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import gdb-1999-05-10

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This commit is contained in:
Stan Shebs
1999-05-11 20:29:07 +00:00
parent 5c746d907d
commit b5a0ac7029
3 changed files with 1932 additions and 0 deletions
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741
gdb/event-loop.c Normal file
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/* Event loop machinery for GDB, the GNU debugger.
Copyright 1999 Free Software Foundation, Inc.
Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
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
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "event-loop.h"
#include <readline/readline.h>
#include <setjmp.h>
#include "top.h"
/* For config.h which may define HAVE_POLL */
#include "defs.h"
#ifdef HAVE_POLL
#include <sys/poll.h>
#endif
#include <errno.h>
/* Event queue:
- the first event in the queue is the head of the queue.
It will be the next to be serviced.
- the last event in the queue
Events can be inserted at the front of the queue or at the end of
the queue. Events will be extracted from the queue for processing
starting from the head. Therefore, events inserted at the head of
the queue will be processed in a last in first out fashoin, while
those inserted at the tail of the queue will be processed in a first
in first out manner. All the fields are NULL if the queue is
empty. */
static struct
{
gdb_event *first_event; /* First pending event */
gdb_event *last_event; /* Last pending event */
}
event_queue;
/* Gdb_notifier is just a list of file descriptors gdb is interested in.
These are the input file descriptor, and the target file
descriptor. We have two flavors of the notifier, one for platforms
that have the POLL function, the other for those that don't, and
only support SELECT. Each of the elements in the gdb_notifier list is
basically a description of what kind of events gdb is interested
in, for each fd. */
/* As of 4/30/99 only the input file descriptor is registered with the
event loop. */
#ifdef HAVE_POLL
/* Poll based implementation of the notifier. */
static struct
{
/* Ptr to head of file handler list. */
file_handler *first_file_handler;
/* Ptr to array of pollfd structures. */
struct pollfd *poll_fds;
/* Number of file descriptors to monitor. */
int num_fds;
}
gdb_notifier;
#else /* ! HAVE_POLL */
/* Select based implementation of the notifier. */
static struct
{
/* Ptr to head of file handler list. */
file_handler *first_file_handler;
/* Masks to be used in the next call to select.
Bits are set in response to calls to create_file_handler. */
fd_mask check_masks[3 * MASK_SIZE];
/* What file descriptors were found ready by select. */
fd_mask ready_masks[3 * MASK_SIZE];
/* Number of valid bits (highest fd value + 1). */
int num_fds;
}
gdb_notifier;
#endif /* HAVE_POLL */
/* All the async_signal_handlers gdb is interested in are kept onto
this list. */
static struct
{
/* Pointer to first in handler list. */
async_signal_handler *first_handler;
/* Pointer to last in handler list. */
async_signal_handler *last_handler;
}
sighandler_list;
/* Is any of the handlers ready? Check this variable using
check_async_ready. This is used by process_event, to determine
whether or not to invoke the invoke_async_signal_handler
function. */
static int async_handler_ready = 0;
static void invoke_async_signal_handler PARAMS ((void));
static int gdb_wait_for_event PARAMS ((void));
static int check_async_ready PARAMS ((void));
extern display_gdb_prompt PARAMS ((char *));
/* Insert an event object into the gdb event queue at
the specified position.
POSITION can be head or tail, with values TAIL, HEAD.
EVENT_PTR points to the event to be inserted into the queue.
The caller must allocate memory for the event. It is freed
after the event has ben handled.
Events in the queue will be processed head to tail, therefore,
events inserted at the head of the queue will be processed
as last in first out. Event appended at the tail of the queue
will be processed first in first out. */
static void
async_queue_event (event_ptr, position)
gdb_event *event_ptr;
queue_position position;
{
if (position == TAIL)
{
/* The event will become the new last_event. */
event_ptr->next_event = NULL;
if (event_queue.first_event == NULL)
event_queue.first_event = event_ptr;
else
event_queue.last_event->next_event = event_ptr;
event_queue.last_event = event_ptr;
}
else if (position == HEAD)
{
/* The event becomes the new first_event. */
event_ptr->next_event = event_queue.first_event;
if (event_queue.first_event == NULL)
event_queue.last_event = event_ptr;
event_queue.first_event = event_ptr;
}
}
/* Process one event.
The event can be the next one to be serviced in the event queue,
or an asynchronous event handler can be invoked in response to
the reception of a signal.
If an event was processed (either way), 1 is returned otherwise
0 is returned.
Scan the queue from head to tail, processing therefore the high
priority events first, by invoking the associated event handler
procedure. */
static int
process_event ()
{
gdb_event *event_ptr, *prev_ptr;
event_handler_func *proc;
int fd;
/* First let's see if there are any asynchronous event handlers that
are ready. These would be the result of invoking any of the
signal handlers. */
if (check_async_ready ())
{
invoke_async_signal_handler ();
return 1;
}
/* Look in the event queue to find an event that is ready
to be processed. */
for (event_ptr = event_queue.first_event; event_ptr != NULL;
event_ptr = event_ptr->next_event)
{
/* Call the handler for the event. */
proc = event_ptr->proc;
fd = event_ptr->fd;
/* Let's get rid of the event from the event queue. We need to
do this now because while processing the event, the proc
function could end up calling 'error' and therefore jump out
to the caller of this function, gdb_do_one_event. In that
case, we would have on the event queue an event wich has been
processed, but not deleted. */
if (event_queue.first_event == event_ptr)
{
event_queue.first_event = event_ptr->next_event;
if (event_ptr->next_event == NULL)
event_queue.last_event = NULL;
}
else
{
prev_ptr = event_queue.first_event;
while (prev_ptr->next_event != event_ptr)
prev_ptr = prev_ptr->next_event;
prev_ptr->next_event = event_ptr->next_event;
if (event_ptr->next_event == NULL)
event_queue.last_event = prev_ptr;
}
free ((char *) event_ptr);
/* Now call the procedure associted with the event. */
(*proc) (fd);
return 1;
}
/* this is the case if there are no event on the event queue. */
return 0;
}
/* Process one high level event. If nothing is ready at this time,
wait for something to happen (via gdb_wait_for_event), then process
it. Returns 1 if something was done otherwise returns 0 (this can
happen if there are no event sources to wait for). */
int
gdb_do_one_event ()
{
int result = 0;
while (1)
{
if (!SET_TOP_LEVEL ())
{
/* Any events already waiting in the queue? */
if (process_event ())
{
result = 1;
break;
}
/* Wait for a new event. If gdb_wait_for_event returns -1,
we should get out because this means that there are no
event sources left. This will make the event loop stop,
and the application exit. */
result = gdb_wait_for_event ();
if (result < 0)
{
result = 0;
break;
}
/* Handle any new events occurred while waiting. */
if (process_event ())
{
result = 1;
break;
}
/* If gdb_wait_for_event has returned 1, it means that one
event has been handled. We break out of the loop. */
if (result)
break;
} /* end of if !set_top_level */
else
{
display_gdb_prompt (0);
/* Maybe better to set a flag to be checked somewhere as to
whether display the prompt or not. */
}
}
return result;
}
/* Add a file handler/descriptor to the list of descriptors we are
interested in.
