Add doc for va_list APIs by DiuDiu777 · Pull Request #146925 · rust-lang/rust

DiuDiu777 · 2025-09-23T08:55:00Z

I observed that PR146521 submitted two weeks ago resolved some documentation issues related to VaListImpl, similar to the previous PR136969.

This PR specifically adds requirements about argument availability for VaListImpl::arg, and also adds safety descriptions to the three associated intrinsic APIs.

rustbot · 2025-09-23T08:55:03Z

Some changes occurred to the intrinsics. Make sure the CTFE / Miri interpreter
gets adapted for the changes, if necessary.

cc @rust-lang/miri, @RalfJung, @oli-obk, @lcnr

rustbot · 2025-09-23T08:55:05Z

r? @tgross35

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library/core/src/ffi/va_list.rs

tgross35

Two small nits and please squash, then r=me. Thanks for the fixes!

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tgross35 · 2025-10-03T22:19:06Z

library/core/src/intrinsics/mod.rs

+/// You must check the following invariants before you call this function:
+///
+/// - `ap` must not be used to access variable arguments after this call


This can be simplified to just:

/// `ap` must not be used to access variable arguments after this call

tgross35 · 2025-10-03T22:19:39Z

library/core/src/ffi/va_list.rs

    ///
-    /// - has a type that is ABI-compatible with the type `T`
-    /// - has a value that is a properly initialized value of type `T`
+    /// - there is a next variable argument available (i.e., the number of arguments already read from `ap` is less than the total number passed)


Please rewrap to 100 chars (same in intrinsics/mod.rs)

DiuDiu777 · 2025-10-04T23:01:03Z

Done! r? @tgross35

rustbot · 2025-10-04T23:01:06Z

Requested reviewer is already assigned to this pull request.

Please choose another assignee.

tgross35 · 2025-11-19T14:14:36Z

Done! r? @tgross35

For future reference, use @rustbot ready to update the labels :)

@bors r+ rollup

bors · 2025-11-19T14:14:39Z

📌 Commit 0d6a313 has been approved by tgross35

It is now in the queue for this repository.

tgross35 · 2025-11-19T14:15:07Z

library/core/src/ffi/va_list.rs

+    /// - there is a next variable argument available.
+    /// - the next argument's type must be ABI-compatible with the type `T`.
+    /// - the next argument must have a properly initialized value of type `T`.


Usually list items start with an uppercase letter, but this is preexisting so 🤷

Add doc for va_list APIs I observed that [PR146521](rust-lang#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](rust-lang#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

Rollup of 7 pull requests Successful merges: - #146341 (minimal dirfd implementation (1/4)) - #146925 (Add doc for va_list APIs) - #147035 (alloc: fix `Debug` implementation of `ExtractIf`) - #147173 (Add support for hexagon-unknown-qurt target) - #149041 (ignore unsized types in mips64 and sparc64 callconvs) - #149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - #149095 (rustc-dev-guide subtree update) r? `@ghost` `@rustbot` modify labels: rollup

Add doc for va_list APIs I observed that [PR146521](rust-lang#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](rust-lang#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

Rollup of 6 pull requests Successful merges: - #146925 (Add doc for va_list APIs) - #147035 (alloc: fix `Debug` implementation of `ExtractIf`) - #147173 (Add support for hexagon-unknown-qurt target) - #149041 (ignore unsized types in mips64 and sparc64 callconvs) - #149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - #149095 (rustc-dev-guide subtree update) r? `@ghost` `@rustbot` modify labels: rollup

Add doc for va_list APIs I observed that [PR146521](rust-lang#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](rust-lang#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

Rollup of 9 pull requests Successful merges: - #146925 (Add doc for va_list APIs) - #147035 (alloc: fix `Debug` implementation of `ExtractIf`) - #147173 (Add support for hexagon-unknown-qurt target) - #148261 (rustc_public: Make Id types !Send / !Sync) - #149041 (ignore unsized types in mips64 and sparc64 callconvs) - #149043 ( rustdoc-json: add rlib path to ExternalCrate to enable robust crate resolution) - #149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - #149095 (rustc-dev-guide subtree update) - #149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

Add doc for va_list APIs I observed that [PR146521](rust-lang#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](rust-lang#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

Rollup of 10 pull requests Successful merges: - #146925 (Add doc for va_list APIs) - #147035 (alloc: fix `Debug` implementation of `ExtractIf`) - #147173 (Add support for hexagon-unknown-qurt target) - #148261 (rustc_public: Make Id types !Send / !Sync) - #148831 (Bump compiler dependencies) - #149041 (ignore unsized types in mips64 and sparc64 callconvs) - #149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - #149071 (Add test scaffolding for the `remote-test-client`) - #149095 (rustc-dev-guide subtree update) - #149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 9 pull requests Successful merges: - #146925 (Add doc for va_list APIs) - #147035 (alloc: fix `Debug` implementation of `ExtractIf`) - #147173 (Add support for hexagon-unknown-qurt target) - #148261 (rustc_public: Make Id types !Send / !Sync) - #149041 (ignore unsized types in mips64 and sparc64 callconvs) - #149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - #149071 (Add test scaffolding for the `remote-test-client`) - #149095 (rustc-dev-guide subtree update) - #149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #146925 - DiuDiu777:va-doc-fix, r=tgross35 Add doc for va_list APIs I observed that [PR146521](#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

