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         Handled = 1,
  60 }; /* for expr->flags */
  61
  62 enum {
  63         Taint_comma = 1,
  64 }; /* for expr->taint */
  65
  66 struct expression {
  67         enum expression_type type:8;
  68         unsigned flags:8;
  69         unsigned smatch_flags:16;
  70         int op;
  71         struct position pos;
  72         struct symbol *ctype;
  73         union {
  74                 // EXPR_VALUE
  75                 struct {
  76                         unsigned long long value;
  77                         unsigned taint;
  78                 };
  79
  80                 // EXPR_FVALUE
  81                 long double fvalue;
  82
  83                 // EXPR_STRING
  84                 struct {
  85                         int wide;
  86                         struct string *string;
  87                 };
  88
  89                 // EXPR_UNOP, EXPR_PREOP and EXPR_POSTOP
  90                 struct /* unop */ {
  91                         struct expression *unop;
  92                         unsigned long op_value;
  93                 };
  94
  95                 // EXPR_SYMBOL, EXPR_TYPE
  96                 struct /* symbol_arg */ {
  97                         struct symbol *symbol;
  98                         struct ident *symbol_name;
  99                 };
 100
 101                 // EXPR_STATEMENT
 102                 struct statement *statement;
 103
 104                 // EXPR_BINOP, EXPR_COMMA, EXPR_COMPARE, EXPR_LOGICAL and EXPR_ASSIGNMENT
 105                 struct /* binop_arg */ {
 106                         struct expression *left, *right;
 107                 };
 108                 // EXPR_DEREF
 109                 struct /* deref_arg */ {
 110                         struct expression *deref;
 111                         struct ident *member;
 112                 };
 113                 // EXPR_SLICE
 114                 struct /* slice */ {
 115                         struct expression *base;
 116                         unsigned r_bitpos, r_nrbits;
 117                 };
 118                 // EXPR_CAST and EXPR_SIZEOF
 119                 struct /* cast_arg */ {
 120                         struct symbol *cast_type;
 121                         struct expression *cast_expression;
 122                 };
 123                 // EXPR_CONDITIONAL
 124                 // EXPR_SELECT
 125                 struct /* conditional_expr */ {
 126                         struct expression *conditional, *cond_true, *cond_false;
 127                 };
 128                 // EXPR_CALL
 129                 struct /* call_expr */ {
 130                         struct expression *fn;
 131                         struct expression_list *args;
 132                 };
 133                 // EXPR_LABEL
 134                 struct /* label_expr */ {
 135                         struct symbol *label_symbol;
 136                 };
 137                 // EXPR_INITIALIZER
 138                 struct expression_list *expr_list;
 139                 // EXPR_IDENTIFIER
 140                 struct /* ident_expr */ {
 141                         struct ident *expr_ident;
 142                         struct symbol *field;
 143                         struct expression *ident_expression;
 144                 };
 145                 // EXPR_INDEX
 146                 struct /* index_expr */ {
 147                         unsigned int idx_from, idx_to;
 148                         struct expression *idx_expression;
 149                 };
 150                 // EXPR_POS
 151                 struct /* initpos_expr */ {
 152                         unsigned int init_offset, init_nr;
 153                         struct expression *init_expr;
 154                 };
 155                 // EXPR_OFFSETOF
 156                 struct {
 157                         struct symbol *in;
 158                         struct expression *down;
 159                         union {
 160                                 struct ident *ident;
 161                                 struct expression *index;
 162                         };
 163                 };
 164         };
 165 };
 166
 167 /* Constant expression values */
 168 int is_zero_constant(struct expression *);
 169 long long get_expression_value(struct expression *);
 170 long long const_expression_value(struct expression *);
 171
 172 /* Expression parsing */
 173 struct token *parse_expression(struct token *token, struct expression **tree);
 174 struct token *conditional_expression(struct token *token, struct expression **tree);
 175 struct token *primary_expression(struct token *token, struct expression **tree);
 176 struct token *parens_expression(struct token *token, struct expression **expr, const char *where);
 177 struct token *assignment_expression(struct token *token, struct expression **tree);
 178
 179 extern void evaluate_symbol_list(struct symbol_list *list);
 180 extern struct symbol *evaluate_statement(struct statement *stmt);
 181 extern struct symbol *evaluate_expression(struct expression *);
 182
 183 extern int expand_symbol(struct symbol *);
 184
 185 static inline struct expression *alloc_expression(struct position pos, int type)
 186 {
 187         struct expression *expr = __alloc_expression(0);
 188         expr->type = type;
 189         expr->pos = pos;
 190         return expr;
 191 }
 192
 193 static inline struct expression *alloc_const_expression(struct position pos, int value)
 194 {
 195         struct expression *expr = __alloc_expression(0);
 196         expr->type = EXPR_VALUE;
 197         expr->pos = pos;
 198         expr->value = value;
 199         expr->ctype = &int_ctype;
 200         return expr;
 201 }
 202
 203 /* Type name parsing */
 204 struct token *typename(struct token *, struct symbol **, int *);
 205
 206 static inline int lookup_type(struct token *token)
 207 {
 208         if (token->pos.type == TOKEN_IDENT) {
 209                 struct symbol *sym = lookup_symbol(token->ident, NS_SYMBOL | NS_TYPEDEF);
 210                 return sym && (sym->namespace & NS_TYPEDEF);
 211         }
 212         return 0;
 213 }
 214
 215 /* Statement parsing */
 216 struct statement *alloc_statement(struct position pos, int type);
 217 struct token *initializer(struct expression **tree, struct token *token);
 218 struct token *compound_statement(struct token *, struct statement *);
 219
 220 /* The preprocessor calls this 'constant_expression()' */
 221 #define constant_expression(token,tree) conditional_expression(token, tree)
 222
 223 /* Cast folding of constant values.. */
 224 void cast_value(struct expression *expr, struct symbol *newtype,
 225         struct expression *old, struct symbol *oldtype);
 226
 227 #endif