src/java.desktop/share/native/libfontmanager/harfbuzz/hb-subset-cff-common.hh
changeset 54232 7c11a7cc7c1d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-subset-cff-common.hh	Fri Mar 01 16:59:19 2019 -0800
@@ -0,0 +1,990 @@
+/*
+ * 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
+ */
+
+#ifndef HB_SUBSET_CFF_COMMON_HH
+#define HB_SUBSET_CFF_COMMON_HH
+
+#include "hb.hh"
+
+#include "hb-subset-plan.hh"
+#include "hb-cff-interp-cs-common.hh"
+
+namespace CFF {
+
+/* Used for writing a temporary charstring */
+struct str_encoder_t
+{
+  str_encoder_t (str_buff_t &buff_)
+    : buff (buff_), error (false) {}
+
+  void reset () { buff.resize (0); }
+
+  void encode_byte (unsigned char b)
+  {
+    if (unlikely (buff.push (b) == &Crap(unsigned char)))
+      set_error ();
+  }
+
+  void encode_int (int v)
+  {
+    if ((-1131 <= v) && (v <= 1131))
+    {
+      if ((-107 <= v) && (v <= 107))
+        encode_byte (v + 139);
+      else if (v > 0)
+      {
+        v -= 108;
+        encode_byte ((v >> 8) + OpCode_TwoBytePosInt0);
+        encode_byte (v & 0xFF);
+      }
+      else
+      {
+        v = -v - 108;
+        encode_byte ((v >> 8) + OpCode_TwoByteNegInt0);
+        encode_byte (v & 0xFF);
+      }
+    }
+    else
+    {
+      if (unlikely (v < -32768))
+        v = -32768;
+      else if (unlikely (v > 32767))
+        v = 32767;
+      encode_byte (OpCode_shortint);
+      encode_byte ((v >> 8) & 0xFF);
+      encode_byte (v & 0xFF);
+    }
+  }
+
+  void encode_num (const number_t& n)
+  {
+    if (n.in_int_range ())
+    {
+      encode_int (n.to_int ());
+    }
+    else
+    {
+      int32_t v = n.to_fixed ();
+      encode_byte (OpCode_fixedcs);
+      encode_byte ((v >> 24) & 0xFF);
+      encode_byte ((v >> 16) & 0xFF);
+      encode_byte ((v >> 8) & 0xFF);
+      encode_byte (v & 0xFF);
+    }
+  }
+
+  void encode_op (op_code_t op)
+  {
+    if (Is_OpCode_ESC (op))
+    {
+      encode_byte (OpCode_escape);
+      encode_byte (Unmake_OpCode_ESC (op));
+    }
+    else
+      encode_byte (op);
+  }
+
+  void copy_str (const byte_str_t &str)
+  {
+    unsigned int  offset = buff.length;
+    buff.resize (offset + str.length);
+    if (unlikely (buff.length < offset + str.length))
+    {
+      set_error ();
+      return;
+    }
+    memcpy (&buff[offset], &str[0], str.length);
+  }
+
+  bool is_error () const { return error; }
+
+  protected:
+  void set_error () { error = true; }
+
+  str_buff_t &buff;
+  bool    error;
+};
+
+struct cff_sub_table_offsets_t {
+  cff_sub_table_offsets_t () : privateDictsOffset (0)
+  {
+    topDictInfo.init ();
+    FDSelectInfo.init ();
+    FDArrayInfo.init ();
+    charStringsInfo.init ();
+    globalSubrsInfo.init ();
+    localSubrsInfos.init ();
+  }
+
+  ~cff_sub_table_offsets_t () { localSubrsInfos.fini (); }
+
+  table_info_t     topDictInfo;
+  table_info_t     FDSelectInfo;
+  table_info_t     FDArrayInfo;
+  table_info_t     charStringsInfo;
+  unsigned int  privateDictsOffset;
+  table_info_t     globalSubrsInfo;
+  hb_vector_t<table_info_t>  localSubrsInfos;
+};
+
+template <typename OPSTR=op_str_t>
+struct cff_top_dict_op_serializer_t : op_serializer_t
+{
+  bool serialize (hb_serialize_context_t *c,
+                  const OPSTR &opstr,
+                  const cff_sub_table_offsets_t &offsets) const
+  {
+    TRACE_SERIALIZE (this);
