1 #ifndef EXPRESSION_H 2 #define EXPRESSION_H 3 /* 4 * sparse/expression.h 5 * 6 * Copyright (C) 2003 Transmeta Corp. 7 * 2003 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 * Declarations and helper functions for expression parsing. 28 */ 29 30 #include "allocate.h" 31 #include "lib.h" 32 #include "symbol.h" 33 34 struct expression_list; 35 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, 67 }; 68 69 70 /* 71 * Flags for tracking the promotion of constness related attributes 72 * from subexpressions to their parents. 73 * 74 * The flags are not independent as one might imply another. 75 * The implications are as follows: 76 * - CEF_INT, CEF_ENUM and 77 * CEF_CHAR imply CEF_ICE. 78 * 79 * Use the CEF_*_SET_MASK and CEF_*_CLEAR_MASK 80 * helper macros defined below to set or clear one of these flags. 81 */ 82 enum constexpr_flag { 83 CEF_NONE = 0, 84 /* 85 * A constant in the sense of [6.4.4]: 86 * - Integer constant [6.4.4.1] 87 * - Floating point constant [6.4.4.2] 88 * - Enumeration constant [6.4.4.3] 89 * - Character constant [6.4.4.4] 90 */ 91 CEF_INT = (1 << 0), 92 CEF_FLOAT = (1 << 1), 93 CEF_ENUM = (1 << 2), 94 CEF_CHAR = (1 << 3), 95 96 /* 97 * A constant expression in the sense of [6.6]: 98 * - integer constant expression [6.6(6)] 99 * - arithmetic constant expression [6.6(8)] 100 * - address constant [6.6(9)] 101 */ 102 CEF_ICE = (1 << 4), 103 CEF_ACE = (1 << 5), 104 CEF_ADDR = (1 << 6), 105 106 /* integer constant expression => arithmetic constant expression */ 107 CEF_SET_ICE = (CEF_ICE | CEF_ACE), 108 109 /* integer constant => integer constant expression */ 110 CEF_SET_INT = (CEF_INT | CEF_SET_ICE), 111 112 /* floating point constant => arithmetic constant expression */ 113 CEF_SET_FLOAT = (CEF_FLOAT | CEF_ACE), 114 115 /* enumeration constant => integer constant expression */ 116 CEF_SET_ENUM = (CEF_ENUM | CEF_SET_ICE), 117 118 /* character constant => integer constant expression */ 119 CEF_SET_CHAR = (CEF_CHAR | CEF_SET_ICE), 120 121 /* 122 * Remove any "Constant" [6.4.4] flag, but retain the "constant 123 * expression" [6.6] flags. 124 */ 125 CEF_CONST_MASK = (CEF_INT | CEF_FLOAT | CEF_CHAR), 126 127 /* 128 * not an integer constant expression => neither of integer, 129 * enumeration and character constant 130 */ 131 CEF_CLR_ICE = (CEF_ICE | CEF_INT | CEF_ENUM | CEF_CHAR), 132 }; 133 134 enum { 135 Handled = 1 << 0, 136 Fake = 1 << 1, 137 }; /* for expr->flags */ 138 139 enum { 140 Taint_comma = 1, 141 }; /* for expr->taint */ 142 143 struct expression { 144 enum expression_type type:8; 145 unsigned flags:8; 146 unsigned smatch_flags:16; 147 int op; 148 struct position pos; 149 struct symbol *ctype; 150 unsigned long parent; 151 union { 152 // EXPR_VALUE 153 struct { 154 unsigned long long value; 155 unsigned taint; 156 }; 157 158 // EXPR_FVALUE 159 long double fvalue; 160 161 // EXPR_STRING 162 struct { 163 int wide; 164 struct string *string; 165 }; 166 167 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP 168 struct /* unop */ { 169 struct expression *unop; 170 unsigned long op_value; 171 }; 172 173 // EXPR_SYMBOL, EXPR_TYPE 174 struct /* symbol_arg */ { 175 struct symbol *symbol; 176 struct ident *symbol_name; 177 }; 178 179 // EXPR_STATEMENT 180 struct statement *statement; 181 182 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT 183 struct /* binop_arg */ { 184 struct expression *left, *right; 185 }; 186 // EXPR_DEREF 187 struct /* deref_arg */ { 188 struct expression *deref; 189 struct ident *member; 190 int member_offset; 191 }; 192 // EXPR_SLICE 193 struct /* slice */ { 194 struct expression *base; 195 unsigned r_bitpos, r_nrbits; 196 }; 197 // EXPR_CAST and EXPR_SIZEOF 