[binutils-gdb] Convert the until/advance commands to thread_fsm mechanism

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cfc3163382898a537c742bee1bf8240b3c09df35

commit cfc3163382898a537c742bee1bf8240b3c09df35
Author: Pedro Alves <palves@redhat.com>
Date:   Wed Sep 9 18:23:24 2015 +0100

    Convert the until/advance commands to thread_fsm mechanism
    
    gdb/ChangeLog:
    2015-09-09  Pedro Alves  <palves@redhat.com>
    
    	* breakpoint.c: Include "thread-fsm.h".
    	(struct until_break_command_continuation_args): Delete.
    	(struct until_break_fsm): New.
    	(until_break_fsm_ops): New global.
    	(new_until_break_fsm, until_break_fsm_should_stop): New functions.
    	(until_break_command_continuation): Delete.
    	(until_break_fsm_clean_up): New function.
    	(until_break_fsm_async_reply_reason): New function.
    	(until_break_command): Adjust to create an until_break_fsm instead
    	of a continuation.
    	(momentary_bkpt_print_it): No longer print MI's async-stop-reason
    	here.
    	* infcmd.c (struct until_next_fsm): New.
    	(until_next_fsm_ops): New global.
    	(new_until_next_fsm, until_next_fsm_should_stop): New function.
    	(until_next_continuation): Delete.
    	(until_next_fsm_clean_up, until_next_fsm_async_reply_reason): New
    	functions.
    	(until_next_command): Adjust to create a new until_next_fsm
    	instead of a continuation.

Diff:
---
 gdb/ChangeLog    |  23 +++++++
 gdb/breakpoint.c | 181 +++++++++++++++++++++++++++++++++++--------------------
 gdb/infcmd.c     |  92 ++++++++++++++++++++++------
 3 files changed, 211 insertions(+), 85 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f6fa8ec..81ba492 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,28 @@
 2015-09-09  Pedro Alves  <palves@redhat.com>
 
+	* breakpoint.c: Include "thread-fsm.h".
+	(struct until_break_command_continuation_args): Delete.
+	(struct until_break_fsm): New.
+	(until_break_fsm_ops): New global.
+	(new_until_break_fsm, until_break_fsm_should_stop): New functions.
+	(until_break_command_continuation): Delete.
+	(until_break_fsm_clean_up): New function.
+	(until_break_fsm_async_reply_reason): New function.
+	(until_break_command): Adjust to create an until_break_fsm instead
+	of a continuation.
+	(momentary_bkpt_print_it): No longer print MI's async-stop-reason
+	here.
+	* infcmd.c (struct until_next_fsm): New.
+	(until_next_fsm_ops): New global.
+	(new_until_next_fsm, until_next_fsm_should_stop): New function.
+	(until_next_continuation): Delete.
+	(until_next_fsm_clean_up, until_next_fsm_async_reply_reason): New
+	functions.
+	(until_next_command): Adjust to create a new until_next_fsm
+	instead of a continuation.
+
+2015-09-09  Pedro Alves  <palves@redhat.com>
+
 	* infcall.c: Include thread_fsm.h.
 	(struct call_return_meta_info): New.
 	(get_call_return_value): New function, factored out from
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 3d2976c..4709de7 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -68,6 +68,7 @@
 #include "interps.h"
 #include "format.h"
 #include "location.h"
+#include "thread-fsm.h"
 
 /* readline include files */
 #include "readline/readline.h"
@@ -11465,29 +11466,109 @@ awatch_command (char *arg, int from_tty)
 }
 
 
-/* Helper routines for the until_command routine in infcmd.c.  Here
-   because it uses the mechanisms of breakpoints.  */
+/* Data for the FSM that manages the until(location)/advance commands
+   in infcmd.c.  Here because it uses the mechanisms of
+   breakpoints.  */
 
