[17/59] libctf: add ctf_member_count

Message ID 20200630233146.338613-18-nick.alcock@oracle.com
State New
Headers show
Series
  • Deduplicating CTF linker
Related show

Commit Message

H.J. Lu via Binutils June 30, 2020, 11:31 p.m.
This returns the number of members in a struct or union, or the number
of enumerations in an enum.  (This was only available before now by
iterating across every member, but it can be returned much faster than
that.)

include/
	* ctf-api.h (ctf_member_count): New.

libctf/
	* ctf-types.c (ctf_member_count): New.
	* libctf.ver: New public function.
---
 include/ctf-api.h  |  1 +
 libctf/ctf-types.c | 24 ++++++++++++++++++++++++
 libctf/libctf.ver  |  1 +
 3 files changed, 26 insertions(+)

-- 
2.27.0.247.g3dff7de930

Patch

diff --git a/include/ctf-api.h b/include/ctf-api.h
index 87446a5f7d1..7cdf4a56235 100644
--- a/include/ctf-api.h
+++ b/include/ctf-api.h
@@ -349,6 +349,7 @@  extern const char *ctf_label_get (ctf_file_t *);
 extern const char *ctf_label_topmost (ctf_file_t *);
 extern int ctf_label_info (ctf_file_t *, const char *, ctf_lblinfo_t *);
 
+extern int ctf_member_count (ctf_file_t *, ctf_id_t);
 extern int ctf_member_iter (ctf_file_t *, ctf_id_t, ctf_member_f *, void *);
 extern int ctf_enum_iter (ctf_file_t *, ctf_id_t, ctf_enum_f *, void *);
 extern int ctf_type_iter (ctf_file_t *, ctf_type_f *, void *);
diff --git a/libctf/ctf-types.c b/libctf/ctf-types.c
index d8f848cf893..93967c6aa8d 100644
--- a/libctf/ctf-types.c
+++ b/libctf/ctf-types.c
@@ -963,6 +963,30 @@  ctf_type_compat (ctf_file_t *lfp, ctf_id_t ltype,
     }
 }
 
+/* Return the number of members in a STRUCT or UNION, or the number of
+   enumerators in an ENUM.  */
+
+int
+ctf_member_count (ctf_file_t *fp, ctf_id_t type)
+{
+  ctf_file_t *ofp = fp;
+  const ctf_type_t *tp;
+  uint32_t kind;
+
+  if ((type = ctf_type_resolve (fp, type)) == CTF_ERR)
+    return -1;			/* errno is set for us.  */
+
+  if ((tp = ctf_lookup_by_id (&fp, type)) == NULL)
+    return -1;			/* errno is set for us.  */
+
+  kind = LCTF_INFO_KIND (fp, tp->ctt_info);
+
+  if (kind != CTF_K_STRUCT && kind != CTF_K_UNION && kind != CTF_K_ENUM)
+    return (ctf_set_errno (ofp, ECTF_NOTSUE));
+
+  return LCTF_INFO_VLEN (fp, tp->ctt_info);
+}
+
 /* Return the type and offset for a given member of a STRUCT or UNION.  */
 
 int
diff --git a/libctf/libctf.ver b/libctf/libctf.ver
index b8c5133d3f9..77b380ca991 100644
--- a/libctf/libctf.ver
+++ b/libctf/libctf.ver
@@ -73,6 +73,7 @@  LIBCTF_1.0 {
 
 	ctf_member_info;
 	ctf_array_info;
+	ctf_member_count;
 
 	ctf_enum_name;
 	ctf_enum_value;