1/*
2 * Copyright © 2012 Google, 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 * Google Author(s): Behdad Esfahbod
25 */
26
27#include "hb.hh"
28#include "hb-shaper.hh"
29#include "hb-machinery.hh"
30
31
32static const hb_shaper_entry_t all_shapers[] = {
33#define HB_SHAPER_IMPLEMENT(name) {#name, _hb_##name##_shape},
34#include "hb-shaper-list.hh"
35#undef HB_SHAPER_IMPLEMENT
36};
37#ifndef HB_NO_SHAPER
38static_assert (0 != ARRAY_LENGTH_CONST (all_shapers), "No shaper enabled.");
39#endif
40
41#if HB_USE_ATEXIT
42static void free_static_shapers ();
43#endif
44
45static struct hb_shapers_lazy_loader_t : hb_lazy_loader_t<const hb_shaper_entry_t,
46 hb_shapers_lazy_loader_t>
47{
48 static hb_shaper_entry_t *create ()
49 {
50 char *env = getenv ("HB_SHAPER_LIST");
51 if (!env || !*env)
52 return nullptr;
53
54 hb_shaper_entry_t *shapers = (hb_shaper_entry_t *) calloc (1, sizeof (all_shapers));
55 if (unlikely (!shapers))
56 return nullptr;
57
58 memcpy (shapers, all_shapers, sizeof (all_shapers));
59
60 /* Reorder shaper list to prefer requested shapers. */
61 unsigned int i = 0;
62 char *end, *p = env;
63 for (;;)
64 {
65 end = strchr (p, ',');
66 if (!end)
67 end = p + strlen (p);
68
69 for (unsigned int j = i; j < ARRAY_LENGTH (all_shapers); j++)
70 if (end - p == (int) strlen (shapers[j].name) &&
71 0 == strncmp (shapers[j].name, p, end - p))
72 {
73 /* Reorder this shaper to position i */
74 struct hb_shaper_entry_t t = shapers[j];
75 memmove (&shapers[i + 1], &shapers[i], sizeof (shapers[i]) * (j - i));
76 shapers[i] = t;
77 i++;
78 }
79
80 if (!*end)
81 break;
82 else
83 p = end + 1;
84 }
85
86#if HB_USE_ATEXIT
87 atexit (free_static_shapers);
88#endif
89
90 return shapers;
91 }
92 static void destroy (const hb_shaper_entry_t *p) { free ((void *) p); }
93 static const hb_shaper_entry_t *get_null () { return all_shapers; }
94} static_shapers;
95
96#if HB_USE_ATEXIT
97static
98void free_static_shapers ()
99{
100 static_shapers.free_instance ();
101}
102#endif
103
104const hb_shaper_entry_t *
105_hb_shapers_get ()
106{
107 return static_shapers.get_unconst ();
108}
109