11 files changed, 36 insertions, 24 deletions

diff --git a/Cargo.lock b/Cargo.lock
index df79334c9..22483516a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1010,6 +1010,7 @@ dependencies = [
  "ra_prof",
  "ra_syntax",
  "ra_tt",
+ "rustc-hash",
  "test_utils",
 ]
 
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index a8d6466ea..bf26048f2 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -15,12 +15,10 @@ use std::{
 
 use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
-use rustc_hash::FxHashMap;
-use rustc_hash::FxHashSet;
+use ra_tt::TokenExpander;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{RelativePath, RelativePathBuf};
-use fmt::Display;
-use ra_tt::TokenExpander;
 
 /// `FileId` is an integer which uniquely identifies a file. File paths are
 /// messy and system-dependent, so most of the code should work directly with
@@ -111,7 +109,7 @@ impl CrateName {
     }
 }
 
-impl Display for CrateName {
+impl fmt::Display for CrateName {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", self.0)
     }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index 2ab314884..80ddb6058 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -7,6 +7,7 @@ use std::{panic, sync::Arc};
 
 use ra_prof::profile;
 use ra_syntax::{ast, Parse, SourceFile, TextRange, TextSize};
+use rustc_hash::FxHashSet;
 
 pub use crate::{
     cancellation::Canceled,
@@ -95,7 +96,7 @@ pub trait FileLoader {
     /// `struct StrPath(str)` for clarity some day, but it's a bit messy, so we
     /// get by with a `&str` for the time being.
     fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId>;
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>>;
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>>;
 }
 
 /// Database which stores all significant input facts: source code and project
@@ -133,16 +134,21 @@ pub trait SourceDatabaseExt: SourceDatabase {
     #[salsa::input]
     fn source_root(&self, id: SourceRootId) -> Arc<SourceRoot>;
 
-    fn source_root_crates(&self, id: SourceRootId) -> Arc<Vec<CrateId>>;
+    fn source_root_crates(&self, id: SourceRootId) -> Arc<FxHashSet<CrateId>>;
 }
 
 fn source_root_crates(
     db: &(impl SourceDatabaseExt + SourceDatabase),
     id: SourceRootId,
-) -> Arc<Vec<CrateId>> {
-    let root = db.source_root(id);
+) -> Arc<FxHashSet<CrateId>> {
     let graph = db.crate_graph();
-    let res = root.walk().filter_map(|it| graph.crate_id_for_crate_root(it)).collect::<Vec<_>>();
+    let res = graph
+        .iter()
+        .filter(|&krate| {
+            let root_file = graph[krate].root_file_id;
+            db.file_source_root(root_file) == id
+        })
+        .collect::<FxHashSet<_>>();
     Arc::new(res)
 }
 
@@ -156,7 +162,7 @@ impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
     fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
         // FIXME: this *somehow* should be platform agnostic...
         if std::path::Path::new(path).is_absolute() {
-            let krate = *self.relevant_crates(anchor).get(0)?;
+            let krate = *self.relevant_crates(anchor).iter().next()?;
             let (extern_source_id, relative_file) =
                 self.0.crate_graph()[krate].extern_source.extern_path(path.as_ref())?;
 
@@ -175,7 +181,7 @@ impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
         }
     }
 
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         let source_root = self.0.file_source_root(file_id);
         self.0.source_root_crates(source_root)
     }
diff --git a/crates/ra_hir_def/src/test_db.rs b/crates/ra_hir_def/src/test_db.rs
index bcfa66ac9..4581d8745 100644
--- a/crates/ra_hir_def/src/test_db.rs
+++ b/crates/ra_hir_def/src/test_db.rs
@@ -7,6 +7,7 @@ use std::{
 
 use hir_expand::db::AstDatabase;
 use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, Upcast};
+use rustc_hash::FxHashSet;
 
 use crate::db::DefDatabase;
 
@@ -59,7 +60,7 @@ impl FileLoader for TestDB {
     fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
         FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
 }
diff --git a/crates/ra_hir_expand/Cargo.toml b/crates/ra_hir_expand/Cargo.toml
index 2cd522766..e5c9f3e99 100644
--- a/crates/ra_hir_expand/Cargo.toml
+++ b/crates/ra_hir_expand/Cargo.toml
@@ -10,6 +10,7 @@ doctest = false
 [dependencies]
 log = "0.4.8"
 either = "1.5.3"
+rustc-hash = "1.0.0"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs
index 1dc9cac66..967d1f3a1 100644
--- a/crates/ra_hir_expand/src/builtin_derive.rs
+++ b/crates/ra_hir_expand/src/builtin_derive.rs
@@ -9,7 +9,7 @@ use ra_syntax::{
 };
 
