang/Sema/Scope.h"
+#include "clang/Sema/SemaCUDA.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include <optional>
@@ -3900,8 +3901,8 @@ void PragmaForceCUDAHostDeviceHandler::HandlePragma(
   }
 
   if (Info->isStr("begin"))
-    Actions.PushForceCUDAHostDevice();
-  else if (!Actions.PopForceCUDAHostDevice())
+    Actions.CUDA().PushForceHostDevice();
+  else if (!Actions.CUDA().PopForceHostDevice())
     PP.Diag(FirstTok.getLocation(),
             diag::err_pragma_cannot_end_force_cuda_host_device);
 

diff --git a/clang/lib/Parse/ParseTemplate.cpp b/clang/lib/Parse/ParseTemplate.cpp
@@ -805,10 +805,12 @@ NamedDecl *Parser::ParseTemplateTemplateParameter(unsigned Depth,
   // identifier, comma, or greater. Provide a fixit if the identifier, comma,
   // or greater appear immediately or after 'struct'. In the latter case,
   // replace the keyword with 'class'.
+  bool TypenameKeyword = false;
   if (!TryConsumeToken(tok::kw_class)) {
     bool Replace = Tok.isOneOf(tok::kw_typename, tok::kw_struct);
     const Token &Next = Tok.is(tok::kw_struct) ? NextToken() : Tok;
     if (Tok.is(tok::kw_typename)) {
+      TypenameKeyword = true;
       Diag(Tok.getLocation(),
            getLangOpts().CPlusPlus17
                ? diag::warn_cxx14_compat_template_template_param_typename
@@ -878,10 +880,9 @@ NamedDecl *Parser::ParseTemplateTemplateParameter(unsigned Depth,
     }
   }
 
-  return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
-                                                ParamList, EllipsisLoc,
-                                                ParamName, NameLoc, Depth,
-                                                Position, EqualLoc, DefaultArg);
+  return Actions.ActOnTemplateTemplateParameter(
+      getCurScope(), TemplateLoc, ParamList, TypenameKeyword, EllipsisLoc,
+      ParamName, NameLoc, Depth, Position, EqualLoc, DefaultArg);
 }
 
 /// ParseNonTypeTemplateParameter - Handle the parsing of non-type

diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
@@ -1404,6 +1404,7 @@ Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
 
   // Parse function body eagerly if it is either '= delete;' or '= default;' as
   // ActOnStartOfFunctionDef needs to know whether the function is deleted.
+  StringLiteral *DeletedMessage = nullptr;
   Sema::FnBodyKind BodyKind = Sema::FnBodyKind::Other;
   SourceLocation KWLoc;
   if (TryConsumeToken(tok::equal)) {
@@ -1415,6 +1416,7 @@ Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
                       : diag::ext_defaulted_deleted_function)
           << 1 /* deleted */;
       BodyKind = Sema::FnBodyKind::Delete;
+      DeletedMessage = ParseCXXDeletedFunctionMessage();
     } else if (TryConsumeToken(tok::kw_default, KWLoc)) {
       Diag(KWLoc, getLangOpts().CPlusPlus11
                       ? diag::warn_cxx98_compat_defaulted_deleted_function
@@ -1473,7 +1475,7 @@ Decl *Parser::ParseFunctionDefinition(ParsingDeclarator &D,
   D.getMutableDeclSpec().abort();
 
   if (BodyKind != Sema::FnBodyKind::Other) {
-    Actions.SetFunctionBodyKind(Res, KWLoc, BodyKind);
+    Actions.SetFunctionBodyKind(Res, KWLoc, BodyKind, DeletedMessage);
     Stmt *GeneratedBody = Res ? Res->getBody() : nullptr;
     Actions.ActOnFinishFunctionBody(Res, GeneratedBody, false);
     return Res;

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
@@ -41,6 +41,7 @@
 #include "clang/Sema/RISCVIntrinsicManager.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/ScopeInfo.h"
+#include "clang/Sema/SemaCUDA.h"
 #include "clang/Sema/SemaConsumer.h"
 #include "clang/Sema/SemaHLSL.h"
 #include "clang/Sema/SemaInternal.h"
@@ -199,6 +200,7 @@ Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
       LateTemplateParser(nullptr), LateTemplateParserCleanup(nullptr),
       OpaqueParser(nullptr), CurContext(nullptr), ExternalSource(nullptr),
       CurScope(nullptr), Ident_super(nullptr),
+      CUDAPtr(std::make_unique<SemaCUDA>(*this)),
       HLSLPtr(std::make_unique<SemaHLSL>(*this)),
       OpenACCPtr(std::make_unique<SemaOpenACC>(*this)),
       SYCLPtr(std::make_unique<SemaSYCL>(*this)),
@@ -1635,15 +1637,15 @@ bool Sema::hasUncompilableErrorOccurred() const {
 // Print notes showing how we can reach FD starting from an a priori
 // known-callable function.
 static void emitCallStackNotes(Sema &S, const FunctionDecl *FD) {
-  auto FnIt = S.DeviceKnownEmittedFns.find(FD);
-  while (FnIt != S.DeviceKnownEmittedFns.end()) {
+  auto FnIt = S.CUDA().DeviceKnownEmittedFns.find(FD);
+  while (FnIt != S.CUDA().DeviceKnownEmittedFns.end()) {
     // Respect error limit.
     if (S.Diags.hasFatalErrorOccurred())
       return;
     DiagnosticBuilder Builder(
         S.Diags.Report(FnIt->second.Loc, diag::note_called_by));
     Builder << FnIt->second.FD;
-    FnIt = S.DeviceKnownEmittedFns.find(FnIt->second.FD);
+    FnIt = S.CUDA().DeviceKnownEmittedFns.find(FnIt->second.FD);
   }
 }
 
