/src/libidn2/lib/context.c

Source
/* context.c - check contextual rule on label
   Copyright (C) 2011-2025 Simon Josefsson

   Libidn2 is free software: you can redistribute it and/or modify it
   under the terms of either:

     * the GNU Lesser General Public License as published by the Free
       Software Foundation; either version 3 of the License, or (at
       your option) any later version.

   or

     * the GNU General Public License as published by the Free
       Software Foundation; either version 2 of the License, or (at
       your option) any later version.

   or both in parallel, as here.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received copies of the GNU General Public License and
   the GNU Lesser General Public License along with this program.  If
   not, see <http://www.gnu.org/licenses/>.
*/

#include <config.h>

#include "idn2.h"
#include "tables.h"
#include <unictype.h>   /* uc_combining_class, UC_CCC_VR */
#include "context.h"

int
_idn2_contextj_rule (const uint32_t *label, size_t llen, size_t pos)
{
  uint32_t cp;

  if (llen == 0)
    return IDN2_OK;

  cp = label[pos];

  if (!_idn2_contextj_p (cp))
    return IDN2_OK;

  switch (cp)
    {
    case 0x200C:    /* ZERO WIDTH NON-JOINER */
      if (pos > 0)
  {
    /* If Canonical_Combining_Class(Before(cp)) .eq.  Virama Then True; */
    uint32_t before_cp = label[pos - 1];
    int cc = uc_combining_class (before_cp);
    if (cc == UC_CCC_VR)
      return IDN2_OK;
  }

      /* See http://permalink.gmane.org/gmane.ietf.idnabis/6980 for
         clarified rule. */

      if (pos == 0 || pos == llen - 1)
  return IDN2_CONTEXTJ;

      {
  int jt;
  size_t tmp;

  /* Search backwards. */
  for (tmp = pos - 1;; tmp--)
    {
      jt = uc_joining_type (label[tmp]);
      if (jt == UC_JOINING_TYPE_L || jt == UC_JOINING_TYPE_D)
        break;
      if (tmp == 0)
        return IDN2_CONTEXTJ;
      if (jt == UC_JOINING_TYPE_T)
        continue;
      return IDN2_CONTEXTJ;
    }

  /* Search forward. */
  for (tmp = pos + 1; tmp < llen; tmp++)
    {
      jt = uc_joining_type (label[tmp]);
      if (jt == UC_JOINING_TYPE_R || jt == UC_JOINING_TYPE_D)
        break;
      if (tmp == llen - 1)
        return IDN2_CONTEXTJ;
      if (jt == UC_JOINING_TYPE_T)
        continue;
      return IDN2_CONTEXTJ;
    }
      }

      return IDN2_OK;
      break;

    case 0x200D:    /* ZERO WIDTH JOINER */
      if (pos > 0)
  {
    uint32_t before_cp = label[pos - 1];
    int cc = uc_combining_class (before_cp);
    if (cc == UC_CCC_VR)
      return IDN2_OK;
  }
      return IDN2_CONTEXTJ;
    }

  return IDN2_CONTEXTJ_NO_RULE;
}

static const char *
_uc_script_name (ucs4_t uc)
{
  const uc_script_t *ucs = uc_script (uc);

  if (!ucs)
    return "";

  return ucs->name;
}

int
_idn2_contexto_rule (const uint32_t *label, size_t llen, size_t pos)
{
  uint32_t cp = label[pos];

  if (!_idn2_contexto_p (cp))
    return IDN2_OK;

  switch (cp)
    {
    case 0x00B7:
      /* MIDDLE DOT */
      if (llen < 3)
  return IDN2_CONTEXTO;
      if (pos == 0 || pos == llen - 1)
  return IDN2_CONTEXTO;
      if (label[pos - 1] == 0x006C && label[pos + 1] == 0x006C)
  return IDN2_OK;
      return IDN2_CONTEXTO;
      break;

    case 0x0375:
      /* GREEK LOWER NUMERAL SIGN (KERAIA) */
      if (pos == llen - 1)
  return IDN2_CONTEXTO;
      if (strcmp (_uc_script_name (label[pos + 1]), "Greek") == 0)
  return IDN2_OK;
      return IDN2_CONTEXTO;
      break;

