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1 /****************************************************************************
2  *
3  * otvjstf.c
4  *
5  *   OpenType JSTF table validation (body).
6  *
7  * Copyright 2004-2018 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 "otvalid.h"
20 #include "otvcommn.h"
21 #include "otvgpos.h"
22 
23 
24   /**************************************************************************
25    *
26    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
27    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
28    * messages during execution.
29    */
30 #undef  FT_COMPONENT
31 #define FT_COMPONENT  trace_otvjstf
32 
33 
34 #define JstfPriorityFunc  otv_JstfPriority_validate
35 #define JstfLookupFunc    otv_GPOS_subtable_validate
36 
37   /* uses otvalid->extra1 (GSUB lookup count) */
38   /* uses otvalid->extra2 (GPOS lookup count) */
39   /* sets otvalid->extra1 (counter)           */
40 
41   static void
otv_JstfPriority_validate(FT_Bytes table,OTV_Validator otvalid)42   otv_JstfPriority_validate( FT_Bytes       table,
43                              OTV_Validator  otvalid )
44   {
45     FT_Bytes  p = table;
46     FT_UInt   table_size;
47     FT_UInt   gsub_lookup_count, gpos_lookup_count;
48 
49     OTV_OPTIONAL_TABLE( ShrinkageEnableGSUB  );
50     OTV_OPTIONAL_TABLE( ShrinkageDisableGSUB );
51     OTV_OPTIONAL_TABLE( ShrinkageEnableGPOS  );
52     OTV_OPTIONAL_TABLE( ShrinkageDisableGPOS );
53     OTV_OPTIONAL_TABLE( ExtensionEnableGSUB  );
54     OTV_OPTIONAL_TABLE( ExtensionDisableGSUB );
55     OTV_OPTIONAL_TABLE( ExtensionEnableGPOS  );
56     OTV_OPTIONAL_TABLE( ExtensionDisableGPOS );
57     OTV_OPTIONAL_TABLE( ShrinkageJstfMax );
58     OTV_OPTIONAL_TABLE( ExtensionJstfMax );
59 
60 
61     OTV_ENTER;
62     OTV_TRACE(( "JstfPriority table\n" ));
63 
64     OTV_LIMIT_CHECK( 20 );
65 
66     gsub_lookup_count = otvalid->extra1;
67     gpos_lookup_count = otvalid->extra2;
68 
69     table_size = 20;
70 
71     otvalid->extra1 = gsub_lookup_count;
72 
73     OTV_OPTIONAL_OFFSET( ShrinkageEnableGSUB );
74     OTV_SIZE_CHECK( ShrinkageEnableGSUB );
75     if ( ShrinkageEnableGSUB )
76       otv_x_ux( table + ShrinkageEnableGSUB, otvalid );
77 
78     OTV_OPTIONAL_OFFSET( ShrinkageDisableGSUB );
79     OTV_SIZE_CHECK( ShrinkageDisableGSUB );
80     if ( ShrinkageDisableGSUB )
81       otv_x_ux( table + ShrinkageDisableGSUB, otvalid );
82 
83     otvalid->extra1 = gpos_lookup_count;
84 
85     OTV_OPTIONAL_OFFSET( ShrinkageEnableGPOS );
86     OTV_SIZE_CHECK( ShrinkageEnableGPOS );
87     if ( ShrinkageEnableGPOS )
88       otv_x_ux( table + ShrinkageEnableGPOS, otvalid );
89 
90     OTV_OPTIONAL_OFFSET( ShrinkageDisableGPOS );
91     OTV_SIZE_CHECK( ShrinkageDisableGPOS );
92     if ( ShrinkageDisableGPOS )
93       otv_x_ux( table + ShrinkageDisableGPOS, otvalid );
94 
95     OTV_OPTIONAL_OFFSET( ShrinkageJstfMax );
96     OTV_SIZE_CHECK( ShrinkageJstfMax );
97     if ( ShrinkageJstfMax )
98     {
99       /* XXX: check lookup types? */
100       OTV_NEST2( JstfMax, JstfLookup );
101       OTV_RUN( table + ShrinkageJstfMax, otvalid );
102     }
103 
104     otvalid->extra1 = gsub_lookup_count;
105 
106     OTV_OPTIONAL_OFFSET( ExtensionEnableGSUB );
107     OTV_SIZE_CHECK( ExtensionEnableGSUB );
108     if ( ExtensionEnableGSUB )
109       otv_x_ux( table + ExtensionEnableGSUB, otvalid );
110 
111     OTV_OPTIONAL_OFFSET( ExtensionDisableGSUB );
112     OTV_SIZE_CHECK( ExtensionDisableGSUB );
113     if ( ExtensionDisableGSUB )
114       otv_x_ux( table + ExtensionDisableGSUB, otvalid );
115 
116     otvalid->extra1 = gpos_lookup_count;
117 
118     OTV_OPTIONAL_OFFSET( ExtensionEnableGPOS );
119     OTV_SIZE_CHECK( ExtensionEnableGPOS );
120     if ( ExtensionEnableGPOS )
121       otv_x_ux( table + ExtensionEnableGPOS, otvalid );
122 
123     OTV_OPTIONAL_OFFSET( ExtensionDisableGPOS );
124     OTV_SIZE_CHECK( ExtensionDisableGPOS );
