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Initial fixed-length list implementation#1277

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alexcrichton merged 19 commits into
bytecodealliance:mainfrom
cpetig:fixed_size_list
Jan 20, 2026
Merged

Initial fixed-length list implementation#1277
alexcrichton merged 19 commits into
bytecodealliance:mainfrom
cpetig:fixed_size_list

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@cpetig cpetig commented Apr 20, 2025

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See WebAssembly/component-model#384 for the commit which added fixed size lists to the component model standard documents.

alexcrichton
alexcrichton reviewed Apr 21, 2025
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Comment thread crates/core/src/abi.rs
@cpetig cpetig force-pushed the fixed_size_list branch from 0d3ff73 to 0e17f59 Compare May 7, 2025 21:09
@cpetig

cpetig commented Jul 13, 2025

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I have a newer version at https://github.com/cpetig/wit-bindgen/tree/work-in-progress which tests more in depth and also supports C++, I need to separate and clean up that one and then push it here for review.

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cpetig commented Jul 13, 2025

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Also this requires bytecodealliance/wasmtime#10619 , and a very recent version of wasm-component-ld for the tests to pass.

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cpetig commented Jan 11, 2026

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This is ready, but depends on bytecodealliance/wasmtime#10619 for successful tests.

@cpetig cpetig marked this pull request as ready for review January 11, 2026 21:01
@cpetig cpetig mentioned this pull request Jan 11, 2026
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alexcrichton
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Looks good to me!

Comment thread crates/test/src/runner.rs Outdated
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cpetig commented Jan 13, 2026 •
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This still has a limitation: The generated Rust and C++ code can't handle non-Copy/POD types. For Functional Safety this isn't an issue as you need to avoid putting string or list into a fixed size array anyway, resources might still make some sense.

I created #1501 to track this limitation.

@cpetig cpetig changed the title Initial fixed size list implementation Initial fixed-length list implementation Jan 13, 2026
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cpetig commented Jan 13, 2026

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TODO: Check for correct usage of "fixed-length" over "fixed-size"

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cpetig commented Jan 20, 2026 •
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I guess I should fix the naming in wasm-tools (fixed length list) before merging this MR (as it shouldn't be urgent), but on the other hand that merge will affect all of wit-bindgen languages anyway.

Second thought: The impact of the wasm-tools change will be identical (all code generators in wit-bindgen have to do a search and replace independently of whether this patch is merged or not). But it will create a conflict with this patch, so I guess it can be merged and then the other change can be discussed separately.

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cpetig commented Jan 20, 2026

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The (discussion of the) rename in wasm-tools happens in bytecodealliance/wasm-tools#2421

alexcrichton
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Let's go ahead and get this merged and renames/refactors can land in parallel

@alexcrichton alexcrichton added this pull request to the merge queue Jan 20, 2026
Merged via the queue into bytecodealliance:main with commit 350e8ad Jan 20, 2026
27 checks passed
@cpetig cpetig self-assigned this Jun 14, 2026
@rvolosatovs rvolosatovs mentioned this pull request Jun 23, 2026
Merged
rvolosatovs added a commit to bytecodealliance/wrpc that referenced this pull request Jun 23, 2026
@rvolosatovs
merge: wit-bindgen 0.42
2a39063 
Merge upstream wit-bindgen 0.42.0 into the vendored bindgen subtree.

