stab.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid ="@(#)stab.c	4.1	(ULTRIX)	7/3/90";
#endif

/************************************************************************
 *									*
 *			Copyright (c) 1985, 1987 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 - Fixed array handling in gentype so, for instance, arrays
 *	      of pointers would generate proper indexes instead of -1.
 *	      (jlr, July 20, 1988)
 *
 *	002 - Replaced missing putchar(';') at end of enum types.
 *	      Caused "assertion failed" message from dbx.
 *	      (Jon Reeves, July 15, 1987)
 *
 *	Victoria Holt, 26-Feb-86
 * 001	Redefined Boolean in mfile1, so took out multiple definition
 *	in this file.
 *
 ******************************************************************/

/*
 * Symbolic debugging info interface.
 *
 * Here we generate pseudo-ops that cause the assembler to put
 * symbolic debugging information into the object file.
 */

#include "mfile1"

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

#define private static
#define and &&
#define or ||
#define not !
#define div /
#define mod %
#define nil 0

#define bytes(bits) ((bits) / SZCHAR)
#define bsize(p) bytes(dimtab[p->sizoff])	/* size in bytes of a symbol */

#define NILINDEX -1
#define FORWARD -2

extern int ddebug;
extern int gdebug;
extern char *malloc();

int stabLCSYM;

/*
 * Flag for producing either sdb or dbx symbol information.
 */
Boolean oldway = false;

/*
 * Generate debugging info for a parameter.
 * The offset isn't known when it is first entered into the symbol table
 * since the types are read later.
 */

fixarg(p)
struct symtab *p;
{
    if (oldway) {
	old_fixarg(p);
    } else if (gdebug) {
	printf("\t.stabs\t\"%s:p", p->sname);
	gentype(p);
	printf("\",0x%x,0,%d,%d\n", N_PSYM, bsize(p), bytes(argoff));
    }
}

/*
 * Determine if the given symbol is a global array with dimension 0,
 * which only makes sense if it's dimension is to be given later.
 * We therefore currently do not generate symbol information for
 * such entries.
 */

#define isglobal(class) ( \
    class == EXTDEF or class == EXTERN or class == STATIC \
)

private Boolean zero_length_array(p)
register struct symtab *p;
{
    Boolean b;
    int t;

    if (not isglobal(p->sclass)) {
	b = false;
    } else {
	t = p->stype;
	if (ISFTN(t)) {
	    t = DECREF(t);
	}
	b = (Boolean) (ISARY(t) and dimtab[p->dimoff] == 0);
    }
    return b;
}

/*
 * Generate debugging info for a given symbol.
 */

outstab(sym)
struct symtab *sym;
{
    register struct symtab *p;
    char *classname;
    int offset;
    Boolean ignore;
    static Boolean firsttime = true;

    if (oldway) {
	old_outstab(sym);
    } else if (gdebug and not zero_length_array(sym)) {
	if (firsttime) {
	    firsttime = false;
	    inittypes();
	}
	ignore = false;
	p = sym;
	offset = bytes(p->offset);
	switch (p->sclass) {
	case REGISTER:
	    classname = "r";
	    offset = p->offset;
	    break;

	/*
	 * Locals are the default class.
	 */
	case AUTO:
	    classname = "";
	    break;

	case STATIC:
	    if (ISFTN(p->stype)) {
		ignore = true;
	    } else if (p->slevel <= 1) {
		classname = "S";
	    } else {
		classname = "V";
	    }
	    break;

	case EXTDEF:
	case EXTERN:
	    if (ISFTN(p->stype)) {
		ignore = true;
	    } else {
		classname = "G";
	    }
	    break;

	case TYPEDEF:
	    classname = "t";
	    break;

	case PARAM:
	case MOS:
	case MOU:
	case MOE:
	    ignore = true;
	    break;

	case ENAME:
	case UNAME:
	case STNAME:
	    entertype(p->stype, NILINDEX, FORWARD, dimtab[p->sizoff + 3]);
	    ignore = true;
	    break;

	default:
	    if ((p->sclass&FIELD) == 0) {
		printf("/* no info for %s (%d) */\n", p->sname, p->sclass);
	    }
	    ignore = true;
	    break;
	}
	if (not ignore) {
	    printf("\t.stabs\t\"%s:%s", p->sname, classname);
	    gentype(p);
	    geninfo(p);
	}
    }
}

