procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
#require test-repo py3
$ 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
> }
Try to find a python3-config that's next to our sys.executable. If
that doesn't work, fall back to looking for a global python3-config
and hope that works out for the best.
$ PYBIN=`"$PYTHON" -c 'import sys, os; print(os.path.dirname(sys.executable))'`
$ if [ -x "$PYBIN/python3-config" ] ; then
> PYTHON_CONFIG="$PYBIN/python3-config"
> else
> PYTHON_CONFIG="`which python3-config`"
> fi
#if clang-libfuzzer
$ CXX=clang++ havefuzz || exit 80
$ $MAKE -s clean all PYTHON_CONFIG="$PYTHON_CONFIG"
#endif
#if no-clang-libfuzzer clang-6.0
$ CXX=clang++-6.0 havefuzz || exit 80
$ $MAKE -s clean all CC=clang-6.0 CXX=clang++-6.0 PYTHON_CONFIG="$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