Refactor the C++ ABI code a little bit to take advantage of
what I'm going to treat as basically universal properties of
array-cookie code. Implement MS array cookies on top of that.
Based on a patch by Timur Iskhodzhanov!
llvm-svn: 155886
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 825e041..a88c6ba 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -78,17 +78,77 @@
// delete[] p;
// }
// Whereas it prints "104" and "104" if you give A a destructor.
- void ReadArrayCookie(CodeGenFunction &CGF, llvm::Value *Ptr,
- const CXXDeleteExpr *expr,
- QualType ElementType, llvm::Value *&NumElements,
- llvm::Value *&AllocPtr, CharUnits &CookieSize) {
- CGF.CGM.ErrorUnsupported(expr, "don't know how to handle array cookies "
- "in the Microsoft C++ ABI");
- }
+
+ bool requiresArrayCookie(const CXXDeleteExpr *expr, QualType elementType);
+ bool requiresArrayCookie(const CXXNewExpr *expr);
+ CharUnits getArrayCookieSizeImpl(QualType type);
+ llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF,
+ llvm::Value *NewPtr,
+ llvm::Value *NumElements,
+ const CXXNewExpr *expr,
+ QualType ElementType);
+ llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
+ llvm::Value *allocPtr,
+ CharUnits cookieSize);
};
}
+bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
+ QualType elementType) {
+ // Microsoft seems to completely ignore the possibility of a
+ // two-argument usual deallocation function.
+ return elementType.isDestructedType();
+}
+
+bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
+ // Microsoft seems to completely ignore the possibility of a
+ // two-argument usual deallocation function.
+ return expr->getAllocatedType().isDestructedType();
+}
+
+CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
+ // The array cookie is always a size_t; we then pad that out to the
+ // alignment of the element type.
+ ASTContext &Ctx = getContext();
+ return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
+ Ctx.getTypeAlignInChars(type));
+}
+
+llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
+ llvm::Value *allocPtr,
+ CharUnits cookieSize) {
+ unsigned AS = cast<llvm::PointerType>(allocPtr->getType())->getAddressSpace();
+ llvm::Value *numElementsPtr =
+ CGF.Builder.CreateBitCast(allocPtr, CGF.SizeTy->getPointerTo(AS));
+ return CGF.Builder.CreateLoad(numElementsPtr);
+}
+
+llvm::Value* MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
+ llvm::Value *newPtr,
+ llvm::Value *numElements,
+ const CXXNewExpr *expr,
+ QualType elementType) {
+ assert(requiresArrayCookie(expr));
+
+ // The size of the cookie.
+ CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
+
+ // Compute an offset to the cookie.
+ llvm::Value *cookiePtr = newPtr;
+
+ // Write the number of elements into the appropriate slot.
+ unsigned AS = cast<llvm::PointerType>(newPtr->getType())->getAddressSpace();
+ llvm::Value *numElementsPtr
+ = CGF.Builder.CreateBitCast(cookiePtr, CGF.SizeTy->getPointerTo(AS));
+ CGF.Builder.CreateStore(numElements, numElementsPtr);
+
+ // Finally, compute a pointer to the actual data buffer by skipping
+ // over the cookie completely.
+ return CGF.Builder.CreateConstInBoundsGEP1_64(newPtr,
+ cookieSize.getQuantity());
+}
+
CGCXXABI *clang::CodeGen::CreateMicrosoftCXXABI(CodeGenModule &CGM) {
return new MicrosoftCXXABI(CGM);
}