Zlib

Zlib

[Greg Schafer]

Hi,

Testing latest release candidate and I have 3 related issues:

1) If zlib is not available at Binutils build time, there are 2 failures in
the testsuite:

FAIL: objdump -W
FAIL: readelf -wa (compressed)

Surely the testsuite should skip these tests in this scenario? I'll file a
PR unless someone can explain why this is acceptable.

2) When Zlib *is* available, shared Zlib is now linked into every single
Binutils binary and the shared libbfd. The initial proposal was for
addr2line, objdump, readelf. Why do the remaining binaries (ar, as, c++filt,
gprof, ld, nm, objcopy, ranlib, size, strings, strip) all need to be linked
against zlib?

3) My understanding is that Zlib support was added because:

  "The gold linker can emit compressed sections. There is a gold flag to
   enable compressed debug sections."

So, because gold can enable compressed debug sections, I'm now forced to
have all my Binutils linked against Zlib, even if I'm not building gold?
This feels kinda wrong.

I believe there should be a user friendly way to disable linking against
zlib.

Thanks for any comments.

Regards
Greg

Re: Zlib

[H.J. Lu]

On Sat, Oct 04, 2008 at 08:17:12PM +1000, Greg Schafer wrote:
> Hi,
> 
> Testing latest release candidate and I have 3 related issues:
> 
> 1) If zlib is not available at Binutils build time, there are 2 failures in
> the testsuite:
> 
> FAIL: objdump -W
> FAIL: readelf -wa (compressed)
> 
> Surely the testsuite should skip these tests in this scenario? I'll file a
> PR unless someone can explain why this is acceptable.
> 
> 2) When Zlib *is* available, shared Zlib is now linked into every single
> Binutils binary and the shared libbfd. The initial proposal was for
> addr2line, objdump, readelf. Why do the remaining binaries (ar, as, c++filt,
> gprof, ld, nm, objcopy, ranlib, size, strings, strip) all need to be linked
> against zlib?
> 
> 3) My understanding is that Zlib support was added because:
> 
>   "The gold linker can emit compressed sections. There is a gold flag to
>    enable compressed debug sections."
> 
> So, because gold can enable compressed debug sections, I'm now forced to
> have all my Binutils linked against Zlib, even if I'm not building gold?
> This feels kinda wrong.
> 
> I believe there should be a user friendly way to disable linking against
> zlib.

1. Check if linker supports --as-needed/--no-as-needed.
2. Use --as-needed -lz --no-as-needed if possible.


H.J.