/* expr.h -> header file for expr.c
- Copyright (C) 1987 Free Software Foundation, Inc.
-
+ Copyright (C) 1987-2015 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,
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
-/*
- * Abbreviations (mnemonics).
- *
- * O operator
- * Q quantity, operand
- * X eXpression
- */
+ 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-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
-{
- 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. */
+/* This is the type of an expression. The operator types are also
+ used while parsing an expression.
-typedef char operator_rankT;
+ NOTE: This enumeration must match the op_rank array in expr.c. */
-#ifdef __STDC__
+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;
-char get_symbol_end(void);
-segT expr(int rank, expressionS *resultP);
-unsigned int get_single_number(void);
+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;
-#else /* __STDC__ */
+ /* 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;
-char get_symbol_end();
-segT expr();
-unsigned int get_single_number();
+extern char get_symbol_end (void);
+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 *, char **, unsigned int *);
+extern void current_location (expressionS *);
-#endif /* __STDC__ */
+extern symbolS *expr_build_uconstant (offsetT);
+extern symbolS *expr_build_dot (void);
-/* end of expr.h */
+int resolve_expression (expressionS *);