1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Reduced graph building
13 //! Here we build the "reduced graph": the graph of the module tree without
14 //! any imports resolved.
16 use resolve_imports::ImportDirectiveSubclass::{self, GlobImport};
18 use Namespace::{self, TypeNS, ValueNS};
19 use {NameBinding, NameBindingKind, ToNameBinding};
20 use ParentLink::{ModuleParentLink, BlockParentLink};
22 use {resolve_error, resolve_struct_error, ResolutionError};
24 use rustc::middle::cstore::{ChildItem, DlDef};
25 use rustc::hir::def::*;
26 use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
27 use rustc::ty::{self, VariantKind};
29 use syntax::ast::Name;
31 use syntax::parse::token;
33 use syntax::ast::{Block, Crate};
34 use syntax::ast::{ForeignItem, ForeignItemKind, Item, ItemKind};
35 use syntax::ast::{Mutability, StmtKind, TraitItemKind};
36 use syntax::ast::{Variant, ViewPathGlob, ViewPathList, ViewPathSimple};
37 use syntax::parse::token::keywords;
38 use syntax::visit::{self, Visitor};
40 use syntax_pos::{Span, DUMMY_SP};
42 impl<'a> ToNameBinding<'a> for (Module<'a>, Span, ty::Visibility) {
43 fn to_name_binding(self) -> NameBinding<'a> {
44 NameBinding { kind: NameBindingKind::Module(self.0), span: self.1, vis: self.2 }
48 impl<'a> ToNameBinding<'a> for (Def, Span, ty::Visibility) {
49 fn to_name_binding(self) -> NameBinding<'a> {
50 NameBinding { kind: NameBindingKind::Def(self.0), span: self.1, vis: self.2 }
54 impl<'b> Resolver<'b> {
55 /// Constructs the reduced graph for the entire crate.
56 pub fn build_reduced_graph(&mut self, krate: &Crate) {
57 let no_implicit_prelude = attr::contains_name(&krate.attrs, "no_implicit_prelude");
58 self.graph_root.no_implicit_prelude.set(no_implicit_prelude);
59 visit::walk_crate(&mut BuildReducedGraphVisitor { resolver: self }, krate);
62 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
63 /// otherwise, reports an error.
64 fn define<T>(&mut self, parent: Module<'b>, name: Name, ns: Namespace, def: T)
65 where T: ToNameBinding<'b>,
67 let binding = def.to_name_binding();
68 if let Err(old_binding) = self.try_define(parent, name, ns, binding.clone()) {
69 self.report_conflict(parent, name, ns, old_binding, &binding);
73 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
74 // If any statements are items, we need to create an anonymous module
75 block.stmts.iter().any(|statement| match statement.node {
76 StmtKind::Item(_) => true,
81 /// Constructs the reduced graph for one item.
82 fn build_reduced_graph_for_item(&mut self, item: &Item) {
83 let parent = self.current_module;
84 let parent_vis = self.current_vis;
85 let name = item.ident.name;
87 let vis = self.resolve_visibility(&item.vis);
90 ItemKind::Use(ref view_path) => {
91 // Extract and intern the module part of the path. For
92 // globs and lists, the path is found directly in the AST;
93 // for simple paths we have to munge the path a little.
94 let module_path: Vec<Name> = match view_path.node {
95 ViewPathSimple(_, ref full_path) => {
101 .map(|seg| seg.identifier.name)
105 ViewPathGlob(ref module_ident_path) |
106 ViewPathList(ref module_ident_path, _) => {
107 module_ident_path.segments
109 .map(|seg| seg.identifier.name)
114 // Build up the import directives.
115 let is_prelude = attr::contains_name(&item.attrs, "prelude_import");
117 match view_path.node {
118 ViewPathSimple(binding, ref full_path) => {
119 let source_name = full_path.segments.last().unwrap().identifier.name;
120 if source_name.as_str() == "mod" || source_name.as_str() == "self" {
123 ResolutionError::SelfImportsOnlyAllowedWithin);
126 let subclass = ImportDirectiveSubclass::single(binding.name, source_name);
127 let span = view_path.span;
128 self.add_import_directive(module_path, subclass, span, item.id, vis);
130 ViewPathList(_, ref source_items) => {
131 // Make sure there's at most one `mod` import in the list.
