/src/libidn2/gl/uninorm/u-normalize-internal.h

Source
/* Decomposition and composition of Unicode strings.
   Copyright (C) 2009-2025 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2009.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file 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 Lesser General Public License for more details.

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

UNIT *
FUNC (uninorm_t nf, const UNIT *s, size_t n,
      UNIT *resultbuf, size_t *lengthp)
{
  int (*decomposer) (ucs4_t uc, ucs4_t *decomposition) = nf->decomposer;
  ucs4_t (*composer) (ucs4_t uc1, ucs4_t uc2) = nf->composer;

  /* The result being accumulated.  */
  UNIT *result;
  size_t length;
  size_t allocated;
  /* The buffer for sorting.  */
  #define SORTBUF_PREALLOCATED 64
  struct ucs4_with_ccc sortbuf_preallocated[2 * SORTBUF_PREALLOCATED];
  struct ucs4_with_ccc *sortbuf; /* array of size 2 * sortbuf_allocated */
  size_t sortbuf_allocated;
  size_t sortbuf_count;

  /* Initialize the accumulator.  */
  if (resultbuf == NULL)
    {
      result = NULL;
      allocated = 0;
    }
  else
    {
      result = resultbuf;
      allocated = *lengthp;
    }
  length = 0;

  /* Initialize the buffer for sorting.  */
  sortbuf = sortbuf_preallocated;
  sortbuf_allocated = SORTBUF_PREALLOCATED;
  sortbuf_count = 0;

  {
    const UNIT *s_end = s + n;

    for (;;)
      {
        int count;
        ucs4_t decomposed[UC_DECOMPOSITION_MAX_LENGTH];
        int decomposed_count;
        int i;

        if (s < s_end)
          {
            /* Fetch the next character.  */
            count = U_MBTOUC_UNSAFE (&decomposed[0], s, s_end - s);
            decomposed_count = 1;

            /* Decompose it, recursively.
               It would be possible to precompute the recursive decomposition
               and store it in a table.  But this would significantly increase
               the size of the decomposition tables, because for example for
               U+1FC1 the recursive canonical decomposition and the recursive
               compatibility decomposition are different.  */
            for (int curr = 0; curr < decomposed_count; )
              {
                /* Invariant: decomposed[0..curr-1] is fully decomposed, i.e.
                   all elements are atomic.  */
                ucs4_t curr_decomposed[UC_DECOMPOSITION_MAX_LENGTH];
                int curr_decomposed_count;

                curr_decomposed_count = decomposer (decomposed[curr], curr_decomposed);
                if (curr_decomposed_count >= 0)
                  {
                    /* Move curr_decomposed[0..curr_decomposed_count-1] over
                       decomposed[curr], making room.  It's not worth using
                       memcpy() here, since the counts are so small.  */
                    int shift = curr_decomposed_count - 1;

                    if (shift < 0)
                      abort ();
                    if (shift > 0)
                      {
                        decomposed_count += shift;
                        if (decomposed_count > UC_DECOMPOSITION_MAX_LENGTH)
                          abort ();
                        for (int j = decomposed_count - 1 - shift; j > curr; j--)
                          decomposed[j + shift] = decomposed[j];
                      }
                    for (; shift >= 0; shift--)
                      decomposed[curr + shift] = curr_decomposed[shift];
                  }
                else
                  {
                    /* decomposed[curr] is atomic.  */
                    curr++;
                  }
              }
          }
        else
          {
            count = 0;
            decomposed_count = 0;
          }

        i = 0;
        for (;;)
          {
            ucs4_t uc;
            int ccc;

            if (s < s_end)
              {
                /* Fetch the next character from the decomposition.  */
                if (i == decomposed_count)
                  break;
                uc = decomposed[i];
                ccc = uc_combining_class (uc);
              }
            else
              {
                /* End of string reached.  */
                uc = 0;
                ccc = 0;
              }

            if (ccc == 0)
              {
                /* Apply the canonical ordering algorithm to the accumulated
                   sequence of characters.  */
                if (sortbuf_count > 1)
                  gl_uninorm_decompose_merge_sort_inplace (sortbuf, sortbuf_count,
                                                           sortbuf + sortbuf_count);

