Paolo Bonzini <bonzini <at> gnu.org> writes: > 2) The AS_VAR_APPEND technique, right now, does not give any speedup in > Autoconf-generated scripts, as far as I could read. It depends on how many appends are taking place. It matters more for coreutils than m4, for example, because coreutils generates a longer as_func_list based on its use of AC_CHECK_FUNCS_ONCE. > Nevertheless, we > are rejecting all shells that do not support +=. This, unlike LINENO, > is a pity, because it means that for everybody who's not using bash or > zsh, but has it installed, the scripts will rerun in bash or zsh. This > means in turn that we get much less coverage of shells in the wild. POSIX requires $LINENO (dash is buggy for not providing it). It does not require +=. So, I can agree with your reluctance on rejecting shells that do not provide POSIX extensions. How about a patch to AS_VAR_APPEND that removes the _AS_DETECT_SUGGESTED line, along with a policy that M4sh will never _AS_DETECT a non-POSIX feature? (M4sh clients could still suggest non-POSIX extensions, if we were to ever export and document a public version of _AS_DETECT_*, but that would be their choice to omit dash support, and not forced on them by M4sh.) I'm committing this: >From 5184bb08838be30118ac26710a1f31bb673c062f Mon Sep 17 00:00:00 2001 From: Eric Blake <ebb9@xxxxxxx> Date: Thu, 30 Oct 2008 09:39:57 -0600 Subject: [PATCH] Don't check for non-POSIX extensions in suggested tests. * lib/m4sugar/m4sh.m4 (_AS_VAR_APPEND_WORKS): Remove suggestion; we still use += if available, but should not reject shells that don't provide it. (_AS_DETECT_SUGGESTED): Document a policy for m4sh. Signed-off-by: Eric Blake <ebb9@xxxxxxx> --- ChangeLog | 8 ++++++++ lib/m4sugar/m4sh.m4 | 7 ++++++- 2 files changed, 14 insertions(+), 1 deletions(-) diff --git a/ChangeLog b/ChangeLog index e19a3f6..914f83b 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,13 @@ 2008-10-30 Eric Blake <ebb9@xxxxxxx> + Don't check for non-POSIX extensions in suggested tests. + * lib/m4sugar/m4sh.m4 (_AS_VAR_APPEND_WORKS): Remove suggestion; + we still use += if available, but should not reject shells that + don't provide it. + (_AS_DETECT_SUGGESTED): Document a policy for m4sh. + +2008-10-30 Eric Blake <ebb9@xxxxxxx> + Work around Solaris /bin/sh case bug. * lib/m4sugar/m4sh.m4 (_AS_CASE, _AS_CASE_DEFAULT): Always provide a non-empty command list. diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4 index 1f1f599..bf18235 100644 --- a/lib/m4sugar/m4sh.m4 +++ b/lib/m4sugar/m4sh.m4 @@ -173,6 +173,9 @@ m4_define([_AS_DETECT_EXPAND], # ------------------------- # Refuse to execute under a shell that does not pass the given TEST. # Does not do AS_REQUIRE for the better-shell detection code. +# +# M4sh should never require something not required by POSIX, although +# other clients are free to do so. m4_defun([_AS_DETECT_REQUIRED], [m4_set_add([_AS_DETECT_REQUIRED_BODY], [$1 || AS_EXIT])]) @@ -181,6 +184,9 @@ m4_defun([_AS_DETECT_REQUIRED], # -------------------------- # Prefer to execute under a shell that passes the given TEST. # Does not do AS_REQUIRE for the better-shell detection code. +# +# M4sh should never suggest something not required by POSIX, although +# other clients are free to do so. m4_defun([_AS_DETECT_SUGGESTED], [m4_set_add([_AS_DETECT_SUGGESTED_BODY], [$1 || AS_EXIT])]) @@ -1679,7 +1685,6 @@ m4_define([_AS_VAR_APPEND_WORKS], # Note that unlike AS_VAR_SET, VALUE must be properly quoted to avoid # field splitting and file name expansion. m4_defun_init([AS_VAR_APPEND], -[_AS_DETECT_SUGGESTED([_AS_VAR_APPEND_WORKS])]dnl [AS_REQUIRE([_AS_VAR_APPEND_PREPARE], [], [M4SH-INIT-FN])], [as_func_append $1 $2]) -- 1.6.0.2 _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