132 let mod_spans = source_items.iter().filter_map(|item| {
133 if item.node.name.name == keywords::SelfValue.name() {
138 }).collect::<Vec<Span>>();
140 if mod_spans.len() > 1 {
141 let mut e = resolve_struct_error(self,
143 ResolutionError::SelfImportCanOnlyAppearOnceInTheList);
144 for other_span in mod_spans.iter().skip(1) {
145 e.span_note(*other_span, "another `self` import appears here");
150 for source_item in source_items {
151 let node = source_item.node;
152 let (module_path, name, rename) = {
153 if node.name.name != keywords::SelfValue.name() {
154 let rename = node.rename.unwrap_or(node.name).name;
155 (module_path.clone(), node.name.name, rename)
157 let name = match module_path.last() {
164 SelfImportOnlyInImportListWithNonEmptyPrefix
169 let module_path = module_path.split_last().unwrap().1;
170 let rename = node.rename.map(|i| i.name).unwrap_or(name);
171 (module_path.to_vec(), name, rename)
174 let subclass = ImportDirectiveSubclass::single(rename, name);
175 let (span, id) = (source_item.span, source_item.node.id);
176 self.add_import_directive(module_path, subclass, span, id, vis);
180 let subclass = GlobImport { is_prelude: is_prelude };
181 let span = view_path.span;
182 self.add_import_directive(module_path, subclass, span, item.id, vis);
187 ItemKind::ExternCrate(_) => {
188 // n.b. we don't need to look at the path option here, because cstore already
190 if let Some(crate_id) = self.session.cstore.extern_mod_stmt_cnum(item.id) {
193 index: CRATE_DEF_INDEX,
195 let parent_link = ModuleParentLink(parent, name);
196 let def = Def::Mod(def_id);
197 let module = self.new_extern_crate_module(parent_link, def, item.id);
198 self.define(parent, name, TypeNS, (module, sp, vis));
200 self.build_reduced_graph_for_external_crate(module);
204 ItemKind::Mod(..) => {
205 let parent_link = ModuleParentLink(parent, name);
206 let def = Def::Mod(self.definitions.local_def_id(item.id));
207 let module = self.new_module(parent_link, Some(def), false);
208 module.no_implicit_prelude.set({
209 parent.no_implicit_prelude.get() ||
210 attr::contains_name(&item.attrs, "no_implicit_prelude")
212 self.define(parent, name, TypeNS, (module, sp, vis));
213 self.module_map.insert(item.id, module);
215 // Descend into the module.
216 self.current_module = module;
217 self.current_vis = ty::Visibility::Restricted(item.id);
220 ItemKind::ForeignMod(..) => {}
222 // These items live in the value namespace.
223 ItemKind::Static(_, m, _) => {
224 let mutbl = m == Mutability::Mutable;
225 let def = Def::Static(self.definitions.local_def_id(item.id), mutbl);
226 self.define(parent, name, ValueNS, (def, sp, vis));
228 ItemKind::Const(_, _) => {
229 let def = Def::Const(self.definitions.local_def_id(item.id));
230 self.define(parent, name, ValueNS, (def, sp, vis));
232 ItemKind::Fn(_, _, _, _, _, _) => {
233 let def = Def::Fn(self.definitions.local_def_id(item.id));
234 self.define(parent, name, ValueNS, (def, sp, vis));
237 // These items live in the type namespace.
238 ItemKind::Ty(..) => {
239 let def = Def::TyAlias(self.definitions.local_def_id(item.id));
240 self.define(parent, name, TypeNS, (def, sp, vis));
243 ItemKind::Enum(ref enum_definition, _) => {
244 let parent_link = ModuleParentLink(parent, name);
245 let def = Def::Enum(self.definitions.local_def_id(item.id));
246 let module = self.new_module(parent_link, Some(def), false);
247 self.define(parent, name, TypeNS, (module, sp, vis));
249 for variant in &(*enum_definition).variants {
250 let item_def_id = self.definitions.local_def_id(item.id);
251 self.build_reduced_graph_for_variant(variant, item_def_id, module, vis);
255 // These items live in both the type and value namespaces.
256 ItemKind::Struct(ref struct_def, _) => {
257 // Define a name in the type namespace.
258 let def = Def::Struct(self.definitions.local_def_id(item.id));
259 self.define(parent, name, TypeNS, (def, sp, vis));
261 // If this is a newtype or unit-like struct, define a name
262 // in the value namespace as well
263 if !struct_def.is_struct() {
264 let def = Def::Struct(self.definitions.local_def_id(struct_def.id()));
265 self.define(parent, name, ValueNS, (def, sp, vis));
268 // Record the def ID and fields of this struct.
