/*

 * Copyright © 2018 Adobe Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Adobe Author(s): Michiharu Ariza

 */

#include "hb.hh"

#ifndef HB_NO_SUBSET_CFF

#include "hb-open-type.hh"

#include "hb-ot-cff1-table.hh"

#include "hb-set.h"

#include "hb-bimap.hh"

#include "hb-subset-cff1.hh"

#include "hb-subset-plan.hh"

#include "hb-subset-cff-common.hh"

#include "hb-cff1-interp-cs.hh"

using namespace CFF;

struct remap_sid_t : hb_inc_bimap_t

{

  unsigned int add (unsigned int sid)

  {

    if ((sid != CFF_UNDEF_SID) && !is_std_std (sid))

      return offset_sid (hb_inc_bimap_t::add (unoffset_sid (sid)));

    else

      return sid;

  }

  unsigned int operator[] (unsigned int sid) const

  {

    if (is_std_std (sid) || (sid == CFF_UNDEF_SID))

      return sid;

    else

      return offset_sid (get (unoffset_sid (sid)));

  }

  static const unsigned int num_std_strings = 391;

  static bool is_std_std (unsigned int sid) { return sid < num_std_strings; }

  static unsigned int offset_sid (unsigned int sid) { return sid + num_std_strings; }

  static unsigned int unoffset_sid (unsigned int sid) { return sid - num_std_strings; }

};

struct cff1_sub_table_info_t : cff_sub_table_info_t

{

  cff1_sub_table_info_t ()

    : cff_sub_table_info_t (),

      encoding_link (0),

      charset_link (0)

   {

    privateDictInfo.init ();

  }

  objidx_t  encoding_link;

  objidx_t  charset_link;

  table_info_t  privateDictInfo;

};

/* a copy of a parsed out cff1_top_dict_values_t augmented with additional operators */

struct cff1_top_dict_values_mod_t : cff1_top_dict_values_t

{

  void init (const cff1_top_dict_values_t *base_= &Null (cff1_top_dict_values_t))

  {

    SUPER::init ();

    base = base_;

  }

  void fini () { SUPER::fini (); }

  unsigned get_count () const { return base->get_count () + SUPER::get_count (); }

  const cff1_top_dict_val_t &get_value (unsigned int i) const

  {

    if (i < base->get_count ())

      return (*base)[i];

    else

      return SUPER::values[i - base->get_count ()];

  }

  const cff1_top_dict_val_t &operator [] (unsigned int i) const { return get_value (i); }

  void reassignSIDs (const remap_sid_t& sidmap)

  {

    for (unsigned int i = 0; i < name_dict_values_t::ValCount; i++)

      nameSIDs[i] = sidmap[base->nameSIDs[i]];

  }

  protected:

  typedef cff1_top_dict_values_t SUPER;

  const cff1_top_dict_values_t *base;

};

struct top_dict_modifiers_t

{

  top_dict_modifiers_t (const cff1_sub_table_info_t &info_,

      const unsigned int (&nameSIDs_)[name_dict_values_t::ValCount])

    : info (info_),

      nameSIDs (nameSIDs_)

  {}

  const cff1_sub_table_info_t &info;

  const unsigned int  (&nameSIDs)[name_dict_values_t::ValCount];

};

struct cff1_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<cff1_top_dict_val_t>

{

  bool serialize (hb_serialize_context_t *c,

      const cff1_top_dict_val_t &opstr,

      const top_dict_modifiers_t &mod) const

  {

    TRACE_SERIALIZE (this);

    op_code_t op = opstr.op;

    switch (op)

    {

      case OpCode_charset:

  if (mod.info.charset_link)

    return_trace (FontDict::serialize_link4_op(c, op, mod.info.charset_link, whence_t::Absolute));

  else

    goto fall_back;

      case OpCode_Encoding:

  if (mod.info.encoding_link)

    return_trace (FontDict::serialize_link4_op(c, op, mod.info.encoding_link, whence_t::Absolute));

  else

    goto fall_back;

      case OpCode_Private:

  return_trace (UnsizedByteStr::serialize_int2 (c, mod.info.privateDictInfo.size) &&

