From 1884eb0b5c55edda4893ddec45e7dbad79758782 Mon Sep 17 00:00:00 2001 From: Anders Carlsson Date: Sat, 22 May 2010 17:35:42 +0000 Subject: Re-land the fix for PR7139. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@104446 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CodeGenFunction.cpp | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'lib/CodeGen/CodeGenFunction.cpp') diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp index d3bf1645a0..222dcc4b8f 100644 --- a/lib/CodeGen/CodeGenFunction.cpp +++ b/lib/CodeGen/CodeGenFunction.cpp @@ -472,7 +472,23 @@ void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type, CGM.ErrorUnsupported(S, Type, OmitOnError); } -void CodeGenFunction::EmitMemSetToZero(llvm::Value *DestPtr, QualType Ty) { +void +CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) { + // If the type contains a pointer to data member we can't memset it to zero. + // Instead, create a null constant and copy it to the destination. + if (CGM.getTypes().ContainsPointerToDataMember(Ty)) { + llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty); + + llvm::GlobalVariable *NullVariable = + new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(), + /*isConstant=*/true, + llvm::GlobalVariable::PrivateLinkage, + NullConstant, llvm::Twine()); + EmitAggregateCopy(DestPtr, NullVariable, Ty, /*isVolatile=*/false); + return; + } + + // Ignore empty classes in C++. if (getContext().getLangOptions().CPlusPlus) { if (const RecordType *RT = Ty->getAs()) { @@ -481,6 +497,9 @@ void CodeGenFunction::EmitMemSetToZero(llvm::Value *DestPtr, QualType Ty) { } } + // Otherwise, just memset the whole thing to zero. This is legal + // because in LLVM, all default initializers (other than the ones we just + // handled above) are guaranteed to have a bit pattern of all zeros. const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext); if (DestPtr->getType() != BP) DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp"); -- cgit v1.2.3-18-g5258