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7a6dbc2f SDJ |
1 | # readlink.m4 serial 14 |
2 | dnl Copyright (C) 2003, 2007, 2009-2018 Free Software Foundation, Inc. | |
2196f55f YQ |
3 | dnl This file is free software; the Free Software Foundation |
4 | dnl gives unlimited permission to copy and/or distribute it, | |
5 | dnl with or without modifications, as long as this notice is preserved. | |
6 | ||
7 | AC_DEFUN([gl_FUNC_READLINK], | |
8 | [ | |
9 | AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) | |
10 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles | |
11 | AC_CHECK_FUNCS_ONCE([readlink]) | |
12 | if test $ac_cv_func_readlink = no; then | |
13 | HAVE_READLINK=0 | |
14 | else | |
15 | AC_CACHE_CHECK([whether readlink signature is correct], | |
16 | [gl_cv_decl_readlink_works], | |
17 | [AC_COMPILE_IFELSE( | |
18 | [AC_LANG_PROGRAM( | |
19 | [[#include <unistd.h> | |
20 | /* Cause compilation failure if original declaration has wrong type. */ | |
21 | ssize_t readlink (const char *, char *, size_t);]])], | |
22 | [gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])]) | |
23 | dnl Solaris 9 ignores trailing slash. | |
24 | dnl FreeBSD 7.2 dereferences only one level of links with trailing slash. | |
25 | AC_CACHE_CHECK([whether readlink handles trailing slash correctly], | |
26 | [gl_cv_func_readlink_works], | |
27 | [# We have readlink, so assume ln -s works. | |
28 | ln -s conftest.no-such conftest.link | |
29 | ln -s conftest.link conftest.lnk2 | |
30 | AC_RUN_IFELSE( | |
31 | [AC_LANG_PROGRAM( | |
32 | [[#include <unistd.h> | |
33 | ]], [[char buf[20]; | |
34 | return readlink ("conftest.lnk2/", buf, sizeof buf) != -1;]])], | |
35 | [gl_cv_func_readlink_works=yes], [gl_cv_func_readlink_works=no], | |
36 | [case "$host_os" in | |
7a6dbc2f SDJ |
37 | # Guess yes on Linux systems. |
38 | linux-* | linux) gl_cv_func_readlink_works="guessing yes" ;; | |
39 | # Guess yes on glibc systems. | |
40 | *-gnu* | gnu*) gl_cv_func_readlink_works="guessing yes" ;; | |
41 | # If we don't know, assume the worst. | |
42 | *) gl_cv_func_readlink_works="guessing no" ;; | |
2196f55f YQ |
43 | esac |
44 | ]) | |
45 | rm -f conftest.link conftest.lnk2]) | |
46 | case "$gl_cv_func_readlink_works" in | |
47 | *yes) | |
48 | if test "$gl_cv_decl_readlink_works" != yes; then | |
49 | REPLACE_READLINK=1 | |
50 | fi | |
51 | ;; | |
52 | *) | |
53 | AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink | |
54 | fails to recognize a trailing slash.]) | |
55 | REPLACE_READLINK=1 | |
56 | ;; | |
57 | esac | |
58 | fi | |
59 | ]) | |
60 | ||
61 | # Like gl_FUNC_READLINK, except prepare for separate compilation | |
62 | # (no REPLACE_READLINK, no AC_LIBOBJ). | |
63 | AC_DEFUN([gl_FUNC_READLINK_SEPARATE], | |
64 | [ | |
65 | AC_CHECK_FUNCS_ONCE([readlink]) | |
66 | gl_PREREQ_READLINK | |
67 | ]) | |
68 | ||
69 | # Prerequisites of lib/readlink.c. | |
70 | AC_DEFUN([gl_PREREQ_READLINK], | |
71 | [ | |
72 | : | |
73 | ]) |