/* Top level stuff for GDB, the GNU debugger.
- Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
- 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
- Free Software Foundation, Inc.
+ Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
+ 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
+ 2008, 2009 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdbcmd.h"
#include "serial.h"
#include "doublest.h"
#include "gdb_assert.h"
+#include "main.h"
+#include "event-loop.h"
+#include "gdbthread.h"
/* readline include files */
#include "readline/readline.h"
/* Initialization file name for gdb. This is overridden in some configs. */
+#ifndef PATH_MAX
+# ifdef FILENAME_MAX
+# define PATH_MAX FILENAME_MAX
+# else
+# define PATH_MAX 512
+# endif
+#endif
+
#ifndef GDBINIT_FILENAME
#define GDBINIT_FILENAME ".gdbinit"
#endif
-char gdbinit[] = GDBINIT_FILENAME;
+char gdbinit[PATH_MAX + 1] = GDBINIT_FILENAME;
int inhibit_gdbinit = 0;
/* Flag for whether we want all the "from_tty" gubbish printed. */
int caution = 1; /* Default is yes, sigh. */
+static void
+show_caution (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("\
+Whether to confirm potentially dangerous operations is %s.\n"),
+ value);
+}
/* stdio stream that command input is being read from. Set to stdin normally.
Set by source_command to the file we are sourcing. Set to NULL if we are
FILE *instream;
+/* Flag to indicate whether a user defined command is currently running. */
+
+int in_user_command;
+
/* Current working directory. */
char *current_directory;
int epoch_interface;
int xgdb_verbose;
-/* gdb prints this when reading a command interactively */
-static char *gdb_prompt_string; /* the global prompt string */
-
/* Buffer used for reading command lines, and the size
allocated for it so far. */
int remote_debug = 0;
-/* Non-zero means the target is running. Note: this is different from
- saying that there is an active target and we are stopped at a
- breakpoint, for instance. This is a real indicator whether the
- target is off and running, which gdb is doing something else. */
-int target_executing = 0;
-
-/* Level of control structure. */
-static int control_level;
-
/* Sbrk location on entry to main. Used for statistics only. */
#ifdef HAVE_SBRK
char *lim_at_start;
char *(*deprecated_readline_hook) (char *);
void (*deprecated_readline_end_hook) (void);
-/* Called as appropriate to notify the interface of the specified breakpoint
- conditions. */
-
-void (*deprecated_create_breakpoint_hook) (struct breakpoint * bpt);
-void (*deprecated_delete_breakpoint_hook) (struct breakpoint * bpt);
-void (*deprecated_modify_breakpoint_hook) (struct breakpoint * bpt);
-
/* Called as appropriate to notify the interface that we have attached
to or detached from an already running process. */
void (*deprecated_interactive_hook) (void);
-/* Called when the registers have changed, as a hint to a GUI
- to minimize window update. */
-
-void (*deprecated_registers_changed_hook) (void);
-
/* Tell the GUI someone changed the register REGNO. -1 means
that the caller does not know which register changed or
that several registers have changed (see value_assign). */
void (*deprecated_context_hook) (int id);
-/* Takes control from error (). Typically used to prevent longjmps out of the
- middle of the GUI. Usually used in conjunction with a catch routine. */
-
-void (*deprecated_error_hook) (void);
-
/* Handler for SIGHUP. */
#ifdef SIGHUP
/* Execute the line P as a command.
