[COMMITTED V2 3/7] ctfc: add function to lookup CTF ID of a TREE type

[David Faust <david.faust@oracle.com>]

Add a new function, ctf_lookup_tree_type, to return the CTF type ID
associated with a type via its is TREE node. The function is exposed via
a prototype in ctfc.h.

gcc/ChangeLog:

	* ctfc.c (ctf_lookup_tree_type): New function.
	* ctfc.h: Likewise.
---
 gcc/ctfc.c | 16 ++++++++++++++++
 gcc/ctfc.h |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/gcc/ctfc.c b/gcc/ctfc.c
index db6ba030301..73c118e3d49 100644
--- a/gcc/ctfc.c
+++ b/gcc/ctfc.c
@@ -791,6 +791,22 @@ ctf_add_sou (ctf_container_ref ctfc, uint32_t flag, const char * name,
   return type;
 }
 
+/* Given a TREE_TYPE node, return the CTF type ID for that type.  */
+
+ctf_id_t
+ctf_lookup_tree_type (ctf_container_ref ctfc, const tree type)
+{
+  dw_die_ref die = lookup_type_die (type);
+  if (die == NULL)
+    return CTF_NULL_TYPEID;
+
+  ctf_dtdef_ref dtd = ctf_dtd_lookup (ctfc, die);
+  if (dtd == NULL)
+    return CTF_NULL_TYPEID;
+
+  return dtd->dtd_type;
+}
+
 /* Check if CTF for TYPE has already been generated.  Mainstay for
    de-duplication.  If CTF type already exists, returns TRUE and updates
    the TYPE_ID for the caller.  */
diff --git a/gcc/ctfc.h b/gcc/ctfc.h
index 825570d807e..14180c1e5de 100644
--- a/gcc/ctfc.h
+++ b/gcc/ctfc.h
@@ -430,6 +430,8 @@ extern int ctf_add_function_arg (ctf_container_ref, dw_die_ref,
 extern int ctf_add_variable (ctf_container_ref, const char *, ctf_id_t,
 			     dw_die_ref, unsigned int);
 
+extern ctf_id_t ctf_lookup_tree_type (ctf_container_ref, const tree);
+
 /* CTF section does not emit location information; at this time, location
    information is needed for BTF CO-RE use-cases.  */
 
-- 
2.33.0