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1999-04-10  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/generic/dl-cache.c (_dl_load_cache_lookup): Rewrite to
	use binary search.
	Based on a patch by Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>.

1999-04-07  H.J. Lu  <hjl@gnu.org>
	* manual/install.texi (Reporting Bugs): Add section about reported
This commit is contained in:
Ulrich Drepper
1999-04-10 11:51:27 +00:00
parent 34df6c3054
commit 3877d9ea5f
3 changed files with 139 additions and 35 deletions
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150
sysdeps/generic/dl-cache.c
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@@ -1,5 +1,5 @@
/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -52,13 +52,56 @@ static size_t cachesize;
binaries. */
int _dl_correct_cache_id = 3;
/* Helper function which must match the one in ldconfig, so that
we rely on the same sort order. */
static int
_dl_cache_libcmp (const char *p1, const char *p2)
{
while (*p1 != '\0')
{
if (*p1 >= '0' && *p1 <= '9')
{
if (*p2 >= '0' && *p2 <= '9')
{
/* Must compare this numerically. */
int val1;
int val2;
val1 = *p1++ - '0';
val2 = *p2++ - '0';
while (*p1 >= '0' && *p1 <= '9')
val1 = val1 * 10 + *p1++ - '0';
while (*p2 >= '0' && *p2 <= '9')
val2 = val2 * 10 + *p2++ - '0';
if (val1 != val2)
return val1 - val2;
}
else
return 1;
}
else if (*p2 >= '0' && *p2 <= '9')
return -1;
else if (*p1 != *p2)
return *p1 - *p2;
else
{
++p1;
++p2;
}
}
return *p1 - *p2;
}
/* Look up NAME in ld.so.cache and return the file name stored there,
or null if none is found. */
const char *
_dl_load_cache_lookup (const char *name)
{
unsigned int i;
int left, right, middle;
int cmpres;
const char *cache_data;
const char *best;
/* Print a message if the loading of libs is traced. */
@@ -87,28 +130,89 @@ _dl_load_cache_lookup (const char *name)
/* Previously looked for the cache file and didn't find it. */
return NULL;
best = NULL;
for (i = 0; i < cache->nlibs; ++i)
if ((cache->libs[i].flags == 1 ||
cache->libs[i].flags == 3) && /* ELF library entry. */
/* Make sure string table indices are not bogus before using them. */
cache->libs[i].key < cachesize - sizeof *cache &&
cache->libs[i].value < cachesize - sizeof *cache &&
/* Does the name match? */
! strcmp (name, ((const char *) &cache->libs[cache->nlibs] +
cache->libs[i].key)))
{
if ((best == NULL) || (cache->libs[i].flags == _dl_correct_cache_id))
{
best = ((const char *) &cache->libs[cache->nlibs]
+ cache->libs[i].value);
/* This is where the strings start. */
cache_data = (const char *) &cache->libs[cache->nlibs];
if (cache->libs[i].flags == _dl_correct_cache_id)
/* We've found an exact match for the shared object and no
general `ELF' release. Stop searching. */
break;
}
}
best = NULL;
/* We use binary search since the table is sorted in the cache file.
It is important to use the same algorithm as used while generating
the cache file. */
left = 0;
right = cache->nlibs - 1;
middle = (left + right) / 2;
cmpres = 1;
while (left <= right)
{
/* Make sure string table indices are not bogus before using them. */
if (cache->libs[middle].key >= cachesize - sizeof *cache)
{
cmpres = 1;
break;
}
/* Actually compare the entry with the key. */
cmpres = _dl_cache_libcmp (name, cache_data + cache->libs[middle].key);
if (cmpres == 0)
/* Found it. */
break;
if (cmpres < 0)
left = middle + 1;
else
right = middle - 1;
middle = (left + right) / 2;
}
if (cmpres == 0)
{
/* LEFT now marks the last entry for which we know the name is
correct. */
left = middle;
/* There might be entries with this name before the one we
found. So we have to find the beginning. */
while (middle > 0
/* Make sure string table indices are not bogus before
using them. */
&& cache->libs[middle - 1].key < cachesize - sizeof *cache
/* Actually compare the entry. */
&& strcmp (name, cache_data + cache->libs[middle - 1].key) == 0)
--middle;
do
{
int flags;
/* Only perform the name test if necessary. */
if (middle > left
/* We haven't seen this string so far. Test whether the
index is ok and whether the name matches. Otherwise
we are done. */
&& (cache->libs[middle].key >= cachesize - sizeof *cache
|| strcmp (name, cache_data + cache->libs[middle].key) != 0))
break;
flags = cache->libs[middle].flags;
if ((flags == 1 || flags == 3)
&& cache->libs[middle].value < cachesize - sizeof *cache)
{
if (best == NULL || flags == _dl_correct_cache_id)
{
best = cache_data + cache->libs[middle].value;
if (flags == _dl_correct_cache_id)
/* We've found an exact match for the shared
object and no general `ELF' release. Stop
searching. */
break;
}
}
}
while (++middle <= right);
}
/* Print our result if wanted. */
if (_dl_debug_libs && best != NULL)