clang/test/CodeGenCXX/arm64-empty-struct.cpp

   1 // RUN: %clang_cc1 -triple arm64-apple-ios -target-abi darwinpcs -emit-llvm -o - %s | FileCheck %s
   2 struct Empty {};
   3
   4 Empty emptyvar;
   5
   6 int take_args(int a, ...) {
   7   __builtin_va_list l;
   8   __builtin_va_start(l, a);
   9 // CHECK: call void @llvm.va_start
  10
  11   emptyvar = __builtin_va_arg(l, Empty);
  12 // CHECK-NOT: getelementptr
  13
  14   // It's conceivable that EMPTY_PTR may not actually be a valid pointer
  15   // (e.g. it's at the very bottom of the stack and the next page is
  16   // invalid). This doesn't matter provided it's never loaded (there's no
  17   // well-defined way to tell), but it becomes a problem if we do try to use it.
  18 // CHECK-NOT: load %struct.Empty, ptr {{%[a-zA-Z0-9._]+}}
  19
  20   int i = __builtin_va_arg(l, int);
  21 // CHECK: va_arg ptr {{%[a-zA-Z0-9._]+}}, i32
  22
  23   __builtin_va_end(l);
  24   return i;
  25 }