Remove custom lookup-single-target implementation in class inliner

Bug: 142116551
Change-Id: Idf1d8bbefb6acbdbf22631e2f9c78cd52fee7a4c
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/classinliner/InlineCandidateProcessor.java b/src/main/java/com/android/tools/r8/ir/optimize/classinliner/InlineCandidateProcessor.java
index 0ba6b03..98f5a47 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/classinliner/InlineCandidateProcessor.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/classinliner/InlineCandidateProcessor.java
@@ -318,7 +318,8 @@
 
         if (user.isInvokeMethod()) {
           InvokeMethod invokeMethod = user.asInvokeMethod();
-          DexEncodedMethod singleTarget = findSingleTarget(invokeMethod);
+          DexEncodedMethod singleTarget =
+              invokeMethod.lookupSingleTarget(appView, method.method.holder);
           if (!isEligibleSingleTarget(singleTarget)) {
             return user; // Not eligible.
           }
@@ -1107,26 +1108,13 @@
     }
   }
 
-  private DexEncodedMethod findSingleTarget(InvokeMethod invoke) {
-    if (isExtraMethodCall(invoke)) {
-      DexType invocationContext = method.method.holder;
-      return invoke.lookupSingleTarget(appView, invocationContext);
-    }
-    // We don't use computeSingleTarget(...) on invoke since it sometimes fails to
-    // find the single target, while this code may be more successful since we exactly
-    // know what is the actual type of the receiver.
-
-    // Note that we also intentionally limit ourselves to methods directly defined in
-    // the instance's class. This may be improved later.
-    return invoke.isInvokeDirect()
-        ? eligibleClassDefinition.lookupDirectMethod(invoke.getInvokedMethod())
-        : eligibleClassDefinition.lookupVirtualMethod(invoke.getInvokedMethod());
-  }
-
   private boolean isEligibleSingleTarget(DexEncodedMethod singleTarget) {
     if (singleTarget == null) {
       return false;
     }
+    if (!singleTarget.isProgramMethod(appView)) {
+      return false;
+    }
     if (isProcessedConcurrently.test(singleTarget)) {
       return false;
     }
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/classinliner/BuilderWithMethodOnParentClassTest.java b/src/test/java/com/android/tools/r8/ir/optimize/classinliner/BuilderWithMethodOnParentClassTest.java
new file mode 100644
index 0000000..7076755
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/classinliner/BuilderWithMethodOnParentClassTest.java
@@ -0,0 +1,74 @@
+// Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.android.tools.r8.ir.optimize.classinliner;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import com.android.tools.r8.NeverInline;
+import com.android.tools.r8.NeverMerge;
+import com.android.tools.r8.NeverPropagateValue;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.CodeInspector;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+@RunWith(Parameterized.class)
+public class BuilderWithMethodOnParentClassTest extends TestBase {
+
+  private final TestParameters parameters;
+
+  @Parameterized.Parameters(name = "{0}")
+  public static TestParametersCollection data() {
+    return getTestParameters().withAllRuntimesAndApiLevels().build();
+  }
+
+  public BuilderWithMethodOnParentClassTest(TestParameters parameters) {
+    this.parameters = parameters;
+  }
+
+  @Test
+  public void test() throws Exception {
+    testForR8(parameters.getBackend())
+        .addInnerClasses(BuilderWithMethodOnParentClassTest.class)
+        .addKeepMainRule(TestClass.class)
+        .enableInliningAnnotations()
+        .enableMemberValuePropagationAnnotations()
+        .enableMergeAnnotations()
+        .setMinApi(parameters.getApiLevel())
+        .compile()
+        .inspect(this::inspect)
+        .run(parameters.getRuntime(), TestClass.class)
+        .assertSuccessWithOutputLines("Hello world!");
+  }
+
+  private void inspect(CodeInspector inspector) {
+    assertThat(inspector.clazz(Builder.class), not(isPresent()));
+    assertThat(inspector.clazz(BuilderBase.class), not(isPresent()));
+  }
+
+  static class TestClass {
+
+    public static void main(String[] args) {
+      System.out.println(new Builder().build());
+    }
+  }
+
+  @NeverMerge
+  static class BuilderBase {
+
+    @NeverInline
+    @NeverPropagateValue
+    String build() {
+      return "Hello world!";
+    }
+  }
+
+  static class Builder extends BuilderBase {}
+}