25 files changed, 149 insertions, 216 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 3c78346c1..1b5de271e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -369,11 +369,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "fnv"
-version = "1.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
 name = "fs_extra"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -873,8 +868,6 @@ dependencies = [
  "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex-syntax 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "rusty-fork 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "tempfile 3.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1352,17 +1345,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "rusty-fork"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "tempfile 3.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "wait-timeout 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
 name = "ryu"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1812,14 +1794,6 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "wait-timeout"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.50 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
 name = "walkdir"
 version = "2.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1930,7 +1904,6 @@ dependencies = [
 "checksum fake-simd 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
 "checksum filetime 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a2df5c1a8c4be27e7707789dc42ae65976e60b394afd293d1419ab915833e646"
 "checksum flexi_logger 0.11.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4a7878fc9e06c948c6f9cddf571758e0c44786a509e646a094ef13ade3b1aab7"
-"checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
 "checksum fs_extra 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5f2a4a2034423744d2cc7ca2068453168dcdb82c438419e639a26bd87839c674"
 "checksum fsevent 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)" = "c4bbbf71584aeed076100b5665ac14e3d85eeb31fdbb45fbd41ef9a682b5ec05"
 "checksum fsevent-sys 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "1a772d36c338d07a032d5375a36f15f9a7043bf0cb8ce7cee658e037c6032874"
@@ -2015,7 +1988,6 @@ dependencies = [
 "checksum rustc-demangle 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "adacaae16d02b6ec37fdc7acfcddf365978de76d1983d3ee22afc260e1ca9619"
 "checksum rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7540fc8b0c49f096ee9c961cda096467dce8084bec6bdca2fc83895fd9b28cb8"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
-"checksum rusty-fork 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9591f190d2852720b679c21f66ad929f9f1d7bb09d1193c26167586029d8489c"
 "checksum ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "eb9e9b8cde282a9fe6a42dd4681319bfb63f121b8a8ee9439c6f4107e58a46f7"
 "checksum salsa 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cad0e2348e2f80725b2980914a08a00267136c3ecf720896d3f7f08eef51e08f"
 "checksum salsa-macros 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7c79744109df21b80aef1367669b0a9e4985bc966e76bf0e9321b222ec0b9fbb"
@@ -2069,7 +2041,6 @@ dependencies = [
 "checksum uuid 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "0238db0c5b605dd1cf51de0f21766f97fba2645897024461d6a00c036819a768"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
-"checksum wait-timeout 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "b9f3bf741a801531993db6478b95682117471f76916f5e690dd8d45395b09349"
 "checksum walkdir 2.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "9d9d7ed3431229a144296213105a390676cc49c9b6a72bd19f3176c98e129fa1"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "92c1eb33641e276cfa214a0522acad57be5c56b10cb348b3c5117db75f3ac4b0"
diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index deb9f95d7..3bbcdb0b8 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -16,11 +16,7 @@ use vfs_filter::IncludeRustFiles;
 
 type Result<T> = std::result::Result<T, failure::Error>;
 
-#[salsa::database(
-    ra_db::SourceDatabaseStorage,
-    db::HirDatabaseStorage,
-    db::PersistentHirDatabaseStorage
-)]
+#[salsa::database(ra_db::SourceDatabaseStorage, db::HirDatabaseStorage, db::DefDatabaseStorage)]
 #[derive(Debug)]
 pub struct BatchDatabase {
     runtime: salsa::Runtime<BatchDatabase>,
diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index 325f1d7b6..78ea8976b 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -12,7 +12,7 @@ use ra_syntax::{
 use crate::{
     Name, AsName, Struct, Enum, EnumVariant, Crate,
     HirDatabase, HirFileId, StructField, FieldSource,
-    type_ref::TypeRef, PersistentHirDatabase,
+    type_ref::TypeRef, DefDatabase,
 };
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
@@ -33,7 +33,7 @@ impl AdtDef {
 }
 
 impl Struct {
-    pub(crate) fn variant_data(&self, db: &impl PersistentHirDatabase) -> Arc<VariantData> {
+    pub(crate) fn variant_data(&self, db: &impl DefDatabase) -> Arc<VariantData> {
         db.struct_data((*self).into()).variant_data.clone()
     }
 }
@@ -52,10 +52,7 @@ impl StructData {
         StructData { name, variant_data }
     }
 
-    pub(crate) fn struct_data_query(
-        db: &impl PersistentHirDatabase,
-        struct_: Struct,
-    ) -> Arc<StructData> {
+    pub(crate) fn struct_data_query(db: &impl DefDatabase, struct_: Struct) -> Arc<StructData> {
         let (_, struct_def) = struct_.source(db);
         Arc::new(StructData::new(&*struct_def))
     }
@@ -68,7 +65,7 @@ fn variants(enum_def: &ast::EnumDef) -> impl Iterator<Item = &ast::EnumVariant>
 impl EnumVariant {
     pub(crate) fn source_impl(
         &self,
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
     ) -> (HirFileId, TreeArc<ast::EnumVariant>) {
         let (file_id, enum_def) = self.parent.source(db);
         let var = variants(&*enum_def)
@@ -79,7 +76,7 @@ impl EnumVariant {
             .to_owned();
         (file_id, var)
     }
-    pub(crate) fn variant_data(&self, db: &impl PersistentHirDatabase) -> Arc<VariantData> {
+    pub(crate) fn variant_data(&self, db: &impl DefDatabase) -> Arc<VariantData> {
         db.enum_data(self.parent).variants[self.id].variant_data.clone()
     }
 }
@@ -91,7 +88,7 @@ pub struct EnumData {
 }
 
