Updates for running on Python 2.

The tool is now able to run on Python 2 with a suitable LRU Cache.
Obviously Python 2 isn't as useful to many people, but when working
with libraries that are Python 2-only, it's necessary to make the
tools work with it.

pythonfuzz/corpus.py

@@ -199,6 +199,7 @@ def mutate(self, buf):
                     v = struct.pack('>H', v)
                 else:
                     v = struct.pack('<H', v)
+                v = bytearray(v)
                 res[pos] = numpy.uint8(res[pos] + v[0])
                 res[pos+1] = numpy.uint8(res[pos] + v[1])
             elif x == 9:
@@ -214,6 +215,7 @@ def mutate(self, buf):
                     v = struct.pack('>I', v)
                 else:
                     v = struct.pack('<I', v)
+                v = bytearray(v)
                 for k in range(4):
                     res[pos+k] = numpy.uint8(res[pos+k] + v[k])
             elif x == 10:
@@ -229,6 +231,7 @@ def mutate(self, buf):
                     v = struct.pack('>Q', v)
                 else:
                     v = struct.pack('<Q', v)
+                v = bytearray(v)
                 for k in range(8):
                     res[pos+k] = numpy.uint8(res[pos+k] + v[k])
             elif x == 11:
@@ -249,6 +252,7 @@ def mutate(self, buf):
                     v = struct.pack('>H', v)
                 else:
                     v = struct.pack('<H', v)
+                v = bytearray(v)
                 res[pos] = numpy.uint8(v[0])
                 res[pos+1] = numpy.uint8(v[1])
             elif x == 13:
@@ -262,6 +266,7 @@ def mutate(self, buf):
                     v = struct.pack('>I', v)
                 else:
                     v = struct.pack('<I', v)
+                v = bytearray(v)
                 for k in range(4):
                     res[pos+k] = numpy.uint8(v[k])
             elif x == 14:

pythonfuzz/fuzzer.py

@@ -16,6 +16,13 @@
 
 SAMPLING_WINDOW = 5 # IN SECONDS
 
+try:
+    lru_cache = functools.lru_cache
+except:
+    import functools32
+    lru_cache = functools32.lru_cache
+
+
 if coverage.version.version_info <= (5, ):
     # Since we're using an old version of coverage.py,
     # we're monkey patching it a bit to improve the performances.
@@ -24,7 +31,7 @@
     # function triggers a lot of syscalls.
     # See the benchmarks here:
     #   - https://github.com/fuzzitdev/pythonfuzz/issues/9
-    @functools.lru_cache(None)
+    @lru_cache(None)
     def abs_file_cache(path):
         """Return the absolute normalized form of `path`."""
         try:
@@ -59,6 +66,7 @@ def write(self, x):
         try:
             target(buf)
         except Exception as e:
+            print("Exception: %r\n" % (e,))
             logging.exception(e)
             child_conn.send(e)
             break
@@ -114,11 +122,14 @@ def write_sample(self, buf, prefix='crash-'):
             crash_path = self._exact_artifact_path
         else:
             crash_path = prefix + m.hexdigest()
+        logging.info('sample written to {}'.format(crash_path))
+        if len(buf) < 200:
+            try:
+                logging.info('sample = {}'.format(buf.hex()))
+            except AttributeError:
+                logging.info('sample = {!r}'.format(buf))
         with open(crash_path, 'wb') as f:
             f.write(buf)
-        logging.info('sample was written to {}'.format(crash_path))
-        if len(buf) < 200:
-            logging.info('sample = {}'.format(buf.hex()))
 
     def start(self):
         logging.info("#0 READ units: {}".format(self._corpus.length))
@@ -134,7 +145,7 @@ def start(self):
                 break
 
             buf = self._corpus.generate_input()
-            parent_conn.send_bytes(buf)
+            parent_conn.send_bytes(bytes(buf))
             if not parent_conn.poll(self._timeout):
                 self._p.kill()
                 logging.info("=================================================================")

setup.py

@@ -15,14 +15,13 @@
     install_requires=[
         'coverage==4.5.4',
         'psutil==5.6.3',
-        'numpy==1.17.3',
+        'numpy<1.17'
     ],
     classifiers=[
         "Programming Language :: Python :: 3",
         "License :: OSI Approved :: Apache Software License",
         "Operating System :: OS Independent",
         "Topic :: Software Development :: Testing"
     ],
-    python_requires='>=3.5.3',
     packages=setuptools.find_packages('.', exclude=("examples",))
 )