/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: 2026-03-31 06:37

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	23.2k	{
39	23.2k	uint32_t cp;
40
41	23.2k	if (llen == 0)
42	0	return IDN2_OK;
43
44	23.2k	cp = label[pos];
45
46	23.2k	if (!_idn2_contextj_p (cp))
47	22.7k	return IDN2_OK;
48
49	584	switch (cp)
50	584	{
51	506	case 0x200C: /* ZERO WIDTH NON-JOINER */
52	506	if (pos > 0)
53	504	{
54		/* If Canonical_Combining_Class(Before(cp)) .eq. Virama Then True; */
55	504	uint32_t before_cp = label[pos - 1];
56	504	int cc = uc_combining_class (before_cp);
57	504	if (cc == UC_CCC_VR)
58	66	return IDN2_OK;
59	504	}
60
61		/* See http://permalink.gmane.org/gmane.ietf.idnabis/6980 for
62		clarified rule. */
63
64	440	if (pos == 0 \|\| pos == llen - 1)
65	14	return IDN2_CONTEXTJ;
66
67	426	{
68	426	int jt;
69	426	size_t tmp;
70
71		/* Search backwards. */
72	426	for (tmp = pos - 1;; tmp--)
73	756	{
74	756	jt = uc_joining_type (label[tmp]);
75	756	if (jt == UC_JOINING_TYPE_L \|\| jt == UC_JOINING_TYPE_D)
76	370	break;
77	386	if (tmp == 0)
78	48	return IDN2_CONTEXTJ;
79	338	if (jt == UC_JOINING_TYPE_T)
80	330	continue;
81	8	return IDN2_CONTEXTJ;
82	338	}
83
84		/* Search forward. */
85	871	for (tmp = pos + 1; tmp < llen; tmp++)
86	871	{
87	871	jt = uc_joining_type (label[tmp]);
88	871	if (jt == UC_JOINING_TYPE_R \|\| jt == UC_JOINING_TYPE_D)
89	329	break;
90	542	if (tmp == llen - 1)
91	39	return IDN2_CONTEXTJ;
92	503	if (jt == UC_JOINING_TYPE_T)
93	501	continue;
94	2	return IDN2_CONTEXTJ;
95	503	}
96	370	}
97
98	329	return IDN2_OK;
99	0	break;
100
101	78	case 0x200D: /* ZERO WIDTH JOINER */
102	78	if (pos > 0)
103	77	{
104	77	uint32_t before_cp = label[pos - 1];
105	77	int cc = uc_combining_class (before_cp);
106	77	if (cc == UC_CCC_VR)
107	66	return IDN2_OK;
108	77	}
109	12	return IDN2_CONTEXTJ;
110	584	}
111
112	0	return IDN2_CONTEXTJ_NO_RULE;
113	584	}
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	5.78k	{
231	5.78k	switch (cp)
232	5.78k	{
233	530	case 0x00B7:
234		/* MIDDLE DOT */
235	821	case 0x0375:
236		/* GREEK LOWER NUMERAL SIGN (KERAIA) */
237	1.07k	case 0x05F3:
238		/* HEBREW PUNCTUATION GERESH */
239	1.31k	case 0x05F4:
240		/* HEBREW PUNCTUATION GERSHAYIM */
241	1.52k	case 0x0660:
242	1.72k	case 0x0661:
243	1.93k	case 0x0662:
244	2.15k	case 0x0663:
245	2.36k	case 0x0664:
246	2.57k	case 0x0665:
247	2.80k	case 0x0666:
248	3.01k	case 0x0667:
249	3.23k	case 0x0668:
250	3.46k	case 0x0669:
251		/* ARABIC-INDIC DIGITS */
252	3.68k	case 0x06F0:
253	3.88k	case 0x06F1:
254	4.09k	case 0x06F2:
255	4.33k	case 0x06F3:
256	4.53k	case 0x06F4:
257	4.73k	case 0x06F5:
258	4.94k	case 0x06F6:
259	5.14k	case 0x06F7:
260	5.37k	case 0x06F8:
261	5.58k	case 0x06F9:
262		/* EXTENDED ARABIC-INDIC DIGITS */
263	5.78k	case 0x30FB:
264		/* KATAKANA MIDDLE DOT */
265	5.78k	return true;
266	0	break;
267	5.78k	}
268
269	0	return false;
270	5.78k	}