#!/usr/bin/env python3
#
# Copyright (C) 2013 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""stack symbolizes native crash dumps."""
import collections
import functools
import os
import pathlib
import re
import subprocess
import symbol
import tempfile
import unittest
import example_crashes
def ConvertTrace(lines):
tracer = TraceConverter()
print("Reading symbols from", symbol.SYMBOLS_DIR)
tracer.ConvertTrace(lines)
class TraceConverter:
process_info_line = re.compile(r"(pid: [0-9]+, tid: [0-9]+.*)")
revision_line = re.compile(r"(Revision: '(.*)')")
signal_line = re.compile(r"(signal [0-9]+ \(.*\).*)")
abort_message_line = re.compile(r"(Abort message: '.*')")
thread_line = re.compile(r"(.*)(--- ){15}---")
dalvik_jni_thread_line = re.compile("(\".*\" prio=[0-9]+ tid=[0-9]+ NATIVE.*)")
dalvik_native_thread_line = re.compile("(\".*\" sysTid=[0-9]+ nice=[0-9]+.*)")
register_line = re.compile("$a")
trace_line = re.compile("$a")
sanitizer_trace_line = re.compile("$a")
value_line = re.compile("$a")
code_line = re.compile("$a")
zipinfo_central_directory_line = re.compile(r"Central\s+directory\s+entry")
zipinfo_central_info_match = re.compile(
r"^\s*(\S+)$\s*offset of local header from start of archive:\s*(\d+)"
r".*^\s*compressed size:\s+(\d+)", re.M | re.S)
unreachable_line = re.compile(r"((\d+ bytes in \d+ unreachable allocations)|"
r"(\d+ bytes unreachable at [0-9a-f]+)|"
r"(referencing \d+ unreachable bytes in \d+ allocation(s)?)|"
r"(and \d+ similar unreachable bytes in \d+ allocation(s)?))")
trace_lines = []
value_lines = []
last_frame = -1
width = "{8}"
spacing = ""
apk_info = dict()
lib_to_path = dict()
# We use the "file" command line tool to extract BuildId from ELF files.
ElfInfo = collections.namedtuple("ElfInfo", ["bitness", "build_id"])
readelf_output = re.compile(r"Class:\s*ELF(?P<bitness>32|64).*"
r"Build ID:\s*(?P<build_id>[0-9a-f]+)",
flags=re.DOTALL)
def UpdateBitnessRegexes(self):
if symbol.ARCH_IS_32BIT:
self.width = "{8}"
self.spacing = ""
else:
self.width = "{16}"
self.spacing = " "
self.register_line = re.compile(" (([ ]*\\b(\S*)\\b +[0-9a-f]" + self.width + "){1,5}$)")
# Note that both trace and value line matching allow for variable amounts of
# whitespace (e.g. \t). This is because the we want to allow for the stack
# tool to operate on AndroidFeedback provided system logs. AndroidFeedback
# strips out double spaces that are found in tombsone files and logcat output.
#
# Examples of matched trace lines include lines from tombstone files like:
# #00 pc 001cf42e /data/data/com.my.project/lib/libmyproject.so
#
# Or lines from AndroidFeedback crash report system logs like:
# 03-25 00:51:05.520 I/DEBUG ( 65): #00 pc 001cf42e /data/data/com.my.project/lib/libmyproject.so
# Please note the spacing differences.
self.trace_line = re.compile(
r".*" # Random start stuff.
r"\#(?P<frame>[0-9]+)" # Frame number.
r"[ \t]+..[ \t]+" # (space)pc(space).
r"(?P<offset>[0-9a-f]" + self.width + ")[ \t]+" # Offset (hex number given without
# 0x prefix).
r"(?P<dso>\[[^\]]+\]|[^\r\n \t]*)" # Library name.
r"( \(offset (?P<so_offset>0x[0-9a-fA-F]+)\))?" # Offset into the file to find the start of the shared so.
r"(?P<symbolpresent> \((?P<symbol>.*?)\))?" # Is the symbol there? (non-greedy)
r"( \(BuildId: (?P<build_id>.*)\))?" # Optional build-id of the ELF file.
r"[ \t]*$") # End of line (to expand non-greedy match).
