Coverage Report

Created: 2025-06-13 06:08

/src/giflib-code/gifalloc.c
Line
Count
Source (jump to first uncovered line)
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/*****************************************************************************
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3
 GIF construction tools
4
5
****************************************************************************/
6
// SPDX-License-Identifier: MIT
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// SPDX-FileCopyrightText: Copyright (C) Eric S. Raymond <esr@thyrsus.com>
8
9
#include <stdio.h>
10
#include <stdlib.h>
11
#include <string.h>
12
13
#include "gif_lib.h"
14
#include "gif_lib_private.h"
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16
0
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
17
18
/******************************************************************************
19
 Miscellaneous utility functions
20
******************************************************************************/
21
22
/* return smallest bitfield size n will fit in */
23
4.08k
int GifBitSize(int n) {
24
4.08k
  register int i;
25
26
5.06k
  for (i = 1; i <= 8; i++) {
27
5.06k
    if ((1 << i) >= n) {
28
4.08k
      break;
29
4.08k
    }
30
5.06k
  }
31
4.08k
  return (i);
32
4.08k
}
33
34
/******************************************************************************
35
 Color map object functions
36
******************************************************************************/
37
38
/*
39
 * Allocate a color map of given size; initialize with contents of
40
 * ColorMap if that pointer is non-NULL.
41
 */
42
2.04k
ColorMapObject *GifMakeMapObject(int ColorCount, const GifColorType *ColorMap) {
43
2.04k
  ColorMapObject *Object;
44
45
  /*** FIXME: Our ColorCount has to be a power of two.  Is it necessary to
46
   * make the user know that or should we automatically round up instead?
47
   */
48
2.04k
  if (ColorCount != (1 << GifBitSize(ColorCount))) {
49
0
    return ((ColorMapObject *)NULL);
50
0
  }
51
52
2.04k
  Object = (ColorMapObject *)malloc(sizeof(ColorMapObject));
53
2.04k
  if (Object == (ColorMapObject *)NULL) {
54
0
    return ((ColorMapObject *)NULL);
55
0
  }
56
57
2.04k
  Object->Colors =
58
2.04k
      (GifColorType *)calloc(ColorCount, sizeof(GifColorType));
59
2.04k
  if (Object->Colors == (GifColorType *)NULL) {
60
0
    free(Object);
61
0
    return ((ColorMapObject *)NULL);
62
0
  }
63
64
2.04k
  Object->ColorCount = ColorCount;
65
2.04k
  Object->BitsPerPixel = GifBitSize(ColorCount);
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2.04k
  Object->SortFlag = false;
67
68
2.04k
  if (ColorMap != NULL) {
69
950
    memcpy((char *)Object->Colors, (char *)ColorMap,
70
950
           ColorCount * sizeof(GifColorType));
71
950
  }
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73
2.04k
  return (Object);
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2.04k
}
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76
/*******************************************************************************
77
 Free a color map object
78
*******************************************************************************/
79
2.04k
void GifFreeMapObject(ColorMapObject *Object) {
80
2.04k
  if (Object != NULL) {
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2.03k
    (void)free(Object->Colors);
82
2.03k
    (void)free(Object);
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2.03k
  }
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2.04k
}
85
86
#ifdef DEBUG
87
void DumpColorMap(ColorMapObject *Object, FILE *fp) {
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  if (Object != NULL) {
89
    int i, j, Len = Object->ColorCount;
90
91
    for (i = 0; i < Len; i += 4) {
92
      for (j = 0; j < 4 && j < Len; j++) {
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        (void)fprintf(fp, "%3d: %02x %02x %02x   ",
94
                      i + j, Object->Colors[i + j].Red,
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                      Object->Colors[i + j].Green,
96
                      Object->Colors[i + j].Blue);
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      }
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      (void)fprintf(fp, "\n");
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    }
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  }
101
}
102
#endif /* DEBUG */
103
104
/*******************************************************************************
105
 Compute the union of two given color maps and return it.  If result can't
106
 fit into 256 colors, NULL is returned, the allocated union otherwise.
107
 ColorIn1 is copied as is to ColorUnion, while colors from ColorIn2 are
108
 copied iff they didn't exist before.  ColorTransIn2 maps the old
109
 ColorIn2 into the ColorUnion color map table./
110
*******************************************************************************/
111
ColorMapObject *GifUnionColorMap(const ColorMapObject *ColorIn1,
112
                                 const ColorMapObject *ColorIn2,
113
0
                                 GifPixelType ColorTransIn2[]) {
114
0
  int i, j, CrntSlot, RoundUpTo, NewGifBitSize;
115
0
  ColorMapObject *ColorUnion;
116
117
  /*
118
   * We don't worry about duplicates within either color map; if
119
   * the caller wants to resolve those, he can perform unions
120
   * with an empty color map.
