contrib/fuzz/manifest.cc
author Pierre-Yves David <pierre-yves.david@octobus.net>
Thu, 01 Sep 2022 15:49:14 +0200
branchstable
changeset 49469 b5c8524827d2
parent 44986 0ff59434af72
permissions -rw-r--r--
dirstate-v2: no longer register the data-file during transaction If the data file change during the transaction, we cannot truncate it. The content of the file itself is fine as it will get backed up at the same time as the docket. Leaving the trailing data at the end of failed transaction is fine. The dirstate-v2 format supports it. The dead data will simply we written over if necessary.

#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.
}
}