# pylint: disable-msg=C6310
# Sanitizer output. This is different from debuggerd output, and it is easier to handle this as
# its own regex. Example:
# 08-19 05:29:26.283 397 403 I : #0 0xb6a15237 (/system/lib/libclang_rt.asan-arm-android.so+0x4f237)
self.sanitizer_trace_line = re.compile(
r".*" # Random start stuff.
r"\#(?P<frame>[0-9]+)" # Frame number.
r"[ \t]+0x[0-9a-f]+[ \t]+" # PC, not interesting to us.
r"\(" # Opening paren.
r"(?P<dso>[^+]+)" # Library name.
r"\+" # '+'
r"0x(?P<offset>[0-9a-f]+)" # Offset (hex number given with
# 0x prefix).
r"\)") # Closing paren.
# pylint: disable-msg=C6310
# Examples of matched value lines include:
# bea4170c 8018e4e9 /data/data/com.my.project/lib/libmyproject.so
# bea4170c 8018e4e9 /data/data/com.my.project/lib/libmyproject.so (symbol)
# 03-25 00:51:05.530 I/DEBUG ( 65): bea4170c 8018e4e9 /data/data/com.my.project/lib/libmyproject.so
# Again, note the spacing differences.
self.value_line = re.compile(r"(.*)([0-9a-f]" + self.width + r")[ \t]+([0-9a-f]" + self.width + r")[ \t]+([^\r\n \t]*)( \((.*)\))?")
# Lines from 'code around' sections of the output will be matched before
# value lines because otheriwse the 'code around' sections will be confused as
# value lines.
#
# Examples include:
# 801cf40c ffffc4cc 00b2f2c5 00b2f1c7 00c1e1a8
# 03-25 00:51:05.530 I/DEBUG ( 65): 801cf40c ffffc4cc 00b2f2c5 00b2f1c7 00c1e1a8
self.code_line = re.compile(r"(.*)[ \t]*[a-f0-9]" + self.width +
r"[ \t]*[a-f0-9]" + self.width +
r"[ \t]*[a-f0-9]" + self.width +
r"[ \t]*[a-f0-9]" + self.width +
r"[ \t]*[a-f0-9]" + self.width +
r"[ \t]*[ \r\n]") # pylint: disable-msg=C6310
def CleanLine(self, ln):
# AndroidFeedback adds zero width spaces into its crash reports. These
# should be removed or the regular expresssions will fail to match.
return ln.encode().decode(encoding='utf8', errors='ignore')
def PrintTraceLines(self, trace_lines):
"""Print back trace."""
maxlen = max(len(tl[1]) for tl in trace_lines)
print("\nStack Trace:")
print(" RELADDR " + self.spacing + "FUNCTION".ljust(maxlen) + " FILE:LINE")
for tl in self.trace_lines:
(addr, symbol_with_offset, location) = tl
print(" %8s %s %s" % (addr, symbol_with_offset.ljust(maxlen), location))
def PrintValueLines(self, value_lines):
"""Print stack data values."""
maxlen = max(len(tl[2]) for tl in self.value_lines)
print("\nStack Data:")
print(" ADDR " + self.spacing + "VALUE " + "FUNCTION".ljust(maxlen) + " FILE:LINE")
for vl in self.value_lines:
(addr, value, symbol_with_offset, location) = vl
print(" %8s %8s %s %s" % (addr, value, symbol_with_offset.ljust(maxlen), location))
def PrintOutput(self, trace_lines, value_lines):
if self.trace_lines:
self.PrintTraceLines(self.trace_lines)
if self.value_lines:
self.PrintValueLines(self.value_lines)
def PrintDivider(self):
print("\n-----------------------------------------------------\n")
def DeleteApkTmpFiles(self):
for _, _, tmp_files in self.apk_info.values():
for tmp_file in tmp_files.values():
os.unlink(tmp_file)
def ConvertTrace(self, lines):
lines = [self.CleanLine(line) for line in lines]
try:
if symbol.ARCH_IS_32BIT is None:
symbol.SetBitness(lines)
self.UpdateBitnessRegexes()
for line in lines:
self.ProcessLine(line)
self.PrintOutput(self.trace_lines, self.value_lines)
finally:
# Delete any temporary files created while processing the lines.
self.DeleteApkTmpFiles()
def MatchTraceLine(self, line):
match = self.trace_line.match(line)
if match:
return {"frame": match.group("frame"),
"offset": match.group("offset"),
"so_offset": match.group("so_offset"),
"dso": match.group("dso"),
"symbol_present": bool(match.group("symbolpresent")),
"symbol_name": match.group("symbol"),
"build_id": match.group("build_id")}
match = self.sanitizer_trace_line.match(line)
if match:
return {"frame": match.group("frame"),
"offset": match.group("offset"),
"so_offset": None,
"dso": match.group("dso"),
"symbol_present": False,
"symbol_name": None,
"build_id": None}
return None
def ExtractLibFromApk(self, apk, shared_lib_name):
# Create a temporary file containing the shared library from the apk.
tmp_file = None
try:
tmp_fd, tmp_file = tempfile.mkstemp()
if subprocess.call(["unzip", "-p", apk, shared_lib_name], stdout=tmp_fd) == 0:
os.close(tmp_fd)
shared_file = tmp_file
tmp_file = None
return shared_file
finally:
if tmp_file:
os.close(tmp_fd)
os.unlink(tmp_file)
return None
def ProcessCentralInfo(self, offset_list, central_info):
match = self.zipinfo_central_info_match.search(central_info)
if not match:
raise Exception("Cannot find all info from zipinfo\n" + central_info)
name = match.group(1)
start = int(match.group(2))
end = start + int(match.group(3))
offset_list.append([name, start, end])
return name, start, end
def GetLibFromApk(self, apk, offset):
# Convert the string to hex.
offset = int(offset, 16)
# Check if we already have information about this offset.
if apk in self.apk_info:
apk_full_path, offset_list, tmp_files = self.apk_info[apk]
for file_name, start, end in offset_list:
if offset >= start and offset < end:
if file_name in tmp_files:
return file_name, tmp_files[file_name]
tmp_file = self.ExtractLibFromApk(apk_full_path, file_name)
if tmp_file:
tmp_files[file_name] = tmp_file
return file_name, tmp_file
break
return None, None
if not "ANDROID_PRODUCT_OUT" in os.environ:
print("ANDROID_PRODUCT_OUT environment variable not set.")
return None, None
out_dir = os.environ["ANDROID_PRODUCT_OUT"]
if not os.path.exists(out_dir):
print("ANDROID_PRODUCT_OUT", out_dir, "does not exist.")
return None, None
if apk.startswith("/"):
apk_full_path = out_dir + apk
else:
apk_full_path = os.path.join(out_dir, apk)
if not os.path.exists(apk_full_path):
print("Cannot find apk", apk)
return None, None
cmd = subprocess.Popen(["zipinfo", "-v", apk_full_path], stdout=subprocess.PIPE,
encoding='utf8')
# Find the first central info marker.
for line in cmd.stdout:
if self.zipinfo_central_directory_line.search(line):
break
central_info = ""
file_name = None
offset_list = []
for line in cmd.stdout:
match = self.zipinfo_central_directory_line.search(line)
if match:
cur_name, start, end = self.ProcessCentralInfo(offset_list, central_info)
if not file_name and offset >= start and offset < end:
file_name = cur_name
central_info = ""
else:
central_info += line
if central_info:
cur_name, start, end = self.ProcessCentralInfo(offset_list, central_info)
if not file_name and offset >= start and offset < end:
file_name = cur_name
# Make sure the offset_list is sorted, the zip file does not guarantee
# that the entries are in order.
offset_list = sorted(offset_list, key=lambda entry: entry[1])
# Save the information from the zip.
tmp_files = dict()
self.apk_info[apk] = [apk_full_path, offset_list, tmp_files]
if not file_name:
return None, None
tmp_shared_lib = self.ExtractLibFromApk(apk_full_path, file_name)
if tmp_shared_lib:
tmp_files[file_name] = tmp_shared_lib
return file_name, tmp_shared_lib
return None, None
# Find all files in the symbols directory and group them by basename (without directory).
@functools.lru_cache(maxsize=None)
def GlobSymbolsDir(self, symbols_dir):
files_by_basename = {}
for path in sorted(pathlib.Path(symbols_dir).glob("**/*")):
if os.path.isfile(path):
files_by_basename.setdefault(path.name, []).append(path)
