[deliverable/binutils-gdb.git] / gdb / vax-tdep.c

/* Print VAX instructions for GDB, the GNU debugger.
   Copyright 1986, 1989, 1991, 1992, 1995, 1996, 1998, 1999, 2000
   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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "symtab.h"
#include "opcode/vax.h"
#include "gdbcore.h"
#include "frame.h"
#include "value.h"

/* Return 1 if P points to an invalid floating point value.
   LEN is the length in bytes -- not relevant on the Vax.  */

/* FIXME: cagney/2002-01-19: The macro below was originally defined in
   tm-vax.h and used in values.c.  Two problems.  Firstly this is a
   very non-portable and secondly it is wrong.  The VAX should be
   using floatformat and associated methods to identify and handle
   invalid floating-point values.  Adding to the poor target's woes
   there is no floatformat_vax_{f,d} and no TARGET_FLOAT_FORMAT
   et.al..  */

/* FIXME: cagney/2002-01-19: It turns out that the only thing that
   uses this macro is the vax disassembler code (so how old is this
   target?).  This target should instead be using the opcodes
   disassembler.  That allowing the macro to be eliminated.  */

#define INVALID_FLOAT(p, len) ((*(short *) p & 0xff80) == 0x8000)

/* Vax instructions are never longer than this.  */
#define MAXLEN 62

/* Number of elements in the opcode table.  */
#define NOPCODES (sizeof votstrs / sizeof votstrs[0])

static unsigned char *print_insn_arg ();
\f
/* Advance PC across any function entry prologue instructions
   to reach some "real" code.  */

CORE_ADDR
vax_skip_prologue (CORE_ADDR pc)
{
  register int op = (unsigned char) read_memory_integer (pc, 1);
  if (op == 0x11)
    pc += 2;			/* skip brb */
  if (op == 0x31)
    pc += 3;			/* skip brw */
  if (op == 0xC2
      && ((unsigned char) read_memory_integer (pc + 2, 1)) == 0x5E)
    pc += 3;			/* skip subl2 */
  if (op == 0x9E
      && ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xAE
      && ((unsigned char) read_memory_integer (pc + 3, 1)) == 0x5E)
    pc += 4;			/* skip movab */
  if (op == 0x9E
      && ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xCE
      && ((unsigned char) read_memory_integer (pc + 4, 1)) == 0x5E)
    pc += 5;			/* skip movab */
  if (op == 0x9E
      && ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xEE
      && ((unsigned char) read_memory_integer (pc + 6, 1)) == 0x5E)
    pc += 7;			/* skip movab */
  return pc;
}

/* Return number of args passed to a frame.
   Can return -1, meaning no way to tell.  */

int
vax_frame_num_args (struct frame_info *fi)
{
  return (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1));
}


/* Print the vax instruction at address MEMADDR in debugged memory,
   from disassembler info INFO.
   Returns length of the instruction, in bytes.  */

static int
vax_print_insn (CORE_ADDR memaddr, disassemble_info *info)
{
  unsigned char buffer[MAXLEN];
  register int i;
  register unsigned char *p;
  const char *d;

  int status = (*info->read_memory_func) (memaddr, buffer, MAXLEN, info);
  if (status != 0)
    {
      (*info->memory_error_func) (status, memaddr, info);
      return -1;
    }

  for (i = 0; i < NOPCODES; i++)
    if (votstrs[i].detail.code == buffer[0]
	|| votstrs[i].detail.code == *(unsigned short *) buffer)
      break;

  /* Handle undefined instructions.  */
  if (i == NOPCODES)
    {
      (*info->fprintf_func) (info->stream, "0%o", buffer[0]);
      return 1;
    }

  (*info->fprintf_func) (info->stream, "%s", votstrs[i].name);

