contrib/fuzz/jsonescapeu8fast.cc

filemerge: stop passing around 3 unused `None` values in `files` argument

Since 67cfffbfb6a0 (filemerge: eliminate most uses of tempfiles,
2017-08-31), we have used only the last entry in the `files` tuple
that gets passed around to various functions. That commit said
"Emphasize that they're unused so we can more easily remove them
later.". It's now "later".

Differential Revision: https://phab.mercurial-scm.org/D11877

#include <Python.h>
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>

#include "pyutil.h"

#include <iostream>
#include <string>
#include "FuzzedDataProvider.h"

extern "C" {

static PYCODETYPE *code;

extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
	contrib::initpy(*argv[0]);
	code = (PYCODETYPE *)Py_CompileString(R"py(
try:
    parsers.jsonescapeu8fast(data, paranoid)
except Exception as e:
    pass
    # uncomment this print if you're editing this Python code
    # to debug failures.
    # print(e)
)py",
	                                      "fuzzer", Py_file_input);
	if (!code) {
		std::cerr << "failed to compile Python code!" << std::endl;
	}
	return 0;
}

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
	FuzzedDataProvider provider(Data, Size);
	bool paranoid = provider.ConsumeBool();
	std::string remainder = provider.ConsumeRemainingBytesAsString();

	PyObject *mtext = PyBytes_FromStringAndSize(
	    (const char *)remainder.c_str(), remainder.size());
	PyObject *locals = PyDict_New();
	PyDict_SetItemString(locals, "data", mtext);
	PyDict_SetItemString(locals, "paranoid", paranoid ? Py_True : Py_False);
	PyObject *res = PyEval_EvalCode(code, contrib::pyglobals(), locals);
	if (!res) {
		PyErr_Print();
	}
	Py_XDECREF(res);
	Py_DECREF(locals);
	Py_DECREF(mtext);
	return 0; // Non-zero return values are reserved for future use.
}
}