libctf: symbol type linking support

[deliverable/binutils-gdb.git] / libctf / ctf-create.c

/* CTF file creation.
   Copyright (C) 2019-2020 Free Software Foundation, Inc.

   This file is part of libctf.

   libctf is free software; you can redistribute it and/or modify it under
   the terms of the GNU General Public License as published by the Free
   Software Foundation; either version 3, or (at your option) any later
   version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING.  If not see
   <http://www.gnu.org/licenses/>.  */

#include <ctf-impl.h>
#include <sys/param.h>
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <zlib.h>

#include <elf.h>
#include "elf-bfd.h"

#ifndef EOVERFLOW
#define EOVERFLOW ERANGE
#endif

#ifndef roundup
#define roundup(x, y)  ((((x) + ((y) - 1)) / (y)) * (y))
#endif

/* Make sure the ptrtab has enough space for at least one more type.

   We start with 4KiB of ptrtab, enough for a thousand types, then grow it 25%
   at a time.  */

static int
ctf_grow_ptrtab (ctf_dict_t *fp)
{
  size_t new_ptrtab_len = fp->ctf_ptrtab_len;

  /* We allocate one more ptrtab entry than we need, for the initial zero,
     plus one because the caller will probably allocate a new type.  */

  if (fp->ctf_ptrtab == NULL)
    new_ptrtab_len = 1024;
  else if ((fp->ctf_typemax + 2) > fp->ctf_ptrtab_len)
    new_ptrtab_len = fp->ctf_ptrtab_len * 1.25;

  if (new_ptrtab_len != fp->ctf_ptrtab_len)
    {
      uint32_t *new_ptrtab;

      if ((new_ptrtab = realloc (fp->ctf_ptrtab,
                                 new_ptrtab_len * sizeof (uint32_t))) == NULL)
        return (ctf_set_errno (fp, ENOMEM));

      fp->ctf_ptrtab = new_ptrtab;
      memset (fp->ctf_ptrtab + fp->ctf_ptrtab_len, 0,
              (new_ptrtab_len - fp->ctf_ptrtab_len) * sizeof (uint32_t));
      fp->ctf_ptrtab_len = new_ptrtab_len;
    }
  return 0;
}

/* To create an empty CTF dict, we just declare a zeroed header and call
   ctf_bufopen() on it.  If ctf_bufopen succeeds, we mark the new dict r/w and
   initialize the dynamic members.  We start assigning type IDs at 1 because
   type ID 0 is used as a sentinel and a not-found indicator.  */

ctf_dict_t *
ctf_create (int *errp)
{
  static const ctf_header_t hdr = { .cth_preamble = { CTF_MAGIC, CTF_VERSION, 0 } };

  ctf_dynhash_t *dthash;
  ctf_dynhash_t *dvhash;
  ctf_dynhash_t *structs = NULL, *unions = NULL, *enums = NULL, *names = NULL;
  ctf_dynhash_t *objthash = NULL, *funchash = NULL;
  ctf_sect_t cts;
  ctf_dict_t *fp;

  libctf_init_debug();
  dthash = ctf_dynhash_create (ctf_hash_integer, ctf_hash_eq_integer,
                               NULL, NULL);
  if (dthash == NULL)
    {
      ctf_set_open_errno (errp, EAGAIN);
      goto err;
    }

  dvhash = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                               NULL, NULL);
  if (dvhash == NULL)
    {
      ctf_set_open_errno (errp, EAGAIN);
      goto err_dt;
    }

  structs = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                                NULL, NULL);
  unions = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                               NULL, NULL);
  enums = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                              NULL, NULL);
  names = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                              NULL, NULL);
  objthash = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                                 free, NULL);
  funchash = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                                 free, NULL);
  if (!structs || !unions || !enums || !names)
    {
      ctf_set_open_errno (errp, EAGAIN);
      goto err_dv;
    }

  cts.cts_name = _CTF_SECTION;
  cts.cts_data = &hdr;
  cts.cts_size = sizeof (hdr);
  cts.cts_entsize = 1;

  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_objthash = objthash;
  fp->ctf_funchash = funchash;
  fp->ctf_dthash = dthash;
  fp->ctf_dvhash = dvhash;
  fp->ctf_dtoldid = 0;
  fp->ctf_snapshots = 1;
  fp->ctf_snapshot_lu = 0;
  fp->ctf_flags |= LCTF_DIRTY;

  ctf_set_ctl_hashes (fp);
  ctf_setmodel (fp, CTF_MODEL_NATIVE);
  if (ctf_grow_ptrtab (fp) < 0)
    {
      ctf_set_open_errno (errp, ctf_errno (fp));
      ctf_dict_close (fp);
      return NULL;
    }

  return fp;

 err_dv:
  ctf_dynhash_destroy (structs);
  ctf_dynhash_destroy (unions);
  ctf_dynhash_destroy (enums);
  ctf_dynhash_destroy (names);
  ctf_dynhash_destroy (objthash);
  ctf_dynhash_destroy (funchash);
  ctf_dynhash_destroy (dvhash);
 err_dt:
  ctf_dynhash_destroy (dthash);
 err:
  return NULL;
}

/* Delete data symbols that have been assigned names from the variable section.
   Must be called from within ctf_serialize, because that is the only place
   you can safely delete variables without messing up ctf_rollback.  */

static int
symtypetab_delete_nonstatic_vars (ctf_dict_t *fp)
{
  ctf_dvdef_t *dvd, *nvd;
  ctf_id_t type;

  for (dvd = ctf_list_next (&fp->ctf_dvdefs); dvd != NULL; dvd = nvd)
    {
      nvd = ctf_list_next (dvd);

      if (((type = (ctf_id_t) (uintptr_t)
            ctf_dynhash_lookup (fp->ctf_objthash, dvd->dvd_name)) > 0)
          && type == dvd->dvd_type)
        ctf_dvd_delete (fp, dvd);
    }

  return 0;
}

/* Determine if a symbol is "skippable" and should never appear in the
   symtypetab sections.  */

int
ctf_symtab_skippable (ctf_link_sym_t *sym)
{
  /* Never skip symbols whose name is not yet known.  */
  if (sym->st_nameidx_set)
    return 0;

  return (sym->st_name == NULL || sym->st_name[0] == 0
          || sym->st_shndx == SHN_UNDEF
          || strcmp (sym->st_name, "_START_") == 0
          || strcmp (sym->st_name, "_END_") == 0
          || (sym->st_type == STT_OBJECT && sym->st_shndx == SHN_EXTABS
              && sym->st_value == 0));
}

/* Symtypetab emission flags.  */

#define CTF_SYMTYPETAB_EMIT_FUNCTION 0x1
#define CTF_SYMTYPETAB_EMIT_PAD 0x2
#define CTF_SYMTYPETAB_FORCE_INDEXED 0x4

/* Get the number of symbols in a symbol hash, the count of symbols, the maximum
   seen, the eventual size, without any padding elements, of the func/data and
   (if generated) index sections, and the size of accumulated padding elements.
   The linker-reported set of symbols is found in SYMFP.

   Also figure out if any symbols need to be moved to the variable section, and
   add them (if not already present).  */

_libctf_nonnull_
static int
symtypetab_density (ctf_dict_t *fp, ctf_dict_t *symfp, ctf_dynhash_t *symhash,
                    size_t *count, size_t *max, size_t *unpadsize,
                    size_t *padsize, size_t *idxsize, int flags)
{
  ctf_next_t *i = NULL;
  const void *name;
  const void *ctf_sym;
  ctf_dynhash_t *linker_known = NULL;
  int err;
  int beyond_max = 0;

  *count = 0;
  *max = 0;
  *unpadsize = 0;
  *idxsize = 0;
  *padsize = 0;

  if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
    {
      /* Make a dynhash citing only symbols reported by the linker of the
         appropriate type, then traverse all potential-symbols we know the types
         of, removing them from linker_known as we go.  Once this is done, the
         only symbols remaining in linker_known are symbols we don't know the
         types of: we must emit pads for those symbols that are below the
         maximum symbol we will emit (any beyond that are simply skipped).  */

      if ((linker_known = ctf_dynhash_create (ctf_hash_string, ctf_hash_eq_string,
                                              NULL, NULL)) == NULL)
        return (ctf_set_errno (fp, ENOMEM));

      while ((err = ctf_dynhash_cnext (symfp->ctf_dynsyms, &i,
                                       &name, &ctf_sym)) == 0)
        {
          ctf_link_sym_t *sym = (ctf_link_sym_t *) ctf_sym;

          if (((flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
               && sym->st_type != STT_FUNC)
              || (!(flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
                  && sym->st_type != STT_OBJECT))
            continue;

          if (ctf_symtab_skippable (sym))
            continue;

          /* This should only be true briefly before all the names are
             finalized, long before we get this far.  */
          if (!ctf_assert (fp, !sym->st_nameidx_set))
            return -1;                          /* errno is set for us.  */

          if (ctf_dynhash_cinsert (linker_known, name, ctf_sym) < 0)
            {
              ctf_dynhash_destroy (linker_known);
              return (ctf_set_errno (fp, ENOMEM));
            }
        }
      if (err != ECTF_NEXT_END)
        {
          ctf_err_warn (fp, 0, err, _("iterating over linker-known symbols during "
                                  "serialization"));
          ctf_dynhash_destroy (linker_known);
          return (ctf_set_errno (fp, err));
        }
    }

  while ((err = ctf_dynhash_cnext (symhash, &i, &name, NULL)) == 0)
    {
      ctf_link_sym_t *sym;

      if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
        {
          /* Linker did not report symbol in symtab.  Remove it from the
             set of known data symbols and continue.  */
          if ((sym = ctf_dynhash_lookup (symfp->ctf_dynsyms, name)) == NULL)
            {
              ctf_dynhash_remove (symhash, name);
              continue;
            }

          /* We don't remove skippable symbols from the symhash because we don't
             want them to be migrated into variables.  */
          if (ctf_symtab_skippable (sym))
            continue;

          if ((flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
              && sym->st_type != STT_FUNC)
            {
              ctf_err_warn (fp, 1, 0, _("Symbol %x added to CTF as a function "
                                        "but is of type %x\n"),
                            sym->st_symidx, sym->st_type);
              ctf_dynhash_remove (symhash, name);
              continue;
            }
          else if (!(flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
                   && sym->st_type != STT_OBJECT)
            {
              ctf_err_warn (fp, 1, 0, _("Symbol %x added to CTF as a data "
                                        "object but is of type %x\n"),
                            sym->st_symidx, sym->st_type);
              ctf_dynhash_remove (symhash, name);
              continue;
            }

          ctf_dynhash_remove (linker_known, name);
        }
      *unpadsize += sizeof (uint32_t);
      (*count)++;

      if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
        {
          if (*max < sym->st_symidx)
            *max = sym->st_symidx;
        }
      else
        (*max)++;
    }
  if (err != ECTF_NEXT_END)
    {
      ctf_err_warn (fp, 0, err, _("iterating over CTF symtypetab during "
                                  "serialization"));
      ctf_dynhash_destroy (linker_known);
      return (ctf_set_errno (fp, err));
    }

  if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
    {
      while ((err = ctf_dynhash_cnext (linker_known, &i, NULL, &ctf_sym)) == 0)
        {
          ctf_link_sym_t *sym = (ctf_link_sym_t *) ctf_sym;

          if (sym->st_symidx > *max)
            beyond_max++;
        }
      if (err != ECTF_NEXT_END)
        {
          ctf_err_warn (fp, 0, err, _("iterating over linker-known symbols "
                                      "during CTF serialization"));
          ctf_dynhash_destroy (linker_known);
          return (ctf_set_errno (fp, err));
        }
    }

  *idxsize = *count * sizeof (uint32_t);
  if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
    *padsize = (ctf_dynhash_elements (linker_known) - beyond_max) * sizeof (uint32_t);

  ctf_dynhash_destroy (linker_known);
  return 0;
}

/* Emit an objt or func symtypetab into DP in a particular order defined by an
   array of ctf_link_sym_t or symbol names passed in.  The index has NIDX
   elements in it: unindexed output would terminate at symbol OUTMAX and is in
   any case no larger than SIZE bytes.  Some index elements are expected to be
   skipped: see symtypetab_density.  The linker-reported set of symbols (if any)
   is found in SYMFP. */
static int
emit_symtypetab (ctf_dict_t *fp, ctf_dict_t *symfp, uint32_t *dp,
                 ctf_link_sym_t **idx, const char **nameidx, uint32_t nidx,
                 uint32_t outmax, int size, int flags)
{
  uint32_t i;
  uint32_t *dpp = dp;
  ctf_dynhash_t *symhash;

  ctf_dprintf ("Emitting table of size %i, outmax %u, %u symtypetab entries, "
               "flags %i\n", size, outmax, nidx, flags);

  /* Empty table? Nothing to do.  */
  if (size == 0)
    return 0;

  if (flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
    symhash = fp->ctf_funchash;
  else
    symhash = fp->ctf_objthash;

  for (i = 0; i < nidx; i++)
    {
      const char *sym_name;
      void *type;

      /* If we have a linker-reported set of symbols, we may be given that set
         to work from, or a set of symbol names.  In both cases we want to look
         at the corresponding linker-reported symbol (if any).  */
      if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
        {
          ctf_link_sym_t *this_link_sym;

          if (idx)
            this_link_sym = idx[i];
          else
            this_link_sym = ctf_dynhash_lookup (symfp->ctf_dynsyms, nameidx[i]);

