/* * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/classLoaderData.hpp" #include "classfile/javaClasses.inline.hpp" #include "classfile/metadataOnStackMark.hpp" #include "classfile/stringTable.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/vmSymbols.hpp" #include "interpreter/linkResolver.hpp" #include "memory/heapInspection.hpp" #include "memory/metadataFactory.hpp" #include "memory/metaspaceClosure.hpp" #include "memory/oopFactory.hpp" #include "memory/resourceArea.hpp" #include "oops/constantPool.hpp" #include "oops/instanceKlass.hpp" #include "oops/objArrayKlass.hpp" #include "oops/objArrayOop.inline.hpp" #include "oops/oop.inline.hpp" #include "runtime/fieldType.hpp" #include "runtime/init.hpp" #include "runtime/javaCalls.hpp" #include "runtime/signature.hpp" #include "runtime/vframe.hpp" #include "utilities/copy.hpp" ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) { Array* tags = MetadataFactory::new_array(loader_data, length, 0, CHECK_NULL); int size = ConstantPool::size(length); return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags); } #ifdef ASSERT // MetaspaceObj allocation invariant is calloc equivalent memory // simple verification of this here (JVM_CONSTANT_Invalid == 0 ) static bool tag_array_is_zero_initialized(Array* tags) { assert(tags != NULL, "invariant"); const int length = tags->length(); for (int index = 0; index < length; ++index) { if (JVM_CONSTANT_Invalid != tags->at(index)) { return false; } } return true; } #endif ConstantPool::ConstantPool(Array* tags) : _tags(tags), _length(tags->length()) { assert(_tags != NULL, "invariant"); assert(tags->length() == _length, "invariant"); assert(tag_array_is_zero_initialized(tags), "invariant"); assert(0 == flags(), "invariant"); assert(0 == version(), "invariant"); assert(NULL == _pool_holder, "invariant"); } void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) { if (cache() != NULL) { MetadataFactory::free_array(loader_data, reference_map()); set_reference_map(NULL); MetadataFactory::free_metadata(loader_data, cache()); set_cache(NULL); } MetadataFactory::free_array(loader_data, resolved_klasses()); set_resolved_klasses(NULL); MetadataFactory::free_array(loader_data, operands()); set_operands(NULL); release_C_heap_structures(); // free tag array MetadataFactory::free_array(loader_data, tags()); set_tags(NULL); } void ConstantPool::release_C_heap_structures() { // walk constant pool and decrement symbol reference counts unreference_symbols(); } void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) { log_trace(cds)("Iter(ConstantPool): %p", this); it->push(&_tags, MetaspaceClosure::_writable); it->push(&_cache); it->push(&_pool_holder); it->push(&_operands); it->push(&_resolved_klasses, MetaspaceClosure::_writable); for (int i = 0; i < length(); i++) { // The only MSO's embedded in the CP entries are Symbols: // JVM_CONSTANT_String (normal and pseudo) // JVM_CONSTANT_Utf8 constantTag ctag = tag_at(i); if (ctag.is_string() || ctag.is_utf8()) { it->push(symbol_at_addr(i)); } } } objArrayOop ConstantPool::resolved_references() const { return (objArrayOop)JNIHandles::resolve(_cache->resolved_references()); } // Create resolved_references array and mapping array for original cp indexes // The ldc bytecode was rewritten to have the resolved reference array index so need a way // to map it back for resolving and some unlikely miscellaneous uses. // The objects created by invokedynamic are appended to this list. void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data, const intStack& reference_map, int constant_pool_map_length, TRAPS) { // Initialized the resolved object cache. int map_length = reference_map.length(); if (map_length > 0) { // Only need mapping back to constant pool entries. The map isn't used for // invokedynamic resolved_reference entries. For invokedynamic entries, // the constant pool cache index has the mapping back to both the constant // pool and to the resolved reference index. if (constant_pool_map_length > 0) { Array* om = MetadataFactory::new_array(loader_data, constant_pool_map_length, CHECK); for (int i = 0; i < constant_pool_map_length; i++) { int x = reference_map.at(i); assert(x == (int)(jushort) x, "klass index is too big"); om->at_put(i, (jushort)x); } set_reference_map(om); } // Create Java array for holding resolved strings, methodHandles, // methodTypes, invokedynamic and invokehandle appendix objects, etc. objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK); Handle refs_handle (THREAD, (oop)stom); // must handleize. set_resolved_references(loader_data->add_handle(refs_handle)); } } void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) { // A ConstantPool can't possibly have 0xffff valid class entries, // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8 // entry for the class's name. So at most we will have 0xfffe class entries. // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate // UnresolvedKlass entries that are temporarily created during class redefinition. assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity"); assert(resolved_klasses() == NULL, "sanity"); Array* rk = MetadataFactory::new_array(loader_data, num_klasses, CHECK); set_resolved_klasses(rk); } void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) { int len = length(); int num_klasses = 0; for (int i = 1; i increment_refcount(); Klass** adr = resolved_klasses()->adr_at(resolved_klass_index); OrderAccess::release_store_ptr((Klass* volatile *)adr, k); // The interpreter assumes when the tag is stored, the klass is resolved // and the Klass* non-NULL, so we need hardware store ordering here. if (k != NULL) { release_tag_at_put(class_index, JVM_CONSTANT_Class); } else { release_tag_at_put(class_index, JVM_CONSTANT_UnresolvedClass); } } // Anonymous class support: void ConstantPool::klass_at_put(int class_index, Klass* k) { assert(k != NULL, "must be valid klass"); CPKlassSlot kslot = klass_slot_at(class_index); int resolved_klass_index = kslot.resolved_klass_index(); Klass** adr = resolved_klasses()->adr_at(resolved_klass_index); OrderAccess::release_store_ptr((Klass* volatile *)adr, k); // The interpreter assumes when the tag is stored, the klass is resolved // and the Klass* non-NULL, so we need hardware store ordering here. release_tag_at_put(class_index, JVM_CONSTANT_Class); } // CDS support. Create a new resolved_references array. void ConstantPool::restore_unshareable_info(TRAPS) { assert(is_constantPool(), "ensure C++ vtable is restored"); assert(on_stack(), "should always be set for shared constant pools"); assert(is_shared(), "should always be set for shared constant pools"); // Only create the new resolved references array if it hasn't been attempted before if (resolved_references() != NULL) return; // restore the C++ vtable from the shared archive restore_vtable(); if (SystemDictionary::Object_klass_loaded()) { // Recreate the object array and add to ClassLoaderData. int map_length = resolved_reference_length(); if (map_length > 0) { objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK); Handle refs_handle (THREAD, (oop)stom); // must handleize. ClassLoaderData* loader_data = pool_holder()->class_loader_data(); set_resolved_references(loader_data->add_handle(refs_handle)); } } } void ConstantPool::remove_unshareable_info() { // Resolved references are not in the shared archive. // Save the length for restoration. It is not necessarily the same length // as reference_map.length() if invokedynamic is saved. set_resolved_reference_length( resolved_references() != NULL ? resolved_references()->length() : 0); set_resolved_references(NULL); // Shared ConstantPools are in the RO region, so the _flags cannot be modified. // The _on_stack flag is used to prevent ConstantPools from deallocation during // class redefinition. Since shared ConstantPools cannot be deallocated anyway, // we always set _on_stack to true to avoid having to change _flags during runtime. _flags |= (_on_stack | _is_shared); } int ConstantPool::cp_to_object_index(int cp_index) { // this is harder don't do this so much. int i = reference_map()->find(cp_index); // We might not find the index for jsr292 call. return (i < 0) ? _no_index_sentinel : i; } void ConstantPool::string_at_put(int which, int obj_index, oop str) { resolved_references()->obj_at_put(obj_index, str); } void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) { ResourceMark rm; int line_number = -1; const char * source_file = NULL; if (JavaThread::current()->has_last_Java_frame()) { // try to identify the method which called this function. vframeStream vfst(JavaThread::current()); if (!vfst.at_end()) { line_number = vfst.method()->line_number_from_bci(vfst.bci()); Symbol* s = vfst.method()->method_holder()->source_file_name(); if (s != NULL) { source_file = s->as_C_string(); } } } if (k != this_cp->pool_holder()) { // only print something if the classes are different if (source_file != NULL) { log_debug(class, resolve)("%s %s %s:%d", this_cp->pool_holder()->external_name(), k->external_name(), source_file, line_number); } else { log_debug(class, resolve)("%s %s", this_cp->pool_holder()->external_name(), k->external_name()); } } } Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int which, bool save_resolution_error, TRAPS) { assert(THREAD->is_Java_thread(), "must be a Java thread"); // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*. // It is not safe to rely on the tag bit's here, since we don't have a lock, and // the entry and tag is not updated atomicly. CPKlassSlot kslot = this_cp->klass_slot_at(which); int resolved_klass_index = kslot.resolved_klass_index(); int name_index = kslot.name_index(); assert(this_cp->tag_at(name_index).is_symbol(), "sanity"); Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index); if (klass != NULL) { return klass; } // This tag doesn't change back to unresolved class unless at a safepoint. if (this_cp->tag_at(which).is_unresolved_klass_in_error()) { // The original attempt to resolve this constant pool entry failed so find the // class of the original error and throw another error of the same class // (JVMS 5.4.3). // If there is a detail message, pass that detail message to the error. // The JVMS does not strictly require us to duplicate the same detail message, // or any internal exception fields such as cause or stacktrace. But since the // detail message is often a class name or other literal string, we will repeat it // if we can find it in the symbol table. throw_resolution_error(this_cp, which, CHECK_0); ShouldNotReachHere(); } Handle mirror_handle; Symbol* name = this_cp->symbol_at(name_index); Handle loader (THREAD, this_cp->pool_holder()->class_loader()); Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain()); Klass* k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD); if (!HAS_PENDING_EXCEPTION) { // preserve the resolved klass from unloading mirror_handle = Handle(THREAD, k->java_mirror()); // Do access check for klasses verify_constant_pool_resolve(this_cp, k, THREAD); } // Failed to resolve class. We must record the errors so that subsequent attempts // to resolve this constant pool entry fail with the same error (JVMS 5.4.3). if (HAS_PENDING_EXCEPTION) { if (save_resolution_error) { save_and_throw_exception(this_cp, which, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL); // If CHECK_NULL above doesn't return the exception, that means that // some other thread has beaten us and has resolved the class. // To preserve old behavior, we return the resolved class. klass = this_cp->resolved_klasses()->at(resolved_klass_index); assert(klass != NULL, "must be resolved if exception was cleared"); return klass; } else { return NULL; // return the pending exception } } // Make this class loader depend upon the class loader owning the class reference ClassLoaderData* this_key = this_cp->pool_holder()->class_loader_data(); this_key->record_dependency(k, CHECK_NULL); // Can throw OOM // logging for class+resolve. if (log_is_enabled(Debug, class, resolve)){ trace_class_resolution(this_cp, k); } Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index); OrderAccess::release_store_ptr((Klass* volatile *)adr, k); // The interpreter assumes when the tag is stored, the klass is resolved // and the Klass* stored in _resolved_klasses is non-NULL, so we need // hardware store ordering here. this_cp->release_tag_at_put(which, JVM_CONSTANT_Class); return k; } // Does not update ConstantPool* - to avoid any exception throwing. Used // by compiler and exception handling. Also used to avoid classloads for // instanceof operations. Returns NULL if the class has not been loaded or // if the verification of constant pool failed Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) { CPKlassSlot kslot = this_cp->klass_slot_at(which); int resolved_klass_index = kslot.resolved_klass_index(); int name_index = kslot.name_index(); assert(this_cp->tag_at(name_index).is_symbol(), "sanity"); Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index); if (k != NULL) { return k; } else { Thread *thread = Thread::current(); Symbol* name = this_cp->symbol_at(name_index); oop loader = this_cp->pool_holder()->class_loader(); oop protection_domain = this_cp->pool_holder()->protection_domain(); Handle h_prot (thread, protection_domain); Handle h_loader (thread, loader); Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread); if (k != NULL) { // Make sure that resolving is legal EXCEPTION_MARK; // return NULL if verification fails verify_constant_pool_resolve(this_cp, k, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; return NULL; } return k; } else { return k; } } } Klass* ConstantPool::klass_ref_at_if_loaded(const constantPoolHandle& this_cp, int which) { return klass_at_if_loaded(this_cp, this_cp->klass_ref_index_at(which)); } Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool, int which) { if (cpool->cache() == NULL) return NULL; // nothing to load yet int cache_index = decode_cpcache_index(which, true); if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) { // FIXME: should be an assert log_debug(class, resolve)("bad operand %d in:", which); cpool->print(); return NULL; } ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index); return e->method_if_resolved(cpool); } bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which) { if (cpool->cache() == NULL) return false; // nothing to load yet int cache_index = decode_cpcache_index(which, true); ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index); return e->has_appendix(); } oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which) { if (cpool->cache() == NULL) return NULL; // nothing to load yet int cache_index = decode_cpcache_index(which, true); ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index); return e->appendix_if_resolved(cpool); } bool ConstantPool::has_method_type_at_if_loaded(const constantPoolHandle& cpool, int which) { if (cpool->cache() == NULL) return false; // nothing to load yet int cache_index = decode_cpcache_index(which, true); ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index); return e->has_method_type(); } oop ConstantPool::method_type_at_if_loaded(const constantPoolHandle& cpool, int which) { if (cpool->cache() == NULL) return NULL; // nothing to load yet int cache_index = decode_cpcache_index(which, true); ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index); return e->method_type_if_resolved(cpool); } Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) { int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached)); return symbol_at(name_index); } Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) { int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached)); return symbol_at(signature_index); } int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) { int i = which; if (!uncached && cache() != NULL) { if (ConstantPool::is_invokedynamic_index(which)) { // Invokedynamic index is index into the constant pool cache int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index(); pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index); assert(tag_at(pool_index).is_name_and_type(), ""); return pool_index; } // change byte-ordering and go via cache i = remap_instruction_operand_from_cache(which); } else { if (tag_at(which).is_invoke_dynamic()) { int pool_index = invoke_dynamic_name_and_type_ref_index_at(which); assert(tag_at(pool_index).is_name_and_type(), ""); return pool_index; } } assert(tag_at(i).is_field_or_method(), "Corrupted constant pool"); assert(!tag_at(i).is_invoke_dynamic(), "Must be handled above"); jint ref_index = *int_at_addr(i); return extract_high_short_from_int(ref_index); } constantTag ConstantPool::impl_tag_ref_at(int which, bool uncached) { int pool_index = which; if (!uncached && cache() != NULL) { if (ConstantPool::is_invokedynamic_index(which)) { // Invokedynamic index is index into resolved_references pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index(); } else { // change byte-ordering and go via cache pool_index = remap_instruction_operand_from_cache(which); } } return tag_at(pool_index); } int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) { guarantee(!ConstantPool::is_invokedynamic_index(which), "an invokedynamic instruction does not have a klass"); int i = which; if (!uncached && cache() != NULL) { // change byte-ordering and go via cache i = remap_instruction_operand_from_cache(which); } assert(tag_at(i).is_field_or_method(), "Corrupted constant pool"); jint ref_index = *int_at_addr(i); return extract_low_short_from_int(ref_index); } int ConstantPool::remap_instruction_operand_from_cache(int operand) { int cpc_index = operand; DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG); assert((int)(u2)cpc_index == cpc_index, "clean u2"); int member_index = cache()->entry_at(cpc_index)->constant_pool_index(); return member_index; } void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) { if (k->is_instance_klass() || k->is_objArray_klass()) { InstanceKlass* holder = this_cp->pool_holder(); Klass* elem = k->is_instance_klass() ? k : ObjArrayKlass::cast(k)->bottom_klass(); // The element type could be a typeArray - we only need the access check if it is // an reference to another class if (elem->is_instance_klass()) { LinkResolver::check_klass_accessability(holder, elem, CHECK); } } } int ConstantPool::name_ref_index_at(int which_nt) { jint ref_index = name_and_type_at(which_nt); return extract_low_short_from_int(ref_index); } int ConstantPool::signature_ref_index_at(int which_nt) { jint ref_index = name_and_type_at(which_nt); return extract_high_short_from_int(ref_index); } Klass* ConstantPool::klass_ref_at(int which, TRAPS) { return klass_at(klass_ref_index_at(which), THREAD); } Symbol* ConstantPool::klass_name_at(int which) const { return symbol_at(klass_slot_at(which).name_index()); } Symbol* ConstantPool::klass_ref_at_noresolve(int which) { jint ref_index = klass_ref_index_at(which); return klass_at_noresolve(ref_index); } Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) { jint ref_index = uncached_klass_ref_index_at(which); return klass_at_noresolve(ref_index); } char* ConstantPool::string_at_noresolve(int which) { return unresolved_string_at(which)->as_C_string(); } BasicType ConstantPool::basic_type_for_signature_at(int which) const { return FieldType::basic_type(symbol_at(which)); } void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) { for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused if (this_cp->tag_at(index).is_string()) { this_cp->string_at(index, CHECK); } } } // Resolve all the classes in the constant pool. If they are all resolved, // the constant pool is read-only. Enhancement: allocate cp entries to // another metaspace, and copy to read-only or read-write space if this // bit is set. bool ConstantPool::resolve_class_constants(TRAPS) { constantPoolHandle cp(THREAD, this); for (int index = 1; index < length(); index++) { // Index 0 is unused if (tag_at(index).is_unresolved_klass() && klass_at_if_loaded(cp, index) == NULL) { return false; } } // set_preresolution(); or some bit for future use return true; } Symbol* ConstantPool::exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) { // Dig out the detailed message to reuse if possible Symbol* message = java_lang_Throwable::detail_message(pending_exception); if (message != NULL) { return message; } // Return specific message for the tag switch (tag.value()) { case JVM_CONSTANT_UnresolvedClass: // return the class name in the error message message = this_cp->klass_name_at(which); break; case JVM_CONSTANT_MethodHandle: // return the method handle name in the error message message = this_cp->method_handle_name_ref_at(which); break; case JVM_CONSTANT_MethodType: // return the method type signature in the error message message = this_cp->method_type_signature_at(which); break; default: ShouldNotReachHere(); } return message; } void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) { Symbol* message = NULL; Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message); assert(error != NULL && message != NULL, "checking"); CLEAR_PENDING_EXCEPTION; ResourceMark rm; THROW_MSG(error, message->as_C_string()); } // If resolution for Class, MethodHandle or MethodType fails, save the exception // in the resolution error table, so that the same exception is thrown again. void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS) { Symbol* error = PENDING_EXCEPTION->klass()->name(); int error_tag = tag.error_value(); if (!PENDING_EXCEPTION-> is_a(SystemDictionary::LinkageError_klass())) { // Just throw the exception and don't prevent these classes from // being loaded due to virtual machine errors like StackOverflow // and OutOfMemoryError, etc, or if the thread was hit by stop() // Needs clarification to section 5.4.3 of the VM spec (see 6308271) } else if (this_cp->tag_at(which).value() != error_tag) { Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION); SystemDictionary::add_resolution_error(this_cp, which, error, message); // CAS in the tag. If a thread beat us to registering this error that's fine. // If another thread resolved the reference, this is a race condition. This // thread may have had a security manager or something temporary. // This doesn't deterministically get an error. So why do we save this? // We save this because jvmti can add classes to the bootclass path after // this error, so it needs to get the same error if the error is first. jbyte old_tag = Atomic::cmpxchg((jbyte)error_tag, (jbyte*)this_cp->tag_addr_at(which), (jbyte)tag.value()); if (old_tag != error_tag && old_tag != tag.value()) { // MethodHandles and MethodType doesn't change to resolved version. assert(this_cp->tag_at(which).is_klass(), "Wrong tag value"); // Forget the exception and use the resolved class. CLEAR_PENDING_EXCEPTION; } } else { // some other thread put this in error state throw_resolution_error(this_cp, which, CHECK); } } // Called to resolve constants in the constant pool and return an oop. // Some constant pool entries cache their resolved oop. This is also // called to create oops from constants to use in arguments for invokedynamic oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS) { oop result_oop = NULL; Handle throw_exception; if (cache_index == _possible_index_sentinel) { // It is possible that this constant is one which is cached in the objects. // We'll do a linear search. This should be OK because this usage is rare. assert(index > 0, "valid index"); cache_index = this_cp->cp_to_object_index(index); } assert(cache_index == _no_index_sentinel || cache_index >= 0, ""); assert(index == _no_index_sentinel || index >= 0, ""); if (cache_index >= 0) { result_oop = this_cp->resolved_references()->obj_at(cache_index); if (result_oop != NULL) { return result_oop; // That was easy... } index = this_cp->object_to_cp_index(cache_index); } jvalue prim_value; // temp used only in a few cases below constantTag tag = this_cp->tag_at(index); switch (tag.value()) { case JVM_CONSTANT_UnresolvedClass: case JVM_CONSTANT_UnresolvedClassInError: case JVM_CONSTANT_Class: { assert(cache_index == _no_index_sentinel, "should not have been set"); Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL); // ldc wants the java mirror. result_oop = resolved->java_mirror(); break; } case JVM_CONSTANT_String: assert(cache_index != _no_index_sentinel, "should have been set"); if (this_cp->is_pseudo_string_at(index)) { result_oop = this_cp->pseudo_string_at(index, cache_index); break; } result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL); break; case