free: ignore impossible code
[smatch.git] / expression.h
blob4964af30de30f7434e1902dedc4a2a95682f9fa1
1 #ifndef EXPRESSION_H
2 #define EXPRESSION_H
3 /*
4 * sparse/expression.h
6 * Copyright (C) 2003 Transmeta Corp.
7 * 2003 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 * Declarations and helper functions for expression parsing.
30 #include "allocate.h"
31 #include "lib.h"
32 #include "symbol.h"
34 struct expression_list;
36 enum expression_type {
37 EXPR_VALUE = 1,
38 EXPR_STRING,
39 EXPR_SYMBOL,
40 EXPR_TYPE,
41 EXPR_BINOP,
42 EXPR_ASSIGNMENT,
43 EXPR_LOGICAL,
44 EXPR_DEREF,
45 EXPR_PREOP,
46 EXPR_POSTOP,
47 EXPR_CAST,
48 EXPR_FORCE_CAST,
49 EXPR_IMPLIED_CAST,
50 EXPR_SIZEOF,
51 EXPR_ALIGNOF,
52 EXPR_PTRSIZEOF,
53 EXPR_CONDITIONAL,
54 EXPR_SELECT, // a "safe" conditional expression
55 EXPR_STATEMENT,
56 EXPR_CALL,
57 EXPR_COMMA,
58 EXPR_COMPARE,
59 EXPR_LABEL,
60 EXPR_INITIALIZER, // initializer list
61 EXPR_IDENTIFIER, // identifier in initializer
62 EXPR_INDEX, // index in initializer
63 EXPR_POS, // position in initializer
64 EXPR_FVALUE,
65 EXPR_SLICE,
66 EXPR_OFFSETOF,
69 enum {
70 Int_const_expr = 1,
71 Float_literal = 2,
72 }; /* for expr->flags */
74 enum {
75 Handled = 1,
76 }; /* for expr->flags */
78 enum {
79 Taint_comma = 1,
80 }; /* for expr->taint */
82 struct expression {
83 struct expression *parent;
84 enum expression_type type:8;
85 unsigned flags:8;
86 unsigned smatch_flags:16;
87 int op;
88 struct position pos;
89 struct symbol *ctype;
90 union {
91 // EXPR_VALUE
92 struct {
93 unsigned long long value;
94 unsigned taint;
97 // EXPR_FVALUE
98 long double fvalue;
100 // EXPR_STRING
101 struct {
102 int wide;
103 struct string *string;
106 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
107 struct /* unop */ {
108 struct expression *unop;
109 unsigned long op_value;
112 // EXPR_SYMBOL, EXPR_TYPE
113 struct /* symbol_arg */ {
114 struct symbol *symbol;
115 struct ident *symbol_name;
118 // EXPR_STATEMENT
119 struct statement *statement;
121 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
122 struct /* binop_arg */ {
123 struct expression *left, *right;
125 // EXPR_DEREF
126 struct /* deref_arg */ {
127 struct expression *deref;
128 struct ident *member;
129 int member_offset;
131 // EXPR_SLICE
132 struct /* slice */ {
133 struct expression *base;
134 unsigned r_bitpos, r_nrbits;
136 // EXPR_CAST and EXPR_SIZEOF
137 struct /* cast_arg */ {
138 struct symbol *cast_type;
139 struct expression *cast_expression;
141 // EXPR_CONDITIONAL
142 // EXPR_SELECT
143 struct /* conditional_expr */ {
144 struct expression *conditional, *cond_true, *cond_false;
146 // EXPR_CALL
147 struct /* call_expr */ {
148 struct expression *fn;
149 struct expression_list *args;
151 // EXPR_LABEL
152 struct /* label_expr */ {
153 struct symbol *label_symbol;
155 // EXPR_INITIALIZER
156 struct expression_list *expr_list;
157 // EXPR_IDENTIFIER
158 struct /* ident_expr */ {
159 int offset;
160 struct ident *expr_ident;
161 struct symbol *field;
162 struct expression *ident_expression;
164 // EXPR_INDEX
165 struct /* index_expr */ {
166 unsigned int idx_from, idx_to;
167 struct expression *idx_expression;
169 // EXPR_POS
170 struct /* initpos_expr */ {
171 unsigned int init_offset, init_nr;
172 struct expression *init_expr;
174 // EXPR_OFFSETOF
175 struct {
176 struct symbol *in;
177 struct expression *down;
178 union {
179 struct ident *ident;
180 struct expression *index;
186 /* Constant expression values */
187 int is_zero_constant(struct expression *);
188 long long get_expression_value(struct expression *);
189 long long const_expression_value(struct expression *);
190 long long get_expression_value_silent(struct expression *expr);
192 /* Expression parsing */
193 struct token *parse_expression(struct token *token, struct expression **tree);
194 struct token *conditional_expression(struct token *token, struct expression **tree);
195 struct token *primary_expression(struct token *token, struct expression **tree);
196 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
197 struct token *assignment_expression(struct token *token, struct expression **tree);
199 extern void evaluate_symbol_list(struct symbol_list *list);
200 extern struct symbol *evaluate_statement(struct statement *stmt);
201 extern struct symbol *evaluate_expression(struct expression *);
203 extern int expand_symbol(struct symbol *);
205 static inline struct expression *alloc_expression(struct position pos, int type)
207 struct expression *expr = __alloc_expression(0);
208 expr->type = type;
209 expr->pos = pos;
210 return expr;
213 static inline struct expression *alloc_const_expression(struct position pos, int value)
215 struct expression *expr = __alloc_expression(0);
216 expr->type = EXPR_VALUE;
217 expr->pos = pos;
218 expr->value = value;
219 expr->ctype = &int_ctype;
220 return expr;
223 /* Type name parsing */
224 struct token *typename(struct token *, struct symbol **, int *);
226 static inline int lookup_type(struct token *token)
228 if (token->pos.type == TOKEN_IDENT) {
229 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
230 return sym && (sym->namespace & NS_TYPEDEF);
232 return 0;
235 /* Statement parsing */
236 struct statement *alloc_statement(struct position pos, int type);
237 struct token *initializer(struct expression **tree, struct token *token);
238 struct token *compound_statement(struct token *, struct statement *);
240 /* The preprocessor calls this 'constant_expression()' */
241 #define constant_expression(token,tree) conditional_expression(token, tree)
243 /* Cast folding of constant values.. */
244 void cast_value(struct expression *expr, struct symbol *newtype,
245 struct expression *old, struct symbol *oldtype);
247 #endif