Correctly handle nested or-patterns in column-wise analyses

Nadrieril · Nadrieril · commit d5e836cf0ce4 · 2023-10-30T15:31:00.000+01:00
diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
@@ -931,7 +931,7 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
             let specialized = pat.specialize(pcx, &ctor);
             for (subpat, column) in specialized.iter().zip(&mut specialized_columns) {
                 if subpat.is_or_pat() {
-                    column.patterns.extend(subpat.iter_fields())
+                    column.patterns.extend(subpat.flatten_or_pat())
                 } else {
                     column.patterns.push(subpat)
                 }
diff --git a/tests/ui/or-patterns/exhaustiveness-pass.rs b/tests/ui/or-patterns/exhaustiveness-pass.rs
@@ -35,4 +35,10 @@ fn main() {
         ((0, 0) | (1, 0),) => {}
         _ => {}
     }
+
+    // This one caused ICE https://github.com/rust-lang/rust/issues/117378
+    match (0u8, 0) {
+        (x @ 0 | x @ (1 | 2), _) => {}
+        (3.., _) => {}
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -931,7 +931,7 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> {`
`931`	`931`	`let specialized = pat.specialize(pcx, &ctor);`
`932`	`932`	`for (subpat, column) in specialized.iter().zip(&mut specialized_columns) {`
`933`	`933`	`if subpat.is_or_pat() {`
`934`		`- column.patterns.extend(subpat.iter_fields())`
	`934`	`+ column.patterns.extend(subpat.flatten_or_pat())`
`935`	`935`	`} else {`
`936`	`936`	`column.patterns.push(subpat)`
`937`	`937`	`}`
Original file line number	Diff line number	Diff line change
`@@ -35,4 +35,10 @@ fn main() {`
`35`	`35`	`((0, 0) \| (1, 0),) => {}`
`36`	`36`	`_ => {}`
`37`	`37`	`}`
	`38`	`+`
	`39`	`+ // This one caused ICE https://github.com/rust-lang/rust/issues/117378`
	`40`	`+ match (0u8, 0) {`
	`41`	`+ (x @ 0 \| x @ (1 \| 2), _) => {}`
	`42`	`+ (3.., _) => {}`
	`43`	`+ }`
`38`	`44`	`}`