Don't highlight missing call to super class constructor for exceptions (PY-7176)

python/src/com/jetbrains/python/inspections/PyBroadExceptionInspection.java

@@ -37,7 +37,7 @@ public class PyBroadExceptionInspection extends PyInspection {
     return new Visitor(holder, session);
   }
 
-  private static boolean equalsException(@NotNull PyClass cls, @NotNull TypeEvalContext context) {
+  public static boolean equalsException(@NotNull PyClass cls, @NotNull TypeEvalContext context) {
     final PyType type = cls.getType(context);
     return "Exception".equals(cls.getName()) && type != null && type.isBuiltin(context);
   }

python/src/com/jetbrains/python/inspections/PyMissingConstructorInspection.java

@@ -9,6 +9,7 @@ import com.jetbrains.python.PyBundle;
 import com.jetbrains.python.PyNames;
 import com.jetbrains.python.actions.AddCallSuperQuickFix;
 import com.jetbrains.python.psi.*;
+import com.jetbrains.python.psi.types.TypeEvalContext;
 import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -48,8 +49,9 @@ public class PyMissingConstructorInspection extends PyInspection {
       if (!superHasConstructor(node)) return;
       PyFunction initMethod = node.findMethodByName(PyNames.INIT, false);
       if (initMethod != null) {
-        if (hasConstructorCall(node, initMethod))
+        if (isExceptionClass(node, myTypeEvalContext) || hasConstructorCall(node, initMethod)) {
           return;
+        }
         if (superClasses.length == 1 || node.isNewStyleClass())
           registerProblem(initMethod.getNameIdentifier(), "Call to constructor of super class is missed",
                           new AddCallSuperQuickFix(node.getSuperClasses()[0], superClasses[0].getText()));
@@ -69,6 +71,18 @@ public class PyMissingConstructorInspection extends PyInspection {
       return false;
     }
 
+    private boolean isExceptionClass(@NotNull PyClass cls, @NotNull TypeEvalContext context) {
+      if (PyBroadExceptionInspection.equalsException(cls, context)) {
+        return true;
+      }
+      for (PyClass baseClass : cls.iterateAncestorClasses()) {
+        if (PyBroadExceptionInspection.equalsException(baseClass, context)) {
+          return true;
+        }
+      }
+      return false;
+    }
+
     private static boolean hasConstructorCall(PyClass node, PyFunction initMethod) {
       PyStatementList statementList = initMethod.getStatementList();
       CallVisitor visitor = new CallVisitor(node);

python/testData/inspections/PyMissingConstructorInspection/exception.py

@@ -0,0 +1,7 @@
+class C(Exception):
+    def __init__(self, x): #pass
+        self.x = x
+
+class C(KeyError):
+    def __init__(self, x): #pass
+        self.x = x

python/testSrc/com/jetbrains/python/inspections/PyMissingConstructorTest.java

@@ -32,6 +32,11 @@ public class PyMissingConstructorTest extends PyTestCase {
   public void testDunderClass() {  // PY-4038
     doTest();
   }
+
+  // PY-7176
+  public void testException() {
+    doTest();
+  }
   
   public void testPy3k() {
     setLanguageLevel(LanguageLevel.PYTHON30);