Merge pull request #20521 from A4-Tacks/suggest-break-expr

Add BreakExpr completion suggest

Author: Veykril

crates/ide-completion/src/context/analysis.rs

@@ -2,7 +2,9 @@
 use std::iter;
 
 use hir::{ExpandResult, InFile, Semantics, Type, TypeInfo, Variant};
-use ide_db::{RootDatabase, active_parameter::ActiveParameter};
+use ide_db::{
+    RootDatabase, active_parameter::ActiveParameter, syntax_helpers::node_ext::find_loops,
+};
 use itertools::Either;
 use stdx::always;
 use syntax::{
@@ -779,6 +781,12 @@ fn expected_type_and_name<'db>(
                     });
                     (ty, None)
                 },
+                ast::BreakExpr(it) => {
+                    let ty = it.break_token()
+                        .and_then(|it| find_loops(sema, &it)?.next())
+                        .and_then(|expr| sema.type_of_expr(&expr));
+                    (ty.map(TypeInfo::original), None)
+                },
                 ast::ClosureExpr(it) => {
                     let ty = sema.type_of_expr(&it.into());
                     ty.and_then(|ty| ty.original.as_callable(sema.db))
@@ -2059,7 +2067,8 @@ fn prev_special_biased_token_at_trivia(mut token: SyntaxToken) -> SyntaxToken {
         | T![|]
         | T![return]
         | T![break]
-        | T![continue] = prev.kind()
+        | T![continue]
+        | T![lifetime_ident] = prev.kind()
     {
         token = prev
     }

crates/ide-completion/src/context/tests.rs

@@ -635,6 +635,125 @@ fn foo() {
     );
 }
 
+#[test]
+fn expected_type_break_expr_in_loop() {
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    let _x: State = loop {
+        {
+            break State::Stop;
+            break $0;
+        }
+    };
+}
+"#,
+        expect![[r#"ty: State, name: ?"#]],
+    );
+
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    let _x: State = 'a: loop {
+        {
+            break State::Stop;
+            break $0;
+        }
+    };
+}
+"#,
+        expect![[r#"ty: State, name: ?"#]],
+    );
+
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    let _x: State = 'a: loop {
+        while true {
+            break $0;
+        }
+    };
+}
+"#,
+        expect![[r#"ty: (), name: ?"#]],
+    );
+}
+
+#[test]
+fn expected_type_break_expr_in_labeled_loop() {
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    let _x: State = 'a: loop {
+        let _y: i32 = loop {
+            {
+                break 'a State::Stop;
+                break 'a $0;
+            }
+        };
+    };
+}
+"#,
+        expect![[r#"ty: State, name: ?"#]],
+    );
+
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    let _x: State = 'a: loop {
+        let _y: i32 = loop {
+            while true {
+                break 'a State::Stop;
+                break 'a $0;
+            }
+        };
+    };
+}
+"#,
+        expect![[r#"ty: State, name: ?"#]],
+    );
+
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    'a: while true {
+        let _x: State = loop {
+            break State::Stop;
+            break 'a $0;
+        };
+    }
+}
+"#,
+        expect![[r#"ty: (), name: ?"#]],
+    );
+}
+
+#[test]
+fn expected_type_break_expr_in_labeled_block() {
+    check_expected_type_and_name(
+        r#"
+enum State { Stop }
+fn foo() {
+    let _x: State = 'a: {
+        let _y: i32 = 'b: {
+            {
+                break 'a State::Stop;
+                break 'a $0;
+            };
+        };
+    };
+}
+"#,
+        expect![[r#"ty: State, name: ?"#]],
+    );
+}
+
 #[test]
 fn expected_type_logic_op() {
     check_expected_type_and_name(

crates/ide-db/src/syntax_helpers/node_ext.rs

@@ -419,6 +419,48 @@ pub fn eq_label_lt(lt1: &Option<ast::Lifetime>, lt2: &Option<ast::Lifetime>) ->
     lt1.as_ref().zip(lt2.as_ref()).is_some_and(|(lt, lbl)| lt.text() == lbl.text())
 }
 