          Dict::serialize_link4_op (c, op, mod.info.privateDictInfo.link, whence_t::Absolute));

      case OpCode_version:

      case OpCode_Notice:

      case OpCode_Copyright:

      case OpCode_FullName:

      case OpCode_FamilyName:

      case OpCode_Weight:

      case OpCode_PostScript:

      case OpCode_BaseFontName:

      case OpCode_FontName:

  return_trace (FontDict::serialize_int2_op (c, op, mod.nameSIDs[name_dict_values_t::name_op_to_index (op)]));

      case OpCode_ROS:

  {

    /* for registry & ordering, reassigned SIDs are serialized

     * for supplement, the original byte string is copied along with the op code */

    op_str_t supp_op;

    supp_op.op = op;

    if ( unlikely (!(opstr.str.length >= opstr.last_arg_offset + 3)))

      return_trace (false);

    supp_op.str = byte_str_t (&opstr.str + opstr.last_arg_offset, opstr.str.length - opstr.last_arg_offset);

    return_trace (UnsizedByteStr::serialize_int2 (c, mod.nameSIDs[name_dict_values_t::registry]) &&

      UnsizedByteStr::serialize_int2 (c, mod.nameSIDs[name_dict_values_t::ordering]) &&

      copy_opstr (c, supp_op));

  }

      fall_back:

      default:

  return_trace (cff_top_dict_op_serializer_t<cff1_top_dict_val_t>::serialize (c, opstr, mod.info));

    }

    return_trace (true);

  }

};

struct cff1_font_dict_op_serializer_t : cff_font_dict_op_serializer_t

{

  bool serialize (hb_serialize_context_t *c,

      const op_str_t &opstr,

      const cff1_font_dict_values_mod_t &mod) const

  {

    TRACE_SERIALIZE (this);

    if (opstr.op == OpCode_FontName)

      return_trace (FontDict::serialize_int2_op (c, opstr.op, mod.fontName));

    else

      return_trace (SUPER::serialize (c, opstr, mod.privateDictInfo));

  }

  private:

  typedef cff_font_dict_op_serializer_t SUPER;

};

struct cff1_cs_opset_flatten_t : cff1_cs_opset_t<cff1_cs_opset_flatten_t, flatten_param_t>

{

  static void flush_args_and_op (op_code_t op, cff1_cs_interp_env_t &env, flatten_param_t& param)

  {

    if (env.arg_start > 0)

      flush_width (env, param);

    switch (op)

    {

      case OpCode_hstem:

      case OpCode_hstemhm:

      case OpCode_vstem:

      case OpCode_vstemhm:

      case OpCode_hintmask:

      case OpCode_cntrmask:

      case OpCode_dotsection:

  if (param.drop_hints)

  {

    env.clear_args ();

    return;

  }

  HB_FALLTHROUGH;

      default:

  SUPER::flush_args_and_op (op, env, param);

  break;

    }

  }

  static void flush_args (cff1_cs_interp_env_t &env, flatten_param_t& param)

  {

    str_encoder_t  encoder (param.flatStr);

    for (unsigned int i = env.arg_start; i < env.argStack.get_count (); i++)

      encoder.encode_num (env.eval_arg (i));

    SUPER::flush_args (env, param);

  }

  static void flush_op (op_code_t op, cff1_cs_interp_env_t &env, flatten_param_t& param)

  {

    str_encoder_t  encoder (param.flatStr);

    encoder.encode_op (op);

  }

  static void flush_width (cff1_cs_interp_env_t &env, flatten_param_t& param)

  {

    assert (env.has_width);

    str_encoder_t  encoder (param.flatStr);

    encoder.encode_num (env.width);

  }

  static void flush_hintmask (op_code_t op, cff1_cs_interp_env_t &env, flatten_param_t& param)

  {

    SUPER::flush_hintmask (op, env, param);

    if (!param.drop_hints)

    {

      str_encoder_t  encoder (param.flatStr);

      for (unsigned int i = 0; i < env.hintmask_size; i++)

  encoder.encode_byte (env.str_ref[i]);

