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-rw-r--r--Lib/test/test_genexps.py2
-rw-r--r--Lib/test/test_syntax.py238
-rw-r--r--Parser/Python.asdl1
-rw-r--r--Python/ast.c109
4 files changed, 314 insertions, 36 deletions
diff --git a/Lib/test/test_genexps.py b/Lib/test/test_genexps.py
index 7af3ac3..1556604 100644
--- a/Lib/test/test_genexps.py
+++ b/Lib/test/test_genexps.py
@@ -137,7 +137,7 @@ Verify that syntax error's are raised for genexps used as lvalues
>>> (y for y in (1,2)) = 10
Traceback (most recent call last):
...
- SyntaxError: assignment to generator expression not possible (<doctest test.test_genexps.__test__.doctests[40]>, line 1)
+ SyntaxError: can't assign to generator expression (<doctest test.test_genexps.__test__.doctests[40]>, line 1)
>>> (y for y in (1,2)) += 10
Traceback (most recent call last):
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index 14f4c95..b61debf 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -1,3 +1,239 @@
+"""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
+
+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():
+
+TODO(jhylton): "assignment to None" is inconsistent with other messages
+
+>>> obj.None = 1
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[1]>, line 1)
+
+>>> None = 1
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[2]>, line 1)
+
+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):
+SyntaxError: can't assign to () (<doctest test.test_syntax[3]>, line 1)
+
+>>> f() = 1
+Traceback (most recent call last):
+SyntaxError: can't assign to function call (<doctest test.test_syntax[4]>, line 1)
+
+>>> del f()
+Traceback (most recent call last):
+SyntaxError: can't delete function call (<doctest test.test_syntax[5]>, line 1)
+
+>>> a + 1 = 2
+Traceback (most recent call last):
+SyntaxError: can't assign to operator (<doctest test.test_syntax[6]>, line 1)
+
+>>> (x for x in x) = 1
+Traceback (most recent call last):
+SyntaxError: can't assign to generator expression (<doctest test.test_syntax[7]>, line 1)
+
+>>> 1 = 1
+Traceback (most recent call last):
+SyntaxError: can't assign to literal (<doctest test.test_syntax[8]>, line 1)
+
+>>> "abc" = 1
+Traceback (most recent call last):
+SyntaxError: can't assign to literal (<doctest test.test_syntax[9]>, line 1)
+
+>>> `1` = 1
+Traceback (most recent call last):
+SyntaxError: can't assign to repr (<doctest test.test_syntax[10]>, line 1)
+
+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):
+SyntaxError: can't assign to literal (<doctest test.test_syntax[11]>, line 1)
+
+>>> [a, b, c + 1] = [1, 2, 3]
+Traceback (most recent call last):
+SyntaxError: can't assign to operator (<doctest test.test_syntax[12]>, line 1)
+
+
+From compiler_complex_args():
+
+>>> def f(None=1):
+... pass
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[13]>, line 1)
+
+
+From ast_for_arguments():
+
+>>> def f(x, y=1, z):
+... pass
+Traceback (most recent call last):
+SyntaxError: non-default argument follows default argument (<doctest test.test_syntax[14]>, line 1)
+
+>>> def f(x, None):
+... pass
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[15]>, line 1)
+
+>>> def f(*None):
+... pass
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[16]>, line 1)
+
+>>> def f(**None):
+... pass
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[17]>, line 1)
+
+
+From ast_for_funcdef():
+
+>>> def None(x):
+... pass
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[18]>, line 1)
+
+
+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):
+SyntaxError: Generator expression must be parenthesized if not sole argument (<doctest test.test_syntax[22]>, line 1)
+>>> 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):
+SyntaxError: more than 255 arguments (<doctest test.test_syntax[24]>, line 1)
+
+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):
+SyntaxError: more than 255 arguments (<doctest test.test_syntax[25]>, line 1)
+
+>>> f(lambda x: x[0] = 3)
+Traceback (most recent call last):
+SyntaxError: lambda cannot contain assignment (<doctest test.test_syntax[26]>, line 1)
+
+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):
+SyntaxError: keyword can't be an expression (<doctest test.test_syntax[27]>, line 1)
+>>> f(a or b=1)
+Traceback (most recent call last):
+SyntaxError: keyword can't be an expression (<doctest test.test_syntax[28]>, line 1)
+>>> f(x.y=1)
+Traceback (most recent call last):
+SyntaxError: keyword can't be an expression (<doctest test.test_syntax[29]>, line 1)
+
+
+From ast_for_expr_stmt():
+
+>>> (x for x in x) += 1
+Traceback (most recent call last):
+SyntaxError: augmented assignment to generator expression not possible (<doctest test.test_syntax[30]>, line 1)
+>>> None += 1
+Traceback (most recent call last):
+SyntaxError: assignment to None (<doctest test.test_syntax[31]>, line 1)
+>>> f() += 1
+Traceback (most recent call last):
+SyntaxError: illegal expression for augmented assignment (<doctest test.test_syntax[32]>, line 1)
+"""
+
import re
import unittest
import warnings
@@ -56,6 +292,8 @@ class SyntaxTestCase(unittest.TestCase):
def test_main():
test_support.run_unittest(SyntaxTestCase)
+ from test import test_syntax
+ test_support.run_doctest(test_syntax, verbosity=True)
if __name__ == "__main__":
test_main()
diff --git a/Parser/Python.asdl b/Parser/Python.asdl
index d49138f..b0d383f 100644
--- a/Parser/Python.asdl
+++ b/Parser/Python.asdl
@@ -55,6 +55,7 @@ module Python
| Dict(expr* keys, expr* values)
| ListComp(expr elt, comprehension* generators)
| GeneratorExp(expr elt, comprehension* generators)
+ -- the grammar constrains where yield expressions can occur
| Yield(expr? value)
-- need sequences for compare to distinguish between
-- x < 4 < 3 and (x < 4) < 3
diff --git a/Python/ast.c b/Python/ast.c
index f155366..a2b69f5 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -329,6 +329,19 @@ static int
set_context(expr_ty e, expr_context_ty ctx, const node *n)
{
asdl_seq *s = NULL;
+ /* If a particular expression type can't be used for assign / delete,
+ set expr_name to its name and an error message will be generated.
