mappings: Keep track of extern blocks

When inserting external items, it's interesting to also be able to
lookup the extern block they were defined in, similarly to impl items.
This is useful to know the ABI or other specifiers of the block the item
has been declared in.

6 files changed, 51 insertions, 18 deletions

diff --git a/gcc/rust/backend/rust-compile-resolve-path.cc b/gcc/rust/backend/rust-compile-resolve-path.cc
index 95d8841..b5bfa3c 100644
--- a/gcc/rust/backend/rust-compile-resolve-path.cc
+++ b/gcc/rust/backend/rust-compile-resolve-path.cc
@@ -159,8 +159,9 @@ HIRCompileBase::query_compile (HirId ref, TyTy::BaseType *lookup,
 			       Location expr_locus, bool is_qualified_path)
 {
   HIR::Item *resolved_item = ctx->get_mappings ()->lookup_hir_item (ref);
+  HirId parent_block;
   HIR::ExternalItem *resolved_extern_item
-    = ctx->get_mappings ()->lookup_hir_extern_item (ref);
+    = ctx->get_mappings ()->lookup_hir_extern_item (ref, &parent_block);
   bool is_hir_item = resolved_item != nullptr;
   bool is_hir_extern_item = resolved_extern_item != nullptr;
   if (is_hir_item)
diff --git a/gcc/rust/checks/errors/rust-unsafe-checker.cc b/gcc/rust/checks/errors/rust-unsafe-checker.cc
index 0d1e0e9..9642baa 100644
--- a/gcc/rust/checks/errors/rust-unsafe-checker.cc
+++ b/gcc/rust/checks/errors/rust-unsafe-checker.cc
@@ -69,7 +69,9 @@ UnsafeChecker::check_use_of_static (HirId node_id, Location locus)
     return;
 
   auto maybe_static_mut = mappings.lookup_hir_item (node_id);
-  auto maybe_extern_static = mappings.lookup_hir_extern_item (node_id);
+  HirId extern_block;
+  auto maybe_extern_static
+    = mappings.lookup_hir_extern_item (node_id, &extern_block);
 
   if (maybe_static_mut)
     check_static_mut (maybe_static_mut, locus);
diff --git a/gcc/rust/hir/rust-ast-lower-base.cc b/gcc/rust/hir/rust-ast-lower-base.cc
index cae4428..a674617 100644
--- a/gcc/rust/hir/rust-ast-lower-base.cc
+++ b/gcc/rust/hir/rust-ast-lower-base.cc
@@ -1038,6 +1038,11 @@ ASTLoweringBase::lower_extern_block (AST::ExternBlock &extern_block)
 {
   HIR::Visibility vis = translate_visibility (extern_block.get_visibility ());
 
+  auto crate_num = mappings->get_current_crate ();
+  Analysis::NodeMapping mapping (crate_num, extern_block.get_node_id (),
+				 mappings->get_next_hir_id (crate_num),
+				 mappings->get_next_localdef_id (crate_num));
+
   std::vector<std::unique_ptr<HIR::ExternalItem>> extern_items;
   for (auto &item : extern_block.get_extern_items ())
     {
@@ -1045,7 +1050,7 @@ ASTLoweringBase::lower_extern_block (AST::ExternBlock &extern_block)
 	continue;
 
       HIR::ExternalItem *lowered
-	= ASTLoweringExternItem::translate (item.get ());
+	= ASTLoweringExternItem::translate (item.get (), mapping.get_hirid ());
       extern_items.push_back (std::unique_ptr<HIR::ExternalItem> (lowered));
     }
 
@@ -1058,17 +1063,14 @@ ASTLoweringBase::lower_extern_block (AST::ExternBlock &extern_block)
 	rust_error_at (extern_block.get_locus (), "unknown ABI option");
     }
 
-  auto crate_num = mappings->get_current_crate ();
-  Analysis::NodeMapping mapping (crate_num, extern_block.get_node_id (),
-				 mappings->get_next_hir_id (crate_num),
-				 mappings->get_next_localdef_id (crate_num));
-
   HIR::ExternBlock *hir_extern_block
     = new HIR::ExternBlock (mapping, abi, std::move (extern_items),
 			    std::move (vis), extern_block.get_inner_attrs (),
 			    extern_block.get_outer_attrs (),
 			    extern_block.get_locus ());
 
