use std::sync::Arc; use rustc_hash::FxHashMap; use ra_arena::{Arena, RawId, impl_arena_id}; use ra_db::{LocalSyntaxPtr, Cancelable}; use ra_syntax::ast::{self, AstNode, LoopBodyOwner, ArgListOwner}; use crate::{Path, type_ref::{Mutability, TypeRef}, Name, HirDatabase, DefId, Def, name::AsName}; #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct ExprId(RawId); impl_arena_id!(ExprId); /// The body of an item (function, const etc.). #[derive(Debug, Eq, PartialEq)] pub struct Body { exprs: Arena, pats: Arena, /// The patterns for the function's arguments. While the argument types are /// part of the function signature, the patterns are not (they don't change /// the external type of the function). /// /// If this `ExprTable` is for the body of a constant, this will just be /// empty. args: Vec, /// The `ExprId` of the actual body expression. body_expr: ExprId, } /// 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 the type inference whenever some whitespace /// is typed. #[derive(Debug, Eq, PartialEq)] pub struct BodySyntaxMapping { body: Arc, expr_syntax_mapping: FxHashMap, expr_syntax_mapping_back: FxHashMap, pat_syntax_mapping: FxHashMap, pat_syntax_mapping_back: FxHashMap, } #[derive(Debug, Clone, Eq, PartialEq)] pub enum Expr { /// This is produced if syntax tree does not have a required expression piece. Missing, Path(Path), If { condition: ExprId, then_branch: ExprId, else_branch: Option, }, Block { statements: Vec, tail: Option, }, Loop { body: ExprId, }, While { condition: ExprId, body: ExprId, }, For { iterable: ExprId, pat: PatId, body: ExprId, }, Call { callee: ExprId, args: Vec, }, MethodCall { receiver: ExprId, method_name: Name, args: Vec, }, Match { expr: ExprId, arms: Vec, }, Continue, Break { expr: Option, }, Return { expr: Option, }, StructLit { path: Option, fields: Vec, spread: Option, }, Field { expr: ExprId, name: Name, }, Try { expr: ExprId, }, Cast { expr: ExprId, type_ref: TypeRef, }, Ref { expr: ExprId, mutability: Mutability, }, UnaryOp { expr: ExprId, op: Option, }, } pub type UnaryOp = ast::PrefixOp; #[derive(Debug, Clone, Eq, PartialEq)] pub struct MatchArm { pats: Vec, // guard: Option, // TODO expr: ExprId, } #[derive(Debug, Clone, Eq, PartialEq)] pub struct StructLitField { name: Name, expr: ExprId, } #[derive(Debug, Clone, Eq, PartialEq)] pub enum Statement { Let { pat: PatId, type_ref: Option, initializer: Option, }, Expr(ExprId), } #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct PatId(RawId); impl_arena_id!(PatId); #[derive(Debug, Clone, Eq, PartialEq)] pub struct Pat; // Queries pub(crate) fn body_hir(db: &impl HirDatabase, def_id: DefId) -> Cancelable> { Ok(Arc::clone(&body_syntax_mapping(db, def_id)?.body)) } struct ExprCollector { exprs: Arena, pats: Arena, expr_syntax_mapping: FxHashMap, expr_syntax_mapping_back: FxHashMap, pat_syntax_mapping: FxHashMap, pat_syntax_mapping_back: FxHashMap, } impl ExprCollector { fn alloc_expr(&mut self, expr: Expr, syntax_ptr: LocalSyntaxPtr) -> ExprId { let id = self.exprs.alloc(expr); self.expr_syntax_mapping.insert(syntax_ptr, id); self.expr_syntax_mapping_back.insert(id, syntax_ptr); id } fn alloc_pat(&mut self, pat: Pat, syntax_ptr: LocalSyntaxPtr) -> PatId { let id = self.pats.alloc(pat); self.pat_syntax_mapping.insert(syntax_ptr, id); self.pat_syntax_mapping_back.insert(id, syntax_ptr); id } fn collect_expr(&mut self, expr: ast::Expr) -> ExprId { let syntax_ptr = LocalSyntaxPtr::new(expr.syntax()); match expr { ast::Expr::IfExpr(e) => { let condition = if let Some(condition) = e.condition() { if condition.pat().is_none() { self.collect_expr_opt(condition.expr()) } else { // TODO handle if let return self.alloc_expr(Expr::Missing, syntax_ptr); } } else { self.exprs.alloc(Expr::Missing) }; let then_branch = self.collect_block_opt(e.then_branch()); let