Revert "Revert r211402 (and r211408,r211410), "CodeGen: Refactor dynamic_cast and typeid" It crashes msvc codegen in clang/test/SemaCXX/undefined-internal.cpp."
This reverts commit r211467 which reverted r211408,r211410, it caused
crashes in test/SemaCXX/undefined-internal.cpp for i686-win32 targets.
llvm-svn: 211473
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index be8dac1..38d49d1 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -25,6 +25,7 @@
#include "CodeGenModule.h"
#include "clang/AST/Mangle.h"
#include "clang/AST/Type.h"
+#include "llvm/IR/CallSite.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Value.h"
@@ -108,6 +109,26 @@
llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF, llvm::Value *ptr,
QualType type) override;
+ bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
+ void EmitBadTypeidCall(CodeGenFunction &CGF) override;
+ llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
+ llvm::Value *ThisPtr,
+ llvm::Type *StdTypeInfoPtrTy) override;
+
+ bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
+ QualType SrcRecordTy) override;
+
+ llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, llvm::Value *Value,
+ QualType SrcRecordTy, QualType DestTy,
+ QualType DestRecordTy,
+ llvm::BasicBlock *CastEnd) override;
+
+ llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, llvm::Value *Value,
+ QualType SrcRecordTy,
+ QualType DestTy) override;
+
+ bool EmitBadCastCall(CodeGenFunction &CGF) override;
+
llvm::Value *
GetVirtualBaseClassOffset(CodeGenFunction &CGF, llvm::Value *This,
const CXXRecordDecl *ClassDecl,
@@ -800,6 +821,194 @@
return CGF.Builder.CreateInBoundsGEP(ptr, offset);
}
+static llvm::Constant *getItaniumDynamicCastFn(CodeGenFunction &CGF) {
+ // void *__dynamic_cast(const void *sub,
+ // const abi::__class_type_info *src,
+ // const abi::__class_type_info *dst,
+ // std::ptrdiff_t src2dst_offset);
+
+ llvm::Type *Int8PtrTy = CGF.Int8PtrTy;
+ llvm::Type *PtrDiffTy =
+ CGF.ConvertType(CGF.getContext().getPointerDiffType());
+
+ llvm::Type *Args[4] = { Int8PtrTy, Int8PtrTy, Int8PtrTy, PtrDiffTy };
+
+ llvm::FunctionType *FTy = llvm::FunctionType::get(Int8PtrTy, Args, false);
+
+ // Mark the function as nounwind readonly.
+ llvm::Attribute::AttrKind FuncAttrs[] = { llvm::Attribute::NoUnwind,
+ llvm::Attribute::ReadOnly };
+ llvm::AttributeSet Attrs = llvm::AttributeSet::get(
+ CGF.getLLVMContext(), llvm::AttributeSet::FunctionIndex, FuncAttrs);
+
+ return CGF.CGM.CreateRuntimeFunction(FTy, "__dynamic_cast", Attrs);
+}
+
+static llvm::Constant *getBadCastFn(CodeGenFunction &CGF) {
+ // void __cxa_bad_cast();
+ llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false);
+ return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_cast");
+}
+
+/// \brief Compute the src2dst_offset hint as described in the
+/// Itanium C++ ABI [2.9.7]
+static CharUnits computeOffsetHint(ASTContext &Context,
+ const CXXRecordDecl *Src,
+ const CXXRecordDecl *Dst) {
+ CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+ /*DetectVirtual=*/false);
+
+ // If Dst is not derived from Src we can skip the whole computation below and
+ // return that Src is not a public base of Dst. Record all inheritance paths.
+ if (!Dst->isDerivedFrom(Src, Paths))
+ return CharUnits::fromQuantity(-2ULL);
+
+ unsigned NumPublicPaths = 0;
+ CharUnits Offset;
+
+ // Now walk all possible inheritance paths.
+ for (CXXBasePaths::paths_iterator I = Paths.begin(), E = Paths.end(); I != E;
+ ++I) {
+ if (I->Access != AS_public) // Ignore non-public inheritance.
+ continue;
+
+ ++NumPublicPaths;
+
+ for (CXXBasePath::iterator J = I->begin(), JE = I->end(); J != JE; ++J) {
+ // If the path contains a virtual base class we can't give any hint.
+ // -1: no hint.
+ if (J->Base->isVirtual())
+ return CharUnits::fromQuantity(-1ULL);
+
+ if (NumPublicPaths > 1) // Won't use offsets, skip computation.
+ continue;
+
+ // Accumulate the base class offsets.
+ const ASTRecordLayout &L = Context.getASTRecordLayout(J->Class);
+ Offset += L.getBaseClassOffset(J->Base->getType()->getAsCXXRecordDecl());
+ }
+ }
+
+ // -2: Src is not a public base of Dst.
+ if (NumPublicPaths == 0)
+ return CharUnits::fromQuantity(-2ULL);
+
+ // -3: Src is a multiple public base type but never a virtual base type.