                if (composer != NULL)
                  {
                    /* Attempt to combine decomposed characters, as specified
                       in the Unicode Standard Annex #15 "Unicode Normalization
                       Forms".  We need to check
                         1. whether the first accumulated character is a
                            "starter" (i.e. has ccc = 0).  This is usually the
                            case.  But when the string starts with a
                            non-starter, the sortbuf also starts with a
                            non-starter.  Btw, this check could also be
                            omitted, because the composition table has only
                            entries (code1, code2) for which code1 is a
                            starter; if the first accumulated character is not
                            a starter, no lookup will succeed.
                         2. If the sortbuf has more than one character, check
                            for each of these characters that are not "blocked"
                            from the starter (i.e. have a ccc that is higher
                            than the ccc of the previous character) whether it
                            can be combined with the first character.
                         3. If only one character is left in sortbuf, check
                            whether it can be combined with the next character
                            (also a starter).  */
                    if (sortbuf_count > 0 && sortbuf[0].ccc == 0)
                      {
                        for (size_t j = 1; j < sortbuf_count; )
                          {
                            if (sortbuf[j].ccc > sortbuf[j - 1].ccc)
                              {
                                ucs4_t combined =
                                  composer (sortbuf[0].code, sortbuf[j].code);
                                if (combined)
                                  {
                                    sortbuf[0].code = combined;
                                    /* sortbuf[0].ccc = 0, still valid.  */
                                    for (size_t k = j + 1; k < sortbuf_count; k++)
                                      sortbuf[k - 1] = sortbuf[k];
                                    sortbuf_count--;
                                    continue;
                                  }
                              }
                            j++;
                          }
                        if (s < s_end && sortbuf_count == 1)
                          {
                            ucs4_t combined =
                              composer (sortbuf[0].code, uc);
                            if (combined)
                              {
                                uc = combined;
                                ccc = 0;
                                /* uc could be further combined with subsequent
                                   characters.  So don't put it into sortbuf[0] in
                                   this round, only in the next round.  */
                                sortbuf_count = 0;
                              }
                          }
                      }
                  }

                for (size_t j = 0; j < sortbuf_count; j++)
                  {
                    ucs4_t muc = sortbuf[j].code;

                    /* Append muc to the result accumulator.  */
                    if (length < allocated)
                      {
                        int ret =
                          U_UCTOMB (result + length, muc, allocated - length);
                        if (ret == -1)
                          {
                            errno = EINVAL;
                            goto fail;
                          }
                        if (ret >= 0)
                          {
                            length += ret;
                            goto done_appending;
                          }
                      }
                    {
                      size_t old_allocated = allocated;
                      size_t new_allocated = 2 * old_allocated;
                      if (new_allocated < 64)
                        new_allocated = 64;
                      if (new_allocated < old_allocated) /* integer overflow? */
                        abort ();
                      {
                        UNIT *larger_result;
                        if (result == NULL)
                          {
                            larger_result =
                              (UNIT *) malloc (new_allocated * sizeof (UNIT));
                            if (larger_result == NULL)
                              {
                                errno = ENOMEM;
                                goto fail;
                              }
                          }
                        else if (result == resultbuf)
                          {
                            larger_result =
                              (UNIT *) malloc (new_allocated * sizeof (UNIT));
                            if (larger_result == NULL)
                              {
                                errno = ENOMEM;
                                goto fail;
                              }
                            U_CPY (larger_result, resultbuf, length);
                          }
                        else
                          {
                            larger_result =
                              (UNIT *) realloc (result, new_allocated * sizeof (UNIT));
                            if (larger_result == NULL)
                              {
                                errno = ENOMEM;
                                goto fail;
                              }
                          }
                        result = larger_result;
                        allocated = new_allocated;
                        {
                          int ret =
                            U_UCTOMB (result + length, muc, allocated - length);
                          if (ret == -1)
                            {
                              errno = EINVAL;
                              goto fail;
                            }
                          if (ret < 0)
                            abort ();
                          length += ret;
                          goto done_appending;
                        }
                      }
                    }
                   done_appending: ;
                  }

