/* expr.h -> header file for expr.c
- Copyright (C) 1987, 1992 Free Software Foundation, Inc.
+ Copyright (C) 1987-2020 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)
+ 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,
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
-
-/*
- * Abbreviations (mnemonics).
- *
- * O operator
- * Q quantity, operand
- * X eXpression
- */
+ 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-bar+42".
- * In other words we permit a (possibly undefined) minuend, a
- * (possibly undefined) subtrahend and an (absolute) augend.
- * RMS says this is so we can have 1-pass assembly for any compiler
- * emmissions, and a 'case' statement might emit 'undefined1 - undefined2'.
+ * 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'.
*
- * To simplify table-driven dispatch, we also have a "segment" for the
- * entire expression. That way we don't require complex reasoning about
- * whether particular components are defined; and we can change component
- * semantics without re-working all the dispatch tables in the assembler.
- * In other words the "type" of an expression is its segment.
+ * 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.
*/
-typedef struct
+/* 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
{
- symbolS *X_add_symbol; /* foo */
- symbolS *X_subtract_symbol; /* bar */
- long X_add_number; /* 42. Must be signed. */
- segT X_seg; /* What segment (expr type)? */
-}
-
-expressionS;
-
-/* result should be type (expressionS *). */
-#define expression(result) expr(0,result)
-
-/* If an expression is SEG_BIG, look here */
-/* for its value. These common data may */
-/* be clobbered whenever expr() is called. */
-extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */
-/* Enough to hold most precise flonum. */
-extern LITTLENUM_TYPE generic_bignum[]; /* Bignums returned here. */
-#define SIZE_OF_LARGE_NUMBER (20) /* Number of littlenums in above. */
+ 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;
-#if __STDC__ == 1
-
-char get_symbol_end (void);
-segT expr (int rank, expressionS * resultP);
-unsigned int get_single_number (void);
-
-#else /* not __STDC__ */
-
-char get_symbol_end ();
-segT expr ();
-unsigned int get_single_number ();
-
-#endif /* not __STDC__ */
-
-/* end of expr.h */
+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 *);
+
+extern bfd_boolean literal_prefix_dollar_hex;
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