as.h

<B>Digital的Unix操作系统VAX 4.2源码</B>

/*static char sccsid[] = "@(#)as.h	4.3 ULTRIX 9/4/90";*/

/************************************************************************
 *									*
 *			Copyright (c) 1985 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
 *									*
 *			Modification History				*
 *
 * 003  Tanya Klinchina, 20-Nov-1989
 *      Added support for vector instructions.
 *
 * 002	David L Ballenger, 24-Feb-1986					*
 *	Add definitions for module and label alignment.			*
 *									*
 *	001 - Added new stab-type FORWARDSTAB, for those stabs		*
 *	      that address forward references.				*
 *	      (Victoria Holt, May 7, 1985)				*
 *									*
 ************************************************************************/

/*
 *	Copyright (c) 1982 Regents of the University of California
 *	@(#)as.h 4.19 8/11/83
 */
#define	reg	register

#include <sys/types.h>
#include <a.out.h>
#include <stab.h>

#define readonly
#define	NINST		300

#define	NEXP		20	/* max number of expr. terms per instruction */
#define	NARG		6	/* max number of args per instruction */
#define	NHASH		1103	/* hash table is dynamically extended */
#define	TNAMESIZE	32	/* maximum length of temporary file names */
#define	NLOC		4	/* number of location ctrs */
/*
 *	Sizes for character buffers.
 *	what			size #define name	comments
 *
 *	name assembly		NCPName	
 *	name save		STRPOOLDALLOP	
 *
 *	-name saving is a simple first fit
 */
#ifndef STRPOOLDALLOP
#	define STRPOOLDALLOP	8192
#endif /* not STRPOOLDALLOP */

#define	NCPName	NCPS
#ifndef NCPS
#	undef	NCPName
#	define	NCPName	4096
#endif /* not NCPS */
/*
 *	Check sizes, and compiler error if sizes botch
 */
#if STRPOOLDALLOP < NCPName
	$$$botch with definition sizes
#endif /* test botches */
/*
 * Symbol types
 */
#define	XUNDEF	0x0
#define	XABS	0x2
#define	XTEXT	0x4
#define	XDATA	0x6
#define	XBSS	0x8

#define	XXTRN	0x1
#define	XTYPE	0x1E

#define	XFORW	0x20	/* Was forward-referenced when undefined */

#define	ERR	(-1)
#define	NBPW	32	/* Bits per word */

#define	AMASK	017

/*
 * Actual argument syntax types
 */
#define ACTRL   0       /* vector ctrl word */
#define	AREG	1	/* %r */
#define	ABASE	2	/* (%r) */
#define	ADECR	3	/* -(%r) */
#define	AINCR	4	/* (%r)+ */
#define	ADISP	5	/* expr(%r) */
#define	AEXP	6	/* expr */
#define	AIMM	7	/* $ expr */
#define	ASTAR	8	/* * */
#define	AINDX	16	/* [%r] */
#define AVECT   32      /* vector instruction argument */
#define AVREG   33      /* vector reg %v */
#define AVIMM   39      /* vector $ expr */
/*
 *	Definitions for the things found in ``instrs''
 */
#define	INSTTAB 1
#include "instrs.h"

/*
 *	Tells outrel what it is relocating
 *	RELOC_PCREL is an implicit argument to outrel; it is or'ed in
 *	with a TYPX
 */
#define	RELOC_PCREL	(1<<TYPLG)
/*
 *	reference types for loader
 */
#define	PCREL	1
#define	LEN1	2
#define	LEN2	4
#define	LEN4	6
#define	LEN8	8
#define	LEN16	10