                /* sortbuf is now empty.  */
                sortbuf_count = 0;
              }

            if (!(s < s_end))
              /* End of string reached.  */
              break;

            /* Append (uc, ccc) to sortbuf.  */
            if (sortbuf_count == sortbuf_allocated)
              {
                struct ucs4_with_ccc *new_sortbuf;

                sortbuf_allocated = 2 * sortbuf_allocated;
                if (sortbuf_allocated < sortbuf_count) /* integer overflow? */
                  abort ();
                new_sortbuf =
                  (struct ucs4_with_ccc *) malloc (2 * sortbuf_allocated * sizeof (struct ucs4_with_ccc));
                if (new_sortbuf == NULL)
                  {
                    errno = ENOMEM;
                    goto fail;
                  }
                memcpy (new_sortbuf, sortbuf,
                        sortbuf_count * sizeof (struct ucs4_with_ccc));
                if (sortbuf != sortbuf_preallocated)
                  free (sortbuf);
                sortbuf = new_sortbuf;
              }
            sortbuf[sortbuf_count].code = uc;
            sortbuf[sortbuf_count].ccc = ccc;
            sortbuf_count++;

            i++;
          }

        if (!(s < s_end))
          /* End of string reached.  */
          break;

        s += count;
      }
  }

  if (length == 0)
    {
      if (result == NULL)
        {
          /* Return a non-NULL value.  NULL means error.  */
          result = (UNIT *) malloc (1);
          if (result == NULL)
            {
              errno = ENOMEM;
              goto fail;
            }
        }
    }
  else if (result != resultbuf && length < allocated)
    {
      /* Shrink the allocated memory if possible.  */
      UNIT *memory;

      memory = (UNIT *) realloc (result, length * sizeof (UNIT));
      if (memory != NULL)
        result = memory;
    }

  if (sortbuf_count > 0)
    abort ();
  if (sortbuf != sortbuf_preallocated)
    free (sortbuf);

  *lengthp = length;
  return result;

 fail:
  {
    int saved_errno = errno;
    if (sortbuf != sortbuf_preallocated)
      free (sortbuf);
    if (result != resultbuf)
      free (result);
    errno = saved_errno;
  }
  return NULL;
}

