"""This module tests SyntaxErrors. | |
Here's an example of the sort of thing that is tested. | |
>>> def f(x): | |
... global x | |
Traceback (most recent call last): | |
SyntaxError: name 'x' is local and global (<doctest test.test_syntax[0]>, line 1) | |
The tests are all raise SyntaxErrors. They were created by checking | |
each C call that raises SyntaxError. There are several modules that | |
raise these exceptions-- ast.c, compile.c, future.c, pythonrun.c, and | |
symtable.c. | |
The parser itself outlaws a lot of invalid syntax. None of these | |
errors are tested here at the moment. We should add some tests; since | |
there are infinitely many programs with invalid syntax, we would need | |
to be judicious in selecting some. | |
The compiler generates a synthetic module name for code executed by | |
doctest. Since all the code comes from the same module, a suffix like | |
[1] is appended to the module name, As a consequence, changing the | |
order of tests in this module means renumbering all the errors after | |
it. (Maybe we should enable the ellipsis option for these tests.) | |
In ast.c, syntax errors are raised by calling ast_error(). | |
Errors from set_context(): | |
>>> obj.None = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[1]>", line 1 | |
SyntaxError: cannot assign to None | |
>>> None = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[2]>", line 1 | |
SyntaxError: cannot assign to None | |
It's a syntax error to assign to the empty tuple. Why isn't it an | |
error to assign to the empty list? It will always raise some error at | |
runtime. | |
>>> () = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[3]>", line 1 | |
SyntaxError: can't assign to () | |
>>> f() = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[4]>", line 1 | |
SyntaxError: can't assign to function call | |
>>> del f() | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[5]>", line 1 | |
SyntaxError: can't delete function call | |
>>> a + 1 = 2 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[6]>", line 1 | |
SyntaxError: can't assign to operator | |
>>> (x for x in x) = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[7]>", line 1 | |
SyntaxError: can't assign to generator expression | |
>>> 1 = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[8]>", line 1 | |
SyntaxError: can't assign to literal | |
>>> "abc" = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[8]>", line 1 | |
SyntaxError: can't assign to literal | |
>>> `1` = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[10]>", line 1 | |
SyntaxError: can't assign to repr | |
If the left-hand side of an assignment is a list or tuple, an illegal | |
expression inside that contain should still cause a syntax error. | |
This test just checks a couple of cases rather than enumerating all of | |
them. | |
>>> (a, "b", c) = (1, 2, 3) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[11]>", line 1 | |
SyntaxError: can't assign to literal | |
>>> [a, b, c + 1] = [1, 2, 3] | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[12]>", line 1 | |
SyntaxError: can't assign to operator | |
>>> a if 1 else b = 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[13]>", line 1 | |
SyntaxError: can't assign to conditional expression | |
From compiler_complex_args(): | |
>>> def f(None=1): | |
... pass | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[14]>", line 1 | |
SyntaxError: cannot assign to None | |
From ast_for_arguments(): | |
>>> def f(x, y=1, z): | |
... pass | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[15]>", line 1 | |
SyntaxError: non-default argument follows default argument | |
>>> def f(x, None): | |
... pass | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[16]>", line 1 | |
SyntaxError: cannot assign to None | |
>>> def f(*None): | |
... pass | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[17]>", line 1 | |
SyntaxError: cannot assign to None | |
>>> def f(**None): | |
... pass | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[18]>", line 1 | |
SyntaxError: cannot assign to None | |
From ast_for_funcdef(): | |
>>> def None(x): | |
... pass | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[19]>", line 1 | |
SyntaxError: cannot assign to None | |
From ast_for_call(): | |
