/src/libidn2/unistring/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.  */
            {
              int curr;

              for (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)
                        {
                          int j;

                          decomposed_count += shift;
                          if (decomposed_count > UC_DECOMPOSITION_MAX_LENGTH)
                            abort ();
                          for (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)
              {
                size_t j;

                /* 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 (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)
                                  {
                                    size_t k;

                                    sortbuf[0].code = combined;
                                    /* sortbuf[0].ccc = 0, still valid.  */
                                    for (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 (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: 2025-12-14 07:00

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	69.8k	{
22	69.8k	int (decomposer) (ucs4_t uc, ucs4_t decomposition) = nf->decomposer;
23	69.8k	ucs4_t (*composer) (ucs4_t uc1, ucs4_t uc2) = nf->composer;
24
25		/* The result being accumulated. */
26	69.8k	UNIT *result;
27	69.8k	size_t length;
28	69.8k	size_t allocated;
29		/* The buffer for sorting. */
30	69.8k	#define SORTBUF_PREALLOCATED 64
31	69.8k	struct ucs4_with_ccc sortbuf_preallocated[2 * SORTBUF_PREALLOCATED];
32	69.8k	struct ucs4_with_ccc sortbuf; / array of size 2 * sortbuf_allocated */
33	69.8k	size_t sortbuf_allocated;
34	69.8k	size_t sortbuf_count;
35
36		/* Initialize the accumulator. */
37	69.8k	if (resultbuf == NULL)
38	69.8k	{
39	69.8k	result = NULL;
40	69.8k	allocated = 0;
41	69.8k	}
42	0	else
43	0	{
44	0	result = resultbuf;
45	0	allocated = *lengthp;
46	0	}
47	69.8k	length = 0;
48
49		/* Initialize the buffer for sorting. */
50	69.8k	sortbuf = sortbuf_preallocated;
51	69.8k	sortbuf_allocated = SORTBUF_PREALLOCATED;
52	69.8k	sortbuf_count = 0;
53
54	69.8k	{
55	69.8k	const UNIT *s_end = s + n;
56
57	69.8k	for (;;)
58	785k	{
59	785k	int count;
60	785k	ucs4_t decomposed[UC_DECOMPOSITION_MAX_LENGTH];
61	785k	int decomposed_count;
62	785k	int i;
63
64	785k	if (s < s_end)
65	715k	{
66		/* Fetch the next character. */
67	715k	count = U_MBTOUC_UNSAFE (&decomposed[0], s, s_end - s);
68	715k	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	715k	{
77	715k	int curr;
78
79	1.49M	for (curr = 0; curr < decomposed_count; )
80	782k	{
81		/* Invariant: decomposed[0..curr-1] is fully decomposed, i.e.
82		all elements are atomic. */
83	782k	ucs4_t curr_decomposed[UC_DECOMPOSITION_MAX_LENGTH];
84	782k	int curr_decomposed_count;
85
86	782k	curr_decomposed_count = decomposer (decomposed[curr], curr_decomposed);
87	782k	if (curr_decomposed_count >= 0)
88	33.9k	{
89		/* Move curr_decomposed[0..curr_decomposed_count-1] over
90		decomposed[curr], making room. It's not worth using
91		memcpy() here, since the counts are so small. */
92	33.9k	int shift = curr_decomposed_count - 1;
93
94	33.9k	if (shift < 0)
95	0	abort ();
96	33.9k	if (shift > 0)
97	33.3k	{
98	33.3k	int j;
99
100	33.3k	decomposed_count += shift;
101	33.3k	if (decomposed_count > UC_DECOMPOSITION_MAX_LENGTH)
102	0	abort ();
103	41.6k	for (j = decomposed_count - 1 - shift; j > curr; j--)
104	8.31k	decomposed[j + shift] = decomposed[j];
105	33.3k	}
106	101k	for (; shift >= 0; shift--)
107	67.2k	decomposed[curr + shift] = curr_decomposed[shift];
