jdk-sandbox: comparison src/java.desktop/share/native/libfontmanager/harfbuzz/hb-subset-cff-common.hh

equal deleted inserted replaced

-:e4813eded7cb
+:7c11a7cc7c1d
+/*
+* 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 */