Pass FROM_TTY as second argument to the defining function. */
+/* Execute command P, in the current user context. */
+
void
execute_command (char *p, int from_tty)
{
enum language flang;
static int warned = 0;
char *line;
+ long time_at_cmd_start = 0;
+#ifdef HAVE_SBRK
+ long space_at_cmd_start = 0;
+#endif
+ extern int display_time;
+ extern int display_space;
+
+ if (target_can_async_p ())
+ {
+ time_at_cmd_start = get_run_time ();
+
+ if (display_space)
+ {
+#ifdef HAVE_SBRK
+ char *lim = (char *) sbrk (0);
+ space_at_cmd_start = lim - lim_at_start;
+#endif
+ }
+ }
free_all_values ();
if (p == NULL)
return;
- serial_log_command (p);
+ target_log_command (p);
while (*p == ' ' || *p == '\t')
p++;
char *arg;
line = p;
- c = lookup_cmd (&p, cmdlist, "", 0, 1);
+ /* If trace-commands is set then this will print this command. */
+ print_command_trace (p);
- /* If the target is running, we allow only a limited set of
- commands. */
- if (target_can_async_p () && target_executing)
- if (strcmp (c->name, "help") != 0
- && strcmp (c->name, "pwd") != 0
- && strcmp (c->name, "show") != 0
- && strcmp (c->name, "stop") != 0)
- error (_("Cannot execute this command while the target is running."));
+ c = lookup_cmd (&p, cmdlist, "", 0, 1);
/* Pass null arg rather than an empty one. */
arg = *p ? p : 0;
/* FIXME: This should be cacheing the frame and only running when
the frame changes. */
- if (target_has_stack)
+ if (has_stack_frames ())
{
flang = get_frame_language ();
if (!warned
}
execute_command (command, instream == stdin);
- /* Do any commands attached to breakpoint we stopped at. */
- bpstat_do_actions (&stop_bpstat);
+
+ /* Do any commands attached to breakpoint we are stopped at. */
+ bpstat_do_actions ();
+
do_cleanups (old_chain);
if (display_time)
long space_now = lim - lim_at_start;
long space_diff = space_now - space_at_cmd_start;
- printf_unfiltered (_("Space used: %ld (%c%ld for this command)\n"),
+ printf_unfiltered (_("Space used: %ld (%s%ld for this command)\n"),
space_now,
- (space_diff >= 0 ? '+' : '-'),
+ (space_diff >= 0 ? "+" : ""),
space_diff);
#endif
}
}
}
-
-/* Read commands from `instream' and execute them until end of file or
- error reading instream. This command loop doesnt care about any
- such things as displaying time and space usage. If the user asks
- for those, they won't work. */
-void
-simplified_command_loop (char *(*read_input_func) (char *),
- void (*execute_command_func) (char *, int))
-{
- struct cleanup *old_chain;
- char *command;
- int stdin_is_tty = ISATTY (stdin);
-
- while (instream && !feof (instream))
- {
- quit_flag = 0;
- if (instream == stdin && stdin_is_tty)
- reinitialize_more_filter ();
- old_chain = make_cleanup (null_cleanup, 0);
-
- /* Get a command-line. */
- command = (*read_input_func) (instream == stdin ?
- get_prompt () : (char *) NULL);
-
- if (command == 0)
- return;
-
- (*execute_command_func) (command, instream == stdin);
-
- /* Do any commands attached to breakpoint we stopped at. */
- bpstat_do_actions (&stop_bpstat);
-
- do_cleanups (old_chain);
- }
-}
\f
/* Commands call this if they do not want to be repeated by null lines. */
substitution. These variables are given default values at the end
of this file. */
static int command_editing_p;
+
/* NOTE 1999-04-29: This variable will be static again, once we modify
gdb to use the event loop as the default command loop and we merge
event-top.c into this file, top.c */
+
/* static */ int history_expansion_p;
+
static int write_history_p;
+static void
+show_write_history_p (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Saving of the history record on exit is %s.\n"),
+ value);
+}
+
static int history_size;
+static void
+show_history_size (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("The size of the command history is %s.\n"),
+ value);
+}
+
static char *history_filename;
+static void
+show_history_filename (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("\
+The filename in which to record the command history is \"%s\".\n"),
+ value);
+}
/* This is like readline(), but it has some gdb-specific behavior.