 impl EnumData {
-    pub(crate) fn enum_data_query(db: &impl PersistentHirDatabase, e: Enum) -> Arc<EnumData> {
+    pub(crate) fn enum_data_query(db: &impl DefDatabase, e: Enum) -> Arc<EnumData> {
         let (_file_id, enum_def) = e.source(db);
         let name = enum_def.name().map(|n| n.as_name());
         let variants = variants(&*enum_def)
@@ -189,7 +186,7 @@ impl VariantDef {
             VariantDef::EnumVariant(it) => it.field(db, name),
         }
     }
-    pub(crate) fn variant_data(self, db: &impl PersistentHirDatabase) -> Arc<VariantData> {
+    pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         match self {
             VariantDef::Struct(it) => it.variant_data(db),
             VariantDef::EnumVariant(it) => it.variant_data(db),
@@ -198,7 +195,7 @@ impl VariantDef {
 }
 
 impl StructField {
-    pub(crate) fn source_impl(&self, db: &impl PersistentHirDatabase) -> (HirFileId, FieldSource) {
+    pub(crate) fn source_impl(&self, db: &impl DefDatabase) -> (HirFileId, FieldSource) {
         let var_data = self.parent.variant_data(db);
         let fields = var_data.fields().unwrap();
         let ss;
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 62301e4ab..45fa4cd11 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -6,7 +6,7 @@ use ra_syntax::{ast::self, TreeArc, SyntaxNode};
 
 use crate::{
     Name, ScopesWithSourceMap, Ty, HirFileId,
-    HirDatabase, PersistentHirDatabase,
+    HirDatabase, DefDatabase,
     type_ref::TypeRef,
     nameres::{ModuleScope, Namespace, ImportId, CrateModuleId},
     expr::{Body, BodySourceMap},
@@ -38,24 +38,21 @@ impl Crate {
         self.crate_id
     }
 
-    pub fn dependencies(&self, db: &impl PersistentHirDatabase) -> Vec<CrateDependency> {
+    pub fn dependencies(&self, db: &impl DefDatabase) -> Vec<CrateDependency> {
         self.dependencies_impl(db)
     }
 
-    pub fn root_module(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
+    pub fn root_module(&self, db: &impl DefDatabase) -> Option<Module> {
         self.root_module_impl(db)
     }
 
-    pub fn edition(&self, db: &impl PersistentHirDatabase) -> Edition {
+    pub fn edition(&self, db: &impl DefDatabase) -> Edition {
         let crate_graph = db.crate_graph();
         crate_graph.edition(self.crate_id)
     }
 
     // FIXME: should this be in source_binder?
-    pub fn source_root_crates(
-        db: &impl PersistentHirDatabase,
-        source_root: SourceRootId,
-    ) -> Vec<Crate> {
+    pub fn source_root_crates(db: &impl DefDatabase, source_root: SourceRootId) -> Vec<Crate> {
         let crate_ids = db.source_root_crates(source_root);
         crate_ids.iter().map(|&crate_id| Crate { crate_id }).collect()
     }
@@ -101,7 +98,6 @@ pub enum ModuleSource {
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub enum Problem {
     UnresolvedModule { candidate: RelativePathBuf },
-    NotDirOwner { move_to: RelativePathBuf, candidate: RelativePathBuf },
 }
 
 impl Module {
@@ -111,7 +107,7 @@ impl Module {
     }
 
     /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
-    pub fn definition_source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, ModuleSource) {
+    pub fn definition_source(&self, db: &impl DefDatabase) -> (HirFileId, ModuleSource) {
         self.definition_source_impl(db)
     }
 
@@ -134,14 +130,14 @@ impl Module {
     }
 
     /// Returns the crate this module is part of.
-    pub fn krate(&self, _db: &impl PersistentHirDatabase) -> Option<Crate> {
+    pub fn krate(&self, _db: &impl DefDatabase) -> Option<Crate> {
         Some(self.krate)
     }
 
     /// Topmost parent of this module. Every module has a `crate_root`, but some
     /// might be missing `krate`. This can happen if a module's file is not included
     /// in the module tree of any target in `Cargo.toml`.
-    pub fn crate_root(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub fn crate_root(&self, db: &impl DefDatabase) -> Module {
         self.crate_root_impl(db)
     }
 
@@ -151,12 +147,12 @@ impl Module {
     }
 
     /// Iterates over all child modules.
-    pub fn children(&self, db: &impl PersistentHirDatabase) -> impl Iterator<Item = Module> {
+    pub fn children(&self, db: &impl DefDatabase) -> impl Iterator<Item = Module> {
         self.children_impl(db)
     }
 
     /// Finds a parent module.
-    pub fn parent(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
+    pub fn parent(&self, db: &impl DefDatabase) -> Option<Module> {
         self.parent_impl(db)
     }
 
@@ -229,7 +225,7 @@ impl StructField {
         self.parent.variant_data(db).fields().unwrap()[self.id].name.clone()
     }
 
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, FieldSource) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, FieldSource) {
         self.source_impl(db)
     }
 
@@ -257,7 +253,7 @@ pub struct Struct {
 }
 
 impl Struct {
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::StructDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::StructDef>) {
         self.id.source(db)
     }
 
@@ -289,7 +285,7 @@ impl Struct {
             .map(|(id, _)| StructField { parent: (*self).into(), id })
     }
 
-    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
+    pub fn generic_params(&self, db: &impl DefDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
 
@@ -325,7 +321,7 @@ pub struct Enum {
 }
 
 impl Enum {
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::EnumDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::EnumDef>) {
         self.id.source(db)
     }
 
@@ -337,7 +333,7 @@ impl Enum {
         db.enum_data(*self).name.clone()
     }
 
-    pub fn variants(&self, db: &impl PersistentHirDatabase) -> Vec<EnumVariant> {
+    pub fn variants(&self, db: &impl DefDatabase) -> Vec<EnumVariant> {
         db.enum_data(*self)
             .variants
             .iter()
@@ -345,7 +341,7 @@ impl Enum {
             .collect()
     }
 
