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  *  Licensed under the Open Software License version 1.1
  10  *
  11  * Declarations and helper functions for expression parsing.
  12  */
  13
  14 #include "allocate.h"
  15
  16 struct expression_list;
  17
  18 enum expression_type {
  19         EXPR_VALUE = 1,
  20         EXPR_STRING,
  21         EXPR_SYMBOL,
  22         EXPR_TYPE,
  23         EXPR_BINOP,
  24         EXPR_ASSIGNMENT,
  25         EXPR_LOGICAL,
  26         EXPR_DEREF,
  27         EXPR_PREOP,
  28         EXPR_POSTOP,
  29         EXPR_CAST,
  30         EXPR_FORCE_CAST,
  31         EXPR_IMPLIED_CAST,
  32         EXPR_SIZEOF,
  33         EXPR_ALIGNOF,
  34         EXPR_PTRSIZEOF,
  35         EXPR_CONDITIONAL,
  36         EXPR_SELECT,            // a "safe" conditional expression
  37         EXPR_STATEMENT,
  38         EXPR_CALL,
  39         EXPR_COMMA,
  40         EXPR_COMPARE,
  41         EXPR_LABEL,
  42         EXPR_INITIALIZER,       // initializer list
  43         EXPR_IDENTIFIER,        // identifier in initializer
  44         EXPR_INDEX,             // index in initializer
  45         EXPR_POS,               // position in initializer
  46         EXPR_FVALUE,
  47         EXPR_SLICE,
  48         EXPR_OFFSETOF,
  49 };
  50
  51 enum {
  52         Int_const_expr = 1,
  53         Float_literal = 2,
  54 }; /* for expr->flags */
  55
  56 enum {
  57         Taint_comma = 1,
  58 };
  59
  60 struct expression {
  61         enum expression_type type:8;
  62         unsigned flags:8;
  63         int op;
  64         struct position pos;
  65         struct symbol *ctype;
  66         union {
  67                 // EXPR_VALUE
  68                 struct {
  69                         unsigned long long value;
  70                         unsigned taint;
  71                 };
  72
  73                 // EXPR_FVALUE
  74                 long double fvalue;
  75
  76                 // EXPR_STRING
  77                 struct string *string;
  78
  79                 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
  80                 struct /* unop */ {
  81                         struct expression *unop;
  82                         unsigned long op_value;
  83                 };
  84
  85                 // EXPR_SYMBOL, EXPR_TYPE
  86                 struct /* symbol_arg */ {
  87                         struct symbol *symbol;
  88                         struct ident *symbol_name;
  89                 };
  90
  91                 // EXPR_STATEMENT
  92                 struct statement *statement;
  93
  94                 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
  95                 struct /* binop_arg */ {
  96                         struct expression *left, *right;
  97                 };
  98                 // EXPR_DEREF
  99                 struct /* deref_arg */ {
 100                         struct expression *deref;
 101                         struct ident *member;
 102                 };
 103                 // EXPR_SLICE
 104                 struct /* slice */ {
 105                         struct expression *base;
 106                         unsigned r_bitpos, r_nrbits;
 107                 };
 108                 // EXPR_CAST and EXPR_SIZEOF
 109                 struct /* cast_arg */ {
 110                         struct symbol *cast_type;
 111                         struct expression *cast_expression;
 112                 };
 113                 // EXPR_CONDITIONAL
 114                 // EXPR_SELECT
 115                 struct /* conditional_expr */ {
 116                         struct expression *conditional, *cond_true, *cond_false;
 117                 };
 118                 // EXPR_CALL
 119                 struct /* call_expr */ {
 120                         struct expression *fn;
 121                         struct expression_list *args;
 122                 };
 123                 // EXPR_LABEL
 124                 struct /* label_expr */ {
 125                         struct symbol *label_symbol;
 126                 };
 127                 // EXPR_INITIALIZER
 128                 struct expression_list *expr_list;
 129                 // EXPR_IDENTIFIER
 130                 struct /* ident_expr */ {
 131                         struct ident *expr_ident;
 132                         struct symbol *field;
 133                         struct expression *ident_expression;
 134                 };
 135                 // EXPR_INDEX
 136                 struct /* index_expr */ {
 137                         unsigned int idx_from, idx_to;
 138                         struct expression *idx_expression;
 139                 };
 140                 // EXPR_POS
 141                 struct /* initpos_expr */ {
 142                         unsigned int init_offset, init_nr;
 143                         struct expression *init_expr;
 144                 };
 145                 // EXPR_OFFSETOF
 146                 struct {
 147                         struct symbol *in;
 148                         struct expression *down;
 149                         union {
 150                                 struct ident *ident;
 151                                 struct expression *index;
 152                         };
 153                 };
 154         };
 155 };
 156
 157 /* Constant expression values */
 158 int is_zero_constant(struct expression *);
 159 long long get_expression_value(struct expression *);
 160 long long const_expression_value(struct expression *);
 161
 162 /* Expression parsing */
 163 struct token *parse_expression(struct token *token, struct expression **tree);
 164 struct token *conditional_expression(struct token *token, struct expression **tree);
 165 struct token *primary_expression(struct token *token, struct expression **tree);
 166 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
 167 struct token *assignment_expression(struct token *token, struct expression **tree);
 168
 169 extern void evaluate_symbol_list(struct symbol_list *list);
 170 extern struct symbol *evaluate_statement(struct statement *stmt);
 171 extern struct symbol *evaluate_expression(struct expression *);
 172
 173 extern int expand_symbol(struct symbol *);
 174
 175 static inline struct expression *alloc_expression(struct position pos, int type)
 176 {
 177         struct expression *expr = __alloc_expression(0);
 178         expr->type = type;
 179         expr->pos = pos;
 180         return expr;
 181 }
 182
 183 static inline struct expression *alloc_const_expression(struct position pos, int value)
 184 {
 185         struct expression *expr = __alloc_expression(0);
 186         expr->type = EXPR_VALUE;
 187         expr->pos = pos;
 188         expr->value = value;
 189         expr->ctype = &int_ctype;
 190         return expr;
 191 }
 192
 193 /* Type name parsing */
 194 struct token *typename(struct token *, struct symbol **, int);
 195
 196 static inline int lookup_type(struct token *token)
 197 {
 198         if (token->pos.type == TOKEN_IDENT) {
 199                 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
 200                 return sym && sym->namespace == NS_TYPEDEF;
 201         }
 202         return 0;
 203 }
 204
 205 /* Statement parsing */
 206 struct statement *alloc_statement(struct position pos, int type);
 207 struct token *initializer(struct expression **tree, struct token *token);
 208 struct token *compound_statement(struct token *, struct statement *);
 209
 210 /* The preprocessor calls this 'constant_expression()' */
 211 #define constant_expression(token,tree) conditional_expression(token, tree)
 212
 213 /* Cast folding of constant values.. */
 214 void cast_value(struct expression *expr, struct symbol *newtype,
 215         struct expression *old, struct symbol *oldtype);
 216
 217 #endif