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

["Daniel Schaefer" <daniel.schaefer@hpe.com>]

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Hi Leif,

you're right. If I revert my commit and include
  NULL|ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
without making any changes to it, the build succeeds.

What do others think? (cc Michael, Pete, Andrew, Ard, who have made changes to this module)
Is this a big hack or should we use it in RISC-V, too and move the module to MdeModulePkg?
Why isn't this a problem on x86? Was it fine on Itanium?

- Daniel

________________________________
From: devel@edk2.groups.io<mailto:devel@edk2.groups.io> <devel@edk2.groups.io><mailto:devel@edk2.groups.io> on behalf of Leif Lindholm <leif@nuviainc.com><mailto:leif@nuviainc.com>
Sent: Thursday, March 12, 2020 11:55
To: devel@edk2.groups.io<mailto:devel@edk2.groups.io> <devel@edk2.groups.io><mailto:devel@edk2.groups.io>; Schaefer, Daniel (DualStudy) <daniel.schaefer@hpe.com><mailto:daniel.schaefer@hpe.com>
Cc: Chang, Abner (HPS SW/FW Technologist) <abner.chang@hpe.com><mailto:abner.chang@hpe.com>; Chen, Gilbert <gilbert.chen@hpe.com><mailto:gilbert.chen@hpe.com>; Dandan Bi <dandan.bi@intel.com><mailto:dandan.bi@intel.com>; Eric Dong <eric.dong@intel.com><mailto: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><mailto:daniel.schaefer@hpe.com>
> Cc: Abner Chang <abner.chang@hpe.com><mailto:abner.chang@hpe.com>
> Cc: Gilbert Chen <gilbert.chen@hpe.com><mailto:gilbert.chen@hpe.com>
> Cc: Leif Lindholm <leif@nuviainc.com><mailto:leif@nuviainc.com>
> Cc: Dandan Bi <dandan.bi@intel.com><mailto:dandan.bi@intel.com>
> Cc: Eric Dong <eric.dong@intel.com><mailto: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
>
>
>
>




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