          /* Unreported symbol number.  No pad, no nothing.  */
          if (!this_link_sym)
            continue;

          /* Symbol of the wrong type, or skippable?  This symbol is not in this
             table.  */
          if (((flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
               && this_link_sym->st_type != STT_FUNC)
              || (!(flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
                  && this_link_sym->st_type != STT_OBJECT))
            continue;

          if (ctf_symtab_skippable (this_link_sym))
            continue;

          sym_name = this_link_sym->st_name;

          /* Linker reports symbol of a different type to the symbol we actually
             added?  Skip the symbol.  No pad, since the symbol doesn't actually
             belong in this table at all.  (Warned about in
             symtypetab_density.)  */
          if ((this_link_sym->st_type == STT_FUNC)
              && (ctf_dynhash_lookup (fp->ctf_objthash, sym_name)))
            continue;

          if ((this_link_sym->st_type == STT_OBJECT)
              && (ctf_dynhash_lookup (fp->ctf_funchash, sym_name)))
            continue;
        }
      else
        sym_name = nameidx[i];

      /* Symbol in index but no type set? Silently skip and (optionally)
         pad.  (In force-indexed mode, this is also where we track symbols of
         the wrong type for this round of insertion.)  */
      if ((type = ctf_dynhash_lookup (symhash, sym_name)) == NULL)
        {
          if (flags & CTF_SYMTYPETAB_EMIT_PAD)
            *dpp++ = 0;
          continue;
        }

      if (!ctf_assert (fp, (((char *) dpp) - (char *) dp) < size))
        return -1;                              /* errno is set for us.  */

      *dpp++ = (ctf_id_t) (uintptr_t) type;

      /* When emitting unindexed output, all later symbols are pads: stop
         early.  */
      if ((flags & CTF_SYMTYPETAB_EMIT_PAD) && idx[i]->st_symidx == outmax)
        break;
    }

  return 0;
}

/* Emit an objt or func symtypetab index into DP in a paticular order defined by
   an array of symbol names passed in.  Stop at NIDX.  The linker-reported set
   of symbols (if any) is found in SYMFP. */
static int
emit_symtypetab_index (ctf_dict_t *fp, ctf_dict_t *symfp, uint32_t *dp,
                       const char **idx, uint32_t nidx, int size, int flags)
{
  uint32_t i;
  uint32_t *dpp = dp;
  ctf_dynhash_t *symhash;

  ctf_dprintf ("Emitting index of size %i, %u entries reported by linker, "
               "flags %i\n", size, nidx, flags);

  /* Empty table? Nothing to do.  */
  if (size == 0)
    return 0;

  if (flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
    symhash = fp->ctf_funchash;
  else
    symhash = fp->ctf_objthash;

  /* Indexes should always be unpadded.  */
  if (!ctf_assert (fp, !(flags & CTF_SYMTYPETAB_EMIT_PAD)))
    return -1;                                  /* errno is set for us.  */

  for (i = 0; i < nidx; i++)
    {
      const char *sym_name;
      void *type;

      if (!(flags & CTF_SYMTYPETAB_FORCE_INDEXED))
        {
          ctf_link_sym_t *this_link_sym;

          this_link_sym = ctf_dynhash_lookup (symfp->ctf_dynsyms, idx[i]);

          /* This is an index: unreported symbols should never appear in it.  */
          if (!ctf_assert (fp, this_link_sym != NULL))
            return -1;                          /* errno is set for us.  */

          /* Symbol of the wrong type, or skippable?  This symbol is not in this
             table.  */
          if (((flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
               && this_link_sym->st_type != STT_FUNC)
              || (!(flags & CTF_SYMTYPETAB_EMIT_FUNCTION)
                  && this_link_sym->st_type != STT_OBJECT))
            continue;

          if (ctf_symtab_skippable (this_link_sym))
            continue;

          sym_name = this_link_sym->st_name;

          /* Linker reports symbol of a different type to the symbol we actually
             added?  Skip the symbol.  */
          if ((this_link_sym->st_type == STT_FUNC)
              && (ctf_dynhash_lookup (fp->ctf_objthash, sym_name)))
            continue;

          if ((this_link_sym->st_type == STT_OBJECT)
              && (ctf_dynhash_lookup (fp->ctf_funchash, sym_name)))
            continue;
        }
      else
        sym_name = idx[i];

      /* Symbol in index and reported by linker, but no type set? Silently skip
         and (optionally) pad.  (In force-indexed mode, this is also where we
         track symbols of the wrong type for this round of insertion.)  */
      if ((type = ctf_dynhash_lookup (symhash, sym_name)) == NULL)
        continue;

      ctf_str_add_ref (fp, sym_name, dpp++);

      if (!ctf_assert (fp, (((char *) dpp) - (char *) dp) <= size))
        return -1;                              /* errno is set for us.  */
    }

  return 0;
}

static unsigned char *
ctf_copy_smembers (ctf_dict_t *fp, ctf_dtdef_t *dtd, unsigned char *t)
{
  ctf_dmdef_t *dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
  ctf_member_t ctm;

  for (; dmd != NULL; dmd = ctf_list_next (dmd))
    {
      ctf_member_t *copied;

      ctm.ctm_name = 0;
      ctm.ctm_type = (uint32_t) dmd->dmd_type;
      ctm.ctm_offset = (uint32_t) dmd->dmd_offset;

      memcpy (t, &ctm, sizeof (ctm));
      copied = (ctf_member_t *) t;
      if (dmd->dmd_name)
        ctf_str_add_ref (fp, dmd->dmd_name, &copied->ctm_name);

      t += sizeof (ctm);
    }

  return t;
}

static unsigned char *
ctf_copy_lmembers (ctf_dict_t *fp, ctf_dtdef_t *dtd, unsigned char *t)
{
  ctf_dmdef_t *dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
  ctf_lmember_t ctlm;

  for (; dmd != NULL; dmd = ctf_list_next (dmd))
    {
      ctf_lmember_t *copied;

      ctlm.ctlm_name = 0;
      ctlm.ctlm_type = (uint32_t) dmd->dmd_type;
      ctlm.ctlm_offsethi = CTF_OFFSET_TO_LMEMHI (dmd->dmd_offset);
      ctlm.ctlm_offsetlo = CTF_OFFSET_TO_LMEMLO (dmd->dmd_offset);

      memcpy (t, &ctlm, sizeof (ctlm));
      copied = (ctf_lmember_t *) t;
      if (dmd->dmd_name)
        ctf_str_add_ref (fp, dmd->dmd_name, &copied->ctlm_name);

      t += sizeof (ctlm);
    }

  return t;
}

static unsigned char *
ctf_copy_emembers (ctf_dict_t *fp, ctf_dtdef_t *dtd, unsigned char *t)
{
  ctf_dmdef_t *dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
  ctf_enum_t cte;

  for (; dmd != NULL; dmd = ctf_list_next (dmd))
    {
      ctf_enum_t *copied;

      cte.cte_value = dmd->dmd_value;
      memcpy (t, &cte, sizeof (cte));
      copied = (ctf_enum_t *) t;
      ctf_str_add_ref (fp, dmd->dmd_name, &copied->cte_name);
      t += sizeof (cte);
    }

  return t;
}

/* Sort a newly-constructed static variable array.  */

typedef struct ctf_sort_var_arg_cb
{
  ctf_dict_t *fp;
  ctf_strs_t *strtab;
} ctf_sort_var_arg_cb_t;

static int
ctf_sort_var (const void *one_, const void *two_, void *arg_)
{
  const ctf_varent_t *one = one_;
  const ctf_varent_t *two = two_;
  ctf_sort_var_arg_cb_t *arg = arg_;

  return (strcmp (ctf_strraw_explicit (arg->fp, one->ctv_name, arg->strtab),
                  ctf_strraw_explicit (arg->fp, two->ctv_name, arg->strtab)));
}

/* Compatibility: just update the threshold for ctf_discard.  */
int
ctf_update (ctf_dict_t *fp)
{
  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  fp->ctf_dtoldid = fp->ctf_typemax;
  return 0;
}

/* If the specified CTF dict is writable and has been modified, reload this dict
   with the updated type definitions, ready for serialization.  In order to make
   this code and the rest of libctf as simple as possible, we perform updates by
   taking the dynamic type definitions and creating an in-memory CTF dict
   containing the definitions, and then call ctf_simple_open_internal() on it.
   We perform one extra trick here for the benefit of callers and to keep our
   code simple: ctf_simple_open_internal() will return a new ctf_dict_t, but we
   want to keep the fp constant for the caller, so after
   ctf_simple_open_internal() returns, we use memcpy to swap the interior of the
   old and new ctf_dict_t's, and then free the old.  */
int
ctf_serialize (ctf_dict_t *fp)
{
  ctf_dict_t ofp, *nfp;
  ctf_header_t hdr, *hdrp;
  ctf_dtdef_t *dtd;
  ctf_dvdef_t *dvd;
  ctf_varent_t *dvarents;
  ctf_strs_writable_t strtab;
  ctf_dict_t *symfp = fp;

  unsigned char *t;
  unsigned long i;
  int symflags = 0;
  size_t buf_size, type_size, objt_size, func_size;
  size_t objt_unpadsize, func_unpadsize, objt_padsize, func_padsize;
  size_t funcidx_size, objtidx_size;
  size_t nvars, nfuncs, nobjts, maxobjt, maxfunc;
  size_t ndynsyms = 0;
  const char **sym_name_order = NULL;
  unsigned char *buf = NULL, *newbuf;
  int err;

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  /* Update required?  */
  if (!(fp->ctf_flags & LCTF_DIRTY))
    return 0;

  /* Fill in an initial CTF header.  We will leave the label, object,
     and function sections empty and only output a header, type section,
     and string table.  The type section begins at a 4-byte aligned
     boundary past the CTF header itself (at relative offset zero).  The flag
     indicating a new-style function info section (an array of CTF_K_FUNCTION
     type IDs in the types section) is flipped on.  */

  memset (&hdr, 0, sizeof (hdr));
  hdr.cth_magic = CTF_MAGIC;
  hdr.cth_version = CTF_VERSION;

  /* This is a new-format func info section, and the symtab and strtab come out
     of the dynsym and dynstr these days.  */
  hdr.cth_flags = (CTF_F_NEWFUNCINFO | CTF_F_DYNSTR);

  /* Iterate through the dynamic type definition list and compute the
     size of the CTF type section we will need to generate.  */

  for (type_size = 0, dtd = ctf_list_next (&fp->ctf_dtdefs);
       dtd != NULL; dtd = ctf_list_next (dtd))
    {
      uint32_t kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
      uint32_t vlen = LCTF_INFO_VLEN (fp, dtd->dtd_data.ctt_info);

      if (dtd->dtd_data.ctt_size != CTF_LSIZE_SENT)
        type_size += sizeof (ctf_stype_t);
      else
        type_size += sizeof (ctf_type_t);

      switch (kind)
        {
        case CTF_K_INTEGER:
        case CTF_K_FLOAT:
          type_size += sizeof (uint32_t);
          break;
        case CTF_K_ARRAY:
          type_size += sizeof (ctf_array_t);
          break;
        case CTF_K_SLICE:
          type_size += sizeof (ctf_slice_t);
          break;
        case CTF_K_FUNCTION:
          type_size += sizeof (uint32_t) * (vlen + (vlen & 1));
          break;
        case CTF_K_STRUCT:
        case CTF_K_UNION:
          if (dtd->dtd_data.ctt_size < CTF_LSTRUCT_THRESH)
            type_size += sizeof (ctf_member_t) * vlen;
          else
            type_size += sizeof (ctf_lmember_t) * vlen;
          break;
        case CTF_K_ENUM:
          type_size += sizeof (ctf_enum_t) * vlen;
          break;
        }
    }

  /* Symbol table stuff is done only if the linker has told this dict about
     potential symbols (usually the case for parent dicts only).  The linker
     will report symbols to the parent dict in a parent/child link, as usual
     with all linker-related matters.  */

  if (!fp->ctf_dynsyms && fp->ctf_parent && fp->ctf_parent->ctf_dynsyms)
    symfp = fp->ctf_parent;

  /* No linker-reported symbols at all: ctf_link_shuffle_syms was never called.
     This must be an unsorted, indexed dict.  Otherwise, this is a sorted
     dict, and the header flags indicate as much.  */
  if (!symfp->ctf_dynsyms)
    symflags = CTF_SYMTYPETAB_FORCE_INDEXED;
  else
    hdr.cth_flags |= CTF_F_IDXSORTED;

  /* Work out the sizes of the object and function sections, and work out the
     number of pad (unassigned) symbols in each, and the overall size of the
     sections.  */

  if (symtypetab_density (fp, symfp, fp->ctf_objthash, &nobjts, &maxobjt,
                          &objt_unpadsize, &objt_padsize, &objtidx_size,
                          symflags) < 0)
    return -1;                                  /* errno is set for us.  */

  ctf_dprintf ("Object symtypetab: %i objects, max %i, unpadded size %i, "
               "%i bytes of pads, index size %i\n", (int) nobjts, (int) maxobjt,
               (int) objt_unpadsize, (int) objt_padsize, (int) objtidx_size);

  if (symtypetab_density (fp, symfp, fp->ctf_funchash, &nfuncs, &maxfunc,
                          &func_unpadsize, &func_padsize, &funcidx_size,
                          symflags | CTF_SYMTYPETAB_EMIT_FUNCTION) < 0)
    return -1;                                  /* errno is set for us.  */

  ctf_dprintf ("Function symtypetab: %i functions, max %i, unpadded size %i, "
               "%i bytes of pads, index size %i\n", (int) nfuncs, (int) maxfunc,
               (int) func_unpadsize, (int) func_padsize, (int) funcidx_size);

