1# serial 23
2
3# Copyright (C) 1997-2001, 2003-2011 Free Software Foundation, Inc.
4#
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9dnl From Jim Meyering.
10
11AC_DEFUN([gl_FUNC_LSTAT],
12[
13  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
14  dnl If lstat does not exist, the replacement <sys/stat.h> does
15  dnl "#define lstat stat", and lstat.c is a no-op.
16  AC_CHECK_FUNCS_ONCE([lstat])
17  if test $ac_cv_func_lstat = yes; then
18    AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK])
19    if test $gl_cv_func_lstat_dereferences_slashed_symlink = no; then
20      REPLACE_LSTAT=1
21    fi
22  else
23    HAVE_LSTAT=0
24  fi
25])
26
27# Prerequisites of lib/lstat.c.
28AC_DEFUN([gl_PREREQ_LSTAT],
29[
30  AC_REQUIRE([AC_C_INLINE])
31  :
32])
33
34AC_DEFUN([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK],
35[
36  dnl We don't use AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK any more, because it
37  dnl is no longer maintained in Autoconf and because it invokes AC_LIBOBJ.
38  AC_CACHE_CHECK([whether lstat correctly handles trailing slash],
39    [gl_cv_func_lstat_dereferences_slashed_symlink],
40    [rm -f conftest.sym conftest.file
41     echo >conftest.file
42     if test "$as_ln_s" = "ln -s" && ln -s conftest.file conftest.sym; then
43       AC_RUN_IFELSE(
44         [AC_LANG_PROGRAM(
45            [AC_INCLUDES_DEFAULT],
46            [[struct stat sbuf;
47              /* Linux will dereference the symlink and fail, as required by
48                 POSIX.  That is better in the sense that it means we will not
49                 have to compile and use the lstat wrapper.  */
50              return lstat ("conftest.sym/", &sbuf) == 0;
51            ]])],
52         [gl_cv_func_lstat_dereferences_slashed_symlink=yes],
53         [gl_cv_func_lstat_dereferences_slashed_symlink=no],
54         [# When cross-compiling, be pessimistic so we will end up using the
55          # replacement version of lstat that checks for trailing slashes and
56          # calls lstat a second time when necessary.
57          gl_cv_func_lstat_dereferences_slashed_symlink=no
58         ])
59     else
60       # If the 'ln -s' command failed, then we probably don't even
61       # have an lstat function.
62       gl_cv_func_lstat_dereferences_slashed_symlink=no
63     fi
64     rm -f conftest.sym conftest.file
65    ])
66  test $gl_cv_func_lstat_dereferences_slashed_symlink = yes &&
67    AC_DEFINE_UNQUOTED([LSTAT_FOLLOWS_SLASHED_SYMLINK], [1],
68      [Define to 1 if `lstat' dereferences a symlink specified
69       with a trailing slash.])
70])
71