mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-15 04:31:49 +08:00
82 lines
2.7 KiB
C
82 lines
2.7 KiB
C
/* expr.h -> header file for expr.c
|
|
Copyright (C) 1987 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, 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
|
|
* emmissions, 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.
|
|
*/
|
|
|
|
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. */
|
|
|
|
typedef char operator_rankT;
|
|
|
|
#ifdef __STDC__
|
|
|
|
char get_symbol_end(void);
|
|
segT expr(int rank, expressionS *resultP);
|
|
unsigned int get_single_number(void);
|
|
|
|
#else /* __STDC__ */
|
|
|
|
char get_symbol_end();
|
|
segT expr();
|
|
unsigned int get_single_number();
|
|
|
|
#endif /* __STDC__ */
|
|
|
|
/* end of expr.h */
|