[wasm] wasm-ld: error: unknown file type: libFoo.bc

[emepetres]

Hi, I'm trying to statically link a .bc library (compiled with emcc) using packager.exe, but ninja last step is failing with wasm-ld: error: unknown file type: libFoo.bc. This used to work in previous versions of mono.

If I use the extension ".a", the error slightly change to emcc: error: libFoo.a: Unknown format, not a static library!

Steps to Reproduce

1. emcc foo.c -std=c++17 -s LEGALIZE_JS_FFI=0 -r -o $CDIR/libFoo.bc -s WASM=1 -s DISABLE_EXCEPTION_CATCHING=0
2. mono $HOME/mono/sdks/wasm/packager.exe --emscripten-sdkdir=$HOME/mono/sdks/builds/toolchains/emsdk --enable-fs --mono-sdkdir=$HOME/mono/sdks/out --appdir=$HOME/.build/bin --builddir=$HOME/.build/obj --template=$HOME/.build/publish/runtime.js --debug --debugrt --linker --link-descriptor=$HOME/.build/link-descriptor.xml --pinvoke-libs=libFoo --native-lib=libFoo.bc HelloFoo.dll

Current Behavior

Ninja build fails on last step

[92/92] bash -c 'source ./emsdk_env.sh && emcc -Oz -g -s USE_ZLIB=1 -s FORCE_FILESYSTEM=1 -s ASSERTIONS=1 -s DISABLE_EXCEPTION_CATCHING=0 -s ALLOW_MEMORY_GROWTH=1 -s TOTAL_MEMORY=134217728 -s NO_EXIT_RUNTIME=1 -s ERROR_ON_UNDEFINED_SYMBOLS=1 -s "EXTRA_EXPORTED_RUNTIME_METHODS=['ccall', 'cwrap', 'setValue', 'getValue', 'UTF8ToString']" -s "EXPORTED_FUNCTIONS=['___cxa_is_pointer_type', '___cxa_can_catch']" -s "DEFAULT_LIBRARY_FUNCS_TO_INCLUDE=['setThrew', 'memset']" -O0  -o /home/jcarnero/.build/bin/dotnet.js --js-library /home/jcarnero/mono/sdks/wasm/src/library_mono.js --js-library /home/jcarnero/mono/sdks/wasm/src/dotnet_support.js --js-library /home/jcarnero/mono/sdks/wasm/src/binding_support.js driver.o pinvoke.o zlib-helper.o corebindings.o libFoo.bc /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-ee-interp.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-ilgen.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-icall-table.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmonosgen-2.0.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-native.a'  && /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/bin/wasm-opt --strip-dwarf /home/jcarnero/.build/bin/dotnet.wasm -o /home/jcarnero/.build/bin/dotnet.wasm
FAILED: /home/jcarnero/.build/bin/dotnet.js /home/jcarnero/.build/bin/dotnet.wasm 
bash -c 'source ./emsdk_env.sh && emcc -Oz -g -s USE_ZLIB=1 -s FORCE_FILESYSTEM=1 -s ASSERTIONS=1 -s DISABLE_EXCEPTION_CATCHING=0 -s ALLOW_MEMORY_GROWTH=1 -s TOTAL_MEMORY=134217728 -s NO_EXIT_RUNTIME=1 -s ERROR_ON_UNDEFINED_SYMBOLS=1 -s "EXTRA_EXPORTED_RUNTIME_METHODS=['ccall', 'cwrap', 'setValue', 'getValue', 'UTF8ToString']" -s "EXPORTED_FUNCTIONS=['___cxa_is_pointer_type', '___cxa_can_catch']" -s "DEFAULT_LIBRARY_FUNCS_TO_INCLUDE=['setThrew', 'memset']" -O0  -o /home/jcarnero/.build/bin/dotnet.js --js-library /home/jcarnero/mono/sdks/wasm/src/library_mono.js --js-library /home/jcarnero/mono/sdks/wasm/src/dotnet_support.js --js-library /home/jcarnero/mono/sdks/wasm/src/binding_support.js driver.o pinvoke.o zlib-helper.o corebindings.o libFoo.bc /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-ee-interp.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-ilgen.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-icall-table.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmonosgen-2.0.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-native.a'  && /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/bin/wasm-opt --strip-dwarf /home/jcarnero/.build/bin/dotnet.wasm -o /home/jcarnero/.build/bin/dotnet.wasm
wasm-ld: error: unknown file type: libFoo.bc
emcc: error: '/home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/bin/wasm-ld -o /tmp/emscripten_temp_t9pnbzm6/dotnet.wasm driver.o -L/home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/system/local/lib pinvoke.o -L/home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/system/lib zlib-helper.o -L/home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm corebindings.o libFoo.bc /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-ee-interp.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-ilgen.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-icall-table.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmonosgen-2.0.a /home/jcarnero/mono/sdks/out/wasm-runtime-release/lib/libmono-native.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libz.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libc.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libcompiler_rt.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libc++.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libc++abi.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libdlmalloc.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libpthread_stub.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libc_rt_wasm.a /home/jcarnero/mono/sdks/builds/toolchains/emsdk/upstream/emscripten/cache/wasm/libsockets.a -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-cxx-exceptions -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --allow-undefined --import-memory --import-table --export __cxa_is_pointer_type --export __cxa_can_catch --export malloc --export free --export stackSave --export stackRestore --export stackAlloc --export __data_end --export __wasm_call_ctors --export fflush --export __errno_location --export memalign --export memset --export htonl --export htons --export ntohs --export _ZSt18uncaught_exceptionv --export setThrew --export usleep --export _get_tzname --export _get_daylight --export _get_timezone --export emscripten_main_thread_process_queued_calls -z stack-size=5242880 --initial-memory=134217728 --no-entry --max-memory=2147483648 --global-base=1024' failed (1)
ninja: build stopped: subcommand failed.

Expected Behavior

ninja build ends sucessfully

On which platforms did you notice this

[ ] macOS
[x] Linux (WSL1)
[ ] Windows

Version Used:

commit 163f458 (HEAD -> master, origin/master, origin/HEAD)
Author: monojenkins jo.shields+jenkins@xamarin.com
Date: Wed Sep 16 11:24:16 2020 -0400

[emepetres]

Thanks to @vargaz on discord, I solved it downgrading emscripten to 1.40.0 under the mono sdk.

However, I feel that this downgrade should be automatically done at make -j -C sdks/wasm runtime, or at least documented on the wasm mono sdk readme.