lac : afe82c1759ca8a37b3d477eaa2b2ad533cfb8e9b

     1: #include "private.h"
     2: #include <gc/gc.h>
     3: #include <string.h>
     4: 
     5: /*
     6:  * Utterly simple hash table implementation
     7:  */
     8: 
     9: static unsigned
    10: ht_hashf (lreg_t key)
    11: {
    12:   return ((uintptr_t) lreg_raw_ptr (key) >> 5) % HT_SIZE;
    13: }
    14: 
    15: static int
    16: _ht_findptr (struct ht_entry *hte, lreg_t key, struct ht_entry **e)
    17: {
    18:   int i = 0;
    19:   struct ht_entry *ptr;
    20: 
    21:   for (ptr = hte; ptr != NULL; ptr = ptr->next)
    22:     {
    23:       i++;
    24:       if (ptr->key == key)
    25: 	{
    26: 	  *e = ptr;
    27: 	  return 0;
    28: 	}
    29:     }
    30:   return 1;
    31: }
    32: 
    33: /* Ret values: < 0 => error, 0 => found, 1 not found */
    34: static int
    35: ht_findptr (ht_t * ht, lreg_t key, struct ht_entry **e)
    36: {
    37:   unsigned n = ht_hashf (key);
    38:   return _ht_findptr (ht->table[n], key, e);
    39: }
    40: 
    41: /* Ret values: < 0 => error, 0 => found, 1 not found */
    42: static int
    43: ht_find (ht_t * ht, lreg_t key, lreg_t * res)
    44: {
    45:   int n;
    46:   struct ht_entry *hte;
    47:   n = ht_findptr (ht, key, &hte);
    48:   if (n == 0)
    49:     *res = hte->value;
    50:   return n;
    51: }
    52: 
    53: static int
    54: _ht_insert (struct ht_entry **htep, lreg_t key, lreg_t value)
    55: {
    56:   struct ht_entry *hte = *htep;
    57:   struct ht_entry *e = GC_malloc (sizeof (struct ht_entry));
    58:   e->key = key;
    59:   e->value = value;
    60:   e->next = hte;
    61:   *htep = e;
    62:   return 0;
    63: }
    64: 
    65: static int
    66: ht_insert (ht_t * ht, lreg_t key, lreg_t value)
    67: {
    68:   unsigned n = ht_hashf (key);
    69:   assert (n < HT_SIZE);
    70:   return _ht_insert (ht->table + n, key, value);
    71: }
    72: 
    73: 
    74: /*
    75:  * Environment stacks. Mostly Activation Records.
    76:  */
    77: 
    78: /* Ret values: < 0 => error, 0 => found, 1 not found */
    79: lreg_t
    80: env_lookup (lenv_t * env, lreg_t key)
    81: {
    82:   int r;
    83:   lreg_t res;
    84: 
    85:   r = ht_find (&env->htable, key, &res);
    86:   if (r == 1)
    87:     {
    88:       raise_exception ("Symbol not found", key);
    89:     }
    90:   if (r)
    91:     {
    92:       raise_exception ("Internal error", key);
    93:     }
    94:   return res;
    95: }
    96: 
    97: int
    98: env_define (lenv_t * env, lreg_t key, lreg_t value)
    99: {
   100:   return ht_insert (&env->htable, key, value);
   101: }
   102: 
   103: /* Ret values: < 0 => error, 0 => found, 1 not found */
   104: int
   105: env_set (lenv_t * env, lreg_t key, lreg_t value)
   106: {
   107:   int r;
   108:   struct ht_entry *hte;
   109:   r = ht_findptr (&env->htable, key, &hte);
   110:   if (r == 0)
   111:     hte->value = value;
   112:   return r;
   113: }
   114: 
   115: void
   116: env_pushnew (lenv_t * env, lenv_t * new)
   117: {
   118:   new->htable = env->htable;
   119: }
   120: 
   121: #if 0
   122: 
   123: static lenv_t le;
   124: int
   125: main ()
   126: {
   127:   int n1, n2;
   128:   lreg_t res = 0;
   129:   lenv_t *le2;
   130:   GC_INIT ();
   131: 
   132:   le.htable = GC_malloc (sizeof (ht_t));
   133: 
   134:   n1 = env_set (&le, LREG (0x505000, 5), LREG (0xa0a000, 0xa));
   135:   printf ("n1 = %d\n", n1);
   136:   n1 = env_lookup (&le, LREG (0x505000, 5), &res);
   137:   printf ("%llx: %d\n", res, n1);
   138:   n1 = env_define (&le, LREG (0x505000, 5), LREG (0xa0a000, 0xa));
   139:   printf ("n1 = %d\n", n1);
   140:   n1 = env_lookup (&le, LREG (0x505000, 5), &res);
   141:   printf ("%llx: %d\n", res, n1);
   142: 
   143:   printf ("Creating new env\n");
   144: 
   145:   le2 = env_pushnew (&le);
   146:   n1 = env_lookup (le2, LREG (0x505000, 5), &res);
   147:   printf ("%llx: %d\n", res, n1);
   148:   n1 = env_define (le2, LREG (0x505000, 5), LREG (0xb0b000, 0xa));
   149:   printf ("n1 = %d\n", n1);
   150:   n1 = env_lookup (le2, LREG (0x505000, 5), &res);
   151:   printf ("%llx: %d\n", res, n1);
   152: 
   153:   printf ("Back to old env\n");
   154: 
   155:   n1 = env_lookup (&le, LREG (0x505000, 5), &res);
   156:   printf ("%llx: %d\n", res, n1);
   157: 
   158: 
   159: }
   160: 
   161: #endif