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1 /*
2  * Copyright © 2018 Adobe Inc.
3  *
4  *  This is part of HarfBuzz, a text shaping library.
5  *
6  * Permission is hereby granted, without written agreement and without
7  * license or royalty fees, to use, copy, modify, and distribute this
8  * software and its documentation for any purpose, provided that the
9  * above copyright notice and the following two paragraphs appear in
10  * all copies of this software.
11  *
12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16  * DAMAGE.
17  *
18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23  *
24  * Adobe Author(s): Michiharu Ariza
25  */
26 #ifndef HB_CFF_INTERP_COMMON_HH
27 #define HB_CFF_INTERP_COMMON_HH
28 
29 namespace CFF {
30 
31 using namespace OT;
32 
33 typedef unsigned int op_code_t;
34 
35 
36 /* === Dict operators === */
37 
38 /* One byte operators (0-31) */
39 #define OpCode_version		  0 /* CFF Top */
40 #define OpCode_Notice		  1 /* CFF Top */
41 #define OpCode_FullName		  2 /* CFF Top */
42 #define OpCode_FamilyName	  3 /* CFF Top */
43 #define OpCode_Weight		  4 /* CFF Top */
44 #define OpCode_FontBBox		  5 /* CFF Top */
45 #define OpCode_BlueValues	  6 /* CFF Private, CFF2 Private */
46 #define OpCode_OtherBlues	  7 /* CFF Private, CFF2 Private */
47 #define OpCode_FamilyBlues	  8 /* CFF Private, CFF2 Private */
48 #define OpCode_FamilyOtherBlues	  9 /* CFF Private, CFF2 Private */
49 #define OpCode_StdHW		 10 /* CFF Private, CFF2 Private */
50 #define OpCode_StdVW		 11 /* CFF Private, CFF2 Private */
51 #define OpCode_escape		 12 /* All. Shared with CS */
52 #define OpCode_UniqueID		 13 /* CFF Top */
53 #define OpCode_XUID		 14 /* CFF Top */
54 #define OpCode_charset		 15 /* CFF Top (0) */
55 #define OpCode_Encoding		 16 /* CFF Top (0) */
56 #define OpCode_CharStrings	 17 /* CFF Top, CFF2 Top */
57 #define OpCode_Private		 18 /* CFF Top, CFF2 FD */
58 #define OpCode_Subrs		 19 /* CFF Private, CFF2 Private */
59 #define OpCode_defaultWidthX	 20 /* CFF Private (0) */
60 #define OpCode_nominalWidthX	 21 /* CFF Private (0) */
61 #define OpCode_vsindexdict	 22 /* CFF2 Private/CS */
62 #define OpCode_blenddict	 23 /* CFF2 Private/CS */
63 #define OpCode_vstore		 24 /* CFF2 Top */
64 #define OpCode_reserved25	 25
65 #define OpCode_reserved26	 26
66 #define OpCode_reserved27	 27
67 
68 /* Numbers */
69 #define OpCode_shortint		 28 /* 16-bit integer, All */
70 #define OpCode_longintdict	 29 /* 32-bit integer, All */
71 #define OpCode_BCD		 30 /* Real number, CFF2 Top/FD */
72 #define OpCode_reserved31	 31
73 
74 /* 1-byte integers */
75 #define OpCode_OneByteIntFirst	 32 /* All. beginning of the range of first byte ints */
76 #define OpCode_OneByteIntLast	246 /* All. ending of the range of first byte int */
77 
78 /* 2-byte integers */
79 #define OpCode_TwoBytePosInt0	247 /* All. first byte of two byte positive int (+108 to +1131) */
80 #define OpCode_TwoBytePosInt1	248
81 #define OpCode_TwoBytePosInt2	249
82 #define OpCode_TwoBytePosInt3	250
83 