  /* Point at first byte of argument data,
     and at descriptor for first argument.  */
  p = buffer + 1 + (votstrs[i].detail.code >= 0x100);
  d = votstrs[i].detail.args;

  if (*d)
    (*info->fprintf_func) (info->stream, " ");

  while (*d)
    {
      p = print_insn_arg (d, p, memaddr + (p - buffer), info);
      d += 2;
      if (*d)
	(*info->fprintf_func) (info->stream, ",");
    }
  return p - buffer;
}

static unsigned char *
print_insn_arg (char *d, register char *p, CORE_ADDR addr,
		disassemble_info *info)
{
  register int regnum = *p & 0xf;
  float floatlitbuf;

  if (*d == 'b')
    {
      if (d[1] == 'b')
	(*info->fprintf_func) (info->stream, "0x%x", addr + *p++ + 1);
      else
	{
	  (*info->fprintf_func) (info->stream, "0x%x", addr + *(short *) p + 2);
	  p += 2;
	}
    }
  else
    switch ((*p++ >> 4) & 0xf)
      {
      case 0:
      case 1:
      case 2:
      case 3:			/* Literal mode */
	if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
	  {
	    *(int *) &floatlitbuf = 0x4000 + ((p[-1] & 0x3f) << 4);
	    (*info->fprintf_func) (info->stream, "$%f", floatlitbuf);
	  }
	else
	  (*info->fprintf_func) (info->stream, "$%d", p[-1] & 0x3f);
	break;

      case 4:			/* Indexed */
	p = (char *) print_insn_arg (d, p, addr + 1, info);
	(*info->fprintf_func) (info->stream, "[%s]", REGISTER_NAME (regnum));
	break;

      case 5:			/* Register */
	(*info->fprintf_func) (info->stream, REGISTER_NAME (regnum));
	break;

      case 7:			/* Autodecrement */
	(*info->fprintf_func) (info->stream, "-");
      case 6:			/* Register deferred */
	(*info->fprintf_func) (info->stream, "(%s)", REGISTER_NAME (regnum));
	break;

      case 9:			/* Autoincrement deferred */
	(*info->fprintf_func) (info->stream, "@");
	if (regnum == PC_REGNUM)
	  {
	    (*info->fprintf_func) (info->stream, "#");
	    info->target = *(long *) p;
	    (*info->print_address_func) (info->target, info);
	    p += 4;
	    break;
	  }
      case 8:			/* Autoincrement */
	if (regnum == PC_REGNUM)
	  {
	    (*info->fprintf_func) (info->stream, "#");
	    switch (d[1])
	      {
	      case 'b':
		(*info->fprintf_func) (info->stream, "%d", *p++);
		break;

	      case 'w':
		(*info->fprintf_func) (info->stream, "%d", *(short *) p);
		p += 2;
		break;

	      case 'l':
		(*info->fprintf_func) (info->stream, "%d", *(long *) p);
		p += 4;
		break;

	      case 'q':
		(*info->fprintf_func) (info->stream, "0x%x%08x",
				       ((long *) p)[1], ((long *) p)[0]);
		p += 8;
		break;

	      case 'o':
		(*info->fprintf_func) (info->stream, "0x%x%08x%08x%08x",
				       ((long *) p)[3], ((long *) p)[2],
				       ((long *) p)[1], ((long *) p)[0]);
		p += 16;
		break;

	      case 'f':
		if (INVALID_FLOAT (p, 4))
		  (*info->fprintf_func) (info->stream,
					 "<<invalid float 0x%x>>",
					 *(int *) p);
		else
		  (*info->fprintf_func) (info->stream, "%f", *(float *) p);
		p += 4;
		break;

	      case 'd':
		if (INVALID_FLOAT (p, 8))
		  (*info->fprintf_func) (info->stream,
					 "<<invalid float 0x%x%08x>>",
					 ((long *) p)[1], ((long *) p)[0]);
		else
		  (*info->fprintf_func) (info->stream, "%f", *(double *) p);
		p += 8;
		break;

	      case 'g':
		(*info->fprintf_func) (info->stream, "g-float");
		p += 8;
		break;

	      case 'h':
		(*info->fprintf_func) (info->stream, "h-float");
		p += 16;
		break;

