Viz.js: wasm-opt: Fatal: error in validating input

[Ghabry]

Emscripten version: 1.39.6

I try to compile this: https://github.com/mdaines/viz.js

Command executed:

make deps-full
make all

deps-full extracts a graphviz archive. You have to manually patch the configure file and get rid of "-ffast-math". (see #9955)

Attached module.wasm that fails to validate and a patch file to make it build against later emscripten versions:
module.zip

Build line:
/usr/bin/wasm-opt --post-emscripten --inline-main --no-exit-runtime -O2 --pass-arg=emscripten-sbrk-ptr@220832 module.wasm -o module.wasm --mvp-features --strip-dwarf

The validation output is gigantic (600000 lines), won't attach it, just run wasm-opt to see it.

The only hint I can give is that it validates when using "deps-lite". This builds Graphviz only with "dot" support. But I need neato and sfdp which is part of "deps-full" :/

[Ghabry]

wasm2wat gives a better error:

module.wasm:00627b2: error: type mismatch in call, expected [i32, i32, i32, i32, i32, i32, f64, i32, i32] but got [i32, i32, f64, i32, i32, i32, i32, i32, i32]
module.wasm:00627b5: error: type mismatch in block, expected [] but got [i32]
module.wasm:0062d8c: error: type mismatch in call, expected [i32, i32, i32, i32, i32, i32, f64, i32, i32] but got [i32, i32, f64, i32, i32, i32, i32, i32, i32]
module.wasm:0062da5: error: type mismatch in block, expected [] but got [i32]

[kripken]

I tried to build this but the second command fails,

$ make all
emcc --version | grep 1.39.6
emcc (Emscripten gcc/clang-like replacement) 1.39.6 (commit 9c48a508eacac4506e18cc27a27ac8bff405e025)
emcc -O2 --memory-init-file 0 -s ALLOW_MEMORY_GROWTH=1 -s USE_ZLIB=1 -s MODULARIZE=0 -s NO_DYNAMIC_EXECUTION=1 -s EXPORTED_FUNCTIONS="['_vizRenderFromString', '_vizCreateFile', '_vizSetY_invert', '_vizSetNop', '_vizLastErrorMessage', '_dtextract']" -s EXPORTED_RUNTIME_METHODS="['Pointer_stringify', 'ccall', 'UTF8ToString']" -o build-full/module.js src/viz.c -Iviz.js/prefix-full/include -Iviz.js/prefix-full/include/graphviz -Lviz.js/prefix-full/lib -Lviz.js/prefix-full/lib/graphviz -lgvplugin_core -lgvplugin_dot_layout -lgvplugin_neato_layout -lcdt -lcgraph -lgvc -lgvpr -lpathplan -lexpat -lxdot
src/viz.c:1:10: fatal error: 'gvc.h' file not found
#include <gvc.h>
         ^~~~~~~
1 error generated.
shared:ERROR: '/sdk/upstream/bin/clang -target wasm32-unknown-emscripten -D__EMSCRIPTEN_major__=1 -D__EMSCRIPTEN_minor__=39 -D__EMSCRIPTEN_tiny__=6 -D_LIBCPP_ABI_VERSION=2 -Dunix -D__unix -D__unix__ -Werror=implicit-function-declaration -Xclang -nostdsysteminc -Xclang -isystem/emscripten/system/include/libcxx -Xclang -isystem/emscripten/system/lib/libcxxabi/include -Xclang -isystem/emscripten/system/include/compat -Xclang -isystem/emscripten/system/include -Xclang -isystem/emscripten/system/include/libc -Xclang -isystem/emscripten/system/lib/libc/musl/arch/emscripten -Xclang -isystem/emscripten/system/local/include -Xclang -isystem/.emscripten_cache/wasm-obj/include -O2 -Iviz.js/prefix-full/include -Iviz.js/prefix-full/include/graphviz -DEMSCRIPTEN src/viz.c -Xclang -isystem/emscripten/system/include/SDL -c -o /tmp/emscripten_temp_eaNutw/viz_0.o -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr' failed (1)
make: *** [Makefile:54: build-full/module.js] Error 1

Please run the final link command it with EMCC_DEBUG=1 in the env. Then in /tmp/emscripten_temp/ you will have some emcc-* files, that should be enough to diagnose this. (If the very first one is bad, then it's a clang bug, otherwise it's binaryen's fault.)

