/*
* Print the stack trace of the current exception on stderr. This is called
* from the JNI ExceptionDescribe call.
*
* For consistency we just invoke the Throwable printStackTrace method,
* which might be overridden in the exception object.
*
* Exceptions thrown during the course of printing the stack trace are
* ignored.
*/
void dvmPrintExceptionStackTrace(void)
{
Thread* self = dvmThreadSelf();
Object* exception;
Method* printMethod;
exception = self->exception;
if (exception == NULL)
return;
self->exception = NULL;
printMethod = dvmFindVirtualMethodHierByDescriptor(exception->clazz,
"printStackTrace", "()V");
if (printMethod != NULL) {
JValue unused;
dvmCallMethod(self, printMethod, exception, &unused);
} else {
LOGW("WARNING: could not find printStackTrace in %s\n",
exception->clazz->descriptor);
}
if (self->exception != NULL) {
LOGW("NOTE: exception thrown while printing stack trace: %s\n",
self->exception->clazz->descriptor);
}
self->exception = exception;
}
/*
* static boolean cacheRegisterMap(String classAndMethodDescr)
*
* If the specified class is loaded, and the named method exists, ensure
* that the method's register map is ready for use. If the class/method
* cannot be found, nothing happens.
*
* This can improve the zygote's sharing of compressed register maps. Do
* this after class preloading.
*
* Returns true if the register map is cached and ready, either as a result
* of this call or earlier activity. Returns false if the class isn't loaded,
* if the method couldn't be found, or if the method has no register map.
*
* (Uncomment logs in dvmGetExpandedRegisterMap0() to gather stats.)
*/
static void Dalvik_dalvik_system_VMDebug_cacheRegisterMap(const u4* args,
JValue* pResult)
{
StringObject* classAndMethodDescStr = (StringObject*) args[0];
ClassObject* clazz;
bool result = false;
if (classAndMethodDescStr == NULL) {
dvmThrowNullPointerException("classAndMethodDesc == null");
RETURN_VOID();
}
char* classAndMethodDesc = NULL;
/*
* Pick the string apart. We have a local copy, so just modify it
* in place.
*/
classAndMethodDesc = dvmCreateCstrFromString(classAndMethodDescStr);
char* methodName = strchr(classAndMethodDesc, '.');
if (methodName == NULL) {
dvmThrowRuntimeException("method name not found in string");
RETURN_VOID();
}
*methodName++ = '\0';
char* methodDescr = strchr(methodName, ':');
if (methodDescr == NULL) {
dvmThrowRuntimeException("method descriptor not found in string");
RETURN_VOID();
}
*methodDescr++ = '\0';
//ALOGD("GOT: %s %s %s", classAndMethodDesc, methodName, methodDescr);
/*
* Find the class, but only if it's already loaded.
*/
clazz = dvmLookupClass(classAndMethodDesc, NULL, false);
if (clazz == NULL) {
ALOGD("Class %s not found in bootstrap loader", classAndMethodDesc);
goto bail;
}
Method* method;
/*
* Find the method, which could be virtual or direct, defined directly
* or inherited.
*/
if (methodName[0] == '<') {
/*
* Constructor or class initializer. Only need to examine the
* "direct" list, and don't need to search up the class hierarchy.
*/
method = dvmFindDirectMethodByDescriptor(clazz, methodName,
methodDescr);
} else {
/*
* Try both lists, and scan up the tree.
*/
method = dvmFindVirtualMethodHierByDescriptor(clazz, methodName,
methodDescr);
if (method == NULL) {
method = dvmFindDirectMethodHierByDescriptor(clazz, methodName,
methodDescr);
}
}
if (method != NULL) {
/*
* Got it. See if there's a register map here.
*/
const RegisterMap* pMap;
pMap = dvmGetExpandedRegisterMap(method);
if (pMap == NULL) {
ALOGV("No map for %s.%s %s",
classAndMethodDesc, methodName, methodDescr);
} else {
ALOGV("Found map %s.%s %s",
classAndMethodDesc, methodName, methodDescr);
result = true;
}
} else {
ALOGV("Unable to find %s.%s %s",
classAndMethodDesc, methodName, methodDescr);
}
bail:
free(classAndMethodDesc);
RETURN_BOOLEAN(result);
}
/*
* This is the common message body for proxy methods.
*
* The method we're calling looks like:
* public Object invoke(Object proxy, Method method, Object[] args)
*
* This means we have to create a Method object, box our arguments into
* a new Object[] array, make the call, and unbox the return value if
* necessary.
*/
static void proxyInvoker(const u4* args, JValue* pResult,
const Method* method, Thread* self)
{
Object* thisObj = (Object*) args[0];
Object* methodObj = NULL;
ArrayObject* argArray = NULL;
Object* handler;
Method* invoke;
ClassObject* returnType;
int hOffset;
JValue invokeResult;
/*
* Retrieve handler object for this proxy instance.
