summaryrefslogtreecommitdiff
path: root/gnulib-m4/stdalign.m4
diff options
context:
space:
mode:
authorManuel A. Fernandez Montecelo <manuel.montezelo@gmail.com>2016-05-26 16:48:39 +0100
committerManuel A. Fernandez Montecelo <manuel.montezelo@gmail.com>2016-05-26 16:48:39 +0100
commit8dfc46115527afe3706e9e4225e9ad019c97d695 (patch)
tree372d5192b218455834781a0037c57e919a06b488 /gnulib-m4/stdalign.m4
parent2291cf138eb72ad38d8c59b8b6f762875c8c4ff2 (diff)
parent5f2b09982312c98863eb9a8dfe2c608b81f58259 (diff)
Merge tag 'upstream/0.9.6'
Upstream version 0.9.6
Diffstat (limited to 'gnulib-m4/stdalign.m4')
-rw-r--r--gnulib-m4/stdalign.m457
1 files changed, 57 insertions, 0 deletions
diff --git a/gnulib-m4/stdalign.m4 b/gnulib-m4/stdalign.m4
new file mode 100644
index 00000000..033b0d39
--- /dev/null
+++ b/gnulib-m4/stdalign.m4
@@ -0,0 +1,57 @@
+# Check for stdalign.h that conforms to C11.
+
+dnl Copyright 2011-2015 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
+ <http://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__) \
+ || __HP_cc || __HP_aCC || __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"])
+])