Python: Port a few queries to new API.

Author: markshannon

python/ql/src/Classes/EqualsOrHash.ql

@@ -13,34 +13,41 @@
 
 import python
 
-FunctionObject defines_equality(ClassObject c, string name) {
+CallableValue defines_equality(ClassValue c, string name) {
     (name = "__eq__" or major_version() = 2 and name = "__cmp__")
     and
     result = c.declaredAttribute(name)
 }
 
-FunctionObject implemented_method(ClassObject c, string name) {
+CallableValue implemented_method(ClassValue c, string name) {
     result = defines_equality(c, name)
     or
     result = c.declaredAttribute("__hash__") and name = "__hash__"
 }
 
-string unimplemented_method(ClassObject c) {
+string unimplemented_method(ClassValue c) {
     not exists(defines_equality(c, _)) and 
     (result = "__eq__" and major_version() = 3 or major_version() = 2 and result = "__eq__ or __cmp__")
     or
     /* Python 3 automatically makes classes unhashable if __eq__ is defined, but __hash__ is not */
     not c.declaresAttribute(result) and result = "__hash__" and major_version() = 2
 }
 
-predicate violates_hash_contract(ClassObject c, string present, string missing, Object method) {
-   not c.unhashable() and
+/** Holds if this class is unhashable */
+predicate unhashable(ClassValue cls) {
+    cls.lookup("__hash__") = Value::named("None")
+    or
+    cls.lookup("__hash__").(CallableValue).neverReturns()
+}
+
+predicate violates_hash_contract(ClassValue c, string present, string missing, Value method) {
+   not unhashable(c) and
    missing = unimplemented_method(c) and
    method = implemented_method(c, present) and
-   not c.unknowableAttributes()
+   not c.failedInference(_)
 }
 
-from ClassObject c, string present, string missing, FunctionObject method
+from ClassValue c, string present, string missing, CallableValue method
 where violates_hash_contract(c, present, missing, method) and
-exists(c.getPyClass()) // Suppress results that aren't from source
+exists(c.getScope()) // Suppress results that aren't from source
 select method, "Class $@ implements " + present + " but does not define " + missing + ".", c, c.getName()

python/ql/src/Classes/EqualsOrNotEquals.ql

@@ -25,26 +25,26 @@ predicate total_ordering(Class cls) {
            n.getId() = "total_ordering")
 }
 
-FunctionObject implemented_method(ClassObject c, string name) {
+CallableValue implemented_method(ClassValue c, string name) {
     result = c.declaredAttribute(name) and name = equals_or_ne()
 }
 
-string unimplemented_method(ClassObject c) {
+string unimplemented_method(ClassValue c) {
     not c.declaresAttribute(result) and result = equals_or_ne()
 }
 
-predicate violates_equality_contract(ClassObject c, string present, string missing, FunctionObject method) {
+predicate violates_equality_contract(ClassValue c, string present, string missing, CallableValue method) {
    missing = unimplemented_method(c) and
    method = implemented_method(c, present) and
-   not c.unknowableAttributes() and
-   not total_ordering(c.getPyClass()) and
+   not c.failedInference(_) and
+   not total_ordering(c.getScope()) and
    /* Python 3 automatically implements __ne__ if __eq__ is defined, but not vice-versa */
    not (major_version() = 3 and present = "__eq__" and missing = "__ne__") and
-   not method.getFunction() instanceof DelegatingEqualityMethod and
-   not c.lookupAttribute(missing).(FunctionObject).getFunction() instanceof DelegatingEqualityMethod
+   not method.getScope() instanceof DelegatingEqualityMethod and
+   not c.lookup(missing).(CallableValue).getScope() instanceof DelegatingEqualityMethod
 }
 
-from ClassObject c, string present, string missing, FunctionObject method
+from ClassValue c, string present, string missing, CallableValue method
 where violates_equality_contract(c, present, missing, method)
 
 select method, "Class $@ implements " + present + " but does not implement " + missing + ".", c, c.getName()

python/ql/src/Classes/IncompleteOrdering.ql

@@ -27,25 +27,25 @@ string ordering_name(int n) {
     result = "__ge__" and n = 4
 }
 
-predicate overrides_ordering_method(ClassObject c, string name) {
+predicate overrides_ordering_method(ClassValue c, string name) {
     name = ordering_name(_) and
     (
         c.declaresAttribute(name)
         or
-        exists(ClassObject sup | 
-            sup = c.getASuperType() and not sup = theObjectType() |
+        exists(ClassValue sup | 
+            sup = c.getASuperType() and not sup = Value::named("object") |
             sup.declaresAttribute(name)
         )
     )
 }
 