*/
hOffset = dvmFindFieldOffset(thisObj->clazz, "h",
"Ljava/lang/reflect/InvocationHandler;");
if (hOffset < 0) {
LOGE("Unable to find 'h' in Proxy object\n");
dvmAbort();
}
handler = dvmGetFieldObject(thisObj, hOffset);
/*
* Find the invoke() method, looking in "this"s class. (Because we
* start here we don't have to convert it to a vtable index and then
* index into this' vtable.)
*/
invoke = dvmFindVirtualMethodHierByDescriptor(handler->clazz, "invoke",
"(Ljava/lang/Object;Ljava/lang/reflect/Method;[Ljava/lang/Object;)Ljava/lang/Object;");
if (invoke == NULL) {
LOGE("Unable to find invoke()\n");
dvmAbort();
}
LOGV("invoke: %s.%s, this=%p, handler=%s\n",
method->clazz->descriptor, method->name,
thisObj, handler->clazz->descriptor);
/*
* Create a java.lang.reflect.Method object for this method.
*
* We don't want to use "method", because that's the concrete
* implementation in the proxy class. We want the abstract Method
* from the declaring interface. We have a pointer to it tucked
* away in the "insns" field.
*
* TODO: this could be cached for performance.
*/
methodObj = dvmCreateReflectMethodObject((Method*) method->insns);
if (methodObj == NULL) {
assert(dvmCheckException(self));
goto bail;
}
/*
* Determine the return type from the signature.
*
* TODO: this could be cached for performance.
*/
returnType = dvmGetBoxedReturnType(method);
if (returnType == NULL) {
char* desc = dexProtoCopyMethodDescriptor(&method->prototype);
LOGE("Could not determine return type for '%s'\n", desc);
free(desc);
assert(dvmCheckException(self));
goto bail;
}
LOGV(" return type will be %s\n", returnType->descriptor);
/*
* Convert "args" array into Object[] array, using the method
* signature to determine types. If the method takes no arguments,
* we must pass null.
*/
argArray = boxMethodArgs(method, args+1);
if (dvmCheckException(self))
goto bail;
/*
* Call h.invoke(proxy, method, args).
*
* We don't need to repackage exceptions, so if one has been thrown
* just jump to the end.
*/
dvmCallMethod(self, invoke, handler, &invokeResult,
thisObj, methodObj, argArray);
if (dvmCheckException(self))
goto bail;
/*
* Unbox the return value. If it's the wrong type, throw a
* ClassCastException. If it's a null pointer and we need a
* primitive type, throw a NullPointerException.
*/
if (returnType->primitiveType == PRIM_VOID) {
LOGVV("+++ ignoring return to void\n");
} else if (invokeResult.l == NULL) {
if (dvmIsPrimitiveClass(returnType)) {
dvmThrowException("Ljava/lang/NullPointerException;",
"null result when primitive expected");
goto bail;
}
pResult->l = NULL;
} else {
if (!dvmUnwrapPrimitive(invokeResult.l, returnType, pResult)) {
dvmThrowExceptionWithClassMessage("Ljava/lang/ClassCastException;",
((Object*)invokeResult.l)->clazz->descriptor);
goto bail;
}
}
bail:
dvmReleaseTrackedAlloc(methodObj, self);
dvmReleaseTrackedAlloc((Object*)argArray, self);
}
/*
* Initialize an exception with an appropriate constructor.
*
* "exception" is the exception object to initialize.
* Either or both of "msg" and "cause" may be null.
* "self" is dvmThreadSelf(), passed in so we don't have to look it up again.
*
* If the process of initializing the exception causes another
* exception (e.g., OutOfMemoryError) to be thrown, return an error
* and leave self->exception intact.
*/
static bool initException(Object* exception, const char* msg, Object* cause,
Thread* self)
{
enum {
kInitUnknown,
kInitNoarg,
kInitMsg,
kInitMsgThrow,
kInitThrow
} initKind = kInitUnknown;
Method* initMethod = NULL;
ClassObject* excepClass = exception->clazz;
StringObject* msgStr = NULL;
bool result = false;
bool needInitCause = false;
assert(self != NULL);
assert(self->exception == NULL);
/* if we have a message, create a String */
if (msg == NULL)
msgStr = NULL;
else {
msgStr = dvmCreateStringFromCstr(msg);
if (msgStr == NULL) {
LOGW("Could not allocate message string \"%s\" while "
"throwing internal exception (%s)\n",
msg, excepClass->descriptor);
goto bail;
}
}
if (cause != NULL) {
if (!dvmInstanceof(cause->clazz, gDvm.classJavaLangThrowable)) {
LOGE("Tried to init exception with cause '%s'\n",
cause->clazz->descriptor);
dvmAbort();
}
}
/*
* The Throwable class has four public constructors:
* (1) Throwable()
* (2) Throwable(String message)
* (3) Throwable(String message, Throwable cause) (added in 1.4)
* (4) Throwable(Throwable cause) (added in 1.4)
*
* The first two are part of the original design, and most exception
* classes should support them. The third prototype was used by
* individual exceptions. e.g. ClassNotFoundException added it in 1.2.