125     if ( ExtensionDisableGPOS )
126       otv_x_ux( table + ExtensionDisableGPOS, otvalid );
127 
128     OTV_OPTIONAL_OFFSET( ExtensionJstfMax );
129     OTV_SIZE_CHECK( ExtensionJstfMax );
130     if ( ExtensionJstfMax )
131     {
132       /* XXX: check lookup types? */
133       OTV_NEST2( JstfMax, JstfLookup );
134       OTV_RUN( table + ExtensionJstfMax, otvalid );
135     }
136 
137     otvalid->extra1 = gsub_lookup_count;
138     otvalid->extra2 = gpos_lookup_count;
139 
140     OTV_EXIT;
141   }
142 
143 
144   /* sets otvalid->extra (glyph count)               */
145   /* sets otvalid->func1 (otv_JstfPriority_validate) */
146 
147   static void
otv_JstfScript_validate(FT_Bytes table,OTV_Validator otvalid)148   otv_JstfScript_validate( FT_Bytes       table,
149                            OTV_Validator  otvalid )
150   {
151     FT_Bytes  p = table;
152     FT_UInt   table_size;
153     FT_UInt   JstfLangSysCount;
154 
155     OTV_OPTIONAL_TABLE( ExtGlyph );
156     OTV_OPTIONAL_TABLE( DefJstfLangSys );
157 
158 
159     OTV_NAME_ENTER( "JstfScript" );
160 
161     OTV_LIMIT_CHECK( 6 );
162     OTV_OPTIONAL_OFFSET( ExtGlyph );
163     OTV_OPTIONAL_OFFSET( DefJstfLangSys );
164     JstfLangSysCount = FT_NEXT_USHORT( p );
165 
166     OTV_TRACE(( " (JstfLangSysCount = %d)\n", JstfLangSysCount ));
167 
168     table_size = JstfLangSysCount * 6 + 6;
169 
170     OTV_SIZE_CHECK( ExtGlyph );
171     if ( ExtGlyph )
172     {
173       otvalid->extra1 = otvalid->glyph_count;
174       OTV_NEST1( ExtenderGlyph );
175       OTV_RUN( table + ExtGlyph, otvalid );
176     }
177 
178     OTV_SIZE_CHECK( DefJstfLangSys );
179     if ( DefJstfLangSys )
180     {
181       OTV_NEST2( JstfLangSys, JstfPriority );
182       OTV_RUN( table + DefJstfLangSys, otvalid );
183     }
184 
185     OTV_LIMIT_CHECK( 6 * JstfLangSysCount );
186 
187     /* JstfLangSysRecord */
188     OTV_NEST2( JstfLangSys, JstfPriority );
189     for ( ; JstfLangSysCount > 0; JstfLangSysCount-- )
190     {
191       p += 4;       /* skip JstfLangSysTag */
192 
193       OTV_RUN( table + FT_NEXT_USHORT( p ), otvalid );
194     }
195 
196     OTV_EXIT;
197   }
198 
199 
200   /* sets otvalid->extra1 (GSUB lookup count) */
201   /* sets otvalid->extra2 (GPOS lookup count) */
202   /* sets otvalid->glyph_count                */
203 
204   FT_LOCAL_DEF( void )
otv_JSTF_validate(FT_Bytes table,FT_Bytes gsub,FT_Bytes gpos,FT_UInt glyph_count,FT_Validator ftvalid)205   otv_JSTF_validate( FT_Bytes      table,
206                      FT_Bytes      gsub,
207                      FT_Bytes      gpos,
208                      FT_UInt       glyph_count,
209                      FT_Validator  ftvalid )
210   {
211     OTV_ValidatorRec  otvalidrec;
212     OTV_Validator     otvalid = &otvalidrec;
213     FT_Bytes          p     = table;
214     FT_UInt           JstfScriptCount;
215 
216 
217     otvalid->root = ftvalid;
218 
219 
220     FT_TRACE3(( "validating JSTF table\n" ));
221     OTV_INIT;
222 
223     OTV_LIMIT_CHECK( 6 );
224 
225     if ( FT_NEXT_ULONG( p ) != 0x10000UL )      /* Version */
226       FT_INVALID_FORMAT;
227 
228     JstfScriptCount = FT_NEXT_USHORT( p );
229 
230     FT_TRACE3(( " (JstfScriptCount = %d)\n", JstfScriptCount ));
231 
232     OTV_LIMIT_CHECK( JstfScriptCount * 6 );
233 
234     if ( gsub )
235       otvalid->extra1 = otv_GSUBGPOS_get_Lookup_count( gsub );
236     else
237       otvalid->extra1 = 0;
238 
239     if ( gpos )
240       otvalid->extra2 = otv_GSUBGPOS_get_Lookup_count( gpos );
241     else
242       otvalid->extra2 = 0;
243 
244     otvalid->glyph_count = glyph_count;
245 
246     /* JstfScriptRecord */
247     for ( ; JstfScriptCount > 0; JstfScriptCount-- )
248     {
249       p += 4;       /* skip JstfScriptTag */
250 
251       /* JstfScript */
252       otv_JstfScript_validate( table + FT_NEXT_USHORT( p ), otvalid );
253     }
254 
255     FT_TRACE4(( "\n" ));
256   }
257 
258 
259 /* END */
260