[Ghabry]

emscripten_temp.zip

emcc-0-base.wasm already fails to validate, so guess I have to report this to https://bugs.llvm.org/ again?

EDIT: Replaced the zip with a "-g4" build. Maybe more useful as it has the function names.

[Ghabry]

An older emscripten (1.38.48) actually tells the concrete issue:
Maybe would be nice to have this error reporting back.

error: asm2wasm seeing an invalid argument type at index 5 (this will not validate) in call from $_multilevel_spring_electrical_embedding to $_remove_overlap (this is likely due to undefined behavior in C, like defining a function one way and calling it in another, which is important to fix)
error: asm2wasm seeing an invalid argument type at index 6 (this will not validate) in call from $_multilevel_spring_electrical_embedding to $_remove_overlap (this is likely due to undefined behavior in C, like defining a function one way and calling it in another, which is important to fix)
error: asm2wasm seeing an invalid argument type at index 5 (this will not validate) in call from $_multilevel_spring_electrical_embedding to $_remove_overlap (this is likely due to undefined behavior in C, like defining a function one way and calling it in another, which is important to fix)
error: asm2wasm seeing an invalid argument type at index 6 (this will not validate) in call from $_multilevel_spring_electrical_embedding to $_remove_overlap (this is likely due to undefined behavior in C, like defining a function one way and calling it in another, which is important to fix)

When libgts is missing the parameters for remove_overlap don't match with the header definition. So this sounds like a library bug, not a clang/binaryen bug.
After fixing this one the code validates...

[kripken]

Yes, this would be an llvm bug then, please file it there (and link to it here).

That old error reporting is from asm2wasm, while in the new backend the linker is lld which handles mismatches like that differently. @sbc100 does it not error or at least warn? (Or perhaps the data reaching the linker is very different if the newer clang/llvm emit something else, so might not be the linker specifically...)

[sbc100]

Certainly an llvm bug if the output of the compiler and linker doesn't validate.

[Ghabry]

Reported: https://bugs.llvm.org/show_bug.cgi?id=44769

[mischnic]

So this sounds like a library bug, not a clang/binaryen bug.

This is the configure test for drand48 ...

char drand48();
int main (){
	return drand48();
}

asm2wasm trace

Thread 1 Crashed:
0   libsystem_kernel.dylib        	0x00007fff65576b66 __pthread_kill + 10
1   libsystem_pthread.dylib       	0x00007fff65741080 pthread_kill + 333
2   libsystem_c.dylib             	0x00007fff654d21ae abort + 127
3   asm2wasm                      	0x0000000106e7613b wasm::handle_unreachable(char const*, char const*, unsigned int) + 203
4   asm2wasm                      	0x0000000106d29b20 unsigned int wasm::getMaxBits<wasm::LocalScanner>(wasm::Expression*, wasm::LocalScanner*) + 1045
5   asm2wasm                      	0x0000000106d295c1 wasm::LocalScanner::visitLocalSet(wasm::LocalSet*) + 129
6   asm2wasm                      	0x0000000106d27df8 wasm::Walker<wasm::LocalScanner, wasm::Visitor<wasm::LocalScanner, void> >::walk(wasm::Expression*&) + 132
7   asm2wasm                      	0x0000000106d27ace wasm::LocalScanner::doWalkFunction(wasm::Function*) + 184
8   asm2wasm                      	0x0000000106d279bd wasm::OptimizeInstructions::doWalkFunction(wasm::Function*) + 109
9   asm2wasm                      	0x0000000106d1e9ea wasm::WalkerPass<wasm::PostWalker<wasm::OptimizeInstructions, wasm::UnifiedExpressionVisitor<wasm::OptimizeInstructions, void> > >::runOnFunction(wasm::PassRunner*, wasm::Module*, wasm::Function*) + 38
10  asm2wasm                      	0x0000000106c5251d wasm::PassRunner::runPassOnFunction(wasm::Pass*, wasm::Function*) + 137
11  asm2wasm                      	0x0000000106c52458 wasm::PassRunner::runOnFunction(wasm::Function*) + 176
12  asm2wasm                      	0x0000000106c35295 wasm::OptimizingIncrementalModuleBuilder::optimizeFunction(wasm::Function*) + 273
13  asm2wasm                      	0x0000000106c34d6b wasm::OptimizingIncrementalModuleBuilder::workerMain(

[stale]

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