-struct until_break_command_continuation_args
+struct until_break_fsm
 {
-  struct breakpoint *breakpoint;
-  struct breakpoint *breakpoint2;
-  int thread_num;
+  /* The base class.  */
+  struct thread_fsm thread_fsm;
+
+  /* The thread that as current when the command was executed.  */
+  int thread;
+
+  /* The breakpoint set at the destination location.  */
+  struct breakpoint *location_breakpoint;
+
+  /* Breakpoint set at the return address in the caller frame.  May be
+     NULL.  */
+  struct breakpoint *caller_breakpoint;
 };
 
-/* This function is called by fetch_inferior_event via the
-   cmd_continuation pointer, to complete the until command.  It takes
-   care of cleaning up the temporary breakpoints set up by the until
-   command.  */
+static void until_break_fsm_clean_up (struct thread_fsm *self);
+static int until_break_fsm_should_stop (struct thread_fsm *self);
+static enum async_reply_reason
+  until_break_fsm_async_reply_reason (struct thread_fsm *self);
+
+/* until_break_fsm's vtable.  */
+
+static struct thread_fsm_ops until_break_fsm_ops =
+{
+  NULL, /* dtor */
+  until_break_fsm_clean_up,
+  until_break_fsm_should_stop,
+  NULL, /* return_value */
+  until_break_fsm_async_reply_reason,
+};
+
+/* Allocate a new until_break_command_fsm.  */
+
+static struct until_break_fsm *
+new_until_break_fsm (int thread,
+		     struct breakpoint *location_breakpoint,
+		     struct breakpoint *caller_breakpoint)
+{
+  struct until_break_fsm *sm;
+
+  sm = XCNEW (struct until_break_fsm);
+  thread_fsm_ctor (&sm->thread_fsm, &until_break_fsm_ops);
+
+  sm->thread = thread;
+  sm->location_breakpoint = location_breakpoint;
+  sm->caller_breakpoint = caller_breakpoint;
+
+  return sm;
+}
+
+/* Implementation of the 'should_stop' FSM method for the
+   until(location)/advance commands.  */
+
+static int
+until_break_fsm_should_stop (struct thread_fsm *self)
+{
+  struct until_break_fsm *sm = (struct until_break_fsm *) self;
+  struct thread_info *tp = inferior_thread ();
+
+  if (bpstat_find_breakpoint (tp->control.stop_bpstat,
+			      sm->location_breakpoint) != NULL
+      || (sm->caller_breakpoint != NULL
+	  && bpstat_find_breakpoint (tp->control.stop_bpstat,
+				     sm->caller_breakpoint) != NULL))
+    thread_fsm_set_finished (self);
+
+  return 1;
+}
+
+/* Implementation of the 'clean_up' FSM method for the
+   until(location)/advance commands.  */
+
 static void
-until_break_command_continuation (void *arg, int err)
+until_break_fsm_clean_up (struct thread_fsm *self)
 {
-  struct until_break_command_continuation_args *a = arg;
+  struct until_break_fsm *sm = (struct until_break_fsm *) self;
 
-  delete_breakpoint (a->breakpoint);
-  if (a->breakpoint2)
-    delete_breakpoint (a->breakpoint2);
-  delete_longjmp_breakpoint (a->thread_num);
+  /* Clean up our temporary breakpoints.  */
+  if (sm->location_breakpoint != NULL)
+    {
+      delete_breakpoint (sm->location_breakpoint);
+      sm->location_breakpoint = NULL;
+    }
+  if (sm->caller_breakpoint != NULL)
+    {
+      delete_breakpoint (sm->caller_breakpoint);
+      sm->caller_breakpoint = NULL;
+    }
+  delete_longjmp_breakpoint (sm->thread);
+}
+
+/* Implementation of the 'async_reply_reason' FSM method for the
+   until(location)/advance commands.  */
+
+static enum async_reply_reason
+until_break_fsm_async_reply_reason (struct thread_fsm *self)
+{
+  return EXEC_ASYNC_LOCATION_REACHED;
 }
 
 void
@@ -11499,12 +11580,13 @@ until_break_command (char *arg, int from_tty, int anywhere)
   struct gdbarch *frame_gdbarch;
   struct frame_id stack_frame_id;
   struct frame_id caller_frame_id;
-  struct breakpoint *breakpoint;
-  struct breakpoint *breakpoint2 = NULL;
+  struct breakpoint *location_breakpoint;
+  struct breakpoint *caller_breakpoint = NULL;
   struct cleanup *old_chain, *cleanup;
   int thread;
   struct thread_info *tp;
   struct event_location *location;
+  struct until_break_fsm *sm;
 
   clear_proceed_status (0);
 
