/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: 2025-10-13 06:15

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	7.07k	{
39	7.07k	uint32_t cp;
40
41	7.07k	if (llen == 0)
42	0	return IDN2_OK;
43
44	7.07k	cp = label[pos];
45
46	7.07k	if (!_idn2_contextj_p (cp))
47	6.80k	return IDN2_OK;
48
49	273	switch (cp)
50	273	{
51	230	case 0x200C: /* ZERO WIDTH NON-JOINER */
52	230	if (pos > 0)
53	229	{
54		/* If Canonical_Combining_Class(Before(cp)) .eq. Virama Then True; */
55	229	uint32_t before_cp = label[pos - 1];
56	229	int cc = uc_combining_class (before_cp);
57	229	if (cc == UC_CCC_VR)
58	34	return IDN2_OK;
59	229	}
60
61		/* See http://permalink.gmane.org/gmane.ietf.idnabis/6980 for
62		clarified rule. */
63
64	196	if (pos == 0 \|\| pos == llen - 1)
65	18	return IDN2_CONTEXTJ;
66
67	178	{
68	178	int jt;
69	178	size_t tmp;
70
71		/* Search backwards. */
72	178	for (tmp = pos - 1;; tmp--)
73	302	{
74	302	jt = uc_joining_type (label[tmp]);
75	302	if (jt == UC_JOINING_TYPE_L \|\| jt == UC_JOINING_TYPE_D)
76	117	break;
77	185	if (tmp == 0)
78	46	return IDN2_CONTEXTJ;
79	139	if (jt == UC_JOINING_TYPE_T)
80	124	continue;
81	15	return IDN2_CONTEXTJ;
82	139	}
83
84		/* Search forward. */
85	300	for (tmp = pos + 1; tmp < llen; tmp++)
86	300	{
87	300	jt = uc_joining_type (label[tmp]);
88	300	if (jt == UC_JOINING_TYPE_R \|\| jt == UC_JOINING_TYPE_D)
89	92	break;
90	208	if (tmp == llen - 1)
91	22	return IDN2_CONTEXTJ;
92	186	if (jt == UC_JOINING_TYPE_T)
93	183	continue;
94	3	return IDN2_CONTEXTJ;
95	186	}
96	117	}
97
98	92	return IDN2_OK;
99	0	break;
100
101	43	case 0x200D: /* ZERO WIDTH JOINER */
102	43	if (pos > 0)
103	42	{
104	42	uint32_t before_cp = label[pos - 1];
105	42	int cc = uc_combining_class (before_cp);
106	42	if (cc == UC_CCC_VR)
107	35	return IDN2_OK;
108	42	}
109	8	return IDN2_CONTEXTJ;
110	273	}
111
112	0	return IDN2_CONTEXTJ_NO_RULE;
113	273	}
114
115		static const char *
116		_uc_script_name (ucs4_t uc)
117	12.8k	{
118	12.8k	const uc_script_t *ucs = uc_script (uc);
119
120	12.8k	if (!ucs)
121	1.99k	return "";
122
123	10.8k	return ucs->name;
124	12.8k	}
125
126		int
127		_idn2_contexto_rule (const uint32_t *label, size_t llen, size_t pos)
128	6.31k	{
129	6.31k	uint32_t cp = label[pos];
130
131	6.31k	if (!_idn2_contexto_p (cp))
132	3.68k	return IDN2_OK;
133
134	2.63k	switch (cp)
135	2.63k	{
136	86	case 0x00B7:
137		/* MIDDLE DOT */
138	86	if (llen < 3)
139	1	return IDN2_CONTEXTO;
140	85	if (pos == 0 \|\| pos == llen - 1)
141	6	return IDN2_CONTEXTO;
142	79	if (label[pos - 1] == 0x006C && label[pos + 1] == 0x006C)
143	36	return IDN2_OK;
144	43	return IDN2_CONTEXTO;
145	0	break;
146
147	86	case 0x0375:
148		/* GREEK LOWER NUMERAL SIGN (KERAIA) */
149	86	if (pos == llen - 1)
150	7	return IDN2_CONTEXTO;
