#include "breakpoint.h"
#include "gdbtypes.h"
#include "expression.h"
+#include "value.h"
#include "language.h"
#include "terminal.h" /* For job_control. */
#include "annotate.h"
/* Prototypes for local functions */
-static char *
-symbol_completion_function PARAMS ((char *, int));
+static char * symbol_completion_function PARAMS ((char *, int));
-static void
-command_loop_marker PARAMS ((int));
+static void command_loop_marker PARAMS ((int));
-static void
-init_main PARAMS ((void));
+static void while_command PARAMS ((char *, int));
-static void
-init_cmd_lists PARAMS ((void));
+static void if_command PARAMS ((char *, int));
-static void
-float_handler PARAMS ((int));
+static enum command_control_type
+execute_control_command PARAMS ((struct command_line *));
-static void
-init_signals PARAMS ((void));
+static struct command_line *
+build_command_line PARAMS ((enum command_control_type, char *));
-static void
-set_verbose PARAMS ((char *, int, struct cmd_list_element *));
+static struct command_line *
+get_command_line PARAMS ((enum command_control_type, char *));
-static void
-show_history PARAMS ((char *, int));
+static void realloc_body_list PARAMS ((struct command_line *, int));
-static void
-set_history PARAMS ((char *, int));
+static enum misc_command_type read_next_line PARAMS ((struct command_line **));
-static void
-set_history_size_command PARAMS ((char *, int, struct cmd_list_element *));
+static enum command_control_type
+recurse_read_control_structure PARAMS ((struct command_line *));
-static void
-show_commands PARAMS ((char *, int));
+static void init_main PARAMS ((void));
-static void
-echo_command PARAMS ((char *, int));
+static void init_cmd_lists PARAMS ((void));
-static void
-pwd_command PARAMS ((char *, int));
+static void float_handler PARAMS ((int));
-static void
-show_version PARAMS ((char *, int));
+static void init_signals PARAMS ((void));
-static void
-document_command PARAMS ((char *, int));
+static void set_verbose PARAMS ((char *, int, struct cmd_list_element *));
-static void
-define_command PARAMS ((char *, int));
+static void show_history PARAMS ((char *, int));
-static void
-validate_comname PARAMS ((char *));
+static void set_history PARAMS ((char *, int));
-static void
-help_command PARAMS ((char *, int));
+static void set_history_size_command PARAMS ((char *, int,
+ struct cmd_list_element *));
-static void
-show_command PARAMS ((char *, int));
+static void show_commands PARAMS ((char *, int));
-static void
-info_command PARAMS ((char *, int));
+static void echo_command PARAMS ((char *, int));
-static void
-complete_command PARAMS ((char *, int));
+static void pwd_command PARAMS ((char *, int));
-static void
-do_nothing PARAMS ((int));
+static void show_version PARAMS ((char *, int));
-static int
-quit_cover PARAMS ((char *));
+static void document_command PARAMS ((char *, int));
-static void
-disconnect PARAMS ((int));
+static void define_command PARAMS ((char *, int));
-static void
-source_cleanup PARAMS ((FILE *));
+static void validate_comname PARAMS ((char *));
+
+static void help_command PARAMS ((char *, int));
+
+static void show_command PARAMS ((char *, int));
+
+static void info_command PARAMS ((char *, int));
+
+static void complete_command PARAMS ((char *, int));
+
+static void do_nothing PARAMS ((int));
+
+static int quit_cover PARAMS ((char *));
+
+static void disconnect PARAMS ((int));
+
+static void source_cleanup PARAMS ((FILE *));
/* If this definition isn't overridden by the header files, assume
that isatty and fileno exist on this system. */
char gdbinit[] = GDBINIT_FILENAME;
int inhibit_gdbinit = 0;
+/* Disable windows if non-zero */
+
+int no_windows = 0;
+
/* Version number of GDB, as a string. */
extern char *version;
int remote_debug = 0;
+/* Level of control structure. */
+static int control_level;
