cli-cmds.c

这个是LINUX下的GDB调度工具的源码

  if (file == NULL)
    {
      error ("source command requires pathname of file to source.");
    }

  file = tilde_expand (file);
  old_cleanups = make_cleanup (xfree, file);

  stream = fopen (file, FOPEN_RT);
  if (!stream)
    {
      if (from_tty)
	perror_with_name (file);
      else
	return;
    }

  script_from_file (stream, file);

  do_cleanups (old_cleanups);
}

static void
echo_command (char *text, int from_tty)
{
  char *p = text;
  int c;

  if (text)
    while ((c = *p++) != '\0')
      {
	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)
	      printf_filtered ("%c", c);
	  }
	else
	  printf_filtered ("%c", c);
      }

  /* Force this output to appear now.  */
  wrap_here ("");
  gdb_flush (gdb_stdout);
}

static void
shell_escape (char *arg, int from_tty)
{
#ifdef CANT_FORK
  /* If ARG is NULL, they want an inferior shell, but `system' just
     reports if the shell is available when passed a NULL arg.  */
  int rc = system (arg ? arg : "");

  if (!arg)
    arg = "inferior shell";

  if (rc == -1)
    {
      fprintf_unfiltered (gdb_stderr, "Cannot execute %s: %s\n", arg,
			  safe_strerror (errno));
      gdb_flush (gdb_stderr);
    }
  else if (rc)
    {
      fprintf_unfiltered (gdb_stderr, "%s exited with status %d\n", arg, rc);
      gdb_flush (gdb_stderr);
    }
#ifdef GLOBAL_CURDIR
  /* Make sure to return to the directory GDB thinks it is, in case the
     shell command we just ran changed it.  */
  chdir (current_directory);
#endif
#else /* Can fork.  */
  int rc, status, pid;

  if ((pid = vfork ()) == 0)
    {
      char *p, *user_shell;

      if ((user_shell = (char *) getenv ("SHELL")) == NULL)
	user_shell = "/bin/sh";

      /* Get the name of the shell for arg0 */
      if ((p = strrchr (user_shell, '/')) == NULL)
	p = user_shell;
      else
	p++;			/* Get past '/' */

      if (!arg)
	execl (user_shell, p, (char *) 0);
      else
	execl (user_shell, p, "-c", arg, (char *) 0);

      fprintf_unfiltered (gdb_stderr, "Cannot execute %s: %s\n", user_shell,
			  safe_strerror (errno));
      gdb_flush (gdb_stderr);
      _exit (0177);
    }

  if (pid != -1)
    while ((rc = wait (&status)) != pid && rc != -1)
      ;
  else
    error ("Fork failed");
#endif /* Can fork.  */
}

static void
edit_command (char *arg, int from_tty)
{
  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  struct symbol *sym;
  char *arg1;
  int cmdlen, log10;
  unsigned m;
  char *editor;
  char *p;

  /* Pull in the current default source line if necessary */
  if (arg == 0)
    {
      set_default_source_symtab_and_line ();
      sal = get_current_source_symtab_and_line ();
    }

  /* bare "edit" edits file with present line.  */

  if (arg == 0)
    {
      if (sal.symtab == 0)
	error ("No default source file yet.");
      sal.line += get_lines_to_list () / 2;
    }
  else
    {

      /* Now should only be one argument -- decode it in SAL */

      arg1 = arg;
      sals = decode_line_1 (&arg1, 0, 0, 0, 0, 0);

      if (! sals.nelts) return;  /*  C++  */
      if (sals.nelts > 1) {
        ambiguous_line_spec (&sals);
        xfree (sals.sals);
        return;
      }

      sal = sals.sals[0];
      xfree (sals.sals);

      if (*arg1)
        error ("Junk at end of line specification.");