    }

  }

  private:

  typedef cff1_cs_opset_t<cff1_cs_opset_flatten_t, flatten_param_t> SUPER;

};

struct range_list_t : hb_vector_t<code_pair_t>

{

  /* replace the first glyph ID in the "glyph" field each range with a nLeft value */

  bool complete (unsigned int last_glyph)

  {

    bool  two_byte = false;

    for (unsigned int i = (*this).length; i > 0; i--)

    {

      code_pair_t &pair = (*this)[i - 1];

      unsigned int  nLeft = last_glyph - pair.glyph - 1;

      if (nLeft >= 0x100)

  two_byte = true;

      last_glyph = pair.glyph;

      pair.glyph = nLeft;

    }

    return two_byte;

  }

};

struct cff1_cs_opset_subr_subset_t : cff1_cs_opset_t<cff1_cs_opset_subr_subset_t, subr_subset_param_t>

{

  static void process_op (op_code_t op, cff1_cs_interp_env_t &env, subr_subset_param_t& param)

  {

    switch (op) {

      case OpCode_return:

  param.current_parsed_str->add_op (op, env.str_ref);

  param.current_parsed_str->set_parsed ();

  env.return_from_subr ();

  param.set_current_str (env, false);

  break;

      case OpCode_endchar:

  param.current_parsed_str->add_op (op, env.str_ref);

  param.current_parsed_str->set_parsed ();

  SUPER::process_op (op, env, param);

  break;

      case OpCode_callsubr:

  process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);

  break;

      case OpCode_callgsubr:

  process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);

  break;

      default:

  SUPER::process_op (op, env, param);

  param.current_parsed_str->add_op (op, env.str_ref);

  break;

    }

  }

  protected:

  static void process_call_subr (op_code_t op, cs_type_t type,

         cff1_cs_interp_env_t &env, subr_subset_param_t& param,

         cff1_biased_subrs_t& subrs, hb_set_t *closure)

  {

    byte_str_ref_t    str_ref = env.str_ref;

    env.call_subr (subrs, type);

    param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);

    closure->add (env.context.subr_num);

    param.set_current_str (env, true);

  }

  private:

  typedef cff1_cs_opset_t<cff1_cs_opset_subr_subset_t, subr_subset_param_t> SUPER;

};

struct cff1_subr_subsetter_t : subr_subsetter_t<cff1_subr_subsetter_t, CFF1Subrs, const OT::cff1::accelerator_subset_t, cff1_cs_interp_env_t, cff1_cs_opset_subr_subset_t, OpCode_endchar>

{

  cff1_subr_subsetter_t (const OT::cff1::accelerator_subset_t &acc_, const hb_subset_plan_t *plan_)

    : subr_subsetter_t (acc_, plan_) {}

  static void complete_parsed_str (cff1_cs_interp_env_t &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)

  {

    /* insert width at the beginning of the charstring as necessary */

    if (env.has_width)

      charstring.set_prefix (env.width);

    /* subroutines/charstring left on the call stack are legally left unmarked

     * unmarked when a subroutine terminates with endchar. mark them.

     */

    param.current_parsed_str->set_parsed ();

    for (unsigned int i = 0; i < env.callStack.get_count (); i++)

    {

      parsed_cs_str_t *parsed_str = param.get_parsed_str_for_context (env.callStack[i]);

      if (likely (parsed_str))

  parsed_str->set_parsed ();

      else

  env.set_error ();

    }

  }

};

struct cff_subset_plan {

  cff_subset_plan ()

    : info (),

      orig_fdcount (0),

      subset_fdcount (1),

      subset_fdselect_format (0),

      drop_hints (false),

      desubroutinize(false)

  {

    topdict_mod.init ();

    subset_fdselect_ranges.init ();

    fdmap.init ();

    subset_charstrings.init ();

    subset_globalsubrs.init ();

    subset_localsubrs.init ();

    fontdicts_mod.init ();

    subset_enc_code_ranges.init ();

    subset_enc_supp_codes.init ();

    subset_charset_ranges.init ();

    sidmap.init ();

    for (unsigned int i = 0; i < name_dict_values_t::ValCount; i++)

      topDictModSIDs[i] = CFF_UNDEF_SID;

