Re: [edk2-devel] [PATCH v2 3/3] MdeModulePkg: Use CopyMem instead of GUID assignment

["Ni, Ray" <ray.ni@intel.com>]

Leif,
Does CompilerIntrinsicsLib exist because GCC doesn't support to disable intrinsic?
How does the linker find the CompilerInstrinsicsLib in linking phase?

Thanks,
Ray

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Leif
> Lindholm
> Sent: Thursday, March 12, 2020 6:55 PM
> To: devel@edk2.groups.io; daniel.schaefer@hpe.com
> Cc: Abner Chang <abner.chang@hpe.com>; Gilbert Chen
> <gilbert.chen@hpe.com>; Bi, Dandan <dandan.bi@intel.com>; Dong, Eric
> <eric.dong@intel.com>
> Subject: Re: [edk2-devel] [PATCH v2 3/3] MdeModulePkg: Use CopyMem
> instead of GUID assignment
> 
> Hi Daniel,
> 
> There is nothing wrong with this patch that just went in (and I should
> have called out sooner if I wanted to stop it), but I think a better
> solution is to implement a RISC-V variant of
> ArmPkg/Library/CompilerIntrinsicsLib/.
> 
> It is perfectly valid for the compiler to generate memcpy calls in
> response to struct operations that are perfectly valid C.
> 
> In fact, we could consider moving the ArmPkg one over into
> MdeModulePkg. I have a feeling that including a
>   NULL|ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
> in your current build would be an alternative solution to your
> compilation error.
> 
> /
>     Leif
> 
> On Mon, Mar 02, 2020 at 11:32:38 +0100, Daniel Schaefer wrote:
> > GCC translates a simple assignment to memcpy, which EDKII doesn't
> provide.
> > See: https://www.mail-archive.com/edk2-
> devel@lists.01.org/msg11928.html
> >
> > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2547
> >
> > Signed-off-by: Daniel Schaefer <daniel.schaefer@hpe.com>
> > Cc: Abner Chang <abner.chang@hpe.com>
> > Cc: Gilbert Chen <gilbert.chen@hpe.com>
> > Cc: Leif Lindholm <leif@nuviainc.com>
> > Cc: Dandan Bi <dandan.bi@intel.com>
> > Cc: Eric Dong <eric.dong@intel.com>
> > ---
> >
> > Notes:
> >     v2:
> >       - Use CopyMem instead of CopyGuid [Dandan]
> >
> >  MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
> b/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
> > index 5cc527679a78..0540e6fa8a44 100644
> > --- a/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
> > +++ b/MdeModulePkg/Library/DeviceManagerUiLib/DeviceManager.c
> > @@ -619,7 +619,7 @@ CreateDeviceManagerForm(
> >          TokenHelp = HiiSetString (HiiHandle, 0, String, NULL);
> >          FreePool (String);
> >
> > -        FormSetGuid = ((EFI_IFR_FORM_SET *)Ptr)->Guid;
> > +        CopyMem (&FormSetGuid, &((EFI_IFR_FORM_SET *) Ptr)->Guid,
> sizeof (EFI_GUID));
> >
> >          //
> >          // Network device process
> > --
> > 2.25.0
> >
> >
> >
> >
> 
>