X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Flink.m4;h=7cc0ceb91c698bbf169f506c89ead995cff97ebb;hb=da8054d48dc22e1c051db54049e005d51a006e69;hp=fc071cd481d4fd33c9ac9fcc39a65590967affcd;hpb=2d9360ffcc03fac61415d14595fd76e6abb59db3;p=gnulib.git

diff --git a/m4/link.m4 b/m4/link.m4
index fc071cd48..7cc0ceb91 100644
--- a/m4/link.m4
+++ b/m4/link.m4
@@ -1,5 +1,5 @@
-# link.m4 serial 2
-dnl Copyright (C) 2009 Free Software Foundation, Inc.
+# link.m4 serial 8
+dnl Copyright (C) 2009-2013 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.
@@ -7,24 +7,49 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_LINK],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_FUNCS_ONCE([link])
   if test $ac_cv_func_link = no; then
     HAVE_LINK=0
-    AC_LIBOBJ([link])
   else
-    AC_CACHE_CHECK([whether link handles trailing slash correctly],
+    AC_CACHE_CHECK([whether link obeys POSIX],
       [gl_cv_func_link_works],
       [touch conftest.a
+       # Assume that if we have lstat, we can also check symlinks.
+       if test $ac_cv_func_lstat = yes; then
+         ln -s conftest.a conftest.lnk
+       fi
        AC_RUN_IFELSE(
          [AC_LANG_PROGRAM(
            [[#include <unistd.h>
-]], [[return !link ("conftest.a", "conftest.b/");]])],
+           ]],
+           [[int result = 0;
+             if (!link ("conftest.a", "conftest.b/"))
+               result |= 1;
+#if HAVE_LSTAT
+             if (!link ("conftest.lnk/", "conftest.b"))
+               result |= 2;
+             if (rename ("conftest.a", "conftest.b"))
+               result |= 4;
+             if (!link ("conftest.b", "conftest.lnk"))
+               result |= 8;
+#endif
+             return result;
+           ]])],
          [gl_cv_func_link_works=yes], [gl_cv_func_link_works=no],
-         [gl_cv_func_link_works="guessing no"])
-       rm -f conftest.a conftest.b])
-    if test $gl_cv_func_link_works != yes; then
-      REPLACE_LINK=1
-      AC_LIBOBJ([link])
-    fi
+         [case "$host_os" in
+                    # Guess yes on glibc systems.
+            *-gnu*) gl_cv_func_link_works="guessing yes" ;;
+                    # If we don't know, assume the worst.
+            *)      gl_cv_func_link_works="guessing no" ;;
+          esac
+         ])
+       rm -f conftest.a conftest.b conftest.lnk])
+    case "$gl_cv_func_link_works" in
+      *yes) ;;
+      *)
+        REPLACE_LINK=1
+        ;;
+    esac
   fi
 ])