Merge branch '0.29.x'

CHANGES.rst

@@ -92,6 +92,13 @@ Other changes
 * Support for Python 2.6 was removed.
 
 
+0.29.4 (2019-02-01)
+===================
+
+* Division of numeric constants by a runtime value of 0 could fail to raise a
+  ``ZeroDivisionError``.  (Github issue #2820)
+
+
 0.29.3 (2019-01-19)
 ===================
 

Cython/Compiler/Optimize.py

@@ -3166,6 +3166,7 @@ class OptimizeBuiltinCalls(Visitor.NodeRefCleanupMixin,
                 PyrexTypes.CFuncTypeArg("op2", PyrexTypes.py_object_type, None),
                 PyrexTypes.CFuncTypeArg("cval", ctype, None),
                 PyrexTypes.CFuncTypeArg("inplace", PyrexTypes.c_bint_type, None),
+                PyrexTypes.CFuncTypeArg("zerodiv_check", PyrexTypes.c_bint_type, None),
             ], exception_value=None if ret_type.is_pyobject else ret_type.exception_value))
         for ctype in (PyrexTypes.c_long_type, PyrexTypes.c_double_type)
         for ret_type in (PyrexTypes.py_object_type, PyrexTypes.c_bint_type)
@@ -3300,12 +3301,22 @@ class OptimizeBuiltinCalls(Visitor.NodeRefCleanupMixin,
             # Cut off at an integer border that is still safe for all operations.
             return node
 
+        if operator in ('TrueDivide', 'FloorDivide', 'Divide', 'Remainder'):
+            if args[1].constant_result == 0:
+                # Don't optimise division by 0. :)
+                return node
+
         args = list(args)
         args.append((ExprNodes.FloatNode if is_float else ExprNodes.IntNode)(
             numval.pos, value=numval.value, constant_result=numval.constant_result,
             type=num_type))
         inplace = node.inplace if isinstance(node, ExprNodes.NumBinopNode) else False
         args.append(ExprNodes.BoolNode(node.pos, value=inplace, constant_result=inplace))
+        if is_float or operator not in ('Eq', 'Ne'):
+            # "PyFloatBinop" and "PyIntBinop" take an additional "check for zero division" argument.
+            zerodivision_check = arg_order == 'CObj' and (
+                not node.cdivision if isinstance(node, ExprNodes.DivNode) else False)
+            args.append(ExprNodes.BoolNode(node.pos, value=zerodivision_check, constant_result=zerodivision_check))
 
         utility_code = TempitaUtilityCode.load_cached(
             "PyFloatBinop" if is_float else "PyIntCompare" if operator in ('Eq', 'Ne') else "PyIntBinop",

tests/run/float_division.pyx

@@ -26,6 +26,39 @@ def float_by_float():
     return 3.0 / 2.0
 
 
+def div_by_0(x):
+    """
+    >>> div_by_0(0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_by_0(0.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_by_0(1)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_by_0(1.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> float('inf') / 0.0  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_by_0(float('inf'))  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_by_0(float('-inf'))  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> float('nan') / 0.0  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_by_0(float('nan'))  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    """
+    return x / 0.0
+
+
 def div_1_by(x):
     """
     >>> div_1_by(1.0)
@@ -42,6 +75,12 @@ def div_1_by(x):
     -0.0
     >>> div_1_by(float('nan'))
     nan
+    >>> div_1_by(0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_1_by(0.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
     """
     return 1.0 / x
 
@@ -116,6 +155,12 @@ def div_neg_2_by(x):
     nan
     >>> div_neg_2_by(float('nan'))
     nan
+    >>> div_neg_2_by(0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_neg_2_by(0.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
     """
     return (-2.0) / x
 
@@ -148,6 +193,12 @@ def div_nan_by(x):
     nan
     >>> div_nan_by(float('nan'))
     nan
+    >>> div_nan_by(0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_nan_by(0.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
     """
     return float("nan") / x
 
@@ -182,6 +233,15 @@ def div_inf_by(x):
     nan
     >>> div_inf_by(float('-inf'))
     nan
+    >>> float("inf") / 0.0  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_inf_by(0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_inf_by(0.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
     """
     return float("inf") / x
 
@@ -196,5 +256,14 @@ def div_neg_inf_by(x):
     inf
     >>> div_neg_inf_by(-1.0)
     inf
+    >>> float("-inf") / 0.0  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_neg_inf_by(0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
+    >>> div_neg_inf_by(0.0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: float division...
     """
     return float("-inf") / x

tests/run/future_division.pyx

@@ -157,3 +157,73 @@ def int_int(int a, int b):
     (0.5, 2.0)
     """
     return a/b, b/a
+
+
+def div_by_0(a):
+    """
+    >>> div_by_0(0)
+    'OK'
+    >>> div_by_0(0.0)
+    'OK'
+    """
+    try:
+        1/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 1"
+    try:
+        1//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 2"
+    try:
+        5.0/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 3"
+    try:
+        5.0//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 4"
+    try:
+        5/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 5"
+    try:
+        5//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 6"
+    try:
+        (2**15)/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 7"
+    try:
+        (2**15)//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 8"
+    try:
+        (2**30)/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 9"
+    try:
+        (2**30)//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 10"
+    return 'OK'

tests/run/modop.pyx

@@ -7,6 +7,9 @@ def modobj(obj2, obj3):
     1
     >>> modobj('%d', 5)
     '5'
+    >>> modobj(1, 0)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    ZeroDivisionError: integer division or modulo by zero
     """
     obj1 = obj2 % obj3
     return obj1

tests/run/non_future_division.pyx

@@ -143,3 +143,73 @@ def int_int(int a, int b):
     (0, 2)
     """
     return a/b, b/a
+
+
+def div_by_0(a):
+    """
+    >>> div_by_0(0)
+    'OK'
+    >>> div_by_0(0.0)
+    'OK'
+    """
+    try:
+        1/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 1"
+    try:
+        1//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 2"
+    try:
+        5.0/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 3"
+    try:
+        5.0//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 4"
+    try:
+        5/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 5"
+    try:
+        5//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 6"
+    try:
+        (2**15)/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 7"
+    try:
+        (2**15)//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 8"
+    try:
+        (2**30)/a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 9"
+    try:
+        (2**30)//a
+    except ZeroDivisionError:
+        pass
+    else:
+        return "FAIL 10"
+    return 'OK'