-    pub fn variant(&self, db: &impl PersistentHirDatabase, name: &Name) -> Option<EnumVariant> {
+    pub fn variant(&self, db: &impl DefDatabase, name: &Name) -> Option<EnumVariant> {
         db.enum_data(*self)
             .variants
             .iter()
@@ -353,7 +349,7 @@ impl Enum {
             .map(|(id, _)| EnumVariant { parent: *self, id })
     }
 
-    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
+    pub fn generic_params(&self, db: &impl DefDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
 
@@ -386,20 +382,17 @@ pub struct EnumVariant {
 }
 
 impl EnumVariant {
-    pub fn source(
-        &self,
-        db: &impl PersistentHirDatabase,
-    ) -> (HirFileId, TreeArc<ast::EnumVariant>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::EnumVariant>) {
         self.source_impl(db)
     }
     pub fn module(&self, db: &impl HirDatabase) -> Module {
         self.parent.module(db)
     }
-    pub fn parent_enum(&self, _db: &impl PersistentHirDatabase) -> Enum {
+    pub fn parent_enum(&self, _db: &impl DefDatabase) -> Enum {
         self.parent
     }
 
-    pub fn name(&self, db: &impl PersistentHirDatabase) -> Option<Name> {
+    pub fn name(&self, db: &impl DefDatabase) -> Option<Name> {
         db.enum_data(self.parent).variants[self.id].name.clone()
     }
 
@@ -465,11 +458,11 @@ impl FnSignature {
 }
 
 impl Function {
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::FnDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::FnDef>) {
         self.id.source(db)
     }
 
-    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub fn module(&self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
@@ -503,12 +496,12 @@ impl Function {
         db.infer(*self)
     }
 
-    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
+    pub fn generic_params(&self, db: &impl DefDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
 
     /// The containing impl block, if this is a method.
-    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
+    pub fn impl_block(&self, db: &impl DefDatabase) -> Option<ImplBlock> {
         let module_impls = db.impls_in_module(self.module(db));
         ImplBlock::containing(module_impls, (*self).into())
     }
@@ -540,11 +533,11 @@ pub struct Const {
 }
 
 impl Const {
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::ConstDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::ConstDef>) {
         self.id.source(db)
     }
 
-    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub fn module(&self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
@@ -553,7 +546,7 @@ impl Const {
     }
 
     /// The containing impl block, if this is a method.
-    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
+    pub fn impl_block(&self, db: &impl DefDatabase) -> Option<ImplBlock> {
         let module_impls = db.impls_in_module(self.module(db));
         ImplBlock::containing(module_impls, (*self).into())
     }
@@ -599,11 +592,11 @@ pub struct Static {
 }
 
 impl Static {
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::StaticDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::StaticDef>) {
         self.id.source(db)
     }
 
-    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub fn module(&self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
@@ -630,15 +623,15 @@ pub struct Trait {
 }
 
 impl Trait {
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::TraitDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::TraitDef>) {
         self.id.source(db)
     }
 
-    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub fn module(&self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
-    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
+    pub fn generic_params(&self, db: &impl DefDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
 }
@@ -655,28 +648,25 @@ pub struct TypeAlias {
 }
 
 impl TypeAlias {
-    pub fn source(
-        &self,
-        db: &impl PersistentHirDatabase,
-    ) -> (HirFileId, TreeArc<ast::TypeAliasDef>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::TypeAliasDef>) {
         self.id.source(db)
     }
 
-    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
+    pub fn generic_params(&self, db: &impl DefDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
 
-    pub fn module(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub fn module(&self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
     /// The containing impl block, if this is a method.
-    pub fn impl_block(&self, db: &impl PersistentHirDatabase) -> Option<ImplBlock> {
+    pub fn impl_block(&self, db: &impl DefDatabase) -> Option<ImplBlock> {
         let module_impls = db.impls_in_module(self.module(db));
         ImplBlock::containing(module_impls, (*self).into())
     }
 
-    pub fn type_ref(self, db: &impl PersistentHirDatabase) -> Arc<TypeRef> {
+    pub fn type_ref(self, db: &impl DefDatabase) -> Arc<TypeRef> {
         db.type_alias_ref(self)
     }
 
diff --git a/crates/ra_hir/src/code_model_impl/function.rs b/crates/ra_hir/src/code_model_impl/function.rs
index c1654b069..334cb302b 100644
--- a/crates/ra_hir/src/code_model_impl/function.rs
+++ b/crates/ra_hir/src/code_model_impl/function.rs
@@ -5,14 +5,11 @@ use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 use crate::{
     Name, AsName, Function, FnSignature,
     type_ref::{TypeRef, Mutability},
-    PersistentHirDatabase,
+    DefDatabase,
 };
 
 impl FnSignature {
-    pub(crate) fn fn_signature_query(
-        db: &impl PersistentHirDatabase,
-        func: Function,
-    ) -> Arc<FnSignature> {
+    pub(crate) fn fn_signature_query(db: &impl DefDatabase, func: Function) -> Arc<FnSignature> {
         let (_, node) = func.source(db);
         let name = node.name().map(|n| n.as_name()).unwrap_or_else(Name::missing);
         let mut params = Vec::new();
diff --git a/crates/ra_hir/src/code_model_impl/konst.rs b/crates/ra_hir/src/code_model_impl/konst.rs
index 8b861a81f..db4e5ce5c 100644
--- a/crates/ra_hir/src/code_model_impl/konst.rs
+++ b/crates/ra_hir/src/code_model_impl/konst.rs
@@ -5,7 +5,7 @@ use ra_syntax::ast::{NameOwner, TypeAscriptionOwner};
 use crate::{

