resolve: Record full parent scope data for imports

Author: petrochenkov

src/librustc_resolve/build_reduced_graph.rs

@@ -126,7 +126,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
         mut uniform_paths_canary_emitted: bool,
         nested: bool,
         item: &Item,
-        expansion: Mark,
+        parent_scope: ParentScope<'a>,
     ) {
         debug!("build_reduced_graph_for_use_tree(parent_prefix={:?}, \
                 uniform_paths_canary_emitted={}, \
@@ -224,7 +224,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                     root_use_tree.span,
                     root_id,
                     ty::Visibility::Invisible,
-                    expansion,
+                    parent_scope.clone(),
                     true, // is_uniform_paths_canary
                 );
             };
@@ -348,7 +348,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                     root_use_tree.span,
                     root_id,
                     vis,
-                    expansion,
+                    parent_scope,
                     false, // is_uniform_paths_canary
                 );
             }
@@ -365,7 +365,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                     root_use_tree.span,
                     root_id,
                     vis,
-                    expansion,
+                    parent_scope,
                     false, // is_uniform_paths_canary
                 );
             }
@@ -403,16 +403,17 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                         uniform_paths_canary_emitted,
                         true,
                         item,
-                        expansion,
+                        parent_scope.clone(),
                     );
                 }
             }
         }
     }
 
     /// Constructs the reduced graph for one item.
-    fn build_reduced_graph_for_item(&mut self, item: &Item, expansion: Mark) {
-        let parent = self.current_module;
+    fn build_reduced_graph_for_item(&mut self, item: &Item, parent_scope: ParentScope<'a>) {
+        let parent = parent_scope.module;
+        let expansion = parent_scope.expansion;
         let ident = item.ident;
         let sp = item.span;
         let vis = self.resolve_visibility(&item.vis);
@@ -429,7 +430,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                     false, // uniform_paths_canary_emitted
                     false,
                     item,
-                    expansion,
+                    parent_scope,
                 );
             }
 
@@ -442,7 +443,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                     self.injected_crate = Some(module);
                 }
 
-                let used = self.process_legacy_macro_imports(item, module, expansion);
+                let used = self.process_legacy_macro_imports(item, module, &parent_scope);
                 let binding =
                     (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.arenas);
                 if ptr::eq(self.current_module, self.graph_root) {
@@ -467,7 +468,7 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                 let directive = self.arenas.alloc_import_directive(ImportDirective {
                     root_id: item.id,
                     id: item.id,
-                    parent,
+                    parent_scope,
                     imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
                     subclass: ImportDirectiveSubclass::ExternCrate {
                         source: orig_name,
@@ -477,7 +478,6 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                     span: item.span,
                     module_path: Vec::new(),
                     vis: Cell::new(vis),
-                    expansion,
                     used: Cell::new(used),
                     is_uniform_paths_canary: false,
                 });
@@ -850,9 +850,9 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
     }
 
     // This returns true if we should consider the underlying `extern crate` to be used.
-    fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>, expansion: Mark)
-                                    -> bool {
-        let allow_shadowing = expansion == Mark::root();
+    fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>,
+                                    parent_scope: &ParentScope<'a>) -> bool {
+        let allow_shadowing = parent_scope.expansion == Mark::root();
         let legacy_imports = self.legacy_macro_imports(&item.attrs);
         let used = legacy_imports != LegacyMacroImports::default();
 
@@ -862,18 +862,17 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
                       "an `extern crate` loading macros must be at the crate root");
         }
 
-        let (graph_root, arenas) = (self.graph_root, self.arenas);
+        let arenas = self.arenas;
         let macro_use_directive = |span| arenas.alloc_import_directive(ImportDirective {
             root_id: item.id,
             id: item.id,
-            parent: graph_root,
+            parent_scope: parent_scope.clone(),
             imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
             subclass: ImportDirectiveSubclass::MacroUse,
             root_span: span,
             span,
             module_path: Vec::new(),
             vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
-            expansion,
             used: Cell::new(false),
             is_uniform_paths_canary: false,
         });
@@ -1004,7 +1003,13 @@ impl<'a, 'b, 'cl> Visitor<'a> for BuildReducedGraphVisitor<'a, 'b, 'cl> {
 
         let orig_current_module = self.resolver.current_module;
         let orig_current_legacy_scope = self.current_legacy_scope;
-        self.resolver.build_reduced_graph_for_item(item, self.expansion);
+        let parent_scope = ParentScope {
+            module: self.resolver.current_module,
+            expansion: self.expansion,
+            legacy: self.current_legacy_scope,
+            derives: Vec::new(),
+        };
+        self.resolver.build_reduced_graph_for_item(item, parent_scope);
         visit::walk_item(self, item);
         self.resolver.current_module = orig_current_module;
         if !macro_use {

src/librustc_resolve/macros.rs

@@ -43,7 +43,7 @@ use std::cell::Cell;
 use std::mem;
 use rustc_data_structures::sync::Lrc;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct InvocationData<'a> {
     def_index: DefIndex,
     /// Module in which the macro was invoked.
@@ -70,6 +70,7 @@ impl<'a> InvocationData<'a> {
 
