resolve: Cache module loading for all foreign modules

It was previously cached for modules loaded from `fn get_module`, but not for modules loaded from `fn build_reduced_graph_for_external_crate_res`.
This also makes all foreign modules use their real parent, span and expansion instead of possibly a parent/span/expansion of their reexport.

An ICE happening on attempt to decode expansions for foreign enums and traits is avoided.

Also local enums and traits are now added to the module map.

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -127,7 +127,6 @@ impl<'a> Resolver<'a> {
     /// If `def_id` refers to a module (in resolver's sense, i.e. a module item, crate root, enum,
     /// or trait), then this function returns that module's resolver representation, otherwise it
     /// returns `None`.
-    /// FIXME: `Module`s for local enums and traits are not currently found.
     crate fn get_module(&mut self, def_id: DefId) -> Option<Module<'a>> {
         if let module @ Some(..) = self.module_map.get(&def_id) {
             return module.copied();
@@ -146,17 +145,21 @@ impl<'a> Resolver<'a> {
                     } else {
                         def_key.disambiguated_data.data.get_opt_name().expect("module without name")
                     };
+                    let expn_id = if def_kind == DefKind::Mod {
+                        self.cstore().module_expansion_untracked(def_id, &self.session)
+                    } else {
+                        // FIXME: Parent expansions for enums and traits are not kept in metadata.
+                        ExpnId::root()
+                    };
 
-                    let module = self.arenas.new_module(
+                    Some(self.new_module(
                         parent,
                         ModuleKind::Def(def_kind, def_id, name),
-                        self.cstore().module_expansion_untracked(def_id, &self.session),
+                        expn_id,
                         self.cstore().get_span_untracked(def_id, &self.session),
                         // FIXME: Account for `#[no_implicit_prelude]` attributes.
                         parent.map_or(false, |module| module.no_implicit_prelude),
-                    );
+                    ))
-                    self.module_map.insert(def_id, module);
-                    Some(module)
                 }
                 _ => None,
             }
@@ -759,7 +762,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             }
 
             ItemKind::Mod(..) => {
-                let module = self.r.arenas.new_module(
+                let module = self.r.new_module(
                     Some(parent),
                     ModuleKind::Def(DefKind::Mod, def_id, ident.name),
                     expansion.to_expn_id(),
@@ -768,7 +771,6 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         || self.r.session.contains_name(&item.attrs, sym::no_implicit_prelude),
                 );
                 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
-                self.r.module_map.insert(def_id, module);
 
                 // Descend into the module.
                 self.parent_scope.module = module;
@@ -799,7 +801,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             }
 
             ItemKind::Enum(_, _) => {
-                let module = self.r.arenas.new_module(
+                let module = self.r.new_module(
                     Some(parent),
                     ModuleKind::Def(DefKind::Enum, def_id, ident.name),
                     expansion.to_expn_id(),
@@ -873,7 +875,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
 
             ItemKind::Trait(..) => {
                 // Add all the items within to a new module.
-                let module = self.r.arenas.new_module(
+                let module = self.r.new_module(
                     Some(parent),
                     ModuleKind::Def(DefKind::Trait, def_id, ident.name),
                     expansion.to_expn_id(),
@@ -916,7 +918,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         let parent = self.parent_scope.module;
         let expansion = self.parent_scope.expansion;
         if self.block_needs_anonymous_module(block) {
-            let module = self.r.arenas.new_module(
+            let module = self.r.new_module(
                 Some(parent),
                 ModuleKind::Block(block.id),
                 expansion.to_expn_id(),
@@ -936,15 +938,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         let expansion = self.parent_scope.expansion;
         // Record primary definitions.
         match res {
-            Res::Def(kind @ (DefKind::Mod | DefKind::Enum | DefKind::Trait), def_id) => {
+            Res::Def(DefKind::Mod | DefKind::Enum | DefKind::Trait, def_id) => {
-                let module = self.r.arenas.new_module(
+                let module = self.r.expect_module(def_id);
-                    Some(parent),
-                    ModuleKind::Def(kind, def_id, ident.name),
-                    expansion.to_expn_id(),
-                    span,
-                    // FIXME: Account for `#[no_implicit_prelude]` attributes.
-                    parent.no_implicit_prelude,
-                );
                 self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
             }
             Res::Def(