+
/* Signal to catch ^Z typed while reading a command: SIGTSTP or SIGCONT. */
#ifndef STOP_SIGNAL
#if 0 == (HAVE_SIGSETMASK)
#define sigsetmask(n)
#endif
+
+/* Hooks for alternate command interfaces. */
+
+/* Called after most modules have been initialized, but before taking users
+ command file. */
+
+void (*init_ui_hook) PARAMS ((void));
+
+/* Called instead of command_loop at top level. Can be invoked via
+ return_to_top_level. */
+
+void (*command_loop_hook) PARAMS ((void));
+
+/* Called instead of fputs for all output. */
+
+void (*fputs_unfiltered_hook) PARAMS ((const char *linebuffer));
+
+/* Called from print_frame_info to list the line we stopped in. */
+
+void (*print_frame_info_listing_hook) PARAMS ((struct symtab *s, int line,
+ int stopline, int noerror));
+/* Replaces most of query. */
+
+int (*query_hook) PARAMS (());
+
+/* Called from gdb_flush to flush output. */
+
+void (*flush_hook) PARAMS ((FILE *stream));
+
+/* Called as appropriate to notify the interface of the specified breakpoint
+ conditions. */
+
+void (*create_breakpoint_hook) PARAMS ((struct breakpoint *bpt));
+void (*delete_breakpoint_hook) PARAMS ((struct breakpoint *bpt));
+void (*enable_breakpoint_hook) PARAMS ((struct breakpoint *bpt));
+void (*disable_breakpoint_hook) PARAMS ((struct breakpoint *bpt));
+
+/* Called during long calculations to allow GUI to repair window damage, and to
+ check for stop buttons, etc... */
+
+void (*interactive_hook) PARAMS ((void));
+
\f
/* Where to go for return_to_top_level (RETURN_ERROR). */
jmp_buf error_return;
current_directory = gdb_dirbuf;
init_cmd_lists (); /* This needs to be done first */
+ initialize_targets (); /* Setup target_terminal macros for utils.c */
+ initialize_utils (); /* Make errors and warnings possible */
initialize_all_files ();
init_main (); /* But that omits this file! Do it now */
init_signals ();
or implicitly set by reading an executable during startup. */
set_language (language_c);
expected_language = current_language; /* don't warn about the change. */
+
+ if (init_ui_hook)
+ init_ui_hook ();
+}
+
+/* Allocate, initialize a new command line structure for one of the
+ control commands (if/while). */
+
+static struct command_line *
+build_command_line (type, args)
+ enum command_control_type type;
+ char *args;
+{
+ struct command_line *cmd;
+
+ cmd = (struct command_line *)xmalloc (sizeof (struct command_line));
+ cmd->next = NULL;
+ cmd->control_type = type;
+
+ cmd->body_count = 1;
+ cmd->body_list
+ = (struct command_line **)xmalloc (sizeof (struct command_line *)
+ * cmd->body_count);
+ memset (cmd->body_list, 0, sizeof (struct command_line *) * cmd->body_count);
+ cmd->line = savestring (args, strlen (args));
+ return cmd;
+}
+
+/* Build and return a new command structure for the control commands
+ such as "if" and "while". */
+
+static struct command_line *
+get_command_line (type, arg)
+ enum command_control_type type;
+ char *arg;
+{
+ struct command_line *cmd;
+ struct cleanup *old_chain = NULL;
+
+ /* Allocate and build a new command line structure. */
+ cmd = build_command_line (type, arg);
+
+ old_chain = make_cleanup (free_command_lines, &cmd);
+
+ /* Read in the body of this command. */
+ if (recurse_read_control_structure (cmd) == invalid_control)
+ {
+ warning ("error reading in control structure\n");
+ do_cleanups (old_chain);
+ return NULL;
+ }
+
+ discard_cleanups (old_chain);
+ return cmd;
+}
+
+/* Execute the command in CMD. */
+
+static enum command_control_type
+execute_control_command (cmd)
+ struct command_line *cmd;
+{
+ struct expression *expr;
+ struct command_line *current;
+ struct cleanup *old_chain = 0;
+ struct cleanup *tmp_chain;
+ value_ptr val;
+ int loop;
+ enum command_control_type ret;
+
+ switch (cmd->control_type)
+ {
+ case simple_control:
+ /* A simple command, execute it and return. */
+ execute_command (cmd->line, 0);
+ return cmd->control_type;
+
+ case continue_control:
+ case break_control:
+ /* Return for "continue", and "break" so we can either
+ continue the loop at the top, or break out. */
+ return cmd->control_type;
+
+ case while_control:
+ {
+ /* Parse the loop control expression for the while statement. */
+ expr = parse_expression (cmd->line);
+ tmp_chain = make_cleanup (free_current_contents, &expr);
+ if (!old_chain)
+ old_chain = tmp_chain;
+
+ ret = simple_control;
+ loop = true;
+
+ /* Keep iterating so long as the expression is true. */
+ while (loop == true)
+ {
+ /* Evaluate the expression. */
+ val = evaluate_expression (expr);
+
+ /* If the value is false, then break out of the loop. */
+ if (!value_true (val))
+ break;
+
+ /* Execute the body of the while statement. */
+ current = *cmd->body_list;
+ while (current)
+ {
+ ret = execute_control_command (current);
+
+ /* If we got an error, or a "break" command, then stop
+ looping. */
+ if (ret == invalid_control || ret == break_control)
+ {
+ loop = false;
+ break;
+ }
+
+ /* If we got a "continue" command, then restart the loop
+ at this point. */
+ if (ret == continue_control)
+ break;
+
+ /* Get the next statement. */
+ current = current->next;
+ }
+ }
+
+ /* Reset RET so that we don't recurse the break all the way down. */
+ if (ret == break_control)
+ ret = simple_control;
+
+ break;
+ }
+
+ case if_control:
+ {
+ /* Parse the conditional for the if statement. */
+ expr = parse_expression (cmd->line);
+ old_chain = make_cleanup (free_current_contents, &expr);
+
+ current = NULL;
+ ret = simple_control;
+
+ /* Evaluate the conditional. */
+ val = evaluate_expression (expr);
+
+ /* Choose which arm to take commands from based on the value of the
+ conditional expression. */
+ if (value_true (val))
+ current = *cmd->body_list;
+ else if (cmd->body_count == 2)
+ current = *(cmd->body_list + 1);
+
+ /* Execute commands in the given arm. */
+ while (current)
+ {
+ ret = execute_control_command (current);
+
+ /* If we got an error, get out. */
+ if (ret != simple_control)
+ break;
+
+ /* Get the next statement in the body. */
+ current = current->next;
+ }
+ break;
+ }
+
+ default:
+ warning ("Invalid control type in command structure.");
+ return invalid_control;
+ }
+
+ if (old_chain)
+ do_cleanups (old_chain);
+
+ return ret;
+}
+
+/* "while" command support. Executes a body of statements while the
+ loop condition is nonzero. */
+
+static void
+while_command (arg, from_tty)
+ char *arg;
+ int from_tty;
+{
+ struct command_line *command = NULL;
+
+ control_level = 1;
+ command = get_command_line (while_control, arg);
+
+ if (command == NULL)
+ return;
+
+ execute_control_command (command);
+ free_command_lines (&command);
+}
+
+/* "if" command support. Execute either the true or false arm depending
+ on the value of the if conditional. */
+
+static void
+if_command (arg, from_tty)
+ char *arg;
+ int from_tty;
+{
+ struct command_line *command = NULL;
+
+ control_level = 1;
+ command = get_command_line (if_control, arg);
+
+ if (command == NULL)
+ return;
+
+ execute_control_command (command);
+ free_command_lines (&command);
}
void
{
register struct command_line *cmdlines;
struct cleanup *old_chain;
-
+ enum command_control_type ret;
+
if (args)
error ("User-defined commands cannot take arguments.");
instream = (FILE *) 0;
while (cmdlines)
{
- execute_command (cmdlines->line, 0);
+ ret = execute_control_command (cmdlines);
+ if (ret != simple_control && ret != break_control)
+ {
+ warning ("Error in control structure.\n");
+ break;
+ }
cmdlines = cmdlines->next;
}
do_cleanups (old_chain);
/* 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;
/* Read a line from the stream "instream" without command line editing.