	      }
	  }
	else
	  (*info->fprintf_func) (info->stream, "(%s)+", REGISTER_NAME (regnum));
	break;

      case 11:			/* Byte displacement deferred */
	(*info->fprintf_func) (info->stream, "@");
      case 10:			/* Byte displacement */
	if (regnum == PC_REGNUM)
	  {
	    info->target = addr + *p + 2;
	    (*info->print_address_func) (info->target, info);
	  }
	else
	  (*info->fprintf_func) (info->stream, "%d(%s)", *p, REGISTER_NAME (regnum));
	p += 1;
	break;

      case 13:			/* Word displacement deferred */
	(*info->fprintf_func) (info->stream, "@");
      case 12:			/* Word displacement */
	if (regnum == PC_REGNUM)
	  {
	    info->target = addr + *(short *) p + 3;
	    (*info->print_address_func) (info->target, info);
	  }
	else
	  (*info->fprintf_func) (info->stream, "%d(%s)",
				 *(short *) p, REGISTER_NAME (regnum));
	p += 2;
	break;

      case 15:			/* Long displacement deferred */
	(*info->fprintf_func) (info->stream, "@");
      case 14:			/* Long displacement */
	if (regnum == PC_REGNUM)
	  {
	    info->target = addr + *(short *) p + 5;
	    (*info->print_address_func) (info->target, info);
	  }
	else
	  (*info->fprintf_func) (info->stream, "%d(%s)",
				 *(long *) p, REGISTER_NAME (regnum));
	p += 4;
      }