JVM_CONSTANT_MethodHandleInError: case JVM_CONSTANT_MethodTypeInError: { throw_resolution_error(this_cp, index, CHECK_NULL); break; } case JVM_CONSTANT_MethodHandle: { int ref_kind = this_cp->method_handle_ref_kind_at(index); int callee_index = this_cp->method_handle_klass_index_at(index); Symbol* name = this_cp->method_handle_name_ref_at(index); Symbol* signature = this_cp->method_handle_signature_ref_at(index); constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(index)); { ResourceMark rm(THREAD); log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s", ref_kind, index, this_cp->method_handle_index_at(index), callee_index, name->as_C_string(), signature->as_C_string()); } Klass* callee = klass_at_impl(this_cp, callee_index, true, CHECK_NULL); // Check constant pool method consistency if ((callee->is_interface() && m_tag.is_method()) || ((!callee->is_interface() && m_tag.is_interface_method()))) { ResourceMark rm(THREAD); char buf[400]; jio_snprintf(buf, sizeof(buf), "Inconsistent constant pool data in classfile for class %s. " "Method %s%s at index %d is %s and should be %s", callee->name()->as_C_string(), name->as_C_string(), signature->as_C_string(), index, callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef", callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef"); THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), buf); } Klass* klass = this_cp->pool_holder(); Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind, callee, name, signature, THREAD); result_oop = value(); if (HAS_PENDING_EXCEPTION) { save_and_throw_exception(this_cp, index, tag, CHECK_NULL); } break; } case JVM_CONSTANT_MethodType: { Symbol* signature = this_cp->method_type_signature_at(index); { ResourceMark rm(THREAD); log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s", index, this_cp->method_type_index_at(index), signature->as_C_string()); } Klass* klass = this_cp->pool_holder(); Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD); result_oop = value(); if (HAS_PENDING_EXCEPTION) { save_and_throw_exception(this_cp, index, tag, CHECK_NULL); } break; } case JVM_CONSTANT_Integer: assert(cache_index == _no_index_sentinel, "should not have been set"); prim_value.i = this_cp->int_at(index); result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL); break; case JVM_CONSTANT_Float: assert(cache_index == _no_index_sentinel, "should not have been set"); prim_value.f = this_cp->float_at(index); result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL); break; case JVM_CONSTANT_Long: assert(cache_index == _no_index_sentinel, "should not have been set"); prim_value.j = this_cp->long_at(index); result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL); break; case JVM_CONSTANT_Double: assert(cache_index == _no_index_sentinel, "should not have been set"); prim_value.d = this_cp->double_at(index); result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL); break; default: DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d", this_cp(), index, cache_index, tag.value())); assert(false, "unexpected constant tag"); break; } if (cache_index >= 0) { // Benign race condition: resolved_references may already be filled in. // The important thing here is that all threads pick up the same result. // It doesn't matter which racing thread wins, as long as only one // result is used by all threads, and all future queries. oop old_result = this_cp->resolved_references()->atomic_compare_exchange_oop(cache_index, result_oop, NULL); if (old_result == NULL) { return result_oop; // was installed } else { // Return the winning thread's result. This can be different than // the result here for MethodHandles. return old_result; } } else { return result_oop; } } oop ConstantPool::uncached_string_at(int which, TRAPS) { Symbol* sym = unresolved_string_at(which); oop str = StringTable::intern(sym, CHECK_(NULL)); assert(java_lang_String::is_instance(str), "must be string"); return str; } oop ConstantPool::resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS) { assert(this_cp->tag_at(index).is_invoke_dynamic(), "Corrupted constant pool"); Handle bsm; int argc; { // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&type], plus optional arguments // The bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry. // It is accompanied by the optional arguments. int bsm_index = this_cp->invoke_dynamic_bootstrap_method_ref_index_at(index); oop bsm_oop = this_cp->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL); if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) { THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle"); } // Extract the optional static arguments. argc = this_cp->invoke_dynamic_argument_count_at(index); if (argc == 0) return bsm_oop; bsm = Handle(THREAD, bsm_oop); } objArrayHandle info; { objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1+argc, CHECK_NULL); info = objArrayHandle(THREAD, info_oop); } info->obj_at_put(0, bsm()); for (int i = 0; i < argc; i++) { int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i); oop arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK_NULL); info->obj_at_put(1+i, arg_oop); } return info(); } oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS) { // If the string has already been interned, this entry will be non-null oop str = this_cp->resolved_references()->obj_at(obj_index); if (str != NULL) return str; Symbol* sym = this_cp->unresolved_string_at(which); str = StringTable::intern(sym, CHECK_(NULL)); this_cp->string_at_put(which, obj_index, str); assert(java_lang_String::is_instance(str), "must be string"); return str; } bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int which) { // Names are interned, so we can compare Symbol*s directly Symbol* cp_name = klass_name_at(which); return (cp_name == k->name()); } // Iterate over symbols and decrement ones which are Symbol*s // This is done during GC. // Only decrement the UTF8 symbols. Strings point to // these symbols but didn't increment the reference count. void ConstantPool::unreference_symbols() { for (int index = 1; index < length(); index++) { // Index 0 is unused constantTag tag = tag_at(index); if (tag.is_symbol()) { symbol_at(index)->decrement_refcount(); } } } // Compare this constant pool's entry at index1 to the constant pool // cp2's entry at index2. bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS) { // The error tags are equivalent to non-error tags when comparing jbyte t1 = tag_at(index1).non_error_value(); jbyte t2 = cp2->tag_at(index2).non_error_value(); if (t1 != t2) { // Not the same entry type so there is nothing else to check. Note // that this style of checking will consider resolved/unresolved // class pairs as different. // From the ConstantPool* API point of view, this is correct // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this // plays out in the context of ConstantPool* merging. return false; } switch (t1) { case JVM_CONSTANT_Class: { Klass* k1 = klass_at(index1, CHECK_false); Klass* k2 = cp2->klass_at(index2, CHECK_false); if (k1 == k2) { return true; } } break; case JVM_CONSTANT_ClassIndex: { int recur1 = klass_index_at(index1); int recur2 = cp2->klass_index_at(index2); bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false); if (match) { return true; } } break; case JVM_CONSTANT_Double: { jdouble d1 = double_at(index1); jdouble d2 = cp2->double_at(index2); if (d1 == d2) { return true; } } break; case JVM_CONSTANT_Fieldref: case JVM_CONSTANT_InterfaceMethodref: case JVM_CONSTANT_Methodref: { int recur1 = uncached_klass_ref_index_at(index1); int recur2 = cp2->uncached_klass_ref_index_at(index2); bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false); if (match) { recur1 = uncached_name_and_type_ref_index_at(index1); recur2 = cp2->uncached_name_and_type_ref_index_at(index2); match = compare_entry_to(recur1, cp2, recur2, CHECK_false); if (match) { return true; } } } break; case JVM_CONSTANT_Float: { jfloat f1 = float_at(index1); jfloat f2 = cp2->float_at(index2); if (f1 == f2) { return true; } } break; case JVM_CONSTANT_Integer: { jint i1 = int_at(index1); jint i2 = cp2->int_at(index2); if (i1 == i2) { return true; } } break; case JVM_CONSTANT_Long: { jlong l1 = long_at(index1); jlong l2 = cp2->long_at(index2); if (l1 == l2) { return true; } } break; case JVM_CONSTANT_NameAndType: { int recur1 = name_ref_index_at(index1); int recur2 = cp2->name_ref_index_at(index2); bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false); if (match) { recur1 = signature_ref_index_at(index1); recur2 = cp2->signature_ref_index_at(index2); match = compare_entry_to(recur1, cp2, recur2, CHECK_false); if (match) { return true; } } } break; case JVM_CONSTANT_StringIndex: { int recur1 = string_index_at(index1); int recur2 = cp2->string_index_at(index2); bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false); if (match) { return true; } } break; case JVM_CONSTANT_UnresolvedClass: { Symbol* k1 = klass_name_at(index1); Symbol* k2 = cp2->klass_name_at(index2); if (k1 == k2) { return true; } } break; case JVM_CONSTANT_MethodType: { int k1 = method_type_index_at(index1); int k2 = cp2->method_type_index_at(index2); bool match = compare_entry_to(k1, cp2, k2, CHECK_false); if (match) { return true; } } break; case JVM_CONSTANT_MethodHandle: { int k1 = method_handle_ref_kind_at(index1); int k2 = cp2->method_handle_ref_kind_at(index2); if (k1 == k2) { int i1 = method_handle_index_at(index1); int i2 = cp2->method_handle_index_at(index2); bool match = compare_entry_to(i1, cp2, i2, CHECK_false); if (match) { return true; } } } break; case JVM_CONSTANT_InvokeDynamic: { int k1 = invoke_dynamic_name_and_type_ref_index_at(index1); int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2); int i1 = invoke_dynamic_bootstrap_specifier_index(index1); int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2); // separate statements and variables because CHECK_false is used bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false); bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false); return (match_entry && match_operand); } break; case JVM_CONSTANT_String: { Symbol* s1 = unresolved_string_at(index1); Symbol* s2 = cp2->unresolved_string_at(index2); if (s1 == s2) { return true; } } break; case JVM_CONSTANT_Utf8: { Symbol* s1 = symbol_at(index1); Symbol* s2 = cp2->symbol_at(index2); if (s1 == s2) { return true; } } break; // Invalid is used as the tag for the second constant pool entry // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should // not be seen by itself. case JVM_CONSTANT_Invalid: // fall through default: ShouldNotReachHere(); break; } return false; } // end compare_entry_to() // Resize the operands array with delta_len and delta_size. // Used in RedefineClasses for CP merge. void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) { int old_len = operand_array_length(operands()); int new_len = old_len + delta_len; int min_len = (delta_len > 0) ? old_len : new_len; int old_size = operands()->length(); int new_size = old_size + delta_size; int min_size = (delta_size > 0) ? old_size : new_size; ClassLoaderData* loader_data = pool_holder()->class_loader_data(); Array* new_ops = MetadataFactory::new_array(loader_data, new_size, CHECK); // Set index in the resized array for existing elements only for (int idx = 0; idx < min_len; idx++) { int offset = operand_offset_at(idx); // offset in original array operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array } // Copy the bootstrap specifiers only Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len), new_ops->adr_at(2*new_len), (min_size - 2*min_len) * sizeof(u2)); // Explicitly deallocate old operands array. // Note, it is not needed for 7u backport. if ( operands() != NULL) { // the safety check MetadataFactory::free_array(loader_data, operands()); } set_operands(new_ops); } // end resize_operands() // Extend the operands array with the length and size of the ext_cp operands. // Used in RedefineClasses for CP merge. void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) { int delta_len = operand_array_length(ext_cp->operands()); if (delta_len == 0) { return; // nothing to do } int delta_size = ext_cp->operands()->length(); assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger"); if (operand_array_length(operands()) == 0) { ClassLoaderData* loader_data = pool_holder()->class_loader_data(); Array* new_ops = MetadataFactory::new_array(loader_data, delta_size, CHECK); // The first element index defines the offset of second part operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array set_operands(new_ops); } else { resize_operands(delta_len, delta_size, CHECK); } } // end extend_operands() // Shrink the operands array to a smaller array with new_len length. // Used in RedefineClasses for CP merge. void ConstantPool::shrink_operands(int new_len, TRAPS) { int old_len = operand_array_length(operands()); if (new_len == old_len) { return; // nothing to do } assert(new_len < old_len, "shrunken operands array must be smaller"); int free_base = operand_next_offset_at(new_len - 1); int delta_len = new_len - old_len; int delta_size = 2*delta_len + free_base - operands()->length(); resize_operands(delta_len, delta_size, CHECK); } // end shrink_operands() void ConstantPool::copy_operands(const constantPoolHandle& from_cp, const constantPoolHandle& to_cp, TRAPS) { int from_oplen = operand_array_length(from_cp->operands()); int old_oplen = operand_array_length(to_cp->operands()); if (from_oplen != 0) { ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data(); // append my operands to the target's operands array if (old_oplen == 0) { // Can't just reuse from_cp's operand list because of deallocation issues int len = from_cp->operands()->length(); Array* new_ops = MetadataFactory::new_array(loader_data, len, CHECK); Copy::conjoint_memory_atomic( from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2)); to_cp->set_operands(new_ops); } else { int old_len = to_cp->operands()->length(); int from_len = from_cp->operands()->length(); int old_off = old_oplen * sizeof(u2); int from_off = from_oplen * sizeof(u2); // Use the metaspace for the destination constant pool Array* new_operands = MetadataFactory::new_array(loader_data, old_len + from_len, CHECK); int fillp = 0, len = 0; // first part of dest Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0), new_operands->adr_at(fillp), (len = old_off) * sizeof(u2)); fillp += len; // first part of src Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0), new_operands->adr_at(fillp), (len = from_off) * sizeof(u2)); fillp += len; // second part of dest Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off), new_operands->adr_at(fillp), (len = old_len - old_off) * sizeof(u2)); fillp += len; // second part of src Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off), new_operands->adr_at(fillp), (len = from_len - from_off) * sizeof(u2)); fillp += len; assert(fillp == new_operands->length(), ""); // Adjust indexes in the first part of the copied operands array. for (int j = 0; j < from_oplen; j++) { int offset = operand_offset_at(new_operands, old_oplen + j); assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy"); offset += old_len; // every new tuple is preceded by old_len extra u2's operand_offset_at_put(new_operands, old_oplen + j, offset); } // replace target operands array with combined array to_cp->set_operands(new_operands); } } } // end copy_operands() // Copy this constant pool's entries at start_i to end_i (inclusive) // to the constant pool to_cp's entries starting at to_i. A total of // (end_i - start_i) + 1 entries are copied. void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) { int dest_i = to_i; // leave original alone for debug purposes for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) { copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK); switch (from_cp->tag_at(src_i).value()) { case JVM_CONSTANT_Double: case JVM_CONSTANT_Long: // double and long take two constant pool entries src_i += 2; dest_i += 2; break; default: // all others take one constant pool entry src_i++; dest_i++; break; } } copy_operands(from_cp, to_cp, CHECK); } // end copy_cp_to_impl() // Copy this constant pool's entry at from_i to the constant pool // to_cp's entry at