151	79	if (strcmp (_uc_script_name (label[pos + 1]), "Greek") == 0)
152	68	return IDN2_OK;
153	11	return IDN2_CONTEXTO;
154	0	break;
155
156	72	case 0x05F3:
157		/* HEBREW PUNCTUATION GERESH */
158	146	case 0x05F4:
159		/* HEBREW PUNCTUATION GERSHAYIM */
160	146	if (pos == 0)
161	2	return IDN2_CONTEXTO;
162	144	if (strcmp (_uc_script_name (label[pos - 1]), "Hebrew") == 0)
163	134	return IDN2_OK;
164	10	return IDN2_CONTEXTO;
165	0	break;
166
167	88	case 0x0660:
168	168	case 0x0661:
169	283	case 0x0662:
170	357	case 0x0663:
171	454	case 0x0664:
172	532	case 0x0665:
173	625	case 0x0666:
174	708	case 0x0667:
175	787	case 0x0668:
176	863	case 0x0669:
177	863	{
178		/* ARABIC-INDIC DIGITS */
179	863	size_t i;
180	18.1k	for (i = 0; i < llen; i++)
181	17.2k	if (label[i] >= 0x6F0 && label[i] <= 0x06F9)
182	4	return IDN2_CONTEXTO;
183	859	return IDN2_OK;
184	0	break;
185	863	}
186
187	122	case 0x06F0:
188	220	case 0x06F1:
189	299	case 0x06F2:
190	387	case 0x06F3:
191	475	case 0x06F4:
192	594	case 0x06F5:
193	695	case 0x06F6:
194	829	case 0x06F7:
195	949	case 0x06F8:
196	1.04k	case 0x06F9:
197	1.04k	{
198		/* EXTENDED ARABIC-INDIC DIGITS */
199	1.04k	size_t i;
200	23.5k	for (i = 0; i < llen; i++)
201	22.4k	if (label[i] >= 0x660 && label[i] <= 0x0669)
202	4	return IDN2_CONTEXTO;
203	1.04k	return IDN2_OK;
204	0	break;
205	1.04k	}
206	401	case 0x30FB:
207	401	{
208		/* KATAKANA MIDDLE DOT */
209	401	size_t i;
210	401	bool script_ok = false;
211
212	4.71k	for (i = 0; !script_ok && i < llen; i++)
213	4.31k	if (strcmp (_uc_script_name (label[i]), "Hiragana") == 0
214	4.24k	\|\| strcmp (_uc_script_name (label[i]), "Katakana") == 0
215	4.04k	\|\| strcmp (_uc_script_name (label[i]), "Han") == 0)
216	355	script_ok = true;
217
218	401	if (script_ok)
219	355	return IDN2_OK;
220	46	return IDN2_CONTEXTO;
221	0	break;
222	401	}
223	2.63k	}
224
225	0	return IDN2_CONTEXTO_NO_RULE;
226	2.63k	}
227
228		bool
229		_idn2_contexto_with_rule (uint32_t cp)
230	0	{
231	0	switch (cp)
232	0	{
233	0	case 0x00B7:
234		/* MIDDLE DOT */
235	0	case 0x0375:
236		/* GREEK LOWER NUMERAL SIGN (KERAIA) */
237	0	case 0x05F3:
238		/* HEBREW PUNCTUATION GERESH */
239	0	case 0x05F4:
240		/* HEBREW PUNCTUATION GERSHAYIM */
241	0	case 0x0660:
242	0	case 0x0661:
243	0	case 0x0662:
244	0	case 0x0663:
245	0	case 0x0664:
246	0	case 0x0665:
247	0	case 0x0666:
248	0	case 0x0667:
249	0	case 0x0668:
250	0	case 0x0669:
251		/* ARABIC-INDIC DIGITS */
252	0	case 0x06F0:
253	0	case 0x06F1:
254	0	case 0x06F2:
255	0	case 0x06F3:
256	0	case 0x06F4:
257	0	case 0x06F5:
258	0	case 0x06F6:
259	0	case 0x06F7:
260	0	case 0x06F8:
261	0	case 0x06F9:
262		/* EXTENDED ARABIC-INDIC DIGITS */
263	0	case 0x30FB:
264		/* KATAKANA MIDDLE DOT */
265	0	return true;
266	0	break;
267	0	}
268
269	0	return false;
270	0	}