natclass.cc

gcc的组建

	}
    }
  throw new java::lang::NoSuchMethodException (name);
}

// Private accessor method for Java code to retrieve the protection domain.
java::security::ProtectionDomain *
java::lang::Class::getProtectionDomain0 ()
{
  return protectionDomain;
}

JArray<jobject> *
java::lang::Class::getSigners()
{
  return hack_signers;
}

void
java::lang::Class::setSigners(JArray<jobject> *s)
{
  hack_signers = s;
}



//
// Some class-related convenience functions.
//

// Find a method declared in the class.  If it is not declared locally
// (or if it is inherited), return NULL.
_Jv_Method *
_Jv_GetMethodLocal (jclass klass, _Jv_Utf8Const *name,
		    _Jv_Utf8Const *signature)
{
  for (int i = 0; i < klass->method_count; ++i)
    {
      if (_Jv_equalUtf8Consts (name, klass->methods[i].name)
	  && _Jv_equalUtf8Consts (signature, klass->methods[i].signature))
	return &klass->methods[i];
    }
  return NULL;
}

_Jv_Method *
_Jv_LookupDeclaredMethod (jclass klass, _Jv_Utf8Const *name,
                          _Jv_Utf8Const *signature,
			  jclass *declarer_result)
{
  for (; klass; klass = klass->getSuperclass())
    {
      _Jv_Method *meth = _Jv_GetMethodLocal (klass, name, signature);

      if (meth)
	{
	  if (declarer_result)
	    *declarer_result = klass;
	  return meth;
	}
    }

  return NULL;
}

#ifdef HAVE_TLS

// NOTE: MCACHE_SIZE should be a power of 2 minus one.
#define MCACHE_SIZE 31

struct _Jv_mcache
{
  jclass klass;
  _Jv_Method *method;
};

static __thread _Jv_mcache *method_cache;
#endif // HAVE_TLS

static void *
_Jv_FindMethodInCache (jclass klass,
                       _Jv_Utf8Const *name,
                       _Jv_Utf8Const *signature)
{
#ifdef HAVE_TLS
  _Jv_mcache *cache = method_cache;
  if (cache)
    {
      int index = name->hash16 () & MCACHE_SIZE;
      _Jv_mcache *mc = &cache[index];
      _Jv_Method *m = mc->method;

      if (mc->klass == klass
	  && _Jv_equalUtf8Consts (m->name, name)
	  && _Jv_equalUtf8Consts (m->signature, signature))
	return mc->method->ncode;
    }
#endif // HAVE_TLS
  return NULL;
}

static void
_Jv_AddMethodToCache (jclass klass, _Jv_Method *method)
{
#ifdef HAVE_TLS
  if (method_cache == NULL)
    method_cache = (_Jv_mcache *) _Jv_MallocUnchecked((MCACHE_SIZE + 1)
						      * sizeof (_Jv_mcache));
  // If the allocation failed, just keep going.
  if (method_cache != NULL)
    {
      int index = method->name->hash16 () & MCACHE_SIZE;
      method_cache[index].method = method;
      method_cache[index].klass = klass;
    }
#endif // HAVE_TLS
}

// Free this thread's method cache.  We explicitly manage this memory
// as the GC does not yet know how to scan TLS on all platforms.
void
_Jv_FreeMethodCache ()
{
#ifdef HAVE_TLS
  if (method_cache != NULL)
    {
      _Jv_Free(method_cache);
      method_cache = NULL;
    }
#endif // HAVE_TLS
}

void *
_Jv_LookupInterfaceMethod (jclass klass, _Jv_Utf8Const *name,
                           _Jv_Utf8Const *signature)
{
  using namespace java::lang::reflect;

  void *ncode = _Jv_FindMethodInCache (klass, name, signature);
  if (ncode != 0)
    return ncode;

  for (; klass; klass = klass->getSuperclass())
    {
      _Jv_Method *meth = _Jv_GetMethodLocal (klass, name, signature);
      if (! meth)
        continue;

      if (Modifier::isStatic(meth->accflags))
	throw new java::lang::IncompatibleClassChangeError
	  (_Jv_GetMethodString (klass, meth));
      if (Modifier::isAbstract(meth->accflags))
	throw new java::lang::AbstractMethodError
	  (_Jv_GetMethodString (klass, meth));
      if (! Modifier::isPublic(meth->accflags))
	throw new java::lang::IllegalAccessError
	  (_Jv_GetMethodString (klass, meth));

