Re: [PATCH 1/8] Add --with-system-zlib in bfd

[Pedro Alves <palves@redhat.com>]

On 03/31/2015 11:46 AM, H.J. Lu wrote:
> On Tue, Mar 31, 2015 at 3:37 AM, Pedro Alves <palves@redhat.com> wrote:
>> On 03/31/2015 11:10 AM, H.J. Lu wrote:
>>> On Mon, Mar 30, 2015 at 11:13 PM, Mike Frysinger <vapier@gentoo.org> wrote:
>>>> On 26 Mar 2015 08:57, H.J. Lu wrote:
>>>>> --- a/bfd/configure.ac
>>>>> +++ b/bfd/configure.ac
>>>>>
>>>>> -# Link in zlib if we can.  This allows us to read compressed debug sections.
>>>>> -# This is used only by compress.c.
>>>>> -AM_ZLIB
>>>>> +# Use the system's zlib library.
>>>>> +zlibdir=-L../zlib
>>>>> +zlibinc="-I\$(srcdir)/../zlib"
>>>>> +AC_ARG_WITH(system-zlib,
>>>>> +[AS_HELP_STRING([--with-system-zlib], [use installed libz])],
>>>>> +zlibdir=
>>>>> +zlibinc=
>>>>> +)
>>>>
>>>> this is wrong.  the 3rd arg is whether the option was specified, not that the
>>>> option was disabled.  you need to check $withval is equal to "no" (or not equal
>>>> to "yes").
>>>> -mike
>>>
>>> That is what gcc/configure.ac has and it works for me.
>>>
>>>
>>
>> Why are we patching every tool's configury instead of tweaking
>> config/zlib.m4 (where AM_ZLIB is from)?  We go from a single
>> place to edit, to the same configure bits spread around the
>> tree.  Seems like a step backwards.
>>
> 
> Replace AM_ZLIB in configure.ac isn't complete. I also needed to change

Never said it was complete.

> 
> * Makefile.am (ZLIB): New.
> (ZLIBINC): Likewise.
> (AM_CFLAGS): Add $(ZLIBINC).
> (libbfd_la_LIBADD): Add $(ZLIB).
> 
> It is better for Makefile.am to use what configure.ac defines

That's orthogonal.  How configure.ac defines what Makefile.am
consumes is the issue.  That can either be through a shared macro,
which makes sure all tools have the exact same command line option
(like AM_ZLIB), or you manually put the same configure.ac bits
everywhere.

Thanks,
Pedro Alves