[PATCH] D46652: [clang-cl, PCH] Implement support for MS-style PCH through headers

[Kim Gräsman via Phabricator via cfe-commits]

kimgr added a comment.

> When using a PCH, tokens are skipped until after the through header is seen.

I know this is what MSVC does (though in their case I think it's an artifact of their implementation), but I remember this being a source of mysterious bugs:

  #define MY_SYMBOL 1
  #include "stdafx.h"  // include pch

The `#define` would silently disappear, and the symbol would never be defined. I wonder if it would be worth adding a warning for this in `SkipTokensUntilPCHThroughHeader`?


Repository:
  rC Clang

https://reviews.llvm.org/D46652