+
+    switch (opstr.op)
+    {
+      case OpCode_CharStrings:
+        return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.charStringsInfo.offset));
+
+      case OpCode_FDArray:
+        return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.FDArrayInfo.offset));
+
+      case OpCode_FDSelect:
+        return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.FDSelectInfo.offset));
+
+      default:
+        return_trace (copy_opstr (c, opstr));
+    }
+    return_trace (true);
+  }
+
+  unsigned int calculate_serialized_size (const OPSTR &opstr) const
+  {
+    switch (opstr.op)
+    {
+      case OpCode_CharStrings:
+      case OpCode_FDArray:
+      case OpCode_FDSelect:
+        return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);
+
+      default:
+        return opstr.str.length;
+    }
+  }
+};
+
+struct cff_font_dict_op_serializer_t : op_serializer_t
+{
+  bool serialize (hb_serialize_context_t *c,
+                  const op_str_t &opstr,
+                  const table_info_t &privateDictInfo) const
+  {
+    TRACE_SERIALIZE (this);
+
+    if (opstr.op == OpCode_Private)
+    {
+      /* serialize the private dict size & offset as 2-byte & 4-byte integers */
+      if (unlikely (!UnsizedByteStr::serialize_int2 (c, privateDictInfo.size) ||
+                    !UnsizedByteStr::serialize_int4 (c, privateDictInfo.offset)))
+        return_trace (false);
+
+      /* serialize the opcode */
+      HBUINT8 *p = c->allocate_size<HBUINT8> (1);
+      if (unlikely (p == nullptr)) return_trace (false);
+      p->set (OpCode_Private);
+
+      return_trace (true);
+    }
+    else
+    {
+      HBUINT8 *d = c->allocate_size<HBUINT8> (opstr.str.length);
+      if (unlikely (d == nullptr)) return_trace (false);
+      memcpy (d, &opstr.str[0], opstr.str.length);
+    }
+    return_trace (true);
+  }
+
+  unsigned int calculate_serialized_size (const op_str_t &opstr) const
+  {
+    if (opstr.op == OpCode_Private)
+      return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (OpCode_shortint) + 2 + OpCode_Size (OpCode_Private);
+    else
+      return opstr.str.length;
+  }
+};
+
+struct cff_private_dict_op_serializer_t : op_serializer_t
+{
+  cff_private_dict_op_serializer_t (bool desubroutinize_, bool drop_hints_)
+    : desubroutinize (desubroutinize_), drop_hints (drop_hints_) {}
+
+  bool serialize (hb_serialize_context_t *c,
+                  const op_str_t &opstr,
+                  const unsigned int subrsOffset) const
+  {
+    TRACE_SERIALIZE (this);
+
+    if (drop_hints && dict_opset_t::is_hint_op (opstr.op))
+      return true;
+    if (opstr.op == OpCode_Subrs)
+    {
+      if (desubroutinize || (subrsOffset == 0))
+        return_trace (true);
+      else
+        return_trace (FontDict::serialize_offset2_op (c, opstr.op, subrsOffset));
+    }
+    else
+      return_trace (copy_opstr (c, opstr));
+  }
+
+  unsigned int calculate_serialized_size (const op_str_t &opstr,
+                                          bool has_localsubr=true) const
+  {
+    if (drop_hints && dict_opset_t::is_hint_op (opstr.op))
+      return 0;
+    if (opstr.op == OpCode_Subrs)
+    {
+      if (desubroutinize || !has_localsubr)
+        return 0;
+      else
+        return OpCode_Size (OpCode_shortint) + 2 + OpCode_Size (opstr.op);
+    }
+    else
+      return opstr.str.length;