compiler/rustc_resolve/src/lib.rs

@@ -1071,12 +1071,17 @@ impl<'a> ResolverArenas<'a> {
         expn_id: ExpnId,
         span: Span,
         no_implicit_prelude: bool,
+        module_map: &mut FxHashMap<DefId, Module<'a>>,
     ) -> Module<'a> {
         let module =
             self.modules.alloc(ModuleData::new(parent, kind, expn_id, span, no_implicit_prelude));
-        if module.def_id().map_or(true, |def_id| def_id.is_local()) {
+        let def_id = module.def_id();
+        if def_id.map_or(true, |def_id| def_id.is_local()) {
             self.local_modules.borrow_mut().push(module);
         }
+        if let Some(def_id) = def_id {
+            module_map.insert(def_id, module);
+        }
         module
     }
     fn local_modules(&'a self) -> std::cell::Ref<'a, Vec<Module<'a>>> {
@@ -1276,12 +1281,14 @@ impl<'a> Resolver<'a> {
         arenas: &'a ResolverArenas<'a>,
     ) -> Resolver<'a> {
         let root_def_id = CRATE_DEF_ID.to_def_id();
+        let mut module_map = FxHashMap::default();
         let graph_root = arenas.new_module(
             None,
             ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
             ExpnId::root(),
             krate.span,
             session.contains_name(&krate.attrs, sym::no_implicit_prelude),
+            &mut module_map,
         );
         let empty_module = arenas.new_module(
             None,
@@ -1289,9 +1296,8 @@ impl<'a> Resolver<'a> {
             ExpnId::root(),
             DUMMY_SP,
             true,
+            &mut FxHashMap::default(),
         );
-        let mut module_map = FxHashMap::default();
-        module_map.insert(root_def_id, graph_root);
 
         let definitions = Definitions::new(session.local_stable_crate_id(), krate.span);
         let root = definitions.get_root_def();
@@ -1434,6 +1440,18 @@ impl<'a> Resolver<'a> {
         resolver
     }
 
+    fn new_module(
+        &mut self,
+        parent: Option<Module<'a>>,
+        kind: ModuleKind,
+        expn_id: ExpnId,
+        span: Span,
+        no_implicit_prelude: bool,
+    ) -> Module<'a> {
+        let module_map = &mut self.module_map;
+        self.arenas.new_module(parent, kind, expn_id, span, no_implicit_prelude, module_map)
+    }
+
     fn create_stable_hashing_context(&self) -> ExpandHasher<'_, 'a> {
         ExpandHasher {
             source_map: CachingSourceMapView::new(self.session.source_map()),

src/test/ui/macros/auxiliary/macro-def-site-super.rs

@@ -0,0 +1,13 @@
+#![feature(decl_macro)]
+
+mod inner1 {
+    pub struct Struct {}
+
+    pub mod inner2 {
+        pub macro mac() {
+            super::Struct
+        }
+    }
+}
+
+pub use inner1::inner2 as public;

src/test/ui/macros/macro-def-site-super.rs

@@ -0,0 +1,10 @@
+// `super` in a `macro` refers to the parent module of the macro itself and not its reexport.
+
+// check-pass
+// aux-build:macro-def-site-super.rs
+
+extern crate macro_def_site_super;
+
+type A = macro_def_site_super::public::mac!();
+
+fn main() {}

src/test/ui/proc-macro/meta-macro-hygiene.rs

@@ -4,6 +4,7 @@
 // compile-flags: -Z span-debug -Z macro-backtrace -Z unpretty=expanded,hygiene -Z trim-diagnostic-paths=no
 // check-pass
 // normalize-stdout-test "\d+#" -> "0#"
+// normalize-stdout-test "expn\d{3,}" -> "expnNNN"
 //
 // We don't care about symbol ids, so we set them all to 0
 // in the stdout

src/test/ui/proc-macro/meta-macro-hygiene.stdout

@@ -1,5 +1,5 @@
 Def site: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5)
-Input: TokenStream [Ident { ident: "$crate", span: $DIR/meta-macro-hygiene.rs:23:37: 23:43 (#4) }, Punct { ch: ':', spacing: Joint, span: $DIR/meta-macro-hygiene.rs:23:43: 23:45 (#4) }, Punct { ch: ':', spacing: Alone, span: $DIR/meta-macro-hygiene.rs:23:43: 23:45 (#4) }, Ident { ident: "dummy", span: $DIR/meta-macro-hygiene.rs:23:45: 23:50 (#4) }, Punct { ch: '!', spacing: Alone, span: $DIR/meta-macro-hygiene.rs:23:50: 23:51 (#4) }, Group { delimiter: Parenthesis, stream: TokenStream [], span: $DIR/meta-macro-hygiene.rs:23:51: 23:53 (#4) }]
+Input: TokenStream [Ident { ident: "$crate", span: $DIR/meta-macro-hygiene.rs:24:37: 24:43 (#4) }, Punct { ch: ':', spacing: Joint, span: $DIR/meta-macro-hygiene.rs:24:43: 24:45 (#4) }, Punct { ch: ':', spacing: Alone, span: $DIR/meta-macro-hygiene.rs:24:43: 24:45 (#4) }, Ident { ident: "dummy", span: $DIR/meta-macro-hygiene.rs:24:45: 24:50 (#4) }, Punct { ch: '!', spacing: Alone, span: $DIR/meta-macro-hygiene.rs:24:50: 24:51 (#4) }, Group { delimiter: Parenthesis, stream: TokenStream [], span: $DIR/meta-macro-hygiene.rs:24:51: 24:53 (#4) }]
 Respanned: TokenStream [Ident { ident: "$crate", span: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5) }, Punct { ch: ':', spacing: Joint, span: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5) }, Punct { ch: ':', spacing: Alone, span: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5) }, Ident { ident: "dummy", span: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5) }, Punct { ch: '!', spacing: Alone, span: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5) }, Group { delimiter: Parenthesis, stream: TokenStream [], span: $DIR/auxiliary/make-macro.rs:7:9: 7:56 (#5) }]
 #![feature /* 0#0 */(prelude_import)]
 // aux-build:make-macro.rs
@@ -8,6 +8,7 @@ Respanned: TokenStream [Ident { ident: "$crate", span: $DIR/auxiliary/make-macro
 // compile-flags: -Z span-debug -Z macro-backtrace -Z unpretty=expanded,hygiene -Z trim-diagnostic-paths=no
 // check-pass
 // normalize-stdout-test "\d+#" -> "0#"
+// normalize-stdout-test "expn\d{3,}" -> "expnNNN"
 //
 // We don't care about symbol ids, so we set them all to 0
 // in the stdout
@@ -48,6 +49,7 @@ crate0::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt:
 crate0::{{expn2}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "produce_it")
 crate0::{{expn3}}: parent: crate0::{{expn2}}, call_site_ctxt: #4, def_site_ctxt: #0, kind: Macro(Bang, "meta_macro::print_def_site")
 crate0::{{expn4}}: parent: crate0::{{expn3}}, call_site_ctxt: #5, def_site_ctxt: #0, kind: Macro(Bang, "$crate::dummy")
+crate1::{{expnNNN}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "include")
 crate2::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
 
