libctf: add ctf_type_kind_forwarded

This is just like ctf_type_kind, except that forwards get the
type of the thing being pointed to rather than CTF_K_FORWARD.

include/
	* ctf-api.h (ctf_type_kind_forwarded): New.
libctf/
	* ctf-types.c (ctf_type_kind_forwarded): New.

include/ChangeLog

@@ -1,3 +1,7 @@
+2020-07-22  Nick Alcock  <nick.alcock@oracle.com>
+
+	* ctf-api.h (ctf_type_kind_forwarded): New.
+
 2020-07-22  Nick Alcock  <nick.alcock@oracle.com>
 
 	* ctf-api.c (ctf_type_name_raw): New.

include/ctf-api.h

@@ -328,6 +328,7 @@ extern const char *ctf_type_name_raw (ctf_file_t *, ctf_id_t);
 extern ssize_t ctf_type_size (ctf_file_t *, ctf_id_t);
 extern ssize_t ctf_type_align (ctf_file_t *, ctf_id_t);
 extern int ctf_type_kind (ctf_file_t *, ctf_id_t);
+extern int ctf_type_kind_forwarded (ctf_file_t *, ctf_id_t);
 extern ctf_id_t ctf_type_reference (ctf_file_t *, ctf_id_t);
 extern ctf_id_t ctf_type_pointer (ctf_file_t *, ctf_id_t);
 extern int ctf_type_encoding (ctf_file_t *, ctf_id_t, ctf_encoding_t *);

libctf/ChangeLog

@@ -1,3 +1,7 @@
+2020-07-22  Nick Alcock  <nick.alcock@oracle.com>
+
+	* ctf-types.c (ctf_type_kind_forwarded): New.
+
 2020-07-22  Nick Alcock  <nick.alcock@oracle.com>
 
 	* ctf-types.c (ctf_type_name_raw): New.

libctf/ctf-types.c

@@ -677,6 +677,26 @@ ctf_type_kind (ctf_file_t *fp, ctf_id_t type)
   return kind;
 }
 
+/* Return the kind of this type, except, for forwards, return the kind of thing
+   this is a forward to.  */
+int
+ctf_type_kind_forwarded (ctf_file_t *fp, ctf_id_t type)
+{
+  int kind;
+  const ctf_type_t *tp;
+
+  if ((kind = ctf_type_kind (fp, type)) < 0)
+    return -1;			/* errno is set for us.  */
+
+  if (kind != CTF_K_FORWARD)
+    return kind;
+
+  if ((tp = ctf_lookup_by_id (&fp, type)) == NULL)
+    return -1;			/* errno is set for us.  */
+
+  return tp->ctt_type;
+}
+
 /* If the type is one that directly references another type (such as POINTER),
    then return the ID of the type to which it refers.  */
 

libctf/libctf.ver

@@ -63,6 +63,7 @@ LIBCTF_1.0 {
 	ctf_type_size;
 	ctf_type_align;
 	ctf_type_kind;
+	ctf_type_kind_forwarded;
 	ctf_type_reference;
 	ctf_type_pointer;
 	ctf_type_encoding;