JS backend: don't translate labels on expression

#KT-7487 Fixed

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/LabelTestGenerated.java

@@ -35,6 +35,12 @@ public class LabelTestGenerated extends AbstractLabelTest {
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("js/js.translator/testData/labels/cases"), Pattern.compile("^(.+)\\.kt$"), true);
     }
 
+    @TestMetadata("labelOnExpression.kt")
+    public void testLabelOnExpression() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("js/js.translator/testData/labels/cases/labelOnExpression.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("labelWithVariableClashing.kt")
     public void testLabelWithVariableClashing() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("js/js.translator/testData/labels/cases/labelWithVariableClashing.kt");

js/js.translator/src/org/jetbrains/kotlin/js/translate/expression/ExpressionVisitor.java

@@ -23,7 +23,6 @@ import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor;
 import org.jetbrains.kotlin.descriptors.VariableDescriptor;
-import org.jetbrains.kotlin.js.translate.context.TemporaryVariable;
 import org.jetbrains.kotlin.js.translate.context.TranslationContext;
 import org.jetbrains.kotlin.js.translate.declaration.ClassTranslator;
 import org.jetbrains.kotlin.js.translate.expression.loopTranslator.LoopTranslatorPackage;
@@ -49,7 +48,6 @@ import java.util.List;
 
 import static org.jetbrains.kotlin.js.translate.context.Namer.getCapturedVarAccessor;
 import static org.jetbrains.kotlin.js.translate.general.Translation.translateAsExpression;
-import static org.jetbrains.kotlin.js.translate.reference.CallExpressionTranslator.shouldBeInlined;
 import static org.jetbrains.kotlin.js.translate.reference.ReferenceTranslator.translateAsFQReference;
 import static org.jetbrains.kotlin.js.translate.utils.BindingUtils.*;
 import static org.jetbrains.kotlin.js.translate.utils.ErrorReportingUtils.message;
@@ -290,13 +288,21 @@ public final class ExpressionVisitor extends TranslatorVisitor<JsNode> {
     ) {
         JetExpression baseExpression = expression.getBaseExpression();
         assert baseExpression != null;
+
+        if (BindingContextUtilPackage.isUsedAsExpression(expression, context.bindingContext())) {
+            return Translation.translateAsExpression(baseExpression, context).source(expression);
+        }
+
         JsScope scope = context.scope();
         assert scope instanceof JsFunctionScope: "Labeled statement is unexpected outside of function scope";
         JsFunctionScope functionScope = (JsFunctionScope) scope;
+
         String labelIdent = getReferencedName(expression.getTargetLabel());
+
         JsName labelName = functionScope.enterLabel(labelIdent);
         JsStatement baseStatement = Translation.translateAsStatement(baseExpression, context);
         functionScope.exitLabel();
+
         return new JsLabel(labelName, baseStatement).source(expression);
     }
 

js/js.translator/testData/labels/cases/labelOnExpression.kt

@@ -0,0 +1,56 @@
+// CHECK_LABELS_COUNT: function=test0 count=0
+// CHECK_LABELS_COUNT: function=test1 count=0
+// CHECK_LABELS_COUNT: function=test2 count=0
+// CHECK_LABELS_COUNT: function=test3 count=0
+
+package foo
+
+fun myRun<R>(f: () -> R) = f()
+
+fun test0() {
+    val a = @aa 1
+
+    assertEquals(1, a)
+    assertEquals(3, @l1 a + @l2 2)
+
+    val b = @bb if (true) @t "then block" else @e "else block"
+
+    assertEquals("then block", b)
+}
+
+fun test1() {
+    run @label {
+        return@label false
+    }
+}
+
+fun test2() {
+    myRun @label {
+        return@label false
+    }
+}
+
+// KT-7487
+public fun test3() {
+    val f = Foo()
+    f.iter @label {
+        return@label false
+    }
+}
+
+class Foo {
+    inline fun iter(body: ()->Boolean) {
+        for (i in 0 .. 10) {
+            if (!body()) break
+        }
+    }
+}
+
+fun box(): String {
+    test0()
+    test1()
+    test2()
+    test3()
+
+    return "OK"
+}