Re: [edk2-devel] [PATCH V2 3/8] MdePkg/UefiDebugLibStdErr: Decrease the name collisions

["Michael D Kinney" <michael.d.kinney@intel.com>]

Hi Ard,

I see no issues with using 'static' on more symbols.

I am not sure how to enforce it, so it would be a good
recommendation for code style and a good recommendation
for a code reviews.

Can you provide an example where code generation is 
improved when 'static' is used.  That would be good to
include with the recommendations and would help encourage
developers to follow the recommendation.

Thanks,

Mike

> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io]
> On Behalf Of Ard Biesheuvel
> Sent: Wednesday, April 24, 2019 10:10 AM
> To: Kinney, Michael D <michael.d.kinney@intel.com>
> Cc: devel@edk2.groups.io; Gao, Zhichao
> <zhichao.gao@intel.com>; Laszlo Ersek
> <lersek@redhat.com>; Gao, Liming <liming.gao@intel.com>;
> Bi, Dandan <dandan.bi@intel.com>
> Subject: Re: [edk2-devel] [PATCH V2 3/8]
> MdePkg/UefiDebugLibStdErr: Decrease the name collisions
> 
> On Wed, 24 Apr 2019 at 18:59, Kinney, Michael D
> <michael.d.kinney@intel.com> wrote:
> >
> > Hi Ard,
> >
> > I see a mix of use of 'static' and 'STATIC' in the
> sources.
> >
> > The reason to use STATIC is if it needs to be replaced
> with
> > something other than 'static' for a specific compiler
> or
> > debug scenario.
> >
> > Long ago, there were some source level debug issue with
> > 'static' symbols, so using the macro STATIC was
> preferred
> > so it could be mapped to nothing for a debug scenario.
> That
> > issue no long exists.
> >
> > Do you know of a reason today to map 'STATIC' to
> anything
> > Other than 'static'?
> >
> > I also looked at the EDK II C Coding Standard.  It is
> also
> > inconsistent and had references to both 'static' and
> 'STATIC'.
> > We should enter a few BZs to update that doc once we
> have
> > clear guidance from this discussion.
> >
> 
> I wasn't aware that lower case static is also in use, so
> I was simply
> extrapolating from personal experience.
> 
> i think there should be no reason to use the preprocessor
> to change
> 'static' into something else, and so I'm happy to settle
> on lowercase
> static, as long as we are consistent. But more
> importantly, now that
> this has come up, what I would like to do is make
> 'static' mandatory
> unless the code requires otherwise: this results in much
> better code
> generation (given that the compiler can infer constness
> for non-const
> static variables but not for ones with external linkage)
> and generally
> improves programmer hygiene when it comes to linking to
> arbitrary
> symbols that are really internal to a library.
> 
> 
> > > -----Original Message-----
> > > From: devel@edk2.groups.io
> [mailto:devel@edk2.groups.io]
> > > On Behalf Of Ard Biesheuvel
> > > Sent: Wednesday, April 24, 2019 1:07 AM
> > > To: edk2-devel-groups-io <devel@edk2.groups.io>; Gao,
> > > Zhichao <zhichao.gao@intel.com>
> > > Cc: Laszlo Ersek <lersek@redhat.com>; Kinney, Michael
> D
> > > <michael.d.kinney@intel.com>; Gao, Liming
> > > <liming.gao@intel.com>; Bi, Dandan
> <dandan.bi@intel.com>
> > > Subject: Re: [edk2-devel] [PATCH V2 3/8]
> > > MdePkg/UefiDebugLibStdErr: Decrease the name
> collisions
> > >
> > > On Wed, 24 Apr 2019 at 06:59, Gao, Zhichao
> > > <zhichao.gao@intel.com> wrote:
> > > >
> > > > REF:
> > > https://bugzilla.tianocore.org/show_bug.cgi?id=1740
> > > >
> > > > Add a 'static' descriptor to the global variables
> that
> > > only
> > > > used in a single file to minimize the name
> collisions.
> > > > This is only for the varable named
> > > 'mExitBootServicesEvent'.
> > > >
> > > > Cc: Laszlo Ersek <lersek@redhat.com>
> > > > Cc: Michael D Kinney <michael.d.kinney@intel.com>
> > > > Cc: Liming Gao <liming.gao@intel.com>
> > > > Cc: Dandan Bi <dandan.bi@intel.com>
> > > > Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
> > > > ---
> > > >
> > >
> MdePkg/Library/UefiDebugLibStdErr/DebugLibConstructor.c |
> > > 4 ++--
> > > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git
> > >
> a/MdePkg/Library/UefiDebugLibStdErr/DebugLibConstructor.c
> > >
> b/MdePkg/Library/UefiDebugLibStdErr/DebugLibConstructor.c
> > > > index d4fdfbab55..bb7b144569 100644
> > > > ---
> > >
> a/MdePkg/Library/UefiDebugLibStdErr/DebugLibConstructor.c
> > > > +++
> > >
> b/MdePkg/Library/UefiDebugLibStdErr/DebugLibConstructor.c
> > > > @@ -15,9 +15,9 @@
> > > >  //
> > > >  // BOOLEAN value to indicate if it is at the post
> > > ExitBootServices pahse
> > > >  //
> > > > -BOOLEAN     mPostEBS = FALSE;
> > > > +BOOLEAN               mPostEBS = FALSE;
> > > >
> > > > -EFI_EVENT   mExitBootServicesEvent;
> > > > +static EFI_EVENT      mExitBootServicesEvent;
> > > >
> > >
> > > Please use STATIC not static.
> > >
> > >
> > > >  //
> > > >  // Pointer to SystemTable
> > > > --
> > > > 2.21.0.windows.1
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> 
>