1 use crate::{ImplTraitContext, Resolver};
2 use rustc_ast::visit::{self, FnKind};
4 use rustc_expand::expand::AstFragment;
5 use rustc_hir::def_id::LocalDefId;
6 use rustc_hir::definitions::*;
7 use rustc_span::hygiene::LocalExpnId;
8 use rustc_span::symbol::sym;
11 pub(crate) fn collect_definitions(
12 resolver: &mut Resolver<'_>,
13 fragment: &AstFragment,
14 expansion: LocalExpnId,
16 let (parent_def, impl_trait_context) = resolver.invocation_parents[&expansion];
17 fragment.visit_with(&mut DefCollector { resolver, parent_def, expansion, impl_trait_context });
20 /// Creates `DefId`s for nodes in the AST.
21 struct DefCollector<'a, 'b> {
22 resolver: &'a mut Resolver<'b>,
23 parent_def: LocalDefId,
24 impl_trait_context: ImplTraitContext,
25 expansion: LocalExpnId,
28 impl<'a, 'b> DefCollector<'a, 'b> {
29 fn create_def(&mut self, node_id: NodeId, data: DefPathData, span: Span) -> LocalDefId {
30 let parent_def = self.parent_def;
31 debug!("create_def(node_id={:?}, data={:?}, parent_def={:?})", node_id, data, parent_def);
32 self.resolver.create_def(
36 self.expansion.to_expn_id(),
37 span.with_parent(None),
41 fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_def: LocalDefId, f: F) {
42 let orig_parent_def = std::mem::replace(&mut self.parent_def, parent_def);
44 self.parent_def = orig_parent_def;
47 fn with_impl_trait<F: FnOnce(&mut Self)>(
49 impl_trait_context: ImplTraitContext,
52 let orig_itc = std::mem::replace(&mut self.impl_trait_context, impl_trait_context);
54 self.impl_trait_context = orig_itc;
57 fn collect_field(&mut self, field: &'a FieldDef, index: Option<usize>) {
58 let index = |this: &Self| {
59 index.unwrap_or_else(|| {
60 let node_id = NodeId::placeholder_from_expn_id(this.expansion);
61 this.resolver.placeholder_field_indices[&node_id]
65 if field.is_placeholder {
66 let old_index = self.resolver.placeholder_field_indices.insert(field.id, index(self));
67 assert!(old_index.is_none(), "placeholder field index is reset for a node ID");
68 self.visit_macro_invoc(field.id);
70 let name = field.ident.map_or_else(|| sym::integer(index(self)), |ident| ident.name);
71 let def = self.create_def(field.id, DefPathData::ValueNs(name), field.span);
72 self.with_parent(def, |this| visit::walk_field_def(this, field));
76 fn visit_macro_invoc(&mut self, id: NodeId) {
77 let id = id.placeholder_to_expn_id();
79 self.resolver.invocation_parents.insert(id, (self.parent_def, self.impl_trait_context));
80 assert!(old_parent.is_none(), "parent `LocalDefId` is reset for an invocation");
84 impl<'a, 'b> visit::Visitor<'a> for DefCollector<'a, 'b> {
85 fn visit_item(&mut self, i: &'a Item) {
86 debug!("visit_item: {:?}", i);
88 // Pick the def data. This need not be unique, but the more
89 // information we encapsulate into, the better
90 let def_data = match &i.kind {
91 ItemKind::Impl { .. } => DefPathData::Impl,
92 ItemKind::ForeignMod(..) => DefPathData::ForeignMod,
95 | ItemKind::TraitAlias(..)
97 | ItemKind::Struct(..)
99 | ItemKind::ExternCrate(..)
