machine.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

/*#@(#)machine.c	4.1	Ultrix	7/17/90*/
/* Copyright (c) 1982 Regents of the University of California */

static char sccsid[] = "@(#)machine.c 1.9 8/5/83";

static char rcsid[] = "$Header: machine.c,v 1.3 84/03/27 10:21:26 linton Exp $";

/*
 * Target machine dependent stuff.
 */

#include "defs.h"
#include "machine.h"
#include "process.h"
#include "runtime.h"
#include "events.h"
#include "main.h"
#include "symbols.h"
#include "source.h"
#include "mappings.h"
#include "object.h"
#include "ops.h"
#include <signal.h>

#ifndef public
typedef unsigned int Address;
typedef unsigned char Byte;
typedef unsigned int Word;

#define NREG 16

#define ARGP 12
#define FRP 13
#define STKP 14
#define PROGCTR 15

#define BITSPERBYTE 8
#define BITSPERWORD (BITSPERBYTE * sizeof(Word))

#define nargspassed(frame) argn(0, frame)

#include "source.h"
#include "symbols.h"

Address pc;
Address prtaddr;

#endif

private Address printop();

/*
 * Decode and print the instructions within the given address range.
 */

public printinst(lowaddr, highaddr)
Address lowaddr;
Address highaddr;
{
    register Address addr;

    for (addr = lowaddr; addr <= highaddr; ) {
	addr = printop(addr);
    }
    prtaddr = addr;
}

/*
 * Another approach:  print n instructions starting at the given address.
 */

public printninst(count, addr)
int count;
Address addr;
{
    register Integer i;
    register Address newaddr;

    if (count <= 0) {
	error("non-positive repetition count");
    } else {
	newaddr = addr;
	for (i = 0; i < count; i++) {
	    newaddr = printop(newaddr);
	}
	prtaddr = newaddr;
    }
}

/*
 * Hacked version of adb's VAX instruction decoder.
 */

private Address printop(addr)
Address addr;
{
    Optab op;
    VaxOpcode ins;
    unsigned char mode;
    int argtype, amode, argno, argval;
    String reg;
    Boolean indexf;
    short offset;

    argval = 0;
    indexf = false;
    printf("%08x  ", addr);
    iread(&ins, addr, sizeof(ins));
    addr += 1;
    op = optab[ins];
    printf("%s", op.iname);
    for (argno = 0; argno < op.numargs; argno++) {
	if (indexf == true) {
	    indexf = false;
	} else if (argno == 0) {
	    printf("\t");
	} else {
	    printf(",");
	}
	argtype = op.argtype[argno];
	if (is_branch_disp(argtype)) {
	    mode = 0xAF + (typelen(argtype) << 5);
	} else {
	    iread(&mode, addr, sizeof(mode));
	    addr += 1;
	}
	reg = regname[regnm(mode)];
	amode = addrmode(mode);
	switch (amode) {
	    case LITSHORT:
	    case LITUPTO31:
	    case LITUPTO47:
	    case LITUPTO63:
		if (typelen(argtype) == TYPF || typelen(argtype) ==TYPD)
		    printf("$%s", fltimm[mode]);
		else
		    printf("$%x", mode);
		argval = mode;
		break;

	    case INDEX:
		printf("[%s]", reg);
		indexf = true;
		argno--;
		break;

	    case REG:
		printf("%s", reg);
		break;

	    case REGDEF:
		printf("(%s)", reg);
		break;

	    case AUTODEC:
		printf("-(%s)", reg);
		break;

	    case AUTOINC:
		if (reg != regname[PROGCTR]) {
		    printf("(%s)+", reg);
		} else {
		    printf("$");
		    switch (typelen(argtype)) {
			case TYPB:
			    argval = printdisp(addr, 1, reg, amode);
			    addr += 1;
			    break;

			case TYPW:
			    argval = printdisp(addr, 2, reg, amode);
			    addr += 2;
			    break;

			case TYPL:
			    argval = printdisp(addr, 4, reg, amode);
			    addr += 4;
			    break;

			case TYPF:
			    iread(&argval, addr, sizeof(argval));
			    printf("%06x", argval);
			    addr += 4;
			    break;

			case TYPQ:
			case TYPD:
			    iread(&argval, addr, sizeof(argval));
			    printf("%06x", argval);
			    iread(&argval, addr+4, sizeof(argval));
			    printf("%06x", argval);
			    addr += 8;
			    break;
		    }
		}
		break;

	    case AUTOINCDEF:
		if (reg == regname[PROGCTR]) {
		    printf("*$");
		    argval = printdisp(addr, 4, reg, amode);
		    addr += 4;
		} else {
		    printf("*(%s)+", reg);
		}
		break;

	    case BYTEDISP:
		argval = printdisp(addr, 1, reg, amode);
		addr += 1;
		break;

	    case BYTEDISPDEF:
		printf("*");
		argval = printdisp(addr, 1, reg, amode);
		addr += 1;
		break;

	    case WORDDISP:
		argval = printdisp(addr, 2, reg, amode);
		addr += 2;
		break;

	    case WORDDISPDEF:
		printf("*");
		argval = printdisp(addr, 2, reg, amode);
		addr += 2;
		break;

	    case LONGDISP:
		argval = printdisp(addr, 4, reg, amode);
		addr += 4;
		break;

	    case LONGDISPDEF:
		printf("*");
		argval = printdisp(addr, 4, reg, amode);
		addr += 4;
		break;
	}
    }
    if (ins == O_CASEB || ins == O_CASEW || ins == O_CASEL) {
	for (argno = 0; argno <= argval; argno++) {
	    iread(&offset, addr, sizeof(offset));
	    printf("\n\t\t%d", offset);
	    addr += 2;
	}
    }
    printf("\n");
    return addr;
}

