gcc/libjava/java/lang/natClass.cc

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// natClass.cc - Implementation of java.lang.Class native methods.
/* Copyright (C) 1998, 1999 Cygnus Solutions
This file is part of libgcj.
This software is copyrighted work licensed under the terms of the
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
details. */
#include <config.h>
#include <stdlib.h>
#include <string.h>
#pragma implementation "Class.h"
#include <cni.h>
#include <jvm.h>
#include <java/lang/Class.h>
#include <java/lang/ClassLoader.h>
#include <java/lang/String.h>
#include <java/lang/reflect/Modifier.h>
#include <java/lang/reflect/Member.h>
#include <java/lang/reflect/Method.h>
#include <java/lang/reflect/Field.h>
#include <java/lang/reflect/Constructor.h>
#include <java/lang/AbstractMethodError.h>
#include <java/lang/ClassNotFoundException.h>
#include <java/lang/IllegalAccessException.h>
#include <java/lang/IllegalAccessError.h>
#include <java/lang/IncompatibleClassChangeError.h>
#include <java/lang/InstantiationException.h>
#include <java/lang/NoClassDefFoundError.h>
#include <java/lang/NoSuchFieldException.h>
#include <java/lang/NoSuchMethodException.h>
#include <java/lang/Thread.h>
#include <java/lang/NullPointerException.h>
#include <java/lang/System.h>
#include <java/lang/SecurityManager.h>
#define CloneableClass _CL_Q34java4lang9Cloneable
extern java::lang::Class CloneableClass;
#define ObjectClass _CL_Q34java4lang6Object
extern java::lang::Class ObjectClass;
#define ErrorClass _CL_Q34java4lang5Error
extern java::lang::Class ErrorClass;
#define ClassClass _CL_Q34java4lang5Class
extern java::lang::Class ClassClass;
#define MethodClass _CL_Q44java4lang7reflect6Method
extern java::lang::Class MethodClass;
#define FieldClass _CL_Q44java4lang7reflect5Field
extern java::lang::Class FieldClass;
// Some constants we use to look up the class initializer.
static _Jv_Utf8Const *void_signature = _Jv_makeUtf8Const ("()V", 3);
static _Jv_Utf8Const *clinit_name = _Jv_makeUtf8Const ("<clinit>", 8);
static _Jv_Utf8Const *init_name = _Jv_makeUtf8Const ("<init>", 6);
// These are the possible values for the `state' field. They more or
// less follow the section numbers in the Java Language Spec. Right
// now we don't bother to represent other interesting states, e.g. the
// states a class might inhabit before it is prepared. Note that
// ordering is important here; in particular `resolved' must come
// between `nothing' and the other states.
#define STATE_NOTHING 0
#define STATE_RESOLVED 1
#define STATE_IN_PROGRESS 6
#define STATE_DONE 9
#define STATE_ERROR 10
// Size of local hash table.
#define HASH_LEN 256
// Hash function for Utf8Consts.
#define HASH_UTF(Utf) (((Utf)->hash) % HASH_LEN)
// This is the table we use to keep track of loaded classes. See Spec
// section 12.2.
static jclass loaded_classes[HASH_LEN];
jclass
java::lang::Class::forName (jstring className)
{
if (! className)
JvThrow (new java::lang::NullPointerException);
#if 0
// FIXME: should check syntax of CLASSNAME and throw
// IllegalArgumentException on failure.
// FIXME: should use class loader from calling method.
jclass klass = _Jv_FindClass (className, NULL);
#else
jsize length = _Jv_GetStringUTFLength (className);
char buffer[length];
_Jv_GetStringUTFRegion (className, 0, length, buffer);
// FIXME: should check syntax of CLASSNAME and throw
// IllegalArgumentException on failure.
_Jv_Utf8Const *name = _Jv_makeUtf8Const (buffer, length);
// FIXME: should use class loader from calling method.
