594 lines
12 KiB
C
594 lines
12 KiB
C
/* Interface to bare machine for GDB running as kernel debugger.
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Copyright (C) 1986, 1989, 1991 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include <stdio.h>
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#include <sys/ioctl.h>
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#include <errno.h>
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#include <sys/types.h>
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#include "gdb_stat.h"
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#if defined (SIGTSTP) && defined (SIGIO)
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#include <sys/time.h>
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#include <sys/resource.h>
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#endif /* SIGTSTP and SIGIO defined (must be 4.2) */
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#include "defs.h"
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#include "signals.h"
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#include "symtab.h"
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#include "frame.h"
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#include "inferior.h"
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#include "wait.h"
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/* Random system calls, mostly no-ops to prevent link problems */
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ioctl (desc, code, arg)
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{}
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int (* signal ()) ()
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{}
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kill ()
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{}
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getpid ()
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{
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return 0;
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}
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sigsetmask ()
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{}
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chdir ()
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{}
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char *
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getcwd (buf, len)
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char *buf;
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unsigned int len;
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{
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buf[0] = '/';
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buf[1] = 0;
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return buf;
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}
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/* Used to check for existence of .gdbinit. Say no. */
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access ()
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{
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return -1;
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}
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exit ()
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{
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error ("Fatal error; restarting.");
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}
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/* Reading "files". The contents of some files are written into kdb's
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data area before it is run. These files are used to contain the
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symbol table for kdb to load, and the source files (in case the
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kdb user wants to print them). The symbols are stored in a file
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named "kdb-symbols" in a.out format (except that all the text and
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data have been stripped to save room).
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The files are stored in the following format:
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int number of bytes of data for this file, including these four.
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char[] name of the file, ending with a null.
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padding to multiple of 4 boundary.
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char[] file contents. The length can be deduced from what was
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specified before. There is no terminating null here.
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If the int at the front is zero, it means there are no more files.
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Opening a file in kdb returns a nonzero value to indicate success,
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but the value does not matter. Only one file can be open, and only
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for reading. All the primitives for input from the file know
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which file is open and ignore what is specified for the descriptor
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or for the stdio stream.
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Input with fgetc can be done either on the file that is open
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or on stdin (which reads from the terminal through tty_input () */
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/* Address of data for the files stored in format described above. */
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char *files_start;
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/* The file stream currently open: */
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char *sourcebeg; /* beginning of contents */
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int sourcesize; /* size of contents */
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char *sourceptr; /* current read pointer */
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int sourceleft; /* number of bytes to eof */
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/* "descriptor" for the file now open.
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Incremented at each close.
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If specified descriptor does not match this,
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it means the program is trying to use a closed descriptor.
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We report an error for that. */
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int sourcedesc;
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open (filename, modes)
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char *filename;
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int modes;
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{
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register char *next;
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if (modes)
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{
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errno = EROFS;
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return -1;
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}
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if (sourceptr)
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{
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errno = EMFILE;
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return -1;
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}
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for (next = files_start; * (int *) next; next += * (int *) next)
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{
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if (!STRCMP (next + 4, filename))
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{
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sourcebeg = next + 4 + strlen (next + 4) + 1;
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sourcebeg = (char *) (((int) sourcebeg + 3) & (-4));
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sourceptr = sourcebeg;
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sourcesize = next + * (int *) next - sourceptr;
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sourceleft = sourcesize;
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return sourcedesc;
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}
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}
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return 0;
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}
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close (desc)
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int desc;
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{
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sourceptr = 0;
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sourcedesc++;
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/* Don't let sourcedesc get big enough to be confused with stdin. */
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if (sourcedesc == 100)
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sourcedesc = 5;
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}
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FILE *
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fopen (filename, modes)
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char *filename;
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char *modes;
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{
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return (FILE *) open (filename, *modes == 'w');
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}
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FILE *
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fdopen (desc)
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int desc;
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{
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return (FILE *) desc;
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}
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fclose (desc)
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int desc;
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{
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close (desc);
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}
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fstat (desc, statbuf)
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struct stat *statbuf;
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{
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if (desc != sourcedesc)
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{
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errno = EBADF;
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return -1;
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}
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statbuf->st_size = sourcesize;
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}
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myread (desc, destptr, size, filename)
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int desc;
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char *destptr;
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int size;
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char *filename;
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{
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int len = min (sourceleft, size);
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if (desc != sourcedesc)
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{
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errno = EBADF;
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return -1;
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}
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memcpy (destptr, sourceptr, len);
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sourceleft -= len;
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return len;
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}
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int
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fread (bufp, numelts, eltsize, stream)
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{
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register int elts = min (numelts, sourceleft / eltsize);
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register int len = elts * eltsize;
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if (stream != sourcedesc)
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{
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errno = EBADF;
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return -1;
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}
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memcpy (bufp, sourceptr, len);