extern	int	reflen[];	/* {LEN*+PCREL} ==> number of bytes */
extern	int	lgreflen[];	/* {LEN*+PCREL} ==> lg number of bytes */
extern	int	len124[];	/* {1,2,4,8,16} ==> {LEN1, LEN2, LEN4, LEN8} */
extern	char	mod124[];	/* {1,2,4,8,16} ==> {bits to construct operands */
extern	int	type_124[];	/* {1,2,4,8,16} ==> {TYPB,TYPW,TYPL,TYPQ,TYPO} */
extern	int	ty_NORELOC[];	/* {TYPB..TYPH} ==> {1 if relocation not OK */
extern	int	ty_float[];	/* {TYPB..TYPH} ==> {1 if floating number */
extern	int	ty_LEN[];	/* {TYPB..TYPH} ==> {LEN1..LEN16} */
extern	int	ty_nbyte[];	/* {TYPB..TYPH} ==> {1,2,4,8,16} */
extern	int	ty_nlg[];	/* {TYPB..TYPH} ==> lg{1,2,4,8,16} */
extern	char	*ty_string[];	/* {TYPB..TYPH} ==> printable */

#define	TMPC	7	
#define	HW	0x1
#define	FW	0x3
#define	DW	0x7
#define	OW	0xF

#define	round(x,y)	(((x)+(y)) & ~(y))

#define	STABTYPS	0340
#define	STABFLAG	0200

/*
 *	Follows are the definitions for the symbol table tags, which are
 *	all unsigned characters..
 *	High value tags are generated by the asembler for internal
 *	use.
 *	Low valued tags are the parser coded tokens the scanner returns.
 *	There are several pertinant bounds in this ordering:
 *		a)	Symbols greater than JXQUESTIONABLE
 *			are used by the jxxx bumper, indicating that
 *			the symbol table entry is a jxxx entry
 *			that has yet to be bumped.
 *		b)	Symbols greater than IGNOREBOUND are not
 *			bequeathed to the loader; they are truly
 *			for assembler internal use only.
 *		c)	Symbols greater than OKTOBUMP represent
 *			indices into the program text that should
 *			be changed in preceeding jumps or aligns
 *			must get turned into their long form.
 */

#define	TAGMASK		0xFF

#	define	JXACTIVE	0xFF	/*jxxx size unknown*/
#	define	JXNOTYET	0xFE	/*jxxx size known, but not yet expanded*/
#	define	JXALIGN		0xFD	/*align jxxx entry*/
#	define	JXINACTIVE	0xFC	/*jxxx size known and expanded*/

#define	JXQUESTIONABLE		0xFB

#	define	JXTUNNEL	0xFA	/*jxxx that jumps to another*/
#	define	OBSOLETE	0xF9	/*erroneously entered symbol*/

#define	IGNOREBOUND	0xF8		/*symbols greater than this are ignored*/
#	define	FLOATINGSTAB	0xF7
#	define	LABELID		0xF6

#define	OKTOBUMP	0xF5
#	define  FORWARDSTAB	0xF3
#	define	FIXEDSTAB	0xF4

/* Definitions pertaining to alignment of modules and labels.  These are
 * expressed as powers of 2.
 *
 * MODULE_ALIGNMENT	This is the maximum alignment factor guaranteed by
 *			ld(1) for a text, data, or bss segment from a module.
 *			This header file is included by ld.c to get this
 *			value.
 *
 * LABEL_ALIGNMENT	This is the alignment guaranteed by as(1) for labels
 *			following jbr instructions or jxxx instructions which
 *			are converted to a bxxx followed by a brw.  See
 *			asjxxx.c for a description.
 *
 * ALIGN_GUARANTEE	The maximumn value for an alignment expression on a
 *			.align statement that as(1) will accept without
 *			issuing a warning message.  This is dependent on
 *			the maximum module alignment guaranteed by ld(1).
 *
 * MAX_ALIGN_EXPR	The maximum value that as will except for an 
 *			alignment expression without issuing an error.
 *
 * LEGAL_ALIGN_VAL(n)	Macro to see if 'n' is in the legal range for an
 *			alignment expression.
 */
#define MODULE_ALIGNMENT	(3)	/* quadword alignment */
#define LABEL_ALIGNMENT		(2)	/* longword alignment */
#define ALIGN_GUARANTEE		MODULE_ALIGNMENT
#define MAX_ALIGN_EXPR		(16)
#define LEGAL_ALIGN_VAL(n)	(((n) >= 0) && ((n) <= MAX_ALIGN_EXPR))

