[Bug c++/57709] -Wshadow is too strict / has false positives

["manu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57709

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |manu at gcc dot gnu.org

--- Comment #4 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #1)
> > clang does no warn on "var_and_method" as variable vs. method are safe, if one
> > tries to use them inappropriately one gets an error.
> 
> Not always.  Think of function pointers or pointer to member functions. 
> clang is not loose in my mind rather than GCC is too strict.

In GCC 4.8 I implemented:

"The option -Wshadow no longer warns if a declaration shadows a function
declaration, unless the former declares a function or pointer to function,
because this is a common and valid case in real-world code."

I think this is a useful heuristic also for member functions, no? I don't have
time to work on this at the moment, but it would be useful to know whether the
maintainers agree, so someone (Jan?) may start working on a patch.
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From: "jason at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/57709] -Wshadow is too strict / has false positives
Date: Tue, 25 Jun 2013 16:51:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57709

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Manuel López-Ibáñez from comment #4)
> "The option -Wshadow no longer warns if a declaration shadows a function
> declaration, unless the former declares a function or pointer to function,
> because this is a common and valid case in real-world code."
> 
> I think this is a useful heuristic also for member functions, no? I don't
> have time to work on this at the moment, but it would be useful to know
> whether the maintainers agree, so someone (Jan?) may start working on a
> patch.

That would be fine.  But it seems less important for member functions, since
there's much less chance of a local variable name conflicting with some random
function declared by an #include file.
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From: "burnus at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/57710] New: [OOP] _vptr not set for allocatable CLASS components
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idW710

            Bug ID: 57710
           Summary: [OOP] _vptr not set for allocatable CLASS components
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code, wrong-code
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org

The following code (minus the IF condition) shows that _vptr is not set for the
allocatable component:
        y.x._data = 0B;
there should be - but isn't - additionally: y.x._vptr = &__vtab_m_T;


Additionally, the test case as is (with IF condition), currently crashes with:

internal compiler error: in gfc_conv_component_ref, at
fortran/trans-expr.c:1654
   if (.not. same_type_as(y%x, z)) call abort ()
 ^
0x632ce2 gfc_conv_component_ref
        ../../gcc/fortran/trans-expr.c:1654
0x63fc89 gfc_conv_variable
        ../../gcc/fortran/trans-expr.c:1921


module m
  type t
  end type t
  type t2
    integer :: ii
    class(t), allocatable :: x
  end type t2
contains
  subroutine fini(x)
     type(t) :: x
  end subroutine fini
end module m

use m
block
  type(t) :: z
  type(t2) :: y
  y%ii = 123
  if (.not. same_type_as(y%x, z)) call abort ()
end block
end