sym.h

这个是LINUX下的GDB调度工具的源码

/* Declarations of internal format of MIPS ECOFF symbols.
   Originally contributed by MIPS Computer Systems and Third Eye Software.
   Changes contributed by Cygnus Support are in the public domain.  

   This file is just aggregated with the files that make up the GNU
   release; it is not considered part of GAS, GDB, or other GNU
   programs.  */

/*
 * |-----------------------------------------------------------|
 * | Copyright (c) 1992, 1991, 1990 MIPS Computer Systems, Inc.|
 * | MIPS Computer Systems, Inc. grants reproduction and use   |
 * | rights to all parties, PROVIDED that this comment is      |
 * | maintained in the copy.                                   |
 * |-----------------------------------------------------------|
 */
#ifndef _SYM_H
#define _SYM_H

/* (C) Copyright 1984 by Third Eye Software, Inc.
 *
 * Third Eye Software, Inc. grants reproduction and use rights to
 * all parties, PROVIDED that this comment is maintained in the copy.
 *
 * Third Eye makes no claims about the applicability of this
 * symbol table to a particular use.
 */

/* 
 * This file contains the definition of the Third Eye Symbol Table.
 *
 * Symbols are assumed to be in 'encounter order' - i.e. the order that
 * the things they represent were encountered by the compiler/assembler/loader.
 * EXCEPT for globals!	These are assumed to be bunched together,
 * probably right after the last 'normal' symbol.  Globals ARE sorted
 * in ascending order.
 *
 * -----------------------------------------------------------------------
 * A brief word about Third Eye naming/use conventions:
 *
 * All arrays and index's are 0 based.
 * All "ifooMax" values are the highest legal value PLUS ONE. This makes
 * them good for allocating arrays, etc. All checks are "ifoo < ifooMax".
 *
 * "isym"	Index into the SYMbol table.
 * "ipd"	Index into the Procedure Descriptor array.
 * "ifd"	Index into the File Descriptor array.
 * "iss"	Index into String Space.
 * "cb"		Count of Bytes.
 * "rgPd"	array whose domain is "0..ipdMax-1" and RanGe is PDR.
 * "rgFd"	array whose domain is "0..ifdMax-1" and RanGe is FDR.
 */


/* 
 * Symbolic Header (HDR) structure.
 * As long as all the pointers are set correctly,
 * we don't care WHAT order the various sections come out in!
 *
 * A file produced solely for the use of CDB will probably NOT have
 * any instructions or data areas in it, as these are available
 * in the original.
 */

typedef struct {
	short	magic;		/* to verify validity of the table */
	short	vstamp;		/* version stamp */
	long	ilineMax;	/* number of line number entries */
	bfd_vma	cbLine;		/* number of bytes for line number entries */
	bfd_vma	cbLineOffset;	/* offset to start of line number entries*/
	long	idnMax;		/* max index into dense number table */
	bfd_vma	cbDnOffset;	/* offset to start dense number table */
	long	ipdMax;		/* number of procedures */
	bfd_vma	cbPdOffset;	/* offset to procedure descriptor table */
	long	isymMax;	/* number of local symbols */
	bfd_vma	cbSymOffset;	/* offset to start of local symbols*/
	long	ioptMax;	/* max index into optimization symbol entries */
	bfd_vma	cbOptOffset;	/* offset to optimization symbol entries */
	long	iauxMax;	/* number of auxillary symbol entries */
	bfd_vma	cbAuxOffset;	/* offset to start of auxillary symbol entries*/
	long	issMax;		/* max index into local strings */
	bfd_vma	cbSsOffset;	/* offset to start of local strings */
	long	issExtMax;	/* max index into external strings */
	bfd_vma	cbSsExtOffset;	/* offset to start of external strings */
	long	ifdMax;		/* number of file descriptor entries */
	bfd_vma	cbFdOffset;	/* offset to file descriptor table */
	long	crfd;		/* number of relative file descriptor entries */
	bfd_vma	cbRfdOffset;	/* offset to relative file descriptor table */
	long	iextMax;	/* max index into external symbols */
	bfd_vma	cbExtOffset;	/* offset to start of external symbol entries*/
	/* If you add machine dependent fields, add them here */
	} HDRR, *pHDRR; 
#define cbHDRR sizeof(HDRR)
#define hdrNil ((pHDRR)0)

/*
 * The FDR and PDR structures speed mapping of address <-> name.
 * They are sorted in ascending memory order and are kept in
 * memory by CDB at runtime.
 */

