//! Defines `Body`: a lowered representation of bodies of functions, statics and //! consts. mod lower; pub mod scope; use std::{mem, ops::Index, sync::Arc}; use drop_bomb::DropBomb; use either::Either; use hir_expand::{ast_id_map::AstIdMap, hygiene::Hygiene, AstId, HirFileId, InFile, MacroDefId}; use ra_arena::{map::ArenaMap, Arena}; use ra_prof::profile; use ra_syntax::{ast, AstNode, AstPtr}; use rustc_hash::FxHashMap; use crate::{ db::DefDatabase, expr::{Expr, ExprId, Pat, PatId}, item_scope::BuiltinShadowMode, item_scope::ItemScope, nameres::CrateDefMap, path::{ModPath, Path}, src::HasSource, AsMacroCall, DefWithBodyId, HasModule, Lookup, ModuleId, }; pub(crate) struct Expander { crate_def_map: Arc<CrateDefMap>, current_file_id: HirFileId, hygiene: Hygiene, ast_id_map: Arc<AstIdMap>, module: ModuleId, recursive_limit: usize, } impl Expander { pub(crate) fn new( db: &dyn DefDatabase, current_file_id: HirFileId, module: ModuleId, ) -> Expander { let crate_def_map = db.crate_def_map(module.krate); let hygiene = Hygiene::new(db.upcast(), current_file_id); let ast_id_map = db.ast_id_map(current_file_id); Expander { crate_def_map, current_file_id, hygiene, ast_id_map, module, recursive_limit: 0 } } pub(crate) fn enter_expand<T: ast::AstNode>( &mut self, db: &dyn DefDatabase, local_scope: Option<&ItemScope>, macro_call: ast::MacroCall, ) -> Option<(Mark, T)> { if self.recursive_limit > 1024 { return None; } let macro_call = InFile::new(self.current_file_id, ¯o_call); if let Some(call_id) = macro_call.as_call_id(db, |path| { if let Some(local_scope) = local_scope { if let Some(def) = path.as_ident().and_then(|n| local_scope.get_legacy_macro(n)) { return Some(def); } } self.resolve_path_as_macro(db, &path) }) { let file_id = call_id.as_file(); if let Some(node) = db.parse_or_expand(file_id) { if let Some(expr) = T::cast(node) { log::debug!("macro expansion {:#?}", expr.syntax()); let mark = Mark { file_id: self.current_file_id, ast_id_map: mem::take(&mut self.ast_id_map), bomb: DropBomb::new("expansion mark dropped"), }; self.hygiene = Hygiene::new(db.upcast(), file_id); self.current_file_id = file_id; self.ast_id_map = db.ast_id_map(file_id); self.recursive_limit += 1; return Some((mark, expr)); } } } // FIXME: Instead of just dropping the error from expansion // report it None } pub(crate) fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) { self.hygiene = Hygiene::new(db.upcast(), mark.file_id); self.current_file_id = mark.file_id; self.ast_id_map = mem::take(&mut mark.ast_id_map); self.recursive_limit -= 1; mark.bomb.defuse(); } pub(crate) fn to_source<T>(&self, value: T) -> InFile<T> { InFile { file_id: self.current_file_id, value } } fn parse_path(&mut self, path: ast::Path) -> Option<Path> { Path::from_src(path, &self.hygiene) } fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroDefId> { self.crate_def_map .resolve_path(db, self.module.local_id, path, BuiltinShadowMode::Other) .0 .take_macros() } fn ast_id<N: AstNode>(&self, item: &N) -> AstId<N> { let file_local_id = self.ast_id_map.ast_id(item); AstId::new(self.current_file_id, file_local_id) } } pub(crate) struct Mark { file_id: HirFileId, ast_id_map: Arc<AstIdMap>, bomb: DropBomb, } /// The body of an item (function, const etc.). #[derive(Debug, Eq, PartialEq)] pub struct Body { pub exprs: Arena<Expr>, pub pats: Arena<Pat>, /// The patterns for the function's parameters. While the parameter types are /// part of the function signature, the patterns are not (they don't change /// the external type of the function). /// /// If this `Body` is for the body of a constant, this will just be /// empty. pub params: Vec<PatId>, /// The `ExprId` of the actual body expression. pub body_expr: ExprId, pub item_scope: ItemScope, } pub type ExprPtr = Either<AstPtr<ast::Expr>, AstPtr<ast::RecordField>>; pub