1  /* Test of alignasof module.
       2     Copyright 2009-2023 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 0;
      99  #endif
     100  }