return files_by_basename
# Use the "file" command line tool to find the bitness and build_id of given ELF file.
@functools.lru_cache(maxsize=None)
def GetLibraryInfo(self, lib):
stdout = subprocess.check_output([symbol.ToolPath("llvm-readelf"), "-h", "-n", lib], text=True)
match = self.readelf_output.search(stdout)
if match:
return self.ElfInfo(bitness=match.group("bitness"), build_id=match.group("build_id"))
return None
# Search for a library with the given basename and build_id anywhere in the symbols directory.
@functools.lru_cache(maxsize=None)
def GetLibraryByBuildId(self, symbols_dir, basename, build_id):
for candidate in self.GlobSymbolsDir(symbols_dir).get(basename, []):
info = self.GetLibraryInfo(candidate)
if info and info.build_id == build_id:
return "/" + str(candidate.relative_to(symbols_dir))
return None
def GetLibPath(self, lib):
if lib in self.lib_to_path:
return self.lib_to_path[lib]
lib_path = self.FindLibPath(lib)
self.lib_to_path[lib] = lib_path
return lib_path
def FindLibPath(self, lib):
symbol_dir = symbol.SYMBOLS_DIR
if os.path.isfile(symbol_dir + lib):
return lib
# Try and rewrite any apex files if not found in symbols.
# For some reason, the directory in symbols does not match
# the path on system.
# The path is com.android.<directory> on device, but
# com.google.android.<directory> in symbols.
new_lib = lib.replace("/com.android.", "/com.google.android.")
if os.path.isfile(symbol_dir + new_lib):
return new_lib
# When using atest, test paths are different between the out/ directory
# and device. Apply fixups.
if not lib.startswith("/data/local/tests/") and not lib.startswith("/data/local/tmp/"):
print("WARNING: Cannot find %s in symbol directory" % lib)
return lib
test_name = lib.rsplit("/", 1)[-1]
test_dir = "/data/nativetest"
test_dir_bitness = ""
if symbol.ARCH_IS_32BIT:
bitness = "32"
else:
bitness = "64"
test_dir_bitness = "64"
# Unfortunately, the location of the real symbol file is not
# standardized, so we need to go hunting for it.
# This is in vendor, look for the value in:
# /data/nativetest{64}/vendor/test_name/test_name
if lib.startswith("/data/local/tests/vendor/"):
lib_path = os.path.join(test_dir + test_dir_bitness, "vendor", test_name, test_name)
if os.path.isfile(symbol_dir + lib_path):
return lib_path
# Look for the path in:
# /data/nativetest{64}/test_name/test_name
lib_path = os.path.join(test_dir + test_dir_bitness, test_name, test_name)
if os.path.isfile(symbol_dir + lib_path):
return lib_path
# CtsXXX tests are in really non-standard locations try:
# /data/nativetest/{test_name}
lib_path = os.path.join(test_dir, test_name)
if os.path.isfile(symbol_dir + lib_path):
return lib_path
# Try:
# /data/nativetest/{test_name}{32|64}
lib_path += bitness
if os.path.isfile(symbol_dir + lib_path):
return lib_path
# Cannot find location, give up and return the original path
print("WARNING: Cannot find %s in symbol directory" % lib)
return lib
def ProcessLine(self, line):
ret = False
process_header = self.process_info_line.search(line)
signal_header = self.signal_line.search(line)
abort_message_header = self.abort_message_line.search(line)
thread_header = self.thread_line.search(line)
register_header = self.register_line.search(line)
revision_header = self.revision_line.search(line)
dalvik_jni_thread_header = self.dalvik_jni_thread_line.search(line)
dalvik_native_thread_header = self.dalvik_native_thread_line.search(line)
unreachable_header = self.unreachable_line.search(line)
if process_header or signal_header or abort_message_header or thread_header or \
register_header or dalvik_jni_thread_header or dalvik_native_thread_header or \
revision_header or unreachable_header:
ret = True
if self.trace_lines or self.value_lines:
self.PrintOutput(self.trace_lines, self.value_lines)