     Name, AsName, Const, ConstSignature, Static,

     type_ref::{TypeRef},

-    PersistentHirDatabase,

+    DefDatabase,

 };

 

 fn const_signature_for<N: NameOwner + TypeAscriptionOwner>(node: &N) -> Arc<ConstSignature> {

@@ -17,7 +17,7 @@ fn const_signature_for<N: NameOwner + TypeAscriptionOwner>(node: &N) -> Arc<Cons
 

 impl ConstSignature {

     pub(crate) fn const_signature_query(

-        db: &impl PersistentHirDatabase,

+        db: &impl DefDatabase,

         konst: Const,

     ) -> Arc<ConstSignature> {

         let (_, node) = konst.source(db);

@@ -25,7 +25,7 @@ impl ConstSignature {
     }

 

     pub(crate) fn static_signature_query(

-        db: &impl PersistentHirDatabase,

+        db: &impl DefDatabase,

         konst: Static,

     ) -> Arc<ConstSignature> {

         let (_, node) = konst.source(db);

diff --git a/crates/ra_hir/src/code_model_impl/krate.rs b/crates/ra_hir/src/code_model_impl/krate.rs
index cc87c6f14..914414fc3 100644
--- a/crates/ra_hir/src/code_model_impl/krate.rs
+++ b/crates/ra_hir/src/code_model_impl/krate.rs
@@ -1,12 +1,9 @@
 use crate::{
-    Crate, CrateDependency, AsName, Module, PersistentHirDatabase,
+    Crate, CrateDependency, AsName, Module, DefDatabase,
 };
 
 impl Crate {
-    pub(crate) fn dependencies_impl(
-        &self,
-        db: &impl PersistentHirDatabase,
-    ) -> Vec<CrateDependency> {
+    pub(crate) fn dependencies_impl(&self, db: &impl DefDatabase) -> Vec<CrateDependency> {
         let crate_graph = db.crate_graph();
         crate_graph
             .dependencies(self.crate_id)
@@ -17,7 +14,7 @@ impl Crate {
             })
             .collect()
     }
-    pub(crate) fn root_module_impl(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
+    pub(crate) fn root_module_impl(&self, db: &impl DefDatabase) -> Option<Module> {
         let module_id = db.crate_def_map(*self).root();
         let module = Module { krate: *self, module_id };
         Some(module)
diff --git a/crates/ra_hir/src/code_model_impl/module.rs b/crates/ra_hir/src/code_model_impl/module.rs
index f7d15c55e..52a33e981 100644
--- a/crates/ra_hir/src/code_model_impl/module.rs
+++ b/crates/ra_hir/src/code_model_impl/module.rs
@@ -4,13 +4,13 @@ use ra_syntax::{ast, SyntaxNode, TreeArc, AstNode};
 use crate::{
     Module, ModuleSource, Problem, Name,
     nameres::{CrateModuleId, ImportId},
-    HirDatabase, PersistentHirDatabase,
+    HirDatabase, DefDatabase,
     HirFileId, SourceItemId,
 };
 
 impl ModuleSource {
     pub(crate) fn new(
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         file_id: Option<FileId>,
         decl_id: Option<SourceItemId>,
     ) -> ModuleSource {
@@ -49,7 +49,7 @@ impl Module {
 
     pub(crate) fn definition_source_impl(
         &self,
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
     ) -> (HirFileId, ModuleSource) {
         let def_map = db.crate_def_map(self.krate);
         let decl_id = def_map[self.module_id].declaration;
@@ -80,7 +80,7 @@ impl Module {
         source_map.get(&source, import)
     }
 
-    pub(crate) fn crate_root_impl(&self, db: &impl PersistentHirDatabase) -> Module {
+    pub(crate) fn crate_root_impl(&self, db: &impl DefDatabase) -> Module {
         let def_map = db.crate_def_map(self.krate);
         self.with_module_id(def_map.root())
     }
@@ -93,10 +93,7 @@ impl Module {
     }
 
     /// Iterates over all child modules.
-    pub(crate) fn children_impl(
-        &self,
-        db: &impl PersistentHirDatabase,
-    ) -> impl Iterator<Item = Module> {
+    pub(crate) fn children_impl(&self, db: &impl DefDatabase) -> impl Iterator<Item = Module> {
         let def_map = db.crate_def_map(self.krate);
         let children = def_map[self.module_id]
             .children
@@ -106,7 +103,7 @@ impl Module {
         children.into_iter()
     }
 
-    pub(crate) fn parent_impl(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
+    pub(crate) fn parent_impl(&self, db: &impl DefDatabase) -> Option<Module> {
         let def_map = db.crate_def_map(self.krate);
         let parent_id = def_map[self.module_id].parent?;
         Some(self.with_module_id(parent_id))
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index c7bad7e2b..d3908f8ac 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -16,8 +16,8 @@ use crate::{
     type_ref::TypeRef,
 };
 
-#[salsa::query_group(PersistentHirDatabaseStorage)]
-pub trait PersistentHirDatabase: SourceDatabase + AsRef<HirInterner> {
+#[salsa::query_group(DefDatabaseStorage)]
+pub trait DefDatabase: SourceDatabase + AsRef<HirInterner> {
     #[salsa::invoke(HirFileId::hir_parse)]
     fn hir_parse(&self, file_id: HirFileId) -> TreeArc<SourceFile>;
 
@@ -71,7 +71,7 @@ pub trait PersistentHirDatabase: SourceDatabase + AsRef<HirInterner> {
 }
 
 #[salsa::query_group(HirDatabaseStorage)]
-pub trait HirDatabase: PersistentHirDatabase {
+pub trait HirDatabase: DefDatabase {
     #[salsa::invoke(ExprScopes::expr_scopes_query)]
     fn expr_scopes(&self, func: Function) -> Arc<ExprScopes>;
 