84 #define OpCode_TwoByteNegInt0	251 /* All. first byte of two byte negative int (-1131 to -108) */
85 #define OpCode_TwoByteNegInt1	252
86 #define OpCode_TwoByteNegInt2	253
87 #define OpCode_TwoByteNegInt3	254
88 
89 /* Two byte escape operators 12, (0-41) */
90 #define OpCode_ESC_Base		256
91 #define Make_OpCode_ESC(byte2)	((op_code_t)(OpCode_ESC_Base + (byte2)))
92 
Unmake_OpCode_ESC(op_code_t op)93 inline op_code_t Unmake_OpCode_ESC (op_code_t op)  { return (op_code_t)(op - OpCode_ESC_Base); }
Is_OpCode_ESC(op_code_t op)94 inline bool Is_OpCode_ESC (op_code_t op) { return op >= OpCode_ESC_Base; }
OpCode_Size(op_code_t op)95 inline unsigned int OpCode_Size (op_code_t op) { return Is_OpCode_ESC (op) ? 2: 1; }
96 
97 #define OpCode_Copyright	Make_OpCode_ESC(0) /* CFF Top */
98 #define OpCode_isFixedPitch	Make_OpCode_ESC(1) /* CFF Top (false) */
99 #define OpCode_ItalicAngle	Make_OpCode_ESC(2) /* CFF Top (0) */
100 #define OpCode_UnderlinePosition Make_OpCode_ESC(3) /* CFF Top (-100) */
101 #define OpCode_UnderlineThickness Make_OpCode_ESC(4) /* CFF Top (50) */
102 #define OpCode_PaintType	Make_OpCode_ESC(5) /* CFF Top (0) */
103 #define OpCode_CharstringType	Make_OpCode_ESC(6) /* CFF Top (2) */
104 #define OpCode_FontMatrix	Make_OpCode_ESC(7) /* CFF Top, CFF2 Top (.001 0 0 .001 0 0)*/
105 #define OpCode_StrokeWidth	Make_OpCode_ESC(8) /* CFF Top (0) */
106 #define OpCode_BlueScale	Make_OpCode_ESC(9) /* CFF Private, CFF2 Private (0.039625) */
107 #define OpCode_BlueShift	Make_OpCode_ESC(10) /* CFF Private, CFF2 Private (7) */
108 #define OpCode_BlueFuzz		Make_OpCode_ESC(11) /* CFF Private, CFF2 Private (1) */
109 #define OpCode_StemSnapH	Make_OpCode_ESC(12) /* CFF Private, CFF2 Private */
110 #define OpCode_StemSnapV	Make_OpCode_ESC(13) /* CFF Private, CFF2 Private */
111 #define OpCode_ForceBold	Make_OpCode_ESC(14) /* CFF Private (false) */
112 #define OpCode_reservedESC15	Make_OpCode_ESC(15)
113 #define OpCode_reservedESC16	Make_OpCode_ESC(16)
114 #define OpCode_LanguageGroup	Make_OpCode_ESC(17) /* CFF Private, CFF2 Private (0) */
115 #define OpCode_ExpansionFactor	Make_OpCode_ESC(18) /* CFF Private, CFF2 Private (0.06) */
116 #define OpCode_initialRandomSeed Make_OpCode_ESC(19) /* CFF Private (0) */
117 #define OpCode_SyntheticBase	Make_OpCode_ESC(20) /* CFF Top */
118 #define OpCode_PostScript	Make_OpCode_ESC(21) /* CFF Top */
119 #define OpCode_BaseFontName	Make_OpCode_ESC(22) /* CFF Top */
120 #define OpCode_BaseFontBlend	Make_OpCode_ESC(23) /* CFF Top */
121 #define OpCode_reservedESC24	Make_OpCode_ESC(24)
122 #define OpCode_reservedESC25	Make_OpCode_ESC(25)
123 #define OpCode_reservedESC26	Make_OpCode_ESC(26)
124 #define OpCode_reservedESC27	Make_OpCode_ESC(27)
125 #define OpCode_reservedESC28	Make_OpCode_ESC(28)
126 #define OpCode_reservedESC29	Make_OpCode_ESC(29)
127 #define OpCode_ROS		Make_OpCode_ESC(30) /* CFF Top_CID */
128 #define OpCode_CIDFontVersion	Make_OpCode_ESC(31) /* CFF Top_CID (0) */
129 #define OpCode_CIDFontRevision	Make_OpCode_ESC(32) /* CFF Top_CID (0) */
