def explain_asan_error(loc, output_stream, color):
if loc:
print("%s:%d" % (loc.filename, loc.line_number),
end=' ',
file=output_stream)
report = os.environ.get('DCC_ASAN_ERROR')
if report:
report = report.replace('-', ' ')
report = report.replace('heap', 'malloc')
report = report.replace('null deref', 'NULL pointer dereferenced')
else:
report = "illegal array, pointer or other operation"
print('runtime error -', color(report, 'red'), file=output_stream)
prefix = '\n' + color('dcc explanation:', 'cyan')
if "malloc buffer overflow" in report:
print(prefix,
"""access past the end of malloc'ed memory.
Make sure you have allocated enough memory for the size of your struct/array.
A common error is to use the size of a pointer instead of the size of the struct or array.
""",
file=output_stream)
print('For more information see:',
explanation_url('malloc_sizeof'),
file=output_stream)
if "stack buffer overflow" in report:
print(prefix,
"""access past the end of a local variable.
Make sure the size of your array is correct.
Make sure your array indices are correct.
""",
file=output_stream)
elif "use after return" in report:
print(
prefix,
"""You have used a pointer to a local variable that no longer exists.
When a function returns its local variables are destroyed.
""",
file=output_stream)
print('For more information see:',
explanation_url('stack_use_after_return'),
file=output_stream)
elif "use after" in report:
print(prefix,
"access to memory that has already been freed.\n",
file=output_stream)
elif "double free" in report:
print(prefix,
"attempt to free memory that has already been freed.\n",
file=output_stream)
elif "null" in report.lower():
print(prefix,
"attempt to access value using a pointer which is NULL.\n",
file=output_stream)
def get(self, message, colorize_output):
explanation = self.get_short_explanation(message, colorize_output)
if explanation and (self.long_explanation
or self.long_explanation_url):
url = self.long_explanation_url or explanation_url(self.label)
explanation += "\n See more information here: " + url
return explanation
def check_bad_characters(line, line_number, danger, expected):
if re.search(rb'[\x00-\x08\x14-\x1f\x7f-\xff]', expected):
return None
m = re.search(rb'^(.*?)([\x00-\x08\x14-\x1f\x7f-\xff])', line)
if not m:
return None
(prefix, offending_char) = m.groups()
offending_value = ord(offending_char)
if offending_value == 0:
description = "zero byte ('" + danger('\\0') + "')"
elif offending_value > 127:
description = "non-ascii byte " + danger("\\x%02x" % (offending_value))
else:
description = "non-printable character " + danger("\\x%02x" %
(offending_value))
column = len(prefix)
explanation = "a " + danger("non-ASCII byte") + " was printed.\n"
explanation += "Byte %d of line %d of program output was a %s\n" % (
column + 1, line_number, description)
explanation += "Here is line %d with non-printable characters replaced with backslash-escaped equivalents:\n" % (
line_number)
line = repr(line)[2:-1] + '\n'
line = re.sub(r'(\\x[0-9a-f][0-9a-f])', danger(r'\1'), line)
explanation += line
if offending_value == 255:
explanation += "\nHave you accidentally printed the special EOF value getchar returns?\n"
explanation += "For more information go to: " + explanation_url(
"eof_byte") + "\n"
return explanation
def explain_output_difference1(loc, output_stream, color):
# values supplied for expected output for this execution
expected_stdout = os.environb.get(b'DCC_EXPECTED_STDOUT', '')
# ignore_case = getenv_boolean('DCC_IGNORE_CASE')
# ignore_empty_lines = getenv_boolean('DCC_IGNORE_EMPTY_LINES')
ignore_trailing_white_space = getenv_boolean(
'DCC_IGNORE_TRAILING_WHITE_SPACE', default=True)
# compare_only_characters = os.environ.get('DCC_COMPARE_ONLY_CHARACTERS')
# value describing discrepency between actual and expected output
reason = os.environ.get('DCC_OUTPUT_ERROR', '')
line_number = getenv_int('DCC_ACTUAL_LINE_NUMBER')
# these values do not include current line
n_expected_bytes_seen = getenv_int('DCC_N_EXPECTED_BYTES_SEEN')
n_actual_bytes_seen = getenv_int('DCC_N_ACTUAL_BYTES_SEEN')
expected_line = os.environb.get(b'DCC_EXPECTED_LINE', '')
actual_line = os.environb.get(b'DCC_ACTUAL_LINE', '')
expected_column = getenv_int('DCC_EXPECTED_COLUMN')
actual_column = getenv_int('DCC_ACTUAL_COLUMN')
if 0 <= actual_column < len(actual_line):
actual_char = actual_line[actual_column]
else:
actual_char = None
if ignore_trailing_white_space and expected_stdout[-1:] == b'\n':
expected_stdout = expected_stdout.rstrip() + b'\n'
n_expected_lines = len(expected_stdout.splitlines())
is_last_expected_line = n_expected_bytes_seen + len(expected_line) >= len(
expected_stdout)
if 0 <= expected_column < len(expected_line):
expected_byte = expected_line[expected_column:expected_column + 1]
else:
expected_byte = None
# primary = lambda text, **kwargs: color(text, style='bold', **kwargs)
danger = lambda text, **kwargs: color(
text, fg='red', style='bold', **kwargs)
success = lambda text, **kwargs: color(
text, fg='green', style='bold', **kwargs)
# info = lambda text, **kwargs: color(text, fg='cyan', style='bold', **kwargs)
if not actual_line.endswith(b"\n"):
print("Execution failed because ", end='', file=output_stream)
else:
print("Execution stopped because ", end='', file=output_stream)
if reason == "expected line too long":
print("internal error: expected line too long", file=output_stream)
return
if reason == "line too long":
print("program wrote",
danger("a line containing over " + str(actual_column) +
" bytes."),
file=output_stream)
print("Do you have an infinite loop?", file=output_stream)
print_line(actual_line, "start of the", danger, output_stream)
return
if reason == "too much output":
print("program produced",
danger("too much output."),
file=output_stream)
print("Your program printed", actual_column, "bytes.")
