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