 use crate::db::AstDatabase;
-use crate::{name, quote, LazyMacroId, MacroCallId, MacroDefId, MacroDefKind};
+use crate::{guess_crate, name, quote, LazyMacroId, MacroCallId, MacroDefId, MacroDefKind};
 
 macro_rules! register_builtin {
     ( $($trait:ident => $expand:ident),* ) => {
@@ -160,8 +160,7 @@ fn find_builtin_crate(db: &dyn AstDatabase, id: LazyMacroId) -> tt::TokenTree {
     let m: MacroCallId = id.into();
     let file_id = m.as_file().original_file(db);
     let cg = db.crate_graph();
-    let krates = db.relevant_crates(file_id);
-    let krate = match krates.get(0) {
+    let krate = match guess_crate(db, file_id) {
         Some(krate) => krate,
         None => {
             let tt = quote! { core };
@@ -172,7 +171,7 @@ fn find_builtin_crate(db: &dyn AstDatabase, id: LazyMacroId) -> tt::TokenTree {
     // XXX
     //  All crates except core itself should have a dependency on core,
     //  We detect `core` by seeing whether it doesn't have such a dependency.
-    let tt = if cg[*krate].dependencies.iter().any(|dep| dep.name == "core") {
+    let tt = if cg[krate].dependencies.iter().any(|dep| dep.name == "core") {
         quote! { core }
     } else {
         quote! { crate }
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index 7579546d2..93da3f149 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -5,7 +5,7 @@ use crate::{
     name, AstId, CrateId, MacroDefId, MacroDefKind, TextSize,
 };
 
-use crate::{quote, EagerMacroId, LazyMacroId, MacroCallId};
+use crate::{guess_crate, quote, EagerMacroId, LazyMacroId, MacroCallId};
 use either::Either;
 use mbe::parse_to_token_tree;
 use ra_db::FileId;
@@ -335,8 +335,7 @@ fn include_expand(
 fn get_env_inner(db: &dyn AstDatabase, arg_id: EagerMacroId, key: &str) -> Option<String> {
     let call_id: MacroCallId = arg_id.into();
     let original_file = call_id.as_file().original_file(db);
-
-    let krate = *db.relevant_crates(original_file).get(0)?;
+    let krate = guess_crate(db, original_file)?;
     db.crate_graph()[krate].env.get(key)
 }
 
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index f440c073b..dc4d7f000 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -424,3 +424,8 @@ impl<N: AstNode> InFile<N> {
         self.with_value(self.value.syntax())
     }
 }
+
+// FIXME: this is obviously wrong, there shouldn't be any guesing here
+fn guess_crate(db: &dyn db::AstDatabase, file_id: FileId) -> Option<CrateId> {
+    db.relevant_crates(file_id).iter().next().copied()
+}
diff --git a/crates/ra_hir_expand/src/test_db.rs b/crates/ra_hir_expand/src/test_db.rs
index fdf225f55..09fc18c36 100644
--- a/crates/ra_hir_expand/src/test_db.rs
+++ b/crates/ra_hir_expand/src/test_db.rs
@@ -6,6 +6,7 @@ use std::{
 };
 
 use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate};
+use rustc_hash::FxHashSet;
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
@@ -44,7 +45,7 @@ impl FileLoader for TestDB {
     fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
         FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
 }
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index e484968a0..ad04e3e0f 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -8,6 +8,7 @@ use std::{
 use hir_def::{db::DefDatabase, AssocItemId, ModuleDefId, ModuleId};
 use hir_expand::{db::AstDatabase, diagnostics::DiagnosticSink};
 use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase, Upcast};
+use rustc_hash::FxHashSet;
 use stdx::format_to;
 
 use crate::{db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator};
@@ -73,7 +74,7 @@ impl FileLoader for TestDB {
     fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
         FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
 }
diff --git a/crates/ra_ide_db/src/lib.rs b/crates/ra_ide_db/src/lib.rs
index 727d743b5..480fd4576 100644
--- a/crates/ra_ide_db/src/lib.rs
+++ b/crates/ra_ide_db/src/lib.rs
@@ -19,7 +19,7 @@ use ra_db::{
     Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase,
     SourceRootId, Upcast,
 };
-use rustc_hash::FxHashMap;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{line_index::LineIndex, symbol_index::SymbolsDatabase};
 
@@ -60,7 +60,7 @@ impl FileLoader for RootDatabase {
     fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
         FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
 }