feat: add semantic indexes for references and module hierarchy

crates/ide/src/analysis.rs

@@ -39,6 +39,7 @@ use crate::{
     references::{self, References, ReferencesConfig},
     rename::{self, RenameConfig, RenameResult},
     selection_ranges,
+    semantic_index::{self, ModuleCallEdge},
     semantic_tokens::{self, SemaToken, SemaTokenConfig},
     signature_help::{self, SignatureHelp, SignatureHelpConfig},
     source_change::SourceChange,
@@ -184,6 +185,22 @@ impl Analysis {
         self.with_db(|db| references::references(db, position, config))
     }
 
+    pub fn module_incoming_calls(
+        &self,
+        file_id: FileId,
+        name_range: TextRange,
+    ) -> Cancellable<Vec<ModuleCallEdge>> {
+        self.with_db(|db| semantic_index::incoming_module_edges(db, file_id, name_range))
+    }
+
+    pub fn module_outgoing_calls(
+        &self,
+        file_id: FileId,
+        name_range: TextRange,
+    ) -> Cancellable<Vec<ModuleCallEdge>> {
+        self.with_db(|db| semantic_index::outgoing_module_edges(db, file_id, name_range))
+    }
+
     pub fn prepare_rename(
         &self,
         position: FilePosition,

crates/ide/src/db/workspace_symbol_index_db.rs

@@ -7,13 +7,15 @@ use vfs::FileId;
 
 use crate::{
     db::root_db::RootDb,
+    semantic_index::{ModuleIndex, SemanticIndex},
     workspace_symbols::{SymbolIndex, WorkspaceSymbol},
 };
 
 #[salsa::query_group(WorkspaceSymbolIndexDbStorage)]
 pub trait WorkspaceSymbolIndexDb: SourceRootDb + HirDb {
     fn file_workspace_symbols(&self, file_id: FileId) -> Arc<[WorkspaceSymbol]>;
     fn source_root_symbol_index(&self, source_root_id: SourceRootId) -> Arc<SymbolIndex>;
+    fn source_root_module_index(&self, source_root_id: SourceRootId) -> Arc<ModuleIndex>;
 }
 
 fn file_workspace_symbols(
@@ -30,9 +32,30 @@ fn source_root_symbol_index(
     Arc::new(SymbolIndex::for_source_root(db, source_root_id))
 }
 
+fn source_root_module_index(
+    db: &dyn WorkspaceSymbolIndexDb,
+    source_root_id: SourceRootId,
+) -> Arc<ModuleIndex> {
+    Arc::new(ModuleIndex::for_source_root(db, source_root_id))
+}
+
 pub(crate) fn source_root_symbol_index_for_root(
     db: &RootDb,
     source_root_id: SourceRootId,
 ) -> Arc<SymbolIndex> {
     WorkspaceSymbolIndexDb::source_root_symbol_index(db, source_root_id)
 }
+
+pub(crate) fn source_root_module_index_for_root(
+    db: &RootDb,
+    source_root_id: SourceRootId,
+) -> Arc<ModuleIndex> {
+    WorkspaceSymbolIndexDb::source_root_module_index(db, source_root_id)
+}
+
+pub(crate) fn source_root_semantic_index_for_root(
+    db: &RootDb,
+    source_root_id: SourceRootId,
+) -> Arc<SemanticIndex> {
+    Arc::new(SemanticIndex::for_source_root(db, source_root_id))
+}

crates/ide/src/lib.rs

@@ -40,6 +40,7 @@ pub mod range;
 pub mod references;
 pub mod rename;
 pub mod selection_ranges;
+pub mod semantic_index;
 pub(crate) mod semantic_target;
 pub mod semantic_tokens;
 pub mod signature_help;

crates/ide/src/module_resolution.rs

@@ -1,7 +1,10 @@
 use std::cmp::Ordering;
 
 use hir::{
-    base_db::{source_db::SourceRootDb, source_root::SourceRootRole},
+    base_db::{
+        source_db::{SourceDb, SourceRootDb},
+        source_root::SourceRootRole,
+    },
     container::InModule,
     db::HirDb,
     hir_def::{
@@ -11,7 +14,7 @@ use hir::{
         lower_ident_opt,
         module::{ModuleId, instantiation::Instantiation},
     },
-    scope::{ModuleEntry, ScopeResolution},
+    scope::ModuleEntry,
     semantics::pathres::PathResolution,
 };
 use syntax::{
@@ -21,7 +24,7 @@ use syntax::{
 use utils::get::GetRef;
 use vfs::{FileId, VfsPath};
 
-use crate::db::root_db::RootDb;
+use crate::db::{root_db::RootDb, workspace_symbol_index_db::source_root_module_index_for_root};
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub(crate) enum ModuleResolution {
@@ -154,13 +157,34 @@ fn resolve_module_name_with_policy(
     name: &Ident,
     policy: ModuleResolutionPolicy,
 ) -> ModuleResolution {
-    match db.unit_scope().resolve_module(name) {
-        ScopeResolution::Unique(module_id) => ModuleResolution::Unique(module_id),
-        ScopeResolution::Unresolved => ModuleResolution::Unresolved,
-        ScopeResolution::Ambiguous(candidates) => {
-            policy.resolve_ambiguous(db, candidates.into_vec())
-        }
+    let candidates = module_candidates(db, name);
+    match candidates.as_slice() {
+        [module_id] => ModuleResolution::Unique(*module_id),
+        [] => ModuleResolution::Unresolved,
+        _ => policy.resolve_ambiguous(db, candidates),
+    }
+}
+
+fn module_candidates(db: &RootDb, name: &Ident) -> Vec<ModuleId> {
+    let mut source_root_ids =
+        db.files().iter().map(|&file_id| db.source_root_id(file_id)).collect::<Vec<_>>();
+    source_root_ids.sort_unstable();
+    source_root_ids.dedup();
+
+    let mut candidates = Vec::new();
+    for source_root_id in source_root_ids {
+        let module_index = source_root_module_index_for_root(db, source_root_id);
+        candidates.extend(
+            module_index
+                .module_definitions(name)
+                .iter()
+                .map(|module| (module.file_id, module.name_range.start(), module.module_id)),
+        );
     }
+
+    candidates.sort_by_key(|(file_id, name_start, _)| (file_id.0, *name_start));
+    candidates.dedup_by_key(|(_, _, module_id)| *module_id);
+    candidates.into_iter().map(|(_, _, module_id)| module_id).collect()
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]