clang/test/CodeGen/arm-vaarg.c

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