to_i. void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS) { int tag = from_cp->tag_at(from_i).value(); switch (tag) { case JVM_CONSTANT_ClassIndex: { jint ki = from_cp->klass_index_at(from_i); to_cp->klass_index_at_put(to_i, ki); } break; case JVM_CONSTANT_Double: { jdouble d = from_cp->double_at(from_i); to_cp->double_at_put(to_i, d); // double takes two constant pool entries so init second entry's tag to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid); } break; case JVM_CONSTANT_Fieldref: { int class_index = from_cp->uncached_klass_ref_index_at(from_i); int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i); to_cp->field_at_put(to_i, class_index, name_and_type_index); } break; case JVM_CONSTANT_Float: { jfloat f = from_cp->float_at(from_i); to_cp->float_at_put(to_i, f); } break; case JVM_CONSTANT_Integer: { jint i = from_cp->int_at(from_i); to_cp->int_at_put(to_i, i); } break; case JVM_CONSTANT_InterfaceMethodref: { int class_index = from_cp->uncached_klass_ref_index_at(from_i); int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i); to_cp->interface_method_at_put(to_i, class_index, name_and_type_index); } break; case JVM_CONSTANT_Long: { jlong l = from_cp->long_at(from_i); to_cp->long_at_put(to_i, l); // long takes two constant pool entries so init second entry's tag to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid); } break; case JVM_CONSTANT_Methodref: { int class_index = from_cp->uncached_klass_ref_index_at(from_i); int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i); to_cp->method_at_put(to_i, class_index, name_and_type_index); } break; case JVM_CONSTANT_NameAndType: { int name_ref_index = from_cp->name_ref_index_at(from_i); int signature_ref_index = from_cp->signature_ref_index_at(from_i); to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index); } break; case JVM_CONSTANT_StringIndex: { jint si = from_cp->string_index_at(from_i); to_cp->string_index_at_put(to_i, si); } break; case JVM_CONSTANT_Class: case JVM_CONSTANT_UnresolvedClass: case JVM_CONSTANT_UnresolvedClassInError: { // Revert to JVM_CONSTANT_ClassIndex int name_index = from_cp->klass_slot_at(from_i).name_index(); assert(from_cp->tag_at(name_index).is_symbol(), "sanity"); to_cp->klass_index_at_put(to_i, name_index); } break; case JVM_CONSTANT_String: { Symbol* s = from_cp->unresolved_string_at(from_i); to_cp->unresolved_string_at_put(to_i, s); } break; case JVM_CONSTANT_Utf8: { Symbol* s = from_cp->symbol_at(from_i); // Need to increase refcount, the old one will be thrown away and deferenced s->increment_refcount(); to_cp->symbol_at_put(to_i, s); } break; case JVM_CONSTANT_MethodType: case JVM_CONSTANT_MethodTypeInError: { jint k = from_cp->method_type_index_at(from_i); to_cp->method_type_index_at_put(to_i, k); } break; case JVM_CONSTANT_MethodHandle: case JVM_CONSTANT_MethodHandleInError: { int k1 = from_cp->method_handle_ref_kind_at(from_i); int k2 = from_cp->method_handle_index_at(from_i); to_cp->method_handle_index_at_put(to_i, k1, k2); } break; case JVM_CONSTANT_InvokeDynamic: { int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i); int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i); k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands to_cp->invoke_dynamic_at_put(to_i, k1, k2); } break; // Invalid is used as the tag for the second constant pool entry // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should // not be seen by itself. case JVM_CONSTANT_Invalid: // fall through default: { ShouldNotReachHere(); } break; } } // end copy_entry_to() // Search constant pool search_cp for an entry that matches this // constant pool's entry at pattern_i. Returns the index of a // matching entry or zero (0) if there is no matching entry. int ConstantPool::find_matching_entry(int pattern_i, const constantPoolHandle& search_cp, TRAPS) { // index zero (0) is not used for (int i = 1; i < search_cp->length(); i++) { bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0); if (found) { return i; } } return 0; // entry not found; return unused index zero (0) } // end find_matching_entry() // Compare this constant pool's bootstrap specifier at idx1 to the constant pool // cp2's bootstrap specifier at idx2. bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2, TRAPS) { int k1 = operand_bootstrap_method_ref_index_at(idx1); int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2); bool match = compare_entry_to(k1, cp2, k2, CHECK_false); if (!match) { return false; } int argc = operand_argument_count_at(idx1); if (argc == cp2->operand_argument_count_at(idx2)) { for (int j = 0; j < argc; j++) { k1 = operand_argument_index_at(idx1, j); k2 = cp2->operand_argument_index_at(idx2, j); match = compare_entry_to(k1, cp2, k2, CHECK_false); if (!match) { return false; } } return true; // got through loop; all elements equal } return false; } // end compare_operand_to() // Search constant pool search_cp for a bootstrap specifier that matches // this constant pool's bootstrap specifier at pattern_i index. // Return the index of a matching bootstrap specifier or (-1) if there is no match. int ConstantPool::find_matching_operand(int pattern_i, const constantPoolHandle& search_cp, int search_len, TRAPS) { for (int i = 0; i < search_len; i++) { bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1)); if (found) { return i; } } return -1; // bootstrap specifier not found; return unused index (-1) } // end find_matching_operand() #ifndef PRODUCT const char* ConstantPool::printable_name_at(int which) { constantTag tag = tag_at(which); if (tag.is_string()) { return string_at_noresolve(which); } else if (tag.is_klass() || tag.is_unresolved_klass()) { return klass_name_at(which)->as_C_string(); } else if (tag.is_symbol()) { return symbol_at(which)->as_C_string(); } return ""; } #endif // PRODUCT // JVMTI GetConstantPool support // For debugging of constant pool const bool debug_cpool = false; #define DBG(code) do { if (debug_cpool) { (code); } } while(0) static void print_cpool_bytes(jint cnt, u1 *bytes) { const char* WARN_MSG = "Must not be such entry!"; jint size = 0; u2 idx1, idx2; for (jint idx = 1; idx < cnt; idx++) { jint ent_size = 0; u1 tag = *bytes++; size++; // count tag printf("const #%03d, tag: %02d ", idx, tag); switch(tag) { case JVM_CONSTANT_Invalid: { printf("Invalid"); break; } case JVM_CONSTANT_Unicode: { printf("Unicode %s", WARN_MSG); break; } case JVM_CONSTANT_Utf8: { u2 len = Bytes::get_Java_u2(bytes); char str[128]; if (len > 127) { len = 127; } strncpy(str, (char *) (bytes+2), len); str[len] = '\0'; printf("Utf8 \"%s\"", str); ent_size = 2 + len; break; } case JVM_CONSTANT_Integer: { u4 val = Bytes::get_Java_u4(bytes); printf("int %d", *(int *) &val); ent_size = 4; break; } case JVM_CONSTANT_Float: { u4 val = Bytes::get_Java_u4(bytes); printf("float %5.3ff", *(float *) &val); ent_size = 4; break; } case JVM_CONSTANT_Long: { u8 val = Bytes::get_Java_u8(bytes); printf("long " INT64_FORMAT, (int64_t) *(jlong *) &val); ent_size = 8; idx++; // Long takes two cpool slots break; } case JVM_CONSTANT_Double: { u8 val = Bytes::get_Java_u8(bytes); printf("double %5.3fd", *(jdouble *)&val); ent_size = 8; idx++; // Double takes two cpool slots break; } case JVM_CONSTANT_Class: { idx1 = Bytes::get_Java_u2(bytes); printf("class #%03d", idx1); ent_size = 2; break; } case JVM_CONSTANT_String: { idx1 = Bytes::get_Java_u2(bytes); printf("String #%03d", idx1); ent_size = 2; break; } case JVM_CONSTANT_Fieldref: { idx1 = Bytes::get_Java_u2(bytes); idx2 = Bytes::get_Java_u2(bytes+2); printf("Field #%03d, #%03d", (int) idx1, (int) idx2); ent_size = 4; break; } case JVM_CONSTANT_Methodref: { idx1 = Bytes::get_Java_u2(bytes); idx2 = Bytes::get_Java_u2(bytes+2); printf("Method #%03d, #%03d", idx1, idx2); ent_size = 4; break; } case JVM_CONSTANT_InterfaceMethodref: { idx1 = Bytes::get_Java_u2(bytes); idx2 = Bytes::get_Java_u2(bytes+2); printf("InterfMethod #%03d, #%03d", idx1, idx2); ent_size = 4; break; } case JVM_CONSTANT_NameAndType: { idx1 = Bytes::get_Java_u2(bytes); idx2 = Bytes::get_Java_u2(bytes+2); printf("NameAndType #%03d, #%03d", idx1, idx2); ent_size = 4; break; } case JVM_CONSTANT_ClassIndex: { printf("ClassIndex %s", WARN_MSG); break; } case