[3.6] bpo-32650 Add support for async generators and more test for coroutines in pdb (GH-5403). (#5411)

(cherry picked from commit c7ab581)

Author: asvetlov

Lib/bdb.py

@@ -3,10 +3,13 @@
 import fnmatch
 import sys
 import os
-from inspect import CO_GENERATOR, CO_COROUTINE
+from inspect import CO_GENERATOR, CO_COROUTINE, CO_ASYNC_GENERATOR
 
 __all__ = ["BdbQuit", "Bdb", "Breakpoint"]
 
+GENERATOR_AND_COROUTINE_FLAGS = CO_GENERATOR | CO_COROUTINE | CO_ASYNC_GENERATOR
+
+
 class BdbQuit(Exception):
     """Exception to give up completely."""
 
@@ -77,7 +80,7 @@ def dispatch_call(self, frame, arg):
             # No need to trace this function
             return # None
         # Ignore call events in generator except when stepping.
-        if self.stopframe and frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE):
+        if self.stopframe and frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS:
             return self.trace_dispatch
         self.user_call(frame, arg)
         if self.quitting: raise BdbQuit
@@ -86,7 +89,7 @@ def dispatch_call(self, frame, arg):
     def dispatch_return(self, frame, arg):
         if self.stop_here(frame) or frame == self.returnframe:
             # Ignore return events in generator except when stepping.
-            if self.stopframe and frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE):
+            if self.stopframe and frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS:
                 return self.trace_dispatch
             try:
                 self.frame_returning = frame
@@ -104,7 +107,7 @@ def dispatch_exception(self, frame, arg):
             # When stepping with next/until/return in a generator frame, skip
             # the internal StopIteration exception (with no traceback)
             # triggered by a subiterator run with the 'yield from' statement.
-            if not (frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE)
+            if not (frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS
                     and arg[0] is StopIteration and arg[2] is None):
                 self.user_exception(frame, arg)
                 if self.quitting: raise BdbQuit
@@ -113,7 +116,7 @@ def dispatch_exception(self, frame, arg):
         # next/until command at the last statement in the generator before the
         # exception.
         elif (self.stopframe and frame is not self.stopframe
-                and self.stopframe.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE)
+                and self.stopframe.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS
                 and arg[0] in (StopIteration, GeneratorExit)):
             self.user_exception(frame, arg)
             if self.quitting: raise BdbQuit
@@ -230,7 +233,7 @@ def set_next(self, frame):
 
     def set_return(self, frame):
         """Stop when returning from the given frame."""
-        if frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE):
+        if frame.f_code.co_flags & GENERATOR_AND_COROUTINE_FLAGS:
             self._set_stopinfo(frame, None, -1)
         else:
             self._set_stopinfo(frame.f_back, frame)

Lib/test/test_pdb.py

@@ -739,7 +739,7 @@ def test_pdb_next_command_for_coroutine():
     ...     await test_coro()
 
     >>> def test_function():
-    ...     loop = asyncio.get_event_loop()
+    ...     loop = asyncio.new_event_loop()
     ...     loop.run_until_complete(test_main())
     ...     loop.close()
     ...     print("finished")
@@ -834,6 +834,47 @@ def test_pdb_return_command_for_generator():
     finished
     """
 
+def test_pdb_return_command_for_coroutine():
+    """Testing no unwindng stack on yield for coroutines for "return" command
+
+    >>> import asyncio
+
+    >>> async def test_coro():
+    ...     await asyncio.sleep(0)
+    ...     await asyncio.sleep(0)
+    ...     await asyncio.sleep(0)
+
+    >>> async def test_main():
+    ...     import pdb; pdb.Pdb(nosigint=True, readrc=False).set_trace()
+    ...     await test_coro()
+
+    >>> def test_function():
+    ...     loop = asyncio.new_event_loop()
+    ...     loop.run_until_complete(test_main())
+    ...     loop.close()
+    ...     print("finished")
+
+    >>> with PdbTestInput(['step',
+    ...                    'step',
+    ...                    'next',
+    ...                    'continue']):
+    ...     test_function()
+    > <doctest test.test_pdb.test_pdb_return_command_for_coroutine[2]>(3)test_main()
+    -> await test_coro()
+    (Pdb) step
+    --Call--
+    > <doctest test.test_pdb.test_pdb_return_command_for_coroutine[1]>(1)test_coro()
+    -> async def test_coro():
+    (Pdb) step
+    > <doctest test.test_pdb.test_pdb_return_command_for_coroutine[1]>(2)test_coro()
+    -> await asyncio.sleep(0)
+    (Pdb) next
+    > <doctest test.test_pdb.test_pdb_return_command_for_coroutine[1]>(3)test_coro()
+    -> await asyncio.sleep(0)
+    (Pdb) continue
+    finished
+    """
+
 def test_pdb_until_command_for_generator():
     """Testing no unwindng stack on yield for generators
        for "until" command if target breakpoing is not reached