Re: ping #3: [RFA] Add --with-libz-prefix option in config/zlib.m4

H.J. Lu
2015-02-18T20:53:42Z

On Wed, Feb 18, 2015 at 12:32 PM, Mark Wielaard <mjw@redhat.com> wrote:
> On Wed, 2015-02-18 at 11:52 -0800, H.J. Lu wrote:
>> On Wed, Feb 18, 2015 at 11:44 AM, Mike Frysinger <vapier@gentoo.org> wrote:
>> > On 18 Feb 2015 08:58, H.J. Lu wrote:
>> >> On Wed, Feb 18, 2015 at 8:54 AM, Mike Frysinger wrote:
>> >> >> Why do you want to turn off zlib? On Linux/x86, zlib is required
>> >> >> for assembler. At least, you should issue an error when --without-libz
>> >> >> is used in binutils for Linux/x86 target.
>> >> >
>> >> > err, when did that happen ? why would zlib be possibly required for an
>> >> > assembler ?
>> >>
>> >> commit 89e7505fcde4bd83948f559f429a0e1eb4262f05
>> >> Author: H.J. Lu <hjl.tools@gmail.com>
>> >> Date: Sun Dec 14 06:41:03 2014 -0800
>> >>
>> >> Compress debug sections for Linux/x86 by default
>> >>
>> >> * config/tc-i386.c (flag_compress_debug): Default to compress
>> >> debug sections for Linux.
>> >
>> > i don't see how that justifies making it a hard requirement
>>
>> Can you elaborate?
>
> That doesn't seem like a smart default. And why is is Linux/x86 only?
> Shouldn't that be something that is done explicitly by a distro
> configuring binutils after making sure it actually is beneficial
> (debuginfo is often compressed in a different way, on the package/file
> level or with dwz). And after making sure all tools actually work with
> it? There are various tools that don't handle the .zdebug format like
> valgrind. And at least elfutils has trouble with it for ET_REL files,
> like kernel modules, because relocations don't actually apply anymore to
> the section data as is (but only after the decompression).
>

Now it becomes a monthly topic:

https://sourceware.org/ml/binutils/2015-01/msg00089.html

--
H.J.