/*
* 在'clazz'中，我们有一个方法指向另一个方法，但它可能指向派生类中的一个方法，我们想要从虚拟函数表中找到实际入口,如果'class'是一个接口，我们不得不在短时间内做更多的挖掘
*
* 对于'direct'方法(private / constructor).我们仅仅返回原生态方法
*
* (这里被适用于反射和JNI调用)
*/
const Method* dvmGetVirtualizedMethod(const ClassObject* clazz,
const Method* meth)
{
Method* actualMeth;
int methodIndex;
if (dvmIsDirectMethod(meth)) {
/* no vtable entry for these */
assert(!dvmIsStaticMethod(meth));
return meth;
}
/*
* If the method was declared in an interface, we need to scan through
* the class' list of interfaces for it, and find the vtable index
* from that.
*
* TODO: use the interface cache.
*/
if (dvmIsInterfaceClass(meth->clazz)) {
int i;
for (i = 0; i < clazz->iftableCount; i++) {
if (clazz->iftable[i].clazz == meth->clazz)
break;
}
if (i == clazz->iftableCount) {
dvmThrowIncompatibleClassChangeError(
"invoking method from interface not implemented by class");
return NULL;
}
methodIndex = clazz->iftable[i].methodIndexArray[meth->methodIndex];
} else {
methodIndex = meth->methodIndex;
}
assert(methodIndex >= 0 && methodIndex < clazz->vtableCount);
actualMeth = clazz->vtable[methodIndex];
/*
* Make sure there's code to execute.
*/
if (dvmIsAbstractMethod(actualMeth)) {
dvmThrowAbstractMethodError(NULL);
return NULL;
}
assert(!dvmIsMirandaMethod(actualMeth));
return actualMeth;
}
GOTO_TARGET_END
GOTO_TARGET(invokeSuper, bool methodCallRange)
{
Method* baseMethod;
u2 thisReg;
EXPORT_PC();
vsrc1 = INST_AA(inst); /* AA (count) or BA (count + arg 5) */
ref = FETCH(1); /* method ref */
vdst = FETCH(2); /* 4 regs -or- first reg */
if (methodCallRange) {
ILOGV("|invoke-super-range args=%d @0x%04x {regs=v%d-v%d}",
vsrc1, ref, vdst, vdst+vsrc1-1);
thisReg = vdst;
} else {
ILOGV("|invoke-super args=%d @0x%04x {regs=0x%04x %x}",
vsrc1 >> 4, ref, vdst, vsrc1 & 0x0f);
thisReg = vdst & 0x0f;
}
/* impossible in well-formed code, but we must check nevertheless */
if (!checkForNull((Object*) GET_REGISTER(thisReg)))
GOTO_exceptionThrown();
/*
* Resolve the method. This is the correct method for the static
* type of the object. We also verify access permissions here.
* The first arg to dvmResolveMethod() is just the referring class
* (used for class loaders and such), so we don't want to pass
* the superclass into the resolution call.
*/
baseMethod = dvmDexGetResolvedMethod(methodClassDex, ref);
if (baseMethod == NULL) {
baseMethod = dvmResolveMethod(curMethod->clazz, ref,METHOD_VIRTUAL);
if (baseMethod == NULL) {
ILOGV("+ unknown method or access denied");
GOTO_exceptionThrown();
}
}
/*
* Combine the object we found with the vtable offset in the
* method's class.
*
* We're using the current method's class' superclass, not the
* superclass of "this". This is because we might be executing
* in a method inherited from a superclass, and we want to run
* in that class' superclass.
*/
if (baseMethod->methodIndex >= curMethod->clazz->super->vtableCount) {
/*
* Method does not exist in the superclass. Could happen if
* superclass gets updated.
