Improve linkage of RTTI data structures. Introduce CodeGenModule::GetAddrOfRTTI which figures out the right linkage of the RTTI information for the given type and whether it should be defined or not. I will migrate clients over to GetAddrOfRTTI in subsequent commits (with tests).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91098 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 3548669..ad8734d 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -352,18 +352,10 @@
llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
QualType Ty = E->getType();
const llvm::Type *LTy = ConvertType(Ty)->getPointerTo();
- if (E->isTypeOperand()) {
- Ty = E->getTypeOperand();
- CanQualType CanTy = CGM.getContext().getCanonicalType(Ty);
- Ty = CanTy.getUnqualifiedType().getNonReferenceType();
- if (const RecordType *RT = Ty->getAs<RecordType>()) {
- const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
- if (RD->isPolymorphic())
- return Builder.CreateBitCast(CGM.GenerateRTTIRef(RD), LTy);
- return Builder.CreateBitCast(CGM.GenerateRTTI(RD), LTy);
- }
- return Builder.CreateBitCast(CGM.GenerateRTTI(Ty), LTy);
- }
+
+ if (E->isTypeOperand())
+ return Builder.CreateBitCast(CGM.GetAddrOfRTTI(E->getTypeOperand()), LTy);
+
Expr *subE = E->getExprOperand();
Ty = subE->getType();
CanQualType CanTy = CGM.getContext().getCanonicalType(Ty);
diff --git a/lib/CodeGen/CGRTTI.cpp b/lib/CodeGen/CGRTTI.cpp
index 0e89e83..c8ce4ec 100644
--- a/lib/CodeGen/CGRTTI.cpp
+++ b/lib/CodeGen/CGRTTI.cpp
@@ -68,27 +68,37 @@
return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
}
+ // FIXME: This should be removed, and clients should pass in the linkage
+ // directly instead.
+ static inline llvm::GlobalVariable::LinkageTypes
+ GetLinkageFromExternFlag(bool Extern) {
+ if (Extern)
+ return llvm::GlobalValue::WeakODRLinkage;
+
+ return llvm::GlobalValue::InternalLinkage;
+ }
+
+ // FIXME: This should be removed, and clients should pass in the linkage
+ // directly instead.
llvm::Constant *BuildName(QualType Ty, bool Hidden, bool Extern) {
+ return BuildName(Ty, Hidden, GetLinkageFromExternFlag(Extern));
+ }
+
+ llvm::Constant *BuildName(QualType Ty, bool Hidden,
+ llvm::GlobalVariable::LinkageTypes Linkage) {
llvm::SmallString<256> OutName;
CGM.getMangleContext().mangleCXXRTTIName(Ty, OutName);
llvm::StringRef Name = OutName.str();
- llvm::GlobalVariable::LinkageTypes linktype;
- linktype = llvm::GlobalValue::LinkOnceODRLinkage;
- if (!Extern)
- linktype = llvm::GlobalValue::InternalLinkage;
+ llvm::GlobalVariable *OGV = CGM.getModule().getGlobalVariable(Name);
+ if (OGV && !OGV->isDeclaration())
+ return llvm::ConstantExpr::getBitCast(OGV, Int8PtrTy);
- llvm::GlobalVariable *GV;
- GV = CGM.getModule().getGlobalVariable(Name);
- if (GV && !GV->isDeclaration())
- return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
+ llvm::Constant *C = llvm::ConstantArray::get(VMContext, Name.substr(4));
- llvm::Constant *C;
- C = llvm::ConstantArray::get(VMContext, Name.substr(4));
-
- llvm::GlobalVariable *OGV = GV;
- GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, linktype,
- C, Name);
+ llvm::GlobalVariable *GV =
+ new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, Linkage,
+ C, Name);
if (OGV) {
GV->takeName(OGV);
llvm::Constant *NewPtr = llvm::ConstantExpr::getBitCast(GV,
@@ -115,9 +125,6 @@
llvm::Constant *BuildTypeRef(QualType Ty) {
llvm::Constant *C;
- if (!CGM.getContext().getLangOptions().RTTI)
