Auto merge of #104160 - Ayush1325:windows-args, r=m-ou-se

[rust.git] / compiler / rustc_mir_build / src / build / matches / mod.rs

diff --git a/compiler/rustc_mir_build/src/build/matches/mod.rs b/compiler/rustc_mir_build/src/build/matches/mod.rs
index a7d89db8baab712e4c85562fcfc105a5c2800ceb..691cbee2c731911acf2997bea4754b5d54c9ee16 100644 (file)
--- a/compiler/rustc_mir_build/src/build/matches/mod.rs
+++ b/compiler/rustc_mir_build/src/build/matches/mod.rs
@@ -84,6 +84,7 @@ pub(crate) fn then_else_break(
                 break_scope,
                 Some(variable_source_info.scope),
                 variable_source_info.span,
+                true,
             ),
             _ => {
                 let temp_scope = temp_scope_override.unwrap_or_else(|| this.local_scope());
@@ -168,7 +169,7 @@ pub(crate) fn match_expr(
         let scrutinee_place =
             unpack!(block = self.lower_scrutinee(block, scrutinee, scrutinee_span,));
 
-        let mut arm_candidates = self.create_match_candidates(scrutinee_place.clone(), &arms);
+        let mut arm_candidates = self.create_match_candidates(&scrutinee_place, &arms);
 
         let match_has_guard = arm_candidates.iter().any(|(_, candidate)| candidate.has_guard);
         let mut candidates =
@@ -230,7 +231,7 @@ fn lower_scrutinee(
     /// Create the initial `Candidate`s for a `match` expression.
     fn create_match_candidates<'pat>(
         &mut self,
-        scrutinee: PlaceBuilder<'tcx>,
+        scrutinee: &PlaceBuilder<'tcx>,
         arms: &'pat [ArmId],
     ) -> Vec<(&'pat Arm<'tcx>, Candidate<'pat, 'tcx>)>
     where
@@ -351,7 +352,7 @@ fn lower_match_arms(
                         None,
                         arm.span,
                         &arm.pattern,
-                        ArmHasGuard(arm.guard.is_some()),
+                        arm.guard.as_ref(),
                         opt_scrutinee_place,
                     );
 
@@ -637,7 +638,7 @@ pub(crate) fn declare_bindings(
         mut visibility_scope: Option<SourceScope>,
         scope_span: Span,
         pattern: &Pat<'tcx>,
-        has_guard: ArmHasGuard,
+        guard: Option<&Guard<'tcx>>,
         opt_match_place: Option<(Option<&Place<'tcx>>, Span)>,
     ) -> Option<SourceScope> {
         self.visit_primary_bindings(
@@ -659,12 +660,16 @@ pub(crate) fn declare_bindings(
                     var,
                     ty,
                     user_ty,
-                    has_guard,
+                    ArmHasGuard(guard.is_some()),
                     opt_match_place.map(|(x, y)| (x.cloned(), y)),
                     pattern.span,
                 );
             },
         );
+        if let Some(Guard::IfLet(guard_pat, _)) = guard {
+            // FIXME: pass a proper `opt_match_place`
+            self.declare_bindings(visibility_scope, scope_span, guard_pat, None, None);
+        }
         visibility_scope
     }
 
@@ -1332,7 +1337,6 @@ fn test_candidates_with_or(
                 bug!("Or-patterns should have been sorted to the end");
             };
             let or_span = match_pair.pattern.span;
-            let place = match_pair.place;
 
             first_candidate.visit_leaves(|leaf_candidate| {
                 self.test_or_pattern(
@@ -1340,7 +1344,7 @@ fn test_candidates_with_or(
                     &mut otherwise,
                     pats,
                     or_span,
-                    place.clone(),
+                    &match_pair.place,
                     fake_borrows,
                 );
             });
@@ -1368,7 +1372,7 @@ fn test_or_pattern<'pat>(
         otherwise: &mut Option<BasicBlock>,
         pats: &'pat [Box<Pat<'tcx>>],
         or_span: Span,
-        place: PlaceBuilder<'tcx>,
+        place: &PlaceBuilder<'tcx>,
         fake_borrows: &mut Option<FxIndexSet<Place<'tcx>>>,
     ) {
         debug!("candidate={:#?}\npats={:#?}", candidate, pats);
@@ -1607,7 +1611,7 @@ fn test_candidates<'pat, 'b, 'c>(
         // encounter a candidate where the test is not relevant; at
         // that point, we stop sorting.
         while let Some(candidate) = candidates.first_mut() {
-            let Some(idx) = self.sort_candidate(&match_place.clone(), &test, candidate) else {
+            let Some(idx) = self.sort_candidate(&match_place, &test, candidate) else {
                 break;
             };
             let (candidate, rest) = candidates.split_first_mut().unwrap();
@@ -1676,7 +1680,7 @@ fn test_candidates<'pat, 'b, 'c>(
             target_blocks
         };
 
-        self.perform_test(span, scrutinee_span, block, match_place, &test, make_target_blocks);
+        self.perform_test(span, scrutinee_span, block, &match_place, &test, make_target_blocks);
     }
 
     /// Determine the fake borrows that are needed from a set of places that
@@ -1757,6 +1761,8 @@ fn calculate_fake_borrows<'b>(
 // Pat binding - used for `let` and function parameters as well.
 
 impl<'a, 'tcx> Builder<'a, 'tcx> {
+    /// If the bindings have already been declared, set `declare_bindings` to
+    /// `false` to avoid duplicated bindings declaration. Used for if-let guards.
     pub(crate) fn lower_let_expr(
         &mut self,
         mut block: BasicBlock,
@@ -1765,6 +1771,7 @@ pub(crate) fn lower_let_expr(
         else_target: region::Scope,
         source_scope: Option<SourceScope>,
         span: Span,
+        declare_bindings: bool,
     ) -> BlockAnd<()> {
         let expr_span = expr.span;
         let expr_place_builder = unpack!(block = self.lower_scrutinee(block, expr, expr_span));
@@ -1784,13 +1791,9 @@ pub(crate) fn lower_let_expr(
         let otherwise_post_guard_block = otherwise_candidate.pre_binding_block.unwrap();
         self.break_for_else(otherwise_post_guard_block, else_target, self.source_info(expr_span));
 
-        self.declare_bindings(
-            source_scope,
-            pat.span.to(span),
-            pat,
-            ArmHasGuard(false),
-            opt_expr_place,
-        );
+        if declare_bindings {
+            self.declare_bindings(source_scope, pat.span.to(span), pat, None, opt_expr_place);
+        }
 
         let post_guard_block = self.bind_pattern(
             self.source_info(pat.span),
@@ -1971,7 +1974,7 @@ fn bind_and_guard_matched_candidate<'pat>(
                     Guard::IfLet(ref pat, scrutinee) => {
                         let s = &this.thir[scrutinee];
                         guard_span = s.span;
-                        this.lower_let_expr(block, s, pat, match_scope, None, arm.span)
+                        this.lower_let_expr(block, s, pat, match_scope, None, arm.span, false)
                     }
                 });