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index 498ed04f2..84fe94289 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -8,7 +8,7 @@ use std::sync::Arc;
 use ra_syntax::ast::{self, NameOwner, TypeParamsOwner};
 
 use crate::{
-    db::PersistentHirDatabase,
+    db::DefDatabase,
     Name, AsName, Function, Struct, Enum, Trait, TypeAlias, ImplBlock
 };
 
@@ -40,7 +40,7 @@ impl_froms!(GenericDef: Function, Struct, Enum, Trait, TypeAlias, ImplBlock);
 
 impl GenericParams {
     pub(crate) fn generic_params_query(
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         def: GenericDef,
     ) -> Arc<GenericParams> {
         let mut generics = GenericParams::default();
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 3d0a881c2..18401f865 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -10,7 +10,7 @@ use ra_arena::{Arena, RawId, ArenaId, impl_arena_id};
 
 use crate::{
     Module,
-    PersistentHirDatabase,
+    DefDatabase,
 };
 
 #[derive(Debug, Default)]
@@ -63,7 +63,7 @@ pub struct HirFileId(HirFileIdRepr);
 impl HirFileId {
     /// For macro-expansion files, returns the file original source file the
     /// expansion originated from.
-    pub fn original_file(self, db: &impl PersistentHirDatabase) -> FileId {
+    pub fn original_file(self, db: &impl DefDatabase) -> FileId {
         match self.0 {
             HirFileIdRepr::File(file_id) => file_id,
             HirFileIdRepr::Macro(macro_call_id) => {
@@ -83,10 +83,7 @@ impl HirFileId {
         }
     }
 
-    pub(crate) fn hir_parse(
-        db: &impl PersistentHirDatabase,
-        file_id: HirFileId,
-    ) -> TreeArc<SourceFile> {
+    pub(crate) fn hir_parse(db: &impl DefDatabase, file_id: HirFileId) -> TreeArc<SourceFile> {
         match file_id.0 {
             HirFileIdRepr::File(file_id) => db.parse(file_id),
             HirFileIdRepr::Macro(macro_call_id) => {
@@ -97,10 +94,7 @@ impl HirFileId {
     }
 }
 
-fn parse_macro(
-    db: &impl PersistentHirDatabase,
-    macro_call_id: MacroCallId,
-) -> Option<TreeArc<SourceFile>> {
+fn parse_macro(db: &impl DefDatabase, macro_call_id: MacroCallId) -> Option<TreeArc<SourceFile>> {
     let loc = macro_call_id.loc(db);
     let syntax = db.file_item(loc.source_item_id);
     let macro_call = ast::MacroCall::cast(&syntax).unwrap();
@@ -190,7 +184,7 @@ pub(crate) struct LocationCtx<DB> {
     file_id: HirFileId,
 }
 
-impl<'a, DB: PersistentHirDatabase> LocationCtx<&'a DB> {
+impl<'a, DB: DefDatabase> LocationCtx<&'a DB> {
     pub(crate) fn new(db: &'a DB, module: Module, file_id: HirFileId) -> LocationCtx<&'a DB> {
         LocationCtx { db, module, file_id }
     }
@@ -205,13 +199,13 @@ impl<'a, DB: PersistentHirDatabase> LocationCtx<&'a DB> {
 
 pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
     fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<N>, Self>;
-    fn from_ast(ctx: LocationCtx<&impl PersistentHirDatabase>, ast: &N) -> Self {
+    fn from_ast(ctx: LocationCtx<&impl DefDatabase>, ast: &N) -> Self {
         let items = ctx.db.file_items(ctx.file_id);
         let item_id = items.id_of(ctx.file_id, ast.syntax());
         Self::from_source_item_id_unchecked(ctx, item_id)
     }
     fn from_source_item_id_unchecked(
-        ctx: LocationCtx<&impl PersistentHirDatabase>,
+        ctx: LocationCtx<&impl DefDatabase>,
         item_id: SourceFileItemId,
     ) -> Self {
         let raw = SourceItemId { file_id: ctx.file_id, item_id };
@@ -219,7 +213,7 @@ pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
 
         Self::interner(ctx.db.as_ref()).loc2id(&loc)
     }
-    fn source(self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<N>) {
+    fn source(self, db: &impl DefDatabase) -> (HirFileId, TreeArc<N>) {
         let int = Self::interner(db.as_ref());
         let loc = int.id2loc(self);
         let syntax = db.file_item(loc.raw);
@@ -227,7 +221,7 @@ pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
             N::cast(&syntax).unwrap_or_else(|| panic!("invalid ItemLoc: {:?}", loc.raw)).to_owned();
         (loc.raw.file_id, ast)
     }
-    fn module(self, db: &impl PersistentHirDatabase) -> Module {
+    fn module(self, db: &impl DefDatabase) -> Module {
         let int = Self::interner(db.as_ref());
         let loc = int.id2loc(self);
         loc.module
@@ -324,7 +318,7 @@ pub struct SourceFileItems {
 
 impl SourceFileItems {
     pub(crate) fn file_items_query(
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         file_id: HirFileId,
     ) -> Arc<SourceFileItems> {
         let source_file = db.hir_parse(file_id);
@@ -332,7 +326,7 @@ impl SourceFileItems {
     }
 
     pub(crate) fn file_item_query(
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         source_item_id: SourceItemId,
     ) -> TreeArc<SyntaxNode> {
         let source_file = db.hir_parse(source_item_id.file_id);
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 0d3861a28..40d368cd9 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -9,7 +9,7 @@ use ra_syntax::{
 
 use crate::{
     Const, TypeAlias, Function, HirFileId,
-    HirDatabase, PersistentHirDatabase,
+    HirDatabase, DefDatabase,
     ModuleDef, Trait, Resolution,
     type_ref::TypeRef,
     ids::LocationCtx,
@@ -59,7 +59,7 @@ impl ImplBlock {
     }
 