@@ -1747,7 +1749,7 @@ class DeferredDiagnosticsEmitter
         (ShouldEmitRootNode || InOMPDeviceContext))
       S.finalizeOpenMPDelayedAnalysis(Caller, FD, Loc);
     if (Caller)
-      S.DeviceKnownEmittedFns[FD] = {Caller, Loc};
+      S.CUDA().DeviceKnownEmittedFns[FD] = {Caller, Loc};
     // Always emit deferred diagnostics for the direct users. This does not
     // lead to explosion of diagnostics since each user is visited at most
     // twice.
@@ -1836,8 +1838,8 @@ void Sema::emitDeferredDiags() {
 // which other not-known-emitted functions.
 //
 // When we see something which is illegal if the current function is emitted
-// (usually by way of CUDADiagIfDeviceCode, CUDADiagIfHostCode, or
-// CheckCUDACall), we first check if the current function is known-emitted.  If
+// (usually by way of DiagIfDeviceCode, DiagIfHostCode, or
+// CheckCall), we first check if the current function is known-emitted.  If
 // so, we immediately output the diagnostic.
 //
 // Otherwise, we "defer" the diagnostic.  It sits in Sema::DeviceDeferredDiags
@@ -1900,8 +1902,8 @@ Sema::targetDiag(SourceLocation Loc, unsigned DiagID, const FunctionDecl *FD) {
                ? diagIfOpenMPDeviceCode(Loc, DiagID, FD)
                : diagIfOpenMPHostCode(Loc, DiagID, FD);
   if (getLangOpts().CUDA)
-    return getLangOpts().CUDAIsDevice ? CUDADiagIfDeviceCode(Loc, DiagID)
-                                      : CUDADiagIfHostCode(Loc, DiagID);
+    return getLangOpts().CUDAIsDevice ? CUDA().DiagIfDeviceCode(Loc, DiagID)
+                                      : CUDA().DiagIfHostCode(Loc, DiagID);
 
   if (getLangOpts().SYCLIsDevice)
     return SYCL().DiagIfDeviceCode(Loc, DiagID);

diff --git a/clang/lib/Sema/SemaAPINotes.cpp b/clang/lib/Sema/SemaAPINotes.cpp
@@ -463,6 +463,8 @@ static void ProcessAPINotes(Sema &S, FunctionOrMethod AnyFunc,
     D = MD;
   }
 
+  assert((FD || MD) && "Expecting Function or ObjCMethod");
+
   // Nullability of return type.
   if (Info.NullabilityAudited)
     applyNullability(S, D, Info.getReturnTypeInfo(), Metadata);

diff --git a/clang/lib/Sema/SemaAccess.cpp b/clang/lib/Sema/SemaAccess.cpp
@@ -10,18 +10,19 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/Basic/Specifiers.h"
-#include "clang/Sema/SemaInternal.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/CXXInheritance.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclFriend.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DependentDiagnostic.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/Basic/Specifiers.h"
 #include "clang/Sema/DelayedDiagnostic.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/Sema/Lookup.h"
+#include "clang/Sema/SemaInternal.h"
+#include "llvm/ADT/STLForwardCompat.h"
 
 using namespace clang;
 using namespace sema;
@@ -1658,21 +1659,24 @@ Sema::AccessResult Sema::CheckConstructorAccess(SourceLocation UseLoc,
   case InitializedEntity::EK_Base:
     PD = PDiag(diag::err_access_base_ctor);
     PD << Entity.isInheritedVirtualBase()
-       << Entity.getBaseSpecifier()->getType() << getSpecialMember(Constructor);
+       << Entity.getBaseSpecifier()->getType()
+       << llvm::to_underlying(getSpecialMember(Constructor));
     break;
 
   case InitializedEntity::EK_Member:
   case InitializedEntity::EK_ParenAggInitMember: {
     const FieldDecl *Field = cast<FieldDecl>(Entity.getDecl());
     PD = PDiag(diag::err_access_field_ctor);
-    PD << Field->getType() << getSpecialMember(Constructor);
+    PD << Field->getType()
+       << llvm::to_underlying(getSpecialMember(Constructor));
     break;
   }
 
   case InitializedEntity::EK_LambdaCapture: {
     StringRef VarName = Entity.getCapturedVarName();
     PD = PDiag(diag::err_access_lambda_capture);
-    PD << VarName << Entity.getType() << getSpecialMember(Constructor);
+    PD << VarName << Entity.getType()
+       << llvm::to_underlying(getSpecialMember(Constructor));
     break;
   }
 

diff --git a/clang/lib/Sema/SemaBase.cpp b/clang/lib/Sema/SemaBase.cpp
@@ -1,5 +1,6 @@
 #include "clang/Sema/SemaBase.h"
 #include "clang/Sema/Sema.h"
+#include "clang/Sema/SemaCUDA.h"
 
 namespace clang {
 
@@ -70,8 +71,8 @@ Sema::SemaDiagnosticBuilder SemaBase::Diag(SourceLocation Loc, unsigned DiagID,
   }
 
   SemaDiagnosticBuilder DB = getLangOpts().CUDAIsDevice
-                                 ? SemaRef.CUDADiagIfDeviceCode(Loc, DiagID)
-                                 : SemaRef.CUDADiagIfHostCode(Loc, DiagID);
+                                 ? SemaRef.CUDA().DiagIfDeviceCode(Loc, DiagID)
+                                 : SemaRef.CUDA().DiagIfHostCode(Loc, DiagID);
   SetIsLastErrorImmediate(DB.isImmediate());
   return DB;
 }