ab9da55419
as appropriate. Fill in structure initializations. Add variable initializations. Add casts. * dwarf2dbg.c (print_stats): Change i to size_t. * listing.c (listing_listing): Change list_line to unsigned int.
602 lines
14 KiB
C
602 lines
14 KiB
C
/* hash.c -- gas hash table code
|
||
Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 98, 1999
|
||
Free Software Foundation, Inc.
|
||
|
||
This file is part of GAS, the GNU Assembler.
|
||
|
||
GAS 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; either version 2, or (at your option)
|
||
any later version.
|
||
|
||
GAS 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 GAS; see the file COPYING. If not, write to the Free
|
||
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||
02111-1307, USA. */
|
||
|
||
/* This version of the hash table code is a wholescale replacement of
|
||
the old hash table code, which was fairly bad. This is based on
|
||
the hash table code in BFD, but optimized slightly for the
|
||
asssembler. The assembler does not need to derive structures that
|
||
are stored in the hash table. Instead, it always stores a pointer.
|
||
The assembler uses the hash table mostly to store symbols, and we
|
||
don't need to confuse the symbol structure with a hash table
|
||
structure. */
|
||
|
||
#include "as.h"
|
||
#include "obstack.h"
|
||
|
||
/* The default number of entries to use when creating a hash table. */
|
||
|
||
#define DEFAULT_SIZE (4051)
|
||
|
||
/* An entry in a hash table. */
|
||
|
||
struct hash_entry
|
||
{
|
||
/* Next entry for this hash code. */
|
||
struct hash_entry *next;
|
||
/* String being hashed. */
|
||
const char *string;
|
||
/* Hash code. This is the full hash code, not the index into the
|
||
table. */
|
||
unsigned long hash;
|
||
/* Pointer being stored in the hash table. */
|
||
PTR data;
|
||
};
|
||
|
||
/* A hash table. */
|
||
|
||
struct hash_control
|
||
{
|
||
/* The hash array. */
|
||
struct hash_entry **table;
|
||
/* The number of slots in the hash table. */
|
||
unsigned int size;
|
||
/* An obstack for this hash table. */
|
||
struct obstack memory;
|
||
|
||
#ifdef HASH_STATISTICS
|
||
/* Statistics. */
|
||
unsigned long lookups;
|
||
unsigned long hash_compares;
|
||
unsigned long string_compares;
|
||
unsigned long insertions;
|
||
unsigned long replacements;
|
||
unsigned long deletions;
|
||
#endif /* HASH_STATISTICS */
|
||
};
|
||
|
||
/* Create a hash table. This return a control block. */
|
||
|
||
struct hash_control *
|
||
hash_new ()
|
||
{
|
||
unsigned int size;
|
||
struct hash_control *ret;
|
||
unsigned int alloc;
|
||
|
||
size = DEFAULT_SIZE;
|
||
|
||
ret = (struct hash_control *) xmalloc (sizeof *ret);
|
||
obstack_begin (&ret->memory, chunksize);
|
||
alloc = size * sizeof (struct hash_entry *);
|
||
ret->table = (struct hash_entry **) obstack_alloc (&ret->memory, alloc);
|
||
memset (ret->table, 0, alloc);
|
||
ret->size = size;
|
||
|
||
#ifdef HASH_STATISTICS
|
||
ret->lookups = 0;
|
||
ret->hash_compares = 0;
|
||
ret->string_compares = 0;
|
||
ret->insertions = 0;
|
||
ret->replacements = 0;
|
||
ret->deletions = 0;
|
||
#endif
|
||
|
||
return ret;
|
||
}
|
||
|
||
/* Delete a hash table, freeing all allocated memory. */
|
||
|
||
void
|
||
hash_die (table)
|
||
struct hash_control *table;
|
||
{
|
||
obstack_free (&table->memory, 0);
|
||
free (table);
|
||
}
|
||
|
||
/* Look up a string in a hash table. This returns a pointer to the
|
||
hash_entry, or NULL if the string is not in the table. If PLIST is
|
||
not NULL, this sets *PLIST to point to the start of the list which
|
||
would hold this hash entry. If PHASH is not NULL, this sets *PHASH
|
||
to the hash code for KEY.
