Stream: git-wasmtime

Topic: wasmtime / PR #3206 Add a cranelift compile-time feature ...

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:37):

alexcrichton opened PR #3206 from refactor-compiler to main:

This commit concludes the saga of refactoring Wasmtime and making
Cranelift an optional dependency by adding a new Cargo feature to the
wasmtime crate called cranelift, which is enabled by default.

This feature is implemented by having a new cfg for wasmtime itself,
cfg(compiler), which is used wherever compilation is necessary. This
bubbles up to disable APIs such as Module::new, Func::new,
Engine::precompile_module, and a number of Config methods affecting
compiler configuration. Checks are added to CI that when built in this
mode Wasmtime continues to successfully build. It's hoped that although
this is effectively "sprinkle #[cfg] until things compile" this won't
be too too bad to maintain over time since it's also an use case we're
interested in supporting.

With cranelift disabled the only way to create a Module is with the
Module::deserialize method, which requires some form of precompiled
artifact.

Two consequences of this change are:

• Module::serialize is also disabled in this mode. The reason for this
  is that serialized modules contain ISA/shared flags encoded in them
  which were used to produce the compiled code. There's no storage for
  this if compilation is disabled. This could probably be re-enabled in
  the future if necessary, but it may not end up being all that necessary.

• Deserialized modules are not checked to ensure that their ISA/shared
  flags are compatible with the host CPU. This is actually already the
  case, though, with normal modules. We'll likely want to fix this in
  the future using a shared implementation for both these locations.

Documentation should be updated to indicate that cranelift can be
disabled, although it's not really the most prominent documentation
because this is expected to be a somewhat niche use case (albeit
important, just not too common).

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:37):

alexcrichton requested pchickey for a review on PR #3206.

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:45):

alexcrichton updated PR #3206 from refactor-compiler to main.

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:45):

alexcrichton updated PR #3206 from refactor-compiler to main.

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:46):

bjorn3 created PR review comment:

cranelift is enabled by default so this is equivalent to not passin --feature

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:46):

bjorn3 submitted PR review.

Wasmtime GitHub notifications bot (Aug 18 2021 at 19:46):

bjorn3 edited PR review comment.

Wasmtime GitHub notifications bot (Aug 18 2021 at 21:11):

pchickey submitted PR review.

Wasmtime GitHub notifications bot (Aug 18 2021 at 21:15):

alexcrichton updated PR #3206 from refactor-compiler to main.

Wasmtime GitHub notifications bot (Aug 18 2021 at 21:47):

alexcrichton merged PR #3206.

Last updated: Dec 23 2024 at 13:07 UTC