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Diffstat (limited to 'compiler/rustc_resolve/src/def_collector.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/def_collector.rs | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/compiler/rustc_resolve/src/def_collector.rs b/compiler/rustc_resolve/src/def_collector.rs new file mode 100644 index 000000000..66641fb2c --- /dev/null +++ b/compiler/rustc_resolve/src/def_collector.rs @@ -0,0 +1,354 @@ +use crate::{ImplTraitContext, Resolver}; +use rustc_ast::visit::{self, FnKind}; +use rustc_ast::walk_list; +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; +use tracing::debug; + +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> { + resolver: &'a mut Resolver<'b>, + parent_def: LocalDefId, + impl_trait_context: ImplTraitContext, + expansion: LocalExpnId, +} + +impl<'a, 'b> DefCollector<'a, 'b> { + 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<F: FnOnce(&mut Self)>(&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<F: FnOnce(&mut Self)>( + &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<usize>) { + 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> visit::Visitor<'a> for DefCollector<'a, 'b> { + 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_hir_id) = struct_def.ctor_id() { + this.create_def(ctor_hir_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, return_impl_trait_id, .. } = sig.header.asyncness { + self.visit_generics(generics); + + let return_impl_trait_id = + self.create_def(return_impl_trait_id, DefPathData::ImplTrait, span); + + // 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.with_parent(return_impl_trait_id, |this| { + this.visit_fn_ret_ty(&sig.decl.output) + }); + let closure_def = self.create_def(closure_id, DefPathData::ClosureExpr, span); + self.with_parent(closure_def, |this| walk_list!(this, visit_block, body)); + return; + } + } + + visit::walk_fn(self, fn_kind, span); + } + + fn visit_use_tree(&mut self, use_tree: &'a UseTree, id: NodeId, _nested: bool) { + self.create_def(id, DefPathData::Use, use_tree.span); + match use_tree.kind { + UseTreeKind::Simple(_, id1, id2) => { + self.create_def(id1, DefPathData::Use, use_tree.prefix.span); + self.create_def(id2, DefPathData::Use, use_tree.prefix.span); + } + UseTreeKind::Glob => (), + UseTreeKind::Nested(..) => {} + } + 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_hir_id) = v.data.ctor_id() { + this.create_def(ctor_hir_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<U: Iterator<Item = impl Clone>>() {} + // ``` + // + // 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::TyAlias(..) => 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(_, _, asyncness, ..) => { + // 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 asyncness { + Async::Yes { closure_id, .. } => { + self.create_def(closure_id, DefPathData::ClosureExpr, expr.span) + } + Async::No => closure_def, + } + } + ExprKind::Async(_, async_id, _) => { + self.create_def(async_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), + TyKind::ImplTrait(node_id, _) => { + let parent_def = match self.impl_trait_context { + ImplTraitContext::Universal(item_def) => self.resolver.create_def( + item_def, + node_id, + DefPathData::ImplTrait, + self.expansion.to_expn_id(), + ty.span, + ), + ImplTraitContext::Existential => { + self.create_def(node_id, DefPathData::ImplTrait, ty.span) + } + }; + self.with_parent(parent_def, |this| visit::walk_ty(this, ty)) + } + _ => 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) + } + } +} |