Record for each MIR local where it has been introduced.

cjgillot · cjgillot · commit 927374b95cff · 2025-06-13T00:30:29.000Z
diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
@@ -140,9 +140,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 // whether or not the right-hand side is a place expression
                 if let LocalInfo::User(BindingForm::Var(VarBindingForm {
                     opt_match_place: Some((opt_match_place, match_span)),
-                    binding_mode: _,
-                    opt_ty_info: _,
-                    pat_span: _,
+                    ..
                 })) = *local_decl.local_info()
                 {
                     let stmt_source_info = self.body.source_info(location);
diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -307,8 +307,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                         LocalInfo::User(BindingForm::Var(mir::VarBindingForm {
                             binding_mode: BindingMode(ByRef::No, Mutability::Not),
                             opt_ty_info: Some(sp),
-                            opt_match_place: _,
-                            pat_span: _,
+                            ..
                         })) => {
                             if suggest {
                                 err.span_note(sp, "the binding is already a mutable borrow");
@@ -738,6 +737,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 opt_ty_info: _,
                 opt_match_place: _,
                 pat_span,
+                introductions: _,
             })) => pat_span,
             _ => local_decl.source_info.span,
         };
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
@@ -926,6 +926,8 @@ pub struct VarBindingForm<'tcx> {
     pub opt_match_place: Option<(Option<Place<'tcx>>, Span)>,
     /// The span of the pattern in which this variable was bound.
     pub pat_span: Span,
+    /// For each introduction place, record here the span and whether this was a shorthand pattern.
+    pub introductions: Vec<(Span, /* is_shorthand */ bool)>,
 }
 
 #[derive(Clone, Debug, TyEncodable, TyDecodable)]
@@ -1131,12 +1133,8 @@ impl<'tcx> LocalDecl<'tcx> {
         matches!(
             self.local_info(),
             LocalInfo::User(
-                BindingForm::Var(VarBindingForm {
-                    binding_mode: BindingMode(ByRef::No, _),
-                    opt_ty_info: _,
-                    opt_match_place: _,
-                    pat_span: _,
-                }) | BindingForm::ImplicitSelf(ImplicitSelfKind::Imm),
+                BindingForm::Var(VarBindingForm { binding_mode: BindingMode(ByRef::No, _), .. })
+                    | BindingForm::ImplicitSelf(ImplicitSelfKind::Imm),
             )
         )
     }
@@ -1148,12 +1146,8 @@ impl<'tcx> LocalDecl<'tcx> {
         matches!(
             self.local_info(),
             LocalInfo::User(
-                BindingForm::Var(VarBindingForm {
-                    binding_mode: BindingMode(ByRef::No, _),
-                    opt_ty_info: _,
-                    opt_match_place: _,
-                    pat_span: _,
-                }) | BindingForm::ImplicitSelf(_),
+                BindingForm::Var(VarBindingForm { binding_mode: BindingMode(ByRef::No, _), .. })
+                    | BindingForm::ImplicitSelf(_),
             )
         )
     }
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
@@ -777,6 +777,7 @@ pub enum PatKind<'tcx> {
         /// (The same binding can occur multiple times in different branches of
         /// an or-pattern, but only one of them will be primary.)
         is_primary: bool,
+        is_shorthand: bool,
     },
 
     /// `Foo(...)` or `Foo{...}` or `Foo`, where `Foo` is a variant name from an ADT with
diff --git a/compiler/rustc_mir_build/src/builder/block.rs b/compiler/rustc_mir_build/src/builder/block.rs
@@ -204,6 +204,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                                 block,
                                 node,
                                 span,
+                                false,
                                 OutsideGuard,
                                 ScheduleDrops::Yes,
                             );
@@ -296,6 +297,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                                 block,
                                 node,
                                 span,
+                                false,
                                 OutsideGuard,
                                 ScheduleDrops::Yes,
                             );
diff --git a/compiler/rustc_mir_build/src/builder/matches/match_pair.rs b/compiler/rustc_mir_build/src/builder/matches/match_pair.rs
@@ -160,7 +160,7 @@ impl<'tcx> MatchPairTree<'tcx> {
                 None
             }
 