+ */
+ const char* expr_name = NULL;
+
+ /* The ast defines augmented store and load contexts, but the
+ implementation here doesn't actually use them. The code may be
+ a little more complex than necessary as a result. It also means
+ that expressions in an augmented assignment have no context.
+ Consider restructuring so that augmented assignment uses
+ set_context(), too
+ */
+ assert(ctx != AugStore && ctx != AugLoad);
switch (e->kind) {
case Attribute_kind:
@@ -358,30 +371,50 @@ set_context(expr_ty e, expr_context_ty ctx, const node *n)
e->v.Tuple.ctx = ctx;
s = e->v.Tuple.elts;
break;
+ case Lambda_kind:
+ expr_name = "lambda";
+ break;
case Call_kind:
- if (ctx == Store)
- return ast_error(n, "can't assign to function call");
- else if (ctx == Del)
- return ast_error(n, "can't delete function call");
- else
- return ast_error(n, "unexpected operation on function call");
+ expr_name = "function call";
break;
+ case BoolOp_kind:
case BinOp_kind:
- return ast_error(n, "can't assign to operator");
+ case UnaryOp_kind:
+ expr_name = "operator";
+ break;
case GeneratorExp_kind:
- return ast_error(n, "assignment to generator expression "
- "not possible");
+ expr_name = "generator expression";
+ break;
+ case ListComp_kind:
+ expr_name = "list comprehension";
+ break;
+ case Dict_kind:
case Num_kind:
case Str_kind:
- return ast_error(n, "can't assign to literal");
- default: {
- char buf[300];
- PyOS_snprintf(buf, sizeof(buf),
- "unexpected expression in assignment %d (line %d)",
- e->kind, e->lineno);
- return ast_error(n, buf);
- }
+ expr_name = "literal";
+ break;
+ case Compare_kind:
+ expr_name = "comparison";
+ break;
+ case Repr_kind:
+ expr_name = "repr";
+ break;
+ default:
+ PyErr_Format(PyExc_SystemError,
+ "unexpected expression in assignment %d (line %d)",
+ e->kind, e->lineno);
+ return 0;
}
+ /* Check for error string set by switch */
+ if (expr_name) {
+ char buf[300];
+ PyOS_snprintf(buf, sizeof(buf),
+ "can't %s %s",
+ ctx == Store ? "assign to" : "delete",
+ expr_name);
+ return ast_error(n, buf);
+ }
+
/* If the LHS is a list or tuple, we need to set the assignment
context for all the tuple elements.
*/
@@ -699,12 +732,8 @@ ast_for_decorator(struct compiling *c, const node *n)
expr_ty name_expr;
REQ(n, decorator);
-
- if ((NCH(n) < 3 && NCH(n) != 5 && NCH(n) != 6)
- || TYPE(CHILD(n, 0)) != AT || TYPE(RCHILD(n, -1)) != NEWLINE) {
- ast_error(n, "Invalid decorator node");
- return NULL;
- }
+ REQ(CHILD(n, 0), AT);
+ REQ(RCHILD(n, -1), NEWLINE);
name_expr = ast_for_dotted_name(c, CHILD(n, 1));
if (!name_expr)
@@ -1610,7 +1639,7 @@ ast_for_call(struct compiling *c, const node *n, expr_ty func)
}
}
if (ngens > 1 || (ngens && (nargs || nkeywords))) {
- ast_error(n, "Generator expression must be parenthesised "
+ ast_error(n, "Generator expression must be parenthesized "
"if not sole argument");
return NULL;
}
@@ -1779,18 +1808,28 @@ ast_for_expr_stmt(struct compiling *c, const node *n)
if (!expr1)
return NULL;
- if (expr1->kind == GeneratorExp_kind) {
- ast_error(ch, "augmented assignment to generator "
- "expression not possible");
- return NULL;
+ // TODO(jhylton): Figure out why set_context() can't be used here.
+ switch (expr1->kind) {
+ case GeneratorExp_kind:
+ ast_error(ch, "augmented assignment to generator "
+ "expression not possible");
+ return NULL;
+ case Name_kind: {
+ const char *var_name = PyString_AS_STRING(expr1->v.Name.id);
+ if (var_name[0] == 'N' && !strcmp(var_name, "None")) {
+ ast_error(ch, "assignment to None");
+ return NULL;
+ }
+ break;
+ }
+ case Attribute_kind:
+ case Subscript_kind:
+ break;
+ default:
+ ast_error(ch, "illegal expression for augmented "
+ "assignment");
+ return NULL;
}
- if (expr1->kind == Name_kind) {
- char *var_name = PyString_AS_STRING(expr1->v.Name.id);
- if (var_name[0] == 'N' && !strcmp(var_name, "None")) {
- ast_error(ch, "assignment to None");
- return NULL;
- }
- }
ch = CHILD(n, 2);
if (TYPE(ch) == testlist)
generated by cgit v0.12 at 2025-01-18 09:08:03 (GMT)