130 #define OpCode_CIDFontType	Make_OpCode_ESC(33) /* CFF Top_CID (0) */
131 #define OpCode_CIDCount		Make_OpCode_ESC(34) /* CFF Top_CID (8720) */
132 #define OpCode_UIDBase		Make_OpCode_ESC(35) /* CFF Top_CID */
133 #define OpCode_FDArray		Make_OpCode_ESC(36) /* CFF Top_CID, CFF2 Top */
134 #define OpCode_FDSelect		Make_OpCode_ESC(37) /* CFF Top_CID, CFF2 Top */
135 #define OpCode_FontName		Make_OpCode_ESC(38) /* CFF Top_CID */
136 
137 
138 /* === CharString operators === */
139 
140 #define OpCode_hstem		  1 /* CFF, CFF2 */
141 #define OpCode_Reserved2	  2
142 #define OpCode_vstem		  3 /* CFF, CFF2 */
143 #define OpCode_vmoveto		  4 /* CFF, CFF2 */
144 #define OpCode_rlineto		  5 /* CFF, CFF2 */
145 #define OpCode_hlineto		  6 /* CFF, CFF2 */
146 #define OpCode_vlineto		  7 /* CFF, CFF2 */
147 #define OpCode_rrcurveto	  8 /* CFF, CFF2 */
148 #define OpCode_Reserved9	  9
149 #define OpCode_callsubr		 10 /* CFF, CFF2 */
150 #define OpCode_return		 11 /* CFF */
151 //#define OpCode_escape		 12 /* CFF, CFF2 */
152 #define OpCode_Reserved13	 13
153 #define OpCode_endchar		 14 /* CFF */
154 #define OpCode_vsindexcs	 15 /* CFF2 */
155 #define OpCode_blendcs		 16 /* CFF2 */
156 #define OpCode_Reserved17	 17
157 #define OpCode_hstemhm		 18 /* CFF, CFF2 */
158 #define OpCode_hintmask		 19 /* CFF, CFF2 */
159 #define OpCode_cntrmask		 20 /* CFF, CFF2 */
160 #define OpCode_rmoveto		 21 /* CFF, CFF2 */
161 #define OpCode_hmoveto		 22 /* CFF, CFF2 */
162 #define OpCode_vstemhm		 23 /* CFF, CFF2 */
163 #define OpCode_rcurveline	 24 /* CFF, CFF2 */
164 #define OpCode_rlinecurve	 25 /* CFF, CFF2 */
165 #define OpCode_vvcurveto	 26 /* CFF, CFF2 */
166 #define OpCode_hhcurveto	 27 /* CFF, CFF2 */
167 //#define OpCode_shortint	 28 /* CFF, CFF2 */
168 #define OpCode_callgsubr	 29 /* CFF, CFF2 */
169 #define OpCode_vhcurveto	 30 /* CFF, CFF2 */
170 #define OpCode_hvcurveto	 31 /* CFF, CFF2 */
171 
172 #define OpCode_fixedcs		255 /* 32-bit fixed */
173 
174 /* Two byte escape operators 12, (0-41) */
175 #define OpCode_dotsection	Make_OpCode_ESC(0) /* CFF (obsoleted) */
176 #define OpCode_ReservedESC1	Make_OpCode_ESC(1)
177 #define OpCode_ReservedESC2	Make_OpCode_ESC(2)
178 #define OpCode_and		Make_OpCode_ESC(3) /* CFF */
179 #define OpCode_or		Make_OpCode_ESC(4) /* CFF */
180 #define OpCode_not		Make_OpCode_ESC(5) /* CFF */
181 #define OpCode_ReservedESC6	Make_OpCode_ESC(6)
182 #define OpCode_ReservedESC7	Make_OpCode_ESC(7)
183 #define OpCode_ReservedESC8	Make_OpCode_ESC(8)
184 #define OpCode_abs		Make_OpCode_ESC(9) /* CFF */
185 #define OpCode_add		Make_OpCode_ESC(10) /* CFF */
186 #define OpCode_sub		Make_OpCode_ESC(11) /* CFF */
187 #define OpCode_div		Make_OpCode_ESC(12) /* CFF */
188 #define OpCode_ReservedESC13	Make_OpCode_ESC(13)
189 #define OpCode_neg		Make_OpCode_ESC(14) /* CFF */
190 #define OpCode_eq		Make_OpCode_ESC(15) /* CFF */
191 #define OpCode_ReservedESC16	Make_OpCode_ESC(16)
192 #define OpCode_ReservedESC17	Make_OpCode_ESC(17)
193 #define OpCode_drop		Make_OpCode_ESC(18) /* CFF */
