1 files changed, 133 insertions, 0 deletions
diff --git a/third_party/jni/emjvm.cpp b/third_party/jni/emjvm.cpp
new file mode 100644
index 00000000..77ec3871
--- /dev/null
+++ b/third_party/jni/emjvm.cpp
@@ -0,0 +1,133 @@
+
+// Emscripten shims for JVM support
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "emjvm.h"
+
+// invoke interface
+
+jint DestroyJavaVM(JavaVM*) { exit(55); return NULL; }
+jint AttachCurrentThread(JavaVM*, JNIEnv**, void*) { exit(66); return NULL; }
+jint DetachCurrentThread(JavaVM*) { exit(77); return NULL; }
+jint GetEnv(JavaVM*, void** env, jint); // forward def
+jint AttachCurrentThreadAsDaemon(JavaVM*, JNIEnv**, void*) { exit(88); return NULL; }
+
+// env - some of these are externs that are implemented in JS
+
+jobject EMJVM_NewGlobalRef(JNIEnv*, jobject obj) {
+  return obj; // XXX no global refcounting, we just keep global singletons alive etc.
+}
+
+extern "C" {
+  extern jstring emjvm_newString(const jchar *chars, jsize len);
+}
+jstring EMJVM_NewString(JNIEnv*, const jchar* unicodeChars, jsize len) {
+  return emjvm_newString(unicodeChars, len);
+}
+
+extern "C" {
+  extern jclass emjvm_getObjectClass(JNIEnv*, jobject obj);
+}
+
+extern "C" {
+  extern jmethodID emjvm_getMethodID(jclass, const char*, const char*);
+}
+extern jmethodID EMJVM_GetMethodID(JNIEnv*, jclass clazz, const char* methodName, const char* sig) {
+  return emjvm_getMethodID(clazz, methodName, sig);
+}
+
+extern "C" {
+  extern jobject emjvm_callObjectMethod(JNIEnv*, jobject, jmethodID, va_list);
+
+  extern void emjvm_deleteLocalRef(JNIEnv*, jobject);
+
+  jsize emjvm_getArrayLength(JNIEnv*, jarray);
+
+  void emjvm_getByteArrayRegion(JNIEnv*, jbyteArray, jsize, jsize, jbyte*);
+
+  jclass emjvm_findClass(JNIEnv*, const char*);
+
+  jmethodID emjvm_getStaticMethodID(JNIEnv*, jclass, const char*, const char*);
+
+  jobject emjvm_callStaticObjectMethod(JNIEnv*, jclass, jmethodID, va_list);
+
+  jboolean emjvm_callBooleanMethod(JNIEnv*, jobject, jmethodID, va_list);
+  jboolean emjvm_callStaticBooleanMethod(JNIEnv*, jclass, jmethodID, va_list);
+
+  void emjvm_callVoidMethod(JNIEnv*, jobject, jmethodID, va_list);
+
+  jint emjvm_callIntMethod(JNIEnv*, jobject, jmethodID, va_list);
+
+  const char* emjvm_getStringUTFChars(JNIEnv*, jstring, jboolean*);
+  jsize emjvm_getStringUTFLength(JNIEnv*, jstring);
+  void emjvm_releaseStringUTFChars(JNIEnv*, jstring, const char*);
+}
+
+// JVM
+
+struct EmJVM {
+  JavaVM jvm;
+  JNIInvokeInterface jvmFunctions;
+
+  JNIEnv env;
+  JNINativeInterface envFunctions;
+
+  EmJVM() {
+    // jvm
+    jvm.functions = &jvmFunctions;
+
+    jvmFunctions.DestroyJavaVM = DestroyJavaVM;
+    jvmFunctions.AttachCurrentThread = AttachCurrentThread;
+    jvmFunctions.DetachCurrentThread = DetachCurrentThread;
+    jvmFunctions.GetEnv = GetEnv;
+    jvmFunctions.AttachCurrentThreadAsDaemon = AttachCurrentThreadAsDaemon;
+
+    // env
+    memset(&envFunctions, 0, sizeof(envFunctions));
+
+    env.functions = &envFunctions;
+
+    envFunctions.NewGlobalRef = EMJVM_NewGlobalRef;
+    envFunctions.NewString = EMJVM_NewString;
+    envFunctions.GetObjectClass = emjvm_getObjectClass;
+    envFunctions.GetMethodID = EMJVM_GetMethodID;
+    envFunctions.CallObjectMethodV = emjvm_callObjectMethod;
+    envFunctions.DeleteLocalRef = emjvm_deleteLocalRef;
+    envFunctions.GetArrayLength = emjvm_getArrayLength;
+    envFunctions.GetByteArrayRegion = emjvm_getByteArrayRegion;
+    envFunctions.FindClass = emjvm_findClass;
+    envFunctions.GetStaticMethodID = emjvm_getStaticMethodID;
+    envFunctions.CallStaticObjectMethodV = emjvm_callStaticObjectMethod;
+    envFunctions.CallBooleanMethodV = emjvm_callBooleanMethod;
+    envFunctions.CallStaticBooleanMethodV = emjvm_callStaticBooleanMethod;
+    envFunctions.CallVoidMethodV = emjvm_callVoidMethod;
+    envFunctions.CallIntMethodV = emjvm_callIntMethod;
+    envFunctions.GetStringUTFChars = emjvm_getStringUTFChars;
+    envFunctions.GetStringUTFLength = emjvm_getStringUTFLength;
+    envFunctions.ReleaseStringUTFChars = emjvm_releaseStringUTFChars;
+  }
+};
+
+EmJVM emJVM;
+
+// implement forward defs
+
+jint GetEnv(JavaVM*, void** env, jint) {
+  *env = &emJVM.env;
+  return 0;
+}
+
+// external access from JS
+
+extern "C" {
+
+JavaVM* emscripten_get_jvm() { return &emJVM.jvm; }
+
+JNIEnv* emscripten_get_jni_env() { return &emJVM.env; }
+
+}
+