Revert "[DebugInfo] Support to emit debugInfo for extern variables"

rnk · rnk · commit 891e25b02d76 · 2019-12-22T12:54:06.000-08:00
This reverts commit d77ae15. The tests committed along with this change do not pass, and should be changed to use %clang_cc1.
diff --git a/clang/include/clang/AST/ASTConsumer.h b/clang/include/clang/AST/ASTConsumer.h
@@ -102,11 +102,6 @@ class ASTConsumer {
   /// modified by the introduction of an implicit zero initializer.
   virtual void CompleteTentativeDefinition(VarDecl *D) {}
 
-  /// CompleteExternalDeclaration - Callback invoked at the end of a translation
-  /// unit to notify the consumer that the given external declaration should be
-  /// completed.
-  virtual void CompleteExternalDeclaration(VarDecl *D) {}
-
   /// Callback invoked when an MSInheritanceAttr has been attached to a
   /// CXXRecordDecl.
   virtual void AssignInheritanceModel(CXXRecordDecl *RD) {}
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
@@ -1389,9 +1389,6 @@ class TargetInfo : public virtual TransferrableTargetInfo,
 
   virtual void setAuxTarget(const TargetInfo *Aux) {}
 
-  /// Whether target allows debuginfo types for decl only variables.
-  virtual bool allowDebugInfoForExternalVar() const { return false; }
-
 protected:
   /// Copy type and layout related info.
   void copyAuxTarget(const TargetInfo *Aux);
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -668,9 +668,6 @@ class Sema final {
   /// All the tentative definitions encountered in the TU.
   TentativeDefinitionsType TentativeDefinitions;
 
-  /// All the external declarations encoutered and used in the TU.
-  SmallVector<VarDecl *, 4> ExternalDeclarations;
-
   typedef LazyVector<const DeclaratorDecl *, ExternalSemaSource,
                      &ExternalSemaSource::ReadUnusedFileScopedDecls, 2, 2>
     UnusedFileScopedDeclsType;
diff --git a/clang/lib/Basic/Targets/BPF.h b/clang/lib/Basic/Targets/BPF.h
@@ -76,8 +76,6 @@ class LLVM_LIBRARY_VISIBILITY BPFTargetInfo : public TargetInfo {
     return None;
   }
 
-  bool allowDebugInfoForExternalVar() const override { return true; }
-
   CallingConvCheckResult checkCallingConvention(CallingConv CC) const override {
     switch (CC) {
     default:
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -4485,7 +4485,7 @@ void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
 
     GVE = DBuilder.createGlobalVariableExpression(
         DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
-        Var->hasLocalLinkage(), true,
+        Var->hasLocalLinkage(),
         Expr.empty() ? nullptr : DBuilder.createExpression(Expr),
         getOrCreateStaticDataMemberDeclarationOrNull(D), TemplateParameters,
         Align);
@@ -4588,29 +4588,10 @@ void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD, const APValue &Init) {
 
   GV.reset(DBuilder.createGlobalVariableExpression(
       DContext, Name, StringRef(), Unit, getLineNumber(VD->getLocation()), Ty,
-      true, true, InitExpr, getOrCreateStaticDataMemberDeclarationOrNull(VarD),
+      true, InitExpr, getOrCreateStaticDataMemberDeclarationOrNull(VarD),
       TemplateParameters, Align));
 }
 
-void CGDebugInfo::EmitExternalVariable(llvm::GlobalVariable *Var,
-                                       const VarDecl *D) {
-  assert(DebugKind >= codegenoptions::LimitedDebugInfo);
-  if (D->hasAttr<NoDebugAttr>())
-    return;
-
-  auto Align = getDeclAlignIfRequired(D, CGM.getContext());
-  llvm::DIFile *Unit = getOrCreateFile(D->getLocation());
-  StringRef Name = D->getName();
-  llvm::DIType *Ty = getOrCreateType(D->getType(), Unit);
-
-  llvm::DIScope *DContext = getDeclContextDescriptor(D);
-  llvm::DIGlobalVariableExpression *GVE =
-      DBuilder.createGlobalVariableExpression(
-          DContext, Name, StringRef(), Unit, getLineNumber(D->getLocation()),
-          Ty, false, false, nullptr, nullptr, nullptr, Align);
-  Var->addDebugInfo(GVE);
-}
-
 llvm::DIScope *CGDebugInfo::getCurrentContextDescriptor(const Decl *D) {
   if (!LexicalBlockStack.empty())
     return LexicalBlockStack.back();
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
@@ -478,9 +478,6 @@ class CGDebugInfo {
   /// Emit a constant global variable's debug info.
   void EmitGlobalVariable(const ValueDecl *VD, const APValue &Init);
 
