1 /****************************************************************************
2 *
3 * otvmod.c
4 *
5 * FreeType's OpenType validation module implementation (body).
6 *
7 * Copyright (C) 2004-2023 by
8 * David Turner, Robert Wilhelm, and Werner Lemberg.
9 *
10 * This file is part of the FreeType project, and may only be used,
11 * modified, and distributed under the terms of the FreeType project
12 * license, LICENSE.TXT. By continuing to use, modify, or distribute
13 * this file you indicate that you have read the license and
14 * understand and accept it fully.
15 *
16 */
17
18
19 #include <freetype/tttables.h>
20 #include <freetype/tttags.h>
21 #include <freetype/ftotval.h>
22 #include <freetype/internal/ftobjs.h>
23 #include <freetype/internal/services/svotval.h>
24
25 #include "otvmod.h"
26 #include "otvalid.h"
27 #include "otvcommn.h"
28
29
30 /**************************************************************************
31 *
32 * The macro FT_COMPONENT is used in trace mode. It is an implicit
33 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
34 * messages during execution.
35 */
36 #undef FT_COMPONENT
37 #define FT_COMPONENT otvmodule
38
39
40 static FT_Error
41 otv_load_table( FT_Face face,
42 FT_Tag tag,
43 FT_Byte* volatile* table,
44 FT_ULong* table_len )
45 {
46 FT_Error error;
47 FT_Memory memory = FT_FACE_MEMORY( face );
48
49
50 error = FT_Load_Sfnt_Table( face, tag, 0, NULL, table_len );
51 if ( FT_ERR_EQ( error, Table_Missing ) )
52 return FT_Err_Ok;
53 if ( error )
54 goto Exit;
55
56 if ( FT_QALLOC( *table, *table_len ) )
57 goto Exit;
58
59 error = FT_Load_Sfnt_Table( face, tag, 0, *table, table_len );
60
61 Exit:
62 return error;
63 }
64
65
66 static FT_Error
67 otv_validate( FT_Face volatile face,
68 FT_UInt ot_flags,
69 FT_Bytes *ot_base,
70 FT_Bytes *ot_gdef,
71 FT_Bytes *ot_gpos,
72 FT_Bytes *ot_gsub,
73 FT_Bytes *ot_jstf )
74 {
75 FT_Error error = FT_Err_Ok;
76 FT_Byte* volatile base;
77 FT_Byte* volatile gdef;
78 FT_Byte* volatile gpos;
79 FT_Byte* volatile gsub;
80 FT_Byte* volatile jstf;
81 FT_Byte* volatile math;
82 FT_ULong len_base, len_gdef, len_gpos, len_gsub, len_jstf;
83 FT_ULong len_math;
84 FT_UInt num_glyphs = (FT_UInt)face->num_glyphs;
85 FT_ValidatorRec volatile valid;
86
87
88 base = gdef = gpos = gsub = jstf = math = NULL;
89 len_base = len_gdef = len_gpos = len_gsub = len_jstf = len_math = 0;
90
91 /*
92 * XXX: OpenType tables cannot handle 32-bit glyph index,
93 * although broken TrueType can have 32-bit glyph index.
94 */
95 if ( face->num_glyphs > 0xFFFFL )
96 {
97 FT_TRACE1(( "otv_validate: Invalid glyphs index (0x0000FFFF - 0x%08lx) ",
98 face->num_glyphs ));
99 FT_TRACE1(( "are not handled by OpenType tables\n" ));
100 num_glyphs = 0xFFFF;
101 }
102
103 /* load tables */
104
105 if ( ot_flags & FT_VALIDATE_BASE )
106 {
107 error = otv_load_table( face, TTAG_BASE, &base, &len_base );
108 if ( error )
109 goto Exit;
110 }
111
112 if ( ot_flags & FT_VALIDATE_GDEF )
113 {
114 error = otv_load_table( face, TTAG_GDEF, &gdef, &len_gdef );
115 if ( error )
116 goto Exit;
117 }
118
119 if ( ot_flags & FT_VALIDATE_GPOS )
120 {
121 error = otv_load_table( face, TTAG_GPOS, &gpos, &len_gpos );
122 if ( error )
123 goto Exit;
124 }
125
126 if ( ot_flags & FT_VALIDATE_GSUB )
127 {
128 error = otv_load_table( face, TTAG_GSUB, &gsub, &len_gsub );
129 if ( error )
