Tweak implementation to make the functions to appear

Author: Fznamznon

clang/include/clang/AST/VTableBuilder.h

@@ -161,7 +161,7 @@ class VTableComponent {
     case CK_CompleteDtorPointer:
       return GlobalDecl(DtorDecl, CXXDtorType::Dtor_Complete);
     case CK_DeletingDtorPointer:
-      return GlobalDecl(DtorDecl, CXXDtorType::Dtor_Deleting);
+      return GlobalDecl(DtorDecl, CXXDtorType::Dtor_VectorDeleting);
     case CK_VCallOffset:
     case CK_VBaseOffset:
     case CK_OffsetToTop:

clang/lib/AST/VTableBuilder.cpp

@@ -2654,11 +2654,11 @@ class VFTableBuilder {
       MethodVFTableLocation Loc(MI.VBTableIndex, WhichVFPtr.getVBaseWithVPtr(),
                                 WhichVFPtr.NonVirtualOffset, MI.VFTableIndex);
       if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
-	if (!Context.getTargetInfo().getCXXABI().isMicrosoft()) {
+        if (!Context.getTargetInfo().getCXXABI().isMicrosoft()) {
           MethodVFTableLocations[GlobalDecl(DD, Dtor_Deleting)] = Loc;
-	} else {
-	  MethodVFTableLocations[GlobalDecl(DD, Dtor_VectorDeleting)] = Loc;
-	}  
+        } else {
+          MethodVFTableLocations[GlobalDecl(DD, Dtor_VectorDeleting)] = Loc;
+        }
       } else {
         MethodVFTableLocations[MD] = Loc;
       }
@@ -3879,12 +3879,9 @@ MicrosoftVTableContext::getMethodVFTableLocation(GlobalDecl GD) {
   assert(hasVtableSlot(cast<CXXMethodDecl>(GD.getDecl())) &&
          "Only use this method for virtual methods or dtors");
   if (isa<CXXDestructorDecl>(GD.getDecl())) {
-    if (!Context.getTargetInfo().getCXXABI().isMicrosoft()) {
-      assert(GD.getDtorType() == Dtor_Deleting);
-    } else {
-      assert(GD.getDtorType() == Dtor_VectorDeleting);
-    }  
-  }  
+    assert(GD.getDtorType() == Dtor_Deleting ||
+           GD.getDtorType() == Dtor_VectorDeleting);
+  }
 
   GD = GD.getCanonicalDecl();
 

clang/lib/CodeGen/CGCXX.cpp

@@ -205,55 +205,42 @@ bool CodeGenModule::TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D) {
 /// this function should be used only where there is an ABI requirement to emit
 /// an alias.
 void CodeGenModule::EmitDefinitionAsAlias(GlobalDecl AliasDecl, GlobalDecl TargetDecl) {
-  // Get the mangled names for the alias and the target.
-  StringRef AliasName = getMangledName(AliasDecl);
-  StringRef TargetName = getMangledName(TargetDecl);
 
-  // Get the LLVM function for the target.
-  llvm::Function *TargetFunction = cast<llvm::Function>(GetOrCreateLLVMFunction(
-        TargetName, /*FnType=*/nullptr, TargetDecl, /*ForVTable=*/false,
-      /*DontDefer=*/true, /*IsThunk=*/false, /*ExtraAttrs=*/llvm::AttributeList(),
-      ForDefinition));
+  // Derive the type for the alias.
+  llvm::PointerType *AliasValueType =
+      getTypes().GetFunctionType(AliasDecl)->getPointerTo();
+  auto *Aliasee = cast<llvm::GlobalValue>(GetAddrOfGlobal(TargetDecl));
 
   // Determine the linkage type for the alias.
   llvm::GlobalValue::LinkageTypes Linkage = getFunctionLinkage(AliasDecl);
 
-  // Ensure that the target has the correct linkage.
-  TargetFunction->setLinkage(Linkage);
-  llvm::Type *ElementType = TargetFunction->getValueType();
-  llvm::GlobalAlias *GA = llvm::GlobalAlias::create(
-     ElementType, // Type of the aliased value
-     0, // Address space, usually 0 for the default address space
-     Linkage, // Linkage of the alias
-     AliasName, // Name of the alias
-     TargetFunction, // The aliased value
-     &getModule()); // The module in which to create the alias
+  // Create the alias with no name.
+  auto *Alias = llvm::GlobalAlias::create(AliasValueType, 0, Linkage, "",
+                                          Aliasee, &getModule());
+  // Destructors are always unnamed_addr.
+  Alias->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
 