+  }
+
+  protected:
+  const bool  desubroutinize;
+  const bool  drop_hints;
+};
+
+struct flatten_param_t
+{
+  str_buff_t     &flatStr;
+  bool  drop_hints;
+};
+
+template <typename ACC, typename ENV, typename OPSET>
+struct subr_flattener_t
+{
+  subr_flattener_t (const ACC &acc_,
+                    const hb_vector_t<hb_codepoint_t> &glyphs_,
+                    bool drop_hints_) : acc (acc_), glyphs (glyphs_),
+                                        drop_hints (drop_hints_) {}
+
+  bool flatten (str_buff_vec_t &flat_charstrings)
+  {
+    if (!flat_charstrings.resize (glyphs.length))
+      return false;
+    for (unsigned int i = 0; i < glyphs.length; i++)
+      flat_charstrings[i].init ();
+    for (unsigned int i = 0; i < glyphs.length; i++)
+    {
+      hb_codepoint_t  glyph = glyphs[i];
+      const byte_str_t str = (*acc.charStrings)[glyph];
+      unsigned int fd = acc.fdSelect->get_fd (glyph);
+      if (unlikely (fd >= acc.fdCount))
+        return false;
+      cs_interpreter_t<ENV, OPSET, flatten_param_t> interp;
+      interp.env.init (str, acc, fd);
+      flatten_param_t  param = { flat_charstrings[i], drop_hints };
+      if (unlikely (!interp.interpret (param)))
+        return false;
+    }
+    return true;
+  }
+
+  const ACC &acc;
+  const hb_vector_t<hb_codepoint_t> &glyphs;
+  bool  drop_hints;
+};
+
+struct subr_closures_t
+{
+  subr_closures_t () : valid (false), global_closure (nullptr)
+  { local_closures.init (); }
+
+  void init (unsigned int fd_count)
+  {
+    valid = true;
+    global_closure = hb_set_create ();
+    if (global_closure == hb_set_get_empty ())
+      valid = false;
+    if (!local_closures.resize (fd_count))
+      valid = false;
+
+    for (unsigned int i = 0; i < local_closures.length; i++)
+    {
+      local_closures[i] = hb_set_create ();
+      if (local_closures[i] == hb_set_get_empty ())
+        valid = false;
+    }
+  }
+
+  void fini ()
+  {
+    hb_set_destroy (global_closure);
+    for (unsigned int i = 0; i < local_closures.length; i++)
+      hb_set_destroy (local_closures[i]);
+    local_closures.fini ();
+  }
+
+  void reset ()
+  {
+    hb_set_clear (global_closure);
+    for (unsigned int i = 0; i < local_closures.length; i++)
+      hb_set_clear (local_closures[i]);
+  }
+
+  bool is_valid () const { return valid; }
+  bool  valid;
+  hb_set_t  *global_closure;
+  hb_vector_t<hb_set_t *> local_closures;
+};
+
+struct parsed_cs_op_t : op_str_t
+{
+  void init (unsigned int subr_num_ = 0)
+  {
+    op_str_t::init ();
+    subr_num = subr_num_;
+    drop_flag = false;
+    keep_flag = false;
+    skip_flag = false;
+  }
+
+  void fini () { op_str_t::fini (); }
+
+  bool for_drop () const { return drop_flag; }
+  void set_drop ()       { if (!for_keep ()) drop_flag = true; }
+
+  bool for_keep () const { return keep_flag; }
+  void set_keep ()       { keep_flag = true; }
+
+  bool for_skip () const { return skip_flag; }
+  void set_skip ()       { skip_flag = true; }
+
+  unsigned int  subr_num;
+
+  protected:
+  bool    drop_flag : 1;
+  bool    keep_flag : 1;
+  bool    skip_flag : 1;
+};
+
+struct parsed_cs_str_t : parsed_values_t<parsed_cs_op_t>
+{
+  void init ()
+  {
+    SUPER::init ();
+    parsed = false;
+    hint_dropped = false;
+    has_prefix_ = false;
+  }
+
+  void add_op (op_code_t op, const byte_str_ref_t& str_ref)
