support `loop_match` on integers #1

folkertdev · 2025-03-12T09:50:35Z

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compiler/rustc_mir_build/src/builder/expr/into.rs

compiler/rustc_mir_build/src/builder/scope.rs

bjorn3 · 2025-03-12T11:18:06Z

compiler/rustc_mir_build/src/builder/scope.rs

+                            // apply the sign
+                            let raw = pu.get() as i128;
+                            let signed = if *neg { -raw } else { raw };
+                            scope.match_arms.target_for_value(recast as u128)


I think you have to truncate it after casting back to u128: https://github.com/rust-lang/rust/blob/57a4736e9f4b7e8089b2db60583607f3b550c862/compiler/rustc_mir_build/src/builder/expr/as_constant.rs#L153-L156

bjorn3 · 2025-03-12T12:28:39Z

compiler/rustc_mir_build/src/builder/expr/into.rs


+                let dropless_arena = rustc_arena::DroplessArena::default();
+                let typeck_results = this.tcx.typeck(this.def_id);
+                let lint_level = this.tcx.local_def_id_to_hir_id(this.def_id);


There is a commented out lint_level field in LoopMatch. That one should probably be uncommented and used here instead. The current code would use the lint level for the whole function. Alternatively adding a FIXME would be fine.

folkertdev force-pushed the loop-match-use-deconstructed-pat branch from f9f52c8 to 264d16b Compare March 12, 2025 10:05

folkertdev commented Mar 12, 2025

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d2c139e

folkertdev force-pushed the loop-match-use-deconstructed-pat branch from 264d16b to d2c139e Compare March 12, 2025 10:37