FieldStreamBase(instanceKlassHandle klass) {
_fields = klass->fields();
_constants = klass->constants();
_index = 0;
_limit = klass->java_fields_count();
init_generic_signature_start_slot();
}
// Field names and signatures are referenced via constantpool indexes. In the new class
// version, the layout of the constantpool can be different, so these indexes should be
// patched.
void patch_indexes_for_fields(instanceKlassHandle k_h, instanceKlassHandle k_h_new) {
typeArrayOop k_fields = k_h->fields();
typeArrayOop k_new_fields = k_h_new->fields();
int n_fields = k_fields->length();
for (int i = 0; i < n_fields; i += instanceKlass::next_offset) {
// name and signature
k_fields->short_at_put(
i + instanceKlass::name_index_offset,
k_new_fields->short_at(i + instanceKlass::name_index_offset)
);
k_fields->short_at_put(
i + instanceKlass::signature_index_offset,
k_new_fields->short_at(i + instanceKlass::signature_index_offset)
);
}
}
AllFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants()) {}
InternalFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants(), k->java_fields_count(), 0) {}
jvmtiError VM_RedefineClasses::compare_class_versions(instanceKlassHandle k_h_old, instanceKlassHandle k_h_new) {
int i;
// Check superclasses, or rather their names, since superclasses themselves can be
// requested to replace.
// Check for NULL superclass first since this might be java.lang.Object
if (k_h_old->super() != k_h_new->super() &&
(k_h_old->super() == NULL || k_h_new->super() == NULL ||
Klass::cast(k_h_old->super())->name() != Klass::cast(k_h_new->super())->name())) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
}
// Check if the number, names and order of directly implemented interfaces are the same.
// I think in principle we should just check if the sets of names of directly implemented
// interfaces are the same, i.e. the order of declaration (which, however, if changed in the
// .java file, also changes in .class file) should not matter. However, comparing sets is
// technically a bit more difficult, and, more importantly, I am not sure at present that the
// order of interfaces does not matter on the implementation level, i.e. that the VM does not
// rely on it somewhere.
objArrayOop k_interfaces = k_h_old->local_interfaces();
objArrayOop k_new_interfaces = k_h_new->local_interfaces();
int n_intfs = k_interfaces->length();
if (n_intfs != k_new_interfaces->length()) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
}
for (i = 0; i < n_intfs; i++) {
if (Klass::cast((klassOop) k_interfaces->obj_at(i))->name() !=
Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
}
}
// Check whether class is in the error init state.
if (k_h_old->is_in_error_state()) {
// TBD #5057930: special error code is needed in 1.6
return JVMTI_ERROR_INVALID_CLASS;
}
// Check whether class modifiers are the same.
jushort old_flags = (jushort) k_h_old->access_flags().get_flags();
jushort new_flags = (jushort) k_h_new->access_flags().get_flags();
if (old_flags != new_flags) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED;
}
// Check if the number, names, types and order of fields declared in these classes
// are the same.
typeArrayOop k_old_fields = k_h_old->fields();
typeArrayOop k_new_fields = k_h_new->fields();
int n_fields = k_old_fields->length();
if (n_fields != k_new_fields->length()) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
}
for (i = 0; i < n_fields; i += instanceKlass::next_offset) {
// access
old_flags = k_old_fields->ushort_at(i + instanceKlass::access_flags_offset);
new_flags = k_new_fields->ushort_at(i + instanceKlass::access_flags_offset);
if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
}
// offset
if (k_old_fields->short_at(i + instanceKlass::low_offset) !=
k_new_fields->short_at(i + instanceKlass::low_offset) ||
k_old_fields->short_at(i + instanceKlass::high_offset) !=
k_new_fields->short_at(i + instanceKlass::high_offset)) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
}
// name and signature
jshort name_index = k_old_fields->short_at(i + instanceKlass::name_index_offset);
jshort sig_index = k_old_fields->short_at(i +instanceKlass::signature_index_offset);
symbolOop name_sym1 = k_h_old->constants()->symbol_at(name_index);
symbolOop sig_sym1 = k_h_old->constants()->symbol_at(sig_index);
name_index = k_new_fields->short_at(i + instanceKlass::name_index_offset);
sig_index = k_new_fields->short_at(i + instanceKlass::signature_index_offset);
symbolOop name_sym2 = k_h_new->constants()->symbol_at(name_index);
symbolOop sig_sym2 = k_h_new->constants()->symbol_at(sig_index);
if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
}
}
// Check if the number, names, signatures and order of methods declared in these classes
// are the same.
objArrayOop k_methods = k_h_old->methods();
objArrayOop k_new_methods = k_h_new->methods();
int n_methods = k_methods->length();
if (n_methods < k_new_methods->length()) return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
else if (n_methods > k_new_methods->length()) return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
for (i = 0; i < n_methods; i++) {
methodOop k_method = (methodOop) k_methods->obj_at(i);
methodOop k_new_method = (methodOop) k_new_methods->obj_at(i);
if (k_method->name() != k_new_method->name()) return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
if (k_method->signature() != k_new_method->signature()) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
}
old_flags = (jushort) k_method->access_flags().get_flags();
new_flags = (jushort) k_new_method->access_flags().get_flags();
if (old_flags != new_flags) {
return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED;
}
}
return JVMTI_ERROR_NONE;
}
jvmdiError compare_class_versions(instanceKlassHandle k_h_old, instanceKlassHandle k_h_new) {
int i;
// Check whether essential class modifiers are the same. The rest can probably differ, e.g.
// why not allow substitute class to be synthetic, if it satisfies other conditions.
