fix Android support

README.md

@@ -1,7 +1,7 @@
 # native-obfuscator
 Java .class to .cpp converter for use with JNI
 
-Currently fully supports only Java 8. Java 9+ support is entirely experimental
+Currently fully supports only Java 8. Java 9+ and Android support is entirely experimental
 
 Warning: blacklist/whitelist usage is recommended because this tool slows down code significantly (like do not obfuscate full Minecraft .jar)
 
@@ -64,8 +64,8 @@ Transpiles .jar file into .cpp files and generates output .jar file
                           Directory for dependent libraries
   -p, --platform=<platform>
                           Target platform: hotspot - standard standalone
-                            HotSpot JRE, std_java - java standard (as for
-                            Android)
+                            HotSpot JRE, std_java - java standard, android -
+                            for Android builds (w/o DefineClass)
       --plain-lib-name=<libraryName>
                           Plain library name for LoaderPlain
   -V, --version           Print version information and exit.
@@ -83,9 +83,10 @@ Transpiles .jar file into .cpp files and generates output .jar file
 
 `-p <platform>` - JVM platform to run library on
 
-Two options are available:
-    - hotspot: will use HotSpot JVM internals and should work with most obfuscators (even with stack trace checking as well)
-    - std_java: will use only minor JVM internals that are also available on Android. Use only this option if you want to run your library on Android
+Three options are available:
+ - `hotspot`: will use HotSpot JVM internals and should work with most obfuscators (even with stack trace checking as well)
+ - `std_java`: will use only minor JVM internals that must be available on all JVMs
+ - `android`: use this method when building library for Android. Will use no JVM internals, as well as no DefineClass for hidden methods (obfuscators that rely on stack for string/name obfuscator will not work due to the fact that some methods will not be hidden)
 
 `-a` - enable annotation processing
 

obfuscator/src/main/java/by/radioegor146/Main.java

@@ -43,7 +43,7 @@ private static class NativeObfuscatorRunner implements Callable<Integer> {
         private String customLibraryDirectory;
 
         @CommandLine.Option(names = {"-p", "--platform"}, defaultValue = "hotspot",
-                description = "Target platform: hotspot - standard standalone HotSpot JRE, std_java - java standard (as for Android)")
+                description = "Target platform: hotspot - standard standalone HotSpot JRE, std_java - java standard, android - for Android builds (w/o DefineClass)")
         private Platform platform;
 
         @CommandLine.Option(names = {"-a", "--annotations"}, description = "Use annotations to ignore/include native obfuscation")

obfuscator/src/main/java/by/radioegor146/NativeObfuscator.java

@@ -131,6 +131,10 @@ public void process(Path inputJarPath, Path outputDir, List<Path> inputLibs,
         cMakeBuilder.addMainFile("string_pool.hpp");
         cMakeBuilder.addMainFile("string_pool.cpp");
 
+        if (platform == Platform.HOTSPOT) {
+            cMakeBuilder.addFlag("USE_HOTSPOT");
+        }
+
         MainSourceBuilder mainSourceBuilder = new MainSourceBuilder();
 
         File jarFile = inputJarPath.toAbsolutePath().toFile();
@@ -299,48 +303,56 @@ public void process(Path inputJarPath, Path outputDir, List<Path> inputLibs,
                 }
             });
 
-            for (ClassNode hiddenClass : hiddenMethodsPool.getClasses()) {
-                String hiddenClassFileName = "data_" + Util.escapeCppNameString(hiddenClass.name.replace('/', '_'));
+            if (platform == Platform.ANDROID) {
+                for (ClassNode hiddenClass : hiddenMethodsPool.getClasses()) {
+                    ClassWriter classWriter = new SafeClassWriter(metadataReader, Opcodes.ASM7 | ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
+                    hiddenClass.accept(classWriter);
+                    Util.writeEntry(out, hiddenClass.name + ".class", classWriter.toByteArray());
+                }
+            } else {
+                for (ClassNode hiddenClass : hiddenMethodsPool.getClasses()) {
+                    String hiddenClassFileName = "data_" + Util.escapeCppNameString(hiddenClass.name.replace('/', '_'));
 
-                cMakeBuilder.addClassFile("output/" + hiddenClassFileName + ".hpp");
-                cMakeBuilder.addClassFile("output/" + hiddenClassFileName + ".cpp");
+                    cMakeBuilder.addClassFile("output/" + hiddenClassFileName + ".hpp");
+                    cMakeBuilder.addClassFile("output/" + hiddenClassFileName + ".cpp");
 
-                mainSourceBuilder.addHeader(hiddenClassFileName + ".hpp");
-                mainSourceBuilder.registerDefine(stringPool.get(hiddenClass.name), hiddenClassFileName);
+                    mainSourceBuilder.addHeader(hiddenClassFileName + ".hpp");
+                    mainSourceBuilder.registerDefine(stringPool.get(hiddenClass.name), hiddenClassFileName);
 
