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-rw-r--r--libebl/eblgstrtab.c386
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diff --git a/libebl/eblgstrtab.c b/libebl/eblgstrtab.c
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+/* Generic string table handling.
+ Copyright (C) 2000, 2001, 2002, 2005 Red Hat, Inc.
+ This file is part of Red Hat elfutils.
+ Written by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+ Red Hat elfutils is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by the
+ Free Software Foundation; version 2 of the License.
+
+ Red Hat elfutils 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with Red Hat elfutils; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
+
+ In addition, as a special exception, Red Hat, Inc. gives You the
+ additional right to link the code of Red Hat elfutils with code licensed
+ under any Open Source Initiative certified open source license
+ (http://www.opensource.org/licenses/index.php) which requires the
+ distribution of source code with any binary distribution and to
+ distribute linked combinations of the two. Non-GPL Code permitted under
+ this exception must only link to the code of Red Hat elfutils through
+ those well defined interfaces identified in the file named EXCEPTION
+ found in the source code files (the "Approved Interfaces"). The files
+ of Non-GPL Code may instantiate templates or use macros or inline
+ functions from the Approved Interfaces without causing the resulting
+ work to be covered by the GNU General Public License. Only Red Hat,
+ Inc. may make changes or additions to the list of Approved Interfaces.
+ Red Hat's grant of this exception is conditioned upon your not adding
+ any new exceptions. If you wish to add a new Approved Interface or
+ exception, please contact Red Hat. You must obey the GNU General Public
+ License in all respects for all of the Red Hat elfutils code and other
+ code used in conjunction with Red Hat elfutils except the Non-GPL Code
+ covered by this exception. If you modify this file, you may extend this
+ exception to your version of the file, but you are not obligated to do
+ so. If you do not wish to provide this exception without modification,
+ you must delete this exception statement from your version and license
+ this file solely under the GPL without exception.
+
+ Red Hat elfutils is an included package of the Open Invention Network.
+ An included package of the Open Invention Network is a package for which
+ Open Invention Network licensees cross-license their patents. No patent
+ license is granted, either expressly or impliedly, by designation as an
+ included package. Should you wish to participate in the Open Invention
+ Network licensing program, please visit www.openinventionnetwork.com
+ <http://www.openinventionnetwork.com>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <inttypes.h>
+#include <libelf.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/param.h>
+
+#include "libebl.h"
+
+#ifndef MIN
+# define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+
+struct Ebl_GStrent
+{
+ const char *string;
+ size_t len;
+ struct Ebl_GStrent *next;
+ struct Ebl_GStrent *left;
+ struct Ebl_GStrent *right;
+ size_t offset;
+ unsigned int width;
+ char reverse[0];
+};
+
+
+struct memoryblock
+{
+ struct memoryblock *next;
+ char memory[0];
+};
+
+
+struct Ebl_GStrtab
+{
+ struct Ebl_GStrent *root;
+ struct memoryblock *memory;
+ char *backp;
+ size_t left;
+ size_t total;
+ unsigned int width;
+ bool nullstr;
+
+ struct Ebl_GStrent null;
+};
+
+
