Bring llvm.annotation* intrinsics support back to where it was in llv…

…m-gcc: can

annotate global, local variables, struct fields, or arbitrary statements (using
the __builtin_annotation), rdar://8037476.

llvm-svn: 139423

clang/include/clang/Basic/Attr.td

@@ -131,7 +131,7 @@ def AnalyzerNoReturn : InheritableAttr {
   let Spellings = ["analyzer_noreturn"];
 }
 
-def Annotate : InheritableAttr {
+def Annotate : InheritableParamAttr {
   let Spellings = ["annotate"];
   let Args = [StringArgument<"Annotation">];
 }

clang/include/clang/Basic/Builtins.def

@@ -741,5 +741,8 @@ LIBBUILTIN(_Block_object_assign, "vv*vC*iC", "f", "Blocks.h", ALL_LANGUAGES)
 LIBBUILTIN(_Block_object_dispose, "vvC*iC", "f", "Blocks.h", ALL_LANGUAGES)
 // FIXME: Also declare NSConcreteGlobalBlock and NSConcreteStackBlock.
 
+// Annotation function
+BUILTIN(__builtin_annotation, "UiUicC*", "nc")
+
 #undef BUILTIN
 #undef LIBBUILTIN

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -4420,6 +4420,9 @@ def err_return_in_block_expression : Error<
 def err_block_returning_array_function : Error<
   "block cannot return %select{array|function}0 type %1">;
 
+// Builtin annotation string.
+def err_builtin_annotation_not_string_constant : Error<
+  "__builtin_annotation requires a non wide string constant">;
 
 // CFString checking
 def err_cfstring_literal_not_string_constant : Error<

clang/lib/CodeGen/CGBuiltin.cpp

@@ -991,6 +991,17 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
     Value *Result = Builder.CreateICmpSLT(BCArg, ZeroCmp);
     return RValue::get(Builder.CreateZExt(Result, ConvertType(E->getType())));
   }
+  case Builtin::BI__builtin_annotation: {
+    llvm::Value *AnnVal = EmitScalarExpr(E->getArg(0));
+    llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::annotation,
+                                      AnnVal->getType());
+
+    // Get the annotation string, go through casts. Sema requires this to be a
+    // non-wide string literal, potentially casted, so the cast<> is safe.
+    const Expr *AnnotationStrExpr = E->getArg(1)->IgnoreParenCasts();
+    llvm::StringRef Str = cast<StringLiteral>(AnnotationStrExpr)->getString();
+    return RValue::get(EmitAnnotationCall(F, AnnVal, Str, E->getExprLoc()));
+  }
   }
 
   // If this is an alias for a libm function (e.g. __builtin_sin) turn it into

clang/lib/CodeGen/CGDecl.cpp

@@ -271,13 +271,8 @@ void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
 
   GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
 
-  // FIXME: Merge attribute handling.
-  if (const AnnotateAttr *AA = D.getAttr<AnnotateAttr>()) {
-    SourceManager &SM = CGM.getContext().getSourceManager();
-    llvm::Constant *Ann =
-      CGM.EmitAnnotateAttr(GV, AA, SM.getExpansionLineNumber(D.getLocation()));
-    CGM.AddAnnotation(Ann);
-  }
+  if (D.hasAttr<AnnotateAttr>())
+    CGM.AddGlobalAnnotations(&D, GV);
 
   if (const SectionAttr *SA = D.getAttr<SectionAttr>())
     GV->setSection(SA->getName());
@@ -853,6 +848,9 @@ CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
         DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
     }
 
+  if (D.hasAttr<AnnotateAttr>())
+      EmitVarAnnotations(&D, emission.Address);
+
   return emission;
 }
 
@@ -1502,4 +1500,7 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
   // Emit debug info for param declaration.
   if (CGDebugInfo *DI = getDebugInfo())
     DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder);
+
+  if (D.hasAttr<AnnotateAttr>())
+      EmitVarAnnotations(&D, DeclPtr);
 }

clang/lib/CodeGen/CGExpr.cpp

@@ -1875,6 +1875,9 @@ LValue CodeGenFunction::EmitLValueForField(llvm::Value *baseAddr,
                                          CGM.getTypes().ConvertTypeForMem(type),
                                          field->getName());
 
+  if (field->hasAttr<AnnotateAttr>())
+    addr = EmitFieldAnnotations(field, addr);
+
   unsigned alignment = getContext().getDeclAlign(field).getQuantity();
   LValue LV = MakeAddrLValue(addr, type, alignment);
   LV.getQuals().addCVRQualifiers(cvr);

