utils.c

早期freebsd实现

/* General utility routines for GDB, the GNU debugger.
   Copyright 1986, 1989, 1990, 1991, 1992 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"
#if !defined(__GO32__)
#include <sys/ioctl.h>
#include <sys/param.h>
#include <pwd.h>
#endif
#include <varargs.h>
#include <ctype.h>
#include <string.h>

#include "signals.h"
#include "gdbcmd.h"
#include "terminal.h"
#include "bfd.h"
#include "target.h"
#include "demangle.h"

/* Prototypes for local functions */

#if !defined (NO_MALLOC_CHECK)

static void
malloc_botch PARAMS ((void));

#endif /* NO_MALLOC_CHECK  */

static void
fatal_dump_core ();	/* Can't prototype with <varargs.h> usage... */

static void
prompt_for_continue PARAMS ((void));

static void 
set_width_command PARAMS ((char *, int, struct cmd_list_element *));

/* If this definition isn't overridden by the header files, assume
   that isatty and fileno exist on this system.  */
#ifndef ISATTY
#define ISATTY(FP)	(isatty (fileno (FP)))
#endif

/* Chain of cleanup actions established with make_cleanup,
   to be executed if an error happens.  */

static struct cleanup *cleanup_chain;

/* Nonzero means a quit has been requested.  */

int quit_flag;

/* Nonzero means quit immediately if Control-C is typed now,
   rather than waiting until QUIT is executed.  */

int immediate_quit;

/* Nonzero means that encoded C++ names should be printed out in their
   C++ form rather than raw.  */

int demangle = 1;

/* Nonzero means that encoded C++ names should be printed out in their
   C++ form even in assembler language displays.  If this is set, but
   DEMANGLE is zero, names are printed raw, i.e. DEMANGLE controls.  */

int asm_demangle = 0;

/* Nonzero means that strings with character values >0x7F should be printed
   as octal escapes.  Zero means just print the value (e.g. it's an
   international character, and the terminal or window can cope.)  */

int sevenbit_strings = 0;

/* String to be printed before error messages, if any.  */

char *error_pre_print;
char *warning_pre_print = "\nwarning: ";

/* Add a new cleanup to the cleanup_chain,
   and return the previous chain pointer
   to be passed later to do_cleanups or discard_cleanups.
   Args are FUNCTION to clean up with, and ARG to pass to it.  */

struct cleanup *
make_cleanup (function, arg)
     void (*function) PARAMS ((PTR));
     PTR arg;
{
  register struct cleanup *new
    = (struct cleanup *) xmalloc (sizeof (struct cleanup));
  register struct cleanup *old_chain = cleanup_chain;

  new->next = cleanup_chain;
  new->function = function;
  new->arg = arg;
  cleanup_chain = new;

  return old_chain;
}

/* Discard cleanups and do the actions they describe
   until we get back to the point OLD_CHAIN in the cleanup_chain.  */

void
do_cleanups (old_chain)
     register struct cleanup *old_chain;
{
  register struct cleanup *ptr;
  while ((ptr = cleanup_chain) != old_chain)
    {
      cleanup_chain = ptr->next;	/* Do this first incase recursion */
      (*ptr->function) (ptr->arg);
      free (ptr);
    }
}

/* Discard cleanups, not doing the actions they describe,
   until we get back to the point OLD_CHAIN in the cleanup_chain.  */

void
discard_cleanups (old_chain)
     register struct cleanup *old_chain;
{
  register struct cleanup *ptr;
  while ((ptr = cleanup_chain) != old_chain)
    {
      cleanup_chain = ptr->next;
      free ((PTR)ptr);
    }
}

/* Set the cleanup_chain to 0, and return the old cleanup chain.  */
struct cleanup *
save_cleanups ()
{
  struct cleanup *old_chain = cleanup_chain;

  cleanup_chain = 0;
  return old_chain;
}

/* Restore the cleanup chain from a previously saved chain.  */
void
restore_cleanups (chain)
     struct cleanup *chain;
{
  cleanup_chain = chain;
}