+  {
+    if (!is_parsed ())
+      SUPER::add_op (op, str_ref);
+  }
+
+  void add_call_op (op_code_t op, const byte_str_ref_t& str_ref, unsigned int subr_num)
+  {
+    if (!is_parsed ())
+    {
+      unsigned int parsed_len = get_count ();
+      if (likely (parsed_len > 0))
+        values[parsed_len-1].set_skip ();
+
+      parsed_cs_op_t val;
+      val.init (subr_num);
+      SUPER::add_op (op, str_ref, val);
+    }
+  }
+
+  void set_prefix (const number_t &num, op_code_t op = OpCode_Invalid)
+  {
+    has_prefix_ = true;
+    prefix_op_ = op;
+    prefix_num_ = num;
+  }
+
+  bool at_end (unsigned int pos) const
+  {
+    return ((pos + 1 >= values.length) /* CFF2 */
+        || (values[pos + 1].op == OpCode_return));
+  }
+
+  bool is_parsed () const { return parsed; }
+  void set_parsed ()      { parsed = true; }
+
+  bool is_hint_dropped () const { return hint_dropped; }
+  void set_hint_dropped ()      { hint_dropped = true; }
+
+  bool is_vsindex_dropped () const { return vsindex_dropped; }
+  void set_vsindex_dropped ()      { vsindex_dropped = true; }
+
+  bool has_prefix () const          { return has_prefix_; }
+  op_code_t prefix_op () const         { return prefix_op_; }
+  const number_t &prefix_num () const { return prefix_num_; }
+
+  protected:
+  bool    parsed;
+  bool    hint_dropped;
+  bool    vsindex_dropped;
+  bool    has_prefix_;
+  op_code_t     prefix_op_;
+  number_t      prefix_num_;
+
+  private:
+  typedef parsed_values_t<parsed_cs_op_t> SUPER;
+};
+
+struct parsed_cs_str_vec_t : hb_vector_t<parsed_cs_str_t>
+{
+  void init (unsigned int len_ = 0)
+  {
+    SUPER::init ();
+    resize (len_);
+    for (unsigned int i = 0; i < length; i++)
+      (*this)[i].init ();
+  }
+  void fini () { SUPER::fini_deep (); }
+
+  private:
+  typedef hb_vector_t<parsed_cs_str_t> SUPER;
+};
+
+struct subr_subset_param_t
+{
+  void init (parsed_cs_str_t *parsed_charstring_,
+             parsed_cs_str_vec_t *parsed_global_subrs_, parsed_cs_str_vec_t *parsed_local_subrs_,
+             hb_set_t *global_closure_, hb_set_t *local_closure_,
+             bool drop_hints_)
+  {
+    parsed_charstring = parsed_charstring_;
+    current_parsed_str = parsed_charstring;
+    parsed_global_subrs = parsed_global_subrs_;
+    parsed_local_subrs = parsed_local_subrs_;
+    global_closure = global_closure_;
+    local_closure = local_closure_;
+    drop_hints = drop_hints_;
+  }
+
+  parsed_cs_str_t *get_parsed_str_for_context (call_context_t &context)
+  {
+    switch (context.type)
+    {
+      case CSType_CharString:
+        return parsed_charstring;
+
+      case CSType_LocalSubr:
+        if (likely (context.subr_num < parsed_local_subrs->length))
+          return &(*parsed_local_subrs)[context.subr_num];
+        break;
+
+      case CSType_GlobalSubr:
+        if (likely (context.subr_num < parsed_global_subrs->length))
+          return &(*parsed_global_subrs)[context.subr_num];
+        break;
+    }
+    return nullptr;
+  }
+
+  template <typename ENV>
+  void set_current_str (ENV &env, bool calling)
+  {
+    parsed_cs_str_t  *parsed_str = get_parsed_str_for_context (env.context);
+    if (likely (parsed_str != nullptr))
+    {
+      /* If the called subroutine is parsed partially but not completely yet,
+       * it must be because we are calling it recursively.
