Can you re-send the patch? that way patchwork can track it. On Thu, Jan 26, 2012 at 6:24 PM, Daniel Jasper <[email protected]> wrote:
> Hi, > > has anyone had a chance to look at this? > > Kind regards, > Daniel > > > On Wed, Jan 18, 2012 at 10:28 PM, Daniel Jasper <[email protected]>wrote: > >> Hi, >> >> here is a new version of the proposed change. Changes: >> >> 1) The warning is more conservative. Members of a class-type can now only >> count as unused if a trivial default constructor and a trivial destructor >> are used (as these don't have side-effects). A smarter analysis for >> side-effect-free constructors and destructors can follow. This prevents >> false positives on RAII-style classes. >> 2) The warning gives up if a class has a template friend (specializations >> of this friend could use any unused member). >> 3) Only instantiations of template classes are analyzed, not the template >> classes themselves (this was a major source of false positives). >> 4) Testcase is include in the patch this time. >> >> Please let me know, what you think! >> >> Cheers, >> Daniel >> >> >> On Thu, Jan 12, 2012 at 7:26 PM, Daniel Jasper <[email protected]>wrote: >> >>> Hi Nico, >>> >>> comments inline. >>> >>> On Wed, Jan 11, 2012 at 10:49 PM, Nico Weber <[email protected]>wrote: >>> >>>> Hi Daniel, >>>> >>>> On Wed, Jan 11, 2012 at 1:11 AM, Daniel Jasper <[email protected]> >>>> wrote: >>>> > Hi, >>>> > >>>> > the attached change is designed to detect and warn about private >>>> unused >>>> > members of C++ classes. It checks whether a class is fully defined in >>>> the >>>> > current translation unit, i.e. all methods are either defined or pure >>>> > virtual and all friends are defined. Otherwise, the private member >>>> could be >>>> > used by a function defined in another translation unit. >>>> >>>> that's a cool warning! Here are a few cases where it flags false >>>> positives (it finds tons of true positives too, but those are boring >>>> :-) ). >>>> >>>> It flags |stackArray| in ICU's cmemory.h. This is declared for storage >>>> and accessed through pointer aliasing, probably not much that can be >>>> done about this: >>>> >>>> http://codesearch.google.com/codesearch#OAMlx_jo-ck/src/third_party/icu/source/common/cmemory.h&exact_package=chromium&q=file:cmemory.h&l=285 >>> >>> >>> As you said in the other email, it is the wrong code line and I think, >>> it is correct to warn about the other |stackArray|. >>> >>> >>>> >>>> In flags StaticResource::instance_ in v8's utils.h: >>>> >>>> http://codesearch.google.com/codesearch#OAMlx_jo-ck/src/v8/src/utils.h&exact_package=chromium&q=file:v8/src/utils.h&l=300 >>>> This is supposed to be accessed through the class below, Access, which >>>> is a friend of utils.h. Do you check if any friends use private >>>> variables? >>>> >>> >>> Yes, I check friends. This is a bug, I know why it happens (it is >>> because of the dependent templates) and I will fix it. >>> >>> >>>> In chromium itself, it flags ShadowingAtExitManager member variables. >>>> This is basically a RAII class which only exists to call a protected >>>> superclass constructor, and which only exists if UNIT_TESTS is >>>> defined: >>>> http://codesearch.google.com/codesearch#OAMlx_jo-ck/src/base/at_exit.h&l=71 >>>> So maybe the "constructor without arguments" heuristic could be >>>> tweaked to exclude constructors that call superclass constructors with >>>> arguments? >>>> (Here's another RAII class whose constructor takes 0 arguments: >>>> >>>> http://codesearch.google.com/codesearch#OAMlx_jo-ck/src/base/logging_unittest.cc&exact_package=chromium&q=logstatesaver&l=26 >>>> ) >>>> >>> >>> I have changed it to be more conservative (I will send a new patch once >>> I have fixed the bug mentioned above). It now only accepts members without >>> initializer or with an argument-less initializer, if the field's type has a >>> trivial default constructor and a trivial destructor. Unfortunately, we now >>> also miss a lot of true positives, but I guess the false positives are >>> worse, especially because there is no easy way to explicitly suppress the >>> warning for these cases within the standard syntax. >>> >>> Cheers, >>> Daniel >>> >>> >>>> >>>> (This is not an exhaustive list, just the things I found after a quick >>>> look.) >>>> >>>> Nico >>>> >>> >>> >> > > _______________________________________________ > cfe-commits mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits > >
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