+ if (NumPublicPaths > 1)
+ return CharUnits::fromQuantity(-3ULL);
+
+ // Otherwise, the Src type is a unique public nonvirtual base type of Dst.
+ // Return the offset of Src from the origin of Dst.
+ return Offset;
+}
+
+static llvm::Constant *getBadTypeidFn(CodeGenFunction &CGF) {
+ // void __cxa_bad_typeid();
+ llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false);
+
+ return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid");
+}
+
+bool ItaniumCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
+ QualType SrcRecordTy) {
+ return IsDeref;
+}
+
+void ItaniumCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
+ llvm::Value *Fn = getBadTypeidFn(CGF);
+ CGF.EmitRuntimeCallOrInvoke(Fn).setDoesNotReturn();
+ CGF.Builder.CreateUnreachable();
+}
+
+llvm::Value *ItaniumCXXABI::EmitTypeid(CodeGenFunction &CGF,
+ QualType SrcRecordTy,
+ llvm::Value *ThisPtr,
+ llvm::Type *StdTypeInfoPtrTy) {
+ llvm::Value *Value =
+ CGF.GetVTablePtr(ThisPtr, StdTypeInfoPtrTy->getPointerTo());
+
+ // Load the type info.
+ Value = CGF.Builder.CreateConstInBoundsGEP1_64(Value, -1ULL);
+ return CGF.Builder.CreateLoad(Value);
+}
+
+bool ItaniumCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
+ QualType SrcRecordTy) {
+ return SrcIsPtr;
+}
+
+llvm::Value *ItaniumCXXABI::EmitDynamicCastCall(
+ CodeGenFunction &CGF, llvm::Value *Value, QualType SrcRecordTy,
+ QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
+ llvm::Type *PtrDiffLTy =
+ CGF.ConvertType(CGF.getContext().getPointerDiffType());
+ llvm::Type *DestLTy = CGF.ConvertType(DestTy);
+
+ llvm::Value *SrcRTTI =
+ CGF.CGM.GetAddrOfRTTIDescriptor(SrcRecordTy.getUnqualifiedType());
+ llvm::Value *DestRTTI =
+ CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
+
+ // Compute the offset hint.
+ const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
+ const CXXRecordDecl *DestDecl = DestRecordTy->getAsCXXRecordDecl();
+ llvm::Value *OffsetHint = llvm::ConstantInt::get(
+ PtrDiffLTy,
+ computeOffsetHint(CGF.getContext(), SrcDecl, DestDecl).getQuantity());
+
+ // Emit the call to __dynamic_cast.
+ Value = CGF.EmitCastToVoidPtr(Value);
+
+ llvm::Value *args[] = {Value, SrcRTTI, DestRTTI, OffsetHint};
+ Value = CGF.EmitNounwindRuntimeCall(getItaniumDynamicCastFn(CGF), args);
+ Value = CGF.Builder.CreateBitCast(Value, DestLTy);
+
+ /// C++ [expr.dynamic.cast]p9:
+ /// A failed cast to reference type throws std::bad_cast
+ if (DestTy->isReferenceType()) {
+ llvm::BasicBlock *BadCastBlock =
+ CGF.createBasicBlock("dynamic_cast.bad_cast");
+
+ llvm::Value *IsNull = CGF.Builder.CreateIsNull(Value);
+ CGF.Builder.CreateCondBr(IsNull, BadCastBlock, CastEnd);
+
+ CGF.EmitBlock(BadCastBlock);
+ EmitBadCastCall(CGF);
+ }
+
+ return Value;
+}
+
+llvm::Value *ItaniumCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF,
+ llvm::Value *Value,
+ QualType SrcRecordTy,
+ QualType DestTy) {
+ llvm::Type *PtrDiffLTy =
+ CGF.ConvertType(CGF.getContext().getPointerDiffType());
+ llvm::Type *DestLTy = CGF.ConvertType(DestTy);
+
+ // Get the vtable pointer.
+ llvm::Value *VTable = CGF.GetVTablePtr(Value, PtrDiffLTy->getPointerTo());
+
+ // Get the offset-to-top from the vtable.
+ llvm::Value *OffsetToTop =
+ CGF.Builder.CreateConstInBoundsGEP1_64(VTable, -2ULL);
+ OffsetToTop = CGF.Builder.CreateLoad(OffsetToTop, "offset.to.top");
+
+ // Finally, add the offset to the pointer.
+ Value = CGF.EmitCastToVoidPtr(Value);
+ Value = CGF.Builder.CreateInBoundsGEP(Value, OffsetToTop);
+
+ return CGF.Builder.CreateBitCast(Value, DestLTy);
+}
+
+bool ItaniumCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
+ llvm::Value *Fn = getBadCastFn(CGF);
+ CGF.EmitRuntimeCallOrInvoke(Fn).setDoesNotReturn();
+ CGF.Builder.CreateUnreachable();
+ return true;
+}
+
llvm::Value *
ItaniumCXXABI::GetVirtualBaseClassOffset(CodeGenFunction &CGF,
llvm::Value *This,