1 /* Generic string table handling.
2 Copyright (C) 2000, 2001, 2002, 2005 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2000.
6 Red Hat elfutils is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by the
8 Free Software Foundation; version 2 of the License.
10 Red Hat elfutils is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with Red Hat elfutils; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
19 In addition, as a special exception, Red Hat, Inc. gives You the
20 additional right to link the code of Red Hat elfutils with code licensed
21 under any Open Source Initiative certified open source license
22 (http://www.opensource.org/licenses/index.php) which requires the
23 distribution of source code with any binary distribution and to
24 distribute linked combinations of the two. Non-GPL Code permitted under
25 this exception must only link to the code of Red Hat elfutils through
26 those well defined interfaces identified in the file named EXCEPTION
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28 of Non-GPL Code may instantiate templates or use macros or inline
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31 Inc. may make changes or additions to the list of Approved Interfaces.
32 Red Hat's grant of this exception is conditioned upon your not adding
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34 exception, please contact Red Hat. You must obey the GNU General Public
35 License in all respects for all of the Red Hat elfutils code and other
36 code used in conjunction with Red Hat elfutils except the Non-GPL Code
37 covered by this exception. If you modify this file, you may extend this
38 exception to your version of the file, but you are not obligated to do
39 so. If you do not wish to provide this exception without modification,
40 you must delete this exception statement from your version and license
41 this file solely under the GPL without exception.
43 Red Hat elfutils is an included package of the Open Invention Network.
44 An included package of the Open Invention Network is a package for which
45 Open Invention Network licensees cross-license their patents. No patent
46 license is granted, either expressly or impliedly, by designation as an
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49 <http://www.openinventionnetwork.com>. */
62 #include <sys/param.h>
67 # define MIN(a, b) ((a) < (b) ? (a) : (b))
75 struct Ebl_GStrent *next;
76 struct Ebl_GStrent *left;
77 struct Ebl_GStrent *right;
86 struct memoryblock *next;
93 struct Ebl_GStrent *root;
94 struct memoryblock *memory;
101 struct Ebl_GStrent null;
105 /* Cache for the pagesize. We correct this value a bit so that `malloc'
106 is not allocating more than a page. */
111 ebl_gstrtabinit (unsigned int width, bool nullstr)
113 struct Ebl_GStrtab *ret;
117 ps = sysconf (_SC_PAGESIZE) - 2 * sizeof (void *);
118 assert (sizeof (struct memoryblock) < ps);
121 ret = (struct Ebl_GStrtab *) calloc (1, sizeof (struct Ebl_GStrtab));
125 ret->nullstr = nullstr;
130 ret->null.string = (char *) calloc (1, width);
139 morememory (struct Ebl_GStrtab *st, size_t len)
141 struct memoryblock *newmem;
145 newmem = (struct memoryblock *) malloc (len);
149 newmem->next = st->memory;
151 st->backp = newmem->memory;
152 st->left = len - offsetof (struct memoryblock, memory);
157 ebl_gstrtabfree (struct Ebl_GStrtab *st)
159 struct memoryblock *mb = st->memory;
168 if (st->null.string != NULL)
169 free ((char *) st->null.string);
175 static struct Ebl_GStrent *
176 newstring (struct Ebl_GStrtab *st, const char *str, size_t len)
178 /* Compute the amount of padding needed to make the structure aligned. */
179 size_t align = ((__alignof__ (struct Ebl_GStrent)
180 - (((uintptr_t) st->backp)
181 & (__alignof__ (struct Ebl_GStrent) - 1)))
182 & (__alignof__ (struct Ebl_GStrent) - 1));
184 /* Make sure there is enough room in the memory block. */
185 if (st->left < align + sizeof (struct Ebl_GStrent) + len * st->width)
187 morememory (st, sizeof (struct Ebl_GStrent) + len * st->width);
191 /* Create the reserved string. */
192 struct Ebl_GStrent *newstr = (struct Ebl_GStrent *) (st->backp + align);
193 newstr->string = str;
195 newstr->width = st->width;
198 newstr->right = NULL;
200 for (int i = len - 2; i >= 0; --i)
201 for (int j = st->width - 1; j >= 0; --j)
202 newstr->reverse[i * st->width + j] = str[(len - 2 - i) * st->width + j];
