[PATCH] D135132: [SourceManager] Improve getFileIDLocal.

[Sam McCall via Phabricator via cfe-commits]

sammccall accepted this revision.
sammccall added inline comments.
This revision is now accepted and ready to land.


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Comment at: clang/lib/Basic/SourceManager.cpp:807
   }
 
   // Find the FileID that contains this.  "I" is an iterator that points to a
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Just checking: we decrement GreaterIndex without a bounds check in the loop and then dereference it in the loop.

I guess this is safe because:
- in the case where it's equal to size(), it's nonzero due to a dummy entry at 0 (and unchanged in this patch)
- in the case where the cache is used, it's also nonzero (guarded)

Maybe this is worth an assertion?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D135132/new/

https://reviews.llvm.org/D135132