scope.c

   1 /*
   2  * Symbol scoping.
   3  *
   4  * This is pretty trivial.
   5  */
   6 #include <stdlib.h>
   7 #include <string.h>
   8
   9 #include "lib.h"
  10 #include "symbol.h"
  11 #include "scope.h"
  12
  13 static struct scope
  14          base_scope = { .next = &base_scope },
  15         *current_scope = &base_scope;
  16
  17 void bind_scope(struct symbol *sym)
  18 {
  19         add_symbol(&current_scope->symbols, sym);
  20 }
  21
  22 void start_symbol_scope(void)
  23 {
  24         struct scope *scope = __alloc_bytes(sizeof(*scope));
  25         memset(scope, 0, sizeof(*scope));
  26         scope->next = current_scope;
  27         current_scope = scope;
  28 }
  29
  30 static void remove_symbol_scope(struct symbol *sym)
  31 {
  32         struct symbol **ptr = sym->id_list;
  33
  34         while (*ptr != sym)
  35                 ptr = &(*ptr)->next_id;
  36         *ptr = sym->next_id;
  37 }
  38
  39 void end_symbol_scope(void)
  40 {
  41         struct scope *scope = current_scope;
  42         struct symbol_list *symbols = scope->symbols;
  43
  44         current_scope = scope->next;
  45         scope->symbols = NULL;
  46         symbol_iterate(symbols, remove_symbol_scope);
  47 }