FD is the file descriptor for the file/stream to be listened to.
For the poll case, MASK is a combination (OR) of
POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM,
POLLWRBAND: these are the events we are interested in. If any of them
occurs, proc should be called.
For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION.
PROC is the procedure that will be called when an event occurs for
FD. CLIENT_DATA is the argument to pass to PROC. */
void
create_file_handler (fd, mask, proc, client_data)
int fd;
int mask;
file_handler_func *proc;
gdb_client_data client_data;
{
file_handler *file_ptr;
#ifndef HAVE_POLL
int index, bit;
#endif
/* Do we already have a file handler for this file? (We may be
changing its associated procedure). */
for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
file_ptr = file_ptr->next_file)
{
if (file_ptr->fd == fd)
break;
}
/* It is a new file descriptor. */
if (file_ptr == NULL)
{
file_ptr = (file_handler *) xmalloc (sizeof (file_handler));
file_ptr->fd = fd;
file_ptr->ready_mask = 0;
file_ptr->next_file = gdb_notifier.first_file_handler;
gdb_notifier.first_file_handler = file_ptr;
}
file_ptr->proc = proc;
file_ptr->client_data = client_data;
file_ptr->mask = mask;
#ifdef HAVE_POLL
gdb_notifier.num_fds++;
gdb_notifier.poll_fds =
(struct pollfd *) realloc (gdb_notifier.poll_fds,
(gdb_notifier.num_fds) * sizeof (struct pollfd));
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd;
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask;
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0;
#else /* ! HAVE_POLL */
index = fd / (NBBY * sizeof (fd_mask));
bit = 1 << (fd % (NBBY * sizeof (fd_mask)));
if (mask & GDB_READABLE)
gdb_notifier.check_masks[index] |= bit;
else
gdb_notifier.check_masks[index] &= ~bit;
if (mask & GDB_WRITABLE)
(gdb_notifier.check_masks + MASK_SIZE)[index] |= bit;
else
(gdb_notifier.check_masks + MASK_SIZE)[index] &= ~bit;
if (mask & GDB_EXCEPTION)
(gdb_notifier.check_masks + 2 * (MASK_SIZE))[index] |= bit;
else
(gdb_notifier.check_masks + 2 * (MASK_SIZE))[index] &= ~bit;
if (gdb_notifier.num_fds <= fd)
gdb_notifier.num_fds = fd + 1;
#endif /* HAVE_POLL */
}
/* Remove the file descriptor FD from the list of monitored fd's:
i.e. we don't care anymore about events on the FD. */
void
delete_file_handler (fd)
int fd;
{
file_handler *file_ptr, *prev_ptr = NULL;
int i, j;
struct pollfd *new_poll_fds;
#ifndef HAVE_POLL
int index, bit;
unsigned long flags;
#endif
/* Find the entry for the given file. */
for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
file_ptr = file_ptr->next_file)
{
if (file_ptr->fd == fd)
break;
}
if (file_ptr == NULL)
return;
/* Deactivate the file descriptor, by clearing its mask,
so that it will not fire again. */
file_ptr->mask = 0;
#ifdef HAVE_POLL
/* Create a new poll_fds array by copying every fd's information but the
one we want to get rid of. */
new_poll_fds =
(struct pollfd *) xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd));
for (i = 0, j = 0; i < gdb_notifier.num_fds; i++)
{
if ((gdb_notifier.poll_fds + i)->fd != fd)
{
(new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd;
(new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events;
(new_poll_fds + j)->revents = (gdb_notifier.poll_fds + i)->revents;
j++;
}
}
free (gdb_notifier.poll_fds);
gdb_notifier.poll_fds = new_poll_fds;
gdb_notifier.num_fds--;
#else /* ! HAVE_POLL */
index = fd / (NBBY * sizeof (fd_mask));
bit = 1 << (fd % (NBBY * sizeof (fd_mask)));
if (file_ptr->mask & GDB_READABLE)
gdb_notifier.check_masks[index] &= ~bit;
if (file_ptr->mask & GDB_WRITABLE)
(gdb_notifier.check_masks + MASK_SIZE)[index] &= ~bit;
if (file_ptr->mask & GDB_EXCEPTION)
(gdb_notifier.check_masks + 2 * (MASK_SIZE))[index] &= ~bit;
/* Find current max fd. */
if ((fd + 1) == gdb_notifier.num_fds)
{
for (gdb_notifier.num_fds = 0; index >= 0; index--)
{
flags = gdb_notifier.check_masks[index]
| (gdb_notifier.check_masks + MASK_SIZE)[index]
| (gdb_notifier.check_masks + 2 * (MASK_SIZE))[index];
if (flags)
{
for (i = (NBBY * sizeof (fd_mask)); i > 0; i--)
{
if (flags & (((unsigned long) 1) << (i - 1)))
break;
}
gdb_notifier.num_fds = index * (NBBY * sizeof (fd_mask)) + i;
break;
}
}
}
#endif /* HAVE_POLL */
/* Get rid of the file handler in the file handler list. */
if (file_ptr == gdb_notifier.first_file_handler)
gdb_notifier.first_file_handler = file_ptr->next_file;
else
{
for (prev_ptr = gdb_notifier.first_file_handler;
prev_ptr->next_file == file_ptr;
prev_ptr = prev_ptr->next_file)
;
prev_ptr->next_file = file_ptr->next_file;
}
free ((char *) file_ptr);
}
/* Handle the given event by calling the procedure associated to the
corresponding file handler. Called by process_event indirectly,
through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
event in the front of the event queue. */
static void
handle_file_event (event_file_desc)
int event_file_desc;
{
file_handler *file_ptr;
int mask, error_mask;
/* Search the file handler list to find one that matches the fd in
the event. */
for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
file_ptr = file_ptr->next_file)
{
if (file_ptr->fd == event_file_desc)
{
/* With poll, the ready_mask could have any of three events
set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot
be used in the requested event mask (events), but they
can be returned in the return mask (revents). We need to
check for those event too, and add them to the mask which
will be passed to the handler. */
/* See if the desired events (mask) match the received
events (ready_mask). */
#ifdef HAVE_POLL
error_mask = POLLHUP | POLLERR | POLLNVAL;
mask = (file_ptr->ready_mask & file_ptr->mask) |
(file_ptr->ready_mask & error_mask);
#else /* ! HAVE_POLL */
mask = file_ptr->ready_mask & file_ptr->mask;
#endif /* HAVE_POLL */
/* Clear the received events for next time around. */
file_ptr->ready_mask = 0;
/* If there was a match, then call the handler. */
if (mask != 0)
(*file_ptr->proc) (file_ptr->client_data, mask);
break;
}
}
}
/* Called by gdb_do_one_event to wait for new events on the
monitored file descriptors. Queue file events as they are
detected by the poll.
