Initial revision

1 files changed, 2127 insertions, 0 deletions

diff --git a/gdb/main.c b/gdb/main.c
new file mode 100644
index 0000000..5845079
--- /dev/null
+++ b/gdb/main.c
@@ -0,0 +1,2127 @@
+/* Top level for GDB, the GNU debugger.
+   Copyright (C) 1986, 1987, 1988, 1989, 1990 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB 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 1, or (at your option)
+any later version.
+
+GDB 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 GDB; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include <stdio.h>
+int fclose ();
+#include "defs.h"
+#include "gdbcmd.h"
+#include "param.h"
+#include "symtab.h"
+#include "inferior.h"
+#include "signals.h"
+#include "target.h"
+#include "breakpoint.h"
+
+#include <getopt.h>
+#include <readline/readline.h>
+#include <readline/history.h>
+
+/* readline defines this.  */
+#undef savestring
+
+#ifdef USG
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+
+#include <string.h>
+#include <sys/file.h>
+#include <setjmp.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#ifdef SET_STACK_LIMIT_HUGE
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <ctype.h>
+
+int original_stack_limit;
+#endif
+
+
+/* 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
+
+/* Initialization file name for gdb.  This is overridden in some configs.  */
+
+#ifndef	GDBINIT_FILENAME
+#define	GDBINIT_FILENAME	".gdbinit"
+#endif
+char gdbinit[] = GDBINIT_FILENAME;
+
+/* Version number of GDB, as a string.  */
+
+extern char *version;
+
+/* Flag for whether we want all the "from_tty" gubbish printed.  */
+
+int caution = 1;			/* Default is yes, sigh. */
+
+/*
+ * Define all cmd_list_element's
+ */
+
+/* Chain containing all defined commands.  */
+
+struct cmd_list_element *cmdlist;
+
+/* Chain containing all defined info subcommands.  */
+
+struct cmd_list_element *infolist;
+
+/* Chain containing all defined enable subcommands. */
+
+struct cmd_list_element *enablelist;
+
+/* Chain containing all defined disable subcommands. */
+
+struct cmd_list_element *disablelist;
+
+/* Chain containing all defined delete subcommands. */
+
+struct cmd_list_element *deletelist;
+
+/* Chain containing all defined "enable breakpoint" subcommands. */
+
+struct cmd_list_element *enablebreaklist;
+
+/* Chain containing all defined set subcommands */
+
+struct cmd_list_element *setlist;
+
+/* Chain containing all defined show subcommands.  */
+struct cmd_list_element *showlist;
+
+/* Chain containing all defined \"set history\".  */
+
+struct cmd_list_element *sethistlist;
+
+/* Chain containing all defined \"show history\".  */
+struct cmd_list_element *showhistlist;
+
+/* Chain containing all defined \"unset history\".  */
+
+struct cmd_list_element *unsethistlist;
+
+/* stdio stream that command input is being read from.  */
+
+FILE *instream;
+
+/* Current working directory.  */
+
+char *current_directory;
+
+/* The directory name is actually stored here (usually).  */
+static char dirbuf[MAXPATHLEN];
+
+/* Function to call before reading a command, if nonzero.
+   The function receives two args: an input stream,
+   and a prompt string.  */
+   
+void (*window_hook) ();
+
+extern int frame_file_full_name;
+int epoch_interface;
+int xgdb_verbose;
+
+/* The external commands we call... */
+extern void init_source_path ();
+extern void directory_command ();
+extern void exec_file_command ();
+extern void symbol_file_command ();
+extern void core_file_command ();
+extern void tty_command ();
+
+extern void help_list ();
+extern void initialize_all_files ();
+extern void init_malloc ();
+
+/* Forward declarations for this file */
+void free_command_lines ();
+char *gdb_readline ();
+char *command_line_input ();
+static void initialize_main ();
+static void initialize_cmd_lists ();
+static void init_signals ();
+static void quit_command ();
+void command_loop ();
+static void source_command ();
+static void print_gdb_version ();
+static void float_handler ();
+static void cd_command ();
+static void read_command_file ();
+
+char *getenv ();
+
+/* gdb prints this when reading a command interactively */
+static char *prompt;
+
+/* Buffer used for reading command lines, and the size
+   allocated for it so far.  */
+
+char *line;
+int linesize = 100;
+
+/* Baud rate specified for talking to serial target systems.  Default
+   is left as a zero pointer, so targets can choose their own defaults.  */
+
+char *baud_rate;
+
+/* Signal to catch ^Z typed while reading a command: SIGTSTP or SIGCONT.  */
+
+#ifndef STOP_SIGNAL
+#ifdef SIGTSTP
+#define STOP_SIGNAL SIGTSTP
+#endif
+#endif
+
+/* This is how `error' returns to command level.  */
+
+jmp_buf to_top_level;
+
+void
+return_to_top_level ()
+{
+  quit_flag = 0;
+  immediate_quit = 0;
+  bpstat_clear_actions(stop_bpstat);	/* Clear queued breakpoint commands */
+  clear_momentary_breakpoints ();
+  disable_current_display ();
+  do_cleanups (0);
+  longjmp (to_top_level, 1);
+}
+
+/* Call FUNC with arg ARGS, catching any errors.
+   If there is no error, return the value returned by FUNC.
+   If there is an error, return zero after printing ERRSTRING
+    (which is in addition to the specific error message already printed).  */
+
+int
+catch_errors (func, args, errstring)
+     int (*func) ();
+     int args;
+     char *errstring;
+{
+  jmp_buf saved;
+  int val;
+  struct cleanup *saved_cleanup_chain;
+
+  saved_cleanup_chain = save_cleanups ();
+
+  bcopy (to_top_level, saved, sizeof (jmp_buf));
+
+  if (setjmp (to_top_level) == 0)
+    val = (*func) (args);
+  else
+    {
+      if (errstring)
+	fprintf (stderr, "%s\n", errstring);
+      val = 0;
+    }
+
+  restore_cleanups (saved_cleanup_chain);
+
+  bcopy (saved, to_top_level, sizeof (jmp_buf));
+  return val;
+}
+
+/* Handler for SIGHUP.  */
+
+static void
+disconnect ()
+{
+  kill_inferior_fast ();
+  signal (SIGHUP, SIG_DFL);
+  kill (getpid (), SIGHUP);
+}
+
+/* Clean up on error during a "source" command (or execution of a
+   user-defined command).  */
+
+static void
+source_cleanup (stream)
+     FILE *stream;
+{
+  /* Restore the previous input stream.  */
+  instream = stream;
+}
+
+/* Read commands from STREAM.  */
+static void
+read_command_file (stream)
+     FILE *stream;
+{
+  struct cleanup *cleanups;
+
+  cleanups = make_cleanup (source_cleanup, instream);
+  instream = stream;
+  command_loop ();
