From: Nick Alcock <nick.alcock@oracle.com>
Date: Thu, 24 Apr 2025 15:55:20 +0000 (+0100)
Subject: libctf: types: ctf_type_resolve_nonrepresentable
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4a4312b684ad779c5c14e0838adc868cc6b14847;p=thirdparty%2Fbinutils-gdb.git

libctf: types: ctf_type_resolve_nonrepresentable

This new internal function allows us to say "resolve a type to its base
type, but treat type 0 like BTF, returning 0 if it is found rather than
erroring with ECTF_NONREPRESENTABLE".  Used in the next commit.
---

diff --git a/libctf/ctf-impl.h b/libctf/ctf-impl.h
index 25617f50b04..c9d1c8cf8ba 100644
--- a/libctf/ctf-impl.h
+++ b/libctf/ctf-impl.h
@@ -811,6 +811,7 @@ extern char *ctf_str_append (char *, const char *);
 extern char *ctf_str_append_noerr (char *, const char *);
 
 extern ctf_id_t ctf_type_resolve_unsliced (ctf_dict_t *, ctf_id_t);
+extern ctf_id_t ctf_type_resolve_nonrepresentable (ctf_dict_t *, ctf_id_t, int allow_zero);
 extern int ctf_type_kind_unsliced (ctf_dict_t *, ctf_id_t);
 extern ssize_t ctf_type_align_natural (ctf_dict_t *fp, ctf_id_t prev_type,
 				       ctf_id_t type, ssize_t bit_offset);
diff --git a/libctf/ctf-types.c b/libctf/ctf-types.c
index 6a714ceb850..ddc9f8c98a5 100644
--- a/libctf/ctf-types.c
+++ b/libctf/ctf-types.c
@@ -677,31 +677,45 @@ ctf_variable_next (ctf_dict_t *fp, ctf_next_t **it, const char **name)
 
 ctf_id_t
 ctf_type_resolve (ctf_dict_t *fp, ctf_id_t type)
+{
+  return ctf_type_resolve_nonrepresentable (fp, type, 0);
+}
+
+/* As with ctf_type_resolve(), but optionally do not consider type 0
+   to be ECTF_NONREPRESENTABLE.  Internal only.  */
+ctf_id_t
+ctf_type_resolve_nonrepresentable (ctf_dict_t *fp, ctf_id_t type, int allow_zero)
 {
   ctf_id_t prev = type, otype = type;
   ctf_dict_t *ofp = fp;
-  const ctf_type_t *tp;
+  const ctf_type_t *tp, *suffix;
 
   if (type == 0)
-    return (ctf_set_typed_errno (ofp, ECTF_NONREPRESENTABLE));
+    {
+      if (allow_zero)
+	return 0;
+      else
+	return (ctf_set_typed_errno (ofp, ECTF_NONREPRESENTABLE));
+    }
 
-  while ((tp = ctf_lookup_by_id (&fp, type)) != NULL)
+  while ((tp = ctf_lookup_by_id (&fp, type, &suffix)) != NULL)
     {
-      switch (LCTF_INFO_KIND (fp, tp->ctt_info))
+      switch (LCTF_KIND (fp, tp))
 	{
 	case CTF_K_TYPEDEF:
 	case CTF_K_VOLATILE:
 	case CTF_K_CONST:
 	case CTF_K_RESTRICT:
-	  if (tp->ctt_type == type || tp->ctt_type == otype
-	      || tp->ctt_type == prev)
+	case CTF_K_VAR:
+	  if (suffix->ctt_type == type || suffix->ctt_type == otype
+	      || suffix->ctt_type == prev)
 	    {
 	      ctf_err_warn (ofp, 0, ECTF_CORRUPT, _("type %lx cycle detected"),
 			    otype);
 	      return (ctf_set_typed_errno (ofp, ECTF_CORRUPT));
 	    }
 	  prev = type;
-	  type = tp->ctt_type;
+	  type = suffix->ctt_type;
 	  break;
 	case CTF_K_UNKNOWN:
 	  return (ctf_set_typed_errno (ofp, ECTF_NONREPRESENTABLE));
@@ -709,7 +723,12 @@ ctf_type_resolve (ctf_dict_t *fp, ctf_id_t type)
 	  return type;
 	}
       if (type == 0)
-	return (ctf_set_typed_errno (ofp, ECTF_NONREPRESENTABLE));
+	{
+	  if (allow_zero)
+	    return 0;
+	  else
+	    return (ctf_set_typed_errno (ofp, ECTF_NONREPRESENTABLE));
+	}
     }
 
   return CTF_ERR;		/* errno is set for us.  */
@@ -728,7 +747,7 @@ ctf_type_resolve_unsliced (ctf_dict_t *fp, ctf_id_t type)
   if ((type = ctf_type_resolve (fp, type)) == CTF_ERR)
     return CTF_ERR;
 
-  if ((tp = ctf_lookup_by_id (&fp, type)) == NULL)
+  if ((tp = ctf_lookup_by_id (&fp, type, NULL)) == NULL)
     return CTF_ERR;		/* errno is set for us.  */
   resolved_type = type;
 
@@ -736,17 +755,17 @@ ctf_type_resolve_unsliced (ctf_dict_t *fp, ctf_id_t type)
     {
       type = resolved_type;
 
-      if ((LCTF_INFO_KIND (fp, tp->ctt_info)) == CTF_K_SLICE)
+      if ((LCTF_KIND (fp, tp)) == CTF_K_SLICE)
 	if ((type = ctf_type_reference (fp, type)) == CTF_ERR)
 	  return (ctf_set_typed_errno (ofp, ctf_errno (fp)));
 
       if ((resolved_type = ctf_type_resolve (fp, type)) == CTF_ERR)
 	return CTF_ERR;
 
-      if ((tp = ctf_lookup_by_id (&fp, resolved_type)) == NULL)
+      if ((tp = ctf_lookup_by_id (&fp, resolved_type, NULL)) == NULL)
 	return CTF_ERR;		/* errno is set for us.  */
     }
-  while (LCTF_INFO_KIND (fp, tp->ctt_info) == CTF_K_SLICE);
+  while (LCTF_KIND (fp, tp) == CTF_K_SLICE);
 
   return type;
 }