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 #include "lib.h"
  16 #include "symbol.h"
  17
  18 struct expression_list;
  19
  20 enum expression_type {
  21         EXPR_VALUE = 1,
  22         EXPR_STRING,
  23         EXPR_SYMBOL,
  24         EXPR_TYPE,
  25         EXPR_BINOP,
  26         EXPR_ASSIGNMENT,
  27         EXPR_LOGICAL,
  28         EXPR_DEREF,
  29         EXPR_PREOP,
  30         EXPR_POSTOP,
  31         EXPR_CAST,
  32         EXPR_FORCE_CAST,
  33         EXPR_IMPLIED_CAST,
  34         EXPR_SIZEOF,
  35         EXPR_ALIGNOF,
  36         EXPR_PTRSIZEOF,
  37         EXPR_CONDITIONAL,
  38         EXPR_SELECT,            // a "safe" conditional expression
  39         EXPR_STATEMENT,
  40         EXPR_CALL,
  41         EXPR_COMMA,
  42         EXPR_COMPARE,
  43         EXPR_LABEL,
  44         EXPR_INITIALIZER,       // initializer list
  45         EXPR_IDENTIFIER,        // identifier in initializer
  46         EXPR_INDEX,             // index in initializer
  47         EXPR_POS,               // position in initializer
  48         EXPR_FVALUE,
  49         EXPR_SLICE,
  50         EXPR_OFFSETOF,
  51 };
  52
  53 enum {
  54         Int_const_expr = 1,
  55         Float_literal = 2,
  56 }; /* for expr->flags */
  57
  58 enum {
  59         Taint_comma = 1,
  60 }; /* for expr->taint */
  61
  62 struct expression {
  63         enum expression_type type:8;
  64         unsigned flags:8;
  65         int op;
  66         struct position pos;
  67         struct symbol *ctype;
  68         union {
  69                 // EXPR_VALUE
  70                 struct {
  71                         unsigned long long value;
  72                         unsigned taint;
  73                 };
  74
  75                 // EXPR_FVALUE
  76                 long double fvalue;
  77
  78                 // EXPR_STRING
  79                 struct string *string;
  80
  81                 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
  82                 struct /* unop */ {
  83                         struct expression *unop;
  84                         unsigned long op_value;
  85                 };
  86
  87                 // EXPR_SYMBOL, EXPR_TYPE
  88                 struct /* symbol_arg */ {
  89                         struct symbol *symbol;
  90                         struct ident *symbol_name;
  91                 };
  92
  93                 // EXPR_STATEMENT
  94                 struct statement *statement;
  95
  96                 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
  97                 struct /* binop_arg */ {
  98                         struct expression *left, *right;
  99                 };
 100                 // EXPR_DEREF
 101                 struct /* deref_arg */ {
 102                         struct expression *deref;
 103                         struct ident *member;
 104                 };
 105                 // EXPR_SLICE
 106                 struct /* slice */ {
 107                         struct expression *base;
 108                         unsigned r_bitpos, r_nrbits;
 109                 };
 110                 // EXPR_CAST and EXPR_SIZEOF
 111                 struct /* cast_arg */ {
 112                         struct symbol *cast_type;
 113                         struct expression *cast_expression;
 114                 };
 115                 // EXPR_CONDITIONAL
 116                 // EXPR_SELECT
 117                 struct /* conditional_expr */ {
 118                         struct expression *conditional, *cond_true, *cond_false;
 119                 };
 120                 // EXPR_CALL
 121                 struct /* call_expr */ {
 122                         struct expression *fn;
 123                         struct expression_list *args;
 124                 };
 125                 // EXPR_LABEL
 126                 struct /* label_expr */ {
 127                         struct symbol *label_symbol;
 128                 };
 129                 // EXPR_INITIALIZER
 130                 struct expression_list *expr_list;
 131                 // EXPR_IDENTIFIER
 132                 struct /* ident_expr */ {
 133                         struct ident *expr_ident;
 134                         struct symbol *field;
 135                         struct expression *ident_expression;
 136                 };
 137                 // EXPR_INDEX
 138                 struct /* index_expr */ {
 139                         unsigned int idx_from, idx_to;
 140                         struct expression *idx_expression;
 141                 };
 142                 // EXPR_POS
 143                 struct /* initpos_expr */ {
 144                         unsigned int init_offset, init_nr;
 145                         struct expression *init_expr;
 146                 };
 147                 // EXPR_OFFSETOF
 148                 struct {
 149                         struct symbol *in;
 150                         struct expression *down;
 151                         union {
 152                                 struct ident *ident;
 153                                 struct expression *index;
 154                         };
 155                 };
 156         };
 157 };
 158
 159 /* Constant expression values */
 160 int is_zero_constant(struct expression *);
 161 long long get_expression_value(struct expression *);
 162 long long const_expression_value(struct expression *);
 163
 164 /* Expression parsing */
 165 struct token *parse_expression(struct token *token, struct expression **tree);
 166 struct token *conditional_expression(struct token *token, struct expression **tree);
 167 struct token *primary_expression(struct token *token, struct expression **tree);
 168 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
 169 struct token *assignment_expression(struct token *token, struct expression **tree);
 170
 171 extern void evaluate_symbol_list(struct symbol_list *list);
 172 extern struct symbol *evaluate_statement(struct statement *stmt);
 173 extern struct symbol *evaluate_expression(struct expression *);
 174
 175 extern int expand_symbol(struct symbol *);
 176
 177 static inline struct expression *alloc_expression(struct position pos, int type)
 178 {
 179         struct expression *expr = __alloc_expression(0);
 180         expr->type = type;
 181         expr->pos = pos;
 182         return expr;
 183 }
 184
 185 static inline struct expression *alloc_const_expression(struct position pos, int value)
 186 {
 187         struct expression *expr = __alloc_expression(0);
 188         expr->type = EXPR_VALUE;
 189         expr->pos = pos;
 190         expr->value = value;
 191         expr->ctype = &int_ctype;
 192         return expr;
 193 }
 194
 195 /* Type name parsing */
 196 struct token *typename(struct token *, struct symbol **, int *);
 197
 198 static inline int lookup_type(struct token *token)
 199 {
 200         if (token->pos.type == TOKEN_IDENT) {
 201                 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
 202                 return sym && (sym->namespace & NS_TYPEDEF);
 203         }
 204         return 0;
 205 }
 206
 207 /* Statement parsing */
 208 struct statement *alloc_statement(struct position pos, int type);
 209 struct token *initializer(struct expression **tree, struct token *token);
 210 struct token *compound_statement(struct token *, struct statement *);
 211
 212 /* The preprocessor calls this 'constant_expression()' */
 213 #define constant_expression(token,tree) conditional_expression(token, tree)
 214
 215 /* Cast folding of constant values.. */
 216 void cast_value(struct expression *expr, struct symbol *newtype,
 217         struct expression *old, struct symbol *oldtype);
 218
 219 #endif