New attribute parsing infrastructure #135726

jdonszelmann · 2025-01-19T11:27:11Z

Another step in the plan outlined in #131229

introduces infrastructure for structured parsers for attributes, as well as converting a couple of complex attributes to have such structured parsers.

This PR may prove too large to review. I left some of my own comments to guide it a little. Some general notes:

The first commit is basically standalone. It just preps some mostly unrelated sources for the rest of the PR to work. It might not have enormous merit on its own, but not negative merit either. Could be merged alone, but also doesn't make the review a whole lot easier. (but it's only +274 -209)
The second commit is the one that introduces new infrastructure. It's the important one to review.
The 3rd commit uses the new infrastructure showing how some of the more complex attributes can be parsed using it. Theoretically can be split up, though the parsers in this commit are the ones that really test the new infrastructure and show that it all works.
The 4th commit fixes up rustdoc and clippy. In the previous 2 they didn't compile yet while the compiler does. Separated them out to separate concerns and make the rest more palatable.
The 5th commit blesses some test outputs. Sometimes that's just because a diagnostic happens slightly earlier than before, which I'd say is acceptable. Sometimes a diagnostic is now only emitted once where it would've been twice before (yay! fixed some bugs). One test I actually moved from crashes to fixed, because it simply doesn't crash anymore. That's why this PR Closes ICE: malformed malformed repr(align(N)) #132391. I think most choices I made here are generally reasonable, but let me know if you disagree anywhere.
The 6th commit adds a derive to pretty print attributes
The 7th removes smir apis for attributes, for the time being. The api will at some point be replaced by one based on rustc_ast_data_structures::AttributeKind

In general, a lot of the additions here are comments. I've found it very important to document new things in the 2nd commit well so other people can start using it.

Closes #132391
Closes #136717

rustbot · 2025-01-19T11:27:23Z

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Noratrieb · 2025-01-19T15:04:26Z

r? oli-obk

compiler/rustc_ast_lowering/src/lib.rs

compiler/rustc_attr_data_structures/src/attributes.rs

compiler/rustc_attr_data_structures/src/lib.rs

klensy · 2025-02-25T10:49:19Z

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

-            struct_span_code_err!(tcx.dcx(), item.span(), E0535, "invalid argument")
+            struct_span_code_err!(tcx.dcx(), items[0].span(), E0535, "invalid argument")


Why? item == items[0], as destructured in let [item] = &items[..] else

Revert accidental cargo submodule update This was accidentally introduced in rust-lang#135726

…=oli-obk" This reverts commit 7d8c6e7, reversing changes made to 617aad8.

Revert "Auto merge of rust-lang#135726 - jdonszelmann:attr-parsing, r=oli-obk" Trying to revert rust-lang#135726 and do some perf. runs on it. r? `@ghost`

Revert accidental cargo submodule update This was accidentally introduced in rust-lang#135726

Rollup merge of rust-lang#137597 - oli-obk:push-unkusxkoqrus, r=Kobzol Revert accidental cargo submodule update This was accidentally introduced in rust-lang#135726

rylev · 2025-02-25T20:10:08Z

See here for explanation for why there was a perf regression here.

@rustbot label: +perf-regression-triaged

Changes to attribute parsing and representation rust-lang/rust#135726 Map methods moved to `TyCtx` rust-lang/rust#137162 rust-lang/rust#137397 Remove `BackendRepr::Unihabited` rust-lang/rust#136985

Notes about tests: - tests/ui/rfcs/rfc-2294-if-let-guard/feature-gate.rs: some messages are now duplicated due to repeated parsing. - tests/ui/rfcs/rfc-2497-if-let-chains/disallowed-positions.rs: ditto. - `tests/ui/proc-macro/macro-rules-derive-cfg.rs`: the diff looks large but the only difference is the insertion of a single invisible-delimited group around a metavar. - `tests/ui/attributes/nonterminal-expansion.rs`: a slight span degradation, somehow related to the recent massive attr parsing rewrite (rust-lang#135726). I couldn't work out exactly what is going wrong, I don't think it's worth holding things up for a single slightly suboptimal error message.

Changes to attribute parsing and representation rust-lang/rust#135726 Map methods moved to `TyCtx` rust-lang/rust#137162 rust-lang/rust#137397 Remove `BackendRepr::Unihabited` rust-lang/rust#136985 Intrinsics rint, roundeven, nearbyint replaced by `round_ties_even`. rust-lang/rust#136543. Use `__sort_of_CPROVER_round_to_integral` to model `round_ties_even`. Rename `sub_ptr` to `offset_from_unsigned`. The feature gate is still `ptr_sub_ptr`. rust-lang/rust#137483. By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses. --------- Co-authored-by: Remi Delmas <delmasrd@amazon.com>

Notes about tests: - tests/ui/rfcs/rfc-2294-if-let-guard/feature-gate.rs: some messages are now duplicated due to repeated parsing. - tests/ui/rfcs/rfc-2497-if-let-chains/disallowed-positions.rs: ditto. - `tests/ui/proc-macro/macro-rules-derive-cfg.rs`: the diff looks large but the only difference is the insertion of a single invisible-delimited group around a metavar. - `tests/ui/attributes/nonterminal-expansion.rs`: a slight span degradation, somehow related to the recent massive attr parsing rewrite (rust-lang#135726). I couldn't work out exactly what is going wrong, I don't think it's worth holding things up for a single slightly suboptimal error message.

Notes about tests: - tests/ui/rfcs/rfc-2294-if-let-guard/feature-gate.rs: some messages are now duplicated due to repeated parsing. - tests/ui/rfcs/rfc-2497-if-let-chains/disallowed-positions.rs: ditto. - `tests/ui/proc-macro/macro-rules-derive-cfg.rs`: the diff looks large but the only difference is the insertion of a single invisible-delimited group around a metavar. - `tests/ui/attributes/nonterminal-expansion.rs`: a slight span degradation, somehow related to the recent massive attr parsing rewrite (rust-lang#135726). I couldn't work out exactly what is going wrong, but I don't think it's worth holding things up for a single slightly suboptimal error message.

rustbot assigned Noratrieb Jan 19, 2025

jdonszelmann force-pushed the attr-parsing branch from 053b11b to 5a3ac64 Compare January 19, 2025 11:33