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Subject: Re: [edk2-devel] [PATCH 01/35] DO NOT APPLY: edk2: turn standard handle types into pointers to non-VOID
To: Andrew Fish <afish@apple.com>, "Ni, Ray" <ray.ni@intel.com>
Cc: "devel@edk2.groups.io" <devel@edk2.groups.io>,
 Achin Gupta <achin.gupta@arm.com>, Anthony Perard
 <anthony.perard@citrix.com>, Ard Biesheuvel <ard.biesheuvel@linaro.org>,
 "You, Benjamin" <benjamin.you@intel.com>,
 "Zhang, Chao B" <chao.b.zhang@intel.com>, "Bi, Dandan"
 <dandan.bi@intel.com>, David Woodhouse <dwmw2@infradead.org>,
 "Dong, Eric" <eric.dong@intel.com>, "Dong, Guo" <guo.dong@intel.com>,
 "Wu, Hao A" <hao.a.wu@intel.com>, "Carsey, Jaben" <jaben.carsey@intel.com>,
 "Wang, Jian J" <jian.j.wang@intel.com>, "Wu, Jiaxin" <jiaxin.wu@intel.com>,
 "Yao, Jiewen" <jiewen.yao@intel.com>,
 Jordan Justen <jordan.l.justen@intel.com>,
 Julien Grall <julien.grall@arm.com>, Leif Lindholm
 <leif.lindholm@linaro.org>, "Gao, Liming" <liming.gao@intel.com>,
 "Ma, Maurice" <maurice.ma@intel.com>,
 Mike Kinney <michael.d.kinney@intel.com>, "Fu, Siyuan"
 <siyuan.fu@intel.com>, Supreeth Venkatesh <supreeth.venkatesh@arm.com>,
 "Gao, Zhichao" <zhichao.gao@intel.com>
References: <20190917194935.24322-1-lersek@redhat.com>
 <20190917194935.24322-2-lersek@redhat.com>
 <734D49CCEBEEF84792F5B80ED585239D5C2E3BE1@SHSMSX104.ccr.corp.intel.com>
 <1FFFA19B-454C-4B46-9DD0-339BB8011838@apple.com>
From: "Laszlo Ersek" <lersek@redhat.com>
Message-ID: <cd4a4e9d-6191-cc1b-5fc4-385f733bab72@redhat.com>
Date: Wed, 18 Sep 2019 10:41:46 +0200
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On 09/17/19 22:22, Andrew Fish wrote:
> 
> 
>> On Sep 17, 2019, at 1:06 PM, Ni, Ray <ray.ni@intel.com> wrote:
>>
>> Laszlo,
>> Thank you very much for this work.
>> They are quite helpful to detect potential issues.
>>
>> But without this specific patch being checked in, future break will still happen.
>> I don't want it to be checked in ASAP because I know that there are quite a lot of close source code that may get build break due to this change.
>> Besides that, what prevent you make the decision to check in the changes?
>>
> 
> Ray,
> 
> I was thinking the same thing. Could we make this an optional feature via a #define? We could always default to the Spec Behavior, and new projects could opt into the stricter version. 
> 
> #ifndef STRICTER_UEFI_TYPES
> typedef VOID    *EFI_PEI_FV_HANDLE;
> #else
> struct EFI_PEI_FV_OBJECT;
> typedef struct EFI_PEI_FV_OBJECT *EFI_PEI_FV_HANDLE;
> #endif

Technically, this would work well.

However, if we wanted to allow new projects to #define
STRICTER_UEFI_TYPES as their normal mode of operation (and not just for
a sanity check in CI), then we'd have to update the UEFI spec too.

Otherwise, code that is technically spec-conformant (albeit semantically
nonsensical), like I mentioned up-thread, would no longer compile:

  EFI_HANDLE Foobar;
  UINT64     Val;

  Foobar = &Val;

Thanks
Laszlo