- return llvm::Constant::getNullValue(Int8PtrTy);
-
llvm::SmallString<256> OutName;
CGM.getMangleContext().mangleCXXRTTI(Ty, OutName);
llvm::StringRef Name = OutName.str();
@@ -181,17 +188,14 @@
llvm::Constant *finish(std::vector<llvm::Constant *> &info,
llvm::GlobalVariable *GV,
- llvm::StringRef Name, bool Hidden, bool Extern) {
- llvm::GlobalVariable::LinkageTypes linktype;
- linktype = llvm::GlobalValue::LinkOnceODRLinkage;
- if (!Extern)
- linktype = llvm::GlobalValue::InternalLinkage;
-
- llvm::Constant *C;
- C = llvm::ConstantStruct::get(VMContext, &info[0], info.size(), false);
+ llvm::StringRef Name, bool Hidden,
+ llvm::GlobalVariable::LinkageTypes Linkage) {
+ llvm::Constant *C =
+ llvm::ConstantStruct::get(VMContext, &info[0], info.size(),
+ /*Packed=*/false);
llvm::GlobalVariable *OGV = GV;
- GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, linktype,
+ GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, Linkage,
C, Name);
if (OGV) {
GV->takeName(OGV);
@@ -206,10 +210,9 @@
}
- llvm::Constant *Buildclass_type_info(const CXXRecordDecl *RD) {
- if (!CGM.getContext().getLangOptions().RTTI)
- return llvm::Constant::getNullValue(Int8PtrTy);
-
+ llvm::Constant *
+ Buildclass_type_info(const CXXRecordDecl *RD,
+ llvm::GlobalVariable::LinkageTypes Linkage) {
llvm::Constant *C;
llvm::SmallString<256> OutName;
@@ -224,8 +227,11 @@
std::vector<llvm::Constant *> info;
+ // If we're in an anonymous namespace, then we always want internal linkage.
+ if (RD->isInAnonymousNamespace())
+ Linkage = llvm::GlobalVariable::InternalLinkage;
+
bool Hidden = CGM.getDeclVisibilityMode(RD) == LangOptions::Hidden;
- bool Extern = !RD->isInAnonymousNamespace();
bool simple = false;
if (RD->getNumBases() == 0)
@@ -237,7 +243,7 @@
C = BuildVtableRef("_ZTVN10__cxxabiv121__vmi_class_type_infoE");
info.push_back(C);
info.push_back(BuildName(CGM.getContext().getTagDeclType(RD), Hidden,
- Extern));
+ Linkage));
// If we have no bases, there are no more fields.
if (RD->getNumBases()) {
@@ -273,7 +279,7 @@
}
}
- return finish(info, GV, Name, Hidden, Extern);
+ return finish(info, GV, Name, Hidden, Linkage);
}
/// - BuildFlags - Build a __flags value for __pbase_type_info.
@@ -366,7 +372,8 @@
info.push_back(BuildType(QualType(PtrMemTy->getClass(), 0)));
// We always generate these as hidden, only the name isn't hidden.
- return finish(info, GV, Name, true, Extern);
+ return finish(info, GV, Name, /*Hidden=*/true,
+ GetLinkageFromExternFlag(Extern));
}
llvm::Constant *BuildSimpleType(QualType Ty, const char *vtbl) {
@@ -391,16 +398,18 @@
info.push_back(BuildName(Ty, Hidden, Extern));
// We always generate these as hidden, only the name isn't hidden.
- return finish(info, GV, Name, true, Extern);
+ return finish(info, GV, Name, /*Hidden=*/true,
+ GetLinkageFromExternFlag(Extern));
}
+ /// BuildType - Builds the type info for the given type.
llvm::Constant *BuildType(QualType Ty) {
const clang::Type &Type
= *CGM.getContext().getCanonicalType(Ty).getTypePtr();
if (const RecordType *RT = Ty.getTypePtr()->getAs<RecordType>())
if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()))
- return Buildclass_type_info(RD);
+ return BuildClassTypeInfo(RD);
switch (Type.getTypeClass()) {
default: {
@@ -438,9 +447,51 @@
return BuildSimpleType(Ty, "_ZTVN10__cxxabiv116__enum_type_infoE");
}
}
+
+ /// BuildClassTypeInfo - Builds the class type info (or a reference to it)
+ /// for the given record decl.
