1 # getcwd.m4 - check for working getcwd that is compatible with glibc
3 # Copyright (C) 2001, 2003-2007, 2009-2020 Free Software Foundation, Inc.
4 # This file is free software; the Free Software Foundation
5 # gives unlimited permission to copy and/or distribute it,
6 # with or without modifications, as long as this notice is preserved.
8 # Written by Paul Eggert.
11 AC_DEFUN([gl_FUNC_GETCWD_NULL],
13 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
14 AC_CHECK_HEADERS_ONCE([unistd.h])
15 AC_CACHE_CHECK([whether getcwd (NULL, 0) allocates memory for result],
16 [gl_cv_func_getcwd_null],
17 [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
21 # else /* on Windows with MSVC */
28 #if defined _WIN32 && ! defined __CYGWIN__
29 /* mingw cwd does not start with '/', but getcwd does allocate.
30 However, mingw fails to honor non-zero size. */
36 char *f = getcwd (NULL, 0);
40 { free (f); return 3; }
42 { free (f); return 4; }
48 [gl_cv_func_getcwd_null=yes],
49 [gl_cv_func_getcwd_null=no],
51 # Guess yes on glibc systems.
52 *-gnu* | gnu*) gl_cv_func_getcwd_null="guessing yes";;
53 # Guess yes on musl systems.
54 *-musl*) gl_cv_func_getcwd_null="guessing yes";;
55 # Guess yes on Cygwin.
56 cygwin*) gl_cv_func_getcwd_null="guessing yes";;
57 # If we don't know, obey --enable-cross-guesses.
58 *) gl_cv_func_getcwd_null="$gl_cross_guess_normal";;
63 AC_DEFUN([gl_FUNC_GETCWD_SIGNATURE],
65 AC_CACHE_CHECK([for getcwd with POSIX signature],
66 [gl_cv_func_getcwd_posix_signature],
69 [[#include <unistd.h>]],
74 char *getcwd (char *, size_t);
77 [gl_cv_func_getcwd_posix_signature=yes],
78 [gl_cv_func_getcwd_posix_signature=no])
82 dnl Guarantee that getcwd will malloc with a NULL first argument. Assumes
83 dnl that either the system getcwd is robust, or that calling code is okay
84 dnl with spurious failures when run from a directory with an absolute name
85 dnl larger than 4k bytes.
87 dnl Assumes that getcwd exists; if you are worried about obsolete
88 dnl platforms that lacked getcwd(), then you need to use the GPL module.
89 AC_DEFUN([gl_FUNC_GETCWD_LGPL],
91 AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
92 AC_REQUIRE([gl_FUNC_GETCWD_NULL])
93 AC_REQUIRE([gl_FUNC_GETCWD_SIGNATURE])
95 case $gl_cv_func_getcwd_null,$gl_cv_func_getcwd_posix_signature in
98 dnl Minimal replacement lib/getcwd-lgpl.c.
104 dnl Check for all known getcwd bugs; useful for a program likely to be
105 dnl executed from an arbitrary location.
106 AC_DEFUN([gl_FUNC_GETCWD],
108 AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
109 AC_REQUIRE([gl_FUNC_GETCWD_NULL])
110 AC_REQUIRE([gl_FUNC_GETCWD_SIGNATURE])
111 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
116 gl_cv_func_getcwd_path_max=yes
119 gl_FUNC_GETCWD_PATH_MAX
120 case "$gl_cv_func_getcwd_null" in
122 gl_FUNC_GETCWD_ABORT_BUG([gl_abort_bug=yes])
127 dnl Define HAVE_MINIMALLY_WORKING_GETCWD and HAVE_PARTLY_WORKING_GETCWD
129 case "$gl_cv_func_getcwd_path_max" in
130 *"no" | *"no, it has the AIX bug") ;;
132 AC_DEFINE([HAVE_MINIMALLY_WORKING_GETCWD], [1],
133 [Define to 1 if getcwd minimally works, that is, its result can be
134 trusted when it succeeds.])
137 case "$gl_cv_func_getcwd_path_max" in
138 *"no, but it is partly working")
139 AC_DEFINE([HAVE_PARTLY_WORKING_GETCWD], [1],
140 [Define to 1 if getcwd works, except it sometimes fails when it
141 shouldn't, setting errno to ERANGE, ENAMETOOLONG, or ENOENT.])
143 *"yes, but with shorter paths")
144 AC_DEFINE([HAVE_GETCWD_SHORTER], [1],
145 [Define to 1 if getcwd works, but with shorter paths
146 than is generally tested with the replacement.])
150 if { case "$gl_cv_func_getcwd_null" in *yes) false;; *) true;; esac; } \
151 || test $gl_cv_func_getcwd_posix_signature != yes \
152 || { case "$gl_cv_func_getcwd_path_max" in *yes*) false;; *) true;; esac; } \
153 || test $gl_abort_bug = yes; then
158 # Prerequisites of lib/getcwd.c, when full replacement is in effect.
159 AC_DEFUN([gl_PREREQ_GETCWD],
161 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
162 AC_REQUIRE([gl_CHECK_TYPE_STRUCT_DIRENT_D_INO])