/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Command-line invocation of the Dalvik VM.
*/
#include "jni.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <assert.h>
/*
* We want failed write() calls to just return with an error.
*/
static void blockSigpipe()
{
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGPIPE);
if (sigprocmask(SIG_BLOCK, &mask, NULL) != 0)
fprintf(stderr, "WARNING: SIGPIPE not blocked\n");
}
/*
* Create a String[] and populate it with the contents of argv.
*/
static jobjectArray createStringArray(JNIEnv* env, char* const argv[], int argc)
{
jclass stringClass = NULL;
jobjectArray strArray = NULL;
jobjectArray result = NULL;
int i;
stringClass = (*env)->FindClass(env, "java/lang/String");
if ((*env)->ExceptionCheck(env)) {
fprintf(stderr, "Got exception while finding class String\n");
goto bail;
}
assert(stringClass != NULL);
strArray = (*env)->NewObjectArray(env, argc, stringClass, NULL);
if ((*env)->ExceptionCheck(env)) {
fprintf(stderr, "Got exception while creating String array\n");
goto bail;
}
assert(strArray != NULL);
for (i = 0; i < argc; i++) {
jstring argStr;
argStr = (*env)->NewStringUTF(env, argv[i]);
if ((*env)->ExceptionCheck(env)) {
fprintf(stderr, "Got exception while allocating Strings\n");
goto bail;
}
assert(argStr != NULL);
(*env)->SetObjectArrayElement(env, strArray, i, argStr);
(*env)->DeleteLocalRef(env, argStr);
}
/* return the array, and ensure we don't delete the local ref to it */
result = strArray;
strArray = NULL;
bail:
(*env)->DeleteLocalRef(env, stringClass);
(*env)->DeleteLocalRef(env, strArray);
return result;
}
/*
* Determine whether or not the specified method is public.
*
* Returns JNI_TRUE on success, JNI_FALSE on failure.
*/
static int methodIsPublic(JNIEnv* env, jclass clazz, jmethodID methodId)
{
static const int PUBLIC = 0x0001; // java.lang.reflect.Modifiers.PUBLIC
jobject refMethod = NULL;
jclass methodClass = NULL;
jmethodID getModifiersId;
int modifiers;
int result = JNI_FALSE;
refMethod = (*env)->ToReflectedMethod(env, clazz, methodId, JNI_FALSE);
if (refMethod == NULL) {
fprintf(stderr, "Dalvik VM unable to get reflected method\n");
goto bail;
}
/*
* We now have a Method instance. We need to call
* its getModifiers() method.
*/
methodClass = (*env)->FindClass(env, "java/lang/reflect/Method");
if (methodClass == NULL) {
fprintf(stderr, "Dalvik VM unable to find class Method\n");
goto bail;
}
getModifiersId = (*env)->GetMethodID(env, methodClass,
"getModifiers", "()I");
if (methodClass == NULL) {
fprintf(stderr, "Dalvik VM unable to find reflect.Method.getModifiers\n");
goto bail;
}
modifiers = (*env)->CallIntMethod(env, refMethod, getModifiersId);
if ((modifiers & PUBLIC) == 0) {
fprintf(stderr, "Dalvik VM: main() is not public\n");
goto bail;
}
result = JNI_TRUE;
bail:
(*env)->DeleteLocalRef(env, refMethod);
(*env)->DeleteLocalRef(env, methodClass);
return result;
}
/*
* Parse arguments. Most of it just gets passed through to the VM. The
* JNI spec defines a handful of standard arguments.
*/
int main(int argc, char* const argv[])
{
JavaVM* vm = NULL;
JNIEnv* env = NULL;
JavaVMInitArgs initArgs;
JavaVMOption* options = NULL;
char* slashClass = NULL;
int optionCount, curOpt, i, argIdx;
int needExtra = JNI_FALSE;
int result = 1;
setvbuf(stdout, NULL, _IONBF, 0);
/* ignore argv[0] */
argv++;
argc--;
/*
* If we're adding any additional stuff, e.g. function hook specifiers,
* add them to the count here.