*/
dvmThrowNoSuchMethodError(baseMethod->name);
GOTO_exceptionThrown();
}
methodToCall = curMethod->clazz->super->vtable[baseMethod->methodIndex];
#if 0
if (dvmIsAbstractMethod(methodToCall)) {
dvmThrowAbstractMethodError("abstract method not implemented");
GOTO_exceptionThrown();
}
#else
assert(!dvmIsAbstractMethod(methodToCall) ||
methodToCall->nativeFunc != NULL);
#endif
LOGVV("+++ base=%s.%s super-virtual=%s.%s",
baseMethod->clazz->descriptor, baseMethod->name,
methodToCall->clazz->descriptor, methodToCall->name);
assert(methodToCall != NULL);
GOTO_invokeMethod(methodCallRange, methodToCall, vsrc1, vdst);
}
/*
* Magic "internal native" code stub, inserted into abstract method
* definitions when a class is first loaded. This throws the expected
* exception so we don't have to explicitly check for it in the interpreter.
*/
void dvmAbstractMethodStub(const u4* args, JValue* pResult)
{
ALOGD("--- called into dvmAbstractMethodStub");
dvmThrowAbstractMethodError("abstract method not implemented");
}
GOTO_TARGET_END
GOTO_TARGET(invokeVirtual, bool methodCallRange, bool)
{
Method* baseMethod;
Object* thisPtr;
EXPORT_PC();
vsrc1 = INST_AA(inst); /* AA (count) or BA (count + arg 5) */
ref = FETCH(1); /* method ref */
vdst = FETCH(2); /* 4 regs -or- first reg */
/*
* The object against which we are executing a method is always
* in the first argument.
*/
if (methodCallRange) {
assert(vsrc1 > 0);
ILOGV("|invoke-virtual-range args=%d @0x%04x {regs=v%d-v%d}",
vsrc1, ref, vdst, vdst+vsrc1-1);
thisPtr = (Object*) GET_REGISTER(vdst);
} else {
assert((vsrc1>>4) > 0);
ILOGV("|invoke-virtual args=%d @0x%04x {regs=0x%04x %x}",
vsrc1 >> 4, ref, vdst, vsrc1 & 0x0f);
thisPtr = (Object*) GET_REGISTER(vdst & 0x0f);
}
if (!checkForNull(thisPtr))
GOTO_exceptionThrown();
/*
* Resolve the method. This is the correct method for the static
* type of the object. We also verify access permissions here.
*/
baseMethod = dvmDexGetResolvedMethod(methodClassDex, ref);
if (baseMethod == NULL) {
baseMethod = dvmResolveMethod(curMethod->clazz, ref,METHOD_VIRTUAL);
if (baseMethod == NULL) {
ILOGV("+ unknown method or access denied");
GOTO_exceptionThrown();
}
}
/*
* Combine the object we found with the vtable offset in the
* method.
*/
assert(baseMethod->methodIndex < thisPtr->clazz->vtableCount);
methodToCall = thisPtr->clazz->vtable[baseMethod->methodIndex];
#if defined(WITH_JIT) && defined(MTERP_STUB)
self->methodToCall = methodToCall;
self->callsiteClass = thisPtr->clazz;
#endif
#if 0
if (dvmIsAbstractMethod(methodToCall)) {
/*
* This can happen if you create two classes, Base and Sub, where
* Sub is a sub-class of Base. Declare a protected abstract
* method foo() in Base, and invoke foo() from a method in Base.
* Base is an "abstract base class" and is never instantiated
* directly. Now, Override foo() in Sub, and use Sub. This
* Works fine unless Sub stops providing an implementation of
* the method.
*/
dvmThrowAbstractMethodError("abstract method not implemented");
GOTO_exceptionThrown();
}
#else
assert(!dvmIsAbstractMethod(methodToCall) ||
methodToCall->nativeFunc != NULL);
#endif
LOGVV("+++ base=%s.%s virtual[%d]=%s.%s",
baseMethod->clazz->descriptor, baseMethod->name,
(u4) baseMethod->methodIndex,
methodToCall->clazz->descriptor, methodToCall->name);
assert(methodToCall != NULL);
#if 0
if (vsrc1 != methodToCall->insSize) {
ALOGW("WRONG METHOD: base=%s.%s virtual[%d]=%s.%s",
baseMethod->clazz->descriptor, baseMethod->name,
(u4) baseMethod->methodIndex,
methodToCall->clazz->descriptor, methodToCall->name);
//dvmDumpClass(baseMethod->clazz);
//dvmDumpClass(methodToCall->clazz);
dvmDumpAllClasses(0);
}
#endif
GOTO_invokeMethod(methodCallRange, methodToCall, vsrc1, vdst);
}
/*
* Find the method corresponding to "methodRef".