      _Jv_AddMethodToCache (klass, meth);

      return meth->ncode;
    }
  throw new java::lang::IncompatibleClassChangeError;
}

// Fast interface method lookup by index.
void *
_Jv_LookupInterfaceMethodIdx (jclass klass, jclass iface, int method_idx)
{
  _Jv_IDispatchTable *cldt = klass->idt;
  int idx = iface->idt->iface.ioffsets[cldt->cls.iindex] + method_idx;
  return cldt->cls.itable[idx];
}

jboolean
_Jv_IsAssignableFrom (jclass source, jclass target)
{
  if (source == target)
    return true;

  // If target is array, so must source be.  
  while (target->isArray ())
    {
      if (! source->isArray())
	return false;
      target = target->getComponentType();
      source = source->getComponentType();
    }

  if (target->isInterface())
    {
      // Abstract classes have no IDT, and IDTs provide no way to check
      // two interfaces for assignability.
      if (__builtin_expect 
          (source->idt == NULL || source->isInterface(), false))
        return _Jv_InterfaceAssignableFrom (source, target);

      _Jv_IDispatchTable *cl_idt = source->idt;
      _Jv_IDispatchTable *if_idt = target->idt;

      if (__builtin_expect ((if_idt == NULL), false))
	return false; // No class implementing TARGET has been loaded.    
      jshort cl_iindex = cl_idt->cls.iindex;
      if (cl_iindex < if_idt->iface.ioffsets[0])
        {
	  jshort offset = if_idt->iface.ioffsets[cl_iindex];
	  if (offset != -1 && offset < cl_idt->cls.itable_length
	      && cl_idt->cls.itable[offset] == target)
	    return true;
	}
      return false;
    }

  // Primitive TYPE classes are only assignable to themselves.
  if (__builtin_expect (target->isPrimitive() || source->isPrimitive(), false))
    return false;

  if (target == &java::lang::Object::class$)
    return true;
  else if (source->ancestors == NULL || target->ancestors == NULL)
    {
      // We need this case when either SOURCE or TARGET has not has
      // its constant-time tables prepared.

      // At this point we know that TARGET can't be Object, so it is
      // safe to use that as the termination point.
      while (source && source != &java::lang::Object::class$)
	{
	  if (source == target)
	    return true;
	  source = source->getSuperclass();
	}
    }
  else if (source->depth >= target->depth
	   && source->ancestors[source->depth - target->depth] == target)
    return true;

  return false;
}

// Interface type checking, the slow way. Returns TRUE if IFACE is a 
// superinterface of SOURCE. This is used when SOURCE is also an interface,
// or a class with no interface dispatch table.
jboolean
_Jv_InterfaceAssignableFrom (jclass source, jclass iface)
{
  for (int i = 0; i < source->interface_count; i++)
    {
      jclass interface = source->interfaces[i];
      if (iface == interface
          || _Jv_InterfaceAssignableFrom (interface, iface))
        return true;      
    }
    
  if (!source->isInterface()
      && source->superclass 
      && _Jv_InterfaceAssignableFrom (source->superclass, iface))
    return true;
        
  return false;
}

jboolean
_Jv_IsInstanceOf(jobject obj, jclass cl)
{
  if (__builtin_expect (!obj, false))
    return false;
  return _Jv_IsAssignableFrom (JV_CLASS (obj), cl);
}