  }

  ~cff_subset_plan ()

  {

    topdict_mod.fini ();

    subset_fdselect_ranges.fini ();

    fdmap.fini ();

    subset_charstrings.fini_deep ();

    subset_globalsubrs.fini_deep ();

    subset_localsubrs.fini_deep ();

    fontdicts_mod.fini ();

    subset_enc_code_ranges.fini ();

    subset_enc_supp_codes.fini ();

    subset_charset_ranges.fini ();

    sidmap.fini ();

  }

  void plan_subset_encoding (const OT::cff1::accelerator_subset_t &acc, hb_subset_plan_t *plan)

  {

    const Encoding *encoding = acc.encoding;

    unsigned int  size0, size1;

    hb_codepoint_t  code, last_code = CFF_UNDEF_CODE;

    hb_vector_t<hb_codepoint_t> supp_codes;

    if (unlikely (!subset_enc_code_ranges.resize (0)))

    {

      plan->check_success (false);

      return;

    }

    supp_codes.init ();

    subset_enc_num_codes = plan->num_output_glyphs () - 1;

    unsigned int glyph;

    for (glyph = 1; glyph < plan->num_output_glyphs (); glyph++)

    {

      hb_codepoint_t  old_glyph;

      if (!plan->old_gid_for_new_gid (glyph, &old_glyph))

      {

  /* Retain the code for the old missing glyph ID */

  old_glyph = glyph;

      }

      code = acc.glyph_to_code (old_glyph);

      if (code == CFF_UNDEF_CODE)

      {

  subset_enc_num_codes = glyph - 1;

  break;

      }

      if ((last_code == CFF_UNDEF_CODE) || (code != last_code + 1))

      {

  code_pair_t pair = { code, glyph };

  subset_enc_code_ranges.push (pair);

      }

      last_code = code;

      if (encoding != &Null (Encoding))

      {

  hb_codepoint_t  sid = acc.glyph_to_sid (old_glyph);

  encoding->get_supplement_codes (sid, supp_codes);

  for (unsigned int i = 0; i < supp_codes.length; i++)

  {

    code_pair_t pair = { supp_codes[i], sid };

    subset_enc_supp_codes.push (pair);

  }

      }

    }

    supp_codes.fini ();

    subset_enc_code_ranges.complete (glyph);

    assert (subset_enc_num_codes <= 0xFF);

    size0 = Encoding0::min_size + HBUINT8::static_size * subset_enc_num_codes;

    size1 = Encoding1::min_size + Encoding1_Range::static_size * subset_enc_code_ranges.length;

    if (size0 < size1)

      subset_enc_format = 0;

    else

      subset_enc_format = 1;

  }

  void plan_subset_charset (const OT::cff1::accelerator_subset_t &acc, hb_subset_plan_t *plan)

  {

    unsigned int  size0, size_ranges;

    hb_codepoint_t  sid, last_sid = CFF_UNDEF_CODE;

    if (unlikely (!subset_charset_ranges.resize (0)))

    {

      plan->check_success (false);

      return;

    }

    unsigned int glyph;

    for (glyph = 1; glyph < plan->num_output_glyphs (); glyph++)

    {

      hb_codepoint_t  old_glyph;

      if (!plan->old_gid_for_new_gid (glyph, &old_glyph))

      {

  /* Retain the SID for the old missing glyph ID */

  old_glyph = glyph;

      }

      sid = acc.glyph_to_sid (old_glyph);

      if (!acc.is_CID ())

  sid = sidmap.add (sid);

      if ((last_sid == CFF_UNDEF_CODE) || (sid != last_sid + 1))

      {

  code_pair_t pair = { sid, glyph };

  subset_charset_ranges.push (pair);

      }

      last_sid = sid;

