[Python-checkins] cpython: Better behavior when stepping over yield[from]. Fixes issue 16596. By Xavier de
guido.van.rossum
python-checkins at python.org
Thu Nov 21 20:30:43 CET 2013
http://hg.python.org/cpython/rev/95eea8624d05
changeset: 87318:95eea8624d05
user: Guido van Rossum <guido at dropbox.com>
date: Thu Nov 21 11:30:06 2013 -0800
summary:
Better behavior when stepping over yield[from]. Fixes issue 16596. By Xavier de Gaye.
files:
Lib/bdb.py | 36 +++-
Lib/pdb.py | 12 +-
Lib/test/test_pdb.py | 305 +++++++++++++++++++++++++++++++
Python/ceval.c | 5 +
4 files changed, 351 insertions(+), 7 deletions(-)
diff --git a/Lib/bdb.py b/Lib/bdb.py
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@@ -3,6 +3,7 @@
import fnmatch
import sys
import os
+from inspect import CO_GENERATOR
__all__ = ["BdbQuit", "Bdb", "Breakpoint"]
@@ -75,24 +76,48 @@
if not (self.stop_here(frame) or self.break_anywhere(frame)):
# 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:
+ return self.trace_dispatch
self.user_call(frame, arg)
if self.quitting: raise BdbQuit
return self.trace_dispatch
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:
+ return self.trace_dispatch
try:
self.frame_returning = frame
self.user_return(frame, arg)
finally:
self.frame_returning = None
if self.quitting: raise BdbQuit
+ # The user issued a 'next' or 'until' command.
+ if self.stopframe is frame and self.stoplineno != -1:
+ self._set_stopinfo(None, None)
return self.trace_dispatch
def dispatch_exception(self, frame, arg):
if self.stop_here(frame):
+ # 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
+ and arg[0] is StopIteration and arg[2] is None):
+ self.user_exception(frame, arg)
+ if self.quitting: raise BdbQuit
+ # Stop at the StopIteration or GeneratorExit exception when the user
+ # has set stopframe in a generator by issuing a return command, or a
+ # 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 arg[0] in (StopIteration, GeneratorExit)):
self.user_exception(frame, arg)
if self.quitting: raise BdbQuit
+
return self.trace_dispatch
# Normally derived classes don't override the following
@@ -115,10 +140,8 @@
if self.stoplineno == -1:
return False
return frame.f_lineno >= self.stoplineno
- while frame is not None and frame is not self.stopframe:
- if frame is self.botframe:
- return True
- frame = frame.f_back
+ if not self.stopframe:
+ return True
return False
def break_here(self, frame):
@@ -207,7 +230,10 @@
def set_return(self, frame):
"""Stop when returning from the given frame."""
- self._set_stopinfo(frame.f_back, frame)
+ if frame.f_code.co_flags & CO_GENERATOR:
+ self._set_stopinfo(frame, None, -1)
+ else:
+ self._set_stopinfo(frame.f_back, frame)
def set_trace(self, frame=None):
"""Start debugging from `frame`.
diff --git a/Lib/pdb.py b/Lib/pdb.py
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -297,8 +297,16 @@
return
exc_type, exc_value, exc_traceback = exc_info
frame.f_locals['__exception__'] = exc_type, exc_value
- self.message(traceback.format_exception_only(exc_type,
- exc_value)[-1].strip())
+
+ # An 'Internal StopIteration' exception is an exception debug event
+ # issued by the interpreter when handling a subgenerator run with
+ # 'yield from' or a generator controled by a for loop. No exception has
+ # actually occured in this case. The debugger uses this debug event to
+ # stop when the debuggee is returning from such generators.
+ prefix = 'Internal ' if (not exc_traceback
+ and exc_type is StopIteration) else ''
+ self.message('%s%s' % (prefix,
+ traceback.format_exception_only(exc_type, exc_value)[-1].strip()))
self.interaction(frame, exc_traceback)
# General interaction function
diff --git a/Lib/test/test_pdb.py b/Lib/test/test_pdb.py
--- a/Lib/test/test_pdb.py
+++ b/Lib/test/test_pdb.py
@@ -600,6 +600,311 @@
(Pdb) continue
"""
+def test_next_until_return_at_return_event():
+ """Test that pdb stops after a next/until/return issued at a return debug event.
