clang/test/CodeGenCXX/arm-vaarg.cpp

   1 // RUN: %clang_cc1 -triple armv7-apple-ios -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: load i8*, i8**
  13 // CHECK-NOT: getelementptr
  14 // CHECK: [[EMPTY_PTR:%[a-zA-Z0-9._]+]] = bitcast i8* {{%[a-zA-Z0-9._]+}} to %struct.Empty*
  15
  16   // It's conceivable that EMPTY_PTR may not actually be a valid pointer
  17   // (e.g. it's at the very bottom of the stack and the next page is
  18   // invalid). This doesn't matter provided it's never loaded (there's no
  19   // well-defined way to tell), but it becomes a problem if we do try to use it.
  20 // CHECK-NOT: load %struct.Empty, %struct.Empty* [[EMPTY_PTR]]
  21
  22   int i = __builtin_va_arg(l, int);
  23 // CHECK: load i32, i32*
  24
  25   __builtin_va_end(l);
  26   return i;
  27 }