203 for (size_t j = 0; j < st->width; ++j)
204 newstr->reverse[(len - 1) * st->width + j] = '\0';
205 st->backp += align + sizeof (struct Ebl_GStrent) + len * st->width;
206 st->left -= align + sizeof (struct Ebl_GStrent) + len * st->width;
212 /* XXX This function should definitely be rewritten to use a balancing
213 tree algorith (AVL, red-black trees). For now a simple, correct
214 implementation is enough. */
215 static struct Ebl_GStrent **
216 searchstring (struct Ebl_GStrent **sep, struct Ebl_GStrent *newstr)
227 /* Compare the strings. */
228 cmpres = memcmp ((*sep)->reverse, newstr->reverse,
229 (MIN ((*sep)->len, newstr->len) - 1) * (*sep)->width);
231 /* We found a matching string. */
234 return searchstring (&(*sep)->left, newstr);
236 return searchstring (&(*sep)->right, newstr);
240 /* Add new string. The actual string is assumed to be permanent. */
242 ebl_gstrtabadd (struct Ebl_GStrtab *st, const char *str, size_t len)
244 struct Ebl_GStrent *newstr;
245 struct Ebl_GStrent **sep;
247 /* Compute the string length if the caller doesn't know it. */
253 for (j = 0; j < st->width; ++j)
254 if (str[len * st->width + j] != '\0')
256 while (j == st->width && ++len);
259 /* Make sure all "" strings get offset 0 but only if the table was
260 created with a special null entry in mind. */
261 if (len == 1 && st->null.string != NULL)
264 /* Allocate memory for the new string and its associated information. */
265 newstr = newstring (st, str, len);
267 /* Search in the array for the place to insert the string. If there
268 is no string with matching prefix and no string with matching
269 leading substring, create a new entry. */
270 sep = searchstring (&st->root, newstr);
273 /* This is not the same entry. This means we have a prefix match. */
274 if ((*sep)->len > newstr->len)
276 struct Ebl_GStrent *subs;
278 /* Check whether we already know this string. */
279 for (subs = (*sep)->next; subs != NULL; subs = subs->next)
280 if (subs->len == newstr->len)
282 /* We have an exact match with a substring. Free the memory
284 st->left += (st->backp - (char *) newstr) * st->width;
285 st->backp = (char *) newstr;
290 /* We have a new substring. This means we don't need the reverse
291 string of this entry anymore. */
292 st->backp -= newstr->len;
293 st->left += newstr->len;
295 newstr->next = (*sep)->next;
296 (*sep)->next = newstr;
298 else if ((*sep)->len != newstr->len)
300 /* When we get here it means that the string we are about to
301 add has a common prefix with a string we already have but
302 it is longer. In this case we have to put it first. */
303 st->total += newstr->len - (*sep)->len;
305 newstr->left = (*sep)->left;
306 newstr->right = (*sep)->right;
311 /* We have an exact match. Free the memory we allocated. */
312 st->left += (st->backp - (char *) newstr) * st->width;
313 st->backp = (char *) newstr;
319 st->total += newstr->len;
326 copystrings (struct Ebl_GStrent *nodep, char **freep, size_t *offsetp)
328 struct Ebl_GStrent *subs;
330 if (nodep->left != NULL)
331 copystrings (nodep->left, freep, offsetp);
333 /* Process the current node. */
334 nodep->offset = *offsetp;
335 *freep = (char *) mempcpy (*freep, nodep->string, nodep->len * nodep->width);
336 *offsetp += nodep->len * nodep->width;
338 for (subs = nodep->next; subs != NULL; subs = subs->next)
340 assert (subs->len < nodep->len);
341 subs->offset = nodep->offset + (nodep->len - subs->len) * nodep->width;
342 assert (subs->offset != 0 || subs->string[0] == '\0');
345 if (nodep->right != NULL)
346 copystrings (nodep->right, freep, offsetp);
351 ebl_gstrtabfinalize (struct Ebl_GStrtab *st, Elf_Data *data)
355 size_t nulllen = st->nullstr ? st->width : 0;
357 /* Fill in the information. */
358 data->d_buf = malloc (st->total + nulllen);
359 if (data->d_buf == NULL)
362 /* The first byte must always be zero if we created the table with a
365 memset (data->d_buf, '\0', st->width);
367 data->d_type = ELF_T_BYTE;
368 data->d_size = st->total + nulllen;
371 data->d_version = EV_CURRENT;
373 /* Now run through the tree and add all the string while also updating
374 the offset members of the elfstrent records. */
375 endp = (char *) data->d_buf + nulllen;
377 copystrings (st->root, &endp, ©len);
378 assert (copylen == st->total * st->width + nulllen);
383 ebl_gstrtaboffset (struct Ebl_GStrent *se)