/* This function is useful for cleanups.
   Do

     foo = xmalloc (...);
     old_chain = make_cleanup (free_current_contents, &foo);

   to arrange to free the object thus allocated.  */

void
free_current_contents (location)
     char **location;
{
  free (*location);
}

/* Provide a known function that does nothing, to use as a base for
   for a possibly long chain of cleanups.  This is useful where we
   use the cleanup chain for handling normal cleanups as well as dealing
   with cleanups that need to be done as a result of a call to error().
   In such cases, we may not be certain where the first cleanup is, unless
   we have a do-nothing one to always use as the base. */

/* ARGSUSED */
void
null_cleanup (arg)
    char **arg;
{
}


/* Provide a hook for modules wishing to print their own warning messages
   to set up the terminal state in a compatible way, without them having
   to import all the target_<...> macros. */

void
warning_setup ()
{
  target_terminal_ours ();
  wrap_here("");			/* Force out any buffered output */
  fflush (stdout);
}

/* Print a warning message.
   The first argument STRING is the warning message, used as a fprintf string,
   and the remaining args are passed as arguments to it.
   The primary difference between warnings and errors is that a warning
   does not force the return to command level. */

/* VARARGS */
void
warning (va_alist)
     va_dcl
{
  va_list args;
  char *string;

  va_start (args);
  target_terminal_ours ();
  wrap_here("");			/* Force out any buffered output */
  fflush (stdout);
  if (warning_pre_print)
    fprintf (stderr, warning_pre_print);
  string = va_arg (args, char *);
  vfprintf (stderr, string, args);
  fprintf (stderr, "\n");
  va_end (args);
}

/* Print an error message and return to command level.
   The first argument STRING is the error message, used as a fprintf string,
   and the remaining args are passed as arguments to it.  */

/* VARARGS */
NORETURN void
error (va_alist)
     va_dcl
{
  va_list args;
  char *string;

  va_start (args);
  target_terminal_ours ();
  wrap_here("");			/* Force out any buffered output */
  fflush (stdout);
  if (error_pre_print)
    fprintf_filtered (stderr, error_pre_print);
  string = va_arg (args, char *);
  vfprintf_filtered (stderr, string, args);
  fprintf_filtered (stderr, "\n");
  va_end (args);
  return_to_top_level ();
}

/* Print an error message and exit reporting failure.
   This is for a error that we cannot continue from.
   The arguments are printed a la printf.

   This function cannot be declared volatile (NORETURN) in an
   ANSI environment because exit() is not declared volatile. */

/* VARARGS */
NORETURN void
fatal (va_alist)
     va_dcl
{
  va_list args;
  char *string;

  va_start (args);
  string = va_arg (args, char *);
  fprintf (stderr, "\ngdb: ");
  vfprintf (stderr, string, args);
  fprintf (stderr, "\n");
  va_end (args);
  exit (1);
}

/* Print an error message and exit, dumping core.
   The arguments are printed a la printf ().  */

/* VARARGS */
static void
fatal_dump_core (va_alist)
     va_dcl
{
  va_list args;
  char *string;

  va_start (args);
  string = va_arg (args, char *);
  /* "internal error" is always correct, since GDB should never dump
     core, no matter what the input.  */
  fprintf (stderr, "\ngdb internal error: ");
  vfprintf (stderr, string, args);
  fprintf (stderr, "\n");
  va_end (args);

  signal (SIGQUIT, SIG_DFL);
  kill (getpid (), SIGQUIT);
  /* We should never get here, but just in case...  */
  exit (1);
}

/* The strerror() function can return NULL for errno values that are
   out of range.  Provide a "safe" version that always returns a
   printable string. */

char *
safe_strerror (errnum)
     int errnum;
{
  char *msg;
  static char buf[32];

  if ((msg = strerror (errnum)) == NULL)
    {
      sprintf (buf, "(undocumented errno %d)", errnum);
      msg = buf;
    }
  return (msg);
}

/* The strsignal() function can return NULL for signal values that are
   out of range.  Provide a "safe" version that always returns a
   printable string. */

char *
safe_strsignal (signo)
     int signo;
{
  char *msg;
  static char buf[32];

  if ((msg = strsignal (signo)) == NULL)
    {
      sprintf (buf, "(undocumented signal %d)", signo);
      msg = buf;
    }
  return (msg);
}


