Python: Start scaffold for magic methods

yoff · yoff · commit 5ed31070452b · 2020-08-14T11:12:23.000+02:00
diff --git a/python/ql/src/semmle/python/Magic.qll b/python/ql/src/semmle/python/Magic.qll
@@ -0,0 +1,36 @@
+import python
+
+module MagicMethod {
+  abstract class Potential extends ControlFlowNode {
+    abstract string getMagicMethodName();
+    abstract ControlFlowNode getArg(int n);
+    ControlFlowNode getSelf() { result = this.getArg(1) }
+  }
+
+  class Actual extends ControlFlowNode {
+    Object resolvedMagicMethod;
+
+    Actual() {
+      exists(Potential pot |
+        this.(Potential) = pot and
+        pot.getSelf().(ClassObject).lookupAttribute(pot.getMagicMethodName()) = resolvedMagicMethod
+      )
+    }
+  }
+}
+
+class MagicBinOp extends MagicMethod::Potential, BinaryExprNode {
+  Operator operator;
+
+  MagicBinOp() { this.getOp() = operator}
+
+  override string getMagicMethodName() {
+    result = operator.getSpecialMethodName()
+  }
+
+  override ControlFlowNode getArg(int n) {
+    n = 1 and result = this.getLeft()
+    or
+    n = 2 and result = this.getRight()
+  }
+}
