From 26fbe7f1e68bb0c96da32491efcf3696fe6c299b Mon Sep 17 00:00:00 2001 From: Holger Weiss Date: Mon, 19 Aug 2013 23:27:12 +0200 Subject: Sync with the latest Gnulib code (6f2d632) --- gl/m4/stdalign.m4 | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 gl/m4/stdalign.m4 (limited to 'gl/m4/stdalign.m4') diff --git a/gl/m4/stdalign.m4 b/gl/m4/stdalign.m4 new file mode 100644 index 00000000..20be01aa --- /dev/null +++ b/gl/m4/stdalign.m4 @@ -0,0 +1,53 @@ +# Check for stdalign.h that conforms to C11. + +dnl Copyright 2011-2013 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 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 + #include + + /* Test that alignof yields a result consistent with offsetof. + This catches GCC bug 52023 + . */ + #ifdef __cplusplus + template struct alignof_helper { char a; t b; }; + # define ao(type) offsetof (alignof_helper, 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) \ + || __GNUC__ || __IBMC__ || __IBMCPP__ || __ICC \ + || 0x5110 <= __SUNPRO_C || 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"]) +]) -- cgit v1.2.3-74-g34f1