jclass klass = (buffer[0] == '['
? _Jv_FindClassFromSignature (name->data, NULL)
: _Jv_FindClass (name, NULL));
#endif
if (! klass)
JvThrow (new java::lang::ClassNotFoundException (className));
return klass;
}
java::lang::reflect::Constructor *
java::lang::Class::getConstructor (JArray<jclass> *)
{
JvFail ("java::lang::Class::getConstructor not implemented");
}
JArray<java::lang::reflect::Constructor *> *
java::lang::Class::getConstructors (void)
{
JvFail ("java::lang::Class::getConstructors not implemented");
}
java::lang::reflect::Constructor *
java::lang::Class::getDeclaredConstructor (JArray<jclass> *)
{
JvFail ("java::lang::Class::getDeclaredConstructor not implemented");
}
JArray<java::lang::reflect::Constructor *> *
java::lang::Class::getDeclaredConstructors (void)
{
JvFail ("java::lang::Class::getDeclaredConstructors not implemented");
}
java::lang::reflect::Field *
java::lang::Class::getField (jstring name, jint hash)
{
java::lang::reflect::Field* rfield;
for (int i = 0; i < field_count; i++)
{
_Jv_Field *field = &fields[i];
if (! _Jv_equal (field->name, name, hash))
continue;
if (! (field->getModifiers() & java::lang::reflect::Modifier::PUBLIC))
continue;
rfield = new java::lang::reflect::Field ();
rfield->offset = (char*) field - (char*) fields;
rfield->declaringClass = this;
rfield->name = name;
return rfield;
}
jclass superclass = getSuperclass();
if (superclass == NULL)
return NULL;
rfield = superclass->getField(name, hash);
for (int i = 0; i < interface_count && rfield == NULL; ++i)
rfield = interfaces[i]->getField (name, hash);
return rfield;
}
java::lang::reflect::Field *
java::lang::Class::getDeclaredField (jstring name)
{
java::lang::SecurityManager *s = java::lang::System::getSecurityManager();
if (s != NULL)
s->checkMemberAccess (this, java::lang::reflect::Member::DECLARED);
int hash = name->hashCode();
for (int i = 0; i < field_count; i++)
{
_Jv_Field *field = &fields[i];
if (! _Jv_equal (field->name, name, hash))
continue;
java::lang::reflect::Field* rfield = new java::lang::reflect::Field ();
rfield->offset = (char*) field - (char*) fields;
rfield->declaringClass = this;
rfield->name = name;
return rfield;
}
JvThrow (new java::lang::NoSuchFieldException (name));
}
JArray<java::lang::reflect::Field *> *
java::lang::Class::getDeclaredFields (void)
{
java::lang::SecurityManager *s = java::lang::System::getSecurityManager();
if (s != NULL)
s->checkMemberAccess (this, java::lang::reflect::Member::DECLARED);
JArray<java::lang::reflect::Field *> *result
= (JArray<java::lang::reflect::Field *> *)
JvNewObjectArray (field_count, &FieldClass, NULL);
java::lang::reflect::Field** fptr = elements (result);
for (int i = 0; i < field_count; i++)
{
_Jv_Field *field = &fields[i];
java::lang::reflect::Field* rfield = new java::lang::reflect::Field ();
rfield->offset = (char*) field - (char*) fields;
rfield->declaringClass = this;
*fptr++ = rfield;
}
return result;
}
java::lang::reflect::Method *
java::lang::Class::getDeclaredMethod (jstring, JArray<jclass> *)
{
JvFail ("java::lang::Class::getDeclaredMethod not implemented");
}
JArray<java::lang::reflect::Method *> *
java::lang::Class::getDeclaredMethods (void)
{
int numMethods = 0;
int i;
for (i = method_count; --i >= 0; )
{
_Jv_Method *method = &methods[i];
if (method->name == NULL
|| _Jv_equalUtf8Consts (method->name, clinit_name)
|| _Jv_equalUtf8Consts (method->name, init_name))
continue;
numMethods++;
}
JArray<java::lang::reflect::Method *> *result
= (JArray<java::lang::reflect::Method *> *)
JvNewObjectArray (numMethods, &MethodClass, NULL);
java::lang::reflect::Method** mptr = elements (result);
for (i = 0; i < method_count; i++)
{
_Jv_Method *method = &methods[i];
if (method->name == NULL
|| _Jv_equalUtf8Consts (method->name, clinit_name)
|| _Jv_equalUtf8Consts (method->name, init_name))
continue;
java::lang::reflect::Method* rmethod = new java::lang::reflect::Method ();
rmethod->offset = (char*) mptr - (char*) elements (result);
rmethod->declaringClass = this;
*mptr++ = rmethod;
}
return result;
}
jstring
java::lang::Class::getName (void)
{
char buffer[name->length + 1];
memcpy (buffer, name->data, name->length);
buffer[name->length] = '\0';
return _Jv_NewStringUTF (buffer);
}
JArray<jclass> *
java::lang::Class::getClasses (void)
{
// FIXME: implement.
return NULL;
}
JArray<jclass> *
java::lang::Class::getDeclaredClasses (void)
{
checkMemberAccess (java::lang::reflect::Member::DECLARED);
JvFail ("java::lang::Class::getDeclaredClasses not implemented");
return NULL; // Placate compiler.