* The general "cause" mechanism was added in 1.4. Some classes,
* such as IllegalArgumentException, initially supported the first
* two, but added the second two in a later release.
*
* Exceptions may be picky about how their "cause" field is initialized.
* If you call ClassNotFoundException(String), it may choose to
* initialize its "cause" field to null. Doing so prevents future
* calls to Throwable.initCause().
*
* So, if "cause" is not NULL, we need to look for a constructor that
* takes a throwable. If we can't find one, we fall back on calling
* #1/#2 and making a separate call to initCause(). Passing a null ref
* for "message" into Throwable(String, Throwable) is allowed, but we
* prefer to use the Throwable-only version because it has different
* behavior.
*
* java.lang.TypeNotPresentException is a strange case -- it has #3 but
* not #2. (Some might argue that the constructor is actually not #3,
* because it doesn't take the message string as an argument, but it
* has the same effect and we can work with it here.)
*
* java.lang.AssertionError is also a strange case -- it has a
* constructor that takes an Object, but not one that takes a String.
* There may be other cases like this, as well, so we generally look
* for an Object-taking constructor if we can't find one that takes
* a String.
*/
if (cause == NULL) {
if (msgStr == NULL) {
initMethod = findExceptionInitMethod(excepClass, false, false);
initKind = kInitNoarg;
} else {
initMethod = findExceptionInitMethod(excepClass, true, false);
if (initMethod != NULL) {
initKind = kInitMsg;
} else {
/* no #2, try #3 */
initMethod = findExceptionInitMethod(excepClass, true, true);
if (initMethod != NULL) {
initKind = kInitMsgThrow;
}
}
}
} else {
if (msgStr == NULL) {
initMethod = findExceptionInitMethod(excepClass, false, true);
if (initMethod != NULL) {
initKind = kInitThrow;
} else {
initMethod = findExceptionInitMethod(excepClass, false, false);
initKind = kInitNoarg;
needInitCause = true;
}
} else {
initMethod = findExceptionInitMethod(excepClass, true, true);
if (initMethod != NULL) {
initKind = kInitMsgThrow;
} else {
initMethod = findExceptionInitMethod(excepClass, true, false);
initKind = kInitMsg;
needInitCause = true;
}
}
}
if (initMethod == NULL) {
/*
* We can't find the desired constructor. This can happen if a
* subclass of java/lang/Throwable doesn't define an expected
* constructor, e.g. it doesn't provide one that takes a string
* when a message has been provided.
*/
LOGW("WARNING: exception class '%s' missing constructor "
"(msg='%s' kind=%d)\n",
excepClass->descriptor, msg, initKind);
assert(strcmp(excepClass->descriptor,
"Ljava/lang/RuntimeException;") != 0);
dvmThrowChainedException("Ljava/lang/RuntimeException;",
"re-throw on exception class missing constructor", NULL);
goto bail;
}
/*
* Call the constructor with the appropriate arguments.
*/
JValue unused;
switch (initKind) {
case kInitNoarg:
LOGVV("+++ exc noarg (ic=%d)\n", needInitCause);
dvmCallMethod(self, initMethod, exception, &unused);
break;
case kInitMsg:
LOGVV("+++ exc msg (ic=%d)\n", needInitCause);
dvmCallMethod(self, initMethod, exception, &unused, msgStr);
break;
case kInitThrow:
LOGVV("+++ exc throw");
assert(!needInitCause);
dvmCallMethod(self, initMethod, exception, &unused, cause);
break;
case kInitMsgThrow:
LOGVV("+++ exc msg+throw");
assert(!needInitCause);
dvmCallMethod(self, initMethod, exception, &unused, msgStr, cause);
break;
default:
assert(false);
goto bail;
}
/*
* It's possible the constructor has thrown an exception. If so, we
* return an error and let our caller deal with it.
*/
if (self->exception != NULL) {
LOGW("Exception thrown (%s) while throwing internal exception (%s)\n",
self->exception->clazz->descriptor, exception->clazz->descriptor);
goto bail;
}
/*
* If this exception was caused by another exception, and we weren't
* able to find a cause-setting constructor, set the "cause" field
* with an explicit call.
*/
if (needInitCause) {
Method* initCause;
initCause = dvmFindVirtualMethodHierByDescriptor(excepClass, "initCause",
"(Ljava/lang/Throwable;)Ljava/lang/Throwable;");
if (initCause != NULL) {
dvmCallMethod(self, initCause, exception, &unused, cause);
if (self->exception != NULL) {
/* initCause() threw an exception; return an error and
* let the caller deal with it.
*/
LOGW("Exception thrown (%s) during initCause() "
"of internal exception (%s)\n",
self->exception->clazz->descriptor,
exception->clazz->descriptor);
goto bail;
}
} else {
LOGW("WARNING: couldn't find initCause in '%s'\n",
excepClass->descriptor);
}
}
result = true;
bail:
dvmReleaseTrackedAlloc((Object*) msgStr, self); // NULL is ok
return result;
}