+/// Find the loop or block to break or continue, multiple results may be caused by macros.
+pub fn find_loops(
+    sema: &hir::Semantics<'_, crate::RootDatabase>,
+    token: &syntax::SyntaxToken,
+) -> Option<impl Iterator<Item = ast::Expr>> {
+    let parent = token.parent()?;
+    let lbl = syntax::match_ast! {
+        match parent {
+            ast::BreakExpr(break_) => break_.lifetime(),
+            ast::ContinueExpr(continue_) => continue_.lifetime(),
+            _ => None,
+        }
+    };
+    let label_matches =
+        move |it: Option<ast::Label>| match (lbl.as_ref(), it.and_then(|it| it.lifetime())) {
+            (Some(lbl), Some(it)) => lbl.text() == it.text(),
+            (None, _) => true,
+            (Some(_), None) => false,
+        };
+
+    let find_ancestors = move |token| {
+        for anc in sema.token_ancestors_with_macros(token).filter_map(ast::Expr::cast) {
+            let node = match &anc {
+                ast::Expr::LoopExpr(loop_) if label_matches(loop_.label()) => anc,
+                ast::Expr::WhileExpr(while_) if label_matches(while_.label()) => anc,
+                ast::Expr::ForExpr(for_) if label_matches(for_.label()) => anc,
+                ast::Expr::BlockExpr(blk)
+                    if blk.label().is_some() && label_matches(blk.label()) =>
+                {
+                    anc
+                }
+                _ => continue,
+            };
+
+            return Some(node);
+        }
+        None
+    };
+
+    sema.descend_into_macros(token.clone()).into_iter().filter_map(find_ancestors).into()
+}
+
 struct TreeWithDepthIterator {
     preorder: Preorder<RustLanguage>,
     depth: u32,

crates/ide/src/goto_definition.rs

@@ -16,15 +16,12 @@ use ide_db::{
     defs::{Definition, IdentClass},
     famous_defs::FamousDefs,
     helpers::pick_best_token,
+    syntax_helpers::node_ext::find_loops,
 };
 use itertools::Itertools;
 use span::FileId;
 use syntax::{
-    AstNode, AstToken,
-    SyntaxKind::*,
-    SyntaxNode, SyntaxToken, T, TextRange,
-    ast::{self, HasLoopBody},
-    match_ast,
+    AstNode, AstToken, SyntaxKind::*, SyntaxNode, SyntaxToken, T, TextRange, ast, match_ast,
 };
 
 #[derive(Debug)]
@@ -510,59 +507,13 @@ fn nav_for_branch_exit_points(
     Some(navs)
 }
 
-pub(crate) fn find_loops(
-    sema: &Semantics<'_, RootDatabase>,
-    token: &SyntaxToken,
-) -> Option<Vec<ast::Expr>> {
-    let parent = token.parent()?;
-    let lbl = match_ast! {
-        match parent {
-            ast::BreakExpr(break_) => break_.lifetime(),
-            ast::ContinueExpr(continue_) => continue_.lifetime(),
-            _ => None,
-        }
-    };
-    let label_matches =
-        |it: Option<ast::Label>| match (lbl.as_ref(), it.and_then(|it| it.lifetime())) {
-            (Some(lbl), Some(it)) => lbl.text() == it.text(),
-            (None, _) => true,
-            (Some(_), None) => false,
-        };
-
-    let find_ancestors = |token: SyntaxToken| {
-        for anc in sema.token_ancestors_with_macros(token).filter_map(ast::Expr::cast) {
-            let node = match &anc {
-                ast::Expr::LoopExpr(loop_) if label_matches(loop_.label()) => anc,
-                ast::Expr::WhileExpr(while_) if label_matches(while_.label()) => anc,
-                ast::Expr::ForExpr(for_) if label_matches(for_.label()) => anc,
-                ast::Expr::BlockExpr(blk)
-                    if blk.label().is_some() && label_matches(blk.label()) =>
-                {
-                    anc
-                }
-                _ => continue,
-            };
-
-            return Some(node);
-        }
-        None
-    };
-
-    sema.descend_into_macros(token.clone())
-        .into_iter()
-        .filter_map(find_ancestors)
-        .collect_vec()
-        .into()
-}
-
 fn nav_for_break_points(
     sema: &Semantics<'_, RootDatabase>,
     token: &SyntaxToken,
 ) -> Option<Vec<NavigationTarget>> {
     let db = sema.db;
 
     let navs = find_loops(sema, token)?
-        .into_iter()
         .filter_map(|expr| {
             let file_id = sema.hir_file_for(expr.syntax());
             let expr_in_file = InFile::new(file_id, expr.clone());

crates/ide/src/highlight_related.rs

@@ -7,8 +7,8 @@ use ide_db::{
     helpers::pick_best_token,
     search::{FileReference, ReferenceCategory, SearchScope},
     syntax_helpers::node_ext::{
-        eq_label_lt, for_each_tail_expr, full_path_of_name_ref, is_closure_or_blk_with_modif,
-        preorder_expr_with_ctx_checker,
+        eq_label_lt, find_loops, for_each_tail_expr, full_path_of_name_ref,
+        is_closure_or_blk_with_modif, preorder_expr_with_ctx_checker,
     },
 };
 use syntax::{
@@ -562,7 +562,7 @@ pub(crate) fn highlight_break_points(
         Some(highlights)
     }
 
-    let Some(loops) = goto_definition::find_loops(sema, &token) else {
+    let Some(loops) = find_loops(sema, &token) else {
         return FxHashMap::default();
     };