If there are no events, this function will block in the
call to poll.
Return -1 if there are no files descriptors to monitor,
otherwise return 0. */
static int
gdb_wait_for_event ()
{
file_handler *file_ptr;
gdb_event *file_event_ptr;
int num_found, i;
#ifndef HAVE_POLL
int mask, bit, index;
#endif
if (gdb_notifier.num_fds == 0)
return -1;
#ifdef HAVE_POLL
num_found =
poll (gdb_notifier.poll_fds, (unsigned long) gdb_notifier.num_fds, -1);
#else /* ! HAVE_POLL */
memcpy (gdb_notifier.ready_masks,
gdb_notifier.check_masks,
3 * MASK_SIZE * sizeof (fd_mask));
num_found = select (gdb_notifier.num_fds,
(SELECT_MASK *) & gdb_notifier.ready_masks[0],
(SELECT_MASK *) & gdb_notifier.ready_masks[MASK_SIZE],
(SELECT_MASK *) & gdb_notifier.ready_masks[2 * MASK_SIZE],
NULL);
/* Clear the masks after an error from select. */
if (num_found == -1)
memset (gdb_notifier.ready_masks,
0, 3 * MASK_SIZE * sizeof (fd_mask));
#endif /* HAVE_POLL */
/* Enqueue all detected file events. */
#ifdef HAVE_POLL
for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
{
if ((gdb_notifier.poll_fds + i)->revents)
num_found--;
else
continue;
for (file_ptr = gdb_notifier.first_file_handler;
file_ptr != NULL;
file_ptr = file_ptr->next_file)
{
if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd)
break;
}
if (file_ptr)
{
/* Enqueue an event only if this is still a new event for
this fd. */
if (file_ptr->ready_mask == 0)
{
file_event_ptr =
(gdb_event *) xmalloc (sizeof (gdb_event));
file_event_ptr->proc = handle_file_event;
file_event_ptr->fd = file_ptr->fd;
async_queue_event (file_event_ptr, TAIL);
}
}
file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
}
#else /* ! HAVE_POLL */
for (file_ptr = gdb_notifier.first_file_handler;
(file_ptr != NULL) && (num_found > 0);
file_ptr = file_ptr->next_file)
{
index = file_ptr->fd / (NBBY * sizeof (fd_mask));
bit = 1 << (file_ptr->fd % (NBBY * sizeof (fd_mask)));
mask = 0;
if (gdb_notifier.ready_masks[index] & bit)
mask |= GDB_READABLE;
if ((gdb_notifier.ready_masks + MASK_SIZE)[index] & bit)
mask |= GDB_WRITABLE;
if ((gdb_notifier.ready_masks + 2 * (MASK_SIZE))[index] & bit)
mask |= GDB_EXCEPTION;
if (!mask)
continue;
else
num_found--;
/* Enqueue an event only if this is still a new event for
this fd. */
if (file_ptr->ready_mask == 0)
{
file_event_ptr =
(gdb_event *) xmalloc (sizeof (gdb_event));
file_event_ptr->proc = handle_file_event;
file_event_ptr->fd = file_ptr->fd;
async_queue_event (file_event_ptr, TAIL);
}
file_ptr->ready_mask = mask;
}
#endif /* HAVE_POLL */
return 0;
}
/* Create an asynchronous handler, allocating memory for it.
Return a pointer to the newly created handler.
This pointer will be used to invoke the handler by
invoke_async_signal_handler.
PROC is the function to call with CLIENT_DATA argument
whenever the handler is invoked. */
async_signal_handler *
create_async_signal_handler (proc, client_data)
async_handler_func *proc;
gdb_client_data client_data;
{
async_signal_handler *async_handler_ptr;
async_handler_ptr =
(async_signal_handler *) xmalloc (sizeof (async_signal_handler));
async_handler_ptr->ready = 0;
async_handler_ptr->next_handler = NULL;
async_handler_ptr->proc = proc;
async_handler_ptr->client_data = client_data;
if (sighandler_list.first_handler == NULL)
sighandler_list.first_handler = async_handler_ptr;
else
sighandler_list.last_handler->next_handler = async_handler_ptr;
sighandler_list.last_handler = async_handler_ptr;
return async_handler_ptr;
}
/* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
be used when the handlers are invoked, after we have waited for
some event. The caller of this function is the interrupt handler
associated with a signal. */
void
mark_async_signal_handler (async_handler_ptr)
async_signal_handler *async_handler_ptr;
{
((async_signal_handler *) async_handler_ptr)->ready = 1;
async_handler_ready = 1;
}
/* Call all the handlers that are ready. */
static void
invoke_async_signal_handler ()
{
async_signal_handler *async_handler_ptr;
if (async_handler_ready == 0)
return;
async_handler_ready = 0;
/* Invoke ready handlers. */
while (1)
{
for (async_handler_ptr = sighandler_list.first_handler;
async_handler_ptr != NULL;
async_handler_ptr = async_handler_ptr->next_handler)
{
if (async_handler_ptr->ready)
break;
}
if (async_handler_ptr == NULL)
break;
async_handler_ptr->ready = 0;
(*async_handler_ptr->proc) (async_handler_ptr->client_data);
}
return;
}
/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
Free the space allocated for it. */
void
delete_async_signal_handler (async_handler_ptr)
async_signal_handler *async_handler_ptr;
{
async_signal_handler *prev_ptr;
if (sighandler_list.first_handler == async_handler_ptr)
{
sighandler_list.first_handler = async_handler_ptr->next_handler;
if (sighandler_list.first_handler == NULL)
sighandler_list.last_handler = NULL;
}
else
{
prev_ptr = sighandler_list.first_handler;
while (prev_ptr->next_handler != async_handler_ptr)
prev_ptr = prev_ptr->next_handler;
prev_ptr->next_handler = async_handler_ptr->next_handler;
if (sighandler_list.last_handler == async_handler_ptr)
sighandler_list.last_handler = prev_ptr;
}
free ((char *) async_handler_ptr);
}
/* Is it necessary to call invoke_async_signal_handler? */
static int
check_async_ready ()
{
return async_handler_ready;
}

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/* Definitions used by the GDB event loop.
