2.0.9 build hits "unexpected relocation type" in llvm

[rsielken]

We are currently building and running cleanly on 2.0.3. I am testing out 2.0.9 to see if we can move up to that version. The first part of that is making sure we can build and right now we cannot:

em++ -DEMSDK -DMOBILE -DOPENGL -DNO_DYNAMIC_LOADING -DNO_EM -g2 -s USE_PTHREADS=1 -s PROXY_TO_PTHREAD=1 -s PTHREAD_POOL_SIZE=8 -s FETCH=1 -s FETCH_SUPPORT_INDEXEDDB=0 -s FULL_ES2=1 -s USE_SDL=2 -s USE_SDL_TTF=2 -s USE_FREETYPE=2 -s USE_LIBPNG=1 -s DISABLE_EXCEPTION_CATCHING=0 -s INITIAL_MEMORY=268435456 -s ALLOW_MEMORY_GROWTH=1 -s FORCE_FILESYSTEM=1 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s OFFSCREEN_FRAMEBUFFER=1 -s DEMANGLE_SUPPORT=1 -s ABORT_ON_WASM_EXCEPTIONS=1  -m32 -march=pentium3 -DGCC3 -DGCC4 -fno-strict-aliasing -DGCC_LBLB_NOT_SUPPORTED  -shared -fPIC   -Wl,--whole-archive -o /vhome/builder/sandboxes/notes/bin/wasm/bin/libnoteswasm.a  `build %1 @lib.libnoteswasm.wasm.tmp -d -s -t` -L/vhome/builder/sandboxes/notes/bin/wasm/bin -lcrypto -Wl,--no-whole-archive -L/system/lib -L/usr/local/lib -L/usr/lib -ldl -lrt -lm -L/vhome/builder/sandboxes/notes/bin/wasm/bin -lstdc++
Iris Macro Substitution Utility Version 2.02
Copyright (c) Iris Associates, Inc., 1984-2001.  All rights reserved.

em++: warning: linking a library with `-shared` will emit a static object file.  This is a form of emulation to support existing build systems.  If you want to build a runtime shared library use the SIDE_MODULE setting. [-Wemcc]
em++: warning: USE_PTHREADS + ALLOW_MEMORY_GROWTH may run non-wasm code slowly, see https://github.com/WebAssembly/design/issues/1271 [-Wpthreads-mem-growth]
em++: warning: ignoring dynamic library libcrypto.so because not compiling to JS or HTML, remember to link it when compiling to JS or HTML at the end [-Wemcc]
em++: warning: ignoring dynamic library libstdc++.so because not compiling to JS or HTML, remember to link it when compiling to JS or HTML at the end [-Wemcc]
unexpected relocation type
UNREACHABLE executed at /b/s/w/ir/cache/builder/emscripten-releases/llvm-project/lld/wasm/InputFiles.cpp:131!
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /local/emsdk/upstream/bin/wasm-ld -o /vhome/builder/sandboxes/notes/bin/wasm/bin/libnoteswasm.a --whole-archive -L/local/emsdk/upstream/emscripten/system/local/lib /vhome/builder/sandboxes/notes/bin/wasm/lib/nem.wasm.a -L/local/emsdk/upstream/emscripten/system/lib /vhome/builder/sandboxes/notes/bin/wasm/lib/mcmdtbls.wasm.o -L/local/emsdk/upstream/emscripten/cache/wasm /vhome/builder/sandboxes/notes/bin/wasm/lib/nem_wasm.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/desk.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/mailer.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/wmisc.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/view.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/actions.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/actpane.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xmlcommon.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/lside.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/lsxui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/wksrep.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/designui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ltssp30.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ltssm30.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/edit.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/assist.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xmlproc.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/schui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/bkmkui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/dxlo.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/irtf.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xrtf2.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/igif.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/hooks.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ibmp.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ijpeg.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ipcx.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/istrings.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/itiff.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/itext.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ihtml.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xical.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/dxli2.wasm.a -L/vhome/builder/sandboxes/notes/bin/wasm/bin --no-whole-archive -L/system/lib -L/usr/local/lib -L/usr/lib -L/vhome/builder/sandboxes/notes/bin/wasm/bin --relocatable -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-cxx-exceptions -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr 
 #0 0x00007fbecf562dd3 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x86bdd3)
 #1 0x00007fbecf560b2e llvm::sys::RunSignalHandlers() (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x869b2e)
 #2 0x00007fbecf563295 SignalHandler(int) (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x86c295)
 #3 0x00007fbed2e003c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x153c0)
 #4 0x00007fbece9e118b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4618b)
 #5 0x00007fbece9c0859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x25859)
 #6 0x00007fbecf4ad511 (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x7b6511)
 #7 0x000000000079292d lld::wasm::ObjFile::calcNewAddend(llvm::wasm::WasmRelocation const&) const (/local/emsdk/upstream/bin/wasm-ld+0x79292d)
 #8 0x000000000078fed9 lld::wasm::InputChunk::writeRelocations(llvm::raw_ostream&) const (/local/emsdk/upstream/bin/wasm-ld+0x78fed9)
 #9 0x00000000007c2c6c lld::wasm::CodeSection::writeRelocations(llvm::raw_ostream&) const (/local/emsdk/upstream/bin/wasm-ld+0x7c2c6c)
#10 0x00000000007ca099 lld::wasm::RelocSection::writeBody() (/local/emsdk/upstream/bin/wasm-ld+0x7ca099)
#11 0x00000000007b691a lld::wasm::SyntheticSection::finalizeContents() (/local/emsdk/upstream/bin/wasm-ld+0x7b691a)
#12 0x00000000007b0778 lld::wasm::(anonymous namespace)::Writer::run() (/local/emsdk/upstream/bin/wasm-ld+0x7b0778)
#13 0x00000000007a8941 lld::wasm::writeResult() (/local/emsdk/upstream/bin/wasm-ld+0x7a8941)
#14 0x000000000078b362 lld::wasm::(anonymous namespace)::LinkerDriver::link(llvm::ArrayRef<char const*>) (/local/emsdk/upstream/bin/wasm-ld+0x78b362)
#15 0x0000000000784b53 lld::wasm::link(llvm::ArrayRef<char const*>, bool, llvm::raw_ostream&, llvm::raw_ostream&) (/local/emsdk/upstream/bin/wasm-ld+0x784b53)
#16 0x000000000048ac1d lldMain(int, char const**, llvm::raw_ostream&, llvm::raw_ostream&, bool) (/local/emsdk/upstream/bin/wasm-ld+0x48ac1d)
#17 0x000000000048a740 main (/local/emsdk/upstream/bin/wasm-ld+0x48a740)
#18 0x00007fbece9c20b3 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b3)
#19 0x000000000048a41a _start (/local/emsdk/upstream/bin/wasm-ld+0x48a41a)
em++: error: '/local/emsdk/upstream/bin/wasm-ld -o /vhome/builder/sandboxes/notes/bin/wasm/bin/libnoteswasm.a --whole-archive -L/local/emsdk/upstream/emscripten/system/local/lib /vhome/builder/sandboxes/notes/bin/wasm/lib/nem.wasm.a -L/local/emsdk/upstream/emscripten/system/lib /vhome/builder/sandboxes/notes/bin/wasm/lib/mcmdtbls.wasm.o -L/local/emsdk/upstream/emscripten/cache/wasm /vhome/builder/sandboxes/notes/bin/wasm/lib/nem_wasm.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/desk.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/mailer.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/wmisc.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/view.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/actions.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/actpane.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xmlcommon.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/lside.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/lsxui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/wksrep.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/designui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ltssp30.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ltssm30.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/edit.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/assist.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xmlproc.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/schui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/bkmkui.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/dxlo.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/irtf.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xrtf2.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/igif.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/hooks.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ibmp.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ijpeg.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ipcx.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/istrings.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/itiff.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/itext.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/ihtml.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/xical.wasm.a /vhome/builder/sandboxes/notes/bin/wasm/lib/dxli2.wasm.a -L/vhome/builder/sandboxes/notes/bin/wasm/bin --no-whole-archive -L/system/lib -L/usr/local/lib -L/usr/lib -L/vhome/builder/sandboxes/notes/bin/wasm/bin --relocatable -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-cxx-exceptions -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr' failed (-6)

I went through this exercise once before with 2.0.5 and we built cleanly but then had runtime errors, so we decided to stay on 2.0.3 and see what would happen with a later update.

Is this something that has changed and needs to be addressed in the emscripten code or do I need to truly file a bug report with https://bugs.llvm.org/ directly?

[sbc100]

Its a shame that error doesn't tel use what the unexpected relocation type is.

Even though this is technically and upstream bug we can deal with it here I think since its a wasm-ld issue and I'm the maintainer of that. Is there any chance you attach a zip file containing a repro code (i.e. all the input files and shell script to try to link them (preferable directly with wasm-ld .. see the line that starts with 0. Program arguments: /local/emsdk/upstream/bin/wasm-ld ...)

On a side note are you sure you want to be using -shared here.. since emscirpten doesn't support shared libraries in the normal sense it advisable not use this flag but instead to use static library (.a archives).

[rsielken]

I stripped down the number of .a files included down to two, put everything in a single directory, and created test.sh to perform the step that was crashing.

