Subject: Re: bug#13928: [PATCH] compile: don't place built object files in $(srcdir), ever ...

From: Stefano Lattarini <[email-masked]>
Date: Sun, 04 Jan 2015 18:18:33 +0100

[I once again have to correct myself, sigh]

On 01/03/2015 02:14 AM, Stefano Lattarini wrote:
> On 01/03/2015 12:23 AM, Stefano Lattarini wrote:
>> Hi Eric.
>>
>> On 01/03/2015 12:14 AM, Eric Blake wrote:
>>> On 01/02/2015 11:49 AM, Stefano Lattarini wrote:
>>>> ... even when a source file is specified as '$(srdir)/foo.c' or
>>>> '$(top_srcdir)/bar.c'. And ditto for dependency-tracking makefile
>>>> fragments (those under '.deps' directories).
>>>
>>>> +++ b/NEWS
>>>
>>>> @@ -88,6 +88,21 @@ New in 1.16:
>>>>       using a private target that is only meant to bootstrap the required
>>>>       makefile fragments.
>>>>
>>>> +  - The 'subdir-object' option no longer causes object files corresponding
>>>> +    to source files specified with an explicit '$(srcdir)' component to be
>>>> +    placed in the source tree rather than in the build tree.
>>>> +
>>>> +    For example, if Makefile.am contains:
>>>> +
>>>> +        AUTOMAKE_OPTIONS = subdir-objects
>>>> +        foo_SOURCES = $(srcdir)/foo.c $(srcdir)/s/bar.c $(top_srcdir)/baz.c
>>>> +
>>>> +    then "make all" will create 'foo.o' and 's/bar.o' $(builddir) rather
>>>
>>> s|'s/bar.o'|'s/bar.o' in|
>>>
>> Thanks, will fix before merging this in a non-rewindable branch (that
>> can't happen before Automake 1.16 is released anyway).
>>
>>>> +    than in $(srcdir), and 'baz.o' in $(top_builddir) rather than in
>>>> +    $(top_srcdir).
>>>> +
>>>> +    This was the second part of automake bug#13928.
>>>> +
>>>>   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>> And thanks for tackling this!
>>>
>> Wait to thank me, I've found another pre-existing bug in this area, affecting
>> non-GNU makes :-/  And by that I mean non-borked ones, like BSD make and
>> Solaris 10 CCS make.
>>
>> On the plus side, the bug only affects "make distclean" (causing spurious
>> failures), and only for packages using a recursive setup and referencing
>> source files in a parent directory from a subdir Make; so it's a minor one.
>> On the negative side, I probably introduced it myself in some 1.12.x
>> release...
>>
Nope, it was pre-existing.  And I appear to have found an easy enough
fix for it; I will soon post a patch if the testsuite is happy on BSD
and Solaris.

>> Hopefully I'll have a fix in a week or so (I'll be AFK for most time in the
>> coming days).
>  >
> Also, it appears this is causing another new testsuite failure with BSD make.
> The following squash-in diff seems to take care of that:
>
> -*-*-*-
>
> diff --git a/bin/automake.in b/bin/automake.in
> index f4327fc..0c44703 100644
> --- a/bin/automake.in
> +++ b/bin/automake.in
> @@ -1677,12 +1677,15 @@ sub handle_single_transform
>                 {
>                   $this_obj_ext = $obj;
>                   $derived_source = 0;
> -                # Don't ever place built object files in $(srcdir), even when
> -                # sources are specified explicitly as (say) '$(srcdir)/foo.c'
> -                # or '$(top_srcdir)/foo.c'.  See automake bug#13928.
> -                my @d = split '/', $directory;
> -                if (@d)
> +                do
>                     {
> +                    last unless option 'subdir-objects';
> +                    # Don't ever place built object files in $(srcdir),
> +                    # even when sources are specified explicitly as (say)
> +                    # '$(srcdir)/foo.c' or '$(top_srcdir)/foo.c'.
> +                    # See automake bug#13928.
> +                    my @d = split '/', $directory;
> +                    last unless @d;
>                       my $d = $d[0];
>                       if ($d eq '$(srcdir)' or $d eq '${srcdir}')
>                         {
> @@ -1690,7 +1693,7 @@ sub handle_single_transform
>                         }
>                       elsif ($d eq '$(top_srcdir)' or $d eq '${top_srcdir}')
>                         {
> -                       $d[0] = '$(top_builddir)';
> +                        $d[0] = '$(top_builddir)';
>                         }
>                       $directory = join '/', @d;
>                     }
>
> -*-*-*-
>
This change was serious bugged BTW.  I've now fixed it, but rather than
posting another squash-in, I will re-post the whole adjust patch series
once I've made sure there are no regressions on an of the UNIX flavors
I can test with (GNU/Linux, Solaris 10, AIX 7.1, NetBSD 5.1, FreeBSD 8.0)

Regards,
   Stefano