clang/test/CodeGenCXX/thunk-returning-memptr.cpp

   1 // RUN: %clang_cc1 -triple=i686 -emit-llvm -o - %s | FileCheck %s
   2
   3
   4 struct X;
   5 typedef void (X::*memptr)();
   6
   7 struct A {
   8   virtual memptr f();
   9 };
  10
  11 struct B {
  12   virtual memptr f();
  13 };
  14
  15 struct C : A, B {
  16   C();
  17   memptr f() override __attribute__((noinline)) { return nullptr; };
  18 };
  19
  20 C::C() {}
  21
  22 // Make sure the member pointer is returned from the thunk via the return slot.
  23 // Because of the tail call, the return value cannot be copied into a local
  24 // alloca. (PR39901)
  25
  26 // CHECK-LABEL: define linkonce_odr void @_ZThn4_N1C1fEv(ptr noalias sret({ i32, i32 }) align 4 %agg.result, ptr noundef %this)
  27 // CHECK: tail call void @_ZN1C1fEv(ptr sret({ i32, i32 }) align 4 %agg.result