Ref gdb/11763 - can't stop a running simulator:

	o	Provide poll_quit callback to simulators
		so that they can poll for SIGINT on
		clueless OS's.

	o	Add sim_stop to simulators so that clients
		can request a halt (eg gdbtk's STOP button)
		Works for PPC!

	o	Re-arange remote-sim.c so that the
		hard work is moved from gdbsim_resume()
		to gdbsim_wait() (where it should be).

3 files changed, 59 insertions, 3 deletions

diff --git a/include/ChangeLog b/include/ChangeLog
index 5fbea8e..22f2fe7 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,17 @@
+Fri Apr 18 13:04:49 1997  Andrew Cagney  <cagney@b1.cygnus.com>
+
+	* remote-sim.h (sim_stop): New interface - asynchronous
+ 	notification of a request to stop / suspend the running
+ 	simulation.
+
+	* remote-sim.h (enum sim_stop): Add sim_running and sim_polling as
+ 	states for use internal to simulators.
+	
+	* callback.h (struct host_callback_strut): Put a magic number at
+ 	the end of the struct to allow basic checking.
+	(struct host_callback_struct ): Add poll_quit - so
+ 	that the console etc can be polled at regular intervals.
+	
 Thu Apr 17 02:17:12 1997  Doug Evans  <dje@canuck.cygnus.com>
 
 	* remote-sim.h (struct _bfd): Declare.
diff --git a/include/callback.h b/include/callback.h
index 0d689cb..1070706 100644
--- a/include/callback.h
+++ b/include/callback.h
@@ -52,6 +52,11 @@ struct host_callback_struct
   int (*write_stderr) PARAMS ((host_callback *, const char *, int));
   void (*flush_stderr) PARAMS ((host_callback *));
 
+  /* When present, call to the client to give it the oportunity to
+     poll any io devices for a request to quit (indicated by a nonzero
+     return value). */
+  int (*poll_quit) PARAMS ((host_callback *));
+
   /* Used when the target has gone away, so we can close open
      handles and free memory etc etc.  */
   int (*shutdown) PARAMS ((host_callback *));
@@ -76,6 +81,12 @@ struct host_callback_struct
   int fdmap[MAX_CALLBACK_FDS];
   char fdopen[MAX_CALLBACK_FDS];
   char alwaysopen[MAX_CALLBACK_FDS];
+
+  /* Marker for thse wanting to do sanity checks.
+     This should remain the last memeber of this struct to help catch
+     miscompilation errors. */
+#define HOST_CALLBACK_MAGIC 4705 /* teds constant */
+  int magic;
 };
 
 extern host_callback default_callback;
diff --git a/include/remote-sim.h b/include/remote-sim.h
index 4bc4335..7e89d4c 100644
--- a/include/remote-sim.h
+++ b/include/remote-sim.h
@@ -53,8 +53,10 @@ typedef enum {
 /* The bfd struct, as an opaque type.  */
 struct _bfd;
 
+
 /* Main simulator entry points.  */
 
+
 /* Initialize the simulator.  This function is called when the simulator
    is selected from the gdb command line.
    KIND specifies how the simulator will be used.  Currently there are only
@@ -67,6 +69,7 @@ struct _bfd;
 
 SIM_DESC sim_open PARAMS ((SIM_OPEN_KIND kind, char **argv));
 
+
 /* Terminate usage of the simulator.  This may involve freeing target memory
    and closing any open files and mmap'd areas.  You cannot assume sim_kill
    has already been called.
@@ -74,62 +77,90 @@ SIM_DESC sim_open PARAMS ((SIM_OPEN_KIND kind, char **argv));
 
 void sim_close PARAMS ((SIM_DESC sd, int quitting));
 
+
 /* Load program PROG into the simulator.
    If ABFD is non-NULL, the bfd for the file has already been opened.
    The result is a return code indicating success.  */
 
 SIM_RC sim_load PARAMS ((SIM_DESC sd, char *prog, struct _bfd *abfd, int from_tty));
 
+
 /* Prepare to run the simulated program.
    ARGV and ENV are NULL terminated lists of pointers.  */
 
 SIM_RC sim_create_inferior PARAMS ((SIM_DESC sd, char **argv, char **env));
 
+
 /* Kill the running program.
    This may involve closing any open files and deleting any mmap'd areas.  */
 
 void sim_kill PARAMS ((SIM_DESC sd));
 
+
 /* Read LENGTH bytes of the simulated program's memory and store in BUF.
    Result is number of bytes read, or zero if error.  */
 
 int sim_read PARAMS ((SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length));
 
+
 /* Store LENGTH bytes from BUF in the simulated program's memory.
    Result is number of bytes write, or zero if error.  */
 
 int sim_write PARAMS ((SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length));
 
+
 /* Fetch register REGNO and store the raw value in BUF.  */
 
 void sim_fetch_register PARAMS ((SIM_DESC sd, int regno, unsigned char *buf));
 
+
 /* Store register REGNO from BUF (in raw format).  */
 
 void sim_store_register PARAMS ((SIM_DESC sd, int regno, unsigned char *buf));
 
+
 /* Print whatever statistics the simulator has collected.
    VERBOSE is currently unused and must always be zero.  */
 
 void sim_info PARAMS ((SIM_DESC sd, int verbose));
 
-/* Fetch why the program stopped.
-   SIGRC will contain either the argument to exit() or the signal number.  */
 
-enum sim_stop { sim_exited, sim_stopped, sim_signalled };
+/* Fetch the reason why the program stopped.
+   SIM_EXITED: The program has terminated. SIGRC indicates the target
+     dependant exit status.
+   SIM_STOPPED: Any of a breakpoint (SIGTRAP), a completed step
+     (SIGTRAP), a sim_stop request (SIGINT), or an internal error
+     condition (SIGABRT) was encountered.
+   SIM_SIGNALLED: The simulator encountered target code that requires
+     the signal SIGRC to be delivered to the simulated program.
+   SIM_RUNNING, SIM_POLLING: The return of one of these values
+     indicates a problem internal to the simulator. */
+
+enum sim_stop { sim_running, sim_polling, sim_exited, sim_stopped, sim_signalled };
 
 void sim_stop_reason PARAMS ((SIM_DESC sd, enum sim_stop *reason, int *sigrc));
 
+
 /* Run (or resume) the program.  */
 
 void sim_resume PARAMS ((SIM_DESC sd, int step, int siggnal));
 
+
+/* Asynchronous request to stop the simulation.
+   A nonzero return indicates that the simulator is able to handle
+   the request */
+
+int sim_stop PARAMS ((SIM_DESC sd));
+
+
 /* Passthru for other commands that the simulator might support.
    If SD is NULL, the command is to be interpreted as refering to
    the global state, however the simulator defines that.  */
 
+
 void sim_do_command PARAMS ((SIM_DESC sd, char *cmd));
 
+
 /* Provide simulator with a standard host_callback_struct.
    If SD is NULL, the command is to be interpreted as refering to
    the global state, however the simulator defines that.  */