Check for deprecated attributes

Signed-off-by: Ashwani Kumar Kamal <[email protected]>

Author: sneaky-potato

gcc/rust/util/rust-attributes.cc

@@ -277,6 +277,102 @@ check_doc_attribute (const AST::Attribute &attribute)
     }
 }
 
+static void
+check_deprecated_attribute (const AST::Attribute &attribute)
+{
+  const auto &input = attribute.get_attr_input ();
+
+  if (input.get_attr_input_type () != AST::AttrInput::META_ITEM)
+    return;
+
+  auto &meta = static_cast<const AST::AttrInputMetaItemContainer &> (input);
+
+  for (auto &current : meta.get_items ())
+  {
+    switch (current->get_kind ())
+    {
+      case AST::MetaItemInner::Kind::MetaItem:
+	{
+	  auto *meta_item =
+	    static_cast<AST::MetaItem *> (current.get ());
+
+	  switch (meta_item->get_item_kind ())
+	  {
+	    case AST::MetaItem::ItemKind::NameValueStr:
+	      {
+		auto *nv =
+		  static_cast<AST::MetaNameValueStr *> (meta_item);
+
+		const std::string key = nv->get_name ().as_string ();
+
+		if (key != "since" && key != "note")
+		{
+		  rust_error_at (nv->get_locus (),
+		   "unknown meta item %qs",
+		   key.c_str ());
+		  rust_inform (nv->get_locus (),
+		 "expected one of %<'since'%>, %<'note'%>");
+		}
+	      }
+	      break;
+
+	    case AST::MetaItem::ItemKind::Path:
+	      {
+		// #[deprecated(a,a)]
+		auto *p =
+		  static_cast<AST::MetaItemPath *> (meta_item);
+
+		std::string ident = p->get_path ().as_string ();
+
+		rust_error_at (p->get_locus (),
+		 "unknown meta item %qs",
+		 ident.c_str ());
+		rust_inform (p->get_locus (),
+	       "expected one of %<'since'%>, %<'note'%>");
+	      }
+	      break;
+
+	    case AST::MetaItem::ItemKind::Word:
+	      {
+		// #[deprecated("a")]
+		auto *w =
+		  static_cast<AST::MetaWord *> (meta_item);
+
+		rust_error_at (w->get_locus (),
+		 "item in %<'deprecated'%> must be a key/value pair");
+	      }
+	      break;
+
+	    case AST::MetaItem::ItemKind::PathExpr:
+	      {
+		// #[deprecated(since=a)]
+		auto *px =
+		  static_cast<AST::MetaItemPathExpr *> (meta_item);
+
+		rust_error_at (px->get_locus (),
+		 "expected unsuffixed literal or identifier, found %qs",
+		 px->get_expr ().as_string ().c_str ());
+	      }
+	      break;
+
+	    case AST::MetaItem::ItemKind::Seq:
+	    case AST::MetaItem::ItemKind::ListPaths:
+	    case AST::MetaItem::ItemKind::ListNameValueStr:
+	    default:
+	      gcc_unreachable ();
+	      break;
+	  }
+	}
+	break;
+
+      case AST::MetaItemInner::Kind::LitExpr:
+      default:
+	gcc_unreachable ();
+	break;
+    }
+  }
+}
+
 static bool
 is_proc_macro_type (const AST::Attribute &attribute)
 {
@@ -370,6 +466,8 @@ AttributeChecker::check_attribute (const AST::Attribute &attribute)
   // and costly
   if (result.name == Attrs::DOC)
     check_doc_attribute (attribute);
+  else if (result.name == Attrs::DEPRECATED)
+    check_deprecated_attribute (attribute);
 }
 
 void