tests/test-fuzz-targets.t

tests: proof test-stdio.py against buffer fill-up

With the previous code, it could in theory happen that the pipe / PTY buffer of
the child stdout / stderr fills up and the process never finishes.

To prevent that, we read all of the stream before waiting for the end of the
process. To ensure that the stream reaches EOF when the child finishes, we must
close the parent "copy" of the child stdout / stderr.

#require test-repo

  $ cd $TESTDIR/../contrib/fuzz
  $ OUT=$TESTTMP ; export OUT

which(1) could exit nonzero, but that's fine because we'll still end
up without a valid executable, so we don't need to check $? here.

  $ if which gmake >/dev/null 2>&1; then
  >     MAKE=gmake
  > else
  >     MAKE=make
  > fi

  $ havefuzz() {
  >     cat > $TESTTMP/dummy.cc <<EOF
  > #include <stdlib.h>
  > #include <stdint.h>
  > int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { return 0; }
  > int main(int argc, char **argv) {
  >     const char data[] = "asdf";
  >     return LLVMFuzzerTestOneInput((const uint8_t *)data, 4);
  > }
  > EOF
  >     $CXX $TESTTMP/dummy.cc -o $TESTTMP/dummy \
  >        -fsanitize=fuzzer-no-link,address || return 1
  > }

#if clang-libfuzzer
  $ CXX=clang++ havefuzz || exit 80
  $ $MAKE -s clean all PYTHON_CONFIG=`which python-config`
#endif
#if no-clang-libfuzzer clang-6.0
  $ CXX=clang++-6.0 havefuzz || exit 80
  $ $MAKE -s clean all CC=clang-6.0 CXX=clang++-6.0 PYTHON_CONFIG=`which python-config`
#endif
#if no-clang-libfuzzer no-clang-6.0
  $ exit 80
#endif

  $ cd $TESTTMP

Run each fuzzer using dummy.cc as a fake input, to make sure it runs
at all. In the future we should instead unpack the corpus for each
fuzzer and use that instead.

  $ for fuzzer in `ls *_fuzzer | sort` ; do
  >   echo run $fuzzer...
  >   ./$fuzzer dummy.cc > /dev/null 2>&1 
  > done
  run bdiff_fuzzer...
  run dirs_fuzzer...
  run dirstate_fuzzer...
  run fm1readmarkers_fuzzer...
  run fncache_fuzzer...
  run jsonescapeu8fast_fuzzer...
  run manifest_fuzzer...
  run mpatch_fuzzer...
  run revlog_fuzzer...
  run xdiff_fuzzer...

Clean up.
  $ cd $TESTDIR/../contrib/fuzz
  $ $MAKE -s clean