|
||
|
||
Each time we look up a string, we move it to the start of the list
|
||
for its hash code, to take advantage of referential locality. */
|
||
|
||
static struct hash_entry *hash_lookup PARAMS ((struct hash_control *,
|
||
const char *,
|
||
struct hash_entry ***,
|
||
unsigned long *));
|
||
|
||
static struct hash_entry *
|
||
hash_lookup (table, key, plist, phash)
|
||
struct hash_control *table;
|
||
const char *key;
|
||
struct hash_entry ***plist;
|
||
unsigned long *phash;
|
||
{
|
||
register unsigned long hash;
|
||
unsigned int len;
|
||
register const unsigned char *s;
|
||
register unsigned int c;
|
||
unsigned int index;
|
||
struct hash_entry **list;
|
||
struct hash_entry *p;
|
||
struct hash_entry *prev;
|
||
|
||
#ifdef HASH_STATISTICS
|
||
++table->lookups;
|
||
#endif
|
||
|
||
hash = 0;
|
||
len = 0;
|
||
s = (const unsigned char *) key;
|
||
while ((c = *s++) != '\0')
|
||
{
|
||
hash += c + (c << 17);
|
||
hash ^= hash >> 2;
|
||
++len;
|
||
}
|
||
hash += len + (len << 17);
|
||
hash ^= hash >> 2;
|
||
|
||
if (phash != NULL)
|
||
*phash = hash;
|
||
|
||
index = hash % table->size;
|
||
list = table->table + index;
|
||
|
||
if (plist != NULL)
|
||
*plist = list;
|
||
|
||
prev = NULL;
|
||
for (p = *list; p != NULL; p = p->next)
|
||
{
|
||
#ifdef HASH_STATISTICS
|
||
++table->hash_compares;
|
||
#endif
|
||
|
||
if (p->hash == hash)
|
||
{
|
||
#ifdef HASH_STATISTICS
|
||
++table->string_compares;
|
||
#endif
|
||
|
||
if (strcmp (p->string, key) == 0)
|
||
{
|
||
if (prev != NULL)
|
||
{
|
||
prev->next = p->next;
|
||
p->next = *list;
|
||
*list = p;
|
||
}
|
||
|
||
return p;
|
||
}
|
||
}
|
||
|
||
prev = p;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Insert an entry into a hash table. This returns NULL on success.
|
||
On error, it returns a printable string indicating the error. It
|
||
is considered to be an error if the entry already exists in the
|
||
hash table. */
|
||
|
||
const char *
|
||
hash_insert (table, key, value)
|
||
struct hash_control *table;
|
||
const char *key;
|
||
PTR value;
|
||
{
|
||
struct hash_entry *p;
|
||
struct hash_entry **list;
|
||
unsigned long hash;
|
||
|
||
p = hash_lookup (table, key, &list, &hash);
|
||
if (p != NULL)
|
||
return "exists";
|
||
|
||
#ifdef HASH_STATISTICS
|
||
++table->insertions;
|
||
#endif
|
||
|
||
p = obstack_alloc (&table->memory, sizeof *p);
|
||
p->string = key;
|
||
p->hash = hash;
|
||
p->data = value;
|
||
|
||
p->next = *list;
|
||
*list = p;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Insert or replace an entry in a hash table. This returns NULL on
|
||
success. On error, it returns a printable string indicating the
|
||
error. If an entry already exists, its value is replaced. */
|
||
|
||
const char *
|
||
hash_jam (table, key, value)
|
||
struct hash_control *table;
|
||
const char *key;
|
||
PTR value;
|
||
{
|
||
struct hash_entry *p;
|
||
struct hash_entry **list;
|
||
unsigned long hash;
|
||
|
||
p = hash_lookup (table, key, &list, &hash);
|
||
if (p != NULL)
|
||
{
|
||
#ifdef HASH_STATISTICS
|
||
++table->replacements;
|
||
#endif
|
||
|
||
p->data = value;
|
||
}
|
||
else
|
||
{
|
||
#ifdef HASH_STATISTICS
|
||
++table->insertions;
|
||
#endif
|
||
|
||
p = obstack_alloc (&table->memory, sizeof *p);
|
||
p->string = key;
|
||
p->hash = hash;
|
||
p->data = value;
|
||
|
||
p->next = *list;
|
||
*list = p;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Replace an existing entry in a hash table. This returns the old
|
||
value stored for the entry. If the entry is not found in the hash
|
||
table, this does nothing and returns NULL. */
|
||
|
||
PTR
|
||
hash_replace (table, key, value)
|
||
struct hash_control *table;
|
||
const char *key;
|
||
PTR value;
|
||
{
|
||
struct hash_entry *p;
|
||
PTR ret;
|
||
|
||
p = hash_lookup (table, key, NULL, NULL);
|
||
if (p == NULL)
