scope.c

   1 /*
   2  * Symbol scoping.
   3  *
   4  * This is pretty trivial.
   5  *
   6  * Copyright (C) 2003 Transmeta Corp, all rights reserved.
   7  */
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 #include "lib.h"
  12 #include "symbol.h"
  13 #include "scope.h"
  14
  15 static struct scope toplevel_scope = { .next = &toplevel_scope };
  16
  17 struct scope    *block_scope = &toplevel_scope,
  18                 *function_scope = &toplevel_scope,
  19                 *file_scope = &toplevel_scope;
  20
  21 void bind_scope(struct symbol *sym, struct scope *scope)
  22 {
  23         sym->scope = scope;
  24         add_symbol(&scope->symbols, sym);
  25 }
  26
  27 static void start_scope(struct scope **s)
  28 {
  29         struct scope *scope = __alloc_bytes(sizeof(*scope));
  30         memset(scope, 0, sizeof(*scope));
  31         scope->next = *s;
  32         *s = scope;
  33 }
  34
  35 void start_symbol_scope(void)
  36 {
  37         start_scope(&block_scope);
  38 }
  39
  40 void start_function_scope(void)
  41 {
  42         start_scope(&function_scope);
  43         start_scope(&block_scope);
  44 }
  45
  46 static void remove_symbol_scope(struct symbol *sym, void *data, int flags)
  47 {
  48         struct symbol **ptr = sym->id_list;
  49
  50         while (*ptr != sym)
  51                 ptr = &(*ptr)->next_id;
  52         *ptr = sym->next_id;
  53 }
  54
  55 static void end_scope(struct scope **s)
  56 {
  57         struct scope *scope = *s;
  58         struct symbol_list *symbols = scope->symbols;
  59
  60         *s = scope->next;
  61         scope->symbols = NULL;
  62         symbol_iterate(symbols, remove_symbol_scope, NULL);
  63 }
  64
  65 void end_symbol_scope(void)
  66 {
  67         end_scope(&block_scope);
  68 }
  69
  70 void end_function_scope(void)
  71 {
  72         end_scope(&block_scope);
  73         end_scope(&function_scope);
  74 }