+       * Handle it as an error. */
+      if (unlikely (calling && !parsed_str->is_parsed () && (parsed_str->values.length > 0)))
+        env.set_error ();
+      else
+        current_parsed_str = parsed_str;
+    }
+    else
+      env.set_error ();
+  }
+
+  parsed_cs_str_t       *current_parsed_str;
+
+  parsed_cs_str_t       *parsed_charstring;
+  parsed_cs_str_vec_t   *parsed_global_subrs;
+  parsed_cs_str_vec_t   *parsed_local_subrs;
+  hb_set_t      *global_closure;
+  hb_set_t      *local_closure;
+  bool    drop_hints;
+};
+
+struct subr_remap_t : remap_t
+{
+  void create (hb_set_t *closure)
+  {
+    /* create a remapping of subroutine numbers from old to new.
+     * no optimization based on usage counts. fonttools doesn't appear doing that either.
+     */
+    reset (closure->get_max () + 1);
+    for (hb_codepoint_t old_num = 0; old_num < length; old_num++)
+    {
+      if (hb_set_has (closure, old_num))
+        add (old_num);
+    }
+
+    if (get_count () < 1240)
+      bias = 107;
+    else if (get_count () < 33900)
+      bias = 1131;
+    else
+      bias = 32768;
+  }
+
+  hb_codepoint_t operator[] (unsigned int old_num) const
+  {
+    if (old_num >= length)
+      return CFF_UNDEF_CODE;
+    else
+      return remap_t::operator[] (old_num);
+  }
+
+  int biased_num (unsigned int old_num) const
+  {
+    hb_codepoint_t new_num = (*this)[old_num];
+    return (int)new_num - bias;
+  }
+
+  protected:
+  int bias;
+};
+
+struct subr_remap_ts
+{
+  subr_remap_ts ()
+  {
+    global_remap.init ();
+    local_remaps.init ();
+  }
+
+  ~subr_remap_ts () { fini (); }
+
+  void init (unsigned int fdCount)
+  {
+    local_remaps.resize (fdCount);
+    for (unsigned int i = 0; i < fdCount; i++)
+      local_remaps[i].init ();
+  }
+
+  void create (subr_closures_t& closures)
+  {
+    global_remap.create (closures.global_closure);
+    for (unsigned int i = 0; i < local_remaps.length; i++)
+      local_remaps[i].create (closures.local_closures[i]);
+  }
+
+  void fini ()
+  {
+    global_remap.fini ();
+    local_remaps.fini_deep ();
+  }
+
+  subr_remap_t         global_remap;
+  hb_vector_t<subr_remap_t>  local_remaps;
+};
+
+template <typename SUBSETTER, typename SUBRS, typename ACC, typename ENV, typename OPSET>
+struct subr_subsetter_t
+{
+  subr_subsetter_t ()
+  {
+    parsed_charstrings.init ();
+    parsed_global_subrs.init ();
+    parsed_local_subrs.init ();
+  }
+
+  ~subr_subsetter_t ()
+  {
+    closures.fini ();
+    remaps.fini ();
+    parsed_charstrings.fini_deep ();
+    parsed_global_subrs.fini_deep ();
+    parsed_local_subrs.fini_deep ();
+  }
+
+  /* Subroutine subsetting with --no-desubroutinize runs in phases:
+   *
+   * 1. execute charstrings/subroutines to determine subroutine closures
+   * 2. parse out all operators and numbers
+   * 3. mark hint operators and operands for removal if --no-hinting
+   * 4. re-encode all charstrings and subroutines with new subroutine numbers
+   *
+   * Phases #1 and #2 are done at the same time in collect_subrs ().
+   * Phase #3 walks charstrings/subroutines forward then backward (hence parsing required),
+   * because we can't tell if a number belongs to a hint op until we see the first moveto.
+   *
+   * Assumption: a callsubr/callgsubr operator must immediately follow a (biased) subroutine number
+   * within the same charstring/subroutine, e.g., not split across a charstring and a subroutine.
