Python: Remove points-to from Module

Author: tausbn

python/ql/lib/LegacyPointsTo.qll

@@ -21,6 +21,7 @@
 
 private import python
 private import semmle.python.pointsto.PointsTo
+private import semmle.python.objects.Modules
 
 /**
  * An extension of `ControlFlowNode` that provides points-to predicates.
@@ -191,3 +192,19 @@ class ExprWithPointsTo extends Expr {
 
   override string getAQlClass() { none() }
 }
+
+/**
+ * An extension of `Module` that provides points-to related methods.
+ */
+class ModuleWithPointsTo extends Module {
+  /** Gets a name exported by this module, that is the names that will be added to a namespace by 'from this-module import *' */
+  string getAnExport() {
+    py_exports(this, result)
+    or
+    exists(ModuleObjectInternal mod | mod.getSource() = this.getEntryNode() |
+      mod.(ModuleValue).exports(result)
+    )
+  }
+
+  override string getAQlClass() { none() }
+}

python/ql/lib/semmle/python/Module.qll

@@ -1,5 +1,4 @@
 import python
-private import semmle.python.objects.Modules
 private import semmle.python.internal.CachedStages
 
 /**
@@ -66,15 +65,6 @@ class Module extends Module_, Scope, AstNode {
   /** Whether this module is a package initializer */
   predicate isPackageInit() { this.getName().matches("%\\_\\_init\\_\\_") and not this.isPackage() }
 
-  /** Gets a name exported by this module, that is the names that will be added to a namespace by 'from this-module import *' */
-  string getAnExport() {
-    py_exports(this, result)
-    or
-    exists(ModuleObjectInternal mod | mod.getSource() = this.getEntryNode() |
-      mod.(ModuleValue).exports(result)
-    )
-  }
-
   /** Gets the source file for this module */
   File getFile() { py_module_path(this, result) }
 

python/ql/src/Variables/UnusedModuleVariable.ql

@@ -13,6 +13,7 @@
  */
 
 import python
+private import LegacyPointsTo
 import Definition
 
 /**
@@ -58,7 +59,7 @@ predicate unused_global(Name unused, GlobalVariable v) {
       // indirectly
       defn.getBasicBlock().reachesExit() and u.getScope() != unused.getScope()
     ) and
-    not unused.getEnclosingModule().getAnExport() = v.getId() and
+    not unused.getEnclosingModule().(ModuleWithPointsTo).getAnExport() = v.getId() and
     not exists(unused.getParentNode().(ClassDef).getDefinedClass().getADecorator()) and
     not exists(unused.getParentNode().(FunctionDef).getDefinedFunction().getADecorator()) and
     unused.defines(v) and

python/ql/test/extractor-tests/exports/Test.ql

@@ -1,4 +1,5 @@
 import python
+private import LegacyPointsTo
 
-from Module m
+from ModuleWithPointsTo m
 select m.toString(), m.getAnExport().toString()