JVM_CONSTANT_UnresolvedClass: { printf("UnresolvedClass: %s", WARN_MSG); break; } case JVM_CONSTANT_UnresolvedClassInError: { printf("UnresolvedClassInErr: %s", WARN_MSG); break; } case JVM_CONSTANT_StringIndex: { printf("StringIndex: %s", WARN_MSG); break; } } printf(";\n"); bytes += ent_size; size += ent_size; } printf("Cpool size: %d\n", size); fflush(0); return; } /* end print_cpool_bytes */ // Returns size of constant pool entry. jint ConstantPool::cpool_entry_size(jint idx) { switch(tag_at(idx).value()) { case JVM_CONSTANT_Invalid: case JVM_CONSTANT_Unicode: return 1; case JVM_CONSTANT_Utf8: return 3 + symbol_at(idx)->utf8_length(); case JVM_CONSTANT_Class: case JVM_CONSTANT_String: case JVM_CONSTANT_ClassIndex: case JVM_CONSTANT_UnresolvedClass: case JVM_CONSTANT_UnresolvedClassInError: case JVM_CONSTANT_StringIndex: case JVM_CONSTANT_MethodType: case JVM_CONSTANT_MethodTypeInError: return 3; case JVM_CONSTANT_MethodHandle: case JVM_CONSTANT_MethodHandleInError: return 4; //tag, ref_kind, ref_index case JVM_CONSTANT_Integer: case JVM_CONSTANT_Float: case JVM_CONSTANT_Fieldref: case JVM_CONSTANT_Methodref: case JVM_CONSTANT_InterfaceMethodref: case JVM_CONSTANT_NameAndType: return 5; case JVM_CONSTANT_InvokeDynamic: // u1 tag, u2 bsm, u2 nt return 5; case JVM_CONSTANT_Long: case JVM_CONSTANT_Double: return 9; } assert(false, "cpool_entry_size: Invalid constant pool entry tag"); return 1; } /* end cpool_entry_size */ // SymbolHashMap is used to find a constant pool index from a string. // This function fills in SymbolHashMaps, one for utf8s and one for // class names, returns size of the cpool raw bytes. jint ConstantPool::hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap) { jint size = 0; for (u2 idx = 1; idx < length(); idx++) { u2 tag = tag_at(idx).value(); size += cpool_entry_size(idx); switch(tag) { case JVM_CONSTANT_Utf8: { Symbol* sym = symbol_at(idx); symmap->add_entry(sym, idx); DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx)); break; } case JVM_CONSTANT_Class: case JVM_CONSTANT_UnresolvedClass: case JVM_CONSTANT_UnresolvedClassInError: { Symbol* sym = klass_name_at(idx); classmap->add_entry(sym, idx); DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx)); break; } case JVM_CONSTANT_Long: case JVM_CONSTANT_Double: { idx++; // Both Long and Double take two cpool slots break; } } } return size; } /* end hash_utf8_entries_to */ // Copy cpool bytes. // Returns: // 0, in case of OutOfMemoryError // -1, in case of internal error // > 0, count of the raw cpool bytes that have been copied int ConstantPool::copy_cpool_bytes(int cpool_size, SymbolHashMap* tbl, unsigned char *bytes) { u2 idx1, idx2; jint size = 0; jint cnt = length(); unsigned char *start_bytes = bytes; for (jint idx = 1; idx < cnt; idx++) { u1 tag = tag_at(idx).value(); jint ent_size = cpool_entry_size(idx); assert(size + ent_size <= cpool_size, "Size mismatch"); *bytes = tag; DBG(printf("#%03hd tag=%03hd, ", idx, tag)); switch(tag) { case JVM_CONSTANT_Invalid: { DBG(printf("JVM_CONSTANT_Invalid")); break; } case JVM_CONSTANT_Unicode: { assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode"); DBG(printf("JVM_CONSTANT_Unicode")); break; } case JVM_CONSTANT_Utf8: { Symbol* sym = symbol_at(idx); char* str = sym->as_utf8(); // Warning! It's crashing on x86 with len = sym->utf8_length() int len = (int) strlen(str); Bytes::put_Java_u2((address) (bytes+1), (u2) len); for (int i = 0; i < len; i++) { bytes[3+i] = (u1) str[i]; } DBG(printf("JVM_CONSTANT_Utf8: %s ", str)); break; } case JVM_CONSTANT_Integer: { jint val = int_at(idx); Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val); break; } case JVM_CONSTANT_Float: { jfloat val = float_at(idx); Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val); break; } case JVM_CONSTANT_Long: { jlong val = long_at(idx); Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val); idx++; // Long takes two cpool slots break; } case JVM_CONSTANT_Double: { jdouble val = double_at(idx); Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val); idx++; // Double takes two cpool slots break; } case JVM_CONSTANT_Class: case JVM_CONSTANT_UnresolvedClass: case JVM_CONSTANT_UnresolvedClassInError: { *bytes = JVM_CONSTANT_Class; Symbol* sym = klass_name_at(idx); idx1 = tbl->symbol_to_value(sym); assert(idx1 != 0, "Have not found a hashtable entry"); Bytes::put_Java_u2((address) (bytes+1), idx1); DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8())); break; } case JVM_CONSTANT_String: { *bytes = JVM_CONSTANT_String; Symbol* sym = unresolved_string_at(idx); idx1 = tbl->symbol_to_value(sym); assert(idx1 != 0, "Have not found a hashtable entry"); Bytes::put_Java_u2((address) (bytes+1), idx1); DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8())); break; } case JVM_CONSTANT_Fieldref: case JVM_CONSTANT_Methodref: case JVM_CONSTANT_InterfaceMethodref: { idx1 = uncached_klass_ref_index_at(idx); idx2 = uncached_name_and_type_ref_index_at(idx); Bytes::put_Java_u2((address) (bytes+1), idx1); Bytes::put_Java_u2((address) (bytes+3), idx2); DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2)); break; } case JVM_CONSTANT_NameAndType: { idx1 = name_ref_index_at(idx); idx2 = signature_ref_index_at(idx); Bytes::put_Java_u2((address) (bytes+1), idx1); Bytes::put_Java_u2((address) (bytes+3), idx2); DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2)); break; } case JVM_CONSTANT_ClassIndex: { *bytes = JVM_CONSTANT_Class; idx1 = klass_index_at(idx); Bytes::put_Java_u2((address) (bytes+1), idx1); DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1)); break; } case JVM_CONSTANT_StringIndex: { *bytes = JVM_CONSTANT_String; idx1 = string_index_at(idx); Bytes::put_Java_u2((address) (bytes+1), idx1); DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1)); break; } case JVM_CONSTANT_MethodHandle: case JVM_CONSTANT_MethodHandleInError: { *bytes = JVM_CONSTANT_MethodHandle; int kind = method_handle_ref_kind_at(idx); idx1 = method_handle_index_at(idx); *(bytes+1) = (unsigned char) kind; Bytes::put_Java_u2((address) (bytes+2), idx1); DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1)); break; } case JVM_CONSTANT_MethodType: case JVM_CONSTANT_MethodTypeInError: { *bytes = JVM_CONSTANT_MethodType; idx1 = method_type_index_at(idx); Bytes::put_Java_u2((address) (bytes+1), idx1); DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1)); break; } case JVM_CONSTANT_InvokeDynamic: { *bytes = tag; idx1 = extract_low_short_from_int(*int_at_addr(idx)); idx2 = extract_high_short_from_int(*int_at_addr(idx)); assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4"); Bytes::put_Java_u2((address) (bytes+1), idx1); Bytes::put_Java_u2((address) (bytes+3), idx2); DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2)); break; } } DBG(printf("\n")); bytes += ent_size; size += ent_size; } assert(size == cpool_size, "Size mismatch"); // Keep temorarily for debugging until it's stable. DBG(print_cpool_bytes(cnt, start_bytes)); return (int)(bytes - start_bytes); } /* end copy_cpool_bytes */ #undef DBG void ConstantPool::set_on_stack(const bool value) { if (value) { // Only record if it's not already set. if (!on_stack()) { assert(!is_shared(), "should always be set for shared constant pools"); _flags |= _on_stack; MetadataOnStackMark::record(this); } } else { // Clearing is done single-threadedly. if (!is_shared()) { _flags &= ~_on_stack; } } } // JSR 292 support for patching constant pool oops after the class is linked and // the oop array for resolved references are created. // We can't do this during classfile parsing, which is how the other indexes are // patched. The other patches are applied early for some error checking // so only defer the pseudo_strings. void ConstantPool::patch_resolved_references(GrowableArray* cp_patches) { for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused Handle patch = cp_patches->at(index); if (patch.not_null()) { assert (tag_at(index).is_string(), "should only be string left"); // Patching a string means pre-resolving it. // The spelling in the constant pool is ignored. // The constant reference may be any object whatever. // If it is not a real interned string, the