import python

private import semmle.python.objects.TObject

private import semmle.python.objects.ObjectInternal

private import semmle.python.pointsto.PointsTo

private import semmle.python.pointsto.PointsToContext

private import semmle.python.pointsto.MRO

private import semmle.python.types.Builtins

abstract class SequenceObjectInternal extends ObjectInternal {

/** Gets the `n`th item of this sequence, if one exists. */

abstract ObjectInternal getItem(int n);

override boolean booleanValue() {

this.length() = 0 and result = false

or

this.length() != 0 and result = true

}

override boolean isDescriptor() { result = false }

pragma[noinline]

override predicate descriptorGetClass(ObjectInternal cls, ObjectInternal value, CfgOrigin origin) {

none()

}

pragma[noinline]

override predicate descriptorGetInstance(

ObjectInternal instance, ObjectInternal value, CfgOrigin origin

) {

none()

}

pragma[noinline]

override predicate binds(ObjectInternal instance, string name, ObjectInternal descriptor) {

none()

}

override string getName() { none() }

override predicate contextSensitiveCallee() { none() }

override ObjectInternal getIterNext() { result = this.getItem(_) }

}

abstract class TupleObjectInternal extends SequenceObjectInternal {

override string toString() { result = "(" + this.contents(0) + ")" }

private string contents(int n) {

n < 4 and n = this.length() and result = ""

or

n = 3 and this.length() > 3 and result = (this.length() - 3).toString() + " more..."

or

result = this.item(n) + ", " + this.contents(n + 1)

}

private string item(int n) {

result = bounded_toString(this.getItem(n))

or

n in [0 .. this.length() - 1] and

not exists(this.getItem(n)) and

result = "?"

}

/** Gets the class declaration for this object, if it is a declared class. */

override ClassDecl getClassDeclaration() { none() }

/** True if this "object" is a class. */

override boolean isClass() { result = false }

override ObjectInternal getClass() { result = ObjectInternal::builtin("tuple") }

/**

* True if this "object" can be meaningfully analyzed for

* truth or false in comparisons. For example, `None` or `int` can be, but `int()`

* or an unknown string cannot.

*/

override predicate notTestableForEquality() { none() }

/**

* Holds if `obj` is the result of calling `this` and `origin` is

* the origin of `obj`.

*/

override predicate callResult(ObjectInternal obj, CfgOrigin origin) { none() }

/**

* Holds if `obj` is the result of calling `this` and `origin` is

* the origin of `obj` with callee context `callee`.

*/

override predicate callResult(PointsToContext callee, ObjectInternal obj, CfgOrigin origin) {

none()

}

override int intValue() { none() }

override string strValue() { none() }

override predicate calleeAndOffset(Function scope, int paramOffset) { none() }

pragma[noinline]

override predicate attribute(string name, ObjectInternal value, CfgOrigin origin) { none() }

pragma[noinline]

override predicate attributesUnknown() { none() }

override predicate subscriptUnknown() { none() }

}

/** A tuple built-in to the interpreter, including the empty tuple. */

class BuiltinTupleObjectInternal extends TBuiltinTuple, TupleObjectInternal {

override predicate introducedAt(ControlFlowNode node, PointsToContext context) { none() }

override Builtin getBuiltin() { this = TBuiltinTuple(result) }

override ControlFlowNode getOrigin() { none() }

override ObjectInternal getItem(int n) { result.getBuiltin() = this.getBuiltin().getItem(n) }

override int length() {

exists(Builtin b |

b = this.getBuiltin() and

result = count(int n | exists(b.getItem(n)))

)

}

override predicate useOriginAsLegacyObject() { none() }

override predicate isNotSubscriptedType() { any() }

}

/** A tuple declared by a tuple expression in the Python source code */

class PythonTupleObjectInternal extends TPythonTuple, TupleObjectInternal {

override predicate introducedAt(ControlFlowNode node, PointsToContext context) {

this = TPythonTuple(node, context)

}

override Builtin getBuiltin() { none() }

override ControlFlowNode getOrigin() { this = TPythonTuple(result, _) }

override ObjectInternal getItem(int n) {

exists(TupleNode t, PointsToContext context |

this = TPythonTuple(t, context) and

PointsToInternal::pointsTo(t.getElement(n), context, result, _)

)

}

override int length() {

exists(TupleNode t |

this = TPythonTuple(t, _) and

result = count(int n | exists(t.getElement(n)))

)

}

override predicate useOriginAsLegacyObject() { none() }

override predicate isNotSubscriptedType() { any() }

}

/** A tuple created by a `*` parameter */

class VarargsTupleObjectInternal extends TVarargsTuple, TupleObjectInternal {

override predicate introducedAt(ControlFlowNode node, PointsToContext context) { none() }

override Builtin getBuiltin() { none() }

override ControlFlowNode getOrigin() { none() }

override ObjectInternal getItem(int n) {

exists(CallNode call, PointsToContext context, int offset, int length |

this = TVarargsTuple(call, context, offset, length) and

n < length and

InterProceduralPointsTo::positional_argument_points_to(call, offset + n, context, result, _)

)

}

override int length() { this = TVarargsTuple(_, _, _, result) }

override predicate useOriginAsLegacyObject() { any() }

override predicate isNotSubscriptedType() { any() }

}

/**

* The `sys.version_info` object. We treat this specially to prevent premature pruning and

* false positives when we are unsure of the actual version of Python that the code is expecting.

*/

class SysVersionInfoObjectInternal extends TSysVersionInfo, SequenceObjectInternal {

override string toString() { result = "sys.version_info" }

override ObjectInternal getItem(int n) {

n = 0 and result = TInt(major_version())

or

n = 1 and result = TInt(minor_version())

}

override predicate introducedAt(ControlFlowNode node, PointsToContext context) { none() }

/** Gets the class declaration for this object, if it is a declared class. */

override ClassDecl getClassDeclaration() {

result = Builtin::special("sys").getMember("version_info").getClass()

}

/** True if this "object" is a class. */

override boolean isClass() { result = false }

override ObjectInternal getClass() { result.getBuiltin() = this.getClassDeclaration() }

override predicate notTestableForEquality() { none() }

/**

* Gets the `Builtin` for this object, if any.

* Objects (except unknown and undefined values) should attempt to return

* exactly one result for either this method or `getOrigin()`.

*/

override Builtin getBuiltin() { none() }

/**

* Gets a control flow node that represents the source origin of this

* objects.

*/

override ControlFlowNode getOrigin() { none() }

/**

* Holds if `obj` is the result of calling `this` and `origin` is

* the origin of `obj`.

*/

override predicate callResult(ObjectInternal obj, CfgOrigin origin) { none() }

/**

* Holds if `obj` is the result of calling `this` and `origin` is

* the origin of `obj` with callee context `callee`.

*/

override predicate callResult(PointsToContext callee, ObjectInternal obj, CfgOrigin origin) {

none()

}

override int intValue() { none() }

override string strValue() { none() }

override predicate calleeAndOffset(Function scope, int paramOffset) { none() }

override predicate attribute(string name, ObjectInternal value, CfgOrigin origin) { none() }

override predicate attributesUnknown() { none() }

override predicate subscriptUnknown() { none() }

override int length() { result = 5 }

override predicate functionAndOffset(CallableObjectInternal function, int offset) { none() }

override predicate useOriginAsLegacyObject() { any() }

override predicate isNotSubscriptedType() { any() }

}