+  do_cleanups (cleanups);
+}
+
+int
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int count;
+  static int inhibit_gdbinit = 0;
+  static int quiet = 0;
+  static int batch = 0;
+
+  /* Pointers to various arguments from command line.  */
+  char *symarg = NULL;
+  char *execarg = NULL;
+  char *corearg = NULL;
+  char *cdarg = NULL;
+  char *ttyarg = NULL;
+
+  /* Pointers to all arguments of +command option.  */
+  char **cmdarg;
+  /* Allocated size of cmdarg.  */
+  int cmdsize;
+  /* Number of elements of cmdarg used.  */
+  int ncmd;
+
+  /* Indices of all arguments of +directory option.  */
+  char **dirarg;
+  /* Allocated size.  */
+  int dirsize;
+  /* Number of elements used.  */
+  int ndir;
+  
+  register int i;
+
+  /* This needs to happen before the first use of malloc.  */
+  init_malloc ();
+
+#if defined (ALIGN_STACK_ON_STARTUP)
+  i = (int) &count & 0x3;
+  if (i != 0)
+    alloca (4 - i);
+#endif
+
+  cmdsize = 1;
+  cmdarg = (char **) xmalloc (cmdsize * sizeof (*cmdarg));
+  ncmd = 0;
+  dirsize = 1;
+  dirarg = (char **) xmalloc (dirsize * sizeof (*dirarg));
+  ndir = 0;
+
+  quit_flag = 0;
+  line = (char *) xmalloc (linesize);
+  line[0] = '\0';		/* Terminate saved (now empty) cmd line */
+  instream = stdin;
+
+  getwd (dirbuf);
+  current_directory = dirbuf;
+
+#ifdef SET_STACK_LIMIT_HUGE
+  {
+    struct rlimit rlim;
+
+    /* Set the stack limit huge so that alloca (particularly stringtab
+     * in dbxread.c) does not fail. */
+    getrlimit (RLIMIT_STACK, &rlim);
+    original_stack_limit = rlim.rlim_cur;
+    rlim.rlim_cur = rlim.rlim_max;
+    setrlimit (RLIMIT_STACK, &rlim);
+  }
+#endif /* SET_STACK_LIMIT_HUGE */
+
+  /* Parse arguments and options.  */
+  {
+    int c;
+    static int print_help;
+    /* When var field is 0, use flag field to record the equivalent
+       short option (or arbitrary numbers starting at 10 for those
+       with no equivalent).  */
+    static struct option long_options[] =
+      {
+	{"quiet", 0, &quiet, 1},
+	{"nx", 0, &inhibit_gdbinit, 1},
+	{"batch", 0, &batch, 1},
+	{"epoch", 0, &epoch_interface, 1},
+	{"fullname", 0, &frame_file_full_name, 1},
+	{"help", 0, &print_help, 1},
+	{"se", 1, 0, 10},
+	{"symbols", 1, 0, 's'},
+	{"s", 1, 0, 's'},
+	{"exec", 1, 0, 'e'},
+	{"core", 1, 0, 'c'},
+	{"c", 1, 0, 'c'},
+	{"command", 1, 0, 'x'},
+	{"x", 1, 0, 'x'},
+	{"directory", 1, 0, 'd'},
+	{"cd", 1, 0, 11},
+	{"tty", 1, 0, 't'},
+	{"b", 1, 0, 'b'},
+/* Allow machine descriptions to add more options... */
+#ifdef ADDITIONAL_OPTIONS
+	ADDITIONAL_OPTIONS
+#endif
+      };
+
+    while (1)
+      {
+	c = getopt_long_only (argc, argv, "",
+			      long_options, &option_index);
+	if (c == EOF)
+	  break;
+
+	/* Long option that takes an argument.  */
+	if (c == 0 && long_options[option_index].flag == 0)
+	  c = long_options[option_index].val;
+
+	switch (c)
+	  {
+	  case 0:
+	    /* Long option that just sets a flag.  */
+	    break;
+	  case 10:
+	    symarg = optarg;
+	    execarg = optarg;
+	    break;
+	  case 11:
+	    cdarg = optarg;
+	    break;
+	  case 's':
+	    symarg = optarg;
+	    break;
+	  case 'e':
+	    execarg = optarg;
+	    break;
+	  case 'c':
+	    corearg = optarg;
+	    break;
+	  case 'x':
+	    cmdarg[ncmd++] = optarg;
+	    if (ncmd >= cmdsize)
+	      {
+		cmdsize *= 2;
+		cmdarg = (char **) xrealloc ((char *)cmdarg,
+					     cmdsize * sizeof (*cmdarg));
+	      }
+	    break;
+	  case 'd':
+	    dirarg[ndir++] = optarg;
+	    if (ndir >= dirsize)
+	      {
+		dirsize *= 2;
+		dirarg = (char **) xrealloc ((char *)dirarg,
+					     dirsize * sizeof (*dirarg));
+	      }
+	    break;
+	  case 't':
+	    ttyarg = optarg;
+	    break;
+	  case 'q':
+	    quiet = 1;
+	    break;
+	  case 'b':
+	    baud_rate = optarg;
+	    break;
+#ifdef ADDITIONAL_OPTION_CASES
+	  ADDITIONAL_OPTION_CASES
+#endif
+	  case '?':
+	    fprintf (stderr,
+		     "Use `%s +help' for a complete list of options.\n",
+		     argv[0]);
+	    exit (1);
+	  }
+
+      }
+    if (print_help)
+      {
+	fputs ("\
+This is GDB, the GNU debugger.  Use the command\n\
+    gdb [options] [executable [core-file]]\n\
+to enter the debugger.\n\
+\n\
+Options available are:\n\
+  -help             Print this message.\n\
+  -quiet            Do not print version number on startup.\n\
+  -fullname         Output information used by emacs-GDB interface.\n\
+  -epoch            Output information used by epoch emacs-GDB interface.\n\
+  -batch            Exit after processing options.\n\
+  -nx               Do not read .gdbinit file.\n\
+  -tty=TTY          Use TTY for input/output by the program being debugged.\n\
+  -cd=DIR           Change current directory to DIR.\n\
+  -directory=DIR    Search for source files in DIR.\n\
+  -command=FILE     Execute GDB commands from FILE.\n\
+  -symbols=SYMFILE  Read symbols from SYMFILE.\n\
+  -exec=EXECFILE    Use EXECFILE as the executable.\n\
+  -se=FILE          Use FILE as symbol file and executable file.\n\
+  -core=COREFILE    Analyze the core dump COREFILE.\n\
+  -b BAUDRATE       Set serial port baud rate used for remote debugging\n\
+", stderr);
+#ifdef ADDITIONAL_OPTION_HELP
+	fputs (ADDITIONAL_OPTION_HELP, stderr);
+#endif
+	fputs ("\n\
+For more information, type \"help\" from within GDB, or consult the\n\
+GDB manual (available as on-line info or a printed manual).\n", stderr);
+	/* Exiting after printing this message seems like
+	   the most useful thing to do.  */
+	exit (0);
+      }
+    
+    /* OK, that's all the options.  The other arguments are filenames.  */
+    count = 0;
+    for (; optind < argc; optind++)
+      switch (++count)
+	{
+	case 1:
+	  symarg = argv[optind];
+	  execarg = argv[optind];
+	  break;
+	case 2:
+	  corearg = argv[optind];
+	  break;
+	case 3:
+	  fprintf (stderr,
+		   "Excess command line arguments ignored. (%s%s)\n",
+		   argv[optind], (optind == argc - 1) ? "" : " ...");
+	  break;
+	}
+    if (batch)
+      quiet = 1;
+  }
+
+  /* Run the init function of each source file */
+
+  initialize_cmd_lists ();	/* This needs to be done first */
+  initialize_all_files ();
+  initialize_main ();		/* But that omits this file!  Do it now */
+  init_signals ();
+
+  if (!quiet)
+    {
+      /* Print all the junk in one place, with a blank line after it
+	 to separate it from important stuff like "no such file".  
