scope.c

   1 /*
   2  * Symbol scoping.
   3  *
   4  * This is pretty trivial.
   5  *
   6  * Copyright (C) 2003 Transmeta Corp.
   7  *
   8  *  Licensed under the Open Software License version 1.1
   9  */
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 #include "lib.h"
  14 #include "symbol.h"
  15 #include "scope.h"
  16
  17 static struct scope toplevel_scope = { .next = &toplevel_scope };
  18
  19 struct scope    *block_scope = &toplevel_scope,
  20                 *function_scope = &toplevel_scope,
  21                 *file_scope = &toplevel_scope;
  22
  23 void bind_scope(struct symbol *sym, struct scope *scope)
  24 {
  25         sym->scope = scope;
  26         add_symbol(&scope->symbols, sym);
  27 }
  28
  29 static void start_scope(struct scope **s)
  30 {
  31         struct scope *scope = __alloc_scope(0);
  32         memset(scope, 0, sizeof(*scope));
  33         scope->next = *s;
  34         *s = scope;
  35 }
  36
  37 void start_symbol_scope(void)
  38 {
  39         start_scope(&block_scope);
  40 }
  41
  42 void start_function_scope(void)
  43 {
  44         start_scope(&function_scope);
  45         start_scope(&block_scope);
  46 }
  47
  48 static void remove_symbol_scope(struct symbol *sym)
  49 {
  50         struct symbol **ptr = sym->id_list;
  51
  52         while (*ptr != sym)
  53                 ptr = &(*ptr)->next_id;
  54         *ptr = sym->next_id;
  55 }
  56
  57 static void end_scope(struct scope **s)
  58 {
  59         struct scope *scope = *s;
  60         struct symbol_list *symbols = scope->symbols;
  61         struct symbol *sym;
  62
  63         *s = scope->next;
  64         scope->symbols = NULL;
  65         FOR_EACH_PTR(symbols, sym) {
  66                 remove_symbol_scope(sym);
  67         } END_FOR_EACH_PTR;
  68 }
  69
  70 void end_symbol_scope(void)
  71 {
  72         end_scope(&block_scope);
  73 }
  74
  75 void end_function_scope(void)
  76 {
  77         end_scope(&block_scope);
  78         end_scope(&function_scope);
  79 }