Refine vtable, rtti and rtti name instantiation so that they follow

the key function.  All the code is wired up, but won't work yet, as I
had to turn off key function calculation as it doesn't work yet.

Also, we refine visibility of the vtable, rtti and rtti name to match
the class, as well as as arrange for all the symbols to be internal
for anonymous namespace entities.

llvm-svn: 89309

1 files changed, 78 insertions, 24 deletions

diff --git a/clang/lib/CodeGen/CGVtable.cpp b/clang/lib/CodeGen/CGVtable.cpp
index d107edcbd76..9be1a3b22b3 100644
--- a/clang/lib/CodeGen/CGVtable.cpp
+++ b/clang/lib/CodeGen/CGVtable.cpp
@@ -787,37 +787,73 @@ llvm::Constant *CodeGenModule::GenerateVtable(const CXXRecordDecl *LayoutClass,
     mangleCXXCtorVtable(getMangleContext(), LayoutClass, Offset/8, RD, Out);
   else
     mangleCXXVtable(getMangleContext(), RD, Out);
+  llvm::StringRef Name = Out.str();
 
-  llvm::GlobalVariable::LinkageTypes linktype;
-  linktype = llvm::GlobalValue::LinkOnceODRLinkage;
   std::vector<llvm::Constant *> methods;
   llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
   int64_t AddressPoint;
 
-  VtableBuilder b(methods, RD, LayoutClass, Offset, *this);
+  llvm::GlobalVariable *GV = getModule().getGlobalVariable(Name);
+  if (GV && AddressPoints[LayoutClass] && !GV->isDeclaration())
+    AddressPoint=(*(*(AddressPoints[LayoutClass]))[RD])[std::make_pair(RD,
+                                                                       Offset)];
+  else {
+    VtableBuilder b(methods, RD, LayoutClass, Offset, *this);
 
-  D1(printf("vtable %s\n", RD->getNameAsCString()));
-  // First comes the vtables for all the non-virtual bases...
-  AddressPoint = b.GenerateVtableForBase(RD, Offset);
+    D1(printf("vtable %s\n", RD->getNameAsCString()));
+    // First comes the vtables for all the non-virtual bases...
+    AddressPoint = b.GenerateVtableForBase(RD, Offset);
 
-  // then the vtables for all the virtual bases.
-  b.GenerateVtableForVBases(RD, Offset);
+    // then the vtables for all the virtual bases.
+    b.GenerateVtableForVBases(RD, Offset);
 
-  CodeGenModule::AddrMap_t *&ref = AddressPoints[LayoutClass];
-  if (ref == 0)
-    ref = new CodeGenModule::AddrMap_t;
+    CodeGenModule::AddrMap_t *&ref = AddressPoints[LayoutClass];
+    if (ref == 0)
+      ref = new CodeGenModule::AddrMap_t;
     
-  (*ref)[RD] = b.getAddressPoints();
+    (*ref)[RD] = b.getAddressPoints();
+
+    bool CreateDefinition = true;
+    if (LayoutClass != RD)
+      CreateDefinition = true;
+    else {
+      // We have to convert it to have a record layout.
+      Types.ConvertTagDeclType(LayoutClass);
+      const CGRecordLayout &CGLayout = Types.getCGRecordLayout(LayoutClass);
+      if (const CXXMethodDecl *KeyFunction = CGLayout.getKeyFunction()) {
+        if (!KeyFunction->getBody()) {
+          // If there is a KeyFunction, and it isn't defined, just build a
+          // reference to the vtable.
+          CreateDefinition = false;
+        }
+      }
+    }
 
