contrib/fuzz/xdiff.cc
author Matt Harbison <matt_harbison@yahoo.com>
Sat, 21 Nov 2020 15:34:54 -0500
changeset 45898 4f6816e8440b
parent 43816 d37658efbec2
permissions -rw-r--r--
make: switch the PYTHON default to `py.exe -3` on Windows Python3 _is_ named `python.exe` on Windows, but that isn't necessarily on PATH when installing from python.org. I do happen to have a python.exe on PATH in `$LOCALAPPDATA/Microsoft/WindowsApps`, but it appears to be 0 bytes (likely because of permission issues), and doesn't run: $ python -V - Cannot open Pulkit hit the same error as I did though, so it isn't just my system: $ make -C . local make: Entering directory `/home/Dell/repos/hg-committed` python setup.py \ build_py -c -d . \ build_ext -i \ build_hgexe -i \ build_mo - Cannot openmake: *** [local] Error 1 The `py.exe` dispatcher lives in the Windows directory (so it is on PATH), looks up the python.org installation, and invokes that interpreter directly. I get a warning with py39, but if it's our issue, it was an existing one: $ make -C .. local make: Entering directory `/c/Users/Matt/hg' py -3 setup.py \ build_py -c -d . \ build_ext -i \ build_hgexe -i \ build_mo C:\Users\Matt\AppData\Local\Programs\Python\Python39\lib\site-packages\setuptools\distutils_patch.py:25: UserWarning: Distutils was imported before Setuptools. This usage is discouraged and may exhibit undesirable behaviors or errors. Please use Setuptools' objects directly or at least import Setuptools first. warnings.warn( The end result is a py3 based hg.exe that annoyingly won't run because it can't find python39.dll. It will run tests (the ones without the `python3` shbang line anyway), because the test runner adjusts PATH to include the python running it. Differential Revision: https://phab.mercurial-scm.org/D9361

/*
 * 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 "FuzzedDataProvider.h"

extern "C" {

int LLVMFuzzerInitialize(int *argc, char ***argv)
{
	return 0;
}

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;
	}
	FuzzedDataProvider provider(Data, Size);
	std::string left = provider.ConsumeRandomLengthString(Size);
	std::string right = provider.ConsumeRemainingBytesAsString();
	mmfile_t a, b;

	a.ptr = (char *)left.c_str();
	a.size = left.size();
	b.ptr = (char *)right.c_str();
	b.size = 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.
}

} // extern "C"