Merging r311391:

------------------------------------------------------------------------
r311391 | stl_msft | 2017-08-21 15:19:33 -0700 (Mon, 21 Aug 2017) | 28 lines

[Driver] Recognize DevDiv internal builds of MSVC, with a different directory structure.

This is a reasonably non-intrusive change, which I've verified
works for both x86 and x64 DevDiv-internal builds.

The idea is to change `bool IsVS2017OrNewer` into a 3-state
`ToolsetLayout VSLayout`. Either a build is DevDiv-internal,
released VS 2017 or newer, or released VS 2015 or older. When looking at
the directory structure, if instead of `"VC"` we see `"x86ret"`, `"x86chk"`,
`"amd64ret"`, or `"amd64chk"`, we recognize this as a DevDiv-internal build.

After we get past the directory structure validation, we use this knowledge
to regenerate paths appropriately. `llvmArchToDevDivInternalArch()` knows how
we use `"i386"` subdirectories, and `MSVCToolChain::getSubDirectoryPath()`
uses that. It also knows that DevDiv-internal builds have an `"inc"`
subdirectory instead of `"include"`.

This may still not be the "right" fix in any sense, but I believe that it's
non-intrusive in the sense that if the special directory names aren't found,
no codepaths are affected. (`ToolsetLayout::OlderVS` and
`ToolsetLayout::VS2017OrNewer` correspond to `IsVS2017OrNewer` being `false`
or `true`, respectively.) I searched for all references to `IsVS2017OrNewer`,
which are places where Clang cares about VS's directory structure, and the
only one that isn't being patched is some logic to deal with
cross-compilation. I'm fine with that not working for DevDiv-internal builds
for the moment (we typically test the native compilers), so I added a comment.

Fixes D36860.
------------------------------------------------------------------------


git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_50@311500 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/Driver/ToolChains/MSVC.h b/lib/Driver/ToolChains/MSVC.h
index d153691a5c..854f88a36f 100644
--- a/lib/Driver/ToolChains/MSVC.h
+++ b/lib/Driver/ToolChains/MSVC.h
@@ -92,7 +92,12 @@ public:
     return getSubDirectoryPath(Type, getArch());
   }
 
-  bool getIsVS2017OrNewer() const { return IsVS2017OrNewer; }
+  enum class ToolsetLayout {
+    OlderVS,
+    VS2017OrNewer,
+    DevDivInternal,
+  };
+  bool getIsVS2017OrNewer() const { return VSLayout == ToolsetLayout::VS2017OrNewer; }
 
   void
   AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
@@ -130,7 +135,7 @@ protected:
   Tool *buildAssembler() const override;
 private:
   std::string VCToolChainPath;
-  bool IsVS2017OrNewer = false;
+  ToolsetLayout VSLayout = ToolsetLayout::OlderVS;
   CudaInstallationDetector CudaInstallation;
 };