correctly infer labelled breaks

3 files changed, 60 insertions, 19 deletions

diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index 905c0cf5d..dc52c6bd9 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -134,7 +134,7 @@ impl ExprCollector<'_> {
         self.make_expr(expr, Err(SyntheticSyntax))
     }
     fn empty_block(&mut self) -> ExprId {
-        self.alloc_expr_desugared(Expr::Block { statements: Vec::new(), tail: None })
+        self.alloc_expr_desugared(Expr::Block { statements: Vec::new(), tail: None, label: None })
     }
     fn missing_expr(&mut self) -> ExprId {
         self.alloc_expr_desugared(Expr::Missing)
@@ -215,7 +215,13 @@ impl ExprCollector<'_> {
             ast::Expr::BlockExpr(e) => self.collect_block(e),
             ast::Expr::LoopExpr(e) => {
                 let body = self.collect_block_opt(e.loop_body());
-                self.alloc_expr(Expr::Loop { body }, syntax_ptr)
+                self.alloc_expr(
+                    Expr::Loop {
+                        body,
+                        label: e.label().and_then(|l| l.lifetime_token()).map(|l| Name::new_lifetime(&l)),
+                    },
+                    syntax_ptr,
+                )
             }
             ast::Expr::WhileExpr(e) => {
                 let body = self.collect_block_opt(e.loop_body());
@@ -230,25 +236,47 @@ impl ExprCollector<'_> {
                             let pat = self.collect_pat(pat);
                             let match_expr = self.collect_expr_opt(condition.expr());
                             let placeholder_pat = self.missing_pat();
-                            let break_ = self.alloc_expr_desugared(Expr::Break { expr: None });
+                            let break_ =
+                                self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
                             let arms = vec![
                                 MatchArm { pat, expr: body, guard: None },
                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
                             ];
                             let match_expr =
                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
-                            return self.alloc_expr(Expr::Loop { body: match_expr }, syntax_ptr);
+                            return self.alloc_expr(
+                                Expr::Loop {
+                                    body: match_expr,
+                                    label: e.label().and_then(|l| l.lifetime_token()).map(|l| Name::new_lifetime(&l)),
+                                },
+                                syntax_ptr,
+                            );
                         }
                     },
                 };
 
-                self.alloc_expr(Expr::While { condition, body }, syntax_ptr)
+                self.alloc_expr(
+                    Expr::While {
+                        condition,
+                        body,
+                        label: e.label().and_then(|l| l.lifetime_token()).map(|l| Name::new_lifetime(&l)),
+                    },
+                    syntax_ptr,
+                )
             }
             ast::Expr::ForExpr(e) => {
                 let iterable = self.collect_expr_opt(e.iterable());
                 let pat = self.collect_pat_opt(e.pat());
                 let body = self.collect_block_opt(e.loop_body());
-                self.alloc_expr(Expr::For { iterable, pat, body }, syntax_ptr)
+                self.alloc_expr(
+                    Expr::For {
+                        iterable,
+                        pat,
+                        body,
+                        label: e.label().and_then(|l| l.lifetime_token()).map(|l| Name::new_lifetime(&l)),
+                    },
+                    syntax_ptr,
+                )
             }
             ast::Expr::CallExpr(e) => {
                 let callee = self.collect_expr_opt(e.expr());
@@ -301,13 +329,18 @@ impl ExprCollector<'_> {
                     .unwrap_or(Expr::Missing);
                 self.alloc_expr(path, syntax_ptr)
             }
-            ast::Expr::ContinueExpr(_e) => {
-                // FIXME: labels
-                self.alloc_expr(Expr::Continue, syntax_ptr)
+            ast::Expr::ContinueExpr(e) => {
+                self.alloc_expr(
+                    Expr::Continue { label: e.lifetime_token().map(|l| Name::new_lifetime(&l)) },
+                    syntax_ptr,
+                )
             }
             ast::Expr::BreakExpr(e) => {
                 let expr = e.expr().map(|e| self.collect_expr(e));
-                self.alloc_expr(Expr::Break { expr }, syntax_ptr)
+                self.alloc_expr(
+                    Expr::Break { expr, label: e.lifetime_token().map(|l| Name::new_lifetime(&l)) },
+                    syntax_ptr,
+                )
             }
             ast::Expr::ParenExpr(e) => {
                 let inner = self.collect_expr_opt(e.expr());
@@ -529,7 +562,8 @@ impl ExprCollector<'_> {
             })
             .collect();
         let tail = block.expr().map(|e| self.collect_expr(e));
-        self.alloc_expr(Expr::Block { statements, tail }, syntax_node_ptr)
+        let label = block.label().and_then(|l| l.lifetime_token()).map(|t| Name::new_lifetime(&t));
+        self.alloc_expr(Expr::Block { statements, tail, label }, syntax_node_ptr)
     }
 