   // Set any additional necessary attributes for the alias.
-  SetCommonAttributes(AliasDecl, GA);
+  SetCommonAttributes(AliasDecl, Alias);
 }
 
 llvm::Function *CodeGenModule::codegenCXXStructor(GlobalDecl GD) {
   // The Microsoft ABI requires that the vector deleting destructor
   // be weak aliased to the scalar deleting destructor.
-  if (getTarget().getCXXABI().isMicrosoft() && GD.getDtorType() == Dtor_VectorDeleting) {
+  auto Dtor = dyn_cast<CXXDestructorDecl>(GD.getDecl());
+  if (Dtor && getTarget().getCXXABI().isMicrosoft() &&
+      GD.getDtorType() == Dtor_VectorDeleting) {
     const CXXDestructorDecl *DtorDecl = cast<CXXDestructorDecl>(GD.getDecl());
 
-    // Create GlobalDecl objects with the correct type for the vector and scalar deleting destructors.
+    // Create GlobalDecl objects with the correct type for the vector and scalar
+    // deleting destructors.
     GlobalDecl VectorDtorGD(DtorDecl, Dtor_VectorDeleting);
     GlobalDecl ScalarDtorGD(DtorDecl, Dtor_Deleting);
 
-    // Emit an alias from the vector deleting destructor to the scalar deleting destructor.
+    // Emit an alias from the vector deleting destructor to the scalar deleting
+    // destructor.
     EmitDefinitionAsAlias(VectorDtorGD, ScalarDtorGD);
 
-    // Return the scalar deleting destructor, which is now aliased by the vector deleting destructor.
-    // Use the mangled name of the scalar deleting destructor.
-    StringRef MangledName = getMangledName(ScalarDtorGD);
-    return cast<llvm::Function>(GetOrCreateLLVMFunction(
-        MangledName, /*FnType=*/nullptr,
-	ScalarDtorGD, /*ForVTable=*/false,
-        /*DontDefer=*/true, /*IsThunk=*/false, /*ExtraAttrs=*/llvm::AttributeList(),
-        ForDefinition));
   }
   const CGFunctionInfo &FnInfo = getTypes().arrangeCXXStructorDeclaration(GD);
   auto *Fn = cast<llvm::Function>(

clang/lib/CodeGen/CGClass.cpp

@@ -1544,8 +1544,8 @@ void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) {
   // outside of the function-try-block, which means it's always
   // possible to delegate the destructor body to the complete
   // destructor.  Do so.
-  if (DtorType == Dtor_Deleting) {
-    if (CXXStructorImplicitParamValue) {
+  if (DtorType == Dtor_Deleting || DtorType == Dtor_VectorDeleting) {
+    if (CXXStructorImplicitParamValue && DtorType == Dtor_VectorDeleting) {
       EmitConditionalArrayDtorCall(Dtor, *this, CXXStructorImplicitParamValue,
                                    false);
     }

clang/lib/CodeGen/MicrosoftCXXABI.cpp

@@ -70,9 +70,8 @@ class MicrosoftCXXABI : public CGCXXABI {
       switch (GD.getDtorType()) {
       case Dtor_Complete:
       case Dtor_Deleting:
-        return true;
       case Dtor_VectorDeleting:
-	return true;
+        return true;
       case Dtor_Base:
         return false;
 
@@ -261,7 +260,7 @@ class MicrosoftCXXABI : public CGCXXABI {
 
         // There's only Dtor_Deleting in vftable but it shares the this
         // adjustment with the base one, so look up the deleting one instead.
-        LookupGD = GlobalDecl(DD, Dtor_Deleting);
+        LookupGD = GlobalDecl(DD, Dtor_VectorDeleting);
       }
       MethodVFTableLocation ML =
           CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
@@ -895,7 +894,8 @@ void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
   // FIXME: Provide a source location here even though there's no
   // CXXMemberCallExpr for dtor call.
   bool UseGlobalDelete = DE->isGlobalDelete();
-  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
+  // FIXME check that vector deletion is actually required.
+  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_VectorDeleting;
   llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE,
                                                   /*CallOrInvoke=*/nullptr);
   if (UseGlobalDelete)
@@ -1443,7 +1443,7 @@ MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
 
     // There's no Dtor_Base in vftable but it shares the this adjustment with
     // the deleting one, so look it up instead.
-    GD = GlobalDecl(DD, Dtor_Deleting);
+    GD = GlobalDecl(DD, Dtor_VectorDeleting);
   }
 
   MethodVFTableLocation ML =
@@ -2015,10 +2015,12 @@ llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
   llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
   CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
 
+  bool UseGlobalDelete = D->isGlobalDelete();
+  bool CallDelete = !UseGlobalDelete;
   ASTContext &Context = getContext();
   llvm::Value *ImplicitParam = llvm::ConstantInt::get(
       llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
-      DtorType == Dtor_Deleting);
+      2 * (DtorType == Dtor_VectorDeleting) + CallDelete);
 
   QualType ThisTy;
   if (CE) {