use std::ops::Index; use std::sync::Arc; use rustc_hash::FxHashMap; use ra_arena::{Arena, RawId, impl_arena_id}; use ra_db::{LocalSyntaxPtr, Cancelable}; use ra_syntax::{SyntaxNodeRef, ast::{self, AstNode, LoopBodyOwner, ArgListOwner, NameOwner}}; 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 `Body` 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, } impl Body { pub fn args(&self) -> &[PatId] { &self.args } pub fn body_expr(&self) -> ExprId { self.body_expr } } impl Index for Body { type Output = Expr; fn index(&self, expr: ExprId) -> &Expr { &self.exprs[expr] } } impl Index for Body { type Output = Pat; fn index(&self, pat: PatId) -> &Pat { &self.pats[pat] } } impl BodySyntaxMapping { pub fn expr_syntax(&self, expr: ExprId) -> Option { self.expr_syntax_mapping_back.get(&expr).cloned() } pub fn syntax_expr(&self, ptr: LocalSyntaxPtr) -> Option { self.expr_syntax_mapping.get(&ptr).cloned() } pub fn node_expr(&self, node: SyntaxNodeRef) -> Option { self.expr_syntax_mapping .get(&LocalSyntaxPtr::new(node)) .cloned() } pub fn pat_syntax(&self, pat: PatId) -> Option { self.pat_syntax_mapping_back.get(&pat).cloned() } pub fn syntax_pat(&self, ptr: LocalSyntaxPtr) -> Option { self.pat_syntax_mapping.get(&ptr).cloned() } pub fn node_pat(&self, node: SyntaxNodeRef) -> Option { self.pat_syntax_mapping .get(&LocalSyntaxPtr::new(node)) .cloned() } pub fn body(&self) -> &Arc { &self.body } } #[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, }, BinaryOp { lhs: ExprId, rhs: ExprId, op: Option, }, Lambda { args: Vec, arg_types: Vec>, body: ExprId, }, } pub use ra_syntax::ast::PrefixOp as UnaryOp; pub use ra_syntax::ast::BinOp as BinaryOp; #[derive(Debug, Clone, Eq, PartialEq)] pub struct MatchArm { pub pats: Vec, // guard: Option, // TODO pub expr: ExprId, } #[derive(Debug, Clone, Eq, PartialEq)] pub struct StructLitField { pub name: Name, pub expr: ExprId, } #[derive(Debug, Clone, Eq, PartialEq)] pub enum Statement { Let { pat: PatId, type_ref: Option, initializer: Option, }, Expr(ExprId), } impl Expr { pub fn walk_child_exprs(&self, mut f: impl FnMut(ExprId)) { match self { Expr::Missing => {} Expr::Path(_) => {} Expr::If { condition, then_branch, else_branch, } => { f(*condition); f(*then_branch); if let Some(else_branch) = else_branch { f(*else_branch); } } Expr::Block { statements, tail } => { for stmt in statements { match stmt { Statement::Let { initializer, .. } => { if let Some(expr) = initializer { f(*expr); } } Statement::Expr(e) => f(*e), } } if let Some(expr) = tail { f(*expr); } } Expr::Loop { body } => f(*body), Expr::While { condition, body } => { f(*condition); f(*body); } Expr::For { iterable, body, .. } => { f(*iterable); f(*body); } Expr::Call { callee, args } => { f(*callee); for arg in args { f(*arg); } } Expr::MethodCall { receiver, args, .. } => { f(*receiver); for arg in args { f(*arg); } } Expr::Match { expr, arms } => { f(*expr); for arm in arms { f(arm.expr); } } Expr::Continue => {} Expr::Break { expr } | Expr::Return { expr } => { if let Some(expr) = expr { f(*expr); } } Expr::StructLit { fields, spread, .. } => { for field in fields { f(field.expr); } if let Some(expr) = spread { f(*expr); } } Expr::Lambda { body, .. } => { f(*body); } Expr::BinaryOp { lhs, rhs, .. } => { f(*lhs); f(*rhs); } Expr::Field { expr, .. } | Expr::Try { expr } | Expr::Cast { expr, .. } | Expr::Ref { expr, .. } | Expr::UnaryOp { expr, .. } => { f(*expr); } } } } #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct PatId(RawId); impl_arena_id!