194 #define OpCode_ReservedESC19	Make_OpCode_ESC(19)
195 #define OpCode_put		Make_OpCode_ESC(20) /* CFF */
196 #define OpCode_get		Make_OpCode_ESC(21) /* CFF */
197 #define OpCode_ifelse		Make_OpCode_ESC(22) /* CFF */
198 #define OpCode_random		Make_OpCode_ESC(23) /* CFF */
199 #define OpCode_mul		Make_OpCode_ESC(24) /* CFF */
200 //#define OpCode_reservedESC25	Make_OpCode_ESC(25)
201 #define OpCode_sqrt		Make_OpCode_ESC(26) /* CFF */
202 #define OpCode_dup		Make_OpCode_ESC(27) /* CFF */
203 #define OpCode_exch		Make_OpCode_ESC(28) /* CFF */
204 #define OpCode_index		Make_OpCode_ESC(29) /* CFF */
205 #define OpCode_roll		Make_OpCode_ESC(30) /* CFF */
206 #define OpCode_reservedESC31	Make_OpCode_ESC(31)
207 #define OpCode_reservedESC32	Make_OpCode_ESC(32)
208 #define OpCode_reservedESC33	Make_OpCode_ESC(33)
209 #define OpCode_hflex		Make_OpCode_ESC(34) /* CFF, CFF2 */
210 #define OpCode_flex		Make_OpCode_ESC(35) /* CFF, CFF2 */
211 #define OpCode_hflex1		Make_OpCode_ESC(36) /* CFF, CFF2 */
212 #define OpCode_flex1		Make_OpCode_ESC(37) /* CFF, CFF2 */
213 
214 
215 #define OpCode_Invalid		0xFFFFu
216 
217 
218 struct number_t
219 {
set_intCFF::number_t220   void set_int (int v)       { value = v; }
to_intCFF::number_t221   int to_int () const        { return value; }
222 
set_fixedCFF::number_t223   void set_fixed (int32_t v) { value = v / 65536.0; }
to_fixedCFF::number_t224   int32_t to_fixed () const  { return value * 65536.0; }
225 
set_realCFF::number_t226   void set_real (double v)   { value = v; }
to_realCFF::number_t227   double to_real () const    { return value; }
228 
in_int_rangeCFF::number_t229   bool in_int_range () const
230   { return ((double) (int16_t) to_int () == value); }
231 
operator >CFF::number_t232   bool operator >  (const number_t &n) const { return value > n.to_real (); }
operator <CFF::number_t233   bool operator <  (const number_t &n) const { return n > *this; }
operator >=CFF::number_t234   bool operator >= (const number_t &n) const { return !(*this < n); }
operator <=CFF::number_t235   bool operator <= (const number_t &n) const { return !(*this > n); }
236 
operator +=CFF::number_t237   const number_t &operator += (const number_t &n)
238   {
239     set_real (to_real () + n.to_real ());
240 
241     return *this;
242   }
243 
244   protected:
245   double value = 0.;
246 };
247 
248 /* byte string */
249 struct UnsizedByteStr : UnsizedArrayOf <HBUINT8>
250 {
as_ubytesCFF::UnsizedByteStr251   hb_ubytes_t as_ubytes (unsigned l) const
252   { return hb_ubytes_t ((const unsigned char *) this, l); }
253 
254   // encode 2-byte int (Dict/CharString) or 4-byte int (Dict)
255   template <typename T, typename V>
serialize_intCFF::UnsizedByteStr256   static bool serialize_int (hb_serialize_context_t *c, op_code_t intOp, V value)
257   {
258     TRACE_SERIALIZE (this);
259 
260     HBUINT8 *p = c->allocate_size<HBUINT8> (1);
261     if (unlikely (!p)) return_trace (false);
262     *p = intOp;
263 
264     T *ip = c->allocate_size<T> (T::static_size);
