Add test for inadequate field propagation of non-constant field

Bug: 173340579
Change-Id: I14f2d0f3bf63d464bb41961931683f4f9f4376b3

src/test/java/com/android/tools/r8/ir/optimize/fields/SwitchOnNonConstantClassIdAfterBranchPruningTest.java

diff --git a/src/test/java/com/android/tools/r8/ir/optimize/fields/SwitchOnNonConstantClassIdAfterBranchPruningTest.java b/src/test/java/com/android/tools/r8/ir/optimize/fields/SwitchOnNonConstantClassIdAfterBranchPruningTest.java
new file mode 100644
index 0000000..f13ba4e
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/fields/SwitchOnNonConstantClassIdAfterBranchPruningTest.java
@@ -0,0 +1,106 @@
+// Copyright (c) 2021, 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.fields;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.android.tools.r8.NeverClassInline;
+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.ClassSubject;
+import com.android.tools.r8.utils.codeinspector.FoundMethodSubject;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class SwitchOnNonConstantClassIdAfterBranchPruningTest extends TestBase {
+
+  private final TestParameters parameters;
+
+  @Parameters(name = "{0}")
+  public static TestParametersCollection data() {
+    return getTestParameters().withAllRuntimesAndApiLevels().build();
+  }
+
+  public SwitchOnNonConstantClassIdAfterBranchPruningTest(TestParameters parameters) {
+    this.parameters = parameters;
+  }
+
+  @Test
+  public void test() throws Exception {
+    testForR8(parameters.getBackend())
+        .addInnerClasses(getClass())
+        .addKeepMainRule(Main.class)
+        .addHorizontallyMergedClassesInspector(
+            inspector -> inspector.assertIsCompleteMergeGroup(A.class, B.class, C.class))
+        .enableNeverClassInliningAnnotations()
+        .setMinApi(parameters.getApiLevel())
+        .noMinification()
+        .compile()
+        .inspect(
+            inspector -> {
+              ClassSubject aClassSubject = inspector.clazz(A.class);
+              assertThat(aClassSubject, isPresent());
+              assertEquals(1, aClassSubject.allInstanceFields().size());
+
+              MethodSubject mMethodSubject =
+                  aClassSubject.uniqueMethodThatMatches(FoundMethodSubject::isVirtual);
+              assertThat(mMethodSubject, isPresent());
+              // TODO(b/173340579): Body from C.m() should have been removed.
+              assertTrue(
+                  mMethodSubject
+                      .streamInstructions()
+                      .anyMatch(instruction -> instruction.isConstString("C")));
+            })
+        .run(parameters.getRuntime(), Main.class)
+        .assertSuccessWithOutputLines("A", "B");
+  }
+
+  static class Main {
+
+    public static void main(String[] args) {
+      new A().m();
+      new B().m();
+      if (alwaysFalse()) {
+        new C().m();
+      }
+    }
+
+    static boolean alwaysFalse() {
+      return false;
+    }
+  }
+
+  @NeverClassInline
+  static class A {
+
+    void m() {
+      System.out.println("A");
+    }
+  }
+
+  @NeverClassInline
+  static class B {
+
+    void m() {
+      System.out.println("B");
+    }
+  }
+
+  @NeverClassInline
+  static class C {
+
+    void m() {
+      System.out.println("C");
+    }
+  }
+}

src/test/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java

diff --git a/src/test/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java b/src/test/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java
index 959a2c9..e8818b2 100644
--- a/src/test/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java
+++ b/src/test/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java
@@ -63,6 +63,10 @@
 
   boolean isConstString(String value, JumboStringMode jumboStringMode);
 
+  default boolean isConstString(String value) {
+    return isConstString(value, JumboStringMode.ALLOW);
+  }
+
   boolean isJumboString();
 
   long getConstNumber();