[PATCH] D68969: [clang-format] Remove the dependency on frontend

Tue Nov 5 08:19:23 PST 2019

MyDeveloperDay added a comment.

In D68969#1733946 <https://reviews.llvm.org/D68969#1733946>, @thakis wrote:

> The revert message said:
>
>   Vlad Tsyrklevich via cfe-commits <cfe-commits at lists.llvm.org>
>   Tue, Oct 29, 1:51 PM (7 days ago)
>   to via, mydeveloperday
>  
>   I've reverted this commit as it was causing UBSan failures on the ubsan bot. These failures looked like:
>   llvm/lib/Support/SourceMgr.cpp:440:48: runtime error: pointer index expression with base 0x000000000000 overflowed to 0xfffffffffffffffa
>  
>   Looking at a backtrace, this line was reached from the `Diags.print(nullptr, llvm::errs(), (ShowColors && !NoShowColors));` call introduced in this change.
>
>
> Is that enough to see what's wrong? If not, @vlad.tsyrklevich , can you give repro steps for that ubsan failure that made you revert ec66603 in efed314 <https://reviews.llvm.org/rGefed314118c7c287a71b8a8d67953a98d8a718d5>?

Note to self: Took me a bit to set up a docker container to build with clang-10 on linux (I'm normally a windows guy), but hopefully, I can debug from here...

  test1.cpp:1:7: warning: code should be clang-formatted [-Wclang-format-violations]
  /llvm-project/llvm/lib/Support/SourceMgr.cpp:440:48: runtime error: applying non-zero offset 1844674407
  3709551610 to null pointer
  SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /buildareas/llvm2/llvm-project/llvm/lib/Support/SourceMgr.cpp:44
  0:48 in

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  https://reviews.llvm.org/D68969/new/

https://reviews.llvm.org/D68969