constant is referred // to as a "pseudo-string", and must be presented to the CP // explicitly, because it may require scavenging. int obj_index = cp_to_object_index(index); pseudo_string_at_put(index, obj_index, patch()); DEBUG_ONLY(cp_patches->at_put(index, Handle());) } } #ifdef ASSERT // Ensure that all the patches have been used. for (int index = 0; index < cp_patches->length(); index++) { assert(cp_patches->at(index).is_null(), "Unused constant pool patch at %d in class file %s", index, pool_holder()->external_name()); } #endif // ASSERT } #ifndef PRODUCT // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) { guarantee(obj->is_constantPool(), "object must be constant pool"); constantPoolHandle cp(THREAD, (ConstantPool*)obj); guarantee(cp->pool_holder() != NULL, "must be fully loaded"); for (int i = 0; i< cp->length(); i++) { if (cp->tag_at(i).is_unresolved_klass()) { // This will force loading of the class Klass* klass = cp->klass_at(i, CHECK); if (klass->is_instance_klass()) { // Force initialization of class InstanceKlass::cast(klass)->initialize(CHECK); } } } } #endif // Printing void ConstantPool::print_on(outputStream* st) const { assert(is_constantPool(), "must be constantPool"); st->print_cr("%s", internal_name()); if (flags() != 0) { st->print(" - flags: 0x%x", flags()); if (has_preresolution()) st->print(" has_preresolution"); if (on_stack()) st->print(" on_stack"); st->cr(); } if (pool_holder() != NULL) { st->print_cr(" - holder: " INTPTR_FORMAT, p2i(pool_holder())); } st->print_cr(" - cache: " INTPTR_FORMAT, p2i(cache())); st->print_cr(" - resolved_references: " INTPTR_FORMAT, p2i(resolved_references())); st->print_cr(" - reference_map: " INTPTR_FORMAT, p2i(reference_map())); st->print_cr(" - resolved_klasses: " INTPTR_FORMAT, p2i(resolved_klasses())); for (int index = 1; index < length(); index++) { // Index 0 is unused ((ConstantPool*)this)->print_entry_on(index, st); switch (tag_at(index).value()) { case JVM_CONSTANT_Long : case JVM_CONSTANT_Double : index++; // Skip entry following eigth-byte constant } } st->cr(); } // Print one constant pool entry void ConstantPool::print_entry_on(const int index, outputStream* st) { EXCEPTION_MARK; st->print(" - %3d : ", index); tag_at(index).print_on(st); st->print(" : "); switch (tag_at(index).value()) { case JVM_CONSTANT_Class : { Klass* k = klass_at(index, CATCH); guarantee(k != NULL, "need klass"); k->print_value_on(st); st->print(" {" PTR_FORMAT "}", p2i(k)); } break; case JVM_CONSTANT_Fieldref : case JVM_CONSTANT_Methodref : case JVM_CONSTANT_InterfaceMethodref : st->print("klass_index=%d", uncached_klass_ref_index_at(index)); st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index)); break; case JVM_CONSTANT_String : if (is_pseudo_string_at(index)) { oop anObj = pseudo_string_at(index); anObj->print_value_on(st); st->print(" {" PTR_FORMAT "}", p2i(anObj)); } else { unresolved_string_at(index)->print_value_on(st); } break; case JVM_CONSTANT_Integer : st->print("%d", int_at(index)); break; case JVM_CONSTANT_Float : st->print("%f", float_at(index)); break; case JVM_CONSTANT_Long : st->print_jlong(long_at(index)); break; case JVM_CONSTANT_Double : st->print("%lf", double_at(index)); break; case JVM_CONSTANT_NameAndType : st->print("name_index=%d", name_ref_index_at(index)); st->print(" signature_index=%d", signature_ref_index_at(index)); break; case JVM_CONSTANT_Utf8 : symbol_at(index)->print_value_on(st); break; case JVM_CONSTANT_ClassIndex: { int name_index = *int_at_addr(index); st->print("klass_index=%d ", name_index); symbol_at(name_index)->print_value_on(st); } break; case JVM_CONSTANT_UnresolvedClass : // fall-through case JVM_CONSTANT_UnresolvedClassInError: { CPKlassSlot kslot = klass_slot_at(index); int resolved_klass_index = kslot.resolved_klass_index(); int name_index = kslot.name_index(); assert(tag_at(name_index).is_symbol(), "sanity"); Klass* klass = resolved_klasses()->at(resolved_klass_index); if (klass != NULL) { klass->print_value_on(st); } else { symbol_at(name_index)->print_value_on(st); } } break; case JVM_CONSTANT_MethodHandle : case JVM_CONSTANT_MethodHandleInError : st->print("ref_kind=%d", method_handle_ref_kind_at(index)); st->print(" ref_index=%d", method_handle_index_at(index)); break; case JVM_CONSTANT_MethodType : case JVM_CONSTANT_MethodTypeInError : st->print("signature_index=%d", method_type_index_at(index)); break; case JVM_CONSTANT_InvokeDynamic : { st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index)); st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index)); int argc = invoke_dynamic_argument_count_at(index); if (argc > 0) { for (int arg_i = 0; arg_i < argc; arg_i++) { int arg = invoke_dynamic_argument_index_at(index, arg_i); st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg); } st->print("}"); } } break; default: ShouldNotReachHere(); break; } st->cr(); } void ConstantPool::print_value_on(outputStream* st) const { assert(is_constantPool(), "must be constantPool"); st->print("constant pool [%d]", length()); if (has_preresolution()) st->print("/preresolution"); if (operands() != NULL) st->print("/operands[%d]", operands()->length()); print_address_on(st); st->print(" for "); pool_holder()->print_value_on(st); if (pool_holder() != NULL) { bool extra = (pool_holder()->constants() != this); if (extra) st->print(" (extra)"); } if (cache() != NULL) { st->print(" cache=" PTR_FORMAT, p2i(cache())); } } #if INCLUDE_SERVICES // Size Statistics void ConstantPool::collect_statistics(KlassSizeStats *sz) const { sz->_cp_all_bytes += (sz->_cp_bytes = sz->count(this)); sz->_cp_all_bytes += (sz->_cp_tags_bytes = sz->count_array(tags())); sz->_cp_all_bytes += (sz->_cp_cache_bytes = sz->count(cache())); sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands())); sz->_cp_all_bytes += (sz->_cp_refmap_bytes = sz->count_array(reference_map())); sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes + sz->_cp_refmap_bytes; sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes; } #endif // INCLUDE_SERVICES // Verification void ConstantPool::verify_on(outputStream* st) { guarantee(is_constantPool(), "object must be constant pool"); for (int i = 0; i< length(); i++) { constantTag tag = tag_at(i); if (tag.is_klass() || tag.is_unresolved_klass()) { guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count"); } else if (tag.is_symbol()) { CPSlot entry = slot_at(i); guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count"); } else if (tag.is_string()) { CPSlot entry = slot_at(i); guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count"); } } if (cache() != NULL) { // Note: cache() can be NULL before a class is completely setup or // in temporary constant pools used during constant pool merging guarantee(cache()->is_constantPoolCache(), "should be constant pool cache"); } if (pool_holder() != NULL) { // Note: pool_holder() can be NULL in temporary constant pools // used during constant pool merging guarantee(pool_holder()->is_klass(), "should be klass"); } } void SymbolHashMap::add_entry(Symbol* sym, u2 value) { char *str = sym->as_utf8(); unsigned int hash = compute_hash(str, sym->utf8_length()); unsigned int index = hash % table_size(); // check if already in map // we prefer the first entry since it is more likely to be what was used in // the class file for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) { assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL"); if (en->hash() == hash && en->symbol() == sym) { return; // already there } } SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value); entry->set_next(bucket(index)); _buckets[index].set_entry(entry); assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL"); } SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) { assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL"); char *str = sym->as_utf8(); int len = sym->utf8_length(); unsigned int hash = SymbolHashMap::compute_hash(str, len); unsigned int index = hash % table_size(); for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) { assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL"); if (en->hash() == hash && en->symbol() == sym) { return en; } } return NULL; }