Mercurial > hg > octave-lyh > gnulib-hg
changeset 11948:325a0b28c47e
link-follow: accomodate mingw and cross-compilation
* m4/link-follow.m4 (gl_AC_FUNC_LINK_FOLLOWS_SYMLINK): Rename...
(gl_FUNC_LINK_FOLLOWS_SYMLINK): ...to this. Change
cross-compilation results to -1, to make linkat easier to
implement when cross-compiling. Trivially support mingw.
* modules/link-follow (configure.ac): Call new name.
* NEWS: Mention this.
Signed-off-by: Eric Blake <ebb9@byu.net>
author | Eric Blake <ebb9@byu.net> |
---|---|
date | Fri, 04 Sep 2009 11:49:02 -0600 |
parents | 7f6946558d8c |
children | 245de403ed19 |
files | ChangeLog NEWS m4/link-follow.m4 modules/link-follow |
diffstat | 4 files changed, 48 insertions(+), 17 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2009-09-04 Eric Blake <ebb9@byu.net> + + link-follow: accomodate mingw and cross-compilation + * m4/link-follow.m4 (gl_AC_FUNC_LINK_FOLLOWS_SYMLINK): Rename... + (gl_FUNC_LINK_FOLLOWS_SYMLINK): ...to this. Change + cross-compilation results to -1, to make linkat easier to + implement when cross-compiling. Trivially support mingw. + * modules/link-follow (configure.ac): Call new name. + * NEWS: Mention this. + 2009-09-03 Eric Blake <ebb9@byu.net> faccessat: compile replacement
--- a/NEWS +++ b/NEWS @@ -6,6 +6,9 @@ Date Modules Changes +2009-09-04 link-follow The macro LINK_FOLLOWS_SYMLINK is now tri-state, + rather than only defined to 1. + 2009-09-03 openat The include files are standardized to POSIX 2008. For openat, include <fcntl.h>; for fchmodat, fstatat, and mkdirat, include
--- a/m4/link-follow.m4 +++ b/m4/link-follow.m4 @@ -1,4 +1,4 @@ -# serial 12 +# serial 13 dnl Run a program to determine whether link(2) follows symlinks. dnl Set LINK_FOLLOWS_SYMLINKS accordingly. @@ -7,14 +7,27 @@ # gives unlimited permission to copy and/or distribute it, # with or without modifications, as long as this notice is preserved. -AC_DEFUN([gl_AC_FUNC_LINK_FOLLOWS_SYMLINK], +dnl This macro can be used to emulate POSIX linkat. If +dnl LINK_FOLLOWS_SYMLINKS is 0, link matches linkat(,0), and +dnl linkat(,AT_SYMLINK_FOLLOW) requires a readlink. If it is 1, +dnl link matches linkat(,AT_SYMLINK_FOLLOW), and there is no way +dnl to do linkat(,0) on symlinks (on all other file types, +dnl link() is sufficient). If it is -1, use a runtime test. +AC_DEFUN([gl_FUNC_LINK_FOLLOWS_SYMLINK], [dnl - AC_CACHE_CHECK([whether link(2) dereferences a symlink], - gl_ac_cv_func_link_follows_symlink, - [ - # Create a regular file. - echo > conftest.file - AC_RUN_IFELSE([AC_LANG_SOURCE([[ + AC_CHECK_FUNCS_ONCE([readlink]) + dnl Mingw lacks link, although gnulib provides a good replacement. + dnl However, it also lacks symlink, so there's nothing to test in + dnl the first place, and no reason to need to distinguish between + dnl linkat variants. So, we set LINK_FOLLOWS_SYMLINKS to 0. + gl_link_follows_symlinks=0 # assume GNU behavior + if test $ac_cv_func_readlink = yes; then + AC_CACHE_CHECK([whether link(2) dereferences a symlink], + gl_cv_func_link_follows_symlink, + [ + # Create a regular file. + echo > conftest.file + AC_RUN_IFELSE([AC_LANG_SOURCE([[ # include <sys/types.h> # include <sys/stat.h> # include <unistd.h> @@ -50,13 +63,18 @@ return SAME_INODE (sb_hard, sb_file) ? 0 : 1; } ]])], - [gl_ac_cv_func_link_follows_symlink=yes], - [gl_ac_cv_func_link_follows_symlink=no], - [gl_ac_cv_func_link_follows_symlink=yes] dnl We're cross compiling. - ) - ]) - if test $gl_ac_cv_func_link_follows_symlink = yes; then - AC_DEFINE([LINK_FOLLOWS_SYMLINKS], [1], - [Define if `link(2)' dereferences symbolic links.]) + [gl_cv_func_link_follows_symlink=yes], + [gl_cv_func_link_follows_symlink=no], + [gl_cv_func_link_follows_symlink=unknown] dnl We're cross compiling. + ) + ]) + case $gl_cv_func_link_follows_symlink in + yes) ;; + no) gl_link_follows_symlinks=1 ;; + *) gl_link_follows_symlinks=-1 ;; + esac fi + AC_DEFINE_UNQUOTED([LINK_FOLLOWS_SYMLINKS], [$gl_link_follows_symlinks], + [Define to 1 if `link(2)' dereferences symbolic links, 0 if it + creates hard links to symlinks, and -1 if unknown.]) ])