[android] Implement android test runner for core unit tests

platform/android/src/test/runtime.cpp

@@ -0,0 +1,73 @@
+#include "runtime.hpp"
+#include "../jni.hpp"
+
+#include <cassert>
+#include <dlfcn.h>
+#include <jni.h>
+#include <signal.h>
+#include <string>
+
+// Required for art / libsigchain
+extern "C" JNIEXPORT void EnsureFrontOfChain(int, struct sigaction*) { }
+extern "C" JNIEXPORT void AddSpecialSignalHandlerFn(int, void*) { }
+extern "C" JNIEXPORT void RemoveSpecialSignalHandlerFn(int, bool (*) (int, siginfo_t*, void*)) { }
+
+namespace {
+const std::string kClassPathCommand{"--class_path="};
+const std::string kClassPath{"-Djava.class.path="};
+const std::string kDefaultDex{"/data/local/tmp/core-tests/classes.dex"};
+} // namespace
+
+namespace mbgl {
+namespace android {
+
+bool initRuntime(int argc, char *argv[]) {
+    void* vmHandle = dlopen("libart.so", RTLD_NOW);
+    assert(vmHandle != nullptr);
+
+    using CreateJavaVMFn = jint (*)(JavaVM** vm, JNIEnv** env, void* vmArgs);
+    CreateJavaVMFn createJavaVMFn = reinterpret_cast<CreateJavaVMFn>(dlsym(vmHandle, "JNI_CreateJavaVM"));
+    assert(createJavaVMFn != nullptr);
+
+    std::string classPath = kClassPath + kDefaultDex;
+    for (int i = 0; i < argc; ++i) {
+        const std::string arg{argv[i]};
+        if (arg.compare(0, kClassPathCommand.length(), kClassPathCommand) == 0) {
+            classPath = kClassPath + arg.substr(kClassPathCommand.length());
+            break;
+        }
+    }
+
+    JavaVMOption options[1];
+    options[0].optionString = classPath.c_str();
+
+    JavaVMInitArgs args;
+    args.version = JNI_VERSION_1_6;
+    args.nOptions = 1;
+    args.options = options;
+    args.ignoreUnrecognized = JNI_FALSE;
+
+    JavaVM* vm;
+    JNIEnv* env;
+
+    if (createJavaVMFn(&vm, &env, &args) != JNI_OK) {
+        return false;
+    }
+
+    void* runtimeHandle = dlopen("libandroid_runtime.so", RTLD_NOW);
+    assert(runtimeHandle != nullptr);
+
+    using RegisterNativesFn = jint (*)(JNIEnv* env);
+    RegisterNativesFn registerNativesFn = reinterpret_cast<RegisterNativesFn>(dlsym(runtimeHandle, "registerFrameworkNatives"));
+    assert(registerNativesFn != nullptr);
+
+    if (registerNativesFn(env) != JNI_OK) {
+        return false;
+    }
+
+    mbgl::android::registerNatives(vm);
+    return true;
+}
+
+} // namespace android
+} // namespace mbgl