/* Print the system error message for errno, and also mention STRING
   as the file name for which the error was encountered.
   Then return to command level.  */

void
perror_with_name (string)
     char *string;
{
  char *err;
  char *combined;

  err = safe_strerror (errno);
  combined = (char *) alloca (strlen (err) + strlen (string) + 3);
  strcpy (combined, string);
  strcat (combined, ": ");
  strcat (combined, err);

  /* I understand setting these is a matter of taste.  Still, some people
     may clear errno but not know about bfd_error.  Doing this here is not
     unreasonable. */
  bfd_error = no_error;
  errno = 0;

  error ("%s.", combined);
}

/* Print the system error message for ERRCODE, and also mention STRING
   as the file name for which the error was encountered.  */

void
print_sys_errmsg (string, errcode)
     char *string;
     int errcode;
{
  char *err;
  char *combined;

  err = safe_strerror (errcode);
  combined = (char *) alloca (strlen (err) + strlen (string) + 3);
  strcpy (combined, string);
  strcat (combined, ": ");
  strcat (combined, err);

  fprintf (stderr, "%s.\n", combined);
}

/* Control C eventually causes this to be called, at a convenient time.  */

void
quit ()
{
  target_terminal_ours ();
  wrap_here ((char *)0);		/* Force out any pending output */
#if !defined(__GO32__)
#ifdef HAVE_TERMIO
  ioctl (fileno (stdout), TCFLSH, 1);
#else /* not HAVE_TERMIO */
  ioctl (fileno (stdout), TIOCFLUSH, 0);
#endif /* not HAVE_TERMIO */
#ifdef TIOCGPGRP
  error ("Quit");
#else
  error ("Quit (expect signal %d when inferior is resumed)", SIGINT);
#endif /* TIOCGPGRP */
#endif
}

/* Control C comes here */

void
request_quit (signo)
     int signo;
{
  quit_flag = 1;

#ifdef USG
  /* Restore the signal handler.  */
  signal (signo, request_quit);
#endif

  if (immediate_quit)
    quit ();
}


/* Memory management stuff (malloc friends).  */

#if defined (NO_MMALLOC)

PTR
mmalloc (md, size)
     PTR md;
     long size;
{
  return (malloc (size));
}

PTR
mrealloc (md, ptr, size)
     PTR md;
     PTR ptr;
     long size;
{
  if (ptr == 0)		/* Guard against old realloc's */
    return malloc (size);
  else
    return realloc (ptr, size);
}

void
mfree (md, ptr)
     PTR md;
     PTR ptr;
{
  free (ptr);
}

#endif	/* NO_MMALLOC */

#if defined (NO_MMALLOC) || defined (NO_MMALLOC_CHECK)

void
init_malloc (md)
     PTR md;
{
}

#else /* have mmalloc and want corruption checking  */

static void
malloc_botch ()
{
  fatal_dump_core ("Memory corruption");
}

/* Attempt to install hooks in mmalloc/mrealloc/mfree for the heap specified
   by MD, to detect memory corruption.  Note that MD may be NULL to specify
   the default heap that grows via sbrk.

   Note that for freshly created regions, we must call mmcheck prior to any
   mallocs in the region.  Otherwise, any region which was allocated prior to
   installing the checking hooks, which is later reallocated or freed, will
   fail the checks!  The mmcheck function only allows initial hooks to be
   installed before the first mmalloc.  However, anytime after we have called
   mmcheck the first time to install the checking hooks, we can call it again
   to update the function pointer to the memory corruption handler.

   Returns zero on failure, non-zero on success. */

void
init_malloc (md)
     PTR md;
{
  if (!mmcheck (md, malloc_botch))
    {
      warning ("internal error: failed to install memory consistency checks");
    }

  mmtrace ();
}

#endif /* Have mmalloc and want corruption checking  */

/* Called when a memory allocation fails, with the number of bytes of
   memory requested in SIZE. */

NORETURN void
nomem (size)
     long size;
{
  if (size > 0)
    {
      fatal ("virtual memory exhausted: can't allocate %ld bytes.", size);
    }