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