+
+ >>> def test_function_2():
+ ... x = 1
+ ... x = 2
+
+ >>> def test_function():
+ ... import pdb; pdb.Pdb(nosigint=True).set_trace()
+ ... test_function_2()
+ ... test_function_2()
+ ... test_function_2()
+ ... end = 1
+
+ >>> with PdbTestInput(['break test_function_2',
+ ... 'continue',
+ ... 'return',
+ ... 'next',
+ ... 'continue',
+ ... 'return',
+ ... 'until',
+ ... 'continue',
+ ... 'return',
+ ... 'return',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[1]>(3)test_function()
+ -> test_function_2()
+ (Pdb) break test_function_2
+ Breakpoint 1 at <doctest test.test_pdb.test_next_until_return_at_return_event[0]>:1
+ (Pdb) continue
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[0]>(2)test_function_2()
+ -> x = 1
+ (Pdb) return
+ --Return--
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[0]>(3)test_function_2()->None
+ -> x = 2
+ (Pdb) next
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[1]>(4)test_function()
+ -> test_function_2()
+ (Pdb) continue
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[0]>(2)test_function_2()
+ -> x = 1
+ (Pdb) return
+ --Return--
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[0]>(3)test_function_2()->None
+ -> x = 2
+ (Pdb) until
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[1]>(5)test_function()
+ -> test_function_2()
+ (Pdb) continue
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[0]>(2)test_function_2()
+ -> x = 1
+ (Pdb) return
+ --Return--
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[0]>(3)test_function_2()->None
+ -> x = 2
+ (Pdb) return
+ > <doctest test.test_pdb.test_next_until_return_at_return_event[1]>(6)test_function()
+ -> end = 1
+ (Pdb) continue
+ """
+
+def test_pdb_next_command_for_generator():
+ """Testing skip unwindng stack on yield for generators for "next" command
+
+ >>> def test_gen():
+ ... yield 0
+ ... return 1
+ ... yield 2
+
+ >>> def test_function():
+ ... import pdb; pdb.Pdb(nosigint=True).set_trace()
+ ... it = test_gen()
+ ... try:
+ ... assert next(it) == 0
+ ... next(it)
+ ... except StopIteration as ex:
+ ... assert ex.value == 1
+ ... print("finished")
+
+ >>> with PdbTestInput(['step',
+ ... 'step',
+ ... 'step',
+ ... 'next',
+ ... 'next',
+ ... 'step',
+ ... 'step',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[1]>(3)test_function()
+ -> it = test_gen()
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[1]>(4)test_function()
+ -> try:
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[1]>(5)test_function()
+ -> assert next(it) == 0
+ (Pdb) step
+ --Call--
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[0]>(1)test_gen()
+ -> def test_gen():
+ (Pdb) next
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[0]>(2)test_gen()
+ -> yield 0
+ (Pdb) next
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[0]>(3)test_gen()
+ -> return 1
+ (Pdb) step
+ --Return--
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[0]>(3)test_gen()->1
+ -> return 1
+ (Pdb) step
+ StopIteration: 1
+ > <doctest test.test_pdb.test_pdb_next_command_for_generator[1]>(6)test_function()
+ -> next(it)
+ (Pdb) continue
+ finished
+ """
+
+def test_pdb_return_command_for_generator():
+ """Testing no unwindng stack on yield for generators
+ for "return" command
+
+ >>> def test_gen():
+ ... yield 0
+ ... return 1
+ ... yield 2
+
+ >>> def test_function():
+ ... import pdb; pdb.Pdb(nosigint=True).set_trace()
+ ... it = test_gen()
+ ... try:
+ ... assert next(it) == 0
+ ... next(it)
+ ... except StopIteration as ex:
+ ... assert ex.value == 1
+ ... print("finished")
+
+ >>> with PdbTestInput(['step',
+ ... 'step',
+ ... 'step',
+ ... 'return',
+ ... 'step',
+ ... 'step',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[1]>(3)test_function()
+ -> it = test_gen()
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[1]>(4)test_function()
+ -> try:
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[1]>(5)test_function()
+ -> assert next(it) == 0
+ (Pdb) step
+ --Call--
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[0]>(1)test_gen()
+ -> def test_gen():
+ (Pdb) return
+ StopIteration: 1
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[1]>(6)test_function()
+ -> next(it)
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[1]>(7)test_function()
+ -> except StopIteration as ex:
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_return_command_for_generator[1]>(8)test_function()
+ -> assert ex.value == 1
+ (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
+
+ >>> def test_gen():
+ ... yield 0
+ ... yield 1
+ ... yield 2
+
+ >>> def test_function():
+ ... import pdb; pdb.Pdb(nosigint=True).set_trace()
+ ... for i in test_gen():
+ ... print(i)
+ ... print("finished")
+
+ >>> with PdbTestInput(['step',
+ ... 'until 4',
+ ... 'step',
+ ... 'step',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_pdb_until_command_for_generator[1]>(3)test_function()
+ -> for i in test_gen():
+ (Pdb) step
+ --Call--
+ > <doctest test.test_pdb.test_pdb_until_command_for_generator[0]>(1)test_gen()
+ -> def test_gen():
+ (Pdb) until 4
+ 0
+ 1
+ > <doctest test.test_pdb.test_pdb_until_command_for_generator[0]>(4)test_gen()
+ -> yield 2
+ (Pdb) step
+ --Return--
+ > <doctest test.test_pdb.test_pdb_until_command_for_generator[0]>(4)test_gen()->2
+ -> yield 2
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_until_command_for_generator[1]>(4)test_function()
+ -> print(i)
+ (Pdb) continue
+ 2
+ finished
+ """
+
+def test_pdb_next_command_in_generator_for_loop():
+ """The next command on returning from a generator controled by a for loop.
