Re: test-stdalign failure on AIX

[Paul Eggert]

On 12/11/19 6:43 PM, Bruno Haible wrote:
> ../../gltests/test-stdalign.c:94: assertion '(uintptr_t) &(static_char_Alignas) 
> % TEST_ALIGNMENT == 0' failed
> IOT/Abort trap (core dumped)

With xlclang 16.01, __attribute__ ((__aligned__ (N))) does not work on 
external variables; the attribute is ignored. Curious, since the 
attribute does work with plain xlc. Anyway, I installed the attached 
patch to work around the problem.

The following program illustrates the bug, which occurs with both 
_Alignas and __attribute__ ((__aligned__)). Perhaps if someone reading 
this knows how to file a bug report with IBM (I don't and couldn't 
easily find out), they could file a bug report against xlclang.

char _Alignas (8) c1, c2;
char __attribute__ ((__aligned__ (8))) c3, c4;

int
main (void)
{
  if ((unsigned long) &c1 % 8 != 0) return 1;
  if ((unsigned long) &c2 % 8 != 0) return 2;
  if ((unsigned long) &c3 % 8 != 0) return 3;
  if ((unsigned long) &c4 % 8 != 0) return 4;
  return 0;
}

0001-stdalign-port-to-xlclang-16.01.patch
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