Android: Add bytecode rewriting for Resources.getIdentifier().

The default implementation simply calls the original method.

Bug: 793816
Change-Id: I2ac147d5318d6a04db2d9cec46659d574383b005
Reviewed-on: https://chromium-review.googlesource.com/824722
Commit-Queue: Eric Stevenson <estevenson@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524092}

build/android/buildhooks/java/org/chromium/build/BuildHooksAndroid.java

@@ -51,6 +51,14 @@ public abstract class BuildHooksAndroid {
 
     protected abstract Context createConfigurationContextImpl(Context context);
 
+    public static int getIdentifier(
+            Resources resources, String name, String defType, String defPackage) {
+        return sInstance.getIdentifierImpl(resources, name, defType, defPackage);
+    }
+
+    protected abstract int getIdentifierImpl(
+            Resources resources, String name, String defType, String defPackage);
+
     public static boolean isEnabled() {
         return sInstance.isEnabledImpl();
     }

build/android/buildhooks/java/org/chromium/build/BuildHooksAndroidImpl.java

@@ -35,6 +35,12 @@ public class BuildHooksAndroidImpl extends BuildHooksAndroid {
         return null;
     }
 
+    @Override
+    protected int getIdentifierImpl(
+            Resources resources, String name, String defType, String defPackage) {
+        return resources.getIdentifier(name, defType, defPackage);
+    }
+
     @Override
     protected boolean isEnabledImpl() {
         return false;

build/android/bytecode/java/org/chromium/bytecode/AssertionEnablerClassAdapter.java

@@ -55,11 +55,11 @@ class AssertionEnablerClassAdapter extends ClassVisitor {
     @Override
     public MethodVisitor visitMethod(final int access, final String name, String desc,
             String signature, String[] exceptions) {
-        return new RewriteAssertMethodVisitorWriter(
+        return new RewriteAssertMethodVisitor(
                 Opcodes.ASM5, super.visitMethod(access, name, desc, signature, exceptions));
     }
 
-    static class RewriteAssertMethodVisitorWriter extends MethodVisitor {
+    static class RewriteAssertMethodVisitor extends MethodVisitor {
         static final String ASSERTION_DISABLED_NAME = "$assertionsDisabled";
         static final String INSERT_INSTRUCTION_NAME = "assertFailureHandler";
         static final String INSERT_INSTRUCTION_DESC =
@@ -69,7 +69,7 @@ class AssertionEnablerClassAdapter extends ClassVisitor {
         boolean mStartLoadingAssert;
         Label mGotoLabel;
 
-        public RewriteAssertMethodVisitorWriter(int api, MethodVisitor mv) {
+        public RewriteAssertMethodVisitor(int api, MethodVisitor mv) {
             super(api, mv);
         }
 

build/android/bytecode/java/org/chromium/bytecode/CustomResourcesClassAdapter.java

@@ -16,6 +16,7 @@ import static org.objectweb.asm.Opcodes.IF_ICMPGE;
 import static org.objectweb.asm.Opcodes.ILOAD;
 import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
 import static org.objectweb.asm.Opcodes.INVOKESTATIC;
+import static org.objectweb.asm.Opcodes.INVOKEVIRTUAL;
 import static org.objectweb.asm.Opcodes.RETURN;
 
 import static org.chromium.bytecode.TypeUtils.ASSET_MANAGER;
@@ -28,6 +29,7 @@ import static org.chromium.bytecode.TypeUtils.CONTEXT_WRAPPER;
 import static org.chromium.bytecode.TypeUtils.DISPLAY_LEAK_ACTIVITY;
 import static org.chromium.bytecode.TypeUtils.INT;
 import static org.chromium.bytecode.TypeUtils.RESOURCES;
+import static org.chromium.bytecode.TypeUtils.STRING;
 import static org.chromium.bytecode.TypeUtils.THEME;
 import static org.chromium.bytecode.TypeUtils.VOID;
 
@@ -59,6 +61,9 @@ import java.util.List;
 class CustomResourcesClassAdapter extends ClassVisitor {
     private static final String IS_ENABLED_METHOD = "isEnabled";
     private static final String IS_ENABLED_DESCRIPTOR = TypeUtils.getMethodDescriptor(BOOLEAN);
+    // Cached since this is used so often.
+    private static final String GET_IDENTIFIER_DESCRIPTOR =
+            TypeUtils.getMethodDescriptor(INT, STRING, STRING, STRING);
 
     // Existing methods are more difficult to handle, and not currently needed.
     private static final List<String> PROHIBITED_METHODS = Arrays.asList(
@@ -102,7 +107,8 @@ class CustomResourcesClassAdapter extends ClassVisitor {
                         + "#" + methodSignature);
             }
         }
-        return super.visitMethod(access, name, desc, signature, exceptions);
+        return new RewriteGetIdentifierMethodVisitor(
+                super.visitMethod(access, name, desc, signature, exceptions));
     }
 
     @Override
@@ -159,6 +165,31 @@ class CustomResourcesClassAdapter extends ClassVisitor {
         }
     }
 
+    /**
+     * Remaps Resources.getIdentifier() method calls to use BuildHooksAndroid.
+     *
+     * resourceObj.getIdentifier(String, String, String) becomes:
+     * BuildHooksAndroid.getIdentifier(resourceObj, String, String, String);
+     */
+    private static final class RewriteGetIdentifierMethodVisitor extends MethodVisitor {
+        RewriteGetIdentifierMethodVisitor(MethodVisitor mv) {
+            super(ASM5, mv);
+        }
+
+        @Override
+        public void visitMethodInsn(
+                int opcode, String owner, String name, String desc, boolean itf) {
+            String methodName = "getIdentifier";
+            if (opcode == INVOKEVIRTUAL && owner.equals(RESOURCES) && name.equals(methodName)
+                    && desc.equals(GET_IDENTIFIER_DESCRIPTOR)) {
+                super.visitMethodInsn(INVOKESTATIC, BUILD_HOOKS_ANDROID, methodName,
+                        TypeUtils.getMethodDescriptor(INT, RESOURCES, STRING, STRING, STRING), itf);
+            } else {
+                super.visitMethodInsn(opcode, owner, name, desc, itf);
+            }
+        }
+    }
+
     /**
      * Generates:
      *

build/android/bytecode/java/org/chromium/bytecode/TypeUtils.java

@@ -31,12 +31,13 @@ class TypeUtils {
     static final String DISPLAY_LEAK_ACTIVITY =
             "com/squareup/leakcanary/internal/DisplayLeakActivity";
     static final String RESOURCES = "android/content/res/Resources";
+    static final String STRING = "java/lang/String";
     static final String THEME = "android/content/res/Resources$Theme";
+
     static final String BOOLEAN = "Z";
     static final String INT = "I";
     static final String VOID = "V";
     private static final Map<String, Type> PRIMITIVE_DESCRIPTORS;
-
     static {
         PRIMITIVE_DESCRIPTORS = new HashMap<>();
         PRIMITIVE_DESCRIPTORS.put(Type.BOOLEAN_TYPE.toString(), Type.BOOLEAN_TYPE);