  /* If the linker has reported any symbols at all, those symbols that the
     linker has not reported are now removed from the ctf_objthash and
     ctf_funchash.  Delete entries from the variable section that duplicate
     newly-added data symbols.  There's no need to migrate new ones in, because
     linker invocations (even ld -r) can only introduce new symbols, not remove
     symbols that already exist, and the compiler always emits both a variable
     and a data symbol simultaneously.  */

  if (symtypetab_delete_nonstatic_vars (fp) < 0)
    return -1;

  /* It is worth indexing each section if it would save space to do so, due to
     reducing the number of pads sufficiently.  A pad is the same size as a
     single index entry: but index sections compress relatively poorly compared
     to constant pads, so it takes a lot of contiguous padding to equal one
     index section entry.  It would be nice to be able to *verify* whether we
     would save space after compression rather than guessing, but this seems
     difficult, since it would require complete reserialization.  Regardless, if
     the linker has not reported any symbols (e.g. if this is not a final link
     but just an ld -r), we must emit things in indexed fashion just as the
     compiler does.  */

  objt_size = objt_unpadsize;
  if (!(symflags & CTF_SYMTYPETAB_FORCE_INDEXED)
      && ((objt_padsize + objt_unpadsize) * CTF_INDEX_PAD_THRESHOLD
          > objt_padsize))
    {
      objt_size += objt_padsize;
      objtidx_size = 0;
    }

  func_size = func_unpadsize;
  if (!(symflags & CTF_SYMTYPETAB_FORCE_INDEXED)
      && ((func_padsize + func_unpadsize) * CTF_INDEX_PAD_THRESHOLD
          > func_padsize))
    {
      func_size += func_padsize;
      funcidx_size = 0;
    }

  /* Computing the number of entries in the CTF variable section is much
     simpler.  */

  for (nvars = 0, dvd = ctf_list_next (&fp->ctf_dvdefs);
       dvd != NULL; dvd = ctf_list_next (dvd), nvars++);

  /* Compute the size of the CTF buffer we need, sans only the string table,
     then allocate a new buffer and memcpy the finished header to the start of
     the buffer.  (We will adjust this later with strtab length info.)  */

  hdr.cth_lbloff = hdr.cth_objtoff = 0;
  hdr.cth_funcoff = hdr.cth_objtoff + objt_size;
  hdr.cth_objtidxoff = hdr.cth_funcoff + func_size;
  hdr.cth_funcidxoff = hdr.cth_objtidxoff + objtidx_size;
  hdr.cth_varoff = hdr.cth_funcidxoff + funcidx_size;
  hdr.cth_typeoff = hdr.cth_varoff + (nvars * sizeof (ctf_varent_t));
  hdr.cth_stroff = hdr.cth_typeoff + type_size;
  hdr.cth_strlen = 0;

  buf_size = sizeof (ctf_header_t) + hdr.cth_stroff + hdr.cth_strlen;

  if ((buf = malloc (buf_size)) == NULL)
    return (ctf_set_errno (fp, EAGAIN));

  memcpy (buf, &hdr, sizeof (ctf_header_t));
  t = (unsigned char *) buf + sizeof (ctf_header_t) + hdr.cth_objtoff;

  hdrp = (ctf_header_t *) buf;
  if ((fp->ctf_flags & LCTF_CHILD) && (fp->ctf_parname != NULL))
    ctf_str_add_ref (fp, fp->ctf_parname, &hdrp->cth_parname);
  if (fp->ctf_cuname != NULL)
    ctf_str_add_ref (fp, fp->ctf_cuname, &hdrp->cth_cuname);

  /* Sort the linker's symbols into name order if need be: if
     ctf_link_shuffle_syms has not been called at all, just use all the symbols
     that were added to this dict, and don't bother sorting them since this is
     probably an ld -r and will likely just be consumed by ld again, with no
     ctf_lookup_by_symbol()s ever done on it.  */

  if ((objtidx_size != 0) || (funcidx_size != 0))
    {
      ctf_next_t *i = NULL;
      void *symname;
      const char **walk;
      int err;

      if (symfp->ctf_dynsyms)
        ndynsyms = ctf_dynhash_elements (symfp->ctf_dynsyms);
      else
        ndynsyms = ctf_dynhash_elements (symfp->ctf_objthash)
          + ctf_dynhash_elements (symfp->ctf_funchash);

      if ((sym_name_order = calloc (ndynsyms, sizeof (const char *))) == NULL)
        goto oom;

      walk = sym_name_order;

      if (symfp->ctf_dynsyms)
        {
          while ((err = ctf_dynhash_next_sorted (symfp->ctf_dynsyms, &i, &symname,
                                                 NULL, ctf_dynhash_sort_by_name,
                                                 NULL)) == 0)
            *walk++ = (const char *) symname;
          if (err != ECTF_NEXT_END)
            goto symerr;
        }
      else
        {
          while ((err = ctf_dynhash_next (symfp->ctf_objthash, &i, &symname,
                                          NULL)) == 0)
            *walk++ = (const char *) symname;
          if (err != ECTF_NEXT_END)
            goto symerr;

          while ((err = ctf_dynhash_next (symfp->ctf_funchash, &i, &symname,
                                          NULL)) == 0)
            *walk++ = (const char *) symname;
          if (err != ECTF_NEXT_END)
            goto symerr;
        }
    }

  /* Emit the object and function sections, and if necessary their indexes.
     Emission is done in symtab order if there is no index, and in index
     (name) order otherwise.  */

  if ((objtidx_size == 0) && symfp->ctf_dynsymidx)
    {
      ctf_dprintf ("Emitting unindexed objt symtypetab\n");
      if (emit_symtypetab (fp, symfp, (uint32_t *) t, symfp->ctf_dynsymidx,
                           NULL, symfp->ctf_dynsymmax + 1, maxobjt, objt_size,
                           symflags | CTF_SYMTYPETAB_EMIT_PAD) < 0)
        goto err;                               /* errno is set for us.  */
    }
  else
    {
      ctf_dprintf ("Emitting indexed objt symtypetab\n");
      if (emit_symtypetab (fp, symfp, (uint32_t *) t, NULL, sym_name_order,
                           ndynsyms, maxobjt, objt_size, symflags) < 0)
        goto err;                               /* errno is set for us.  */
    }

  t += objt_size;

  if ((funcidx_size == 0) && symfp->ctf_dynsymidx)
    {
      ctf_dprintf ("Emitting unindexed func symtypetab\n");
      if (emit_symtypetab (fp, symfp, (uint32_t *) t, symfp->ctf_dynsymidx,
                           NULL, symfp->ctf_dynsymmax + 1, maxfunc,
                           func_size, symflags | CTF_SYMTYPETAB_EMIT_FUNCTION
                           | CTF_SYMTYPETAB_EMIT_PAD) < 0)
        goto err;                               /* errno is set for us.  */
    }
  else
    {
      ctf_dprintf ("Emitting indexed func symtypetab\n");
      if (emit_symtypetab (fp, symfp, (uint32_t *) t, NULL, sym_name_order,
                           ndynsyms, maxfunc, func_size,
                           symflags | CTF_SYMTYPETAB_EMIT_FUNCTION) < 0)
        goto err;                               /* errno is set for us.  */
    }

  t += func_size;

  if (objtidx_size > 0)
    if (emit_symtypetab_index (fp, symfp, (uint32_t *) t, sym_name_order,
                               ndynsyms, objtidx_size, symflags) < 0)
      goto err;

  t += objtidx_size;

  if (funcidx_size > 0)
    if (emit_symtypetab_index (fp, symfp, (uint32_t *) t, sym_name_order,
                               ndynsyms, funcidx_size,
                               symflags | CTF_SYMTYPETAB_EMIT_FUNCTION) < 0)
      goto err;

  t += funcidx_size;
  free (sym_name_order);
  sym_name_order = NULL;

  /* Work over the variable list, translating everything into ctf_varent_t's and
     prepping the string table.  */

  dvarents = (ctf_varent_t *) t;
  for (i = 0, dvd = ctf_list_next (&fp->ctf_dvdefs); dvd != NULL;
       dvd = ctf_list_next (dvd), i++)
    {
      ctf_varent_t *var = &dvarents[i];

      ctf_str_add_ref (fp, dvd->dvd_name, &var->ctv_name);
      var->ctv_type = (uint32_t) dvd->dvd_type;
    }
  assert (i == nvars);

  t += sizeof (ctf_varent_t) * nvars;

  assert (t == (unsigned char *) buf + sizeof (ctf_header_t) + hdr.cth_typeoff);

  /* We now take a final lap through the dynamic type definition list and copy
     the appropriate type records to the output buffer, noting down the
     strings as we go.  */

  for (dtd = ctf_list_next (&fp->ctf_dtdefs);
       dtd != NULL; dtd = ctf_list_next (dtd))
    {
      uint32_t kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
      uint32_t vlen = LCTF_INFO_VLEN (fp, dtd->dtd_data.ctt_info);

      ctf_array_t cta;
      uint32_t encoding;
      size_t len;
      ctf_stype_t *copied;
      const char *name;

      if (dtd->dtd_data.ctt_size != CTF_LSIZE_SENT)
        len = sizeof (ctf_stype_t);
      else
        len = sizeof (ctf_type_t);

      memcpy (t, &dtd->dtd_data, len);
      copied = (ctf_stype_t *) t;  /* name is at the start: constant offset.  */
      if (copied->ctt_name
          && (name = ctf_strraw (fp, copied->ctt_name)) != NULL)
        ctf_str_add_ref (fp, name, &copied->ctt_name);
      t += len;

      switch (kind)
        {
        case CTF_K_INTEGER:
        case CTF_K_FLOAT:
          if (kind == CTF_K_INTEGER)
            {
              encoding = CTF_INT_DATA (dtd->dtd_u.dtu_enc.cte_format,
                                       dtd->dtd_u.dtu_enc.cte_offset,
                                       dtd->dtd_u.dtu_enc.cte_bits);
            }
          else
            {
              encoding = CTF_FP_DATA (dtd->dtd_u.dtu_enc.cte_format,
                                      dtd->dtd_u.dtu_enc.cte_offset,
                                      dtd->dtd_u.dtu_enc.cte_bits);
            }
          memcpy (t, &encoding, sizeof (encoding));
          t += sizeof (encoding);
          break;

        case CTF_K_SLICE:
          memcpy (t, &dtd->dtd_u.dtu_slice, sizeof (struct ctf_slice));
          t += sizeof (struct ctf_slice);
          break;

        case CTF_K_ARRAY:
          cta.cta_contents = (uint32_t) dtd->dtd_u.dtu_arr.ctr_contents;
          cta.cta_index = (uint32_t) dtd->dtd_u.dtu_arr.ctr_index;
          cta.cta_nelems = dtd->dtd_u.dtu_arr.ctr_nelems;
          memcpy (t, &cta, sizeof (cta));
          t += sizeof (cta);
          break;

        case CTF_K_FUNCTION:
          {
            uint32_t *argv = (uint32_t *) (uintptr_t) t;
            uint32_t argc;

            for (argc = 0; argc < vlen; argc++)
              *argv++ = dtd->dtd_u.dtu_argv[argc];

            if (vlen & 1)
              *argv++ = 0;      /* Pad to 4-byte boundary.  */

            t = (unsigned char *) argv;
            break;
          }

        case CTF_K_STRUCT:
        case CTF_K_UNION:
          if (dtd->dtd_data.ctt_size < CTF_LSTRUCT_THRESH)
            t = ctf_copy_smembers (fp, dtd, t);
          else
            t = ctf_copy_lmembers (fp, dtd, t);
          break;

        case CTF_K_ENUM:
          t = ctf_copy_emembers (fp, dtd, t);
          break;
        }
    }
  assert (t == (unsigned char *) buf + sizeof (ctf_header_t) + hdr.cth_stroff);

  /* Construct the final string table and fill out all the string refs with the
     final offsets.  Then purge the refs list, because we're about to move this
     strtab onto the end of the buf, invalidating all the offsets.  */
  strtab = ctf_str_write_strtab (fp);
  ctf_str_purge_refs (fp);

  if (strtab.cts_strs == NULL)
    goto oom;

  /* Now the string table is constructed, we can sort the buffer of
     ctf_varent_t's.  */
  ctf_sort_var_arg_cb_t sort_var_arg = { fp, (ctf_strs_t *) &strtab };
  ctf_qsort_r (dvarents, nvars, sizeof (ctf_varent_t), ctf_sort_var,
               &sort_var_arg);

  if ((newbuf = ctf_realloc (fp, buf, buf_size + strtab.cts_len)) == NULL)
    {
      free (strtab.cts_strs);
      goto oom;
    }
  buf = newbuf;
  memcpy (buf + buf_size, strtab.cts_strs, strtab.cts_len);
  hdrp = (ctf_header_t *) buf;
  hdrp->cth_strlen = strtab.cts_len;
  buf_size += hdrp->cth_strlen;
  free (strtab.cts_strs);

  /* Finally, we are ready to ctf_simple_open() the new dict.  If this is
     successful, we then switch nfp and fp and free the old dict.  */

  if ((nfp = ctf_simple_open_internal ((char *) buf, buf_size, NULL, 0,
                                       0, NULL, 0, fp->ctf_syn_ext_strtab,
                                       1, &err)) == NULL)
    {
      free (buf);
      return (ctf_set_errno (fp, err));
    }