@@ -11554,14 +11636,16 @@ until_break_command (char *arg, int from_tty, int anywhere)
   if (frame_id_p (caller_frame_id))
     {
       struct symtab_and_line sal2;
+      struct gdbarch *caller_gdbarch;
 
       sal2 = find_pc_line (frame_unwind_caller_pc (frame), 0);
       sal2.pc = frame_unwind_caller_pc (frame);
-      breakpoint2 = set_momentary_breakpoint (frame_unwind_caller_arch (frame),
-					      sal2,
-					      caller_frame_id,
-					      bp_until);
-      make_cleanup_delete_breakpoint (breakpoint2);
+      caller_gdbarch = frame_unwind_caller_arch (frame);
+      caller_breakpoint = set_momentary_breakpoint (caller_gdbarch,
+						    sal2,
+						    caller_frame_id,
+						    bp_until);
+      make_cleanup_delete_breakpoint (caller_breakpoint);
 
       set_longjmp_breakpoint (tp, caller_frame_id);
       make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
@@ -11573,38 +11657,21 @@ until_break_command (char *arg, int from_tty, int anywhere)
   if (anywhere)
     /* If the user told us to continue until a specified location,
        we don't specify a frame at which we need to stop.  */
-    breakpoint = set_momentary_breakpoint (frame_gdbarch, sal,
-					   null_frame_id, bp_until);
+    location_breakpoint = set_momentary_breakpoint (frame_gdbarch, sal,
+						    null_frame_id, bp_until);
   else
     /* Otherwise, specify the selected frame, because we want to stop
        only at the very same frame.  */
-    breakpoint = set_momentary_breakpoint (frame_gdbarch, sal,
-					   stack_frame_id, bp_until);
-  make_cleanup_delete_breakpoint (breakpoint);
+    location_breakpoint = set_momentary_breakpoint (frame_gdbarch, sal,
+						    stack_frame_id, bp_until);
+  make_cleanup_delete_breakpoint (location_breakpoint);
 
-  proceed (-1, GDB_SIGNAL_DEFAULT);
+  sm = new_until_break_fsm (tp->num, location_breakpoint, caller_breakpoint);
+  tp->thread_fsm = &sm->thread_fsm;
 
-  /* If we are running asynchronously, and proceed call above has
-     actually managed to start the target, arrange for breakpoints to
-     be deleted when the target stops.  Otherwise, we're already
-     stopped and delete breakpoints via cleanup chain.  */
-
-  if (is_running (inferior_ptid))
-    {
-      struct until_break_command_continuation_args *args =
-        XNEW (struct until_break_command_continuation_args);
-
-      args->breakpoint = breakpoint;
-      args->breakpoint2 = breakpoint2;
-      args->thread_num = thread;
+  discard_cleanups (old_chain);
 
-      discard_cleanups (old_chain);
-      add_continuation (inferior_thread (),
-			until_break_command_continuation, args,
-			xfree);
-    }
-  else
-    do_cleanups (old_chain);
+  proceed (-1, GDB_SIGNAL_DEFAULT);
 
   do_cleanups (cleanup);
 }
@@ -13195,22 +13262,6 @@ momentary_bkpt_check_status (bpstat bs)
 static enum print_stop_action
 momentary_bkpt_print_it (bpstat bs)
 {
-  struct ui_out *uiout = current_uiout;
-
-  if (ui_out_is_mi_like_p (uiout))
-    {
-      struct breakpoint *b = bs->breakpoint_at;
-
-      switch (b->type)
-	{
-	case bp_until:
-	  ui_out_field_string
-	    (uiout, "reason",
-	     async_reason_lookup (EXEC_ASYNC_LOCATION_REACHED));
-	  break;
-	}
-    }
-
   return PRINT_UNKNOWN;
 }
 