print("Do you have an infinite loop?", file=output_stream)
print_line(actual_line, "last", danger, output_stream)
return
if reason == "zero byte":
print("a",
danger("zero byte ('\\0')"),
"was printed.",
file=output_stream)
print("Byte",
actual_column,
"of line",
line_number,
"of program's output was a zero byte ('\\0')",
file=output_stream)
if len(expected_line):
print("Here are the characters on the line before the zero byte:",
file=output_stream)
print(sanitize(actual_line), file=output_stream)
print("\nFor more information go to:",
explanation_url("zero_byte"),
file=output_stream)
return
if n_actual_bytes_seen == 0 and len(actual_line) == 0:
print("program produced", danger("no output."), file=output_stream)
print(n_expected_lines,
"lines of output were expected",
file=output_stream)
print_line(expected_line, "first expected", success, output_stream)
return
if len(actual_line) == 0:
print("of", danger("missing output lines."), file=output_stream)
print(
"Your program printed",
line_number,
"lines of correct output but stopped before printing all the expected output.",
file=output_stream)
print_line(expected_line, "next expected", success, output_stream)
return
if n_expected_bytes_seen == 0 and len(expected_line) == 0:
print("program produced",
danger("output when no output was expected."),
file=output_stream)
print_line(actual_line, "unexpected", danger, output_stream)
return
if len(expected_line) == 0:
print("of", danger("unexpected extra output."), file=output_stream)
print(
"The program produced all the expected output and then produced extra output.",
file=output_stream)
print_line(actual_line, "extra", danger, output_stream)
return
if is_last_expected_line and expected_byte == b'\n' and actual_char is None:
print('the last', danger("newline was missing."), file=output_stream)
print(
"Your program produced all the expected output, except the last newline ('\\n') was missing.",
file=output_stream)
print("\nFor more information go to",
explanation_url("missing_newline"),
file=output_stream)
return
show_line_length = max(len(expected_line) + 8, 80)
bad_characters_explanation = check_bad_characters(actual_line, line_number,
danger, expected_line)
if bad_characters_explanation:
print(bad_characters_explanation, end='', file=output_stream)
return
print("of an", danger('incorrect output line.'), file=output_stream)
print('Byte',
actual_column + 1,
'of line',
line_number,
"of program output was incorrect.",
file=output_stream)
if not actual_line[actual_column + 1:]:
if actual_line.rstrip(b'\n') + expected_byte == expected_line.rstrip(
b'\n'):
print("A",
"'" + danger(sanitize(expected_byte)) + "'",
"was missing from the end of the output line.",
file=output_stream)
elif actual_column > 1:
print(
"The characters you printed were correct, but more characters were expected.",
file=output_stream)
print("The correct output line was:", file=output_stream)
print(success(
sanitize(expected_line, max_line_length_shown=show_line_length)),
file=output_stream)
print("Your program printed this line:", file=output_stream)
correct_prefix = success(sanitize(actual_line[0:actual_column]))
print(correct_prefix, end='', file=output_stream)
incorrect_byte = actual_line[actual_column:actual_column + 1]
if incorrect_byte == ' ':
print(danger(sanitize(incorrect_byte), bg='red'),
end='',
file=output_stream)
else:
print(danger(sanitize(incorrect_byte)), end='', file=output_stream)
print(sanitize(actual_line[actual_column + 1:],
max_line_length_shown=show_line_length - actual_column),
file=output_stream)