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