Merge #5692

5692: Add support for extern crate r=jonas-schievink a=Nashenas88

This adds syntax highlighting, hover and goto def functionality for extern crate.

Fixes #5690 

Co-authored-by: Paul Daniel Faria <[email protected]>

Author: bors[bot]

crates/ra_assists/src/handlers/add_turbo_fish.rs

@@ -41,7 +41,7 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
     let name_ref = ast::NameRef::cast(ident.parent())?;
     let def = match classify_name_ref(&ctx.sema, &name_ref)? {
         NameRefClass::Definition(def) => def,
-        NameRefClass::FieldShorthand { .. } => return None,
+        NameRefClass::ExternCrate(_) | NameRefClass::FieldShorthand { .. } => return None,
     };
     let fun = match def {
         Definition::ModuleDef(hir::ModuleDef::Function(it)) => it,

crates/ra_assists/src/utils.rs

@@ -257,7 +257,7 @@ pub use prelude::*;
             .find(|dep| &dep.name.to_string() == std_crate)?
             .krate;
 
-        let mut module = std_crate.root_module(db)?;
+        let mut module = std_crate.root_module(db);
         for segment in path {
             module = module.children(db).find_map(|child| {
                 let name = child.name(db)?;

crates/ra_hir/src/code_model.rs

@@ -83,9 +83,9 @@ impl Crate {
             .collect()
     }
 
-    pub fn root_module(self, db: &dyn HirDatabase) -> Option<Module> {
+    pub fn root_module(self, db: &dyn HirDatabase) -> Module {
         let module_id = db.crate_def_map(self.id).root;
-        Some(Module::new(self, module_id))
+        Module::new(self, module_id)
     }
 
     pub fn root_file(self, db: &dyn HirDatabase) -> FileId {

crates/ra_hir/src/semantics.rs

@@ -8,7 +8,7 @@ use hir_def::{
     resolver::{self, HasResolver, Resolver},
     AsMacroCall, FunctionId, TraitId, VariantId,
 };
-use hir_expand::{diagnostics::AstDiagnostic, hygiene::Hygiene, ExpansionInfo};
+use hir_expand::{diagnostics::AstDiagnostic, hygiene::Hygiene, name::AsName, ExpansionInfo};
 use hir_ty::associated_type_shorthand_candidates;
 use itertools::Itertools;
 use ra_db::{FileId, FileRange};
@@ -24,8 +24,8 @@ use crate::{
     diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
-    AssocItem, Callable, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module,
-    ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, VariantDef,
+    AssocItem, Callable, Crate, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef,
+    Module, ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, VariantDef,
 };
 use resolver::TypeNs;
 
@@ -228,6 +228,10 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.resolve_path(path)
     }
 
+    pub fn resolve_extern_crate(&self, extern_crate: &ast::ExternCrate) -> Option<Crate> {
+        self.imp.resolve_extern_crate(extern_crate)
+    }
+
     pub fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantDef> {
         self.imp.resolve_variant(record_lit).map(VariantDef::from)
     }
@@ -443,6 +447,17 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(path.syntax()).resolve_path(self.db, path)
     }
 
+    fn resolve_extern_crate(&self, extern_crate: &ast::ExternCrate) -> Option<Crate> {
+        let krate = self.scope(extern_crate.syntax()).krate()?;
+        krate.dependencies(self.db).into_iter().find_map(|dep| {
+            if dep.name == extern_crate.name_ref()?.as_name() {
+                Some(dep.krate)
+            } else {
+                None
+            }
+        })
+    }
+
     fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantId> {
         self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
     }
@@ -612,6 +627,10 @@ impl<'a> SemanticsScope<'a> {
         Some(Module { id: self.resolver.module()? })
     }
 
+    pub fn krate(&self) -> Option<Crate> {
+        Some(Crate { id: self.resolver.krate()? })
+    }
+
     /// Note: `FxHashSet<TraitId>` should be treated as an opaque type, passed into `Type
     // FIXME: rename to visible_traits to not repeat scope?
     pub fn traits_in_scope(&self) -> FxHashSet<TraitId> {

crates/ra_ide/src/display/short_label.rs

@@ -47,6 +47,12 @@ impl ShortLabel for ast::Module {
     }
 }
 
+impl ShortLabel for ast::SourceFile {
+    fn short_label(&self) -> Option<String> {
+        None
+    }
+}
+
 impl ShortLabel for ast::TypeAlias {
     fn short_label(&self) -> Option<String> {
         short_label_from_node(self, "type ")

crates/ra_ide/src/goto_definition.rs

@@ -1,6 +1,6 @@
 use hir::Semantics;
 use ra_ide_db::{
-    defs::{classify_name, classify_name_ref, NameClass},
+    defs::{classify_name, classify_name_ref},
     symbol_index, RootDatabase,
 };
 use ra_syntax::{
@@ -40,10 +40,7 @@ pub(crate) fn goto_definition(
                 reference_definition(&sema, &name_ref).to_vec()
             },
             ast::Name(name) => {
-                let def = match classify_name(&sema, &name)? {
-                    NameClass::Definition(def) | NameClass::ConstReference(def) => def,
-                    NameClass::FieldShorthand { local: _, field } => field,
-                };
+                let def = classify_name(&sema, &name)?.definition(sema.db);
                 let nav = def.try_to_nav(sema.db)?;
                 vec![nav]
             },
@@ -86,8 +83,7 @@ pub(crate) fn reference_definition(
 ) -> ReferenceResult {
     let name_kind = classify_name_ref(sema, name_ref);
     if let Some(def) = name_kind {
-        let def = def.definition();
-
+        let def = def.definition(sema.db);
         return match def.try_to_nav(sema.db) {
             Some(nav) => ReferenceResult::Exact(nav),
             None => ReferenceResult::Approximate(Vec::new()),
@@ -133,6 +129,32 @@ mod tests {
         assert_eq!(expected, FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() });
     }
 
