Clang 5.0.0 RC2 doesn't recognize DevDiv internal builds of MSVC

[StephanTLavavej]

Bugzilla Link	34269
Resolution	FIXED
Resolved on	Aug 22, 2017 15:01
Version	5.0
OS	Windows NT
Blocks	#33196
CC	@zmodem

Extended Description

Mail thread: https://lists.llvm.org/pipermail/cfe-dev/2017-August/055022.html

Fixed in master by r311391: https://reviews.llvm.org/D36860

To summarize, there's a regression between Clang 4.0.1 and 5.0.0 RC2, where Clang no longer recognizes the DevDiv-internal directory structure of MSVC builds. This makes it more difficult for us to test MSVC's STL with Clang (such testing helps us avoid writing code that unintentionally depends on non-Standard behavior of C1XX, and also helps us find bugs in Clang).

While I figured out a workaround for this regression (explicitly pass -fms-compatibility-version and invoke link.exe separately), it would be great if the fix r311391 could be merged into 5.0.0.

[zmodem]

While I figured out a workaround for this regression (explicitly pass
-fms-compatibility-version and invoke link.exe separately), it would be
great if the fix r311391 could be merged into 5.0.0.

It looks pretty safe to me. Let's have it bake in trunk for a bit, then I'll merge it.

[zmodem]

Merged in r311500.