+ 	 Also, we skip most of the noise, like Emacs, if started with
+	 a file name rather than with no arguments.  */
+      if (execarg == 0) {
+	print_gdb_version (1);
+	printf ("Type \"help\" for a list of commands.\n\n");
+      }
+    }
+
+  /* Now perform all the actions indicated by the arguments.  */
+  if (cdarg != NULL)
+    {
+      if (!setjmp (to_top_level))
+	{
+	  cd_command (cdarg, 0);
+	  init_source_path ();
+	}
+    }
+  for (i = 0; i < ndir; i++)
+    if (!setjmp (to_top_level))
+      directory_command (dirarg[i], 0);
+  free (dirarg);
+  if (execarg != NULL
+      && symarg != NULL
+      && strcmp (execarg, symarg) == 0)
+    {
+      /* The exec file and the symbol-file are the same.  If we can't open
+	 it, better only print one error message.  */
+      if (!setjmp (to_top_level))
+	{
+	  exec_file_command (execarg, !batch);
+	  symbol_file_command (symarg, !batch);
+	}
+    }
+  else
+    {
+      if (execarg != NULL)
+	if (!setjmp (to_top_level))
+	  exec_file_command (execarg, !batch);
+      if (symarg != NULL)
+	if (!setjmp (to_top_level))
+	  symbol_file_command (symarg, !batch);
+    }
+  if (corearg != NULL)
+    if (!setjmp (to_top_level))
+      core_file_command (corearg, !batch);
+    else if (!setjmp (to_top_level))
+      attach_command (corearg, !batch);
+
+  if (ttyarg != NULL)
+    if (!setjmp (to_top_level))
+      tty_command (ttyarg, !batch);
+
+#ifdef ADDITIONAL_OPTION_HANDLER
+  ADDITIONAL_OPTION_HANDLER;
+#endif
+
+  {
+    struct stat homebuf, cwdbuf;
+    char *homedir, *homeinit;
+
+    /* Read init file, if it exists in home directory  */
+    homedir = getenv ("HOME");
+    if (homedir)
+      {
+	homeinit = (char *) alloca (strlen (getenv ("HOME")) +
+				    strlen (gdbinit) + 10);
+	strcpy (homeinit, getenv ("HOME"));
+	strcat (homeinit, "/");
+	strcat (homeinit, gdbinit);
+	if (!inhibit_gdbinit && access (homeinit, R_OK) == 0)
+	  if (!setjmp (to_top_level))
+	    source_command (homeinit, 0);
+
+	/* Do stats; no need to do them elsewhere since we'll only
+	   need them if homedir is set.  Make sure that they are
+	   zero in case one of them fails (this guarantees that they
+	   won't match if either exists).  */
+	
+	bzero (&homebuf, sizeof (struct stat));
+	bzero (&cwdbuf, sizeof (struct stat));
+	
+	stat (homeinit, &homebuf);
+	stat (gdbinit, &cwdbuf); /* We'll only need this if
+					 homedir was set.  */
+      }
+    
+    /* Read the input file in the current directory, *if* it isn't
+       the same file (it should exist, also).  */
+
+    if (!homedir
+	|| bcmp ((char *) &homebuf,
+		 (char *) &cwdbuf,
+		 sizeof (struct stat)))
+      if (!inhibit_gdbinit && access (gdbinit, R_OK) == 0)
+	if (!setjmp (to_top_level))
+	  source_command (gdbinit, 0);
+  }
+
+  for (i = 0; i < ncmd; i++)
+    if (!setjmp (to_top_level))
+      {
+	if (cmdarg[i][0] == '-' && cmdarg[i][1] == '\0')
+	  read_command_file (stdin);
+	else
+	  source_command (cmdarg[i], !batch);
+      }
+  free (cmdarg);
+
+  if (batch)
+    {
+      /* We have hit the end of the batch file.  */
+      exit (0);
+    }
+
+  /* Do any host- or target-specific hacks.  This is used for i960 targets
+     to force the user to set a nindy target and spec its parameters.  */
+
+#ifdef BEFORE_MAIN_LOOP_HOOK
+  BEFORE_MAIN_LOOP_HOOK;
+#endif
+
+  /* The command loop.  */
+
+  while (1)
+    {
+      if (!setjmp (to_top_level))
+	{
+	  command_loop ();
+          quit_command ((char *)0, instream == stdin);
+	}
+    }
+  /* No exit -- exit is through quit_command.  */
+}
+
+/* Execute the line P as a command.
+   Pass FROM_TTY as second argument to the defining function.  */
+
+void
+execute_command (p, from_tty)
+     char *p;
+     int from_tty;
+{
+  register struct cmd_list_element *c;
+  register struct command_line *cmdlines;
+
+  free_all_values ();
+
+  /* This can happen when command_line_input hits end of file.  */
+  if (p == NULL)
+      return;
+  
+  while (*p == ' ' || *p == '\t') p++;
+  if (*p)
+    {
+      char *arg;
+      
+      c = lookup_cmd (&p, cmdlist, "", 0, 1);
+      /* Pass null arg rather than an empty one.  */
+      arg = *p ? p : 0;
+      if (c->class == class_user)
+	{
+	  struct cleanup *old_chain;
+	  
+	  if (*p)
+	    error ("User-defined commands cannot take arguments.");
+	  cmdlines = c->user_commands;
+	  if (cmdlines == 0)
+	    /* Null command */
+	    return;
+
+	  /* Set the instream to 0, indicating execution of a
+	     user-defined function.  */
+	  old_chain =  make_cleanup (source_cleanup, instream);
+	  instream = (FILE *) 0;
+	  while (cmdlines)
+	    {
+	      execute_command (cmdlines->line, 0);
+	      cmdlines = cmdlines->next;
+	    }
+	  do_cleanups (old_chain);
+	}
+      else if (c->type == set_cmd || c->type == show_cmd)
+	do_setshow_command (arg, from_tty & caution, c);
+      else if (c->function == NO_FUNCTION)
+	error ("That is not a command, just a help topic.");
+      else
+	(*c->function) (arg, from_tty & caution);
+    }
+}
+
+/* ARGSUSED */
+static void
+do_nothing (foo)
+     int foo;
+{
+}
+
+/* Read commands from `instream' and execute them
+   until end of file or error reading instream.  */
+void
+command_loop ()
+{
+  struct cleanup *old_chain;
+  char *command;
+  int stdin_is_tty = ISATTY (stdin);
+
+  while (!feof (instream))
+    {
+      if (window_hook && instream == stdin)
+	(*window_hook) (instream, prompt);
+
+      quit_flag = 0;
+      if (instream == stdin && stdin_is_tty)
+	reinitialize_more_filter ();
+      old_chain = make_cleanup (do_nothing, 0);
+      command = command_line_input (instream == stdin ? prompt : 0,
+				      instream == stdin);
+      if (command == 0)
+	return;
+      execute_command (command, instream == stdin);
+      /* Do any commands attached to breakpoint we stopped at.  */
+      bpstat_do_actions (&stop_bpstat);
+      do_cleanups (old_chain);
+    }
+}
+
+/* Commands call this if they do not want to be repeated by null lines.  */
+
+void
+dont_repeat ()
+{
+  /* If we aren't reading from standard input, we are saving the last
+     thing read from stdin in line and don't want to delete it.  Null lines
+     won't repeat here in any case.  */
+  if (instream == stdin)
+    *line = 0;
+}
+
+/* Read a line from the stream "instream" without command line editing.
+
+   It prints PRROMPT once at the start.
+
+   If RETURN_RESULT is set it allocates
+   space for whatever the user types and returns the result.
+   If not, it just discards what the user types and returns a garbage
+   non-NULL value.
+
+   No matter what return_result is, a NULL return means end of file.  */
+char *
+gdb_readline (prrompt, return_result)
+     char *prrompt;
+     int return_result;
+{
+  int c;
+  char *result;
+  int input_index = 0;
+  int result_size = 80;
+
+  if (prrompt)
+    {
+      printf (prrompt);
+      fflush (stdout);
+    }
+  
+  if (return_result)
+    result = (char *) xmalloc (result_size);
+
+  while (1)
+    {
+      /* Read from stdin if we are executing a user defined command.
