[PATCH] D53866: [Preamble] Fix preamble for circular #includes

[Nikolai Kosjar via Phabricator via cfe-commits]

nik added a comment.

In https://reviews.llvm.org/D53866#1281978, @ilya-biryukov wrote:

> Why does resetting the conditional stack is the right thing to do here?


Because this case can be detected and handled without loosing the benefits of the preamble.

> Failing to build the preamble in that case seems like the best thing we could do. WDYT?

See above - we would not have the benefits of the preamble anymore.

>   I can see how it can hide the problem, but can't come up with with a consistent model to handle the fact that the file contents were trimmed.

If we are in preamble-generation-mode and the main file #includes itself, then it should see the full file content of the file, not the truncated preamble version of it.
Would this be more consistent?


Repository:
  rC Clang

https://reviews.llvm.org/D53866