-# readlink.m4 serial 3
-dnl Copyright (C) 2003, 2007 Free Software Foundation, Inc.
+# readlink.m4 serial 11
+dnl Copyright (C) 2003, 2007, 2009-2011 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.
AC_DEFUN([gl_FUNC_READLINK],
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
- AC_CHECK_FUNCS(readlink)
+ AC_CHECK_FUNCS_ONCE([readlink])
if test $ac_cv_func_readlink = no; then
HAVE_READLINK=0
- AC_LIBOBJ(readlink)
- gl_PREREQ_READLINK
+ else
+ AC_CACHE_CHECK([whether readlink signature is correct],
+ [gl_cv_decl_readlink_works],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+ /* Cause compilation failure if original declaration has wrong type. */
+ ssize_t readlink (const char *, char *, size_t);]])],
+ [gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])])
+ dnl Solaris 9 ignores trailing slash.
+ dnl FreeBSD 7.2 dereferences only one level of links with trailing slash.
+ AC_CACHE_CHECK([whether readlink handles trailing slash correctly],
+ [gl_cv_func_readlink_works],
+ [# We have readlink, so assume ln -s works.
+ ln -s conftest.no-such conftest.link
+ ln -s conftest.link conftest.lnk2
+ AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+]], [[char buf[20];
+ return readlink ("conftest.lnk2/", buf, sizeof buf) != -1;]])],
+ [gl_cv_func_readlink_works=yes], [gl_cv_func_readlink_works=no],
+ [gl_cv_func_readlink_works="guessing no"])
+ rm -f conftest.link conftest.lnk2])
+ if test "$gl_cv_func_readlink_works" != yes; then
+ AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink
+ fails to recognize a trailing slash.])
+ REPLACE_READLINK=1
+ elif test "$gl_cv_decl_readlink_works" != yes; then
+ REPLACE_READLINK=1
+ fi
fi
])
+# Like gl_FUNC_READLINK, except prepare for separate compilation
+# (no REPLACE_READLINK, no AC_LIBOBJ).
+AC_DEFUN([gl_FUNC_READLINK_SEPARATE],
+[
+ AC_CHECK_FUNCS_ONCE([readlink])
+ gl_PREREQ_READLINK
+])
+
# Prerequisites of lib/readlink.c.
AC_DEFUN([gl_PREREQ_READLINK],
[