    }

    bool two_byte = subset_charset_ranges.complete (glyph);

    size0 = Charset0::min_size + HBUINT16::static_size * (plan->num_output_glyphs () - 1);

    if (!two_byte)

      size_ranges = Charset1::min_size + Charset1_Range::static_size * subset_charset_ranges.length;

    else

      size_ranges = Charset2::min_size + Charset2_Range::static_size * subset_charset_ranges.length;

    if (size0 < size_ranges)

      subset_charset_format = 0;

    else if (!two_byte)

      subset_charset_format = 1;

    else

      subset_charset_format = 2;

  }

  bool collect_sids_in_dicts (const OT::cff1::accelerator_subset_t &acc)

  {

    sidmap.reset ();

    for (unsigned int i = 0; i < name_dict_values_t::ValCount; i++)

    {

      unsigned int sid = acc.topDict.nameSIDs[i];

      if (sid != CFF_UNDEF_SID)

      {

  (void)sidmap.add (sid);

  topDictModSIDs[i] = sidmap[sid];

      }

    }

    if (acc.fdArray != &Null (CFF1FDArray))

      for (unsigned int i = 0; i < orig_fdcount; i++)

  if (fdmap.has (i))

    (void)sidmap.add (acc.fontDicts[i].fontName);

    return true;

  }

  bool create (const OT::cff1::accelerator_subset_t &acc,

         hb_subset_plan_t *plan)

  {

    /* make sure notdef is first */

    hb_codepoint_t old_glyph;

    if (!plan->old_gid_for_new_gid (0, &old_glyph) || (old_glyph != 0)) return false;

    num_glyphs = plan->num_output_glyphs ();

    orig_fdcount = acc.fdCount;

    drop_hints = plan->flags & HB_SUBSET_FLAGS_NO_HINTING;

    desubroutinize = plan->flags & HB_SUBSET_FLAGS_DESUBROUTINIZE;

    /* check whether the subset renumbers any glyph IDs */

    gid_renum = false;

    for (hb_codepoint_t new_glyph = 0; new_glyph < plan->num_output_glyphs (); new_glyph++)

    {

      if (!plan->old_gid_for_new_gid(new_glyph, &old_glyph))

  continue;

      if (new_glyph != old_glyph) {

  gid_renum = true;

  break;

      }

    }

    subset_charset = gid_renum || !acc.is_predef_charset ();

    subset_encoding = !acc.is_CID() && !acc.is_predef_encoding ();

    /* top dict INDEX */

    {

      /* Add encoding/charset to a (copy of) top dict as necessary */

      topdict_mod.init (&acc.topDict);

      bool need_to_add_enc = (subset_encoding && !acc.topDict.has_op (OpCode_Encoding));

      bool need_to_add_set = (subset_charset && !acc.topDict.has_op (OpCode_charset));

      if (need_to_add_enc || need_to_add_set)

      {

  if (need_to_add_enc)

    topdict_mod.add_op (OpCode_Encoding);

  if (need_to_add_set)

    topdict_mod.add_op (OpCode_charset);

      }

    }

    /* Determine re-mapping of font index as fdmap among other info */

    if (acc.fdSelect != &Null (CFF1FDSelect))

    {

  if (unlikely (!hb_plan_subset_cff_fdselect (plan,

          orig_fdcount,

          *acc.fdSelect,

          subset_fdcount,

          info.fd_select.size,

          subset_fdselect_format,

          subset_fdselect_ranges,

          fdmap)))

  return false;

    }

    else

      fdmap.identity (1);

    /* remove unused SIDs & reassign SIDs */

    {

      /* SIDs for name strings in dicts are added before glyph names so they fit in 16-bit int range */

      if (unlikely (!collect_sids_in_dicts (acc)))

  return false;

      if (unlikely (sidmap.get_population () > 0x8000)) /* assumption: a dict won't reference that many strings */

  return false;

      if (subset_charset) plan_subset_charset (acc, plan);

      topdict_mod.reassignSIDs (sidmap);

    }

    if (desubroutinize)

    {

      /* Flatten global & local subrs */

      subr_flattener_t<const OT::cff1::accelerator_subset_t, cff1_cs_interp_env_t, cff1_cs_opset_flatten_t, OpCode_endchar>

        flattener(acc, plan);

      if (!flattener.flatten (subset_charstrings))

  return false;

