contrib/fuzz/manifest.cc

dirstate: introduce a symbolic constant for the NONNORMAL marker

This is going to be clearer and easier to track than -1. Ultimately I would
like to get ride of this special value everywhere but in the lower level,
however we need to clarify the API first. This changeset is part of such
clarification.

Differential Revision: https://phab.mercurial-scm.org/D10927

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

#include "FuzzedDataProvider.h"
#include "pyutil.h"

#include <string>

extern "C" {

static PYCODETYPE *code;

extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
	contrib::initpy(*argv[0]);
	code = (PYCODETYPE *)Py_CompileString(R"py(
try:
  lm = parsers.lazymanifest(mdata)
  # iterate the whole thing, which causes the code to fully parse
  # every line in the manifest
  for e, _, _ in lm.iterentries():
      # also exercise __getitem__ et al
      lm[e]
      e in lm
      (e + 'nope') in lm
  lm[b'xyzzy'] = (b'\0' * nlen, 'x')
  # do an insert, text should change
  assert lm.text() != mdata, "insert should change text and didn't: %r %r" % (lm.text(), mdata)
  cloned = lm.filtercopy(lambda x: x != 'xyzzy')
  assert cloned.text() == mdata, 'cloned text should equal mdata'
  cloned.diff(lm)
  del lm[b'xyzzy']
  cloned.diff(lm)
  # should be back to the same
  assert lm.text() == mdata, "delete should have restored text but didn't: %r %r" % (lm.text(), mdata)
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;
	}
	FuzzedDataProvider provider(Data, Size);
	Py_ssize_t nodelength = provider.ConsumeBool() ? 20 : 32;
	PyObject *nlen = PyLong_FromSsize_t(nodelength);
	PyObject *mtext =
	    PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size);
	PyObject *locals = PyDict_New();
	PyDict_SetItemString(locals, "mdata", mtext);
	PyDict_SetItemString(locals, "nlen", nlen);
	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.
}
}