>>> def f(it, *varargs): | |
... return list(it) | |
>>> L = range(10) | |
>>> f(x for x in L) | |
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9] | |
>>> f(x for x in L, 1) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[23]>", line 1 | |
SyntaxError: Generator expression must be parenthesized if not sole argument | |
>>> f((x for x in L), 1) | |
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9] | |
>>> f(i0, i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, | |
... i12, i13, i14, i15, i16, i17, i18, i19, i20, i21, i22, | |
... i23, i24, i25, i26, i27, i28, i29, i30, i31, i32, i33, | |
... i34, i35, i36, i37, i38, i39, i40, i41, i42, i43, i44, | |
... i45, i46, i47, i48, i49, i50, i51, i52, i53, i54, i55, | |
... i56, i57, i58, i59, i60, i61, i62, i63, i64, i65, i66, | |
... i67, i68, i69, i70, i71, i72, i73, i74, i75, i76, i77, | |
... i78, i79, i80, i81, i82, i83, i84, i85, i86, i87, i88, | |
... i89, i90, i91, i92, i93, i94, i95, i96, i97, i98, i99, | |
... i100, i101, i102, i103, i104, i105, i106, i107, i108, | |
... i109, i110, i111, i112, i113, i114, i115, i116, i117, | |
... i118, i119, i120, i121, i122, i123, i124, i125, i126, | |
... i127, i128, i129, i130, i131, i132, i133, i134, i135, | |
... i136, i137, i138, i139, i140, i141, i142, i143, i144, | |
... i145, i146, i147, i148, i149, i150, i151, i152, i153, | |
... i154, i155, i156, i157, i158, i159, i160, i161, i162, | |
... i163, i164, i165, i166, i167, i168, i169, i170, i171, | |
... i172, i173, i174, i175, i176, i177, i178, i179, i180, | |
... i181, i182, i183, i184, i185, i186, i187, i188, i189, | |
... i190, i191, i192, i193, i194, i195, i196, i197, i198, | |
... i199, i200, i201, i202, i203, i204, i205, i206, i207, | |
... i208, i209, i210, i211, i212, i213, i214, i215, i216, | |
... i217, i218, i219, i220, i221, i222, i223, i224, i225, | |
... i226, i227, i228, i229, i230, i231, i232, i233, i234, | |
... i235, i236, i237, i238, i239, i240, i241, i242, i243, | |
... i244, i245, i246, i247, i248, i249, i250, i251, i252, | |
... i253, i254, i255) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[25]>", line 1 | |
SyntaxError: more than 255 arguments | |
The actual error cases counts positional arguments, keyword arguments, | |
and generator expression arguments separately. This test combines the | |
three. | |
>>> f(i0, i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, | |
... i12, i13, i14, i15, i16, i17, i18, i19, i20, i21, i22, | |
... i23, i24, i25, i26, i27, i28, i29, i30, i31, i32, i33, | |
... i34, i35, i36, i37, i38, i39, i40, i41, i42, i43, i44, | |
... i45, i46, i47, i48, i49, i50, i51, i52, i53, i54, i55, | |
... i56, i57, i58, i59, i60, i61, i62, i63, i64, i65, i66, | |
... i67, i68, i69, i70, i71, i72, i73, i74, i75, i76, i77, | |
... i78, i79, i80, i81, i82, i83, i84, i85, i86, i87, i88, | |
... i89, i90, i91, i92, i93, i94, i95, i96, i97, i98, i99, | |
... i100, i101, i102, i103, i104, i105, i106, i107, i108, | |
... i109, i110, i111, i112, i113, i114, i115, i116, i117, | |
... i118, i119, i120, i121, i122, i123, i124, i125, i126, | |
... i127, i128, i129, i130, i131, i132, i133, i134, i135, | |
... i136, i137, i138, i139, i140, i141, i142, i143, i144, | |
... i145, i146, i147, i148, i149, i150, i151, i152, i153, | |
... i154, i155, i156, i157, i158, i159, i160, i161, i162, | |
... i163, i164, i165, i166, i167, i168, i169, i170, i171, | |
... i172, i173, i174, i175, i176, i177, i178, i179, i180, | |
... i181, i182, i183, i184, i185, i186, i187, i188, i189, | |
... i190, i191, i192, i193, i194, i195, i196, i197, i198, | |
... i199, i200, i201, i202, i203, i204, i205, i206, i207, | |
... i208, i209, i210, i211, i212, i213, i214, i215, i216, | |
... i217, i218, i219, i220, i221, i222, i223, i224, i225, | |
... i226, i227, i228, i229, i230, i231, i232, i233, i234, | |
... i235, i236, i237, i238, i239, i240, i241, i242, i243, | |
... (x for x in i244), i245, i246, i247, i248, i249, i250, i251, | |
... i252=1, i253=1, i254=1, i255=1) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[26]>", line 1 | |
SyntaxError: more than 255 arguments | |
>>> f(lambda x: x[0] = 3) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[27]>", line 1 | |
