use crate::{ImplTraitContext, Resolver}; use rustc_ast::visit::{self, FnKind}; use rustc_ast::*; use rustc_expand::expand::AstFragment; use rustc_hir::def_id::LocalDefId; use rustc_hir::definitions::*; use rustc_span::hygiene::LocalExpnId; use rustc_span::symbol::sym; use rustc_span::Span; pub(crate) fn collect_definitions( resolver: &mut Resolver<'_, '_>, fragment: &AstFragment, expansion: LocalExpnId, ) { let (parent_def, impl_trait_context) = resolver.invocation_parents[&expansion]; fragment.visit_with(&mut DefCollector { resolver, parent_def, expansion, impl_trait_context }); } /// Creates `DefId`s for nodes in the AST. struct DefCollector<'a, 'b, 'tcx> { resolver: &'a mut Resolver<'b, 'tcx>, parent_def: LocalDefId, impl_trait_context: ImplTraitContext, expansion: LocalExpnId, } impl<'a, 'b, 'tcx> DefCollector<'a, 'b, 'tcx> { fn create_def(&mut self, node_id: NodeId, data: DefPathData, span: Span) -> LocalDefId { let parent_def = self.parent_def; debug!("create_def(node_id={:?}, data={:?}, parent_def={:?})", node_id, data, parent_def); self.resolver.create_def( parent_def, node_id, data, self.expansion.to_expn_id(), span.with_parent(None), ) } fn with_parent(&mut self, parent_def: LocalDefId, f: F) { let orig_parent_def = std::mem::replace(&mut self.parent_def, parent_def); f(self); self.parent_def = orig_parent_def; } fn with_impl_trait( &mut self, impl_trait_context: ImplTraitContext, f: F, ) { let orig_itc = std::mem::replace(&mut self.impl_trait_context, impl_trait_context); f(self); self.impl_trait_context = orig_itc; } fn collect_field(&mut self, field: &'a FieldDef, index: Option) { let index = |this: &Self| { index.unwrap_or_else(|| { let node_id = NodeId::placeholder_from_expn_id(this.expansion); this.resolver.placeholder_field_indices[&node_id] }) }; if field.is_placeholder { let old_index = self.resolver.placeholder_field_indices.insert(field.id, index(self)); assert!(old_index.is_none(), "placeholder field index is reset for a node ID"); self.visit_macro_invoc(field.id); } else { let name = field.ident.map_or_else(|| sym::integer(index(self)), |ident| ident.name); let def = self.create_def(field.id, DefPathData::ValueNs(name), field.span); self.with_parent(def, |this| visit::walk_field_def(this, field)); } } fn visit_macro_invoc(&mut self, id: NodeId) { let id = id.placeholder_to_expn_id(); let old_parent = self.resolver.invocation_parents.insert(id, (self.parent_def, self.impl_trait_context)); assert!(old_parent.is_none(), "parent `LocalDefId` is reset for an invocation"); } } impl<'a, 'b, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'b, 'tcx> { fn visit_item(&mut self, i: &'a Item) { debug!("visit_item: {:?}", i); // Pick the def data. This need not be unique, but the more // information we encapsulate into, the better let def_data = match &i.kind { ItemKind::Impl { .. } => DefPathData::Impl, ItemKind::ForeignMod(..) => DefPathData::ForeignMod, ItemKind::Mod(..) | ItemKind::Trait(..) | ItemKind::TraitAlias(..) | ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) | ItemKind::ExternCrate(..) | ItemKind::TyAlias(..) => DefPathData::TypeNs(i.ident.name), ItemKind::Static(..) | ItemKind::Const(..) | ItemKind::Fn(..) => { DefPathData::ValueNs(i.ident.name) } ItemKind::MacroDef(..) => DefPathData::MacroNs(i.ident.name), ItemKind::MacCall(..) => { visit::walk_item(self, i); return self.visit_macro_invoc(i.id); } ItemKind::GlobalAsm(..) => DefPathData::GlobalAsm, ItemKind::Use(..) => { return visit::walk_item(self, i); } }; let def = self.create_def(i.id, def_data, i.span); self.with_parent(def, |this| { this.with_impl_trait(ImplTraitContext::Existential, |this| { match i.kind { ItemKind::Struct(ref struct_def, _) | ItemKind::Union(ref struct_def, _) => { // If this is a unit or tuple-like struct, register the constructor. if let Some(ctor_node_id) = struct_def.ctor_node_id() { this.create_def(ctor_node_id, DefPathData::Ctor, i.span); } } _ => {} } visit::walk_item(this, i); }) }); } fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) { if let FnKind::Fn(_, _, sig, _, generics, body) = fn_kind { if let Async::Yes { closure_id, .. } = sig.header.asyncness { self.visit_generics(generics); // For async functions, we need to create their inner defs inside of a // closure to match their desugared representation. Besides that, // we must mirror everything that `visit::walk_fn` below does. self.visit_fn_header(&sig.header); for param in &sig.decl.inputs { self.visit_param(param); } self.visit_fn_ret_ty(&sig.decl.output); // If this async fn has no body (i.e. it's an async fn signature in a trait) // then the closure_def will never be used, and we should avoid generating a // def-id for it. if let Some(body) = body { let closure_def = self.create_def(closure_id, DefPathData::ClosureExpr, span); self.with_parent(closure_def, |this| this.visit_block(body)); } return; } } visit::walk_fn(self, fn_kind); } fn