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[objcopy] Fix quadratic-time when handling --redefine-syms

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objcopy/
	* objcopy.c (struct redefine_node): Delete the field "next".
	(redefine_sym_list): Deleted.
	(redefine_specific_htab): New hash table.
	(redefine_specific_reverse_htab): Likewise.
	(eq_string_redefnode): New function.
	(htab_hash_redefnode): Likewise.
	(create_symbol2redef_htab): Likewise.
	(add_specific_symbol_node): Likewise.
	(create_symbol_htabs): Create redefine_specific_htab and
	redefine_specific_reverse_htab.
	(lookup_sym_redefinition): Use hash table instead of list.
	(redefine_list_append): Likewise, and rename to add_redefine_and_check.
	(copy_main): Use redefine_specific_htab instead of redefine_sym_list.
	Update comments.
This commit is contained in:
Jiong Wang 2017-04-05 17:22:47 +01:00
parent 9014582538
commit 0f65a5d84d
2 changed files with 89 additions and 34 deletions
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17
binutils/ChangeLog
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@ -1,3 +1,20 @@
2017-04-05 Jiong Wang <jiong.wang@arm.com>
* objcopy.c (struct redefine_node): Delete the field "next".
(redefine_sym_list): Deleted.
(redefine_specific_htab): New hash table.
(redefine_specific_reverse_htab): Likewise.
(eq_string_redefnode): New function.
(htab_hash_redefnode): Likewise.
(create_symbol2redef_htab): Likewise.
(add_specific_symbol_node): Likewise.
(create_symbol_htabs): Create redefine_specific_htab and
redefine_specific_reverse_htab.
(lookup_sym_redefinition): Use hash table instead of list.
(redefine_list_append): Likewise, and rename to add_redefine_and_check.
(copy_main): Use redefine_specific_htab instead of redefine_sym_list.
Update comments.
2017-04-04 H.J. Lu <hongjiu.lu@intel.com>
* NEWS: Mention support for ELF SHF_GNU_MBIND and