SyntaxError: lambda cannot contain assignment | |
The grammar accepts any test (basically, any expression) in the | |
keyword slot of a call site. Test a few different options. | |
>>> f(x()=2) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[28]>", line 1 | |
SyntaxError: keyword can't be an expression | |
>>> f(a or b=1) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[29]>", line 1 | |
SyntaxError: keyword can't be an expression | |
>>> f(x.y=1) | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[30]>", line 1 | |
SyntaxError: keyword can't be an expression | |
More set_context(): | |
>>> (x for x in x) += 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[31]>", line 1 | |
SyntaxError: can't assign to generator expression | |
>>> None += 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[32]>", line 1 | |
SyntaxError: cannot assign to None | |
>>> f() += 1 | |
Traceback (most recent call last): | |
File "<doctest test.test_syntax[33]>", line 1 | |
SyntaxError: can't assign to function call | |
Test continue in finally in weird combinations. | |
continue in for loop under finally should be ok. | |
>>> def test(): | |
... try: | |
... pass | |
... finally: | |
... for abc in range(10): | |
... continue | |
... print abc | |
>>> test() | |
9 | |
Start simple, a continue in a finally should not be allowed. | |
>>> def test(): | |
... for abc in range(10): | |
... try: | |
... pass | |
... finally: | |
... continue | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[36]>", line 6 | |
SyntaxError: 'continue' not supported inside 'finally' clause | |
This is essentially a continue in a finally which should not be allowed. | |
>>> def test(): | |
... for abc in range(10): | |
... try: | |
... pass | |
... finally: | |
... try: | |
... continue | |
... except: | |
... pass | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[37]>", line 6 | |
SyntaxError: 'continue' not supported inside 'finally' clause | |
>>> def foo(): | |
... try: | |
... pass | |
... finally: | |
... continue | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[38]>", line 5 | |
SyntaxError: 'continue' not supported inside 'finally' clause | |
>>> def foo(): | |
... for a in (): | |
... try: | |
... pass | |
... finally: | |
... continue | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[39]>", line 6 | |
SyntaxError: 'continue' not supported inside 'finally' clause | |
>>> def foo(): | |
... for a in (): | |
... try: | |
... pass | |
... finally: | |
... try: | |
... continue | |
... finally: | |
... pass | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[40]>", line 7 | |
SyntaxError: 'continue' not supported inside 'finally' clause | |
>>> def foo(): | |
... for a in (): | |
... try: pass | |
... finally: | |
... try: | |
... pass | |
... except: | |
... continue | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[41]>", line 8 | |
SyntaxError: 'continue' not supported inside 'finally' clause | |
There is one test for a break that is not in a loop. The compiler | |
uses a single data structure to keep track of try-finally and loops, | |
so we need to be sure that a break is actually inside a loop. If it | |
isn't, there should be a syntax error. | |
>>> try: | |
... print 1 | |
... break | |
... print 2 | |
... finally: | |
... print 3 | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[42]>", line 3 | |
SyntaxError: 'break' outside loop | |
This should probably raise a better error than a SystemError (or none at all). | |
In 2.5 there was a missing exception and an assert was triggered in a debug | |
build. The number of blocks must be greater than CO_MAXBLOCKS. SF #1565514 | |
>>> while 1: | |
... while 2: | |
... while 3: | |
... while 4: | |
... while 5: | |
... while 6: | |
... while 8: | |
... while 9: | |
... while 10: | |
... while 11: | |
... while 12: | |
... while 13: | |
... while 14: | |
... while 15: | |
... while 16: | |
... while 17: | |
... while 18: | |
... while 19: | |
... while 20: | |
... while 21: | |
... while 22: | |
... break | |
Traceback (most recent call last): | |
... | |
SystemError: too many statically nested blocks | |
This tests assignment-context; there was a bug in Python 2.5 where compiling | |
a complex 'if' (one with 'elif') would fail to notice an invalid suite, | |
