Issue 21217: inspect.getsourcelines finds wrong lines when lambda used argument to decorator (original) (raw)

Created on 2014-04-14 17:31 by ballingt, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Files
File name Uploaded Description Edit
issue21217.patch akaptur,2014-04-14 22:49 review
issue21217-v2.patch akaptur,2014-04-15 17:40 review
issue21217-v3.patch akaptur,2014-04-15 18:18 review
issue21217-v4.patch ballingt,2015-04-13 20:31
issue21217-v5.patch ballingt,2015-04-13 21:00 review
issue21217-v6.patch ballingt,2015-04-13 22:25 review
Messages (22)
msg216127 - (view) Author: Thomas Ballinger (ballingt) * Date: 2014-04-14 17:31
https://gist.github.com/thomasballinger/10666031 """ inspect.getsourcelines incorrectly guesses what lines correspond to the function foo see getblock in inspect.py once it finds a lambda, def or class it finishes it then stops so get getsourcelines returns only the first two noop decorator lines of bar, while normal behavior is to return all decorators as it does for foo """ import inspect from pprint import pprint def noop(arg): def inner(func): return func return inner @noop(1) @noop(2) def foo(): return 1 @noop(1) @noop(lambda: None) @noop(1) def bar(): return 1 pprint(inspect.getsourcelines(foo)) pprint(inspect.getsourcelines(bar))
msg216128 - (view) Author: Thomas Ballinger (ballingt) * Date: 2014-04-14 17:36
"The code object's co_lnotab is how inspect should be getting the sourcelines of the code, instead of looking for the first codeblock." I'm looking at this now, thanks to Yhg1s for the above.
msg216245 - (view) Author: A Kaptur (akaptur) * (Python triager) Date: 2014-04-14 22:49
This patch adds tests demonstrating broken behavior inspect.getsource and inspect.getsourcelines of decorators containing lambda functions, and modifies inspect.getsourcelines to behave correctly. We use co_lnotab to extract line numbers on all objects with a code object. inspect.getsourcelines can also take a class, which cannot use co_lnotab as there is no associated code object. @ballingt and I paired on this patch. Some open questions about inspect.getsource not created or addressed by this patch: - Is this a bug that should be patched in previous versions as well? - the docs for say it can take a traceback. What is the correct behavior here? There aren't any tests at the moment. We suggest the line of code that caused the traceback, i.e. the line at tb.tb_lineno - We added tests of decorated classes. The source of decorated classes does not include the decorators, which is different than the usual behavior of decorated functions. What is the correct behavior here? - inspect.getblock and inspect.BlockFinder use the term "block" in a way that is inconsistent with its typical use in the interpreter (that is, in ceval.c). Should this be renamed? If so, to what? ("chunk"?)
msg216344 - (view) Author: A Kaptur (akaptur) * (Python triager) Date: 2014-04-15 17:40
v2 of the patch incorporating the comments at http://bugs.python.org/review/21217/
msg216345 - (view) Author: Yury Selivanov (yselivanov) * (Python committer) Date: 2014-04-15 17:45
Apart from one nit, the patch is looking good. Also, could you please sign the contributor agreement, as described here: https://docs.python.org/devguide/coredev.html#sign-a-contributor-agreement
msg216351 - (view) Author: PCManticore (Claudiu.Popa) * (Python triager) Date: 2014-04-15 18:01
"- We added tests of decorated classes. The source of decorated classes does not include the decorators, which is different than the usual behavior of decorated functions. What is the correct behavior here?" There is an open issue for this, http://bugs.python.org/issue1764286. It has a patch which uses inspect.unwrap in order to unwrap the decorated functions.
msg216352 - (view) Author: Yury Selivanov (yselivanov) * (Python committer) Date: 2014-04-15 18:02
Claudiu: I'll take a look at your patch, thanks!
msg216357 - (view) Author: A Kaptur (akaptur) * (Python triager) Date: 2014-04-15 18:18
v3 of patch, including misc/news update, docstring for function, and removing class decorator tests, since it sounds like those are better handled in http://bugs.python.org/issue1764286.
msg240738 - (view) Author: Thomas Ballinger (ballingt) * Date: 2015-04-13 20:31
v4 of patch, with tests updated for changed lines in inspect fodder file
msg240749 - (view) Author: Thomas Ballinger (ballingt) * Date: 2015-04-13 21:00
Patch reformatted to be non-git style, NEWS item removed
msg240787 - (view) Author: Thomas Ballinger (ballingt) * Date: 2015-04-13 22:25
Use dis.findlinestarts() to find lines of function instead of grubbing with co_lnotab manually, making dis module dependency non-optional.
msg240791 - (view) Author: Alyssa Coghlan (ncoghlan) * (Python committer) Date: 2015-04-13 22:35
It sounds like at least a somewhat functional dis module is a pragmatic requirement for a Python implementation to support introspection, so +1 for reverting to the mandatory dependency on dis rather than duplicating its logic.
msg241050 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-04-14 22:42
New changeset ac86e5b2d45b by Antoine Pitrou in branch 'default': Issue #21217: inspect.getsourcelines() now tries to compute the start and https://hg.python.org/cpython/rev/ac86e5b2d45b
msg241051 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2015-04-14 22:42
I've committed the latest patch. Thank you, Thomas!
msg241077 - (view) Author: Thomas Ballinger (ballingt) * Date: 2015-04-15 03:48
Thanks Antoine! Could you add Allison Kaptur to NEWS and ACKS? This was an update to her original patch, and we paired on the whole thing.
