symbol.h

   1 /* Hash size must be a prime number. */
   2 #define HASH_SIZE 104729
   3
   4 struct symbol_hash
   5 {
   6         char name[MAXSYMBOL];
   7         int address;
   8 };
   9
  10 /*
  11 * Returns current value of RAM address.
  12 */
  13 int get_ram_address();
  14
  15 /*
  16 * Increments ROM Address value.
  17 * ROM Address used to store location of instruction tied to symbols.
  18 * This number correponds to the instruction number of the "jump" instruction.
  19 */
  20 void inc_rom_address();
  21
  22 /*
  23 * Returns current value of ROM address.
  24 */
  25 int get_rom_address();
  26
  27 /*
  28 * Prints out hash.
  29 * Must pass hash pointer and length of hash array
  30 */
  31 void print_hash();
  32
  33 /*
  34 * Calculates Hash value.
  35 * Returns integer value of hash based on string input
  36 */
  37 int hash(char symbol[]);
  38
  39 /*
  40 * Adds pair (symbol, address) to the table.
  41 * If address is set to < 0, hash chooses address.
  42 * Returns 1 if entry added to table and 0 otherwise.
  43 */
  44 int add_entry(char symbol[], int address);
  45
  46 /*
  47 * Look from beginning of hash for an empty slot and return it's address
  48 * This should be used only when a hash collision occurs as there is a
  49 * performance penalty for finding this value later.
  50 */
  51 int next_hash_space(void);
  52
  53 /*
  54 * Returns address associated with symbol.
  55 * If array found in hash, address is returned,
  56 * otherwise return -1
  57 */
  58 int get_address(char symbol[]);