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 437d919..98c386a 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -1385,22 +1385,81 @@ queue_signal_command (char *signum_exp, int from_tty)
   tp->suspend.stop_signal = oursig;
 }
 
-/* Continuation args to be passed to the "until" command
-   continuation.  */
-struct until_next_continuation_args
+/* Data for the FSM that manages the until (with no argument)
+   command.  */
+
+struct until_next_fsm
 {
-  /* The thread that was current when the command was executed.  */
+  /* The base class.  */
+  struct thread_fsm thread_fsm;
+
+  /* The thread that as current when the command was executed.  */
   int thread;
 };
 
-/* A continuation callback for until_next_command.  */
+static int until_next_fsm_should_stop (struct thread_fsm *self);
+static void until_next_fsm_clean_up (struct thread_fsm *self);
+static enum async_reply_reason
+  until_next_fsm_async_reply_reason (struct thread_fsm *self);
+
+/* until_next_fsm's vtable.  */
+
+static struct thread_fsm_ops until_next_fsm_ops =
+{
+  NULL, /* dtor */
+  until_next_fsm_clean_up,
+  until_next_fsm_should_stop,
+  NULL, /* return_value */
+  until_next_fsm_async_reply_reason,
+};
+
+/* Allocate a new until_next_fsm.  */
+
+static struct until_next_fsm *
+new_until_next_fsm (int thread)
+{
+  struct until_next_fsm *sm;
+
+  sm = XCNEW (struct until_next_fsm);
+  thread_fsm_ctor (&sm->thread_fsm, &until_next_fsm_ops);
+
+  sm->thread = thread;
+
+  return sm;
+}
+
+/* Implementation of the 'should_stop' FSM method for the until (with
+   no arg) command.  */
+
+static int
+until_next_fsm_should_stop (struct thread_fsm *self)
+{
+  struct thread_info *tp = inferior_thread ();
+
+  if (tp->control.stop_step)
+    thread_fsm_set_finished (self);
+
+  return 1;
+}
+
+/* Implementation of the 'clean_up' FSM method for the until (with no
+   arg) command.  */
 
 static void
-until_next_continuation (void *arg, int err)
+until_next_fsm_clean_up (struct thread_fsm *self)
 {
-  struct until_next_continuation_args *a = arg;
+  struct until_next_fsm *sm = (struct until_next_fsm *) self;
 
-  delete_longjmp_breakpoint (a->thread);
+  delete_longjmp_breakpoint (sm->thread);
+}
+
+/* Implementation of the 'async_reply_reason' FSM method for the until
+   (with no arg) command.  */
+
+static enum async_reply_reason
+until_next_fsm_async_reply_reason (struct thread_fsm *self)
+{
+  return EXEC_ASYNC_END_STEPPING_RANGE;
 }
 
 /* Proceed until we reach a different source line with pc greater than
@@ -1421,6 +1480,7 @@ until_next_command (int from_tty)
   struct thread_info *tp = inferior_thread ();
   int thread = tp->num;
   struct cleanup *old_chain;
+  struct until_next_fsm *sm;
 
   clear_proceed_status (0);
   set_step_frame ();
@@ -1460,20 +1520,12 @@ until_next_command (int from_tty)
   set_longjmp_breakpoint (tp, get_frame_id (frame));
   old_chain = make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
 
-  proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
-
-  if (is_running (inferior_ptid))
-    {
-      struct until_next_continuation_args *cont_args;
+  sm = new_until_next_fsm (tp->num);
+  tp->thread_fsm = &sm->thread_fsm;
+  discard_cleanups (old_chain);
 
-      discard_cleanups (old_chain);
-      cont_args = XNEW (struct until_next_continuation_args);
-      cont_args->thread = inferior_thread ()->num;
+  proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
 
-      add_continuation (tp, until_next_continuation, cont_args, xfree);
-    }
-  else
-    do_cleanups (old_chain);
 }
 
 static void