When creating a this-adjustment thunk where the return value is of C++

class type (that uses a return slot), pass the return slot to the
callee directly rather than allocating new storage and trying to copy
the object. This appears to have been the cause of the remaining two
Boost.Interprocess failures.

llvm-svn: 104215

1 files changed, 45 insertions, 4 deletions

diff --git a/clang/test/CodeGenCXX/thunks.cpp b/clang/test/CodeGenCXX/thunks.cpp
index 7d2edaa7457..8144770763d 100644
--- a/clang/test/CodeGenCXX/thunks.cpp
+++ b/clang/test/CodeGenCXX/thunks.cpp
@@ -86,10 +86,6 @@ void C::f() { }
 
 }
 
-// This is from Test5:
-// CHECK: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
-// CHECK: define internal void @_ZThn8_N12_GLOBAL__N_11C1fEv(
-
 // Check that the thunk gets internal linkage.
 namespace {
 
@@ -134,4 +130,49 @@ void f(B b) {
 }
 }
 
+namespace Test6 {
+  struct X {
+    X();
+    X(const X&);
+    X &operator=(const X&);
+    ~X();
+  };
+
+  struct P {
+    P();
+    P(const P&);
+    ~P();
+    X first;
+    X second;
+  };
+
+  P getP();
+
+  struct Base1 {
+    int i;
+
+    virtual X f() { return X(); }
+  };
+
+  struct Base2 {
+    float real;
 
+    virtual X f() { return X(); }
+  };
+
+  struct Thunks : Base1, Base2 {
+    long l;
+
+    virtual X f();
+  };
+
+  // CHECK: define void @_ZThn16_N5Test66Thunks1fEv
+  // CHECK-NOT: memcpy
+  // CHECK: {{call void @_ZN5Test66Thunks1fEv.*sret}}
+  // CHECK: ret void
+  X Thunks::f() { return X(); }
+}
+
+// This is from Test5:
+// CHECK: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
+// CHECK: define internal void @_ZThn8_N12_GLOBAL__N_11C1fEv(