 /// Binding produced by a `macro_rules` item.
 /// Not modularized, can shadow previous legacy bindings, etc.
+#[derive(Debug)]
 pub struct LegacyBinding<'a> {
     binding: &'a NameBinding<'a>,
     /// Legacy scope into which the `macro_rules` item was planted.
@@ -82,7 +83,7 @@ pub struct LegacyBinding<'a> {
 /// (named or unnamed), or even further if it escapes with `#[macro_use]`.
 /// Some macro invocations need to introduce legacy scopes too because they
 /// potentially can expand into macro definitions.
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub enum LegacyScope<'a> {
     /// Created when invocation data is allocated in the arena,
     /// must be replaced with a proper scope later.
@@ -96,8 +97,8 @@ pub enum LegacyScope<'a> {
     Invocation(&'a InvocationData<'a>),
 }
 
-/// Everything you need to resolve a macro path.
-#[derive(Clone)]
+/// Everything you need to resolve a macro or import path.
+#[derive(Clone, Debug)]
 pub struct ParentScope<'a> {
     crate module: Module<'a>,
     crate expansion: Mark,

src/librustc_resolve/resolve_imports.rs

@@ -16,6 +16,7 @@ use {NameBinding, NameBindingKind, ToNameBinding, PathResult, PrivacyError};
 use Resolver;
 use {names_to_string, module_to_string};
 use {resolve_error, ResolutionError};
+use macros::ParentScope;
 
 use rustc_data_structures::ptr_key::PtrKey;
 use rustc::ty;
@@ -88,13 +89,12 @@ pub struct ImportDirective<'a> {
     /// Span of the *root* use tree (see `root_id`).
     pub root_span: Span,
 
-    pub parent: Module<'a>,
+    pub parent_scope: ParentScope<'a>,
     pub module_path: Vec<Ident>,
     /// The resolution of `module_path`.
     pub imported_module: Cell<Option<ModuleOrUniformRoot<'a>>>,
     pub subclass: ImportDirectiveSubclass<'a>,
     pub vis: Cell<ty::Visibility>,
-    pub expansion: Mark,
     pub used: Cell<bool>,
 
     /// Whether this import is a "canary" for the `uniform_paths` feature,
@@ -307,8 +307,9 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             };
             match self.resolve_ident_in_module(module, ident, ns, false, path_span) {
                 Err(Determined) => continue,
-                Ok(binding)
-                    if !self.is_accessible_from(binding.vis, single_import.parent) => continue,
+                Ok(binding) if !self.is_accessible_from(
+                    binding.vis, single_import.parent_scope.module
+                ) => continue,
                 Ok(_) | Err(Undetermined) => return Err(Undetermined),
             }
         }
@@ -381,8 +382,9 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
 
             match result {
                 Err(Determined) => continue,
-                Ok(binding)
-                    if !self.is_accessible_from(binding.vis, glob_import.parent) => continue,
+                Ok(binding) if !self.is_accessible_from(
+                    binding.vis, glob_import.parent_scope.module
+                ) => continue,
                 Ok(_) | Err(Undetermined) => return Err(Undetermined),
             }
         }
@@ -400,11 +402,11 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
                                 root_span: Span,
                                 root_id: NodeId,
                                 vis: ty::Visibility,
-                                expansion: Mark,
+                                parent_scope: ParentScope<'a>,
                                 is_uniform_paths_canary: bool) {
-        let current_module = self.current_module;
+        let current_module = parent_scope.module;
         let directive = self.arenas.alloc_import_directive(ImportDirective {
-            parent: current_module,
+            parent_scope,
             module_path,
             imported_module: Cell::new(None),
             subclass,
@@ -413,7 +415,6 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             root_span,
             root_id,
             vis: Cell::new(vis),
-            expansion,
             used: Cell::new(false),
             is_uniform_paths_canary,
         });
@@ -431,7 +432,7 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             // We don't add prelude imports to the globs since they only affect lexical scopes,
             // which are not relevant to import resolution.
             GlobImport { is_prelude: true, .. } => {}
-            GlobImport { .. } => self.current_module.globs.borrow_mut().push(directive),
+            GlobImport { .. } => current_module.globs.borrow_mut().push(directive),
             _ => unreachable!(),
         }
     }
@@ -462,7 +463,7 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             },
             span: directive.span,
             vis,
-            expansion: directive.expansion,
+            expansion: directive.parent_scope.expansion,
         })
     }
 
