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Diffstat (limited to 'gas/expr.h')
| -rw-r--r-- | gas/expr.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/gas/expr.h b/gas/expr.h new file mode 100644 index 0000000..da90743 --- /dev/null +++ b/gas/expr.h @@ -0,0 +1,162 @@ +/* expr.h -> header file for expr.c + Copyright (C) 1987, 92-97, 1998 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 2, 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, 59 Temple Place - Suite 330, Boston, MA + 02111-1307, 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, + /* this must be the largest value */ + O_max +} operatorT; + +typedef struct expressionS +{ + /* The main symbol. */ + struct symbol *X_add_symbol; + /* The second symbol, if needed. */ + struct symbol *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 : 5; +#else + unsigned X_op : 5; +#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; +} expressionS; + +/* "result" should be type (expressionS *). */ +#define expression(result) expr (0, result) + +/* 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_end PARAMS ((void)); +extern void expr_begin PARAMS ((void)); +extern void expr_set_precedence PARAMS ((void)); +extern segT expr PARAMS ((int rank, expressionS * resultP)); +extern unsigned int get_single_number PARAMS ((void)); +extern struct symbol *make_expr_symbol PARAMS ((expressionS * expressionP)); +extern int expr_symbol_where + PARAMS ((struct symbol *, char **, unsigned int *)); + +extern struct symbol * expr_build_uconstant PARAMS ((offsetT)); +extern struct symbol * expr_build_unary PARAMS ((operatorT, struct symbol *)); +extern struct symbol * expr_build_binary + PARAMS ((operatorT, struct symbol *, struct symbol *)); +extern struct symbol * expr_build_dot PARAMS ((void)); + +/* end of expr.h */ |