269 let field_names = struct_def.fields().iter().enumerate().map(|(index, field)| {
270 self.resolve_visibility(&field.vis);
271 field.ident.map(|ident| ident.name)
272 .unwrap_or_else(|| token::intern(&index.to_string()))
274 let item_def_id = self.definitions.local_def_id(item.id);
275 self.structs.insert(item_def_id, field_names);
278 ItemKind::Union(..) => panic!("`union` is not yet implemented"),
280 ItemKind::DefaultImpl(_, _) | ItemKind::Impl(..) => {}
282 ItemKind::Trait(_, _, _, ref items) => {
283 let def_id = self.definitions.local_def_id(item.id);
285 // Add all the items within to a new module.
286 let parent_link = ModuleParentLink(parent, name);
287 let def = Def::Trait(def_id);
288 let module_parent = self.new_module(parent_link, Some(def), false);
289 self.define(parent, name, TypeNS, (module_parent, sp, vis));
291 // Add the names of all the items to the trait info.
293 let item_def_id = self.definitions.local_def_id(item.id);
294 let mut is_static_method = false;
295 let (def, ns) = match item.node {
296 TraitItemKind::Const(..) => (Def::AssociatedConst(item_def_id), ValueNS),
297 TraitItemKind::Method(ref sig, _) => {
298 is_static_method = !sig.decl.has_self();
299 (Def::Method(item_def_id), ValueNS)
301 TraitItemKind::Type(..) => (Def::AssociatedTy(def_id, item_def_id), TypeNS),
302 TraitItemKind::Macro(_) => panic!("unexpanded macro in resolve!"),
305 self.define(module_parent, item.ident.name, ns, (def, item.span, vis));
307 self.trait_item_map.insert((item.ident.name, def_id), is_static_method);
310 ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
313 visit::walk_item(&mut BuildReducedGraphVisitor { resolver: self }, item);
314 self.current_module = parent;
315 self.current_vis = parent_vis;
318 // Constructs the reduced graph for one variant. Variants exist in the
319 // type and value namespaces.
320 fn build_reduced_graph_for_variant(&mut self,
324 vis: ty::Visibility) {
325 let name = variant.node.name.name;
326 if variant.node.data.is_struct() {
327 // Not adding fields for variants as they are not accessed with a self receiver
328 let variant_def_id = self.definitions.local_def_id(variant.node.data.id());
329 self.structs.insert(variant_def_id, Vec::new());
332 // Variants are always treated as importable to allow them to be glob used.
333 // All variants are defined in both type and value namespaces as future-proofing.
334 let def = Def::Variant(item_id, self.definitions.local_def_id(variant.node.data.id()));
335 self.define(parent, name, ValueNS, (def, variant.span, vis));
336 self.define(parent, name, TypeNS, (def, variant.span, vis));
339 /// Constructs the reduced graph for one foreign item.
340 fn build_reduced_graph_for_foreign_item(&mut self, foreign_item: &ForeignItem) {
341 let parent = self.current_module;
342 let name = foreign_item.ident.name;
344 let def = match foreign_item.node {
345 ForeignItemKind::Fn(..) => {
346 Def::Fn(self.definitions.local_def_id(foreign_item.id))
348 ForeignItemKind::Static(_, m) => {
349 Def::Static(self.definitions.local_def_id(foreign_item.id), m)
352 let vis = self.resolve_visibility(&foreign_item.vis);
353 self.define(parent, name, ValueNS, (def, foreign_item.span, vis));
356 fn build_reduced_graph_for_block(&mut self, block: &Block) {
357 let parent = self.current_module;
358 if self.block_needs_anonymous_module(block) {
359 let block_id = block.id;
361 debug!("(building reduced graph for block) creating a new anonymous module for block \
365 let parent_link = BlockParentLink(parent, block_id);
366 let new_module = self.new_module(parent_link, None, false);
367 self.module_map.insert(block_id, new_module);
368 self.current_module = new_module; // Descend into the block.
371 visit::walk_block(&mut BuildReducedGraphVisitor { resolver: self }, block);
372 self.current_module = parent;
375 /// Builds the reduced graph for a single item in an external crate.
376 fn build_reduced_graph_for_external_crate_def(&mut self, parent: Module<'b>, xcdef: ChildItem) {
377 let def = match xcdef.def {
382 if let Def::ForeignMod(def_id) = def {
383 // Foreign modules have no names. Recur and populate eagerly.
