hb-private.hh revision 6843569d2c70c1771ce964e3d1a4cf91e14e7687 
1/*
2 * Copyright © 2007,2008,2009  Red Hat, Inc.
3 * Copyright © 2011  Google, Inc.
4 *
5 *  This is part of HarfBuzz, a text shaping library.
6 *
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
12 *
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17 * DAMAGE.
18 *
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 *
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
27 */
28
29#ifndef HB_PRIVATE_HH
30#define HB_PRIVATE_HH
31
32#if HAVE_CONFIG_H
33#include "config.h"
34#endif
35
36#include "hb-common.h"
37
38#include <stdlib.h>
39#include <string.h>
40#include <assert.h>
41
42/* We only use these two for debug output.  However, the debug code is
43 * always seen by the compiler (and optimized out in non-debug builds.
44 * If including these becomes a problem, we can start thinking about
45 * someway around that. */
46#include <stdio.h>
47#include <errno.h>
48
49HB_BEGIN_DECLS
50
51
52/* Essentials */
53
54#ifndef NULL
55# define NULL ((void *) 0)
56#endif
57
58#undef FALSE
59#define FALSE 0
60
61#undef TRUE
62#define TRUE 1
63
64
65/* Basics */
66
67HB_END_DECLS
68
69#undef MIN
70template <typename Type> static inline Type MIN (const Type &a, const Type &b) { return a < b ? a : b; }
71
72#undef MAX
73template <typename Type> static inline Type MAX (const Type &a, const Type &b) { return a > b ? a : b; }
74
75HB_BEGIN_DECLS
76
77#undef  ARRAY_LENGTH
78#define ARRAY_LENGTH(__array) ((signed int) (sizeof (__array) / sizeof (__array[0])))
79
80#define HB_STMT_START do
81#define HB_STMT_END   while (0)
82
83#define _ASSERT_STATIC1(_line, _cond) typedef int _static_assert_on_line_##_line##_failed[(_cond)?1:-1]
84#define _ASSERT_STATIC0(_line, _cond) _ASSERT_STATIC1 (_line, (_cond))
85#define ASSERT_STATIC(_cond) _ASSERT_STATIC0 (__LINE__, (_cond))
86
87#define ASSERT_STATIC_EXPR(_cond) ((void) sizeof (char[(_cond) ? 1 : -1]))
88
89
90/* Lets assert int types.  Saves trouble down the road. */
91
92ASSERT_STATIC (sizeof (int8_t) == 1);
93ASSERT_STATIC (sizeof (uint8_t) == 1);
94ASSERT_STATIC (sizeof (int16_t) == 2);
95ASSERT_STATIC (sizeof (uint16_t) == 2);
96ASSERT_STATIC (sizeof (int32_t) == 4);
97ASSERT_STATIC (sizeof (uint32_t) == 4);
98ASSERT_STATIC (sizeof (int64_t) == 8);
99ASSERT_STATIC (sizeof (uint64_t) == 8);
100
101ASSERT_STATIC (sizeof (hb_codepoint_t) == 4);
102ASSERT_STATIC (sizeof (hb_position_t) == 4);
103ASSERT_STATIC (sizeof (hb_mask_t) == 4);
104ASSERT_STATIC (sizeof (hb_var_int_t) == 4);
105
106/* Misc */
107
108
109#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
110#define _HB_BOOLEAN_EXPR(expr) ((expr) ? 1 : 0)
111#define likely(expr) (__builtin_expect (_HB_BOOLEAN_EXPR(expr), 1))
112#define unlikely(expr) (__builtin_expect (_HB_BOOLEAN_EXPR(expr), 0))
113#else
114#define likely(expr) (expr)
115#define unlikely(expr) (expr)
116#endif
117
118#ifndef __GNUC__
119#undef __attribute__
120#define __attribute__(x)
121#endif
122
123#if __GNUC__ >= 3
124#define HB_PURE_FUNC	__attribute__((pure))
125#define HB_CONST_FUNC	__attribute__((const))
126#else
127#define HB_PURE_FUNC
128#define HB_CONST_FUNC
129#endif
130#if __GNUC__ >= 4
131#define HB_UNUSED	__attribute__((unused))
132#else
133#define HB_UNUSED
134#endif
135
136#ifndef HB_INTERNAL
137# define HB_INTERNAL __attribute__((__visibility__("hidden")))
138#endif
139
140
141#if (defined(__WIN32__) && !defined(__WINE__)) || defined(_MSC_VER)
142#define snprintf _snprintf
143#endif
144
145#ifdef _MSC_VER
146#undef inline
147#define inline __inline
148#endif
149
150#ifdef __STRICT_ANSI__
151#undef inline