/*
 * Since type names are lost in the travels and because C has
 * structural type equivalence we keep a table of type words that
 * we've already seen.  The first time we see a type, it is assigned
 * (inline) a number and future references just list that number.
 * Structures, unions, enums, and arrays must be handled carefully
 * since not all the necessary information is in the type word.
 */

typedef struct Typeid *Typeid;

struct Typeid {
    TWORD tword;
    int tarray;
    int tstruct;
    int tstrtag;
    int tnum;
    Typeid chain;
};

#define TABLESIZE 2003

private int tcount = 1;
private int t_int, t_char;
private Typeid typetable[TABLESIZE];

/*
 * Look for the given type word in the type table.
 */

private Typeid typelookup(type, arrindex, strindex, strtag)
TWORD type;
int arrindex;
int strindex;
int strtag;
{
    register TWORD tword;
    register int i1, i2;
    Typeid t;

    t = typetable[type mod TABLESIZE];
    while (t != nil) {
	if (t->tword == type and
	  strindex == t->tstruct and strtag == t->tstrtag) {
	    if (arrindex == NILINDEX) {
		break;
	    } else {
		tword = type;
		i1 = arrindex;
		i2 = t->tarray;
		while (ISARY(tword) and dimtab[i1] == dimtab[i2]) {
		    ++i1;
		    ++i2;
		    tword >>= TSHIFT;
		}
		if (!ISARY(tword)) {
		    break;
		}
	    }
	}
	t = t->chain;
    }
    return t;
}

/*
 * Enter a type word and associated symtab indices into the type table.
 */

private int entertype(type, arrindex, strindex, strtag)
TWORD type;
int arrindex;
int strindex;
int strtag;
{
    register Typeid t;
    register int i;

    t = (Typeid) malloc(sizeof(struct Typeid));
    t->tword = type;
    t->tarray = arrindex;
    t->tstruct = strindex;
    t->tstrtag = strtag;
    t->tnum = tcount;
    ++tcount;
    i = type mod TABLESIZE;
    t->chain = typetable[i];
    typetable[i] = t;
    return t->tnum;
}

/*
 * Change the information associated with a type table entry.
 * Since I'm lazy this just creates a new entry with the number
 * as the old one.
 */

private reentertype(typeid, type, arrindex, strindex, strtag)
Typeid typeid;
TWORD type;
int arrindex;
int strindex;
int strtag;
{
    register Typeid t;
    register int i;

    t = (Typeid) malloc(sizeof(struct Typeid));
    t->tword = type;
    t->tarray = arrindex;
    t->tstruct = strindex;
    t->tstrtag = strtag;
    t->tnum = typeid->tnum;
    i = type mod TABLESIZE;
    t->chain = typetable[i];
    typetable[i] = t;
}

/*
 * Initialize type table with predefined types.
 */

#define builtintype(type) entertype(type, NILINDEX, NILINDEX, NILINDEX)

private inittypes()
{
    int t;