|
||
return NULL;
|
||
|
||
#ifdef HASH_STATISTICS
|
||
++table->replacements;
|
||
#endif
|
||
|
||
ret = p->data;
|
||
|
||
p->data = value;
|
||
|
||
return ret;
|
||
}
|
||
|
||
/* Find an entry in a hash table, returning its value. Returns NULL
|
||
if the entry is not found. */
|
||
|
||
PTR
|
||
hash_find (table, key)
|
||
struct hash_control *table;
|
||
const char *key;
|
||
{
|
||
struct hash_entry *p;
|
||
|
||
p = hash_lookup (table, key, NULL, NULL);
|
||
if (p == NULL)
|
||
return NULL;
|
||
|
||
return p->data;
|
||
}
|
||
|
||
/* Delete an entry from a hash table. This returns the value stored
|
||
for that entry, or NULL if there is no such entry. */
|
||
|
||
PTR
|
||
hash_delete (table, key)
|
||
struct hash_control *table;
|
||
const char *key;
|
||
{
|
||
struct hash_entry *p;
|
||
struct hash_entry **list;
|
||
|
||
p = hash_lookup (table, key, &list, NULL);
|
||
if (p == NULL)
|
||
return NULL;
|
||
|
||
if (p != *list)
|
||
abort ();
|
||
|
||
#ifdef HASH_STATISTICS
|
||
++table->deletions;
|
||
#endif
|
||
|
||
*list = p->next;
|
||
|
||
/* Note that we never reclaim the memory for this entry. If gas
|
||
ever starts deleting hash table entries in a big way, this will
|
||
have to change. */
|
||
|
||
return p->data;
|
||
}
|
||
|
||
/* Traverse a hash table. Call the function on every entry in the
|
||
hash table. */
|
||
|
||
void
|
||
hash_traverse (table, pfn)
|
||
struct hash_control *table;
|
||
void (*pfn) PARAMS ((const char *key, PTR value));
|
||
{
|
||
unsigned int i;
|
||
|
||
for (i = 0; i < table->size; ++i)
|
||
{
|
||
struct hash_entry *p;
|
||
|
||
for (p = table->table[i]; p != NULL; p = p->next)
|
||
(*pfn) (p->string, p->data);
|
||
}
|
||
}
|
||
|
||
/* Print hash table statistics on the specified file. NAME is the
|
||
name of the hash table, used for printing a header. */
|
||
|
||
void
|
||
hash_print_statistics (f, name, table)
|
||
FILE *f ATTRIBUTE_UNUSED;
|
||
const char *name ATTRIBUTE_UNUSED;
|
||
struct hash_control *table ATTRIBUTE_UNUSED;
|
||
{
|
||
#ifdef HASH_STATISTICS
|
||
unsigned int i;
|
||
unsigned long total;
|
||
unsigned long empty;
|
||
|
||
fprintf (f, "%s hash statistics:\n", name);
|
||
fprintf (f, "\t%lu lookups\n", table->lookups);
|
||
fprintf (f, "\t%lu hash comparisons\n", table->hash_compares);
|
||
fprintf (f, "\t%lu string comparisons\n", table->string_compares);
|
||
fprintf (f, "\t%lu insertions\n", table->insertions);
|
||
fprintf (f, "\t%lu replacements\n", table->replacements);
|
||
fprintf (f, "\t%lu deletions\n", table->deletions);
|
||
|
||
total = 0;
|
||
empty = 0;
|
||
for (i = 0; i < table->size; ++i)
|
||
{
|
||
struct hash_entry *p;
|
||
|
||
if (table->table[i] == NULL)
|
||
++empty;
|
||
else
|
||
{
|
||
for (p = table->table[i]; p != NULL; p = p->next)
|
||
++total;
|
||
}
|
||
}
|
||
|
||
fprintf (f, "\t%g average chain length\n", (double) total / table->size);
|
||
fprintf (f, "\t%lu empty slots\n", empty);
|
||
#endif
|
||
}
|
||
|
||
#ifdef TEST
|
||
|
||
/* This test program is left over from the old hash table code. */
|
||
|
||
#define TABLES (6) /* number of hash tables to maintain */
|
||
/* (at once) in any testing */
|
||
#define STATBUFSIZE (12) /* we can have 12 statistics */
|
||
|
||
int statbuf[STATBUFSIZE]; /* display statistics here */
|
||
char answer[100]; /* human farts here */
|
||
char *hashtable[TABLES]; /* we test many hash tables at once */
|
||
char *h; /* points to curent hash_control */
|
||
char **pp;
|
||
char *p;
|
||
char *name;
|
||
char *value;
|
||
int size;
|
||
int used;
|
||
char command;
|
||
int number; /* number 0:TABLES-1 of current hashed */
|
||
/* symbol table */
|
||
|
||
int
|
||
main ()
|
||
{
|
||
void applicatee ();
|
||
void destroy ();
|
||
char *what ();
|
||
int *ip;
|
||
|
||
number = 0;
|
||
h = 0;
|
||
printf ("type h <RETURN> for help\n");
|
||
for (;;)
|
||
