/* expr.h -> header file for expr.c | |

Copyright (C) 1987-2016 Free Software Foundation, Inc. | |

This file is part of GAS, the GNU Assembler. | |

GAS is free software; you can redistribute it and/or modify | |

it under the terms of the GNU General Public License as published by | |

the Free Software Foundation; either version 3, or (at your option) | |

any later version. | |

GAS is distributed in the hope that it will be useful, | |

but WITHOUT ANY WARRANTY; without even the implied warranty of | |

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |

GNU General Public License for more details. | |

You should have received a copy of the GNU General Public License | |

along with GAS; see the file COPYING. If not, write to the Free | |

Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA | |

02110-1301, USA. */ | |

/* | |

* By popular demand, we define a struct to represent an expression. | |

* This will no doubt mutate as expressions become baroque. | |

* | |

* Currently, we support expressions like "foo OP bar + 42". In other | |

* words we permit a (possibly undefined) symbol, a (possibly | |

* undefined) symbol and the operation used to combine the symbols, | |

* and an (absolute) augend. RMS says this is so we can have 1-pass | |

* assembly for any compiler emissions, and a 'case' statement might | |

* emit 'undefined1 - undefined2'. | |

* | |

* The type of an expression used to be stored as a segment. That got | |

* confusing because it overloaded the concept of a segment. I added | |

* an operator field, instead. | |

*/ | |

/* This is the type of an expression. The operator types are also | |

used while parsing an expression. | |

NOTE: This enumeration must match the op_rank array in expr.c. */ | |

typedef enum { | |

/* An illegal expression. */ | |

O_illegal, | |

/* A nonexistent expression. */ | |

O_absent, | |

/* X_add_number (a constant expression). */ | |

O_constant, | |

/* X_add_symbol + X_add_number. */ | |

O_symbol, | |

/* X_add_symbol + X_add_number - the base address of the image. */ | |

O_symbol_rva, | |

/* A register (X_add_number is register number). */ | |

O_register, | |

/* A big value. If X_add_number is negative or 0, the value is in | |

generic_floating_point_number. Otherwise the value is in | |

generic_bignum, and X_add_number is the number of LITTLENUMs in | |

the value. */ | |

O_big, | |

/* (- X_add_symbol) + X_add_number. */ | |

O_uminus, | |

/* (~ X_add_symbol) + X_add_number. */ | |

O_bit_not, | |

/* (! X_add_symbol) + X_add_number. */ | |

O_logical_not, | |

/* (X_add_symbol * X_op_symbol) + X_add_number. */ | |

O_multiply, | |

/* (X_add_symbol / X_op_symbol) + X_add_number. */ | |

O_divide, | |

/* (X_add_symbol % X_op_symbol) + X_add_number. */ | |

O_modulus, | |

/* (X_add_symbol << X_op_symbol) + X_add_number. */ | |

O_left_shift, | |

/* (X_add_symbol >> X_op_symbol) + X_add_number. */ | |

O_right_shift, | |

/* (X_add_symbol | X_op_symbol) + X_add_number. */ | |

O_bit_inclusive_or, | |

/* (X_add_symbol |~ X_op_symbol) + X_add_number. */ | |

O_bit_or_not, | |

/* (X_add_symbol ^ X_op_symbol) + X_add_number. */ | |

O_bit_exclusive_or, | |

/* (X_add_symbol & X_op_symbol) + X_add_number. */ | |

O_bit_and, | |

/* (X_add_symbol + X_op_symbol) + X_add_number. */ | |

O_add, | |

/* (X_add_symbol - X_op_symbol) + X_add_number. */ | |

O_subtract, | |

/* (X_add_symbol == X_op_symbol) + X_add_number. */ | |

O_eq, | |

/* (X_add_symbol != X_op_symbol) + X_add_number. */ | |

O_ne, | |

/* (X_add_symbol < X_op_symbol) + X_add_number. */ | |

O_lt, | |