/* 
 * File Descriptor
 *
 * There is one of these for EVERY FILE, whether compiled with
 * full debugging symbols or not.  The name of a file should be
 * the path name given to the compiler.	 This allows the user
 * to simply specify the names of the directories where the COMPILES
 * were done, and we will be able to find their files.
 * A field whose comment starts with "R - " indicates that it will be
 * setup at runtime.
 */
typedef struct fdr {
	bfd_vma	adr;		/* memory address of beginning of file */
	long	rss;		/* file name (of source, if known) */
	long	issBase;	/* file's string space */
	bfd_vma	cbSs;		/* number of bytes in the ss */
	long	isymBase;	/* beginning of symbols */
	long	csym;		/* count file's of symbols */
	long	ilineBase;	/* file's line symbols */
	long	cline;		/* count of file's line symbols */
	long	ioptBase;	/* file's optimization entries */
	long	copt;		/* count of file's optimization entries */
	unsigned short ipdFirst;/* start of procedures for this file */
	short	cpd;		/* count of procedures for this file */
	long	iauxBase;	/* file's auxiliary entries */
	long	caux;		/* count of file's auxiliary entries */
	long	rfdBase;	/* index into the file indirect table */
	long	crfd;		/* count file indirect entries */
	unsigned lang: 5;	/* language for this file */
	unsigned fMerge : 1;	/* whether this file can be merged */
	unsigned fReadin : 1;	/* true if it was read in (not just created) */
	unsigned fBigendian : 1;/* if set, was compiled on big endian machine */
				/*	aux's will be in compile host's sex */
	unsigned glevel : 2;	/* level this file was compiled with */
	unsigned reserved : 22;  /* reserved for future use */
	bfd_vma	cbLineOffset;	/* byte offset from header for this file ln's */
	bfd_vma	cbLine;		/* size of lines for this file */
	} FDR, *pFDR;
#define cbFDR sizeof(FDR)
#define fdNil ((pFDR)0)
#define ifdNil -1
#define ifdTemp 0
#define ilnNil -1


/* 
 * Procedure Descriptor
 *
 * There is one of these for EVERY TEXT LABEL.
 * If a procedure is in a file with full symbols, then isym
 * will point to the PROC symbols, else it will point to the
 * global symbol for the label.
 */

typedef struct pdr {
	bfd_vma	adr;		/* memory address of start of procedure */
	long	isym;		/* start of local symbol entries */
	long	iline;		/* start of line number entries*/
	long	regmask;	/* save register mask */
	long	regoffset;	/* save register offset */
	long	iopt;		/* start of optimization symbol entries*/
	long	fregmask;	/* save floating point register mask */
	long	fregoffset;	/* save floating point register offset */
	long	frameoffset;	/* frame size */
	short	framereg;	/* frame pointer register */
	short	pcreg;		/* offset or reg of return pc */
	long	lnLow;		/* lowest line in the procedure */
	long	lnHigh;		/* highest line in the procedure */
	bfd_vma	cbLineOffset;	/* byte offset for this procedure from the fd base */
	/* These fields are new for 64 bit ECOFF.  */
	unsigned gp_prologue : 8; /* byte size of GP prologue */
	unsigned gp_used : 1;	/* true if the procedure uses GP */
	unsigned reg_frame : 1;	/* true if register frame procedure */
	unsigned prof : 1;	/* true if compiled with -pg */
	unsigned reserved : 13;	/* reserved: must be zero */
	unsigned localoff : 8;	/* offset of local variables from vfp */
	} PDR, *pPDR;
#define cbPDR sizeof(PDR)
#define pdNil ((pPDR) 0)
#define ipdNil	-1

/*
 * The structure of the runtime procedure descriptor created by the loader
 * for use by the static exception system.
 */
/*
 * If 0'd out because exception_info chokes Visual C++ and because there
 * don't seem to be any references to this structure elsewhere in gdb.
 */
#if 0
typedef struct runtime_pdr {
	bfd_vma	adr;		/* memory address of start of procedure */
	long	regmask;	/* save register mask */
	long	regoffset;	/* save register offset */
	long	fregmask;	/* save floating point register mask */
	long	fregoffset;	/* save floating point register offset */
	long	frameoffset;	/* frame size */
	short	framereg;	/* frame pointer register */
	short	pcreg;		/* offset or reg of return pc */
	long	irpss;		/* index into the runtime string table */
	long	reserved;
	struct exception_info *exception_info;/* pointer to exception array */
} RPDR, *pRPDR;
#define cbRPDR sizeof(RPDR)
#define rpdNil ((pRPDR) 0)
#endif

/*
 * Line Numbers
 *
 * Line Numbers are segregated from the normal symbols because they
 * are [1] smaller , [2] are of no interest to your
 * average loader, and [3] are never needed in the middle of normal
 * scanning and therefore slow things down.
 *
 * By definition, the first LINER for any given procedure will have
 * the first line of a procedure and represent the first address.
 */

typedef	long LINER, *pLINER;
#define lineNil ((pLINER)0)
#define cbLINER sizeof(LINER)
#define ilineNil	-1



/*
 * The Symbol Structure		(GFW, to those who Know!)
 */

typedef struct {
	long	iss;		/* index into String Space of name */
	bfd_vma	value;		/* value of symbol */
	unsigned st : 6;	/* symbol type */
	unsigned sc  : 5;	/* storage class - text, data, etc */
	unsigned reserved : 1;	/* reserved */
	unsigned index : 20;	/* index into sym/aux table */
	} SYMR, *pSYMR;
#define symNil ((pSYMR)0)
#define cbSYMR sizeof(SYMR)
#define isymNil -1
#define indexNil 0xfffff