AccessFlags old_flags = k_h_old->access_flags();
AccessFlags new_flags = k_h_new->access_flags();
if (old_flags.is_public() != new_flags.is_public() ||
old_flags.is_final() != new_flags.is_final() ||
old_flags.is_interface() != new_flags.is_interface() ||
old_flags.is_abstract() != new_flags.is_abstract()) {
return JVMDI_ERROR_CLASS_MODIFIERS_CHANGE_NOT_IMPLEMENTED;
}
// Check superclasses, or rather their names, since superclasses themselves can be
// requested to replace
if (Klass::cast(k_h_old->super())->name() != Klass::cast(k_h_new->super())->name()) {
return JVMDI_ERROR_HIERARCHY_CHANGE_NOT_IMPLEMENTED;
}
// Check if the number, names and order of directly implemented interfaces are the same.
// I think in principle we should just check if the sets of names of directly implemented
// interfaces are the same, i.e. the order of declaration (which, however, if changed in the
// .java file, also changes in .class file) should not matter. However, comparing sets is
// technically a bit more difficult, and, more importantly, I am not sure at present that the
// order of interfaces does not matter on the implementation level, i.e. that the VM does not
// rely on it somewhere.
objArrayOop k_interfaces = k_h_old->local_interfaces();
objArrayOop k_new_interfaces = k_h_new->local_interfaces();
int n_intfs = k_interfaces->length();
if (n_intfs != k_new_interfaces->length()) {
return JVMDI_ERROR_HIERARCHY_CHANGE_NOT_IMPLEMENTED;
}
for (i = 0; i < n_intfs; i++) {
if (Klass::cast((klassOop) k_interfaces->obj_at(i))->name() !=
Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) {
return JVMDI_ERROR_HIERARCHY_CHANGE_NOT_IMPLEMENTED;
}
}
// Check if the number, names, types and order of fields declared in these classes
// are the same.
typeArrayOop k_old_fields = k_h_old->fields();
typeArrayOop k_new_fields = k_h_new->fields();
int n_fields = k_old_fields->length();
if (n_fields != k_new_fields->length()) {
return JVMDI_ERROR_SCHEMA_CHANGE_NOT_IMPLEMENTED;
}
for (i = 0; i < n_fields; i += instanceKlass::next_offset) {
// access
if (k_old_fields->ushort_at(i + instanceKlass::access_flags_offset) !=
k_new_fields->ushort_at(i + instanceKlass::access_flags_offset)) {
return JVMDI_ERROR_SCHEMA_CHANGE_NOT_IMPLEMENTED;
}
// offset
if (k_old_fields->short_at(i + instanceKlass::low_offset) !=
k_new_fields->short_at(i + instanceKlass::low_offset) ||
k_old_fields->short_at(i + instanceKlass::high_offset) !=
k_new_fields->short_at(i + instanceKlass::high_offset)) {
return JVMDI_ERROR_SCHEMA_CHANGE_NOT_IMPLEMENTED;
}
// name and signature
jshort name_index = k_old_fields->short_at(i + instanceKlass::name_index_offset);
jshort sig_index = k_old_fields->short_at(i +instanceKlass::signature_index_offset);
symbolOop name_sym1 = k_h_old->constants()->symbol_at(name_index);
symbolOop sig_sym1 = k_h_old->constants()->symbol_at(sig_index);
name_index = k_new_fields->short_at(i + instanceKlass::name_index_offset);
sig_index = k_new_fields->short_at(i + instanceKlass::signature_index_offset);
symbolOop name_sym2 = k_h_new->constants()->symbol_at(name_index);
symbolOop sig_sym2 = k_h_new->constants()->symbol_at(sig_index);
if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
return JVMDI_ERROR_SCHEMA_CHANGE_NOT_IMPLEMENTED;
}
}
// Check if the number, names, signatures and order of methods declared in these classes
// are the same.
objArrayOop k_methods = k_h_old->methods();
objArrayOop k_new_methods = k_h_new->methods();
int n_methods = k_methods->length();
if (n_methods < k_new_methods->length()) return JVMDI_ERROR_ADD_METHOD_NOT_IMPLEMENTED;
else if (n_methods > k_new_methods->length()) return JVMDI_ERROR_DELETE_METHOD_NOT_IMPLEMENTED;
for (i = 0; i < n_methods; i++) {
methodOop k_method = (methodOop) k_methods->obj_at(i);
methodOop k_new_method = (methodOop) k_new_methods->obj_at(i);
if (k_method->name() != k_new_method->name()) return JVMDI_ERROR_DELETE_METHOD_NOT_IMPLEMENTED;
if (k_method->signature() != k_new_method->signature()) {
return JVMDI_ERROR_DELETE_METHOD_NOT_IMPLEMENTED;
}
old_flags = k_method->access_flags();
new_flags = k_new_method->access_flags();
// It's probably safer to not compare the values of access_flags directly, since
// some bits in them encode some implementation-specific information, e.g.
// something about inlined tables. This may be different in the new version,
// but should not affect method changeability.
if (old_flags.is_public() != new_flags.is_public() ||
old_flags.is_protected() != new_flags.is_protected() ||
old_flags.is_private() != new_flags.is_private() ||
old_flags.is_static() != new_flags.is_static() ||
old_flags.is_final() != new_flags.is_final() ||
old_flags.is_synchronized() != new_flags.is_synchronized() ||
old_flags.is_strict() != new_flags.is_strict() ||
old_flags.is_interface() != new_flags.is_interface() ||
old_flags.is_abstract() != new_flags.is_abstract()) {
return JVMDI_ERROR_METHOD_MODIFIERS_CHANGE_NOT_IMPLEMENTED;
}
}
return JVMDI_ERROR_NONE;
}
