Replace java.util.LinkedHashMap.eldest()

Provide an alternate implementation for the above method and replace the
calls to it, since the method is not available on host VM.

Change-Id: I329d86b457d1859b137da8fb2790ddd7f8efa788

3 files changed, 68 insertions, 2 deletions

diff --git a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/CreateInfo.java b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/CreateInfo.java
index 7faaed92461a..98acd2f15657 100644
--- a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/CreateInfo.java
+++ b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/CreateInfo.java
@@ -20,6 +20,7 @@ import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
 import com.android.tools.layoutlib.java.AutoCloseable;
 import com.android.tools.layoutlib.java.Charsets;
 import com.android.tools.layoutlib.java.IntegralToString;
+import com.android.tools.layoutlib.java.LinkedHashMap_Delegate;
 import com.android.tools.layoutlib.java.Objects;
 import com.android.tools.layoutlib.java.System_Delegate;
 import com.android.tools.layoutlib.java.UnsafeByteSequence;
@@ -133,6 +134,7 @@ public final class CreateInfo implements ICreateInfo {
             UnsafeByteSequence.class,
             Charsets.class,
             System_Delegate.class,
+            LinkedHashMap_Delegate.class,
         };
 
     /**
diff --git a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/ReplaceMethodCallsAdapter.java b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/ReplaceMethodCallsAdapter.java
index 1e2623f1948a..384d8ca6c01e 100644
--- a/tools/layoutlib/create/src/com/android/tools/layoutlib/create/ReplaceMethodCallsAdapter.java
+++ b/tools/layoutlib/create/src/com/android/tools/layoutlib/create/ReplaceMethodCallsAdapter.java
@@ -16,6 +16,7 @@
 
 package com.android.tools.layoutlib.create;
 
+import com.android.tools.layoutlib.java.LinkedHashMap_Delegate;
 import com.android.tools.layoutlib.java.System_Delegate;
 
 import org.objectweb.asm.ClassVisitor;
@@ -26,8 +27,10 @@ import org.objectweb.asm.Type;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Set;
 
 /**
@@ -44,7 +47,7 @@ public class ReplaceMethodCallsAdapter extends ClassVisitor {
             "([CI[CII)V", "([BI[BII)V", "([SI[SII)V", "([II[III)V",
             "([JI[JII)V", "([FI[FII)V", "([DI[DII)V", "([ZI[ZII)V"));
 
-    private static final List<MethodReplacer> METHOD_REPLACERS = new ArrayList<MethodReplacer>(2);
+    private static final List<MethodReplacer> METHOD_REPLACERS = new ArrayList<MethodReplacer>(5);
 
     private static final String ANDROID_LOCALE_CLASS =
             "com/android/layoutlib/bridge/android/AndroidLocale";
@@ -74,7 +77,8 @@ public class ReplaceMethodCallsAdapter extends ClassVisitor {
         // Case 2: java.util.Locale.toLanguageTag() and java.util.Locale.getScript()
         METHOD_REPLACERS.add(new MethodReplacer() {
 
-            String LOCALE_TO_STRING = Type.getMethodDescriptor(STRING, Type.getType(Locale.class));
+            private final String LOCALE_TO_STRING =
+                    Type.getMethodDescriptor(STRING, Type.getType(Locale.class));
 
             @Override
             public boolean isNeeded(String owner, String name, String desc) {
@@ -129,6 +133,30 @@ public class ReplaceMethodCallsAdapter extends ClassVisitor {
                 mi.owner = Type.getInternalName(System_Delegate.class);
             }
         });
+
+        // Case 5: java.util.LinkedHashMap.eldest()
+        METHOD_REPLACERS.add(new MethodReplacer() {
+
+            private final String VOID_TO_MAP_ENTRY =
+                    Type.getMethodDescriptor(Type.getType(Map.Entry.class));
+            private final String LINKED_HASH_MAP = Type.getInternalName(LinkedHashMap.class);
+
+            @Override
+            public boolean isNeeded(String owner, String name, String desc) {
+                return LINKED_HASH_MAP.equals(owner) &&
+                        "eldest".equals(name) &&
+                        VOID_TO_MAP_ENTRY.equals(desc);
+            }
+
+            @Override
+            public void replace(MethodInformation mi) {
+                assert isNeeded(mi.owner, mi.name, mi.desc);
+                mi.opcode = Opcodes.INVOKESTATIC;
+                mi.owner = Type.getInternalName(LinkedHashMap_Delegate.class);
+                mi.desc = Type.getMethodDescriptor(
+                        Type.getType(Map.Entry.class), Type.getType(LinkedHashMap.class));
+            }
+        });
     }
 
     public static boolean isReplacementNeeded(String owner, String name, String desc) {
diff --git a/tools/layoutlib/create/src/com/android/tools/layoutlib/java/LinkedHashMap_Delegate.java b/tools/layoutlib/create/src/com/android/tools/layoutlib/java/LinkedHashMap_Delegate.java
new file mode 100644
index 000000000000..59cc75f52e36
--- /dev/null
+++ b/tools/layoutlib/create/src/com/android/tools/layoutlib/java/LinkedHashMap_Delegate.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+package com.android.tools.layoutlib.java;
+
+import com.android.tools.layoutlib.create.ReplaceMethodCallsAdapter;
+
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+/**
+ * Provides alternate implementation to java.util.LinkedHashMap#eldest(), which is present as a
+ * non-public method in the Android VM, but not present on the host VM. This is injected in the
+ * layoutlib using {@link ReplaceMethodCallsAdapter}.
+ */
+public class LinkedHashMap_Delegate {
+    public static <K,V> Map.Entry<K,V> eldest(LinkedHashMap<K,V> map) {
+        Iterator<Entry<K, V>> iterator = map.entrySet().iterator();
+        return iterator.hasNext() ? iterator.next() : null;
+    }
+}