scope.c

   1 /*
   2  * Symbol scoping.
   3  *
   4  * This is pretty trivial.
   5  *
   6  * Copyright (C) 2003 Transmeta Corp.
   7  *               2003-2004 Linus Torvalds
   8  *
   9  *  Licensed under the Open Software License version 1.1
  10  */
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 #include "lib.h"
  15 #include "allocate.h"
  16 #include "symbol.h"
  17 #include "scope.h"
  18
  19 static struct scope toplevel_scope = { .next = &toplevel_scope };
  20
  21 struct scope    *block_scope = &toplevel_scope,
  22                 *function_scope = &toplevel_scope,
  23                 *file_scope = &toplevel_scope;
  24
  25 void bind_scope(struct symbol *sym, struct scope *scope)
  26 {
  27         sym->scope = scope;
  28         add_symbol(&scope->symbols, sym);
  29 }
  30
  31 static void start_scope(struct scope **s)
  32 {
  33         struct scope *scope = __alloc_scope(0);
  34         memset(scope, 0, sizeof(*scope));
  35         scope->next = *s;
  36         *s = scope;
  37 }
  38
  39 void start_symbol_scope(void)
  40 {
  41         start_scope(&block_scope);
  42 }
  43
  44 void start_function_scope(void)
  45 {
  46         start_scope(&function_scope);
  47         start_scope(&block_scope);
  48 }
  49
  50 static void remove_symbol_scope(struct symbol *sym)
  51 {
  52         struct symbol **ptr = sym->id_list;
  53
  54         while (*ptr != sym)
  55                 ptr = &(*ptr)->next_id;
  56         *ptr = sym->next_id;
  57 }
  58
  59 static void end_scope(struct scope **s)
  60 {
  61         struct scope *scope = *s;
  62         struct symbol_list *symbols = scope->symbols;
  63         struct symbol *sym;
  64
  65         *s = scope->next;
  66         scope->symbols = NULL;
  67         FOR_EACH_PTR(symbols, sym) {
  68                 remove_symbol_scope(sym);
  69         } END_FOR_EACH_PTR(sym);
  70 }
  71
  72 void end_symbol_scope(void)
  73 {
  74         end_scope(&block_scope);
  75 }
  76
  77 void end_function_scope(void)
  78 {
  79         end_scope(&block_scope);
  80         end_scope(&function_scope);
  81 }