     /// Returns the syntax of the impl block
-    pub fn source(&self, db: &impl PersistentHirDatabase) -> (HirFileId, TreeArc<ast::ImplBlock>) {
+    pub fn source(&self, db: &impl DefDatabase) -> (HirFileId, TreeArc<ast::ImplBlock>) {
         let source_map = db.impls_in_module_source_map(self.module);
         let (file_id, source) = self.module.definition_source(db);
         (file_id, source_map.get(&source, self.impl_id))
@@ -73,11 +73,11 @@ impl ImplBlock {
         self.module
     }
 
-    pub fn target_trait_ref(&self, db: &impl PersistentHirDatabase) -> Option<TypeRef> {
+    pub fn target_trait_ref(&self, db: &impl DefDatabase) -> Option<TypeRef> {
         db.impls_in_module(self.module).impls[self.impl_id].target_trait().cloned()
     }
 
-    pub fn target_type(&self, db: &impl PersistentHirDatabase) -> TypeRef {
+    pub fn target_type(&self, db: &impl DefDatabase) -> TypeRef {
         db.impls_in_module(self.module).impls[self.impl_id].target_type().clone()
     }
 
@@ -97,11 +97,11 @@ impl ImplBlock {
         None
     }
 
-    pub fn items(&self, db: &impl PersistentHirDatabase) -> Vec<ImplItem> {
+    pub fn items(&self, db: &impl DefDatabase) -> Vec<ImplItem> {
         db.impls_in_module(self.module).impls[self.impl_id].items().to_vec()
     }
 
-    pub fn generic_params(&self, db: &impl PersistentHirDatabase) -> Arc<GenericParams> {
+    pub fn generic_params(&self, db: &impl DefDatabase) -> Arc<GenericParams> {
         db.generic_params((*self).into())
     }
 
@@ -124,7 +124,7 @@ pub struct ImplData {
 
 impl ImplData {
     pub(crate) fn from_ast(
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         file_id: HirFileId,
         module: Module,
         node: &ast::ImplBlock,
@@ -193,11 +193,7 @@ pub struct ModuleImplBlocks {
 }
 
 impl ModuleImplBlocks {
-    fn collect(
-        db: &impl PersistentHirDatabase,
-        module: Module,
-        source_map: &mut ImplSourceMap,
-    ) -> Self {
+    fn collect(db: &impl DefDatabase, module: Module, source_map: &mut ImplSourceMap) -> Self {
         let mut m = ModuleImplBlocks {
             module,
             impls: Arena::default(),
@@ -228,7 +224,7 @@ impl ModuleImplBlocks {
 }
 
 pub(crate) fn impls_in_module_with_source_map_query(
-    db: &impl PersistentHirDatabase,
+    db: &impl DefDatabase,
     module: Module,
 ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
     let mut source_map = ImplSourceMap::default();
@@ -238,15 +234,12 @@ pub(crate) fn impls_in_module_with_source_map_query(
     (Arc::new(result), Arc::new(source_map))
 }
 
-pub(crate) fn impls_in_module(
-    db: &impl PersistentHirDatabase,
-    module: Module,
-) -> Arc<ModuleImplBlocks> {
+pub(crate) fn impls_in_module(db: &impl DefDatabase, module: Module) -> Arc<ModuleImplBlocks> {
     db.impls_in_module_with_source_map(module).0
 }
 
 pub(crate) fn impls_in_module_source_map_query(
-    db: &impl PersistentHirDatabase,
+    db: &impl DefDatabase,
     module: Module,
 ) -> Arc<ImplSourceMap> {
     db.impls_in_module_with_source_map(module).1
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 5926b5758..a89c916f8 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -43,7 +43,7 @@ mod code_model_impl;
 mod marks;
 
 use crate::{
-    db::{HirDatabase, PersistentHirDatabase},
+    db::{HirDatabase, DefDatabase},
     name::{AsName, KnownName},
     ids::{SourceItemId, SourceFileItems},
 };
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
index f1cad77c5..10d4c1b8c 100644
--- a/crates/ra_hir/src/mock.rs
+++ b/crates/ra_hir/src/mock.rs
@@ -13,11 +13,7 @@ use crate::{db, HirInterner};
 
 pub const WORKSPACE: SourceRootId = SourceRootId(0);
 
-#[salsa::database(
-    ra_db::SourceDatabaseStorage,
-    db::HirDatabaseStorage,
-    db::PersistentHirDatabaseStorage
-)]
+#[salsa::database(ra_db::SourceDatabaseStorage, db::HirDatabaseStorage, db::DefDatabaseStorage)]
 #[derive(Debug)]
 pub struct MockDatabase {
     events: Mutex<Option<Vec<salsa::Event<MockDatabase>>>>,
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index e9235bc59..d361cf9e6 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -62,7 +62,7 @@ use test_utils::tested_by;
 
 use crate::{
     ModuleDef, Name, Crate, Module, Problem,
-    PersistentHirDatabase, Path, PathKind, HirFileId,
+    DefDatabase, Path, PathKind, HirFileId,
     ids::{SourceItemId, SourceFileItemId, MacroCallId},
 };
 
