Re: Debian-specific Autoconf patches

[Paul Eggert]

Ralf Wildenhues <address@hidden> writes:

>> +** AC_TRY_COMMAND, AC_TRY_EVAL
>> +  These never-documented macros have been marked with a comment
>> +  saying that they may be removed in a future release.
>
> Do you intend to then replace them with something safer?

I'd rather not promise a replacement now.  If we can think of a better
way to support the need behind these (never-documented) interfaces,
fine, but I can't think of one offhand now.  Perhaps after we start
assuming shell functions....

> I'm not sure about the best way to solve this: one possibility is to
> document the "we single-quote all arguments now" strategy, and tell
> people to use eval to access $ac_configure_args if they have to.

But there has never been any documentation for ac_configure_args, or
for how it's to be quoted.  This gives us the freedom to change the
implementation without breaking published interfaces.

I would not start documenting ac_configure_args now either.  Because
we may change it again (once we start assuming shell functions :-).

> The other way would be to resurrect the "we only enclose the arguments
> in single-quotes if they actually contain special characters",

If that doesn't introduce any bugs in the new way of doing things, and
if it happens to work better with older libraries, then it would be a
win.  But don't old, incompatible-with-2.59 libraries have a lot of
other problems?  I'm not sure we want to spend a lot of time worrying
about them at this point.

> The first `s' verb in that sed script looks like a no-op to me.

Thanks for catching that.  I installed this patch:

2006-05-27  Paul Eggert  <address@hidden>

        * NEWS: Reword notice for AC_TRY_COMMAND, AC_TRY_EVAL,
        ac_config_guess, ac_config_sub, ac_configure.
        * lib/autoconf/status.m4 (_AC_OUTPUT_CONFIG_STATUS):
        Fix typo that prevented an unnecessary space from being removed.
        Problems reported by Ralf Wildenhues in:
        http://lists.gnu.org/archive/html/autoconf-patches/2006-05/msg00143.html

Index: NEWS
===================================================================
RCS file: /cvsroot/autoconf/autoconf/NEWS,v
retrieving revision 1.373
diff -p -u -r1.373 NEWS
--- NEWS        26 May 2006 22:29:50 -0000      1.373
+++ NEWS        27 May 2006 21:56:14 -0000
@@ -1,12 +1,11 @@
 * Major changes in Autoconf 2.59d
 
-** AC_TRY_COMMAND, AC_TRY_EVAL
-  These never-documented macros have been marked with a comment
-  saying that they may be removed in a future release.
-
-** ac_config_guess, ac_config_sub, ac_configure
-  These never-documented variables have been marked with a comment
-  saying that we intend to remove them in a future release.
+** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
+  These never-documented macros and variables have been marked with
+  comments saying that they may be removed in a future release,
+  because their use can lead to unintended code being executed.
+  If you need functionality that only these macros or variables
+  currently supply, please write address@hidden
 
 ** AC_SUBST, AC_DEFINE
   Literal arguments to these are passed to m4_pattern_allow now.
Index: lib/autoconf/status.m4
===================================================================
RCS file: /cvsroot/autoconf/autoconf/lib/autoconf/status.m4,v
retrieving revision 1.109
diff -p -u -r1.109 status.m4
--- lib/autoconf/status.m4      26 May 2006 22:29:50 -0000      1.109
+++ lib/autoconf/status.m4      27 May 2006 21:56:14 -0000
@@ -1217,7 +1217,7 @@ ac_cs_version="\\
 m4_ifset([AC_PACKAGE_NAME], [AC_PACKAGE_NAME ])config.status[]dnl
 m4_ifset([AC_PACKAGE_VERSION], [ AC_PACKAGE_VERSION])
 configured by $[0], generated by m4_PACKAGE_STRING,
-  with options \\"`echo "$ac_configure_args" | sed 's/^ / /; 
s/[[\\""\`\$]]/\\\\&/g'`\\"
+  with options \\"`echo "$ac_configure_args" | sed 's/^ //; 
s/[[\\""\`\$]]/\\\\&/g'`\\"
 
 Copyright (C) 2006 Free Software Foundation, Inc.
 This config.status script is free software; the Free Software Foundation