else_branch = e.else_branch().map(|e| self.collect_block(e)); self.alloc_expr( Expr::If { condition, then_branch, else_branch, }, syntax_ptr, ) } ast::Expr::BlockExpr(e) => self.collect_block_opt(e.block()), ast::Expr::LoopExpr(e) => { let body = self.collect_block_opt(e.loop_body()); self.alloc_expr(Expr::Loop { body }, syntax_ptr) } ast::Expr::WhileExpr(e) => { let condition = if let Some(condition) = e.condition() { if condition.pat().is_none() { self.collect_expr_opt(condition.expr()) } else { // TODO handle while let return self.alloc_expr(Expr::Missing, syntax_ptr); } } else { self.exprs.alloc(Expr::Missing) }; let body = self.collect_block_opt(e.loop_body()); self.alloc_expr(Expr::While { condition, body }, 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, ) } ast::Expr::CallExpr(e) => { let callee = self.collect_expr_opt(e.expr()); let args = if let Some(arg_list) = e.arg_list() { arg_list.args().map(|e| self.collect_expr(e)).collect() } else { Vec::new() }; self.alloc_expr(Expr::Call { callee, args }, syntax_ptr) } ast::Expr::MethodCallExpr(e) => { let receiver = self.collect_expr_opt(e.expr()); let args = if let Some(arg_list) = e.arg_list() { arg_list.args().map(|e| self.collect_expr(e)).collect() } else { Vec::new() }; let method_name = e .name_ref() .map(|nr| nr.as_name()) .unwrap_or_else(Name::missing); self.alloc_expr( Expr::MethodCall { receiver, method_name, args, }, syntax_ptr, ) } ast::Expr::MatchExpr(e) => { let expr = self.collect_expr_opt(e.expr()); let arms = if let Some(match_arm_list) = e.match_arm_list() { match_arm_list .arms() .map(|arm| MatchArm { pats: arm.pats().map(|p| self.collect_pat(p)).collect(), expr: self.collect_expr_opt(arm.expr()), }) .collect() } else { Vec::new() }; self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr) } ast::Expr::PathExpr(e) => { let path = e .path() .and_then(Path::from_ast) .map(Expr::Path) .unwrap_or(Expr::Missing); self.alloc_expr(path, syntax_ptr) } ast::Expr::ContinueExpr(_e) => { // TODO: labels self.alloc_expr(Expr::Continue, syntax_ptr) } ast::Expr::BreakExpr(e) => { let expr = e.expr().map(|e| self.collect_expr(e)); self.alloc_expr(Expr::Break { expr }, syntax_ptr) } ast::Expr::ParenExpr(e) => { let inner = self.collect_expr_opt(e.expr()); // make the paren expr point to the inner expression as well self.expr_syntax_mapping.insert(syntax_ptr, inner); inner } ast::Expr::ReturnExpr(e) => { let expr = e.expr().map(|e| self.collect_expr(e)); self.alloc_expr(Expr::Return { expr }, syntax_ptr) } ast::Expr::StructLit(e) => { let path = e.path().and_then(Path::from_ast); let fields = if let Some(nfl) = e.named_field_list() { nfl.fields() .map(|field| StructLitField { name: field .name_ref() .map(|nr| nr.as_name()) .unwrap_or_else(Name::missing), expr: if let Some(e) = field.expr() { self.collect_expr(e) } else if let Some(nr) = field.name_ref() { // field shorthand let id = self.exprs.alloc(Expr::Path(Path::from_name_ref(nr))); self.expr_syntax_mapping .insert(LocalSyntaxPtr::new(nr.syntax()), id); self.expr_syntax_mapping_back .insert(id, LocalSyntaxPtr::new(nr.syntax())); id } else { self.exprs.alloc(Expr::Missing) }, }) .collect() } else { Vec::new() }; let spread = e.spread().map(|s| self.collect_expr(s)); self.alloc_expr( Expr::StructLit { path, fields, spread, }, syntax_ptr, ) } ast::Expr::FieldExpr(e) => { let expr = self.collect_expr_opt(e.expr()); let name = e .name_ref() .map(|nr| nr.as_name()) .unwrap_or_else(Name::missing); self.alloc_expr(Expr::Field { expr, name }, syntax_ptr) } ast::Expr::TryExpr(e) => { let expr = self.collect_expr_opt(e.expr()); self.alloc_expr(Expr::Try { expr }, syntax_ptr) } ast::Expr::CastExpr(e) => { let expr = self.collect_expr_opt(e.expr()); let type_ref = TypeRef::from_ast_opt(e.type_ref()); self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr) } ast::Expr::RefExpr(e) => { let expr = self.collect_expr_opt(e.expr()); let mutability = Mutability::from_mutable(e.is_mut()); self.alloc_expr(Expr::Ref { expr, mutability }, syntax_ptr) } ast::Expr::PrefixExpr(e) => { let expr = self.collect_expr_opt(e.expr()); let op = e.op(); self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr) } // We should never get to these because they're handled in MatchExpr resp. StructLit: ast::Expr::MatchArmList(_) | ast::Expr::MatchArm(_) | ast::Expr::MatchGuard(_) => { panic!