sim_calls.c

gdb-6.0 linux 下的调试工具

/*  This file is part of the program psim.

    Copyright 1994, 1995, 1996, 1998, 2003 Andrew Cagney

    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 <signal.h> /* FIXME - should be machine dependant version */
#include <stdarg.h>
#include <ctype.h>

#include "psim.h"
#include "options.h"

#undef printf_filtered /* blow away the mapping */

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif

#include "defs.h"
#include "bfd.h"
#include "gdb/callback.h"
#include "gdb/remote-sim.h"

/* Define the rate at which the simulator should poll the host
   for a quit. */
#ifndef POLL_QUIT_INTERVAL
#define POLL_QUIT_INTERVAL 0x20
#endif

static int poll_quit_count = POLL_QUIT_INTERVAL;

/* Structures used by the simulator, for gdb just have static structures */

static psim *simulator;
static device *root_device;
static host_callback *callbacks;

/* We use GDB's gdbarch_register_name function to map GDB register
   numbers onto names, which we can then look up in the register
   table.  Since the `set architecture' command can select a new
   processor variant at run-time, the meanings of the register numbers
   can change, so we need to make sure the sim uses the same
   name/number mapping that GDB uses.

   (We don't use the REGISTER_NAME macro, which is a wrapper for
   gdbarch_register_name.  We #include GDB's "defs.h", which tries to
   #include GDB's "config.h", but gets ours instead, and REGISTER_NAME
   ends up not getting defined.  Simpler to just use
   gdbarch_register_name directly.)

   We used to just use the REGISTER_NAMES macro from GDB's
   target-dependent header files, which expanded into an initializer
   for an array of strings.  That was kind of nice, because it meant
   that libsim.a had only a compile-time dependency on GDB; using
   gdbarch_register_name directly means that there are now link-time
   and run-time dependencies too.

   Perhaps the host_callback structure could provide a function for
   retrieving register names; that would be cleaner.  */

SIM_DESC
sim_open (SIM_OPEN_KIND kind,
	  host_callback *callback,
	  struct bfd *abfd,
	  char **argv)
{
  callbacks = callback;

  /* Note: The simulation is not created by sim_open() because
     complete information is not yet available */
  /* trace the call */
  TRACE(trace_gdb, ("sim_open called\n"));

  if (root_device != NULL)
    sim_io_printf_filtered("Warning - re-open of simulator leaks memory\n");
  root_device = psim_tree();
  simulator = NULL;

  psim_options(root_device, argv + 1);

  if (ppc_trace[trace_opts])
    print_options ();

  /* fudge our descriptor for now */
  return (SIM_DESC) 1;
}


void
sim_close (SIM_DESC sd, int quitting)
{
  TRACE(trace_gdb, ("sim_close(quitting=%d) called\n", quitting));
  if (ppc_trace[trace_print_info] && simulator != NULL)
    psim_print_info (simulator, ppc_trace[trace_print_info]);
}


SIM_RC
sim_load (SIM_DESC sd, char *prog, bfd *abfd, int from_tty)
{
  TRACE(trace_gdb, ("sim_load(prog=%s, from_tty=%d) called\n",
		    prog, from_tty));
  ASSERT(prog != NULL);

  /* create the simulator */
  TRACE(trace_gdb, ("sim_load() - first time, create the simulator\n"));
  simulator = psim_create(prog, root_device);

  /* bring in all the data section */
  psim_init(simulator);