121
   */
122
123
  /* Allocate table which will hold the result for sure. */
124
0
  ColorUnion = GifMakeMapObject(
125
0
      MAX(ColorIn1->ColorCount, ColorIn2->ColorCount) * 2, NULL);
126
127
0
  if (ColorUnion == NULL) {
128
0
    return (NULL);
129
0
  }
130
131
  /*
132
   * Copy ColorIn1 to ColorUnion.
133
   */
134
0
  for (i = 0; i < ColorIn1->ColorCount; i++) {
135
0
    ColorUnion->Colors[i] = ColorIn1->Colors[i];
136
0
  }
137
0
  CrntSlot = ColorIn1->ColorCount;
138
139
  /*
140
   * Potentially obnoxious hack:
141
   *
142
   * Back CrntSlot down past all contiguous {0, 0, 0} slots at the end
143
   * of table 1.  This is very useful if your display is limited to
144
   * 16 colors.
145
   */
146
0
  while (ColorIn1->Colors[CrntSlot - 1].Red == 0 &&
147
0
         ColorIn1->Colors[CrntSlot - 1].Green == 0 &&
148
0
         ColorIn1->Colors[CrntSlot - 1].Blue == 0) {
149
0
    CrntSlot--;
150
0
  }
151
152
  /* Copy ColorIn2 to ColorUnion (use old colors if they exist): */
153
0
  for (i = 0; i < ColorIn2->ColorCount && CrntSlot <= 256; i++) {
154
    /* Let's see if this color already exists: */
155
0
    for (j = 0; j < ColorIn1->ColorCount; j++) {
156
0
      if (memcmp(&ColorIn1->Colors[j], &ColorIn2->Colors[i],
157
0
                 sizeof(GifColorType)) == 0) {
158
0
        break;
159
0
      }
160
0
    }
161
162
0
    if (j < ColorIn1->ColorCount) {
163
0
      ColorTransIn2[i] = j; /* color exists in Color1 */
164
0
    } else {
165
      /* Color is new - copy it to a new slot: */
166
0
      ColorUnion->Colors[CrntSlot] = ColorIn2->Colors[i];
167
0
      ColorTransIn2[i] = CrntSlot++;
168
0
    }
169
0
  }
170
171
0
  if (CrntSlot > 256) {
172
0
    GifFreeMapObject(ColorUnion);
173
0
    return ((ColorMapObject *)NULL);
174
0
  }
175
176
0
  NewGifBitSize = GifBitSize(CrntSlot);
177
0
  RoundUpTo = (1 << NewGifBitSize);
178
179
0
  if (RoundUpTo != ColorUnion->ColorCount) {
180
0
    register GifColorType *Map = ColorUnion->Colors;
181
182
    /*
183
     * Zero out slots up to next power of 2.
184
     * We know these slots exist because of the way ColorUnion's
185
     * start dimension was computed.
186
     */
187
0
    for (j = CrntSlot; j < RoundUpTo; j++) {
188
0
      Map[j].Red = Map[j].Green = Map[j].Blue = 0;
189
0
    }
190
191
    /* perhaps we can shrink the map? */
192
0
    if (RoundUpTo < ColorUnion->ColorCount) {
193
0
      GifColorType *new_map = (GifColorType *)reallocarray(
194
0
          Map, RoundUpTo, sizeof(GifColorType));
195
0
      if (new_map == NULL) {
196
0
        GifFreeMapObject(ColorUnion);
197
0
        return ((ColorMapObject *)NULL);
198
0
      }
199
0
      ColorUnion->Colors = new_map;
200
0
    }
201
0
  }
202
203
0
  ColorUnion->ColorCount = RoundUpTo;
204
0
  ColorUnion->BitsPerPixel = NewGifBitSize;
205
206
0
  return (ColorUnion);
207
0
}
208
209
/*******************************************************************************
210
 Apply a given color translation to the raster bits of an image
211
*******************************************************************************/
212
0
void GifApplyTranslation(SavedImage *Image, const GifPixelType Translation[]) {
213
0
  register int i;
214
0
  register int RasterSize =
215
0
      Image->ImageDesc.Height * Image->ImageDesc.Width;
216
217
0
  for (i = 0; i < RasterSize; i++) {
218
0
    Image->RasterBits[i] = Translation[Image->RasterBits[i]];
219
0
  }
220
0
}
221
222
