rustc: introduce DefId::as_local(self) -> Option<LocalDefId> and use it.

Author: eddyb

src/librustc/hir/def_id.rs

@@ -139,13 +139,23 @@ impl DefId {
     }
 
     #[inline]
-    pub fn assert_local(self) -> LocalDefId {
-        assert!(self.is_local());
-        LocalDefId {
-            index: self.index,
+    pub fn as_local(self) -> Option<LocalDefId> {
+        if self.is_local() {
+            Some(LocalDefId {
+                index: self.index,
+            })
+        } else {
+            None
         }
     }
 
+    #[inline]
+    pub fn assert_local(self) -> LocalDefId {
+        self.as_local().unwrap_or_else(|| {
+            bug!("DefId::assert_local: `{:?}` isn't local", self)
+        })
+    }
+
     pub fn describe_as_module(&self, tcx: TyCtxt<'_>) -> String {
         if self.is_local() && self.index == CRATE_DEF_INDEX {
             format!("top-level module")

src/librustc/hir/lowering.rs

@@ -975,7 +975,7 @@ impl<'a> LoweringContext<'a> {
     }
 
     fn def_key(&mut self, id: DefId) -> DefKey {
-        if id.is_local() {
+        if let Some(id) = id.as_local() {
             self.resolver.definitions().def_key(id.index)
         } else {
             self.resolver.cstore().def_key(id)

src/librustc/hir/map/hir_id_validator.rs

@@ -1,4 +1,4 @@
-use crate::hir::def_id::{DefId, DefIndex, CRATE_DEF_INDEX};
+use crate::hir::def_id::{DefIndex, CRATE_DEF_INDEX, LocalDefId};
 use crate::hir::{self, intravisit, HirId, ItemLocalId};
 use crate::hir::itemlikevisit::ItemLikeVisitor;
 use rustc_data_structures::fx::FxHashSet;
@@ -119,7 +119,7 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
             self.error(|| format!(
                 "ItemLocalIds not assigned densely in {}. \
                 Max ItemLocalId = {}, missing IDs = {:?}; seens IDs = {:?}",
-                self.hir_map.def_path(DefId::local(owner_def_index)).to_string_no_crate(),
+                self.hir_map.def_path(LocalDefId { index: owner_def_index }).to_string_no_crate(),
                 max,
                 missing_items,
                 self.hir_ids_seen
@@ -154,8 +154,8 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
             self.error(|| format!(
                 "HirIdValidator: The recorded owner of {} is {} instead of {}",
                 self.hir_map.node_to_string(hir_id),
-                self.hir_map.def_path(DefId::local(hir_id.owner)).to_string_no_crate(),
-                self.hir_map.def_path(DefId::local(owner)).to_string_no_crate()));
+                self.hir_map.def_path(hir_id.owner_local_def_id()).to_string_no_crate(),
+                self.hir_map.def_path(LocalDefId { index: owner }).to_string_no_crate()));
         }
 
         self.hir_ids_seen.insert(hir_id.local_id);

src/librustc/hir/map/mod.rs

@@ -246,19 +246,17 @@ impl<'hir> Map<'hir> {
         self.definitions
     }
 
-    pub fn def_key(&self, def_id: DefId) -> DefKey {
-        assert!(def_id.is_local());
+    pub fn def_key(&self, def_id: LocalDefId) -> DefKey {
         self.definitions.def_key(def_id.index)
     }
 
     pub fn def_path_from_hir_id(&self, id: HirId) -> Option<DefPath> {
         self.opt_local_def_id(id).map(|def_id| {
-            self.def_path(def_id)
+            self.def_path(def_id.assert_local())
         })
     }
 
-    pub fn def_path(&self, def_id: DefId) -> DefPath {
-        assert!(def_id.is_local());
+    pub fn def_path(&self, def_id: LocalDefId) -> DefPath {
         self.definitions.def_path(def_id.index)
     }
 

src/librustc/ich/hcx.rs

@@ -131,7 +131,7 @@ impl<'a> StableHashingContext<'a> {
 
     #[inline]
     pub fn def_path_hash(&self, def_id: DefId) -> DefPathHash {
-        if def_id.is_local() {
+        if let Some(def_id) = def_id.as_local() {
             self.definitions.def_path_hash(def_id.index)
         } else {
             self.cstore.def_path_hash(def_id)

src/librustc/ty/context.rs

@@ -1343,7 +1343,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn def_key(self, id: DefId) -> hir_map::DefKey {
-        if id.is_local() {
+        if let Some(id) = id.as_local() {
             self.hir().def_key(id)
         } else {
             self.cstore.def_key(id)
@@ -1356,7 +1356,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Note that if `id` is not local to this crate, the result will
     ///  be a non-local `DefPath`.
     pub fn def_path(self, id: DefId) -> hir_map::DefPath {
-        if id.is_local() {
+        if let Some(id) = id.as_local() {
             self.hir().def_path(id)
         } else {
             self.cstore.def_path(id)
@@ -1375,7 +1375,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     #[inline]
     pub fn def_path_hash(self, def_id: DefId) -> hir_map::DefPathHash {
-        if def_id.is_local() {
+        if let Some(def_id) = def_id.as_local() {
             self.hir().definitions().def_path_hash(def_id.index)
         } else {
             self.cstore.def_path_hash(def_id)

src/librustc_mir/borrow_check/nll/mod.rs

@@ -258,7 +258,7 @@ pub(in crate::borrow_check) fn compute_regions<'cx, 'tcx>(
     // Dump facts if requested.
     let polonius_output = all_facts.and_then(|all_facts| {
         if infcx.tcx.sess.opts.debugging_opts.nll_facts {
-            let def_path = infcx.tcx.hir().def_path(def_id);
+            let def_path = infcx.tcx.def_path(def_id);
             let dir_path =
                 PathBuf::from("nll-facts").join(def_path.to_filename_friendly_no_crate());
             all_facts.write_to_dir(dir_path, location_table).unwrap();

src/librustc_passes/entry.rs

@@ -33,7 +33,7 @@ struct EntryContext<'a, 'tcx> {
 impl<'a, 'tcx> ItemLikeVisitor<'tcx> for EntryContext<'a, 'tcx> {
     fn visit_item(&mut self, item: &'tcx Item) {
         let def_id = self.map.local_def_id(item.hir_id);
-        let def_key = self.map.def_key(def_id);
+        let def_key = self.map.def_key(def_id.assert_local());
         let at_root = def_key.parent == Some(CRATE_DEF_INDEX);
         find_item(item, self, at_root);
     }

src/librustc_typeck/check/mod.rs

@@ -645,9 +645,8 @@ pub struct InheritedBuilder<'tcx> {
 
 impl Inherited<'_, 'tcx> {
     pub fn build(tcx: TyCtxt<'tcx>, def_id: DefId) -> InheritedBuilder<'tcx> {
-        let hir_id_root = if def_id.is_local() {
-            let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap();
-            DefId::local(hir_id.owner)
+        let hir_id_root = if let Some(def_id) = def_id.as_local() {
+            tcx.hir().local_def_id_to_hir_id(def_id).owner_def_id()
         } else {
             def_id
         };