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -1018,3 +1018,50 @@ void CodeGenFunction::unprotectFromPeepholes(PeepholeProtection protection) {
   // In theory, we could try to duplicate the peepholes now, but whatever.
   protection.Inst->eraseFromParent();
 }
+
+llvm::Value *CodeGenFunction::EmitAnnotationCall(llvm::Value *AnnotationFn,
+                                                 llvm::Value *AnnotatedVal,
+                                                 llvm::StringRef AnnotationStr,
+                                                 SourceLocation Location) {
+  llvm::Value *Args[4] = {
+    AnnotatedVal,
+    Builder.CreateBitCast(CGM.EmitAnnotationString(AnnotationStr), Int8PtrTy),
+    Builder.CreateBitCast(CGM.EmitAnnotationUnit(Location), Int8PtrTy),
+    CGM.EmitAnnotationLineNo(Location)
+  };
+  return Builder.CreateCall(AnnotationFn, Args);
+}
+
+void CodeGenFunction::EmitVarAnnotations(const VarDecl *D, llvm::Value *V) {
+  assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
+  // FIXME We create a new bitcast for every annotation because that's what
+  // llvm-gcc was doing.
+  for (specific_attr_iterator<AnnotateAttr>
+       ai = D->specific_attr_begin<AnnotateAttr>(),
+       ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
+    EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation),
+                       Builder.CreateBitCast(V, CGM.Int8PtrTy, V->getName()),
+                       (*ai)->getAnnotation(), D->getLocation());
+}
+
+llvm::Value *CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D,
+                                                   llvm::Value *V) {
+  assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
+  llvm::Type *VTy = V->getType();
+  llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation,
+                                    CGM.Int8PtrTy);
+
+  for (specific_attr_iterator<AnnotateAttr>
+       ai = D->specific_attr_begin<AnnotateAttr>(),
+       ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) {
+    // FIXME Always emit the cast inst so we can differentiate between
+    // annotation on the first field of a struct and annotation on the struct
+    // itself.
+    if (VTy != CGM.Int8PtrTy)
+      V = Builder.Insert(new llvm::BitCastInst(V, CGM.Int8PtrTy));
+    V = EmitAnnotationCall(F, V, (*ai)->getAnnotation(), D->getLocation());
+    V = Builder.CreateBitCast(V, VTy);
+  }
+
+  return V;
+}

clang/lib/CodeGen/CodeGenFunction.h

@@ -2271,6 +2271,23 @@ class CodeGenFunction : public CodeGenTypeCache {
 
   void EmitCXXThrowExpr(const CXXThrowExpr *E);
 
+  //===--------------------------------------------------------------------===//
+  //                         Annotations Emission
+  //===--------------------------------------------------------------------===//
+
+  /// Emit an annotation call (intrinsic or builtin).
+  llvm::Value *EmitAnnotationCall(llvm::Value *AnnotationFn,
+                                  llvm::Value *AnnotatedVal,
+                                  llvm::StringRef AnnotationStr,
+                                  SourceLocation Location);
+
+  /// Emit local annotations for the local variable V, declared by D.
+  void EmitVarAnnotations(const VarDecl *D, llvm::Value *V);
+
+  /// Emit field annotations for the given field & value. Returns the
+  /// annotation result.
+  llvm::Value *EmitFieldAnnotations(const FieldDecl *D, llvm::Value *V);
+
   //===--------------------------------------------------------------------===//
   //                             Internal Helpers
   //===--------------------------------------------------------------------===//

clang/lib/CodeGen/CodeGenModule.cpp

@@ -44,6 +44,8 @@
 using namespace clang;
 using namespace CodeGen;
 
+static const char AnnotationSection[] = "llvm.metadata";
+
 static CGCXXABI &createCXXABI(CodeGenModule &CGM) {
   switch (CGM.getContext().getTargetInfo().getCXXABI()) {
   case CXXABI_ARM: return *CreateARMCXXABI(CGM);
@@ -131,7 +133,7 @@ void CodeGenModule::Release() {
       AddGlobalCtor(ObjCInitFunction);
   EmitCtorList(GlobalCtors, "llvm.global_ctors");
   EmitCtorList(GlobalDtors, "llvm.global_dtors");
-  EmitAnnotations();
+  EmitGlobalAnnotations();
   EmitLLVMUsed();
 
   SimplifyPersonality();
@@ -382,22 +384,6 @@ void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
   }
 }
 
-void CodeGenModule::EmitAnnotations() {
-  if (Annotations.empty())
-    return;
-
-  // Create a new global variable for the ConstantStruct in the Module.
-  llvm::Constant *Array =
-  llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(),
-                                                Annotations.size()),
-                           Annotations);
-  llvm::GlobalValue *gv =
-  new llvm::GlobalVariable(TheModule, Array->getType(), false,
-                           llvm::GlobalValue::AppendingLinkage, Array,
-                           "llvm.global.annotations");
-  gv->setSection("llvm.metadata");
-}
-
 llvm::GlobalValue::LinkageTypes
 CodeGenModule::getFunctionLinkage(const FunctionDecl *D) {
   GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
@@ -642,54 +628,78 @@ void CodeGenModule::EmitDeferred() {
   }
 }
 
