[PATCH v2 1/5][STAGE1] c-family: add btf_type_tag and btf_decl_tag attributes

[David Faust]

Add two new c-family attributes, "btf_type_tag" and "btf_decl_tag"
along with a simple shared handler for them.

gcc/c-family/
        * c-attribs.cc (c_common_attribute_table): Add btf_decl_tag and
        btf_type_tag attributes.
        (handle_btf_tag_attribute): New handler for both new attributes.
---
 gcc/c-family/c-attribs.cc | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/gcc/c-family/c-attribs.cc b/gcc/c-family/c-attribs.cc
index f3181e7b57c..b51a8e755ae 100644
--- a/gcc/c-family/c-attribs.cc
+++ b/gcc/c-family/c-attribs.cc
@@ -189,6 +189,8 @@ static tree handle_fd_arg_attribute (tree *, tree, tree, 
int, bool *);
 static tree handle_flag_enum_attribute (tree *, tree, tree, int, bool *);
 static tree handle_null_terminated_string_arg_attribute (tree *, tree, tree, 
int, bool *);
 
+static tree handle_btf_tag_attribute (tree *, tree, tree, int, bool *);
+
 /* Helper to define attribute exclusions.  */
 #define ATTR_EXCL(name, function, type, variable)      \
   { name, function, type, variable }
@@ -640,7 +642,11 @@ const struct attribute_spec c_common_gnu_attributes[] =
   { "flag_enum",             0, 0, false, true, false, false,
                              handle_flag_enum_attribute, NULL },
   { "null_terminated_string_arg", 1, 1, false, true, true, false,
-                             handle_null_terminated_string_arg_attribute, NULL}
+                             handle_null_terminated_string_arg_attribute, 
NULL},
+  { "btf_type_tag",          1, 1, false, true, false, false,
+                             handle_btf_tag_attribute, NULL},
+  { "btf_decl_tag",          1, 1, true, false, false, false,
+                             handle_btf_tag_attribute, NULL}
 };
 
 const struct scoped_attribute_specs c_common_gnu_attribute_table =
@@ -5099,6 +5105,23 @@ handle_null_terminated_string_arg_attribute (tree *node, 
tree name, tree args,
   return NULL_TREE;
 }
 
+/* Handle the "btf_decl_tag" and "btf_type_tag" attributes.  */
+
+static tree
+handle_btf_tag_attribute (tree * ARG_UNUSED (node), tree name, tree args,
+                         int ARG_UNUSED (flags), bool *no_add_attrs)
+{
+  if (!args)
+    *no_add_attrs = true;
+  else if (TREE_CODE (TREE_VALUE (args)) != STRING_CST)
+    {
+      error ("%qE attribute requires a string", name);
+      *no_add_attrs = true;
+    }
+
+  return NULL_TREE;
+}
+
 /* Handle the "nonstring" variable attribute.  */
 
 static tree
-- 
2.45.2