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Factor vtable related GlobalVariable creation out into a separate function. Add vtable linkage test. 

llvm-svn: 90667
This commit is contained in:
Anders Carlsson 2009-12-05 17:04:47 +00:00
parent 19323e02e9
commit 21bbc1e705
2 changed files with 58 additions and 24 deletions
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64
clang/lib/CodeGen/CGVtable.cpp
View File

@ -747,17 +747,11 @@ bool VtableBuilder::OverrideMethod(GlobalDecl GD, bool MorallyVirtual,
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
const bool isPure = MD->isPure();
typedef CXXMethodDecl::method_iterator meth_iter;
// FIXME: Should OverrideOffset's be Offset?
// FIXME: Don't like the nested loops. For very large inheritance
// heirarchies we could have a table on the side with the final overridder
// and just replace each instance of an overridden method once. Would be
// nice to measure the cost/benefit on real code.
for (meth_iter mi = MD->begin_overridden_methods(),
e = MD->end_overridden_methods();
mi != e; ++mi) {
for (CXXMethodDecl::method_iterator mi = MD->begin_overridden_methods(),
e = MD->end_overridden_methods(); mi != e; ++mi) {
GlobalDecl OGD;
const CXXMethodDecl *OMD = *mi;
@ -1332,6 +1326,33 @@ public:
};
}
/// createGlobalVariable - Create a global variable to be used for storing
/// either a vtable, a construction vtable or a VTT. The returned global
// variable will have the correct linkage set based on the given record decl.
static llvm::GlobalVariable *
createGlobalVariable(CodeGenModule &CGM, const CXXRecordDecl *RD,
const llvm::Type *Type, llvm::Constant *Init,
const llvm::Twine &Name) {
// Figure out the right linkage.
llvm::GlobalVariable::LinkageTypes Linkage =
llvm::GlobalValue::LinkOnceODRLinkage;
if (RD->isInAnonymousNamespace())
Linkage = llvm::GlobalValue::InternalLinkage;
// Create the variable.
llvm::GlobalVariable *V =
new llvm::GlobalVariable(CGM.getModule(), Type, /*isConstant=*/true,
Linkage, Init, Name);
bool Hidden = CGM.getDeclVisibilityMode(RD) == LangOptions::Hidden;
if (Hidden)
V->setVisibility(llvm::GlobalVariable::HiddenVisibility);
return V;
}
llvm::Constant *CodeGenModule::GenerateVTT(const CXXRecordDecl *RD) {
// Only classes that have virtual bases need a VTT.
if (RD->getNumVBases() == 0)
@ -1341,26 +1362,21 @@ llvm::Constant *CodeGenModule::GenerateVTT(const CXXRecordDecl *RD) {
getMangleContext().mangleCXXVTT(RD, OutName);
llvm::StringRef Name = OutName.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);
D1(printf("vtt %s\n", RD->getNameAsCString()));
std::vector<llvm::Constant *> inits;
VTTBuilder b(inits, RD, *this);
llvm::Constant *C;
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, Name);
bool Hidden = getDeclVisibilityMode(RD) == LangOptions::Hidden;
if (Hidden)
vtt->setVisibility(llvm::GlobalVariable::HiddenVisibility);
return llvm::ConstantExpr::getBitCast(vtt, Ptr8Ty);
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
const llvm::ArrayType *Type = llvm::ArrayType::get(Int8PtrTy, inits.size());
llvm::Constant *Init = llvm::ConstantArray::get(Type, inits);
llvm::GlobalVariable *VTT =
createGlobalVariable(*this, RD, Type, Init, Name);
return llvm::ConstantExpr::getBitCast(VTT, Int8PtrTy);
}
void CGVtableInfo::GenerateClassData(const CXXRecordDecl *RD) {

18
clang/test/CodeGenCXX/vtable-linkage.cpp Normal file
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@ -0,0 +1,18 @@
// RUN: clang-cc %s -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s
namespace {
// The vtables should have internal linkage.
struct A {
virtual void f() { }
};
struct B : virtual A {
virtual void f() { }
};
// CHECK: @_ZTVN12_GLOBAL__N_11BE = internal constant
// CHECK: @_ZTTN12_GLOBAL__N_11BE = internal constant
// CHECK: @_ZTVN12_GLOBAL__N_11AE = internal constant
}
void f() { B b; }