longjmp(..., 0) seems broken

[yamt]

longjmp(..., 0) seems broken.
a simplest fix would be something like yamt/garbage@3926373

Version of emscripten/emsdk:
installed with homebrew:

emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.50-git
clang version 18.0.0
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin

Failing command line in full:

1. modify https://github.com/yamt/garbage/blob/74c397a5edd9d2bd69138d904464fc7e3f0a7291/wasm/longjmp/a.c#L166 to unskip the test
2. run test_emcc.sh in the same directory

Full link command and output with -v appended:

 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/clang -target wasm32-unknown-emscripten -fignore-exceptions -fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -wasm-enable-sjlj -mllvm -disable-lsr --sysroot=/usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot -DEMSCRIPTEN -Werror=implicit-function-declaration -Xclang -iwithsysroot/include/fakesdl -Xclang -iwithsysroot/include/compat -v -Os a.c -c -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a_0.o
clang version 18.0.0
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin
 (in-process)
 "/usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/clang-18" -cc1 -triple wasm32-unknown-emscripten -emit-obj -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name a.c -mrelocation-model static -mframe-pointer=none -ffp-contract=on -fno-rounding-math -mconstructor-aliases -target-feature +exception-handling -exception-model=wasm -target-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/Users/yamamoto/git/garbage/wasm/longjmp -target-linker-version 820.1 -v -fcoverage-compilation-dir=/Users/yamamoto/git/garbage/wasm/longjmp -resource-dir /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/lib/clang/18 -D EMSCRIPTEN -isysroot /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot -internal-isystem /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/lib/clang/18/include -internal-isystem /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/wasm32-emscripten -internal-isystem /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include -Os -Werror=implicit-function-declaration -ferror-limit 19 -fvisibility=default -fgnuc-version=4.2.1 -fignore-exceptions -fcolor-diagnostics -vectorize-loops -vectorize-slp -iwithsysroot/include/fakesdl -iwithsysroot/include/compat -mllvm -combiner-global-alias-analysis=false -mllvm -wasm-enable-sjlj -mllvm -disable-lsr -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a_0.o -x c a.c
clang -cc1 version 18.0.0 based upon LLVM 18.0.0git default target x86_64-apple-darwin21.6.0
ignoring nonexistent directory "/usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/wasm32-emscripten"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/fakesdl
 /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/compat
 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/lib/clang/18/include
 /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include
End of search list.
 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/clang -target wasm32-unknown-emscripten -fignore-exceptions -fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -wasm-enable-sjlj -mllvm -disable-lsr --sysroot=/usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot -DEMSCRIPTEN -Werror=implicit-function-declaration -Xclang -iwithsysroot/include/fakesdl -Xclang -iwithsysroot/include/compat -v -Os lib.c -c -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/lib_1.o
clang version 18.0.0
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin
 (in-process)
 "/usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/clang-18" -cc1 -triple wasm32-unknown-emscripten -emit-obj -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name lib.c -mrelocation-model static -mframe-pointer=none -ffp-contract=on -fno-rounding-math -mconstructor-aliases -target-feature +exception-handling -exception-model=wasm -target-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/Users/yamamoto/git/garbage/wasm/longjmp -target-linker-version 820.1 -v -fcoverage-compilation-dir=/Users/yamamoto/git/garbage/wasm/longjmp -resource-dir /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/lib/clang/18 -D EMSCRIPTEN -isysroot /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot -internal-isystem /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/lib/clang/18/include -internal-isystem /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/wasm32-emscripten -internal-isystem /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include -Os -Werror=implicit-function-declaration -ferror-limit 19 -fvisibility=default -fgnuc-version=4.2.1 -fignore-exceptions -fcolor-diagnostics -vectorize-loops -vectorize-slp -iwithsysroot/include/fakesdl -iwithsysroot/include/compat -mllvm -combiner-global-alias-analysis=false -mllvm -wasm-enable-sjlj -mllvm -disable-lsr -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/lib_1.o -x c lib.c