+  mappings->insert_hir_extern_block (hir_extern_block);
+
   return hir_extern_block;
 }
 
diff --git a/gcc/rust/hir/rust-ast-lower-extern.h b/gcc/rust/hir/rust-ast-lower-extern.h
index 28d160b..eeb59c9 100644
--- a/gcc/rust/hir/rust-ast-lower-extern.h
+++ b/gcc/rust/hir/rust-ast-lower-extern.h
@@ -31,13 +31,15 @@ class ASTLoweringExternItem : public ASTLoweringBase
   using Rust::HIR::ASTLoweringBase::visit;
 
 public:
-  static HIR::ExternalItem *translate (AST::ExternalItem *item)
+  static HIR::ExternalItem *translate (AST::ExternalItem *item,
+				       HirId parent_hirid)
   {
     ASTLoweringExternItem resolver;
     item->accept_vis (resolver);
 
     rust_assert (resolver.translated != nullptr);
-    resolver.mappings->insert_hir_extern_item (resolver.translated);
+    resolver.mappings->insert_hir_extern_item (resolver.translated,
+					       parent_hirid);
     resolver.mappings->insert_location (
       resolver.translated->get_mappings ().get_hirid (),
       resolver.translated->get_locus ());
diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index c7bf182..6a6deeb 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -371,23 +371,45 @@ Mappings::lookup_hir_trait_item (HirId id)
 }
 
 void
-Mappings::insert_hir_extern_item (HIR::ExternalItem *item)
+Mappings::insert_hir_extern_block (HIR::ExternBlock *block)
+{
+  auto id = block->get_mappings ().get_hirid ();
+  rust_assert (lookup_hir_extern_block (id) == nullptr);
+
+  hirExternBlockMappings[id] = block;
+  insert_node_to_hir (block->get_mappings ().get_nodeid (), id);
+}
+
+HIR::ExternBlock *
+Mappings::lookup_hir_extern_block (HirId id)
+{
+  auto it = hirExternBlockMappings.find (id);
+  if (it == hirExternBlockMappings.end ())
+    return nullptr;
+
+  return it->second;
+}
+
+void
+Mappings::insert_hir_extern_item (HIR::ExternalItem *item, HirId parent_block)
 {
   auto id = item->get_mappings ().get_hirid ();
-  rust_assert (lookup_hir_extern_item (id) == nullptr);
+  rust_assert (lookup_hir_extern_item (id, nullptr) == nullptr);
 
-  hirExternItemMappings[id] = item;
+  hirExternItemMappings[id] = {item, parent_block};
   insert_node_to_hir (item->get_mappings ().get_nodeid (), id);
 }
 
 HIR::ExternalItem *
-Mappings::lookup_hir_extern_item (HirId id)
+Mappings::lookup_hir_extern_item (HirId id, HirId *parent_block)
 {
   auto it = hirExternItemMappings.find (id);
   if (it == hirExternItemMappings.end ())
     return nullptr;
 
-  return it->second;
+  *parent_block = it->second.second;
+
+  return it->second.first;
 }
 
 void
diff --git a/gcc/rust/util/rust-hir-map.h b/gcc/rust/util/rust-hir-map.h
index c8cebef..98fcfe6 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -115,8 +115,11 @@ public:
   void insert_hir_trait_item (HIR::TraitItem *item);
   HIR::TraitItem *lookup_hir_trait_item (HirId id);
 
-  void insert_hir_extern_item (HIR::ExternalItem *item);
-  HIR::ExternalItem *lookup_hir_extern_item (HirId id);
+  void insert_hir_extern_block (HIR::ExternBlock *block);
+  HIR::ExternBlock *lookup_hir_extern_block (HirId id);
+
+  void insert_hir_extern_item (HIR::ExternalItem *item, HirId parent_block);
+  HIR::ExternalItem *lookup_hir_extern_item (HirId id, HirId *parent_block);
 
   void insert_hir_impl_block (HIR::ImplBlock *item);
   HIR::ImplBlock *lookup_hir_impl_block (HirId id);
@@ -312,7 +315,8 @@ private:
   std::map<HirId, HIR::ImplBlock *> hirImplItemsToImplMappings;
   std::map<HirId, HIR::ImplBlock *> hirImplBlockMappings;
   std::map<HirId, HIR::TraitItem *> hirTraitItemMappings;
-  std::map<HirId, HIR::ExternalItem *> hirExternItemMappings;
+  std::map<HirId, HIR::ExternBlock *> hirExternBlockMappings;
+  std::map<HirId, std::pair<HIR::ExternalItem *, HirId>> hirExternItemMappings;
   std::map<HirId, HIR::PathExprSegment *> hirPathSegMappings;
   std::map<HirId, HIR::GenericParam *> hirGenericParamMappings;
   std::map<HirId, HIR::Trait *> hirTraitItemsToTraitMappings;