Do not force-intern Strings in images.

Interning all image Strings breaks the reference equality
semantics. See android.net.Uri.NOT_CACHED for an example
where it goes against the intent of the Java code.

Instead, only put interned strings (weakly and strongly) to
the image intern tables. Since image interns are referenced
as long as the image is memory, we can promote weak interns
to strong interns. Doing this before the image layout helps
ImageWriter::CalculateNewObjectOffsets() which would not
have previously found weak interns.

Added a regression test that relies on better initialization
of app image classes, so it shall be "active" only after an
improvement in that area. (This can be checked by commenting
out the NoClinitInDependency() check in CompilerDriver's
InitializeClassVisitor::TryInitializeClass().)

Bug: 134746125
Test: 176-app-image-string
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: aosp_taimen-userdebug boots.
Test: run-gtests.sh
Test: testrunner.py --target --optimizing
Change-Id: I51fa1edf953c9060c41f39812f3ba27f12b02801

1 files changed, 27 insertions, 0 deletions

diff --git a/test/176-app-image-string/src/Main.java b/test/176-app-image-string/src/Main.java
new file mode 100644
index 0000000000..f842c10605
--- /dev/null
+++ b/test/176-app-image-string/src/Main.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+public class Main {
+    public static final String internedString = "test-string";
+    public static final String nonInternedCopy = new String("test-string");
+
+    public static void main(String args[]) throws Exception {
+        if (internedString == nonInternedCopy) {
+            throw new AssertionError();
+        }
+        System.out.println("pass");
+    }
+}