/******************************************************************************
223
 Extension record functions
224
******************************************************************************/
225
int GifAddExtensionBlock(int *ExtensionBlockCount,
226
                         ExtensionBlock **ExtensionBlocks, int Function,
227
51.7k
                         unsigned int Len, unsigned char ExtData[]) {
228
51.7k
  ExtensionBlock *ep;
229
230
51.7k
  if (*ExtensionBlocks == NULL) {
231
4.88k
    *ExtensionBlocks =
232
4.88k
        (ExtensionBlock *)malloc(sizeof(ExtensionBlock));
233
46.8k
  } else {
234
46.8k
    ExtensionBlock *ep_new = (ExtensionBlock *)reallocarray(
235
46.8k
        *ExtensionBlocks, (*ExtensionBlockCount + 1),
236
46.8k
        sizeof(ExtensionBlock));
237
46.8k
    if (ep_new == NULL) {
238
0
      return (GIF_ERROR);
239
0
    }
240
46.8k
    *ExtensionBlocks = ep_new;
241
46.8k
  }
242
243
51.7k
  if (*ExtensionBlocks == NULL) {
244
0
    return (GIF_ERROR);
245
0
  }
246
247
51.7k
  ep = &(*ExtensionBlocks)[(*ExtensionBlockCount)++];
248
249
51.7k
  ep->Function = Function;
250
51.7k
  ep->ByteCount = Len;
251
51.7k
  ep->Bytes = (GifByteType *)malloc(ep->ByteCount);
252
51.7k
  if (ep->Bytes == NULL) {
253
0
    return (GIF_ERROR);
254
0
  }
255
256
51.7k
  if (ExtData != NULL) {
257
51.7k
    memcpy(ep->Bytes, ExtData, Len);
258
51.7k
  }
259
260
51.7k
  return (GIF_OK);
261
51.7k
}
262
263
void GifFreeExtensions(int *ExtensionBlockCount,
264
44.1k
                       ExtensionBlock **ExtensionBlocks) {
265
44.1k
  ExtensionBlock *ep;
266
267
44.1k
  if (*ExtensionBlocks == NULL) {
268
39.2k
    return;
269
39.2k
  }
270
271
4.88k
  for (ep = *ExtensionBlocks;
272
56.6k
       ep < (*ExtensionBlocks + *ExtensionBlockCount); ep++) {
273
51.7k
    (void)free((char *)ep->Bytes);
274
51.7k
  }
275
4.88k
  (void)free((char *)*ExtensionBlocks);
276
4.88k
  *ExtensionBlocks = NULL;
277
4.88k
  *ExtensionBlockCount = 0;
278
4.88k
}
279
280
/******************************************************************************
281
   Image block allocation functions
282
******************************************************************************/
283
284
/* Private Function:
285
 * Frees the last image in the GifFile->SavedImages array
286
 */
287
0
void FreeLastSavedImage(GifFileType *GifFile) {
288
0
  SavedImage *sp;
289
290
0
  if ((GifFile == NULL) || (GifFile->SavedImages == NULL)) {
291
0
    return;
292
0
  }
293
294
  /* Remove one SavedImage from the GifFile */
295
0
  GifFile->ImageCount--;
296
0
  sp = &GifFile->SavedImages[GifFile->ImageCount];
297
298
  /* Deallocate its Colormap */
299
0
  if (sp->ImageDesc.ColorMap != NULL) {
300
0
    GifFreeMapObject(sp->ImageDesc.ColorMap);
301
0
    sp->ImageDesc.ColorMap = NULL;
302
0
  }
303
304
  /* Deallocate the image data */
305
0
  if (sp->RasterBits != NULL) {
306
0
    free((char *)sp->RasterBits);
307
0
  }
308
309
  /* Deallocate any extensions */
310
0
  GifFreeExtensions(&sp->ExtensionBlockCount, &sp->ExtensionBlocks);
311
312
  /*** FIXME: We could realloc the GifFile->SavedImages structure but is
313
   * there a point to it? Saves some memory but we'd have to do it every
314
   * time.  If this is used in GifFreeSavedImages then it would be
315
   * inefficient (The whole array is going to be deallocated.)  If we just
316
   * use it when we want to free the last Image it's convenient to do it
317
   * here.