+   */
+  bool subset (ACC &acc, const hb_vector_t<hb_codepoint_t> &glyphs, bool drop_hints)
+  {
+    closures.init (acc.fdCount);
+    remaps.init (acc.fdCount);
+
+    parsed_charstrings.init (glyphs.length);
+    parsed_global_subrs.init (acc.globalSubrs->count);
+    parsed_local_subrs.resize (acc.fdCount);
+    for (unsigned int i = 0; i < acc.fdCount; i++)
+    {
+      parsed_local_subrs[i].init (acc.privateDicts[i].localSubrs->count);
+    }
+    if (unlikely (!closures.valid))
+      return false;
+
+    /* phase 1 & 2 */
+    for (unsigned int i = 0; i < glyphs.length; i++)
+    {
+      hb_codepoint_t  glyph = glyphs[i];
+      const byte_str_t str = (*acc.charStrings)[glyph];
+      unsigned int fd = acc.fdSelect->get_fd (glyph);
+      if (unlikely (fd >= acc.fdCount))
+        return false;
+
+      cs_interpreter_t<ENV, OPSET, subr_subset_param_t> interp;
+      interp.env.init (str, acc, fd);
+
+      subr_subset_param_t  param;
+      param.init (&parsed_charstrings[i],
+                  &parsed_global_subrs,  &parsed_local_subrs[fd],
+                  closures.global_closure, closures.local_closures[fd],
+                  drop_hints);
+
+      if (unlikely (!interp.interpret (param)))
+        return false;
+
+      /* finalize parsed string esp. copy CFF1 width or CFF2 vsindex to the parsed charstring for encoding */
+      SUBSETTER::finalize_parsed_str (interp.env, param, parsed_charstrings[i]);
+    }
+
+    if (drop_hints)
+    {
+      /* mark hint ops and arguments for drop */
+      for (unsigned int i = 0; i < glyphs.length; i++)
+      {
+        unsigned int fd = acc.fdSelect->get_fd (glyphs[i]);
+        if (unlikely (fd >= acc.fdCount))
+          return false;
+        subr_subset_param_t  param;
+        param.init (&parsed_charstrings[i],
+                    &parsed_global_subrs,  &parsed_local_subrs[fd],
+                    closures.global_closure, closures.local_closures[fd],
+                    drop_hints);
+
+        drop_hints_param_t  drop;
+        if (drop_hints_in_str (parsed_charstrings[i], param, drop))
+        {
+          parsed_charstrings[i].set_hint_dropped ();
+          if (drop.vsindex_dropped)
+            parsed_charstrings[i].set_vsindex_dropped ();
+        }
+      }
+
+      /* after dropping hints recreate closures of actually used subrs */
+      closures.reset ();
+      for (unsigned int i = 0; i < glyphs.length; i++)
+      {
+        unsigned int fd = acc.fdSelect->get_fd (glyphs[i]);
+        if (unlikely (fd >= acc.fdCount))
+          return false;
+        subr_subset_param_t  param;
+        param.init (&parsed_charstrings[i],
+                    &parsed_global_subrs,  &parsed_local_subrs[fd],
+                    closures.global_closure, closures.local_closures[fd],
+                    drop_hints);
+        collect_subr_refs_in_str (parsed_charstrings[i], param);
+      }
+    }
+
+    remaps.create (closures);
+
+    return true;
+  }
+
+  bool encode_charstrings (ACC &acc, const hb_vector_t<hb_codepoint_t> &glyphs, str_buff_vec_t &buffArray) const
+  {
+    if (unlikely (!buffArray.resize (glyphs.length)))
+      return false;
+    for (unsigned int i = 0; i < glyphs.length; i++)
+    {
+      unsigned int  fd = acc.fdSelect->get_fd (glyphs[i]);
+      if (unlikely (fd >= acc.fdCount))
+        return false;
+      if (unlikely (!encode_str (parsed_charstrings[i], fd, buffArray[i])))
+        return false;
+    }
+    return true;
+  }
+
+  bool encode_subrs (const parsed_cs_str_vec_t &subrs, const subr_remap_t& remap, unsigned int fd, str_buff_vec_t &buffArray) const
+  {
+    unsigned int  count = remap.get_count ();
+
+    if (unlikely (!buffArray.resize (count)))
+      return false;
+    for (unsigned int old_num = 0; old_num < subrs.length; old_num++)