- gdb can use readline in both the synchronous and async modes during
+ gdb may want readline in both the synchronous and async modes during
a single gdb invocation. At the ordinary top-level prompt we might
be using the async readline. That means we can't use
rl_pre_input_hook, since it doesn't work properly in async mode.
However, for a secondary prompt (" >", such as occurs during a
- `define'), gdb just calls readline() directly, running it in
- synchronous mode. So for operate-and-get-next to work in this
- situation, we have to switch the hooks around. That is what
- gdb_readline_wrapper is for. */
+ `define'), gdb wants a synchronous response.
+
+ We used to call readline() directly, running it in synchronous
+ mode. But mixing modes this way is not supported, and as of
+ readline 5.x it no longer works; the arrow keys come unbound during
+ the synchronous call. So we make a nested call into the event
+ loop. That's what gdb_readline_wrapper is for. */
+
+/* A flag set as soon as gdb_readline_wrapper_line is called; we can't
+ rely on gdb_readline_wrapper_result, which might still be NULL if
+ the user types Control-D for EOF. */
+static int gdb_readline_wrapper_done;
+
+/* The result of the current call to gdb_readline_wrapper, once a newline
+ is seen. */
+static char *gdb_readline_wrapper_result;
+
+/* Any intercepted hook. Operate-and-get-next sets this, expecting it
+ to be called after the newline is processed (which will redisplay
+ the prompt). But in gdb_readline_wrapper we will not get a new
+ prompt until the next call, or until we return to the event loop.
+ So we disable this hook around the newline and restore it before we
+ return. */
+static void (*saved_after_char_processing_hook) (void);
+
+/* This function is called when readline has seen a complete line of
+ text. */
+
+static void
+gdb_readline_wrapper_line (char *line)
+{
+ gdb_assert (!gdb_readline_wrapper_done);
+ gdb_readline_wrapper_result = line;
+ gdb_readline_wrapper_done = 1;
+
+ /* Prevent operate-and-get-next from acting too early. */
+ saved_after_char_processing_hook = after_char_processing_hook;
+ after_char_processing_hook = NULL;
+
+ /* Prevent parts of the prompt from being redisplayed if annotations
+ are enabled, and readline's state getting out of sync. */
+ if (async_command_editing_p)
+ rl_callback_handler_remove ();
+}
+
+struct gdb_readline_wrapper_cleanup
+ {
+ void (*handler_orig) (char *);
+ int already_prompted_orig;
+ };
+
+static void
+gdb_readline_wrapper_cleanup (void *arg)
+{
+ struct gdb_readline_wrapper_cleanup *cleanup = arg;
+
+ rl_already_prompted = cleanup->already_prompted_orig;
+
+ gdb_assert (input_handler == gdb_readline_wrapper_line);
+ input_handler = cleanup->handler_orig;
+ gdb_readline_wrapper_result = NULL;
+ gdb_readline_wrapper_done = 0;
+
+ after_char_processing_hook = saved_after_char_processing_hook;
+ saved_after_char_processing_hook = NULL;
+
+ xfree (cleanup);
+}
+
char *
gdb_readline_wrapper (char *prompt)
{
- /* Set the hook that works in this case. */
+ struct cleanup *back_to;
+ struct gdb_readline_wrapper_cleanup *cleanup;
+ char *retval;
+
+ cleanup = xmalloc (sizeof (*cleanup));
+ cleanup->handler_orig = input_handler;
+ input_handler = gdb_readline_wrapper_line;
+
+ cleanup->already_prompted_orig = rl_already_prompted;
+
+ back_to = make_cleanup (gdb_readline_wrapper_cleanup, cleanup);
+
+ /* Display our prompt and prevent double prompt display. */
+ display_gdb_prompt (prompt);
+ rl_already_prompted = 1;
+
if (after_char_processing_hook)
- {
- rl_pre_input_hook = (Function *) after_char_processing_hook;
- after_char_processing_hook = NULL;
- }