  (void) ctf_setmodel (nfp, ctf_getmodel (fp));

  nfp->ctf_parent = fp->ctf_parent;
  nfp->ctf_parent_unreffed = fp->ctf_parent_unreffed;
  nfp->ctf_refcnt = fp->ctf_refcnt;
  nfp->ctf_flags |= fp->ctf_flags & ~LCTF_DIRTY;
  if (nfp->ctf_dynbase == NULL)
    nfp->ctf_dynbase = buf;             /* Make sure buf is freed on close.  */
  nfp->ctf_dthash = fp->ctf_dthash;
  nfp->ctf_dtdefs = fp->ctf_dtdefs;
  nfp->ctf_dvhash = fp->ctf_dvhash;
  nfp->ctf_dvdefs = fp->ctf_dvdefs;
  nfp->ctf_dtoldid = fp->ctf_dtoldid;
  nfp->ctf_add_processing = fp->ctf_add_processing;
  nfp->ctf_snapshots = fp->ctf_snapshots + 1;
  nfp->ctf_specific = fp->ctf_specific;
  nfp->ctf_nfuncidx = fp->ctf_nfuncidx;
  nfp->ctf_nobjtidx = fp->ctf_nobjtidx;
  nfp->ctf_objthash = fp->ctf_objthash;
  nfp->ctf_funchash = fp->ctf_funchash;
  nfp->ctf_dynsyms = fp->ctf_dynsyms;
  nfp->ctf_ptrtab = fp->ctf_ptrtab;
  nfp->ctf_dynsymidx = fp->ctf_dynsymidx;
  nfp->ctf_dynsymmax = fp->ctf_dynsymmax;
  nfp->ctf_ptrtab_len = fp->ctf_ptrtab_len;
  nfp->ctf_link_inputs = fp->ctf_link_inputs;
  nfp->ctf_link_outputs = fp->ctf_link_outputs;
  nfp->ctf_errs_warnings = fp->ctf_errs_warnings;
  nfp->ctf_funcidx_names = fp->ctf_funcidx_names;
  nfp->ctf_objtidx_names = fp->ctf_objtidx_names;
  nfp->ctf_funcidx_sxlate = fp->ctf_funcidx_sxlate;
  nfp->ctf_objtidx_sxlate = fp->ctf_objtidx_sxlate;
  nfp->ctf_str_prov_offset = fp->ctf_str_prov_offset;
  nfp->ctf_syn_ext_strtab = fp->ctf_syn_ext_strtab;
  nfp->ctf_in_flight_dynsyms = fp->ctf_in_flight_dynsyms;
  nfp->ctf_link_in_cu_mapping = fp->ctf_link_in_cu_mapping;
  nfp->ctf_link_out_cu_mapping = fp->ctf_link_out_cu_mapping;
  nfp->ctf_link_type_mapping = fp->ctf_link_type_mapping;
  nfp->ctf_link_memb_name_changer = fp->ctf_link_memb_name_changer;
  nfp->ctf_link_memb_name_changer_arg = fp->ctf_link_memb_name_changer_arg;
  nfp->ctf_link_variable_filter = fp->ctf_link_variable_filter;
  nfp->ctf_link_variable_filter_arg = fp->ctf_link_variable_filter_arg;
  nfp->ctf_link_flags = fp->ctf_link_flags;
  nfp->ctf_dedup_atoms = fp->ctf_dedup_atoms;
  nfp->ctf_dedup_atoms_alloc = fp->ctf_dedup_atoms_alloc;
  memcpy (&nfp->ctf_dedup, &fp->ctf_dedup, sizeof (fp->ctf_dedup));

  nfp->ctf_snapshot_lu = fp->ctf_snapshots;

  memcpy (&nfp->ctf_lookups, fp->ctf_lookups, sizeof (fp->ctf_lookups));
  nfp->ctf_structs = fp->ctf_structs;
  nfp->ctf_unions = fp->ctf_unions;
  nfp->ctf_enums = fp->ctf_enums;
  nfp->ctf_names = fp->ctf_names;

  fp->ctf_dthash = NULL;
  ctf_str_free_atoms (nfp);
  nfp->ctf_str_atoms = fp->ctf_str_atoms;
  nfp->ctf_prov_strtab = fp->ctf_prov_strtab;
  fp->ctf_str_atoms = NULL;
  fp->ctf_prov_strtab = NULL;
  memset (&fp->ctf_dtdefs, 0, sizeof (ctf_list_t));
  memset (&fp->ctf_errs_warnings, 0, sizeof (ctf_list_t));
  fp->ctf_add_processing = NULL;
  fp->ctf_ptrtab = NULL;
  fp->ctf_funcidx_names = NULL;
  fp->ctf_objtidx_names = NULL;
  fp->ctf_funcidx_sxlate = NULL;
  fp->ctf_objtidx_sxlate = NULL;
  fp->ctf_objthash = NULL;
  fp->ctf_funchash = NULL;
  fp->ctf_dynsyms = NULL;
  fp->ctf_dynsymidx = NULL;
  fp->ctf_link_inputs = NULL;
  fp->ctf_link_outputs = NULL;
  fp->ctf_syn_ext_strtab = NULL;
  fp->ctf_link_in_cu_mapping = NULL;
  fp->ctf_link_out_cu_mapping = NULL;
  fp->ctf_link_type_mapping = NULL;
  fp->ctf_dedup_atoms = NULL;
  fp->ctf_dedup_atoms_alloc = NULL;
  fp->ctf_parent_unreffed = 1;

  fp->ctf_dvhash = NULL;
  memset (&fp->ctf_dvdefs, 0, sizeof (ctf_list_t));
  memset (fp->ctf_lookups, 0, sizeof (fp->ctf_lookups));
  memset (&fp->ctf_in_flight_dynsyms, 0, sizeof (fp->ctf_in_flight_dynsyms));
  memset (&fp->ctf_dedup, 0, sizeof (fp->ctf_dedup));
  fp->ctf_structs.ctn_writable = NULL;
  fp->ctf_unions.ctn_writable = NULL;
  fp->ctf_enums.ctn_writable = NULL;
  fp->ctf_names.ctn_writable = NULL;

  memcpy (&ofp, fp, sizeof (ctf_dict_t));
  memcpy (fp, nfp, sizeof (ctf_dict_t));
  memcpy (nfp, &ofp, sizeof (ctf_dict_t));

  nfp->ctf_refcnt = 1;                          /* Force nfp to be freed.  */
  ctf_dict_close (nfp);

  return 0;

symerr:
  ctf_err_warn (fp, 0, err, _("error serializing symtypetabs"));
  goto err;
oom:
  free (buf);
  free (sym_name_order);
  return (ctf_set_errno (fp, EAGAIN));
err:
  free (buf);
  free (sym_name_order);
  return -1;                                    /* errno is set for us.  */
}

ctf_names_t *
ctf_name_table (ctf_dict_t *fp, int kind)
{
  switch (kind)
    {
    case CTF_K_STRUCT:
      return &fp->ctf_structs;
    case CTF_K_UNION:
      return &fp->ctf_unions;
    case CTF_K_ENUM:
      return &fp->ctf_enums;
    default:
      return &fp->ctf_names;
    }
}

int
ctf_dtd_insert (ctf_dict_t *fp, ctf_dtdef_t *dtd, int flag, int kind)
{
  const char *name;
  if (ctf_dynhash_insert (fp->ctf_dthash, (void *) (uintptr_t) dtd->dtd_type,
                          dtd) < 0)
    return -1;

  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,
                              (char *) name, (void *) (uintptr_t)
                              dtd->dtd_type) < 0)
        {
          ctf_dynhash_remove (fp->ctf_dthash, (void *) (uintptr_t)
                              dtd->dtd_type);
          return -1;
        }
    }
  ctf_list_append (&fp->ctf_dtdefs, dtd);
  return 0;
}

void
ctf_dtd_delete (ctf_dict_t *fp, ctf_dtdef_t *dtd)
{
  ctf_dmdef_t *dmd, *nmd;
  int kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
  int name_kind = kind;
  const char *name;

  ctf_dynhash_remove (fp->ctf_dthash, (void *) (uintptr_t) dtd->dtd_type);

  switch (kind)
    {
    case CTF_K_STRUCT:
    case CTF_K_UNION:
    case CTF_K_ENUM:
      for (dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
           dmd != NULL; dmd = nmd)
        {
          if (dmd->dmd_name != NULL)
              free (dmd->dmd_name);
          nmd = ctf_list_next (dmd);
          free (dmd);
        }
      break;
    case CTF_K_FUNCTION:
      free (dtd->dtd_u.dtu_argv);
      break;
    case CTF_K_FORWARD:
      name_kind = dtd->dtd_data.ctt_type;
      break;
    }

  if (dtd->dtd_data.ctt_name
      && (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_str_remove_ref (fp, name, &dtd->dtd_data.ctt_name);
    }

  ctf_list_delete (&fp->ctf_dtdefs, dtd);
  free (dtd);
}

ctf_dtdef_t *
ctf_dtd_lookup (const ctf_dict_t *fp, ctf_id_t type)
{
  return (ctf_dtdef_t *)
    ctf_dynhash_lookup (fp->ctf_dthash, (void *) (uintptr_t) type);
}

ctf_dtdef_t *
ctf_dynamic_type (const ctf_dict_t *fp, ctf_id_t id)
{
  ctf_id_t idx;

  if (!(fp->ctf_flags & LCTF_RDWR))
    return NULL;

  if ((fp->ctf_flags & LCTF_CHILD) && LCTF_TYPE_ISPARENT (fp, id))
    fp = fp->ctf_parent;

  idx = LCTF_TYPE_TO_INDEX(fp, id);

  if ((unsigned long) idx <= fp->ctf_typemax)
    return ctf_dtd_lookup (fp, id);
  return NULL;
}

int
ctf_dvd_insert (ctf_dict_t *fp, ctf_dvdef_t *dvd)
{
  if (ctf_dynhash_insert (fp->ctf_dvhash, dvd->dvd_name, dvd) < 0)
    return -1;
  ctf_list_append (&fp->ctf_dvdefs, dvd);
  return 0;
}

void
ctf_dvd_delete (ctf_dict_t *fp, ctf_dvdef_t *dvd)
{
  ctf_dynhash_remove (fp->ctf_dvhash, dvd->dvd_name);
  free (dvd->dvd_name);

  ctf_list_delete (&fp->ctf_dvdefs, dvd);
  free (dvd);
}

ctf_dvdef_t *
ctf_dvd_lookup (const ctf_dict_t *fp, const char *name)
{
  return (ctf_dvdef_t *) ctf_dynhash_lookup (fp->ctf_dvhash, name);
}

/* Discard all of the dynamic type definitions and variable definitions that
   have been added to the dict since the last call to ctf_update().  We locate
   such types by scanning the dtd list and deleting elements that have type IDs
   greater than ctf_dtoldid, which is set by ctf_update(), above, and by
   scanning the variable list and deleting elements that have update IDs equal
   to the current value of the last-update snapshot count (indicating that they
   were added after the most recent call to ctf_update()).  */
int
ctf_discard (ctf_dict_t *fp)
{
  ctf_snapshot_id_t last_update =
    { fp->ctf_dtoldid,
      fp->ctf_snapshot_lu + 1 };

  /* Update required?  */
  if (!(fp->ctf_flags & LCTF_DIRTY))
    return 0;

  return (ctf_rollback (fp, last_update));
}

ctf_snapshot_id_t
ctf_snapshot (ctf_dict_t *fp)
{
  ctf_snapshot_id_t snapid;
  snapid.dtd_id = fp->ctf_typemax;
  snapid.snapshot_id = fp->ctf_snapshots++;
  return snapid;
}

/* Like ctf_discard(), only discards everything after a particular ID.  */
int
ctf_rollback (ctf_dict_t *fp, ctf_snapshot_id_t id)
{
  ctf_dtdef_t *dtd, *ntd;
  ctf_dvdef_t *dvd, *nvd;

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (fp->ctf_snapshot_lu >= id.snapshot_id)
    return (ctf_set_errno (fp, ECTF_OVERROLLBACK));

  for (dtd = ctf_list_next (&fp->ctf_dtdefs); dtd != NULL; dtd = ntd)
    {
      int kind;
      const char *name;

      ntd = ctf_list_next (dtd);

      if (LCTF_TYPE_TO_INDEX (fp, dtd->dtd_type) <= id.dtd_id)
        continue;

      kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
      if (kind == CTF_K_FORWARD)
        kind = dtd->dtd_data.ctt_type;

      if (dtd->dtd_data.ctt_name
          && (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_str_remove_ref (fp, name, &dtd->dtd_data.ctt_name);
        }

      ctf_dynhash_remove (fp->ctf_dthash, (void *) (uintptr_t) dtd->dtd_type);
      ctf_dtd_delete (fp, dtd);
    }

  for (dvd = ctf_list_next (&fp->ctf_dvdefs); dvd != NULL; dvd = nvd)
    {
      nvd = ctf_list_next (dvd);

      if (dvd->dvd_snapshots <= id.snapshot_id)
        continue;

      ctf_dvd_delete (fp, dvd);
    }

  fp->ctf_typemax = id.dtd_id;
  fp->ctf_snapshots = id.snapshot_id;

  if (fp->ctf_snapshots == fp->ctf_snapshot_lu)
    fp->ctf_flags &= ~LCTF_DIRTY;

  return 0;
}

static ctf_id_t
ctf_add_generic (ctf_dict_t *fp, uint32_t flag, const char *name, int kind,
                 ctf_dtdef_t **rp)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type;

  if (flag != CTF_ADD_NONROOT && flag != CTF_ADD_ROOT)
    return (ctf_set_errno (fp, EINVAL));