100 | ItemKind::TyAlias(..) => DefPathData::TypeNs(i.ident.name),
101 ItemKind::Static(..) | ItemKind::Const(..) | ItemKind::Fn(..) => {
102 DefPathData::ValueNs(i.ident.name)
104 ItemKind::MacroDef(..) => DefPathData::MacroNs(i.ident.name),
105 ItemKind::MacCall(..) => {
106 visit::walk_item(self, i);
107 return self.visit_macro_invoc(i.id);
109 ItemKind::GlobalAsm(..) => DefPathData::GlobalAsm,
110 ItemKind::Use(..) => {
111 return visit::walk_item(self, i);
114 let def = self.create_def(i.id, def_data, i.span);
116 self.with_parent(def, |this| {
117 this.with_impl_trait(ImplTraitContext::Existential, |this| {
119 ItemKind::Struct(ref struct_def, _) | ItemKind::Union(ref struct_def, _) => {
120 // If this is a unit or tuple-like struct, register the constructor.
121 if let Some(ctor_node_id) = struct_def.ctor_node_id() {
122 this.create_def(ctor_node_id, DefPathData::Ctor, i.span);
127 visit::walk_item(this, i);
132 fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) {
133 if let FnKind::Fn(_, _, sig, _, generics, body) = fn_kind {
134 if let Async::Yes { closure_id, .. } = sig.header.asyncness {
135 self.visit_generics(generics);
137 // For async functions, we need to create their inner defs inside of a
138 // closure to match their desugared representation. Besides that,
139 // we must mirror everything that `visit::walk_fn` below does.
140 self.visit_fn_header(&sig.header);
141 for param in &sig.decl.inputs {
142 self.visit_param(param);
144 self.visit_fn_ret_ty(&sig.decl.output);
145 // If this async fn has no body (i.e. it's an async fn signature in a trait)
146 // then the closure_def will never be used, and we should avoid generating a
148 if let Some(body) = body {
149 let closure_def = self.create_def(closure_id, DefPathData::ClosureExpr, span);
150 self.with_parent(closure_def, |this| this.visit_block(body));
156 visit::walk_fn(self, fn_kind);
159 fn visit_use_tree(&mut self, use_tree: &'a UseTree, id: NodeId, _nested: bool) {
160 self.create_def(id, DefPathData::Use, use_tree.span);
161 visit::walk_use_tree(self, use_tree, id);
164 fn visit_foreign_item(&mut self, foreign_item: &'a ForeignItem) {
165 if let ForeignItemKind::MacCall(_) = foreign_item.kind {
166 return self.visit_macro_invoc(foreign_item.id);
169 let def = self.create_def(
171 DefPathData::ValueNs(foreign_item.ident.name),
175 self.with_parent(def, |this| {
176 visit::walk_foreign_item(this, foreign_item);
180 fn visit_variant(&mut self, v: &'a Variant) {
181 if v.is_placeholder {
182 return self.visit_macro_invoc(v.id);
184 let def = self.create_def(v.id, DefPathData::TypeNs(v.ident.name), v.span);
185 self.with_parent(def, |this| {
186 if let Some(ctor_node_id) = v.data.ctor_node_id() {
187 this.create_def(ctor_node_id, DefPathData::Ctor, v.span);
189 visit::walk_variant(this, v)
193 fn visit_variant_data(&mut self, data: &'a VariantData) {
194 // The assumption here is that non-`cfg` macro expansion cannot change field indices.
195 // It currently holds because only inert attributes are accepted on fields,
196 // and every such attribute expands into a single field after it's resolved.
197 for (index, field) in data.fields().iter().enumerate() {
198 self.collect_field(field, Some(index));
202 fn visit_generic_param(&mut self, param: &'a GenericParam) {
203 if param.is_placeholder {
204 self.visit_macro_invoc(param.id);
207 let name = param.ident.name;
208 let def_path_data = match param.kind {
209 GenericParamKind::Lifetime { .. } => DefPathData::LifetimeNs(name),
210 GenericParamKind::Type { .. } => DefPathData::TypeNs(name),
211 GenericParamKind::Const { .. } => DefPathData::ValueNs(name),
213 self.create_def(param.id, def_path_data, param.ident.span);
215 // impl-Trait can happen inside generic parameters, like
217 // fn foo<U: Iterator<Item = impl Clone>>() {}
220 // In that case, the impl-trait is lowered as an additional generic parameter.
