Add impl mappings to inherent impl items

When lowering impl blocks to HIR we keep track of all the inherent impl
items for lookup later but we also need to be able to reverse lookup impl
items back to their respective impl block.

4 files changed, 50 insertions, 11 deletions

diff --git a/gcc/rust/hir/rust-ast-lower-item.h b/gcc/rust/hir/rust-ast-lower-item.h
index edbc498..18ead3c 100644
--- a/gcc/rust/hir/rust-ast-lower-item.h
+++ b/gcc/rust/hir/rust-ast-lower-item.h
@@ -360,12 +360,14 @@ public:
 				   mappings->get_next_localdef_id (crate_num));
 
     std::vector<std::unique_ptr<HIR::InherentImplItem> > impl_items;
+    std::vector<HirId> impl_item_ids;
     for (auto &impl_item : impl_block.get_impl_items ())
       {
 	HIR::InherentImplItem *lowered
 	  = ASTLowerImplItem::translate (impl_item.get (),
 					 mapping.get_hirid ());
 	impl_items.push_back (std::unique_ptr<HIR::InherentImplItem> (lowered));
+	impl_item_ids.push_back (lowered->get_impl_mappings ().get_hirid ());
       }
 
     translated
@@ -381,6 +383,13 @@ public:
 			       translated);
     mappings->insert_location (crate_num, mapping.get_hirid (),
 			       impl_block.get_locus ());
+
+    for (auto &impl_item_id : impl_item_ids)
+      {
+	mappings->insert_impl_item_mapping (impl_item_id,
+					    static_cast<HIR::InherentImpl *> (
+					      translated));
+      }
   }
 
 private:
diff --git a/gcc/rust/hir/tree/rust-hir-path.h b/gcc/rust/hir/tree/rust-hir-path.h
index 8dbde9c..d6f9fc0 100644
--- a/gcc/rust/hir/tree/rust-hir-path.h
+++ b/gcc/rust/hir/tree/rust-hir-path.h
@@ -255,6 +255,12 @@ public:
       }
   }
 
+  size_t get_num_segments () const { return segments.size (); }
+
+  std::vector<PathExprSegment> &get_segments () { return segments; }
+
+  PathExprSegment &get_root_seg () { return segments.at (0); }
+
   PathExprSegment get_final_segment () const { return segments.back (); }
 };
 
diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index 891618e..0dcbd4f 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -524,5 +524,24 @@ Mappings::resolve_nodeid_to_stmt (CrateNum crate, NodeId id, HIR::Stmt **stmt)
   return resolved_stmt != nullptr;
 }
 
+void
+Mappings::iterate_impl_items (
+  std::function<bool (HirId, HIR::InherentImplItem *, HIR::InherentImpl *)> cb)
+{
+  for (auto it = hirImplItemMappings.begin (); it != hirImplItemMappings.end ();
+       it++)
+    {
+      for (auto iy = it->second.begin (); iy != it->second.end (); iy++)
+	{
+	  auto id = iy->first;
+	  auto impl_item = iy->second.second;
+	  auto impl = lookup_associated_impl (
+	    impl_item->get_impl_mappings ().get_hirid ());
+	  if (!cb (id, impl_item, impl))
+	    return;
+	}
+    }
+}
+
 } // namespace Analysis
 } // namespace Rust
diff --git a/gcc/rust/util/rust-hir-map.h b/gcc/rust/util/rust-hir-map.h
index 2e8a629..9777ee3 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -158,20 +158,24 @@ public:
     return hirNodesWithinCrate[crate];
   }
 
-  void
-  iterate_impl_items (std::function<bool (HirId, HIR::InherentImplItem *)> cb)
+  void insert_impl_item_mapping (HirId impl_item_id, HIR::InherentImpl *impl)
   {
-    for (auto it = hirImplItemMappings.begin ();
-	 it != hirImplItemMappings.end (); it++)
-      {
-	for (auto iy = it->second.begin (); iy != it->second.end (); iy++)
-	  {
-	    if (!cb (iy->first, iy->second.second))
-	      return;
-	  }
-      }
+    rust_assert (hirImplItemsToImplMappings.find (impl_item_id)
+		 == hirImplItemsToImplMappings.end ());
+    hirImplItemsToImplMappings[impl_item_id] = impl;
   }
 
+  HIR::InherentImpl *lookup_associated_impl (HirId impl_item_id)
+  {
+    auto lookup = hirImplItemsToImplMappings.find (impl_item_id);
+    rust_assert (lookup != hirImplItemsToImplMappings.end ());
+    return lookup->second;
+  }
+
+  void iterate_impl_items (
+    std::function<bool (HirId, HIR::InherentImplItem *, HIR::InherentImpl *)>
+      cb);
+
 private:
   Mappings ();
 
@@ -198,6 +202,7 @@ private:
 	   std::map<HirId, std::pair<HirId, HIR::InherentImplItem *> > >
     hirImplItemMappings;
   std::map<CrateNum, std::map<HirId, HIR::SelfParam *> > hirSelfParamMappings;
+  std::map<HirId, HIR::InherentImpl *> hirImplItemsToImplMappings;
 
   // location info
   std::map<CrateNum, std::map<NodeId, Location> > locations;