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (LCTF_INDEX_TO_TYPE (fp, fp->ctf_typemax, 1) >= CTF_MAX_TYPE)
    return (ctf_set_errno (fp, ECTF_FULL));

  if (LCTF_INDEX_TO_TYPE (fp, fp->ctf_typemax, 1) == (CTF_MAX_PTYPE - 1))
    return (ctf_set_errno (fp, ECTF_FULL));

  /* Make sure ptrtab always grows to be big enough for all types.  */
  if (ctf_grow_ptrtab (fp) < 0)
      return CTF_ERR;           /* errno is set for us. */

  if ((dtd = malloc (sizeof (ctf_dtdef_t))) == NULL)
    return (ctf_set_errno (fp, EAGAIN));

  type = ++fp->ctf_typemax;
  type = LCTF_INDEX_TO_TYPE (fp, type, (fp->ctf_flags & LCTF_CHILD));

  memset (dtd, 0, sizeof (ctf_dtdef_t));
  dtd->dtd_data.ctt_name = ctf_str_add_ref (fp, name, &dtd->dtd_data.ctt_name);
  dtd->dtd_type = type;

  if (dtd->dtd_data.ctt_name == 0 && name != NULL && name[0] != '\0')
    {
      free (dtd);
      return (ctf_set_errno (fp, EAGAIN));
    }

  if (ctf_dtd_insert (fp, dtd, flag, kind) < 0)
    {
      free (dtd);
      return CTF_ERR;                   /* errno is set for us.  */
    }
  fp->ctf_flags |= LCTF_DIRTY;

  *rp = dtd;
  return type;
}

/* When encoding integer sizes, we want to convert a byte count in the range
   1-8 to the closest power of 2 (e.g. 3->4, 5->8, etc).  The clp2() function
   is a clever implementation from "Hacker's Delight" by Henry Warren, Jr.  */
static size_t
clp2 (size_t x)
{
  x--;

  x |= (x >> 1);
  x |= (x >> 2);
  x |= (x >> 4);
  x |= (x >> 8);
  x |= (x >> 16);

  return (x + 1);
}

ctf_id_t
ctf_add_encoded (ctf_dict_t *fp, uint32_t flag,
                 const char *name, const ctf_encoding_t *ep, uint32_t kind)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type;

  if (ep == NULL)
    return (ctf_set_errno (fp, EINVAL));

  if ((type = ctf_add_generic (fp, flag, name, kind, &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (kind, flag, 0);
  dtd->dtd_data.ctt_size = clp2 (P2ROUNDUP (ep->cte_bits, CHAR_BIT)
                                 / CHAR_BIT);
  dtd->dtd_u.dtu_enc = *ep;

  return type;
}

ctf_id_t
ctf_add_reftype (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref, uint32_t kind)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type;
  ctf_dict_t *tmp = fp;
  int child = fp->ctf_flags & LCTF_CHILD;

  if (ref == CTF_ERR || ref > CTF_MAX_TYPE)
    return (ctf_set_errno (fp, EINVAL));

  if (ref != 0 && ctf_lookup_by_id (&tmp, ref) == NULL)
    return CTF_ERR;             /* errno is set for us.  */

  if ((type = ctf_add_generic (fp, flag, NULL, kind, &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (kind, flag, 0);
  dtd->dtd_data.ctt_type = (uint32_t) ref;

  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.  */

  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;
    }

  return type;
}

ctf_id_t
ctf_add_slice (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref,
               const ctf_encoding_t *ep)
{
  ctf_dtdef_t *dtd;
  ctf_id_t resolved_ref = ref;
  ctf_id_t type;
  int kind;
  const ctf_type_t *tp;
  ctf_dict_t *tmp = fp;

  if (ep == NULL)
    return (ctf_set_errno (fp, EINVAL));

  if ((ep->cte_bits > 255) || (ep->cte_offset > 255))
    return (ctf_set_errno (fp, ECTF_SLICEOVERFLOW));

  if (ref == CTF_ERR || ref > CTF_MAX_TYPE)
    return (ctf_set_errno (fp, EINVAL));

  if (ref != 0 && ((tp = ctf_lookup_by_id (&tmp, ref)) == NULL))
    return CTF_ERR;             /* errno is set for us.  */

  /* Make sure we ultimately point to an integral type.  We also allow slices to
     point to the unimplemented type, for now, because the compiler can emit
     such slices, though they're not very much use.  */

  resolved_ref = ctf_type_resolve_unsliced (tmp, ref);
  kind = ctf_type_kind_unsliced (tmp, resolved_ref);

  if ((kind != CTF_K_INTEGER) && (kind != CTF_K_FLOAT) &&
      (kind != CTF_K_ENUM)
      && (ref != 0))
    return (ctf_set_errno (fp, ECTF_NOTINTFP));

  if ((type = ctf_add_generic (fp, flag, NULL, CTF_K_SLICE, &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_SLICE, flag, 0);
  dtd->dtd_data.ctt_size = clp2 (P2ROUNDUP (ep->cte_bits, CHAR_BIT)
                                 / CHAR_BIT);
  dtd->dtd_u.dtu_slice.cts_type = (uint32_t) ref;
  dtd->dtd_u.dtu_slice.cts_bits = ep->cte_bits;
  dtd->dtd_u.dtu_slice.cts_offset = ep->cte_offset;

  return type;
}

ctf_id_t
ctf_add_integer (ctf_dict_t *fp, uint32_t flag,
                 const char *name, const ctf_encoding_t *ep)
{
  return (ctf_add_encoded (fp, flag, name, ep, CTF_K_INTEGER));
}

ctf_id_t
ctf_add_float (ctf_dict_t *fp, uint32_t flag,
               const char *name, const ctf_encoding_t *ep)
{
  return (ctf_add_encoded (fp, flag, name, ep, CTF_K_FLOAT));
}

ctf_id_t
ctf_add_pointer (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref)
{
  return (ctf_add_reftype (fp, flag, ref, CTF_K_POINTER));
}

ctf_id_t
ctf_add_array (ctf_dict_t *fp, uint32_t flag, const ctf_arinfo_t *arp)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type;
  ctf_dict_t *tmp = fp;

  if (arp == NULL)
    return (ctf_set_errno (fp, EINVAL));

  if (arp->ctr_contents != 0
      && ctf_lookup_by_id (&tmp, arp->ctr_contents) == NULL)
    return CTF_ERR;             /* errno is set for us.  */

  tmp = fp;
  if (ctf_lookup_by_id (&tmp, arp->ctr_index) == NULL)
    return CTF_ERR;             /* errno is set for us.  */

  if ((type = ctf_add_generic (fp, flag, NULL, CTF_K_ARRAY, &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_ARRAY, flag, 0);
  dtd->dtd_data.ctt_size = 0;
  dtd->dtd_u.dtu_arr = *arp;

  return type;
}

int
ctf_set_array (ctf_dict_t *fp, ctf_id_t type, const ctf_arinfo_t *arp)
{
  ctf_dtdef_t *dtd = ctf_dtd_lookup (fp, type);

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (dtd == NULL
      || LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info) != CTF_K_ARRAY)
    return (ctf_set_errno (fp, ECTF_BADID));

  fp->ctf_flags |= LCTF_DIRTY;
  dtd->dtd_u.dtu_arr = *arp;

  return 0;
}

ctf_id_t
ctf_add_function (ctf_dict_t *fp, uint32_t flag,
                  const ctf_funcinfo_t *ctc, const ctf_id_t *argv)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type;
  uint32_t vlen;
  uint32_t *vdat = NULL;
  ctf_dict_t *tmp = fp;
  size_t i;

  if (ctc == NULL || (ctc->ctc_flags & ~CTF_FUNC_VARARG) != 0
      || (ctc->ctc_argc != 0 && argv == NULL))
    return (ctf_set_errno (fp, EINVAL));

  vlen = ctc->ctc_argc;
  if (ctc->ctc_flags & CTF_FUNC_VARARG)
    vlen++;            /* Add trailing zero to indicate varargs (see below).  */

  if (ctc->ctc_return != 0
      && ctf_lookup_by_id (&tmp, ctc->ctc_return) == NULL)
    return CTF_ERR;             /* errno is set for us.  */

  if (vlen > CTF_MAX_VLEN)
    return (ctf_set_errno (fp, EOVERFLOW));

  if (vlen != 0 && (vdat = malloc (sizeof (ctf_id_t) * vlen)) == NULL)
    return (ctf_set_errno (fp, EAGAIN));

  for (i = 0; i < ctc->ctc_argc; i++)
    {
      tmp = fp;
      if (argv[i] != 0 && ctf_lookup_by_id (&tmp, argv[i]) == NULL)
        {
          free (vdat);
          return CTF_ERR;          /* errno is set for us.  */
        }
      vdat[i] = (uint32_t) argv[i];
    }

  if ((type = ctf_add_generic (fp, flag, NULL, CTF_K_FUNCTION,
                               &dtd)) == CTF_ERR)
    {
      free (vdat);
      return CTF_ERR;              /* errno is set for us.  */
    }

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_FUNCTION, flag, vlen);
  dtd->dtd_data.ctt_type = (uint32_t) ctc->ctc_return;

  if (ctc->ctc_flags & CTF_FUNC_VARARG)
    vdat[vlen - 1] = 0;            /* Add trailing zero to indicate varargs.  */
  dtd->dtd_u.dtu_argv = vdat;

  return type;
}

ctf_id_t
ctf_add_struct_sized (ctf_dict_t *fp, uint32_t flag, const char *name,
                      size_t size)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type = 0;

  /* Promote root-visible forwards to structs.  */
  if (name != NULL)
    type = ctf_lookup_by_rawname (fp, CTF_K_STRUCT, name);

  if (type != 0 && ctf_type_kind (fp, type) == CTF_K_FORWARD)
    dtd = ctf_dtd_lookup (fp, type);
  else if ((type = ctf_add_generic (fp, flag, name, CTF_K_STRUCT,
                                    &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_STRUCT, flag, 0);

  if (size > CTF_MAX_SIZE)
    {
      dtd->dtd_data.ctt_size = CTF_LSIZE_SENT;
      dtd->dtd_data.ctt_lsizehi = CTF_SIZE_TO_LSIZE_HI (size);
      dtd->dtd_data.ctt_lsizelo = CTF_SIZE_TO_LSIZE_LO (size);
    }
  else
    dtd->dtd_data.ctt_size = (uint32_t) size;

  return type;
}

ctf_id_t
ctf_add_struct (ctf_dict_t *fp, uint32_t flag, const char *name)
{
  return (ctf_add_struct_sized (fp, flag, name, 0));
}

ctf_id_t
ctf_add_union_sized (ctf_dict_t *fp, uint32_t flag, const char *name,
                     size_t size)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type = 0;

  /* Promote root-visible forwards to unions.  */
  if (name != NULL)
    type = ctf_lookup_by_rawname (fp, CTF_K_UNION, name);

  if (type != 0 && ctf_type_kind (fp, type) == CTF_K_FORWARD)
    dtd = ctf_dtd_lookup (fp, type);
  else if ((type = ctf_add_generic (fp, flag, name, CTF_K_UNION,
                                    &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_UNION, flag, 0);

  if (size > CTF_MAX_SIZE)
    {
      dtd->dtd_data.ctt_size = CTF_LSIZE_SENT;
      dtd->dtd_data.ctt_lsizehi = CTF_SIZE_TO_LSIZE_HI (size);
      dtd->dtd_data.ctt_lsizelo = CTF_SIZE_TO_LSIZE_LO (size);
    }
  else
    dtd->dtd_data.ctt_size = (uint32_t) size;

  return type;
}

ctf_id_t
ctf_add_union (ctf_dict_t *fp, uint32_t flag, const char *name)
{
  return (ctf_add_union_sized (fp, flag, name, 0));
}

ctf_id_t
ctf_add_enum (ctf_dict_t *fp, uint32_t flag, const char *name)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type = 0;

  /* Promote root-visible forwards to enums.  */
  if (name != NULL)
    type = ctf_lookup_by_rawname (fp, CTF_K_ENUM, name);

  if (type != 0 && ctf_type_kind (fp, type) == CTF_K_FORWARD)
    dtd = ctf_dtd_lookup (fp, type);
  else if ((type = ctf_add_generic (fp, flag, name, CTF_K_ENUM,
                                    &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_ENUM, flag, 0);
  dtd->dtd_data.ctt_size = fp->ctf_dmodel->ctd_int;

  return type;
}

ctf_id_t
ctf_add_enum_encoded (ctf_dict_t *fp, uint32_t flag, const char *name,
                      const ctf_encoding_t *ep)
{
  ctf_id_t type = 0;

