Rollup merge of rust-lang#66673 - petrochenkov:toresolve, r=Centril

Move def collector from `rustc` to `rustc_resolve`

It's used only from `rustc_resolve`, so we can move it there, thus reducing the size of `rustc` (rust-lang#65031).

It's quite possible that we can merge the def collector pass into the "build reduced graph" pass (they are always run together and do similar things), but it's some larger work.

r? @eddyb

src/librustc/hir/map/definitions.rs

@@ -105,7 +105,7 @@ pub struct Definitions {
     /// we know what parent node that fragment should be attached to thanks to this table.
     invocation_parents: FxHashMap<ExpnId, DefIndex>,
     /// Indices of unnamed struct or variant fields with unresolved attributes.
-    pub(super) placeholder_field_indices: NodeMap<usize>,
+    placeholder_field_indices: NodeMap<usize>,
 }
 
 /// A unique identifier that we can use to lookup a definition
@@ -535,6 +535,15 @@ impl Definitions {
         let old_parent = self.invocation_parents.insert(invoc_id, parent);
         assert!(old_parent.is_none(), "parent `DefIndex` is reset for an invocation");
     }
+
+    pub fn placeholder_field_index(&self, node_id: ast::NodeId) -> usize {
+        self.placeholder_field_indices[&node_id]
+    }
+
+    pub fn set_placeholder_field_index(&mut self, node_id: ast::NodeId, index: usize) {
+        let old_index = self.placeholder_field_indices.insert(node_id, index);
+        assert!(old_index.is_none(), "placeholder field index is reset for a node ID");
+    }
 }
 
 impl DefPathData {

src/librustc/hir/map/mod.rs

@@ -1,5 +1,4 @@
 use self::collector::NodeCollector;
-pub use self::def_collector::DefCollector;
 pub use self::definitions::{
     Definitions, DefKey, DefPath, DefPathData, DisambiguatedDefPathData, DefPathHash
 };
@@ -25,7 +24,6 @@ use syntax_pos::{Span, DUMMY_SP};
 
 pub mod blocks;
 mod collector;
-mod def_collector;
 pub mod definitions;
 mod hir_id_validator;
 

src/librustc_resolve/build_reduced_graph.rs

@@ -5,6 +5,7 @@
 //! unexpanded macros in the fragment are visited and registered.
 //! Imports are also considered items and placed into modules here, but not resolved yet.
 
+use crate::def_collector::collect_definitions;
 use crate::macros::{LegacyBinding, LegacyScope};
 use crate::resolve_imports::ImportDirective;
 use crate::resolve_imports::ImportDirectiveSubclass::{self, GlobImport, SingleImport};
@@ -16,7 +17,6 @@ use crate::{ResolutionError, Determinacy, PathResult, CrateLint};
 use rustc::bug;
 use rustc::hir::def::{self, *};
 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
-use rustc::hir::map::DefCollector;
 use rustc::ty;
 use rustc::middle::cstore::CrateStore;
 use rustc_metadata::cstore::LoadedMacro;
@@ -167,8 +167,7 @@ impl<'a> Resolver<'a> {
         fragment: &AstFragment,
         parent_scope: ParentScope<'a>,
     ) -> LegacyScope<'a> {
-        let mut def_collector = DefCollector::new(&mut self.definitions, parent_scope.expansion);
-        fragment.visit_with(&mut def_collector);
+        collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
         let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
         fragment.visit_with(&mut visitor);
         visitor.parent_scope.legacy

src/librustc/hir/map/def_collector.rs → src/librustc_resolve/def_collector.rs

@@ -1,26 +1,31 @@
-use crate::hir::map::definitions::*;
-use crate::hir::def_id::DefIndex;
-
+use log::debug;
+use rustc::hir::map::definitions::*;
+use rustc::hir::def_id::DefIndex;
 use syntax::ast::*;
 use syntax::visit;
 use syntax::symbol::{kw, sym};
 use syntax::token::{self, Token};
+use syntax_expand::expand::AstFragment;
 use syntax_pos::hygiene::ExpnId;
 use syntax_pos::Span;
 
+crate fn collect_definitions(
+    definitions: &mut Definitions,
+    fragment: &AstFragment,
+    expansion: ExpnId,
+) {
+    let parent_def = definitions.invocation_parent(expansion);
+    fragment.visit_with(&mut DefCollector { definitions, parent_def, expansion });
+}
+
 /// Creates `DefId`s for nodes in the AST.
-pub struct DefCollector<'a> {
+struct DefCollector<'a> {
     definitions: &'a mut Definitions,
     parent_def: DefIndex,
     expansion: ExpnId,
 }
 
 impl<'a> DefCollector<'a> {
-    pub fn new(definitions: &'a mut Definitions, expansion: ExpnId) -> Self {
-        let parent_def = definitions.invocation_parent(expansion);
-        DefCollector { definitions, parent_def, expansion }
-    }
-
     fn create_def(&mut self,
                   node_id: NodeId,
                   data: DefPathData,
@@ -82,7 +87,7 @@ impl<'a> DefCollector<'a> {
                 .or_else(|| index.map(sym::integer))
                 .unwrap_or_else(|| {
                     let node_id = NodeId::placeholder_from_expn_id(self.expansion);
-                    sym::integer(self.definitions.placeholder_field_indices[&node_id])
+                    sym::integer(self.definitions.placeholder_field_index(node_id))
                 });
             let def = self.create_def(field.id, DefPathData::ValueNs(name), field.span);
             self.with_parent(def, |this| visit::walk_struct_field(this, field));
@@ -186,7 +191,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
         for (index, field) in data.fields().iter().enumerate() {
             self.collect_field(field, Some(index));
             if field.is_placeholder && field.ident.is_none() {
-                self.definitions.placeholder_field_indices.insert(field.id, index);
+                self.definitions.set_placeholder_field_index(field.id, index);
             }
         }
     }

src/librustc_resolve/lib.rs

@@ -68,6 +68,7 @@ use rustc_error_codes::*;
 
 type Res = def::Res<NodeId>;
 
+mod def_collector;
 mod diagnostics;
 mod late;
 mod macros;