691053 - nsGNOMEShellService include declaration of class gfxUnknownSurface but it is not linker with implementation

Status: RESOLVED INVALID

(Firefox :: General, defect)

Description

[Jan Hubicka]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0) Gecko/20100101 Firefox/7.0
Build ID: 2011092200

Steps to reproduce:

Built Mozilla trunk with GCC LTO


Actual results:

/usr/bin/python2.6 /abuild/jh/mozilla-central2/mozilla-central/config/pythonpath.py -I../../../config /abuild/jh/mozilla-central2/mozilla-central/config/expandlibs_exec.py --uselist --  /abuild/jh/trunk-install/bin/g++ -flto=24 -fuse-linker-plugin -fno-fat-lto-objects  -fno-rtti -fno-exceptions -Wall -Wpointer-arith -Woverloaded-virtual -Wsynth -Wno-ctor-dtor-privacy -Wno-non-virtual-dtor -Wcast-align -Wno-invalid-offsetof -Wno-variadic-macros -Werror=return-type -pedantic -Wno-long-long -fno-strict-aliasing -std=gnu++0x -pthread -pipe  -DNDEBUG -DTRIMMED -O3 -fomit-frame-pointer -fPIC -shared -Wl,-z,defs -Wl,-h,libbrowsercomps.so -o libbrowsercomps.so  nsModule.o    -lpthread   -Wl,-rpath-link,/abuild/jh/build-mozilla-new14-gnu-ld/dist/bin -Wl,-rpath-link,/usr/local/lib   ../feeds/src/libbrowser_feeds_s.a ../privatebrowsing/src/libprivatebrowsing_s.a ../about/libbrowserabout_s.a ../dirprovider/libbrowserdir_s.a  ../shell/src/libshellservice_s.a ../migration/src/libmigration_s.a /abuild/jh/build-mozilla-new14-gnu-ld/dist/lib/libunicharutil_external_s.a /abuild/jh/build-mozilla-new14-gnu-ld/dist/lib/libmozreg_s.a /abuild/jh/build-mozilla-new14-gnu-ld/dist/lib/libxpcomglue_s.a -L/abuild/jh/build-mozilla-new14-gnu-ld/dist/bin -lxpcom -lmozalloc -lxul  -L/abuild/jh/build-mozilla-new14-gnu-ld/dist/bin -L/abuild/jh/build-mozilla-new14-gnu-ld/dist/lib -lplds4 -lplc4 -lnspr4 -lpthread -ldl  -lgtk-x11-2.0 -latk-1.0 -lgio-2.0 -lpangoft2-1.0 -lfreetype -lz -lfontconfig -lgdk-x11-2.0 -lgdk_pixbuf-2.0 -lpangocairo-1.0 -lpango-1.0 -lcairo -lgobject-2.0 -lgmodule-2.0 -lglib-2.0     -Wl,--version-script -Wl,/abuild/jh/mozilla-central2/mozilla-central/build/unix/gnu-ld-scripts/components-version-script -Wl,-Bsymbolic -ldl
/tmp/ccIn3nN7.ltrans10.ltrans.o:(.data.rel.ro._ZTV17gfxUnknownSurface[_ZTV17gfxUnknownSurface]+0x18): undefined reference to `gfxASurface::BeginPrinting(nsAString const&, nsAString const&)'
collect2: error: ld returned 1 exit status


The problem is that due to problems with Linker plugin API we are not able to optimize out the unused virtual destructor of the class. For this reason the class stays in and prevents Mozilla from linking.
I am working on fix at binutils/GCC side (it is a missed optimization), but it is not valid in C++ to do so.


Expected results:

It should've linked

Comment 1

[Jan Hubicka]

More detailed explanation why the symbol gets stuck in the library is here
http://sourceware.org/bugzilla/show_bug.cgi?id=13229
it is all bit fragile.

Honza

Comment 2

[Sylvestre Ledru [:Sylvestre]]

I don't think this is happening anymore