Re: [platform-testers] automake-1.16.92 released

[Frederic Berat]

On Sun, Jun 30, 2024 at 10:28 PM Karl Berry <karl@freefriends.org> wrote:

> Hi Frederic,
>
> Hello,


>     NetworkManager:
>     Use of uninitialized value $var in string eq at
>     /usr/share/automake-1.16/Automake/Variable.pm line 754, <GEN2> line
> 1169.
>
> From the Makefile.am you sent me separately (attached here for the
> record), it seems that is coming from the use of $() in:
>
> introspection/%.h: introspection/%.c
>         $()
>
> Accordingly, I changed scan_variable_expansions (in Variable.pm) to not
> worry if the variable name is empty (patch and test below). Could you
> retry NetworkManager or the other packages and make sure the Perl
> warning is gone, please?
>

All 3 packages are built successfully with the patch.


>
> It wasn't entirely clear to me if the line
> _vapi_name = $(subst /,_,$(subst -,_,$(subst .,_,$(1))))
> might also be causing trouble, but I think Automake already recognizes
> that ok (and gives a warning, by default, but an Automake warning, not a
> Perl warning.)
>
> As an aside, I'm curious as to why the $() is used. It seems
> a mysterious way to do nothing. Do you know? --thanks, karl.
>

No clue, sorry. We'd need to ask the corresponding projects.

Fred.

>
>
> -----------------------------------------------------------------------------
> automake: avoid Perl-level warning on empty variable $().
>
> https://lists.gnu.org/archive/html/automake/2024-06/msg00085.html
>
> * lib/Automake/Variable.pm (scan_variable_expansions): recognize
> and do nothing if the variable name is empty: $().
> * t/varempty.sh: new test.
> * t/list-of-tests.mk (handwritten_TESTS): add it.
> diff --git a/lib/Automake/Variable.pm b/lib/Automake/Variable.pm
> index db1f6378d..f97aab59f 100644
> --- a/lib/Automake/Variable.pm
> +++ b/lib/Automake/Variable.pm
> @@ -751,7 +751,11 @@ sub scan_variable_expansions ($)
>    while ($text =~ m{\$(?:\{([^\}]*)\}|\(([^\)]*)\)|(\$))}g)
>      {
>        my $var = $1 || $2 || $3;
> -      next if $var eq '$';
> +      next if (! defined $var) || ($var eq '$');
> +      # we check for $var being defined because NetworkManager and other
> +      # packages use the strange construct $().
> +      # https://lists.gnu.org/archive/html/automake/2024-06/msg00085.html
> +
>        # The occurrence may look like $(string1[:subst1=[subst2]]) but
>        # we want only 'string1'.
>        $var =~ s/:[^:=]*=[^=]*$//;
> diff --git a/t/list-of-tests.mk b/t/list-of-tests.mk
> index 1e0f364ba..e80ace470 100644
> --- a/t/list-of-tests.mk
> +++ b/t/list-of-tests.mk
> @@ -1282,6 +1282,7 @@ t/vala-per-target-flags.sh \
>  t/vala-recursive-setup.sh \
>  t/vala-vapi.sh \
>  t/vala-vpath.sh \
> +t/varempty.sh \
>  t/vars.sh \
>  t/vars3.sh \
>  t/var-recurs.sh \
> diff --git a/t/varempty.sh b/t/varempty.sh
> new file mode 100644
> index 000000000..9eb45c421
> --- /dev/null
> +++ b/t/varempty.sh
> @@ -0,0 +1,36 @@
> +#! /bin/sh
> +# Copyright (C) 2024 Free Software Foundation, Inc.
> +#
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 2, or (at your option)
> +# any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <https://www.gnu.org/licenses/>.
> +
> +# An empty variable name $() should not cause a Perl warning, namely:
> +#   Use of uninitialized value $var in string eq at
> +#   .../lib/Automake/Variable.pm line 754, <GEN2> line 3.
> +# (in scan_variable_expansions)
> +#
> +# This showed up with the NetworkManager and other packages in Fedora:
> +# https://lists.gnu.org/archive/html/automake/2024-06/msg00085.html
> +# (The actual purpose of the "$()" is unclear.)
> +
> +. test-init.sh
> +
> +cat > Makefile.am << 'END'
> +x:
> +       $()
> +END
> +
> +$ACLOCAL
> +$AUTOMAKE
> +
> +:
> Running command: git commit \-q \-F \.\/vc\-dwim\-log\-wBh6_U
> \-\-author\=Karl\ Berry\ \<karl\@freefriends\.org\> \-\- ChangeLog
> + set +x
>
> compile finished at Sun Jun 30 13:26:51 2024
>
>