msg241079 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-04-15 04:00
New changeset 582e8e71f635 by Benjamin Peterson in branch 'default': add Allison Kaptur (#21217) https://hg.python.org/cpython/rev/582e8e71f635
msg245868 - (view) Author: Terry J. Reedy (terry.reedy) * (Python committer) Date: 2015-06-26 20:46
I strongly suspect that ac86e5b2d45b is the cause of the regression reported in #24485. def outer(): def inner(): inner1 from inspect import getsource print(getsource(outer)) omits the body of inner. Ditto if outer is a method. All is okay if outer is a method and the source of the class is requested. Could the authors, Allison and Thomas, take a look and try to fix _line_number_helper to pass the added test (and possibly incorporate it into findsource)? Since there is a new issue already, this one can be left closed and further work posted to #24485.
msg245872 - (view) Author: Yury Selivanov (yselivanov) * (Python committer) Date: 2015-06-26 22:22
Here's an update on #24485 regression. Looks like getsource() is now using code objects instead of tokenizer to determine blocks first/last lines. The problem with this particular case is that "inner" function's code object is completely independent from "outer"'s. So, for an outer() function below: def outer(): def inner(): never_reached1 never_reached2 the code object contains the following opcodes: 71 0 LOAD_CONST 1 (<code object inner ...>) 3 LOAD_CONST 2 ('outer1..inner') 6 MAKE_FUNCTION 0 9 STORE_FAST 0 (inner) 12 LOAD_CONST 0 (None) 15 RETURN_VALUE The correct solution is to use co_lnotab along with co_firstlineno to iterate through opcodes recursively accounting for MAKE_FUNCTION's code objects. *However*, I don't think we can solve this for classes, i.e. def outer_with_class(): class Foo: b = 1 a = 2 there is no way (as far as I know) to get information about the Foo class start/end lineno. I think that the only way we can solve this is to revert the patch for this issue.
msg245876 - (view) Author: Meador Inge (meador.inge) * (Python committer) Date: 2015-06-27 02:17
> I think that the only way we can solve this is to revert the patch for this issue. I agree with this. It seems like doing this analysis at the bytecode level is the wrong approach. Perhaps the syntactical analysis being used before should be beefed up to handle things like the lambda case.
msg245915 - (view) Author: Meador Inge (meador.inge) * (Python committer) Date: 2015-06-28 19:17
FYI, I posted a patch to handle this case and the regression noted in on .
msg247202 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-07-23 14:10
New changeset 4e42a62d5648 by Yury Selivanov in branch '3.5': Issue #24485: Revert backwards compatibility breaking changes of #21217. https://hg.python.org/cpython/rev/4e42a62d5648 New changeset 98a2bbf2cce2 by Yury Selivanov in branch 'default': Merge 3.5 (issues #21217, #24485). https://hg.python.org/cpython/rev/98a2bbf2cce2
msg247245 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-07-24 04:00
New changeset 5400e21e92a7 by Meador Inge in branch '3.5': Issue #24485: Function source inspection fails on closures. https://hg.python.org/cpython/rev/5400e21e92a7 New changeset 0e7d64595223 by Meador Inge in branch 'default': Issue #24485: Function source inspection fails on closures. https://hg.python.org/cpython/rev/0e7d64595223
History
Date User Action Args
2022-04-11 14:58:01 admin set github: 65416
2015-07-24 04:00:15 python-dev set messages: +
2015-07-23 14:10:52 python-dev set messages: +
2015-06-28 19:17:56 meador.inge set messages: +
2015-06-27 02:17:30 meador.inge set nosy: + meador.ingemessages: +
2015-06-26 22:22:48 yselivanov set messages: +
2015-06-26 20:46:46 terry.reedy set nosy: + terry.reedymessages: +
2015-04-15 04:00:51 python-dev set messages: +
2015-04-15 03:48:03 ballingt set messages: +
2015-04-14 22:42:37 pitrou set status: open -> closedresolution: fixedmessages: + stage: patch review -> resolved
2015-04-14 22:42:10 python-dev set nosy: + python-devmessages: +
2015-04-13 22:35:08 ncoghlan set nosy: + ncoghlanmessages: +
2015-04-13 22:25:21 ballingt set files: + issue21217-v6.patchmessages: +
2015-04-13 21:11:47 pitrou set nosy: + pitrou
2015-04-13 21:00:44 ballingt set files: + issue21217-v5.patchmessages: +
2015-04-13 20:31:14 ballingt set files: + issue21217-v4.patchmessages: +
2014-04-15 18🔞05 akaptur set files: + issue21217-v3.patchmessages: +
2014-04-15 18:02:42 yselivanov set messages: +
2014-04-15 18:01:12 Claudiu.Popa set nosy: + Claudiu.Popamessages: +
2014-04-15 17:45:39 yselivanov set messages: +
2014-04-15 17:40:09 akaptur set files: + issue21217-v2.patchmessages: +
2014-04-14 22:49:51 akaptur set files: + issue21217.patchversions: - Python 3.1, Python 2.7, Python 3.2, Python 3.3, Python 3.4keywords: + patchnosy: + akapturmessages: + stage: patch review
2014-04-14 20:31:46 yselivanov set nosy: + yselivanov
2014-04-14 17:36:00 ballingt set messages: +
2014-04-14 17:31:00 ballingt create