Coverage Report

Created: 2026-01-09 06:20

Line	Count	Source
1		/* Decomposition and composition of Unicode strings.
2		Copyright (C) 2009-2025 Free Software Foundation, Inc.
3		Written by Bruno Haible <bruno@clisp.org>, 2009.
4
5		This file is free software: you can redistribute it and/or modify
6		it under the terms of the GNU Lesser General Public License as
7		published by the Free Software Foundation; either version 2.1 of the
8		License, or (at your option) any later version.
9
10		This file is distributed in the hope that it will be useful,
11		but WITHOUT ANY WARRANTY; without even the implied warranty of
12		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13		GNU Lesser General Public License for more details.
14
15		You should have received a copy of the GNU Lesser General Public License
16		along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18		UNIT *
19		FUNC (uninorm_t nf, const UNIT *s, size_t n,
20		UNIT resultbuf, size_t lengthp)
21	71.1k	{
22	71.1k	int (decomposer) (ucs4_t uc, ucs4_t decomposition) = nf->decomposer;
23	71.1k	ucs4_t (*composer) (ucs4_t uc1, ucs4_t uc2) = nf->composer;
24
25		/* The result being accumulated. */
26	71.1k	UNIT *result;
27	71.1k	size_t length;
28	71.1k	size_t allocated;
29		/* The buffer for sorting. */
30	71.1k	#define SORTBUF_PREALLOCATED 64
31	71.1k	struct ucs4_with_ccc sortbuf_preallocated[2 * SORTBUF_PREALLOCATED];
32	71.1k	struct ucs4_with_ccc sortbuf; / array of size 2 * sortbuf_allocated */
33	71.1k	size_t sortbuf_allocated;
34	71.1k	size_t sortbuf_count;
35
36		/* Initialize the accumulator. */
37	71.1k	if (resultbuf == NULL)
38	71.1k	{
39	71.1k	result = NULL;
40	71.1k	allocated = 0;
41	71.1k	}
42	0	else
43	0	{
44	0	result = resultbuf;
45	0	allocated = *lengthp;
46	0	}
47	71.1k	length = 0;
48
49		/* Initialize the buffer for sorting. */
50	71.1k	sortbuf = sortbuf_preallocated;
51	71.1k	sortbuf_allocated = SORTBUF_PREALLOCATED;
52	71.1k	sortbuf_count = 0;
53
54	71.1k	{
55	71.1k	const UNIT *s_end = s + n;
56
57	71.1k	for (;;)
58	816k	{
59	816k	int count;
60	816k	ucs4_t decomposed[UC_DECOMPOSITION_MAX_LENGTH];
61	816k	int decomposed_count;
62	816k	int i;
63
64	816k	if (s < s_end)
65	745k	{
66		/* Fetch the next character. */
67	745k	count = U_MBTOUC_UNSAFE (&decomposed[0], s, s_end - s);
68	745k	decomposed_count = 1;
69
70		/* Decompose it, recursively.
71		It would be possible to precompute the recursive decomposition
72		and store it in a table. But this would significantly increase
73		the size of the decomposition tables, because for example for
74		U+1FC1 the recursive canonical decomposition and the recursive
75		compatibility decomposition are different. */
76	1.55M	for (int curr = 0; curr < decomposed_count; )
77	809k	{
78		/* Invariant: decomposed[0..curr-1] is fully decomposed, i.e.
79		all elements are atomic. */
80	809k	ucs4_t curr_decomposed[UC_DECOMPOSITION_MAX_LENGTH];
81	809k	int curr_decomposed_count;
82
83	809k	curr_decomposed_count = decomposer (decomposed[curr], curr_decomposed);
84	809k	if (curr_decomposed_count >= 0)
85	32.4k	{
86		/* Move curr_decomposed[0..curr_decomposed_count-1] over
87		decomposed[curr], making room. It's not worth using
88		memcpy() here, since the counts are so small. */
89	32.4k	int shift = curr_decomposed_count - 1;
90
91	32.4k	if (shift < 0)
92	0	abort ();
93	32.4k	if (shift > 0)
94	31.6k	{
95	31.6k	decomposed_count += shift;
96	31.6k	if (decomposed_count > UC_DECOMPOSITION_MAX_LENGTH)
97	0	abort ();
98	39.1k	for (int j = decomposed_count - 1 - shift; j > curr; j--)
99	7.51k	decomposed[j + shift] = decomposed[j];