318
   */
319
0
}
320
321
/*
322
 * Append an image block to the SavedImages array
323
 */
324
SavedImage *GifMakeSavedImage(GifFileType *GifFile,
325
0
                              const SavedImage *CopyFrom) {
326
  // cppcheck-suppress ctunullpointer
327
0
  if (GifFile->SavedImages == NULL) {
328
0
    GifFile->SavedImages = (SavedImage *)malloc(sizeof(SavedImage));
329
0
  } else {
330
0
    SavedImage *newSavedImages = (SavedImage *)reallocarray(
331
0
        GifFile->SavedImages, (GifFile->ImageCount + 1),
332
0
        sizeof(SavedImage));
333
0
    if (newSavedImages == NULL) {
334
0
      return ((SavedImage *)NULL);
335
0
    }
336
0
    GifFile->SavedImages = newSavedImages;
337
0
  }
338
0
  if (GifFile->SavedImages == NULL) {
339
0
    return ((SavedImage *)NULL);
340
0
  } else {
341
0
    SavedImage *sp = &GifFile->SavedImages[GifFile->ImageCount++];
342
343
0
    if (CopyFrom != NULL) {
344
0
      memcpy((char *)sp, CopyFrom, sizeof(SavedImage));
345
346
      /*
347
       * Make our own allocated copies of the heap fields in
348
       * the copied record.  This guards against potential
349
       * aliasing problems.
350
       */
351
352
      /* first, the local color map */
353
0
      if (CopyFrom->ImageDesc.ColorMap != NULL) {
354
0
        sp->ImageDesc.ColorMap = GifMakeMapObject(
355
0
            CopyFrom->ImageDesc.ColorMap->ColorCount,
356
0
            CopyFrom->ImageDesc.ColorMap->Colors);
357
0
        if (sp->ImageDesc.ColorMap == NULL) {
358
0
          FreeLastSavedImage(GifFile);
359
0
          return (SavedImage *)(NULL);
360
0
        }
361
0
      }
362
363
      /* next, the raster */
364
0
      sp->RasterBits = (unsigned char *)reallocarray(
365
0
          NULL,
366
0
          (CopyFrom->ImageDesc.Height *
367
0
           CopyFrom->ImageDesc.Width),
368
0
          sizeof(GifPixelType));
369
0
      if (sp->RasterBits == NULL) {
370
0
        FreeLastSavedImage(GifFile);
371
0
        return (SavedImage *)(NULL);
372
0
      }
373
0
      memcpy(sp->RasterBits, CopyFrom->RasterBits,
374
0
             sizeof(GifPixelType) *
375
0
                 CopyFrom->ImageDesc.Height *
376
0
                 CopyFrom->ImageDesc.Width);
377
378
      /* finally, the extension blocks */
379
0
      if (CopyFrom->ExtensionBlocks != NULL) {
380
0
        sp->ExtensionBlocks =
381
0
            (ExtensionBlock *)reallocarray(
382
0
                NULL, CopyFrom->ExtensionBlockCount,
383
0
                sizeof(ExtensionBlock));
384
0
        if (sp->ExtensionBlocks == NULL) {
385
0
          FreeLastSavedImage(GifFile);
386
0
          return (SavedImage *)(NULL);
387
0
        }
388
0
        memcpy(sp->ExtensionBlocks,
389
0
               CopyFrom->ExtensionBlocks,
390
0
               sizeof(ExtensionBlock) *
391
0
                   CopyFrom->ExtensionBlockCount);
392
0
      }
393
0
    } else {
394
0
      memset((char *)sp, '\0', sizeof(SavedImage));
395
0
    }
396
397
0
    return (sp);
398
0
  }
399
0
}
400
401
737
void GifFreeSavedImages(GifFileType *GifFile) {
402
737
  SavedImage *sp;
403
404
737
  if ((GifFile == NULL) || (GifFile->SavedImages == NULL)) {
405
0
    return;
406
0
  }
407
737
  for (sp = GifFile->SavedImages;
408
44.0k
       sp < GifFile->SavedImages + GifFile->ImageCount; sp++) {
409
43.2k
    if (sp->ImageDesc.ColorMap != NULL) {
410
940
      GifFreeMapObject(sp->ImageDesc.ColorMap);
411
940
      sp->ImageDesc.ColorMap = NULL;
412
940
    }
413
414
43.2k
    if (sp->RasterBits != NULL) {
415
43.2k
      free((char *)sp->RasterBits);
416
43.2k
    }
417
418
43.2k
    GifFreeExtensions(&sp->ExtensionBlockCount,
419
43.2k
                      &sp->ExtensionBlocks);
420
43.2k
  }
421
737
  free((char *)GifFile->SavedImages);
422
737
  GifFile->SavedImages = NULL;
423
737
}
424
425
/* end */