Copyright 1999 Free Software Foundation, Inc.
Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
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
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <stdlib.h>
#include <sys/types.h>
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>
#include "defs.h"
/* An event loop listens for events from multiple event sources. When
an event arrives, it is queued and processed by calling the
appropriate event handler. The event loop then continues to listen
for more events. An event loop completes when there are no event
sources to listen on. External event sources can be plugged into
the loop.
There are 3 main components:
- a list of file descriptors to be monitored, GDB_NOTIFIER.
- a list of events that have occurred, EVENT_QUEUE.
- a list of signal handling functions, SIGHANDLER_LIST.
GDB_NOTIFIER keeps track of the event sources. Event sources for
gdb are currently the UI and the target. Gdb communicates with the
command line user interface via the readline library and usually
communicates with remote targets via a serial port. Serial ports
are represented in GDB as file descriptors and select/poll calls.
For native targets instead, the communication consists of calls to
ptrace and waits (via signals) or calls to poll/select (via file
descriptors). In the current gdb, the code handling events related
to the target resides in the wait_for_inferior function and in
various target specific files (*-tdep.c).
EVENT_QUEUE keeps track of the events that have happened during the
last iteration of the event loop, and need to be processed. An
event is represented by a procedure to be invoked in order to
process the event. The queue is scanned head to tail. If the
event of interest is a change of state in a file descriptor, then a
call to poll or select will be made to detect it.
If the events generate signals, they are also queued by special
functions that are invoked through traditional signal handlers.
The actions to be taken is response to such events will be executed
when the SIGHANDLER_LIST is scanned, the next time through the
infinite loop.
Corollary tasks are the creation and deletion of event sources. */
typedef PTR gdb_client_data;
typedef struct gdb_event gdb_event;
typedef void (file_handler_func) PARAMS ((gdb_client_data, int mask));
typedef void (async_handler_func) PARAMS ((gdb_client_data));
typedef void (event_handler_func) PARAMS ((int));
/* Event for the GDB event system. Events are queued by calling
async_queue_event and serviced later on by gdb_do_one_event. An
event can be, for instance, a file descriptor becoming ready to be
read. Servicing an event simply means that the procedure PROC will
be called. We have 2 queues, one for file handlers that we listen
to in the event loop, and one for the file handlers+events that are
ready. The procedure PROC associated with each event is always the
same (handle_file_event). Its duty is to invoke the handler
associated with the file descriptor whose state change generated
the event, plus doing other cleanups adn such. */
struct gdb_event
{
event_handler_func *proc; /* Procedure to call to service this event. */
int fd; /* File descriptor that is ready. */
struct gdb_event *next_event; /* Next in list of events or NULL. */
};
/* Information about each file descriptor we register with the event
loop. */
typedef struct file_handler
{
int fd; /* File descriptor. */
int mask; /* Events we want to monitor: POLLIN, etc. */
int ready_mask; /* Events that have been seen since
the last time. */
file_handler_func *proc; /* Procedure to call when fd is ready. */
gdb_client_data client_data; /* Argument to pass to proc. */
struct file_handler *next_file; /* Next registered file descriptor. */
}
file_handler;
/* PROC is a function to be invoked when the READY flag is set. This
happens when there has been a signal and the corresponding signal
handler has 'triggered' this async_signal_handler for
execution. The actual work to be done in response to a signal will
be carried out by PROC at a later time, within process_event. This
provides a deferred execution of signal handlers.
Async_init_signals takes care of setting up such an
asyn_signal_handler for each interesting signal. */
typedef struct async_signal_handler
{
int ready; /* If ready, call this handler from the main event loop,
using invoke_async_handler. */
struct async_signal_handler *next_handler; /* Ptr to next handler */
async_handler_func *proc; /* Function to call to do the work */
gdb_client_data client_data; /* Argument to async_handler_func */
}
async_signal_handler;
/* Where to add an event onto the event queue, by queue_event. */
typedef enum
{
/* Add at tail of queue. It will be processed in first in first
out order. */
TAIL,
/* Add at head of queue. It will be processed in last in first out
order. */
HEAD
}
queue_position;
/* Tell create_file_handler what events we are interested in.
This is used by the select version of the event loop. */
#define GDB_READABLE (1<<1)
#define GDB_WRITABLE (1<<2)
#define GDB_EXCEPTION (1<<3)
/* Type of the mask arguments to select. */
#ifndef NO_FD_SET
#define SELECT_MASK fd_set
#else
#ifndef _AIX
typedef long fd_mask;
#endif
#if defined(_IBMR2)
#define SELECT_MASK void
#else
#define SELECT_MASK int
#endif
#endif
/* Define "NBBY" (number of bits per byte) if it's not already defined. */
#ifndef NBBY
#define NBBY 8
#endif
/* Define the number of fd_masks in an fd_set */
#ifndef FD_SETSIZE
#ifdef OPEN_MAX
#define FD_SETSIZE OPEN_MAX
#else
#define FD_SETSIZE 256
#endif
#endif
#if !defined(howmany)
#define howmany(x, y) (((x)+((y)-1))/(y))
#endif
#ifndef NFDBITS
#define NFDBITS NBBY*sizeof(fd_mask)
#endif
#define MASK_SIZE howmany(FD_SETSIZE, NFDBITS)
/* Stack for prompts. Each prompt is composed as a prefix, a prompt
and a suffix. The prompt to be displayed at any given time is the
one on top of the stack. A stack is necessary because of cases in
which the execution of a gdb command requires further input from
the user, like for instance 'commands' for breakpoints and
'actions' for tracepoints. In these cases, the prompt is '>' and
gdb should process input using the asynchronous readline interface
and the event loop. In order to achieve this, we need to save
somewhere the state of GDB, i.e. that it is processing user input
as part of a command and not as part of the top level command loop.
