Stream: git-wasmtime

Topic: wasmtime / PR #9941 Replace `signals-based-traps` with au...

Wasmtime GitHub notifications bot (Jan 07 2025 at 19:16):

alexcrichton opened PR #9941 from alexcrichton:rejigger-features to bytecodealliance:main:

This commit refactors the platform support of the wasmtime crate itself to remove the previously added signals-based-traps feature in favor of auto-detecting whether it's there or not. The build.rs script for the wasmtime crate will now detect the target platform and auto-enable this feature as necessary.

The signals-based-traps cargo feature is removed and split into two custom #[cfg] directives that the build script sets:

• has_virtual_memory - this is used to gate mmap implementations for example. This is enabled on unix || windows and will be off for no_std targets for example. This is split out of "signals-based-traps" to better handle platforms like iOS which have virtual memory but don't execute native code (removing the need for native signals).

• has_native_signals - gates signal handlers on Unix for example. This is disabled on MIRI but otherwise enabled for unix || windows. This is intended to in the future get disabled for iOS by default for example since it's not necessary when using Pulley. This is additionally off-by-default for no_std platforms.

Two new crate features were added for no_std or "custom" platforms to opt-in to the wasmtime-platform.h C APIs for implementing virtual memory and signals. These are used in the min-platform embedding example.

This commit additionally updates some various documentation here and there to be more up-to-date.

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Wasmtime GitHub notifications bot (Jan 07 2025 at 19:16):

alexcrichton requested fitzgen for a review on PR #9941.

Wasmtime GitHub notifications bot (Jan 07 2025 at 19:16):

alexcrichton requested wasmtime-fuzz-reviewers for a review on PR #9941.

Wasmtime GitHub notifications bot (Jan 07 2025 at 19:16):

alexcrichton requested wasmtime-core-reviewers for a review on PR #9941.

Wasmtime GitHub notifications bot (Jan 07 2025 at 19:16):

alexcrichton requested wasmtime-default-reviewers for a review on PR #9941.

Wasmtime GitHub notifications bot (Jan 07 2025 at 19:17):

alexcrichton commented on PR #9941:

One of the rough high-level goals here is that in conjunction with https://github.com/bytecodealliance/wasmtime/pull/9837 I hope to disable has_native_signals on Pulley-only platforms in the near future to statically remove all that code. That should make Wasmtime more portable by default since when there's no Cranelift backend there's no need to install signal handlers which often has lots of platform/architecture-specific implications.

Wasmtime GitHub notifications bot (Jan 07 2025 at 20:08):

alexcrichton updated PR #9941.

Wasmtime GitHub notifications bot (Jan 07 2025 at 21:44):

github-actions[bot] commented on PR #9941:

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Wasmtime GitHub notifications bot (Jan 07 2025 at 22:44):

github-actions[bot] commented on PR #9941:

Label Messager: wasmtime:config

It looks like you are changing Wasmtime's configuration options. Make sure to
complete this check list:

• [ ] If you added a new Config method, you wrote extensive documentation for
  it.

  <details>

  Our documentation should be of the following form:

  ```text
  Short, simple summary sentence.

  More details. These details can be multiple paragraphs. There should be
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• [ ] If you added a new Config method, or modified an existing one, you
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  For example, if you expose a new strategy for allocating the next instance
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  Often, all that is required of you is to ensure that there is a knob for this
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• [ ] If you are enabling a configuration option by default, make sure that it
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Wasmtime GitHub notifications bot (Jan 08 2025 at 08:40):

bjorn3 submitted PR review.

Wasmtime GitHub notifications bot (Jan 08 2025 at 08:40):

bjorn3 created PR review comment:

wasm32-unknown-emscripten is marked as unix, but has neither signals, nor virtual memory. I guess it is not all too important that Wasmtime works on Emscripten though.

Wasmtime GitHub notifications bot (Jan 08 2025 at 15:49):

alexcrichton created PR review comment:

That's a good point yeah, although this unix || windows logic matches what's currently in the sys module so we technically already didn't support Emscripten. It should be reasonable though to add support here though in the future.

Wasmtime GitHub notifications bot (Jan 08 2025 at 15:49):

alexcrichton submitted PR review.

Wasmtime GitHub notifications bot (Jan 14 2025 at 20:10):

fitzgen submitted PR review:

LGTM! I'm glad that this leaves the ability to turn off signals usage at engine config-time, even if the target supports it, as I think that is a use case we need to support.

Wasmtime GitHub notifications bot (Jan 14 2025 at 20:56):

alexcrichton updated PR #9941.

Wasmtime GitHub notifications bot (Jan 14 2025 at 20:57):

alexcrichton has enabled auto merge for PR #9941.

Wasmtime GitHub notifications bot (Jan 14 2025 at 23:22):

alexcrichton updated PR #9941.

Wasmtime GitHub notifications bot (Jan 14 2025 at 23:22):

alexcrichton has enabled auto merge for PR #9941.

Wasmtime GitHub notifications bot (Jan 15 2025 at 00:15):

alexcrichton updated PR #9941.

Wasmtime GitHub notifications bot (Jan 15 2025 at 00:16):

alexcrichton has enabled auto merge for PR #9941.

Wasmtime GitHub notifications bot (Jan 15 2025 at 00:23):

alexcrichton updated PR #9941.

Wasmtime GitHub notifications bot (Jan 15 2025 at 00:55):

alexcrichton updated PR #9941.

Wasmtime GitHub notifications bot (Jan 15 2025 at 00:55):

alexcrichton has enabled auto merge for PR #9941.

Wasmtime GitHub notifications bot (Jan 15 2025 at 01:35):

alexcrichton merged PR #9941.

Last updated: Jan 24 2025 at 00:11 UTC