108	33.9k	}
109	748k	else
110	748k	{
111		/* decomposed[curr] is atomic. */
112	748k	curr++;
113	748k	}
114	782k	}
115	715k	}
116	715k	}
117	69.8k	else
118	69.8k	{
119	69.8k	count = 0;
120	69.8k	decomposed_count = 0;
121	69.8k	}
122
123	785k	i = 0;
124	785k	for (;;)
125	1.53M	{
126	1.53M	ucs4_t uc;
127	1.53M	int ccc;
128
129	1.53M	if (s < s_end)
130	1.46M	{
131		/* Fetch the next character from the decomposition. */
132	1.46M	if (i == decomposed_count)
133	715k	break;
134	748k	uc = decomposed[i];
135	748k	ccc = uc_combining_class (uc);
136	748k	}
137	69.8k	else
138	69.8k	{
139		/* End of string reached. */
140	69.8k	uc = 0;
141	69.8k	ccc = 0;
142	69.8k	}
143
144	818k	if (ccc == 0)
145	692k	{
146	692k	size_t j;
147
148		/* Apply the canonical ordering algorithm to the accumulated
149		sequence of characters. */
150	692k	if (sortbuf_count > 1)
151	24.4k	gl_uninorm_decompose_merge_sort_inplace (sortbuf, sortbuf_count,
152	24.4k	sortbuf + sortbuf_count);
153
154	692k	if (composer != NULL)
155	692k	{
156		/* Attempt to combine decomposed characters, as specified
157		in the Unicode Standard Annex #15 "Unicode Normalization
158		Forms". We need to check
159		1. whether the first accumulated character is a
160		"starter" (i.e. has ccc = 0). This is usually the
161		case. But when the string starts with a
162		non-starter, the sortbuf also starts with a
163		non-starter. Btw, this check could also be
164		omitted, because the composition table has only
165		entries (code1, code2) for which code1 is a
166		starter; if the first accumulated character is not
167		a starter, no lookup will succeed.
168		2. If the sortbuf has more than one character, check
169		for each of these characters that are not "blocked"
170		from the starter (i.e. have a ccc that is higher
171		than the ccc of the previous character) whether it
172		can be combined with the first character.
173		3. If only one character is left in sortbuf, check
174		whether it can be combined with the next character
175		(also a starter). */
176	692k	if (sortbuf_count > 0 && sortbuf[0].ccc == 0)
177	623k	{
178	718k	for (j = 1; j < sortbuf_count; )
179	95.8k	{
180	95.8k	if (sortbuf[j].ccc > sortbuf[j - 1].ccc)
181	32.9k	{
182	32.9k	ucs4_t combined =
183	32.9k	composer (sortbuf[0].code, sortbuf[j].code);
184	32.9k	if (combined)
185	13.3k	{
186	13.3k	size_t k;
187
188	13.3k	sortbuf[0].code = combined;
189		/* sortbuf[0].ccc = 0, still valid. */
190	52.6k	for (k = j + 1; k < sortbuf_count; k++)
191	39.3k	sortbuf[k - 1] = sortbuf[k];
192	13.3k	sortbuf_count--;
193	13.3k	continue;
194	13.3k	}
195	32.9k	}
196	82.5k	j++;
197	82.5k	}
198	623k	if (s < s_end && sortbuf_count == 1)
199	547k	{
200	547k	ucs4_t combined =
201	547k	composer (sortbuf[0].code, uc);
202	547k	if (combined)
203	6.58k	{
204	6.58k	uc = combined;
205	6.58k	ccc = 0;
206		/* uc could be further combined with subsequent
207		characters. So don't put it into sortbuf[0] in
208		this round, only in the next round. */
209	6.58k	sortbuf_count = 0;
210	6.58k	}
211	547k	}
212	623k	}
213	692k	}
214
215	1.42M	for (j = 0; j < sortbuf_count; j++)
216	729k	{
217	729k	ucs4_t muc = sortbuf[j].code;
218
219		/* Append muc to the result accumulator. */
220	729k	if (length < allocated)
221	658k	{
222	658k	int ret =
223	658k	U_UCTOMB (result + length, muc, allocated - length);
224	658k	if (ret == -1)
225	0	{
226	0	errno = EINVAL;
227	0	goto fail;
228	0	}
229	658k	if (ret >= 0)
230	658k	{
231	658k	length += ret;
232	658k	goto done_appending;
233	658k	}
234	658k	}
235	70.5k	{
