| 1 | # link.m4 serial 8 |
| 2 | dnl Copyright (C) 2009-2014 Free Software Foundation, Inc. |
| 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_LINK], |
| 8 | [ |
| 9 | AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) |
| 10 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| 11 | AC_CHECK_FUNCS_ONCE([link]) |
| 12 | if test $ac_cv_func_link = no; then |
| 13 | HAVE_LINK=0 |
| 14 | else |
| 15 | AC_CACHE_CHECK([whether link obeys POSIX], |
| 16 | [gl_cv_func_link_works], |
| 17 | [touch conftest.a |
| 18 | # Assume that if we have lstat, we can also check symlinks. |
| 19 | if test $ac_cv_func_lstat = yes; then |
| 20 | ln -s conftest.a conftest.lnk |
| 21 | fi |
| 22 | AC_RUN_IFELSE( |
| 23 | [AC_LANG_PROGRAM( |
| 24 | [[#include <unistd.h> |
| 25 | ]], |
| 26 | [[int result = 0; |
| 27 | if (!link ("conftest.a", "conftest.b/")) |
| 28 | result |= 1; |
| 29 | #if HAVE_LSTAT |
| 30 | if (!link ("conftest.lnk/", "conftest.b")) |
| 31 | result |= 2; |
| 32 | if (rename ("conftest.a", "conftest.b")) |
| 33 | result |= 4; |
| 34 | if (!link ("conftest.b", "conftest.lnk")) |
| 35 | result |= 8; |
| 36 | #endif |
| 37 | return result; |
| 38 | ]])], |
| 39 | [gl_cv_func_link_works=yes], [gl_cv_func_link_works=no], |
| 40 | [case "$host_os" in |
| 41 | # Guess yes on glibc systems. |
| 42 | *-gnu*) gl_cv_func_link_works="guessing yes" ;; |
| 43 | # If we don't know, assume the worst. |
| 44 | *) gl_cv_func_link_works="guessing no" ;; |
| 45 | esac |
| 46 | ]) |
| 47 | rm -f conftest.a conftest.b conftest.lnk]) |
| 48 | case "$gl_cv_func_link_works" in |
| 49 | *yes) ;; |
| 50 | *) |
| 51 | REPLACE_LINK=1 |
| 52 | ;; |
| 53 | esac |
| 54 | fi |
| 55 | ]) |