-/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the
-/// annotation information for a given GlobalValue.  The annotation struct is
-/// {i8 *, i8 *, i8 *, i32}.  The first field is a constant expression, the
-/// GlobalValue being annotated.  The second field is the constant string
-/// created from the AnnotateAttr's annotation.  The third field is a constant
-/// string containing the name of the translation unit.  The fourth field is
-/// the line number in the file of the annotated value declaration.
-///
-/// FIXME: this does not unique the annotation string constants, as llvm-gcc
-///        appears to.
-///
+void CodeGenModule::EmitGlobalAnnotations() {
+  if (Annotations.empty())
+    return;
+
+  // Create a new global variable for the ConstantStruct in the Module.
+  llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
+    Annotations[0]->getType(), Annotations.size()), Annotations);
+  llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(),
+    Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array,
+    "llvm.global.annotations");
+  gv->setSection(AnnotationSection);
+}
+
+llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) {
+  llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str);
+  if (i != AnnotationStrings.end())
+    return i->second;
+
+  // Not found yet, create a new global.
+  llvm::Constant *s = llvm::ConstantArray::get(getLLVMContext(), Str, true);
+  llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(),
+    true, llvm::GlobalValue::PrivateLinkage, s, ".str");
+  gv->setSection(AnnotationSection);
+  gv->setUnnamedAddr(true);
+  AnnotationStrings[Str] = gv;
+  return gv;
+}
+
+llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
+  SourceManager &SM = getContext().getSourceManager();
+  PresumedLoc PLoc = SM.getPresumedLoc(Loc);
+  if (PLoc.isValid())
+    return EmitAnnotationString(PLoc.getFilename());
+  return EmitAnnotationString(SM.getBufferName(Loc));
+}
+
+llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
+  SourceManager &SM = getContext().getSourceManager();
+  PresumedLoc PLoc = SM.getPresumedLoc(L);
+  unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
+    SM.getExpansionLineNumber(L);
+  return llvm::ConstantInt::get(Int32Ty, LineNo);
+}
+
 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
                                                 const AnnotateAttr *AA,
-                                                unsigned LineNo) {
-  llvm::Module *M = &getModule();
-
-  // get [N x i8] constants for the annotation string, and the filename string
-  // which are the 2nd and 3rd elements of the global annotation structure.
-  llvm::Type *SBP = llvm::Type::getInt8PtrTy(VMContext);
-  llvm::Constant *anno = llvm::ConstantArray::get(VMContext,
-                                                  AA->getAnnotation(), true);
-  llvm::Constant *unit = llvm::ConstantArray::get(VMContext,
-                                                  M->getModuleIdentifier(),
-                                                  true);
-
-  // Get the two global values corresponding to the ConstantArrays we just
-  // created to hold the bytes of the strings.
-  llvm::GlobalValue *annoGV =
-    new llvm::GlobalVariable(*M, anno->getType(), false,
-                             llvm::GlobalValue::PrivateLinkage, anno,
-                             GV->getName());
-  // translation unit name string, emitted into the llvm.metadata section.
-  llvm::GlobalValue *unitGV =
-    new llvm::GlobalVariable(*M, unit->getType(), false,
-                             llvm::GlobalValue::PrivateLinkage, unit,
-                             ".str");
-  unitGV->setUnnamedAddr(true);
+                                                SourceLocation L) {
+  // Get the globals for file name, annotation, and the line number.
+  llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
+                 *UnitGV = EmitAnnotationUnit(L),
+                 *LineNoCst = EmitAnnotationLineNo(L);
 
   // Create the ConstantStruct for the global annotation.
   llvm::Constant *Fields[4] = {
-    llvm::ConstantExpr::getBitCast(GV, SBP),
-    llvm::ConstantExpr::getBitCast(annoGV, SBP),
-    llvm::ConstantExpr::getBitCast(unitGV, SBP),
-    llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), LineNo)
+    llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
+    llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
+    llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
+    LineNoCst
   };
   return llvm::ConstantStruct::getAnon(Fields);
 }
 
+void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
+                                         llvm::GlobalValue *GV) {
+  assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
+  // Get the struct elements for these annotations.
+  for (specific_attr_iterator<AnnotateAttr>
+       ai = D->specific_attr_begin<AnnotateAttr>(),
+       ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
+    Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation()));
+}
+
 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
   // Never defer when EmitAllDecls is specified.
   if (Features.EmitAllDecls)
@@ -1297,11 +1307,8 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
     cast<llvm::GlobalValue>(Entry)->eraseFromParent();
   }
 
-  if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) {
-    SourceManager &SM = Context.getSourceManager();
-    AddAnnotation(EmitAnnotateAttr(
-        GV, AA, SM.getExpansionLineNumber(D->getLocation())));
-  }
+  if (D->hasAttr<AnnotateAttr>())
+    AddGlobalAnnotations(D, GV);
 
   GV->setInitializer(Init);
 
@@ -1530,6 +1537,8 @@ void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
     AddGlobalCtor(Fn, CA->getPriority());
   if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
     AddGlobalDtor(Fn, DA->getPriority());
+  if (D->hasAttr<AnnotateAttr>())
+    AddGlobalAnnotations(D, Fn);
 }
 
 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {