Trying to build with -fwasm-exceptions is failed with an error about undefined __cxa_find_matching_catch_2

[aharondavid]

emcc 3.1.55.
Windows 11.

Trying to build with -fwasm-exceptions is failed with the following error:
error : undefined symbol: __cxa_find_matching_catch_2 (referenced by root reference (e.g. compiled C/C++ code))

Setting the -fwasm-exceptions is follow by the next steps:

1. My project is built by one static wasm file that linking with several libs.
2. first, I set the flag -fwasm-exceptions to all my source\lib in my project.
3. verify that there is no additional used in -fno-exceptions`` -fyes-exceptions
4. linking with -fwasm-exceptions

result:
get linking error:
error : undefined symbol: __cxa_find_matching_catch_2 (referenced by root reference (e.g. compiled C/C++ code))

The build command:

emcc.bat Emscripten/Debug/TEApiWrapper81_for_emscripten.o Emscripten/Debug/Main.o --pre-js pre-js.js -ljpeg.Emscripten -lxml2 -lprjplg.Emscripten -lproj -lexpat -lgdal -lgeos -lgeos_c -l3ds.Emscripten -lTerraExplorerX.Emscripten -lCore.Emscripten -l7zip.Emscripten -lzip.Emscripten -llibzip.Emscripten -lgisplg.Emscripten -lMptDll.Emscripten -lOpenGL.Emscripten -lPlgShell.Emscripten -lSLLogger.Emscripten -lSLLoggerLib.Emscripten -lSLStrings.Emscripten -lTerraCommon.Emscripten -lTerra.Emscripten -lTESWQ.Emscripten -lWFSPlugin.Emscripten -lOGRPlugin.Emscripten -lsl_png.Emscripten -ldraco.Emscripten -lOpenCTM.Emscripten -lwebp.Emscripten -lMPTPlg.Emscripten -lOGRSpatialReference244.Emscripten -s ALLOW_TABLE_GROWTH -s WASM_BIGINT -s EXPORTED_RUNTIME_METHODS=ccall,cwrap,addFunction,allocateUTF8 -s EXPORTED_FUNCTIONS=_main --bind -s USE_PTHREADS -s ALLOW_MEMORY_GROWTH=1 -s ASSERTIONS -s FETCH -s TEXTDECODER=0 -lidbfs.js -s PTHREAD_POOL_SIZE=GetThreadPoolSize() -s REVERSE_DEPS=all -s STACK_SIZE=5mb -s DEFAULT_PTHREAD_STACK_SIZE=5mb -s ALLOW_BLOCKING_ON_MAIN_THREAD=1 -s PTHREAD_POOL_SIZE_STRICT=2 -fwasm-exceptions -O0 --preload-file com.skyline.terraexplorer -o C:/Projects/TerraExplorer_v8_0_0_Dev/SLSource/Emscripten/Debug/TEF/TerraExplorerApp.Emscripten.js -LC:/Projects/TerraExplorer_v8_0_0_Dev/SLSource/Emscripten/Debug/ -LC:/Projects/TerraExplorer_v8_0_0_Dev/SLSource/Emscripten/TerraExplorerApp.Emscripten/libs

The output result:

undefined symbol: __cxa_find_matching_catch_2 (referenced by root reference (e.g. compiled C/C++ code))
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: ___cxa_find_matching_catch_2 may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: __cxa_find_matching_catch_3 (referenced by root reference (e.g. compiled C/C++ code))
warning: ___cxa_find_matching_catch_3 may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: __cxa_find_matching_catch_4 (referenced by root reference (e.g. compiled C/C++ code))
warning: ___cxa_find_matching_catch_4 may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: __resumeException (referenced by root reference (e.g. compiled C/C++ code))
warning: ___resumeException may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
error: undefined symbol: llvm_eh_typeid_for (referenced by root reference (e.g. compiled C/C++ code))
warning: _llvm_eh_typeid_for may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
warning: JS library symbol '$allocateUTF8' is deprecated. Please open a bug if you have a continuing need for this symbol [-Wdeprecated]

The attach full_log.csv file is contain the output build after turning on the EMCC_DEBUG:
full_log.csv

[sbc100]

__cxa_find_matching_catch_NN symbols come from object file that were built without -fwasm-exceptions. Can you do a clean build and be sure to build all of your object files and libraries with that flag?

You may be able to add -Wl,--trace-symbol=__cxa_find_matching_catch_2 to your link flags to find out exactly which object file references that symbol.

[aharondavid]

You right - there was one thread party lib that built with emconfigure but without the -fwasm-exceptions.

Thanks!