152#define inline __inline__
153#endif
154
155
156#if __GNUC__ >= 3
157#define HB_FUNC __PRETTY_FUNCTION__
158#elif defined(_MSC_VER)
159#define HB_FUNC __FUNCSIG__
160#else
161#define HB_FUNC __func__
162#endif
163
164
165/* Return the number of 1 bits in mask. */
166static inline HB_CONST_FUNC unsigned int
167_hb_popcount32 (uint32_t mask)
168{
169#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
170  return __builtin_popcount (mask);
171#else
172  /* "HACKMEM 169" */
173  register uint32_t y;
174  y = (mask >> 1) &033333333333;
175  y = mask - y - ((y >>1) & 033333333333);
176  return (((y + (y >> 3)) & 030707070707) % 077);
177#endif
178}
179
180/* Returns the number of bits needed to store number */
181static inline HB_CONST_FUNC unsigned int
182_hb_bit_storage (unsigned int number)
183{
184#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(__OPTIMIZE__)
185  return likely (number) ? (sizeof (unsigned int) * 8 - __builtin_clz (number)) : 0;
186#else
187  register unsigned int n_bits = 0;
188  while (number) {
189    n_bits++;
190    number >>= 1;
191  }
192  return n_bits;
193#endif
194}
195
196/* Returns the number of zero bits in the least significant side of number */
197static inline HB_CONST_FUNC unsigned int
198_hb_ctz (unsigned int number)
199{
200#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(__OPTIMIZE__)
201  return likely (number) ? __builtin_ctz (number) : 0;
202#else
203  register unsigned int n_bits = 0;
204  if (unlikely (!number)) return 0;
205  while (!(number & 1)) {
206    n_bits++;
207    number >>= 1;
208  }
209  return n_bits;
210#endif
211}
212
213static inline bool
214_hb_unsigned_int_mul_overflows (unsigned int count, unsigned int size)
215{
216  return (size > 0) && (count >= ((unsigned int) -1) / size);
217}
218
219
220/* Type of bsearch() / qsort() compare function */
221typedef int (*hb_compare_func_t) (const void *, const void *);
222
223
224HB_END_DECLS
225
226
227/* arrays and maps */
228
229
230template <typename Type, unsigned int StaticSize>
231struct hb_prealloced_array_t {
232
233  unsigned int len;
234  unsigned int allocated;
235  Type *array;
236  Type static_array[StaticSize];
237
238  inline Type& operator [] (unsigned int i)
239  {
240    return array[i];
241  }
242
243  inline Type *push (void)
244  {
245    if (!array) {
246      array = static_array;
247      allocated = ARRAY_LENGTH (static_array);
248    }
249    if (likely (len < allocated))
250      return &array[len++];
251
252    /* Need to reallocate */
253    unsigned int new_allocated = allocated + (allocated >> 1) + 8;
254    Type *new_array = NULL;
255
256    if (array == static_array) {
257      new_array = (Type *) calloc (new_allocated, sizeof (Type));
258      if (new_array)
259        memcpy (new_array, array, len * sizeof (Type));
260    } else {
261      bool overflows = (new_allocated < allocated) || _hb_unsigned_int_mul_overflows (new_allocated, sizeof (Type));
262      if (likely (!overflows)) {
263	new_array = (Type *) realloc (array, new_allocated * sizeof (Type));
264      }
265    }
266
267    if (unlikely (!new_array))
268      return NULL;
269
270    array = new_array;
271    allocated = new_allocated;
272    return &array[len++];
273  }
274
275  inline void pop (void)
276  {
277    len--;
278    /* TODO: shrink array if needed */
279  }
280
281  inline void shrink (unsigned int l)
282  {
283     if (l < len)
284       len = l;
285    /* TODO: shrink array if needed */
286  }
287
288  template <typename T>
289  inline Type *find (T v) {
290    for (unsigned int i = 0; i < len; i++)
291      if (array[i] == v)