*
* We use "referrer" to find the DexFile with the constant pool that
* "methodRef" is an index into. We also use its class loader. The method
* being resolved may very well be in a different DEX file.
*
* If this is a static method, we ensure that the method's class is
* initialized.
*/
Method* dvmResolveMethod(const ClassObject* referrer, u4 methodIdx,
MethodType methodType)
{
DvmDex* pDvmDex = referrer->pDvmDex;
ClassObject* resClass;
const DexMethodId* pMethodId;
Method* resMethod;
assert(methodType != METHOD_INTERFACE);
LOGVV("--- resolving method %u (referrer=%s)", methodIdx,
referrer->descriptor);
pMethodId = dexGetMethodId(pDvmDex->pDexFile, methodIdx);
resClass = dvmResolveClass(referrer, pMethodId->classIdx, false);
if (resClass == NULL) {
/* can't find the class that the method is a part of */
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
}
if (dvmIsInterfaceClass(resClass)) {
/* method is part of an interface */
dvmThrowIncompatibleClassChangeErrorWithClassMessage(
resClass->descriptor);
return NULL;
}
const char* name = dexStringById(pDvmDex->pDexFile, pMethodId->nameIdx);
DexProto proto;
dexProtoSetFromMethodId(&proto, pDvmDex->pDexFile, pMethodId);
/*
* We need to chase up the class hierarchy to find methods defined
* in super-classes. (We only want to check the current class
* if we're looking for a constructor; since DIRECT calls are only
* for constructors and private methods, we don't want to walk up.)
*/
if (methodType == METHOD_DIRECT) {
resMethod = dvmFindDirectMethod(resClass, name, &proto);
} else if (methodType == METHOD_STATIC) {
resMethod = dvmFindDirectMethodHier(resClass, name, &proto);
} else {
resMethod = dvmFindVirtualMethodHier(resClass, name, &proto);
}
if (resMethod == NULL) {
std::string msg;
msg += resClass->descriptor;
msg += ".";
msg += name;
dvmThrowNoSuchMethodError(msg.c_str());
return NULL;
}
LOGVV("--- found method %d (%s.%s)",
methodIdx, resClass->descriptor, resMethod->name);
/* see if this is a pure-abstract method */
if (dvmIsAbstractMethod(resMethod) && !dvmIsAbstractClass(resClass)) {
dvmThrowAbstractMethodError(name);
return NULL;
}
/*
* If we're the first to resolve this class, we need to initialize
* it now. Only necessary for METHOD_STATIC.
*/
if (methodType == METHOD_STATIC) {
if (!dvmIsClassInitialized(resMethod->clazz) &&
!dvmInitClass(resMethod->clazz))
{
assert(dvmCheckException(dvmThreadSelf()));
return NULL;
} else {
assert(!dvmCheckException(dvmThreadSelf()));
}
} else {
/*
* Edge case: if the <clinit> for a class creates an instance
* of itself, we will call <init> on a class that is still being
* initialized by us.
*/
assert(dvmIsClassInitialized(resMethod->clazz) ||
dvmIsClassInitializing(resMethod->clazz));
}
/*
* If the class has been initialized, add a pointer to our data structure
* so we don't have to jump through the hoops again. If this is a
* static method and the defining class is still initializing (i.e. this
* thread is executing <clinit>), don't do the store, otherwise other
* threads could call the method without waiting for class init to finish.
*/
if (methodType == METHOD_STATIC && !dvmIsClassInitialized(resMethod->clazz))
{
LOGVV("--- not caching resolved method %s.%s (class init=%d/%d)",
resMethod->clazz->descriptor, resMethod->name,
dvmIsClassInitializing(resMethod->clazz),
dvmIsClassInitialized(resMethod->clazz));
} else {
dvmDexSetResolvedMethod(pDvmDex, methodIdx, resMethod);
}
return resMethod;
}