@@ -196,10 +196,7 @@ enum ReachedFixedPoint {
 }
 
 impl CrateDefMap {
-    pub(crate) fn crate_def_map_query(
-        db: &impl PersistentHirDatabase,
-        krate: Crate,
-    ) -> Arc<CrateDefMap> {
+    pub(crate) fn crate_def_map_query(db: &impl DefDatabase, krate: Crate) -> Arc<CrateDefMap> {
         let start = std::time::Instant::now();
         let def_map = {
             let edition = krate.edition(db);
@@ -268,7 +265,7 @@ impl CrateDefMap {
 
     pub(crate) fn resolve_path(
         &self,
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         original_module: CrateModuleId,
         path: &Path,
     ) -> (PerNs<ModuleDef>, Option<usize>) {
@@ -280,7 +277,7 @@ impl CrateDefMap {
     // the result.
     fn resolve_path_fp(
         &self,
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         mode: ResolveMode,
         original_module: CrateModuleId,
         path: &Path,
@@ -422,7 +419,7 @@ impl CrateDefMap {
 
     pub(crate) fn resolve_name_in_module(
         &self,
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         module: CrateModuleId,
         name: &Name,
     ) -> PerNs<ModuleDef> {
@@ -442,7 +439,7 @@ impl CrateDefMap {
         self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it))
     }
 
-    fn resolve_in_prelude(&self, db: &impl PersistentHirDatabase, name: &Name) -> PerNs<ModuleDef> {
+    fn resolve_in_prelude(&self, db: &impl DefDatabase, name: &Name) -> PerNs<ModuleDef> {
         if let Some(prelude) = self.prelude {
             let resolution = if prelude.krate == self.krate {
                 self[prelude.module_id].scope.items.get(name).cloned()
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index 3ea8d592c..c5b73cfbe 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -6,7 +6,7 @@ use ra_db::FileId;
 
 use crate::{
     Function, Module, Struct, Enum, Const, Static, Trait, TypeAlias,
-    PersistentHirDatabase, HirFileId, Name, Path, Problem, Crate,
+    DefDatabase, HirFileId, Name, Path, Problem, Crate,
     KnownName,
     nameres::{Resolution, PerNs, ModuleDef, ReachedFixedPoint, ResolveMode, raw},
     ids::{AstItemDef, LocationCtx, MacroCallLoc, SourceItemId, MacroCallId},
@@ -14,10 +14,7 @@ use crate::{
 
 use super::{CrateDefMap, CrateModuleId, ModuleData, CrateMacroId};
 
-pub(super) fn collect_defs(
-    db: &impl PersistentHirDatabase,
-    mut def_map: CrateDefMap,
-) -> CrateDefMap {
+pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
     // populate external prelude
     for dep in def_map.krate.dependencies(db) {
         log::debug!("crate dep {:?} -> {:?}", dep.name, dep.krate);
@@ -57,7 +54,7 @@ struct DefCollector<DB> {
 
 impl<'a, DB> DefCollector<&'a DB>
 where
-    DB: PersistentHirDatabase,
+    DB: DefDatabase,
 {
     fn collect(&mut self) {
         let crate_graph = self.db.crate_graph();
@@ -370,7 +367,7 @@ struct ModCollector<'a, D> {
 
 impl<DB> ModCollector<'_, &'_ mut DefCollector<&'_ DB>>
 where
-    DB: PersistentHirDatabase,
+    DB: DefDatabase,
 {
     fn collect(&mut self, items: &[raw::RawItem]) {
         for item in items {
@@ -523,7 +520,7 @@ fn is_macro_rules(path: &Path) -> bool {
 }
 
 fn resolve_submodule(
-    db: &impl PersistentHirDatabase,
+    db: &impl DefDatabase,
     file_id: HirFileId,
     name: &Name,
     is_root: bool,
diff --git a/crates/ra_hir/src/nameres/raw.rs b/crates/ra_hir/src/nameres/raw.rs
index 3226bbf0d..f8ba398ec 100644
--- a/crates/ra_hir/src/nameres/raw.rs
+++ b/crates/ra_hir/src/nameres/raw.rs
@@ -12,7 +12,7 @@ use ra_syntax::{
 };
 
 use crate::{
-    PersistentHirDatabase, Name, AsName, Path, HirFileId, ModuleSource,
+    DefDatabase, Name, AsName, Path, HirFileId, ModuleSource,
     ids::{SourceFileItemId, SourceFileItems},
 };
 
@@ -47,15 +47,12 @@ impl ImportSourceMap {
 }
 
 impl RawItems {
-    pub(crate) fn raw_items_query(
-        db: &impl PersistentHirDatabase,
-        file_id: FileId,
-    ) -> Arc<RawItems> {
+    pub(crate) fn raw_items_query(db: &impl DefDatabase, file_id: FileId) -> Arc<RawItems> {
         db.raw_items_with_source_map(file_id).0
     }
 
     pub(crate) fn raw_items_with_source_map_query(
-        db: &impl PersistentHirDatabase,
+        db: &impl DefDatabase,
         file_id: FileId,
     ) -> (Arc<RawItems>, Arc<ImportSourceMap>) {
         let mut collector = RawItemsCollector {
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index 132ee0ca2..cff7e7481 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -407,7 +407,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
                     let substs =
                         Ty::substs_from_path_segment(self.db, &self.resolver, segment, typable);
-                    self.db.type_for_def(typable, Namespace::Types).apply_substs(substs)
+                    self.db.type_for_def(typable, Namespace::Types).subst(&substs)
                 }
                 Resolution::LocalBinding(_) => {
                     // can't have a local binding in an associated item path
@@ -466,7 +466,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 let typable: Option<TypableDef> = def.into();
                 let typable = typable?;
                 let substs = Ty::substs_from_path(self.db, &self.resolver, path, typable);
-                let ty = self.db.type_for_def(typable, Namespace::Values).apply_substs(substs);
+                let ty = self.db.type_for_def(typable, Namespace::Values).subst(&substs);
                 let ty = self.insert_type_vars(ty);
                 Some(ty)
             }
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 0f2172ddf..5d8ad4aa7 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -1792,6 +1792,29 @@ fn test<R>(query_response: Canonical<QueryResponse<R>>) {
 }
 
