[COMMITTED 129/146] gccrs: mappings: Add get_lang_item_node

[arthur . cohen]

From: Arthur Cohen <arthur.co...@embecosm.com>

This method errors out if the lang item has not been declared yet.

gcc/rust/ChangeLog:

        * util/rust-hir-map.cc (Mappings::get_lang_item_node): New.
        * util/rust-hir-map.h: New function.
---
 gcc/rust/util/rust-hir-map.cc | 10 ++++++++++
 gcc/rust/util/rust-hir-map.h  |  1 +
 2 files changed, 11 insertions(+)

diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index f11a77954ae..b94591e014c 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -1299,5 +1299,15 @@ Mappings::lookup_lang_item_node (LangItem::Kind 
item_type)
   return it->second;
 }
 
+NodeId
+Mappings::get_lang_item_node (LangItem::Kind item_type)
+{
+  if (auto lookup = lookup_lang_item_node (item_type))
+    return *lookup;
+
+  rust_fatal_error (UNKNOWN_LOCATION, "failed to find lang item %qs",
+                   LangItem::ToString (item_type).c_str ());
+}
+
 } // namespace Analysis
 } // namespace Rust
diff --git a/gcc/rust/util/rust-hir-map.h b/gcc/rust/util/rust-hir-map.h
index aba51be4827..21e532812ff 100644
--- a/gcc/rust/util/rust-hir-map.h
+++ b/gcc/rust/util/rust-hir-map.h
@@ -261,6 +261,7 @@ public:
 
   void insert_lang_item_node (LangItem::Kind item_type, NodeId node_id);
   tl::optional<NodeId &> lookup_lang_item_node (LangItem::Kind item_type);
+  NodeId get_lang_item_node (LangItem::Kind item_type);
 
   // This will fatal_error when this lang item does not exist
   DefId get_lang_item (LangItem::Kind item_type, location_t locus);
-- 
2.45.2