1038799 - mouse_cursor_monitor_x11.o: requires dynamic R_X86_64_PC32 reloc against 'XFixesGetCursorImage'

Status: RESOLVED FIXED

(Core :: WebRTC, defect)

Description

[Gian-Carlo Pascutto [:gcp]]

https://tbpl.mozilla.org/?tree=Try&rev=8aa224675687

The current patch set in bug 983504 fails with linker errors in 2 specific configs. The sheriffs pointed out that these specific configs are non-unified builds. Indeed, I can reproduce the problem by doing a local debug build with ac_add_options --disable-unified_compilation:

3:35.21 ../../../build/unix/gold/ld: warning: hidden symbol 'XFixesQueryExtension' in /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/libXfixes.so is referenced by DSO /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/libgdk-x11-2.0.so
[...]
 3:35.21 ../../../build/unix/gold/ld: error: /home/morbo/hg/mozilla-central/objdir-desktop/toolkit/library/build/../../../media/webrtc/trunk/webrtc/modules/modules_desktop_capture/mouse_cursor_monitor_x11.o: requires dynamic R_X86_64_PC32 reloc against 'XFixesGetCursorImage' which may overflow at runtime; recompile with -fPIC
 3:35.21 ../../../build/unix/gold/ld: error: read-only segment has dynamic relocations
 3:35.21 ../../../build/unix/gold/ld: error: hidden symbol 'XFixesGetCursorImage' is not defined locally
 3:35.21 ../../../build/unix/gold/ld: error: hidden symbol 'XFixesQueryExtension' is not defined locally
 3:35.21 ../../../build/unix/gold/ld: error: hidden symbol 'XFixesSelectCursorInput' is not defined locally
 3:35.21 ../../../build/unix/gold/ld: error: hidden symbol 'XFixesGetCursorImage' is not defined locally
 3:35.21 ../../../build/unix/gold/ld: error: hidden symbol 'XFixesQueryExtension' is not defined locally
 3:35.21 ../../../build/unix/gold/ld: error: hidden symbol 'XFixesSelectCursorInput' is not defined locally
 3:35.21 collect2: error: ld returned 1 exit status

This is linking with GNU gold. Linking with GNU bfd gives the same error as on the tryserver, which is a bit less informative.

As far as I can tell, this is not a problem of bad includes (there's only one Xfixes.h, and gcc -E shows the symbols being defined), nor of missing libraries on the link (-lXfixes is on the link line, and in fact mouse_cursor_monitor_x11 uses some functions from it without getting the undefined error on them).

As far as I can tell, we already compile the relevant code with -fPIC.

Comment 1

[Randell Jesup [:jesup] (needinfo me)]

Include order issue; patch ready

Comment 2

[Randell Jesup [:jesup] (needinfo me)]

Attachment: fix non-unified build issues with screen/window sharing

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

Comment on attachment 8456381 [details] [diff] [review]
fix non-unified build issues with screen/window sharing

Not sure *why* Xdamage being included fixes this - but it does.  Without it we still fail link.  Thank you xorg!

Comment 4

[Mike Hommey [:glandium]]

(In reply to Randell Jesup [:jesup] from comment #3)
> Comment on attachment 8456381 [details] [diff] [review]
> fix non-unified build issues with screen/window sharing
> 
> Not sure *why* Xdamage being included fixes this - but it does.  Without it
> we still fail link.  Thank you xorg!

So, the reason is that Xdamage is wrapped and includes Xfixes.

Adding Xfixes to config/system-headers would fix it.

Comment 5

[Gian-Carlo Pascutto [:gcp]]

Attempting that failed, after some digging, the wrapped header is in:
./objdir-desktop/config/system_wrappers/X11/extensions/Xfixes.h

Yet the include path on compilation looks like:
-I../../../../../../dist/system_wrappers -include /home/morbo/hg/mozilla-inbound/config/gcc_hidden.h -D_FILE_OFFSET_BITS='64' -DCHROMIUM_BUILD -DUSE_LIBJPEG_TURBO='1' -DUSE_NSS='1' -DENABLE_ONE_CLICK_SIGNIN -DGTK_DISABLE_SINGLE_INCLUDES='1' -D_ISOC99_SOURCE='1' -DENABLE_REMOTING='1' -DENABLE_WEBRTC='1' -DENABLE_CONFIGURATION_POLICY -DENABLE_INPUT_SPEECH -DENABLE_NOTIFICATIONS -DENABLE_GPU='1' -DENABLE_EGLIMAGE='1' -DUSE_SKIA='1' -DENABLE_TASK_MANAGER='1' -DENABLE_WEB_INTENTS='1' -DENABLE_EXTENSIONS='1' -DENABLE_PLUGIN_INSTALLATION='1' -DENABLE_PROTECTOR_SERVICE='1' -DENABLE_SESSION_SERVICE='1' -DENABLE_THEMES='1' -DENABLE_BACKGROUND='1' -DENABLE_AUTOMATION='1' -DENABLE_PRINTING='1' -DENABLE_CAPTIVE_PORTAL_DETECTION='1' -DWEBRTC_MOZILLA_BUILD -DWEBRTC_MODULE_UTILITY_VIDEO -DWEBRTC_LINUX -DUSE_X11 -D__STDC_FORMAT_MACROS -DDYNAMIC_ANNOTATIONS_ENABLED='1' -DWTF_USE_DYNAMIC_ANNOTATIONS='1' -D_DEBUG -DMOZ_GLUE_IN_PROGRAM -DMOZILLA_INTERNAL_API -DIMPL_LIBXUL  -DSTATIC_EXPORTABLE_JS_API -DNO_NSPR_10_SUPPORT -I. -I/home/morbo/hg/mozilla-inbound/media/webrtc/trunk/webrtc/modules/../.. -I/home/morbo/hg/mozilla-inbound/media/webrtc/trunk/webrtc/modules/../.. -I/home/morbo/hg/mozilla-inbound/media/webrtc/trunk/webrtc/modules/../system_wrappers/interface -I/home/morbo/hg/mozilla-inbound/ipc/chromium/src -I/home/morbo/hg/mozilla-inbound/ipc/glue -I../../../../../../ipc/ipdl/_ipdlheaders  -I../../../../../../dist/include

morbo@tahrbox:~/hg/mozilla-inbound$ find -name system_wrappers
./media/webrtc/trunk/webrtc/system_wrappers
./objdir-desktop/config/system_wrappers
./objdir-desktop/dist/system_wrappers
./objdir-desktop/media/webrtc/trunk/webrtc/system_wrappers

Comment 6

[Gian-Carlo Pascutto [:gcp]]

dist/system_wrappers is just a symlink to config/system_wrappers so that isn't the issue.

Comment 7

[Gian-Carlo Pascutto [:gcp]]

Attachment: Patch 1. Fix non-unified build issue with screensharing

Problems were caused by ccache, patch should work.

Comment 8

[Gian-Carlo Pascutto [:gcp]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d77d27828c76

Comment 9

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/d77d27828c76