4.4BSD/usr/src/contrib/gdb-4.7.lbl/gdb/gould-pinsn.c
/* Print GOULD RISC instructions for GDB, the GNU debugger.
Copyright 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 of the License, or
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "defs.h"
#include "symtab.h"
#include "frame.h"
#include "gdbcore.h"
#if defined GOULD_PN
#include "opcode/pn.h"
#else
#include "opcode/np1.h"
#endif
/* GOULD RISC instructions are never longer than this many bytes. */
#define MAXLEN 4
/* Number of elements in the opcode table. */
#define NOPCODES (sizeof gld_opcodes / sizeof gld_opcodes[0])
/* Print the GOULD instruction at address MEMADDR in debugged memory,
on STREAM. Returns length of the instruction, in bytes. */
int
print_insn (memaddr, stream)
CORE_ADDR memaddr;
FILE *stream;
{
unsigned char buffer[MAXLEN];
register int i;
register char *d;
register int bestmask;
unsigned best;
int temp, index, bestlen;
read_memory (memaddr, buffer, MAXLEN);
bestmask = 0;
index = -1;
best = 0xffffffff;
for (i = 0; i < NOPCODES; i++)
{
register unsigned int opcode = gld_opcodes[i].opcode;
register unsigned int mask = gld_opcodes[i].mask;
register unsigned int len = gld_opcodes[i].length;
register unsigned int test;
/* Get possible opcode bytes into integer */
test = buffer[0] << 24;
test |= buffer[1] << 16;
test |= buffer[2] << 8;
test |= buffer[3];
/* Mask with opcode and see if match */
if ((opcode & mask) == (test & mask))
{
/* See if second or third match */
if (index >= 0)
{
/* Take new one if it looks good */
if (bestlen == MAXLEN && len == MAXLEN)
{
/* See if lower bits matched */
if (((bestmask & 3) == 0) &&
((mask & 3) != 0))
{
bestmask = mask;
bestlen = len;
best = test;
index = i;
}
}
}
else
{
/* First match, save it */
bestmask = mask;
bestlen = len;
best = test;
index = i;
}
}
}
/* Handle undefined instructions. */
if (index < 0)
{
fprintf (stream, "undefined 0%o",(buffer[0]<<8)+buffer[1]);
return 2;
}
/* Print instruction name */
fprintf (stream, "%-12s", gld_opcodes[index].name);
/* Adjust if short instruction */
if (gld_opcodes[index].length < 4)
{
best >>= 16;
i = 0;
}
else
{
i = 16;
}
/* Dump out instruction arguments */
for (d = gld_opcodes[index].args; *d; ++d)
{
switch (*d)
{
case 'f':
fprintf (stream, "%d", (best >> (7 + i)) & 7);
break;
case 'r':
fprintf (stream, "r%d", (best >> (7 + i)) & 7);
break;
case 'R':
fprintf (stream, "r%d", (best >> (4 + i)) & 7);
break;
case 'b':
fprintf (stream, "b%d", (best >> (7 + i)) & 7);
break;
case 'B':
fprintf (stream, "b%d", (best >> (4 + i)) & 7);
break;
case 'v':
fprintf (stream, "b%d", (best >> (7 + i)) & 7);
break;
case 'V':
fprintf (stream, "b%d", (best >> (4 + i)) & 7);
break;
case 'X':
temp = (best >> 20) & 7;
if (temp)
fprintf (stream, "r%d", temp);
else
putc ('0', stream);
break;
case 'A':
temp = (best >> 16) & 7;
if (temp)
fprintf (stream, "(b%d)", temp);
break;
case 'S':
fprintf (stream, "#%d", best & 0x1f);
break;
case 'I':
fprintf (stream, "#%x", best & 0xffff);
break;
case 'O':
fprintf (stream, "%x", best & 0xffff);
break;
case 'h':
fprintf (stream, "%d", best & 0xfffe);
break;
case 'd':
fprintf (stream, "%d", best & 0xfffc);
break;
case 'T':
fprintf (stream, "%d", (best >> 8) & 0xff);
break;
case 'N':
fprintf (stream, "%d", best & 0xff);
break;
default:
putc (*d, stream);
break;
}
}
/* Return length of instruction */
return (gld_opcodes[index].length);
}
/*
* Find the number of arguments to a function.
*/
findarg(frame)
struct frame_info *frame;
{
register struct symbol *func;
register unsigned pc;
#ifdef notdef
/* find starting address of frame function */
pc = get_pc_function_start (frame->pc);
/* find function symbol info */
func = find_pc_function (pc);
/* call blockframe code to look for match */
if (func != NULL)
return (func->value.block->nsyms / sizeof(int));
#endif
return (-1);
}
/*
* In the case of the NPL, the frame's norminal address is Br2 and the
* previous routines frame is up the stack X bytes. Finding out what
* 'X' is can be tricky.
*
* 1.) stored in the code function header xA(Br1).
* 2.) must be careful of recurssion.
*/
FRAME_ADDR
findframe(thisframe)
FRAME thisframe;
{
register FRAME_ADDR pointer;
FRAME_ADDR framechain();
#if 0
struct frame_info *frame;
/* Setup toplevel frame structure */
frame->pc = read_pc();
frame->next_frame = 0;
frame->frame = read_register (SP_REGNUM); /* Br2 */
/* Search for this frame (start at current Br2) */
do
{
pointer = framechain(frame);
frame->next_frame = frame->frame;
frame->frame = pointer;
frame->pc = FRAME_SAVED_PC(frame);
}
while (frame->next_frame != thisframe);
#endif
pointer = framechain (thisframe);
/* stop gap for now, end at __base3 */
if (thisframe->pc == 0)
return 0;
return pointer;
}
/*
* Gdb front-end and internal framechain routine.
* Go back up stack one level. Tricky...
*/
FRAME_ADDR
framechain(frame)
register struct frame_info *frame;
{
register CORE_ADDR func, prevsp;
register unsigned value;
/* Get real function start address from internal frame address */
func = get_pc_function_start(frame->pc);
/* If no stack given, read register Br1 "(sp)" */
if (!frame->frame)
prevsp = read_register (SP_REGNUM);
else
prevsp = frame->frame;
/* Check function header, case #2 */
value = read_memory_integer (func, 4);
if (value)
{
/* 32bit call push value stored in function header */
prevsp += value;
}
else
{
/* read half-word from suabr at start of function */
prevsp += read_memory_integer (func + 10, 2);
}
return (prevsp);
}