self.PrintDivider()
self.trace_lines = []
self.value_lines = []
self.last_frame = -1
if process_header:
print(process_header.group(1))
if signal_header:
print(signal_header.group(1))
if abort_message_header:
print(abort_message_header.group(1))
if register_header:
print(register_header.group(1))
if thread_header:
print(thread_header.group(1))
if dalvik_jni_thread_header:
print(dalvik_jni_thread_header.group(1))
if dalvik_native_thread_header:
print(dalvik_native_thread_header.group(1))
if revision_header:
print(revision_header.group(1))
if unreachable_header:
print(unreachable_header.group(1))
return True
trace_line_dict = self.MatchTraceLine(line)
if trace_line_dict is not None:
ret = True
frame = int(trace_line_dict["frame"])
code_addr = trace_line_dict["offset"]
area = trace_line_dict["dso"]
so_offset = trace_line_dict["so_offset"]
symbol_present = trace_line_dict["symbol_present"]
symbol_name = trace_line_dict["symbol_name"]
build_id = trace_line_dict["build_id"]
if frame <= self.last_frame and (self.trace_lines or self.value_lines):
self.PrintOutput(self.trace_lines, self.value_lines)
self.PrintDivider()
self.trace_lines = []
self.value_lines = []
self.last_frame = frame
if area == "<unknown>" or area == "[heap]" or area == "[stack]":
self.trace_lines.append((code_addr, "", area))
else:
# If this is an apk, it usually means that there is actually
# a shared so that was loaded directly out of it. In that case,
# extract the shared library and the name of the shared library.
lib = None
# The format of the map name:
# Some.apk!libshared.so
# or
# Some.apk
if so_offset:
# If it ends in apk, we are done.
apk = None
if area.endswith(".apk"):
apk = area
else:
index = area.rfind(".so!")
if index != -1:
# Sometimes we'll see something like:
# #01 pc abcd libart.so!libart.so (offset 0x134000)
# Remove everything after the ! and zero the offset value.
area = area[0:index + 3]
so_offset = 0
else:
index = area.rfind(".apk!")
if index != -1:
apk = area[0:index + 4]
if apk:
lib_name, lib = self.GetLibFromApk(apk, so_offset)
else:
# Sometimes we'll see something like:
# #01 pc abcd libart.so!libart.so
# Remove everything after the !.
index = area.rfind(".so!")
if index != -1:
area = area[0:index + 3]
if not lib:
lib = area
lib_name = None
if build_id:
# If we have the build_id, do a brute-force search of the symbols directory.
basename = os.path.basename(lib).split("!")[-1]
lib = self.GetLibraryByBuildId(symbol.SYMBOLS_DIR, basename, build_id)
if not lib:
print("WARNING: Cannot find {} with build id {} in symbols directory."
.format(basename, build_id))
else:
# When using atest, test paths are different between the out/ directory
# and device. Apply fixups.
lib = self.GetLibPath(lib)
# If a calls b which further calls c and c is inlined to b, we want to
# display "a -> b -> c" in the stack trace instead of just "a -> c"
info = symbol.SymbolInformation(lib, code_addr)
nest_count = len(info) - 1
for (source_symbol, source_location, symbol_with_offset) in info:
if not source_symbol:
if symbol_present:
source_symbol = symbol.CallCppFilt(symbol_name)
else:
source_symbol = "<unknown>"
if not symbol.VERBOSE:
source_symbol = symbol.FormatSymbolWithoutParameters(source_symbol)
symbol_with_offset = symbol.FormatSymbolWithoutParameters(symbol_with_offset)
if not source_location:
source_location = area
if lib_name:
source_location += "(" + lib_name + ")"
if nest_count > 0:
nest_count = nest_count - 1
arrow = "v------>"
if not symbol.ARCH_IS_32BIT:
arrow = "v-------------->"
self.trace_lines.append((arrow, source_symbol, source_location))
else:
if not symbol_with_offset:
symbol_with_offset = source_symbol
self.trace_lines.append((code_addr, symbol_with_offset, source_location))
if self.code_line.match(line):