      /* if line was specified by address,
         first print exactly which line, and which file.
         In this case, sal.symtab == 0 means address is outside
         of all known source files, not that user failed to give a filename.  */
      if (*arg == '*')
        {
          if (sal.symtab == 0)
	    /* FIXME-32x64--assumes sal.pc fits in long.  */
	    error ("No source file for address %s.",
		   hex_string ((unsigned long) sal.pc));
          sym = find_pc_function (sal.pc);
          if (sym)
	    {
	      print_address_numeric (sal.pc, 1, gdb_stdout);
	      printf_filtered (" is in ");
	      fputs_filtered (SYMBOL_PRINT_NAME (sym), gdb_stdout);
	      printf_filtered (" (%s:%d).\n", sal.symtab->filename, sal.line);
	    }
          else
	    {
	      print_address_numeric (sal.pc, 1, gdb_stdout);
	      printf_filtered (" is at %s:%d.\n",
			       sal.symtab->filename, sal.line);
	    }
        }

      /* If what was given does not imply a symtab, it must be an undebuggable
         symbol which means no source code.  */

      if (sal.symtab == 0)
        error ("No line number known for %s.", arg);
    }

  if ((editor = (char *) getenv ("EDITOR")) == NULL)
      editor = "/bin/ex";
  
  /* Approximate base-10 log of line to 1 unit for digit count */
  for(log10=32, m=0x80000000; !(sal.line & m) && log10>0; log10--, m=m>>1);
  log10 = 1 + (int)((log10 + (0 == ((m-1) & sal.line)))/3.32192809);

  cmdlen = strlen(editor) + 1
         + (NULL == sal.symtab->dirname ? 0 : strlen(sal.symtab->dirname) + 1)
	 + (NULL == sal.symtab->filename? 0 : strlen(sal.symtab->filename)+ 1)
	 + log10 + 2;
  
  p = xmalloc(cmdlen);
  sprintf(p,"%s +%d %s%s",editor,sal.line,
     (NULL == sal.symtab->dirname ? "./" :
        (NULL != sal.symtab->filename && *(sal.symtab->filename) != '/') ?
	   sal.symtab->dirname : ""),
     (NULL == sal.symtab->filename ? "unknown" : sal.symtab->filename)
  );
  shell_escape(p, from_tty);

  xfree(p);
}

static void
list_command (char *arg, int from_tty)
{
  struct symtabs_and_lines sals, sals_end;
  struct symtab_and_line sal, sal_end, cursal;
  struct symbol *sym;
  char *arg1;
  int no_end = 1;
  int dummy_end = 0;
  int dummy_beg = 0;
  int linenum_beg = 0;
  char *p;

  /* Pull in the current default source line if necessary */
  if (arg == 0 || arg[0] == '+' || arg[0] == '-')
    {
      set_default_source_symtab_and_line ();
      cursal = get_current_source_symtab_and_line ();
    }

  /* "l" or "l +" lists next ten lines.  */

  if (arg == 0 || strcmp (arg, "+") == 0)
    {
      print_source_lines (cursal.symtab, cursal.line,
			  cursal.line + get_lines_to_list (), 0);
      return;
    }

  /* "l -" lists previous ten lines, the ones before the ten just listed.  */
  if (strcmp (arg, "-") == 0)
    {
      print_source_lines (cursal.symtab,
			  max (get_first_line_listed () - get_lines_to_list (), 1),
			  get_first_line_listed (), 0);
      return;
    }

  /* Now if there is only one argument, decode it in SAL
     and set NO_END.
     If there are two arguments, decode them in SAL and SAL_END
     and clear NO_END; however, if one of the arguments is blank,
     set DUMMY_BEG or DUMMY_END to record that fact.  */

  if (!have_full_symbols () && !have_partial_symbols ())
    error ("No symbol table is loaded.  Use the \"file\" command.");

  arg1 = arg;
  if (*arg1 == ',')
    dummy_beg = 1;
  else
    {
      sals = decode_line_1 (&arg1, 0, 0, 0, 0, 0);

      if (!sals.nelts)
	return;			/*  C++  */
      if (sals.nelts > 1)
	{
	  ambiguous_line_spec (&sals);
	  xfree (sals.sals);
	  return;
	}

      sal = sals.sals[0];
      xfree (sals.sals);
    }

  /* Record whether the BEG arg is all digits.  */

  for (p = arg; p != arg1 && *p >= '0' && *p <= '9'; p++);
  linenum_beg = (p == arg1);

