tests/test-alignasof.c

   1 /* Test of alignasof module.
   2    Copyright 2009-2024 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Paul Eggert, inspired by Bruno Haible's test-alignof.c.  */
  18
  19 #include <config.h>
  20
  21 #include <stddef.h>
  22 #include <stdint.h>
  23
  24 #include "macros.h"
  25
  26 typedef long double longdouble;
  27 typedef struct { char a[1]; } struct1;
  28 typedef struct { char a[2]; } struct2;
  29 typedef struct { char a[3]; } struct3;
  30 typedef struct { char a[4]; } struct4;
  31
  32 #if (202311 <= __STDC_VERSION__ || __alignas_is_defined \
  33      || 201103 <= __cplusplus)
  34 /* mingw can go up only to 8.  8 is all that GNU Emacs needs, so let's
  35    limit the test to 8 for now.  */
  36 # define TEST_ALIGNMENT 8
  37 #else
  38 # undef alignas
  39 # define alignas(alignment)
  40 # define TEST_ALIGNMENT 1
  41 #endif
  42
  43 #define CHECK_STATIC(type) \
  44   typedef struct { char slot1; type slot2; } type##_helper; \
  45   static_assert (alignof (type) == offsetof (type##_helper, slot2)); \
  46   const int type##_alignment = alignof (type); \
  47   type alignas (TEST_ALIGNMENT) static_##type##_alignas
  48
  49 #define CHECK_ALIGNED(var) ASSERT ((uintptr_t) &(var) % TEST_ALIGNMENT == 0)
  50
  51 CHECK_STATIC (char);
  52 CHECK_STATIC (short);
  53 CHECK_STATIC (int);
  54 CHECK_STATIC (long);
  55 #ifdef INT64_MAX
  56 CHECK_STATIC (int64_t);
  57 #endif
  58 CHECK_STATIC (float);
  59 CHECK_STATIC (double);
  60 /* CHECK_STATIC (longdouble); */
  61 CHECK_STATIC (struct1);
  62 CHECK_STATIC (struct2);
  63 CHECK_STATIC (struct3);
  64 CHECK_STATIC (struct4);
  65
  66 int
  67 main ()
  68 {
  69 #if defined __SUNPRO_C && __SUNPRO_C < 0x5150
  70   /* Avoid a test failure due to Sun Studio Developer Bug Report #2125432.  */
  71   fputs ("Skipping test: known Sun C compiler bug\n", stderr);
  72   return 77;
  73 #elif defined __HP_cc && __ia64
  74   /* Avoid a test failure due to HP-UX Itanium cc bug; see:
  75      https://lists.gnu.org/r/bug-gnulib/2017-03/msg00078.html  */
  76   fputs ("Skipping test: known HP-UX Itanium cc compiler bug\n", stderr);
  77   return 77;
  78 #elif defined __clang__ && defined __ibmxl__
  79   /* Avoid a test failure with IBM xlc 16.1.  It ignores alignas (8),
  80      _Alignas (8), and __attribute__ ((__aligned__ (8))).  */
  81   fputs ("Skipping test: known AIX XL C compiler deficiency\n", stderr);
  82   return 77;
  83 #else
  84   CHECK_ALIGNED (static_char_alignas);
  85   CHECK_ALIGNED (static_short_alignas);
  86   CHECK_ALIGNED (static_int_alignas);
  87   CHECK_ALIGNED (static_long_alignas);
  88 # ifdef INT64_MAX
  89   CHECK_ALIGNED (static_int64_t_alignas);
  90 # endif
  91   CHECK_ALIGNED (static_float_alignas);
  92   CHECK_ALIGNED (static_double_alignas);
  93   /* CHECK_ALIGNED (static_longdouble_alignas); */
  94   CHECK_ALIGNED (static_struct1_alignas);
  95   CHECK_ALIGNED (static_struct2_alignas);
  96   CHECK_ALIGNED (static_struct3_alignas);
  97   CHECK_ALIGNED (static_struct4_alignas);
  98   return test_exit_status;
  99 #endif
 100 }