-            PatKind::Binding { mode, var, ref subpattern, .. } => {
+            PatKind::Binding { mode, var, is_shorthand, ref subpattern, .. } => {
                 // In order to please the borrow checker, when lowering a pattern
                 // like `x @ subpat` we must establish any bindings in `subpat`
                 // before establishing the binding for `x`.
@@ -199,6 +199,7 @@ impl<'tcx> MatchPairTree<'tcx> {
                         source,
                         var_id: var,
                         binding_mode: mode,
+                        is_shorthand,
                     });
                 }
 
diff --git a/compiler/rustc_mir_build/src/builder/matches/mod.rs b/compiler/rustc_mir_build/src/builder/matches/mod.rs
@@ -600,6 +600,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     block,
                     var,
                     irrefutable_pat.span,
+                    false,
                     OutsideGuard,
                     ScheduleDrops::Yes,
                 );
@@ -629,6 +630,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     block,
                     var,
                     irrefutable_pat.span,
+                    false,
                     OutsideGuard,
                     ScheduleDrops::Yes,
                 );
@@ -821,6 +823,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         block: BasicBlock,
         var: LocalVarId,
         span: Span,
+        is_shorthand: bool,
         for_guard: ForGuard,
         schedule_drop: ScheduleDrops,
     ) -> Place<'tcx> {
@@ -834,6 +837,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         {
             self.schedule_drop(span, region_scope, local_id, DropKind::Storage);
         }
+        let local_info = self.local_decls[local_id].local_info.as_mut().unwrap_crate_local();
+        if let LocalInfo::User(BindingForm::Var(var_info)) = &mut **local_info {
+            var_info.introductions.push((span, is_shorthand));
+        }
         Place::from(local_id)
     }
 
@@ -1230,6 +1237,7 @@ struct Binding<'tcx> {
     source: Place<'tcx>,
     var_id: LocalVarId,
     binding_mode: BindingMode,
+    is_shorthand: bool,
 }
 
 /// Indicates that the type of `source` must be a subtype of the
@@ -2693,6 +2701,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 block,
                 binding.var_id,
                 binding.span,
+                binding.is_shorthand,
                 RefWithinGuard,
                 schedule_drops,
             );
@@ -2709,6 +2718,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         block,
                         binding.var_id,
                         binding.span,
+                        binding.is_shorthand,
                         OutsideGuard,
                         schedule_drops,
                     );
@@ -2748,6 +2758,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     block,
                     binding.var_id,
                     binding.span,
+                    binding.is_shorthand,
                     OutsideGuard,
                     schedule_drops,
                 ),
@@ -2801,6 +2812,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     opt_ty_info: None,
                     opt_match_place,
                     pat_span,
+                    introductions: Vec::new(),
                 },
             )))),
         };
diff --git a/compiler/rustc_mir_build/src/builder/mod.rs b/compiler/rustc_mir_build/src/builder/mod.rs
@@ -1045,6 +1045,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                                 opt_ty_info: param.ty_span,
                                 opt_match_place: Some((None, span)),
                                 pat_span: span,
+                                introductions: vec![(span, false)],
                             }))
                         };
                     self.var_indices.insert(var, LocalsForNode::One(local));
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -368,6 +368,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
                     ty: var_ty,
                     subpattern: self.lower_opt_pattern(sub),
                     is_primary: id == pat.hir_id,
+                    is_shorthand: false,
                 }
             }
 
@@ -385,9 +386,13 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
                 let res = self.typeck_results.qpath_res(qpath, pat.hir_id);
                 let subpatterns = fields
                     .iter()
-                    .map(|field| FieldPat {
-                        field: self.typeck_results.field_index(field.hir_id),
-                        pattern: *self.lower_pattern(field.pat),
+                    .map(|field| {
+                        let mut pattern = *self.lower_pattern(field.pat);
+                        if let PatKind::Binding { ref mut is_shorthand, .. } = pattern.kind {
+                            *is_shorthand = field.is_shorthand;
+                        }
+                        let field = self.typeck_results.field_index(field.hir_id);
+                        FieldPat { field, pattern }
                     })
                     .collect();
 
diff --git a/compiler/rustc_mir_build/src/thir/print.rs b/compiler/rustc_mir_build/src/thir/print.rs
@@ -677,13 +677,14 @@ impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
                 self.print_pat(subpattern, depth_lvl + 3);
                 print_indented!(self, "}", depth_lvl + 1);
             }
-            PatKind::Binding { name, mode, var, ty, subpattern, is_primary } => {
+            PatKind::Binding { name, mode, var, ty, subpattern, is_primary, is_shorthand } => {
                 print_indented!(self, "Binding {", depth_lvl + 1);
                 print_indented!(self, format!("name: {:?}", name), depth_lvl + 2);
                 print_indented!(self, format!("mode: {:?}", mode), depth_lvl + 2);
                 print_indented!(self, format!("var: {:?}", var), depth_lvl + 2);
                 print_indented!(self, format!("ty: {:?}", ty), depth_lvl + 2);
                 print_indented!(self, format!("is_primary: {:?}", is_primary), depth_lvl + 2);
+                print_indented!(self, format!("is_shorthand: {:?}", is_shorthand), depth_lvl + 2);
 