  /* First, create the enum if need be, using most of the same machinery as
     ctf_add_enum(), to ensure that we do not allow things past that are not
     enums or forwards to them.  (This includes other slices: you cannot slice a
     slice, which would be a useless thing to do anyway.)  */

  if (name != NULL)
    type = ctf_lookup_by_rawname (fp, CTF_K_ENUM, name);

  if (type != 0)
    {
      if ((ctf_type_kind (fp, type) != CTF_K_FORWARD) &&
          (ctf_type_kind_unsliced (fp, type) != CTF_K_ENUM))
        return (ctf_set_errno (fp, ECTF_NOTINTFP));
    }
  else if ((type = ctf_add_enum (fp, flag, name)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  /* Now attach a suitable slice to it.  */

  return ctf_add_slice (fp, flag, type, ep);
}

ctf_id_t
ctf_add_forward (ctf_dict_t *fp, uint32_t flag, const char *name,
                 uint32_t kind)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type = 0;

  if (!ctf_forwardable_kind (kind))
    return (ctf_set_errno (fp, ECTF_NOTSUE));

  /* If the type is already defined or exists as a forward tag, just
     return the ctf_id_t of the existing definition.  */

  if (name != NULL)
    type = ctf_lookup_by_rawname (fp, kind, name);

  if (type)
    return type;

  if ((type = ctf_add_generic (fp, flag, name, kind, &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_FORWARD, flag, 0);
  dtd->dtd_data.ctt_type = kind;

  return type;
}

ctf_id_t
ctf_add_typedef (ctf_dict_t *fp, uint32_t flag, const char *name,
                 ctf_id_t ref)
{
  ctf_dtdef_t *dtd;
  ctf_id_t type;
  ctf_dict_t *tmp = fp;

  if (ref == CTF_ERR || ref > CTF_MAX_TYPE)
    return (ctf_set_errno (fp, EINVAL));

  if (ref != 0 && ctf_lookup_by_id (&tmp, ref) == NULL)
    return CTF_ERR;             /* errno is set for us.  */

  if ((type = ctf_add_generic (fp, flag, name, CTF_K_TYPEDEF,
                               &dtd)) == CTF_ERR)
    return CTF_ERR;             /* errno is set for us.  */

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_TYPEDEF, flag, 0);
  dtd->dtd_data.ctt_type = (uint32_t) ref;

  return type;
}

ctf_id_t
ctf_add_volatile (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref)
{
  return (ctf_add_reftype (fp, flag, ref, CTF_K_VOLATILE));
}

ctf_id_t
ctf_add_const (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref)
{
  return (ctf_add_reftype (fp, flag, ref, CTF_K_CONST));
}

ctf_id_t
ctf_add_restrict (ctf_dict_t *fp, uint32_t flag, ctf_id_t ref)
{
  return (ctf_add_reftype (fp, flag, ref, CTF_K_RESTRICT));
}

int
ctf_add_enumerator (ctf_dict_t *fp, ctf_id_t enid, const char *name,
                    int value)
{
  ctf_dtdef_t *dtd = ctf_dtd_lookup (fp, enid);
  ctf_dmdef_t *dmd;

  uint32_t kind, vlen, root;
  char *s;

  if (name == NULL)
    return (ctf_set_errno (fp, EINVAL));

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (dtd == NULL)
    return (ctf_set_errno (fp, ECTF_BADID));

  kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
  root = LCTF_INFO_ISROOT (fp, dtd->dtd_data.ctt_info);
  vlen = LCTF_INFO_VLEN (fp, dtd->dtd_data.ctt_info);

  if (kind != CTF_K_ENUM)
    return (ctf_set_errno (fp, ECTF_NOTENUM));

  if (vlen == CTF_MAX_VLEN)
    return (ctf_set_errno (fp, ECTF_DTFULL));

  for (dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
       dmd != NULL; dmd = ctf_list_next (dmd))
    {
      if (strcmp (dmd->dmd_name, name) == 0)
        return (ctf_set_errno (fp, ECTF_DUPLICATE));
    }

  if ((dmd = malloc (sizeof (ctf_dmdef_t))) == NULL)
    return (ctf_set_errno (fp, EAGAIN));

  if ((s = strdup (name)) == NULL)
    {
      free (dmd);
      return (ctf_set_errno (fp, EAGAIN));
    }

  dmd->dmd_name = s;
  dmd->dmd_type = CTF_ERR;
  dmd->dmd_offset = 0;
  dmd->dmd_value = value;

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (kind, root, vlen + 1);
  ctf_list_append (&dtd->dtd_u.dtu_members, dmd);

  fp->ctf_flags |= LCTF_DIRTY;

  return 0;
}

int
ctf_add_member_offset (ctf_dict_t *fp, ctf_id_t souid, const char *name,
                       ctf_id_t type, unsigned long bit_offset)
{
  ctf_dtdef_t *dtd = ctf_dtd_lookup (fp, souid);
  ctf_dmdef_t *dmd;

  ssize_t msize, malign, ssize;
  uint32_t kind, vlen, root;
  char *s = NULL;

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (dtd == NULL)
    return (ctf_set_errno (fp, ECTF_BADID));

  if (name != NULL && name[0] == '\0')
    name = NULL;

  kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
  root = LCTF_INFO_ISROOT (fp, dtd->dtd_data.ctt_info);
  vlen = LCTF_INFO_VLEN (fp, dtd->dtd_data.ctt_info);

  if (kind != CTF_K_STRUCT && kind != CTF_K_UNION)
    return (ctf_set_errno (fp, ECTF_NOTSOU));

  if (vlen == CTF_MAX_VLEN)
    return (ctf_set_errno (fp, ECTF_DTFULL));

  if (name != NULL)
    {
      for (dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
           dmd != NULL; dmd = ctf_list_next (dmd))
        {
          if (dmd->dmd_name != NULL && strcmp (dmd->dmd_name, name) == 0)
            return (ctf_set_errno (fp, ECTF_DUPLICATE));
        }
    }

  if ((msize = ctf_type_size (fp, type)) < 0 ||
      (malign = ctf_type_align (fp, type)) < 0)
    {
      /* The unimplemented type, and any type that resolves to it, has no size
         and no alignment: it can correspond to any number of compiler-inserted
         types.  */

      if (ctf_errno (fp) == ECTF_NONREPRESENTABLE)
        {
          msize = 0;
          malign = 0;
          ctf_set_errno (fp, 0);
        }
      else
        return -1;              /* errno is set for us.  */
    }

  if ((dmd = malloc (sizeof (ctf_dmdef_t))) == NULL)
    return (ctf_set_errno (fp, EAGAIN));

  if (name != NULL && (s = strdup (name)) == NULL)
    {
      free (dmd);
      return (ctf_set_errno (fp, EAGAIN));
    }

  dmd->dmd_name = s;
  dmd->dmd_type = type;
  dmd->dmd_value = -1;

  if (kind == CTF_K_STRUCT && vlen != 0)
    {
      if (bit_offset == (unsigned long) - 1)
        {
          /* Natural alignment.  */

          ctf_dmdef_t *lmd = ctf_list_prev (&dtd->dtd_u.dtu_members);
          ctf_id_t ltype = ctf_type_resolve (fp, lmd->dmd_type);
          size_t off = lmd->dmd_offset;

          ctf_encoding_t linfo;
          ssize_t lsize;

          /* Propagate any error from ctf_type_resolve.  If the last member was
             of unimplemented type, this may be -ECTF_NONREPRESENTABLE: we
             cannot insert right after such a member without explicit offset
             specification, because its alignment and size is not known.  */
          if (ltype == CTF_ERR)
            {
              free (dmd);
              return -1;        /* errno is set for us.  */
            }

          if (ctf_type_encoding (fp, ltype, &linfo) == 0)
            off += linfo.cte_bits;
          else if ((lsize = ctf_type_size (fp, ltype)) > 0)
            off += lsize * CHAR_BIT;

          /* Round up the offset of the end of the last member to
             the next byte boundary, convert 'off' to bytes, and
             then round it up again to the next multiple of the
             alignment required by the new member.  Finally,
             convert back to bits and store the result in
             dmd_offset.  Technically we could do more efficient
             packing if the new member is a bit-field, but we're
             the "compiler" and ANSI says we can do as we choose.  */

          off = roundup (off, CHAR_BIT) / CHAR_BIT;
          off = roundup (off, MAX (malign, 1));
          dmd->dmd_offset = off * CHAR_BIT;
          ssize = off + msize;
        }
      else
        {
          /* Specified offset in bits.  */

          dmd->dmd_offset = bit_offset;
          ssize = ctf_get_ctt_size (fp, &dtd->dtd_data, NULL, NULL);
          ssize = MAX (ssize, ((signed) bit_offset / CHAR_BIT) + msize);
        }
    }
  else
    {
      dmd->dmd_offset = 0;
      ssize = ctf_get_ctt_size (fp, &dtd->dtd_data, NULL, NULL);
      ssize = MAX (ssize, msize);
    }

  if ((size_t) ssize > CTF_MAX_SIZE)
    {
      dtd->dtd_data.ctt_size = CTF_LSIZE_SENT;
      dtd->dtd_data.ctt_lsizehi = CTF_SIZE_TO_LSIZE_HI (ssize);
      dtd->dtd_data.ctt_lsizelo = CTF_SIZE_TO_LSIZE_LO (ssize);
    }
  else
    dtd->dtd_data.ctt_size = (uint32_t) ssize;

  dtd->dtd_data.ctt_info = CTF_TYPE_INFO (kind, root, vlen + 1);
  ctf_list_append (&dtd->dtd_u.dtu_members, dmd);

  fp->ctf_flags |= LCTF_DIRTY;
  return 0;
}

int
ctf_add_member_encoded (ctf_dict_t *fp, ctf_id_t souid, const char *name,
                        ctf_id_t type, unsigned long bit_offset,
                        const ctf_encoding_t encoding)
{
  ctf_dtdef_t *dtd = ctf_dtd_lookup (fp, type);
  int kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
  int otype = type;

  if ((kind != CTF_K_INTEGER) && (kind != CTF_K_FLOAT) && (kind != CTF_K_ENUM))
    return (ctf_set_errno (fp, ECTF_NOTINTFP));

  if ((type = ctf_add_slice (fp, CTF_ADD_NONROOT, otype, &encoding)) == CTF_ERR)
    return -1;                  /* errno is set for us.  */

  return ctf_add_member_offset (fp, souid, name, type, bit_offset);
}

int
ctf_add_member (ctf_dict_t *fp, ctf_id_t souid, const char *name,
                ctf_id_t type)
{
  return ctf_add_member_offset (fp, souid, name, type, (unsigned long) - 1);
}

int
ctf_add_variable (ctf_dict_t *fp, const char *name, ctf_id_t ref)
{
  ctf_dvdef_t *dvd;
  ctf_dict_t *tmp = fp;

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (ctf_dvd_lookup (fp, name) != NULL)
    return (ctf_set_errno (fp, ECTF_DUPLICATE));

  if (ctf_lookup_by_id (&tmp, ref) == NULL)
    return -1;                  /* errno is set for us.  */

  /* Make sure this type is representable.  */
  if ((ctf_type_resolve (fp, ref) == CTF_ERR)
      && (ctf_errno (fp) == ECTF_NONREPRESENTABLE))
    return -1;

  if ((dvd = malloc (sizeof (ctf_dvdef_t))) == NULL)
    return (ctf_set_errno (fp, EAGAIN));

  if (name != NULL && (dvd->dvd_name = strdup (name)) == NULL)
    {
      free (dvd);
      return (ctf_set_errno (fp, EAGAIN));
    }
  dvd->dvd_type = ref;
  dvd->dvd_snapshots = fp->ctf_snapshots;

  if (ctf_dvd_insert (fp, dvd) < 0)
    {
      free (dvd->dvd_name);
      free (dvd);
      return -1;                        /* errno is set for us.  */
    }

  fp->ctf_flags |= LCTF_DIRTY;
  return 0;
}

int
ctf_add_funcobjt_sym (ctf_dict_t *fp, int is_function, const char *name, ctf_id_t id)
{
  ctf_dict_t *tmp = fp;
  char *dupname;
  ctf_dynhash_t *h = is_function ? fp->ctf_funchash : fp->ctf_objthash;

  if (!(fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (fp, ECTF_RDONLY));

  if (ctf_dynhash_lookup (fp->ctf_objthash, name) != NULL ||
      ctf_dynhash_lookup (fp->ctf_funchash, name) != NULL)
    return (ctf_set_errno (fp, ECTF_DUPLICATE));

  if (ctf_lookup_by_id (&tmp, id) == NULL)
    return -1;                                  /* errno is set for us.  */

  if (is_function && ctf_type_kind (fp, id) != CTF_K_FUNCTION)
    return (ctf_set_errno (fp, ECTF_NOTFUNC));

  if ((dupname = strdup (name)) == NULL)
    return (ctf_set_errno (fp, ENOMEM));

  if (ctf_dynhash_insert (h, dupname, (void *) (uintptr_t) id) < 0)
    {
      free (dupname);
      return (ctf_set_errno (fp, ENOMEM));
    }
  return 0;
}

int
ctf_add_objt_sym (ctf_dict_t *fp, const char *name, ctf_id_t id)
{
  return (ctf_add_funcobjt_sym (fp, 0, name, id));
}

int
ctf_add_func_sym (ctf_dict_t *fp, const char *name, ctf_id_t id)
{
  return (ctf_add_funcobjt_sym (fp, 1, name, id));
}

typedef struct ctf_bundle
{
  ctf_dict_t *ctb_dict;         /* CTF dict handle.  */
  ctf_id_t ctb_type;            /* CTF type identifier.  */
  ctf_dtdef_t *ctb_dtd;         /* CTF dynamic type definition (if any).  */
} ctf_bundle_t;

static int
enumcmp (const char *name, int value, void *arg)
{
  ctf_bundle_t *ctb = arg;
  int bvalue;

  if (ctf_enum_value (ctb->ctb_dict, ctb->ctb_type, name, &bvalue) < 0)
    {
      ctf_err_warn (ctb->ctb_dict, 0, 0,
                    _("conflict due to enum %s iteration error"), name);
      return 1;
    }
  if (value != bvalue)
    {
      ctf_err_warn (ctb->ctb_dict, 1, ECTF_CONFLICT,
                    _("conflict due to enum value change: %i versus %i"),
                    value, bvalue);
      return 1;
    }
  return 0;
}

static int
enumadd (const char *name, int value, void *arg)
{
  ctf_bundle_t *ctb = arg;

  return (ctf_add_enumerator (ctb->ctb_dict, ctb->ctb_type,
                              name, value) < 0);
}

static int
membcmp (const char *name, ctf_id_t type _libctf_unused_, unsigned long offset,
         void *arg)
{
  ctf_bundle_t *ctb = arg;
  ctf_membinfo_t ctm;