+    {
+      hb_codepoint_t new_num = remap[old_num];
+      if (new_num != CFF_UNDEF_CODE)
+      {
+        if (unlikely (!encode_str (subrs[old_num], fd, buffArray[new_num])))
+          return false;
+      }
+    }
+    return true;
+  }
+
+  bool encode_globalsubrs (str_buff_vec_t &buffArray)
+  {
+    return encode_subrs (parsed_global_subrs, remaps.global_remap, 0, buffArray);
+  }
+
+  bool encode_localsubrs (unsigned int fd, str_buff_vec_t &buffArray) const
+  {
+    return encode_subrs (parsed_local_subrs[fd], remaps.local_remaps[fd], fd, buffArray);
+  }
+
+  protected:
+  struct drop_hints_param_t
+  {
+    drop_hints_param_t ()
+      : seen_moveto (false),
+        ends_in_hint (false),
+        vsindex_dropped (false) {}
+
+    bool  seen_moveto;
+    bool  ends_in_hint;
+    bool  vsindex_dropped;
+  };
+
+  bool drop_hints_in_subr (parsed_cs_str_t &str, unsigned int pos,
+                           parsed_cs_str_vec_t &subrs, unsigned int subr_num,
+                           const subr_subset_param_t &param, drop_hints_param_t &drop)
+  {
+    drop.ends_in_hint = false;
+    bool has_hint = drop_hints_in_str (subrs[subr_num], param, drop);
+
+    /* if this subr ends with a stem hint (i.e., not a number a potential argument for moveto),
+     * then this entire subroutine must be a hint. drop its call. */
+    if (drop.ends_in_hint)
+    {
+      str.values[pos].set_drop ();
+      /* if this subr call is at the end of the parent subr, propagate the flag
+       * otherwise reset the flag */
+      if (!str.at_end (pos))
+        drop.ends_in_hint = false;
+    }
+
+    return has_hint;
+  }
+
+  /* returns true if it sees a hint op before the first moveto */
+  bool drop_hints_in_str (parsed_cs_str_t &str, const subr_subset_param_t &param, drop_hints_param_t &drop)
+  {
+    bool  seen_hint = false;
+
+    for (unsigned int pos = 0; pos < str.values.length; pos++)
+    {
+      bool  has_hint = false;
+      switch (str.values[pos].op)
+      {
+        case OpCode_callsubr:
+          has_hint = drop_hints_in_subr (str, pos,
+                                        *param.parsed_local_subrs, str.values[pos].subr_num,
+                                        param, drop);
+
+          break;
+
+        case OpCode_callgsubr:
+          has_hint = drop_hints_in_subr (str, pos,
+                                        *param.parsed_global_subrs, str.values[pos].subr_num,
+                                        param, drop);
+          break;
+
+        case OpCode_rmoveto:
+        case OpCode_hmoveto:
+        case OpCode_vmoveto:
+          drop.seen_moveto = true;
+          break;
+
+        case OpCode_hintmask:
+        case OpCode_cntrmask:
+          if (drop.seen_moveto)
+          {
+            str.values[pos].set_drop ();
+            break;
+          }
+          HB_FALLTHROUGH;
+
+        case OpCode_hstemhm:
+        case OpCode_vstemhm:
+        case OpCode_hstem:
+        case OpCode_vstem:
+          has_hint = true;
+          str.values[pos].set_drop ();
+          if (str.at_end (pos))
+            drop.ends_in_hint = true;
+          break;
+
+        case OpCode_dotsection:
+          str.values[pos].set_drop ();
+          break;
+
+        default:
+          /* NONE */
+          break;
+      }
+      if (has_hint)
+      {
+        for (int i = pos - 1; i >= 0; i--)
+        {
+          parsed_cs_op_t  &csop = str.values[(unsigned)i];
+          if (csop.for_drop ())
+            break;
+          csop.set_drop ();
+          if (csop.op == OpCode_vsindexcs)
+            drop.vsindex_dropped = true;
+        }
+        seen_hint |= has_hint;
+      }
+    }
+
+    return seen_hint;
+  }
+
+  void collect_subr_refs_in_subr (parsed_cs_str_t &str, unsigned int pos,
