//! Defines `Body`: a lowered representation of bodies of functions, statics and //! consts. mod lower; #[cfg(test)] mod tests; pub mod scope; use std::{mem, ops::Index, sync::Arc}; use base_db::CrateId; use cfg::{CfgExpr, CfgOptions}; use drop_bomb::DropBomb; use either::Either; use hir_expand::{ ast_id_map::AstIdMap, hygiene::Hygiene, AstId, ExpandResult, HirFileId, InFile, MacroDefId, }; use la_arena::{Arena, ArenaMap}; use profile::Count; use rustc_hash::FxHashMap; use syntax::{ast, AstNode, AstPtr, SyntaxNodePtr}; use crate::{ attr::{Attrs, RawAttrs}, db::DefDatabase, expr::{Expr, ExprId, Label, LabelId, Pat, PatId}, item_scope::BuiltinShadowMode, nameres::DefMap, path::{ModPath, Path}, src::HasSource, AsMacroCall, BlockId, DefWithBodyId, HasModule, LocalModuleId, Lookup, ModuleId, UnresolvedMacro, }; pub use lower::LowerCtx; /// A subset of Expander that only deals with cfg attributes. We only need it to /// avoid cyclic queries in crate def map during enum processing. #[derive(Debug)] pub(crate) struct CfgExpander { cfg_options: CfgOptions, hygiene: Hygiene, krate: CrateId, } #[derive(Debug)] pub struct Expander { cfg_expander: CfgExpander, def_map: Arc<DefMap>, current_file_id: HirFileId, ast_id_map: Arc<AstIdMap>, module: LocalModuleId, recursion_limit: usize, } #[cfg(test)] const EXPANSION_RECURSION_LIMIT: usize = 32; #[cfg(not(test))] const EXPANSION_RECURSION_LIMIT: usize = 128; impl CfgExpander { pub(crate) fn new( db: &dyn DefDatabase, current_file_id: HirFileId, krate: CrateId, ) -> CfgExpander { let hygiene = Hygiene::new(db.upcast(), current_file_id); let cfg_options = db.crate_graph()[krate].cfg_options.clone(); CfgExpander { cfg_options, hygiene, krate } } pub(crate) fn parse_attrs(&self, db: &dyn DefDatabase, owner: &dyn ast::AttrsOwner) -> Attrs { RawAttrs::new(db, owner, &self.hygiene).filter(db, self.krate) } pub(crate) fn is_cfg_enabled(&self, db: &dyn DefDatabase, owner: &dyn ast::AttrsOwner) -> bool { let attrs = self.parse_attrs(db, owner); attrs.is_cfg_enabled(&self.cfg_options) } } impl Expander { pub fn new(db: &dyn DefDatabase, current_file_id: HirFileId, module: ModuleId) -> Expander { let cfg_expander = CfgExpander::new(db, current_file_id, module.krate); let def_map = module.def_map(db); let ast_id_map = db.ast_id_map(current_file_id); Expander { cfg_expander, def_map, current_file_id, ast_id_map, module: module.local_id, recursion_limit: 0, } } pub fn enter_expand<T: ast::AstNode>( &mut self, db: &dyn DefDatabase, macro_call: ast::MacroCall, ) -> Result<ExpandResult<Option<(Mark, T)>>, UnresolvedMacro> { if self.recursion_limit + 1 > EXPANSION_RECURSION_LIMIT { cov_mark::hit!(your_stack_belongs_to_me); return Ok(ExpandResult::str_err( "reached recursion limit during macro expansion".into(), )); } let macro_call = InFile::new(self.current_file_id, ¯o_call); let resolver = |path: ModPath| -> Option<MacroDefId> { self.resolve_path_as_macro(db, &path) }; let mut err = None; let call_id = macro_call.as_call_id_with_errors(db, self.def_map.krate(), resolver, &mut |e| { err.get_or_insert(e); })?; let call_id = match call_id { Ok(it) => it, Err(_) => { return Ok(ExpandResult { value: None, err }); } }; if err.is_none() { err = db.macro_expand_error(call_id); } let file_id = call_id.as_file(); let raw_node = match db.parse_or_expand(file_id) { Some(it) => it, None => { // Only `None` if the macro expansion produced no usable AST. if err.is_none() { log::warn!("no error despite `parse_or_expand` failing"); } return Ok(ExpandResult::only_err(err.unwrap_or_else(|| { mbe::ExpandError::Other("failed to parse macro invocation".into()) }))); } }; let node = match T::cast(raw_node) { Some(it) => it, None => { // This can happen without being an error, so only forward previous errors. return Ok(ExpandResult { value: None, err }); } }; log::debug!("macro expansion {:#?}", node.syntax()); self.recursion_limit += 1; 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.cfg_expander.hygiene = Hygiene::new(db.upcast(), file_id); self.current_file_id = file_id; self.ast_id_map = db.ast_id_map(file_id); Ok(ExpandResult { value: Some((mark, node)), err }) } pub fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) { self.cfg_expander.