-  llvm::Constant *C;
-  llvm::ArrayType *type = llvm::ArrayType::get(Ptr8Ty, methods.size());
-  C = llvm::ConstantArray::get(type, methods);
-  llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), type,
-                                                      true, linktype, C,
-                                                      Out.str());
-  bool Hidden = getDeclVisibilityMode(RD) == LangOptions::Hidden;
-  if (Hidden)
-    GV->setVisibility(llvm::GlobalVariable::HiddenVisibility);
+    llvm::Constant *C = 0;
+    llvm::Type *type = Ptr8Ty;
+    llvm::GlobalVariable::LinkageTypes linktype
+      = llvm::GlobalValue::ExternalLinkage;
+    if (CreateDefinition) {
+      llvm::ArrayType *ntype = llvm::ArrayType::get(Ptr8Ty, methods.size());
+      C = llvm::ConstantArray::get(ntype, methods);
+      linktype = llvm::GlobalValue::LinkOnceODRLinkage;
+      if (LayoutClass->isInAnonymousNamespace())
+        linktype = llvm::GlobalValue::InternalLinkage;
+      type = ntype;
+    }
+    llvm::GlobalVariable *OGV = GV;
+    GV = new llvm::GlobalVariable(getModule(), type, true, linktype, C, Name);
+    if (OGV) {
+      GV->takeName(OGV);
+      llvm::Constant *NewPtr = llvm::ConstantExpr::getBitCast(GV,
+                                                              OGV->getType());
+      OGV->replaceAllUsesWith(NewPtr);
+      OGV->eraseFromParent();
+    }
+    bool Hidden = getDeclVisibilityMode(RD) == LangOptions::Hidden;
+    if (Hidden)
+      GV->setVisibility(llvm::GlobalVariable::HiddenVisibility);
+  }
   llvm::Constant *vtable = llvm::ConstantExpr::getBitCast(GV, Ptr8Ty);
   llvm::Constant *AddressPointC;
   uint32_t LLVMPointerWidth = getContext().Target.getPointerWidth(0);
@@ -1000,9 +1036,12 @@ llvm::Constant *CodeGenModule::GenerateVTT(const CXXRecordDecl *RD) {
   llvm::SmallString<256> OutName;
   llvm::raw_svector_ostream Out(OutName);
   mangleCXXVTT(getMangleContext(), RD, Out);
+  llvm::StringRef Name = Out.str();
 
   llvm::GlobalVariable::LinkageTypes linktype;
   linktype = llvm::GlobalValue::LinkOnceODRLinkage;
+  if (RD->isInAnonymousNamespace())
+    linktype = llvm::GlobalValue::InternalLinkage;
   std::vector<llvm::Constant *> inits;
   llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
 
@@ -1014,7 +1053,7 @@ llvm::Constant *CodeGenModule::GenerateVTT(const CXXRecordDecl *RD) {
   llvm::ArrayType *type = llvm::ArrayType::get(Ptr8Ty, inits.size());
   C = llvm::ConstantArray::get(type, inits);
   llvm::GlobalVariable *vtt = new llvm::GlobalVariable(getModule(), type, true,
-                                                 linktype, C, Out.str());
+                                                       linktype, C, Name);
   bool Hidden = getDeclVisibilityMode(RD) == LangOptions::Hidden;
   if (Hidden)
     vtt->setVisibility(llvm::GlobalVariable::HiddenVisibility);
@@ -1032,8 +1071,23 @@ llvm::Constant *CGVtableInfo::getVtable(const CXXRecordDecl *RD) {
   if (vtbl)
     return vtbl;
   vtbl = CGM.GenerateVtable(RD, RD);
-  CGM.GenerateRtti(RD);
-  CGM.GenerateVTT(RD);
+
+  bool CreateDefinition = true;
+  // We have to convert it to have a record layout.
+  CGM.getTypes().ConvertTagDeclType(RD);
+  const CGRecordLayout &CGLayout = CGM.getTypes().getCGRecordLayout(RD);
+  if (const CXXMethodDecl *KeyFunction = CGLayout.getKeyFunction()) {
+    if (!KeyFunction->getBody()) {
+      // If there is a KeyFunction, and it isn't defined, just build a
+      // reference to the vtable.
+      CreateDefinition = false;
+    }
+  }
+
+  if (CreateDefinition) {
+    CGM.GenerateRtti(RD);
+    CGM.GenerateVTT(RD);
+  }
   return vtbl;
 }