[PATCH 3/5] Add require_valid to Python breakpoint and breakpoint location

[Tom Tromey <tom@tromey.com>]

This adds a require_valid method to the Python breakpoint and
breakpoint location objects.  These will be used in subsequent
patches.

Note that the breakpoint location implementation checks that the
breakpoint is valid.  This was done by all users of the macro, so it
seemed more convenient to do this here.
---
 gdb/python/py-breakpoint.c   | 17 +++++++++++++++++
 gdb/python/python-internal.h |  3 +++
 2 files changed, 20 insertions(+)

diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 8781c17838b..40d1244abcf 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -69,6 +69,15 @@ struct gdbpy_breakpoint_location_object : public PyObject
 
   /* Implementation of 'repr'.  */
   gdbpy_ref<> repr ();
+
+  /* If this breakpoint location is not valid, throw an exception.  */
+  void require_valid () const
+  {
+    owner->require_valid ();
+    if (owner->bp != bp_loc->owner)
+      return gdbpy_err_format (PyExc_RuntimeError,
+			       _("Breakpoint location is invalid."));
+  }
 };
 
 static_assert (gdb::is_python_allocatable_v<gdbpy_breakpoint_location_object>);
@@ -159,6 +168,14 @@ static struct pybp_code pybp_watch_types[] =
   {NULL} /* Sentinel.  */
 };
 
+void
+gdbpy_breakpoint_object::require_valid () const
+{
+  if (bp == nullptr)
+    gdbpy_err_format (PyExc_RuntimeError, _("Breakpoint %d is invalid."),
+		      number);
+}
+
 /* Python function which checks the validity of a breakpoint object.  */
 static PyObject *
 bppy_is_valid (PyObject *self, PyObject *args)
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 55e5e8eaabe..2d990ee6ac1 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -427,6 +427,9 @@ struct gdbpy_breakpoint_object : public PyObject
 
   /* 1 is this is a FinishBreakpoint object, 0 otherwise.  */
   int is_finish_bp;
+
+  /* If this breakpoint is not valid, throw an exception.  */
+  void require_valid () const;
 };
 
 static_assert (gdb::is_python_allocatable_v<gdbpy_breakpoint_object>);

-- 
2.49.0