+	 This is the right thing for prompt_for_continue, at least.  */
+      c = fgetc (instream ? instream : stdin);
+      if (c == EOF || c == '\n')
+	break;
+      if (return_result)
+	{
+	  result[input_index++] = c;
+	  while (input_index >= result_size)
+	    {
+	      result_size *= 2;
+	      result = (char *) xrealloc (result, result_size);
+	    }
+	}
+    }
+
+  if (c == EOF)
+    {
+      if (return_result)
+	free (result);
+      return NULL;
+    }
+
+  if (return_result)
+    {
+      result[input_index++] = '\0';
+      return result;
+    }
+  else
+    /* Return any old non-NULL pointer.  */
+    return (char *) "non-NULL";
+}
+
+/* Declaration for fancy readline with command line editing.  */
+char *readline ();
+
+/* Variables which control command line editing and history
+   substitution.  These variables are given default values at the end
+   of this file.  */
+static int command_editing_p;
+static int history_expansion_p;
+static int write_history_p;
+static int history_size;
+static char *history_filename;
+
+/* Variables which are necessary for fancy command line editing.  */
+char *gdb_completer_word_break_characters =
+  " \t\n!@#$%^&*()-+=|~`}{[]\"';:?/>.<,";
+
+/* Functions that are used as part of the fancy command line editing.  */
+
+/* This can be used for functions which don't want to complete on symbols
+   but don't want to complete on anything else either.  */
+/* ARGSUSED */
+char **
+noop_completer (text)
+     char *text;
+{
+  return NULL;
+}
+
+/* Generate symbol names one by one for the completer.  If STATE is
+   zero, then we need to initialize, otherwise the initialization has
+   already taken place.  TEXT is what we expect the symbol to start
+   with.  RL_LINE_BUFFER is available to be looked at; it contains the
+   entire text of the line.  RL_POINT is the offset in that line of
+   the cursor.  You should pretend that the line ends at RL_POINT.
+   The result is NULL if there are no more completions, else a char
+   string which is a possible completion.  */
+char *
+symbol_completion_function (text, state)
+     char *text;
+     int state;
+{
+  static char **list = (char **)NULL;
+  static int index;
+  char *output;
+  extern char *rl_line_buffer;
+  extern int rl_point;
+  char *tmp_command, *p;
+  struct cmd_list_element *c, *result_list;
+
+  if (!state)
+    {
+      /* Free the storage used by LIST, but not by the strings inside.  This is
+	 because rl_complete_internal () frees the strings. */
+      if (list)
+	free (list);
+      list = 0;
+      index = 0;
+
+      /* Decide whether to complete on a list of gdb commands or on
+	 symbols.  */
+      tmp_command = (char *) alloca (rl_point + 1);
+      p = tmp_command;
+      
+      strncpy (tmp_command, rl_line_buffer, rl_point);
+      tmp_command[rl_point] = '\0';
+
+      if (rl_point == 0)
+	{
+	  /* An empty line we want to consider ambiguous; that is,
+	     it could be any command.  */
+	  c = (struct cmd_list_element *) -1;
+	  result_list = 0;
+	}
+      else
+	c = lookup_cmd_1 (&p, cmdlist, &result_list, 1);
+
+      /* Move p up to the next interesting thing.  */
+      while (*p == ' ' || *p == '\t')
+	p++;
+
+      if (!c)
+	/* He's typed something unrecognizable.  Sigh.  */
+	list = (char **) 0;
+      else if (c == (struct cmd_list_element *) -1)
+	{
+	  /* If we didn't recognize everything up to the thing that
+	     needs completing, and we don't know what command it is
+	     yet, we are in trouble.  Part of the trouble might be
+	     that the list of delimiters used by readline includes
+	     '-', which we use in commands.  Check for this.  */
+	  if (p + strlen(text) != tmp_command + rl_point) {
+	    if (tmp_command[rl_point - strlen(text) - 1] == '-')
+	      text = p;
+	    else {
+	      /* This really should not produce an error.  Better would
+		 be to pretend to hit RETURN here; this would produce a
+		 response like "Ambiguous command: foo, foobar, etc",
+		 and leave the line available for re-entry with ^P.  Instead,
+		 this error blows away the user's typed input without
+		 any way to get it back.  */
+	      error ("  Unrecognized command.");
+	    }
+	  }
+	  
+	  /* He's typed something ambiguous.  This is easier.  */
+	  if (result_list)
+	    list = complete_on_cmdlist (*result_list->prefixlist, text);
+	  else
+	    list = complete_on_cmdlist (cmdlist, text);
+	}
+      else
+	{
+	  /* If we've gotten this far, gdb has recognized a full
+	     command.  There are several possibilities:
+
+	     1) We need to complete on the command.
+	     2) We need to complete on the possibilities coming after
+	     the command.
+	     2) We need to complete the text of what comes after the
+	     command.   */
+
+	  if (!*p && *text)
+	    /* Always (might be longer versions of thie command).  */
+	    list = complete_on_cmdlist (result_list, text);
+	  else if (!*p && !*text)
+	    {
+	      if (c->prefixlist)
+		list = complete_on_cmdlist (*c->prefixlist, "");
+	      else
+		list = (*c->completer) ("");
+	    }
+	  else
+	    {
+	      if (c->prefixlist && !c->allow_unknown)
+		{
+#if 0
+		  /* Something like "info adsfkdj".  But error() is not
+		     the proper response; just return no completions
+		     instead.  */
+		  *p = '\0';
+		  error ("\"%s\" command requires a subcommand.",
+			 tmp_command);
+#else
+		  list = NULL;
+#endif
+		}
+	      else
+		list = (*c->completer) (text);
+	    }
+	}
+    }
+
+  /* If the debugged program wasn't compiled with symbols, or if we're
+     clearly completing on a command and no command matches, return
+     NULL.  */
+  if (!list)
+    return ((char *)NULL);
+
+  output = list[index];
+  if (output)
+    index++;
+
+  return (output);
+}
+
+#ifdef STOP_SIGNAL
+static void
+stop_sig ()
+{
+#if STOP_SIGNAL == SIGTSTP
+  signal (SIGTSTP, SIG_DFL);
+  sigsetmask (0);
+  kill (getpid (), SIGTSTP);
+  signal (SIGTSTP, stop_sig);
+#else
+  signal (STOP_SIGNAL, stop_sig);
+#endif
+  printf ("%s", prompt);
+  fflush (stdout);
+
+  /* Forget about any previous command -- null line now will do nothing.  */
+  dont_repeat ();
+}
+#endif /* STOP_SIGNAL */
+
+#if 0
+Writing the history file upon a terminating signal is not useful,
+  because the info is rarely relevant and is in the core dump anyway.
+  It is an annoyance to have the file cluttering up the place.
+/* The list of signals that would terminate us if not caught.
+   We catch them, but just so that we can write the history file,
+   and so forth. */
+int terminating_signals[] = {
+  SIGHUP, SIGINT, SIGILL, SIGTRAP, SIGIOT,
+  SIGEMT, SIGFPE, SIGKILL, SIGBUS, SIGSEGV, SIGSYS,
+  SIGPIPE, SIGALRM, SIGTERM,
+#ifdef SIGXCPU
+  SIGXCPU,
+#endif
+#ifdef SIGXFSZ
+  SIGXFSZ,
+#endif
+#ifdef SIGVTALRM
+  SIGVTALRM,
+#endif
+#ifdef SIGPROF
+  SIGPROF,
+#endif
+#ifdef SIGLOST
+  SIGLOST,
+#endif
+#ifdef SIGUSR1
+  SIGUSR1, SIGUSR2
+#endif
+    };
+
+#define TERMSIGS_LENGTH (sizeof (terminating_signals) / sizeof (int))
+
+static void
+catch_termination (sig)
+     int sig;
+{
+  /* We are probably here because GDB has a bug.  Write out the history
+     so that we might have a better chance of reproducing it.  */
+  /* Tell the user what we are doing so he can delete the file if
+     it is unwanted.  */
+  write_history (history_filename);
+  printf ("\n%s written.\n", history_filename);
+  signal (sig, SIG_DFL);
+  kill (getpid (), sig);
+}
+#endif
+
+/* Initialize signal handlers. */
+static void
+init_signals ()
+{
+  extern void request_quit ();
+#if 0
+  register int i;
+
+  for (i = 0; i < TERMSIGS_LENGTH; i++)
+    signal (terminating_signals[i], catch_termination);
+#endif
+
+  signal (SIGINT, request_quit);
+
+  /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
+     passed to the inferior, which we don't want.  It would be
+     possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
+     on BSD4.3 systems using vfork, that will (apparently) affect the
+     GDB process as well as the inferior (the signal handling tables
+     being shared between the two, apparently).  Since we establish
+     a handler for SIGQUIT, when we call exec it will set the signal
+     to SIG_DFL for us.  */
+  signal (SIGQUIT, do_nothing);
+  if (signal (SIGHUP, do_nothing) != SIG_IGN)
+    signal (SIGHUP, disconnect);
+  signal (SIGFPE, float_handler);
+}
+
+/* Read one line from the command input stream `instream'
+   into the local static buffer `linebuffer' (whose current length
+   is `linelength').
