As discussed in #4530 . This required switching to using
`llvm::IntrusiveRefCntPtr` in a number of places.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
This teaches the driver library to track when its being used with
fuzzing and disables the `clang` subcommand from actually running Clang.
The Clang libraries have a large backlog of fuzzer-found issues that
isn't being actively reduced, so we can't productively fuzz into it.
This lets us more productively fuzz at the top level.
This is also available on the command line itself, which should be
useful if anyone wants to fuzz Carbon from the command line using tools
like AFL -- they can inject this flag to avoid getting noise from the
fuzzer hitting known issues in Clang.
This makes something like `bazel run :toolchain -- clang -- -c test.cpp`
work, because that can be run in-process. Note that `bazel run
:toolchain -- clang -- test.cpp` still requires subprocessing, and does
not work.
Note, the vision here is that we are trying to align how clang and
carbon compile c++ code. This is work towards intertwining command
execution.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
josh11bandJosh L
Jon Ross-Perkins
Chandler Carruth