Emit retags in codegen to support BorrowSanitizer (part 1) by icmccorm · Pull Request #156208 · rust-lang/rust

icmccorm · 2026-05-05T21:27:12Z

This is the first of several PRs that will add experimental support for emitting retags as function calls in codegen. Each PR will be a minimal, improved slice of the changes in #155965.

This PR contains all of the changes that will affect codegen backends. It adds methods to IntrinsicCallBuilderMethods for emitting each kind of retag call.

cc: @RalfJung

rustbot · 2026-05-05T21:27:16Z

The GCC codegen subtree was changed

cc @antoyo, @GuillaumeGomez

rustbot · 2026-05-05T21:27:18Z

r? @jackh726

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saethlin · 2026-05-05T21:45:44Z

r? saethlin

rustbot · 2026-05-15T16:38:19Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

saethlin · 2026-05-17T02:39:56Z

@bors r+

rust-bors · 2026-05-17T02:39:59Z

📌 Commit e15861b has been approved by saethlin

It is now in the queue for this repository.

@RalfJung

…-1, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 1) Tracking issue: rust-lang#154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/593004012) This is the first of several PRs that will add experimental support for emitting retags as function calls in codegen. Each PR will be a minimal, improved slice of the changes in rust-lang#155965. This PR contains all of the changes that will affect codegen backends. It adds methods to `IntrinsicCallBuilderMethods` for emitting each kind of retag call. cc: @RalfJung

JonathanBrouwer · 2026-05-17T12:25:52Z

@bors try jobs=aarch64-apple

rust-bors · 2026-05-17T12:25:58Z

⌛ Trying commit e15861b with merge e6b753f…

To cancel the try build, run the command @bors try cancel.

Workflow: https://github.com/rust-lang/rust/actions/runs/25990798832

Emit retags in codegen to support BorrowSanitizer (part 1) try-job: aarch64-apple

JonathanBrouwer · 2026-05-17T13:51:23Z

@bors try cancel

rust-bors · 2026-05-17T13:51:27Z

Try build cancelled. Cancelled workflows:

https://github.com/rust-lang/rust/actions/runs/25990798832

…uwer Rollup of 14 pull requests Successful merges: - #151742 (Remove redundant information in `rustc_abi::Variants`) - #151362 (Add interior-mutability suggestion to `static_mut_refs`) - #156121 (compiler: suggest `.collect()` when `String` is expected and `Iterator` is found) - #156208 (Emit retags in codegen to support BorrowSanitizer (part 1)) - #156596 (Split `LintExpectationId`s) - #156607 (ci: Update FreeBSD version to FreeBSD 14) - #156376 (suggest hex escapes for C-style escapes) - #156577 (Test EII UI tests with prefer-dynamic) - #156585 (explicit tail calls: ignore some tests on unsupported LLVM targets) - #156598 (Avoid rustfix suggestions for macro-expanded unused imports) - #156616 (rustdoc: add test case for `-Drustdoc::` and `--cap-lints`) - #156633 (Add regression test for issue #41261) - #156635 (rename unexpected_try_recover function) - #156636 (minor `rustc_mir_transform` cleanup)

…uwer Rollup of 14 pull requests Successful merges: - rust-lang/rust#151742 (Remove redundant information in `rustc_abi::Variants`) - rust-lang/rust#151362 (Add interior-mutability suggestion to `static_mut_refs`) - rust-lang/rust#156121 (compiler: suggest `.collect()` when `String` is expected and `Iterator` is found) - rust-lang/rust#156208 (Emit retags in codegen to support BorrowSanitizer (part 1)) - rust-lang/rust#156596 (Split `LintExpectationId`s) - rust-lang/rust#156607 (ci: Update FreeBSD version to FreeBSD 14) - rust-lang/rust#156376 (suggest hex escapes for C-style escapes) - rust-lang/rust#156577 (Test EII UI tests with prefer-dynamic) - rust-lang/rust#156585 (explicit tail calls: ignore some tests on unsupported LLVM targets) - rust-lang/rust#156598 (Avoid rustfix suggestions for macro-expanded unused imports) - rust-lang/rust#156616 (rustdoc: add test case for `-Drustdoc::` and `--cap-lints`) - rust-lang/rust#156633 (Add regression test for issue rust-lang/rust#41261) - rust-lang/rust#156635 (rename unexpected_try_recover function) - rust-lang/rust#156636 (minor `rustc_mir_transform` cleanup)

@RalfJung

…-2, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 2) Tracking issue: rust-lang#154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/593004012) This is one of several PRs that will add experimental support for emitting retags as function calls in codegen. Each PR will be a minimal, improved slice of the changes in rust-lang#155965. This PR adds a new unstable flag `-Zcodegen-emit-retag`, which will enable experimental retag calls in generated code. This flag is a nop for now, but the relevant methods have been added to codegen_ssa, and they are called wherever retags are necessary. Subsequent PRs will complete this implementation. This does not depend on rust-lang#156208. r? @RalfJung