-  /// Emit information about an external variable.
-  void EmitExternalVariable(llvm::GlobalVariable *GV, const VarDecl *Decl);
-
   /// Emit C++ using directive.
   void EmitUsingDirective(const UsingDirectiveDecl &UD);
 
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -336,10 +336,6 @@ namespace clang {
       Gen->CompleteTentativeDefinition(D);
     }
 
-    void CompleteExternalDeclaration(VarDecl *D) override {
-      Gen->CompleteExternalDeclaration(D);
-    }
-
     void AssignInheritanceModel(CXXRecordDecl *RD) override {
       Gen->AssignInheritanceModel(RD);
     }
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -3730,10 +3730,6 @@ void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
   EmitGlobalVarDefinition(D);
 }
 
-void CodeGenModule::EmitExternalDeclaration(const VarDecl *D) {
-  EmitExternalVarDeclaration(D);
-}
-
 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
   return Context.toCharUnitsFromBits(
       getDataLayout().getTypeStoreSizeInBits(Ty));
@@ -4117,19 +4113,6 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
       DI->EmitGlobalVariable(GV, D);
 }
 
-void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
-  if (CGDebugInfo *DI = getModuleDebugInfo())
-    if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo) {
-      QualType ASTTy = D->getType();
-      llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
-      llvm::PointerType *PTy =
-          llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
-      llvm::Constant *GV = GetOrCreateLLVMGlobal(D->getName(), PTy, D);
-      DI->EmitExternalVariable(
-          cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
-    }
-}
-
 static bool isVarDeclStrongDefinition(const ASTContext &Context,
                                       CodeGenModule &CGM, const VarDecl *D,
                                       bool NoCommon) {
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
@@ -1170,8 +1170,6 @@ class CodeGenModule : public CodeGenTypeCache {
 
   void EmitTentativeDefinition(const VarDecl *D);
 
-  void EmitExternalDeclaration(const VarDecl *D);
-
   void EmitVTable(CXXRecordDecl *Class);
 
   void RefreshTypeCacheForClass(const CXXRecordDecl *Class);
@@ -1407,7 +1405,6 @@ class CodeGenModule : public CodeGenTypeCache {
   void EmitMultiVersionFunctionDefinition(GlobalDecl GD, llvm::GlobalValue *GV);
 
   void EmitGlobalVarDefinition(const VarDecl *D, bool IsTentative = false);
-  void EmitExternalVarDeclaration(const VarDecl *D);
   void EmitAliasDefinition(GlobalDecl GD);
   void emitIFuncDefinition(GlobalDecl GD);
   void emitCPUDispatchDefinition(GlobalDecl GD);
diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -290,10 +290,6 @@ namespace {
       Builder->EmitTentativeDefinition(D);
     }
 
-    void CompleteExternalDeclaration(VarDecl *D) override {
-      Builder->EmitExternalDeclaration(D);
-    }
-
     void HandleVTable(CXXRecordDecl *RD) override {
       if (Diags.hasErrorOccurred())
         return;
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
@@ -1136,13 +1136,6 @@ void Sema::ActOnEndOfTranslationUnit() {
       Consumer.CompleteTentativeDefinition(VD);
   }
 
-  for (auto D : ExternalDeclarations) {
-    if (!D || D->isInvalidDecl() || D->getPreviousDecl() || !D->isUsed())
-      continue;
-
-    Consumer.CompleteExternalDeclaration(D);
-  }
-
   // If there were errors, disable 'unused' warnings since they will mostly be
   // noise. Don't warn for a use from a module: either we should warn on all
   // file-scope declarations in modules or not at all, but whether the
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
@@ -12220,10 +12220,6 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl) {
         Diag(Var->getLocation(), diag::note_private_extern);
       }
 