 SyntaxContexts:

src/test/ui/proc-macro/nonterminal-token-hygiene.rs

@@ -4,6 +4,7 @@
 // compile-flags: -Z span-debug -Z macro-backtrace -Z unpretty=expanded,hygiene
 // compile-flags: -Z trim-diagnostic-paths=no
 // normalize-stdout-test "\d+#" -> "0#"
+// normalize-stdout-test "expn\d{3,}" -> "expnNNN"
 // aux-build:test-macros.rs
 
 #![feature(decl_macro)]

src/test/ui/proc-macro/nonterminal-token-hygiene.stdout

@@ -6,19 +6,19 @@ PRINT-BANG INPUT (DEBUG): TokenStream [
         stream: TokenStream [
             Ident {
                 ident: "struct",
-                span: $DIR/nonterminal-token-hygiene.rs:30:5: 30:11 (#5),
+                span: $DIR/nonterminal-token-hygiene.rs:31:5: 31:11 (#5),
             },
             Ident {
                 ident: "S",
-                span: $DIR/nonterminal-token-hygiene.rs:30:12: 30:13 (#5),
+                span: $DIR/nonterminal-token-hygiene.rs:31:12: 31:13 (#5),
             },
             Punct {
                 ch: ';',
                 spacing: Alone,
-                span: $DIR/nonterminal-token-hygiene.rs:30:13: 30:14 (#5),
+                span: $DIR/nonterminal-token-hygiene.rs:31:13: 31:14 (#5),
             },
         ],
-        span: $DIR/nonterminal-token-hygiene.rs:20:27: 20:32 (#6),
+        span: $DIR/nonterminal-token-hygiene.rs:21:27: 21:32 (#6),
     },
 ]
 #![feature /* 0#0 */(prelude_import)]
@@ -29,6 +29,7 @@ PRINT-BANG INPUT (DEBUG): TokenStream [
 // compile-flags: -Z span-debug -Z macro-backtrace -Z unpretty=expanded,hygiene
 // compile-flags: -Z trim-diagnostic-paths=no
 // normalize-stdout-test "\d+#" -> "0#"
+// normalize-stdout-test "expn\d{3,}" -> "expnNNN"
 // aux-build:test-macros.rs
 
 #![feature /* 0#0 */(decl_macro)]
@@ -72,6 +73,7 @@ crate0::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt:
 crate0::{{expn2}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "outer")
 crate0::{{expn3}}: parent: crate0::{{expn2}}, call_site_ctxt: #4, def_site_ctxt: #4, kind: Macro(Bang, "inner")
 crate0::{{expn4}}: parent: crate0::{{expn3}}, call_site_ctxt: #6, def_site_ctxt: #0, kind: Macro(Bang, "print_bang")
+crate1::{{expnNNN}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "include")
 crate2::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
 
 SyntaxContexts:

src/test/ui/use/use-from-trait-xc.stderr

@@ -38,7 +38,7 @@ error[E0432]: unresolved import `use_from_trait_xc::Baz::new`
   --> $DIR/use-from-trait-xc.rs:23:5
    |
 LL | use use_from_trait_xc::Baz::new as baznew;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `new` in `Baz`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `new` in `sub::Baz`
 
 error[E0603]: struct `Foo` is private
   --> $DIR/use-from-trait-xc.rs:14:24