It prints PRROMPT once at the start.
- Action is compatible with "readline", e.g. space for the result is
+ Action is compatible with "readline", e.g. space for the result is
malloc'd and should be freed by the caller.
A NULL return means end of file. */
/* end-sanitize-mpw */
gdb_flush (gdb_stdout);
}
-
+
result = (char *) xmalloc (result_size);
while (1)
return linebuffer;
}
\f
+
+/* Expand the body_list of COMMAND so that it can hold NEW_LENGTH
+ code bodies. This is typically used when we encounter an "else"
+ clause for an "if" command. */
+
+static void
+realloc_body_list (command, new_length)
+ struct command_line *command;
+ int new_length;
+{
+ int n;
+ struct command_line **body_list;
+
+ n = command->body_count;
+
+ /* Nothing to do? */
+ if (new_length <= n)
+ return;
+
+ body_list = (struct command_line **)
+ xmalloc (sizeof (struct command_line *) * new_length);
+
+ memcpy (body_list, command->body_list, sizeof (struct command_line *) * n);
+
+ free (command->body_list);
+ command->body_list = body_list;
+ command->body_count = new_length;
+}
+
+/* Read one line from the input stream. If the command is an "else" or
+ "end", return such an indication to the caller. */
+
+static enum misc_command_type
+read_next_line (command)
+ struct command_line **command;
+{
+ char *p, *p1, *prompt_ptr, control_prompt[256];
+ int i = 0;
+
+ if (control_level >= 254)
+ error ("Control nesting too deep!\n");
+
+ /* Set a prompt based on the nesting of the control commands. */
+ if (instream == stdin)
+ {
+ for (i = 0; i < control_level; i++)
+ control_prompt[i] = ' ';
+ control_prompt[i] = '>';
+ control_prompt[i+1] = '\0';
+ prompt_ptr = (char *)&control_prompt[0];
+ }
+ else
+ prompt_ptr = NULL;
+
+ p = command_line_input (prompt_ptr, instream == stdin, NULL);
+
+ /* Not sure what to do here. */
+ if (p == NULL)
+ return end_command;
+
+ /* Strip leading and trailing whitespace. */
+ while (*p == ' ' || *p == '\t')
+ p++;
+
+ p1 = p + strlen (p);
+ while (p1 != p && (p1[-1] == ' ' || p1[-1] == '\t'))
+ p1--;
+
+ /* Blanks and comments don't really do anything, but we need to
+ distinguish them from else, end and other commands which can be
+ executed. */
+ if (p1 == p || p[0] == '#')
+ return nop_command;
+
+ /* Is this the end of a simple, while, or if control structure? */
+ if (p1 - p == 3 && !strncmp (p, "end", 3))
+ return end_command;
+
+ /* Is the else clause of an if control structure? */
+ if (p1 - p == 4 && !strncmp (p, "else", 4))
+ return else_command;
+
+ /* Check for while, if, break, continue, etc and build a new command
+ line structure for them. */
+ if (p1 - p > 5 && !strncmp (p, "while", 5))
+ *command = build_command_line (while_control, p + 6);
+ else if (p1 - p > 2 && !strncmp (p, "if", 2))
+ *command = build_command_line (if_control, p + 3);
+ else if (p1 - p == 5 && !strncmp (p, "loop_break", 5))
+ {
+ *command = (struct command_line *)
+ xmalloc (sizeof (struct command_line));
+ (*command)->next = NULL;
+ (*command)->line = NULL;
+ (*command)->control_type = break_control;
+ (*command)->body_count = 0;
+ (*command)->body_list = NULL;
+ }
+ else if (p1 - p == 8 && !strncmp (p, "loop_continue", 8))
+ {
+ *command = (struct command_line *)
+ xmalloc (sizeof (struct command_line));
+ (*command)->next = NULL;
+ (*command)->line = NULL;
+ (*command)->control_type = continue_control;
+ (*command)->body_count = 0;
+ (*command)->body_list = NULL;
+ }
+ else
+ {
+ /* A normal command. */
+ *command = (struct command_line *)
+ xmalloc (sizeof (struct command_line));
+ (*command)->next = NULL;
+ (*command)->line = savestring (p, p1 - p);
+ (*command)->control_type = simple_control;
+ (*command)->body_count = 0;
+ (*command)->body_list = NULL;
+ }
+
+ /* Nothing special. */
+ return ok_command;
+}
+
+/* Recursively read in the control structures and create a command_line
+ tructure from them.