236	70.5k	size_t old_allocated = allocated;
237	70.5k	size_t new_allocated = 2 * old_allocated;
238	70.5k	if (new_allocated < 64)
239	67.6k	new_allocated = 64;
240	70.5k	if (new_allocated < old_allocated) /* integer overflow? */
241	0	abort ();
242	70.5k	{
243	70.5k	UNIT *larger_result;
244	70.5k	if (result == NULL)
245	67.6k	{
246	67.6k	larger_result =
247	67.6k	(UNIT ) malloc (new_allocated sizeof (UNIT));
248	67.6k	if (larger_result == NULL)
249	0	{
250	0	errno = ENOMEM;
251	0	goto fail;
252	0	}
253	67.6k	}
254	2.94k	else if (result == resultbuf)
255	0	{
256	0	larger_result =
257	0	(UNIT ) malloc (new_allocated sizeof (UNIT));
258	0	if (larger_result == NULL)
259	0	{
260	0	errno = ENOMEM;
261	0	goto fail;
262	0	}
263	0	U_CPY (larger_result, resultbuf, length);
264	0	}
265	2.94k	else
266	2.94k	{
267	2.94k	larger_result =
268	2.94k	(UNIT ) realloc (result, new_allocated sizeof (UNIT));
269	2.94k	if (larger_result == NULL)
270	0	{
271	0	errno = ENOMEM;
272	0	goto fail;
273	0	}
274	2.94k	}
275	70.5k	result = larger_result;
276	70.5k	allocated = new_allocated;
277	70.5k	{
278	70.5k	int ret =
279	70.5k	U_UCTOMB (result + length, muc, allocated - length);
280	70.5k	if (ret == -1)
281	0	{
282	0	errno = EINVAL;
283	0	goto fail;
284	0	}
285	70.5k	if (ret < 0)
286	0	abort ();
287	70.5k	length += ret;
288	70.5k	goto done_appending;
289	70.5k	}
290	70.5k	}
291	70.5k	}
292	729k	done_appending: ;
293	729k	}
294
295		/* sortbuf is now empty. */
296	692k	sortbuf_count = 0;
297	692k	}
298
299	818k	if (!(s < s_end))
300		/* End of string reached. */
301	69.8k	break;
302
303		/* Append (uc, ccc) to sortbuf. */
304	748k	if (sortbuf_count == sortbuf_allocated)
305	636	{
306	636	struct ucs4_with_ccc *new_sortbuf;
307
308	636	sortbuf_allocated = 2 * sortbuf_allocated;
309	636	if (sortbuf_allocated < sortbuf_count) /* integer overflow? */
310	0	abort ();
311	636	new_sortbuf =
312	636	(struct ucs4_with_ccc ) malloc (2 sortbuf_allocated * sizeof (struct ucs4_with_ccc));
313	636	if (new_sortbuf == NULL)
314	0	{
315	0	errno = ENOMEM;
316	0	goto fail;
317	0	}
318	636	memcpy (new_sortbuf, sortbuf,
319	636	sortbuf_count * sizeof (struct ucs4_with_ccc));
320	636	if (sortbuf != sortbuf_preallocated)
321	636	free (sortbuf);
322	636	sortbuf = new_sortbuf;
323	636	}
324	748k	sortbuf[sortbuf_count].code = uc;
325	748k	sortbuf[sortbuf_count].ccc = ccc;
326	748k	sortbuf_count++;
327
328	748k	i++;
329	748k	}
330
331	785k	if (!(s < s_end))
332		/* End of string reached. */
333	69.8k	break;
334
335	715k	s += count;
336	715k	}
337	69.8k	}
338
339	69.8k	if (length == 0)
340	2.23k	{
341	2.23k	if (result == NULL)
342	2.23k	{
343		/* Return a non-NULL value. NULL means error. */
344	2.23k	result = (UNIT *) malloc (1);
345	2.23k	if (result == NULL)
346	0	{
347	0	errno = ENOMEM;
348	0	goto fail;
349	0	}
350	2.23k	}
351	2.23k	}
352	67.6k	else if (result != resultbuf && length < allocated)
353	67.3k	{
354		/* Shrink the allocated memory if possible. */
355	67.3k	UNIT *memory;
356
357	67.3k	memory = (UNIT ) realloc (result, length sizeof (UNIT));
358	67.3k	if (memory != NULL)
359	67.3k	result = memory;
360	67.3k	}
361
362	69.8k	if (sortbuf_count > 0)
363	0	abort ();
364	69.8k	if (sortbuf != sortbuf_preallocated)
365	69.8k	free (sortbuf);
366
367	69.8k	*lengthp = length;
368	69.8k	return result;
369
370	0	fail:
371	0	{
372	0	int saved_errno = errno;
373	0	if (sortbuf != sortbuf_preallocated)
374	0	free (sortbuf);
375	0	if (result != resultbuf)
376	0	free (result);
377	0	errno = saved_errno;
378	0	}
379		return NULL;
380	69.8k	}