projects / deliverable / binutils-gdb.git / blame
| Commit | Line | Data |
|---|---|---|
| 9c9d63b1 PM |
1 | # stddef_h.m4 serial 9 |
| 2 | dnl Copyright (C) 2009-2021 Free Software Foundation, Inc. | |
| f434ba03 PA |
3 | dnl This file is free software; the Free Software Foundation |
| 4 | dnl gives unlimited permission to copy and/or distribute it, | |
| 5 | dnl with or without modifications, as long as this notice is preserved. | |
| 6 | ||
| 9c9d63b1 PM |
7 | dnl A placeholder for <stddef.h>, for platforms that have issues. |
| 8 | ||
| f434ba03 PA |
9 | AC_DEFUN([gl_STDDEF_H], |
| 10 | [ | |
| 11 | AC_REQUIRE([gl_STDDEF_H_DEFAULTS]) | |
| 12 | AC_REQUIRE([gt_TYPE_WCHAR_T]) | |
| 9c9d63b1 PM |
13 | |
| 14 | dnl Persuade OpenBSD <stddef.h> to declare max_align_t. | |
| 15 | AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) | |
| 16 | ||
| 770d76d7 | 17 | STDDEF_H= |
| c0c3707f CB |
18 | |
| 19 | dnl Test whether the type max_align_t exists and whether its alignment | |
| 20 | dnl "is as great as is supported by the implementation in all contexts". | |
| 21 | AC_CACHE_CHECK([for good max_align_t], | |
| 22 | [gl_cv_type_max_align_t], | |
| 23 | [AC_COMPILE_IFELSE( | |
| 24 | [AC_LANG_PROGRAM( | |
| 25 | [[#include <stddef.h> | |
| 26 | unsigned int s = sizeof (max_align_t); | |
| 9c9d63b1 | 27 | #if defined __GNUC__ || defined __clang__ || defined __IBM__ALIGNOF__ |
| c0c3707f CB |
28 | int check1[2 * (__alignof__ (double) <= __alignof__ (max_align_t)) - 1]; |
| 29 | int check2[2 * (__alignof__ (long double) <= __alignof__ (max_align_t)) - 1]; | |
| 30 | #endif | |
| 9c9d63b1 PM |
31 | typedef struct { char a; max_align_t b; } max_helper; |
| 32 | typedef struct { char a; long b; } long_helper; | |
| 33 | typedef struct { char a; double b; } double_helper; | |
| 34 | typedef struct { char a; long double b; } long_double_helper; | |
| 35 | int check3[2 * (offsetof (long_helper, b) <= offsetof (max_helper, b)) - 1]; | |
| 36 | int check4[2 * (offsetof (double_helper, b) <= offsetof (max_helper, b)) - 1]; | |
| 37 | int check5[2 * (offsetof (long_double_helper, b) <= offsetof (max_helper, b)) - 1]; | |
| c0c3707f CB |
38 | ]])], |
| 39 | [gl_cv_type_max_align_t=yes], | |
| 40 | [gl_cv_type_max_align_t=no]) | |
| 41 | ]) | |
| 42 | if test $gl_cv_type_max_align_t = no; then | |
| 43 | HAVE_MAX_ALIGN_T=0 | |
| 44 | STDDEF_H=stddef.h | |
| 45 | fi | |
| 46 | ||
| f434ba03 PA |
47 | if test $gt_cv_c_wchar_t = no; then |
| 48 | HAVE_WCHAR_T=0 | |
| 49 | STDDEF_H=stddef.h | |
| 50 | fi | |
| c0c3707f | 51 | |
| f434ba03 PA |
52 | AC_CACHE_CHECK([whether NULL can be used in arbitrary expressions], |
| 53 | [gl_cv_decl_null_works], | |
| 54 | [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stddef.h> | |
| 55 | int test[2 * (sizeof NULL == sizeof (void *)) -1]; | |
| 56 | ]])], | |
| 57 | [gl_cv_decl_null_works=yes], | |
| 58 | [gl_cv_decl_null_works=no])]) | |
| 59 | if test $gl_cv_decl_null_works = no; then | |
| 60 | REPLACE_NULL=1 | |
| 61 | STDDEF_H=stddef.h | |
| 62 | fi | |
| c0c3707f | 63 | |
| 770d76d7 PA |
64 | AC_SUBST([STDDEF_H]) |
| 65 | AM_CONDITIONAL([GL_GENERATE_STDDEF_H], [test -n "$STDDEF_H"]) | |
| f434ba03 | 66 | if test -n "$STDDEF_H"; then |
| 770d76d7 | 67 | gl_NEXT_HEADERS([stddef.h]) |
| f434ba03 PA |
68 | fi |
| 69 | ]) | |
| 70 | ||
| 71 | AC_DEFUN([gl_STDDEF_MODULE_INDICATOR], | |
| 72 | [ | |
| 73 | dnl Use AC_REQUIRE here, so that the default settings are expanded once only. | |
| 74 | AC_REQUIRE([gl_STDDEF_H_DEFAULTS]) | |
| 75 | gl_MODULE_INDICATOR_SET_VARIABLE([$1]) | |
| 76 | ]) | |
| 77 | ||
| 78 | AC_DEFUN([gl_STDDEF_H_DEFAULTS], | |
| 79 | [ | |
| 80 | dnl Assume proper GNU behavior unless another module says otherwise. | |
| 81 | REPLACE_NULL=0; AC_SUBST([REPLACE_NULL]) | |
| 4a626d0a | 82 | HAVE_MAX_ALIGN_T=1; AC_SUBST([HAVE_MAX_ALIGN_T]) |
| f434ba03 | 83 | HAVE_WCHAR_T=1; AC_SUBST([HAVE_WCHAR_T]) |
| f434ba03 | 84 | ]) |