 #[test]
+fn bug_1030() {
+    assert_snapshot_matches!(infer(r#"
+struct HashSet<T, H>;
+struct FxHasher;
+type FxHashSet<T> = HashSet<T, FxHasher>;
+
+impl<T, H> HashSet<T, H> {
+    fn default() -> HashSet<T, H> {}
+}
+
+pub fn main_loop() {
+    FxHashSet::default();
+}
+"#),
+    @r###"
+[144; 146) '{}': ()
+[169; 198) '{     ...t(); }': ()
+[175; 193) 'FxHash...efault': fn default<{unknown}, {unknown}>() -> HashSet<T, H>
+[175; 195) 'FxHash...ault()': HashSet<{unknown}, {unknown}>"###
+    );
+}
+
+#[test]
 fn cross_crate_associated_method_call() {
     let (mut db, pos) = MockDatabase::with_position(
         r#"
diff --git a/crates/ra_hir/src/type_alias.rs b/crates/ra_hir/src/type_alias.rs
index d02762d20..e35adcb2f 100644
--- a/crates/ra_hir/src/type_alias.rs
+++ b/crates/ra_hir/src/type_alias.rs
@@ -2,12 +2,9 @@
 
 use std::sync::Arc;
 
-use crate::{TypeAlias, db::PersistentHirDatabase, type_ref::TypeRef};
+use crate::{TypeAlias, db::DefDatabase, type_ref::TypeRef};
 
-pub(crate) fn type_alias_ref_query(
-    db: &impl PersistentHirDatabase,
-    typ: TypeAlias,
-) -> Arc<TypeRef> {
+pub(crate) fn type_alias_ref_query(db: &impl DefDatabase, typ: TypeAlias) -> Arc<TypeRef> {
     let (_, node) = typ.source(db);
     Arc::new(TypeRef::from_ast_opt(node.type_ref()))
 }
diff --git a/crates/ra_ide_api/Cargo.toml b/crates/ra_ide_api/Cargo.toml
index 97c8bab18..c64226801 100644
--- a/crates/ra_ide_api/Cargo.toml
+++ b/crates/ra_ide_api/Cargo.toml
@@ -30,7 +30,12 @@ ra_assists = { path = "../ra_assists" }
 
 [dev-dependencies]
 insta = "0.7.0"
-proptest = "0.9.0"
+
+[dev-dependencies.proptest]
+version = "0.9.0"
+# Disable `fork` feature to allow compiling on webassembly
+default-features = false
+features = ["std", "bit-set", "break-dead-code"]
 
 [features]
 jemalloc = [ "jemallocator", "jemalloc-ctl" ]
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide_api/src/db.rs
index 00f4bdfd2..ea4255d35 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide_api/src/db.rs
@@ -15,7 +15,7 @@ use crate::{LineIndex, symbol_index::{self, SymbolsDatabase}};
     LineIndexDatabaseStorage,
     symbol_index::SymbolsDatabaseStorage,
     hir::db::HirDatabaseStorage,
-    hir::db::PersistentHirDatabaseStorage
+    hir::db::DefDatabaseStorage
 )]
 #[derive(Debug)]
 pub(crate) struct RootDatabase {
diff --git a/crates/ra_ide_api/src/diagnostics.rs b/crates/ra_ide_api/src/diagnostics.rs
index aabb614b9..b9dc424c6 100644
--- a/crates/ra_ide_api/src/diagnostics.rs
+++ b/crates/ra_ide_api/src/diagnostics.rs
@@ -157,27 +157,6 @@ fn check_module(
                     fix: Some(fix),
                 }
             }
-            Problem::NotDirOwner { move_to, candidate } => {
-                let move_file = FileSystemEdit::MoveFile {
-                    src: file_id,
-                    dst_source_root: source_root,
-                    dst_path: move_to.clone(),
-                };
-                let create_file =
-                    FileSystemEdit::CreateFile { source_root, path: move_to.join(candidate) };
-                let fix = SourceChange {
-                    label: "move file and create module".to_string(),
-                    source_file_edits: Vec::new(),
-                    file_system_edits: vec![move_file, create_file],
-                    cursor_position: None,
-                };
-                Diagnostic {
-                    range: name_node.range(),
-                    message: "can't declare module at this location".to_string(),
-                    severity: Severity::Error,
-                    fix: Some(fix),
-                }
-            }
         };
         acc.push(diag)
     }
diff --git a/crates/ra_ide_api_light/Cargo.toml b/crates/ra_ide_api_light/Cargo.toml
index a30833dc3..4e69f5325 100644
--- a/crates/ra_ide_api_light/Cargo.toml
+++ b/crates/ra_ide_api_light/Cargo.toml
@@ -17,5 +17,10 @@ ra_fmt = { path = "../ra_fmt" }
 
 [dev-dependencies]
 test_utils = { path = "../test_utils" }
-proptest = "0.9.0"
 insta = "0.7.0"
+
+[dev-dependencies.proptest]
+version = "0.9.0"
+# Disable `fork` feature to allow compiling on webassembly
+default-features = false
+features = ["std", "bit-set", "break-dead-code"]
diff --git a/crates/ra_text_edit/Cargo.toml b/crates/ra_text_edit/Cargo.toml
index 5769940df..b40026004 100644
--- a/crates/ra_text_edit/Cargo.toml
+++ b/crates/ra_text_edit/Cargo.toml
@@ -7,7 +7,12 @@ publish = false
 
 [dependencies]
 text_unit = "0.1.6"
-proptest = "0.9.0"
+
+[dependencies.proptest]
+version = "0.9.0"
+# Disable `fork` feature to allow compiling on webassembly
+default-features = false
+features = ["std", "bit-set", "break-dead-code"]
 
 [dev-dependencies]
 test_utils = { path = "../test_utils" }