+ (*after_char_processing_hook) ();
+ gdb_assert (after_char_processing_hook == NULL);
- return readline (prompt);
+ /* gdb_do_one_event argument is unused. */
+ while (gdb_do_one_event (NULL) >= 0)
+ if (gdb_readline_wrapper_done)
+ break;
+
+ retval = gdb_readline_wrapper_result;
+ do_cleanups (back_to);
+ return retval;
}
\f
}
/* Don't use fancy stuff if not talking to stdin. */
- if (deprecated_readline_hook && instream == NULL)
+ if (deprecated_readline_hook && input_from_terminal_p ())
{
rl = (*deprecated_readline_hook) (local_prompt);
}
- else if (command_editing_p && instream == stdin && ISATTY (instream))
+ else if (command_editing_p && input_from_terminal_p ())
{
rl = gdb_readline_wrapper (local_prompt);
}
}
strcpy (linebuffer, history_value);
p = linebuffer + strlen (linebuffer);
- xfree (history_value);
}
+ xfree (history_value);
}
/* If we just got an empty line, and that is supposed
program to parse, and is just canonical program name and version
number, which starts after last space. */
- fprintf_filtered (stream, "GNU gdb %s\n", version);
+ fprintf_filtered (stream, "GNU gdb %s%s\n", PKGVERSION, version);
/* Second line is a copyright notice. */
- fprintf_filtered (stream, "Copyright 2004 Free Software Foundation, Inc.\n");
+ fprintf_filtered (stream, "Copyright (C) 2009 Free Software Foundation, Inc.\n");
/* Following the copyright is a brief statement that the program is
free software, that users are free to copy and change it on
there is no warranty. */
fprintf_filtered (stream, "\
-GDB is free software, covered by the GNU General Public License, and you are\n\
-welcome to change it and/or distribute copies of it under certain conditions.\n\
-Type \"show copying\" to see the conditions.\n\
-There is absolutely no warranty for GDB. Type \"show warranty\" for details.\n");
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\n\
+This is free software: you are free to change and redistribute it.\n\
+There is NO WARRANTY, to the extent permitted by law. Type \"show copying\"\n\
+and \"show warranty\" for details.\n");
/* After the required info we print the configuration information. */
fprintf_filtered (stream, "%s", host_name);
}
fprintf_filtered (stream, "\".");
+
+ if (REPORT_BUGS_TO[0])
+ {
+ fprintf_filtered (stream,
+ _("\nFor bug reporting instructions, please see:\n"));
+ fprintf_filtered (stream, "%s.", REPORT_BUGS_TO);
+ }
}
\f
/* get_prompt: access method for the GDB prompt string. */
if (! ptid_equal (inferior_ptid, null_ptid) && target_has_execution)
{
char *s;
+ struct inferior *inf = current_inferior ();
/* This is something of a hack. But there's no reliable way to
see if a GUI is running. The `use_windows' variable doesn't
cut it. */
if (deprecated_init_ui_hook)
- s = "A debugging session is active.\nDo you still want to close the debugger?";
- else if (attach_flag)
- s = "The program is running. Quit anyway (and detach it)? ";
+ s = _("A debugging session is active.\nDo you still want to close the debugger?");
+ else if (inf->attach_flag)
+ s = _("The program is running. Quit anyway (and detach it)? ");
else
- s = "The program is running. Exit anyway? ";
+ s = _("The program is running. Quit anyway (and kill it)? ");
if (!query ("%s", s))
return 0;
return 1;
}
-/* Helper routine for quit_force that requires error handling. */
-
struct qt_args
{
char *args;
int from_tty;
};
+/* Callback for iterate_over_threads. Finds any thread of inferior
+ given by ARG (really an int*). */
+
static int
-quit_target (void *arg)
+any_thread_of (struct thread_info *thread, void *arg)
{
- struct qt_args *qt = (struct qt_args *)arg;
+ int pid = * (int *)arg;
