check_unused_ret.c: ignore unreachable assignments
[smatch.git] / symbol.h
blobe5673057792c8bc8abb4e3eb908cc31208216dd5
1 #ifndef SYMBOL_H
2 #define SYMBOL_H
3 /*
4 * Basic symbol and namespace definitions.
6 * Copyright (C) 2003 Transmeta Corp.
7 * 2003 Linus Torvalds
9 * Licensed under the Open Software License version 1.1
12 #include "token.h"
13 #include "target.h"
16 * An identifier with semantic meaning is a "symbol".
18 * There's a 1:n relationship: each symbol is always
19 * associated with one identifier, while each identifier
20 * can have one or more semantic meanings due to C scope
21 * rules.
23 * The progression is symbol -> token -> identifier. The
24 * token contains the information on where the symbol was
25 * declared.
27 enum namespace {
28 NS_NONE = 0,
29 NS_MACRO = 1,
30 NS_TYPEDEF = 2,
31 NS_STRUCT = 4, // Also used for unions and enums.
32 NS_LABEL = 8,
33 NS_SYMBOL = 16,
34 NS_ITERATOR = 32,
35 NS_PREPROCESSOR = 64,
36 NS_UNDEF = 128,
37 NS_KEYWORD = 256,
40 enum type {
41 SYM_UNINITIALIZED,
42 SYM_PREPROCESSOR,
43 SYM_BASETYPE,
44 SYM_NODE,
45 SYM_PTR,
46 SYM_FN,
47 SYM_ARRAY,
48 SYM_STRUCT,
49 SYM_UNION,
50 SYM_ENUM,
51 SYM_TYPEDEF,
52 SYM_TYPEOF,
53 SYM_MEMBER,
54 SYM_BITFIELD,
55 SYM_LABEL,
56 SYM_RESTRICT,
57 SYM_FOULED,
58 SYM_KEYWORD,
59 SYM_BAD,
62 enum keyword {
63 KW_SPECIFIER = 1 << 0,
64 KW_MODIFIER = 1 << 1,
65 KW_QUALIFIER = 1 << 2,
66 KW_ATTRIBUTE = 1 << 3,
67 KW_STATEMENT = 1 << 4,
68 KW_ASM = 1 << 5,
69 KW_MODE = 1 << 6,
70 KW_SHORT = 1 << 7,
71 KW_LONG = 1 << 8,
72 KW_EXACT = 1 << 9,
75 struct context {
76 struct expression *context;
77 unsigned int in, out;
80 extern struct context *alloc_context(void);
82 DECLARE_PTR_LIST(context_list, struct context);
84 struct ctype {
85 unsigned long modifiers;
86 unsigned long alignment;
87 struct context_list *contexts;
88 unsigned int as;
89 struct symbol *base_type;
92 struct decl_state {
93 struct ctype ctype;
94 struct ident **ident;
95 struct symbol_op *mode;
96 unsigned char prefer_abstract, is_inline, storage_class, is_tls;
99 struct symbol_op {
100 enum keyword type;
101 int (*evaluate)(struct expression *);
102 int (*expand)(struct expression *, int);
103 int (*args)(struct expression *);
105 /* keywords */
106 struct token *(*declarator)(struct token *token, struct decl_state *ctx);
107 struct token *(*statement)(struct token *token, struct statement *stmt);
108 struct token *(*toplevel)(struct token *token, struct symbol_list **list);
109 struct token *(*attribute)(struct token *token, struct symbol *attr, struct decl_state *ctx);
110 struct symbol *(*to_mode)(struct symbol *);
112 int test, set, class;
115 extern int expand_safe_p(struct expression *expr, int cost);
116 extern int expand_constant_p(struct expression *expr, int cost);
118 #define SYM_ATTR_WEAK 0
119 #define SYM_ATTR_NORMAL 1
120 #define SYM_ATTR_STRONG 2
122 struct symbol {
123 enum type type:8;
124 enum namespace namespace:9;
125 unsigned char used:1, attr:2, enum_member:1, bound:1;
126 struct position pos; /* Where this symbol was declared */
127 struct position endpos; /* Where this symbol ends*/
128 struct ident *ident; /* What identifier this symbol is associated with */
129 struct symbol *next_id; /* Next semantic symbol that shares this identifier */
130 struct symbol *replace; /* What is this symbol shadowed by in copy-expression */
131 struct scope *scope;
132 union {
133 struct symbol *same_symbol;
134 struct symbol *next_subobject;
137 struct symbol_op *op;
139 union {
140 struct /* NS_MACRO */ {
141 struct token *expansion;
142 struct token *arglist;
143 struct scope *used_in;
145 struct /* NS_PREPROCESSOR */ {
146 int (*handler)(struct stream *, struct token **, struct token *);
