Fix for PR7040: Don't try to compute the LLVM type for a function where it
isn't possible to compute.
This patch is mostly refactoring; the key change is the addition of the code
starting with the comment, "Check whether the function has a computable LLVM
signature." The solution here is essentially the same as the way the
vtable code handles such functions.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105151 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index 5258779..60f1f6f 100644
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -304,6 +304,44 @@
getMangleContext().mangleCXXDtor(D, Type, Name.getBuffer());
}
+llvm::Constant *
+CodeGenModule::GetCXXMemberFunctionPointerValue(const CXXMethodDecl *MD) {
+ assert(MD->isInstance() && "Member function must not be static!");
+
+ MD = MD->getCanonicalDecl();
+
+ const llvm::Type *PtrDiffTy = Types.ConvertType(Context.getPointerDiffType());
+
+ // Get the function pointer (or index if this is a virtual function).
+ if (MD->isVirtual()) {
+ uint64_t Index = VTables.getMethodVTableIndex(MD);
+
+ // FIXME: We shouldn't use / 8 here.
+ uint64_t PointerWidthInBytes = Context.Target.getPointerWidth(0) / 8;
+
+ // Itanium C++ ABI 2.3:
+ // For a non-virtual function, this field is a simple function pointer.
+ // For a virtual function, it is 1 plus the virtual table offset
+ // (in bytes) of the function, represented as a ptrdiff_t.
+ return llvm::ConstantInt::get(PtrDiffTy, (Index * PointerWidthInBytes) + 1);
+ }
+
+ const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
+ const llvm::Type *Ty;
+ // Check whether the function has a computable LLVM signature.
+ if (!CodeGenTypes::VerifyFuncTypeComplete(FPT)) {
+ // The function has a computable LLVM signature; use the correct type.
+ Ty = Types.GetFunctionType(Types.getFunctionInfo(MD), FPT->isVariadic());
+ } else {
+ // Use an arbitrary non-function type to tell GetAddrOfFunction that the
+ // function type is incomplete.
+ Ty = PtrDiffTy;
+ }
+
+ llvm::Constant *FuncPtr = GetAddrOfFunction(MD, Ty);
+ return llvm::ConstantExpr::getPtrToInt(FuncPtr, PtrDiffTy);
+}
+
static llvm::Value *BuildVirtualCall(CodeGenFunction &CGF, uint64_t VTableIndex,
llvm::Value *This, const llvm::Type *Ty) {
Ty = Ty->getPointerTo()->getPointerTo()->getPointerTo();