The prompt stack represents part of the saved state. Another part
would be the function that readline would invoke after a whole line
of input has ben entered. This second piece would be something
like, for instance, where to return within the code for the actions
commands after a line has been read. This latter portion has not
beeen implemented yet. The need for a 3-part prompt arises from
the annotation level. When this is set to 2, the prompt is actually
composed of a prefix, the prompt itself and a suffix. */
/* At any particular time there will be always at least one prompt on
the stack, the one being currently displayed by gdb. If gdb is
using annotation level equal 2, there will be 2 prompts on the
stack: the usual one, w/o prefix and suffix (at top - 1), and the
'composite' one with prefix and suffix added (at top). At this
time, this is the only use of the prompt stack. Resetting annotate
to 0 or 1, pops the top of the stack, resetting its size to one
element. The MAXPROMPTS limit is safe, for now. Once other cases
are dealt with (like the different prompts used for 'commands' or
'actions') this array implementation of the prompt stack may have
to change. */
#define MAXPROMPTS 10
struct prompts
{
struct
{
char *prefix;
char *prompt;
char *suffix;
}
prompt_stack[MAXPROMPTS];
int top;
};
#define PROMPT(X) the_prompts.prompt_stack[the_prompts.top + X].prompt
#define PREFIX(X) the_prompts.prompt_stack[the_prompts.top + X].prefix
#define SUFFIX(X) the_prompts.prompt_stack[the_prompts.top + X].suffix
extern void delete_file_handler PARAMS ((int));
extern void
create_file_handler PARAMS ((int, int, file_handler_func, gdb_client_data));
extern int gdb_do_one_event PARAMS ((void));
extern void mark_async_signal_handler PARAMS ((async_signal_handler *));
extern async_signal_handler *
create_async_signal_handler PARAMS ((async_handler_func *, gdb_client_data));

950
gdb/event-top.c Normal file
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@ -0,0 +1,950 @@
/* Top level stuff for GDB, the GNU debugger.
Copyright 1999 Free Software Foundation, Inc.
Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
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
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "event-loop.h"
#ifdef HAVE_POLL
#include <sys/poll.h>
#endif
#include "inferior.h"
/* readline include files */
#include <readline/readline.h>
#include <readline/history.h>
/* readline defines this. */
#undef savestring
extern FILE *instream;
static void command_line_handler PARAMS ((char *));
static void gdb_readline2 PARAMS ((void));
static void pop_prompt PARAMS ((void));
static void push_prompt PARAMS ((char *, char *, char *));
/* Signal handlers. */
void handle_sigint PARAMS ((int));
void handle_sigquit PARAMS ((int));
void handle_sighup PARAMS ((int));
void handle_sigfpe PARAMS ((int));
void handle_sigwinch PARAMS ((int));
/* Functions to be invoked by the event loop in response to
signals. */
void async_request_quit PARAMS ((void));
void async_do_nothing PARAMS ((void));
void async_disconnect PARAMS ((void));
void async_float_handler PARAMS ((void));
/* Functions from top.c. */
extern void command_loop_marker PARAMS ((int));
extern int quit_cover PARAMS ((PTR));
extern void quit_command PARAMS ((char *, int));
extern void execute_command PARAMS ((char *, int));
/* Variables from top.c. */
extern int source_line_number;
extern char *source_file_name;
extern char *source_error;
extern char *source_pre_error;
extern int history_expansion_p;
extern int server_command;
/* 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
/* Hook for alternate command interface. */
void (*async_hook) PARAMS ((void));
/* Readline offers an alternate interface, via callback
functions. These are all included in the file callback.c in the
readline distribution. This file provides (mainly) a function, which
the event loop uses as callback (i.e. event handler) whenever an event
is detected on the standard input file descriptor.
readline_callback_read_char is called (by the GDB event loop) whenever
there is a new character ready on the input stream. This function
incrementally builds a buffer internal to readline where it
accumulates the line read up to the point of invocation. In the
special case in which the character read is newline, the function
invokes a GDB supplied callback routine, which does the processing of
a full command line. This latter routine is the asynchronous analog
of the old command_line_input in gdb. Instead of invoking (and waiting
for) readline to read the command line and pass it back to
command_loop for processing, the new command_line_handler function has
the command line already available as its parameter. INPUT_HANDLER is
to be set to the function that readline will invoke when a complete
line of input is ready. CALL_READLINE is to be set to the function
that readline offers as callback to the event_loop. */
void (*input_handler) PARAMS ((char *));
void (*call_readline) PARAMS ((void));
/* Important variables for the event loop. */
/* This is used to determine if GDB is using the readline library or
its own simplified form of readline. It is used by the asynchronous
form of the set editing command.