-string unimplemented_ordering(ClassObject c, int n) {
-    not c = theObjectType() and
+string unimplemented_ordering(ClassValue c, int n) {
+    not c = Value::named("object") and
     not overrides_ordering_method(c, result) and 
     result = ordering_name(n)
 }
 
-string unimplemented_ordering_methods(ClassObject c, int n) {
+string unimplemented_ordering_methods(ClassValue c, int n) {
     n = 0 and result = "" and exists(unimplemented_ordering(c, _))
     or
     exists(string prefix, int nm1 |
@@ -58,14 +58,14 @@ string unimplemented_ordering_methods(ClassObject c, int n) {
     )
 }
 
-Object ordering_method(ClassObject c, string name) {
+Value ordering_method(ClassValue c, string name) {
     /* If class doesn't declare a method then don't blame this class (the superclass will be blamed). */
    name = ordering_name(_) and result = c.declaredAttribute(name)
 }
 
-from ClassObject c, Object ordering, string name
-where not c.unknowableAttributes() and  
-not total_ordering(c.getPyClass())
+from ClassValue c, Value ordering, string name
+where not c.failedInference(_) and
+not total_ordering(c.getScope())
 and ordering = ordering_method(c, name) and
 exists(unimplemented_ordering(c, _))
 

python/ql/src/Expressions/HashedButNoHash.ql

@@ -17,37 +17,39 @@ import python
  * For numpy arrays, the index may be a list, which are not hashable and needs to be treated specially.
  */
 
-predicate numpy_array_type(ClassObject na) {
-    exists(ModuleObject np | np.getName() = "numpy" or np.getName() = "numpy.core" |
-        na.getAnImproperSuperType() = np.attr("ndarray")
+predicate numpy_array_type(ClassValue na) {
+    exists(ModuleValue np | np.getName() = "numpy" or np.getName() = "numpy.core" |
+        na.getASuperType() = np.attr("ndarray")
     )
 }
 
-predicate has_custom_getitem(ClassObject cls) {
-    cls.lookupAttribute("__getitem__") instanceof PyFunctionObject
+predicate has_custom_getitem(Value v) {
+    v.getClass().lookup("__getitem__") instanceof PythonFunctionValue
     or
-    numpy_array_type(cls)
+    numpy_array_type(v.getClass())
 }
 
 predicate explicitly_hashed(ControlFlowNode f) {
      exists(CallNode c, GlobalVariable hash | c.getArg(0) = f and c.getFunction().(NameNode).uses(hash) and hash.getId() = "hash")
 }
 
-predicate unhashable_subscript(ControlFlowNode f, ClassObject c, ControlFlowNode origin) {
+predicate unhashable_subscript(ControlFlowNode f, ClassValue c, ControlFlowNode origin) {
     is_unhashable(f, c, origin) and
     exists(SubscriptNode sub | sub.getIndex() = f |
-        exists(ClassObject custom_getitem |
-            sub.getObject().refersTo(_, custom_getitem, _) and
+        exists(Value custom_getitem |
+            sub.getObject().pointsTo(custom_getitem) and
             not has_custom_getitem(custom_getitem)
         )
     )
 }
 
-predicate is_unhashable(ControlFlowNode f, ClassObject cls, ControlFlowNode origin) {
-    f.refersTo(_, cls, origin) and
-    (not cls.hasAttribute("__hash__") and not cls.unknowableAttributes() and cls.isNewStyle()
-     or
-     cls.lookupAttribute("__hash__") = theNoneObject()
+predicate is_unhashable(ControlFlowNode f, ClassValue cls, ControlFlowNode origin) {
+    exists(Value v |
+        f.pointsTo(v, origin) and v.getClass() = cls
+        |
+        not cls.hasAttribute("__hash__") and not cls.failedInference(_) and cls.isNewStyle()
+        or
+        cls.lookup("__hash__") = Value::named("None")
     )
 }
 
@@ -70,7 +72,7 @@ predicate typeerror_is_caught(ControlFlowNode f) {
         try.getAHandler().getType().refersTo(theTypeErrorType()))
 }
 
