diff options
Diffstat (limited to 'gnulib-m4/stdalign.m4')
| -rw-r--r-- | gnulib-m4/stdalign.m4 | 104 |
1 files changed, 91 insertions, 13 deletions
diff --git a/gnulib-m4/stdalign.m4 b/gnulib-m4/stdalign.m4 index 78577cb..324e91d 100644 --- a/gnulib-m4/stdalign.m4 +++ b/gnulib-m4/stdalign.m4 @@ -1,4 +1,4 @@ -# Check for stdalign.h that conforms to C11. +# Check for alignas and alignof that conform to C23. dnl Copyright 2011-2022 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation @@ -9,12 +9,18 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_STDALIGN_H], [ - AC_CACHE_CHECK([for working stdalign.h], + AC_CACHE_CHECK([for alignas and alignof], [gl_cv_header_working_stdalign_h], - [AC_COMPILE_IFELSE( + [gl_save_CFLAGS=$CFLAGS + for gl_working in "yes, keywords" "yes, <stdalign.h> macros"; do + AS_CASE([$gl_working], + [*stdalign.h*], [CFLAGS="$gl_save_CFLAGS -DINCLUDE_STDALIGN_H"]) + AC_COMPILE_IFELSE( [AC_LANG_PROGRAM( [[#include <stdint.h> - #include <stdalign.h> + #ifdef INCLUDE_STDALIGN_H + #include <stdalign.h> + #endif #include <stddef.h> /* Test that alignof yields a result consistent with offsetof. @@ -30,7 +36,7 @@ AC_DEFUN([gl_STDALIGN_H], char test_long[ao (long int) % _Alignof (long int) == 0 ? 1 : -1]; char test_alignof[alignof (double) == _Alignof (double) ? 1 : -1]; - /* Test _Alignas only on platforms where gnulib can help. */ + /* Test alignas only on platforms where gnulib can help. */ #if \ ((defined __cplusplus && 201103 <= __cplusplus) \ || (__TINYC__ && defined __attribute__) \ @@ -45,12 +51,84 @@ AC_DEFUN([gl_STDALIGN_H], ? 1 : -1]; #endif ]])], - [gl_cv_header_working_stdalign_h=yes], - [gl_cv_header_working_stdalign_h=no])]) - - if test $gl_cv_header_working_stdalign_h = yes; then - GL_GENERATE_STDALIGN_H=false - else - GL_GENERATE_STDALIGN_H=true - fi + [gl_cv_header_working_stdalign_h=$gl_working], + [gl_cv_header_working_stdalign_h=no]) + + CFLAGS=$gl_save_CFLAGS + test "$gl_cv_header_working_stdalign_h" != no && break + done]) + + GL_GENERATE_STDALIGN_H=false + AS_CASE([$gl_cv_header_working_stdalign_h], + [no], + [GL_GENERATE_STDALIGN_H=true], + [yes*keyword*], + [AC_DEFINE([HAVE_C_ALIGNASOF], [1], + [Define to 1 if the alignas and alignof keywords work.])]) + + AC_CHECK_HEADERS_ONCE([stdalign.h]) + + dnl The "zz" puts this toward config.h's end, to avoid potential + dnl collisions with other definitions. + AH_VERBATIM([zzalignas], +[#if !defined HAVE_C_ALIGNASOF && __cplusplus < 201103 && !defined alignof +# if HAVE_STDALIGN_H +# include <stdalign.h> +# else + /* Substitute. Keep consistent with gnulib/lib/stdalign.in.h. */ +# ifndef _GL_STDALIGN_H +# define _GL_STDALIGN_H +# undef _Alignas +# undef _Alignof +# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ + && !defined __clang__) \ + || (defined __clang__ && __clang_major__ < 8)) +# ifdef __cplusplus +# if (201103 <= __cplusplus || defined _MSC_VER) +# define _Alignof(type) alignof (type) +# else + template <class __t> struct __alignof_helper { char __a; __t __b; }; +# define _Alignof(type) offsetof (__alignof_helper<type>, __b) +# define _GL_STDALIGN_NEEDS_STDDEF 1 +# endif +# else +# define _Alignof(type) offsetof (struct { char __a; type __b; }, __b) +# define _GL_STDALIGN_NEEDS_STDDEF 1 +# endif +# endif +# if ! (defined __cplusplus && (201103 <= __cplusplus || defined _MSC_VER)) +# define alignof _Alignof +# endif +# define __alignof_is_defined 1 +# if !defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 +# if defined __cplusplus && (201103 <= __cplusplus || defined _MSC_VER) +# define _Alignas(a) alignas (a) +# elif (!defined __attribute__ \ + && ((defined __APPLE__ && defined __MACH__ \ + ? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \ + : __GNUC__ && !defined __ibmxl__) \ + || (4 <= __clang_major__) \ + || (__ia64 && (61200 <= __HP_cc || 61200 <= __HP_aCC)) \ + || __ICC || 0x590 <= __SUNPRO_C || 0x0600 <= __xlC__)) +# define _Alignas(a) __attribute__ ((__aligned__ (a))) +# elif 1300 <= _MSC_VER +# define _Alignas(a) __declspec (align (a)) +# endif +# endif +# if ((defined _Alignas \ + && !(defined __cplusplus && (201103 <= __cplusplus || defined _MSC_VER))) \ + || (defined __STDC_VERSION__ && 201112 <= __STDC_VERSION__)) +# define alignas _Alignas +# endif +# if (defined alignas \ + || (defined __cplusplus && (201103 <= __cplusplus || defined _MSC_VER))) +# define __alignas_is_defined 1 +# endif +# if _GL_STDALIGN_NEEDS_STDDEF +# include <stddef.h> +# endif +# endif /* _GL_STDALIGN_H */ +# endif +#endif]) ]) |