Migrate sanitizers to RegisterNatives.

Author: DanAlbert

sanitizers/app/build.gradle

@@ -55,6 +55,10 @@ android {
                     "x86_64",
                 )
             }
+
+            // Allows buildTypes which inherit from debug to match dependencies
+            // with the debug buildType.
+            matchingFallbacks = ["debug"]
         }
 
         release {
@@ -136,6 +140,7 @@ android {
     }
 
     buildFeatures {
+        prefab true
         viewBinding true
     }
 
@@ -147,6 +152,7 @@ android {
 }
 
 dependencies {
+    implementation project(":base")
     implementation libs.appcompat
     implementation libs.material
     implementation libs.androidx.constraintlayout

sanitizers/app/src/main/cpp/CMakeLists.txt

@@ -2,9 +2,10 @@ cmake_minimum_required(VERSION 3.22.1)
 project(sanitizers LANGUAGES CXX)
 
 include(AppLibrary)
+find_package(base CONFIG REQUIRED)
 
 add_app_library(sanitizers SHARED native-lib.cpp)
-target_link_libraries(sanitizers PRIVATE log)
+target_link_libraries(sanitizers PRIVATE base::base log)
 
 if(SANITIZE)
     # For asan and ubsan, we need to copy some files from the NDK into our APK.

sanitizers/app/src/main/cpp/native-lib.cpp

@@ -1,10 +1,9 @@
+#include <base/macros.h>
 #include <jni.h>
 
 #include <string>
 
-extern "C" JNIEXPORT jstring JNICALL
-Java_com_example_sanitizers_MainActivity_stringFromJNI(JNIEnv* env,
-                                                       jobject /* this */) {
+jstring StringFromJni(JNIEnv* env, jobject /* this */) {
   // Use-after-free error, caught by asan and hwasan.
   int* foo = new int;
   *foo = 3;
@@ -18,3 +17,23 @@ Java_com_example_sanitizers_MainActivity_stringFromJNI(JNIEnv* env,
   std::string hello = "Hello from C++";
   return env->NewStringUTF(hello.c_str());
 }
+
+extern "C" JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* _Nonnull vm,
+                                             void* _Nullable) {
+  JNIEnv* env;
+  if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
+    return JNI_ERR;
+  }
+
+  jclass c = env->FindClass("com/example/sanitizers/MainActivity");
+  if (c == nullptr) return JNI_ERR;
+
+  static const JNINativeMethod methods[] = {
+      {"stringFromJNI", "()Ljava/lang/String;",
+       reinterpret_cast<void*>(StringFromJni)},
+  };
+  int rc = env->RegisterNatives(c, methods, arraysize(methods));
+  if (rc != JNI_OK) return rc;
+
+  return JNI_VERSION_1_6;
+}