libctf: rip out dead code handling typedefs with no name

There is special code in libctf to handle typedefs with no name, which
the code calls "anonymous typedef nodes".

These monsters are obviously not something C programs can include: the
whole point of a ttypedef is to introduce a new name.  Looking back at
the history of DWARF in GCC, the only thing (outside C++ anonymous
namespaces) which can generate a DW_TAG_typedef without a DW_AT_name is
obsolete code to handle the long-removed -feliminate-dwarf2-dups option.
Looking at OpenSolaris, typedef nodes with no name couldn't be generated
by the DWARF->CTF converter at all (and its deduplicator barfed on
them): the only reason for the existence of this code is a special case
working around a peculiarity of stabs whereby types could sometimes be
referenced before they were introduced.

We don't need to carry code in libctf to handle special cases in an
obsolete OpenSolaris converter (that yields a format that isn't readable
by libctf anyway).  So drop it.

libctf/ChangeLog
2021-01-27  Nick Alcock  <nick.alcock@oracle.com>

	* ctf-open.c (init_types): Rip out code to check anonymous typedef
	nodes.
	* ctf-create.c (ctf_add_reftype): Likewise.
	* ctf-lookup.c (refresh_pptrtab): Likewise.

1 files changed, 6 insertions, 17 deletions

diff --git a/libctf/ctf-create.c b/libctf/ctf-create.c
index c5f79d1..cf47384 100644
--- a/libctf/ctf-create.c
+++ b/libctf/ctf-create.c
@@ -1629,29 +1629,18 @@ ctf_add_reftype (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref, uint32_t kind)
   if (kind != CTF_K_POINTER)
     return type;
 
-  /* If we are adding a pointer, update the ptrtab, both the directly pointed-to
-     type and (if an anonymous typedef node is being pointed at) the type that
-     points at too.  Note that ctf_typemax is at this point one higher than we
-     want to check against, because it's just been incremented for the addition
-     of this type.  The pptrtab is lazily-updated as needed, so is not touched
-     here.  */
+  /* If we are adding a pointer, update the ptrtab, pointing at this type from
+     the type it points to.  Note that ctf_typemax is at this point one higher
+     than we want to check against, because it's just been incremented for the
+     addition of this type.  The pptrtab is lazily-updated as needed, so is not
+     touched here.  */
 
   uint32_t type_idx = LCTF_TYPE_TO_INDEX (fp, type);
   uint32_t ref_idx = LCTF_TYPE_TO_INDEX (fp, ref);
 
   if (LCTF_TYPE_ISCHILD (fp, ref) == child
       && ref_idx < fp->ctf_typemax)
-    {
-      fp->ctf_ptrtab[ref_idx] = type_idx;
-
-      ctf_id_t refref_idx = LCTF_TYPE_TO_INDEX (fp, dtd->dtd_data.ctt_type);
-
-      if (tmp == fp
-	  && (LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info) == CTF_K_TYPEDEF)
-	  && strcmp (ctf_strptr (fp, dtd->dtd_data.ctt_name), "") == 0
-	  && refref_idx < fp->ctf_typemax)
-	fp->ctf_ptrtab[refref_idx] = type_idx;
-    }
+    fp->ctf_ptrtab[ref_idx] = type_idx;
 
   return type;
 }