1 /* ELF string table handling.
2 Copyright (C) 2000, 2001, 2002 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
27 found in the source code files (the "Approved Interfaces"). The files
28 of Non-GPL Code may instantiate templates or use macros or inline
29 functions from the Approved Interfaces without causing the resulting
30 work to be covered by the GNU General Public License. Only Red Hat,
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
33 any new exceptions. If you wish to add a new Approved Interface or
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
47 included package. Should you wish to participate in the Open Invention
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49 <http://www.openinventionnetwork.com>. */
63 #include <sys/param.h>
69 # define MIN(a, b) ((a) < (b) ? (a) : (b))
75 const wchar_t *string;
77 struct Ebl_WStrent *next;
78 struct Ebl_WStrent *left;
79 struct Ebl_WStrent *right;
87 struct memoryblock *next;
94 struct Ebl_WStrent *root;
95 struct memoryblock *memory;
101 struct Ebl_WStrent 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_wstrtabinit (bool nullstr)
113 struct Ebl_WStrtab *ret;
117 ps = sysconf (_SC_PAGESIZE) - 2 * sizeof (void *);
118 assert (sizeof (struct memoryblock) < ps);
121 ret = (struct Ebl_WStrtab *) calloc (1, sizeof (struct Ebl_WStrtab));
124 ret->nullstr = nullstr;
128 ret->null.string = L"";
136 morememory (struct Ebl_WStrtab *st, size_t len)
138 struct memoryblock *newmem;
142 newmem = (struct memoryblock *) malloc (len);
146 newmem->next = st->memory;
148 st->backp = newmem->memory;
149 st->left = len - offsetof (struct memoryblock, memory);
156 ebl_wstrtabfree (struct Ebl_WStrtab *st)
158 struct memoryblock *mb = st->memory;
171 static struct Ebl_WStrent *
172 newstring (struct Ebl_WStrtab *st, const wchar_t *str, size_t len)
174 struct Ebl_WStrent *newstr;
178 /* Compute the amount of padding needed to make the structure aligned. */
179 align = ((__alignof__ (struct Ebl_WStrent)
180 - (((uintptr_t) st->backp)
181 & (__alignof__ (struct Ebl_WStrent) - 1)))
182 & (__alignof__ (struct Ebl_WStrent) - 1));
184 /* Make sure there is enough room in the memory block. */
185 if (st->left < align + sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t))
188 sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t)))
194 /* Create the reserved string. */
195 newstr = (struct Ebl_WStrent *) (st->backp + align);
196 newstr->string = str;
200 newstr->right = NULL;
202 for (i = len - 2; i >= 0; --i)
203 newstr->reverse[i] = str[len - 2 - i];
204 newstr->reverse[len - 1] = L'\0';
205 st->backp += align + sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t);
206 st->left -= align + sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t);
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_WStrent **
216 searchstring (struct Ebl_WStrent **sep, struct Ebl_WStrent *newstr)
227 /* Compare the strings. */
228 cmpres = wmemcmp ((*sep)->reverse, newstr->reverse,
229 MIN ((*sep)->len, newstr->len) - 1);
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_wstrtabadd (struct Ebl_WStrtab *st, const wchar_t *str, size_t len)
244 struct Ebl_WStrent *newstr;
245 struct Ebl_WStrent **sep;
247 /* Compute the string length if the caller doesn't know it. */
249 len = wcslen (str) + 1;
251 /* Make sure all "" strings get offset 0 but only if the table was
252 created with a special null entry in mind. */
253 if (len == 1 && st->null.string != NULL)
256 /* Allocate memory for the new string and its associated information. */
257 newstr = newstring (st, str, len);
261 /* Search in the array for the place to insert the string. If there
262 is no string with matching prefix and no string with matching
263 leading substring, create a new entry. */
264 sep = searchstring (&st->root, newstr);
267 /* This is not the same entry. This means we have a prefix match. */
268 if ((*sep)->len > newstr->len)
270 struct Ebl_WStrent *subs;
272 /* Check whether we already know this string. */
273 for (subs = (*sep)->next; subs != NULL; subs = subs->next)
274 if (subs->len == newstr->len)
276 /* We have an exact match with a substring. Free the memory
278 st->left += st->backp - (char *) newstr;
279 st->backp = (char *) newstr;
284 /* We have a new substring. This means we don't need the reverse
285 string of this entry anymore. */
286 st->backp -= newstr->len;
287 st->left += newstr->len;
289 newstr->next = (*sep)->next;
290 (*sep)->next = newstr;
292 else if ((*sep)->len != newstr->len)
294 /* When we get here it means that the string we are about to
295 add has a common prefix with a string we already have but
296 it is longer. In this case we have to put it first. */
297 st->total += newstr->len - (*sep)->len;
299 newstr->left = (*sep)->left;
300 newstr->right = (*sep)->right;
305 /* We have an exact match. Free the memory we allocated. */
306 st->left += st->backp - (char *) newstr;
307 st->backp = (char *) newstr;
313 st->total += newstr->len;
320 copystrings (struct Ebl_WStrent *nodep, wchar_t **freep, size_t *offsetp)
322 struct Ebl_WStrent *subs;
324 if (nodep->left != NULL)
325 copystrings (nodep->left, freep, offsetp);
327 /* Process the current node. */
328 nodep->offset = *offsetp;
329 *freep = wmempcpy (*freep, nodep->string, nodep->len);
330 *offsetp += nodep->len * sizeof (wchar_t);
332 for (subs = nodep->next; subs != NULL; subs = subs->next)
334 assert (subs->len < nodep->len);
335 subs->offset = nodep->offset + nodep->len - subs->len;
336 assert (subs->offset != 0 || subs->string[0] == '\0');
339 if (nodep->right != NULL)
340 copystrings (nodep->right, freep, offsetp);
345 ebl_wstrtabfinalize (struct Ebl_WStrtab *st, Elf_Data *data)
349 size_t nulllen = st->nullstr ? 1 : 0;
351 /* Fill in the information. */
352 data->d_buf = malloc ((st->total + nulllen) * sizeof (wchar_t));
353 if (data->d_buf == NULL)
356 /* The first byte must always be zero if we created the table with a
359 *((wchar_t *) data->d_buf) = L'\0';
361 data->d_type = ELF_T_BYTE;
362 data->d_size = st->total + nulllen;
365 data->d_version = EV_CURRENT;
367 /* Now run through the tree and add all the string while also updating
368 the offset members of the elfstrent records. */
369 endp = (wchar_t *) data->d_buf + nulllen;
370 copylen = sizeof (wchar_t) * nulllen;
371 copystrings (st->root, &endp, ©len);
372 assert (copylen == (st->total + nulllen) * sizeof (wchar_t));
377 ebl_wstrtaboffset (struct Ebl_WStrent *se)