contrib/fuzz/dirs.cc

rust-cpython: mark PySharedState as Sync so &'PySharedState can be Send

The goal is to store &'static PySharedState in $leaked struct, which allows
us to move the $leaked struct out of the macro. Currently, it depends on
inner.$data_member(py), which can't be generalized.

PySharedState is Sync because any mutation or read operation is synchronized
by the Python GIL, py: Python<'a>, which should guarantee that &'PySharedState
can be sent to another thread.

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

#include "pyutil.h"

#include <string>

extern "C" {

static PyCodeObject *code;

extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
	contrib::initpy(*argv[0]);
	code = (PyCodeObject *)Py_CompileString(R"py(
from parsers import dirs
try:
  files = mdata.split('\n')
  d = dirs(files)
  list(d)
  'a' in d
  if files:
    files[0] in d
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);
	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;
	}
	PyObject *mtext =
	    PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size);
	PyObject *locals = PyDict_New();
	PyDict_SetItemString(locals, "mdata", mtext);
	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.
}
}