bpo-32650: Add native coroutine support to bdb when stepping over line (GH-5400) (#5402)

(cherry picked from commit 4687702)

Author: miss-islington

Lib/bdb.py

@@ -3,7 +3,7 @@
 import fnmatch
 import sys
 import os
-from inspect import CO_GENERATOR
+from inspect import CO_GENERATOR, CO_COROUTINE
 
 __all__ = ["BdbQuit", "Bdb", "Breakpoint"]
 
@@ -77,7 +77,7 @@ 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:
+ if self.stopframe and frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE):
  return self.trace_dispatch
  self.user_call(frame, arg)
  if self.quitting: raise BdbQuit
@@ -86,7 +86,7 @@ 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:
+ if self.stopframe and frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE):
  return self.trace_dispatch
  try:
  self.frame_returning = frame
@@ -104,7 +104,7 @@ 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
+ if not (frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE)
  and arg[0] is StopIteration and arg[2] is None):
  self.user_exception(frame, arg)
  if self.quitting: raise BdbQuit
@@ -113,7 +113,7 @@ 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
+ and self.stopframe.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE)
  and arg[0] in (StopIteration, GeneratorExit)):
  self.user_exception(frame, arg)
  if self.quitting: raise BdbQuit
@@ -230,7 +230,7 @@ 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:
+ if frame.f_code.co_flags & (CO_GENERATOR | CO_COROUTINE):
  self._set_stopinfo(frame, None, -1)
  else:
  self._set_stopinfo(frame.f_back, frame)

Lib/test/test_pdb.py

@@ -724,6 +724,61 @@ def test_pdb_next_command_for_generator():
  finished
  """
 
+def test_pdb_next_command_for_coroutine():
+ """Testing skip unwindng stack on yield for coroutines for "next" 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.get_event_loop()
+ ... loop.run_until_complete(test_main())
+ ... loop.close()
+ ... print("finished")
+
+ >>> with PdbTestInput(['step',
+ ... 'step',
+ ... 'next',
+ ... 'next',
+ ... 'next',
+ ... 'step',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[2]>(3)test_main()
+ -> await test_coro()
+ (Pdb) step
+ --Call--
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[1]>(1)test_coro()
+ -> async def test_coro():
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[1]>(2)test_coro()
+ -> await asyncio.sleep(0)
+ (Pdb) next
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[1]>(3)test_coro()
+ -> await asyncio.sleep(0)
+ (Pdb) next
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[1]>(4)test_coro()
+ -> await asyncio.sleep(0)
+ (Pdb) next
+ Internal StopIteration
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[2]>(3)test_main()
+ -> await test_coro()
+ (Pdb) step
+ --Return--
+ > <doctest test.test_pdb.test_pdb_next_command_for_coroutine[2]>(3)test_main()->None
+ -> await test_coro()
+ (Pdb) continue
+ finished
+ """
+
 def test_pdb_return_command_for_generator():
  """Testing no unwindng stack on yield for generators
  for "return" command

Misc/NEWS.d/next/Core and Builtins/2018-01-28-23-01-39.bpo-32650.Bbi7ek.rst

@@ -0,0 +1,2 @@
+Pdb and other debuggers dependent on bdb.py will correctly step over (next
+command) native coroutines. Patch by Pablo Galindo.