(PatId); #[derive(Debug, Clone, Eq, PartialEq)] pub enum Pat { Missing, Bind { name: Name, }, TupleStruct { path: Option, args: Vec, }, } impl Pat { pub fn walk_child_pats(&self, f: impl FnMut(PatId)) { match self { Pat::Missing | Pat::Bind { .. } => {} Pat::TupleStruct { args, .. } => { args.iter().map(|pat| *pat).for_each(f); } } } } // 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 new() -> Self { 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(), } } 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 empty_block(&mut self) -> ExprId { let block = Expr::Block { statements: Vec::new(), tail: None, }; self.exprs.alloc(block) } fn collect_expr(&mut self, expr: ast::Expr) -> ExprId { let syntax_ptr = LocalSyntaxPtr::new(expr.syntax()); match expr { ast::Expr::IfExpr(e) => { if let Some(pat) = e.condition().and_then(|c| c.pat()) { // if let -- desugar to match let pat = self.collect_pat(pat); let match_expr = self.collect_expr_opt(e.condition().expect("checked above").expr()); let then_branch = self.collect_block_opt(e.then_branch()); let else_branch = e .else_branch() .map(|e| self.collect_block(e)) .unwrap_or_else(|| self.empty_block()); let placeholder_pat = self.pats.alloc(Pat::Missing); let arms = vec![ MatchArm { pats: vec![pat], expr: then_branch, }, MatchArm { pats: vec![placeholder_pat], expr: else_branch, }, ]; self.alloc_expr( Expr::Match { expr: match_expr, arms, }, syntax_ptr, ) } else { let condition = self.collect_expr_opt(e.condition().and_then(|c| c.expr())); 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) } ast::Expr::LambdaExpr(e) => { let mut args = Vec::new(); let mut arg_types = Vec::new(); if let Some(pl) = e.param_list() { for param in pl.params() { let pat = self.collect_pat_opt(param.pat()); let type_ref = param.type_ref().map(TypeRef::from_ast); args.push(pat); arg_types.push(type_ref); } } let body = self.collect_expr_opt(e.body()); self.alloc_expr( Expr::Lambda { args, arg_types, body, }, syntax_ptr, ) } ast::Expr::BinExpr(e) => { let lhs = self.collect_expr_opt(e.lhs()); let rhs = self.collect_expr_opt(e.rhs()); let op = e.op(); self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr) } // TODO implement HIR for these: ast::Expr::Label(_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::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()); match pat { ast::Pat::BindPat(bp) => { let name = bp .name() .map(|nr| nr.as_name()) .unwrap_or_else(Name::missing); self.alloc_pat(Pat::Bind { name }, syntax_ptr) } ast::Pat::TupleStructPat(p) => { let path = p.path().and_then(Path::from_ast); let args = p.args().map(|p| self.collect_pat(p)).collect(); self.alloc_pat(Pat::TupleStruct { path, args }, syntax_ptr) } _ => { // TODO self.alloc_pat(Pat::Missing, syntax_ptr) } } } fn collect_pat_opt(&mut self, pat: Option) -> PatId { if let Some(pat) = pat { self.collect_pat(pat) } else { self.pats.alloc(Pat::Missing) } } 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 collect_fn_body_syntax(node: ast::FnDef) -> BodySyntaxMapping { let mut collector = ExprCollector::new(); let args = if let Some(param_list) = node.param_list() { let mut args = Vec::new(); if let Some(self_param) = param_list.self_param() { let self_param = LocalSyntaxPtr::new( self_param .self_kw() .expect("self param without self keyword") .syntax(), ); let arg = collector.alloc_pat( Pat::Bind { name: Name::self_param(), }, self_param, ); args.push(arg); } 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()); collector.into_body_syntax_mapping(args, body) } pub(crate) fn body_syntax_mapping( db: &impl HirDatabase, def_id: DefId, ) -> Cancelable> { let def = def_id.resolve(db)?; let body_syntax_mapping = match def { Def::Function(f) => { let node = f.syntax(db); let node = node.borrowed(); collect_fn_body_syntax(node) } // TODO: consts, etc. _ => panic!("Trying to get body for item type without body"), }; Ok(Arc::new(body_syntax_mapping)) }