292	return &array[i];
293    return NULL;
294  }
295  template <typename T>
296  inline const Type *find (T v) const {
297    for (unsigned int i = 0; i < len; i++)
298      if (array[i] == v)
299	return &array[i];
300    return NULL;
301  }
302
303  inline void sort (void)
304  {
305    qsort (array, len, sizeof (Type), (hb_compare_func_t) Type::cmp);
306  }
307
308  template <typename T>
309  inline Type *bsearch (T *key)
310  {
311    return (Type *) ::bsearch (key, array, len, sizeof (Type), (hb_compare_func_t) Type::cmp);
312  }
313  template <typename T>
314  inline const Type *bsearch (T *key) const
315  {
316    return (const Type *) ::bsearch (key, array, len, sizeof (Type), (hb_compare_func_t) Type::cmp);
317  }
318};
319
320template <typename Type>
321struct hb_array_t : hb_prealloced_array_t<Type, 2> {};
322
323
324template <typename item_t>
325struct hb_set_t
326{
327  hb_array_t <item_t> items;
328
329  public:
330
331  template <typename T>
332  inline bool insert (T v)
333  {
334    item_t *item = items.find (v);
335    if (item)
336      item->finish ();
337    else
338      item = items.push ();
339    if (unlikely (!item)) return false;
340    *item = v;
341    return true;
342  }
343
344  template <typename T>
345  inline void remove (T v)
346  {
347    item_t *item = items.find (v);
348    if (!item) return;
349
350    item->finish ();
351    *item = items[items.len - 1];
352    items.pop ();
353  }
354
355  template <typename T>
356  inline item_t *get (T v)
357  {
358    return items.find (v);
359  }
360
361  void finish (void) {
362    for (unsigned i = 0; i < items.len; i++)
363      items[i].finish ();
364  }
365
366};
367
368
369HB_BEGIN_DECLS
370
371
372/* Big-endian handling */
373
374static inline uint16_t hb_be_uint16 (const uint16_t v)
375{
376  const uint8_t *V = (const uint8_t *) &v;
377  return (uint16_t) (V[0] << 8) + V[1];
378}
379
380#define hb_be_uint16_put(v,V)	HB_STMT_START { v[0] = (V>>8); v[1] = (V); } HB_STMT_END
381#define hb_be_uint16_get(v)	(uint16_t) ((v[0] << 8) + v[1])
382#define hb_be_uint16_eq(a,b)	(a[0] == b[0] && a[1] == b[1])
383
384#define hb_be_uint32_put(v,V)	HB_STMT_START { v[0] = (V>>24); v[1] = (V>>16); v[2] = (V>>8); v[3] = (V); } HB_STMT_END
385#define hb_be_uint32_get(v)	(uint32_t) ((v[0] << 24) + (v[1] << 16) + (v[2] << 8) + v[3])
386#define hb_be_uint32_eq(a,b)	(a[0] == b[0] && a[1] == b[1] && a[2] == b[2] && a[3] == b[3])
387
388
389/* ASCII tag/character handling */
390
391static inline unsigned char ISALPHA (unsigned char c)
392{ return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); }
393static inline unsigned char ISALNUM (unsigned char c)
394{ return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'); }
395static inline unsigned char TOUPPER (unsigned char c)
396{ return (c >= 'a' && c <= 'z') ? c - 'a' + 'A' : c; }
397static inline unsigned char TOLOWER (unsigned char c)
398{ return (c >= 'A' && c <= 'Z') ? c - 'A' + 'a' : c; }
399
400#define HB_TAG_CHAR4(s)   (HB_TAG(((const char *) s)[0], \
401				  ((const char *) s)[1], \
402				  ((const char *) s)[2], \
403				  ((const char *) s)[3]))
404
405
406/* Debug */
407
408#ifndef HB_DEBUG
409#define HB_DEBUG 0
410#endif
411
412static inline bool /* always returns TRUE */
413_hb_trace (const char *what,
414	   const char *function,
415	   const void *obj,
416	   unsigned int depth,
417	   unsigned int max_depth)
418{
419  (void) ((depth < max_depth) && fprintf (stderr, "%s(%p) %-*d-> %s\n", what, obj, depth, depth, function));
420  return TRUE;
421}
422
423
424HB_END_DECLS
425
426#endif /* HB_PRIVATE_HH */
427