{
|
||
printf ("hash_test command: ");
|
||
gets (answer);
|
||
command = answer[0];
|
||
if (isupper (command))
|
||
command = tolower (command); /* ecch! */
|
||
switch (command)
|
||
{
|
||
case '#':
|
||
printf ("old hash table #=%d.\n", number);
|
||
whattable ();
|
||
break;
|
||
case '?':
|
||
for (pp = hashtable; pp < hashtable + TABLES; pp++)
|
||
{
|
||
printf ("address of hash table #%d control block is %xx\n"
|
||
,pp - hashtable, *pp);
|
||
}
|
||
break;
|
||
case 'a':
|
||
hash_traverse (h, applicatee);
|
||
break;
|
||
case 'd':
|
||
hash_traverse (h, destroy);
|
||
hash_die (h);
|
||
break;
|
||
case 'f':
|
||
p = hash_find (h, name = what ("symbol"));
|
||
printf ("value of \"%s\" is \"%s\"\n", name, p ? p : "NOT-PRESENT");
|
||
break;
|
||
case 'h':
|
||
printf ("# show old, select new default hash table number\n");
|
||
printf ("? display all hashtable control block addresses\n");
|
||
printf ("a apply a simple display-er to each symbol in table\n");
|
||
printf ("d die: destroy hashtable\n");
|
||
printf ("f find value of nominated symbol\n");
|
||
printf ("h this help\n");
|
||
printf ("i insert value into symbol\n");
|
||
printf ("j jam value into symbol\n");
|
||
printf ("n new hashtable\n");
|
||
printf ("r replace a value with another\n");
|
||
printf ("s say what %% of table is used\n");
|
||
printf ("q exit this program\n");
|
||
printf ("x delete a symbol from table, report its value\n");
|
||
break;
|
||
case 'i':
|
||
p = hash_insert (h, name = what ("symbol"), value = what ("value"));
|
||
if (p)
|
||
{
|
||
printf ("symbol=\"%s\" value=\"%s\" error=%s\n", name, value,
|
||
p);
|
||
}
|
||
break;
|
||
case 'j':
|
||
p = hash_jam (h, name = what ("symbol"), value = what ("value"));
|
||
if (p)
|
||
{
|
||
printf ("symbol=\"%s\" value=\"%s\" error=%s\n", name, value, p);
|
||
}
|
||
break;
|
||
case 'n':
|
||
h = hashtable[number] = (char *) hash_new ();
|
||
break;
|
||
case 'q':
|
||
exit (EXIT_SUCCESS);
|
||
case 'r':
|
||
p = hash_replace (h, name = what ("symbol"), value = what ("value"));
|
||
printf ("old value was \"%s\"\n", p ? p : "{}");
|
||
break;
|
||
case 's':
|
||
hash_say (h, statbuf, STATBUFSIZE);
|
||
for (ip = statbuf; ip < statbuf + STATBUFSIZE; ip++)
|
||
{
|
||
printf ("%d ", *ip);
|
||
}
|
||
printf ("\n");
|
||
break;
|
||
case 'x':
|
||
p = hash_delete (h, name = what ("symbol"));
|
||
printf ("old value was \"%s\"\n", p ? p : "{}");
|
||
break;
|
||
default:
|
||
printf ("I can't understand command \"%c\"\n", command);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
char *
|
||
what (description)
|
||
char *description;
|
||
{
|
||
char *retval;
|
||
char *malloc ();
|
||
|
||
printf (" %s : ", description);
|
||
gets (answer);
|
||
/* will one day clean up answer here */
|
||
retval = malloc (strlen (answer) + 1);
|
||
if (!retval)
|
||
{
|
||
error ("room");
|
||
}
|
||
(void) strcpy (retval, answer);
|
||
return (retval);
|
||
}
|
||
|
||
void
|
||
destroy (string, value)
|
||
char *string;
|
||
char *value;
|
||
{
|
||
free (string);
|
||
free (value);
|
||
}
|
||
|
||
|
||
void
|
||
applicatee (string, value)
|
||
char *string;
|
||
char *value;
|
||
{
|
||
printf ("%.20s-%.20s\n", string, value);
|
||
}
|
||
|
||
void
|
||
whattable () /* determine number: what hash table to use */
|
||
/* also determine h: points to hash_control */
|
||
{
|
||
|
||
for (;;)
|
||
{
|
||
printf (" what hash table (%d:%d) ? ", 0, TABLES - 1);
|
||
gets (answer);
|
||
sscanf (answer, "%d", &number);
|
||
if (number >= 0 && number < TABLES)
|
||
{
|
||
h = hashtable[number];
|
||
if (!h)
|
||
{
|
||
printf ("warning: current hash-table-#%d. has no hash-control\n", number);
|
||
}
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
printf ("invalid hash table number: %d\n", number);
|
||
}
|
||
}
|
||
}
|
||
|
||
#endif /* #ifdef TEST */
|
||
|
||
/* end of hash.c */
|