130 goto Exit;
131 }
132
133 if ( ot_flags & FT_VALIDATE_JSTF )
134 {
135 error = otv_load_table( face, TTAG_JSTF, &jstf, &len_jstf );
136 if ( error )
137 goto Exit;
138 }
139
140 if ( ot_flags & FT_VALIDATE_MATH )
141 {
142 error = otv_load_table( face, TTAG_MATH, &math, &len_math );
143 if ( error )
144 goto Exit;
145 }
146
147 /* validate tables */
148
149 if ( base )
150 {
151 ft_validator_init( &valid, base, base + len_base, FT_VALIDATE_DEFAULT );
152 if ( ft_setjmp( valid.jump_buffer ) == 0 )
153 otv_BASE_validate( base, &valid );
154 error = valid.error;
155 if ( error )
156 goto Exit;
157 }
158
159 if ( gpos )
160 {
161 ft_validator_init( &valid, gpos, gpos + len_gpos, FT_VALIDATE_DEFAULT );
162 if ( ft_setjmp( valid.jump_buffer ) == 0 )
163 otv_GPOS_validate( gpos, num_glyphs, &valid );
164 error = valid.error;
165 if ( error )
166 goto Exit;
167 }
168
169 if ( gsub )
170 {
171 ft_validator_init( &valid, gsub, gsub + len_gsub, FT_VALIDATE_DEFAULT );
172 if ( ft_setjmp( valid.jump_buffer ) == 0 )
173 otv_GSUB_validate( gsub, num_glyphs, &valid );
174 error = valid.error;
175 if ( error )
176 goto Exit;
177 }
178
179 if ( gdef )
180 {
181 ft_validator_init( &valid, gdef, gdef + len_gdef, FT_VALIDATE_DEFAULT );
182 if ( ft_setjmp( valid.jump_buffer ) == 0 )
183 otv_GDEF_validate( gdef, gsub, gpos, num_glyphs, &valid );
184 error = valid.error;
185 if ( error )
186 goto Exit;
187 }
188
189 if ( jstf )
190 {
191 ft_validator_init( &valid, jstf, jstf + len_jstf, FT_VALIDATE_DEFAULT );
192 if ( ft_setjmp( valid.jump_buffer ) == 0 )
193 otv_JSTF_validate( jstf, gsub, gpos, num_glyphs, &valid );
194 error = valid.error;
195 if ( error )
196 goto Exit;
197 }
198
199 if ( math )
200 {
201 ft_validator_init( &valid, math, math + len_math, FT_VALIDATE_DEFAULT );
202 if ( ft_setjmp( valid.jump_buffer ) == 0 )
203 otv_MATH_validate( math, num_glyphs, &valid );
204 error = valid.error;
205 if ( error )
206 goto Exit;
207 }
208
209 *ot_base = (FT_Bytes)base;
210 *ot_gdef = (FT_Bytes)gdef;
211 *ot_gpos = (FT_Bytes)gpos;
212 *ot_gsub = (FT_Bytes)gsub;
213 *ot_jstf = (FT_Bytes)jstf;
214
215 Exit:
216 if ( error )
217 {
218 FT_Memory memory = FT_FACE_MEMORY( face );
219
220
221 FT_FREE( base );
222 FT_FREE( gdef );
223 FT_FREE( gpos );
224 FT_FREE( gsub );
225 FT_FREE( jstf );
226 }
227
228 {
229 FT_Memory memory = FT_FACE_MEMORY( face );
230
231
232 FT_FREE( math ); /* Can't return this as API is frozen */
233 }
234
235 return error;
236 }
237
238
239 static
240 const FT_Service_OTvalidateRec otvalid_interface =
241 {
242 otv_validate /* validate */
243 };
244
245
246 static
247 const FT_ServiceDescRec otvalid_services[] =
248 {
249 { FT_SERVICE_ID_OPENTYPE_VALIDATE, &otvalid_interface },
250 { NULL, NULL }
251 };
252
253
254 static FT_Pointer
255 otvalid_get_service( FT_Module module,
256 const char* service_id )
257 {
258 FT_UNUSED( module );
259
260 return ft_service_list_lookup( otvalid_services, service_id );
261 }
262
263
264 FT_CALLBACK_TABLE_DEF
265 const FT_Module_Class otv_module_class =
266 {
267 0,
268 sizeof ( FT_ModuleRec ),
269 "otvalid",
270 0x10000L,
271 0x20000L,
272
273 NULL, /* module-specific interface */
274
275 (FT_Module_Constructor)NULL, /* module_init */
276 (FT_Module_Destructor) NULL, /* module_done */
277 (FT_Module_Requester) otvalid_get_service /* get_interface */
278 };
279
280
281 /* END */