simple way to generate short-circuit boolean && and ||

idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -497,12 +497,17 @@ public class ExpressionCodegen extends JetVisitor {
         final IElementType opToken = expression.getOperationReference().getReferencedNameElementType();
         if (opToken == JetTokens.EQ) {
             generateAssignmentExpression(expression);
-            return;
         }
-        if (JetTokens.AUGMENTED_ASSIGNMENTS.contains(opToken)) {
+        else if (JetTokens.AUGMENTED_ASSIGNMENTS.contains(opToken)) {
             generateAugmentedAssignment(expression);
-            return;
         }
+        else if (opToken == JetTokens.ANDAND) {
+            generateBooleanAnd(expression);
+        }
+        else if (opToken == JetTokens.OROR) {
+            generateBooleanOr(expression);
+        }
+        else {
             DeclarationDescriptor op = bindingContext.resolveReferenceExpression(expression.getOperationReference());
             if (op instanceof FunctionDescriptor) {
                 JetType returnType = bindingContext.getExpressionType(expression);
@@ -534,6 +539,33 @@ public class ExpressionCodegen extends JetVisitor {
             }
             throw new UnsupportedOperationException("Don't know how to generate binary op " + expression);
         }
+    }
+
+    private void generateBooleanAnd(JetBinaryExpression expression) {
+        gen(expression.getLeft(), Type.BOOLEAN_TYPE);
+        Label ifFalse = new Label();
+        v.ifeq(ifFalse);
+        gen(expression.getRight(), Type.BOOLEAN_TYPE);
+        Label end = new Label();
+        v.goTo(end);
+        v.mark(ifFalse);
+        v.aconst(false);
+        v.mark(end);
+        myStack.push(StackValue.onStack(Type.BOOLEAN_TYPE));
+    }
+
+    private void generateBooleanOr(JetBinaryExpression expression) {
+        gen(expression.getLeft(), Type.BOOLEAN_TYPE);
+        Label ifTrue = new Label();
+        v.ifne(ifTrue);
+        gen(expression.getRight(), Type.BOOLEAN_TYPE);
+        Label end = new Label();
+        v.goTo(end);
+        v.mark(ifTrue);
+        v.aconst(true);
+        v.mark(end);
+        myStack.push(StackValue.onStack(Type.BOOLEAN_TYPE));
+    }
 
     private static boolean isNumberPrimitive(DeclarationDescriptor descriptor) {
         if (!(descriptor instanceof ClassDescriptor)) {

idea/tests/org/jetbrains/jet/codegen/NamespaceGenTest.java

@@ -451,6 +451,36 @@ public class NamespaceGenTest extends LightCodeInsightFixtureTestCase {
         assertEquals(0, main.invoke(null, 4));
     }
 
+    public void testAnd() throws Exception {
+        loadText("fun foo(a : Int): Boolean = a > 0 && a/0 > 0");
+        final Method main = generateFunction();
+        assertEquals(false, main.invoke(null, 0));
+        boolean hadException = false;
+        try {
+            main.invoke(null, 5);
+        } catch (InvocationTargetException e) {
+            if (e.getTargetException() instanceof ArithmeticException) {
+                hadException = true;
+            }
+        }
+        assertTrue(hadException);
+    }
+
+    public void testOr() throws Exception {
+        loadText("fun foo(a : Int): Boolean = a > 0 || a/0 > 0");
+        final Method main = generateFunction();
+        assertEquals(true, main.invoke(null, 5));
+        boolean hadException = false;
+        try {
+            main.invoke(null, 0);
+        } catch (InvocationTargetException e) {
+            if (e.getTargetException() instanceof ArithmeticException) {
+                hadException = true;
+            }
+        }
+        assertTrue(hadException);
+    }
+
     private void binOpTest(final String text, final Object arg1, final Object arg2, final Object expected) throws Exception {
         loadText(text);
         System.out.println(generateToText());