106
binutils/objcopy.c
View File

@ -54,12 +54,11 @@ struct is_specified_symbol_predicate_data
bfd_boolean found;
};
/* A list to support redefine_sym. */
/* A node includes symbol name mapping to support redefine_sym. */
struct redefine_node
{
char *source;
char *target;
struct redefine_node *next;
};
struct addsym_node
@ -249,7 +248,8 @@ static htab_t localize_specific_htab = NULL;
static htab_t globalize_specific_htab = NULL;
static htab_t keepglobal_specific_htab = NULL;
static htab_t weaken_specific_htab = NULL;
static struct redefine_node *redefine_sym_list = NULL;
static htab_t redefine_specific_htab = NULL;
static htab_t redefine_specific_reverse_htab = NULL;
static struct addsym_node *add_sym_list = NULL, **add_sym_tail = &add_sym_list;
static int add_symbols = 0;
@ -947,6 +947,34 @@ find_section_list (const char *name, bfd_boolean add, unsigned int context)
return p;
}
/* S1 is the entry node already in the table, S2 is the key node. */
static int
eq_string_redefnode (const void *s1, const void *s2)
{
struct redefine_node *node1 = (struct redefine_node *) s1;
struct redefine_node *node2 = (struct redefine_node *) s2;
return !strcmp ((const char *) node1->source, (const char *) node2->source);
}
/* P is redefine node. Hash value is generated from its "source" filed. */
static hashval_t
htab_hash_redefnode (const void *p)
{
struct redefine_node *redefnode = (struct redefine_node *) p;
return htab_hash_string (redefnode->source);
}
/* Create hashtab used for redefine node. */
static htab_t
create_symbol2redef_htab (void)
{
return htab_create_alloc (16, htab_hash_redefnode, eq_string_redefnode, NULL,
xcalloc, free);
}
/* There is htab_hash_string but no htab_eq_string. Makes sense. */
static int
@ -971,6 +999,10 @@ create_symbol_htabs (void)
globalize_specific_htab = create_symbol_htab ();
keepglobal_specific_htab = create_symbol_htab ();
weaken_specific_htab = create_symbol_htab ();
redefine_specific_htab = create_symbol2redef_htab ();
/* As there is no bidirectional hash table in libiberty, need a reverse table
to check duplicated target string. */
redefine_specific_reverse_htab = create_symbol_htab ();
}
/* Add a symbol to strip_specific_list. */
@ -981,6 +1013,14 @@ add_specific_symbol (const char *name, htab_t htab)
*htab_find_slot (htab, name, INSERT) = (char *) name;
}
/* Like add_specific_symbol, but the element type is void *. */
static void
add_specific_symbol_node (const void *node, htab_t htab)
{
*htab_find_slot (htab, node, INSERT) = (void *) node;
}
/* Add symbols listed in `filename' to strip_specific_list. */
#define IS_WHITESPACE(c) ((c) == ' ' || (c) == '\t')
@ -1439,7 +1479,7 @@ filter_symbols (bfd *abfd, bfd *obfd, asymbol **osyms,
to[dst_count++] = create_new_symbol (ptr, obfd);
}
if (redefine_sym_list || section_rename_list)
if (htab_elements (redefine_specific_htab) || section_rename_list)
{
char *new_name;
@ -1625,42 +1665,40 @@ filter_symbols (bfd *abfd, bfd *obfd, asymbol **osyms,
static const char *
lookup_sym_redefinition (const char *source)
{
struct redefine_node *list;
struct redefine_node key_node = {(char *) source, NULL};
struct redefine_node *redef_node
= (struct redefine_node *) htab_find (redefine_specific_htab, &key_node);
for (list = redefine_sym_list; list != NULL; list = list->next)
if (strcmp (source, list->source) == 0)
return list->target;
return source;
return redef_node == NULL ? source : redef_node->target;
}
/* Add a node to a symbol redefine list. */
/* Insert a node into symbol redefine hash tabel. */
static void
redefine_list_append (const char *cause, const char *source, const char *target)
add_redefine_and_check (const char *cause, const char *source,
const char *target)
{
struct redefine_node **p;
struct redefine_node *list;
struct redefine_node *new_node;
for (p = &redefine_sym_list; (list = *p) != NULL; p = &list->next)
{
if (strcmp (source, list->source) == 0)
fatal (_("%s: Multiple redefinition of symbol \"%s\""),
cause, source);
if (strcmp (target, list->target) == 0)
fatal (_("%s: Symbol \"%s\" is target of more than one redefinition"),
cause, target);
}
new_node = (struct redefine_node *) xmalloc (sizeof (struct redefine_node));
struct redefine_node *new_node
= (struct redefine_node *) xmalloc (sizeof (struct redefine_node));
new_node->source = strdup (source);
new_node->target = strdup (target);
new_node->next = NULL;
*p = new_node;
if (htab_find (redefine_specific_htab, new_node) != HTAB_EMPTY_ENTRY)
fatal (_("%s: Multiple redefinition of symbol \"%s\""),
cause, source);
if (htab_find (redefine_specific_reverse_htab, target) != HTAB_EMPTY_ENTRY)
fatal (_("%s: Symbol \"%s\" is target of more than one redefinition"),
cause, target);
/* Insert the NEW_NODE into hash table for quick search. */
add_specific_symbol_node (new_node, redefine_specific_htab);
/* Insert the target string into the reverse hash table, this is needed for
duplicated target string check. */
add_specific_symbol (new_node->target, redefine_specific_reverse_htab);
}
/* Handle the --redefine-syms option. Read lines containing "old new"
@ -1745,7 +1783,7 @@ add_redefine_syms_file (const char *filename)
end_of_line:
/* Append the redefinition to the list. */
if (buf[0] != '\0')
redefine_list_append (filename, &buf[0], &buf[outsym_off]);
add_redefine_and_check (filename, &buf[0], &buf[outsym_off]);
lineno++;
len = 0;
@ -2695,13 +2733,13 @@ copy_object (bfd *ibfd, bfd *obfd, const bfd_arch_info_type *input_arch)
|| htab_elements (globalize_specific_htab) != 0
|| htab_elements (keepglobal_specific_htab) != 0
|| htab_elements (weaken_specific_htab) != 0
|| htab_elements (redefine_specific_htab) != 0
|| prefix_symbols_string
|| sections_removed
|| sections_copied
|| convert_debugging
|| change_leading_char
|| remove_leading_char
|| redefine_sym_list
|| section_rename_list
|| weaken
|| add_symbols)
@ -4750,7 +4788,7 @@ copy_main (int argc, char *argv[])
case OPTION_REDEFINE_SYM:
{
/* Push this redefinition onto redefine_symbol_list. */
/* Insert this redefinition onto redefine_specific_htab. */
int len;
const char *s;
@ -4771,7 +4809,7 @@ copy_main (int argc, char *argv[])
target = (char *) xmalloc (len + 1);
strcpy (target, nextarg);
redefine_list_append ("--redefine-sym", source, target);
add_redefine_and_check ("--redefine-sym", source, target);
free (source);
free (target);