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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:16:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:16:24 +0000 |
commit | 9221dca64f0c8b5de72727491e41cf63e902eaab (patch) | |
tree | d8cbbf520eb4b5c656a54b2e36947008dcb751ad /gl/m4/stdalign.m4 | |
parent | Initial commit. (diff) | |
download | man-db-9221dca64f0c8b5de72727491e41cf63e902eaab.tar.xz man-db-9221dca64f0c8b5de72727491e41cf63e902eaab.zip |
Adding upstream version 2.8.5.upstream/2.8.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gl/m4/stdalign.m4')
-rw-r--r-- | gl/m4/stdalign.m4 | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/gl/m4/stdalign.m4 b/gl/m4/stdalign.m4 new file mode 100644 index 0000000..601fd21 --- /dev/null +++ b/gl/m4/stdalign.m4 @@ -0,0 +1,57 @@ +# Check for stdalign.h that conforms to C11. + +dnl Copyright 2011-2019 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +# Prepare for substituting <stdalign.h> if it is not supported. + +AC_DEFUN([gl_STDALIGN_H], +[ + AC_CACHE_CHECK([for working stdalign.h], + [gl_cv_header_working_stdalign_h], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[#include <stdalign.h> + #include <stddef.h> + + /* Test that alignof yields a result consistent with offsetof. + This catches GCC bug 52023 + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. */ + #ifdef __cplusplus + template <class t> struct alignof_helper { char a; t b; }; + # define ao(type) offsetof (alignof_helper<type>, b) + #else + # define ao(type) offsetof (struct { char a; type b; }, b) + #endif + char test_double[ao (double) % _Alignof (double) == 0 ? 1 : -1]; + 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. */ + #if \ + ((defined __cplusplus && 201103 <= __cplusplus) \ + || (defined __APPLE__ && defined __MACH__ \ + ? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \ + : __GNUC__) \ + || (__ia64 && (61200 <= __HP_cc || 61200 <= __HP_aCC)) \ + || __ICC || 0x590 <= __SUNPRO_C || 0x0600 <= __xlC__ \ + || 1300 <= _MSC_VER) + struct alignas_test { char c; char alignas (8) alignas_8; }; + char test_alignas[offsetof (struct alignas_test, alignas_8) == 8 + ? 1 : -1]; + #endif + ]])], + [gl_cv_header_working_stdalign_h=yes], + [gl_cv_header_working_stdalign_h=no])]) + + if test $gl_cv_header_working_stdalign_h = yes; then + STDALIGN_H='' + else + STDALIGN_H='stdalign.h' + fi + + AC_SUBST([STDALIGN_H]) + AM_CONDITIONAL([GL_GENERATE_STDALIGN_H], [test -n "$STDALIGN_H"]) +]) |