math: use comparisons to handle subtraction better
[smatch.git] / scope.c
blob3d0bb7f78b08dc30dc52253088e276de4d7cb045
1 /*
2 * Symbol scoping.
4 * This is pretty trivial.
6 * Copyright (C) 2003 Transmeta Corp.
7 * 2003-2004 Linus Torvalds
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:
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
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.
27 #include <stdlib.h>
28 #include <string.h>
29 #include <stdio.h>
31 #include "lib.h"
32 #include "allocate.h"
33 #include "symbol.h"
34 #include "scope.h"
36 static struct scope builtin_scope = { .next = &builtin_scope };
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
43 void bind_scope(struct symbol *sym, struct scope *scope)
45 sym->scope = scope;
46 add_symbol(&scope->symbols, sym);
49 void rebind_scope(struct symbol *sym, struct scope *new)
51 struct scope *old = sym->scope;
53 if (old == new)
54 return;
56 if (old)
57 delete_ptr_list_entry((struct ptr_list**) &old->symbols, sym, 1);
59 bind_scope(sym, new);
62 static void start_scope(struct scope **s, struct position pos)
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;
72 void start_file_scope(void)
74 struct scope *scope = __alloc_scope(0);
76 memset(scope, 0, sizeof(*scope));
77 scope->next = &builtin_scope;
78 file_scope = scope;
80 /* top-level stuff defaults to file scope, "extern" etc will choose global scope */
81 function_scope = scope;
82 block_scope = scope;
85 void start_symbol_scope(struct position pos)
87 start_scope(&block_scope, pos);
90 void start_function_scope(struct position pos)
92 start_scope(&function_scope, pos);
93 start_scope(&block_scope, pos);
96 static void remove_symbol_scope(struct symbol *sym)
98 struct symbol **ptr = &sym->ident->symbols;
100 while (*ptr != sym)
101 ptr = &(*ptr)->next_id;
102 *ptr = sym->next_id;
105 static void end_scope(struct scope **s)
107 struct scope *scope = *s;
108 struct symbol_list *symbols = scope->symbols;
109 struct symbol *sym;
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);
118 void end_file_scope(void)
120 end_scope(&file_scope);
123 void new_file_scope(void)
125 if (file_scope != &builtin_scope)
126 end_file_scope();
127 start_file_scope();
130 void end_symbol_scope(void)
132 end_scope(&block_scope);
135 void end_function_scope(void)
137 end_scope(&block_scope);
138 end_scope(&function_scope);
141 int is_outer_scope(struct scope *scope)
143 if (scope == block_scope)
144 return 0;
145 if (scope == &builtin_scope && block_scope->next == &builtin_scope)
146 return 0;
147 return 1;