+   The buffer is made bigger as necessary.
+   Returns the address of the start of the line.
+
+   NULL is returned for end of file.
+
+   *If* the instream == stdin & stdin is a terminal, the line read
+   is copied into the file line saver (global var char *line,
+   length linesize) so that it can be duplicated.
+
+   This routine either uses fancy command line editing or
+   simple input as the user has requested.  */
+
+char *
+command_line_input (prrompt, repeat)
+     char *prrompt;
+     int repeat;
+{
+  static char *linebuffer = 0;
+  static int linelength = 0;
+  register char *p;
+  char *p1;
+  char *rl;
+  char *local_prompt = prrompt;
+  register int c;
+  char *nline;
+  char got_eof = 0;
+
+  if (linebuffer == 0)
+    {
+      linelength = 80;
+      linebuffer = (char *) xmalloc (linelength);
+    }
+
+  p = linebuffer;
+
+  /* Control-C quits instantly if typed while in this loop
+     since it should not wait until the user types a newline.  */
+  immediate_quit++;
+#ifdef STOP_SIGNAL
+  signal (STOP_SIGNAL, stop_sig);
+#endif
+
+  while (1)
+    {
+      /* Don't use fancy stuff if not talking to stdin.  */
+      if (command_editing_p && instream == stdin
+	  && ISATTY (instream))
+	rl = readline (local_prompt);
+      else
+	rl = gdb_readline (local_prompt, 1);
+
+      if (!rl || rl == (char *) EOF)
+	{
+	  got_eof = 1;
+	  break;
+	}
+      if (strlen(rl) + 1 + (p - linebuffer) > linelength)
+	{
+	  linelength = strlen(rl) + 1 + (p - linebuffer);
+	  nline = (char *) xrealloc (linebuffer, linelength);
+	  p += nline - linebuffer;
+	  linebuffer = nline;
+	}
+      p1 = rl;
+      /* Copy line.  Don't copy null at end.  (Leaves line alone
+         if this was just a newline)  */
+      while (*p1)
+	*p++ = *p1++;
+
+      free (rl);			/* Allocated in readline.  */
+
+      if (p == linebuffer || *(p - 1) != '\\')
+	break;
+
+      p--;			/* Put on top of '\'.  */
+      local_prompt = (char *) 0;
+  }
+
+#ifdef STOP_SIGNAL
+  signal (SIGTSTP, SIG_DFL);
+#endif
+  immediate_quit--;
+
+  if (got_eof)
+    return NULL;
+
+  /* Do history expansion if that is wished.  */
+  if (history_expansion_p && instream == stdin
+      && ISATTY (instream))
+    {
+      char *history_value;
+      int expanded;
+
+      *p = '\0';		/* Insert null now.  */
+      expanded = history_expand (linebuffer, &history_value);
+      if (expanded)
+	{
+	  /* Print the changes.  */
+	  printf ("%s\n", history_value);
+
+	  /* If there was an error, call this function again.  */
+	  if (expanded < 0)
+	    {
+	      free (history_value);
+	      return command_line_input (prrompt, repeat);
+	    }
+	  if (strlen (history_value) > linelength)
+	    {
+	      linelength = strlen (history_value) + 1;
+	      linebuffer = (char *) xrealloc (linebuffer, linelength);
+	    }
+	  strcpy (linebuffer, history_value);
+	  p = linebuffer + strlen(linebuffer);
+	  free (history_value);
+	}
+    }
+
+  /* If we just got an empty line, and that is supposed
+     to repeat the previous command, return the value in the
+     global buffer.  */
+  if (repeat)
+    {
+      if (p == linebuffer)
+	return line;
+      p1 = linebuffer;
+      while (*p1 == ' ' || *p1 == '\t')
+	p1++;
+      if (!*p1)
+	return line;
+    }
+
+  *p = 0;
+
+  /* Add line to history if appropriate.  */
+  if (instream == stdin
+      && ISATTY (stdin) && *linebuffer)
+    add_history (linebuffer);
+
+  /* Note: lines consisting soley of comments are added to the command
+     history.  This is useful when you type a command, and then
+     realize you don't want to execute it quite yet.  You can comment
+     out the command and then later fetch it from the value history
+     and remove the '#'.  The kill ring is probably better, but some
+     people are in the habit of commenting things out.  */
+  p1 = linebuffer;
+  while ((c = *p1++) != '\0')
+    {
+      if (c == '"')
+	while ((c = *p1++) != '"')
+	  {
+	    /* Make sure an escaped '"' doesn't make us think the string
+	       is ended.  */
+	    if (c == '\\')
+	      parse_escape (&p1);
+	    if (c == '\0')
+	      break;
+	  }
+      else if (c == '\'')
+	while ((c = *p1++) != '\'')
+	  {
+	    /* Make sure an escaped '\'' doesn't make us think the string
+	       is ended.  */
+	    if (c == '\\')
+	      parse_escape (&p1);
+	    if (c == '\0')
+	      break;
+	  }
+      else if (c == '#')
+	{
+	  /* Found a comment.  */
+	  p1[-1] = '\0';
+	  break;
+	}
+    }
+
+  /* Save into global buffer if appropriate.  */
+  if (repeat)
+    {
+      if (linelength > linesize)
+	{
+	  line = xrealloc (line, linelength);
+	  linesize = linelength;
+	}
+      strcpy (line, linebuffer);
+      return line;
+    }
+
+  return linebuffer;
+}
+
+/* Read lines from the input stream
+   and accumulate them in a chain of struct command_line's
+   which is then returned.  */
+
+struct command_line *
+read_command_lines ()
+{
+  struct command_line *first = 0;
+  register struct command_line *next, *tail = 0;
+  register char *p, *p1;
+  struct cleanup *old_chain = 0;
+
+  while (1)
+    {
+      dont_repeat ();
+      p = command_line_input (0, instream == stdin);
+      if (p == NULL)
+	/* Treat end of file like "end".  */
+	break;
+      
+      /* Remove leading and trailing blanks.  */
+      while (*p == ' ' || *p == '\t') p++;
+      p1 = p + strlen (p);
+      while (p1 != p && (p1[-1] == ' ' || p1[-1] == '\t')) p1--;
+
+      /* Is this "end"?  */
+      if (p1 - p == 3 && !strncmp (p, "end", 3))
+	break;
+
+      /* No => add this line to the chain of command lines.  */
+      next = (struct command_line *) xmalloc (sizeof (struct command_line));
+      next->line = savestring (p, p1 - p);
+      next->next = 0;
+      if (tail)
+	{
+	  tail->next = next;
+	}
+      else
+	{
+	  /* We just read the first line.