ezannoni: as of 4/29/99 I expect that this
variable will not be used after gdb is changed to use the event
loop as default engine, and event-top.c is merged into top.c. */
int async_command_editing_p;
/* This variable contains the new prompt that the user sets with the
set prompt command. */
char *new_async_prompt;
/* This is the annotation suffix that will be used when the
annotation_level is 2. */
char *async_annotation_suffix;
/* This is the file descriptor for the input stream that GDB uses to
read commands from. */
int input_fd;
/* This is the prompt stack. Prompts will be pushed on the stack as
needed by the different 'kinds' of user inputs GDB is asking
for. See event-loop.h. */
struct prompts the_prompts;
/* signal handling variables */
/* Each of these is a pointer to a function that the event loop will
invoke if the corresponding signal has received. The real signal
handlers mark these functions as ready to be executed and the event
loop, in a later iteration, calls them. See the function
invoke_async_signal_handler. */
async_signal_handler *sigint_token;
#ifdef SIGHUP
async_signal_handler *sighup_token;
#endif
async_signal_handler *sigquit_token;
async_signal_handler *sigfpe_token;
#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
async_signal_handler *sigwinch_token;
#endif
/* Structure to save a partially entered command. This is used when
the user types '\' at the end of a command line. This is necessary
because each line of input is handled by a different call to
command_line_handler, and normally there is no state retained
between different calls. */
int more_to_come = 0;
struct readline_input_state
{
char *linebuffer;
char *linebuffer_ptr;
}
readline_input_state;
/* Initialize all the necessary variables, start the event loop,
register readline, and stdin. */
void
setup_event_loop ()
{
int length = strlen (PREFIX (0)) + strlen (PROMPT (0)) + strlen (SUFFIX (0)) + 1;
char *a_prompt = (char *) xmalloc (length);
/* Set things up for readline to be invoked via the alternate
interface, i.e. via a callback function (rl_callback_read_char). */
call_readline = rl_callback_read_char;
/* When readline has read an end-of-line character, it passes the
complete line to gdb for processing. command_line_handler is the
function that does this. */
input_handler = command_line_handler;
/* Tell readline what the prompt to display is and what function it
will need to call after a whole line is read. */
strcpy (a_prompt, PREFIX (0));
strcat (a_prompt, PROMPT (0));
strcat (a_prompt, SUFFIX (0));
rl_callback_handler_install (a_prompt, input_handler);
/* Tell readline to use the same input stream that gdb uses. */
rl_instream = instream;
/* Get a file descriptor for the input stream, so that we can
register it with the event loop. */
input_fd = fileno (instream);
/* Now we need to create the event sources for the input file descriptor. */
/* At this point in time, this is the only event source that we
register with the even loop. Another source is going to be the
target program (inferior), but that must be registered only when
it actually exists (I.e. after we say 'run' or after we connect
to a remote target. */
#ifdef HAVE_POLL
create_file_handler (input_fd, POLLIN,
(file_handler_func *) call_readline, 0);
#else
create_file_handler (input_fd, GDB_READABLE,
(file_handler_func *) call_readline, 0);
#endif
/* Loop until there is something to do. This is the entry point to
the event loop engine. gdb_do_one_event will process one event
for each invocation. It always returns 1, unless there are no
more event sources registered. In this case it returns 0. */
while (gdb_do_one_event () != 0)
;
/* We are done with the event loop. There are no more event sources
to listen to. So we exit GDB. */
return;
}
/* Change the function to be invoked every time there is a character
ready on stdin. This is used when the user sets the editing off,
therefore bypassing readline, and letting gdb handle the input
itself, via gdb_readline2. Also it is used in the opposite case in
which the user sets editing on again, by restoring readline
handling of the input. */
void
change_line_handler ()
{
if (async_command_editing_p)
{
/* Turn on editing by using readline. */
call_readline = rl_callback_read_char;
}
else
{
/* Turn off editing by using gdb_readline2. */
rl_callback_handler_remove ();
call_readline = gdb_readline2;
}
/* To tell the event loop to change the handler associated with the
input file descriptor, we need to create a new event source,
corresponding to the same fd, but with a new event handler
function. */
delete_file_handler (input_fd);
#ifdef HAVE_POLL
create_file_handler (input_fd, POLLIN,
(file_handler_func *) call_readline, 0);
#else
create_file_handler (input_fd, GDB_READABLE,
(file_handler_func *) call_readline, 0);
#endif
}
/* Displays the prompt. The prompt that is displayed is the current
top of the prompt stack, if the argument NEW_PROMPT is
0. Otherwise, it displays whatever NEW_PROMPT is. This is used
after each gdb command has completed, and in the following cases:
1. when the user enters a command line which is ended by '\'
indicating that the command will continue on the next line.
In that case the prompt that is displayed is the empty string.
2. When the user is entering 'commands' for a breakpoint, or
actions for a tracepoint. In this case the prompt will be '>'
3. Other????
FIXME: 2. & 3. not implemented yet for async. */
void
display_gdb_prompt (new_prompt)
char *new_prompt;
{
int prompt_length = 0;
if (!new_prompt)
{
/* Just use the top of the prompt stack. */
prompt_length = strlen (PREFIX (0)) +
strlen (SUFFIX (0)) +
strlen (PROMPT (0)) + 1;
new_prompt = (char *) alloca (prompt_length);
/* Prefix needs to have new line at end. */
strcpy (new_prompt, PREFIX (0));
strcat (new_prompt, PROMPT (0));
/* Suffix needs to have a new line at end and \032 \032 at
beginning. */
strcat (new_prompt, SUFFIX (0));
}
if (async_command_editing_p)
{
rl_callback_handler_remove ();
rl_callback_handler_install (new_prompt, input_handler);
}
else if (new_prompt)
{
/* Don't use a _filtered function here. It causes the assumed
character position to be off, since the newline we read from
the user is not accounted for. */
fputs_unfiltered (new_prompt, gdb_stdout);
#ifdef MPW
/* Move to a new line so the entered line doesn't have a prompt
on the front of it. */
fputs_unfiltered ("\n", gdb_stdout);
#endif /* MPW */
gdb_flush (gdb_stdout);
}
}
/* Used when the user requests a different annotation level, with
'set annotate'. It pushes a new prompt (with prefix and suffix) on top
of the prompt stack, if the annotation level desired is 2, otherwise
it pops the top of the prompt stack when we want the annotation level
to be the normal ones (1 or 2). */
void
change_annotation_level ()
{
char *prefix, *suffix;
if (!PREFIX (0) || !PROMPT (0) || !SUFFIX (0))
{
/* The prompt stack has not been initialized to "", we are
using gdb w/o the --async switch */
warning ("Command has same effect as set annotate");
return;
}
if (annotation_level > 1)
{
if (!strcmp (PREFIX (0), "") && !strcmp (SUFFIX (0), ""))
{
/* Push a new prompt if the previous annotation_level was not >1. */
prefix = (char *) alloca (strlen (async_annotation_suffix) + 10);
strcpy (prefix, "\n\032\032pre-");
strcat (prefix, async_annotation_suffix);
strcat (prefix, "\n");
suffix = (char *) alloca (strlen (async_annotation_suffix) + 6);
strcpy (suffix, "\n\032\032");
strcat (suffix, async_annotation_suffix);
strcat (suffix, "\n");
push_prompt (prefix, (char *) 0, suffix);
}
}
else
{
if (strcmp (PREFIX (0), "") && strcmp (SUFFIX (0), ""))
{
/* Pop the top of the stack, we are going back to annotation < 1. */
pop_prompt ();
}
}
}
/* Pushes a new prompt on the prompt stack. Each prompt has three
parts: prefix, prompt, suffix. Usually prefix and suffix are empty
strings, except when the annotation level is 2. Memory is allocated
within savestring for the new prompt. */
static void
push_prompt (prefix, prompt, suffix)
char *prefix;
char *prompt;
char *suffix;
{
the_prompts.top++;
PREFIX (0) = savestring (prefix, strlen (prefix));
if (prompt)
PROMPT (0) = savestring (prompt, strlen (prompt));
else
