X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fstrcasestr.m4;h=09692a790b670545c10863f789e5a59d8bbd191d;hb=cd19e83484e2c0ff9fd68e7439dd97128c6a2703;hp=0ad895acfdf96ebe0f1a33add94124fdbf997460;hpb=0ce8aa7c1dfb56c1f64dcc799a4038eac1f55e95;p=gnulib.git

diff --git a/m4/strcasestr.m4 b/m4/strcasestr.m4
index 0ad895acf..09692a790 100644
--- a/m4/strcasestr.m4
+++ b/m4/strcasestr.m4
@@ -1,20 +1,67 @@
-# strcasestr.m4 serial 11
-dnl Copyright (C) 2005, 2007, 2008 Free Software Foundation, Inc.
+# strcasestr.m4 serial 20
+dnl Copyright (C) 2005, 2007-2011 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=yes],
+             [gl_cv_func_strcasestr_works_always="guessing no"])
+          ])
+        ])
+      if test "$gl_cv_func_strcasestr_works_always" != yes; then
+        REPLACE_STRCASESTR=1
+      fi
+    fi
   fi
 ]) # gl_FUNC_STRCASESTR_SIMPLE
 
@@ -22,57 +69,63 @@ dnl Additionally, check that strcasestr is efficient.
 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 */
+#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 Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a
+    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],
-	   [
+         AC_EGREP_CPP([Lucky user],
+           [
 #include <features.h>
 #ifdef __GNU_LIBRARY__
- #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2)
+ #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \
+     && !defined __UCLIBC__
   Lucky user
  #endif
 #endif
 #ifdef __CYGWIN__
  #include <cygwin/version.h>
- #if CYGWIN_VERSION_DLL_MAJOR >= 1007
+ #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 7)
   Lucky user
  #endif
 #endif
-	   ],
-	   [gl_cv_func_strcasestr_linear=yes],
-	   [gl_cv_func_strcasestr_linear="guessing no"])
-	])
+           ],
+           [gl_cv_func_strcasestr_linear=yes],
+           [gl_cv_func_strcasestr_linear="guessing no"])
+        ])
       ])
     if test "$gl_cv_func_strcasestr_linear" != yes; then
       REPLACE_STRCASESTR=1
-      AC_LIBOBJ([strcasestr])
     fi
   fi
 ]) # gl_FUNC_STRCASESTR