xref: /illumos-gate/usr/src/tools/smatch/src/scope.c (revision 1f5207b7)
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