}
// This is marked as unimplemented in the JCL book.
jclass
java::lang::Class::getDeclaringClass (void)
{
JvFail ("java::lang::Class::getDeclaringClass unimplemented");
return NULL; // Placate compiler.
}
JArray<java::lang::reflect::Field *> *
java::lang::Class::getFields (void)
{
JvFail ("java::lang::Class::getFields not implemented");
}
JArray<jclass> *
java::lang::Class::getInterfaces (void)
{
jobjectArray r = JvNewObjectArray (interface_count, getClass (), NULL);
jobject *data = elements (r);
for (int i = 0; i < interface_count; ++i)
data[i] = interfaces[i];
return reinterpret_cast<JArray<jclass> *> (r);
}
java::lang::reflect::Method *
java::lang::Class::getMethod (jstring, JArray<jclass> *)
{
JvFail ("java::lang::Class::getMethod not implemented");
}
JArray<java::lang::reflect::Method *> *
java::lang::Class::getMethods (void)
{
JvFail ("java::lang::Class::getMethods not implemented");
}
jboolean
java::lang::Class::isAssignableFrom (jclass klass)
{
if (this == klass)
return true;
// Primitive types must be equal, which we just tested for.
if (isPrimitive () || ! klass || klass->isPrimitive())
return false;
// If target is array, so must source be.
if (isArray ())
{
if (! klass->isArray())
return false;
return getComponentType()->isAssignableFrom(klass->getComponentType());
}
if (isAssignableFrom (klass->getSuperclass()))
return true;
if (isInterface())
{
// See if source implements this interface.
for (int i = 0; i < klass->interface_count; ++i)
{
jclass interface = klass->interfaces[i];
// FIXME: ensure that class is prepared here.
// See Spec 12.3.2.
if (isAssignableFrom (interface))
return true;
}
}
return false;
}
jboolean
java::lang::Class::isInstance (jobject obj)
{
if (! obj || isPrimitive ())
return false;
return isAssignableFrom (obj->getClass());
}
jboolean
java::lang::Class::isInterface (void)
{
return (accflags & java::lang::reflect::Modifier::INTERFACE) != 0;
}
jobject
java::lang::Class::newInstance (void)
{
// FIXME: do accessibility checks here. There currently doesn't
// seem to be any way to do these.
// FIXME: we special-case one check here just to pass a Plum Hall
// test. Once access checking is implemented, remove this.
if (this == &ClassClass)
JvThrow (new java::lang::IllegalAccessException);
if (isPrimitive ()
|| isInterface ()
|| isArray ()
|| java::lang::reflect::Modifier::isAbstract(accflags))
JvThrow (new java::lang::InstantiationException);
_Jv_Method *meth = _Jv_GetMethodLocal (this, init_name, void_signature);
if (! meth)
JvThrow (new java::lang::NoSuchMethodException);
jobject r = JvAllocObject (this);
((void (*) (jobject)) meth->ncode) (r);
return r;
}
// Initialize the constants.
void
java::lang::Class::resolveConstants (void)
{
for (int i = 0; i < constants.size; ++i)
{
if (constants.tags[i] == CONSTANT_String)
{
jstring str;
str = _Jv_NewStringUtf8Const ((_Jv_Utf8Const *) constants.data[i]);
constants.data[i] = (void *) str;
constants.tags[i] = CONSTANT_ResolvedString;
}
else if (constants.tags[i] == CONSTANT_Class)
{
_Jv_Utf8Const *name = (_Jv_Utf8Const *) constants.data[i];
jclass klass = _Jv_FindClassFromSignature (name->data, loader);
if (! klass)
{
jstring str = _Jv_NewStringUtf8Const (name);
JvThrow (new java::lang::ClassNotFoundException (str));
}
constants.data[i] = (void *) klass;
constants.tags[i] = CONSTANT_ResolvedClass;
}
}
}
// FIXME.
void
java::lang::Class::hackRunInitializers (void)
{
_Jv_Method *meth = _Jv_GetMethodLocal (this, clinit_name, void_signature);
if (meth)
((void (*) (void)) meth->ncode) ();
}
// This implements the initialization process for a class. From Spec
// section 12.4.2.
void
java::lang::Class::initializeClass (void)
{
// Short-circuit to avoid needless locking.
if (state == STATE_DONE)
return;
// Step 1.
