MS ABI: Use the correct this arg when generating implicit array copy ctor

We assumed the last argument of the copy constructor was the this
pointer.  However, this is not the case under the MS ABI.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219775 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index d7010c7e91607d6b05ae5b5075ccd1e0ca619dee..1bba4a70a1413d20fed7f5c7fddec498c46f396f 100644 (file)
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -580,9 +580,8 @@ static void EmitMemberInitializer(CodeGenFunction &CGF,
     CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(MemberInit->getInit());
     if (BaseElementTy.isPODType(CGF.getContext()) ||
         (CE && CE->getConstructor()->isTrivial())) {
-      // Find the source pointer. We know it's the last argument because
-      // we know we're in an implicit copy constructor.
-      unsigned SrcArgIndex = Args.size() - 1;
+      unsigned SrcArgIndex =
+          CGF.CGM.getCXXABI().getSrcArgforCopyCtor(Constructor, Args);
       llvm::Value *SrcPtr
         = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(Args[SrcArgIndex]));
       LValue ThisRHSLV = CGF.MakeNaturalAlignAddrLValue(SrcPtr, RecordTy);

diff --git a/test/CodeGenCXX/pr20897.cpp b/test/CodeGenCXX/pr20897.cpp
index 06828c0ec07e064a3eca76973417b65257e65b50..49d669bd7eabcfbf5022735e6da68c5840fb6d75 100644 (file)
--- a/test/CodeGenCXX/pr20897.cpp
+++ b/test/CodeGenCXX/pr20897.cpp
@@ -15,3 +15,19 @@ struct __declspec(dllexport) Derived : virtual Base {
   bool a : 1;
   bool b : 1;
 };
+
+// __declspec(dllexport) causes us to export the implicit copy constructor.
+struct __declspec(dllexport) Derived2 : virtual Base {
+// CHECK-LABEL: define weak_odr dllexport x86_thiscallcc %struct.Derived2* @"\01??0Derived2@@QAE@ABU0@@Z"
+// CHECK:      %[[this:.*]] = load %struct.Derived2** {{.*}}
+// CHECK-NEXT: store %struct.Derived2* %[[this]], %struct.Derived2** %[[retval:.*]]
+// CHECK:      %[[dest_a_gep:.*]] = getelementptr inbounds %struct.Derived2* %[[this]], i32 0, i32 1
+// CHECK-NEXT: %[[src_load:.*]]   = load %struct.Derived2** {{.*}}
+// CHECK-NEXT: %[[src_a_gep:.*]]  = getelementptr inbounds %struct.Derived2* %[[src_load:.*]], i32 0, i32 1
+// CHECK-NEXT: %[[dest_a_bitcast:.*]]  = bitcast [1 x i32]* %[[dest_a_gep]] to i8*
+// CHECK-NEXT: %[[src_a_bitcast:.*]] = bitcast [1 x i32]* %[[src_a_gep]] to i8*
+// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* %[[dest_a_bitcast]], i8* %[[src_a_bitcast]], i32 4, i32 4, i1 false)
+// CHECK-NEXT: %[[dest_this:.*]] = load %struct.Derived2** %[[retval]]
+// CHECK-NEXT: ret %struct.Derived2* %[[dest_this]]
+  int Array[1];
+};