/*
 * Print the displacement of an instruction that uses displacement
 * addressing.
 */

private int printdisp(addr, nbytes, reg, mode)
Address addr;
int nbytes;
char *reg;
int mode;
{
    char byte;
    short hword;
    int argval;
    Symbol f;

    switch (nbytes) {
	case 1:
	    iread(&byte, addr, sizeof(byte));
	    argval = byte;
	    break;

	case 2:
	    iread(&hword, addr, sizeof(hword));
	    argval = hword;
	    break;

	case 4:
	    iread(&argval, addr, sizeof(argval));
	    break;
    }
    if (reg == regname[PROGCTR] && mode >= BYTEDISP) {
	argval += addr + nbytes;
    }
    if (reg == regname[PROGCTR]) {
	f = whatblock((Address) argval + 2);
	if (codeloc(f) == argval + 2) {
	    printf("%s", symname(f));
	} else {
	    printf("%x", argval);
	}
    } else {
	printf("%d(%s)", argval, reg);
    }
    return argval;
}

/*
 * Print the contents of the addresses within the given range
 * according to the given format.
 */

typedef struct {
    String name;
    String printfstring;
    int length;
} Format;

private Format fmt[] = {
    { "d", " %d", sizeof(short) },
    { "D", " %ld", sizeof(long) },
    { "o", " %o", sizeof(short) },
    { "O", " %lo", sizeof(long) },
    { "x", " %04x", sizeof(short) },
    { "X", " %08x", sizeof(long) },
    { "b", " \\%o", sizeof(char) },
    { "c", " '%c'", sizeof(char) },
    { "s", "%c", sizeof(char) },
    { "f", " %f", sizeof(float) },
    { "g", " %g", sizeof(double) },
    { nil, nil, 0 }
};

private Format *findformat(s)
String s;
{
    register Format *f;

    f = &fmt[0];
    while (f->name != nil and not streq(f->name, s)) {
	++f;
    }
    if (f->name == nil) {
	error("bad print format \"%s\"", s);
    }
    return f;
}

public Address printdata(lowaddr, highaddr, format)
Address lowaddr;
Address highaddr;
String format;
{
    register int n;
    register Address addr;
    register Format *f;
    int value;

    if (lowaddr > highaddr) {
	error("first address larger than second");
    }
    f = findformat(format);
    n = 0;
    value = 0;
    for (addr = lowaddr; addr <= highaddr; addr += f->length) {
	if (n == 0) {
	    printf("%08x: ", addr);
	}
	dread(&value, addr, f->length);
	printf(f->printfstring, value);
	++n;
	if (n >= (16 div f->length)) {
	    putchar('\n');
	    n = 0;
	}
    }
    if (n != 0) {
	putchar('\n');
    }
    prtaddr = addr;
    return addr;
}

/*
 * The other approach is to print n items starting with a given address.
 */

public printndata(count, startaddr, format)
int count;
Address startaddr;
String format;
{
    register int i, n;
    register Address addr;
    register Format *f;
    register Boolean isstring;
    char c;
    union {
	char charv;
	short shortv;
	int intv;
	float floatv;
	double doublev;
    } value;

    if (count <= 0) {
	error("non-positive repetition count");
    }
    f = findformat(format);
    isstring = (Boolean) streq(f->name, "s");
    n = 0;
    addr = startaddr;
    value.intv = 0;
    for (i = 0; i < count; i++) {
	if (n == 0) {
	    printf("%08x: ", addr);
	}
	if (isstring) {
	    putchar('"');
	    dread(&c, addr, sizeof(char));
	    while (c != '\0') {
		printchar(c);
		++addr;
		dread(&c, addr, sizeof(char));
	    }
	    putchar('"');
	    putchar('\n');
	    n = 0;
	    addr += sizeof(String);
	} else {
	    dread(&value, addr, f->length);
	    printf(f->printfstring, value);
	    ++n;
	    if (n >= (16 div f->length)) {
		putchar('\n');
		n = 0;
	    }
	    addr += f->length;
	}
    }
    if (n != 0) {
	putchar('\n');
    }
    prtaddr = addr;
}

/*
 * Print out a value according to the given format.
 */

public printvalue(v, format)
long v;
String format;
{
    Format *f;
    char *p, *q;

    f = findformat(format);
    if (streq(f->name, "s")) {
	putchar('"');
	p = (char *) &v;
	q = p + sizeof(v);
	while (p < q) {
	    printchar(*p);
	    ++p;
	}
	putchar('"');
    } else {
	printf(f->printfstring, v);
    }
    putchar('\n');
}

/*
 * Print out an execution time error.
 * Assumes the source position of the error has been calculated.
 *
 * Have to check if the -r option was specified; if so then
 * the object file information hasn't been read in yet.
 */

public printerror()
{
    extern Integer sys_nsig;