visit_use_tree(&mut self, use_tree: &'a UseTree, id: NodeId, _nested: bool) { self.create_def(id, DefPathData::Use, use_tree.span); visit::walk_use_tree(self, use_tree, id); } fn visit_foreign_item(&mut self, foreign_item: &'a ForeignItem) { if let ForeignItemKind::MacCall(_) = foreign_item.kind { return self.visit_macro_invoc(foreign_item.id); } let def = self.create_def( foreign_item.id, DefPathData::ValueNs(foreign_item.ident.name), foreign_item.span, ); self.with_parent(def, |this| { visit::walk_foreign_item(this, foreign_item); }); } fn visit_variant(&mut self, v: &'a Variant) { if v.is_placeholder { return self.visit_macro_invoc(v.id); } let def = self.create_def(v.id, DefPathData::TypeNs(v.ident.name), v.span); self.with_parent(def, |this| { if let Some(ctor_node_id) = v.data.ctor_node_id() { this.create_def(ctor_node_id, DefPathData::Ctor, v.span); } visit::walk_variant(this, v) }); } fn visit_variant_data(&mut self, data: &'a VariantData) { // The assumption here is that non-`cfg` macro expansion cannot change field indices. // It currently holds because only inert attributes are accepted on fields, // and every such attribute expands into a single field after it's resolved. for (index, field) in data.fields().iter().enumerate() { self.collect_field(field, Some(index)); } } fn visit_generic_param(&mut self, param: &'a GenericParam) { if param.is_placeholder { self.visit_macro_invoc(param.id); return; } let name = param.ident.name; let def_path_data = match param.kind { GenericParamKind::Lifetime { .. } => DefPathData::LifetimeNs(name), GenericParamKind::Type { .. } => DefPathData::TypeNs(name), GenericParamKind::Const { .. } => DefPathData::ValueNs(name), }; self.create_def(param.id, def_path_data, param.ident.span); // impl-Trait can happen inside generic parameters, like // ``` // fn foo>() {} // ``` // // In that case, the impl-trait is lowered as an additional generic parameter. self.with_impl_trait(ImplTraitContext::Universal(self.parent_def), |this| { visit::walk_generic_param(this, param) }); } fn visit_assoc_item(&mut self, i: &'a AssocItem, ctxt: visit::AssocCtxt) { let def_data = match &i.kind { AssocItemKind::Fn(..) | AssocItemKind::Const(..) => DefPathData::ValueNs(i.ident.name), AssocItemKind::Type(..) => DefPathData::TypeNs(i.ident.name), AssocItemKind::MacCall(..) => return self.visit_macro_invoc(i.id), }; let def = self.create_def(i.id, def_data, i.span); self.with_parent(def, |this| visit::walk_assoc_item(this, i, ctxt)); } fn visit_pat(&mut self, pat: &'a Pat) { match pat.kind { PatKind::MacCall(..) => self.visit_macro_invoc(pat.id), _ => visit::walk_pat(self, pat), } } fn visit_anon_const(&mut self, constant: &'a AnonConst) { let def = self.create_def(constant.id, DefPathData::AnonConst, constant.value.span); self.with_parent(def, |this| visit::walk_anon_const(this, constant)); } fn visit_expr(&mut self, expr: &'a Expr) { let parent_def = match expr.kind { ExprKind::MacCall(..) => return self.visit_macro_invoc(expr.id), ExprKind::Closure(ref closure) => { // Async closures desugar to closures inside of closures, so // we must create two defs. let closure_def = self.create_def(expr.id, DefPathData::ClosureExpr, expr.span); match closure.asyncness { Async::Yes { closure_id, .. } => { self.create_def(closure_id, DefPathData::ClosureExpr, expr.span) } Async::No => closure_def, } } ExprKind::Gen(_, _, _) => self.create_def(expr.id, DefPathData::ClosureExpr, expr.span), _ => self.parent_def, }; self.with_parent(parent_def, |this| visit::walk_expr(this, expr)); } fn visit_ty(&mut self, ty: &'a Ty) { match ty.kind { TyKind::MacCall(..) => self.visit_macro_invoc(ty.id), _ => visit::walk_ty(self, ty), } } fn visit_stmt(&mut self, stmt: &'a Stmt) { match stmt.kind { StmtKind::MacCall(..) => self.visit_macro_invoc(stmt.id), _ => visit::walk_stmt(self, stmt), } } fn visit_arm(&mut self, arm: &'a Arm) { if arm.is_placeholder { self.visit_macro_invoc(arm.id) } else { visit::walk_arm(self, arm) } } fn visit_expr_field(&mut self, f: &'a ExprField) { if f.is_placeholder { self.visit_macro_invoc(f.id) } else { visit::walk_expr_field(self, f) } } fn visit_pat_field(&mut self, fp: &'a PatField) { if fp.is_placeholder { self.visit_macro_invoc(fp.id) } else { visit::walk_pat_field(self, fp) } } fn visit_param(&mut self, p: &'a Param) { if p.is_placeholder { self.visit_macro_invoc(p.id) } else { self.with_impl_trait(ImplTraitContext::Universal(self.parent_def), |this| { visit::walk_param(this, p) }) } } // This method is called only when we are visiting an individual field // after expanding an attribute on it. fn visit_field_def(&mut self, field: &'a FieldDef) { self.collect_field(field, None); } fn visit_crate(&mut self, krate: &'a Crate) { if krate.is_placeholder { self.visit_macro_invoc(krate.id) } else { visit::walk_crate(self, krate) } } }