  while (*arg1 == ' ' || *arg1 == '\t')
    arg1++;
  if (*arg1 == ',')
    {
      no_end = 0;
      arg1++;
      while (*arg1 == ' ' || *arg1 == '\t')
	arg1++;
      if (*arg1 == 0)
	dummy_end = 1;
      else
	{
	  if (dummy_beg)
	    sals_end = decode_line_1 (&arg1, 0, 0, 0, 0, 0);
	  else
	    sals_end = decode_line_1 (&arg1, 0, sal.symtab, sal.line, 0, 0);
	  if (sals_end.nelts == 0)
	    return;
	  if (sals_end.nelts > 1)
	    {
	      ambiguous_line_spec (&sals_end);
	      xfree (sals_end.sals);
	      return;
	    }
	  sal_end = sals_end.sals[0];
	  xfree (sals_end.sals);
	}
    }

  if (*arg1)
    error ("Junk at end of line specification.");

  if (!no_end && !dummy_beg && !dummy_end
      && sal.symtab != sal_end.symtab)
    error ("Specified start and end are in different files.");
  if (dummy_beg && dummy_end)
    error ("Two empty args do not say what lines to list.");

  /* if line was specified by address,
     first print exactly which line, and which file.
     In this case, sal.symtab == 0 means address is outside
     of all known source files, not that user failed to give a filename.  */
  if (*arg == '*')
    {
      if (sal.symtab == 0)
	/* FIXME-32x64--assumes sal.pc fits in long.  */
	error ("No source file for address %s.",
	       hex_string ((unsigned long) sal.pc));
      sym = find_pc_function (sal.pc);
      if (sym)
	{
	  print_address_numeric (sal.pc, 1, gdb_stdout);
	  printf_filtered (" is in ");
	  fputs_filtered (SYMBOL_PRINT_NAME (sym), gdb_stdout);
	  printf_filtered (" (%s:%d).\n", sal.symtab->filename, sal.line);
	}
      else
	{
	  print_address_numeric (sal.pc, 1, gdb_stdout);
	  printf_filtered (" is at %s:%d.\n",
			   sal.symtab->filename, sal.line);
	}
    }

  /* If line was not specified by just a line number,
     and it does not imply a symtab, it must be an undebuggable symbol
     which means no source code.  */

  if (!linenum_beg && sal.symtab == 0)
    error ("No line number known for %s.", arg);

  /* If this command is repeated with RET,
     turn it into the no-arg variant.  */

  if (from_tty)
    *arg = 0;

  if (dummy_beg && sal_end.symtab == 0)
    error ("No default source file yet.  Do \"help list\".");
  if (dummy_beg)
    print_source_lines (sal_end.symtab,
			max (sal_end.line - (get_lines_to_list () - 1), 1),
			sal_end.line + 1, 0);
  else if (sal.symtab == 0)
    error ("No default source file yet.  Do \"help list\".");
  else if (no_end)
    {
      int first_line = sal.line - get_lines_to_list () / 2;

      if (first_line < 1) first_line = 1;

      print_source_lines (sal.symtab,
		          first_line,
			  first_line + get_lines_to_list (),
			  0);
    }
  else
    print_source_lines (sal.symtab, sal.line,
			(dummy_end
			 ? sal.line + get_lines_to_list ()
			 : sal_end.line + 1),
			0);
}

/* Dump a specified section of assembly code.  With no command line
   arguments, this command will dump the assembly code for the
   function surrounding the pc value in the selected frame.  With one
   argument, it will dump the assembly code surrounding that pc value.
   Two arguments are interpeted as bounds within which to dump
   assembly.  */

static void
disassemble_command (char *arg, int from_tty)
{
  CORE_ADDR low, high;
  char *name;
  CORE_ADDR pc, pc_masked;
  char *space_index;
#if 0
  asection *section;
#endif

  name = NULL;
  if (!arg)
    {
      if (!deprecated_selected_frame)
	error ("No frame selected.\n");

      pc = get_frame_pc (deprecated_selected_frame);
      if (find_pc_partial_function (pc, &name, &low, &high) == 0)
	error ("No function contains program counter for selected frame.\n");
#if defined(TUI)
      /* NOTE: cagney/2003-02-13 The `tui_active' was previously
	 `tui_version'.  */
      if (tui_active)
	/* FIXME: cagney/2004-02-07: This should be an observer.  */
	low = tui_get_low_disassembly_address (low, pc);
#endif
      low += DEPRECATED_FUNCTION_START_OFFSET;
    }