mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-15 09:47:20 +00:00
115 lines
4.0 KiB
Plaintext
115 lines
4.0 KiB
Plaintext
# readlink.m4 serial 16
|
|
dnl Copyright (C) 2003, 2007, 2009-2021 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_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
|
|
AC_CHECK_FUNCS_ONCE([readlink])
|
|
if test $ac_cv_func_readlink = no; then
|
|
HAVE_READLINK=0
|
|
else
|
|
AC_CACHE_CHECK([whether readlink signature is correct],
|
|
[gl_cv_decl_readlink_works],
|
|
[AC_COMPILE_IFELSE(
|
|
[AC_LANG_PROGRAM(
|
|
[[#include <unistd.h>
|
|
/* Cause compilation failure if original declaration has wrong type. */
|
|
ssize_t readlink (const char *, char *, size_t);]])],
|
|
[gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])])
|
|
dnl Solaris 9 ignores trailing slash.
|
|
dnl FreeBSD 7.2 dereferences only one level of links with trailing slash.
|
|
AC_CACHE_CHECK([whether readlink handles trailing slash correctly],
|
|
[gl_cv_func_readlink_trailing_slash],
|
|
[# We have readlink, so assume ln -s works.
|
|
ln -s conftest.no-such conftest.link
|
|
ln -s conftest.link conftest.lnk2
|
|
AC_RUN_IFELSE(
|
|
[AC_LANG_PROGRAM(
|
|
[[#include <unistd.h>
|
|
]], [[char buf[20];
|
|
return readlink ("conftest.lnk2/", buf, sizeof buf) != -1;]])],
|
|
[gl_cv_func_readlink_trailing_slash=yes],
|
|
[gl_cv_func_readlink_trailing_slash=no],
|
|
[case "$host_os" in
|
|
# Guess yes on Linux or glibc systems.
|
|
linux-* | linux | *-gnu* | gnu*)
|
|
gl_cv_func_readlink_trailing_slash="guessing yes" ;;
|
|
# Guess no on AIX or HP-UX.
|
|
aix* | hpux*)
|
|
gl_cv_func_readlink_trailing_slash="guessing no" ;;
|
|
# If we don't know, obey --enable-cross-guesses.
|
|
*)
|
|
gl_cv_func_readlink_trailing_slash="$gl_cross_guess_normal" ;;
|
|
esac
|
|
])
|
|
rm -f conftest.link conftest.lnk2])
|
|
case "$gl_cv_func_readlink_trailing_slash" in
|
|
*yes)
|
|
if test "$gl_cv_decl_readlink_works" != yes; then
|
|
REPLACE_READLINK=1
|
|
fi
|
|
;;
|
|
*)
|
|
AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink
|
|
fails to recognize a trailing slash.])
|
|
REPLACE_READLINK=1
|
|
;;
|
|
esac
|
|
|
|
AC_CACHE_CHECK([whether readlink truncates results correctly],
|
|
[gl_cv_func_readlink_truncate],
|
|
[# We have readlink, so assume ln -s works.
|
|
ln -s ab conftest.link
|
|
AC_RUN_IFELSE(
|
|
[AC_LANG_PROGRAM(
|
|
[[#include <unistd.h>
|
|
]], [[char c;
|
|
return readlink ("conftest.link", &c, 1) != 1;]])],
|
|
[gl_cv_func_readlink_truncate=yes],
|
|
[gl_cv_func_readlink_truncate=no],
|
|
[case "$host_os" in
|
|
# Guess yes on Linux or glibc systems.
|
|
linux-* | linux | *-gnu* | gnu*)
|
|
gl_cv_func_readlink_truncate="guessing yes" ;;
|
|
# Guess no on AIX or HP-UX.
|
|
aix* | hpux*)
|
|
gl_cv_func_readlink_truncate="guessing no" ;;
|
|
# If we don't know, obey --enable-cross-guesses.
|
|
*)
|
|
gl_cv_func_readlink_truncate="$gl_cross_guess_normal" ;;
|
|
esac
|
|
])
|
|
rm -f conftest.link conftest.lnk2])
|
|
case $gl_cv_func_readlink_truncate in
|
|
*yes)
|
|
if test "$gl_cv_decl_readlink_works" != yes; then
|
|
REPLACE_READLINK=1
|
|
fi
|
|
;;
|
|
*)
|
|
AC_DEFINE([READLINK_TRUNCATE_BUG], [1], [Define to 1 if readlink
|
|
sets errno instead of truncating a too-long link.])
|
|
REPLACE_READLINK=1
|
|
;;
|
|
esac
|
|
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],
|
|
[
|
|
:
|
|
])
|