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-rw-r--r--m4/assert_h.m473
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diff --git a/m4/assert_h.m4 b/m4/assert_h.m4
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+# assert-h.m4
+dnl Copyright (C) 2011-2023 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.
+
+dnl From Paul Eggert.
+
+AC_DEFUN([gl_ASSERT_H],
+[
+ AC_CACHE_CHECK([for static_assert], [gl_cv_static_assert],
+ [gl_save_CFLAGS=$CFLAGS
+ for gl_working in "yes, a keyword" "yes, an <assert.h> macro"; do
+ AS_CASE([$gl_working],
+ [*assert.h*], [CFLAGS="$gl_save_CFLAGS -DINCLUDE_ASSERT_H"])
+
+ AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#if defined __clang__ && __STDC_VERSION__ < 202311
+ #pragma clang diagnostic error "-Wc2x-extensions"
+ #pragma clang diagnostic error "-Wc++1z-extensions"
+ #endif
+ #ifdef INCLUDE_ASSERT_H
+ #include <assert.h>
+ #endif
+ static_assert (2 + 2 == 4, "arithmetic does not work");
+ static_assert (2 + 2 == 4);
+ ]],
+ [[
+ static_assert (sizeof (char) == 1, "sizeof does not work");
+ static_assert (sizeof (char) == 1);
+ ]])],
+ [gl_cv_static_assert=$gl_working],
+ [gl_cv_static_assert=no])
+ CFLAGS=$gl_save_CFLAGS
+ test "$gl_cv_static_assert" != no && break
+ done])
+
+ GL_GENERATE_ASSERT_H=false
+ AS_CASE([$gl_cv_static_assert],
+ [yes*keyword*],
+ [AC_DEFINE([HAVE_C_STATIC_ASSERT], [1],
+ [Define to 1 if the static_assert keyword works.])],
+ [no],
+ [GL_GENERATE_ASSERT_H=true
+ gl_NEXT_HEADERS([assert.h])])
+
+ dnl The "zz" puts this toward config.h's end, to avoid potential
+ dnl collisions with other definitions.
+ dnl #undef assert so that programs are not tempted to use it without
+ dnl specifically including assert.h.
+ dnl #undef __ASSERT_H__ so that on IRIX, when programs later include
+ dnl <assert.h>, this include actually defines assert.
+ dnl Break the #undef_s apart with a comment so that 'configure' does
+ dnl not comment them out.
+ AH_VERBATIM([zzstatic_assert],
+[#if (!defined HAVE_C_STATIC_ASSERT && !defined assert \
+ && (!defined __cplusplus \
+ || (__cpp_static_assert < 201411 \
+ && __GNUG__ < 6 && __clang_major__ < 6)))
+ #include <assert.h>
+ #undef/**/assert
+ #ifdef __sgi
+ #undef/**/__ASSERT_H__
+ #endif
+ /* Solaris 11.4 <assert.h> defines static_assert as a macro with 2 arguments.
+ We need it also to be invocable with a single argument. */
+ #if defined __sun && (__STDC_VERSION__ - 0 >= 201112L) && !defined __cplusplus
+ #undef/**/static_assert
+ #define static_assert _Static_assert
+ #endif
+#endif])
+])