147 int normal;
149 struct /* NS_SYMBOL */ {
150 unsigned long offset;
151 int bit_size;
152 unsigned int bit_offset:8,
153 arg_count:10,
154 variadic:1,
155 initialized:1,
156 examined:1,
157 expanding:1,
158 evaluated:1,
159 string:1,
160 designated_init:1;
161 struct expression *array_size;
162 struct ctype ctype;
163 struct symbol_list *arguments;
164 struct statement *stmt;
165 struct symbol_list *symbol_list;
166 struct statement *inline_stmt;
167 struct symbol_list *inline_symbol_list;
168 struct expression *initializer;
169 struct entrypoint *ep;
170 long long value; /* Initial value */
171 struct symbol *definition;
174 union /* backend */ {
175 struct basic_block *bb_target; /* label */
176 void *aux; /* Auxiliary info, e.g. backend information */
177 struct { /* sparse ctags */
178 char kind;
179 unsigned char visited:1;
182 pseudo_t pseudo;
185 /* Modifiers */
186 #define MOD_AUTO 0x0001
187 #define MOD_REGISTER 0x0002
188 #define MOD_STATIC 0x0004
189 #define MOD_EXTERN 0x0008
191 #define MOD_CONST 0x0010
192 #define MOD_VOLATILE 0x0020
193 #define MOD_SIGNED 0x0040
194 #define MOD_UNSIGNED 0x0080
196 #define MOD_CHAR 0x0100
197 #define MOD_SHORT 0x0200
198 #define MOD_LONG 0x0400
199 #define MOD_LONGLONG 0x0800
200 #define MOD_LONGLONGLONG 0x1000
202 #define MOD_TYPEDEF 0x10000
204 #define MOD_TLS 0x20000
205 #define MOD_INLINE 0x40000
206 #define MOD_ADDRESSABLE 0x80000
208 #define MOD_NOCAST 0x100000
209 #define MOD_NODEREF 0x200000
210 #define MOD_ACCESSED 0x400000
211 #define MOD_TOPLEVEL 0x800000 // scoping..
213 #define MOD_ASSIGNED 0x2000000
214 #define MOD_TYPE 0x4000000
215 #define MOD_SAFE 0x8000000 // non-null/non-trapping pointer
217 #define MOD_USERTYPE 0x10000000
218 #define MOD_NORETURN 0x20000000
219 #define MOD_EXPLICITLY_SIGNED 0x40000000
220 #define MOD_BITWISE 0x80000000
223 #define MOD_NONLOCAL (MOD_EXTERN | MOD_TOPLEVEL)
224 #define MOD_STORAGE (MOD_AUTO | MOD_REGISTER | MOD_STATIC | MOD_EXTERN | MOD_INLINE | MOD_TOPLEVEL)
225 #define MOD_SIGNEDNESS (MOD_SIGNED | MOD_UNSIGNED | MOD_EXPLICITLY_SIGNED)
226 #define MOD_LONG_ALL (MOD_LONG | MOD_LONGLONG | MOD_LONGLONGLONG)
227 #define MOD_SPECIFIER (MOD_CHAR | MOD_SHORT | MOD_LONG_ALL | MOD_SIGNEDNESS)
228 #define MOD_SIZE (MOD_CHAR | MOD_SHORT | MOD_LONG_ALL)
229 #define MOD_IGNORE (MOD_TOPLEVEL | MOD_STORAGE | MOD_ADDRESSABLE | \
230 MOD_ASSIGNED | MOD_USERTYPE | MOD_ACCESSED | MOD_EXPLICITLY_SIGNED)
231 #define MOD_PTRINHERIT (MOD_VOLATILE | MOD_CONST | MOD_NODEREF | MOD_STORAGE | MOD_NORETURN)
234 /* Current parsing/evaluation function */
235 extern struct symbol *current_fn;
237 /* Abstract types */
238 extern struct symbol int_type,
239 fp_type;
241 /* C types */
242 extern struct symbol bool_ctype, void_ctype, type_ctype,
243 char_ctype, schar_ctype, uchar_ctype,
244 short_ctype, sshort_ctype, ushort_ctype,
245 int_ctype, sint_ctype, uint_ctype,
246 long_ctype, slong_ctype, ulong_ctype,
247 llong_ctype, sllong_ctype, ullong_ctype,
248 lllong_ctype, slllong_ctype, ulllong_ctype,
249 float_ctype, double_ctype, ldouble_ctype,
250 string_ctype, ptr_ctype, lazy_ptr_ctype,
251 incomplete_ctype, label_ctype, bad_ctype,
252 null_ctype;
254 /* Special internal symbols */
255 extern struct symbol zero_int;
257 #define __IDENT(n,str,res) \
258 extern struct ident n
259 #include "ident-list.h"
261 #define symbol_is_typename(sym) ((sym)->type == SYM_TYPE)
263 extern struct symbol_list *translation_unit_used_list;
265 extern void access_symbol(struct symbol *);
267 extern const char * type_difference(struct ctype *c1, struct ctype *c2,
268 unsigned long mod1, unsigned long mod2);
270 extern struct symbol *lookup_symbol(struct ident *, enum namespace);