- if (! ptid_equal (inferior_ptid, null_ptid) && target_has_execution)
+ if (PIDGET (thread->ptid) == pid)
+ return 1;
+
+ return 0;
+}
+
+/* Callback for iterate_over_inferiors. Kills or detaches the given
+ inferior, depending on how we originally gained control of it. */
+
+static int
+kill_or_detach (struct inferior *inf, void *args)
+{
+ struct qt_args *qt = args;
+ struct thread_info *thread;
+
+ thread = iterate_over_threads (any_thread_of, &inf->pid);
+ if (thread)
{
- if (attach_flag)
- target_detach (qt->args, qt->from_tty);
+ switch_to_thread (thread->ptid);
+ if (inf->attach_flag)
+ target_detach (qt->args, qt->from_tty);
else
- target_kill ();
+ target_kill ();
}
- /* UDI wants this, to kill the TIP. */
- target_close (¤t_target, 1);
+ return 0;
+}
+
+/* Helper routine for quit_force that requires error handling. */
+
+static int
+quit_target (void *arg)
+{
+ struct qt_args *qt = (struct qt_args *)arg;
+
+ /* Kill or detach all inferiors. */
+ if (target_has_execution)
+ iterate_over_inferiors (kill_or_detach, qt);
+
+ /* Give all pushed targets a chance to do minimal cleanup, and pop
+ them all out. */
+ pop_all_targets (1);
/* Save the history information if it is appropriate to do so. */
if (write_history_p && history_filename)
exit_code = (int) value_as_long (val);
}
+ else if (return_child_result)
+ exit_code = return_child_result_value;
qt.args = args;
qt.from_tty = from_tty;
exit (exit_code);
}
-/* Returns whether GDB is running on a terminal and whether the user
- desires that questions be asked of them on that terminal. */
+/* Returns whether GDB is running on a terminal and input is
+ currently coming from that terminal. */
int
input_from_terminal_p (void)
{
- return gdb_has_a_terminal () && (instream == stdin) & caution;
+ if (gdb_has_a_terminal () && instream == stdin)
+ return 1;
+
+ /* If INSTREAM is unset, and we are not in a user command, we
+ must be in Insight. That's like having a terminal, for our
+ purposes. */
+ if (instream == NULL && !in_user_command)
+ return 1;
+
+ return 0;
}
\f
static void
that was read. */
#ifdef __MSDOS__
/* No leading dots in file names are allowed on MSDOS. */
- history_filename = concat (current_directory, "/_gdb_history", NULL);
+ history_filename = concat (current_directory, "/_gdb_history",
+ (char *)NULL);
#else
- history_filename = concat (current_directory, "/.gdb_history", NULL);
+ history_filename = concat (current_directory, "/.gdb_history",
+ (char *)NULL);
#endif
}
read_history (history_filename);
}
+static void
+show_new_async_prompt (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Gdb's prompt is \"%s\".\n"), value);
+}
+
+static void
+show_async_command_editing_p (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("\
+Editing of command lines as they are typed is %s.\n"),
+ value);
+}
+
+static void
+show_annotation_level (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Annotation_level is %s.\n"), value);
+}
+
+static void
+show_exec_done_display_p (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("\
+Notification of completion for asynchronous execution commands is %s.\n"),
+ value);
+}
static void
init_main (void)
{
write_history_p = 0;
/* Setup important stuff for command line editing. */
+ rl_completion_word_break_hook = gdb_completion_word_break_characters;
rl_completion_entry_function = readline_line_completion_function;
rl_completer_word_break_characters = default_word_break_characters ();
rl_completer_quote_characters = get_gdb_completer_quote_characters ();
15 is Control-o, the same binding this function has in Bash. */
rl_add_defun ("operate-and-get-next", gdb_rl_operate_and_get_next, 15);