/* (X_add_symbol <= X_op_symbol) + X_add_number. */ | |

O_le, | |

/* (X_add_symbol >= X_op_symbol) + X_add_number. */ | |

O_ge, | |

/* (X_add_symbol > X_op_symbol) + X_add_number. */ | |

O_gt, | |

/* (X_add_symbol && X_op_symbol) + X_add_number. */ | |

O_logical_and, | |

/* (X_add_symbol || X_op_symbol) + X_add_number. */ | |

O_logical_or, | |

/* X_op_symbol [ X_add_symbol ] */ | |

O_index, | |

/* machine dependent operators */ | |

O_md1, O_md2, O_md3, O_md4, O_md5, O_md6, O_md7, O_md8, | |

O_md9, O_md10, O_md11, O_md12, O_md13, O_md14, O_md15, O_md16, | |

O_md17, O_md18, O_md19, O_md20, O_md21, O_md22, O_md23, O_md24, | |

O_md25, O_md26, O_md27, O_md28, O_md29, O_md30, O_md31, O_md32, | |

/* this must be the largest value */ | |

O_max | |

} operatorT; | |

typedef struct expressionS { | |

/* The main symbol. */ | |

symbolS *X_add_symbol; | |

/* The second symbol, if needed. */ | |

symbolS *X_op_symbol; | |

/* A number to add. */ | |

offsetT X_add_number; | |

/* The type of the expression. We can't assume that an arbitrary | |

compiler can handle a bitfield of enum type. FIXME: We could | |

check this using autoconf. */ | |

#ifdef __GNUC__ | |

operatorT X_op : 8; | |

#else | |

unsigned char X_op; | |

#endif | |

/* Non-zero if X_add_number should be regarded as unsigned. This is | |

only valid for O_constant expressions. It is only used when an | |

O_constant must be extended into a bignum (i.e., it is not used | |

when performing arithmetic on these values). | |

FIXME: This field is not set very reliably. */ | |

unsigned int X_unsigned : 1; | |

/* This is used to implement "word size + 1 bit" arithmetic, so that e.g. | |

expressions used with .sleb128 directives can use the full range available | |

for an unsigned word, but can also properly represent all values of a | |

signed word. */ | |

unsigned int X_extrabit : 1; | |

/* 7 additional bits can be defined if needed. */ | |

/* Machine dependent field */ | |

unsigned short X_md; | |

} expressionS; | |

enum expr_mode | |

{ | |

expr_evaluate, | |

expr_normal, | |

expr_defer | |

}; | |

/* "result" should be type (expressionS *). */ | |

#define expression(result) expr (0, result, expr_normal) | |

#define expression_and_evaluate(result) expr (0, result, expr_evaluate) | |

#define deferred_expression(result) expr (0, result, expr_defer) | |

/* If an expression is O_big, look here for its value. These common | |

data may be clobbered whenever expr() is called. */ | |

/* Flonums returned here. Big enough to hold most precise flonum. */ | |

extern FLONUM_TYPE generic_floating_point_number; | |

/* Bignums returned here. */ | |

extern LITTLENUM_TYPE generic_bignum[]; | |

/* Number of littlenums in above. */ | |

#define SIZE_OF_LARGE_NUMBER (20) | |

typedef char operator_rankT; | |

extern char get_symbol_name (char **); | |

extern char restore_line_pointer (char); | |

extern void expr_begin (void); | |

extern void expr_set_precedence (void); | |

extern void expr_set_rank (operatorT, operator_rankT); | |

extern void add_to_result (expressionS *, offsetT, int); | |

extern void subtract_from_result (expressionS *, offsetT, int); | |

extern segT expr (int, expressionS *, enum expr_mode); | |

extern unsigned int get_single_number (void); | |

extern symbolS *make_expr_symbol (expressionS * expressionP); | |

extern int expr_symbol_where (symbolS *, const char **, unsigned int *); | |

extern void current_location (expressionS *); | |

extern symbolS *expr_build_uconstant (offsetT); | |

extern symbolS *expr_build_dot (void); | |

int resolve_expression (expressionS *); |