expr.h revision 33965
133965Sjdp/* expr.h -> header file for expr.c 233965Sjdp Copyright (C) 1987, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc. 333965Sjdp 433965Sjdp This file is part of GAS, the GNU Assembler. 533965Sjdp 633965Sjdp GAS is free software; you can redistribute it and/or modify 733965Sjdp it under the terms of the GNU General Public License as published by 833965Sjdp the Free Software Foundation; either version 2, or (at your option) 933965Sjdp any later version. 1033965Sjdp 1133965Sjdp GAS is distributed in the hope that it will be useful, 1233965Sjdp but WITHOUT ANY WARRANTY; without even the implied warranty of 1333965Sjdp MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1433965Sjdp GNU General Public License for more details. 1533965Sjdp 1633965Sjdp You should have received a copy of the GNU General Public License 1733965Sjdp along with GAS; see the file COPYING. If not, write to the Free 1833965Sjdp Software Foundation, 59 Temple Place - Suite 330, Boston, MA 1933965Sjdp 02111-1307, USA. */ 2033965Sjdp 2133965Sjdp/* 2233965Sjdp * By popular demand, we define a struct to represent an expression. 2333965Sjdp * This will no doubt mutate as expressions become baroque. 2433965Sjdp * 2533965Sjdp * Currently, we support expressions like "foo OP bar + 42". In other 2633965Sjdp * words we permit a (possibly undefined) symbol, a (possibly 2733965Sjdp * undefined) symbol and the operation used to combine the symbols, 2833965Sjdp * and an (absolute) augend. RMS says this is so we can have 1-pass 2933965Sjdp * assembly for any compiler emissions, and a 'case' statement might 3033965Sjdp * emit 'undefined1 - undefined2'. 3133965Sjdp * 3233965Sjdp * The type of an expression used to be stored as a segment. That got 3333965Sjdp * confusing because it overloaded the concept of a segment. I added 3433965Sjdp * an operator field, instead. 3533965Sjdp */ 3633965Sjdp 3733965Sjdp/* This is the type of an expression. The operator types are also 3833965Sjdp used while parsing an expression. 3933965Sjdp 4033965Sjdp NOTE: This enumeration must match the op_rank array in expr.c. */ 4133965Sjdp 4233965Sjdptypedef enum 4333965Sjdp{ 4433965Sjdp /* An illegal expression. */ 4533965Sjdp O_illegal, 4633965Sjdp /* A nonexistent expression. */ 4733965Sjdp O_absent, 4833965Sjdp /* X_add_number (a constant expression). */ 4933965Sjdp O_constant, 5033965Sjdp /* X_add_symbol + X_add_number. */ 5133965Sjdp O_symbol, 5233965Sjdp /* X_add_symbol + X_add_number - the base address of the image. */ 5333965Sjdp O_symbol_rva, 5433965Sjdp /* A register (X_add_number is register number). */ 5533965Sjdp O_register, 5633965Sjdp /* A big value. If X_add_number is negative or 0, the value is in 5733965Sjdp generic_floating_point_number. Otherwise the value is in 5833965Sjdp generic_bignum, and X_add_number is the number of LITTLENUMs in 5933965Sjdp the value. */ 6033965Sjdp O_big, 6133965Sjdp /* (- X_add_symbol) + X_add_number. */ 6233965Sjdp O_uminus, 6333965Sjdp /* (~ X_add_symbol) + X_add_number. */ 6433965Sjdp O_bit_not, 6533965Sjdp /* (! X_add_symbol) + X_add_number. */ 6633965Sjdp O_logical_not, 6733965Sjdp /* (X_add_symbol * X_op_symbol) + X_add_number. */ 6833965Sjdp O_multiply, 6933965Sjdp /* (X_add_symbol / X_op_symbol) + X_add_number. */ 7033965Sjdp O_divide, 7133965Sjdp /* X_add_symbol % X_op_symbol) + X_add_number. */ 7233965Sjdp O_modulus, 7333965Sjdp /* X_add_symbol << X_op_symbol) + X_add_number. */ 7433965Sjdp O_left_shift, 7533965Sjdp /* X_add_symbol >> X_op_symbol) + X_add_number. */ 