100	31.6k	}
101	96.5k	for (; shift >= 0; shift--)
102	64.0k	decomposed[curr + shift] = curr_decomposed[shift];
103	32.4k	}
104	776k	else
105	776k	{
106		/* decomposed[curr] is atomic. */
107	776k	curr++;
108	776k	}
109	809k	}
110	745k	}
111	71.1k	else
112	71.1k	{
113	71.1k	count = 0;
114	71.1k	decomposed_count = 0;
115	71.1k	}
116
117	816k	i = 0;
118	816k	for (;;)
119	1.59M	{
120	1.59M	ucs4_t uc;
121	1.59M	int ccc;
122
123	1.59M	if (s < s_end)
124	1.52M	{
125		/* Fetch the next character from the decomposition. */
126	1.52M	if (i == decomposed_count)
127	745k	break;
128	776k	uc = decomposed[i];
129	776k	ccc = uc_combining_class (uc);
130	776k	}
131	71.1k	else
132	71.1k	{
133		/* End of string reached. */
134	71.1k	uc = 0;
135	71.1k	ccc = 0;
136	71.1k	}
137
138	848k	if (ccc == 0)
139	719k	{
140		/* Apply the canonical ordering algorithm to the accumulated
141		sequence of characters. */
142	719k	if (sortbuf_count > 1)
143	27.1k	gl_uninorm_decompose_merge_sort_inplace (sortbuf, sortbuf_count,
144	27.1k	sortbuf + sortbuf_count);
145
146	719k	if (composer != NULL)
147	719k	{
148		/* Attempt to combine decomposed characters, as specified
149		in the Unicode Standard Annex #15 "Unicode Normalization
150		Forms". We need to check
151		1. whether the first accumulated character is a
152		"starter" (i.e. has ccc = 0). This is usually the
153		case. But when the string starts with a
154		non-starter, the sortbuf also starts with a
155		non-starter. Btw, this check could also be
156		omitted, because the composition table has only
157		entries (code1, code2) for which code1 is a
158		starter; if the first accumulated character is not
159		a starter, no lookup will succeed.
160		2. If the sortbuf has more than one character, check
161		for each of these characters that are not "blocked"
162		from the starter (i.e. have a ccc that is higher
163		than the ccc of the previous character) whether it
164		can be combined with the first character.
165		3. If only one character is left in sortbuf, check
166		whether it can be combined with the next character
167		(also a starter). */
168	719k	if (sortbuf_count > 0 && sortbuf[0].ccc == 0)
169	648k	{
170	746k	for (size_t j = 1; j < sortbuf_count; )
171	98.3k	{
172	98.3k	if (sortbuf[j].ccc > sortbuf[j - 1].ccc)
173	38.6k	{
174	38.6k	ucs4_t combined =
175	38.6k	composer (sortbuf[0].code, sortbuf[j].code);
176	38.6k	if (combined)
177	13.5k	{
178	13.5k	sortbuf[0].code = combined;
179		/* sortbuf[0].ccc = 0, still valid. */
180	60.1k	for (size_t k = j + 1; k < sortbuf_count; k++)
181	46.6k	sortbuf[k - 1] = sortbuf[k];
182	13.5k	sortbuf_count--;
183	13.5k	continue;
184	13.5k	}
185	38.6k	}
186	84.7k	j++;
187	84.7k	}
188	648k	if (s < s_end && sortbuf_count == 1)
189	568k	{
190	568k	ucs4_t combined =
191	568k	composer (sortbuf[0].code, uc);
192	568k	if (combined)
193	5.87k	{
194	5.87k	uc = combined;
195	5.87k	ccc = 0;
196		/* uc could be further combined with subsequent
197		characters. So don't put it into sortbuf[0] in
198		this round, only in the next round. */
199	5.87k	sortbuf_count = 0;
200	5.87k	}
201	568k	}
202	648k	}
203	719k	}
204
205	1.47M	for (size_t j = 0; j < sortbuf_count; j++)
206	757k	{
207	757k	ucs4_t muc = sortbuf[j].code;
208
209		/* Append muc to the result accumulator. */
210	757k	if (length < allocated)
211	685k	{
212	685k	int ret =
213	685k	U_UCTOMB (result + length, muc, allocated - length);
214	685k	if (ret == -1)
215	0	{
216	0	errno = EINVAL;
217	0	goto fail;
218	0	}
219	685k	if (ret >= 0)
220	685k	{
221	685k	length += ret;
222	685k	goto done_appending;