  /* Don't check nameless members (e.g. anonymous structs/unions) against each
     other.  */
  if (name[0] == 0)
    return 0;

  if (ctf_member_info (ctb->ctb_dict, ctb->ctb_type, name, &ctm) < 0)
    {
      ctf_err_warn (ctb->ctb_dict, 0, 0,
                    _("conflict due to struct member %s iteration error"),
                    name);
      return 1;
    }
  if (ctm.ctm_offset != offset)
    {
      ctf_err_warn (ctb->ctb_dict, 1, ECTF_CONFLICT,
                    _("conflict due to struct member %s offset change: "
                      "%lx versus %lx"),
                    name, ctm.ctm_offset, offset);
      return 1;
    }
  return 0;
}

static int
membadd (const char *name, ctf_id_t type, unsigned long offset, void *arg)
{
  ctf_bundle_t *ctb = arg;
  ctf_dmdef_t *dmd;
  char *s = NULL;

  if ((dmd = malloc (sizeof (ctf_dmdef_t))) == NULL)
    return (ctf_set_errno (ctb->ctb_dict, EAGAIN));

  if (name != NULL && (s = strdup (name)) == NULL)
    {
      free (dmd);
      return (ctf_set_errno (ctb->ctb_dict, EAGAIN));
    }

  /* For now, dmd_type is copied as the src_fp's type; it is reset to an
    equivalent dst_fp type by a final loop in ctf_add_type(), below.  */
  dmd->dmd_name = s;
  dmd->dmd_type = type;
  dmd->dmd_offset = offset;
  dmd->dmd_value = -1;

  ctf_list_append (&ctb->ctb_dtd->dtd_u.dtu_members, dmd);

  ctb->ctb_dict->ctf_flags |= LCTF_DIRTY;
  return 0;
}

/* The ctf_add_type routine is used to copy a type from a source CTF dictionary
   to a dynamic destination dictionary.  This routine operates recursively by
   following the source type's links and embedded member types.  If the
   destination dict already contains a named type which has the same attributes,
   then we succeed and return this type but no changes occur.  */
static ctf_id_t
ctf_add_type_internal (ctf_dict_t *dst_fp, ctf_dict_t *src_fp, ctf_id_t src_type,
                       ctf_dict_t *proc_tracking_fp)
{
  ctf_id_t dst_type = CTF_ERR;
  uint32_t dst_kind = CTF_K_UNKNOWN;
  ctf_dict_t *tmp_fp = dst_fp;
  ctf_id_t tmp;

  const char *name;
  uint32_t kind, forward_kind, flag, vlen;

  const ctf_type_t *src_tp, *dst_tp;
  ctf_bundle_t src, dst;
  ctf_encoding_t src_en, dst_en;
  ctf_arinfo_t src_ar, dst_ar;

  ctf_funcinfo_t ctc;

  ctf_id_t orig_src_type = src_type;

  if (!(dst_fp->ctf_flags & LCTF_RDWR))
    return (ctf_set_errno (dst_fp, ECTF_RDONLY));

  if ((src_tp = ctf_lookup_by_id (&src_fp, src_type)) == NULL)
    return (ctf_set_errno (dst_fp, ctf_errno (src_fp)));

  if ((ctf_type_resolve (src_fp, src_type) == CTF_ERR)
      && (ctf_errno (src_fp) == ECTF_NONREPRESENTABLE))
    return (ctf_set_errno (dst_fp, ECTF_NONREPRESENTABLE));

  name = ctf_strptr (src_fp, src_tp->ctt_name);
  kind = LCTF_INFO_KIND (src_fp, src_tp->ctt_info);
  flag = LCTF_INFO_ISROOT (src_fp, src_tp->ctt_info);
  vlen = LCTF_INFO_VLEN (src_fp, src_tp->ctt_info);

  /* If this is a type we are currently in the middle of adding, hand it
     straight back.  (This lets us handle self-referential structures without
     considering forwards and empty structures the same as their completed
     forms.)  */

  tmp = ctf_type_mapping (src_fp, src_type, &tmp_fp);

  if (tmp != 0)
    {
      if (ctf_dynhash_lookup (proc_tracking_fp->ctf_add_processing,
                              (void *) (uintptr_t) src_type))
        return tmp;

      /* If this type has already been added from this dictionary, and is the
         same kind and (if a struct or union) has the same number of members,
         hand it straight back.  */

      if (ctf_type_kind_unsliced (tmp_fp, tmp) == (int) kind)
        {
          if (kind == CTF_K_STRUCT || kind == CTF_K_UNION
              || kind == CTF_K_ENUM)
            {
              if ((dst_tp = ctf_lookup_by_id (&tmp_fp, dst_type)) != NULL)
                if (vlen == LCTF_INFO_VLEN (tmp_fp, dst_tp->ctt_info))
                  return tmp;
            }
          else
            return tmp;
        }
    }

  forward_kind = kind;
  if (kind == CTF_K_FORWARD)
    forward_kind = src_tp->ctt_type;

  /* If the source type has a name and is a root type (visible at the top-level
     scope), lookup the name in the destination dictionary and verify that it is
     of the same kind before we do anything else.  */

  if ((flag & CTF_ADD_ROOT) && name[0] != '\0'
      && (tmp = ctf_lookup_by_rawname (dst_fp, forward_kind, name)) != 0)
    {
      dst_type = tmp;
      dst_kind = ctf_type_kind_unsliced (dst_fp, dst_type);
    }

  /* If an identically named dst_type exists, fail with ECTF_CONFLICT
     unless dst_type is a forward declaration and src_type is a struct,
     union, or enum (i.e. the definition of the previous forward decl).

     We also allow addition in the opposite order (addition of a forward when a
     struct, union, or enum already exists), which is a NOP and returns the
     already-present struct, union, or enum.  */

  if (dst_type != CTF_ERR && dst_kind != kind)
    {
      if (kind == CTF_K_FORWARD
          && (dst_kind == CTF_K_ENUM || dst_kind == CTF_K_STRUCT
              || dst_kind == CTF_K_UNION))
        {
          ctf_add_type_mapping (src_fp, src_type, dst_fp, dst_type);
          return dst_type;
        }

      if (dst_kind != CTF_K_FORWARD
          || (kind != CTF_K_ENUM && kind != CTF_K_STRUCT
              && kind != CTF_K_UNION))
        {
          ctf_err_warn (dst_fp, 1, ECTF_CONFLICT,
                        _("ctf_add_type: conflict for type %s: "
                          "kinds differ, new: %i; old (ID %lx): %i"),
                        name, kind, dst_type, dst_kind);
          return (ctf_set_errno (dst_fp, ECTF_CONFLICT));
        }
    }

  /* We take special action for an integer, float, or slice since it is
     described not only by its name but also its encoding.  For integers,
     bit-fields exploit this degeneracy.  */

  if (kind == CTF_K_INTEGER || kind == CTF_K_FLOAT || kind == CTF_K_SLICE)
    {
      if (ctf_type_encoding (src_fp, src_type, &src_en) != 0)
        return (ctf_set_errno (dst_fp, ctf_errno (src_fp)));

      if (dst_type != CTF_ERR)
        {
          ctf_dict_t *fp = dst_fp;

          if ((dst_tp = ctf_lookup_by_id (&fp, dst_type)) == NULL)
            return CTF_ERR;

          if (ctf_type_encoding (dst_fp, dst_type, &dst_en) != 0)
            return CTF_ERR;                     /* errno set for us.  */

          if (LCTF_INFO_ISROOT (fp, dst_tp->ctt_info) & CTF_ADD_ROOT)
            {
              /* The type that we found in the hash is also root-visible.  If
                 the two types match then use the existing one; otherwise,
                 declare a conflict.  Note: slices are not certain to match
                 even if there is no conflict: we must check the contained type
                 too.  */

              if (memcmp (&src_en, &dst_en, sizeof (ctf_encoding_t)) == 0)
                {
                  if (kind != CTF_K_SLICE)
                    {
                      ctf_add_type_mapping (src_fp, src_type, dst_fp, dst_type);
                      return dst_type;
                    }
                }
              else
                  {
                    return (ctf_set_errno (dst_fp, ECTF_CONFLICT));
                  }
            }
          else
            {
              /* We found a non-root-visible type in the hash.  If its encoding
                 is the same, we can reuse it, unless it is a slice.  */

              if (memcmp (&src_en, &dst_en, sizeof (ctf_encoding_t)) == 0)
                {
                  if (kind != CTF_K_SLICE)
                    {
                      ctf_add_type_mapping (src_fp, src_type, dst_fp, dst_type);
                      return dst_type;
                    }
                }
            }
        }
    }

  src.ctb_dict = src_fp;
  src.ctb_type = src_type;
  src.ctb_dtd = NULL;

  dst.ctb_dict = dst_fp;
  dst.ctb_type = dst_type;
  dst.ctb_dtd = NULL;

  /* Now perform kind-specific processing.  If dst_type is CTF_ERR, then we add
     a new type with the same properties as src_type to dst_fp.  If dst_type is
     not CTF_ERR, then we verify that dst_type has the same attributes as
     src_type.  We recurse for embedded references.  Before we start, we note
     that we are processing this type, to prevent infinite recursion: we do not
     re-process any type that appears in this list.  The list is emptied
     wholesale at the end of processing everything in this recursive stack.  */

  if (ctf_dynhash_insert (proc_tracking_fp->ctf_add_processing,
                          (void *) (uintptr_t) src_type, (void *) 1) < 0)
    return ctf_set_errno (dst_fp, ENOMEM);

  switch (kind)
    {
    case CTF_K_INTEGER:
      /*  If we found a match we will have either returned it or declared a
          conflict.  */
      dst_type = ctf_add_integer (dst_fp, flag, name, &src_en);
      break;

    case CTF_K_FLOAT:
      /* If we found a match we will have either returned it or declared a
       conflict.  */
      dst_type = ctf_add_float (dst_fp, flag, name, &src_en);
      break;

    case CTF_K_SLICE:
      /* We have checked for conflicting encodings: now try to add the
         contained type.  */
      src_type = ctf_type_reference (src_fp, src_type);
      src_type = ctf_add_type_internal (dst_fp, src_fp, src_type,
                                        proc_tracking_fp);

      if (src_type == CTF_ERR)
        return CTF_ERR;                         /* errno is set for us.  */

      dst_type = ctf_add_slice (dst_fp, flag, src_type, &src_en);
      break;

    case CTF_K_POINTER:
    case CTF_K_VOLATILE:
    case CTF_K_CONST:
    case CTF_K_RESTRICT:
      src_type = ctf_type_reference (src_fp, src_type);
      src_type = ctf_add_type_internal (dst_fp, src_fp, src_type,
                                        proc_tracking_fp);

      if (src_type == CTF_ERR)
        return CTF_ERR;                         /* errno is set for us.  */

      dst_type = ctf_add_reftype (dst_fp, flag, src_type, kind);
      break;

    case CTF_K_ARRAY:
      if (ctf_array_info (src_fp, src_type, &src_ar) != 0)
        return (ctf_set_errno (dst_fp, ctf_errno (src_fp)));

      src_ar.ctr_contents =
        ctf_add_type_internal (dst_fp, src_fp, src_ar.ctr_contents,
                               proc_tracking_fp);
      src_ar.ctr_index = ctf_add_type_internal (dst_fp, src_fp,
                                                src_ar.ctr_index,
                                                proc_tracking_fp);
      src_ar.ctr_nelems = src_ar.ctr_nelems;

      if (src_ar.ctr_contents == CTF_ERR || src_ar.ctr_index == CTF_ERR)
        return CTF_ERR;                         /* errno is set for us.  */

      if (dst_type != CTF_ERR)
        {
          if (ctf_array_info (dst_fp, dst_type, &dst_ar) != 0)
            return CTF_ERR;                     /* errno is set for us.  */

          if (memcmp (&src_ar, &dst_ar, sizeof (ctf_arinfo_t)))
            {
              ctf_err_warn (dst_fp, 1, ECTF_CONFLICT,
                            _("conflict for type %s against ID %lx: array info "
                              "differs, old %lx/%lx/%x; new: %lx/%lx/%x"),
                            name, dst_type, src_ar.ctr_contents,
                            src_ar.ctr_index, src_ar.ctr_nelems,
                            dst_ar.ctr_contents, dst_ar.ctr_index,
                            dst_ar.ctr_nelems);
              return (ctf_set_errno (dst_fp, ECTF_CONFLICT));
            }
        }
      else
        dst_type = ctf_add_array (dst_fp, flag, &src_ar);
      break;

    case CTF_K_FUNCTION:
      ctc.ctc_return = ctf_add_type_internal (dst_fp, src_fp,
                                              src_tp->ctt_type,
                                              proc_tracking_fp);
      ctc.ctc_argc = 0;
      ctc.ctc_flags = 0;

      if (ctc.ctc_return == CTF_ERR)
        return CTF_ERR;                         /* errno is set for us.  */

      dst_type = ctf_add_function (dst_fp, flag, &ctc, NULL);
      break;

    case CTF_K_STRUCT:
    case CTF_K_UNION:
      {
        ctf_dmdef_t *dmd;
        int errs = 0;
        size_t size;
        ssize_t ssize;
        ctf_dtdef_t *dtd;