+
+ >>> def test_gen():
+ ... yield 0
+ ... return 1
+
+ >>> def test_function():
+ ... import pdb; pdb.Pdb(nosigint=True).set_trace()
+ ... for i in test_gen():
+ ... print('value', i)
+ ... x = 123
+
+ >>> with PdbTestInput(['break test_gen',
+ ... 'continue',
+ ... 'next',
+ ... 'next',
+ ... 'next',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_pdb_next_command_in_generator_for_loop[1]>(3)test_function()
+ -> for i in test_gen():
+ (Pdb) break test_gen
+ Breakpoint 6 at <doctest test.test_pdb.test_pdb_next_command_in_generator_for_loop[0]>:1
+ (Pdb) continue
+ > <doctest test.test_pdb.test_pdb_next_command_in_generator_for_loop[0]>(2)test_gen()
+ -> yield 0
+ (Pdb) next
+ value 0
+ > <doctest test.test_pdb.test_pdb_next_command_in_generator_for_loop[0]>(3)test_gen()
+ -> return 1
+ (Pdb) next
+ Internal StopIteration: 1
+ > <doctest test.test_pdb.test_pdb_next_command_in_generator_for_loop[1]>(3)test_function()
+ -> for i in test_gen():
+ (Pdb) next
+ > <doctest test.test_pdb.test_pdb_next_command_in_generator_for_loop[1]>(5)test_function()
+ -> x = 123
+ (Pdb) continue
+ """
+
+def test_pdb_next_command_subiterator():
+ """The next command in a generator with a subiterator.
+
+ >>> def test_subgenerator():
+ ... yield 0
+ ... return 1
+
+ >>> def test_gen():
+ ... x = yield from test_subgenerator()
+ ... return x
+
+ >>> def test_function():
+ ... import pdb; pdb.Pdb(nosigint=True).set_trace()
+ ... for i in test_gen():
+ ... print('value', i)
+ ... x = 123
+
+ >>> with PdbTestInput(['step',
+ ... 'step',
+ ... 'next',
+ ... 'next',
+ ... 'next',
+ ... 'continue']):
+ ... test_function()
+ > <doctest test.test_pdb.test_pdb_next_command_subiterator[2]>(3)test_function()
+ -> for i in test_gen():
+ (Pdb) step
+ --Call--
+ > <doctest test.test_pdb.test_pdb_next_command_subiterator[1]>(1)test_gen()
+ -> def test_gen():
+ (Pdb) step
+ > <doctest test.test_pdb.test_pdb_next_command_subiterator[1]>(2)test_gen()
+ -> x = yield from test_subgenerator()
+ (Pdb) next
+ value 0
+ > <doctest test.test_pdb.test_pdb_next_command_subiterator[1]>(3)test_gen()
+ -> return x
+ (Pdb) next
+ Internal StopIteration: 1
+ > <doctest test.test_pdb.test_pdb_next_command_subiterator[2]>(3)test_function()
+ -> for i in test_gen():
+ (Pdb) next
+ > <doctest test.test_pdb.test_pdb_next_command_subiterator[2]>(5)test_function()
+ -> x = 123
+ (Pdb) continue
+ """
+
class PdbTestCase(unittest.TestCase):
diff --git a/Python/ceval.c b/Python/ceval.c
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1904,6 +1904,9 @@
Py_DECREF(v);
if (retval == NULL) {
PyObject *val;
+ if (tstate->c_tracefunc != NULL
+ && PyErr_ExceptionMatches(PyExc_StopIteration))
+ call_exc_trace(tstate->c_tracefunc, tstate->c_traceobj, f);
err = _PyGen_FetchStopIterationValue(&val);
if (err < 0)
goto error;
@@ -2654,6 +2657,8 @@
if (PyErr_Occurred()) {
if (!PyErr_ExceptionMatches(PyExc_StopIteration))
goto error;
+ else if (tstate->c_tracefunc != NULL)
+ call_exc_trace(tstate->c_tracefunc, tstate->c_traceobj, f);
PyErr_Clear();
}
/* iterator ended normally */
--
Repository URL: http://hg.python.org/cpython
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