Consolidate some Python exception-printing functions

A few places in the Python code would either call gdbpy_print_stack,
or throw a gdb "quit", depending on the pending exception.  This patch
consolidates these into a helper function.

gdb/ChangeLog
2018-12-27  Tom Tromey  <tom@tromey.com>

	* python/python-internal.h (gdbpy_print_stack_or_quit): Declare.
	* python/py-unwind.c (pyuw_sniffer): Use
	gdbpy_print_stack_or_quit.
	* python/py-framefilter.c (throw_quit_or_print_exception):
	Remove.
	(gdbpy_apply_frame_filter): Use gdbpy_print_stack_or_quit.
	* python/python.c (gdbpy_print_stack_or_quit): New function.

gdb/python/py-framefilter.c

@@ -1054,21 +1054,6 @@ bootstrap_python_frame_filters (struct frame_info *frame,
     return iterable.release ();
 }
 
-/* A helper function that will either print an exception or, if it is
-   a KeyboardException, throw a quit.  This can only be called when
-   the Python exception is set.  */
-
-static void
-throw_quit_or_print_exception ()
-{
-  if (PyErr_ExceptionMatches (PyExc_KeyboardInterrupt))
-    {
-      PyErr_Clear ();
-      throw_quit ("Quit");
-    }
-  gdbpy_print_stack ();
-}
-
 /*  This is the only publicly exported function in this file.  FRAME
     is the source frame to start frame-filter invocation.  FLAGS is an
     integer holding the flags for printing.  The following elements of
@@ -1139,7 +1124,7 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang,
 	 initialization error.  This return code will trigger a
 	 default backtrace.  */
 
-      throw_quit_or_print_exception ();
+      gdbpy_print_stack_or_quit ();
       return EXT_LANG_BT_NO_FILTERS;
     }
 
@@ -1162,7 +1147,7 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang,
 	{
 	  if (PyErr_Occurred ())
 	    {
-	      throw_quit_or_print_exception ();
+	      gdbpy_print_stack_or_quit ();
 	      return EXT_LANG_BT_ERROR;
 	    }
 	  break;
@@ -1196,7 +1181,7 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang,
       /* Do not exit on error printing a single frame.  Print the
 	 error and continue with other frames.  */
       if (success == EXT_LANG_BT_ERROR)
-	throw_quit_or_print_exception ();
+	gdbpy_print_stack_or_quit ();
     }
 
   return success;

gdb/python/py-unwind.c

@@ -535,12 +535,7 @@ pyuw_sniffer (const struct frame_unwind *self, struct frame_info *this_frame,
     {
       /* If the unwinder is cancelled due to a Ctrl-C, then propagate
 	 the Ctrl-C as a GDB exception instead of swallowing it.  */
-      if (PyErr_ExceptionMatches (PyExc_KeyboardInterrupt))
-	{
-	  PyErr_Clear ();
-	  quit ();
-	}
-      gdbpy_print_stack ();
+      gdbpy_print_stack_or_quit ();
       return 0;
     }
   if (pyo_unwind_info == Py_None)

gdb/python/python-internal.h

@@ -654,6 +654,7 @@ extern const struct language_defn *python_language;
 
 int gdbpy_print_python_errors_p (void);
 void gdbpy_print_stack (void);
+void gdbpy_print_stack_or_quit ();
 void gdbpy_handle_exception () ATTRIBUTE_NORETURN;
 
 gdbpy_ref<> python_string_to_unicode (PyObject *obj);

gdb/python/python.c

@@ -1268,6 +1268,20 @@ gdbpy_print_stack (void)
     }
 }
 
+/* Like gdbpy_print_stack, but if the exception is a
+   KeyboardException, throw a gdb "quit" instead.  */
+
+void
+gdbpy_print_stack_or_quit ()
+{
+  if (PyErr_ExceptionMatches (PyExc_KeyboardInterrupt))
+    {
+      PyErr_Clear ();
+      throw_quit ("Quit");
+    }
+  gdbpy_print_stack ();
+}
+
 
 
 /* Return a sequence holding all the Progspaces.  */