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Samsung / walrus

WebAssembly Lightweight RUntime
Apache License 2.0
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Implement emscripten compatibility #187

Closed kulcsaradam closed 7 months ago

kulcsaradam commented 8 months ago

Change runExports so that wasi imports can be used. Improve fd_write so that emscipten compiled programs can be used. Also add example programs.

kulcsaradam commented 8 months ago

This patch should enable to compile c programs which use stdout with emcc to run from walrus.

Emcc compile flags: --no-entry, -sEXPORTED_FUNCTIONS, -sEXPORTED_RUNTIME_METHODS and Walrus --run-export flag should be used.

-sEXPORTED_FUNCTIONS and at least one function ran by --run-export should be the same. See test/wasi/hello_world.c for example on how to compile and run.

clover2123 commented 8 months ago

I wonder that we need to add --run-export flag to run a c program compiled with emcc. Other WASM engines can just run the compiled wasm files without any options (--no-entry flag is not required either). I think that it is possible to directly start running the main function in c program using wasi. What do you think about this?

kulcsaradam commented 8 months ago

Both of you are right. After reading the documentation through more carefully I came up on this: https://github.com/WebAssembly/WASI/blob/main/legacy/application-abi.md By default environments should run the _start function if the user does not select any function to run.

I will be implementing this and then update the patch.

kulcsaradam commented 8 months ago

I have changed it so that executeWASM start a _start function by default.

I have also found out that by doing this, if wast files have a _start function they will be ran by the Shell and then we started to wonder if we should seperate the running of wast and wasm files somehow?

I looked at some other runtimes and for example, wasmer completely seperates the running and parsing of those two types of files by different methods. I can make an issue if you would like to move on with this.

Also I have updated wasi.cmake so that it doesnt spam messages when building on Windows.

kulcsaradam commented 7 months ago

Rebased to latest patch.

kulcsaradam commented 7 months ago

I found a bug that was accidentally left in. Fixed it before the pr is merged. Latest branch should be ready for merge.

kulcsaradam commented 7 months ago

Rebased to latest patch.