Re: [C++ PATCH] PR c++/90590 Suppress warning for enumeration value not handled in switch warning

[Matthew Beliveau <mbelivea at redhat dot com>]

ping

On Tue, Jul 23, 2019 at 10:27 AM Matthew Beliveau <mbelivea@redhat.com> wrote:
>
> ping
>
> On Tue, Jul 16, 2019 at 8:40 AM Marek Polacek <polacek@redhat.com> wrote:
> >
> > On Mon, Jul 15, 2019 at 09:47:26AM -0400, Matthew Beliveau wrote:
> > > Okay I kept the TYPE_MAIN_VARIANT and dropped the accidental new line!
> > > Hopefully this should be fine!
> >
> > CCing Joseph as this is c-family/ stuff.
> >
> > > Bootstrapped/regtested on x86_64-linux, ok for trunk?
> > >
> > > 2019-07-12  Matthew Beliveau  <mbelivea@redhat.com>
> > >
> > >       PR c++/90590
> > >       * c-warn.c (c_do_switch_warnings): Suppress warning for enumerators
> > >       with reserved names that are in a system header.
> > >
> > >       * c-c++-common/pr90590-1.c: New test.
> > >       * c-c++-common/pr90590-1.h: New test.
> > >       * c-c++-common/pr90590-2.c: New test.
> > >       * c-c++-common/pr90590-2.h: New test.
> > >
> > > diff --git gcc/c-family/c-warn.c gcc/c-family/c-warn.c
> > > index b5d09e761d7..51c54a283e5 100644
> > > --- gcc/c-family/c-warn.c
> > > +++ gcc/c-family/c-warn.c
> > > @@ -34,6 +34,7 @@ along with GCC; see the file COPYING3.  If not see
> > >  #include "gcc-rich-location.h"
> > >  #include "gimplify.h"
> > >  #include "c-family/c-indentation.h"
> > > +#include "c-family/c-spellcheck.h"
> > >  #include "calls.h"
> > >  #include "stor-layout.h"
> > >
> > > @@ -1628,6 +1629,15 @@ c_do_switch_warnings (splay_tree cases, location_t switch_location,
> > >        if (cond && tree_int_cst_compare (cond, value))
> > >       continue;
> > >
> > > +      /* If the enumerator is defined in a system header and uses a reserved
> > > +      name, then we continue to avoid throwing a warning.  */
> > > +      location_t loc = DECL_SOURCE_LOCATION
> > > +         (TYPE_STUB_DECL (TYPE_MAIN_VARIANT (type)));
> > > +      if (in_system_header_at (loc)
> > > +       && name_reserved_for_implementation_p
> > > +           (IDENTIFIER_POINTER (TREE_PURPOSE (chain))))
> > > +     continue;
> > > +
> > >        /* If there is a default_node, the only relevant option is
> > >        Wswitch-enum.  Otherwise, if both are enabled then we prefer
> > >        to warn using -Wswitch because -Wswitch is enabled by -Wall
> > > diff --git gcc/testsuite/c-c++-common/pr90590-1.c gcc/testsuite/c-c++-common/pr90590-1.c
> > > new file mode 100644
> > > index 00000000000..4e11debb7fa
> > > --- /dev/null
> > > +++ gcc/testsuite/c-c++-common/pr90590-1.c
> > > @@ -0,0 +1,15 @@
> > > +// PR c++/90590
> > > +// { dg-options -Wswitch }
> > > +#include "pr90590-1.h"
> > > +
> > > +void
> > > +g ()
> > > +{
> > > +  enum E e = _A;
> > > +  switch (e) // { dg-bogus "enumeration value '_C' not handled in switch" }
> > > +    {
> > > +    case _A:
> > > +    case _B:
> > > +      break;
> > > +    }
> > > +}
> > > diff --git gcc/testsuite/c-c++-common/pr90590-1.h gcc/testsuite/c-c++-common/pr90590-1.h
> > > new file mode 100644
> > > index 00000000000..22f1a7d5d52
> > > --- /dev/null
> > > +++ gcc/testsuite/c-c++-common/pr90590-1.h
> > > @@ -0,0 +1,2 @@
> > > +#pragma GCC system_header
> > > +enum E { _A, _B, _C };
> > > diff --git gcc/testsuite/c-c++-common/pr90590-2.c gcc/testsuite/c-c++-common/pr90590-2.c
> > > new file mode 100644
> > > index 00000000000..23da97f9d74
> > > --- /dev/null
> > > +++ gcc/testsuite/c-c++-common/pr90590-2.c
> > > @@ -0,0 +1,11 @@
> > > +// PR c++/90590
> > > +// { dg-options -Wswitch }
> > > +
> > > +#include "pr90590-2.h"
> > > +
> > > +void
> > > +fn ()
> > > +{
> > > +  switch (c.b) // { dg-bogus "enumeration value" }
> > > +    ;
> > > +}
> > > diff --git gcc/testsuite/c-c++-common/pr90590-2.h gcc/testsuite/c-c++-common/pr90590-2.h
> > > new file mode 100644
> > > index 00000000000..e4f8635576f
> > > --- /dev/null
> > > +++ gcc/testsuite/c-c++-common/pr90590-2.h
> > > @@ -0,0 +1,4 @@
> > > +#pragma GCC system_header
> > > +struct {
> > > +  enum { _A } b;
> > > +} c;
> >
> >
> > Marek