     fn collect_block_items(&mut self, block: &ast::BlockExpr) {
diff --git a/crates/ra_hir_def/src/body/scope.rs b/crates/ra_hir_def/src/body/scope.rs
index 09e92b74e..e48ff38f9 100644
--- a/crates/ra_hir_def/src/body/scope.rs
+++ b/crates/ra_hir_def/src/body/scope.rs
@@ -138,10 +138,10 @@ fn compute_block_scopes(
 fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope: ScopeId) {
     scopes.set_scope(expr, scope);
     match &body[expr] {
-        Expr::Block { statements, tail } => {
+        Expr::Block { statements, tail, .. } => {
             compute_block_scopes(&statements, *tail, body, scopes, scope);
         }
-        Expr::For { iterable, pat, body: body_expr } => {
+        Expr::For { iterable, pat, body: body_expr, .. } => {
             compute_expr_scopes(*iterable, body, scopes, scope);
             let scope = scopes.new_scope(scope);
             scopes.add_bindings(body, scope, *pat);
diff --git a/crates/ra_hir_def/src/expr.rs b/crates/ra_hir_def/src/expr.rs
index f25c6f958..8683f6c7f 100644
--- a/crates/ra_hir_def/src/expr.rs
+++ b/crates/ra_hir_def/src/expr.rs
@@ -52,18 +52,22 @@ pub enum Expr {
     Block {
         statements: Vec<Statement>,
         tail: Option<ExprId>,
+        label: Option<Name>,
     },
     Loop {
         body: ExprId,
+        label: Option<Name>,
     },
     While {
         condition: ExprId,
         body: ExprId,
+        label: Option<Name>,
     },
     For {
         iterable: ExprId,
         pat: PatId,
         body: ExprId,
+        label: Option<Name>,
     },
     Call {
         callee: ExprId,
@@ -79,9 +83,12 @@ pub enum Expr {
         expr: ExprId,
         arms: Vec<MatchArm>,
     },
-    Continue,
+    Continue {
+        label: Option<Name>,
+    },
     Break {
         expr: Option<ExprId>,
+        label: Option<Name>,
     },
     Return {
         expr: Option<ExprId>,
@@ -225,7 +232,7 @@ impl Expr {
                     f(*else_branch);
                 }
             }
-            Expr::Block { statements, tail } => {
+            Expr::Block { statements, tail, .. } => {
                 for stmt in statements {
                     match stmt {
                         Statement::Let { initializer, .. } => {
@@ -241,8 +248,8 @@ impl Expr {
                 }
             }
             Expr::TryBlock { body } => f(*body),
-            Expr::Loop { body } => f(*body),
-            Expr::While { condition, body } => {
+            Expr::Loop { body, .. } => f(*body),
+            Expr::While { condition, body, .. } => {
                 f(*condition);
                 f(*body);
             }
@@ -268,8 +275,8 @@ impl Expr {
                     f(arm.expr);
                 }
             }
-            Expr::Continue => {}
-            Expr::Break { expr } | Expr::Return { expr } => {
+            Expr::Continue { .. } => {},
+            Expr::Break { expr, .. } | Expr::Return { expr } => {
                 if let Some(expr) = expr {
                     f(*expr);
                 }