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