Make drop-glue take advantage of -Zshare-generics.

[rust.git] / src / librustc_mir / monomorphize / collector.rs

diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index f5f00c9343561dd318954d91df45fe9258fa2be5..91e685babbcdd514dc38c3413775babd5b187e6a 100644 (file)
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -418,7 +418,7 @@ fn check_recursion_limit<'tcx>(
     let recursion_depth = recursion_depths.get(&def_id).cloned().unwrap_or(0);
     debug!(" => recursion depth={}", recursion_depth);
 
-    let recursion_depth = if Some(def_id) == tcx.lang_items().drop_in_place_fn() {
+    let adjusted_recursion_depth = if Some(def_id) == tcx.lang_items().drop_in_place_fn() {
         // HACK: drop_in_place creates tight monomorphization loops. Give
         // it more margin.
         recursion_depth / 4
@@ -429,7 +429,7 @@ fn check_recursion_limit<'tcx>(
     // Code that needs to instantiate the same function recursively
     // more than the recursion limit is assumed to be causing an
     // infinite expansion.
-    if recursion_depth > *tcx.sess.recursion_limit.get() {
+    if adjusted_recursion_depth > *tcx.sess.recursion_limit.get() {
         let error = format!("reached the recursion limit while instantiating `{}`", instance);
         if let Some(hir_id) = tcx.hir().as_local_hir_id(def_id) {
             tcx.sess.span_fatal(tcx.hir().span(hir_id), &error);
@@ -713,7 +713,8 @@ fn visit_instance_use<'tcx>(
 // need a mono item.
 fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) -> bool {
     let def_id = match instance.def {
-        ty::InstanceDef::Item(def_id) => def_id,
+        ty::InstanceDef::Item(def_id) | ty::InstanceDef::DropGlue(def_id, Some(_)) => def_id,
+
         ty::InstanceDef::VtableShim(..)
         | ty::InstanceDef::ReifyShim(..)
         | ty::InstanceDef::ClosureOnceShim { .. }
@@ -725,12 +726,14 @@ fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx
     };
 
     if tcx.is_foreign_item(def_id) {
-        // We can always link to foreign items.
+        // Foreign items are always linked against, there's no way of
+        // instantiating them.
         return false;
     }
 
     if def_id.is_local() {
-        // Local items cannot be referred to locally without monomorphizing them locally.
+        // Local items cannot be referred to locally without
+        // monomorphizing them locally.
         return true;
     }
 
@@ -745,6 +748,7 @@ fn should_monomorphize_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx
     if !tcx.is_mir_available(def_id) {
         bug!("cannot create local mono-item for {:?}", def_id)
     }
+
     return true;
 
     fn is_available_upstream_generic<'tcx>(
@@ -954,7 +958,7 @@ fn visit_item(&mut self, item: &'v hir::Item<'v>) {
                 // Nothing to do, just keep recursing.
             }
 
-            hir::ItemKind::Impl(..) => {
+            hir::ItemKind::Impl { .. } => {
                 if self.mode == MonoItemCollectionMode::Eager {
                     create_mono_items_for_default_impls(self.tcx, item, self.output);
                 }
@@ -1098,7 +1102,7 @@ fn create_mono_items_for_default_impls<'tcx>(
     output: &mut Vec<MonoItem<'tcx>>,
 ) {
     match item.kind {
-        hir::ItemKind::Impl(_, _, _, ref generics, .., ref impl_item_refs) => {
+        hir::ItemKind::Impl { ref generics, ref items, .. } => {
             for param in generics.params {
                 match param.kind {
                     hir::GenericParamKind::Lifetime { .. } => {}
@@ -1119,7 +1123,7 @@ fn create_mono_items_for_default_impls<'tcx>(
                 let param_env = ty::ParamEnv::reveal_all();
                 let trait_ref = tcx.normalize_erasing_regions(param_env, trait_ref);
                 let overridden_methods: FxHashSet<_> =
-                    impl_item_refs.iter().map(|iiref| iiref.ident.modern()).collect();
+                    items.iter().map(|iiref| iiref.ident.modern()).collect();
                 for method in tcx.provided_trait_methods(trait_ref.def_id) {
                     if overridden_methods.contains(&method.ident.modern()) {
                         continue;