+/* Cache for the pagesize. We correct this value a bit so that `malloc'
+ is not allocating more than a page. */
+static size_t ps;
+
+
+struct Ebl_GStrtab *
+ebl_gstrtabinit (unsigned int width, bool nullstr)
+{
+ struct Ebl_GStrtab *ret;
+
+ if (ps == 0)
+ {
+ ps = sysconf (_SC_PAGESIZE) - 2 * sizeof (void *);
+ assert (sizeof (struct memoryblock) < ps);
+ }
+
+ ret = (struct Ebl_GStrtab *) calloc (1, sizeof (struct Ebl_GStrtab));
+ if (ret != NULL)
+ {
+ ret->width = width;
+ ret->nullstr = nullstr;
+
+ if (nullstr)
+ {
+ ret->null.len = 1;
+ ret->null.string = (char *) calloc (1, width);
+ }
+ }
+
+ return ret;
+}
+
+
+static void
+morememory (struct Ebl_GStrtab *st, size_t len)
+{
+ struct memoryblock *newmem;
+
+ if (len < ps)
+ len = ps;
+ newmem = (struct memoryblock *) malloc (len);
+ if (newmem == NULL)
+ abort ();
+
+ newmem->next = st->memory;
+ st->memory = newmem;
+ st->backp = newmem->memory;
+ st->left = len - offsetof (struct memoryblock, memory);
+}
+
+
+void
+ebl_gstrtabfree (struct Ebl_GStrtab *st)
+{
+ struct memoryblock *mb = st->memory;
+
+ while (mb != NULL)
+ {
+ void *old = mb;
+ mb = mb->next;
+ free (old);
+ }
+
+ if (st->null.string != NULL)
+ free ((char *) st->null.string);
+
+ free (st);
+}
+
+
+static struct Ebl_GStrent *
+newstring (struct Ebl_GStrtab *st, const char *str, size_t len)
+{
+ /* Compute the amount of padding needed to make the structure aligned. */
+ size_t align = ((__alignof__ (struct Ebl_GStrent)
+ - (((uintptr_t) st->backp)
+ & (__alignof__ (struct Ebl_GStrent) - 1)))
+ & (__alignof__ (struct Ebl_GStrent) - 1));
+
+ /* Make sure there is enough room in the memory block. */
+ if (st->left < align + sizeof (struct Ebl_GStrent) + len * st->width)
+ {
+ morememory (st, sizeof (struct Ebl_GStrent) + len * st->width);
+ align = 0;
+ }
+
+ /* Create the reserved string. */
+ struct Ebl_GStrent *newstr = (struct Ebl_GStrent *) (st->backp + align);
+ newstr->string = str;
+ newstr->len = len;
+ newstr->width = st->width;
+ newstr->next = NULL;
+ newstr->left = NULL;
+ newstr->right = NULL;
+ newstr->offset = 0;
+ for (int i = len - 2; i >= 0; --i)
+ for (int j = st->width - 1; j >= 0; --j)
+ newstr->reverse[i * st->width + j] = str[(len - 2 - i) * st->width + j];
+ for (size_t j = 0; j < st->width; ++j)
+ newstr->reverse[(len - 1) * st->width + j] = '\0';
+ st->backp += align + sizeof (struct Ebl_GStrent) + len * st->width;
+ st->left -= align + sizeof (struct Ebl_GStrent) + len * st->width;
+
+ return newstr;
+}
+
+
+/* XXX This function should definitely be rewritten to use a balancing
+ tree algorith (AVL, red-black trees). For now a simple, correct
+ implementation is enough. */
+static struct Ebl_GStrent **
+searchstring (struct Ebl_GStrent **sep, struct Ebl_GStrent *newstr)
+{
+ int cmpres;
+
+ /* More strings? */
+ if (*sep == NULL)
+ {
+ *sep = newstr;
+ return sep;
+ }
+
+ /* Compare the strings. */
+ cmpres = memcmp ((*sep)->reverse, newstr->reverse,
+ (MIN ((*sep)->len, newstr->len) - 1) * (*sep)->width);
+ if (cmpres == 0)
+ /* We found a matching string. */
+ return sep;
+ else if (cmpres > 0)
+ return searchstring (&(*sep)->left, newstr);
+ else
+ return searchstring (&(*sep)->right, newstr);
+}
+
+
+/* Add new string. The actual string is assumed to be permanent. */
+struct Ebl_GStrent *
+ebl_gstrtabadd (struct Ebl_GStrtab *st, const char *str, size_t len)
+{
+ struct Ebl_GStrent *newstr;
+ struct Ebl_GStrent **sep;
+
+ /* Compute the string length if the caller doesn't know it. */
+ if (len == 0)
+ {
+ size_t j;
+
+ do
+ for (j = 0; j < st->width; ++j)
+ if (str[len * st->width + j] != '\0')