@RalfJung

Emit retags in codegen to support BorrowSanitizer (part 2) Tracking issue: #154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/593004012) This is one of several PRs that will add experimental support for emitting retags as function calls in codegen. Each PR will be a minimal, improved slice of the changes in #155965. This PR adds a new unstable flag `-Zcodegen-emit-retag`, which will enable experimental retag calls in generated code. This flag is a nop for now, but the relevant methods have been added to codegen_ssa, and they are called wherever retags are necessary. Subsequent PRs will complete this implementation. This does not depend on #156208. r? @RalfJung

@RalfJung

Rollup merge of #156210 - BorrowSanitizer:codegen-emit-retag-2, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 2) Tracking issue: #154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/593004012) This is one of several PRs that will add experimental support for emitting retags as function calls in codegen. Each PR will be a minimal, improved slice of the changes in #155965. This PR adds a new unstable flag `-Zcodegen-emit-retag`, which will enable experimental retag calls in generated code. This flag is a nop for now, but the relevant methods have been added to codegen_ssa, and they are called wherever retags are necessary. Subsequent PRs will complete this implementation. This does not depend on #156208. r? @RalfJung

@RalfJung

…-3, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 3) Tracking issue: rust-lang#154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/593004012) This is one of several PRs that will add experimental support for emitting retags as function calls in codegen. This PR adds `RetagPlan`, which describes where the pointers that need to be retagged live within the layout of a type. We create a `RetagPlan` ahead of time because only a subset of the variants of a type might contain retagable values. We only want to branch to these variants, and ignore all of the others. If a type can generate a `RetagPlan`, then we will use it as a guide for inserting calls to our retag intrinsics. If a type does not generate a `RetagPlan`, then it does not need to be retagged, and we can skip it. This does not emit a `RetagPlan::EmitRetag` yet. That will come in a subsequent PR. Previous parts: rust-lang#156208, rust-lang#156210 cc: @RalfJung r? @saethlin

@RalfJung

Rollup merge of #157825 - BorrowSanitizer:codegen-emit-retag-3, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 3) Tracking issue: #154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/593004012) This is one of several PRs that will add experimental support for emitting retags as function calls in codegen. This PR adds `RetagPlan`, which describes where the pointers that need to be retagged live within the layout of a type. We create a `RetagPlan` ahead of time because only a subset of the variants of a type might contain retagable values. We only want to branch to these variants, and ignore all of the others. If a type can generate a `RetagPlan`, then we will use it as a guide for inserting calls to our retag intrinsics. If a type does not generate a `RetagPlan`, then it does not need to be retagged, and we can skip it. This does not emit a `RetagPlan::EmitRetag` yet. That will come in a subsequent PR. Previous parts: #156208, #156210 cc: @RalfJung r? @saethlin

rustbot assigned jackh726 May 5, 2026

icmccorm mentioned this pull request May 5, 2026

Emit retags in codegen to support BorrowSanitizer (part 2) #156210

Merged

rustbot assigned saethlin and unassigned jackh726 May 5, 2026

Add trait methods for experimental retags to cg.

e15861b

icmccorm force-pushed the codegen-emit-retag-1 branch from 824ce42 to e15861b Compare May 15, 2026 16:38

rust-bors Bot 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-review Status: Awaiting review from the assignee but also interested parties. labels May 17, 2026

JonathanBrouwer mentioned this pull request May 17, 2026

Rollup of 11 pull requests #156658

Closed

rust-bors Bot pushed a commit that referenced this pull request May 17, 2026

Auto merge of #156208 - BorrowSanitizer:codegen-emit-retag-1, r=<try>

e6b753f

Emit retags in codegen to support BorrowSanitizer (part 1) try-job: aarch64-apple

JonathanBrouwer mentioned this pull request May 17, 2026

Rollup of 14 pull requests #156670

Merged

rust-bors Bot merged commit ff42fc0 into rust-lang:main May 18, 2026
11 of 12 checks passed

icmccorm mentioned this pull request May 18, 2026

Interop Safety: Improving cross-language analysis by augmenting LLVM IR with Rust type information rust-lang/all-hands-2026#26

Open

ehuss added this to the 1.97.0 milestone May 28, 2026

icmccorm mentioned this pull request May 30, 2026

BorrowSanitizer rust-lang/rust-project-goals#624

Open

icmccorm deleted the codegen-emit-retag-1 branch June 7, 2026 21:12

icmccorm mentioned this pull request Jun 12, 2026

Emit retags in codegen to support BorrowSanitizer (part 3) #157825

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Emit retags in codegen to support BorrowSanitizer (part 1)#156208

Emit retags in codegen to support BorrowSanitizer (part 1)#156208
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BorrowSanitizer:codegen-emit-retag-1

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