[PATCH] D105169: [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default

[Martin Storsjö via Phabricator via cfe-commits]

mstorsjo added a comment.

I've bisected a crash in generated code down to this commit. The code that crashes is clean when run in ubsan. The misbehaviour happens across 4 tested architectures (i686, x86_64, armv7, aarch64).

The misbehaviour occurs in this preprocessed source, https://martin.st/temp/seek-preproc.c, compiled with `clang -target x86_64-linux-gnu -c -O3 seek-preproc.c`.

The whole failing testcase can be reproduced (on e.g. linux) with these steps:

  git clone git://source.ffmpeg.org/ffmpeg
  cd ffmpeg
  ./configure --cc=clang
  make -j4 fate-seek-acodec-flac

(The failing object file is `libavformat/seek.o`.)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D105169/new/

https://reviews.llvm.org/D105169