/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: 2025-12-31 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	24.8k	{
39	24.8k	uint32_t cp;
40
41	24.8k	if (llen == 0)
42	0	return IDN2_OK;
43
44	24.8k	cp = label[pos];
45
46	24.8k	if (!_idn2_contextj_p (cp))
47	24.3k	return IDN2_OK;
48
49	468	switch (cp)
50	468	{
51	388	case 0x200C: /* ZERO WIDTH NON-JOINER */
52	388	if (pos > 0)
53	386	{
54		/* If Canonical_Combining_Class(Before(cp)) .eq. Virama Then True; */
55	386	uint32_t before_cp = label[pos - 1];
56	386	int cc = uc_combining_class (before_cp);
57	386	if (cc == UC_CCC_VR)
58	66	return IDN2_OK;
59	386	}
60
61		/* See http://permalink.gmane.org/gmane.ietf.idnabis/6980 for
62		clarified rule. */
63
64	322	if (pos == 0 \|\| pos == llen - 1)
65	14	return IDN2_CONTEXTJ;
66
67	308	{
68	308	int jt;
69	308	size_t tmp;
70
71		/* Search backwards. */
72	308	for (tmp = pos - 1;; tmp--)
73	546	{
74	546	jt = uc_joining_type (label[tmp]);
75	546	if (jt == UC_JOINING_TYPE_L \|\| jt == UC_JOINING_TYPE_D)
76	259	break;
77	287	if (tmp == 0)
78	42	return IDN2_CONTEXTJ;
79	245	if (jt == UC_JOINING_TYPE_T)
80	238	continue;
81	7	return IDN2_CONTEXTJ;
82	245	}
83
84		/* Search forward. */
85	807	for (tmp = pos + 1; tmp < llen; tmp++)
86	807	{
87	807	jt = uc_joining_type (label[tmp]);
88	807	if (jt == UC_JOINING_TYPE_R \|\| jt == UC_JOINING_TYPE_D)
89	216	break;
90	591	if (tmp == llen - 1)
91	41	return IDN2_CONTEXTJ;
92	550	if (jt == UC_JOINING_TYPE_T)
93	548	continue;
94	2	return IDN2_CONTEXTJ;
95	550	}
96	259	}
97
98	216	return IDN2_OK;
99	0	break;
100
101	80	case 0x200D: /* ZERO WIDTH JOINER */
102	80	if (pos > 0)
103	79	{
104	79	uint32_t before_cp = label[pos - 1];
105	79	int cc = uc_combining_class (before_cp);
106	79	if (cc == UC_CCC_VR)
107	66	return IDN2_OK;
108	79	}
109	14	return IDN2_CONTEXTJ;
110	468	}
111
112	0	return IDN2_CONTEXTJ_NO_RULE;
113	468	}
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	5.76k	{
231	5.76k	switch (cp)
232	5.76k	{
233	399	case 0x00B7:
234		/* MIDDLE DOT */
235	836	case 0x0375:
236		/* GREEK LOWER NUMERAL SIGN (KERAIA) */
237	1.05k	case 0x05F3:
238		/* HEBREW PUNCTUATION GERESH */
239	1.24k	case 0x05F4:
240		/* HEBREW PUNCTUATION GERSHAYIM */
241	1.46k	case 0x0660:
242	1.69k	case 0x0661:
243	1.90k	case 0x0662:
244	2.11k	case 0x0663:
245	2.32k	case 0x0664:
246	2.54k	case 0x0665:
247	2.77k	case 0x0666:
248	2.99k	case 0x0667:
249	3.22k	case 0x0668:
250	3.45k	case 0x0669:
251		/* ARABIC-INDIC DIGITS */
252	3.66k	case 0x06F0:
253	3.85k	case 0x06F1:
254	4.06k	case 0x06F2:
255	4.30k	case 0x06F3:
256	4.50k	case 0x06F4:
257	4.70k	case 0x06F5:
258	4.94k	case 0x06F6:
259	5.14k	case 0x06F7:
260	5.34k	case 0x06F8:
261	5.57k	case 0x06F9:
262		/* EXTENDED ARABIC-INDIC DIGITS */
263	5.76k	case 0x30FB:
264		/* KATAKANA MIDDLE DOT */
265	5.76k	return true;
266	0	break;
267	5.76k	}
268
269	0	return false;
270	5.76k	}