leading to spurious errors. | |
>>> if 1: | |
... x() = 1 | |
... elif 1: | |
... pass | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[44]>", line 2 | |
SyntaxError: can't assign to function call | |
>>> if 1: | |
... pass | |
... elif 1: | |
... x() = 1 | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[45]>", line 4 | |
SyntaxError: can't assign to function call | |
>>> if 1: | |
... x() = 1 | |
... elif 1: | |
... pass | |
... else: | |
... pass | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[46]>", line 2 | |
SyntaxError: can't assign to function call | |
>>> if 1: | |
... pass | |
... elif 1: | |
... x() = 1 | |
... else: | |
... pass | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[47]>", line 4 | |
SyntaxError: can't assign to function call | |
>>> if 1: | |
... pass | |
... elif 1: | |
... pass | |
... else: | |
... x() = 1 | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[48]>", line 6 | |
SyntaxError: can't assign to function call | |
>>> f(a=23, a=234) | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[49]>", line 1 | |
SyntaxError: keyword argument repeated | |
>>> del () | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[50]>", line 1 | |
SyntaxError: can't delete () | |
>>> {1, 2, 3} = 42 | |
Traceback (most recent call last): | |
... | |
File "<doctest test.test_syntax[50]>", line 1 | |
SyntaxError: can't assign to literal | |
Corner-case that used to crash: | |
>>> def f(*xx, **__debug__): pass | |
Traceback (most recent call last): | |
SyntaxError: cannot assign to __debug__ | |
""" | |
import re | |
import unittest | |
import warnings | |
from test import test_support | |
class SyntaxTestCase(unittest.TestCase): | |
def _check_error(self, code, errtext, | |
filename="<testcase>", mode="exec", subclass=None): | |
"""Check that compiling code raises SyntaxError with errtext. | |
errtest is a regular expression that must be present in the | |
test of the exception raised. If subclass is specified it | |
is the expected subclass of SyntaxError (e.g. IndentationError). | |
""" | |
try: | |
compile(code, filename, mode) | |
except SyntaxError, err: | |
if subclass and not isinstance(err, subclass): | |
self.fail("SyntaxError is not a %s" % subclass.__name__) | |
mo = re.search(errtext, str(err)) | |
if mo is None: | |
self.fail("%s did not contain '%r'" % (err, errtext,)) | |
else: | |
self.fail("compile() did not raise SyntaxError") | |
def test_paren_arg_with_default(self): | |
self._check_error("def f((x)=23): pass", | |
"parenthesized arg with default") | |
def test_assign_call(self): | |
self._check_error("f() = 1", "assign") | |
def test_assign_del(self): | |
self._check_error("del f()", "delete") | |
def test_global_err_then_warn(self): | |
# Bug tickler: The SyntaxError raised for one global statement | |
# shouldn't be clobbered by a SyntaxWarning issued for a later one. | |
source = re.sub('(?m)^ *:', '', """\ | |
:def error(a): | |
: global a # SyntaxError | |
:def warning(): | |
: b = 1 | |
: global b # SyntaxWarning | |
:""") | |
warnings.filterwarnings(action='ignore', category=SyntaxWarning) | |
self._check_error(source, "global") | |
warnings.filters.pop(0) | |
def test_break_outside_loop(self): | |
self._check_error("break", "outside loop") | |
def test_delete_deref(self): | |
source = re.sub('(?m)^ *:', '', """\ | |
:def foo(x): | |
: def bar(): | |
: print x | |
: del x | |
:""") | |
self._check_error(source, "nested scope") | |
def test_unexpected_indent(self): | |
self._check_error("foo()\n bar()\n", "unexpected indent", | |
subclass=IndentationError) | |
def test_no_indent(self): | |
self._check_error("if 1:\nfoo()", "expected an indented block", | |
subclass=IndentationError) | |
def test_bad_outdent(self): | |
self._check_error("if 1:\n foo()\n bar()", | |
"unindent does not match .* level", | |
subclass=IndentationError) | |
def test_kwargs_last(self): | |
self._check_error("int(base=10, '2')", "non-keyword arg") | |
def test_main(): | |
test_support.run_unittest(SyntaxTestCase) | |
from test import test_syntax | |
with test_support.check_py3k_warnings(("backquote not supported", | |
SyntaxWarning)): | |
test_support.run_doctest(test_syntax, verbosity=True) | |
if __name__ == "__main__": | |
test_main() |