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 #include "allocate.h"
  15
  16 struct expression_list;
  17
  18 enum expression_type {
  19         EXPR_VALUE = 1,
  20         EXPR_STRING,
  21         EXPR_SYMBOL,
  22         EXPR_TYPE,
  23         EXPR_BINOP,
  24         EXPR_ASSIGNMENT,
  25         EXPR_LOGICAL,
  26         EXPR_DEREF,
  27         EXPR_PREOP,
  28         EXPR_POSTOP,
  29         EXPR_CAST,
  30         EXPR_IMPLIED_CAST,
  31         EXPR_SIZEOF,
  32         EXPR_ALIGNOF,
  33         EXPR_PTRSIZEOF,
  34         EXPR_CONDITIONAL,
  35         EXPR_SELECT,            // a "safe" conditional expression
  36         EXPR_STATEMENT,
  37         EXPR_CALL,
  38         EXPR_COMMA,
  39         EXPR_COMPARE,
  40         EXPR_LABEL,
  41         EXPR_INITIALIZER,       // initializer list
  42         EXPR_IDENTIFIER,        // identifier in initializer
  43         EXPR_INDEX,             // index in initializer
  44         EXPR_POS,               // position in initializer
  45         EXPR_FVALUE,
  46         EXPR_SLICE,
  47 };
  48
  49 struct expression {
  50         enum expression_type type;
  51         int op;
  52         struct position pos;
  53         struct symbol *ctype;
  54         union {
  55                 // EXPR_VALUE
  56                 unsigned long long value;
  57
  58                 // EXPR_FVALUE
  59                 long double fvalue;
  60
  61                 // EXPR_STRING
  62                 struct string *string;
  63
  64                 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
  65                 struct /* unop */ {
  66                         struct expression *unop;
  67                         unsigned long op_value;
  68                 };
  69
  70                 // EXPR_SYMBOL, EXPR_TYPE
  71                 struct /* symbol_arg */ {
  72                         struct symbol *symbol;
  73                         struct ident *symbol_name;
  74                 };
  75
  76                 // EXPR_STATEMENT
  77                 struct statement *statement;
  78
  79                 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
  80                 struct /* binop_arg */ {
  81                         struct expression *left, *right;
  82                 };
  83                 // EXPR_DEREF
  84                 struct /* deref_arg */ {
  85                         struct expression *deref;
  86                         struct ident *member;
  87                 };
  88                 // EXPR_SLICE
  89                 struct /* slice */ {
  90                         struct expression *base;
  91                         unsigned r_bitpos, r_nrbits;
  92                 };
  93                 // EXPR_CAST and EXPR_SIZEOF
  94                 struct /* cast_arg */ {
  95                         struct symbol *cast_type;
  96                         struct expression *cast_expression;
  97                 };
  98                 // EXPR_CONDITIONAL
  99                 // EXPR_SELECT
 100                 struct /* conditional_expr */ {
 101                         struct expression *conditional, *cond_true, *cond_false;
 102                 };
 103                 // EXPR_CALL
 104                 struct /* call_expr */ {
 105                         struct expression *fn;
 106                         struct expression_list *args;
 107                 };
 108                 // EXPR_LABEL
 109                 struct /* label_expr */ {
 110                         struct symbol *label_symbol;
 111                 };
 112                 // EXPR_INITIALIZER
 113                 struct expression_list *expr_list;
 114                 // EXPR_IDENTIFIER
 115                 struct /* ident_expr */ {
 116                         struct ident *expr_ident;
 117                         struct expression *ident_expression;
 118                 };
 119                 // EXPR_INDEX
 120                 struct /* index_expr */ {
 121                         unsigned int idx_from, idx_to;
 122                         struct expression *idx_expression;
 123                 };
 124                 // EXPR_POS
 125                 struct /* initpos_expr */ {
 126                         unsigned int init_offset, init_nr;
 127                         struct expression *init_expr;
 128                 };
 129         };
 130 };
 131
 132 /* Constant expression values */
 133 long long get_expression_value(struct expression *);
 134
 135 /* Expression parsing */
 136 struct token *parse_expression(struct token *token, struct expression **tree);
 137 struct token *conditional_expression(struct token *token, struct expression **tree);
 138 struct token *primary_expression(struct token *token, struct expression **tree);
 139 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
 140 struct token *assignment_expression(struct token *token, struct expression **tree);
 141
 142 extern void evaluate_symbol_list(struct symbol_list *list);
 143 extern struct symbol *evaluate_statement(struct statement *stmt);
 144 extern struct symbol *evaluate_expression(struct expression *);
 145
 146 extern void expand_symbol(struct symbol *);
 147
 148 static inline struct expression *alloc_expression(struct position pos, int type)
 149 {
 150         struct expression *expr = __alloc_expression(0);
 151         expr->type = type;
 152         expr->pos = pos;
 153         return expr;
 154 }
 155
 156 static inline struct expression *alloc_const_expression(struct position pos, int value)
 157 {
 158         struct expression *expr = __alloc_expression(0);
 159         expr->type = EXPR_VALUE;
 160         expr->pos = pos;
 161         expr->value = value;
 162         expr->ctype = &int_ctype;
 163         return expr;
 164 }
 165
 166 /* Type name parsing */
 167 struct token *typename(struct token *, struct symbol **);
 168
 169 static inline int lookup_type(struct token *token)
 170 {
 171         if (token->pos.type == TOKEN_IDENT) {
 172                 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
 173                 return sym && sym->namespace == NS_TYPEDEF;
 174         }
 175         return 0;
 176 }
 177
 178 /* Statement parsing */
 179 struct statement *alloc_statement(struct position pos, int type);
 180 struct token *initializer(struct expression **tree, struct token *token);
 181 struct token *compound_statement(struct token *, struct statement *);
 182
 183 /* The preprocessor calls this 'constant_expression()' */
 184 #define constant_expression(token,tree) conditional_expression(token, tree)
 185
 186 /* Cast folding of constant values.. */
 187 void cast_value(struct expression *expr, struct symbol *newtype,
 188         struct expression *old, struct symbol *oldtype);
 189
 190 #endif