# Code lines should be ignored. If this were exluded the 'code around'
# sections would trigger value_line matches.
return ret
if self.value_line.match(line):
ret = True
match = self.value_line.match(line)
(unused_, addr, value, area, symbol_present, symbol_name) = match.groups()
if area == "<unknown>" or area == "[heap]" or area == "[stack]" or not area:
self.value_lines.append((addr, value, "", area))
else:
info = symbol.SymbolInformation(area, value)
(source_symbol, source_location, object_symbol_with_offset) = info.pop()
# If there is no information, skip this.
if source_symbol or source_location or object_symbol_with_offset:
if not source_symbol:
if symbol_present:
source_symbol = symbol.CallCppFilt(symbol_name)
else:
source_symbol = "<unknown>"
if not source_location:
source_location = area
if not object_symbol_with_offset:
object_symbol_with_offset = source_symbol
self.value_lines.append((addr,
value,
object_symbol_with_offset,
source_location))
return ret
class RegisterPatternTests(unittest.TestCase):
def assert_register_matches(self, abi, example_crash, stupid_pattern):
tc = TraceConverter()
lines = example_crash.split('\n')
symbol.SetBitness(lines)
tc.UpdateBitnessRegexes()
for line in lines:
tc.ProcessLine(line)
is_register = (re.search(stupid_pattern, line) is not None)
matched = (tc.register_line.search(line) is not None)
self.assertEqual(matched, is_register, line)
tc.PrintOutput(tc.trace_lines, tc.value_lines)
def test_arm_registers(self):
self.assert_register_matches("arm", example_crashes.arm, '\\b(r0|r4|r8|ip|scr)\\b')
def test_arm64_registers(self):
self.assert_register_matches("arm64", example_crashes.arm64, '\\b(x0|x4|x8|x12|x16|x20|x24|x28|sp|v[1-3]?[0-9])\\b')
def test_x86_registers(self):
self.assert_register_matches("x86", example_crashes.x86, '\\b(eax|esi|xcs|eip)\\b')
def test_x86_64_registers(self):
self.assert_register_matches("x86_64", example_crashes.x86_64, '\\b(rax|rsi|r8|r12|cs|rip)\\b')
def test_riscv64_registers(self):
self.assert_register_matches("riscv64", example_crashes.riscv64, '\\b(gp|t2|t6|s3|s7|s11|a3|a7|sp)\\b')
class LibmemunreachablePatternTests(unittest.TestCase):
def test_libmemunreachable(self):
tc = TraceConverter()
lines = example_crashes.libmemunreachable.split('\n')
symbol.SetBitness(lines)
self.assertTrue(symbol.ARCH_IS_32BIT)
tc.UpdateBitnessRegexes()
header_lines = 0
trace_lines = 0
for line in lines:
tc.ProcessLine(line)
if re.search(tc.unreachable_line, line) is not None:
header_lines += 1
if tc.MatchTraceLine(line) is not None:
trace_lines += 1
self.assertEqual(header_lines, 3)
self.assertEqual(trace_lines, 2)
tc.PrintOutput(tc.trace_lines, tc.value_lines)
class LongASANStackTests(unittest.TestCase):
# Test that a long ASAN-style (non-padded frame numbers) stack trace is not split into two
# when the frame number becomes two digits. This happened before as the frame number was
# handled as a string and not converted to an integral.
def test_long_asan_crash(self):
tc = TraceConverter()
lines = example_crashes.long_asan_crash.splitlines()
symbol.SetBitness(lines)
tc.UpdateBitnessRegexes()
# Test by making sure trace_line_count is monotonically non-decreasing. If the stack trace
# is split, a separator is printed and trace_lines is flushed.
trace_line_count = 0
for line in lines:
tc.ProcessLine(line)
self.assertLessEqual(trace_line_count, len(tc.trace_lines))
trace_line_count = len(tc.trace_lines)
# The split happened at transition of frame #9 -> #10. Make sure we have parsed (and stored)
# more than ten frames.
self.assertGreater(trace_line_count, 10)
tc.PrintOutput(tc.trace_lines, tc.value_lines)
class ValueLinesTest(unittest.TestCase):
def test_value_line_skipped(self):
tc = TraceConverter()
symbol.ARCH_IS_32BIT = True
tc.UpdateBitnessRegexes()
tc.ProcessLine(" 12345678 00001000 .")
self.assertEqual([], tc.value_lines)
if __name__ == '__main__':
unittest.main(verbosity=2)