X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Flstat.m4;h=fe161d40101dce4335e51d747acd00090d9cd215;hb=395f9e6a19b504609aa8b0bd7f8cc55d4547d8dd;hp=20e6fc3157e85f69740aeb2eef8d09cb631c4a1f;hpb=7c3f8da8f075e3813ced160d5b53a28c6f7dfe78;p=gnulib.git

diff --git a/m4/lstat.m4 b/m4/lstat.m4
index 20e6fc315..fe161d401 100644
--- a/m4/lstat.m4
+++ b/m4/lstat.m4
@@ -1,7 +1,6 @@
-#serial 14
+# serial 23
 
-# Copyright (C) 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 Free Software
-# Foundation, Inc.
+# Copyright (C) 1997-2001, 2003-2011 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -11,9 +10,61 @@ dnl From Jim Meyering.
 
 AC_DEFUN([gl_FUNC_LSTAT],
 [
-  AC_LIBSOURCES([lstat.c, lstat.h])
+  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
+  dnl If lstat does not exist, the replacement <sys/stat.h> does
+  dnl "#define lstat stat", and lstat.c is a no-op.
+  AC_CHECK_FUNCS_ONCE([lstat])
+  if test $ac_cv_func_lstat = yes; then
+    AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
+    if test $gl_cv_func_lstat_dereferences_slashed_symlink = no; then
+      REPLACE_LSTAT=1
+    fi
+  else
+    HAVE_LSTAT=0
+  fi
+])
 
-  AC_REQUIRE([AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
-  dnl Note: AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK does AC_LIBOBJ(lstat).
+# Prerequisites of lib/lstat.c.
+AC_DEFUN([gl_PREREQ_LSTAT],
+[
+  AC_REQUIRE([AC_C_INLINE])
   :
 ])
+
+AC_DEFUN([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK],
+[
+  dnl We don't use AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK any more, because it
+  dnl is no longer maintained in Autoconf and because it invokes AC_LIBOBJ.
+  AC_CACHE_CHECK([whether lstat correctly handles trailing slash],
+    [gl_cv_func_lstat_dereferences_slashed_symlink],
+    [rm -f conftest.sym conftest.file
+     echo >conftest.file
+     if test "$as_ln_s" = "ln -s" && ln -s conftest.file conftest.sym; then
+       AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM(
+            [AC_INCLUDES_DEFAULT],
+            [[struct stat sbuf;
+              /* Linux will dereference the symlink and fail, as required by
+                 POSIX.  That is better in the sense that it means we will not
+                 have to compile and use the lstat wrapper.  */
+              return lstat ("conftest.sym/", &sbuf) == 0;
+            ]])],
+         [gl_cv_func_lstat_dereferences_slashed_symlink=yes],
+         [gl_cv_func_lstat_dereferences_slashed_symlink=no],
+         [# When cross-compiling, be pessimistic so we will end up using the
+          # replacement version of lstat that checks for trailing slashes and
+          # calls lstat a second time when necessary.
+          gl_cv_func_lstat_dereferences_slashed_symlink=no
+         ])
+     else
+       # If the 'ln -s' command failed, then we probably don't even
+       # have an lstat function.
+       gl_cv_func_lstat_dereferences_slashed_symlink=no
+     fi
+     rm -f conftest.sym conftest.file
+    ])
+  test $gl_cv_func_lstat_dereferences_slashed_symlink = yes &&
+    AC_DEFINE_UNQUOTED([LSTAT_FOLLOWS_SLASHED_SYMLINK], [1],
+      [Define to 1 if `lstat' dereferences a symlink specified
+       with a trailing slash.])
+])