    case 0x05F3:
      /* HEBREW PUNCTUATION GERESH */
    case 0x05F4:
      /* HEBREW PUNCTUATION GERSHAYIM */
      if (pos == 0)
  return IDN2_CONTEXTO;
      if (strcmp (_uc_script_name (label[pos - 1]), "Hebrew") == 0)
  return IDN2_OK;
      return IDN2_CONTEXTO;
      break;

    case 0x0660:
    case 0x0661:
    case 0x0662:
    case 0x0663:
    case 0x0664:
    case 0x0665:
    case 0x0666:
    case 0x0667:
    case 0x0668:
    case 0x0669:
      {
  /* ARABIC-INDIC DIGITS */
  size_t i;
  for (i = 0; i < llen; i++)
    if (label[i] >= 0x6F0 && label[i] <= 0x06F9)
      return IDN2_CONTEXTO;
  return IDN2_OK;
  break;
      }

    case 0x06F0:
    case 0x06F1:
    case 0x06F2:
    case 0x06F3:
    case 0x06F4:
    case 0x06F5:
    case 0x06F6:
    case 0x06F7:
    case 0x06F8:
    case 0x06F9:
      {
  /* EXTENDED ARABIC-INDIC DIGITS */
  size_t i;
  for (i = 0; i < llen; i++)
    if (label[i] >= 0x660 && label[i] <= 0x0669)
      return IDN2_CONTEXTO;
  return IDN2_OK;
  break;
      }
    case 0x30FB:
      {
  /* KATAKANA MIDDLE DOT */
  size_t i;
  bool script_ok = false;

  for (i = 0; !script_ok && i < llen; i++)
    if (strcmp (_uc_script_name (label[i]), "Hiragana") == 0
        || strcmp (_uc_script_name (label[i]), "Katakana") == 0
        || strcmp (_uc_script_name (label[i]), "Han") == 0)
      script_ok = true;

  if (script_ok)
    return IDN2_OK;
  return IDN2_CONTEXTO;
  break;
      }
    }

  return IDN2_CONTEXTO_NO_RULE;
}

bool
_idn2_contexto_with_rule (uint32_t cp)
{
  switch (cp)
    {
    case 0x00B7:
      /* MIDDLE DOT */
    case 0x0375:
      /* GREEK LOWER NUMERAL SIGN (KERAIA) */
    case 0x05F3:
      /* HEBREW PUNCTUATION GERESH */
    case 0x05F4:
      /* HEBREW PUNCTUATION GERSHAYIM */
    case 0x0660:
    case 0x0661:
    case 0x0662:
    case 0x0663:
    case 0x0664:
    case 0x0665:
    case 0x0666:
    case 0x0667:
    case 0x0668:
    case 0x0669:
      /* ARABIC-INDIC DIGITS */
    case 0x06F0:
    case 0x06F1:
    case 0x06F2:
    case 0x06F3:
    case 0x06F4:
    case 0x06F5:
    case 0x06F6:
    case 0x06F7:
    case 0x06F8:
    case 0x06F9:
      /* EXTENDED ARABIC-INDIC DIGITS */
    case 0x30FB:
      /* KATAKANA MIDDLE DOT */
      return true;
      break;
    }

