[all-commits] [llvm/llvm-project] 69721f: [DFSan] Support fast16labels mode in dfsan_union.

[Matt Morehouse via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 69721fc9d1b5df9a7a32d2fee6d72c8c7c9bf644
      https://github.com/llvm/llvm-project/commit/69721fc9d1b5df9a7a32d2fee6d72c8c7c9bf644
  Author: Matt Morehouse <mascasa at google.com>
  Date:   2020-08-17 (Mon, 17 Aug 2020)

  Changed paths:
    M compiler-rt/lib/dfsan/dfsan.cpp
    M compiler-rt/test/dfsan/custom.cpp

  Log Message:
  -----------
  [DFSan] Support fast16labels mode in dfsan_union.

While the instrumentation never calls dfsan_union in fast16labels mode,
the custom wrappers do.  We detect fast16labels mode by checking whether
any labels have been created.  If not, we must be using fast16labels
mode.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D86012