-                ClassWriter classWriter = new SafeClassWriter(metadataReader, Opcodes.ASM7 | ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
-                hiddenClass.accept(classWriter);
-                byte[] rawData = classWriter.toByteArray();
-                List<Byte> data = new ArrayList<>(rawData.length);
-                for (byte b : rawData) {
-                    data.add(b);
-                }
+                    ClassWriter classWriter = new SafeClassWriter(metadataReader, Opcodes.ASM7 | ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
+                    hiddenClass.accept(classWriter);
+                    byte[] rawData = classWriter.toByteArray();
+                    List<Byte> data = new ArrayList<>(rawData.length);
+                    for (byte b : rawData) {
+                        data.add(b);
+                    }
 
-                if (debug != null) {
-                    Util.writeEntry(debug, hiddenClass.name + ".class", rawData);
-                }
+                    if (debug != null) {
+                        Util.writeEntry(debug, hiddenClass.name + ".class", rawData);
+                    }
 
-                try (BufferedWriter hppWriter = Files.newBufferedWriter(cppOutput.resolve(hiddenClassFileName + ".hpp"))) {
-                    hppWriter.append("#include \"../native_jvm.hpp\"\n\n");
-                    hppWriter.append("#ifndef ").append(hiddenClassFileName.toUpperCase()).append("_HPP_GUARD\n\n");
-                    hppWriter.append("#define ").append(hiddenClassFileName.toUpperCase()).append("_HPP_GUARD\n\n");
-                    hppWriter.append("namespace native_jvm::data::__ngen_").append(hiddenClassFileName).append(" {\n");
-                    hppWriter.append("    const jbyte* get_class_data();\n");
-                    hppWriter.append("    const jsize get_class_data_length();\n");
-                    hppWriter.append("}\n\n");
-                    hppWriter.append("#endif\n");
-                }
+                    try (BufferedWriter hppWriter = Files.newBufferedWriter(cppOutput.resolve(hiddenClassFileName + ".hpp"))) {
+                        hppWriter.append("#include \"../native_jvm.hpp\"\n\n");
+                        hppWriter.append("#ifndef ").append(hiddenClassFileName.toUpperCase()).append("_HPP_GUARD\n\n");
+                        hppWriter.append("#define ").append(hiddenClassFileName.toUpperCase()).append("_HPP_GUARD\n\n");
+                        hppWriter.append("namespace native_jvm::data::__ngen_").append(hiddenClassFileName).append(" {\n");
+                        hppWriter.append("    const jbyte* get_class_data();\n");
+                        hppWriter.append("    const jsize get_class_data_length();\n");
+                        hppWriter.append("}\n\n");
+                        hppWriter.append("#endif\n");
+                    }
 
-                try (BufferedWriter cppWriter = Files.newBufferedWriter(cppOutput.resolve(hiddenClassFileName + ".cpp"))) {
-                    cppWriter.append("#include \"").append(hiddenClassFileName).append(".hpp\"\n\n");
-                    cppWriter.append("namespace native_jvm::data::__ngen_").append(hiddenClassFileName).append(" {\n");
-                    cppWriter.append("    static const jbyte class_data[").append(String.valueOf(data.size())).append("] = { ");
-                    cppWriter.append(data.stream().map(String::valueOf).collect(Collectors.joining(", ")));
-                    cppWriter.append("};\n");
-                    cppWriter.append("    static const jsize class_data_length = ").append(String.valueOf(data.size())).append(";\n\n");
-                    cppWriter.append("    const jbyte* get_class_data() { return class_data; }\n");
-                    cppWriter.append("    const jsize get_class_data_length() { return class_data_length; }\n");
-                    cppWriter.append("}\n");
+                    try (BufferedWriter cppWriter = Files.newBufferedWriter(cppOutput.resolve(hiddenClassFileName + ".cpp"))) {
+                        cppWriter.append("#include \"").append(hiddenClassFileName).append(".hpp\"\n\n");
+                        cppWriter.append("namespace native_jvm::data::__ngen_").append(hiddenClassFileName).append(" {\n");
+                        cppWriter.append("    static const jbyte class_data[").append(String.valueOf(data.size())).append("] = { ");
+                        cppWriter.append(data.stream().map(String::valueOf).collect(Collectors.joining(", ")));
+                        cppWriter.append("};\n");
+                        cppWriter.append("    static const jsize class_data_length = ").append(String.valueOf(data.size())).append(";\n\n");
+                        cppWriter.append("    const jbyte* get_class_data() { return class_data; }\n");
+                        cppWriter.append("    const jsize get_class_data_length() { return class_data_length; }\n");
+                        cppWriter.append("}\n");
+                    }
                 }
             }
 

