view contrib/fuzz/xdiff.cc @ 43025:3518da504303

vfs: give all vfs an options attribute by default

Multiple code path assume vfs have an options attribute, including the vfs module
itself. So for consistency we explicitly add one to all vfs.

This will prevent various crash in the next changesets.

Differential Revision: https://phab.mercurial-scm.org/D6935

/*
 * xdiff.cc - fuzzer harness for thirdparty/xdiff
 *
 * 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 "thirdparty/xdiff/xdiff.h"
#include <inttypes.h>
#include <stdlib.h>

#include "fuzzutil.h"

extern "C" {

int hunk_consumer(long a1, long a2, long b1, long b2, void *priv)
{
	// TODO: probably also test returning -1 from this when things break?
	return 0;
}

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
	// Don't allow fuzzer inputs larger than 100k, since we'll just bog
	// down and not accomplish much.
	if (Size > 100000) {
		return 0;
	}
	auto maybe_inputs = SplitInputs(Data, Size);
	if (!maybe_inputs) {
		return 0;
	}
	auto inputs = std::move(maybe_inputs.value());
	mmfile_t a, b;

	a.ptr = inputs.left.get();
	a.size = inputs.left_size;
	b.ptr = inputs.right.get();
	b.size = inputs.right_size;
	xpparam_t xpp = {
	    XDF_INDENT_HEURISTIC, /* flags */
	};
	xdemitconf_t xecfg = {
	    XDL_EMIT_BDIFFHUNK, /* flags */
	    hunk_consumer,      /* hunk_consume_func */
	};
	xdemitcb_t ecb = {
	    NULL, /* priv */
	};
	xdl_diff(&a, &b, &xpp, &xecfg, &ecb);
	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"