  /* get the start address */
  if (abfd == NULL)
    {
      abfd = bfd_openr (prog, 0);
      if (abfd == NULL)
	error ("psim: can't open \"%s\": %s\n", 
	       prog, bfd_errmsg (bfd_get_error ()));
      if (!bfd_check_format (abfd, bfd_object)) 
	{
	  const char *errmsg = bfd_errmsg (bfd_get_error ());
	  bfd_close (abfd);
	  error ("psim: \"%s\" is not an object file: %s\n",
		 prog, errmsg);
	}
      bfd_close (abfd);
    }

  return SIM_RC_OK;
}


int
sim_read (SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length)
{
  int result = psim_read_memory(simulator, MAX_NR_PROCESSORS,
				buf, mem, length);
  TRACE(trace_gdb, ("sim_read(mem=0x%lx, buf=0x%lx, length=%d) = %d\n",
		    (long)mem, (long)buf, length, result));
  return result;
}


int
sim_write (SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length)
{
  int result = psim_write_memory(simulator, MAX_NR_PROCESSORS,
				 buf, mem, length,
				 1/*violate_ro*/);
  TRACE(trace_gdb, ("sim_write(mem=0x%lx, buf=0x%lx, length=%d) = %d\n",
		    (long)mem, (long)buf, length, result));
  return result;
}


int
sim_fetch_register (SIM_DESC sd, int regno, unsigned char *buf, int length)
{
  const char *regname;

  if (simulator == NULL) {
    return 0;
  }

  /* GDB will sometimes ask for the contents of a register named "";
     we ignore such requests, and leave garbage in *BUF.  In GDB
     terms, the empty string means "the register with this number is
     not present in the currently selected architecture variant."
     That's following the kludge we're using for the MIPS processors.
     But there are loops that just walk through the entire list of
     names and try to get everything.  */
  regname = gdbarch_register_name (current_gdbarch, regno);
  if (! regname || regname[0] == '\0')
    return -1;

  TRACE(trace_gdb, ("sim_fetch_register(regno=%d(%s), buf=0x%lx)\n",
		    regno, regname, (long)buf));
  return psim_read_register(simulator, MAX_NR_PROCESSORS,
			    buf, regname, raw_transfer);
}


int
sim_store_register (SIM_DESC sd, int regno, unsigned char *buf, int length)
{
  const char *regname;

  if (simulator == NULL)
    return 0;

  /* See comments in sim_fetch_register, above.  */
  regname = gdbarch_register_name (current_gdbarch, regno);
  if (! regname || regname[0] == '\0')
    return -1;

  TRACE(trace_gdb, ("sim_store_register(regno=%d(%s), buf=0x%lx)\n",
		    regno, regname, (long)buf));
  return psim_write_register(simulator, MAX_NR_PROCESSORS,
			     buf, regname, raw_transfer);
}


void
sim_info (SIM_DESC sd, int verbose)
{
  TRACE(trace_gdb, ("sim_info(verbose=%d) called\n", verbose));
  psim_print_info (simulator, verbose);
}


SIM_RC
sim_create_inferior (SIM_DESC sd,
		     struct bfd *abfd,
		     char **argv,
		     char **envp)
{
  unsigned_word entry_point;
  TRACE(trace_gdb, ("sim_create_inferior(start_address=0x%x, ...)\n",
		    entry_point));

  if (simulator == NULL)
    error ("No program loaded");

  if (abfd != NULL)
    entry_point = bfd_get_start_address (abfd);
  else
    entry_point = 0xfff00000; /* ??? */

  psim_init(simulator);
  psim_stack(simulator, argv, envp);

  ASSERT (psim_write_register(simulator, -1 /* all start at same PC */,
			      &entry_point, "pc", cooked_transfer) > 0);
  return SIM_RC_OK;
}


void
sim_stop_reason (SIM_DESC sd, enum sim_stop *reason, int *sigrc)
{
  psim_status status = psim_get_status(simulator);

  switch (status.reason) {
  case was_continuing:
    *reason = sim_stopped;
    if (status.signal == 0)
      *sigrc = SIGTRAP;
    else
      *sigrc = status.signal;
    break;
  case was_trap:
    *reason = sim_stopped;
    *sigrc = SIGTRAP;
    break;
  case was_exited:
    *reason = sim_exited;
    *sigrc = status.signal;
    break;
  case was_signalled:
    *reason = sim_signalled;
    *sigrc = status.signal;
    break;
  }

  TRACE(trace_gdb, ("sim_stop_reason(reason=0x%lx(%ld), sigrc=0x%lx(%ld))\n",
		    (long)reason, (long)*reason, (long)sigrc, (long)*sigrc));
}