builder@Sandbox:~/12934$ ./test.sh 

https://github.com/emscripten-core/emscripten/issues/12934

unexpected relocation type
UNREACHABLE executed at /b/s/w/ir/cache/builder/emscripten-releases/llvm-project/lld/wasm/InputFiles.cpp:131!
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /local/emsdk/upstream/bin/wasm-ld -o libnoteswasm.a --whole-archive nem.wasm.a nem_wasm.wasm.a --no-whole-archive --relocatable -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-cxx-exceptions -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr 
 #0 0x00007f56c20b4dd3 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x86bdd3)
 #1 0x00007f56c20b2b2e llvm::sys::RunSignalHandlers() (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x869b2e)
 #2 0x00007f56c20b5295 SignalHandler(int) (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x86c295)
 #3 0x00007f56c59523c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x153c0)
 #4 0x00007f56c153318b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4618b)
 #5 0x00007f56c1512859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x25859)
 #6 0x00007f56c1fff511 (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x7b6511)
 #7 0x000000000079292d lld::wasm::ObjFile::calcNewAddend(llvm::wasm::WasmRelocation const&) const (/local/emsdk/upstream/bin/wasm-ld+0x79292d)
 #8 0x000000000078fed9 lld::wasm::InputChunk::writeRelocations(llvm::raw_ostream&) const (/local/emsdk/upstream/bin/wasm-ld+0x78fed9)
 #9 0x00000000007c2c6c lld::wasm::CodeSection::writeRelocations(llvm::raw_ostream&) const (/local/emsdk/upstream/bin/wasm-ld+0x7c2c6c)
#10 0x00000000007ca099 lld::wasm::RelocSection::writeBody() (/local/emsdk/upstream/bin/wasm-ld+0x7ca099)
#11 0x00000000007b691a lld::wasm::SyntheticSection::finalizeContents() (/local/emsdk/upstream/bin/wasm-ld+0x7b691a)
#12 0x00000000007b0778 lld::wasm::(anonymous namespace)::Writer::run() (/local/emsdk/upstream/bin/wasm-ld+0x7b0778)
#13 0x00000000007a8941 lld::wasm::writeResult() (/local/emsdk/upstream/bin/wasm-ld+0x7a8941)
#14 0x000000000078b362 lld::wasm::(anonymous namespace)::LinkerDriver::link(llvm::ArrayRef<char const*>) (/local/emsdk/upstream/bin/wasm-ld+0x78b362)
#15 0x0000000000784b53 lld::wasm::link(llvm::ArrayRef<char const*>, bool, llvm::raw_ostream&, llvm::raw_ostream&) (/local/emsdk/upstream/bin/wasm-ld+0x784b53)
#16 0x000000000048ac1d lldMain(int, char const**, llvm::raw_ostream&, llvm::raw_ostream&, bool) (/local/emsdk/upstream/bin/wasm-ld+0x48ac1d)
#17 0x000000000048a740 main (/local/emsdk/upstream/bin/wasm-ld+0x48a740)
#18 0x00007f56c15140b3 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b3)
#19 0x000000000048a41a _start (/local/emsdk/upstream/bin/wasm-ld+0x48a41a)
./test.sh: line 14:  9325 Aborted                 (core dumped) /local/emsdk/upstream/bin/wasm-ld -o libnoteswasm.a --whole-archive nem.wasm.a nem_wasm.wasm.a --no-whole-archive --relocatable -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-cxx-exceptions -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr

Here is the zip file with the file including the core from the run shown above:
12934-20201201.zip

Let me know if you need anything else to help here.

Your comment on -shared is noted.

[rsielken]

Any luck in fixing/avoiding this? Any additional information needed or workaround that we can use? I'd like to upgrade our EMSDK version for other fixes but can't if we can't build.

[mbelew]

I'm also seeing this issue. When we build one of our third party libraries - https://www.cryptopp.com/release820.html
Download and unzip cryptopp820.zip. Then use this make command:

emmake make CXXFLAGS="-s ERROR_ON_UNDEFINED_SYMBOLS=1 -s USE_PTHREADS=1 -s FETCH=1 -s DISABLE_EXCEPTION_CATCHING=0 -std=c++14 -O2 -fPIC" dynamic

The issue starts at 2.0.9, but 2.0.8 is ok.

This output is from trying a 2.0.10 build:
out.txt

[mbelew]

Incidentally, I noticed this libpthread.so in the stack trace:

0x00007f56c20b5295 SignalHandler(int) (/local/emsdk/upstream/bin/../lib/libLLVM-12git.so+0x86c295)
#3 0x00007f56c59523c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x153c0)

I experimented with changing CXXFLAGS, removing USE_PTHREADS=1. The library now compiles without the crash. So something is amiss with linking pthreads.

Our primary app uses threads extensively, so this is a big blocker that's keeping us from upgrading and using the new debug features.

[sbc100]

Fix is in https://reviews.llvm.org/D93554

[rsielken]

I had hoped this would have been included in 2.0.12 (although I knew this issue was still open and not closed), but I pulled 2.0.12, did a build, and see the same error.

https://emscripten.org/docs/introducing_emscripten/release_notes.html listed
An upstream LLVM regression with global initializer linking has been fixed (#13038).
for 2.0.11, so I hoped that had included https://reviews.llvm.org/D93554 too.

But, it doesn't look like https://reviews.llvm.org/D93554 has made it into EMSDK yet. Is there any target on when that will be picked up? Is there some way to patch 2.0.12 to pick up that fix?

[sbc100]

I'm afraid https://reviews.llvm.org/D93554 has not yet landed in LLVM

[sbc100]

This is now landed. The change will be in 2.0.13, or "tot" in a few hours.