clang -cc1 version 18.0.0 based upon LLVM 18.0.0git default target x86_64-apple-darwin21.6.0
ignoring nonexistent directory "/usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/wasm32-emscripten"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/fakesdl
 /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include/compat
 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/lib/clang/18/include
 /usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/include
End of search list.
 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/clang --version
 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/wasm-ld -o a.out.wasm /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a_0.o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/lib_1.o -L/usr/local/Cellar/emscripten/3.1.50/libexec/cache/sysroot/lib/wasm32-emscripten -lGL -lal -lhtml5 -lstubs -lnoexit -lc -ldlmalloc -lcompiler_rt-wasm-sjlj -lc++-noexcept -lc++abi-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -wasm-enable-sjlj -mllvm -disable-lsr -mllvm -exception-model=wasm /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/tmpv8io9b3_libemscripten_js_symbols.so --strip-debug --export-if-defined=main --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=__main_argc_argv --export=stackSave --export=stackRestore --export=stackAlloc --export=__errno_location --export=__get_temp_ret --export=__set_temp_ret --export=__wasm_call_ctors --export-table -z stack-size=65536 --initial-memory=16777216 --max-memory=16777216 --no-entry --table-base=1 --global-base=1024
 /usr/local/Cellar/emscripten/3.1.50/libexec/llvm/bin/llvm-objcopy a.out.wasm a.out.wasm --remove-section=.debug* --remove-section=producers
 /usr/local/Cellar/emscripten/3.1.50/libexec/binaryen/bin/wasm-emscripten-finalize --dyncalls-i64 --pass-arg=legalize-js-interface-exported-helpers a.out.wasm -o a.out.wasm --detect-features
 /usr/local/opt/node/bin/node /usr/local/Cellar/emscripten/3.1.50/libexec/src/compiler.js /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/tmpoo2qqlln.json
 /usr/local/Cellar/emscripten/3.1.50/libexec/binaryen/bin/wasm-opt --strip-target-features --post-emscripten -Os --low-memory-unused --zero-filled-memory --pass-arg=directize-initial-contents-immutable a.out.wasm -o a.out.wasm --mvp-features --enable-exception-handling --enable-mutable-globals --enable-sign-ext
 /usr/local/opt/node/bin/node /usr/local/Cellar/emscripten/3.1.50/libexec/tools/acorn-optimizer.js /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a.out.js AJSDCE minifyWhitespace -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a.out.jso1.js
 /usr/local/opt/node/bin/node /usr/local/Cellar/emscripten/3.1.50/libexec/tools/acorn-optimizer.js /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emcc_acorn_info_it1x5l_l.js emitDCEGraph noPrint
 /usr/local/Cellar/emscripten/3.1.50/libexec/binaryen/bin/wasm-metadce --graph-file=/var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emcc_dce_graph_45y1axkk.json a.out.wasm -o a.out.wasm --mvp-features --enable-exception-handling --enable-mutable-globals --enable-sign-ext
 /usr/local/opt/node/bin/node /usr/local/Cellar/emscripten/3.1.50/libexec/tools/acorn-optimizer.js /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emcc_acorn_info_yf68h4x9.js applyDCEGraphRemovals minifyWhitespace -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a.out.jso2.js
 /usr/local/opt/node/bin/node /usr/local/Cellar/emscripten/3.1.50/libexec/tools/acorn-optimizer.js /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a.out.jso2.js AJSDCE minifyWhitespace -o /var/folders/74/hw1sphgx0lv63q6pq_n5grw00000gn/T/emscripten_temp_0i7uh0s_/a.out.jso3.js
 /usr/local/Cellar/emscripten/3.1.50/libexec/binaryen/bin/wasm-opt --minify-imports-and-exports-and-modules a.out.wasm -o a.out.wasm --mvp-features --enable-exception-handling --enable-mutable-globals --enable-sign-ext

[kripken]

In the testcase I see you use dynamic linking, is this bug limited to there then? If so we should add it to the title.

[sbc100]

Seems like a reasonable patch. I suppose we would apply it to __wasm_longjmp in system/lib/compiler-rt/emscripten_setjmp.c?

[yamt]

In the testcase I see you use dynamic linking, is this bug limited to there then? If so we should add it to the title.

the problem is not specific to dynamic linking.
the test script happens to test both static and dynamic link for other reasons.

[yamt]

I suppose we would apply it to __wasm_longjmp in system/lib/compiler-rt/emscripten_setjmp.c?

i think so, yes.