  return (unsigned char *) p;
}

void
_initialize_vax_tdep (void)
{
  tm_print_insn = vax_print_insn;
}
Commit	Line	Data
	1	/* Print VAX instructions for GDB, the GNU debugger.
	2	Copyright 1986, 1989, 1991, 1992, 1995, 1996, 1998, 1999, 2000
	3	Free Software Foundation, Inc.
	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software
	19	Foundation, Inc., 59 Temple Place - Suite 330,
	20	Boston, MA 02111-1307, USA. */
	21
	22	#include "defs.h"
	23	#include "symtab.h"
	24	#include "opcode/vax.h"
	25	#include "gdbcore.h"
	26	#include "frame.h"
	27	#include "value.h"
	28
	29	/* Return 1 if P points to an invalid floating point value.
	30	LEN is the length in bytes -- not relevant on the Vax. */
	31
	32	/* FIXME: cagney/2002-01-19: The macro below was originally defined in
	33	tm-vax.h and used in values.c. Two problems. Firstly this is a
	34	very non-portable and secondly it is wrong. The VAX should be
	35	using floatformat and associated methods to identify and handle
	36	invalid floating-point values. Adding to the poor target's woes
	37	there is no floatformat_vax_{f,d} and no TARGET_FLOAT_FORMAT
	38	et.al.. */
	39
	40	/* FIXME: cagney/2002-01-19: It turns out that the only thing that
	41	uses this macro is the vax disassembler code (so how old is this
	42	target?). This target should instead be using the opcodes
	43	disassembler. That allowing the macro to be eliminated. */
	44
	45	#define INVALID_FLOAT(p, len) (((short ) p & 0xff80) == 0x8000)
	46
	47	/* Vax instructions are never longer than this. */
	48	#define MAXLEN 62
	49
	50	/* Number of elements in the opcode table. */
	51	#define NOPCODES (sizeof votstrs / sizeof votstrs[0])
	52
	53	static unsigned char *print_insn_arg ();
	54	\f
	55	/* Advance PC across any function entry prologue instructions
	56	to reach some "real" code. */
	57
	58	CORE_ADDR
	59	vax_skip_prologue (CORE_ADDR pc)
	60	{
	61	register int op = (unsigned char) read_memory_integer (pc, 1);
	62	if (op == 0x11)
	63	pc += 2; /* skip brb */
	64	if (op == 0x31)
	65	pc += 3; /* skip brw */
	66	if (op == 0xC2
	67	&& ((unsigned char) read_memory_integer (pc + 2, 1)) == 0x5E)
	68	pc += 3; /* skip subl2 */
	69	if (op == 0x9E
	70	&& ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xAE
	71	&& ((unsigned char) read_memory_integer (pc + 3, 1)) == 0x5E)
	72	pc += 4; /* skip movab */
	73	if (op == 0x9E
	74	&& ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xCE
	75	&& ((unsigned char) read_memory_integer (pc + 4, 1)) == 0x5E)
	76	pc += 5; /* skip movab */
	77	if (op == 0x9E
	78	&& ((unsigned char) read_memory_integer (pc + 1, 1)) == 0xEE
	79	&& ((unsigned char) read_memory_integer (pc + 6, 1)) == 0x5E)
	80	pc += 7; /* skip movab */
	81	return pc;
	82	}
	83
	84	/* Return number of args passed to a frame.
	85	Can return -1, meaning no way to tell. */
	86
	87	int
	88	vax_frame_num_args (struct frame_info *fi)
	89	{
	90	return (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1));
	91	}
	92
	93
	94
	95	/* Print the vax instruction at address MEMADDR in debugged memory,
	96	from disassembler info INFO.
	97	Returns length of the instruction, in bytes. */
	98
	99	static int
	100	vax_print_insn (CORE_ADDR memaddr, disassemble_info *info)
	101	{
	102	unsigned char buffer[MAXLEN];
	103	register int i;
	104	register unsigned char *p;
	105	const char *d;
	106
	107	int status = (*info->read_memory_func) (memaddr, buffer, MAXLEN, info);
	108	if (status != 0)
	109	{
	110	(*info->memory_error_func) (status, memaddr, info);
	111	return -1;
	112	}
	113
	114	for (i = 0; i < NOPCODES; i++)
	115	if (votstrs[i].detail.code == buffer[0]
	116	\|\| votstrs[i].detail.code == (unsigned short ) buffer)
	117	break;
	118
	119	/* Handle undefined instructions. */
	120	if (i == NOPCODES)
	121	{
	122	(*info->fprintf_func) (info->stream, "0%o", buffer[0]);
	123	return 1;
	124	}
	125
	126	(*info->fprintf_func) (info->stream, "%s", votstrs[i].name);
	127
	128	/* Point at first byte of argument data,
	129	and at descriptor for first argument. */
	130	p = buffer + 1 + (votstrs[i].detail.code >= 0x100);
	131	d = votstrs[i].detail.args;
	132
	133	if (*d)
	134	(*info->fprintf_func) (info->stream, " ");
	135
	136	while (*d)
	137	{
	138	p = print_insn_arg (d, p, memaddr + (p - buffer), info);
	139	d += 2;
	140	if (*d)
	141	(*info->fprintf_func) (info->stream, ",");
	142	}
	143	return p - buffer;
	144	}
	145
	146	static unsigned char *
	147	print_insn_arg (char d, register char p, CORE_ADDR addr,
