libctf: remove static/dynamic name lookup distinction

libctf internally maintains a set of hash tables for type name lookups,
one for each valid C type namespace (struct, union, enum, and everything
else).

Or, rather, it maintains *two* sets of hash tables: one, a ctf_hash *,
is meant for lookups in ctf_(buf)open()ed dicts with fixed content; the
other, a ctf_dynhash *, is meant for lookups in ctf_create()d dicts.

This distinction was somewhat valuable in the far pre-binutils past when
two different hashtable implementations were used (one expanding, the
other fixed-size), but those days are long gone: the hash table
implementations are almost identical, both wrappers around the libiberty
hashtab. The ctf_dynhash has many more capabilities than the ctf_hash
(iteration, deletion, etc etc) and has no downsides other than starting
at a fixed, arbitrary small size.

That limitation is easy to lift (via a new ctf_dynhash_create_sized()),
following which we can throw away nearly all the ctf_hash
implementation, and all the code to choose between readable and writable
hashtabs; the few convenience functions that are still useful (for
insertion of name -> type mappings) can also be generalized a bit so
that the extra string verification they do is potentially available to
other string lookups as well.

(libctf still has two hashtable implementations, ctf_dynhash, above,
and ctf_dynset, which is a key-only hashtab that can avoid a great many
malloc()s, used for high-volume applications in the deduplicator.)

libctf/

	* ctf-create.c (ctf_create): Eliminate ctn_writable.
	(ctf_dtd_insert): Likewise.
	(ctf_dtd_delete): Likewise.
	(ctf_rollback): Likewise.
	(ctf_name_table): Eliminate ctf_names_t.
	* ctf-hash.c (ctf_dynhash_create): Comment update.
        Reimplement in terms of...
	(ctf_dynhash_create_sized): ... this new function.
	(ctf_hash_create): Remove.
	(ctf_hash_size): Remove.
	(ctf_hash_define_type): Remove.
	(ctf_hash_destroy): Remove.
	(ctf_hash_lookup_type): Rename to...
	(ctf_dynhash_lookup_type): ... this.
	(ctf_hash_insert_type): Rename to...
	(ctf_dynhash_insert_type): ... this, moving validation to...
	* ctf-string.c (ctf_strptr_validate): ... this new function.
	* ctf-impl.h (struct ctf_names): Extirpate.
	(struct ctf_lookup.ctl_hash): Now a ctf_dynhash_t.
	(struct ctf_dict): All ctf_names_t fields are now ctf_dynhash_t.
	(ctf_name_table): Now returns a ctf_dynhash_t.
	(ctf_lookup_by_rawhash): Remove.
	(ctf_hash_create): Likewise.
	(ctf_hash_insert_type): Likewise.
	(ctf_hash_define_type): Likewise.
	(ctf_hash_lookup_type): Likewise.
	(ctf_hash_size): Likewise.
	(ctf_hash_destroy): Likewise.
	(ctf_dynhash_create_sized): New.
	(ctf_dynhash_insert_type): New.
	(ctf_dynhash_lookup_type): New.
	(ctf_strptr_validate): New.
	* ctf-lookup.c (ctf_lookup_by_name_internal): Adapt.
	* ctf-open.c (init_types): Adapt.
	(ctf_set_ctl_hashes): Adapt.
	(ctf_dict_close): Adapt.
	* ctf-serialize.c (ctf_serialize): Adapt.
	* ctf-types.c (ctf_lookup_by_rawhash): Remove.

libctf/ctf-create.c

@@ -154,10 +154,10 @@ ctf_create (int *errp)
   if ((fp = ctf_bufopen_internal (&cts, NULL, NULL, NULL, 1, errp)) == NULL)
     goto err_dv;
 
-  fp->ctf_structs.ctn_writable = structs;
-  fp->ctf_unions.ctn_writable = unions;
-  fp->ctf_enums.ctn_writable = enums;
-  fp->ctf_names.ctn_writable = names;
+  fp->ctf_structs = structs;
+  fp->ctf_unions = unions;
+  fp->ctf_enums = enums;
+  fp->ctf_names = names;
   fp->ctf_objthash = objthash;
   fp->ctf_funchash = funchash;
   fp->ctf_dthash = dthash;
@@ -203,19 +203,19 @@ ctf_update (ctf_dict_t *fp)
   return 0;
 }
 
-ctf_names_t *
+ctf_dynhash_t *
 ctf_name_table (ctf_dict_t *fp, int kind)
 {
   switch (kind)
     {
     case CTF_K_STRUCT:
-      return &fp->ctf_structs;
+      return fp->ctf_structs;
     case CTF_K_UNION:
-      return &fp->ctf_unions;
+      return fp->ctf_unions;
     case CTF_K_ENUM:
-      return &fp->ctf_enums;
+      return fp->ctf_enums;
     default:
-      return &fp->ctf_names;
+      return fp->ctf_names;
     }
 }
 
@@ -230,7 +230,7 @@ ctf_dtd_insert (ctf_dict_t *fp, ctf_dtdef_t *dtd, int flag, int kind)
   if (flag == CTF_ADD_ROOT && dtd->dtd_data.ctt_name
       && (name = ctf_strraw (fp, dtd->dtd_data.ctt_name)) != NULL)
     {
-      if (ctf_dynhash_insert (ctf_name_table (fp, kind)->ctn_writable,
+      if (ctf_dynhash_insert (ctf_name_table (fp, kind),
 			      (char *) name, (void *) (uintptr_t)
 			      dtd->dtd_type) < 0)
 	{
@@ -287,8 +287,7 @@ ctf_dtd_delete (ctf_dict_t *fp, ctf_dtdef_t *dtd)
       && (name = ctf_strraw (fp, dtd->dtd_data.ctt_name)) != NULL
       && LCTF_INFO_ISROOT (fp, dtd->dtd_data.ctt_info))
     {
-      ctf_dynhash_remove (ctf_name_table (fp, name_kind)->ctn_writable,
-			  name);
+      ctf_dynhash_remove (ctf_name_table (fp, name_kind), name);
       ctf_str_remove_ref (fp, name, &dtd->dtd_data.ctt_name);
     }
 
@@ -410,8 +409,7 @@ ctf_rollback (ctf_dict_t *fp, ctf_snapshot_id_t id)
 	  && (name = ctf_strraw (fp, dtd->dtd_data.ctt_name)) != NULL
 	  && LCTF_INFO_ISROOT (fp, dtd->dtd_data.ctt_info))
 	{
-	  ctf_dynhash_remove (ctf_name_table (fp, kind)->ctn_writable,
-			      name);
+	  ctf_dynhash_remove (ctf_name_table (fp, kind), name);
 	  ctf_str_remove_ref (fp, name, &dtd->dtd_data.ctt_name);
 	}