265     if (unlikely (!ip)) return_trace (false);
266     return_trace (c->check_assign (*ip, value, HB_SERIALIZE_ERROR_INT_OVERFLOW));
267   }
268 
269   template <typename V>
serialize_int4CFF::UnsizedByteStr270   static bool serialize_int4 (hb_serialize_context_t *c, V value)
271   { return serialize_int<HBINT32> (c, OpCode_longintdict, value); }
272 
273   template <typename V>
serialize_int2CFF::UnsizedByteStr274   static bool serialize_int2 (hb_serialize_context_t *c, V value)
275   { return serialize_int<HBINT16> (c, OpCode_shortint, value); }
276 
277   /* Defining null_size allows a Null object may be created. Should be safe because:
278    * A descendent struct Dict uses a Null pointer to indicate a missing table,
279    * checked before access.
280    */
281   DEFINE_SIZE_MIN(0);
282 };
283 
284 /* A byte string associated with the current offset and an error condition */
285 struct byte_str_ref_t
286 {
byte_str_ref_tCFF::byte_str_ref_t287   byte_str_ref_t ()
288     : str () {}
289 
byte_str_ref_tCFF::byte_str_ref_t290   byte_str_ref_t (const hb_ubytes_t &str_, unsigned int offset_ = 0)
291     : str (str_) { set_offset (offset_); }
292 
resetCFF::byte_str_ref_t293   void reset (const hb_ubytes_t &str_, unsigned int offset_ = 0)
294   {
295     str = str_;
296     set_offset (offset_);
297   }
298 
operator []CFF::byte_str_ref_t299   const unsigned char& operator [] (int i) {
300     if (unlikely ((unsigned int) (get_offset () + i) >= str.length))
301     {
302       set_error ();
303       return Null (unsigned char);
304     }
305     return str.arrayZ[get_offset () + i];
306   }
307 
head_uncheckedCFF::byte_str_ref_t308   unsigned char head_unchecked () const { return str.arrayZ[get_offset ()]; }
309 
310   /* Conversion to hb_ubytes_t */
operator hb_ubytes_tCFF::byte_str_ref_t311   operator hb_ubytes_t () const { return str.sub_array (get_offset ()); }
312 
sub_arrayCFF::byte_str_ref_t313   hb_ubytes_t sub_array (unsigned int offset_, unsigned int len_) const
314   { return str.sub_array (offset_, len_); }
315 
availCFF::byte_str_ref_t316   bool avail (unsigned int count=1) const
317   { return get_offset () + count <= str.length; }
incCFF::byte_str_ref_t318   void inc (unsigned int count=1)
319   {
320     /* Automatically puts us in error if count is out-of-range. */
321     set_offset (get_offset () + count);
322   }
323 
324   /* We (ab)use ubytes backwards_length as a cursor (called offset),
325    * as well as to store error condition. */
326 
get_offsetCFF::byte_str_ref_t327   unsigned get_offset () const { return str.backwards_length; }
set_offsetCFF::byte_str_ref_t328   void set_offset (unsigned offset) { str.backwards_length = offset; }
329 
set_errorCFF::byte_str_ref_t330   void set_error ()      { str.backwards_length = str.length + 1; }
in_errorCFF::byte_str_ref_t331   bool in_error () const { return str.backwards_length > str.length; }
332 
total_sizeCFF::byte_str_ref_t333   unsigned total_size () const { return str.length; }
334 
