X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fstrerror_r.m4;h=89758273ee8a76f6229ac54703107616f38675c4;hb=c604bb86746f7f16471a598df94845e42d0e1b5f;hp=1c0af3691dc0f7b01dffcc6020835d0e7d8f6847;hpb=87b0e84c4c747d1c29df645debfce815f6e09466;p=gnulib.git

diff --git a/m4/strerror_r.m4 b/m4/strerror_r.m4
index 1c0af3691..89758273e 100644
--- a/m4/strerror_r.m4
+++ b/m4/strerror_r.m4
@@ -1,4 +1,4 @@
-# strerror_r.m4 serial 9
+# strerror_r.m4 serial 11
 dnl Copyright (C) 2002, 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,
@@ -7,8 +7,7 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_STRERROR_R],
 [
   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
-  AC_REQUIRE([gl_HEADER_ERRNO_H])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS])
 
   dnl Persuade Solaris <string.h> to declare strerror_r().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
@@ -20,7 +19,40 @@ AC_DEFUN([gl_FUNC_STRERROR_R],
     HAVE_DECL_STRERROR_R=0
   fi
 
-  AC_CHECK_FUNCS([strerror_r])
+  if test $ac_cv_func_strerror_r = yes; then
+    if test -z "$ERRNO_H"; then
+      if test $gl_cv_func_strerror_r_posix_signature = yes; then
+        case "$gl_cv_func_strerror_r_works" in
+          dnl The system's strerror_r has bugs.  Replace it.
+          *no) REPLACE_STRERROR_R=1 ;;
+        esac
+      else
+        dnl The system's strerror_r() has a wrong signature. Replace it.
+        REPLACE_STRERROR_R=1
+      fi
+    else
+      dnl The system's strerror_r() cannot know about the new errno values we
+      dnl add to <errno.h>. Replace it.
+      REPLACE_STRERROR_R=1
+    fi
+  fi
+])
+
+# Prerequisites of lib/strerror_r.c.
+AC_DEFUN([gl_PREREQ_STRERROR_R], [
+  dnl glibc >= 2.3.4 and cygwin 1.7.9 have a function __xpg_strerror_r.
+  AC_CHECK_FUNCS([__xpg_strerror_r])
+  AC_CHECK_FUNCS_ONCE([catgets])
+])
+
+# Detect if strerror_r works, but without affecting whether a replacement
+# strerror_r will be used.
+AC_DEFUN([gl_FUNC_STRERROR_R_WORKS],
+[
+  AC_REQUIRE([gl_HEADER_ERRNO_H])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+  AC_CHECK_FUNCS_ONCE([strerror_r])
   if test $ac_cv_func_strerror_r = yes; then
     if test -z "$ERRNO_H"; then
       dnl The POSIX prototype is:  int strerror_r (int, char *, size_t);
@@ -42,6 +74,7 @@ AC_DEFUN([gl_FUNC_STRERROR_R],
         dnl HP-UX 11.31 strerror_r always fails when the buffer length argument
         dnl is less than 80.
         dnl FreeBSD 8.s strerror_r claims failure on 0
+        dnl MacOS X 10.5 strerror_r treats 0 like -1
         dnl Solaris 10 strerror_r corrupts errno on failure
         AC_CACHE_CHECK([whether strerror_r works],
           [gl_cv_func_strerror_r_works],
@@ -57,15 +90,21 @@ AC_DEFUN([gl_FUNC_STRERROR_R],
                   errno = 0;
                   if (strerror_r (EACCES, buf, sizeof buf) != 0)
                     result |= 2;
+                  strcpy (buf, "Unknown");
                   if (strerror_r (0, buf, sizeof buf) != 0)
                     result |= 4;
                   if (errno)
                     result |= 8;
-                  errno = 0;
-                  if (strerror_r (-3, buf, sizeof buf) != 0)
+                  if (strstr (buf, "nknown") || strstr (buf, "ndefined"))
                     result |= 0x10;
-                  if (errno)
+                  errno = 0;
+                  *buf = 0;
+                  if (strerror_r (-3, buf, sizeof buf) < 0)
                     result |= 0x20;
+                  if (errno)
+                    result |= 0x40;
+                  if (!*buf)
+                    result |= 0x80;
                   return result;
                 ]])],
              [gl_cv_func_strerror_r_works=yes],
@@ -85,25 +124,44 @@ changequote(,)dnl
 changequote([,])dnl
              ])
           ])
-        case "$gl_cv_func_strerror_r_works" in
-          *no) REPLACE_STRERROR_R=1 ;;
-        esac
       else
-        dnl The system's strerror() has a wrong signature. Replace it.
-        REPLACE_STRERROR_R=1
+        dnl The system's strerror() has a wrong signature.
         dnl glibc >= 2.3.4 and cygwin 1.7.9 have a function __xpg_strerror_r.
         AC_CHECK_FUNCS([__xpg_strerror_r])
+        dnl In glibc < 2.14, __xpg_strerror_r does not populate buf on failure.
+        dnl In cygwin < 1.7.10, __xpg_strerror_r clobbers strerror's buffer.
+        if test $ac_cv_func___xpg_strerror_r = yes; then
+          AC_CACHE_CHECK([whether __xpg_strerror_r works],
+            [gl_cv_func_strerror_r_works],
+            [AC_RUN_IFELSE(
+               [AC_LANG_PROGRAM(
+                  [[#include <errno.h>
+                    #include <string.h>
+                    extern int __xpg_strerror_r(int, char *, size_t);
+                  ]],
+                  [[int result = 0;
+                    char buf[256] = "^";
+                    char copy[256];
+                    char *str = strerror (-1);
+                    strcpy (copy, str);
+                    if (__xpg_strerror_r (-2, buf, 1) == 0)
+                      result |= 1;
+                    if (*buf)
+                      result |= 2;
+                    __xpg_strerror_r (-2, buf, 256);
+                    if (strcmp (str, copy))
+                      result |= 4;
+                    return result;
+                  ]])],
+               [gl_cv_func_strerror_r_works=yes],
+               [gl_cv_func_strerror_r_works=no],
+               [dnl Guess no on all platforms that have __xpg_strerror_r,
+                dnl at least until fixed glibc and cygwin are more common.
+                gl_cv_func_strerror_r_works="guessing no"
+               ])
+            ])
+        fi
       fi
-    else
-      dnl The system's strerror_r() cannot know about the new errno values we
-      dnl add to <errno.h>. Replace it.
-      REPLACE_STRERROR_R=1
     fi
   fi
 ])
-
-# Prerequisites of lib/strerror_r.c.
-AC_DEFUN([gl_PREREQ_STRERROR_R], [
-  AC_CHECK_FUNCS_ONCE([catgets])
-  :
-])