*
* We're over-allocating, because this includes the options to the VM
* plus the options to the program.
*/
optionCount = argc;
options = (JavaVMOption*) malloc(sizeof(JavaVMOption) * optionCount);
memset(options, 0, sizeof(JavaVMOption) * optionCount);
/*
* Copy options over. Everything up to the name of the class starts
* with a '-' (the function hook stuff is strictly internal).
*
* [Do we need to catch & handle "-jar" here?]
*/
for (curOpt = argIdx = 0; argIdx < argc; argIdx++) {
if (argv[argIdx][0] != '-' && !needExtra)
break;
options[curOpt++].optionString = strdup(argv[argIdx]);
/* some options require an additional arg */
needExtra = JNI_FALSE;
if (strcmp(argv[argIdx], "-classpath") == 0 ||
strcmp(argv[argIdx], "-cp") == 0)
/* others? */
{
needExtra = JNI_TRUE;
}
}
if (needExtra) {
fprintf(stderr, "Dalvik VM requires value after last option flag\n");
goto bail;
}
/* insert additional internal options here */
assert(curOpt <= optionCount);
initArgs.version = JNI_VERSION_1_4;
initArgs.options = options;
initArgs.nOptions = curOpt;
initArgs.ignoreUnrecognized = JNI_FALSE;
//printf("nOptions = %d\n", initArgs.nOptions);
blockSigpipe();
/*
* Start VM. The current thread becomes the main thread of the VM.
*/
if (JNI_CreateJavaVM(&vm, &env, &initArgs) < 0) {
fprintf(stderr, "Dalvik VM init failed (check log file)\n");
goto bail;
}
/*
* Make sure they provided a class name. We do this after VM init
* so that things like "-Xrunjdwp:help" have the opportunity to emit
* a usage statement.
*/
if (argIdx == argc) {
fprintf(stderr, "Dalvik VM requires a class name\n");
goto bail;
}
/*
* We want to call main() with a String array with our arguments in it.
* Create an array and populate it. Note argv[0] is not included.
*/
jobjectArray strArray;
strArray = createStringArray(env, &argv[argIdx+1], argc-argIdx-1);
if (strArray == NULL)
goto bail;
/*
* Find [class].main(String[]).
*/
jclass startClass;
jmethodID startMeth;
char* cp;
/* convert "com.android.Blah" to "com/android/Blah" */
slashClass = strdup(argv[argIdx]);
for (cp = slashClass; *cp != '\0'; cp++)
if (*cp == '.')
*cp = '/';
startClass = (*env)->FindClass(env, slashClass);
if (startClass == NULL) {
fprintf(stderr, "Dalvik VM unable to locate class '%s'\n", slashClass);
goto bail;
}
startMeth = (*env)->GetStaticMethodID(env, startClass,
"main", "([Ljava/lang/String;)V");
if (startMeth == NULL) {
fprintf(stderr, "Dalvik VM unable to find static main(String[]) in '%s'\n",
slashClass);
goto bail;
}
/*
* Make sure the method is public. JNI doesn't prevent us from calling
* a private method, so we have to check it explicitly.
*/
if (!methodIsPublic(env, startClass, startMeth))
goto bail;
/*
* Invoke main().
*/
(*env)->CallStaticVoidMethod(env, startClass, startMeth, strArray);
if (!(*env)->ExceptionCheck(env))
result = 0;
bail:
/*printf("Shutting down Dalvik VM\n");*/
if (vm != NULL) {
/*
* This allows join() and isAlive() on the main thread to work
* correctly, and also provides uncaught exception handling.
*/
if ((*vm)->DetachCurrentThread(vm) != JNI_OK) {
fprintf(stderr, "Warning: unable to detach main thread\n");
result = 1;
}
if ((*vm)->DestroyJavaVM(vm) != 0)
fprintf(stderr, "Warning: Dalvik VM did not shut down cleanly\n");
/*printf("\nDalvik VM has exited\n");*/
}
for (i = 0; i < optionCount; i++)
free((char*) options[i].optionString);
free(options);
free(slashClass);
/*printf("--- VM is down, process exiting\n");*/
return result;
}