New error building for Windows: cyclic dependency in module 'ucrt': ucrt -> _visualc_intrinsics -> ucrt

[marcprux]

My swift-sqlcipher package that I build daily for Windows with gha-setup-swift (along with macOS, iOS, Linux, and Android) suddenly started failing, I'm guessing as a result of 6a902d9 or bfce834.

The build errors (from the CI run) are:

C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\include\xmmintrin.h:79:10: error: cyclic dependency in module 'ucrt': ucrt -> _visualc_intrinsics -> ucrt

#include <malloc.h>

         ^

C:\Library\Developer\Platforms\Windows.platform\Developer\SDKs\Windows.sdk\usr\lib\swift\shims/LibcOverlayShims.h:27:10: note: while building module 'ucrt' imported from C:\Library\Developer\Platforms\Windows.platform\Developer\SDKs\Windows.sdk\usr\lib\swift\shims/LibcOverlayShims.h:27:

#include <errno.h>

         ^

<module-includes>:27:10: note: in file included from <module-includes>:27:

#include "wchar.h"

         ^

C:\Program Files (x86)\Windows Kits\10\Include\10.0.26100.0\ucrt/wchar.h:29:10: note: in file included from C:\Program Files (x86)\Windows Kits\10\Include\10.0.26100.0\ucrt/wchar.h:29:

#include <intrin.h>

         ^

C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\include\intrin.h:35:18: error: could not build module '_visualc_intrinsics'

        #include <immintrin.h>

                 ^

<module-includes>:1:10: note: in file included from <module-includes>:1:

#include "LibcOverlayShims.h"

         ^

C:\Library\Developer\Platforms\Windows.platform\Developer\SDKs\Windows.sdk\usr\lib\swift\shims/LibcOverlayShims.h:27:10: error: could not build module 'ucrt'

#include <errno.h>

         ^

<unknown>:0: error: could not build C module 'SwiftOverlayShims'

[lxbndr]

I was struggling to reproduce this locally, and finally realized that it is caused by more recent UCRT Version 10.0.26100.0 on GHA-hosted runners. With previous version this issue doesn't appear even on latest VS toolset (which was my first suspect, as updates are often break builds). It is reproducible even when building with build.ps1.

[compnerd]

@lxbndr thanks for that investigation! It sounds like we need to add another header into the curt module that might be getting put into the wrong module.

[marcprux]

FTR, this is also failing my swift-algorithms CI for Windows.

[compnerd]

Yes, this is going to fail on all packages. This is expected behaviour. You have updated your Windows SDK version to something that is unsupported. You should be able to select the "lower" version with the -windows-sdk-version flag.

[Steelskin]

The problematic include order is <wchar.h> (ucrt) -> <intrin.h> (_visualc_intrinsics) -> ... -> <xmmintrin.h> (_visualc_intrinsics) -> <malloc.h> (ucrt).

Windows SDK 10.0.26100.0 adds an include to <intrin.h> in <wchar.h>, this is why the issue started happening. I am not sure how to fix this, though.

[lxbndr]

On my test I see inclusion of ...\Swift\Toolchains\6.0.3+Asserts\usr\lib\swift\clang\include\intrin.h:20. As well as xmmintrin.h. Could it be clang _Builtin_intrinsics is being prioritized over _visualc_intrinsics?

[lxbndr]

Ah, I see the modulemap update is already on the go. Thanks!