/*
 *	astoks.h contains reserved word codings the parser should
 *	know about
 */
#include "astoks.h"

/*
 *	The structure for one symbol table entry.
 *	Symbol table entries are used for both user defined symbols,
 *	and symbol slots generated to create the jxxx jump from
 *	slots.
 *	Caution: the instructions are stored in a shorter version
 *	of the struct symtab, using all fields in sym_nm and
 *	tag.  The fields used in sym_nm are carefully redeclared
 *	in struct Instab and struct instab (see below).
 *	If struct nlist gets changed, then Instab and instab may
 *	have to be changed.
 */

struct symtab{
		struct	nlist	s_nm;
		u_char	s_tag;		/* assembler tag */
		u_char	s_ptype;	/* if tag == NAME */
		u_char	s_jxneedalign;	/* if a jbr/jxxx needs alignment */
		short	s_index;	/* which segment */
		struct	symtab *s_dest;	/* if JXXX, where going to */
#ifdef DJXXX
		short	s_jxline;	/* source line of the jump from */
#endif
};
/*
 *	Redefinitions of the fields in symtab for
 *	use when the symbol table entry marks a jxxx instruction.
 */
#define	s_jxbump	s_ptype		/* tag == JX..., how far to expand */
#define	s_jxfear	s_desc		/* how far needs to be bumped */
/*
 *	Redefinitions of fields in the struct nlist for symbols so that
 *	one saves typing, and so that they conform 
 *	with the old naming conventions.
 */
#define	s_name	s_nm.n_un.n_name
#define	i_name	s_name
#define	FETCHNAME(sp)	(((struct strdesc *)(sp)->s_name)->sd_string)
#define	STRLEN(sp)	(((struct strdesc *)(sp)->s_name)->sd_strlen)
#define	STROFF(sp)	(((struct strdesc *)(sp)->s_name)->sd_stroff)
#define	STRPLACE(sp)	(((struct strdesc *)(sp)->s_name)->sd_place)
#define	s_nmx	s_nm.n_un.n_strx	/* string table index */
#define	s_type	s_nm.n_type		/* type of the symbol */
#define	s_other	s_nm.n_other		/* other information for sdb */
#define	s_desc	s_nm.n_desc		/* type descriptor */
#define	s_value	s_nm.n_value		/* value of the symbol, or sdb delta */

struct	instab{
	struct	nlist	s_nm;		/* instruction name, type (opcode) */
	u_char	s_tag;			
	u_char	s_eopcode;
	char    s_format;               /* vector instruction format */
	u_char	s_ctrlcode;    		/* vector instruction CMP/CVT code */
};
typedef	struct	instab	*Iptr;
/*
 *	The fields nm.n_desc and nm.n_value total 6 bytes; this is
 *	just enough for the 6 bytes describing the argument types.
 *	We use a macro to define access to these 6 bytes, assuming that
 *	they are allocated adjacently.
 *	IF THE FORMAT OF STRUCT nlist CHANGES, THESE MAY HAVE TO BE CHANGED.
 *
 *	Instab is cleverly declared to look very much like the combination of
 *	a struct symtab and a struct nlist.
 */
/*
 *	With the 1981 VAX architecture reference manual,
 *	DEC defined and named two byte opcodes. 
 *	In addition, DEC defined four new one byte instructions for
 *	queue manipulation.
 *	The assembler was patched in 1982 to reflect this change.
 *
 *	The two byte opcodes are preceded with an escape byte
 *	(usually an ESCD) and an opcode byte.
 *	For one byte opcodes, the opcode is called the primary opcode.
 *	For two byte opcodes, the second opcode is called the primary opcode.
 *
 *	We store the primary opcode in I_popcode,
 *	and the escape opcode in I_eopcode.