Mercurial > gnulib
view m4/link.m4 @ 40189:3ba41edecde6
progreloc: Speed up executable lookup on various platforms.
* lib/progreloc.c: Include <errno.h>.
(safe_read, full_read): New functions.
(find_executable): On GNU/kFreeBSD, FreeBSD, DragonFly, NetBSD, Solaris,
prefer the information from the /proc file system to a PATH search.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Tue, 19 Feb 2019 21:42:54 +0100 |
parents | b06060465f09 |
children |
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# link.m4 serial 10 dnl Copyright (C) 2009-2019 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_LINK], [ AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CHECK_FUNCS_ONCE([link]) if test $ac_cv_func_link = no; then HAVE_LINK=0 else AC_CACHE_CHECK([whether link obeys POSIX], [gl_cv_func_link_works], [touch conftest.a # Assume that if we have lstat, we can also check symlinks. if test $ac_cv_func_lstat = yes; then ln -s conftest.a conftest.lnk fi AC_RUN_IFELSE( [AC_LANG_PROGRAM( [[#include <unistd.h> #include <stdio.h> ]], [[int result = 0; if (!link ("conftest.a", "conftest.b/")) result |= 1; #if HAVE_LSTAT if (!link ("conftest.lnk/", "conftest.b")) result |= 2; if (rename ("conftest.a", "conftest.b")) result |= 4; if (!link ("conftest.b", "conftest.lnk")) result |= 8; #endif return result; ]])], [gl_cv_func_link_works=yes], [gl_cv_func_link_works=no], [case "$host_os" in # Guess yes on Linux systems. linux-* | linux) gl_cv_func_link_works="guessing yes" ;; # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_link_works="guessing yes" ;; # If we don't know, assume the worst. *) gl_cv_func_link_works="guessing no" ;; esac ]) rm -f conftest.a conftest.b conftest.lnk]) case "$gl_cv_func_link_works" in *yes) ;; *) REPLACE_LINK=1 ;; esac fi ])