Doc tweak.

[gnulib.git] / m4 / strstr.m4

diff --git a/m4/strstr.m4 b/m4/strstr.m4
index fe01d5f..f48bebb 100644 (file)
--- a/m4/strstr.m4
+++ b/m4/strstr.m4
@@ -1,4 +1,4 @@
-# strstr.m4 serial 3
+# strstr.m4 serial 5
 dnl Copyright (C) 2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -11,6 +11,7 @@ AC_DEFUN([gl_FUNC_STRSTR],
   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 */
@@ -20,6 +21,7 @@ AC_DEFUN([gl_FUNC_STRSTR],
     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)
@@ -34,14 +36,20 @@ AC_DEFUN([gl_FUNC_STRSTR],
       }
     return !result;]])],
       [gl_cv_func_strstr_linear=yes], [gl_cv_func_strstr_linear=no],
-      [dnl Only glibc >= 2.9 is known to have an strstr that works in
-       dnl linear time.
-       AC_EGREP_CPP([Lucky GNU user],
+      [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 GNU user
+  Lucky user
+ #endif
+#endif
+#ifdef __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007
+  Lucky user
  #endif
 #endif
         ],