/* General utility routines for the remote server for GDB.
   Copyright (C) 1986, 1989, 1993 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 <stdio.h>
#include <sys/ioctl.h>
#include "defs.h"
#include <setjmp.h>

void error ();
void fatal ();

/* 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;

/* 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) ();
     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)
    {
      (*ptr->function) (ptr->arg);
      cleanup_chain = ptr->next;
      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);
    }
}

/* 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);
}

/* Generally useful subroutines used throughout the program.  */

/* Like malloc but get error if no storage available.  */

PTR
xmalloc (size)
     long size;
{
  register char *val = (char *) malloc (size);
  if (!val)
    fatal ("virtual memory exhausted.", 0);
  return val;
}

/* Like realloc but get error if no storage available.  */

PTR
xrealloc (ptr, size)
     PTR ptr;
     long size;
{
  register char *val = (char *) realloc (ptr, size);
  if (!val)
    fatal ("virtual memory exhausted.", 0);
  return val;
}

/* 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;
{
  extern int sys_nerr;
  extern char *sys_errlist[];
  extern int errno;
  char *err;
  char *combined;

  if (errno < sys_nerr)
    err = sys_errlist[errno];
  else
    err = "unknown error";

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

  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;
{
  extern int sys_nerr;
  extern char *sys_errlist[];
  char *err;
  char *combined;

  if (errcode < sys_nerr)
    err = sys_errlist[errcode];
  else
    err = "unknown error";

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

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

void
quit ()
{
  fflush (stdout);
  ioctl (fileno (stdout), TIOCFLUSH, 0);
  error ("Quit");
}

/* Control C comes here */

void
request_quit (ignored)
     int ignored;
{
  quit_flag = 1;
  if (immediate_quit)
    quit ();
}

/* Print an error message and return to command level.
   STRING is the error message, used as a fprintf string,
   and ARG is passed as an argument to it.  */

NORETURN void
error (string, arg1, arg2, arg3)
     char *string;
     int arg1, arg2, arg3;
{
  extern jmp_buf toplevel;

  fflush (stdout);
  fprintf (stderr, string, arg1, arg2, arg3);
  fprintf (stderr, "\n");
  longjmp(toplevel, 1);
}

/* Print an error message and exit reporting failure.
   This is for a error that we cannot continue from.
   STRING and ARG are passed to fprintf.  */

void
fatal (string, arg)
     char *string;
     int arg;
{
  fprintf (stderr, "gdb: ");
  fprintf (stderr, string, arg);
  fprintf (stderr, "\n");
  exit (1);
}

/* Make a copy of the string at PTR with SIZE characters
   (and add a null character at the end in the copy).
   Uses malloc to get the space.  Returns the address of the copy.  */

char *
savestring (ptr, size)
     const char *ptr;
     int size;
{
  register char *p = (char *) xmalloc (size + 1);
  bcopy (ptr, p, size);
  p[size] = 0;
  return p;
}

void
print_spaces (n, file)
     register int n;
     register FILE *file;
{
  while (n-- > 0)
    fputc (' ', file);
}

/* Ask user a y-or-n question and return 1 iff answer is yes.
   Takes three args which are given to printf to print the question.
   The first, a control string, should end in "? ".
   It should not say how to answer, because we do that.  */

int
query (ctlstr, arg1, arg2)
     char *ctlstr;
{
  register int answer;

  /* Automatically answer "yes" if input is not from a terminal.  */
  /***********if (!input_from_terminal_p ())
    return 1; *************************/

  while (1)
    {
      printf (ctlstr, arg1, arg2);
      printf ("(y or n) ");
      fflush (stdout);
      answer = fgetc (stdin);
      clearerr (stdin);		/* in case of C-d */
      if (answer != '\n')
	while (fgetc (stdin) != '\n')
	  clearerr (stdin);
      if (answer >= 'a')
	answer -= 040;
      if (answer == 'Y')
	return 1;
      if (answer == 'N')
	return 0;
      printf ("Please answer y or n.\n");
    }
}

/* Parse a C escape sequence.  STRING_PTR points to a variable
   containing a pointer to the string to parse.  That pointer
   is updated past the characters we use.  The value of the
   escape sequence is returned.

   A negative value means the sequence \ newline was seen,
   which is supposed to be equivalent to nothing at all.

   If \ is followed by a null character, we return a negative
   value and leave the string pointer pointing at the null character.

   If \ is followed by 000, we return 0 and leave the string pointer
   after the zeros.  A value of 0 does not mean end of string.  */

int
parse_escape (string_ptr)
     char **string_ptr;
{
  register int c = *(*string_ptr)++;
  switch (c)
    {
    case 'a':
      return '\a';
    case 'b':
      return '\b';
    case 'e':
      return 033;
    case 'f':
      return '\f';
    case 'n':
      return '\n';
    case 'r':
      return '\r';
    case 't':
      return '\t';
    case 'v':
      return '\v';
    case '\n':
      return -2;
    case 0:
      (*string_ptr)--;
      return 0;
    case '^':
      c = *(*string_ptr)++;
      if (c == '\\')
	c = parse_escape (string_ptr);
      if (c == '?')
	return 0177;
      return (c & 0200) | (c & 037);

    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
      {
	register int i = c - '0';
	register int count = 0;
	while (++count < 3)
	  {
	    if ((c = *(*string_ptr)++) >= '0' && c <= '7')
	      {
		i *= 8;
		i += c - '0';
	      }
	    else
	      {
		(*string_ptr)--;
		break;
	      }
	  }
	return i;
      }
    default:
      return c;
    }
}

void
printchar (ch, stream)
     unsigned char ch;
     FILE *stream;
{
  register int c = ch;
  if (c < 040 || c >= 0177)
    {
      if (c == '\n')
	fprintf (stream, "\\n");
      else if (c == '\b')
	fprintf (stream, "\\b");
      else if (c == '\t')
	fprintf (stream, "\\t");
      else if (c == '\f')
	fprintf (stream, "\\f");
      else if (c == '\r')
	fprintf (stream, "\\r");
      else if (c == 033)
	fprintf (stream, "\\e");
      else if (c == '\a')
	fprintf (stream, "\\a");
      else
	fprintf (stream, "\\%03o", c);
    }
  else
    {
      if (c == '\\' || c == '"' || c == '\'')
	fputc ('\\', stream);
      fputc (c, stream);
    }
}