  return false;
}

Coverage Report

Created: 2026-06-08 06:48

Line	Count	Source
1		/* context.c - check contextual rule on label
2		Copyright (C) 2011-2025 Simon Josefsson
3
4		Libidn2 is free software: you can redistribute it and/or modify it
5		under the terms of either:
6
7		* the GNU Lesser General Public License as published by the Free
8		Software Foundation; either version 3 of the License, or (at
9		your option) any later version.
10
11		or
12
13		* the GNU General Public License as published by the Free
14		Software Foundation; either version 2 of the License, or (at
15		your option) any later version.
16
17		or both in parallel, as here.
18
19		This program is distributed in the hope that it will be useful,
20		but WITHOUT ANY WARRANTY; without even the implied warranty of
21		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22		GNU General Public License for more details.
23
24		You should have received copies of the GNU General Public License and
25		the GNU Lesser General Public License along with this program. If
26		not, see <http://www.gnu.org/licenses/>.
27		*/
28
29		#include <config.h>
30
31		#include "idn2.h"
32		#include "tables.h"
33		#include <unictype.h> /* uc_combining_class, UC_CCC_VR */
34		#include "context.h"
35
36		int
37		_idn2_contextj_rule (const uint32_t *label, size_t llen, size_t pos)
38	24.4k	{
39	24.4k	uint32_t cp;
40
41	24.4k	if (llen == 0)
42	0	return IDN2_OK;
43
44	24.4k	cp = label[pos];
45
46	24.4k	if (!_idn2_contextj_p (cp))
47	23.9k	return IDN2_OK;
48
49	508	switch (cp)
50	508	{
51	395	case 0x200C: /* ZERO WIDTH NON-JOINER */
52	395	if (pos > 0)
53	394	{
54		/* If Canonical_Combining_Class(Before(cp)) .eq. Virama Then True; */
55	394	uint32_t before_cp = label[pos - 1];
56	394	int cc = uc_combining_class (before_cp);
57	394	if (cc == UC_CCC_VR)
58	66	return IDN2_OK;
59	394	}
60
61		/* See http://permalink.gmane.org/gmane.ietf.idnabis/6980 for
62		clarified rule. */
63
64	329	if (pos == 0 \|\| pos == llen - 1)
65	17	return IDN2_CONTEXTJ;
66
67	312	{
68	312	int jt;
69	312	size_t tmp;
70
71		/* Search backwards. */
72	448	for (tmp = pos - 1;; tmp--)
73	760	{
74	760	jt = uc_joining_type (label[tmp]);
75	760	if (jt == UC_JOINING_TYPE_L \|\| jt == UC_JOINING_TYPE_D)
76	262	break;
77	498	if (tmp == 0)
78	46	return IDN2_CONTEXTJ;
79	452	if (jt == UC_JOINING_TYPE_T)
80	448	continue;
81	4	return IDN2_CONTEXTJ;
82	452	}
83
84		/* Search forward. */
85	856	for (tmp = pos + 1; tmp < llen; tmp++)
86	856	{
87	856	jt = uc_joining_type (label[tmp]);
88	856	if (jt == UC_JOINING_TYPE_R \|\| jt == UC_JOINING_TYPE_D)
89	222	break;
90	634	if (tmp == llen - 1)
91	38	return IDN2_CONTEXTJ;
92	596	if (jt == UC_JOINING_TYPE_T)
93	594	continue;
94	2	return IDN2_CONTEXTJ;
95	596	}
96	262	}
97
98	222	return IDN2_OK;
99	0	break;
100
101	113	case 0x200D: /* ZERO WIDTH JOINER */
102	113	if (pos > 0)
103	111	{
104	111	uint32_t before_cp = label[pos - 1];
105	111	int cc = uc_combining_class (before_cp);
106	111	if (cc == UC_CCC_VR)
107	102	return IDN2_OK;
108	111	}
109	11	return IDN2_CONTEXTJ;
110	508	}
111
112	0	return IDN2_CONTEXTJ_NO_RULE;
113	508	}
114
115		static const char *
116		_uc_script_name (ucs4_t uc)
117	0	{
118	0	const uc_script_t *ucs = uc_script (uc);
119
120	0	if (!ucs)
121	0	return "";
122
123	0	return ucs->name;
124	0	}
125
126		int