223	685k	}
224	685k	}
225	71.9k	{
226	71.9k	size_t old_allocated = allocated;
227	71.9k	size_t new_allocated = 2 * old_allocated;
228	71.9k	if (new_allocated < 64)
229	68.8k	new_allocated = 64;
230	71.9k	if (new_allocated < old_allocated) /* integer overflow? */
231	0	abort ();
232	71.9k	{
233	71.9k	UNIT *larger_result;
234	71.9k	if (result == NULL)
235	68.8k	{
236	68.8k	larger_result =
237	68.8k	(UNIT ) malloc (new_allocated sizeof (UNIT));
238	68.8k	if (larger_result == NULL)
239	0	{
240	0	errno = ENOMEM;
241	0	goto fail;
242	0	}
243	68.8k	}
244	3.09k	else if (result == resultbuf)
245	0	{
246	0	larger_result =
247	0	(UNIT ) malloc (new_allocated sizeof (UNIT));
248	0	if (larger_result == NULL)
249	0	{
250	0	errno = ENOMEM;
251	0	goto fail;
252	0	}
253	0	U_CPY (larger_result, resultbuf, length);
254	0	}
255	3.09k	else
256	3.09k	{
257	3.09k	larger_result =
258	3.09k	(UNIT ) realloc (result, new_allocated sizeof (UNIT));
259	3.09k	if (larger_result == NULL)
260	0	{
261	0	errno = ENOMEM;
262	0	goto fail;
263	0	}
264	3.09k	}
265	71.9k	result = larger_result;
266	71.9k	allocated = new_allocated;
267	71.9k	{
268	71.9k	int ret =
269	71.9k	U_UCTOMB (result + length, muc, allocated - length);
270	71.9k	if (ret == -1)
271	0	{
272	0	errno = EINVAL;
273	0	goto fail;
274	0	}
275	71.9k	if (ret < 0)
276	0	abort ();
277	71.9k	length += ret;
278	71.9k	goto done_appending;
279	71.9k	}
280	71.9k	}
281	71.9k	}
282	757k	done_appending: ;
283	757k	}
284
285		/* sortbuf is now empty. */
286	719k	sortbuf_count = 0;
287	719k	}
288
289	848k	if (!(s < s_end))
290		/* End of string reached. */
291	71.1k	break;
292
293		/* Append (uc, ccc) to sortbuf. */
294	776k	if (sortbuf_count == sortbuf_allocated)
295	603	{
296	603	struct ucs4_with_ccc *new_sortbuf;
297
298	603	sortbuf_allocated = 2 * sortbuf_allocated;
299	603	if (sortbuf_allocated < sortbuf_count) /* integer overflow? */
300	0	abort ();
301	603	new_sortbuf =
302	603	(struct ucs4_with_ccc ) malloc (2 sortbuf_allocated * sizeof (struct ucs4_with_ccc));
303	603	if (new_sortbuf == NULL)
304	0	{
305	0	errno = ENOMEM;
306	0	goto fail;
307	0	}
308	603	memcpy (new_sortbuf, sortbuf,
309	603	sortbuf_count * sizeof (struct ucs4_with_ccc));
310	603	if (sortbuf != sortbuf_preallocated)
311	603	free (sortbuf);
312	603	sortbuf = new_sortbuf;
313	603	}
314	776k	sortbuf[sortbuf_count].code = uc;
315	776k	sortbuf[sortbuf_count].ccc = ccc;
316	776k	sortbuf_count++;
317
318	776k	i++;
319	776k	}
320
321	816k	if (!(s < s_end))
322		/* End of string reached. */
323	71.1k	break;
324
325	745k	s += count;
326	745k	}
327	71.1k	}
328
329	71.1k	if (length == 0)
330	2.25k	{
331	2.25k	if (result == NULL)
332	2.25k	{
333		/* Return a non-NULL value. NULL means error. */
334	2.25k	result = (UNIT *) malloc (1);
335	2.25k	if (result == NULL)
336	0	{
337	0	errno = ENOMEM;
338	0	goto fail;
339	0	}
340	2.25k	}
341	2.25k	}
342	68.8k	else if (result != resultbuf && length < allocated)
343	68.6k	{
344		/* Shrink the allocated memory if possible. */
345	68.6k	UNIT *memory;
346
347	68.6k	memory = (UNIT ) realloc (result, length sizeof (UNIT));
348	68.6k	if (memory != NULL)
349	68.6k	result = memory;
350	68.6k	}
351
352	71.1k	if (sortbuf_count > 0)
353	0	abort ();
354	71.1k	if (sortbuf != sortbuf_preallocated)
355	71.1k	free (sortbuf);
356
357	71.1k	*lengthp = length;
358	71.1k	return result;
359
360	0	fail:
361	0	{
362	0	int saved_errno = errno;
363	0	if (sortbuf != sortbuf_preallocated)
364	0	free (sortbuf);
365	0	if (result != resultbuf)
366	0	free (result);
367	0	errno = saved_errno;
368	0	}
369		return NULL;
370	71.1k	}