Re: [edk2-devel] [PATCH] CryptoPkg/FltUsedLib: Add FltUsedLib for float.

["Laszlo Ersek" <lersek@redhat.com>]

On 03/31/20 09:13, Ard Biesheuvel wrote:
> On Tue, 31 Mar 2020 at 03:40, Jiang, Guomin <guomin.jiang@intel.com> wrote:
>>
>> Hi Laszlo,
>>
>> Thanks for you spending time review the changes.
>>
>> And I just want to present how to reproduce the build error.
>>
>> When build OvmfPkgX64, you can encounter this issue with your local change. The error as below:
>> TcgPei.lib(AutoGen.obj) : error LNK2001: unresolved external symbol _fltused
>> c:\sourcecodes\tiano\Build\OvmfX64\DEBUG_VS2019\X64\SecurityPkg\Tcg\TcgPei\TcgPei\DEBUG\TcgPei.dll : fatal error LNK1120: 1 unresolved externals
>>
>> The build command: build -p OvmfPkg\OvmfPkgX64.dsc -b DEBUG -t VS2019 -a X64 -D TPM_ENABLE
>> The code changes for reproducing this symptom:
>> -  int  GLOBAL_USED _fltused = 1;
>> + //int  GLOBAL_USED _fltused = 1;
>> The machine: WIN10
>> The branch: edk2 master
>>
> 
> Doesn't the build error go away as well if you simply add FloatUsed.c
> to all BaseCryptLib flavours if Visual Studio is being used?
> 
> Something like
> 
> diff --git a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
> b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
> index 1bbe4f435aec..f40bf18e7f5d 100644
> --- a/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
> +++ b/CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
> @@ -27,6 +27,7 @@ [Defines]
>  #
> 
>  [Sources]
> +  FloatUsed.c         | MSFT
>    InternalCryptLib.h
>    Hash/CryptMd4.c
>    Hash/CryptMd5.c
> 

This is *exactly* what I've had in mind!

(With the additional (optional) tweak that IMO "FloatUsed.c" belongs
with the openssl INF files, as those are where the floating point usage
originates from. The cryptlib instances themselves have no floating
point code, AIUI.)

Thanks
Laszlo