- c = add_set_cmd ("prompt", class_support, var_string,
- (char *) &new_async_prompt, "Set gdb's prompt",
- &setlist);
- deprecated_add_show_from_set (c, &showlist);
- set_cmd_sfunc (c, set_async_prompt);
+ add_setshow_string_cmd ("prompt", class_support,
+ &new_async_prompt, _("\
+Set gdb's prompt"), _("\
+Show gdb's prompt"), NULL,
+ set_async_prompt,
+ show_new_async_prompt,
+ &setlist, &showlist);
add_com ("dont-repeat", class_support, dont_repeat_command, _("\
Don't repeat this command.\n\
Without an argument, command line editing is enabled. To edit, use\n\
EMACS-like or VI-like commands like control-P or ESC."),
set_async_editing_command,
- NULL, /* FIXME: i18n: */
+ show_async_command_editing_p,
&setlist, &showlist);
add_setshow_boolean_cmd ("save", no_class, &write_history_p, _("\
Use \"on\" to enable the saving, and \"off\" to disable it.\n\
Without an argument, saving is enabled."),
NULL,
- NULL, /* FIXME: i18n: */
+ show_write_history_p,
&sethistlist, &showhistlist);
- c = add_set_cmd ("size", no_class, var_integer, (char *) &history_size,
- "Set the size of the command history,\n\
-ie. the number of previous commands to keep a record of.", &sethistlist);
- deprecated_add_show_from_set (c, &showhistlist);
- set_cmd_sfunc (c, set_history_size_command);
+ add_setshow_integer_cmd ("size", no_class, &history_size, _("\
+Set the size of the command history,"), _("\
+Show the size of the command history,"), _("\
+ie. the number of previous commands to keep a record of."),
+ set_history_size_command,
+ show_history_size,
+ &sethistlist, &showhistlist);
- c = 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);
- set_cmd_completer (c, filename_completer);
- deprecated_add_show_from_set (c, &showhistlist);
+ add_setshow_filename_cmd ("filename", no_class, &history_filename, _("\
+Set the filename in which to record the command history"), _("\
+Show the filename in which to record the command history"), _("\
+(the list of previous commands of which a record is kept)."),
+ NULL,
+ show_history_filename,
+ &sethistlist, &showhistlist);
add_setshow_boolean_cmd ("confirm", class_support, &caution, _("\
Set whether to confirm potentially dangerous operations."), _("\
Show whether to confirm potentially dangerous operations."), NULL,
NULL,
- NULL, /* FIXME: i18n: */
+ show_caution,
&setlist, &showlist);
add_setshow_zinteger_cmd ("annotate", class_obscure, &annotation_level, _("\
0 == normal; 1 == fullname (for use when running under emacs)\n\
2 == output annotated suitably for use by programs that control GDB."),
set_async_annotation_level,
- NULL, /* FIXME: i18n: */
+ show_annotation_level,
&setlist, &showlist);
add_setshow_boolean_cmd ("exec-done-display", class_support,
Show notification of completion for asynchronous execution commands."), _("\
Use \"on\" to enable the notification, and \"off\" to disable it."),
NULL,
- NULL, /* FIXME: i18n: */
+ show_exec_done_display_p,
&setlist, &showlist);
+
+ add_setshow_filename_cmd ("data-directory", class_maintenance,
+ &gdb_datadir, _("Set GDB's data directory."),
+ _("Show GDB's data directory."),
+ _("\
+When set, GDB uses the specified path to search for data files."),
+ NULL, NULL,
+ &setlist,
+ &showlist);
}
void
/* Run the init function of each source file */
- getcwd (gdb_dirbuf, sizeof (gdb_dirbuf));
- current_directory = gdb_dirbuf;
-
#ifdef __MSDOS__
/* Make sure we return to the original directory upon exit, come
what may, since the OS doesn't do that for us. */
init_cli_cmds();
init_main (); /* But that omits this file! Do it now */
+ initialize_stdin_serial ();
+
async_init_signals ();
/* We need a default language for parsing expressions, so simple things like