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* expr.c (make_expr_symbol): No longer static. Use symbol_create, not

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symbol_new, for symbols holding expression values.
* expr.h (make_expr_symbol): Move declaration here.
This commit is contained in:
Ken Raeburn 1994-09-28 19:09:16 +00:00
parent 67b9f39403
commit 648acaa0c0
2 changed files with 85 additions and 27 deletions
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6
gas/ChangeLog
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@ -1,3 +1,9 @@
Wed Sep 28 14:56:39 1994 Ken Raeburn <raeburn@cujo.cygnus.com>
* expr.c (make_expr_symbol): No longer static. Use symbol_create,
not symbol_new, for symbols holding expression values.
* expr.h (make_expr_symbol): Move declaration here.
Wed Sep 28 11:50:40 1994 Ian Lance Taylor (ian@sanguine.cygnus.com)
* config/tc-mips.c: Include subsegs.h.

106
gas/expr.h
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@ -1,5 +1,5 @@
/* expr.h -> header file for expr.c
Copyright (C) 1987, 1992 Free Software Foundation, Inc.
Copyright (C) 1987, 1992, 1993 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
@ -17,44 +17,95 @@
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
*/
/*
* 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
* emissions, 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
{
struct symbol *X_add_symbol; /* "foo", above */
struct symbol *X_subtract_symbol; /* "bar", above */
offsetT X_add_number; /* 42, above -- must be signed */
/* What segment (expr type)? */
segT X_seg;
/* 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,
/* 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_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
} operatorT;
typedef struct expressionS
{
/* The type of the expression. */
operatorT X_op;
/* 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;
/* 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.
If we ever need more flags here, we can make them bitfields. */
int X_unsigned;
} expressionS;
/* "result" should be type (expressionS *). */
#define expression(result) expr(0,result)
#define expression(result) expr (0, result)
/* If an expression is SEG_BIG, look here for its value. These common
/* 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;
@ -68,5 +119,6 @@ typedef char operator_rankT;
char get_symbol_end PARAMS ((void));
segT expr PARAMS ((int rank, expressionS * resultP));
unsigned int get_single_number PARAMS ((void));
symbolS *make_expr_symbol PARAMS ((expressionS * expressionP));
/* end of expr.h */