221 self.with_impl_trait(ImplTraitContext::Universal(self.parent_def), |this| {
222 visit::walk_generic_param(this, param)
226 fn visit_assoc_item(&mut self, i: &'a AssocItem, ctxt: visit::AssocCtxt) {
227 let def_data = match &i.kind {
228 AssocItemKind::Fn(..) | AssocItemKind::Const(..) => DefPathData::ValueNs(i.ident.name),
229 AssocItemKind::Type(..) => DefPathData::TypeNs(i.ident.name),
230 AssocItemKind::MacCall(..) => return self.visit_macro_invoc(i.id),
233 let def = self.create_def(i.id, def_data, i.span);
234 self.with_parent(def, |this| visit::walk_assoc_item(this, i, ctxt));
237 fn visit_pat(&mut self, pat: &'a Pat) {
239 PatKind::MacCall(..) => self.visit_macro_invoc(pat.id),
240 _ => visit::walk_pat(self, pat),
244 fn visit_anon_const(&mut self, constant: &'a AnonConst) {
245 let def = self.create_def(constant.id, DefPathData::AnonConst, constant.value.span);
246 self.with_parent(def, |this| visit::walk_anon_const(this, constant));
249 fn visit_expr(&mut self, expr: &'a Expr) {
250 let parent_def = match expr.kind {
251 ExprKind::MacCall(..) => return self.visit_macro_invoc(expr.id),
252 ExprKind::Closure(ref closure) => {
253 // Async closures desugar to closures inside of closures, so
254 // we must create two defs.
255 let closure_def = self.create_def(expr.id, DefPathData::ClosureExpr, expr.span);
256 match closure.asyncness {
257 Async::Yes { closure_id, .. } => {
258 self.create_def(closure_id, DefPathData::ClosureExpr, expr.span)
260 Async::No => closure_def,
263 ExprKind::Async(_, async_id, _) => {
264 self.create_def(async_id, DefPathData::ClosureExpr, expr.span)
266 _ => self.parent_def,
269 self.with_parent(parent_def, |this| visit::walk_expr(this, expr));
272 fn visit_ty(&mut self, ty: &'a Ty) {
274 TyKind::MacCall(..) => self.visit_macro_invoc(ty.id),
275 _ => visit::walk_ty(self, ty),
279 fn visit_stmt(&mut self, stmt: &'a Stmt) {
281 StmtKind::MacCall(..) => self.visit_macro_invoc(stmt.id),
282 _ => visit::walk_stmt(self, stmt),
286 fn visit_arm(&mut self, arm: &'a Arm) {
287 if arm.is_placeholder { self.visit_macro_invoc(arm.id) } else { visit::walk_arm(self, arm) }
290 fn visit_expr_field(&mut self, f: &'a ExprField) {
291 if f.is_placeholder {
292 self.visit_macro_invoc(f.id)
294 visit::walk_expr_field(self, f)
298 fn visit_pat_field(&mut self, fp: &'a PatField) {
299 if fp.is_placeholder {
300 self.visit_macro_invoc(fp.id)
302 visit::walk_pat_field(self, fp)
306 fn visit_param(&mut self, p: &'a Param) {
307 if p.is_placeholder {
308 self.visit_macro_invoc(p.id)
310 self.with_impl_trait(ImplTraitContext::Universal(self.parent_def), |this| {
311 visit::walk_param(this, p)
316 // This method is called only when we are visiting an individual field
317 // after expanding an attribute on it.
318 fn visit_field_def(&mut self, field: &'a FieldDef) {
319 self.collect_field(field, None);
322 fn visit_crate(&mut self, krate: &'a Crate) {
323 if krate.is_placeholder {
324 self.visit_macro_invoc(krate.id)
326 visit::walk_crate(self, krate)