Mario (Jun 15 2022 at 15:46): Mario (Jun 15 2022 at 15:46):Hi,
It seems I can use wasmtime to embed wat into Rust/C. If I wanted to compile this code with the embedded wat into wasm, would there be an overhead in the wasm module?
Mario (Jun 15 2022 at 15:47):Referring to this section in the docs: https://docs.wasmtime.dev/examples-rust-hello-world.html
I would like to compile the hello.rs file into a wasm module, could not find any compiletime strategies so now looking at a way to do it at runtime
Alex Crichton (Jun 15 2022 at 16:06):Sorry when you say "embed wat" do you meant embedding a translation from the text format of WebAssembly to the binary format? Or do you mean embedding a wasm engine in general?
Mario (Jun 15 2022 at 16:07):The former; to embed wat so that its inlined in the final wasm binary. I was not able to see a way to do it like inline_asm!, so I started looking at wasmtime... It may not be the correct strategy, please let me know
Alex Crichton (Jun 15 2022 at 16:18):Wasmtime in general cannot be compiled to WebAssembly itself, and in general I don't think there's any way to embed *.wat text syntax into a wasm binary and run it at runtime of the wasm binary itself, or at least not a portable way of doing so.
Mario (Jun 15 2022 at 16:21):So the only solution is to either write all of your code in a high level language or write all of your code in wat, given that you want the final output to be a wasm binary?
Alex Crichton (Jun 15 2022 at 16:25):I think LLVM has a textual format for its object file format which you may be able to use, but I'm not personally aware of a great way of writing *.wat and linking it into a final wasm binary myself.
Mario (Jun 15 2022 at 16:29):Oh thanks for the pointer, I'll check out LLVM
Mario (Jun 15 2022 at 16:58):@Alex Crichton does this also apply to embedding wasm byte code too?
Alex Crichton (Jun 15 2022 at 16:58):to the best of my knowledge yeah, it's not easy to do. You basically need to craft an input to wasm-ld which I don't think is a trivial operation (in that I don't know of off-the-shelf methods to do that)
Mario (Jun 15 2022 at 17:05):Ah I see, okay I’ll look into doing it first and then trying to package it so that others can use it
Last updated: Dec 23 2024 at 13:07 UTC