libctf: link: improve BTF child dict naming

BTF dicts don't have a cuname, which means that when the deduplicator runs
over them any child dicts that result from conflicted types found in those
CUs end up with no name either.  Detect such unnamed dicts and propagate
in the name the linker gave them at input time instead.  (There is always
*some* such name, even if it's something totally useless like "#1"; usually
it's much more useful.)

diff --git a/libctf/ctf-link.c b/libctf/ctf-link.c
index d7927a45dcaf6f45416e8afd1dc75aed9a2e8670..62a87d16111bd87163714adec83c09fec6677f7a 100644 (file)
--- a/libctf/ctf-link.c
+++ b/libctf/ctf-link.c
@@ -586,6 +586,15 @@ ctf_link_deduplicating_count_inputs (ctf_dict_t *fp, ctf_dynhash_t *cu_names,
          return -1;                            /* errno is set for us.  */
        }
 
+      /* If this is an unnamed, zero-archive dict, propagate the input name into the
+        dict itself, for the sake of deduplicator child dict naming.  */
+
+      if (one_input->clin_arc
+         && ctf_archive_count (one_input->clin_arc) == 1
+         && one_input->clin_arc->ctfi_dict != NULL &&
+         ctf_cuname (one_input->clin_arc->ctfi_dict) == NULL)
+       ctf_cuname_set (one_input->clin_arc->ctfi_dict, name);
+
       count += one_count;
       narcs++;
     }