PROMPT (0) = savestring (PROMPT (-1), strlen (PROMPT (-1)));
SUFFIX (0) = savestring (suffix, strlen (suffix));
}
/* Pops the top of the prompt stack, and frees the memory allocated for it. */
static void
pop_prompt ()
{
if (strcmp (PROMPT (0), PROMPT (-1)))
{
free (PROMPT (-1));
PROMPT (-1) = savestring (PROMPT (0), strlen (PROMPT (0)));
}
free (PREFIX (0));
free (PROMPT (0));
free (SUFFIX (0));
the_prompts.top--;
}
/* Handles a gdb command. This function is called by
command_line_handler, which has processed one or more input lines
into COMMAND. */
/* NOTE: 4/30/99 This is the asynchronous version of the command_loop
function. The command_loop function will be obsolete when we
switch to use the event loop at every execution of gdb. */
void
command_handler (command)
char *command;
{
struct cleanup *old_chain;
int stdin_is_tty = ISATTY (stdin);
long time_at_cmd_start;
#ifdef HAVE_SBRK
long space_at_cmd_start = 0;
#endif
extern int display_time;
extern int display_space;
#if defined(TUI)
extern int insert_mode;
#endif
quit_flag = 0;
if (instream == stdin && stdin_is_tty)
reinitialize_more_filter ();
old_chain = make_cleanup ((make_cleanup_func) command_loop_marker, 0);
#if defined(TUI)
insert_mode = 0;
#endif
/* If readline returned a NULL command, it means that the
connection with the terminal is gone. This happens at the
end of a testsuite run, after Expect has hung up
but GDB is still alive. In such a case, we just quit gdb
killing the inferior program too. */
if (command == 0)
quit_command ((char *) 0, stdin == instream);
time_at_cmd_start = get_run_time ();
if (display_space)
{
#ifdef HAVE_SBRK
extern char **environ;
char *lim = (char *) sbrk (0);
space_at_cmd_start = (long) (lim - (char *) &environ);
#endif
}
execute_command (command, instream == stdin);
/* Do any commands attached to breakpoint we stopped at. */
bpstat_do_actions (&stop_bpstat);
do_cleanups (old_chain);
if (display_time)
{
long cmd_time = get_run_time () - time_at_cmd_start;
printf_unfiltered ("Command execution time: %ld.%06ld\n",
cmd_time / 1000000, cmd_time % 1000000);
}
if (display_space)
{
#ifdef HAVE_SBRK
extern char **environ;
char *lim = (char *) sbrk (0);
long space_now = lim - (char *) &environ;
long space_diff = space_now - space_at_cmd_start;
printf_unfiltered ("Space used: %ld (%c%ld for this command)\n",
space_now,
(space_diff >= 0 ? '+' : '-'),
space_diff);
#endif
}
}
/* Handle a complete line of input. This is called by the callback
mechanism within the readline library. Deal with incomplete commands
as well, by saving the partial input in a global buffer. */
/* NOTE: 4/30/99 This is the asynchronous version of the
command_line_input function. command_line_input will become
obsolete once we use the event loop as the default mechanism in
GDB. */
static void
command_line_handler (rl)
char *rl;
{
static char *linebuffer = 0;
static unsigned linelength = 0;
register char *p;
char *p1;
int change_prompt = 0;
extern char *line;
extern int linesize;
char *nline;
char got_eof = 0;
int repeat = (instream == stdin);
if (annotation_level > 1 && instream == stdin)
{
printf_unfiltered ("\n\032\032post-");
printf_unfiltered (async_annotation_suffix);
printf_unfiltered ("\n");
}
if (linebuffer == 0)
{
linelength = 80;
linebuffer = (char *) xmalloc (linelength);
}
p = linebuffer;
if (more_to_come)
{
strcpy (linebuffer, readline_input_state.linebuffer);
p = readline_input_state.linebuffer_ptr;
free (readline_input_state.linebuffer);
more_to_come = 0;
change_prompt = 1;
}
#ifdef STOP_SIGNAL
if (job_control)
signal (STOP_SIGNAL, stop_sig);
#endif
/* Make sure that all output has been output. Some machines may let
you get away with leaving out some of the gdb_flush, but not all. */
wrap_here ("");
gdb_flush (gdb_stdout);
gdb_flush (gdb_stderr);
if (source_file_name != NULL)
{
++source_line_number;
sprintf (source_error,
"%s%s:%d: Error in sourced command file:\n",
source_pre_error,
source_file_name,
source_line_number);
error_pre_print = source_error;
}
/* If we are in this case, then command_handler will call quit
and exit from gdb. */
if (!rl || rl == (char *) EOF)
{
got_eof = 1;
command_handler (0);
}
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) == '\\')
{
/* We come here also if the line entered is empty (just a 'return') */
p--; /* Put on top of '\'. */
if (*p == '\\')
{
readline_input_state.linebuffer = savestring (linebuffer,
strlen (linebuffer));
readline_input_state.linebuffer_ptr = p;
/* We will not invoke a execute_command if there is more
input expected to complete the command. So, we need to
print an empty prompt here. */
display_gdb_prompt ("");
more_to_come = 1;
}
}
#ifdef STOP_SIGNAL
if (job_control)
signal (STOP_SIGNAL, SIG_DFL);
#endif
#define SERVER_COMMAND_LENGTH 7
server_command =
(p - linebuffer > SERVER_COMMAND_LENGTH)
&& STREQN (linebuffer, "server ", SERVER_COMMAND_LENGTH);
if (server_command)
{
/* Note that we don't set `line'. Between this and the check in
dont_repeat, this insures that repeating will still do the
right thing. */
*p = '\0';
command_handler (linebuffer + SERVER_COMMAND_LENGTH);
display_gdb_prompt (0);
return;
}
/* 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_unfiltered ("%s\n", history_value);
/* If there was an error, call this function again. */
if (expanded < 0)
{
free (history_value);
return;
}
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 && p == linebuffer && *p != '\\')
{
command_handler (line);
display_gdb_prompt (0);
return;
}
for (p1 = linebuffer; *p1 == ' ' || *p1 == '\t'; p1++);
if (repeat && !*p1)
{
command_handler (line);
display_gdb_prompt (0);
return;
}
*p = 0;
/* Add line to history if appropriate. */
if (instream == stdin
&& ISATTY (stdin) && *linebuffer)
add_history (linebuffer);
/* Note: lines consisting solely 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. */
if (*p1 == '#')
*p1 = '\0'; /* Found a comment. */
/* Save into global buffer if appropriate. */
if (repeat)
{
if (linelength > linesize)
{
line = xrealloc (line, linelength);
linesize = linelength;
}
strcpy (line, linebuffer);
if (!more_to_come)
{
command_handler (line);
display_gdb_prompt (0);
}
return;
}
command_handler (linebuffer);
display_gdb_prompt (0);
return;
}
/* Does reading of input from terminal w/o the editing features
provided by the readline library. */
/* NOTE: 4/30/99 Asynchronous version of gdb_readline. gdb_readline
will become obsolete when the event loop is made the default
execution for gdb. */
static void
gdb_readline2 ()
{
int c;
char *result;
int input_index = 0;
int result_size = 80;
result = (char *) xmalloc (result_size);
/* We still need the while loop here, even though it would seem
obvious to invoke gdb_readline2 at every character entered. If
not using the readline library, the terminal is in cooked mode,
which sends the characters all at once. Poll will notice that the
input fd has changed state only after enter is pressed. At this
point we still need to fetch all the chars entered. */
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)
{
if (input_index > 0)
/* The last line does not end with a newline. Return it, and
if we are called again fgetc will still return EOF and
we'll return NULL then. */
break;
free (result);
command_line_handler (0);
}
if (c == '\n')
#ifndef CRLF_SOURCE_FILES
break;
#else
{
if (input_index > 0 && result[input_index - 1] == '\r')
input_index--;
break;
}
#endif
result[input_index++] = c;
while (input_index >= result_size)
{
result_size *= 2;
result = (char *) xrealloc (result, result_size);
}
}
result[input_index++] = '\0';
command_line_handler (result);
}
/* Initialization of signal handlers and tokens. There is a function
handle_sig* for each of the signals GDB cares about. Specifically:
SIGINT, SIGFPE, SIGQUIT, SIGTSTP, SIGHUP, SIGWINCH. These
functions are the actual signal handlers associated to the signals
via calls to signal(). The only job for these functions is to
enqueue the appropriate event/procedure with the event loop. Such
procedures are the old signal handlers. The event loop will take
care of invoking the queued procedures to perform the usual tasks
associated with the reception of the signal. */
/* NOTE: 4/30/99 This is the asynchronous version of init_signals.