7633965Sjdp O_right_shift, 7733965Sjdp /* X_add_symbol | X_op_symbol) + X_add_number. */ 7833965Sjdp O_bit_inclusive_or, 7933965Sjdp /* X_add_symbol |~ X_op_symbol) + X_add_number. */ 8033965Sjdp O_bit_or_not, 8133965Sjdp /* X_add_symbol ^ X_op_symbol) + X_add_number. */ 8233965Sjdp O_bit_exclusive_or, 8333965Sjdp /* X_add_symbol & X_op_symbol) + X_add_number. */ 8433965Sjdp O_bit_and, 8533965Sjdp /* X_add_symbol + X_op_symbol) + X_add_number. */ 8633965Sjdp O_add, 8733965Sjdp /* X_add_symbol - X_op_symbol) + X_add_number. */ 8833965Sjdp O_subtract, 8933965Sjdp /* (X_add_symbol == X_op_symbol) + X_add_number. */ 9033965Sjdp O_eq, 9133965Sjdp /* (X_add_symbol != X_op_symbol) + X_add_number. */ 9233965Sjdp O_ne, 9333965Sjdp /* (X_add_symbol < X_op_symbol) + X_add_number. */ 9433965Sjdp O_lt, 9533965Sjdp /* (X_add_symbol <= X_op_symbol) + X_add_number. */ 9633965Sjdp O_le, 9733965Sjdp /* (X_add_symbol >= X_op_symbol) + X_add_number. */ 9833965Sjdp O_ge, 9933965Sjdp /* (X_add_symbol > X_op_symbol) + X_add_number. */ 10033965Sjdp O_gt, 10133965Sjdp /* (X_add_symbol && X_op_symbol) + X_add_number. */ 10233965Sjdp O_logical_and, 10333965Sjdp /* (X_add_symbol || X_op_symbol) + X_add_number. */ 10433965Sjdp O_logical_or, 10533965Sjdp /* this must be the largest value */ 10633965Sjdp O_max 10733965Sjdp} operatorT; 10833965Sjdp 10933965Sjdptypedef struct expressionS 11033965Sjdp{ 11133965Sjdp /* The main symbol. */ 11233965Sjdp struct symbol *X_add_symbol; 11333965Sjdp /* The second symbol, if needed. */ 11433965Sjdp struct symbol *X_op_symbol; 11533965Sjdp /* A number to add. */ 11633965Sjdp offsetT X_add_number; 11733965Sjdp /* The type of the expression. We can't assume that an arbitrary 11833965Sjdp compiler can handle a bitfield of enum type. FIXME: We could 11933965Sjdp check this using autoconf. */ 12033965Sjdp#ifdef __GNUC__ 12133965Sjdp operatorT X_op : 5; 12233965Sjdp#else 12333965Sjdp unsigned X_op : 5; 12433965Sjdp#endif 12533965Sjdp /* Non-zero if X_add_number should be regarded as unsigned. This is 12633965Sjdp only valid for O_constant expressions. It is only used when an 12733965Sjdp O_constant must be extended into a bignum (i.e., it is not used 12833965Sjdp when performing arithmetic on these values). 12933965Sjdp FIXME: This field is not set very reliably. */ 13033965Sjdp unsigned int X_unsigned : 1; 13133965Sjdp} expressionS; 13233965Sjdp 13333965Sjdp/* "result" should be type (expressionS *). */ 13433965Sjdp#define expression(result) expr (0, result) 13533965Sjdp 13633965Sjdp/* If an expression is O_big, look here for its value. These common 13733965Sjdp data may be clobbered whenever expr() is called. */ 13833965Sjdp/* Flonums returned here. Big enough to hold most precise flonum. */ 13933965Sjdpextern FLONUM_TYPE generic_floating_point_number; 14033965Sjdp/* Bignums returned here. */ 14133965Sjdpextern LITTLENUM_TYPE generic_bignum[]; 14233965Sjdp/* Number of littlenums in above. */ 14333965Sjdp#define SIZE_OF_LARGE_NUMBER (20) 14433965Sjdp 14533965Sjdptypedef char operator_rankT; 14633965Sjdp 14733965Sjdpextern char get_symbol_end PARAMS ((void)); 14833965Sjdpextern void expr_begin PARAMS ((void)); 14933965Sjdpextern segT expr PARAMS ((int rank, expressionS * resultP)); 15033965Sjdpextern unsigned int get_single_number PARAMS ((void)); 15133965Sjdpextern struct symbol *make_expr_symbol PARAMS ((expressionS * expressionP)); 15233965Sjdpextern int expr_symbol_where 15333965Sjdp PARAMS ((struct symbol *, char **, unsigned int *)); 15433965Sjdp 15533965Sjdp/* end of expr.h */ 156