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sourceleft -= len;
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return elts;
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}
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int
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fgetc (desc)
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int desc;
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{
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if (desc == (int) stdin)
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return tty_input ();
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if (desc != sourcedesc)
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{
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errno = EBADF;
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return -1;
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}
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if (sourceleft-- <= 0)
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return EOF;
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return *sourceptr++;
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}
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lseek (desc, pos)
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int desc;
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int pos;
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{
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if (desc != sourcedesc)
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{
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errno = EBADF;
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return -1;
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}
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if (pos < 0 || pos > sourcesize)
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{
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errno = EINVAL;
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return -1;
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}
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sourceptr = sourcebeg + pos;
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sourceleft = sourcesize - pos;
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}
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/* Output in kdb can go only to the terminal, so the stream
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specified may be ignored. */
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printf (a1, a2, a3, a4, a5, a6, a7, a8, a9)
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{
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char buffer[1024];
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sprintf (buffer, a1, a2, a3, a4, a5, a6, a7, a8, a9);
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display_string (buffer);
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}
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fprintf (ign, a1, a2, a3, a4, a5, a6, a7, a8, a9)
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{
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char buffer[1024];
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sprintf (buffer, a1, a2, a3, a4, a5, a6, a7, a8, a9);
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display_string (buffer);
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}
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fwrite (buf, numelts, size, stream)
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register char *buf;
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int numelts, size;
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{
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register int i = numelts * size;
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while (i-- > 0)
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fputc (*buf++, stream);
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}
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fputc (c, ign)
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{
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char buf[2];
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buf[0] = c;
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buf[1] = 0;
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display_string (buf);
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}
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/* sprintf refers to this, but loading this from the
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library would cause fflush to be loaded from it too.
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In fact there should be no need to call this (I hope). */
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_flsbuf ()
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{
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error ("_flsbuf was actually called.");
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}
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fflush (ign)
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{
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}
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/* Entries into core and inflow, needed only to make things link ok. */
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exec_file_command ()
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{}
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core_file_command ()
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{}
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char *
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get_exec_file (err)
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int err;
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{
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/* Makes one printout look reasonable; value does not matter otherwise. */
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return "run";
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}
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/* Nonzero if there is a core file. */
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have_core_file_p ()
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{
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return 0;
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}
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kill_command ()
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{
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inferior_pid = 0;
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}
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terminal_inferior ()
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{}
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terminal_ours ()
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{}
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terminal_init_inferior ()
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{}
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write_inferior_register ()
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{}
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read_inferior_register ()
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{}
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read_memory (memaddr, myaddr, len)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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{
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memcpy (myaddr, memaddr, len);
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}
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/* Always return 0 indicating success. */
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write_memory (memaddr, myaddr, len)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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{
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memcpy (memaddr, myaddr, len);
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return 0;
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}
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static REGISTER_TYPE saved_regs[NUM_REGS];
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REGISTER_TYPE
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read_register (regno)
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int regno;
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{
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if (regno < 0 || regno >= NUM_REGS)
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error ("Register number %d out of range.", regno);
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return saved_regs[regno];
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}
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void
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write_register (regno, value)
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int regno;
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REGISTER_TYPE value;
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{
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if (regno < 0 || regno >= NUM_REGS)
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error ("Register number %d out of range.", regno);
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saved_regs[regno] = value;
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}
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/* System calls needed in relation to running the "inferior". */
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vfork ()
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{
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/* Just appear to "succeed". Say the inferior's pid is 1. */
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return 1;
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}
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/* These are called by code that normally runs in the inferior
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that has just been forked. That code never runs, when standalone,
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and these definitions are so it will link without errors. */
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ptrace ()
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{}
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setpgrp ()
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{}
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execle ()
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{}
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_exit ()
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{}
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/* Malloc calls these. */
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malloc_warning (str)
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char *str;
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{
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printf ("\n%s.\n\n", str);
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}
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char *next_free;
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char *memory_limit;
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char *
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sbrk (amount)
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int amount;
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{
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if (next_free + amount > memory_limit)
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return (char *) -1;
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next_free += amount;
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return next_free - amount;
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}
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/* Various ways malloc might ask where end of memory is. */
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char *
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ulimit ()
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{
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return memory_limit;
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}
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int
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vlimit ()
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{
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return memory_limit - next_free;
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}
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getrlimit (addr)
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struct rlimit *addr;
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{
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addr->rlim_cur = memory_limit - next_free;
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}
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/* Context switching to and from program being debugged. */
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/* GDB calls here to run the user program.