Rollup of 9 pull requests Successful merges: - rust-lang/rust#146925 (Add doc for va_list APIs) - rust-lang/rust#147035 (alloc: fix `Debug` implementation of `ExtractIf`) - rust-lang/rust#147173 (Add support for hexagon-unknown-qurt target) - rust-lang/rust#148261 (rustc_public: Make Id types !Send / !Sync) - rust-lang/rust#149041 (ignore unsized types in mips64 and sparc64 callconvs) - rust-lang/rust#149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - rust-lang/rust#149071 (Add test scaffolding for the `remote-test-client`) - rust-lang/rust#149095 (rustc-dev-guide subtree update) - rust-lang/rust#149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

Add doc for va_list APIs I observed that [PR146521](rust-lang#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](rust-lang#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#146925 (Add doc for va_list APIs) - rust-lang#147035 (alloc: fix `Debug` implementation of `ExtractIf`) - rust-lang#147173 (Add support for hexagon-unknown-qurt target) - rust-lang#148261 (rustc_public: Make Id types !Send / !Sync) - rust-lang#149041 (ignore unsized types in mips64 and sparc64 callconvs) - rust-lang#149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - rust-lang#149071 (Add test scaffolding for the `remote-test-client`) - rust-lang#149095 (rustc-dev-guide subtree update) - rust-lang#149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 9 pull requests Successful merges: - rust-lang/rust#146925 (Add doc for va_list APIs) - rust-lang/rust#147035 (alloc: fix `Debug` implementation of `ExtractIf`) - rust-lang/rust#147173 (Add support for hexagon-unknown-qurt target) - rust-lang/rust#148261 (rustc_public: Make Id types !Send / !Sync) - rust-lang/rust#149041 (ignore unsized types in mips64 and sparc64 callconvs) - rust-lang/rust#149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - rust-lang/rust#149071 (Add test scaffolding for the `remote-test-client`) - rust-lang/rust#149095 (rustc-dev-guide subtree update) - rust-lang/rust#149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

Add doc for va_list APIs I observed that [PR146521](rust-lang#146521) submitted two weeks ago resolved some documentation issues related to `VaListImpl`, similar to the previous [PR136969](rust-lang#136969). This PR specifically adds requirements about argument availability for `VaListImpl::arg`, and also adds safety descriptions to the three associated intrinsic APIs.

…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#146925 (Add doc for va_list APIs) - rust-lang#147035 (alloc: fix `Debug` implementation of `ExtractIf`) - rust-lang#147173 (Add support for hexagon-unknown-qurt target) - rust-lang#148261 (rustc_public: Make Id types !Send / !Sync) - rust-lang#149041 (ignore unsized types in mips64 and sparc64 callconvs) - rust-lang#149056 (fix the fragment_in_dst_padding_gets_overwritten test on s390x) - rust-lang#149071 (Add test scaffolding for the `remote-test-client`) - rust-lang#149095 (rustc-dev-guide subtree update) - rust-lang#149108 ([AIX][ppc64le-linux-gnu] Add Amy Kwan to target maintainers) r? `@ghost` `@rustbot` modify labels: rollup

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Sep 23, 2025

rustbot assigned tgross35 Sep 23, 2025

RalfJung reviewed Sep 23, 2025

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library/core/src/ffi/va_list.rs Outdated Show resolved Hide resolved

DiuDiu777 force-pushed the va-doc-fix branch from f151fb8 to 9c6f170 Compare September 23, 2025 10:10

tgross35 requested changes Oct 3, 2025

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rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Oct 3, 2025

add doc for va_list APIs

0d6a313

DiuDiu777 force-pushed the va-doc-fix branch from 9c6f170 to 0d6a313 Compare October 4, 2025 08:33

tgross35 approved these changes Nov 19, 2025

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bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Nov 19, 2025

tgross35 reviewed Nov 19, 2025

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matthiaskrgr mentioned this pull request Nov 19, 2025

Rollup of 7 pull requests #149104

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Rollup of 9 pull requests #149119

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Rollup of 9 pull requests #149132

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bors merged commit 2eeec77 into rust-lang:main Nov 20, 2025
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hxuhack mentioned this pull request Feb 12, 2026

Add a goal for Improving Unsafe Code Documentation in the Rust Standard Library rust-lang/rust-project-goals#511

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Add doc for va_list APIs#146925

Add doc for va_list APIs#146925
bors merged 1 commit intorust-lang:mainfrom
DiuDiu777:va-doc-fix

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