Issue 306 in webp: Underlinking in libwebpmux (undefined reference to 'pow')

[floppyma… via monorail]

Status: New
Owner: ----
Labels: Type-Defect Priority-Medium

New issue 306 by floppyma...@gmail.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306

src/mux/anim_encode.c uses the pow(3) function from the C math library (libm). However, libwebpmux.la does not get linked against libm, leading to errors like the ones below.

../src/mux/.libs/libwebpmux.so: error: undefined reference to 'pow'
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:523: webpmux] Error 1
make[1]: *** Waiting for unfinished jobs....
../src/mux/.libs/libwebpmux.so: error: undefined reference to 'pow'
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:515: gif2webp] Error 1


I have attached a full build log.

Attachments:
media-libs:libwebp-0.5.1:20160814-190700.log 223 KB

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[pascal.m… via monorail]

Updates:
Status: Started

Comment #1 on issue 306 by pascal.m...@gmail.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c1

Thanks for the report!
Indeed, some binary seem to be missing a -lm library linking directive.
Let's see if this patch [1] fixes things...

[1] https://chromium-review.googlesource.com/370280

[floppyma… via monorail]

Comment #2 on issue 306 by floppyma...@gmail.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c2

I think the proper fix would be to add -lm to libwebpmux_la_LDADD in master/src/mux/Makefile.am.

libwebpmux.so may be built/installed as a shared lib, and this would make sure the proper entry is added to DT_NEEDED.

[floppyma… via monorail]

Comment #3 on issue 306 by floppyma...@gmail.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c3

Sorry, that should probably be libwebpmux_la_LIBADD, not LDADD.

[jz… via monorail]

Updates:
Owner: jz...@google.com

Comment #4 on issue 306 by jz...@google.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c4

This is definitely a bug, but I wasn't able to reproduce it when building from source on a fresh gentoo install (using stage3-20160811 as the base), with the flags from the log. I seem to always end up with a -lm dependency reference in libwebpmux.la. Is there anything special about your setup?

[floppyma… via monorail]

Comment #5 on issue 306 by floppyma...@gmail.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c5

> Is there anything special about your setup?

I currently have ld.gold set as the default linker; that may effect how the -Wl,--as-needed option gets processed.

[bugdro… via monorail]

Comment #6 on issue 306 by bugd...@chromium.org: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c6

The following revision refers to this bug:
https://chromium.googlesource.com/webm/libwebp/+/aaf2530cc38a69a46f0e612a281ddcbda566663a

commit aaf2530cc38a69a46f0e612a281ddcbda566663a
Author: James Zern
Date: Tue Aug 16 05:32:46 2016

{extras,mux}/Makefile.am: add missing -lm

+ libwebpmux.pc

quality_estimate.c, anim_encode.c rely on functions from math.h

BUG=webp:306

Change-Id: I3a8eb48febfd52bfbeb04f4dc615ccbed72926f7

[modify] https://crrev.com/aaf2530cc38a69a46f0e612a281ddcbda566663a/extras/Makefile.am
[modify] https://crrev.com/aaf2530cc38a69a46f0e612a281ddcbda566663a/src/mux/Makefile.am
[modify] https://crrev.com/aaf2530cc38a69a46f0e612a281ddcbda566663a/src/mux/libwebpmux.pc.in

[jz… via monorail]

Updates:
Status: Fixed

Comment #7 on issue 306 by jz...@google.com: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c7

Within the discussion on the change it was determined that using the pre-generated configure from the 0.5.1 would produce the behavior. Rerunning ./autogen.sh would work around the issue. Due to some reorganization in the master branch the bug was hidden.
Thanks again for the report and helping with the repro.

[bugdro… via monorail]

Updates:
Labels: merge-merged-0.5.2

Comment #8 on issue 306 by bugd...@chromium.org: Underlinking in libwebpmux (undefined reference to 'pow')
https://bugs.chromium.org/p/webp/issues/detail?id=306#c8

The following revision refers to this bug:

https://chromium.googlesource.com/webm/libwebp/+/03f1c00877242ccc4765575bfa3ff9073b273fc2

commit 03f1c00877242ccc4765575bfa3ff9073b273fc2

Author: James Zern
Date: Tue Aug 16 05:32:46 2016

mux/Makefile.am: add missing -lm

+ libwebpmux.pc

anim_encode.c relies on functions from math.h

BUG=webp:306

Change-Id: I3a8eb48febfd52bfbeb04f4dc615ccbed72926f7
(cherry picked from commit aaf2530cc38a69a46f0e612a281ddcbda566663a)

[modify] https://crrev.com/03f1c00877242ccc4765575bfa3ff9073b273fc2/src/mux/Makefile.am
[modify] https://crrev.com/03f1c00877242ccc4765575bfa3ff9073b273fc2/src/mux/libwebpmux.pc.in