+ llvm::Constant *BuildClassTypeInfo(const CXXRecordDecl *RD) {
+ const CXXMethodDecl *KeyFunction = 0;
+
+ if (RD->isDynamicClass())
+ KeyFunction = CGM.getContext().getKeyFunction(RD);
+
+ if (KeyFunction) {
+ // If the key function is defined in this translation unit, then the RTTI
+ // related constants should also be emitted here, with external linkage.
+ if (KeyFunction->getBody())
+ return Buildclass_type_info(RD, llvm::GlobalValue::ExternalLinkage);
+
+ // Otherwise, we just want a reference to the type info.
+ return Buildclass_type_infoRef(RD);
+ }
+
+ // If there is no key function (or if the record doesn't have any virtual
+ // member functions or virtual bases), emit the type info with weak_odr
+ // linkage.
+ return Buildclass_type_info(RD, llvm::GlobalValue::WeakODRLinkage);
+ }
};
}
+llvm::Constant *CodeGenModule::GetAddrOfRTTI(const CXXRecordDecl *RD) {
+ if (!getContext().getLangOptions().RTTI) {
+ const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
+ return llvm::Constant::getNullValue(Int8PtrTy);
+ }
+
+ return RTTIBuilder(*this).BuildClassTypeInfo(RD);
+}
+
+llvm::Constant *CodeGenModule::GetAddrOfRTTI(QualType Ty) {
+ if (!getContext().getLangOptions().RTTI) {
+ const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
+ return llvm::Constant::getNullValue(Int8PtrTy);
+ }
+
+ return RTTIBuilder(*this).BuildType(Ty);
+}
+
llvm::Constant *CodeGenModule::GenerateRTTIRef(const CXXRecordDecl *RD) {
RTTIBuilder b(*this);
@@ -450,7 +501,7 @@
llvm::Constant *CodeGenModule::GenerateRTTI(const CXXRecordDecl *RD) {
RTTIBuilder b(*this);
- return b.Buildclass_type_info(RD);
+ return b.Buildclass_type_info(RD, llvm::GlobalValue::ExternalLinkage);
}
llvm::Constant *CodeGenModule::GenerateRTTI(QualType Ty) {
diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
index ef680d9..752f69c 100644
--- a/lib/CodeGen/CGVtable.cpp
+++ b/lib/CodeGen/CGVtable.cpp
@@ -203,7 +203,7 @@
LLVMPointerWidth(cgm.getContext().Target.getPointerWidth(0)) {
Ptr8Ty = llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext), 0);
if (BuildVtable)
- rtti = cgm.GenerateRTTIRef(MostDerivedClass);
+ rtti = CGM.GetAddrOfRTTI(MostDerivedClass);
}
// getVtableComponents - Returns a reference to the vtable components.
@@ -1409,8 +1409,6 @@
}
Vtable = GenerateVtable(Linkage, /*GenerateDefinition=*/true, RD, RD, 0);
-
- CGM.GenerateRTTI(RD);
GenerateVTT(Linkage, RD);
}
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 466aaa6..cc7ec9c 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -212,6 +212,13 @@
llvm::Constant *GetAddrOfFunction(GlobalDecl GD,
const llvm::Type *Ty = 0);
+ /// GetAddrOfRTTI - Get the address of the RTTI structure for the given type.
+ llvm::Constant *GetAddrOfRTTI(QualType Ty);
+
+ /// GetAddrOfRTTI - Get the address of the RTTI structure for the given record
+ /// decl.
+ llvm::Constant *GetAddrOfRTTI(const CXXRecordDecl *RD);
+
/// GenerateRTTI - Generate the rtti information for the given type.
llvm::Constant *GenerateRTTI(const CXXRecordDecl *RD);