-      if (Context.getTargetInfo().allowDebugInfoForExternalVar() &&
-          !Var->isInvalidDecl() && !getLangOpts().CPlusPlus)
-        ExternalDeclarations.push_back(Var);
-
       return;
 
     case VarDecl::TentativeDefinition:
diff --git a/clang/test/CodeGen/debug-info-extern-basic.c b/clang/test/CodeGen/debug-info-extern-basic.c
diff --git a/clang/test/CodeGen/debug-info-extern-duplicate.c b/clang/test/CodeGen/debug-info-extern-duplicate.c
diff --git a/clang/test/CodeGen/debug-info-extern-multi.c b/clang/test/CodeGen/debug-info-extern-multi.c
diff --git a/clang/test/CodeGen/debug-info-extern-unused.c b/clang/test/CodeGen/debug-info-extern-unused.c
diff --git a/llvm/include/llvm/IR/DIBuilder.h b/llvm/include/llvm/IR/DIBuilder.h
@@ -583,7 +583,7 @@ namespace llvm {
     ///                    specified)
     DIGlobalVariableExpression *createGlobalVariableExpression(
         DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
-        unsigned LineNo, DIType *Ty, bool isLocalToUnit, bool isDefined = true,
+        unsigned LineNo, DIType *Ty, bool isLocalToUnit,
         DIExpression *Expr = nullptr, MDNode *Decl = nullptr,
         MDTuple *templateParams = nullptr, uint32_t AlignInBits = 0);
 
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
@@ -640,14 +640,13 @@ static void checkGlobalVariableScope(DIScope *Context) {
 
 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
-    unsigned LineNumber, DIType *Ty, bool isLocalToUnit,
-    bool isDefined, DIExpression *Expr,
+    unsigned LineNumber, DIType *Ty, bool isLocalToUnit, DIExpression *Expr,
     MDNode *Decl, MDTuple *templateParams, uint32_t AlignInBits) {
   checkGlobalVariableScope(Context);
 
   auto *GV = DIGlobalVariable::getDistinct(
       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
-      LineNumber, Ty, isLocalToUnit, isDefined, cast_or_null<DIDerivedType>(Decl),
+      LineNumber, Ty, isLocalToUnit, true, cast_or_null<DIDerivedType>(Decl),
       templateParams, AlignInBits);
   if (!Expr)
     Expr = createExpression();
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
@@ -1289,7 +1289,7 @@ LLVMMetadataRef LLVMDIBuilderCreateGlobalVariableExpression(
   return wrap(unwrap(Builder)->createGlobalVariableExpression(
       unwrapDI<DIScope>(Scope), {Name, NameLen}, {Linkage, LinkLen},
       unwrapDI<DIFile>(File), LineNo, unwrapDI<DIType>(Ty), LocalToUnit,
-      true, unwrap<DIExpression>(Expr), unwrapDI<MDNode>(Decl),
+      unwrap<DIExpression>(Expr), unwrapDI<MDNode>(Decl),
       nullptr, AlignInBits));
 }
 
diff --git a/llvm/unittests/Transforms/Utils/CloningTest.cpp b/llvm/unittests/Transforms/Utils/CloningTest.cpp
@@ -764,7 +764,7 @@ class CloneModule : public ::testing::Test {
 
     DBuilder.createGlobalVariableExpression(
         Subprogram, "unattached", "unattached", File, 1,
-        DBuilder.createNullPtrType(), false, true, Expr);
+        DBuilder.createNullPtrType(), false, Expr);
 
     auto *Entry = BasicBlock::Create(C, "", F);
     IBuilder.SetInsertPoint(Entry);

Original file line number	Diff line number	Diff line change
`@@ -76,8 +76,6 @@ class LLVM_LIBRARY_VISIBILITY BPFTargetInfo : public TargetInfo {`
`76`	`76`	`return None;`
`77`	`77`	`}`
`78`	`78`
`79`		`- bool allowDebugInfoForExternalVar() const override { return true; }`
`80`		`-`
`81`	`79`	`CallingConvCheckResult checkCallingConvention(CallingConv CC) const override {`
`82`	`80`	`switch (CC) {`
`83`	`81`	`default:`
Original file line number	Diff line number	Diff line change
`@@ -336,10 +336,6 @@ namespace clang {`
`336`	`336`	`Gen->CompleteTentativeDefinition(D);`
`337`	`337`	`}`
`338`	`338`
`339`		`- void CompleteExternalDeclaration(VarDecl *D) override {`
`340`		`- Gen->CompleteExternalDeclaration(D);`
`341`		`- }`
`342`		`-`
`343`	`339`	`void AssignInheritanceModel(CXXRecordDecl *RD) override {`
`344`	`340`	`Gen->AssignInheritanceModel(RD);`
`345`	`341`	`}`