Allow for '.' for patterns when parsing -keepattributes

PG allow for patterns that has '.' in them when parsing
-keepattributes. We should ensure not to throw an error since
developers can add such rules to their libraries.

Bug: 147470785
Change-Id: I54845ecae12d608faf95294eadec461b848c823d
diff --git a/src/main/java/com/android/tools/r8/shaking/ProguardConfigurationParser.java b/src/main/java/com/android/tools/r8/shaking/ProguardConfigurationParser.java
index ab9e92f..a589f9a 100644
--- a/src/main/java/com/android/tools/r8/shaking/ProguardConfigurationParser.java
+++ b/src/main/java/com/android/tools/r8/shaking/ProguardConfigurationParser.java
@@ -1803,7 +1803,8 @@
           codePoint ->
               IdentifierUtils.isDexIdentifierPart(codePoint)
                   || codePoint == '!'
-                  || codePoint == '*');
+                  || codePoint == '*'
+                  || codePoint == '.');
     }
 
     private String acceptString(Predicate<Integer> codepointAcceptor) {
diff --git a/src/test/java/com/android/tools/r8/shaking/attributes/KeepAttributesDotsTest.java b/src/test/java/com/android/tools/r8/shaking/attributes/KeepAttributesDotsTest.java
new file mode 100644
index 0000000..97763b1
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/shaking/attributes/KeepAttributesDotsTest.java
@@ -0,0 +1,112 @@
+// Copyright (c) 2020, 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.shaking.attributes;
+
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import com.android.tools.r8.CompilationFailedException;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestRuntime;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import com.android.tools.r8.utils.codeinspector.CodeInspector;
+import com.android.tools.r8.utils.codeinspector.FieldSubject;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import java.io.IOException;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.util.List;
+import java.util.concurrent.ExecutionException;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+@RunWith(Parameterized.class)
+public class KeepAttributesDotsTest extends TestBase {
+
+  private final TestParameters parameters;
+  private final String keepAttributes;
+
+  @Parameterized.Parameters(name = "-keepattributes {1}")
+  public static List<Object[]> data() {
+    return buildParameters(
+        getTestParameters().withNoneRuntime().build(),
+        new String[] {".", "...", "XYZ,..", "XYZ,..,A.B"});
+  }
+
+  public KeepAttributesDotsTest(TestParameters parameters, String keepAttributes) {
+    this.parameters = parameters;
+    this.keepAttributes = keepAttributes;
+  }
+
+  @Test
+  public void testProguard() throws ExecutionException, CompilationFailedException, IOException {
+    testForProguard()
+        .addProgramClassesAndInnerClasses(Main.class)
+        .addKeepAllClassesRule()
+        .addKeepAttributes(keepAttributes)
+        .addKeepRules("-dontwarn com.android.tools.r8.shaking.attributes.*")
+        .run(TestRuntime.getCheckedInJdk8(), Main.class)
+        .assertSuccessWithOutputLines("Hello World!")
+        .inspect(this::inspect);
+  }
+
+  @Test
+  public void testR8() throws IOException, CompilationFailedException, ExecutionException {
+    testForR8(Backend.CF)
+        .addProgramClassesAndInnerClasses(Main.class)
+        .addKeepAttributes(keepAttributes)
+        .addKeepAllClassesRule()
+        .run(TestRuntime.getCheckedInJdk8(), Main.class)
+        .assertSuccessWithOutputLines("Hello World!")
+        .inspect(this::inspect);
+  }
+
+  private void inspect(CodeInspector inspector) {
+    ClassSubject clazz = inspector.clazz(Main.class);
+    assertTrue(clazz.getDexClass().annotations.isEmpty());
+    MethodSubject main = clazz.uniqueMethodWithName("main");
+    assertTrue(main.getMethod().annotations.isEmpty());
+    FieldSubject field = clazz.uniqueFieldWithName("field");
+    assertTrue(field.getField().annotations.isEmpty());
+    assertTrue(clazz.getDexClass().sourceFile == null || clazz.getDexClass().sourceFile.size == 0);
+    assertNull(main.getLineNumberTable());
+    assertTrue(main.getLocalVariableTable().isEmpty());
+  }
+
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target({ElementType.METHOD})
+  public @interface MethodRuntimeAnnotation {}
+
+  @Retention(RetentionPolicy.CLASS)
+  @Target({ElementType.METHOD})
+  public @interface MethodCompileTimeAnnotation {}
+
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target({ElementType.TYPE})
+  public @interface ClassRuntimeAnnotation {}
+
+  @Retention(RetentionPolicy.CLASS)
+  @Target({ElementType.TYPE})
+  public @interface ClassCompileTimeAnnotation {}
+
+  @ClassCompileTimeAnnotation
+  @ClassRuntimeAnnotation
+  public static class Main {
+
+    public static class Inner<T> {}
+
+    public Inner<Boolean> field;
+
+    @MethodCompileTimeAnnotation
+    @MethodRuntimeAnnotation
+    public static void main(String[] args) {
+      System.out.println("Hello World!");
+    }
+  }
+}