+ break;
+ while (j == st->width && ++len);
+ }
+
+ /* Make sure all "" strings get offset 0 but only if the table was
+ created with a special null entry in mind. */
+ if (len == 1 && st->null.string != NULL)
+ return &st->null;
+
+ /* Allocate memory for the new string and its associated information. */
+ newstr = newstring (st, str, len);
+
+ /* Search in the array for the place to insert the string. If there
+ is no string with matching prefix and no string with matching
+ leading substring, create a new entry. */
+ sep = searchstring (&st->root, newstr);
+ if (*sep != newstr)
+ {
+ /* This is not the same entry. This means we have a prefix match. */
+ if ((*sep)->len > newstr->len)
+ {
+ struct Ebl_GStrent *subs;
+
+ /* Check whether we already know this string. */
+ for (subs = (*sep)->next; subs != NULL; subs = subs->next)
+ if (subs->len == newstr->len)
+ {
+ /* We have an exact match with a substring. Free the memory
+ we allocated. */
+ st->left += (st->backp - (char *) newstr) * st->width;
+ st->backp = (char *) newstr;
+
+ return subs;
+ }
+
+ /* We have a new substring. This means we don't need the reverse
+ string of this entry anymore. */
+ st->backp -= newstr->len;
+ st->left += newstr->len;
+
+ newstr->next = (*sep)->next;
+ (*sep)->next = newstr;
+ }
+ else if ((*sep)->len != newstr->len)
+ {
+ /* When we get here it means that the string we are about to
+ add has a common prefix with a string we already have but
+ it is longer. In this case we have to put it first. */
+ st->total += newstr->len - (*sep)->len;
+ newstr->next = *sep;
+ newstr->left = (*sep)->left;
+ newstr->right = (*sep)->right;
+ *sep = newstr;
+ }
+ else
+ {
+ /* We have an exact match. Free the memory we allocated. */
+ st->left += (st->backp - (char *) newstr) * st->width;
+ st->backp = (char *) newstr;
+
+ newstr = *sep;
+ }
+ }
+ else
+ st->total += newstr->len;
+
+ return newstr;
+}
+
+
+static void
+copystrings (struct Ebl_GStrent *nodep, char **freep, size_t *offsetp)
+{
+ struct Ebl_GStrent *subs;
+
+ if (nodep->left != NULL)
+ copystrings (nodep->left, freep, offsetp);
+
+ /* Process the current node. */
+ nodep->offset = *offsetp;
+ *freep = (char *) mempcpy (*freep, nodep->string, nodep->len * nodep->width);
+ *offsetp += nodep->len * nodep->width;
+
+ for (subs = nodep->next; subs != NULL; subs = subs->next)
+ {
+ assert (subs->len < nodep->len);
+ subs->offset = nodep->offset + (nodep->len - subs->len) * nodep->width;
+ assert (subs->offset != 0 || subs->string[0] == '\0');
+ }
+
+ if (nodep->right != NULL)
+ copystrings (nodep->right, freep, offsetp);
+}
+
+
+void
+ebl_gstrtabfinalize (struct Ebl_GStrtab *st, Elf_Data *data)
+{
+ size_t copylen;
+ char *endp;
+ size_t nulllen = st->nullstr ? st->width : 0;
+
+ /* Fill in the information. */
+ data->d_buf = malloc (st->total + nulllen);
+ if (data->d_buf == NULL)
+ abort ();
+
+ /* The first byte must always be zero if we created the table with a
+ null string. */
+ if (st->nullstr)
+ memset (data->d_buf, '\0', st->width);
+
+ data->d_type = ELF_T_BYTE;
+ data->d_size = st->total + nulllen;
+ data->d_off = 0;
+ data->d_align = 1;
+ data->d_version = EV_CURRENT;
+
+ /* Now run through the tree and add all the string while also updating
+ the offset members of the elfstrent records. */
+ endp = (char *) data->d_buf + nulllen;
+ copylen = nulllen;
+ copystrings (st->root, &endp, &copylen);
+ assert (copylen == st->total * st->width + nulllen);
+}
+
+
+size_t
+ebl_gstrtaboffset (struct Ebl_GStrent *se)
+{
+ return se->offset;
+}
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