From d0e26c6527fbd5cc34737c330b101b4d3d7f937a Mon Sep 17 00:00:00 2001
From: Mikhail Zarechenskiy <mikhail.zarechenskiy@jetbrains.com>
Date: Thu, 25 May 2017 12:16:04 +0300
Subject: [PATCH] Support underscores in non local destructuring declarations

---
 .../org/jetbrains/kotlin/codegen/ExpressionCodegen.java  | 3 ++-
 .../org/jetbrains/kotlin/codegen/PropertyCodegen.java    | 5 ++++-
 .../script/destructuringDeclarationUnderscore.kts        | 9 +++++++++
 .../kotlin/codegen/ScriptCodegenTestGenerated.java       | 6 ++++++
 4 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 compiler/testData/codegen/script/destructuringDeclarationUnderscore.kts

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
index 7a6b13cb8b2..1727d783106 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
@@ -73,6 +73,7 @@ import org.jetbrains.kotlin.resolve.calls.callUtil.CallUtilKt;
 import org.jetbrains.kotlin.resolve.calls.model.*;
 import org.jetbrains.kotlin.resolve.calls.util.CallMaker;
 import org.jetbrains.kotlin.resolve.calls.util.FakeCallableDescriptorForObject;
+import org.jetbrains.kotlin.resolve.calls.util.UnderscoreUtilKt;
 import org.jetbrains.kotlin.resolve.constants.CompileTimeConstant;
 import org.jetbrains.kotlin.resolve.constants.ConstantValue;
 import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator;
@@ -3495,7 +3496,7 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
             VariableDescriptor variableDescriptor = getVariableDescriptorNotNull(variableDeclaration);
 
             // Do not call `componentX` for destructuring entry called _
-            if (variableDescriptor.getName().isSpecial()) continue;
+            if (UnderscoreUtilKt.isSingleUnderscore(variableDeclaration)) continue;
 
             if (asProperty && variableDescriptor instanceof PropertyDescriptor) {
                 StackValue.Property propertyValue = intermediateValueForProperty(
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java
index fd86281e06f..7362932c291 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java
@@ -38,6 +38,7 @@ import org.jetbrains.kotlin.resolve.DescriptorFactory;
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils;
 import org.jetbrains.kotlin.resolve.annotations.AnnotationUtilKt;
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
+import org.jetbrains.kotlin.resolve.calls.util.UnderscoreUtilKt;
 import org.jetbrains.kotlin.resolve.constants.ConstantValue;
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOriginKt;
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodGenericSignature;
@@ -142,12 +143,14 @@ public class PropertyCodegen {
     }
 
     private void genDestructuringDeclaration(
-            @Nullable KtDestructuringDeclarationEntry entry,
+            @NotNull KtDestructuringDeclarationEntry entry,
             @NotNull PropertyDescriptor descriptor
     ) {
         assert kind == OwnerKind.PACKAGE || kind == OwnerKind.IMPLEMENTATION || kind == OwnerKind.DEFAULT_IMPLS
                 : "Generating property with a wrong kind (" + kind + "): " + descriptor;
 
+        if (UnderscoreUtilKt.isSingleUnderscore(entry)) return;
+
         genBackingFieldAndAnnotations(entry, descriptor, false);
 
         generateGetter(entry, descriptor, null);
diff --git a/compiler/testData/codegen/script/destructuringDeclarationUnderscore.kts b/compiler/testData/codegen/script/destructuringDeclarationUnderscore.kts
new file mode 100644
index 00000000000..2fc183d4a7f
--- /dev/null
+++ b/compiler/testData/codegen/script/destructuringDeclarationUnderscore.kts
@@ -0,0 +1,9 @@
+val (_, b, _) = A()
+
+class A {
+    operator fun component1(): Int = throw RuntimeException()
+    operator fun component2() = 2
+    operator fun component3(): Int = throw RuntimeException()
+}
+
+// expected: b: 2
\ No newline at end of file
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/ScriptCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/ScriptCodegenTestGenerated.java
index 8f6f23d6e1f..4e534d2ab6c 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/ScriptCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/ScriptCodegenTestGenerated.java
@@ -54,6 +54,12 @@ public class ScriptCodegenTestGenerated extends AbstractScriptCodegenTest {
         doTest(fileName);
     }
 
+    @TestMetadata("destructuringDeclarationUnderscore.kts")
+    public void testDestructuringDeclarationUnderscore() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/script/destructuringDeclarationUnderscore.kts");
+        doTest(fileName);
+    }
+
     @TestMetadata("empty.kts")
     public void testEmpty() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/script/empty.kts");