1 /*
2 * Symbol scoping.
3 *
4 * This is pretty trivial.
5 *
6 * Copyright (C) 2003 Transmeta Corp.
7 * 2003-2004 Linus Torvalds
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27 #include <stdlib.h>
28 #include <string.h>
29 #include <stdio.h>
30
31 #include "lib.h"
32 #include "allocate.h"
33 #include "symbol.h"
34 #include "scope.h"
35
36 static struct scope builtin_scope = { .next = &builtin_scope };
37
38 struct scope *block_scope = &builtin_scope, // regular automatic variables etc
39 *function_scope = &builtin_scope, // labels, arguments etc
40 *file_scope = &builtin_scope, // static
41 *global_scope = &builtin_scope; // externally visible
42
bind_scope(struct symbol * sym,struct scope * scope)43 void bind_scope(struct symbol *sym, struct scope *scope)
44 {
45 sym->scope = scope;
46 add_symbol(&scope->symbols, sym);
47 }
48
rebind_scope(struct symbol * sym,struct scope * new)49 void rebind_scope(struct symbol *sym, struct scope *new)
50 {
51 struct scope *old = sym->scope;
52
53 if (old == new)
54 return;
55
56 if (old)
57 delete_ptr_list_entry((struct ptr_list**) &old->symbols, sym, 1);
58
59 bind_scope(sym, new);
60 }
61
start_scope(struct scope ** s,struct position pos)62 static void start_scope(struct scope **s, struct position pos)
63 {
64 struct scope *scope = __alloc_scope(0);
65 memset(scope, 0, sizeof(*scope));
66 scope->token = __alloc_token(0);
67 scope->token->pos = pos;
68 scope->next = *s;
69 *s = scope;
70 }
71
start_file_scope(void)72 void start_file_scope(void)
73 {
74 struct scope *scope = __alloc_scope(0);
75
76 memset(scope, 0, sizeof(*scope));
77 scope->next = &builtin_scope;
78 file_scope = scope;
79
80 /* top-level stuff defaults to file scope, "extern" etc will choose global scope */
81 function_scope = scope;
82 block_scope = scope;
83 }
84
start_symbol_scope(struct position pos)85 void start_symbol_scope(struct position pos)
86 {
87 start_scope(&block_scope, pos);
88 }
89
start_function_scope(struct position pos)90 void start_function_scope(struct position pos)
91 {
92 start_scope(&function_scope, pos);
93 start_scope(&block_scope, pos);
94 }
95
remove_symbol_scope(struct symbol * sym)96 static void remove_symbol_scope(struct symbol *sym)
97 {
98 struct symbol **ptr = &sym->ident->symbols;
99
100 while (*ptr != sym)
101 ptr = &(*ptr)->next_id;
102 *ptr = sym->next_id;
103 }
104
end_scope(struct scope ** s)105 static void end_scope(struct scope **s)
106 {
107 struct scope *scope = *s;
108 struct symbol_list *symbols = scope->symbols;
109 struct symbol *sym;
110
111 *s = scope->next;
112 scope->symbols = NULL;
113 FOR_EACH_PTR(symbols, sym) {
114 remove_symbol_scope(sym);
115 } END_FOR_EACH_PTR(sym);
116 }
117
end_file_scope(void)118 void end_file_scope(void)
119 {
120 end_scope(&file_scope);
121 }
122
new_file_scope(void)123 void new_file_scope(void)
124 {
125 if (file_scope != &builtin_scope)
126 end_file_scope();
127 start_file_scope();
128 }
129
end_symbol_scope(void)130 void end_symbol_scope(void)
131 {
132 end_scope(&block_scope);
133 }
134
end_function_scope(void)135 void end_function_scope(void)
136 {
137 end_scope(&block_scope);
138 end_scope(&function_scope);
139 }
140
is_outer_scope(struct scope * scope)141 int is_outer_scope(struct scope *scope)
142 {
143 if (scope == block_scope)
144 return 0;
145 if (scope == &builtin_scope && block_scope->next == &builtin_scope)
146 return 0;
147 return 1;
148 }
149
150