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