_Jv_MonitorEnter (this);
// FIXME: This should actually be handled by calling into the class
// loader. For now we put it here.
if (state < STATE_RESOLVED)
{
// We set the state before calling resolveConstants to avoid
// infinite recursion when processing String or Class.
state = STATE_RESOLVED;
resolveConstants ();
}
// Step 2.
java::lang::Thread *self = java::lang::Thread::currentThread();
// FIXME: `self' can be null at startup. Hence this nasty trick.
self = (java::lang::Thread *) ((long) self | 1);
while (state == STATE_IN_PROGRESS && thread && thread != self)
wait ();
// Steps 3 & 4.
if (state == STATE_DONE || state == STATE_IN_PROGRESS || thread == self)
{
_Jv_MonitorExit (this);
return;
}
// Step 5.
if (state == STATE_ERROR)
{
_Jv_MonitorExit (this);
JvThrow (new java::lang::NoClassDefFoundError);
}
// Step 6.
thread = self;
state = STATE_IN_PROGRESS;
_Jv_MonitorExit (this);
// Step 7.
if (! isInterface () && superclass)
{
// FIXME: We can't currently catch a Java exception in C++ code.
// So instead we call a Java trampoline. It returns an
// exception, or null.
jobject except = superclass->hackTrampoline(0, NULL);
if (except)
{
// Caught an exception.
_Jv_MonitorEnter (this);
state = STATE_ERROR;
notify ();
_Jv_MonitorExit (this);
JvThrow (except);
}
}
// Step 8.
// FIXME: once again we have to go through a trampoline.
java::lang::Throwable *except = hackTrampoline (1, NULL);
// Steps 9, 10, 11.
if (! except)
{
_Jv_MonitorEnter (this);
state = STATE_DONE;
}
else
{
if (! ErrorClass.isInstance(except))
{
// Once again we must use the trampoline. In this case we
// have to detect an OutOfMemoryError.
except = hackTrampoline(2, except);
}
_Jv_MonitorEnter (this);
state = STATE_ERROR;
}
notify ();
_Jv_MonitorExit (this);
if (except)
JvThrow (except);
}
//
// Some class-related convenience functions.
//
_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;
}
void *
_Jv_LookupInterfaceMethod (jclass klass, _Jv_Utf8Const *name,
_Jv_Utf8Const *signature)
{
// FIXME: can't do this until we have a working class loader.
// This probably isn't the right thing to do anyway, since we can't
// call a method of a class until the class is linked. But this
// captures the general idea.
// klass->getClassLoader()->resolveClass(klass);
for (; klass; klass = klass->getSuperclass())
{
_Jv_Method *meth = _Jv_GetMethodLocal (klass, name, signature);
if (! meth)
continue;
if (java::lang::reflect::Modifier::isStatic(meth->accflags))
JvThrow (new java::lang::IncompatibleClassChangeError);
if (java::lang::reflect::Modifier::isAbstract(meth->accflags))
JvThrow (new java::lang::AbstractMethodError);
if (! java::lang::reflect::Modifier::isPublic(meth->accflags))
JvThrow (new java::lang::IllegalAccessError);
return meth->ncode;
}
JvThrow (new java::lang::IncompatibleClassChangeError);
return NULL; // Placate compiler.
}
void
_Jv_InitClass (jclass klass)
{
klass->initializeClass();
}
// This function is called many times during startup, before main() is
// run. We do our runtime initialization here the very first time we
// are called. At that point in time we know for certain we are
// running single-threaded, so we don't need to lock when modifying
// `init'. CLASSES is NULL-terminated.