("collect_expr called on {:?}", expr) } ast::Expr::NamedFieldList(_) | ast::Expr::NamedField(_) => { panic!("collect_expr called on {:?}", expr) } // TODO implement HIR for these: ast::Expr::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::LambdaExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::IndexExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::TupleExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::ArrayExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::BinExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), ast::Expr::Literal(_e) => self.alloc_expr(Expr::Missing, syntax_ptr), } } fn collect_expr_opt(&mut self, expr: Option) -> ExprId { if let Some(expr) = expr { self.collect_expr(expr) } else { self.exprs.alloc(Expr::Missing) } } fn collect_block(&mut self, block: ast::Block) -> ExprId { let statements = block .statements() .map(|s| match s { ast::Stmt::LetStmt(stmt) => { let pat = self.collect_pat_opt(stmt.pat()); let type_ref = stmt.type_ref().map(TypeRef::from_ast); let initializer = stmt.initializer().map(|e| self.collect_expr(e)); Statement::Let { pat, type_ref, initializer, } } ast::Stmt::ExprStmt(stmt) => Statement::Expr(self.collect_expr_opt(stmt.expr())), }) .collect(); let tail = block.expr().map(|e| self.collect_expr(e)); self.alloc_expr( Expr::Block { statements, tail }, LocalSyntaxPtr::new(block.syntax()), ) } fn collect_block_opt(&mut self, block: Option) -> ExprId { if let Some(block) = block { self.collect_block(block) } else { self.exprs.alloc(Expr::Missing) } } fn collect_pat(&mut self, pat: ast::Pat) -> PatId { let syntax_ptr = LocalSyntaxPtr::new(pat.syntax()); // TODO self.alloc_pat(Pat, syntax_ptr) } fn collect_pat_opt(&mut self, pat: Option) -> PatId { if let Some(pat) = pat { self.collect_pat(pat) } else { // TODO self.pats.alloc(Pat) } } fn into_body_syntax_mapping(self, args: Vec, body_expr: ExprId) -> BodySyntaxMapping { let body = Body { exprs: self.exprs, pats: self.pats, args, body_expr, }; BodySyntaxMapping { body: Arc::new(body), expr_syntax_mapping: self.expr_syntax_mapping, expr_syntax_mapping_back: self.expr_syntax_mapping_back, pat_syntax_mapping: self.pat_syntax_mapping, pat_syntax_mapping_back: self.pat_syntax_mapping_back, } } } pub(crate) fn body_syntax_mapping( db: &impl HirDatabase, def_id: DefId, ) -> Cancelable> { let def = def_id.resolve(db)?; let mut collector = ExprCollector { exprs: Arena::default(), pats: Arena::default(), expr_syntax_mapping: FxHashMap::default(), expr_syntax_mapping_back: FxHashMap::default(), pat_syntax_mapping: FxHashMap::default(), pat_syntax_mapping_back: FxHashMap::default(), }; let (body, args) = match def { Def::Function(f) => { let node = f.syntax(db); let node = node.borrowed(); let args = if let Some(param_list) = node.param_list() { let mut args = Vec::new(); // TODO self param for param in param_list.params() { let pat = if let Some(pat) = param.pat() { pat } else { continue; }; args.push(collector.collect_pat(pat)); } args } else { Vec::new() }; let body = collector.collect_block_opt(node.body()); (body, args) } // TODO: consts, etc. _ => panic!("Trying to get body for item type without body"), }; Ok(Arc::new(collector.into_body_syntax_mapping(args, body))) }