New upstream version 1.58.1+dfsg1

[rustc.git] / compiler / rustc_mir_build / src / thir / pattern / usefulness.rs

diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
index d959d2f7f6f3f9ca292c8cd072b0799bf5c06486..286473c38e36d2920fd15a34fab64d09c510a117 100644 (file)
--- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
@@ -289,6 +289,7 @@ use super::deconstruct_pat::{Constructor, DeconstructedPat, Fields, SplitWildcar
 use rustc_data_structures::captures::Captures;
 
 use rustc_arena::TypedArena;
+use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::def_id::DefId;
 use rustc_hir::HirId;
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -443,9 +444,7 @@ impl<'p, 'tcx> Matrix<'p, 'tcx> {
     /// expands it.
     fn push(&mut self, row: PatStack<'p, 'tcx>) {
         if !row.is_empty() && row.head().is_or_pat() {
-            for row in row.expand_or_pat() {
-                self.patterns.push(row);
-            }
+            self.patterns.extend(row.expand_or_pat());
         } else {
             self.patterns.push(row);
         }
@@ -797,7 +796,7 @@ fn is_useful<'p, 'tcx>(
         return ret;
     }
 
-    assert!(rows.iter().all(|r| r.len() == v.len()));
+    debug_assert!(rows.iter().all(|r| r.len() == v.len()));
 
     let ty = v.head().ty();
     let is_non_exhaustive = cx.is_foreign_non_exhaustive_enum(ty);
@@ -810,8 +809,9 @@ fn is_useful<'p, 'tcx>(
         // We try each or-pattern branch in turn.
         let mut matrix = matrix.clone();
         for v in v.expand_or_pat() {
-            let usefulness =
-                is_useful(cx, &matrix, &v, witness_preference, hir_id, is_under_guard, false);
+            let usefulness = ensure_sufficient_stack(|| {
+                is_useful(cx, &matrix, &v, witness_preference, hir_id, is_under_guard, false)
+            });
             ret.extend(usefulness);
             // If pattern has a guard don't add it to the matrix.
             if !is_under_guard {
@@ -842,8 +842,9 @@ fn is_useful<'p, 'tcx>(
             // We cache the result of `Fields::wildcards` because it is used a lot.
             let spec_matrix = start_matrix.specialize_constructor(pcx, &ctor);
             let v = v.pop_head_constructor(cx, &ctor);
-            let usefulness =
-                is_useful(cx, &spec_matrix, &v, witness_preference, hir_id, is_under_guard, false);
+            let usefulness = ensure_sufficient_stack(|| {
+                is_useful(cx, &spec_matrix, &v, witness_preference, hir_id, is_under_guard, false)
+            });
             let usefulness = usefulness.apply_constructor(pcx, start_matrix, &ctor);
 
             // When all the conditions are met we have a match with a `non_exhaustive` enum