@@ -568,12 +569,12 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             let scope = match ident.span.reverse_glob_adjust(module.expansion,
                                                              directive.span.ctxt().modern()) {
                 Some(Some(def)) => self.macro_def_scope(def),
-                Some(None) => directive.parent,
+                Some(None) => directive.parent_scope.module,
                 None => continue,
             };
             if self.is_accessible_from(binding.vis, scope) {
                 let imported_binding = self.import(binding, directive);
-                let _ = self.try_define(directive.parent, ident, ns, imported_binding);
+                let _ = self.try_define(directive.parent_scope.module, ident, ns, imported_binding);
             }
         }
 
@@ -587,7 +588,7 @@ impl<'a, 'crateloader> Resolver<'a, 'crateloader> {
             let dummy_binding = self.dummy_binding;
             let dummy_binding = self.import(dummy_binding, directive);
             self.per_ns(|this, ns| {
-                let _ = this.try_define(directive.parent, target, ns, dummy_binding);
+                let _ = this.try_define(directive.parent_scope.module, target, ns, dummy_binding);
             });
         }
     }
@@ -854,7 +855,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                names_to_string(&directive.module_path[..]),
                module_to_string(self.current_module).unwrap_or_else(|| "???".to_string()));
 
-        self.current_module = directive.parent;
+        self.current_module = directive.parent_scope.module;
 
         let module = if let Some(module) = directive.imported_module.get() {
             module
@@ -865,7 +866,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
             directive.vis.set(ty::Visibility::Invisible);
             let result = self.resolve_path(
                 Some(if directive.is_uniform_paths_canary {
-                    ModuleOrUniformRoot::Module(directive.parent)
+                    ModuleOrUniformRoot::Module(directive.parent_scope.module)
                 } else {
                     ModuleOrUniformRoot::UniformRoot(keywords::Invalid.name())
                 }),
@@ -907,7 +908,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                 return
             };
 
-            let parent = directive.parent;
+            let parent = directive.parent_scope.module;
             match result[ns].get() {
                 Err(Undetermined) => indeterminate = true,
                 Err(Determined) => {
@@ -939,12 +940,12 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
 
     // If appropriate, returns an error to report.
     fn finalize_import(&mut self, directive: &'b ImportDirective<'b>) -> Option<(Span, String)> {
-        self.current_module = directive.parent;
+        self.current_module = directive.parent_scope.module;
         let ImportDirective { ref module_path, span, .. } = *directive;
 
         let module_result = self.resolve_path(
             Some(if directive.is_uniform_paths_canary {
-                ModuleOrUniformRoot::Module(directive.parent)
+                ModuleOrUniformRoot::Module(directive.parent_scope.module)
             } else {
                 ModuleOrUniformRoot::UniformRoot(keywords::Invalid.name())
             }),
@@ -992,7 +993,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
                 }
 
                 if let ModuleOrUniformRoot::Module(module) = module {
-                    if module.def_id() == directive.parent.def_id() {
+                    if module.def_id() == directive.parent_scope.module.def_id() {
                         // Importing a module into itself is not allowed.
                         return Some((directive.span,
                             "Cannot glob-import a module into itself.".to_string()));
@@ -1186,7 +1187,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
         if let Some(Def::Trait(_)) = module.def() {
             self.session.span_err(directive.span, "items in traits are not importable.");
             return;
-        } else if module.def_id() == directive.parent.def_id()  {
+        } else if module.def_id() == directive.parent_scope.module.def_id()  {
             return;
         } else if let GlobImport { is_prelude: true, .. } = directive.subclass {
             self.prelude = Some(module);
@@ -1210,7 +1211,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
             };
             if self.is_accessible_from(binding.pseudo_vis(), scope) {
                 let imported_binding = self.import(binding, directive);
-                let _ = self.try_define(directive.parent, ident, ns, imported_binding);
+                let _ = self.try_define(directive.parent_scope.module, ident, ns, imported_binding);
             }
         }