        /* Technically to match a struct or union we need to check both
           ways (src members vs. dst, dst members vs. src) but we make
           this more optimal by only checking src vs. dst and comparing
           the total size of the structure (which we must do anyway)
           which covers the possibility of dst members not in src.
           This optimization can be defeated for unions, but is so
           pathological as to render it irrelevant for our purposes.  */

        if (dst_type != CTF_ERR && kind != CTF_K_FORWARD
            && dst_kind != CTF_K_FORWARD)
          {
            if (ctf_type_size (src_fp, src_type) !=
                ctf_type_size (dst_fp, dst_type))
              {
                ctf_err_warn (dst_fp, 1, ECTF_CONFLICT,
                              _("conflict for type %s against ID %lx: union "
                                "size differs, old %li, new %li"), name,
                              dst_type, (long) ctf_type_size (src_fp, src_type),
                              (long) ctf_type_size (dst_fp, dst_type));
                return (ctf_set_errno (dst_fp, ECTF_CONFLICT));
              }

            if (ctf_member_iter (src_fp, src_type, membcmp, &dst))
              {
                ctf_err_warn (dst_fp, 1, ECTF_CONFLICT,
                              _("conflict for type %s against ID %lx: members "
                                "differ, see above"), name, dst_type);
                return (ctf_set_errno (dst_fp, ECTF_CONFLICT));
              }

            break;
          }

        /* Unlike the other cases, copying structs and unions is done
           manually so as to avoid repeated lookups in ctf_add_member
           and to ensure the exact same member offsets as in src_type.  */

        dst_type = ctf_add_generic (dst_fp, flag, name, kind, &dtd);
        if (dst_type == CTF_ERR)
          return CTF_ERR;                       /* errno is set for us.  */

        dst.ctb_type = dst_type;
        dst.ctb_dtd = dtd;

        /* Pre-emptively add this struct to the type mapping so that
           structures that refer to themselves work.  */
        ctf_add_type_mapping (src_fp, src_type, dst_fp, dst_type);

        if (ctf_member_iter (src_fp, src_type, membadd, &dst) != 0)
          errs++;              /* Increment errs and fail at bottom of case.  */

        if ((ssize = ctf_type_size (src_fp, src_type)) < 0)
          return CTF_ERR;                       /* errno is set for us.  */

        size = (size_t) ssize;
        if (size > CTF_MAX_SIZE)
          {
            dtd->dtd_data.ctt_size = CTF_LSIZE_SENT;
            dtd->dtd_data.ctt_lsizehi = CTF_SIZE_TO_LSIZE_HI (size);
            dtd->dtd_data.ctt_lsizelo = CTF_SIZE_TO_LSIZE_LO (size);
          }
        else
          dtd->dtd_data.ctt_size = (uint32_t) size;

        dtd->dtd_data.ctt_info = CTF_TYPE_INFO (kind, flag, vlen);

        /* Make a final pass through the members changing each dmd_type (a
           src_fp type) to an equivalent type in dst_fp.  We pass through all
           members, leaving any that fail set to CTF_ERR, unless they fail
           because they are marking a member of type not representable in this
           version of CTF, in which case we just want to silently omit them:
           no consumer can do anything with them anyway.  */
        for (dmd = ctf_list_next (&dtd->dtd_u.dtu_members);
             dmd != NULL; dmd = ctf_list_next (dmd))
          {
            ctf_dict_t *dst = dst_fp;
            ctf_id_t memb_type;

            memb_type = ctf_type_mapping (src_fp, dmd->dmd_type, &dst);
            if (memb_type == 0)
              {
                if ((dmd->dmd_type =
                     ctf_add_type_internal (dst_fp, src_fp, dmd->dmd_type,
                                            proc_tracking_fp)) == CTF_ERR)
                  {
                    if (ctf_errno (dst_fp) != ECTF_NONREPRESENTABLE)
                      errs++;
                  }
              }
            else
              dmd->dmd_type = memb_type;
          }

        if (errs)
          return CTF_ERR;                       /* errno is set for us.  */
        break;
      }

    case CTF_K_ENUM:
      if (dst_type != CTF_ERR && kind != CTF_K_FORWARD
          && dst_kind != CTF_K_FORWARD)
        {
          if (ctf_enum_iter (src_fp, src_type, enumcmp, &dst)
              || ctf_enum_iter (dst_fp, dst_type, enumcmp, &src))
            {
              ctf_err_warn (dst_fp, 1, ECTF_CONFLICT,
                            _("conflict for enum %s against ID %lx: members "
                              "differ, see above"), name, dst_type);
              return (ctf_set_errno (dst_fp, ECTF_CONFLICT));
            }
        }
      else
        {
          dst_type = ctf_add_enum (dst_fp, flag, name);
          if ((dst.ctb_type = dst_type) == CTF_ERR
              || ctf_enum_iter (src_fp, src_type, enumadd, &dst))
            return CTF_ERR;                     /* errno is set for us */
        }
      break;

    case CTF_K_FORWARD:
      if (dst_type == CTF_ERR)
          dst_type = ctf_add_forward (dst_fp, flag, name, forward_kind);
      break;

    case CTF_K_TYPEDEF:
      src_type = ctf_type_reference (src_fp, src_type);
      src_type = ctf_add_type_internal (dst_fp, src_fp, src_type,
                                        proc_tracking_fp);

      if (src_type == CTF_ERR)
        return CTF_ERR;                         /* errno is set for us.  */

      /* If dst_type is not CTF_ERR at this point, we should check if
         ctf_type_reference(dst_fp, dst_type) != src_type and if so fail with
         ECTF_CONFLICT.  However, this causes problems with bitness typedefs
         that vary based on things like if 32-bit then pid_t is int otherwise
         long.  We therefore omit this check and assume that if the identically
         named typedef already exists in dst_fp, it is correct or
         equivalent.  */

      if (dst_type == CTF_ERR)
          dst_type = ctf_add_typedef (dst_fp, flag, name, src_type);

      break;

    default:
      return (ctf_set_errno (dst_fp, ECTF_CORRUPT));
    }

  if (dst_type != CTF_ERR)
    ctf_add_type_mapping (src_fp, orig_src_type, dst_fp, dst_type);
  return dst_type;
}

ctf_id_t
ctf_add_type (ctf_dict_t *dst_fp, ctf_dict_t *src_fp, ctf_id_t src_type)
{
  ctf_id_t id;

  if (!src_fp->ctf_add_processing)
    src_fp->ctf_add_processing = ctf_dynhash_create (ctf_hash_integer,
                                                     ctf_hash_eq_integer,
                                                     NULL, NULL);

  /* We store the hash on the source, because it contains only source type IDs:
     but callers will invariably expect errors to appear on the dest.  */
  if (!src_fp->ctf_add_processing)
    return (ctf_set_errno (dst_fp, ENOMEM));

  id = ctf_add_type_internal (dst_fp, src_fp, src_type, src_fp);
  ctf_dynhash_empty (src_fp->ctf_add_processing);

  return id;
}

/* Write the compressed CTF data stream to the specified gzFile descriptor.  */
int
ctf_gzwrite (ctf_dict_t *fp, gzFile fd)
{
  const unsigned char *buf;
  ssize_t resid;
  ssize_t len;

  resid = sizeof (ctf_header_t);
  buf = (unsigned char *) fp->ctf_header;
  while (resid != 0)
    {
      if ((len = gzwrite (fd, buf, resid)) <= 0)
        return (ctf_set_errno (fp, errno));
      resid -= len;
      buf += len;
    }

  resid = fp->ctf_size;
  buf = fp->ctf_buf;
  while (resid != 0)
    {
      if ((len = gzwrite (fd, buf, resid)) <= 0)
        return (ctf_set_errno (fp, errno));
      resid -= len;
      buf += len;
    }

  return 0;
}

/* Compress the specified CTF data stream and write it to the specified file
   descriptor.  */
int
ctf_compress_write (ctf_dict_t *fp, int fd)
{
  unsigned char *buf;
  unsigned char *bp;
  ctf_header_t h;
  ctf_header_t *hp = &h;
  ssize_t header_len = sizeof (ctf_header_t);
  ssize_t compress_len;
  ssize_t len;
  int rc;
  int err = 0;

  if (ctf_serialize (fp) < 0)
    return -1;                                  /* errno is set for us.  */

  memcpy (hp, fp->ctf_header, header_len);
  hp->cth_flags |= CTF_F_COMPRESS;
  compress_len = compressBound (fp->ctf_size);

  if ((buf = malloc (compress_len)) == NULL)
    {
      ctf_err_warn (fp, 0, 0, _("ctf_compress_write: cannot allocate %li bytes"),
                    (unsigned long) compress_len);
      return (ctf_set_errno (fp, ECTF_ZALLOC));
    }

  if ((rc = compress (buf, (uLongf *) &compress_len,
                      fp->ctf_buf, fp->ctf_size)) != Z_OK)
    {
      err = ctf_set_errno (fp, ECTF_COMPRESS);
      ctf_err_warn (fp, 0, 0, _("zlib deflate err: %s"), zError (rc));
      goto ret;
    }

  while (header_len > 0)
    {
      if ((len = write (fd, hp, header_len)) < 0)
        {
          err = ctf_set_errno (fp, errno);
          ctf_err_warn (fp, 0, 0, _("ctf_compress_write: error writing header"));
          goto ret;
        }
      header_len -= len;
      hp += len;
    }

  bp = buf;
  while (compress_len > 0)
    {
      if ((len = write (fd, bp, compress_len)) < 0)
        {
          err = ctf_set_errno (fp, errno);
          ctf_err_warn (fp, 0, 0, _("ctf_compress_write: error writing"));
          goto ret;
        }
      compress_len -= len;
      bp += len;
    }

ret:
  free (buf);
  return err;
}

/* Optionally compress the specified CTF data stream and return it as a new
   dynamically-allocated string.  */
unsigned char *
ctf_write_mem (ctf_dict_t *fp, size_t *size, size_t threshold)
{
  unsigned char *buf;
  unsigned char *bp;
  ctf_header_t *hp;
  ssize_t header_len = sizeof (ctf_header_t);
  ssize_t compress_len;
  int rc;

  if (ctf_serialize (fp) < 0)
    return NULL;                                /* errno is set for us.  */

  compress_len = compressBound (fp->ctf_size);
  if (fp->ctf_size < threshold)
    compress_len = fp->ctf_size;
  if ((buf = malloc (compress_len
                     + sizeof (struct ctf_header))) == NULL)
    {
      ctf_set_errno (fp, ENOMEM);
      ctf_err_warn (fp, 0, 0, _("ctf_write_mem: cannot allocate %li bytes"),
                    (unsigned long) (compress_len + sizeof (struct ctf_header)));
      return NULL;
    }

  hp = (ctf_header_t *) buf;
  memcpy (hp, fp->ctf_header, header_len);
  bp = buf + sizeof (struct ctf_header);
  *size = sizeof (struct ctf_header);

  if (fp->ctf_size < threshold)
    {
      hp->cth_flags &= ~CTF_F_COMPRESS;
      memcpy (bp, fp->ctf_buf, fp->ctf_size);
      *size += fp->ctf_size;
    }
  else
    {
      hp->cth_flags |= CTF_F_COMPRESS;
      if ((rc = compress (bp, (uLongf *) &compress_len,
                          fp->ctf_buf, fp->ctf_size)) != Z_OK)
        {
          ctf_set_errno (fp, ECTF_COMPRESS);
          ctf_err_warn (fp, 0, 0, _("zlib deflate err: %s"), zError (rc));
          free (buf);
          return NULL;
        }
      *size += compress_len;
    }
  return buf;
}

/* Write the uncompressed CTF data stream to the specified file descriptor.  */
int
ctf_write (ctf_dict_t *fp, int fd)
{
  const unsigned char *buf;
  ssize_t resid;
  ssize_t len;

  if (ctf_serialize (fp) < 0)
    return -1;                                  /* errno is set for us.  */

  resid = sizeof (ctf_header_t);
  buf = (unsigned char *) fp->ctf_header;
  while (resid != 0)
    {
      if ((len = write (fd, buf, resid)) <= 0)
        {
          ctf_err_warn (fp, 0, errno, _("ctf_write: error writing header"));
          return (ctf_set_errno (fp, errno));
        }
      resid -= len;
      buf += len;
    }

  resid = fp->ctf_size;
  buf = fp->ctf_buf;
  while (resid != 0)
    {
      if ((len = write (fd, buf, resid)) <= 0)
        {
          ctf_err_warn (fp, 0, errno, _("ctf_write: error writing"));
          return (ctf_set_errno (fp, errno));
        }
      resid -= len;
      buf += len;
    }

  return 0;
}