expression.h

   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 enum {
  70         Int_const_expr = 1,
  71         Float_literal = 2,
  72 }; /* for expr->flags */
  73
  74 enum {
  75         Taint_comma = 1,
  76 }; /* for expr->taint */
  77
  78 struct expression {
  79         enum expression_type type:8;
  80         unsigned flags:8;
  81         int op;
  82         struct position pos;
  83         struct symbol *ctype;
  84         union {
  85                 // EXPR_VALUE
  86                 struct {
  87                         unsigned long long value;
  88                         unsigned taint;
  89                 };
  90
  91                 // EXPR_FVALUE
  92                 long double fvalue;
  93
  94                 // EXPR_STRING
  95                 struct {
  96                         int wide;
  97                         struct string *string;
  98                 };
  99
 100                 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
 101                 struct /* unop */ {
 102                         struct expression *unop;
 103                         unsigned long op_value;
 104                 };
 105
 106                 // EXPR_SYMBOL, EXPR_TYPE
 107                 struct /* symbol_arg */ {
 108                         struct symbol *symbol;
 109                         struct ident *symbol_name;
 110                 };
 111
 112                 // EXPR_STATEMENT
 113                 struct statement *statement;
 114
 115                 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
 116                 struct /* binop_arg */ {
 117                         struct expression *left, *right;
 118                 };
 119                 // EXPR_DEREF
 120                 struct /* deref_arg */ {
 121                         struct expression *deref;
 122                         struct ident *member;
 123                 };
 124                 // EXPR_SLICE
 125                 struct /* slice */ {
 126                         struct expression *base;
 127                         unsigned r_bitpos, r_nrbits;
 128                 };
 129                 // EXPR_CAST and EXPR_SIZEOF
 130                 struct /* cast_arg */ {
 131                         struct symbol *cast_type;
 132                         struct expression *cast_expression;
 133                 };
 134                 // EXPR_CONDITIONAL
 135                 // EXPR_SELECT
 136                 struct /* conditional_expr */ {
 137                         struct expression *conditional, *cond_true, *cond_false;
 138                 };
 139                 // EXPR_CALL
 140                 struct /* call_expr */ {
 141                         struct expression *fn;
 142                         struct expression_list *args;
 143                 };
 144                 // EXPR_LABEL
 145                 struct /* label_expr */ {
 146                         struct symbol *label_symbol;
 147                 };
 148                 // EXPR_INITIALIZER
 149                 struct expression_list *expr_list;
 150                 // EXPR_IDENTIFIER
 151                 struct /* ident_expr */ {
 152                         int offset;
 153                         struct ident *expr_ident;
 154                         struct symbol *field;
 155                         struct expression *ident_expression;
 156                 };
 157                 // EXPR_INDEX
 158                 struct /* index_expr */ {
 159                         unsigned int idx_from, idx_to;
 160                         struct expression *idx_expression;
 161                 };
 162                 // EXPR_POS
 163                 struct /* initpos_expr */ {
 164                         unsigned int init_offset, init_nr;
 165                         struct expression *init_expr;
 166                 };
 167                 // EXPR_OFFSETOF
 168                 struct {
 169                         struct symbol *in;
 170                         struct expression *down;
 171                         union {
 172                                 struct ident *ident;
 173                                 struct expression *index;
 174                         };
 175                 };
 176         };
 177 };
 178
 179 /* Constant expression values */
 180 int is_zero_constant(struct expression *);
 181 long long get_expression_value(struct expression *);
 182 long long const_expression_value(struct expression *);
 183 long long get_expression_value_silent(struct expression *expr);
 184
 185 /* Expression parsing */
 186 struct token *parse_expression(struct token *token, struct expression **tree);
 187 struct token *conditional_expression(struct token *token, struct expression **tree);
 188 struct token *primary_expression(struct token *token, struct expression **tree);
 189 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
 190 struct token *assignment_expression(struct token *token, struct expression **tree);
 191
 192 extern void evaluate_symbol_list(struct symbol_list *list);
 193 extern struct symbol *evaluate_statement(struct statement *stmt);
 194 extern struct symbol *evaluate_expression(struct expression *);
 195
 196 extern int expand_symbol(struct symbol *);
 197
 198 static inline struct expression *alloc_expression(struct position pos, int type)
 199 {
 200         struct expression *expr = __alloc_expression(0);
 201         expr->type = type;
 202         expr->pos = pos;
 203         return expr;
 204 }
 205
 206 static inline struct expression *alloc_const_expression(struct position pos, int value)
 207 {
 208         struct expression *expr = __alloc_expression(0);
 209         expr->type = EXPR_VALUE;
 210         expr->pos = pos;
 211         expr->value = value;
 212         expr->ctype = &int_ctype;
 213         return expr;
 214 }
 215
 216 /* Type name parsing */
 217 struct token *typename(struct token *, struct symbol **, int *);
 218
 219 static inline int lookup_type(struct token *token)
 220 {
 221         if (token->pos.type == TOKEN_IDENT) {
 222                 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
 223                 return sym && (sym->namespace & NS_TYPEDEF);
 224         }
 225         return 0;
 226 }
 227
 228 /* Statement parsing */
 229 struct statement *alloc_statement(struct position pos, int type);
 230 struct token *initializer(struct expression **tree, struct token *token);
 231 struct token *compound_statement(struct token *, struct statement *);
 232
 233 /* The preprocessor calls this 'constant_expression()' */
 234 #define constant_expression(token,tree) conditional_expression(token, tree)
 235
 236 /* Cast folding of constant values.. */
 237 void cast_value(struct expression *expr, struct symbol *newtype,
 238         struct expression *old, struct symbol *oldtype);
 239
 240 #endif