384 for child in self.session.cstore.item_children(def_id) {
385 self.build_reduced_graph_for_external_crate_def(parent, child);
390 let name = xcdef.name;
391 let vis = if parent.is_trait() { ty::Visibility::Public } else { xcdef.vis };
394 Def::Mod(_) | Def::ForeignMod(_) | Def::Enum(..) => {
395 debug!("(building reduced graph for external crate) building module {} {:?}",
397 let parent_link = ModuleParentLink(parent, name);
398 let module = self.new_module(parent_link, Some(def), true);
399 let _ = self.try_define(parent, name, TypeNS, (module, DUMMY_SP, vis));
401 Def::Variant(_, variant_id) => {
402 debug!("(building reduced graph for external crate) building variant {}", name);
403 // Variants are always treated as importable to allow them to be glob used.
404 // All variants are defined in both type and value namespaces as future-proofing.
405 let _ = self.try_define(parent, name, TypeNS, (def, DUMMY_SP, vis));
406 let _ = self.try_define(parent, name, ValueNS, (def, DUMMY_SP, vis));
407 if self.session.cstore.variant_kind(variant_id) == Some(VariantKind::Struct) {
408 // Not adding fields for variants as they are not accessed with a self receiver
409 self.structs.insert(variant_id, Vec::new());
415 Def::AssociatedConst(..) |
417 debug!("(building reduced graph for external crate) building value (fn/static) {}",
419 let _ = self.try_define(parent, name, ValueNS, (def, DUMMY_SP, vis));
421 Def::Trait(def_id) => {
422 debug!("(building reduced graph for external crate) building type {}", name);
424 // If this is a trait, add all the trait item names to the trait
427 let trait_item_def_ids = self.session.cstore.trait_item_def_ids(def_id);
428 for trait_item_def in &trait_item_def_ids {
429 let trait_item_name =
430 self.session.cstore.item_name(trait_item_def.def_id());
432 debug!("(building reduced graph for external crate) ... adding trait item \
436 self.trait_item_map.insert((trait_item_name, def_id), false);
439 let parent_link = ModuleParentLink(parent, name);
440 let module = self.new_module(parent_link, Some(def), true);
441 let _ = self.try_define(parent, name, TypeNS, (module, DUMMY_SP, vis));
443 Def::TyAlias(..) | Def::AssociatedTy(..) => {
444 debug!("(building reduced graph for external crate) building type {}", name);
445 let _ = self.try_define(parent, name, TypeNS, (def, DUMMY_SP, vis));
448 if self.session.cstore.tuple_struct_definition_if_ctor(def_id).is_none() => {
449 debug!("(building reduced graph for external crate) building type and value for {}",
451 let _ = self.try_define(parent, name, TypeNS, (def, DUMMY_SP, vis));
452 if let Some(ctor_def_id) = self.session.cstore.struct_ctor_def_id(def_id) {
453 let def = Def::Struct(ctor_def_id);
454 let _ = self.try_define(parent, name, ValueNS, (def, DUMMY_SP, vis));
457 // Record the def ID and fields of this struct.
458 let fields = self.session.cstore.struct_field_names(def_id);
459 self.structs.insert(def_id, fields);
461 Def::Struct(..) => {}
469 bug!("didn't expect `{:?}`", def);
474 /// Builds the reduced graph rooted at the 'use' directive for an external
476 fn build_reduced_graph_for_external_crate(&mut self, root: Module<'b>) {
477 let root_cnum = root.def_id().unwrap().krate;
478 for child in self.session.cstore.crate_top_level_items(root_cnum) {
479 self.build_reduced_graph_for_external_crate_def(root, child);
483 /// Ensures that the reduced graph rooted at the given external module
484 /// is built, building it if it is not.
485 pub fn populate_module_if_necessary(&mut self, module: Module<'b>) {
486 if module.populated.get() { return }
487 for child in self.session.cstore.item_children(module.def_id().unwrap()) {
488 self.build_reduced_graph_for_external_crate_def(module, child);
490 module.populated.set(true)
494 struct BuildReducedGraphVisitor<'a, 'b: 'a> {
495 resolver: &'a mut Resolver<'b>,
498 impl<'a, 'b> Visitor for BuildReducedGraphVisitor<'a, 'b> {
499 fn visit_item(&mut self, item: &Item) {
500 self.resolver.build_reduced_graph_for_item(item);
503 fn visit_foreign_item(&mut self, foreign_item: &ForeignItem) {
504 self.resolver.build_reduced_graph_for_foreign_item(foreign_item);
507 fn visit_block(&mut self, block: &Block) {
508 self.resolver.build_reduced_graph_for_block(block);