obfuscator/src/main/java/by/radioegor146/Platform.java

@@ -2,5 +2,6 @@
 
 public enum Platform {
     HOTSPOT,
-    STD_JAVA
+    STD_JAVA,
+    ANDROID
 }

obfuscator/src/main/java/by/radioegor146/bytecode/IndyPreprocessor.java

@@ -25,6 +25,7 @@ private static void processIndy(ClassNode classNode, MethodNode methodNode,
 
 
         switch (platform) {
+            case ANDROID:
             case STD_JAVA: {
                 Type[] bsmArguments = Type.getArgumentTypes(invokeDynamicInsnNode.bsm.getDesc());
                 int targetArgLength = bsmArguments.length - 3;
@@ -256,6 +257,7 @@ private static void processIndy(ClassNode classNode, MethodNode methodNode,
                 }
                 break;
             }
+            case ANDROID:
             case STD_JAVA: {
                 invokeInstructions.add(new InsnNode(Opcodes.SWAP)); // 2
                 invokeInstructions.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, "java/lang/invoke/MethodHandle",

obfuscator/src/main/java/by/radioegor146/source/CMakeFilesBuilder.java

@@ -4,17 +4,20 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class CMakeFilesBuilder {
 
     private final String projectName;
     private final List<String> classFiles;
     private final List<String> mainFiles;
+    private final List<String> flags;
 
     public CMakeFilesBuilder(String projectName) {
         this.projectName = projectName;
         classFiles = new ArrayList<>();
         mainFiles = new ArrayList<>();
+        flags = new ArrayList<>();
     }
 
     public void addClassFile(String classFile) {
@@ -25,12 +28,18 @@ public void addMainFile(String mainFile) {
         mainFiles.add(mainFile);
     }
 
+    public void addFlag(String flag) {
+        flags.add(flag);
+    }
+
     public String build() {
         String template = Util.readResource("sources/CMakeLists.txt");
         return Util.dynamicFormat(template, Util.createMap(
                 "classfiles", String.join(" ", classFiles),
                 "mainfiles", String.join(" ", mainFiles),
-                "projectname", projectName
+                "projectname", projectName,
+                "definitions", flags.stream().map(flag -> String.format("-D%s=1", flag))
+                        .collect(Collectors.joining(" "))
         ));
     }
 }

obfuscator/src/main/resources/sources/CMakeLists.txt

@@ -28,4 +28,6 @@ include_directories(${JNI_INCLUDE_DIRS})
 
 set(CLASS_FILES $classfiles)
 set(MAIN_FILES $mainfiles)
+add_definitions($definitions)
+
 add_library($projectname SHARED ${CLASS_FILES} ${MAIN_FILES})

obfuscator/src/main/resources/sources/native_jvm.cpp

@@ -18,9 +18,11 @@ namespace native_jvm::utils {
     jmethodID init_cause_method;
     jclass methodhandles_lookup_class;
     jmethodID lookup_init_method;
+#ifdef USE_HOTSPOT
     jclass methodhandle_natives_class;
     jmethodID link_call_site_method;
     bool is_jvm11_link_call_site;
+#endif
 
     void init_utils(JNIEnv *env) {
         jclass clazz = env->FindClass("[Z");
@@ -102,6 +104,7 @@ namespace native_jvm::utils {
         if (env->ExceptionCheck())
             return;
 
+#ifdef USE_HOTSPOT
         jclass _methodhandle_natives_class = env->FindClass("java/lang/invoke/MethodHandleNatives");
         if (env->ExceptionCheck())
             return;
@@ -119,8 +122,10 @@ namespace native_jvm::utils {
             if (env->ExceptionCheck())
                 return;
         }
+#endif
     }
 
+#ifdef USE_HOTSPOT
     jobject link_call_site(JNIEnv *env, jobject caller_obj, jobject bootstrap_method_obj,
         jobject name_obj, jobject type_obj, jobject static_arguments, jobject appendix_result) {
         if (is_jvm11_link_call_site) {
@@ -130,6 +135,7 @@ namespace native_jvm::utils {
         return env->CallStaticObjectMethod(methodhandle_natives_class, link_call_site_method, caller_obj,
             bootstrap_method_obj, name_obj, type_obj, static_arguments, appendix_result);
     }
+#endif
 
     template <>
     jarray create_array_value<1>(JNIEnv *env, jint size) {

obfuscator/src/main/resources/sources/native_jvm.hpp

@@ -70,8 +70,10 @@ namespace native_jvm::utils {
         return result_array;
     }
 
+#ifdef USE_HOTSPOT
     jobject link_call_site(JNIEnv *env, jobject caller_obj, jobject bootstrap_method_obj,
             jobject name_obj, jobject type_obj, jobject static_arguments, jobject appendix_result);
+#endif
 
     jclass find_class_wo_static(JNIEnv *env, jobject classloader, jstring class_name);