void *
_Jv_CheckCast (jclass c, jobject obj)
{
  if (__builtin_expect 
      (obj != NULL && ! _Jv_IsAssignableFrom(JV_CLASS (obj), c), false))
    throw new java::lang::ClassCastException
      ((new java::lang::StringBuffer
	(obj->getClass()->getName()))->append
       (JvNewStringUTF(" cannot be cast to "))->append
       (c->getName())->toString());

  return obj;
}

void
_Jv_CheckArrayStore (jobject arr, jobject obj)
{
  if (obj)
    {
      JvAssert (arr != NULL);
      jclass elt_class = (JV_CLASS (arr))->getComponentType();
      if (elt_class == &java::lang::Object::class$)
	return;
      jclass obj_class = JV_CLASS (obj);
      if (__builtin_expect 
          (! _Jv_IsAssignableFrom (obj_class, elt_class), false))
	throw new java::lang::ArrayStoreException
		((new java::lang::StringBuffer
		 (JvNewStringUTF("Cannot store ")))->append
		 (obj_class->getName())->append
		 (JvNewStringUTF(" in array of type "))->append
		 (elt_class->getName())->toString());
    }
}

jboolean
_Jv_IsAssignableFromSlow (jclass source, jclass target)
{
  // First, strip arrays.
  while (target->isArray ())
    {
      // If target is array, source must be as well.
      if (! source->isArray ())
       return false;
      target = target->getComponentType ();
      source = source->getComponentType ();
    }

  // Quick success.
  if (target == &java::lang::Object::class$)
    return true;

  // Ensure that the classes have their supers installed.
  _Jv_Linker::wait_for_state (source, JV_STATE_LOADING);
  _Jv_Linker::wait_for_state (target, JV_STATE_LOADING);

  do
    {
      if (source == target)
       return true;

      if (target->isPrimitive () || source->isPrimitive ())
       return false;

      if (target->isInterface ())
       {
         for (int i = 0; i < source->interface_count; ++i)
           {
             // We use a recursive call because we also need to
             // check superinterfaces.
             if (_Jv_IsAssignableFromSlow (source->getInterface (i), target))
               return true;
           }
       }
      source = source->getSuperclass ();
    }
  while (source != NULL);

  return false;
}

// Lookup an interface method by name.  This is very similar to
// purpose to _getMethod, but the interfaces are quite different.  It
// might be a good idea for _getMethod to call this function.
//
// Return true of the method is found, with the class in FOUND_CLASS
// and the index in INDEX.
bool
_Jv_getInterfaceMethod (jclass search_class, jclass &found_class, int &index,
			const _Jv_Utf8Const *utf_name,  
			const _Jv_Utf8Const *utf_sig)
{
   for (jclass klass = search_class; klass; klass = klass->getSuperclass())
    {
      // FIXME: Throw an exception?
      if (!klass->isInterface ())
	return false;
      
      int i = klass->method_count;
      while (--i >= 0)
	{
	  if (_Jv_equalUtf8Consts (klass->methods[i].name, utf_name)
	      && _Jv_equalUtf8Consts (klass->methods[i].signature, utf_sig))
	    {
	      // Found it.
	      using namespace java::lang::reflect;

	      // FIXME: Method must be public.  Throw an exception?
	      if (! Modifier::isPublic (klass->methods[i].accflags))
		break;

	      found_class = klass;
	      // Interface method indexes count from 1.
	      index = i+1;
	      return true;
	    }
	}
    }

  // If we haven't found a match, and this class is an interface, then
  // check all the superinterfaces.
  if (search_class->isInterface())
    {
      for (int i = 0; i < search_class->interface_count; ++i)
	{
	  using namespace java::lang::reflect;
	  bool found = _Jv_getInterfaceMethod (search_class->interfaces[i], 
					   found_class, index,
					   utf_name, utf_sig);
	  if (found)
	    return true;
	}
    }

  return false;
}