type ExprSource = InFile<ExprPtr>; pub type PatPtr = Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>; pub type PatSource = InFile<PatPtr>; /// An item body together with the mapping from syntax nodes to HIR expression /// IDs. This is needed to go from e.g. a position in a file to the HIR /// expression containing it; but for type inference etc., we want to operate on /// a structure that is agnostic to the actual positions of expressions in the /// file, so that we don't recompute types whenever some whitespace is typed. /// /// One complication here is that, due to macro expansion, a single `Body` might /// be spread across several files. So, for each ExprId and PatId, we record /// both the HirFileId and the position inside the file. However, we only store /// AST -> ExprId mapping for non-macro files, as it is not clear how to handle /// this properly for macros. #[derive(Default, Debug, Eq, PartialEq)] pub struct BodySourceMap { expr_map: FxHashMap<ExprSource, ExprId>, expr_map_back: ArenaMap<ExprId, Result<ExprSource, SyntheticSyntax>>, pat_map: FxHashMap<PatSource, PatId>, pat_map_back: ArenaMap<PatId, Result<PatSource, SyntheticSyntax>>, field_map: FxHashMap<(ExprId, usize), AstPtr<ast::RecordField>>, expansions: FxHashMap<InFile<AstPtr<ast::MacroCall>>, HirFileId>, } #[derive(Default, Debug, Eq, PartialEq, Clone, Copy)] pub struct SyntheticSyntax; impl Body { pub(crate) fn body_with_source_map_query( db: &dyn DefDatabase, def: DefWithBodyId, ) -> (Arc<Body>, Arc<BodySourceMap>) { let _p = profile("body_with_source_map_query"); let mut params = None; let (file_id, module, body) = match def { DefWithBodyId::FunctionId(f) => { let f = f.lookup(db); let src = f.source(db); params = src.value.param_list(); (src.file_id, f.module(db), src.value.body().map(ast::Expr::from)) } DefWithBodyId::ConstId(c) => { let c = c.lookup(db); let src = c.source(db); (src.file_id, c.module(db), src.value.body()) } DefWithBodyId::StaticId(s) => { let s = s.lookup(db); let src = s.source(db); (src.file_id, s.module(db), src.value.body()) } }; let expander = Expander::new(db, file_id, module); let (body, source_map) = Body::new(db, def, expander, params, body); (Arc::new(body), Arc::new(source_map)) } pub(crate) fn body_query(db: &dyn DefDatabase, def: DefWithBodyId) -> Arc<Body> { db.body_with_source_map(def).0 } fn new( db: &dyn DefDatabase, def: DefWithBodyId, expander: Expander, params: Option<ast::ParamList>, body: Option<ast::Expr>, ) -> (Body, BodySourceMap) { lower::lower(db, def, expander, params, body) } } impl Index<ExprId> for Body { type Output = Expr; fn index(&self, expr: ExprId) -> &Expr { &self.exprs[expr] } } impl Index<PatId> for Body { type Output = Pat; fn index(&self, pat: PatId) -> &Pat { &self.pats[pat] } } impl BodySourceMap { pub fn expr_syntax(&self, expr: ExprId) -> Result<ExprSource, SyntheticSyntax> { self.expr_map_back[expr] } pub fn node_expr(&self, node: InFile<&ast::Expr>) -> Option<ExprId> { let src = node.map(|it| Either::Left(AstPtr::new(it))); self.expr_map.get(&src).cloned() } pub fn node_macro_file(&self, node: InFile<&ast::MacroCall>) -> Option<HirFileId> { let src = node.map(|it| AstPtr::new(it)); self.expansions.get(&src).cloned() } pub fn field_init_shorthand_expr(&self, node: InFile<&ast::RecordField>) -> Option<ExprId> { let src = node.map(|it| Either::Right(AstPtr::new(it))); self.expr_map.get(&src).cloned() } pub fn pat_syntax(&self, pat: PatId) -> Result<PatSource, SyntheticSyntax> { self.pat_map_back[pat] } pub fn node_pat(&self, node: InFile<&ast::Pat>) -> Option<PatId> { let src = node.map(|it| Either::Left(AstPtr::new(it))); self.pat_map.get(&src).cloned() } pub fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::RecordField> { self.field_map[&(expr, field)] } }