335   protected:
336   hb_ubytes_t       str;
337 };
338 
339 using byte_str_array_t = hb_vector_t<hb_ubytes_t>;
340 
341 /* stack */
342 template <typename ELEM, int LIMIT>
343 struct cff_stack_t
344 {
operator []CFF::cff_stack_t345   ELEM& operator [] (unsigned int i)
346   {
347     if (unlikely (i >= count))
348     {
349       set_error ();
350       return Crap (ELEM);
351     }
352     return elements[i];
353   }
354 
pushCFF::cff_stack_t355   void push (const ELEM &v)
356   {
357     if (likely (count < LIMIT))
358       elements[count++] = v;
359     else
360       set_error ();
361   }
pushCFF::cff_stack_t362   ELEM &push ()
363   {
364     if (likely (count < LIMIT))
365       return elements[count++];
366     else
367     {
368       set_error ();
369       return Crap (ELEM);
370     }
371   }
372 
popCFF::cff_stack_t373   ELEM& pop ()
374   {
375     if (likely (count > 0))
376       return elements[--count];
377     else
378     {
379       set_error ();
380       return Crap (ELEM);
381     }
382   }
popCFF::cff_stack_t383   void pop (unsigned int n)
384   {
385     if (likely (count >= n))
386       count -= n;
387     else
388       set_error ();
389   }
390 
peekCFF::cff_stack_t391   const ELEM& peek ()
392   {
393     if (unlikely (count == 0))
394     {
395       set_error ();
396       return Null (ELEM);
397     }
398     return elements[count - 1];
399   }
400 
unpopCFF::cff_stack_t401   void unpop ()
402   {
403     if (likely (count < LIMIT))
404       count++;
405     else
406       set_error ();
407   }
408 
clearCFF::cff_stack_t409   void clear () { count = 0; }
410 
in_errorCFF::cff_stack_t411   bool in_error () const { return (error); }
set_errorCFF::cff_stack_t412   void set_error ()      { error = true; }
413 
get_countCFF::cff_stack_t414   unsigned int get_count () const { return count; }
is_emptyCFF::cff_stack_t415   bool is_empty () const          { return !count; }
416 
sub_arrayCFF::cff_stack_t417   hb_array_t<const ELEM> sub_array (unsigned start, unsigned length) const
418   { return hb_array_t<const ELEM> (elements).sub_array (start, length); }
419 
420   private:
421   bool error = false;
422   unsigned int count = 0;
423   ELEM elements[LIMIT];
424 };
425 
426 /* argument stack */
427 template <typename ARG=number_t>
428 struct arg_stack_t : cff_stack_t<ARG, 513>
429 {
push_intCFF::arg_stack_t430   void push_int (int v)
431   {
432     ARG &n = S::push ();
433     n.set_int (v);
434   }
435 
push_fixedCFF::arg_stack_t436   void push_fixed (int32_t v)
437   {
438     ARG &n = S::push ();
439     n.set_fixed (v);
440   }
441 
push_realCFF::arg_stack_t442   void push_real (double v)
443   {
444     ARG &n = S::push ();
445     n.set_real (v);
446   }
447 
pop_numCFF::arg_stack_t448   ARG& pop_num () { return this->pop (); }
449 
pop_intCFF::arg_stack_t450   int pop_int ()  { return this->pop ().to_int (); }
451 
pop_uintCFF::arg_stack_t452   unsigned int pop_uint ()
453   {
454     int i = pop_int ();
455     if (unlikely (i < 0))
456     {