+
+ The parent_control parameter is the control structure in which the
+ following commands are nested. */
+
+static enum command_control_type
+recurse_read_control_structure (current_cmd)
+ struct command_line *current_cmd;
+{
+ int current_body, i;
+ enum misc_command_type val;
+ enum command_control_type ret;
+ struct command_line **body_ptr, *child_tail, *next;
+ struct cleanup *old_chains, *tmp_chains;
+
+ old_chains = NULL;
+ child_tail = NULL;
+ current_body = 1;
+
+ /* Sanity checks. */
+ if (current_cmd->control_type == simple_control)
+ {
+ error ("Recursed on a simple control type\n");
+ return invalid_control;
+ }
+
+ if (current_body > current_cmd->body_count)
+ {
+ error ("Allocated body is smaller than this command type needs\n");
+ return invalid_control;
+ }
+
+ /* Read lines from the input stream and build control structures. */
+ while (1)
+ {
+ dont_repeat ();
+
+ next = NULL;
+ val = read_next_line (&next);
+
+ /* Just skip blanks and comments. */
+ if (val == nop_command)
+ continue;
+
+ if (val == end_command)
+ {
+ if (current_cmd->control_type == while_control
+ || current_cmd->control_type == if_control)
+ {
+ /* Success reading an entire control structure. */
+ ret = simple_control;
+ break;
+ }
+ else
+ {
+ ret = invalid_control;
+ break;
+ }
+ }
+
+ /* Not the end of a control structure. */
+ if (val == else_command)
+ {
+ if (current_cmd->control_type == if_control
+ && current_body == 1)
+ {
+ realloc_body_list (current_cmd, 2);
+ current_body = 2;
+ child_tail = NULL;
+ continue;
+ }
+ else
+ {
+ ret = invalid_control;
+ break;
+ }
+ }
+
+ if (child_tail)
+ {
+ child_tail->next = next;
+ }
+ else
+ {
+ /* We have just read the first line of the child's control
+ structure. From now on, arrange to throw away the line
+ we have if we quit or get an error. */
+ body_ptr = current_cmd->body_list;
+ for (i = 1; i < current_body; i++)
+ body_ptr++;
+
+ *body_ptr = next;
+
+ tmp_chains = make_cleanup (free_command_lines, body_ptr);
+
+ if (!old_chains)
+ old_chains = tmp_chains;
+ }
+
+ child_tail = next;
+
+ /* If the latest line is another control structure, then recurse
+ on it. */
+ if (next->control_type == while_control
+ || next->control_type == if_control)
+ {
+ control_level++;
+ ret = recurse_read_control_structure (next);
+ control_level--;
+
+ if (ret != simple_control)
+ break;
+ }
+ }
+
+ dont_repeat ();
+ if (ret == invalid_control && old_chains)
+ do_cleanups (old_chains);
+ else if (old_chains)
+ discard_cleanups (old_chains);
+
+ return ret;
+}
+
+
/* 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;
+ struct command_line *head, *tail, *next;
+ struct cleanup *old_chain;
+ enum command_control_type ret;
+ enum misc_command_type val;
+
+ head = tail = NULL;
+ old_chain = NULL;
while (1)
{
- dont_repeat ();
- p = command_line_input ((char *) NULL, instream == stdin, "commands");
- 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--;
+ val = read_next_line (&next);
- /* Is this "end"? */
- if (p1 - p == 3 && !strncmp (p, "end", 3))
- break;
+ /* Ignore blank lines or comments. */
+ if (val == nop_command)
+ continue;
+
+ if (val == end_command)
+ {
+ ret = simple_control;
+ 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 (val != ok_command)
+ {
+ ret = invalid_control;
+ break;
+ }
+
+ if (next->control_type == while_control
+ || next->control_type == if_control)
+ {
+ control_level++;
+ ret = recurse_read_control_structure (next);
+ control_level--;
+
+ if (ret == invalid_control)
+ break;
+ }
+
