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