Emit retags in codegen to support BorrowSanitizer (part 5) - #159245
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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. |
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…-5, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 5) 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/592364811) This is one of several PRs that add experimental support for emitting retags as function calls in codegen. This PR adds support for emitting global arrays that specify the ranges of interior mutable and pinned data. For example, ```rust fn cell(x: &(i32, Cell<i32>)) { ... } ``` This program will have IR similar to the following: ```llvm @anon.0 = unnamed_addr constant [16 x i8] c"\04...\04..." define void @cell(ptr %0) { start: %x = call ptr @__rust_retag_reg(ptr %0, i64 8, i8 1, ptr @anon.0, ptr null) ... } ``` The last four bytes at offset four are interior mutable. Users can disable this behavior by passing `no-precise-im` or `no-precise-pin` as options to `-Zcodegen-emit-retag`. In that case, the last two parameters to the retag intrinsic will always be null pointers. BorrowSanitizer will be able to switch to using nightly once this is merged. Thank you @saethlin for reviewing these PRs! Note: we still do not support retagging SIMD types, since cg-ssa does not support `insertelement`. Related: rust-lang#158100 Cc: @RalfJung r? @saethlin
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…-5, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 5) 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/592364811) This is one of several PRs that add experimental support for emitting retags as function calls in codegen. This PR adds support for emitting global arrays that specify the ranges of interior mutable and pinned data. For example, ```rust fn cell(x: &(i32, Cell<i32>)) { ... } ``` This program will have IR similar to the following: ```llvm @anon.0 = unnamed_addr constant [16 x i8] c"\04...\04..." define void @cell(ptr %0) { start: %x = call ptr @__rust_retag_reg(ptr %0, i64 8, i8 1, ptr @anon.0, ptr null) ... } ``` The last four bytes at offset four are interior mutable. Users can disable this behavior by passing `no-precise-im` or `no-precise-pin` as options to `-Zcodegen-emit-retag`. In that case, the last two parameters to the retag intrinsic will always be null pointers. BorrowSanitizer will be able to switch to using nightly once this is merged. Thank you @saethlin for reviewing these PRs! Note: we still do not support retagging SIMD types, since cg-ssa does not support `insertelement`. Related: rust-lang#158100 Cc: @RalfJung r? @saethlin
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Rollup of 14 pull requests Successful merges: - #159245 (Emit retags in codegen to support BorrowSanitizer (part 5)) - #159864 (Report "capacity overflow" for oversized Rc<[T]>/Arc<[T]>) - #160079 (make atomic operations const) - #160124 (Structurally prevent zero-count `BackendRepr::SimdVector`s) - #160162 (Make `#[fundamental]` only apply to the first argument of `Box`) - #160210 (Remove an outdated FIXME) - #160282 (Improve diagnostic for patterns in function pointer types) - #157928 (Eagerly fetch typeck results when linting) - #159672 (Improve suggestions when multiples tuples implement the same trait) - #159861 (Add documentation for the `non_exhaustive` attribute) - #159907 (Fix `hidden_glob_reexports` in `rustc_ast`) - #159998 (Align expect messages with guidance) - #160145 (Expand checks for register_tool) - #160307 (Update `minifier` version to `0.4.0`)
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Rollup merge of #159245 - BorrowSanitizer:codegen-emit-retag-5, r=saethlin Emit retags in codegen to support BorrowSanitizer (part 5) Tracking issue: #154760 [Zulip Thread](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/Staging.20for.20emitting.20retags.20in.20codegen/with/592364811) This is one of several PRs that add experimental support for emitting retags as function calls in codegen. This PR adds support for emitting global arrays that specify the ranges of interior mutable and pinned data. For example, ```rust fn cell(x: &(i32, Cell<i32>)) { ... } ``` This program will have IR similar to the following: ```llvm @anon.0 = unnamed_addr constant [16 x i8] c"\04...\04..." define void @cell(ptr %0) { start: %x = call ptr @__rust_retag_reg(ptr %0, i64 8, i8 1, ptr @anon.0, ptr null) ... } ``` The last four bytes at offset four are interior mutable. Users can disable this behavior by passing `no-precise-im` or `no-precise-pin` as options to `-Zcodegen-emit-retag`. In that case, the last two parameters to the retag intrinsic will always be null pointers. BorrowSanitizer will be able to switch to using nightly once this is merged. Thank you @saethlin for reviewing these PRs! Note: we still do not support retagging SIMD types, since cg-ssa does not support `insertelement`. Related: #158100 Cc: @RalfJung r? @saethlin
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Tracking issue: #154760
Zulip Thread
This is one of several PRs that add experimental support for emitting retags as function calls in codegen.
This PR adds support for emitting global arrays that specify the ranges of interior mutable and pinned data. For example,
This program will have IR similar to the following:
The last four bytes at offset four are interior mutable.
Users can disable this behavior by passing
no-precise-imorno-precise-pinas options to-Zcodegen-emit-retag. In that case, the last two parameters to the retag intrinsic will always be null pointers.BorrowSanitizer will be able to switch to using nightly once this is merged. Thank you @saethlin for reviewing these PRs!
Note: we still do not support retagging SIMD types, since cg-ssa does not support
insertelement.Related: #158100
Cc: @RalfJung
r? @saethlin