198 struct /* cast_arg */ { 199 struct symbol *cast_type; 200 struct expression *cast_expression; 201 }; 202 // EXPR_CONDITIONAL 203 // EXPR_SELECT 204 struct /* conditional_expr */ { 205 struct expression *conditional, *cond_true, *cond_false; 206 }; 207 // EXPR_CALL 208 struct /* call_expr */ { 209 struct expression *fn; 210 struct expression_list *args; 211 }; 212 // EXPR_LABEL 213 struct /* label_expr */ { 214 struct symbol *label_symbol; 215 }; 216 // EXPR_INITIALIZER 217 struct expression_list *expr_list; 218 // EXPR_IDENTIFIER 219 struct /* ident_expr */ { 220 int offset; 221 struct ident *expr_ident; 222 struct symbol *field; 223 struct expression *ident_expression; 224 }; 225 // EXPR_INDEX 226 struct /* index_expr */ { 227 unsigned int idx_from, idx_to; 228 struct expression *idx_expression; 229 }; 230 // EXPR_POS 231 struct /* initpos_expr */ { 232 unsigned int init_offset, init_nr; 233 struct expression *init_expr; 234 }; 235 // EXPR_OFFSETOF 236 struct { 237 struct symbol *in; 238 struct expression *down; 239 union { 240 struct ident *ident; 241 struct expression *index; 242 }; 243 }; 244 }; 245 }; 246 247 /* Constant expression values */ 248 int is_zero_constant(struct expression *); 249 int expr_truth_value(struct expression *expr); 250 long long get_expression_value(struct expression *); 251 long long const_expression_value(struct expression *); 252 long long get_expression_value_silent(struct expression *expr); 253 254 /* Expression parsing */ 255 struct token *parse_expression(struct token *token, struct expression **tree); 256 struct token *conditional_expression(struct token *token, struct expression **tree); 257 struct token *primary_expression(struct token *token, struct expression **tree); 258 struct token *parens_expression(struct token *token, struct expression **expr, const char *where); 259 struct token *assignment_expression(struct token *token, struct expression **tree); 260 261 extern void evaluate_symbol_list(struct symbol_list *list); 262 extern struct symbol *evaluate_statement(struct statement *stmt); 263 extern struct symbol *evaluate_expression(struct expression *); 264 265 extern int expand_symbol(struct symbol *); 266 267 static inline struct expression *alloc_expression(struct position pos, int type) 268 { 269 struct expression *expr = __alloc_expression(0); 270 expr->type = type; 271 expr->pos = pos; 272 expr->flags = CEF_NONE; 273 return expr; 274 } 275 276 static inline struct expression *alloc_const_expression(struct position pos, int value) 277 { 278 struct expression *expr = __alloc_expression(0); 279 expr->type = EXPR_VALUE; 280 expr->pos = pos; 281 expr->value = value; 282 expr->ctype = &int_ctype; 283 expr->flags = CEF_SET_INT; 284 return expr; 285 } 286 287 /* Type name parsing */ 288 struct token *typename(struct token *, struct symbol **, int *); 289 290 static inline int lookup_type(struct token *token) 291 { 292 if (token->pos.type == TOKEN_IDENT) { 293 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF); 294 return sym && (sym->namespace & NS_TYPEDEF); 295 } 296 return 0; 297 } 298 299 /* Statement parsing */ 300 struct statement *alloc_statement(struct position pos, int type); 301 struct token *initializer(struct expression **tree, struct token *token); 302 struct token *compound_statement(struct token *, struct statement *); 303 304 /* The preprocessor calls this 'constant_expression()' */ 305 #define constant_expression(token,tree) conditional_expression(token, tree) 306 307 /* Cast folding of constant values.. */ 308 void cast_value(struct expression *expr, struct symbol *newtype, 309 struct expression *old, struct symbol *oldtype); 310 311 #endif 312