unpretty=thir-tree: don't require the final expr to be the body's value
#141357
+4
−9
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
r? @nnethercote rustbot has assigned @nnethercote. Use |
rustbot
added
S-waiting-on-review
compiler-errors
approved these changes
May 21, 2025
|
r? compiler-errors @bors r+ rollup |
bors
added
S-waiting-on-bors
matthiaskrgr
added a commit
to matthiaskrgr/rust
that referenced
this pull request
May 21, 2025
…dy-expr, r=compiler-errors lower bodies' params to thir before the body's value Two motivations for this: - Lowering params first means errors from lowering the params are emitted before errors from lowering the body's expression. This comes up in [tests/ui/associated-consts/associated-const-type-parameter-pattern.stderr](https://github.com/rust-lang/rust/compare/master...dianne:rust:thir-lower-params-before-body-expr?expand=1#diff-acac6ea10e991af0da91633e08b2739f9f9ca0c8f826401b6ba829914d0806f2), where both the params and expression encounter errors in translating consts to patterns. This change puts the errors in the order they appear in the source file. - Guard patterns (rust-lang#129967) contain expressions, so lowering params containing guard patterns may add more expressions to the THIR. However, there's a check for `-Zunpretty=thir-tree` that the final expression in the THIR corresponds to its value [(link)](https://github.com/rust-lang/rust/blob/c43786c9b7b8d8dcc3f9c604e0e3074c16ed69d3/compiler/rustc_mir_build/src/builder/mod.rs#L453-L455); lowering params last would break this. As an alternative way to get guard patterns to work, I think the pretty-printer could use the expression returned by `thir_body` and the check could be removed or changed (rust-lang#141357).
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
May 21, 2025
…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#140526 (docs: Specify that common sort functions sort in an ascending direction) - rust-lang#141230 (std: fix doctest and explain for `as_slices` and `as_mut_slices` in `VecDeque`) - rust-lang#141341 (limit impls of `VaArgSafe` to just types that are actually safe) - rust-lang#141347 (incorrectly prefer builtin `dyn` impls :3) - rust-lang#141351 (Move -Zcrate-attr injection to just after crate root parsing) - rust-lang#141356 (lower bodies' params to thir before the body's value) - rust-lang#141357 (`unpretty=thir-tree`: don't require the final expr to be the body's value) - rust-lang#141363 (Document why we allow escaping bound vars in LTA norm) r? `@ghost` `@rustbot` modify labels: rollup
rust-timer
added a commit
to rust-lang-ci/rust
that referenced
this pull request
May 22, 2025
Rollup merge of rust-lang#141357 - dianne:unhardcode-unpretty-thir-tree-body-expr, r=compiler-errors `unpretty=thir-tree`: don't require the final expr to be the body's value Two motivations for this: - I couldn't find a comment motivating this hard-coding. I can imagine it might be easier to read `unpretty=thir-flat` output if the final expression in the THIR is always the body's value, but if that's the reason, that should be the justification in the source. I can also imagine it's meant to check that all expressions will be visited by the pretty-printer, but the existing check doesn't quite do that either. - Guard patterns (rust-lang#129967) contain expressions, so lowering params containing guard patterns may add more expressions to the THIR. Currently a body's params are lowered after its expression, so guard expressions in params would end up last, breaking this. As an alternative, the params could be lowered first (rust-lang#141356).
rust-timer
added a commit
to rust-lang-ci/rust
that referenced
this pull request
May 22, 2025
Rollup merge of rust-lang#141356 - dianne:thir-lower-params-before-body-expr, r=compiler-errors lower bodies' params to thir before the body's value Two motivations for this: - Lowering params first means errors from lowering the params are emitted before errors from lowering the body's expression. This comes up in [tests/ui/associated-consts/associated-const-type-parameter-pattern.stderr](https://github.com/rust-lang/rust/compare/master...dianne:rust:thir-lower-params-before-body-expr?expand=1#diff-acac6ea10e991af0da91633e08b2739f9f9ca0c8f826401b6ba829914d0806f2), where both the params and expression encounter errors in translating consts to patterns. This change puts the errors in the order they appear in the source file. - Guard patterns (rust-lang#129967) contain expressions, so lowering params containing guard patterns may add more expressions to the THIR. However, there's a check for `-Zunpretty=thir-tree` that the final expression in the THIR corresponds to its value [(link)](https://github.com/rust-lang/rust/blob/c43786c9b7b8d8dcc3f9c604e0e3074c16ed69d3/compiler/rustc_mir_build/src/builder/mod.rs#L453-L455); lowering params last would break this. As an alternative way to get guard patterns to work, I think the pretty-printer could use the expression returned by `thir_body` and the check could be removed or changed (rust-lang#141357).
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Two motivations for this:
unpretty=thir-flatoutput if the final expression in the THIR is always the body's value, but if that's the reason, that should be the justification in the source. I can also imagine it's meant to check that all expressions will be visited by the pretty-printer, but the existing check doesn't quite do that either.