5 files changed, 13 insertions, 8 deletions

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)
     }
 }