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 #include <stdio.h>
  14
  15 #include "lib.h"
  16 #include "allocate.h"
  17 #include "symbol.h"
  18 #include "scope.h"
  19
  20 static struct scope builtin_scope = { .next = &builtin_scope };
  21
  22 struct scope    *block_scope = &builtin_scope,          // regular automatic variables etc
  23                 *function_scope = &builtin_scope,       // labels, arguments etc
  24                 *file_scope = &builtin_scope,           // static
  25                 *global_scope = &builtin_scope;         // externally visible
  26
  27 void bind_scope(struct symbol *sym, struct scope *scope)
  28 {
  29         sym->scope = scope;
  30         add_symbol(&scope->symbols, sym);
  31 }
  32
  33 static void start_scope(struct scope **s)
  34 {
  35         struct scope *scope = __alloc_scope(0);
  36         memset(scope, 0, sizeof(*scope));
  37         scope->next = *s;
  38         *s = scope;
  39 }
  40
  41 void start_file_scope(void)
  42 {
  43         struct scope *scope = __alloc_scope(0);
  44         struct symbol *sym;
  45
  46         memset(scope, 0, sizeof(*scope));
  47         scope->next = &builtin_scope;
  48         file_scope = scope;
  49
  50         /* top-level stuff defaults to file scopt, "extern" etc will choose global scope */
  51         function_scope = scope;
  52         block_scope = scope;
  53
  54         /* Make the builtin macros visible again */
  55         FOR_EACH_PTR(builtin_scope.symbols, sym) {
  56                 if (sym->namespace == NS_INVISIBLEMACRO)
  57                         sym->namespace = NS_MACRO;
  58         } END_FOR_EACH_PTR(sym);
  59 }
  60
  61 void start_symbol_scope(void)
  62 {
  63         start_scope(&block_scope);
  64 }
  65
  66 void start_function_scope(void)
  67 {
  68         start_scope(&function_scope);
  69         start_scope(&block_scope);
  70 }
  71
  72 static void remove_symbol_scope(struct symbol *sym)
  73 {
  74         struct symbol **ptr = sym->id_list;
  75
  76         while (*ptr != sym)
  77                 ptr = &(*ptr)->next_id;
  78         *ptr = sym->next_id;
  79 }
  80
  81 static void end_scope(struct scope **s)
  82 {
  83         struct scope *scope = *s;
  84         struct symbol_list *symbols = scope->symbols;
  85         struct symbol *sym;
  86
  87         *s = scope->next;
  88         scope->symbols = NULL;
  89         FOR_EACH_PTR(symbols, sym) {
  90                 remove_symbol_scope(sym);
  91         } END_FOR_EACH_PTR(sym);
  92 }
  93
  94 void end_file_scope(void)
  95 {
  96         end_scope(&file_scope);
  97 }
  98
  99 void end_symbol_scope(void)
 100 {
 101         end_scope(&block_scope);
 102 }
 103
 104 void end_function_scope(void)
 105 {
 106         end_scope(&block_scope);
 107         end_scope(&function_scope);
 108 }