+	     From now on, arrange to throw away the lines we have
+	     if we quit or get an error while inside this function.  */
+	  first = next;
+	  old_chain = make_cleanup (free_command_lines, &first);
+	}
+      tail = next;
+    }
+
+  dont_repeat ();
+
+  /* Now we are about to return the chain to our caller,
+     so freeing it becomes his responsibility.  */
+  if (first)
+    discard_cleanups (old_chain);
+  return first;
+}
+
+/* Free a chain of struct command_line's.  */
+
+void
+free_command_lines (lptr)
+      struct command_line **lptr;
+{
+  register struct command_line *l = *lptr;
+  register struct command_line *next;
+
+  while (l)
+    {
+      next = l->next;
+      free (l->line);
+      free (l);
+      l = next;
+    }
+}
+
+/* Add an element to the list of info subcommands.  */
+
+void
+add_info (name, fun, doc)
+     char *name;
+     void (*fun) ();
+     char *doc;
+{
+  add_cmd (name, no_class, fun, doc, &infolist);
+}
+
+/* Add an alias to the list of info subcommands.  */
+
+void
+add_info_alias (name, oldname, abbrev_flag)
+     char *name;
+     char *oldname;
+     int abbrev_flag;
+{
+  add_alias_cmd (name, oldname, 0, abbrev_flag, &infolist);
+}
+
+/* The "info" command is defined as a prefix, with allow_unknown = 0.
+   Therefore, its own definition is called only for "info" with no args.  */
+
+/* ARGSUSED */
+static void
+info_command (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  printf ("\"info\" must be followed by the name of an info command.\n");
+  help_list (infolist, "info ", -1, stdout);
+}
+
+/* The "show" command with no arguments shows all the settings.  */
+
+/* ARGSUSED */
+static void
+show_command (arg, from_tty)
+     char *arg;
+     int from_tty;
+{
+  cmd_show_list (showlist, from_tty, "");
+}
+
+/* Add an element to the list of commands.  */
+
+void
+add_com (name, class, fun, doc)
+     char *name;
+     enum command_class class;
+     void (*fun) ();
+     char *doc;
+{
+  add_cmd (name, class, fun, doc, &cmdlist);
+}
+
+/* Add an alias or abbreviation command to the list of commands.  */
+
+void
+add_com_alias (name, oldname, class, abbrev_flag)
+     char *name;
+     char *oldname;
+     enum command_class class;
+     int abbrev_flag;
+{
+  add_alias_cmd (name, oldname, class, abbrev_flag, &cmdlist);
+}
+
+void
+error_no_arg (why)
+     char *why;
+{
+  error ("Argument required (%s).", why);
+}
+
+static void
+help_command (command, from_tty)
+     char *command;
+     int from_tty; /* Ignored */
+{
+  help_cmd (command, stdout);
+}
+
+static void
+validate_comname (comname)
+     char *comname;
+{
+  register char *p;
+
+  if (comname == 0)
+    error_no_arg ("name of command to define");
+
+  p = comname;
+  while (*p)
+    {
+      if (!(*p >= 'A' && *p <= 'Z')
+	  && !(*p >= 'a' && *p <= 'z')
+	  && !(*p >= '0' && *p <= '9')
+	  && *p != '-')
+	error ("Junk in argument list: \"%s\"", p);
+      p++;
+    }
+}
+
+static void
+define_command (comname, from_tty)
+     char *comname;
+     int from_tty;
+{
+  register struct command_line *cmds;
+  register struct cmd_list_element *c, *newc;
+  char *tem = comname;
+  extern void not_just_help_class_command ();
+
+  validate_comname (comname);
+
+  c = lookup_cmd (&tem, cmdlist, "", -1, 1);
+  if (c)
+    {
+      if (c->class == class_user || c->class == class_alias)
+	tem = "Redefine command \"%s\"? ";
+      else
+	tem = "Really redefine built-in command \"%s\"? ";
+      if (!query (tem, comname))
+	error ("Command \"%s\" not redefined.", comname);
+    }
+
+  if (from_tty)
+    {
+      printf ("Type commands for definition of \"%s\".\n\
+End with a line saying just \"end\".\n", comname);
+      fflush (stdout);
+    }
+  comname = savestring (comname, strlen (comname));
+
+  cmds = read_command_lines ();
+
+  if (c && c->class == class_user)
+    free_command_lines (&c->user_commands);
+
+  newc = add_cmd (comname, class_user, not_just_help_class_command,
+	   (c && c->class == class_user)
+	   ? c->doc : savestring ("User-defined.", 13), &cmdlist);
+  newc->user_commands = cmds;
+}
+
+static void
+document_command (comname, from_tty)
+     char *comname;
+     int from_tty;
+{
+  struct command_line *doclines;
+  register struct cmd_list_element *c;
+  char *tem = comname;
+
+  validate_comname (comname);
+
+  c = lookup_cmd (&tem, cmdlist, "", 0, 1);
+
+  if (c->class != class_user)
+    error ("Command \"%s\" is built-in.", comname);
+
+  if (from_tty)
+    printf ("Type documentation for \"%s\".\n\
+End with a line saying just \"end\".\n", comname);
+
+  doclines = read_command_lines ();
+
+  if (c->doc) free (c->doc);
+
+  {
+    register struct command_line *cl1;
+    register int len = 0;
+
+    for (cl1 = doclines; cl1; cl1 = cl1->next)
+      len += strlen (cl1->line) + 1;
+
+    c->doc = (char *) xmalloc (len + 1);
+    *c->doc = 0;
+
+    for (cl1 = doclines; cl1; cl1 = cl1->next)
+      {
+	strcat (c->doc, cl1->line);
+	if (cl1->next)
+	  strcat (c->doc, "\n");
+      }
+  }
+
+  free_command_lines (&doclines);
+}
+
+static void
+print_gdb_version (shout)
+     int shout;
+{
+  printf ("GDB %s, Copyright (C) 1991 Free Software Foundation, Inc.\n",
+	  version);
+  if (shout)
+    printf ("\
+There is ABSOLUTELY NO WARRANTY for GDB; type \"info warranty\" for details.\n\
+GDB is free software and you are welcome to distribute copies of it\n\
+ under certain conditions; type \"info copying\" to see the conditions.\n");
+}
+
+static void
+version_info (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  immediate_quit++;
+  print_gdb_version (0);
+  immediate_quit--;
+}
+
+/* xgdb calls this to reprint the usual GDB prompt.  */
+
+void
+print_prompt ()
+{
+  printf ("%s", prompt);
+  fflush (stdout);
+}
+
+static void
+quit_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  if (inferior_pid != 0)
+    {
+      if (query ("The program is running.  Quit anyway? "))
+	{
+	  target_kill (args, from_tty);
+	}
+      else
+	error ("Not confirmed.");
+    }
+  /* Save the history information if it is appropriate to do so.  */
+  if (write_history_p && history_filename)
+    write_history (history_filename);
+  exit (0);
+}
+
+int
+input_from_terminal_p ()
+{
+  return (instream == stdin) & caution;
+}
+
+static void
+pwd_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  if (args) error ("The \"pwd\" command does not take an argument: %s", args);
+  getwd (dirbuf);
+
+  if (strcmp (dirbuf, current_directory))
+    printf ("Working directory %s\n (canonically %s).\n",
+	    current_directory, dirbuf);
+  else
+    printf ("Working directory %s.\n", current_directory);
+}
+
+static void
+cd_command (dir, from_tty)
+     char *dir;
+     int from_tty;
+{
+  int len;
+  int change;
+
+  if (dir == 0)
+    error_no_arg ("new working directory");
+
+  dir = tilde_expand (dir);
+  make_cleanup (free, dir);
+
+  len = strlen (dir);
+  dir = savestring (dir, len - (len > 1 && dir[len-1] == '/'));
+  if (dir[0] == '/')
+    current_directory = dir;
+  else
+    {
+      current_directory = concat (current_directory, "/", dir);
+      free (dir);
+    }
+
+  /* Now simplify any occurrences of `.' and `..' in the pathname.  */
+
+  change = 1;
+  while (change)
+    {
+      char *p;
+      change = 0;
+
+      for (p = current_directory; *p;)
+	{
+	  if (!strncmp (p, "/./", 2)
+	      && (p[2] == 0 || p[2] == '/'))
+	    strcpy (p, p + 2);
+	  else if (!strncmp (p, "/..", 3)
+		   && (p[3] == 0 || p[3] == '/')
+		   && p != current_directory)
+	    {
+	      char *q = p;
+	      while (q != current_directory && q[-1] != '/') q--;
+	      if (q != current_directory)
+		{
+		  strcpy (q-1, p+3);
+		  p = q-1;
+		}
+	    }
+	  else p++;
+	}
+    }
+
+  if (chdir (dir) < 0)
+    perror_with_name (dir);
+
+  forget_cached_source_info ();
+
+  if (from_tty)
+    pwd_command ((char *) 0, 1);
+}
+
+static void
+source_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  FILE *stream;
+  struct cleanup *cleanups;
+  char *file = args;
+
+  if (file == 0)
+    /* Let source without arguments read .gdbinit.  */
+    file = gdbinit;
+
+  file = tilde_expand (file);
+  make_cleanup (free, file);
+
+  stream = fopen (file, "r");
+  if (stream == 0)
+    perror_with_name (file);
+
+  cleanups = make_cleanup (fclose, stream);
+
+  read_command_file (stream);
+
+  do_cleanups (cleanups);
+}
+
+/* ARGSUSED */
+static void
+echo_command (text, from_tty)
+     char *text;
+     int from_tty;
+{
+  char *p = text;
+  register int c;
+
+  if (text)
+    while (c = *p++)
+      {
+	if (c == '\\')
+	  {
+	    /* \ at end of argument is used after spaces
+	       so they won't be lost.  */
+	    if (*p == 0)
+	      return;
+
+	    c = parse_escape (&p);
+	    if (c >= 0)
+	      fputc (c, stdout);
+	  }
+	else
+	  fputc (c, stdout);
+      }
+}
+
+/* ARGSUSED */
+static void
+dump_me_command (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  if (query ("Should GDB dump core? "))
+    {
+      signal (SIGQUIT, SIG_DFL);
+      kill (getpid (), SIGQUIT);
+    }
+}
+
+/* Functions to manipulate command line editing control variables.  */
+
+/* Number of commands to print in each call to editing_info.  */
+#define Hist_print 10
+static void
+editing_info (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  /* Index for history commands.  Relative to history_base.  */
+  int offset;
+
+  /* Number of the history entry which we are planning to display next.