                 if let Some(subpattern) = subpattern {
                     print_indented!(self, "subpattern: Some( ", depth_lvl + 2);
diff --git a/tests/ui/thir-print/thir-tree-match.stdout b/tests/ui/thir-print/thir-tree-match.stdout
@@ -16,6 +16,7 @@ params: [
                         var: LocalVarId(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).2))
                         ty: Foo
                         is_primary: true
+                        is_shorthand: false
                         subpattern: None
                     }
                 }

Original file line number	Diff line number	Diff line change
`@@ -926,6 +926,8 @@ pub struct VarBindingForm<'tcx> {`
`926`	`926`	`pub opt_match_place: Option<(Option<Place<'tcx>>, Span)>,`
`927`	`927`	`/// The span of the pattern in which this variable was bound.`
`928`	`928`	`pub pat_span: Span,`
	`929`	`+ /// For each introduction place, record here the span and whether this was a shorthand pattern.`
	`930`	`+ pub introductions: Vec<(Span, /* is_shorthand */ bool)>,`
`929`	`931`	`}`
`930`	`932`
`931`	`933`	`#[derive(Clone, Debug, TyEncodable, TyDecodable)]`
`@@ -1131,12 +1133,8 @@ impl<'tcx> LocalDecl<'tcx> {`
`1131`	`1133`	`matches!(`
`1132`	`1134`	`self.local_info(),`
`1133`	`1135`	`LocalInfo::User(`
`1134`		`- BindingForm::Var(VarBindingForm {`
`1135`		`- binding_mode: BindingMode(ByRef::No, _),`
`1136`		`- opt_ty_info: _,`
`1137`		`- opt_match_place: _,`
`1138`		`- pat_span: _,`
`1139`		`- }) \| BindingForm::ImplicitSelf(ImplicitSelfKind::Imm),`
	`1136`	`+ BindingForm::Var(VarBindingForm { binding_mode: BindingMode(ByRef::No, _), .. })`
	`1137`	`+ \| BindingForm::ImplicitSelf(ImplicitSelfKind::Imm),`
`1140`	`1138`	`)`
`1141`	`1139`	`)`
`1142`	`1140`	`}`
`@@ -1148,12 +1146,8 @@ impl<'tcx> LocalDecl<'tcx> {`
`1148`	`1146`	`matches!(`
`1149`	`1147`	`self.local_info(),`
`1150`	`1148`	`LocalInfo::User(`
`1151`		`- BindingForm::Var(VarBindingForm {`
`1152`		`- binding_mode: BindingMode(ByRef::No, _),`
`1153`		`- opt_ty_info: _,`
`1154`		`- opt_match_place: _,`
`1155`		`- pat_span: _,`
`1156`		`- }) \| BindingForm::ImplicitSelf(_),`
	`1149`	`+ BindingForm::Var(VarBindingForm { binding_mode: BindingMode(ByRef::No, _), .. })`
	`1150`	`+ \| BindingForm::ImplicitSelf(_),`
`1157`	`1151`	`)`
`1158`	`1152`	`)`
`1159`	`1153`	`}`
Original file line number	Diff line number	Diff line change
`@@ -160,7 +160,7 @@ impl<'tcx> MatchPairTree<'tcx> {`
`160`	`160`	`None`
`161`	`161`	`}`
`162`	`162`
`163`		`- PatKind::Binding { mode, var, ref subpattern, .. } => {`
	`163`	`+ PatKind::Binding { mode, var, is_shorthand, ref subpattern, .. } => {`
`164`	`164`	`// In order to please the borrow checker, when lowering a pattern`
`165`	`165`	// like `x @ subpat` we must establish any bindings in `subpat`
`166`	`166`	// before establishing the binding for `x`.
`@@ -199,6 +199,7 @@ impl<'tcx> MatchPairTree<'tcx> {`
`199`	`199`	`source,`
`200`	`200`	`var_id: var,`
`201`	`201`	`binding_mode: mode,`
	`202`	`+ is_shorthand,`
`202`	`203`	`});`
`203`	`204`	`}`
`204`	`205`