Abstract out the emission of vtables, add basic support for vtable emission when using -cxx-abi microsoft
Reviewed at http://llvm-reviews.chandlerc.com/D1532
llvm-svn: 191523
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index b08e9b7..2934e63 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -34,6 +34,9 @@
namespace {
class ItaniumCXXABI : public CodeGen::CGCXXABI {
+ /// VTables - All the vtables which have been defined.
+ llvm::DenseMap<const CXXRecordDecl *, llvm::GlobalVariable *> VTables;
+
protected:
bool UseARMMethodPtrABI;
bool UseARMGuardVarABI;
@@ -142,6 +145,20 @@
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd);
+ void emitVTableDefinitions(CodeGenVTables &CGVT, const CXXRecordDecl *RD);
+
+ llvm::Value *getVTableAddressPointInStructor(
+ CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
+ BaseSubobject Base, const CXXRecordDecl *NearestVBase,
+ bool &NeedsVirtualOffset);
+
+ llvm::Constant *
+ getVTableAddressPointForConstExpr(BaseSubobject Base,
+ const CXXRecordDecl *VTableClass);
+
+ llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
+ CharUnits VPtrOffset);
+
llvm::Value *getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
llvm::Value *This, llvm::Type *Ty);
@@ -150,8 +167,7 @@
CXXDtorType DtorType, SourceLocation CallLoc,
llvm::Value *This);
- void EmitVirtualInheritanceTables(llvm::GlobalVariable::LinkageTypes Linkage,
- const CXXRecordDecl *RD);
+ void emitVirtualInheritanceTables(const CXXRecordDecl *RD);
StringRef GetPureVirtualCallName() { return "__cxa_pure_virtual"; }
StringRef GetDeletedVirtualCallName() { return "__cxa_deleted_virtual"; }
@@ -888,6 +904,113 @@
This, VTT, VTTTy, ArgBeg, ArgEnd);
}
+void ItaniumCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
+ const CXXRecordDecl *RD) {
+ llvm::GlobalVariable *VTable = getAddrOfVTable(RD, CharUnits());
+ if (VTable->hasInitializer())
+ return;
+
+ VTableContext &VTContext = CGM.getVTableContext();
+ const VTableLayout &VTLayout = VTContext.getVTableLayout(RD);
+ llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
+
+ // Create and set the initializer.
+ llvm::Constant *Init = CGVT.CreateVTableInitializer(
+ RD, VTLayout.vtable_component_begin(), VTLayout.getNumVTableComponents(),
+ VTLayout.vtable_thunk_begin(), VTLayout.getNumVTableThunks());
+ VTable->setInitializer(Init);
+
+ // Set the correct linkage.
+ VTable->setLinkage(Linkage);
+
+ // Set the right visibility.
+ CGM.setTypeVisibility(VTable, RD, CodeGenModule::TVK_ForVTable);
+
+ // If this is the magic class __cxxabiv1::__fundamental_type_info,
+ // we will emit the typeinfo for the fundamental types. This is the
+ // same behaviour as GCC.
+ const DeclContext *DC = RD->getDeclContext();
+ if (RD->getIdentifier() &&
+ RD->getIdentifier()->isStr("__fundamental_type_info") &&
+ isa<NamespaceDecl>(DC) && cast<NamespaceDecl>(DC)->getIdentifier() &&
+ cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__cxxabiv1") &&
+ DC->getParent()->isTranslationUnit())
+ CGM.EmitFundamentalRTTIDescriptors();
+}
+
+llvm::Value *ItaniumCXXABI::getVTableAddressPointInStructor(
+ CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
+ const CXXRecordDecl *NearestVBase, bool &NeedsVirtualOffset) {
+ bool NeedsVTTParam = CGM.getCXXABI().NeedsVTTParameter(CGF.CurGD);
+ NeedsVirtualOffset = (NeedsVTTParam && NearestVBase);
+
+ llvm::Value *VTableAddressPoint;
+ if (NeedsVTTParam && (Base.getBase()->getNumVBases() || NearestVBase)) {
+ // Get the secondary vpointer index.