457       i = 0;
458       S::set_error ();
459     }
460     return (unsigned) i;
461   }
462 
push_longint_from_substrCFF::arg_stack_t463   void push_longint_from_substr (byte_str_ref_t& str_ref)
464   {
465     push_int ((str_ref[0] << 24) | (str_ref[1] << 16) | (str_ref[2] << 8) | (str_ref[3]));
466     str_ref.inc (4);
467   }
468 
push_fixed_from_substrCFF::arg_stack_t469   bool push_fixed_from_substr (byte_str_ref_t& str_ref)
470   {
471     if (unlikely (!str_ref.avail (4)))
472       return false;
473     push_fixed ((int32_t)*(const HBUINT32*)&str_ref[0]);
474     str_ref.inc (4);
475     return true;
476   }
477 
478   private:
479   typedef cff_stack_t<ARG, 513> S;
480 };
481 
482 /* an operator prefixed by its operands in a byte string */
483 struct op_str_t
484 {
485   /* This used to have a hb_ubytes_t. Using a pointer and length
486    * in a particular order, saves 8 bytes in this struct and more
487    * in our parsed_cs_op_t subclass. */
488 
489   const unsigned char *ptr = nullptr;
490 
491   op_code_t  op;
492 
493   uint8_t length = 0;
494 };
495 
496 /* base of OP_SERIALIZER */
497 struct op_serializer_t
498 {
499   protected:
copy_opstrCFF::op_serializer_t500   bool copy_opstr (hb_serialize_context_t *c, const op_str_t& opstr) const
501   {
502     TRACE_SERIALIZE (this);
503 
504     unsigned char *d = c->allocate_size<unsigned char> (opstr.length);
505     if (unlikely (!d)) return_trace (false);
506     /* Faster than hb_memcpy for small strings. */
507     for (unsigned i = 0; i < opstr.length; i++)
508       d[i] = opstr.ptr[i];
509     return_trace (true);
510   }
511 };
512 
513 template <typename VAL>
514 struct parsed_values_t
515 {
initCFF::parsed_values_t516   void init ()
517   {
518     opStart = 0;
519     values.init ();
520   }
finiCFF::parsed_values_t521   void fini () { values.fini (); }
522 
allocCFF::parsed_values_t523   void alloc (unsigned n)
524   {
525     values.alloc (n);
526   }
527 
add_opCFF::parsed_values_t528   void add_op (op_code_t op, const byte_str_ref_t& str_ref = byte_str_ref_t ())
529   {
530     VAL *val = values.push ();
531     val->op = op;
532     auto arr = str_ref.sub_array (opStart, str_ref.get_offset () - opStart);
533     val->ptr = arr.arrayZ;
534     val->length = arr.length;
535     opStart = str_ref.get_offset ();
536   }
537 
add_opCFF::parsed_values_t538   void add_op (op_code_t op, const byte_str_ref_t& str_ref, const VAL &v)
539   {
540     VAL *val = values.push (v);
541     val->op = op;
542     auto arr = str_ref.sub_array (opStart, str_ref.get_offset () - opStart);
543     val->ptr = arr.arrayZ;
544     val->length = arr.length;
545     opStart = str_ref.get_offset ();
546   }
547 
has_opCFF::parsed_values_t548   bool has_op (op_code_t op) const
549   {
550     for (const auto& v : values)
551       if (v.op == op) return true;
552     return false;
553   }
554 
get_countCFF::parsed_values_t555   unsigned get_count () const { return values.length; }
