lower bodies' params to thir before the body's value #141356
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matthiaskrgr
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…ee-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).
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…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
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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).
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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).
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Two motivations for this:
-Zunpretty=thir-treethat the final expression in the THIR corresponds to its value (link); 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 bythir_bodyand the check could be removed or changed (unpretty=thir-tree: don't require the final expr to be the body's value #141357).