+                                  unsigned int subr_num, parsed_cs_str_vec_t &subrs,
+                                  hb_set_t *closure,
+                                  const subr_subset_param_t &param)
+  {
+    hb_set_add (closure, subr_num);
+    collect_subr_refs_in_str (subrs[subr_num], param);
+  }
+
+  void collect_subr_refs_in_str (parsed_cs_str_t &str, const subr_subset_param_t &param)
+  {
+    for (unsigned int pos = 0; pos < str.values.length; pos++)
+    {
+      if (!str.values[pos].for_drop ())
+      {
+        switch (str.values[pos].op)
+        {
+          case OpCode_callsubr:
+            collect_subr_refs_in_subr (str, pos,
+                                       str.values[pos].subr_num, *param.parsed_local_subrs,
+                                       param.local_closure, param);
+            break;
+
+          case OpCode_callgsubr:
+            collect_subr_refs_in_subr (str, pos,
+                                       str.values[pos].subr_num, *param.parsed_global_subrs,
+                                       param.global_closure, param);
+            break;
+
+          default: break;
+        }
+      }
+    }
+  }
+
+  bool encode_str (const parsed_cs_str_t &str, const unsigned int fd, str_buff_t &buff) const
+  {
+    buff.init ();
+    str_encoder_t  encoder (buff);
+    encoder.reset ();
+    /* if a prefix (CFF1 width or CFF2 vsindex) has been removed along with hints,
+     * re-insert it at the beginning of charstreing */
+    if (str.has_prefix () && str.is_hint_dropped ())
+    {
+      encoder.encode_num (str.prefix_num ());
+      if (str.prefix_op () != OpCode_Invalid)
+        encoder.encode_op (str.prefix_op ());
+    }
+    for (unsigned int i = 0; i < str.get_count(); i++)
+    {
+      const parsed_cs_op_t  &opstr = str.values[i];
+      if (!opstr.for_drop () && !opstr.for_skip ())
+      {
+        switch (opstr.op)
+        {
+          case OpCode_callsubr:
+            encoder.encode_int (remaps.local_remaps[fd].biased_num (opstr.subr_num));
+            encoder.encode_op (OpCode_callsubr);
+            break;
+
+          case OpCode_callgsubr:
+            encoder.encode_int (remaps.global_remap.biased_num (opstr.subr_num));
+            encoder.encode_op (OpCode_callgsubr);
+            break;
+
+          default:
+            encoder.copy_str (opstr.str);
+            break;
+        }
+      }
+    }
+    return !encoder.is_error ();
+  }
+
+  protected:
+  subr_closures_t             closures;
+
+  parsed_cs_str_vec_t          parsed_charstrings;
+  parsed_cs_str_vec_t          parsed_global_subrs;
+  hb_vector_t<parsed_cs_str_vec_t>  parsed_local_subrs;
+
+  subr_remap_ts         remaps;
+
+  private:
+  typedef typename SUBRS::count_type subr_count_type;
+};
+
+} /* namespace CFF */
+
+HB_INTERNAL bool
+hb_plan_subset_cff_fdselect (const hb_vector_t<hb_codepoint_t> &glyphs,
+                            unsigned int fdCount,
+                            const CFF::FDSelect &src, /* IN */
+                            unsigned int &subset_fd_count /* OUT */,
+                            unsigned int &subset_fdselect_size /* OUT */,
+                            unsigned int &subset_fdselect_format /* OUT */,
+                            hb_vector_t<CFF::code_pair_t> &fdselect_ranges /* OUT */,
+                            CFF::remap_t &fdmap /* OUT */);
+
+HB_INTERNAL bool
+hb_serialize_cff_fdselect (hb_serialize_context_t *c,
+                          unsigned int num_glyphs,
+                          const CFF::FDSelect &src,
+                          unsigned int fd_count,
+                          unsigned int fdselect_format,
+                          unsigned int size,
+                          const hb_vector_t<CFF::code_pair_t> &fdselect_ranges);
+
+#endif /* HB_SUBSET_CFF_COMMON_HH */