- Bump wit-bindgen-core 0.41 -> 0.42 and wit-parser 0.227 -> 0.230.
- Adapt to the wit-parser 0.230 API break: `TypeDefKind` gained a
  `FixedSizeList(Type, u32)` variant. Handle it in the introspection async-path
  walk like a `List` (element indexed by a wildcard path), and add arms to the
  Rust and Go generators' type/codec matches. Full fixed-size-list code
  generation is not supported yet (upstream adds Rust support in bytecodealliance/wit-bindgen#1277, ported
  later at 0.52), so the generator arms panic with an "unsupported" message;
  no fixture exercises them.
- Port upstream features bytecodealliance/wit-bindgen#1244 + bytecodealliance/wit-bindgen#1270 (`serde::Deserialize` for the bindgen
  config): gate `serde::Deserialize` derives on `Opts` (`serde(default,
  rename_all = "kebab-case")`) and `WithOption` (`rename_all = "kebab-case"`)
  behind a new optional `serde` feature, matching upstream. wRPC has neither
  `ExportKey`/`AsyncConfig`/`Ownership` config types nor an `async_` option, so
  only `Opts`/`WithOption` apply.

Non-carries (not applicable to wRPC, dropped from the merge):
- more `wit-bindgen test` subcommand backends (`crates/test/src/{csharp,
  moonbit}.rs`, `crates/test/LICENSE-*`) and the new `tests/runtime-async/`
  guest runtime test tree; wRPC keeps its own `wrpc-test` crate.
- the async-task / futures-stream-ABI refactors (bytecodealliance/wit-bindgen#1233/bytecodealliance/wit-bindgen#1241/bytecodealliance/wit-bindgen#1249/bytecodealliance/wit-bindgen#1260/bytecodealliance/wit-bindgen#1264/
  bytecodealliance/wit-bindgen#1268/bytecodealliance/wit-bindgen#1278/bytecodealliance/wit-bindgen#1279/bytecodealliance/wit-bindgen#1247/bytecodealliance/wit-bindgen#1240/bytecodealliance/wit-bindgen#1291/bytecodealliance/wit-bindgen#1306 etc.) and bytecodealliance/wit-bindgen#1214's canonical-ABI
  guest-code warning squashing do not apply to wRPC's transport-stub generator.

rust codegen (237) and go codegen (79) tests pass; `cargo clippy --workspace`
(and `--features serde`) and `cargo doc --workspace` are clean; wasmtime and all
examples build.

Assisted-by: claude:claude-opus-4-8
Upstream diff: bytecodealliance/wit-bindgen@v0.41.0...v0.42.0
rvolosatovs added a commit to bytecodealliance/wrpc that referenced this pull request Jun 23, 2026
@rvolosatovs
merge: wit-bindgen 0.42
bd124d1 
Merge upstream wit-bindgen 0.42.0 into the vendored bindgen subtree.

- Bump wit-bindgen-core 0.41 -> 0.42 and wit-parser 0.227 -> 0.230.
- Adapt to the wit-parser 0.230 API break: `TypeDefKind` gained a
  `FixedSizeList(Type, u32)` variant. Handle it in the introspection async-path
  walk like a `List` (element indexed by a wildcard path), and add arms to the
  Rust and Go generators' type/codec matches. Full fixed-size-list code
  generation is not supported yet (upstream adds Rust support in bytecodealliance/wit-bindgen#1277, ported
  later at 0.52), so the generator arms panic with an "unsupported" message;
  no fixture exercises them.
- Port upstream features bytecodealliance/wit-bindgen#1244 + bytecodealliance/wit-bindgen#1270 (`serde::Deserialize` for the bindgen
  config): gate `serde::Deserialize` derives on `Opts` (`serde(default,
  rename_all = "kebab-case")`) and `WithOption` (`rename_all = "kebab-case"`)
  behind a new optional `serde` feature, matching upstream. wRPC has neither
  `ExportKey`/`AsyncConfig`/`Ownership` config types nor an `async_` option, so
  only `Opts`/`WithOption` apply.

