Description

hoodmane

opened on Jun 28, 2023

Issue body actions

There is a WIP proposal to enable webassembly stack switching which have been implemented in v8.
https://github.com/WebAssembly/js-promise-integration
It is not possible to switch stacks that contain JS frames so the Emscripten JS trampolines that allow calling functions with the wrong number of arguments don't work in this case. However, the js-promise-integration proposal requires the type reflection for Wasm/JS API proposal, which allows us to actually count the number of arguments a function expects. I propose that for better compatibility with stack switching, we check if type reflection is available, and if so we use a switch block to decide the appropriate signature. If type reflection is unavailable, we should use the current EMJS trampoline.

I'm working on a patch for this.

Linked PRs

• gh-106213: Make Emscripten trampolines work with JSPI #106219
• gh-106213: Shorten Emscripten wasm-gc trampoline by a little #133984
• [3.14] gh-106213: Shorten Emscripten wasm-gc trampoline by a little (GH-133984) #134376

Activity

1. AlexWaygood

   added

   OS-wasi

   on Jun 28, 2023
2. brettcannon

   added a commit that references this issue on Sep 15, 2023

   gh-106213: Make Emscripten trampolines work with JSPI (GH-106219)

   6b179ad
3. csm10495

   added a commit that references this issue on Sep 28, 2023

   pythongh-106213: Make Emscripten trampolines work with JSPI (pythonGH…

   f9cabbf
4. brettcannon

   closed this as completedon Oct 19, 2023
5. hoodmane

   added a commit that references this issue on May 13, 2025

   pythongh-106213 Shorten Emscripten trampolines by a little

   de6ffa6
6. freakboy3742

   added a commit that references this issue on May 20, 2025

   gh-106213: Shorten Emscripten wasm-gc trampoline by a little (#133984)

   3b7888b
7. miss-islington

   added a commit that references this issue on May 20, 2025

   pythongh-106213: Shorten Emscripten wasm-gc trampoline by a little (p…

   f4a6798
8. freakboy3742

   added a commit that references this issue on May 20, 2025

   [3.14] gh-106213: Shorten Emscripten wasm-gc trampoline by a little (G…

   2d90cc8
9. lkollar

   added a commit that references this issue on May 26, 2025

   pythongh-106213: Shorten Emscripten wasm-gc trampoline by a little (p…

   b42ee0a
10. Pranjal095

    added a commit that references this issue on Jul 12, 2025

    pythongh-106213: Shorten Emscripten wasm-gc trampoline by a little (p…

    3537a59
11. taegyunkim

    added a commit that references this issue on Aug 4, 2025

    pythongh-106213: Shorten Emscripten wasm-gc trampoline by a little (p…

    273e67c

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