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by gwbas1c 1539 days ago
At least in in-browser Blazor (C# compiled to WASM) I have full access to the page's Javascript environment: I can call most Javascript methods available, and I can even call eval.

I'm still new to WASM, but I assume this functionality is part of the WASM runtime? (As opposed to a hook that's part of the Javascript part of Blazor?)
1 comments
jitl 1539 days ago
You are assuming wrong, this is Blazor’s JS support library. By “default” WebAssembly has nothing outside the WASM bytecode, not even memory/allocator. It’s up to the host environment to provide the WASM module a Memory and whatever “imports” it needs.
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klibertp 1539 days ago
Memory can also be statically reserved in a binary, like the .data section in x86 asm. IIRC (tell me if I'm very wrong) Emscripten malloc works by reserving a large buffer up front and then managing pointers to (parts of) it. Otherwise, you can allocate memory buffer dynamically from JS[1] and pass the pointer to it to the WASM. Obviously, you can do this in response to the request coming from WASM, but you don't have to.

[1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

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