On 10/18/2010 10:07 AM, Peter Rosin wrote:
So, your patch needs more work, either in autoconf.texi (documenting that LN_S needs to be set in the environment rather than on the configure command line) or we need to think or some other way to fixup the _AS_LN_S_PREPARE result after command-line parsing, or restructure the code otherwise.The below one-liner makes the tests pass. I don't know if we should perhaps use test "${LN_S+set}" = set instead, and I don't know if it's ok to clobber as_ln_s from "the outside" like this. I also suppose there's an area of the configure script that will run with unexpected outcome of any AS_LN_S([foo], [bar]) macros (between the _AS_LN_S_PREPARE expansion and AC_PROG_LN_S, at least as long as _AS_LN_S_PREPARE is expanded first but that seems pretty hard to change).
Something like the attached... still requires writing ChangeLogs. Paolo
>From f03240084e8dfb4474f2325b694394a7b7f42280 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <[email protected]> Date: Thu, 21 Oct 2010 12:01:41 +0200 Subject: [PATCH] allow overriding of as_ln_s with LN_S. --- doc/autoconf.texi | 3 +++ lib/autoconf/functions.m4 | 25 ++++++++++--------------- lib/autoconf/programs.m4 | 2 +- lib/m4sugar/m4sh.m4 | 2 +- tests/base.at | 25 +++++++++++++++++++++++++ tests/m4sh.at | 26 ++++++++++++++++++++++++++ 6 files changed, 66 insertions(+), 17 deletions(-) diff --git a/doc/autoconf.texi b/doc/autoconf.texi index 0640320..6749ea0 100644 --- a/doc/autoconf.texi +++ b/doc/autoconf.texi @@ -4119,6 +4119,9 @@ Particular Programs @code{LN_S} to @samp{ln -s}; otherwise, if @samp{ln} works, set @code{LN_S} to @samp{ln}, and otherwise set it to @samp{cp -p}. +The result of this test can be overridden by setting the @code{LN_S} +variable. + If you make a link in a directory other than the current directory, its meaning depends on whether @samp{ln} or @samp{ln -s} is used. To safely create links using @samp{$(LN_S)}, either find out which form is used diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4 index f2048bf..bb8dcf0 100644 --- a/lib/autoconf/functions.m4 +++ b/lib/autoconf/functions.m4 @@ -856,21 +856,16 @@ AC_DEFUN([AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK], [ac_cv_func_lstat_dereferences_slashed_symlink], [rm -f conftest.sym conftest.file echo >conftest.file -if test "$as_ln_s" = "ln -s" && ln -s conftest.file conftest.sym; then - AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT], - [struct stat sbuf; - /* Linux will dereference the symlink and fail, as required by POSIX. - That is better in the sense that it means we will not - have to compile and use the lstat wrapper. */ - return lstat ("conftest.sym/", &sbuf) == 0;])], - [ac_cv_func_lstat_dereferences_slashed_symlink=yes], - [ac_cv_func_lstat_dereferences_slashed_symlink=no], - [ac_cv_func_lstat_dereferences_slashed_symlink=no]) -else - # If the `ln -s' command failed, then we probably don't even - # have an lstat function. - ac_cv_func_lstat_dereferences_slashed_symlink=no -fi +AS_LN_S([conftest.file], [conftest.sym]) +AC_RUN_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT], + [struct stat sbuf; + /* Linux will dereference the symlink and fail, as required by POSIX. + That is better in the sense that it means we will not + have to compile and use the lstat wrapper. */ + return lstat ("conftest.sym/", &sbuf) == 0;])], + [ac_cv_func_lstat_dereferences_slashed_symlink=yes], + [ac_cv_func_lstat_dereferences_slashed_symlink=no], + [ac_cv_func_lstat_dereferences_slashed_symlink=no]) rm -f conftest.sym conftest.file ]) diff --git a/lib/autoconf/programs.m4 b/lib/autoconf/programs.m4 index c90d9b2..dd8de61 100644 --- a/lib/autoconf/programs.m4 +++ b/lib/autoconf/programs.m4 @@ -799,7 +799,7 @@ AN_MAKEVAR([LN], [AC_PROG_LN_S]) AN_PROGRAM([ln], [AC_PROG_LN_S]) AC_DEFUN([AC_PROG_LN_S], [AC_MSG_CHECKING([whether ln -s works]) -AC_SUBST([LN_S], [$as_ln_s])dnl +AC_SUBST([LN_S], [${LN_S-$as_ln_s}])dnl if test "$LN_S" = "ln -s"; then AC_MSG_RESULT([yes]) else diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4 index 13ad849..a5ec8ea 100644 --- a/lib/m4sugar/m4sh.m4 +++ b/lib/m4sugar/m4sh.m4 @@ -1217,7 +1217,7 @@ rmdir conf$$.dir 2>/dev/null # simulated with `ln' or `cp'? m4_defun_init([AS_LN_S], [AS_REQUIRE([_AS_LN_S_PREPARE])], -[$as_ln_s $1 $2]) +[${LN_S-$as_ln_s} $1 $2]) # _AS_MKDIR_P diff --git a/tests/base.at b/tests/base.at index cf12099..3e754d7 100644 --- a/tests/base.at +++ b/tests/base.at @@ -707,3 +707,28 @@ libdir=${exec_prefix}/lib ]]) AT_CLEANUP + + +## ------------- ## +## AC_PROG_LN_S ## +## ------------- ## + +AT_SETUP([AC_PROG_LN_S]) + +AT_DATA([configure.ac], +[[AC_INIT +AC_PROG_LN_S +rm -f foo link +echo foo > file +$LN_S file link || AC_MSG_ERROR([$LN_S failed]) +grep foo link || AC_MSG_ERROR([link not created correctly]) +]]) + +AT_CHECK_AUTOCONF +AT_CHECK_CONFIGURE +AT_CHECK_CONFIGURE([LN_S='cp -p']) +rm -f foo +AT_CHECK([grep foo link], [], [ignore]) +AT_CHECK_CONFIGURE([LN_S=false], [1], [ignore], [ignore]) + +AT_CLEANUP diff --git a/tests/m4sh.at b/tests/m4sh.at index 08680c3..5be8d75 100644 --- a/tests/m4sh.at +++ b/tests/m4sh.at @@ -518,6 +518,32 @@ AT_CHECK([$CONFIG_SHELL ./script]) AT_CLEANUP +## --------- ## +## AS_LN_S. ## +## --------- ## + +# Create symbolic links. +AT_SETUP([AS@&t...@_ln_s]) +AT_KEYWORDS([m4sh]) + +AT_DATA_M4SH([script.as], +[[AS_INIT +rm -f foo link +echo foo > file +AS_LN_S([file], [link]) || AS_EXIT([1]) +grep foo link || AS_EXIT([1]) +]]) + +AT_CHECK_M4SH +AT_CHECK([$CONFIG_SHELL ./script], [], [foo +]) +AT_CHECK([env LN_S='cp -p' $CONFIG_SHELL ./script], [], [foo +]) +rm -f foo +AT_CHECK([grep foo link], [], [ignore]) +AT_CHECK([env LN_S='false' $CONFIG_SHELL ./script], [1]) + +AT_CLEANUP ## -------------------- ## -- 1.7.2.3