271 extern struct symbol *create_symbol(int stream, const char *name, int type, int namespace);
272 extern void init_symbols(void);
273 extern void init_ctype(void);
274 extern struct symbol *alloc_symbol(struct position, int type);
275 extern void show_type(struct symbol *);
276 extern const char *modifier_string(unsigned long mod);
277 extern void show_symbol(struct symbol *);
278 extern int show_symbol_expr_init(struct symbol *sym);
279 extern void show_type_list(struct symbol *);
280 extern void show_symbol_list(struct symbol_list *, const char *);
281 extern void add_symbol(struct symbol_list **, struct symbol *);
282 extern void bind_symbol(struct symbol *, struct ident *, enum namespace);
284 extern struct symbol *examine_symbol_type(struct symbol *);
285 extern struct symbol *examine_pointer_target(struct symbol *);
286 extern void examine_simple_symbol_type(struct symbol *);
287 extern const char *show_typename(struct symbol *sym);
288 extern const char *builtin_typename(struct symbol *sym);
289 extern const char *builtin_ctypename(struct ctype *ctype);
290 extern const char* get_type_name(enum type type);
292 extern void debug_symbol(struct symbol *);
293 extern void merge_type(struct symbol *sym, struct symbol *base_type);
294 extern void check_declaration(struct symbol *sym);
296 static inline struct symbol *get_base_type(const struct symbol *sym)
298 return examine_symbol_type(sym->ctype.base_type);
301 static inline int is_int_type(const struct symbol *type)
303 if (type->type == SYM_NODE)
304 type = type->ctype.base_type;
305 if (type->type == SYM_ENUM)
306 type = type->ctype.base_type;
307 return type->type == SYM_BITFIELD ||
308 type->ctype.base_type == &int_type;
311 static inline int is_enum_type(const struct symbol *type)
313 if (type->type == SYM_NODE)
314 type = type->ctype.base_type;
315 return (type->type == SYM_ENUM);
318 static inline int is_type_type(struct symbol *type)
320 return (type->ctype.modifiers & MOD_TYPE) != 0;
323 static inline int is_ptr_type(struct symbol *type)
325 if (type->type == SYM_NODE)
326 type = type->ctype.base_type;
327 return type->type == SYM_PTR || type->type == SYM_ARRAY || type->type == SYM_FN;
330 static inline int is_float_type(struct symbol *type)
332 if (type->type == SYM_NODE)
333 type = type->ctype.base_type;
334 return type->ctype.base_type == &fp_type;
337 static inline int is_byte_type(struct symbol *type)
339 return type->bit_size == bits_in_char && type->type != SYM_BITFIELD;
342 static inline int is_void_type(struct symbol *type)
344 if (type->type == SYM_NODE)
345 type = type->ctype.base_type;
346 return type == &void_ctype;
349 static inline int is_function(struct symbol *type)
351 return type && type->type == SYM_FN;
354 static inline int is_extern_inline(struct symbol *sym)
356 return (sym->ctype.modifiers & MOD_EXTERN) &&
357 (sym->ctype.modifiers & MOD_INLINE) &&
358 is_function(sym->ctype.base_type);
361 static inline int get_sym_type(struct symbol *type)
363 if (type->type == SYM_NODE)
364 type = type->ctype.base_type;
365 if (type->type == SYM_ENUM)
366 type = type->ctype.base_type;
367 return type->type;
370 static inline struct symbol *lookup_keyword(struct ident *ident, enum namespace ns)
372 if (!ident->keyword)
373 return NULL;
374 return lookup_symbol(ident, ns);
377 #define is_restricted_type(type) (get_sym_type(type) == SYM_RESTRICT)
378 #define is_fouled_type(type) (get_sym_type(type) == SYM_FOULED)
379 #define is_bitfield_type(type) (get_sym_type(type) == SYM_BITFIELD)
380 extern int is_ptr_type(struct symbol *);
382 void create_fouled(struct symbol *type);
383 struct symbol *befoul(struct symbol *type);
385 #endif /* SYMBOL_H */