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);
+ head = next;
+ old_chain = make_cleanup (free_command_lines, &head);
}
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;
+ if (head)
+ {
+ if (ret != invalid_control)
+ {
+ discard_cleanups (old_chain);
+ return head;
+ }
+ else
+ do_cleanups (old_chain);
+ }
+
+ return NULL;
}
/* Free a chain of struct command_line's. */
{
register struct command_line *l = *lptr;
register struct command_line *next;
+ struct command_line **blist;
+ int i;
while (l)
{
+ if (l->body_count > 0)
+ {
+ blist = l->body_list;
+ for (i = 0; i < l->body_count; i++, blist++)
+ free_command_lines (blist);
+ }
next = l->next;
free (l->line);
free ((PTR)l);
c = lookup_cmd (&tem, cmdlist, "", -1, 1);
if (c && !STREQ (comname, c->name))
c = 0;
-
+
if (c)
{
if (c->class == class_user || c->class == class_alias)
comname = savestring (comname, strlen (comname));
- /* If the rest of the commands will be case insensitive, this one
+ /* If the rest of the commands will be case insensitive, this one
should behave in the same manner. */
for (tem = comname; *tem; tem++)
if (isupper(*tem)) *tem = tolower(*tem);
gdb_flush (gdb_stdout);
}
+ control_level = 0;
cmds = read_command_lines ();
if (c && c->class == class_user)
/* 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
"show commands +" does. This is unnecessary if arg is null,
because "show commands +" is not useful after "show commands". */
/* Called by do_setshow_command. An elaborate joke. */
/* ARGSUSED */
-static void
+static void
set_verbose (args, from_tty, c)
char *args;
int from_tty;
{
char *cmdname = "verbose";
struct cmd_list_element *showcmd;
-
+
showcmd = lookup_cmd_1 (&cmdname, showlist, NULL, 1);
if (info_verbose)
error ("Erroneous arithmetic operation.");
}
-/* Return whether we are running a batch file or from terminal. */
-int
-batch_mode ()
-{
- return !(instream == stdin && ISATTY (stdin));
-}
-
\f
static void
init_cmd_lists ()
init_main ()
{
struct cmd_list_element *c;
-
+
#ifdef DEFAULT_PROMPT
prompt = savestring (DEFAULT_PROMPT, strlen(DEFAULT_PROMPT));
#else
command_editing_p = 1;
history_expansion_p = 0;
write_history_p = 0;
-
+
/* 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;
"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\
add_show_from_set (c, &showlist);
c->function.sfunc = set_verbose;
set_verbose (NULL, 0, c);
-
+
add_show_from_set
(add_set_cmd ("editing", class_support, var_boolean, (char *)&command_editing_p,
"Set editing of command lines as they are typed.\n\
add_cmd ("version", no_class, show_version,
"Show what version of GDB this is.", &showlist);
+ add_com ("while", class_support, while_command,
+"Execute nested commands WHILE the conditional expression is non zero.\n\
+The conditional expression must follow the word `while' and must in turn be\
+followed by a new line. The nested commands must be entered one per line,\
+and should be terminated by the word `end'.");
+
+ add_com ("if", class_support, if_command,
+"Execute nested commands once IF the conditional expression is non zero.\n\
+The conditional expression must follow the word `if' and must in turn be\
+followed by a new line. The nested commands must be entered one per line,\
+and should be terminated by the word 'else' or `end'. If an else clause\
+is used, the same rules apply to its nested commands as to the first ones.");
+
/* If target is open when baud changes, it doesn't take effect until the
next open (I think, not sure). */
add_show_from_set (add_set_cmd ("remotebaud", no_class,