127		_idn2_contexto_rule (const uint32_t *label, size_t llen, size_t pos)
128	0	{
129	0	uint32_t cp = label[pos];
130
131	0	if (!_idn2_contexto_p (cp))
132	0	return IDN2_OK;
133
134	0	switch (cp)
135	0	{
136	0	case 0x00B7:
137		/* MIDDLE DOT */
138	0	if (llen < 3)
139	0	return IDN2_CONTEXTO;
140	0	if (pos == 0 \|\| pos == llen - 1)
141	0	return IDN2_CONTEXTO;
142	0	if (label[pos - 1] == 0x006C && label[pos + 1] == 0x006C)
143	0	return IDN2_OK;
144	0	return IDN2_CONTEXTO;
145	0	break;
146
147	0	case 0x0375:
148		/* GREEK LOWER NUMERAL SIGN (KERAIA) */
149	0	if (pos == llen - 1)
150	0	return IDN2_CONTEXTO;
151	0	if (strcmp (_uc_script_name (label[pos + 1]), "Greek") == 0)
152	0	return IDN2_OK;
153	0	return IDN2_CONTEXTO;
154	0	break;
155
156	0	case 0x05F3:
157		/* HEBREW PUNCTUATION GERESH */
158	0	case 0x05F4:
159		/* HEBREW PUNCTUATION GERSHAYIM */
160	0	if (pos == 0)
161	0	return IDN2_CONTEXTO;
162	0	if (strcmp (_uc_script_name (label[pos - 1]), "Hebrew") == 0)
163	0	return IDN2_OK;
164	0	return IDN2_CONTEXTO;
165	0	break;
166
167	0	case 0x0660:
168	0	case 0x0661:
169	0	case 0x0662:
170	0	case 0x0663:
171	0	case 0x0664:
172	0	case 0x0665:
173	0	case 0x0666:
174	0	case 0x0667:
175	0	case 0x0668:
176	0	case 0x0669:
177	0	{
178		/* ARABIC-INDIC DIGITS */
179	0	size_t i;
180	0	for (i = 0; i < llen; i++)
181	0	if (label[i] >= 0x6F0 && label[i] <= 0x06F9)
182	0	return IDN2_CONTEXTO;
183	0	return IDN2_OK;
184	0	break;
185	0	}
186
187	0	case 0x06F0:
188	0	case 0x06F1:
189	0	case 0x06F2:
190	0	case 0x06F3:
191	0	case 0x06F4:
192	0	case 0x06F5:
193	0	case 0x06F6:
194	0	case 0x06F7:
195	0	case 0x06F8:
196	0	case 0x06F9:
197	0	{
198		/* EXTENDED ARABIC-INDIC DIGITS */
199	0	size_t i;
200	0	for (i = 0; i < llen; i++)
201	0	if (label[i] >= 0x660 && label[i] <= 0x0669)
202	0	return IDN2_CONTEXTO;
203	0	return IDN2_OK;
204	0	break;
205	0	}
206	0	case 0x30FB:
207	0	{
208		/* KATAKANA MIDDLE DOT */
209	0	size_t i;
210	0	bool script_ok = false;
211
212	0	for (i = 0; !script_ok && i < llen; i++)
213	0	if (strcmp (_uc_script_name (label[i]), "Hiragana") == 0
214	0	\|\| strcmp (_uc_script_name (label[i]), "Katakana") == 0
215	0	\|\| strcmp (_uc_script_name (label[i]), "Han") == 0)
216	0	script_ok = true;
217
218	0	if (script_ok)
219	0	return IDN2_OK;
220	0	return IDN2_CONTEXTO;
221	0	break;
222	0	}
223	0	}
224
225	0	return IDN2_CONTEXTO_NO_RULE;
226	0	}
227
228		bool
229		_idn2_contexto_with_rule (uint32_t cp)
230	5.73k	{
231	5.73k	switch (cp)
232	5.73k	{
233	510	case 0x00B7:
234		/* MIDDLE DOT */
235	804	case 0x0375:
236		/* GREEK LOWER NUMERAL SIGN (KERAIA) */
237	1.00k	case 0x05F3:
238		/* HEBREW PUNCTUATION GERESH */
239	1.25k	case 0x05F4:
240		/* HEBREW PUNCTUATION GERSHAYIM */
241	1.47k	case 0x0660:
242	1.67k	case 0x0661:
243	1.88k	case 0x0662:
244	2.09k	case 0x0663:
245	2.30k	case 0x0664:
246	2.50k	case 0x0665:
247	2.72k	case 0x0666:
248	2.94k	case 0x0667:
249	3.17k	case 0x0668:
250	3.39k	case 0x0669:
251		/* ARABIC-INDIC DIGITS */
252	3.59k	case 0x06F0:
253	3.78k	case 0x06F1:
254	4.02k	case 0x06F2:
255	4.30k	case 0x06F3:
256	4.52k	case 0x06F4:
257	4.72k	case 0x06F5:
258	4.93k	case 0x06F6:
259	5.13k	case 0x06F7:
260	5.34k	case 0x06F8:
261	5.54k	case 0x06F9:
262		/* EXTENDED ARABIC-INDIC DIGITS */
263	5.73k	case 0x30FB:
264		/* KATAKANA MIDDLE DOT */
265	5.73k	return true;
266	0	break;
267	5.73k	}
268
269	0	return false;
270	5.73k	}