+ uint64_t VirtualPointerIndex =
+ CGM.getVTables().getSecondaryVirtualPointerIndex(VTableClass, Base);
+
+ /// Load the VTT.
+ llvm::Value *VTT = CGF.LoadCXXVTT();
+ if (VirtualPointerIndex)
+ VTT = CGF.Builder.CreateConstInBoundsGEP1_64(VTT, VirtualPointerIndex);
+
+ // And load the address point from the VTT.
+ VTableAddressPoint = CGF.Builder.CreateLoad(VTT);
+ } else {
+ llvm::Constant *VTable =
+ CGM.getCXXABI().getAddrOfVTable(VTableClass, CharUnits());
+ uint64_t AddressPoint = CGM.getVTableContext().getVTableLayout(VTableClass)
+ .getAddressPoint(Base);
+ VTableAddressPoint =
+ CGF.Builder.CreateConstInBoundsGEP2_64(VTable, 0, AddressPoint);
+ }
+
+ return VTableAddressPoint;
+}
+
+llvm::Constant *ItaniumCXXABI::getVTableAddressPointForConstExpr(
+ BaseSubobject Base, const CXXRecordDecl *VTableClass) {
+ llvm::Constant *VTable = getAddrOfVTable(VTableClass, CharUnits());
+
+ // Find the appropriate vtable within the vtable group.
+ uint64_t AddressPoint =
+ CGM.getVTableContext().getVTableLayout(VTableClass).getAddressPoint(Base);
+ llvm::Value *Indices[] = {
+ llvm::ConstantInt::get(CGM.Int64Ty, 0),
+ llvm::ConstantInt::get(CGM.Int64Ty, AddressPoint)
+ };
+
+ return llvm::ConstantExpr::getInBoundsGetElementPtr(VTable, Indices);
+}
+
+llvm::GlobalVariable *ItaniumCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
+ CharUnits VPtrOffset) {
+ assert(VPtrOffset.isZero() && "Itanium ABI only supports zero vptr offsets");
+
+ llvm::GlobalVariable *&VTable = VTables[RD];
+ if (VTable)
+ return VTable;
+
+ // Queue up this v-table for possible deferred emission.
+ CGM.addDeferredVTable(RD);
+
+ SmallString<256> OutName;
+ llvm::raw_svector_ostream Out(OutName);
+ CGM.getCXXABI().getMangleContext().mangleCXXVTable(RD, Out);
+ Out.flush();
+ StringRef Name = OutName.str();
+
+ VTableContext &VTContext = CGM.getVTableContext();
+ llvm::ArrayType *ArrayType = llvm::ArrayType::get(
+ CGM.Int8PtrTy, VTContext.getVTableLayout(RD).getNumVTableComponents());
+
+ VTable = CGM.CreateOrReplaceCXXRuntimeVariable(
+ Name, ArrayType, llvm::GlobalValue::ExternalLinkage);
+ VTable->setUnnamedAddr(true);
+ return VTable;
+}
+
llvm::Value *ItaniumCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
GlobalDecl GD,
llvm::Value *This,
@@ -919,11 +1042,10 @@
/*ImplicitParam=*/0, QualType(), 0, 0);
}
-void ItaniumCXXABI::EmitVirtualInheritanceTables(
- llvm::GlobalVariable::LinkageTypes Linkage, const CXXRecordDecl *RD) {
+void ItaniumCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
CodeGenVTables &VTables = CGM.getVTables();
llvm::GlobalVariable *VTT = VTables.GetAddrOfVTT(RD);
- VTables.EmitVTTDefinition(VTT, Linkage, RD);
+ VTables.EmitVTTDefinition(VTT, CGM.getVTableLinkage(RD), RD);
}
void ARMCXXABI::EmitReturnFromThunk(CodeGenFunction &CGF,