+     Relative to history_base.  */
+  static int num = 0;
+
+  /* The first command in the history which doesn't exist (i.e. one more
+     than the number of the last command).  Relative to history_base.  */
+  int hist_len;
+
+  struct _hist_entry *history_get();
+  extern int history_base;
+
+#if 0
+  /* This is all reported by individual "show" commands.  */
+  printf_filtered ("Interactive command editing is %s.\n",
+	  command_editing_p ? "on" : "off");
+
+  printf_filtered ("History expansion of command input is %s.\n",
+	  history_expansion_p ? "on" : "off");
+  printf_filtered ("Writing of a history record upon exit is %s.\n",
+	  write_history_p ? "enabled" : "disabled");
+  printf_filtered ("The size of the history list (number of stored commands) is %d.\n",
+	  history_size);
+  printf_filtered ("The name of the history record is \"%s\".\n\n",
+	  history_filename ? history_filename : "");
+#endif /* 0 */
+
+  /* Print out some of the commands from the command history.  */
+  /* First determine the length of the history list.  */
+  hist_len = history_size;
+  for (offset = 0; offset < history_size; offset++)
+    {
+      if (!history_get (history_base + offset))
+	{
+	  hist_len = offset;
+	  break;
+	}
+    }
+
+  if (args)
+    {
+      if (args[0] == '+' && args[1] == '\0')
+	/* "info editing +" should print from the stored position.  */
+	;
+      else
+	/* "info editing <exp>" should print around command number <exp>.  */
+	num = (parse_and_eval_address (args) - history_base) - Hist_print / 2;
+    }
+  /* "info editing" means print the last Hist_print commands.  */
+  else
+    {
+      num = hist_len - Hist_print;
+    }
+
+  if (num < 0)
+    num = 0;
+
+  /* If there are at least Hist_print commands, we want to display the last
+     Hist_print rather than, say, the last 6.  */
+  if (hist_len - num < Hist_print)
+    {
+      num = hist_len - Hist_print;
+      if (num < 0)
+	num = 0;
+    }
+
+#if 0
+  /* No need for a header now that "info editing" only prints one thing.  */
+  if (num == hist_len - Hist_print)
+    printf_filtered ("The list of the last %d commands is:\n\n", Hist_print);
+  else
+    printf_filtered ("Some of the stored commands are:\n\n");
+#endif /* 0 */
+
+  for (offset = num; offset < num + Hist_print && offset < hist_len; offset++)
+    {
+      printf_filtered ("%5d  %s\n", history_base + offset,
+	      (history_get (history_base + offset))->line);
+    }
+
+  /* The next command we want to display is the next one that we haven't
+     displayed yet.  */
+  num += Hist_print;
+  
+  /* If the user repeats this command with return, it should do what
+     "info editing +" does.  This is unnecessary if arg is null,
+     because "info editing +" is not useful after "info editing".  */
+  if (from_tty && args)
+    {
+      args[0] = '+';
+      args[1] = '\0';
+    }
+}
+
+/* Called by do_setshow_command.  */
+static void
+set_history_size_command (args, from_tty, c)
+     char *args;
+     int from_tty;
+     struct cmd_list_element *c;
+{
+  if (history_size == UINT_MAX)
+    unstifle_history ();
+  else
+    stifle_history (history_size);
+}
+
+static void
+set_history (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  printf ("\"set history\" must be followed by the name of a history subcommand.\n");
+  help_list (sethistlist, "set history ", -1, stdout);
+}
+
+static void
+show_history (args, from_tty)
+     char *args;
+     int from_tty;
+{
+  cmd_show_list (showhistlist, from_tty);
+}
+
+int info_verbose = 0;		/* Default verbose msgs off */
+
+/* Called by do_setshow_command.  An elaborate joke.  */
+static void 
+set_verbose (args, from_tty, c)
+     char *args;
+     int from_tty;
+     struct cmd_list_element *c;
+{
+  char *cmdname = "verbose";
+  struct cmd_list_element *showcmd;
+  
+  showcmd = lookup_cmd_1 (&cmdname, showlist, NULL, 1);
+
+  if (info_verbose)
+    {
+      c->doc = "Set verbose printing of informational messages.";
+      showcmd->doc = "Show verbose printing of informational messages.";
+    }
+  else
+    {
+      c->doc = "Set verbosity.";
+      showcmd->doc = "Show verbosity.";
+    }
+}
+
+static void
+float_handler ()
+{
+  /* This message is based on ANSI C, section 4.7.  Note that integer
+     divide by zero causes this, so "float" is a misnomer.  */
+  error ("Erroneous arithmetic operation.");
+}
+
+/* Return whether we are running a batch file or from terminal.  */
+int
+batch_mode ()
+{
+  return !(instream == stdin && ISATTY (stdin));
+}
+
+
+static void
+initialize_cmd_lists ()
+{
+  cmdlist = (struct cmd_list_element *) 0;
+  infolist = (struct cmd_list_element *) 0;
+  enablelist = (struct cmd_list_element *) 0;
+  disablelist = (struct cmd_list_element *) 0;
+  deletelist = (struct cmd_list_element *) 0;
+  enablebreaklist = (struct cmd_list_element *) 0;
+  setlist = (struct cmd_list_element *) 0;
+  showlist = NULL;
+  sethistlist = (struct cmd_list_element *) 0;
+  showhistlist = NULL;
+  unsethistlist = (struct cmd_list_element *) 0;
+}
+
+static void
+initialize_main ()
+{
+  struct cmd_list_element *c;
+  
+  char *tmpenv;
+  
+#ifdef DEFAULT_PROMPT
+  prompt = savestring (DEFAULT_PROMPT, strlen(DEFAULT_PROMPT));
+#else
+  prompt = savestring ("(gdb) ", 6);
+#endif
+
+  /* Set the important stuff up for command editing.  */
+  command_editing_p = 1;
+  history_expansion_p = 0;
+  write_history_p = 0;
+  
+  if (tmpenv = getenv ("HISTSIZE"))
+    history_size = atoi (tmpenv);
+  else
+    history_size = 256;
+
+  stifle_history (history_size);
+
+  if (tmpenv = getenv ("GDBHISTFILE"))
+    history_filename = savestring (tmpenv, strlen(tmpenv));
+  else
+    /* We include the current directory so that if the user changes
+       directories the file written will be the same as the one
+       that was read.  */
+    history_filename = concat (current_directory, "/.gdb_history", "");
+
+  read_history (history_filename);
+
+  /* Setup important stuff for command line editing.  */
+  rl_completion_entry_function = (int (*)()) symbol_completion_function;
+  rl_completer_word_break_characters = gdb_completer_word_break_characters;
+  rl_readline_name = "gdb";
+
+  /* Define the classes of commands.