Non-carries (not applicable to wRPC, dropped from the merge):
- more `wit-bindgen test` subcommand backends (`crates/test/src/{csharp,
  moonbit}.rs`, `crates/test/LICENSE-*`) and the new `tests/runtime-async/`
  guest runtime test tree; wRPC keeps its own `wrpc-test` crate.
- the async-task / futures-stream-ABI refactors (bytecodealliance/wit-bindgen#1233/bytecodealliance/wit-bindgen#1241/bytecodealliance/wit-bindgen#1249/bytecodealliance/wit-bindgen#1260/bytecodealliance/wit-bindgen#1264/
  bytecodealliance/wit-bindgen#1268/bytecodealliance/wit-bindgen#1278/bytecodealliance/wit-bindgen#1279/bytecodealliance/wit-bindgen#1247/bytecodealliance/wit-bindgen#1240/bytecodealliance/wit-bindgen#1291/bytecodealliance/wit-bindgen#1306 etc.) and bytecodealliance/wit-bindgen#1214's canonical-ABI
  guest-code warning squashing do not apply to wRPC's transport-stub generator.

rust codegen (237) and go codegen (79) tests pass; `cargo clippy --workspace`
(and `--features serde`) and `cargo doc --workspace` are clean; wasmtime and all
examples build.

Assisted-by: claude:claude-opus-4-8
Upstream diff: bytecodealliance/wit-bindgen@v0.41.0...v0.42.0
rvolosatovs added a commit to bytecodealliance/wrpc that referenced this pull request Jun 23, 2026
@rvolosatovs
merge: wit-bindgen 0.42
071299d 
Merge upstream wit-bindgen 0.42.0 into the vendored bindgen subtree.

- Bump wit-bindgen-core 0.41 -> 0.42 and wit-parser 0.227 -> 0.230.
- Adapt to the wit-parser 0.230 API break: `TypeDefKind` gained a
  `FixedSizeList(Type, u32)` variant. Handle it in the introspection async-path
  walk like a `List` (element indexed by a wildcard path), and add arms to the
  Rust and Go generators' type/codec matches. Full fixed-size-list code
  generation is not supported yet (upstream adds Rust support in bytecodealliance/wit-bindgen#1277, ported
  later at 0.52), so the generator arms panic with an "unsupported" message;
  no fixture exercises them.
- Port upstream features bytecodealliance/wit-bindgen#1244 + bytecodealliance/wit-bindgen#1270 (`serde::Deserialize` for the bindgen
  config): gate `serde::Deserialize` derives on `Opts` (`serde(default,
  rename_all = "kebab-case")`) and `WithOption` (`rename_all = "kebab-case"`)
  behind a new optional `serde` feature, matching upstream. wRPC has neither
  `ExportKey`/`AsyncConfig`/`Ownership` config types nor an `async_` option, so
  only `Opts`/`WithOption` apply.

Non-carries (not applicable to wRPC, dropped from the merge):
- more `wit-bindgen test` subcommand backends (`crates/test/src/{csharp,
  moonbit}.rs`, `crates/test/LICENSE-*`) and the new `tests/runtime-async/`
  guest runtime test tree; wRPC keeps its own `wrpc-test` crate.
- the async-task / futures-stream-ABI refactors (bytecodealliance/wit-bindgen#1233/bytecodealliance/wit-bindgen#1241/bytecodealliance/wit-bindgen#1249/bytecodealliance/wit-bindgen#1260/bytecodealliance/wit-bindgen#1264/
  bytecodealliance/wit-bindgen#1268/bytecodealliance/wit-bindgen#1278/bytecodealliance/wit-bindgen#1279/bytecodealliance/wit-bindgen#1247/bytecodealliance/wit-bindgen#1240/bytecodealliance/wit-bindgen#1291/bytecodealliance/wit-bindgen#1306 etc.) and bytecodealliance/wit-bindgen#1214's canonical-ABI
  guest-code warning squashing do not apply to wRPC's transport-stub generator.

rust codegen (237) and go codegen (79) tests pass; `cargo clippy --workspace`
(and `--features serde`) and `cargo doc --workspace` are clean; wasmtime and all
examples build.

Assisted-by: claude:claude-opus-4-8
Upstream diff: bytecodealliance/wit-bindgen@v0.41.0...v0.42.0
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