--- /dev/null
+/* 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 *));
+\f
+
+/* 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;
+}
+\f
+
+/* 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;
+}
+\f
+
+/* 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;
+}
--- /dev/null
+/* 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));
+
--- /dev/null
+/* 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;
+\f
+
+/* 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--;
+}
+\f
+/* 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);
+}
+\f
+
+/* 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
+\f
+
+/* 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));
+}
+
+
+
+
projects / binutils-gdb.git / commitdiff