annotate contrib/fuzz/bdiff.cc @ 43153:741fb1a95da2

fuzz: new target to fuzz jsonescapeu8fast

This code just feels complicated enough we should go ahead and give it
a dedicated fuzzer: we've found bugs in similar things before.

Differential Revision: https://phab.mercurial-scm.org/D7034

/*
 * bdiff.cc - fuzzer harness for bdiff.c
 *
 * Copyright 2018, Google Inc.
 *
 * This software may be used and distributed according to the terms of
 * the GNU General Public License, incorporated herein by reference.
 */
#include <memory>
#include <stdlib.h>

#include "fuzzutil.h"

extern "C" {
#include "bdiff.h"

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
	auto maybe_inputs = SplitInputs(Data, Size);
	if (!maybe_inputs) {
		return 0;
	}
	auto inputs = std::move(maybe_inputs.value());

	struct bdiff_line *a, *b;
	int an = bdiff_splitlines(inputs.left.get(), inputs.left_size, &a);
	int bn = bdiff_splitlines(inputs.right.get(), inputs.right_size, &b);
	struct bdiff_hunk l;
	bdiff_diff(a, an, b, bn, &l);
	free(a);
	free(b);
	bdiff_freehunks(l.next);
	return 0; // Non-zero return values are reserved for future use.
}

#ifdef HG_FUZZER_INCLUDE_MAIN
int main(int argc, char **argv)
{
	const char data[] = "asdf";
	return LLVMFuzzerTestOneInput((const uint8_t *)data, 4);
}
#endif

} // extern "C"