init_signals will become obsolete as we move to have to event loop
as the default for gdb. */
void
async_init_signals ()
{
signal (SIGINT, handle_sigint);
sigint_token =
create_async_signal_handler ((async_handler_func *) async_request_quit, NULL);
/* If SIGTRAP was set to SIG_IGN, then the SIG_IGN will get passed
to the inferior and breakpoints will be ignored. */
#ifdef SIGTRAP
signal (SIGTRAP, SIG_DFL);
#endif
/* 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 can affect the
GDB process as well as the inferior (the signal handling tables
might be in memory, shared between the two). Since we establish
a handler for SIGQUIT, when we call exec it will set the signal
to SIG_DFL for us. */
signal (SIGQUIT, handle_sigquit);
sigquit_token =
create_async_signal_handler ((async_handler_func *) async_do_nothing, NULL);
#ifdef SIGHUP
if (signal (SIGHUP, handle_sighup) != SIG_IGN)
sighup_token =
create_async_signal_handler ((async_handler_func *) async_disconnect, NULL);
else
sighup_token =
create_async_signal_handler ((async_handler_func *) async_do_nothing, NULL);
#endif
signal (SIGFPE, handle_sigfpe);
sigfpe_token =
create_async_signal_handler ((async_handler_func *) async_float_handler, NULL);
#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
signal (SIGWINCH, handle_sigwinch);
sigwinch_token =
create_async_signal_handler ((async_handler_func *) SIGWINCH_HANDLER, NULL);
#endif
}
/* Tell the event loop what to do if SIGINT is received.
See event-signal.c. */
void
handle_sigint (sig)
int sig;
{
signal (sig, handle_sigint);
/* If immediate_quit is set, we go ahead and process the SIGINT right
away, even if we usually would defer this to the event loop. The
assumption here is that it is safe to process ^C immediately if
immediate_quit is set. If we didn't, SIGINT would be really
processed only the next time through the event loop. To get to
that point, though, the command that we want to interrupt needs to
finish first, which is unacceptable. */
if (immediate_quit)
async_request_quit ();
else
/* If immediate quit is not set, we process SIGINT the next time
through the loop, which is fine. */
mark_async_signal_handler (sigint_token);
}
/* Do the quit. All the checks have been done by the caller. */
void
async_request_quit ()
{
quit_flag = 1;
#ifdef REQUEST_QUIT
REQUEST_QUIT;
#else
quit ();
#endif
}
/* Tell the event loop what to do if SIGQUIT is received.
See event-signal.c. */
void
handle_sigquit (sig)
int sig;
{
mark_async_signal_handler (sigquit_token);
signal (sig, handle_sigquit);
}
/* Called by the event loop in response to a SIGQUIT. */
void
async_do_nothing ()
{
/* Empty function body. */
}
#ifdef SIGHUP
/* Tell the event loop what to do if SIGHUP is received.
See event-signal.c. */
void
handle_sighup (sig)
int sig;
{
mark_async_signal_handler (sighup_token);
signal (sig, handle_sighup);
}
/* Called by the event loop to process a SIGHUP. */
void
async_disconnect ()
{
catch_errors (quit_cover, NULL,
"Could not kill the program being debugged",
RETURN_MASK_ALL);
signal (SIGHUP, SIG_DFL); /*FIXME: ??????????? */
kill (getpid (), SIGHUP);
}
#endif
/* Tell the event loop what to do if SIGFPE is received.
See event-signal.c. */
void
handle_sigfpe (sig)
int sig;
{
mark_async_signal_handler (sigfpe_token);
signal (sig, handle_sigfpe);
}
/* Event loop will call this functin to process a SIGFPE. */
void
async_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.");
}
/* Tell the event loop what to do if SIGWINCH is received.
See event-signal.c. */
#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
void
handle_sigwinch (sig)
int sig;
{
mark_async_signal_handler (sigwinch_token);
signal (sig, handle_sigwinch);
}
#endif
/* Called by do_setshow_command. */
/* ARGSUSED */
void
set_async_editing_command (args, from_tty, c)
char *args;
int from_tty;
struct cmd_list_element *c;
{
change_line_handler ();
}
/* Called by do_setshow_command. */
/* ARGSUSED */
void
set_async_annotation_level (args, from_tty, c)
char *args;
int from_tty;
struct cmd_list_element *c;
{
change_annotation_level ();
}
/* Called by do_setshow_command. */
/* ARGSUSED */
void
set_async_prompt (args, from_tty, c)
char *args;
int from_tty;
struct cmd_list_element *c;
{
PROMPT (0) = savestring (new_async_prompt, strlen (new_async_prompt));
}