MS ABI: Don't push destructor cleanups for aggregate parameters in thunks

The target method of the thunk will perform the cleanup.  This can't be
tested in 32-bit x86 yet because passing something by value would create
an inalloca, and we refuse to generate broken code for that.

llvm-svn: 213976

1 files changed, 25 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/microsoft-abi-byval-thunks.cpp b/clang/test/CodeGenCXX/microsoft-abi-byval-thunks.cpp
new file mode 100644
index 00000000000..a9ffc120142
--- /dev/null
+++ b/clang/test/CodeGenCXX/microsoft-abi-byval-thunks.cpp
@@ -0,0 +1,25 @@
+// RUN: not %clang_cc1 %s -fno-rtti -triple=i686-pc-win32 -emit-llvm -o /dev/null 2>&1 | FileCheck --check-prefix=CHECK32
+// RUN: %clang_cc1 %s -fno-rtti -triple=x86_64-pc-win32 -emit-llvm -o - | FileCheck --check-prefix=CHECK64
+
+namespace byval_thunk {
+struct Agg {
+  Agg();
+  Agg(const Agg &);
+  ~Agg();
+  int x;
+};
+
+struct A { virtual void foo(Agg x); };
+struct B { virtual void foo(Agg x); };
+struct C : A, B { virtual void foo(Agg x); };
+C c;
+
+// CHECK32: cannot compile this non-trivial argument copy for thunk yet
+
+// CHECK64-LABEL: define linkonce_odr void @"\01?foo@C@byval_thunk@@W7EAAXUAgg@2@@Z"
+// CHECK64:             (%"struct.byval_thunk::C"* %this, %"struct.byval_thunk::Agg"* %x)
+// CHECK64:   getelementptr i8* %{{.*}}, i32 -8
+// CHECK64:   call void @"\01?foo@C@byval_thunk@@UEAAXUAgg@2@@Z"(%"struct.byval_thunk::C"* %2, %"struct.byval_thunk::Agg"* %x)
+// CHECK64-NOT: call
+// CHECK64:   ret void
+}