binutils-gdb/gas/hash.h

/* hash.h -- header file for gas hash table routines
   Copyright (C) 1987-2020 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 3, 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, 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */

#ifndef HASH_H
#define HASH_H

struct hash_control;

/* Set the size of the hash table used.  */

void set_gas_hash_table_size (unsigned long);

/* Create a hash table.  This return a control block.  */

extern struct hash_control *hash_new (void);
extern struct hash_control *hash_new_sized (unsigned long);

/* Delete a hash table, freeing all allocated memory.  */

extern void hash_die (struct hash_control *);

/* 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.  */

extern const char *hash_insert (struct hash_control *,
				const char *key, void *value);

/* 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.  */

extern const char *hash_jam (struct hash_control *,
			     const char *key, void *value);

/* 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.  */

extern void *hash_replace (struct hash_control *, const char *key,
			 void *value);

/* Find an entry in a hash table, returning its value.  Returns NULL
   if the entry is not found.  */

extern void *hash_find (struct hash_control *, const char *key);

/* As hash_find, but KEY is of length LEN and is not guaranteed to be
   NUL-terminated.  */

extern void *hash_find_n (struct hash_control *, const char *key, size_t len);

/* Delete an entry from a hash table.  This returns the value stored
   for that entry, or NULL if there is no such entry.  */

extern void *hash_delete (struct hash_control *, const char *key, int);

/* Traverse a hash table.  Call the function on every entry in the
   hash table.  */

extern void hash_traverse (struct hash_control *,
			   void (*pfn) (const char *key, void *value));

/* Print hash table statistics on the specified file.  NAME is the
   name of the hash table, used for printing a header.  */

extern void hash_print_statistics (FILE *, const char *name,
				   struct hash_control *);

/* Insert ELEMENT into HTAB.  If the element exists, it is overwritten.  */

extern void htab_insert (htab_t, void *);

/* Print statistics about a hash table.  */

extern void htab_print_statistics (FILE *f, const char *name, htab_t table);

/* String hash table functions.  */

struct string_tuple
{
  const char *key;
  char *value;
};

typedef struct string_tuple string_tuple_t;

/* Hash function for a string_tuple.  */

static hashval_t
hash_string_tuple (const void *e)
{
  string_tuple_t *tuple = (string_tuple_t *) e;
  return htab_hash_string (tuple->key);
}

/* Equality function for a string_tuple.  */

static int
eq_string_tuple (const void *a, const void *b)
{
  const string_tuple_t *ea = (const string_tuple_t *) a;
  const string_tuple_t *eb = (const string_tuple_t *) b;

  return strcmp (ea->key, eb->key) == 0;
}

static inline string_tuple_t *
string_tuple_alloc (const char *key, char *value)
{
  string_tuple_t *tuple = XNEW (string_tuple_t);
  tuple->key = key;
  tuple->value = value;
  return tuple;
}

static inline void *
str_hash_find (htab_t table, const char *key)
{
  string_tuple_t needle = { key, NULL };
  string_tuple_t *tuple = htab_find (table, &needle);
  return tuple != NULL ? tuple->value : NULL;
}

static inline void *
str_hash_find_n (htab_t table, const char *key, size_t n)
{
  char *tmp = XNEWVEC (char, n + 1);
  memcpy (tmp, key, n);
  tmp[n] = '\0';
  string_tuple_t needle = { tmp, NULL };
  string_tuple_t *tuple = htab_find (table, &needle);
  free (tmp);
  return tuple != NULL ? tuple->value : NULL;
}

static inline void
str_hash_delete (htab_t table, const char *key)
{
  string_tuple_t needle = { key, NULL };
  htab_remove_elt (table, &needle);
}

static inline void
str_hash_insert (htab_t table, const char *key, void *value)
{
  htab_insert (table, string_tuple_alloc (key, value));
}

static inline htab_t
str_htab_create (void)
{
  return htab_create_alloc (16, hash_string_tuple, eq_string_tuple,
			    NULL, xcalloc, free);
}

#endif /* HASH_H */