-from ControlFlowNode f, ClassObject c, ControlFlowNode origin
+from ControlFlowNode f, ClassValue c, ControlFlowNode origin
 where
 not typeerror_is_caught(f)
 and

python/ql/src/Expressions/NonCallableCalled.ql

@@ -14,11 +14,11 @@
 import python
 import Exceptions.NotImplemented
 
-from Call c, ClassObject t, Expr f, AstNode origin
-where f = c.getFunc() and f.refersTo(_, t, origin) and
-      not t.isCallable() and not t.unknowableAttributes()
-      and not t.isDescriptorType()
-      and not t = theNoneType()
+from Call c, Value v, ClassValue t, Expr f, AstNode origin
+where f = c.getFunc() and f.pointsTo(v, origin) and t = v.getClass() and
+      not t.isCallable() and not t.failedInference(_)
+      and not t.hasAttribute("__get__")
+      and not v = Value::named("None")
       and not use_of_not_implemented_in_raise(_, f)
 
 select c, "Call to a $@ of $@.", origin, "non-callable", t, t.toString()

python/ql/src/semmle/python/objects/ObjectAPI.qll

@@ -384,6 +384,11 @@ class ClassValue extends Value {
         result = this.(PythonClassObjectInternal).getScope()
     }
 
+    /** Gets the attribute declared in this class */
+    Value declaredAttribute(string name) {
+        Types::declaredAttribute(this, name, result, _)
+    }
+
     /** Holds if this class has the attribute `name`, including
      * attributes declared by super classes.
      */

python/ql/test/3/query-tests/Classes/equals-hash/EqualsOrHash.expected

@@ -1 +1 @@
-| equals_hash.py:24:5:24:23 | Function __hash__ | Class $@ implements __hash__ but does not define __eq__. | equals_hash.py:19:1:19:19 | class Hash | Hash |
+| equals_hash.py:24:5:24:23 | Function Hash.__hash__ | Class $@ implements __hash__ but does not define __eq__. | equals_hash.py:19:1:19:19 | class Hash | Hash |

python/ql/test/3/query-tests/Classes/equals-ne/EqualsOrNotEquals.expected

@@ -1 +1 @@
-| test.py:9:5:9:28 | Function __ne__ | Class $@ implements __ne__ but does not implement __eq__. | test.py:7:1:7:13 | class NotOK2 | NotOK2 |
+| test.py:9:5:9:28 | Function NotOK2.__ne__ | Class $@ implements __ne__ but does not implement __eq__. | test.py:7:1:7:13 | class NotOK2 | NotOK2 |

python/ql/test/query-tests/Classes/incomplete-ordering/IncompleteOrdering.expected

@@ -1 +1 @@
-| incomplete_ordering.py:3:1:3:26 | class PartOrdered | Class PartOrdered implements $@, but does not implement __le__ or __gt__ or __ge__. | incomplete_ordering.py:13:5:13:28 | Function __lt__ | __lt__ |
+| incomplete_ordering.py:3:1:3:26 | class PartOrdered | Class PartOrdered implements $@, but does not implement __le__ or __gt__ or __ge__. | incomplete_ordering.py:13:5:13:28 | Function PartOrdered.__lt__ | __lt__ |

python/ql/test/query-tests/Expressions/callable/NonCallableCalled.expected

@@ -1,5 +1,5 @@
 | test.py:16:5:16:12 | non() | Call to a $@ of $@. | test.py:15:11:15:23 | NonCallable() | non-callable | test.py:3:1:3:26 | class NonCallable | class NonCallable |
-| test.py:17:5:17:8 | Tuple() | Call to a $@ of $@. | test.py:17:5:17:6 | Tuple | non-callable | file://:Compiled Code:0:0:0:0 | builtin-class tuple | builtin-class tuple |
-| test.py:18:5:18:8 | List() | Call to a $@ of $@. | test.py:18:5:18:6 | List | non-callable | file://:Compiled Code:0:0:0:0 | builtin-class list | builtin-class list |
+| test.py:17:5:17:8 | Tuple() | Call to a $@ of $@. | test.py:17:5:17:6 | Tuple | non-callable | file://:0:0:0:0 | builtin-class tuple | builtin-class tuple |
+| test.py:18:5:18:8 | List() | Call to a $@ of $@. | test.py:18:5:18:6 | List | non-callable | file://:0:0:0:0 | builtin-class list | builtin-class list |
 | test.py:26:9:26:16 | non() | Call to a $@ of $@. | test.py:15:11:15:23 | NonCallable() | non-callable | test.py:3:1:3:26 | class NonCallable | class NonCallable |
-| test.py:47:12:47:27 | NotImplemented() | Call to a $@ of $@. | test.py:47:12:47:25 | NotImplemented | non-callable | file://:Compiled Code:0:0:0:0 | builtin-class NotImplementedType | builtin-class NotImplementedType |
+| test.py:47:12:47:27 | NotImplemented() | Call to a $@ of $@. | test.py:47:12:47:25 | NotImplemented | non-callable | file://:0:0:0:0 | builtin-class NotImplementedType | builtin-class NotImplementedType |