-# strstr.m4 serial 4
-dnl Copyright (C) 2008 Free Software Foundation, Inc.
+# strstr.m4 serial 6
+dnl Copyright (C) 2008, 2009 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 Check that strstr is efficient.
-AC_DEFUN([gl_FUNC_STRSTR],
+dnl Check that strstr works.
+AC_DEFUN([gl_FUNC_STRSTR_SIMPLE],
[
AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
- AC_CACHE_CHECK([whether strstr works in linear time],
- [gl_cv_func_strstr_linear],
- [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+ AC_REQUIRE([gl_FUNC_MEMCHR])
+ if test "$gl_cv_func_memchr_works" != yes; then
+ REPLACE_STRSTR=1
+ AC_LIBOBJ([strstr])
+ fi
+]) # gl_FUNC_STRSTR_SIMPLE
+
+dnl Additionally, check that strstr is efficient.
+AC_DEFUN([gl_FUNC_STRSTR],
+[
+ AC_REQUIRE([gl_FUNC_STRSTR_SIMPLE])
+ if test $REPLACE_STRSTR = 0; then
+ AC_CACHE_CHECK([whether strstr works in linear time],
+ [gl_cv_func_strstr_linear],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <signal.h> /* for signal */
#include <string.h> /* for memmem */
#include <stdlib.h> /* for malloc */
#include <unistd.h> /* for alarm */
void *result = 0;
/* Failure to compile this test due to missing alarm is okay,
since all such platforms (mingw) also have quadratic strstr. */
+ signal (SIGALRM, SIG_DFL);
alarm (5);
/* Check for quadratic performance. */
if (haystack && needle)
result = strstr (haystack, needle);
}
return !result;]])],
- [gl_cv_func_strstr_linear=yes], [gl_cv_func_strstr_linear=no],
- [dnl Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a
- dnl strstr that works in linear time.
- AC_EGREP_CPP([Lucky user],
- [
+ [gl_cv_func_strstr_linear=yes], [gl_cv_func_strstr_linear=no],
+ [dnl Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a
+ dnl strstr that works in linear time.
+ AC_EGREP_CPP([Lucky user],
+ [
#include <features.h>
#ifdef __GNU_LIBRARY__
#if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2)
Lucky user
#endif
#endif
- ],
- [gl_cv_func_strstr_linear=yes],
- [gl_cv_func_strstr_linear="guessing no"])
+ ],
+ [gl_cv_func_strstr_linear=yes],
+ [gl_cv_func_strstr_linear="guessing no"])
+ ])
])
- ])
- if test "$gl_cv_func_strstr_linear" != yes; then
- REPLACE_STRSTR=1
- AC_LIBOBJ([strstr])
+ if test "$gl_cv_func_strstr_linear" != yes; then
+ REPLACE_STRSTR=1
+ AC_LIBOBJ([strstr])
+ fi
fi
]) # gl_FUNC_STRSTR