    t_int = builtintype(INT);
    t_char = builtintype(CHAR);
    maketype("int", t_int, t_int, 0x80000000L, 0x7fffffffL);
    maketype("char", t_char, t_char, 0L, 127L);
    maketype("long", builtintype(LONG), t_int, 0x80000000L, 0x7fffffffL);
    maketype("short", builtintype(SHORT), t_int, 0xffff8000L, 0x7fffL);
    maketype("unsigned char", builtintype(UCHAR), t_int, 0L, 255L);
    maketype("unsigned short", builtintype(USHORT), t_int, 0L, 0xffffL);
    maketype("unsigned long", builtintype(ULONG), t_int, 0L, 0xffffffffL);
    maketype("unsigned int", builtintype(UNSIGNED), t_int, 0L, 0xffffffffL);
    maketype("float", builtintype(FLOAT), t_int, 4L, 0L);
    maketype("double", builtintype(DOUBLE), t_int, 8L, 0L);
    t = builtintype(UNDEF);
    printf("\t.stabs\t\"void:t%d=%d", t, t);
    geninfo(nil);
    t = builtintype(FARG);
    printf("\t.stabs\t\"???:t%d=%d", t, t_int);
    geninfo(nil);
}

/*
 * Generate info for a new range type.
 */

private maketype(name, tnum, eqtnum, lower, upper)
char *name;
int tnum, eqtnum;
long lower, upper;
{
    printf("\t.stabs\t\"%s:t%d=r%d;%d;%d;", name, tnum, eqtnum, lower, upper);
    geninfo(nil);
}

/*
 * Generate debugging information for the given type of the given symbol.
 */

private gentype(sym)
struct symtab *sym;
{
    register struct symtab *p;
    register TWORD t;
    register TWORD basictype;
    register Typeid typeid;
    int i, arrindex, strindex, strtag;

    p = sym;
    t = p->stype;
    if (ISFTN(t)) {
	t = DECREF(t);
    }
    basictype = BTYPE(t);
    if (ISARY(t)) {
	arrindex = p->dimoff;
    } else {
	arrindex = NILINDEX;
    }
    if (basictype == STRTY or basictype == UNIONTY or basictype == ENUMTY) {
	strindex = dimtab[p->sizoff + 1];
	if (strindex == -1) {
	    strindex = FORWARD;
	    strtag = dimtab[p->sizoff + 3];
	} else {
	    strtag = NILINDEX;
	}
    } else {
	strindex = NILINDEX;
	strtag = NILINDEX;
    }
    i = arrindex;
    typeid = typelookup(t, arrindex, strindex, strtag);
    while (t != basictype and typeid == nil) {
	printf("%d=", entertype(t, i, strindex, strtag));
	switch (t&TMASK) {
	case PTR:
	    printf("*");
	    break;

	case FTN:
	    printf("f");
	    break;

	case ARY:
	    printf("ar%d;0;%d;", t_int, dimtab[i++] - 1);
	    break;
	}
	t = DECREF(t);
	if (i == NILINDEX && ISARY(t)) {
	    i = p->dimoff;
	}
	if (t == basictype) {
	    typeid = typelookup(t, NILINDEX, strindex, strtag);
	} else {
	    typeid = typelookup(t, i, strindex, strtag);
	}
    }
    if (typeid == nil) {
	if (strindex == FORWARD) {
	    typeid = typelookup(t, NILINDEX, FORWARD, dimtab[p->sizoff + 3]);
	    if (typeid == nil) {
		cerror("unbelievable forward reference");
	    }
	    printf("%d", typeid->tnum);
	} else {
	    genstruct(t, NILINDEX, strindex, p->sname, bsize(p));
	}
    } else {
	printf("%d", typeid->tnum);
    }
}

/*
 * Generate type information for structures, unions, and enumerations.
 */

private genstruct(t, structid, index, name, size)
TWORD t;
int structid;
int index;
char *name;
int size;
{
    register int i;
    register struct symtab *field;
    int id;

    if (structid == NILINDEX) {
	id = entertype(t, NILINDEX, index, NILINDEX);
    } else {
	id = structid;
    }
    switch (t) {
    case STRTY:
    case UNIONTY:
	printf("%d=%c%d", id, t == STRTY ? 's' : 'u', size);
	i = index;
	while (dimtab[i] != -1) {