use std::sync::Arc; use ra_arena::{impl_arena_id, Arena, RawId}; use rustc_hash::FxHashMap; use crate::{ db::HirDatabase, expr::{Body, Expr, ExprId, Pat, PatId, Statement}, DefWithBody, Name, }; #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct ScopeId(RawId); impl_arena_id!(ScopeId); #[derive(Debug, PartialEq, Eq)] pub struct ExprScopes { body: Arc, scopes: Arena, scope_by_expr: FxHashMap, } #[derive(Debug, PartialEq, Eq)] pub(crate) struct ScopeEntry { name: Name, pat: PatId, } impl ScopeEntry { pub(crate) fn name(&self) -> &Name { &self.name } pub(crate) fn pat(&self) -> PatId { self.pat } } #[derive(Debug, PartialEq, Eq)] pub(crate) struct ScopeData { parent: Option, entries: Vec, } impl ExprScopes { pub(crate) fn expr_scopes_query(db: &impl HirDatabase, def: DefWithBody) -> Arc { let body = db.body_hir(def); let res = ExprScopes::new(body); Arc::new(res) } fn new(body: Arc) -> ExprScopes { let mut scopes = ExprScopes { body: body.clone(), scopes: Arena::default(), scope_by_expr: FxHashMap::default(), }; let root = scopes.root_scope(); scopes.add_params_bindings(root, body.params()); compute_expr_scopes(body.body_expr(), &body, &mut scopes, root); scopes } pub(crate) fn entries(&self, scope: ScopeId) -> &[ScopeEntry] { &self.scopes[scope].entries } pub(crate) fn scope_chain<'a>( &'a self, scope: Option, ) -> impl Iterator + 'a { std::iter::successors(scope, move |&scope| self.scopes[scope].parent) } pub(crate) fn scope_for(&self, expr: ExprId) -> Option { self.scope_by_expr.get(&expr).copied() } pub(crate) fn scope_by_expr(&self) -> &FxHashMap { &self.scope_by_expr } fn root_scope(&mut self) -> ScopeId { self.scopes.alloc(ScopeData { parent: None, entries: vec![] }) } fn new_scope(&mut self, parent: ScopeId) -> ScopeId { self.scopes.alloc(ScopeData { parent: Some(parent), entries: vec![] }) } fn add_bindings(&mut self, body: &Body, scope: ScopeId, pat: PatId) { match &body[pat] { Pat::Bind { name, .. } => { // bind can have a sub pattern, but it's actually not allowed // to bind to things in there let entry = ScopeEntry { name: name.clone(), pat }; self.scopes[scope].entries.push(entry) } p => p.walk_child_pats(|pat| self.add_bindings(body, scope, pat)), } } fn add_params_bindings(&mut self, scope: ScopeId, params: &[PatId]) { let body = Arc::clone(&self.body); params.iter().for_each(|pat| self.add_bindings(&body, scope, *pat)); } fn set_scope(&mut self, node: ExprId, scope: ScopeId) { self.scope_by_expr.insert(node, scope); } } fn compute_block_scopes( statements: &[Statement], tail: Option, body: &Body, scopes: &mut ExprScopes, mut scope: ScopeId, ) { for stmt in statements { match stmt { Statement::Let { pat, initializer, .. } => { if let Some(expr) = initializer { scopes.set_scope(*expr, scope); compute_expr_scopes(*expr, body, scopes, scope); } scope = scopes.new_scope(scope); scopes.add_bindings(body, scope, *pat); } Statement::Expr(expr) => { scopes.set_scope(*expr, scope); compute_expr_scopes(*expr, body, scopes, scope); } } } if let Some(expr) = tail { compute_expr_scopes(expr, body, scopes, scope); } } 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 } => { compute_block_scopes(&statements, *tail, body, scopes, scope); } 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); compute_expr_scopes(*body_expr, body, scopes, scope); } Expr::Lambda { args, body: body_expr, .. } => { let scope = scopes.new_scope(scope); scopes.add_params_bindings(scope, &args); compute_expr_scopes(*body_expr, body, scopes, scope); } Expr::Match { expr, arms } => { compute_expr_scopes(*expr, body, scopes, scope); for arm in arms { let scope = scopes.new_scope(scope); for pat in &arm.pats { scopes.add_bindings(body, scope, *pat); } scopes.set_scope(arm.expr, scope); compute_expr_scopes(arm.expr, body, scopes, scope); } } e => e.walk_child_exprs(|e| compute_expr_scopes(e, body, scopes, scope)), }; } #[cfg(test)] mod tests { use ra_db::SourceDatabase; use ra_syntax::{algo::find_node_at_offset, ast, AstNode}; use test_utils::{assert_eq_text, extract_offset}; use crate::{mock::MockDatabase, source_binder::SourceAnalyzer}; fn do_check(code: &str, expected: &[&str]) { let (off, code) = extract_offset(code); let code = { let mut buf = String::new(); let off = u32::from(off) as usize; buf.push_str(&code[..off]); buf.push_str("marker"); buf.push_str(&code[off..]); buf }; let (db, _source_root, file_id) = MockDatabase::with_single_file(&code); let file = db.parse(file_id).ok().unwrap(); let marker: ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap(); let analyzer = SourceAnalyzer::new(&db, file_id, marker.syntax(), None); let scopes = analyzer.scopes(); let expr_id = analyzer.body_source_map().node_expr(&marker.into()).unwrap(); let scope = scopes.scope_for(expr_id); let actual = scopes .scope_chain(scope) .flat_map(|scope| scopes.entries(scope)) .map(|it| it.name().to_string()) .collect::>() .join("\n"); let expected = expected.join("\n"); assert_eq_text!(&expected, &actual); } #[test] fn test_lambda_scope() { do_check( r" fn quux(foo: i32) { let f = |bar, baz: i32| { <|> }; }", &["bar", "baz", "foo"], ); } #[test] fn test_call_scope() { do_check( r" fn quux() { f(|x| <|> ); }", &["x"], ); } #[test] fn test_method_call_scope() { do_check( r" fn quux() { z.f(|x| <|> ); }", &["x"], ); } #[test] fn test_loop_scope() { do_check( r" fn quux() { loop { let x = (); <|> }; }", &["x"], ); } #[test] fn test_match() { do_check( r" fn quux() { match () { Some(x) => { <|> } }; }", &["x"], ); } #[test] fn test_shadow_variable() { do_check( r" fn foo(x: String) { let x : &str = &x<|>; }", &["x"], ); } fn do_check_local_name(code: &str, expected_offset: u32) { let (off, code) = extract_offset(code); let (db, _source_root, file_id) = MockDatabase::with_single_file(&code); let file = db.parse(file_id).ok().unwrap(); let expected_name = find_node_at_offset::(file.syntax(), expected_offset.into()) .expect("failed to find a name at the target offset"); let name_ref: ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap(); let analyzer = SourceAnalyzer::new(&db, file_id, name_ref.syntax(), None); let local_name_entry = analyzer.resolve_local_name(&name_ref).unwrap(); let local_name = local_name_entry.ptr().either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr()); assert_eq!(local_name.range(), expected_name.syntax().text_range()); } #[test] fn test_resolve_local_name() { do_check_local_name( r#" fn foo(x: i32, y: u32) { { let z = x * 2; } { let t = x<|> * 3; } }"#, 21, ); } #[test] fn test_resolve_local_name_declaration() { do_check_local_name( r#" fn foo(x: String) { let x : &str = &x<|>; }"#, 21, ); } #[test] fn test_resolve_local_name_shadow() { do_check_local_name( r" fn foo(x: String) { let x : &str = &x; x<|> } ", 53, ); } #[test] fn ref_patterns_contribute_bindings() { do_check_local_name( r" fn foo() { if let Some(&from) = bar() { from<|>; } } ", 53, ); } }