/* Run (or resume) the program.  */

int
sim_stop (SIM_DESC sd)
{
  psim_stop (simulator);
  return 1;
}

void
sim_resume (SIM_DESC sd, int step, int siggnal)
{
  TRACE(trace_gdb, ("sim_resume(step=%d, siggnal=%d)\n",
		    step, siggnal));

  if (step)
    {
      psim_step (simulator);
    }
  else
    {
      psim_run (simulator);
    }
}

void
sim_do_command (SIM_DESC sd, char *cmd)
{
  TRACE(trace_gdb, ("sim_do_commands(cmd=%s) called\n",
		    cmd ? cmd : "(null)"));
  if (cmd != NULL) {
    char **argv = buildargv(cmd);
    psim_command(root_device, argv);
    freeargv(argv);
  }
}


/* Polling, if required */

void
sim_io_poll_quit (void)
{
  if (callbacks->poll_quit != NULL && poll_quit_count-- < 0)
    {
      poll_quit_count = POLL_QUIT_INTERVAL;
      if (callbacks->poll_quit (callbacks))
	psim_stop (simulator);
    }
}



/* Map simulator IO operations onto the corresponding GDB I/O
   functions.
   
   NB: Only a limited subset of operations are mapped across.  More
   advanced operations (such as dup or write) must either be mapped to
   one of the below calls or handled internally */

int
sim_io_read_stdin(char *buf,
		  int sizeof_buf)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    return callbacks->read_stdin(callbacks, buf, sizeof_buf);
    break;
  case DONT_USE_STDIO:
    return callbacks->read(callbacks, 0, buf, sizeof_buf);
    break;
  default:
    error("sim_io_read_stdin: unaccounted switch\n");
    break;
  }
  return 0;
}

int
sim_io_write_stdout(const char *buf,
		    int sizeof_buf)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    return callbacks->write_stdout(callbacks, buf, sizeof_buf);
    break;
  case DONT_USE_STDIO:
    return callbacks->write(callbacks, 1, buf, sizeof_buf);
    break;
  default:
    error("sim_io_write_stdout: unaccounted switch\n");
    break;
  }
  return 0;
}

int
sim_io_write_stderr(const char *buf,
		    int sizeof_buf)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    /* NB: I think there should be an explicit write_stderr callback */
    return callbacks->write(callbacks, 3, buf, sizeof_buf);
    break;
  case DONT_USE_STDIO:
    return callbacks->write(callbacks, 3, buf, sizeof_buf);
    break;
  default:
    error("sim_io_write_stderr: unaccounted switch\n");
    break;
  }
  return 0;
}


void
sim_io_printf_filtered(const char *fmt,
		       ...)
{
  char message[1024];
  va_list ap;
  /* format the message */
  va_start(ap, fmt);
  vsprintf(message, fmt, ap);
  va_end(ap);
  /* sanity check */
  if (strlen(message) >= sizeof(message))
    error("sim_io_printf_filtered: buffer overflow\n");
  callbacks->printf_filtered(callbacks, "%s", message);
}

void
sim_io_flush_stdoutput(void)
{
  switch (CURRENT_STDIO) {
  case DO_USE_STDIO:
    callbacks->flush_stdout (callbacks);
    break;
  case DONT_USE_STDIO:
    break;
  default:
    error("sim_io_read_stdin: unaccounted switch\n");
    break;
  }
}

void
sim_io_error (SIM_DESC sd, const char *fmt, ...)
{
  va_list ap;
  va_start(ap, fmt);
  callbacks->evprintf_filtered (callbacks, fmt, ap);
  va_end(ap);
  callbacks->error (callbacks, "");
}

/****/

void *
zalloc(long size)
{
  void *memory = (void*)xmalloc(size);
  if (memory == NULL)
    error("xmalloc failed\n");
  memset(memory, 0, size);
  return memory;
}

void zfree(void *data)
{
  free(data);
}