-# strcasestr.m4 serial 7
-dnl Copyright (C) 2005, 2007, 2008 Free Software Foundation, Inc.
+# strcasestr.m4 serial 21
+dnl Copyright (C) 2005, 2007-2014 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 strcasestr is present.
+dnl Check that strcasestr is present and works.
AC_DEFUN([gl_FUNC_STRCASESTR_SIMPLE],
[
+ AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+
dnl Persuade glibc <string.h> to declare strcasestr().
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
- AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
- AC_REPLACE_FUNCS([strcasestr])
+ AC_REQUIRE([gl_FUNC_MEMCHR])
+ AC_CHECK_FUNCS([strcasestr])
if test $ac_cv_func_strcasestr = no; then
HAVE_STRCASESTR=0
- gl_PREREQ_STRCASESTR
+ else
+ if test "$gl_cv_func_memchr_works" != yes; then
+ REPLACE_STRCASESTR=1
+ else
+ dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092.
+ AC_CACHE_CHECK([whether strcasestr works],
+ [gl_cv_func_strcasestr_works_always],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <string.h> /* for strcasestr */
+#define P "_EF_BF_BD"
+#define HAYSTACK "F_BD_CE_BD" P P P P "_C3_88_20" P P P "_C3_A7_20" P
+#define NEEDLE P P P P P
+]], [[return !!strcasestr (HAYSTACK, NEEDLE);
+ ]])],
+ [gl_cv_func_strcasestr_works_always=yes],
+ [gl_cv_func_strcasestr_works_always=no],
+ [dnl glibc 2.12 and cygwin 1.7.7 have a known bug. uClibc is not
+ dnl affected, since it uses different source code for strcasestr
+ dnl than glibc.
+ dnl Assume that it works on all other platforms, even if it is not
+ dnl linear.
+ AC_EGREP_CPP([Lucky user],
+ [
+#ifdef __GNU_LIBRARY__
+ #include <features.h>
+ #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \
+ || defined __UCLIBC__
+ Lucky user
+ #endif
+#elif defined __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7)
+ Lucky user
+ #endif
+#else
+ Lucky user
+#endif
+ ],
+ [gl_cv_func_strcasestr_works_always="guessing yes"],
+ [gl_cv_func_strcasestr_works_always="guessing no"])
+ ])
+ ])
+ case "$gl_cv_func_strcasestr_works_always" in
+ *yes) ;;
+ *)
+ REPLACE_STRCASESTR=1
+ ;;
+ esac
+ fi
fi
]) # gl_FUNC_STRCASESTR_SIMPLE
dnl Additionally, check that strcasestr is efficient.
-AC_DEFUN([gl_FUNC_STRCASESTR])
+AC_DEFUN([gl_FUNC_STRCASESTR],
[
AC_REQUIRE([gl_FUNC_STRCASESTR_SIMPLE])
- if test $ac_cv_func_strcasestr = yes; then
+ if test $HAVE_STRCASESTR = 1 && test $REPLACE_STRCASESTR = 0; then
AC_CACHE_CHECK([whether strcasestr works in linear time],
[gl_cv_func_strcasestr_linear],
- [AC_RUN_IFELSE([AC_LANG_PROGRAM([
-#include <string.h> /* for memmem */
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <signal.h> /* for signal */
+#include <string.h> /* for strcasestr */
#include <stdlib.h> /* for malloc */
#include <unistd.h> /* for alarm */
-], [[size_t m = 1000000;
+static void quit (int sig) { exit (sig + 128); }
+]], [[
+ int result = 0;
+ size_t m = 1000000;
char *haystack = (char *) malloc (2 * m + 2);
char *needle = (char *) malloc (m + 2);
- void *result = 0;
/* Failure to compile this test due to missing alarm is okay,
since all such platforms (mingw) also lack strcasestr. */
+ signal (SIGALRM, quit);
alarm (5);
/* Check for quadratic performance. */
if (haystack && needle)
{
- memset (haystack, 'A', 2 * m);
- haystack[2 * m] = 'B';
- haystack[2 * m + 1] = 0;
- memset (needle, 'A', m);
- needle[m] = 'B';
- needle[m + 1] = 0;
- result = strcasestr (haystack, needle);
+ memset (haystack, 'A', 2 * m);
+ haystack[2 * m] = 'B';
+ haystack[2 * m + 1] = 0;
+ memset (needle, 'A', m);
+ needle[m] = 'B';
+ needle[m + 1] = 0;
+ if (!strcasestr (haystack, needle))
+ result |= 1;
}
- return !result;]])],
- [gl_cv_func_strcasestr_linear=yes], [gl_cv_func_strcasestr_linear=no],
- [dnl pessimistically assume the worst, since even glibc 2.6.1
- dnl has quadratic complexity in its strcasestr
- gl_cv_func_strcasestr_linear="guessing no"])])
- if test "$gl_cv_func_strcasestr_linear" != yes; then
- REPLACE_STRCASESTR=1
- AC_LIBOBJ([strcasestr])
- fi
+ return result;
+ ]])],
+ [gl_cv_func_strcasestr_linear=yes], [gl_cv_func_strcasestr_linear=no],
+ [dnl Only glibc > 2.12 and cygwin > 1.7.7 are known to have a
+ dnl strcasestr that works in linear time.
+ AC_EGREP_CPP([Lucky user],
+ [
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+ #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \
+ && !defined __UCLIBC__
+ Lucky user
+ #endif
+#endif
+#ifdef __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7)
+ Lucky user
+ #endif
+#endif
+ ],
+ [gl_cv_func_strcasestr_linear="guessing yes"],
+ [gl_cv_func_strcasestr_linear="guessing no"])
+ ])
+ ])
+ case "$gl_cv_func_strcasestr_linear" in
+ *yes) ;;
+ *)
+ REPLACE_STRCASESTR=1
+ ;;
+ esac
fi
]) # gl_FUNC_STRCASESTR
projects / gnulib.git / blobdiff