From bbfd5babab059af14eed20b63b2aabedaa6a6ac7 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Sat, 5 Feb 2011 18:48:55 +0000
Subject: [PATCH] Pass a 'ForVTable' flag to GetAddrOfThunk and pass it along
 to GetOrCreateLLVMFunction so that we won't assert when building a thunk for
 an implicit virtual member function that is not marked used.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124967 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGVTables.cpp                     | 11 ++++----
 lib/CodeGen/CodeGenModule.h                   |  3 ++-
 .../vtable-available-externally.cpp           | 26 +++++++++++++++++++
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index eadfe9f146..27b4432920 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -2451,7 +2451,8 @@ CodeGenVTables::getAddressPoint(BaseSubobject Base, const CXXRecordDecl *RD) {
 }
 
 llvm::Constant *CodeGenModule::GetAddrOfThunk(GlobalDecl GD, 
-                                              const ThunkInfo &Thunk) {
+                                              const ThunkInfo &Thunk,
+                                              bool ForVTable) {
   const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
 
   // Compute the mangled name.
@@ -2463,7 +2464,7 @@ llvm::Constant *CodeGenModule::GetAddrOfThunk(GlobalDecl GD,
     getCXXABI().getMangleContext().mangleThunk(MD, Thunk, Name);
   
   const llvm::Type *Ty = getTypes().GetFunctionTypeForVTable(GD);
-  return GetOrCreateLLVMFunction(Name, Ty, GD, /*ForVTable=*/false);
+  return GetOrCreateLLVMFunction(Name, Ty, GD, ForVTable);
 }
 
 static llvm::Value *PerformTypeAdjustment(CodeGenFunction &CGF,
@@ -2681,7 +2682,7 @@ void CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD,
 
 void CodeGenVTables::EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk)
 {
-  llvm::Constant *Entry = CGM.GetAddrOfThunk(GD, Thunk);
+  llvm::Constant *Entry = CGM.GetAddrOfThunk(GD, Thunk, /*ForVTable=*/false);
   
   // Strip off a bitcast if we got one back.
   if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
@@ -2701,7 +2702,7 @@ void CodeGenVTables::EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk)
 
     // Remove the name from the old thunk function and get a new thunk.
     OldThunkFn->setName(llvm::StringRef());
-    Entry = CGM.GetAddrOfThunk(GD, Thunk);
+    Entry = CGM.GetAddrOfThunk(GD, Thunk, /*ForVTable=*/false);
     
     // If needed, replace the old thunk with a bitcast.
     if (!OldThunkFn->use_empty()) {
@@ -2912,7 +2913,7 @@ CodeGenVTables::CreateVTableInitializer(const CXXRecordDecl *RD,
             VTableThunks[NextVTableThunkIndex].first == I) {
           const ThunkInfo &Thunk = VTableThunks[NextVTableThunkIndex].second;
         
-          Init = CGM.GetAddrOfThunk(GD, Thunk);
+          Init = CGM.GetAddrOfThunk(GD, Thunk, /*ForVTable=*/true);
         
           NextVTableThunkIndex++;
         } else {
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 1ed56d5b92..7b6e12358d 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -325,7 +325,8 @@ public:
   llvm::Constant *GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH = false);
 
   /// GetAddrOfThunk - Get the address of the thunk for the given global decl.
-  llvm::Constant *GetAddrOfThunk(GlobalDecl GD, const ThunkInfo &Thunk);
+  llvm::Constant *GetAddrOfThunk(GlobalDecl GD, const ThunkInfo &Thunk,
+                                 bool ForVTable);
 
   /// GetWeakRefReference - Get a reference to the target of VD.
   llvm::Constant *GetWeakRefReference(const ValueDecl *VD);
diff --git a/test/CodeGenCXX/vtable-available-externally.cpp b/test/CodeGenCXX/vtable-available-externally.cpp
index 594709d589..f56e3d147f 100644
--- a/test/CodeGenCXX/vtable-available-externally.cpp
+++ b/test/CodeGenCXX/vtable-available-externally.cpp
@@ -118,3 +118,29 @@ struct B : A {
 B::~B() { }
 
 }
+
+// Check that we don't assert on this test.
+namespace Test6 {
+
+struct A {
+  virtual ~A();
+  int a;
+};
+
+struct B {
+  virtual ~B();
+  int b;
+};
+
+struct C : A, B { 
+  C();
+};
+
+struct D : C {
+  virtual void f();
+  D();
+};
+
+D::D() { }
+
+}
-- 
2.40.0