+     They will appear in the help list in the reverse of this order.  */
+
+  add_cmd ("obscure", class_obscure, NO_FUNCTION, "Obscure features.", &cmdlist);
+  add_cmd ("aliases", class_alias, NO_FUNCTION, "Aliases of other commands.", &cmdlist);
+  add_cmd ("user-defined", class_user, NO_FUNCTION, "User-defined commands.\n\
+The commands in this class are those defined by the user.\n\
+Use the \"define\" command to define a command.", &cmdlist);
+  add_cmd ("support", class_support, NO_FUNCTION, "Support facilities.", &cmdlist);
+  add_cmd ("status", class_info, NO_FUNCTION, "Status inquiries.", &cmdlist);
+  add_cmd ("files", class_files, NO_FUNCTION, "Specifying and examining files.", &cmdlist);
+  add_cmd ("breakpoints", class_breakpoint, NO_FUNCTION, "Making program stop at certain points.", &cmdlist);
+  add_cmd ("data", class_vars, NO_FUNCTION, "Examining data.", &cmdlist);
+  add_cmd ("stack", class_stack, NO_FUNCTION, "Examining the stack.\n\
+The stack is made up of stack frames.  Gdb assigns numbers to stack frames\n\
+counting from zero for the innermost (currently executing) frame.\n\n\
+At any time gdb identifies one frame as the \"selected\" frame.\n\
+Variable lookups are done with respect to the selected frame.\n\
+When the program being debugged stops, gdb selects the innermost frame.\n\
+The commands below can be used to select other frames by number or address.",
+	   &cmdlist);
+  add_cmd ("running", class_run, NO_FUNCTION, "Running the program.", &cmdlist);
+
+  add_com ("pwd", class_files, pwd_command,
+	   "Print working directory.  This is used for your program as well.");
+  add_com ("cd", class_files, cd_command,
+	   "Set working directory to DIR for debugger and program being debugged.\n\
+The change does not take effect for the program being debugged\n\
+until the next time it is started.");
+
+  add_show_from_set
+    (add_set_cmd ("prompt", class_support, var_string, (char *)&prompt,
+	   "Set gdb's prompt",
+	   &setlist),
+     &showlist);
+  
+  add_com ("echo", class_support, echo_command,
+	   "Print a constant string.  Give string as argument.\n\
+C escape sequences may be used in the argument.\n\
+No newline is added at the end of the argument;\n\
+use \"\\n\" if you want a newline to be printed.\n\
+Since leading and trailing whitespace are ignored in command arguments,\n\
+if you want to print some you must use \"\\\" before leading whitespace\n\
+to be printed or after trailing whitespace.");
+  add_com ("document", class_support, document_command,
+	   "Document a user-defined command.\n\
+Give command name as argument.  Give documentation on following lines.\n\
+End with a line of just \"end\".");
+  add_com ("define", class_support, define_command,
+	   "Define a new command name.  Command name is argument.\n\
+Definition appears on following lines, one command per line.\n\
+End with a line of just \"end\".\n\
+Use the \"document\" command to give documentation for the new command.\n\
+Commands defined in this way do not take arguments.");
+
+#ifdef __STDC__
+  add_com ("source", class_support, source_command,
+	   "Read commands from a file named FILE.\n\
+Note that the file \"" GDBINIT_FILENAME "\" is read automatically in this way\n\
+when gdb is started.");
+#else
+  /* Punt file name, we can't help it easily.  */
+  add_com ("source", class_support, source_command,
+	   "Read commands from a file named FILE.\n\
+Note that the file \".gdbinit\" is read automatically in this way\n\
+when gdb is started.");
+#endif
+
+  add_com ("quit", class_support, quit_command, "Exit gdb.");
+  add_com ("help", class_support, help_command, "Print list of commands.");
+  add_com_alias ("q", "quit", class_support, 1);
+  add_com_alias ("h", "help", class_support, 1);
+
+
+  c = add_set_cmd ("verbose", class_support, var_boolean, (char *)&info_verbose,
+		   "Set ",
+		   &setlist),
+  add_show_from_set (c, &showlist);
+  c->function = set_verbose;
+  set_verbose (NULL, 0, c);
+  
+  add_com ("dump-me", class_obscure, dump_me_command,
+	   "Get fatal error; make debugger dump its core.");
+
+  add_show_from_set
+    (add_set_cmd ("editing", class_support, var_boolean, (char *)&command_editing_p,
+	   "Set command line editing.\n\
+Use \"on\" to enable to enable the editing, and \"off\" to disable it.\n\
+Without an argument, command line editing is enabled.", &setlist),
+     &showlist);
+
+  add_prefix_cmd ("history", class_support, set_history,
+		  "Generic command for setting command history parameters.",
+		  &sethistlist, "set history ", 0, &setlist);
+  add_prefix_cmd ("history", class_support, show_history,
+		  "Generic command for showing command history parameters.",
+		  &showhistlist, "show history ", 0, &showlist);
+
+  add_show_from_set
+    (add_set_cmd ("expansion", no_class, var_boolean, (char *)&history_expansion_p,
+	   "Set history expansion on command input.\n\
+Without an argument, history expansion is enabled.", &sethistlist),
+     &showhistlist);
+
+  add_show_from_set
+    (add_set_cmd ("write", no_class, var_boolean, (char *)&write_history_p,
+	   "Set saving of the history record on exit.\n\
+Use \"on\" to enable to enable the saving, and \"off\" to disable it.\n\
+Without an argument, saving is enabled.", &sethistlist),
+     &showhistlist);
+
+  c = add_set_cmd ("size", no_class, var_uinteger, (char *)&history_size,
+		   "Set the size of the command history, \n\
+ie. the number of previous commands to keep a record of.", &sethistlist);
+  add_show_from_set (c, &showhistlist);
+  c->function = set_history_size_command;
+
+  add_show_from_set
+    (add_set_cmd ("filename", no_class, var_filename, (char *)&history_filename,
+	   "Set the filename in which to record the command history\n\
+ (the list of previous commands of which a record is kept).", &sethistlist),
+     &showhistlist);
+
+  add_show_from_set
+    (add_set_cmd ("caution", class_support, var_boolean,
+		  (char *)&caution,
+	   "Set expected caution of user.\n\
+If on (the default), more warnings are printed, and the user is asked whether\n\
+they really want to do various major commands.", &setlist),
+     &showlist);
+
+  add_prefix_cmd ("info", class_info, info_command,
+		  "Generic command for printing status.",
+		  &infolist, "info ", 0, &cmdlist);
+  add_com_alias ("i", "info", class_info, 1);
+
+  add_prefix_cmd ("show", class_info, show_command,
+		  "Generic command for showing things set with \"set\".",
+		  &showlist, "show ", 0, &cmdlist);
+  /* Another way to get at the same thing.  */
+  add_info ("set", show_command, "Show all GDB settings.");
+
+  add_info ("editing", editing_info, "Status of command editor.");
+
+  add_info ("version", version_info, "Report what version of GDB this is.");
+}