expr.h revision 60484
150476Speter/* expr.h -> header file for expr.c 226419Sache Copyright (C) 1987, 92-98, 1999 Free Software Foundation, Inc. 326419Sache 426419Sache This file is part of GAS, the GNU Assembler. 526419Sache 626419Sache GAS is free software; you can redistribute it and/or modify 726419Sache it under the terms of the GNU General Public License as published by 836307Sphk the Free Software Foundation; either version 2, or (at your option) 936307Sphk any later version. 1036307Sphk 1136307Sphk GAS is distributed in the hope that it will be useful, 1236307Sphk but WITHOUT ANY WARRANTY; without even the implied warranty of 1336307Sphk MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1436307Sphk GNU General Public License for more details. 1536307Sphk 1636307Sphk You should have received a copy of the GNU General Public License 1736307Sphk along with GAS; see the file COPYING. If not, write to the Free 1836307Sphk Software Foundation, 59 Temple Place - Suite 330, Boston, MA 1936307Sphk 02111-1307, USA. */ 2026419Sache 2126419Sache/* 2226419Sache * By popular demand, we define a struct to represent an expression. 2336307Sphk * This will no doubt mutate as expressions become baroque. 2436307Sphk * 2536307Sphk * Currently, we support expressions like "foo OP bar + 42". In other 2636307Sphk * words we permit a (possibly undefined) symbol, a (possibly 2736307Sphk * undefined) symbol and the operation used to combine the symbols, 2836307Sphk * and an (absolute) augend. RMS says this is so we can have 1-pass 2936307Sphk * assembly for any compiler emissions, and a 'case' statement might 3036307Sphk * emit 'undefined1 - undefined2'. 3136307Sphk * 3236307Sphk * The type of an expression used to be stored as a segment. That got 3336307Sphk * confusing because it overloaded the concept of a segment. I added 3436307Sphk * an operator field, instead. 3526419Sache */ 3626419Sache 3726419Sache/* This is the type of an expression. The operator types are also 3836307Sphk used while parsing an expression. 3936307Sphk 4036307Sphk NOTE: This enumeration must match the op_rank array in expr.c. */ 4136307Sphk 4236307Sphktypedef enum 4336307Sphk{ 4436307Sphk /* An illegal expression. */ 4526419Sache O_illegal, 4626419Sache /* A nonexistent expression. */ 4726419Sache O_absent, 4836307Sphk /* X_add_number (a constant expression). */ 4936307Sphk O_constant, 5036307Sphk /* X_add_symbol + X_add_number. */ 5136307Sphk O_symbol, 5236307Sphk /* X_add_symbol + X_add_number - the base address of the image. */ 5336307Sphk O_symbol_rva, 5436307Sphk /* A register (X_add_number is register number). */ 5526419Sache O_register, 5626419Sache /* A big value. If X_add_number is negative or 0, the value is in 5726419Sache generic_floating_point_number. Otherwise the value is in 5826419Sache generic_bignum, and X_add_number is the number of LITTLENUMs in 5926419Sache the value. */ 6026419Sache O_big, 6126419Sache /* (- X_add_symbol) + X_add_number. */ 6226419Sache O_uminus, 6326419Sache /* (~ X_add_symbol) + X_add_number. */ 6426419Sache O_bit_not, 6526419Sache /* (! X_add_symbol) + X_add_number. */ 6653943Sache O_logical_not, 6726419Sache /* (X_add_symbol * X_op_symbol) + X_add_number. */ 6826419Sache O_multiply, 6926419Sache /* (X_add_symbol / X_op_symbol) + X_add_number. */ 7026419Sache O_divide, 7126419Sache /* X_add_symbol % X_op_symbol) + X_add_number. */ 7226419Sache O_modulus, 7326419Sache /* X_add_symbol << X_op_symbol) + X_add_number. */ 7426419Sache O_left_shift, 7526419Sache /* X_add_symbol >> X_op_symbol) + X_add_number. */ 7626419Sache O_right_shift, 7726419Sache /* X_add_symbol | X_op_symbol) + X_add_number. */ 7853943Sache O_bit_inclusive_or, 7953943Sache /* X_add_symbol |~ X_op_symbol) + X_add_number. */ 8053943Sache O_bit_or_not, 8153943Sache /* X_add_symbol ^ X_op_symbol) + X_add_number. */ 8253943Sache O_bit_exclusive_or, 8353943Sache /* X_add_symbol & X_op_symbol) + X_add_number. */ 8453943Sache O_bit_and, 8553943Sache /* X_add_symbol + X_op_symbol) + X_add_number. */ 8653943Sache O_add, 8753943Sache /* X_add_symbol - X_op_symbol) + X_add_number. */ 8853943Sache O_subtract, 8953943Sache /* (X_add_symbol == X_op_symbol) + X_add_number. */ 9053943Sache O_eq, 9153943Sache /* (X_add_symbol != X_op_symbol) + X_add_number. */ 9253943Sache O_ne, 9353943Sache /* (X_add_symbol < X_op_symbol) + X_add_number. */ 9453943Sache O_lt, 9553943Sache /* (X_add_symbol <= X_op_symbol) + X_add_number. */ 9653943Sache O_le, 9753943Sache /* (X_add_symbol >= X_op_symbol) + X_add_number. */ 98 O_ge, 99 /* (X_add_symbol > X_op_symbol) + X_add_number. */ 100 O_gt, 101 /* (X_add_symbol && X_op_symbol) + X_add_number. */ 102 O_logical_and, 103 /* (X_add_symbol || X_op_symbol) + X_add_number. */ 104 O_logical_or, 105 /* X_op_symbol [ X_add_symbol ] */ 106 O_index, 107 /* machine dependent operators */ 108 O_md1, O_md2, O_md3, O_md4, O_md5, O_md6, O_md7, O_md8, 109 O_md9, O_md10, O_md11, O_md12, O_md13, O_md14, O_md15, O_md16, 110 /* this must be the largest value */ 111 O_max 112} operatorT; 113 114typedef struct expressionS 115{ 116 /* The main symbol. */ 117 symbolS *X_add_symbol; 118 /* The second symbol, if needed. */ 119 symbolS *X_op_symbol; 120 /* A number to add. */ 121 offsetT X_add_number; 122 123 /* The type of the expression. We can't assume that an arbitrary 124 compiler can handle a bitfield of enum type. FIXME: We could 125 check this using autoconf. */ 126#ifdef __GNUC__ 127 operatorT X_op : 8; 128#else 129 unsigned char X_op; 130#endif 131 132 /* Non-zero if X_add_number should be regarded as unsigned. This is 133 only valid for O_constant expressions. It is only used when an 134 O_constant must be extended into a bignum (i.e., it is not used 135 when performing arithmetic on these values). 136 FIXME: This field is not set very reliably. */ 137 unsigned int X_unsigned : 1; 138 139 /* 7 additional bits can be defined if needed. */ 140 141 /* Machine dependent field */ 142 unsigned short X_md; 143} expressionS; 144 145/* "result" should be type (expressionS *). */ 146#define expression(result) expr (0, result) 147 148/* If an expression is O_big, look here for its value. These common 149 data may be clobbered whenever expr() is called. */ 150/* Flonums returned here. Big enough to hold most precise flonum. */ 151extern FLONUM_TYPE generic_floating_point_number; 152/* Bignums returned here. */ 153extern LITTLENUM_TYPE generic_bignum[]; 154/* Number of littlenums in above. */ 155#define SIZE_OF_LARGE_NUMBER (20) 156 157typedef char operator_rankT; 158 159extern char get_symbol_end PARAMS ((void)); 160extern void expr_begin PARAMS ((void)); 161extern void expr_set_precedence PARAMS ((void)); 162extern segT expr PARAMS ((int rank, expressionS * resultP)); 163extern unsigned int get_single_number PARAMS ((void)); 164extern symbolS *make_expr_symbol PARAMS ((expressionS * expressionP)); 165extern int expr_symbol_where 166 PARAMS ((symbolS *, char **, unsigned int *)); 167 168extern symbolS *expr_build_uconstant PARAMS ((offsetT)); 169extern symbolS *expr_build_unary PARAMS ((operatorT, symbolS *)); 170extern symbolS *expr_build_binary PARAMS ((operatorT, symbolS *, symbolS *)); 171extern symbolS *expr_build_dot PARAMS ((void)); 172 173/* end of expr.h */ 174