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 #include "lib.h"
  16 #include "symbol.h"
  17
  18 struct expression_list;
  19
  20 enum expression_type {
  21         EXPR_VALUE = 1,
  22         EXPR_STRING,
  23         EXPR_SYMBOL,
  24         EXPR_TYPE,
  25         EXPR_BINOP,
  26         EXPR_ASSIGNMENT,
  27         EXPR_LOGICAL,
  28         EXPR_DEREF,
  29         EXPR_PREOP,
  30         EXPR_POSTOP,
  31         EXPR_CAST,
  32         EXPR_FORCE_CAST,
  33         EXPR_IMPLIED_CAST,
  34         EXPR_SIZEOF,
  35         EXPR_ALIGNOF,
  36         EXPR_PTRSIZEOF,
  37         EXPR_CONDITIONAL,
  38         EXPR_SELECT,            // a "safe" conditional expression
  39         EXPR_STATEMENT,
  40         EXPR_CALL,
  41         EXPR_COMMA,
  42         EXPR_COMPARE,
  43         EXPR_LABEL,
  44         EXPR_INITIALIZER,       // initializer list
  45         EXPR_IDENTIFIER,        // identifier in initializer
  46         EXPR_INDEX,             // index in initializer
  47         EXPR_POS,               // position in initializer
  48         EXPR_FVALUE,
  49         EXPR_SLICE,
  50         EXPR_OFFSETOF,
  51 };
  52
  53 enum {
  54         Int_const_expr = 1,
  55         Float_literal = 2,
  56 }; /* for expr->flags */
  57
  58 enum {
  59         Taint_comma = 1,
  60 }; /* for expr->taint */
  61
  62 struct expression {
  63         enum expression_type type:8;
  64         unsigned flags:8;
  65         int op;
  66         struct position pos;
  67         struct symbol *ctype;
  68         union {
  69                 // EXPR_VALUE
  70                 struct {
  71                         unsigned long long value;
  72                         unsigned taint;
  73                 };
  74
  75                 // EXPR_FVALUE
  76                 long double fvalue;
  77
  78                 // EXPR_STRING
  79                 struct {
  80                         int wide;
  81                         struct string *string;
  82                 };
  83
  84                 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
  85                 struct /* unop */ {
  86                         struct expression *unop;
  87                         unsigned long op_value;
  88                 };
  89
  90                 // EXPR_SYMBOL, EXPR_TYPE
  91                 struct /* symbol_arg */ {
  92                         struct symbol *symbol;
  93                         struct ident *symbol_name;
  94                 };
  95
  96                 // EXPR_STATEMENT
  97                 struct statement *statement;
  98
  99                 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
 100                 struct /* binop_arg */ {
 101                         struct expression *left, *right;
 102                 };
 103                 // EXPR_DEREF
 104                 struct /* deref_arg */ {
 105                         struct expression *deref;
 106                         struct ident *member;
 107                 };
 108                 // EXPR_SLICE
 109                 struct /* slice */ {
 110                         struct expression *base;
 111                         unsigned r_bitpos, r_nrbits;
 112                 };
 113                 // EXPR_CAST and EXPR_SIZEOF
 114                 struct /* cast_arg */ {
 115                         struct symbol *cast_type;
 116                         struct expression *cast_expression;
 117                 };
 118                 // EXPR_CONDITIONAL
 119                 // EXPR_SELECT
 120                 struct /* conditional_expr */ {
 121                         struct expression *conditional, *cond_true, *cond_false;
 122                 };
 123                 // EXPR_CALL
 124                 struct /* call_expr */ {
 125                         struct expression *fn;
 126                         struct expression_list *args;
 127                 };
 128                 // EXPR_LABEL
 129                 struct /* label_expr */ {
 130                         struct symbol *label_symbol;
 131                 };
 132                 // EXPR_INITIALIZER
 133                 struct expression_list *expr_list;
 134                 // EXPR_IDENTIFIER
 135                 struct /* ident_expr */ {
 136                         struct ident *expr_ident;
 137                         struct symbol *field;
 138                         struct expression *ident_expression;
 139                 };
 140                 // EXPR_INDEX
 141                 struct /* index_expr */ {
 142                         unsigned int idx_from, idx_to;
 143                         struct expression *idx_expression;
 144                 };
 145                 // EXPR_POS
 146                 struct /* initpos_expr */ {
 147                         unsigned int init_offset, init_nr;
 148                         struct expression *init_expr;
 149                 };
 150                 // EXPR_OFFSETOF
 151                 struct {
 152                         struct symbol *in;
 153                         struct expression *down;
 154                         union {
 155                                 struct ident *ident;
 156                                 struct expression *index;
 157                         };
 158                 };
 159         };
 160 };
 161
 162 /* Constant expression values */
 163 int is_zero_constant(struct expression *);
 164 long long get_expression_value(struct expression *);
 165 long long const_expression_value(struct expression *);
 166
 167 /* Expression parsing */
 168 struct token *parse_expression(struct token *token, struct expression **tree);
 169 struct token *conditional_expression(struct token *token, struct expression **tree);
 170 struct token *primary_expression(struct token *token, struct expression **tree);
 171 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
 172 struct token *assignment_expression(struct token *token, struct expression **tree);
 173
 174 extern void evaluate_symbol_list(struct symbol_list *list);
 175 extern struct symbol *evaluate_statement(struct statement *stmt);
 176 extern struct symbol *evaluate_expression(struct expression *);
 177
 178 extern int expand_symbol(struct symbol *);
 179
 180 static inline struct expression *alloc_expression(struct position pos, int type)
 181 {
 182         struct expression *expr = __alloc_expression(0);
 183         expr->type = type;
 184         expr->pos = pos;
 185         return expr;
 186 }
 187
 188 static inline struct expression *alloc_const_expression(struct position pos, int value)
 189 {
 190         struct expression *expr = __alloc_expression(0);
 191         expr->type = EXPR_VALUE;
 192         expr->pos = pos;
 193         expr->value = value;
 194         expr->ctype = &int_ctype;
 195         return expr;
 196 }
 197
 198 /* Type name parsing */
 199 struct token *typename(struct token *, struct symbol **, int *);
 200
 201 static inline int lookup_type(struct token *token)
 202 {
 203         if (token->pos.type == TOKEN_IDENT) {
 204                 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
 205                 return sym && (sym->namespace & NS_TYPEDEF);
 206         }
 207         return 0;
 208 }
 209
 210 /* Statement parsing */
 211 struct statement *alloc_statement(struct position pos, int type);
 212 struct token *initializer(struct expression **tree, struct token *token);
 213 struct token *compound_statement(struct token *, struct statement *);
 214
 215 /* The preprocessor calls this 'constant_expression()' */
 216 #define constant_expression(token,tree) conditional_expression(token, tree)
 217
 218 /* Cast folding of constant values.. */
 219 void cast_value(struct expression *expr, struct symbol *newtype,
 220         struct expression *old, struct symbol *oldtype);
 221
 222 #endif