operator []CFF::parsed_values_t556   const VAL &operator [] (unsigned int i) const { return values[i]; }
557 
558   unsigned int       opStart;
559   hb_vector_t<VAL>   values;
560 };
561 
562 template <typename ARG=number_t>
563 struct interp_env_t
564 {
interp_env_tCFF::interp_env_t565   interp_env_t () {}
interp_env_tCFF::interp_env_t566   interp_env_t (const hb_ubytes_t &str_)
567   {
568     str_ref.reset (str_);
569   }
in_errorCFF::interp_env_t570   bool in_error () const
571   { return str_ref.in_error () || argStack.in_error (); }
572 
set_errorCFF::interp_env_t573   void set_error () { str_ref.set_error (); }
574 
fetch_opCFF::interp_env_t575   op_code_t fetch_op ()
576   {
577     op_code_t  op = OpCode_Invalid;
578     if (unlikely (!str_ref.avail ()))
579       return OpCode_Invalid;
580     op = (op_code_t) str_ref.head_unchecked ();
581     str_ref.inc ();
582     if (op == OpCode_escape) {
583       if (unlikely (!str_ref.avail ()))
584 	return OpCode_Invalid;
585       op = Make_OpCode_ESC (str_ref.head_unchecked ());
586       str_ref.inc ();
587     }
588     return op;
589   }
590 
eval_argCFF::interp_env_t591   const ARG& eval_arg (unsigned int i) { return argStack[i]; }
592 
pop_argCFF::interp_env_t593   ARG& pop_arg () { return argStack.pop (); }
pop_n_argsCFF::interp_env_t594   void pop_n_args (unsigned int n) { argStack.pop (n); }
595 
clear_argsCFF::interp_env_t596   void clear_args () { pop_n_args (argStack.get_count ()); }
597 
598   byte_str_ref_t
599 		str_ref;
600   arg_stack_t<ARG>
601 		argStack;
602 };
603 
604 using num_interp_env_t =  interp_env_t<>;
605 
606 template <typename ARG=number_t>
607 struct opset_t
608 {
process_opCFF::opset_t609   static void process_op (op_code_t op, interp_env_t<ARG>& env)
610   {
611     switch (op) {
612       case OpCode_shortint:
613 	env.argStack.push_int ((int16_t)((env.str_ref[0] << 8) | env.str_ref[1]));
614 	env.str_ref.inc (2);
615 	break;
616 
617       case OpCode_TwoBytePosInt0: case OpCode_TwoBytePosInt1:
618       case OpCode_TwoBytePosInt2: case OpCode_TwoBytePosInt3:
619 	env.argStack.push_int ((int16_t)((op - OpCode_TwoBytePosInt0) * 256 + env.str_ref[0] + 108));
620 	env.str_ref.inc ();
621 	break;
622 
623       case OpCode_TwoByteNegInt0: case OpCode_TwoByteNegInt1:
624       case OpCode_TwoByteNegInt2: case OpCode_TwoByteNegInt3:
625 	env.argStack.push_int ((-(int16_t)(op - OpCode_TwoByteNegInt0) * 256 - env.str_ref[0] - 108));
626 	env.str_ref.inc ();
627 	break;
628 
629       default:
630 	/* 1-byte integer */
631 	if (likely ((OpCode_OneByteIntFirst <= op) && (op <= OpCode_OneByteIntLast)))
632 	{
633 	  env.argStack.push_int ((int)op - 139);
634 	} else {
635 	  /* invalid unknown operator */
636 	  env.clear_args ();
637 	  env.set_error ();
638 	}
639 	break;
640     }
641   }
642 };
643 
644 template <typename ENV>
645 struct interpreter_t
646 {
interpreter_tCFF::interpreter_t647   interpreter_t (ENV& env_) : env (env_) {}
648   ENV& env;
649 };
650 
651 } /* namespace CFF */
652 
653 #endif /* HB_CFF_INTERP_COMMON_HH */
654