python: Move the rewrite out to Scope.qll

Author: yoff

python/ql/lib/semmle/python/Scope.qll

@@ -1,4 +1,16 @@
 import python
+private import semmle.python.dataflow.new.internal.ImportResolution
+
+/**
+ * Gets a name exported by module `m`, that is the names that will be added to a namespace by 'from this-module import *'.
+ *
+ * This aims to be the same as m.getAnExport(), but without using the points-to machinery.
+ */
+private string getAModuleExport(Module m) {
+  py_exports(m, result)
+  or
+  ImportResolution::module_export(m, result, _)
+}
 
 /**
  * A Scope. A scope is the lexical extent over which all identifiers with the same name refer to the same variable.
@@ -74,9 +86,9 @@ class Scope extends Scope_ {
       or
       exists(Module m | m = this.getEnclosingScope() and m.isPublic() |
         /* If the module has an __all__, is this in it */
-        not exists(m.getAnExport())
+        not exists(getAModuleExport(m))
         or
-        m.getAnExport() = this.getName()
+        getAModuleExport(m) = this.getName()
       )
       or
       exists(Class c | c = this.getEnclosingScope() |