    }

    else

    {

      cff1_subr_subsetter_t       subr_subsetter (acc, plan);

      /* Subset subrs: collect used subroutines, leaving all unused ones behind */

      if (!subr_subsetter.subset ())

  return false;

      /* encode charstrings, global subrs, local subrs with new subroutine numbers */

      if (!subr_subsetter.encode_charstrings (subset_charstrings))

  return false;

      if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))

  return false;

      /* local subrs */

      if (!subset_localsubrs.resize (orig_fdcount))

  return false;

      for (unsigned int fd = 0; fd < orig_fdcount; fd++)

      {

  subset_localsubrs[fd].init ();

  if (fdmap.has (fd))

  {

    if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))

      return false;

  }

      }

    }

    /* Encoding */

    if (subset_encoding)

      plan_subset_encoding (acc, plan);

    /* private dicts & local subrs */

    if (!acc.is_CID ())

      fontdicts_mod.push (cff1_font_dict_values_mod_t ());

    else

    {

      + hb_iter (acc.fontDicts)

      | hb_filter ([&] (const cff1_font_dict_values_t &_)

  { return fdmap.has (&_ - &acc.fontDicts[0]); } )

      | hb_map ([&] (const cff1_font_dict_values_t &_)

  {

    cff1_font_dict_values_mod_t mod;

    mod.init (&_, sidmap[_.fontName]);

    return mod;

  })

      | hb_sink (fontdicts_mod)

      ;

    }

    return ((subset_charstrings.length == plan->num_output_glyphs ())

     && (fontdicts_mod.length == subset_fdcount));

  }

  cff1_top_dict_values_mod_t  topdict_mod;

  cff1_sub_table_info_t   info;

  unsigned int    num_glyphs;

  unsigned int    orig_fdcount;

  unsigned int    subset_fdcount;

  unsigned int    subset_fdselect_format;

  hb_vector_t<code_pair_t>   subset_fdselect_ranges;

  /* font dict index remap table from fullset FDArray to subset FDArray.

   * set to CFF_UNDEF_CODE if excluded from subset */

  hb_inc_bimap_t   fdmap;

  str_buff_vec_t    subset_charstrings;

  str_buff_vec_t    subset_globalsubrs;

  hb_vector_t<str_buff_vec_t> subset_localsubrs;

  hb_vector_t<cff1_font_dict_values_mod_t>  fontdicts_mod;

  bool    drop_hints;

  bool    gid_renum;

  bool    subset_encoding;

  uint8_t subset_enc_format;

  unsigned int  subset_enc_num_codes;

  range_list_t  subset_enc_code_ranges;

  hb_vector_t<code_pair_t>  subset_enc_supp_codes;

  uint8_t subset_charset_format;

  range_list_t  subset_charset_ranges;

  bool    subset_charset;

  remap_sid_t sidmap;

  unsigned int  topDictModSIDs[name_dict_values_t::ValCount];

  bool    desubroutinize;

};

static bool _serialize_cff1 (hb_serialize_context_t *c,

           cff_subset_plan &plan,

           const OT::cff1::accelerator_subset_t  &acc,

           unsigned int num_glyphs)

{

  /* private dicts & local subrs */

  for (int i = (int)acc.privateDicts.length; --i >= 0 ;)

  {

    if (plan.fdmap.has (i))

    {

      objidx_t  subrs_link = 0;

      if (plan.subset_localsubrs[i].length > 0)

      {

  CFF1Subrs *dest = c->start_embed <CFF1Subrs> ();

  if (unlikely (!dest)) return false;

  c->push ();

  if (likely (dest && dest->serialize (c, plan.subset_localsubrs[i])))

    subrs_link = c->pop_pack ();

  else

  {

    c->pop_discard ();

    return false;

  }

      }

      PrivateDict *pd = c->start_embed<PrivateDict> ();

      if (unlikely (!pd)) return false;

      c->push ();

      cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);

      /* N.B. local subrs immediately follows its corresponding private dict. i.e., subr offset == private dict size */

      if (likely (pd->serialize (c, acc.privateDicts[i], privSzr, subrs_link)))

