[PATCH] D54113: [sanitizer] Use AT_EXECFN in ReExec() if available

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added a comment.

`$EXEC_ORIGIN` (`$ORIGIN` without tracing the symlink) does not exist in vanilla glibc https://sourceware.org/ml/libc-alpha/2017-10/msg01109.html

This breaks `TSanitizer-x86_64-Test-Nolibc` as `getauxval` is a glibc symbol, which can be fixed by https://reviews.llvm.org/D54160

  ld.lld: error: undefined symbol: getauxval
  >>> referenced by sanitizer_linux.cc:646 (../projects/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc:646)
  >>>               sanitizer_linux.cc.o:(__sanitizer::ReExec()) in archive libRTSanitizerCommon.test.nolibc.x86_64.a


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D54113