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.recursion_limit -= 1; mark.bomb.defuse(); } pub(crate) fn to_source<T>(&self, value: T) -> InFile<T> { InFile { file_id: self.current_file_id, value } } pub(crate) fn parse_attrs(&self, db: &dyn DefDatabase, owner: &dyn ast::AttrsOwner) -> Attrs { self.cfg_expander.parse_attrs(db, owner) } pub(crate) fn cfg_options(&self) -> &CfgOptions { &self.cfg_expander.cfg_options } pub fn current_file_id(&self) -> HirFileId { self.current_file_id } fn parse_path(&mut self, db: &dyn DefDatabase, path: ast::Path) -> Option<Path> { let ctx = LowerCtx::with_hygiene(db, &self.cfg_expander.hygiene); Path::from_src(path, &ctx) } fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroDefId> { self.def_map.resolve_path(db, self.module, 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) } } #[derive(Debug)] pub 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>, pub labels: Arena<Label>, /// 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, /// Block expressions in this body that may contain inner items. block_scopes: Vec<BlockId>, _c: Count<Self>, } pub type ExprPtr = AstPtr<ast::Expr>; pub type ExprSource = InFile<ExprPtr>; pub type PatPtr = Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>; pub type PatSource = InFile<PatPtr>; pub type LabelPtr = AstPtr<ast::Label>; pub type LabelSource = InFile<LabelPtr>; /// 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>>, label_map: FxHashMap<LabelSource, LabelId>, label_map_back: ArenaMap<LabelId, LabelSource>, /// We don't create explicit nodes for record fields (`S { record_field: 92 }`). /// Instead, we use id of expression (`92`) to identify the field. field_map: FxHashMap<InFile<AstPtr<ast::RecordExprField>>, ExprId>, field_map_back: FxHashMap<ExprId, InFile<AstPtr<ast::RecordExprField>>>, expansions: FxHashMap<InFile<AstPtr<ast::MacroCall>>, HirFileId>, /// Diagnostics accumulated during body lowering. These contain `AstPtr`s and so are stored in /// the source map (since they're just as volatile). diagnostics: Vec<BodyDiagnostic>, } #[derive(Default, Debug, Eq, PartialEq, Clone, Copy)] pub struct SyntheticSyntax; #[derive(Debug, Eq, PartialEq)] pub enum BodyDiagnostic { InactiveCode { node: InFile<SyntaxNodePtr>, cfg: CfgExpr, opts: CfgOptions }, MacroError { node: InFile<AstPtr<ast::MacroCall>>, message: String }, UnresolvedProcMacro { node: InFile<AstPtr<ast::MacroCall>> }, UnresolvedMacroCall { node: InFile<AstPtr<ast::MacroCall>>, path: ModPath }, } impl Body { pub(crate) fn body_with_source_map_query( db: &dyn DefDatabase, def: DefWithBodyId, ) -> (Arc<Body>, Arc<BodySourceMap>) { let _p = profile::span("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 (mut body, source_map) = Body::new(db, expander, params, body); body.shrink_to_fit(); (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 } /// Returns an iterator over all block expressions in this body that define inner items. pub fn blocks<'a>( &'a self, db: &'a dyn DefDatabase, ) -> impl Iterator<Item = (BlockId, Arc<DefMap>)> + '_ { self.block_scopes .iter() .map(move |block| (*block, db.block_def_map(*block).expect("block ID without DefMap"))) } fn new( db: &dyn DefDatabase, expander: Expander, params: Option<ast::ParamList>, body: Option<ast::Expr>, ) -> (Body, BodySourceMap) { lower::lower(db, expander, params, body) } fn shrink_to_fit(&mut self) { let Self { _c: _, body_expr: _, block_scopes, exprs, labels, params, pats } = self; block_scopes.shrink_to_fit(); exprs.shrink_to_fit(); labels.shrink_to_fit(); params.shrink_to_fit(); pats.shrink_to_fit(); } } 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 Index<LabelId> for Body { type Output = Label; fn index(&self, label: LabelId) -> &Label { &self.labels[label] } } // FIXME: Change `node_` prefix to something more reasonable. // Perhaps `expr_syntax` and `expr_id`? impl BodySourceMap { pub fn expr_syntax(&self, expr: ExprId) -> Result<ExprSource, SyntheticSyntax> { self.expr_map_back[expr].clone() } pub fn node_expr(&self, node: InFile<&ast::Expr>) -> Option<ExprId> { let src = node.map(|it| 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 pat_syntax(&self, pat: PatId) -> Result<PatSource, SyntheticSyntax> { self.pat_map_back[pat].clone() } 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 node_self_param(&self, node: InFile<&ast::SelfParam>) -> Option<PatId> { let src = node.map(|it| Either::Right(AstPtr::new(it))); self.pat_map.get(&src).cloned() } pub fn label_syntax(&self, label: LabelId) -> LabelSource { self.label_map_back[label].clone() } pub fn node_label(&self, node: InFile<&ast::Label>) -> Option<LabelId> { let src = node.map(|it| AstPtr::new(it)); self.label_map.get(&src).cloned() } pub fn field_syntax(&self, expr: ExprId) -> InFile<AstPtr<ast::RecordExprField>> { self.field_map_back[&expr].clone() } pub fn node_field(&self, node: InFile<&ast::RecordExprField>) -> Option<ExprId> { let src = node.map(|it| AstPtr::new(it)); self.field_map.get(&src).cloned() } /// Get a reference to the body source map's diagnostics. pub fn diagnostics(&self) -> &[BodyDiagnostic] { &self.diagnostics } }