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- /* expr.h -> header file for expr.c
- Copyright (C) 1987-2022 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,
- /* The section index of X_add_symbol. */
- O_secidx,
- /* 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);
- extern uint32_t generic_bignum_to_int32 (void);
- extern uint64_t generic_bignum_to_int64 (void);
- extern int resolve_expression (expressionS *);
- extern bool literal_prefix_dollar_hex;
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