Compilation error in "AkBitFuncs.h" when building against prebuilt x64 libs with clang in wwise 2023.1.8.8601

Question

We have noticed compilation errors in "C:\Program Files (x86)\Audiokinetic\Wwise2023.1.8.8601\SDK\include\AK\Tools\Common\AkBitFuncs.h" when building against prebuilt x64 libs with clang (ie. https://clang.llvm.org) in wwise 2023.1.8.8601

This appears to be due to the fact that _MSC_VER is #defined in clang.
Please see the following documentation for more information 
https://clang.llvm.org/docs/UsersManual.html#microsoft-extensions

For instance, the following code snippet does not compile with clang due to the fact that the MSVC-specific _BitScanForward function is not defined.
Note that the commented-out code can be used as a workaround but requires modifying headers in the wwise distribution :-/.

Please note that I have tried to disable MS compatibility and extensions using the following switches to no avail.
    -fno-ms-compatibility
    -fno-ms-extensions

I thought it was worth bringing this issue to the attention of the AK developers in order to hopefully avoid this problem for future releases.

-------------------------------------------------------------------------------------------
//#if defined _MSC_VER && !defined(__clang__)
#if defined _MSC_VER
    AkForceInline AkUInt32 AkBitScanForward(AkUInt32 in_bits)
    {
        unsigned long ret = 0;
        _BitScanForward(&ret, in_bits);
        return in_bits ? ret : 32;
    }

#elif defined(__clang__) || defined (__GNUC__)
    AkForceInline AkUInt32 AkBitScanForward(AkUInt32 in_bits)
    {
        return in_bits ? __builtin_ctz(in_bits) : 32;
    }
#else
    AkForceInline AkUInt32 AkBitScanForward(AkUInt32 in_bits)
    {
        if (in_bits == 0) return 32;
        AkUInt32 ret = 0;
        if ((in_bits & 0x0000FFFFULL) == 0) { ret += 16; in_bits >>= 16; }
        if ((in_bits & 0x000000FFULL) == 0) { ret += 8;  in_bits >>= 8; }
        if ((in_bits & 0x0000000FULL) == 0) { ret += 4;  in_bits >>= 4; }
        if ((in_bits & 0x00000003ULL) == 0) { ret += 2;  in_bits >>= 2; }
        if ((in_bits & 0x00000001ULL) == 0) { ret += 1;  in_bits >>= 1; }
        return ret;
    }
#endif

Answer 1

Thanks for the report. We'll look into this and resolve it in a future release.