	148	disassemble_info *info)
	149	{
	150	register int regnum = *p & 0xf;
	151	float floatlitbuf;
	152
	153	if (*d == 'b')
	154	{
	155	if (d[1] == 'b')
	156	(info->fprintf_func) (info->stream, "0x%x", addr + p++ + 1);
	157	else
	158	{
	159	(info->fprintf_func) (info->stream, "0x%x", addr + (short *) p + 2);
	160	p += 2;
	161	}
	162	}
	163	else
	164	switch ((*p++ >> 4) & 0xf)
	165	{
	166	case 0:
	167	case 1:
	168	case 2:
	169	case 3: /* Literal mode */
	170	if (d[1] == 'd' \|\| d[1] == 'f' \|\| d[1] == 'g' \|\| d[1] == 'h')
	171	{
	172	(int ) &floatlitbuf = 0x4000 + ((p[-1] & 0x3f) << 4);
	173	(*info->fprintf_func) (info->stream, "$%f", floatlitbuf);
	174	}
	175	else
	176	(*info->fprintf_func) (info->stream, "$%d", p[-1] & 0x3f);
	177	break;
	178
	179	case 4: /* Indexed */
	180	p = (char *) print_insn_arg (d, p, addr + 1, info);
	181	(*info->fprintf_func) (info->stream, "[%s]", REGISTER_NAME (regnum));
	182	break;
	183
	184	case 5: /* Register */
	185	(*info->fprintf_func) (info->stream, REGISTER_NAME (regnum));
	186	break;
	187
	188	case 7: /* Autodecrement */
	189	(*info->fprintf_func) (info->stream, "-");
	190	case 6: /* Register deferred */
	191	(*info->fprintf_func) (info->stream, "(%s)", REGISTER_NAME (regnum));
	192	break;
	193
	194	case 9: /* Autoincrement deferred */
	195	(*info->fprintf_func) (info->stream, "@");
	196	if (regnum == PC_REGNUM)
	197	{
	198	(*info->fprintf_func) (info->stream, "#");
	199	info->target = (long ) p;
	200	(*info->print_address_func) (info->target, info);
	201	p += 4;
	202	break;
	203	}
	204	case 8: /* Autoincrement */
	205	if (regnum == PC_REGNUM)
	206	{
	207	(*info->fprintf_func) (info->stream, "#");
	208	switch (d[1])
	209	{
	210	case 'b':
	211	(info->fprintf_func) (info->stream, "%d", p++);
	212	break;
	213
	214	case 'w':
	215	(info->fprintf_func) (info->stream, "%d", (short *) p);
	216	p += 2;
	217	break;
	218
	219	case 'l':
	220	(info->fprintf_func) (info->stream, "%d", (long *) p);
	221	p += 4;
	222	break;
	223
	224	case 'q':
	225	(*info->fprintf_func) (info->stream, "0x%x%08x",
	226	((long ) p)[1], ((long ) p)[0]);
	227	p += 8;
	228	break;
	229
	230	case 'o':
	231	(*info->fprintf_func) (info->stream, "0x%x%08x%08x%08x",
	232	((long ) p)[3], ((long ) p)[2],
	233	((long ) p)[1], ((long ) p)[0]);
	234	p += 16;
	235	break;
	236
	237	case 'f':
	238	if (INVALID_FLOAT (p, 4))
	239	(*info->fprintf_func) (info->stream,
	240	"<<invalid float 0x%x>>",
	241	(int ) p);
	242	else
	243	(info->fprintf_func) (info->stream, "%f", (float *) p);
	244	p += 4;
	245	break;
	246
	247	case 'd':
	248	if (INVALID_FLOAT (p, 8))
	249	(*info->fprintf_func) (info->stream,
	250	"<<invalid float 0x%x%08x>>",
	251	((long ) p)[1], ((long ) p)[0]);
	252	else
	253	(info->fprintf_func) (info->stream, "%f", (double *) p);
	254	p += 8;
	255	break;
	256
	257	case 'g':
	258	(*info->fprintf_func) (info->stream, "g-float");
	259	p += 8;
	260	break;
	261
	262	case 'h':
	263	(*info->fprintf_func) (info->stream, "h-float");
	264	p += 16;
	265	break;
	266
	267	}
	268	}
	269	else
	270	(*info->fprintf_func) (info->stream, "(%s)+", REGISTER_NAME (regnum));
	271	break;
	272
	273	case 11: /* Byte displacement deferred */
	274	(*info->fprintf_func) (info->stream, "@");
	275	case 10: /* Byte displacement */
	276	if (regnum == PC_REGNUM)
	277	{
	278	info->target = addr + *p + 2;
	279	(*info->print_address_func) (info->target, info);
	280	}
	281	else
	282	(info->fprintf_func) (info->stream, "%d(%s)", p, REGISTER_NAME (regnum));
	283	p += 1;
	284	break;
	285
	286	case 13: /* Word displacement deferred */
	287	(*info->fprintf_func) (info->stream, "@");
	288	case 12: /* Word displacement */
	289	if (regnum == PC_REGNUM)
	290	{
	291	info->target = addr + (short ) p + 3;
	292	(*info->print_address_func) (info->target, info);
	293	}
	294	else
	295	(*info->fprintf_func) (info->stream, "%d(%s)",
	296	(short ) p, REGISTER_NAME (regnum));
	297	p += 2;
	298	break;
	299
	300	case 15: /* Long displacement deferred */
	301	(*info->fprintf_func) (info->stream, "@");
	302	case 14: /* Long displacement */
	303	if (regnum == PC_REGNUM)
	304	{
	305	info->target = addr + (short ) p + 5;
	306	(*info->print_address_func) (info->target, info);
	307	}
	308	else
	309	(*info->fprintf_func) (info->stream, "%d(%s)",
	310	(long ) p, REGISTER_NAME (regnum));
	311	p += 4;
	312	}
	313
	314	return (unsigned char *) p;
	315	}
	316
	317	void
	318	_initialize_vax_tdep (void)
	319	{
	320	tm_print_insn = vax_print_insn;
	321	}