+    #[test]
+    fn goto_def_for_extern_crate() {
+        check(
+            r#"
+            //- /main.rs
+            extern crate std<|>;
+            //- /std/lib.rs
+            // empty
+            //^ file
+            "#,
+        )
+    }
+
+    #[test]
+    fn goto_def_for_renamed_extern_crate() {
+        check(
+            r#"
+            //- /main.rs
+            extern crate std as abc<|>;
+            //- /std/lib.rs
+            // empty
+            //^ file
+            "#,
+        )
+    }
+
     #[test]
     fn goto_def_in_items() {
         check(

crates/ra_ide/src/hover.rs

@@ -85,8 +85,8 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
     let node = token.parent();
     let definition = match_ast! {
         match node {
-            ast::NameRef(name_ref) => classify_name_ref(&sema, &name_ref).map(|d| d.definition()),
-            ast::Name(name) => classify_name(&sema, &name).map(|d| d.definition()),
+            ast::NameRef(name_ref) => classify_name_ref(&sema, &name_ref).map(|d| d.definition(sema.db)),
+            ast::Name(name) => classify_name(&sema, &name).map(|d| d.definition(sema.db)),
             _ => None,
         }
     };
@@ -304,7 +304,10 @@ fn hover_for_definition(db: &RootDatabase, def: Definition) -> Option<Markup> {
                     let docs = Documentation::from_ast(&it).map(Into::into);
                     hover_markup(docs, it.short_label(), mod_path)
                 }
-                _ => None,
+                ModuleSource::SourceFile(it) => {
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
+                }
             },
             ModuleDef::Function(it) => from_def_source(db, it, mod_path),
             ModuleDef::Adt(Adt::Struct(it)) => from_def_source(db, it, mod_path),
@@ -1137,6 +1140,46 @@ fn bar() { fo<|>o(); }
         );
     }
 
+    #[test]
+    fn test_hover_extern_crate() {
+        check(
+            r#"
+//- /main.rs
+extern crate st<|>d;
+//- /std/lib.rs
+//! Standard library for this test
+//!
+//! Printed?
+//! abc123
+            "#,
+            expect![[r#"
+            *std*
+            Standard library for this test
+
+            Printed?
+            abc123
+            "#]],
+        );
+        check(
+            r#"
+//- /main.rs
+extern crate std as ab<|>c;
+//- /std/lib.rs
+//! Standard library for this test
+//!
+//! Printed?
+//! abc123
+            "#,
+            expect![[r#"
+            *abc*
+            Standard library for this test
+
+            Printed?
+            abc123
+            "#]],
+        );
+    }
+
     #[test]
     fn test_hover_mod_with_same_name_as_function() {
         check(

crates/ra_ide/src/references.rs

@@ -130,13 +130,13 @@ fn find_name(
     opt_name: Option<ast::Name>,
 ) -> Option<RangeInfo<Definition>> {
     if let Some(name) = opt_name {
-        let def = classify_name(sema, &name)?.definition();
+        let def = classify_name(sema, &name)?.definition(sema.db);
         let range = name.syntax().text_range();
         return Some(RangeInfo::new(range, def));
     }
     let name_ref =
         sema.find_node_at_offset_with_descend::<ast::NameRef>(&syntax, position.offset)?;
-    let def = classify_name_ref(sema, &name_ref)?.definition();
+    let def = classify_name_ref(sema, &name_ref)?.definition(sema.db);
     let range = name_ref.syntax().text_range();
     Some(RangeInfo::new(range, def))
 }

crates/ra_ide/src/syntax_highlighting.rs

@@ -495,6 +495,7 @@ fn highlight_element(
             };
 
             match name_kind {
+                Some(NameClass::ExternCrate(_)) => HighlightTag::Module.into(),
                 Some(NameClass::Definition(def)) => {
                     highlight_name(db, def, false) | HighlightModifier::Definition
                 }
@@ -522,6 +523,7 @@ fn highlight_element(
             let possibly_unsafe = is_possibly_unsafe(&name_ref);
             match classify_name_ref(sema, &name_ref) {
                 Some(name_kind) => match name_kind {
+                    NameRefClass::ExternCrate(_) => HighlightTag::Module.into(),
                     NameRefClass::Definition(def) => {
                         if let Definition::Local(local) = &def {
                             if let Some(name) = local.name(db) {

crates/ra_ide/src/syntax_highlighting/tests.rs

@@ -391,6 +391,23 @@ macro_rules! noop {
     );
 }
 
+#[test]
+fn test_extern_crate() {
+    check_highlighting(
+        r#"
+        //- /main.rs
+        extern crate std;
+        extern crate alloc as abc;
+        //- /std/lib.rs
+        pub struct S;
+        //- /alloc/lib.rs
+        pub struct A
+        "#,
+        expect_file!["crates/ra_ide/test_data/highlight_extern_crate.html"],
+        false,
+    );
+}
+
 /// Highlights the code given by the `ra_fixture` argument, renders the
 /// result as HTML, and compares it with the HTML file given as `snapshot`.
 /// Note that the `snapshot` file is overwritten by the rendered HTML.