void
_Jv_RegisterClasses (jclass *classes)
{
static bool init = false;
if (! init)
{
init = true;
_Jv_InitThreads ();
_Jv_InitGC ();
_Jv_InitializeSyncMutex ();
}
JvSynchronize sync (&ClassClass);
for (; *classes; ++classes)
{
jclass klass = *classes;
jint hash = HASH_UTF (klass->name);
klass->next = loaded_classes[hash];
loaded_classes[hash] = klass;
}
}
void
_Jv_RegisterClass (jclass klass)
{
jclass classes[2];
classes[0] = klass;
classes[1] = NULL;
_Jv_RegisterClasses (classes);
}
jclass
_Jv_FindClassInCache (_Jv_Utf8Const *name, java::lang::ClassLoader *loader)
{
JvSynchronize sync (&ClassClass);
jint hash = HASH_UTF (name);
jclass klass;
for (klass = loaded_classes[hash]; klass; klass = klass->next)
{
if (loader == klass->loader && _Jv_equalUtf8Consts (name, klass->name))
break;
}
return klass;
}
#if 0
jclass
_Jv_FindClassInCache (jstring name, java::lang::ClassLoader *loader)
{
JvSynchronize sync (&ClassClass);
jint hash = name->hashCode();
jclass klass = loaded_classes[(_Jv_ushort) hash % HASH_LEN];
for ( ; klass; klass = klass->next)
{
if (loader == klass->loader
&& _Jv_equalUtf8Consts (klass->name, name, hash))
break;
}
return klass;
}
#endif
jclass
_Jv_FindClass (_Jv_Utf8Const* name, java::lang::ClassLoader *loader)
{
jclass klass = _Jv_FindClassInCache (name, loader);
if (loader && ! klass)
{
klass = loader->loadClass(_Jv_NewStringUtf8Const (name));
if (klass)
_Jv_RegisterClass (klass);
}
return klass;
}
#if 0
jclass
_Jv_FindClass (jstring name, java::lang::ClassLoader *loader)
{
jclass klass = _Jv_FindClassInCache (name, loader);
if (loader && ! klass)
{
klass = loader->loadClass(name);
if (klass)
_Jv_RegisterClass (klass);
}
return klass;
}
#endif
jclass
_Jv_NewClass (_Jv_Utf8Const *name, jclass superclass,
java::lang::ClassLoader *loader)
{
jclass ret = (jclass) JvAllocObject (&ClassClass);
ret->next = NULL;
ret->name = name;
ret->accflags = 0;
ret->superclass = superclass;
ret->constants.size = 0;
ret->constants.tags = NULL;
ret->constants.data = NULL;
ret->methods = NULL;
ret->method_count = 0;
ret->vtable_method_count = 0;
ret->fields = NULL;
ret->size_in_bytes = 0;
ret->field_count = 0;
ret->static_field_count = 0;
ret->vtable = NULL;
ret->interfaces = NULL;
ret->loader = loader;
ret->interface_count = 0;
ret->state = 0;
ret->thread = NULL;
_Jv_RegisterClass (ret);
return ret;
}
jclass
_Jv_FindArrayClass (jclass element)
{
_Jv_Utf8Const *array_name;
int len;
if (element->isPrimitive())
{
// For primitive types the array is cached in the class.
jclass ret = (jclass) element->methods;
if (ret)
return ret;
len = 3;
}
else
len = element->name->length + 5;
{
char signature[len];
int index = 0;
signature[index++] = '[';
// Compute name of array class to see if we've already cached it.
if (element->isPrimitive())
{
signature[index++] = (char) element->method_count;
}
else
{
size_t length = element->name->length;
const char *const name = element->name->data;
if (name[0] != '[')
signature[index++] = 'L';
memcpy (&signature[index], name, length);
index += length;
if (name[0] != '[')
signature[index++] = ';';
}
array_name = _Jv_makeUtf8Const (signature, index);
}
jclass array_class = _Jv_FindClassInCache (array_name, element->loader);
if (! array_class)
{
// Create new array class.
array_class = _Jv_NewClass (array_name, &ObjectClass, element->loader);
// Note that `vtable_method_count' doesn't include the initial
// NULL slot.
int dm_count = ObjectClass.vtable_method_count + 1;
// Create a new vtable by copying Object's vtable (except the
// class pointer, of course). Note that we allocate this as
// unscanned memory -- the vtables are handled specially by the
// GC.
int size = (sizeof (_Jv_VTable) +
((dm_count - 1) * sizeof (void *)));
_Jv_VTable *vtable = (_Jv_VTable *) _Jv_AllocBytes (size);
vtable->clas = array_class;
memcpy (vtable->method, ObjectClass.vtable->method,
dm_count * sizeof (void *));
array_class->vtable = vtable;
array_class->vtable_method_count = ObjectClass.vtable_method_count;
// Stash the pointer to the element type.
array_class->methods = (_Jv_Method *) element;
// Register our interfaces.
// FIXME: for JDK 1.2 we need Serializable.
static jclass interfaces[] = { &CloneableClass };
array_class->interfaces = interfaces;
array_class->interface_count = 1;
// FIXME: initialize other Class instance variables,
// e.g. `fields'.
array_class->state = STATE_DONE;
}
// For primitive types, point back at this array.
if (element->isPrimitive())
element->methods = (_Jv_Method *) array_class;
return array_class;
}
jboolean
_Jv_IsInstanceOf(jobject obj, jclass cl)
{
return cl->isInstance(obj);
}