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The frame pointer for this function is saved in
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gdb_stack by save_frame_pointer; then we restore
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all of the user program's registers, including PC and PS. */
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static int fault_code;
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static REGISTER_TYPE gdb_stack;
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resume ()
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{
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REGISTER_TYPE restore[NUM_REGS];
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PUSH_FRAME_PTR;
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save_frame_pointer ();
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memcpy (restore, saved_regs, sizeof restore);
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POP_REGISTERS;
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/* Control does not drop through here! */
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}
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save_frame_pointer (val)
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CORE_ADDR val;
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{
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gdb_stack = val;
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}
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/* Fault handlers call here, running in the user program stack.
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They must first push a fault code,
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old PC, old PS, and any other info about the fault.
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The exact format is machine-dependent and is known only
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in the definition of PUSH_REGISTERS. */
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fault ()
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{
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/* Transfer all registers and fault code to the stack
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in canonical order: registers in order of GDB register number,
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followed by fault code. */
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PUSH_REGISTERS;
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/* Transfer them to saved_regs and fault_code. */
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save_registers ();
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restore_gdb ();
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/* Control does not reach here */
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}
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restore_gdb ()
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{
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CORE_ADDR new_fp = gdb_stack;
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/* Switch to GDB's stack */
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POP_FRAME_PTR;
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/* Return from the function `resume'. */
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}
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/* Assuming register contents and fault code have been pushed on the stack as
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arguments to this function, copy them into the standard place
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for the program's registers while GDB is running. */
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save_registers (firstreg)
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int firstreg;
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{
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memcpy (saved_regs, &firstreg, sizeof saved_regs);
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fault_code = (&firstreg)[NUM_REGS];
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}
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/* Store into the structure such as `wait' would return
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the information on why the program faulted,
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converted into a machine-independent signal number. */
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static int fault_table[] = FAULT_TABLE;
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int
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wait (w)
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WAITTYPE *w;
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{
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WSETSTOP (*w, fault_table[fault_code / FAULT_CODE_UNITS]);
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return inferior_pid;
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}
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/* Allocate a big space in which files for kdb to read will be stored.
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Whatever is left is where malloc can allocate storage.
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Initialize it, so that there will be space in the executable file
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for it. Then the files can be put into kdb by writing them into
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kdb's executable file. */
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/* The default size is as much space as we expect to be available
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for kdb to use! */
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#ifndef HEAP_SIZE
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#define HEAP_SIZE 400000
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#endif
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char heap[HEAP_SIZE] = {0};
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#ifndef STACK_SIZE
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#define STACK_SIZE 100000
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#endif
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int kdb_stack_beg[STACK_SIZE / sizeof (int)];
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int kdb_stack_end;
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_initialize_standalone ()
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{
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register char *next;
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/* Find start of data on files. */
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files_start = heap;
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/* Find the end of the data on files. */
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for (next = files_start; * (int *) next; next += * (int *) next) {}
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/* That is where free storage starts for sbrk to give out. */
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next_free = next;
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memory_limit = heap + sizeof heap;
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}
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