      {

  unsigned fd = plan.fdmap[i];

  plan.fontdicts_mod[fd].privateDictInfo.size = c->length ();

  plan.fontdicts_mod[fd].privateDictInfo.link = c->pop_pack ();

      }

      else

      {

  c->pop_discard ();

  return false;

      }

    }

  }

  if (!acc.is_CID ())

    plan.info.privateDictInfo = plan.fontdicts_mod[0].privateDictInfo;

  /* CharStrings */

  {

    CFF1CharStrings  *cs = c->start_embed<CFF1CharStrings> ();

    if (unlikely (!cs)) return false;

    c->push ();

    if (likely (cs->serialize (c, plan.subset_charstrings)))

      plan.info.char_strings_link = c->pop_pack ();

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  /* FDArray (FD Index) */

  if (acc.fdArray != &Null (CFF1FDArray))

  {

    CFF1FDArray *fda = c->start_embed<CFF1FDArray> ();

    if (unlikely (!fda)) return false;

    c->push ();

    cff1_font_dict_op_serializer_t  fontSzr;

    auto it = + hb_zip (+ hb_iter (plan.fontdicts_mod), + hb_iter (plan.fontdicts_mod));

    if (likely (fda->serialize (c, it, fontSzr)))

      plan.info.fd_array_link = c->pop_pack (false);

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  /* FDSelect */

  if (acc.fdSelect != &Null (CFF1FDSelect))

  {

    c->push ();

    if (likely (hb_serialize_cff_fdselect (c, num_glyphs, *acc.fdSelect, acc.fdCount,

             plan.subset_fdselect_format, plan.info.fd_select.size,

             plan.subset_fdselect_ranges)))

      plan.info.fd_select.link = c->pop_pack ();

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  /* Charset */

  if (plan.subset_charset)

  {

    Charset *dest = c->start_embed<Charset> ();

    if (unlikely (!dest)) return false;

    c->push ();

    if (likely (dest->serialize (c,

         plan.subset_charset_format,

         plan.num_glyphs,

         plan.subset_charset_ranges)))

      plan.info.charset_link = c->pop_pack ();

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  /* Encoding */

  if (plan.subset_encoding)

  {

    Encoding *dest = c->start_embed<Encoding> ();

    if (unlikely (!dest)) return false;

    c->push ();

    if (likely (dest->serialize (c,

         plan.subset_enc_format,

         plan.subset_enc_num_codes,

         plan.subset_enc_code_ranges,

         plan.subset_enc_supp_codes)))

      plan.info.encoding_link = c->pop_pack ();

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  /* global subrs */

  {

    c->push ();

    CFF1Subrs *dest = c->start_embed <CFF1Subrs> ();

    if (unlikely (!dest)) return false;

    if (likely (dest->serialize (c, plan.subset_globalsubrs)))

      c->pop_pack ();

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  /* String INDEX */

  {

    CFF1StringIndex *dest = c->start_embed<CFF1StringIndex> ();

    if (unlikely (!dest)) return false;

    c->push ();

    if (likely (dest->serialize (c, *acc.stringIndex, plan.sidmap)))

      c->pop_pack ();

    else

    {

      c->pop_discard ();

      return false;

    }

  }

  OT::cff1 *cff = c->allocate_min<OT::cff1> ();

  if (unlikely (!cff))

    return false;

  /* header */

  cff->version.major = 0x01;

  cff->version.minor = 0x00;

  cff->nameIndex = cff->min_size;

  cff->offSize = 4; /* unused? */

  /* name INDEX */

  if (unlikely (!(*acc.nameIndex).copy (c))) return false;

  /* top dict INDEX */

  {

    /* serialize singleton TopDict */

    TopDict *top = c->start_embed<TopDict> ();

    if (!top) return false;

    c->push ();

    cff1_top_dict_op_serializer_t topSzr;

    unsigned top_size = 0;

    top_dict_modifiers_t  modifier (plan.info, plan.topDictModSIDs);

    if (likely (top->serialize (c, plan.topdict_mod, topSzr, modifier)))

    {

      top_size = c->length ();