/* * Copyright (c) 2022, 2026, 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 "cds/aotClassLinker.hpp" #include "cds/aotConstantPoolResolver.hpp" #include "cds/archiveBuilder.hpp" #include "cds/cdsConfig.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/systemDictionaryShared.hpp" #include "classfile/vmClasses.hpp" #include "interpreter/bytecodeStream.hpp" #include "interpreter/interpreterRuntime.hpp" #include "memory/resourceArea.hpp" #include "oops/constantPool.inline.hpp" #include "oops/instanceKlass.hpp" #include "oops/klass.inline.hpp" #include "runtime/handles.inline.hpp" // Returns true if we CAN PROVE that cp_index will always resolve to // the same information at both dump time and run time. This is a // necessary (but not sufficient) condition for pre-resolving cp_index // during CDS archive assembly. bool AOTConstantPoolResolver::is_resolution_deterministic(ConstantPool* cp, int cp_index) { assert(!is_in_archivebuilder_buffer(cp), "sanity"); if (cp->tag_at(cp_index).is_klass()) { // We require cp_index to be already resolved. This is fine for now, are we // currently archive only CP entries that are already resolved. Klass* resolved_klass = cp->resolved_klass_at(cp_index); return resolved_klass != nullptr && is_class_resolution_deterministic(cp->pool_holder(), resolved_klass); } else if (cp->tag_at(cp_index).is_invoke_dynamic()) { return is_indy_resolution_deterministic(cp, cp_index); } else if (cp->tag_at(cp_index).is_field() || cp->tag_at(cp_index).is_method() || cp->tag_at(cp_index).is_interface_method()) { int klass_cp_index = cp->uncached_klass_ref_index_at(cp_index); if (!cp->tag_at(klass_cp_index).is_klass()) { // Not yet resolved return false; } Klass* k = cp->resolved_klass_at(klass_cp_index); if (!is_class_resolution_deterministic(cp->pool_holder(), k)) { return false; } if (!k->is_instance_klass()) { // TODO: support non instance klasses as well. return false; } // Here, We don't check if this entry can actually be resolved to a valid Field/Method. // This method should be called by the ConstantPool to check Fields/Methods that // have already been successfully resolved. return true; } else { return false; } } bool AOTConstantPoolResolver::is_class_resolution_deterministic(InstanceKlass* cp_holder, Klass* resolved_class) { assert(!is_in_archivebuilder_buffer(cp_holder), "sanity"); assert(!is_in_archivebuilder_buffer(resolved_class), "sanity"); if (resolved_class->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(resolved_class); if (!ik->in_aot_cache() && SystemDictionaryShared::is_excluded_class(ik)) { return false; } if (cp_holder->is_subtype_of(ik)) { // All super types of ik will be resolved in ik->class_loader() before // ik is defined in this loader, so it's safe to archive the resolved klass reference. return true; } if (CDSConfig::is_dumping_aot_linked_classes()) { // Need to call try_add_candidate instead of is_candidate, as this may be called // before AOTClassLinker::add_candidates(). if (AOTClassLinker::try_add_candidate(ik)) { return true; } else { return false; } } else if (AOTClassLinker::is_vm_class(ik)) { if (ik->class_loader() != cp_holder->class_loader()) { // At runtime, cp_holder() may not be able to resolve to the same // ik. For example, a different version of ik may be defined in // cp->pool_holder()'s loader using MethodHandles.Lookup.defineClass(). return false; } else { return true; } } else { return false; } } else if (resolved_class->is_objArray_klass()) { if (CDSConfig::is_dumping_dynamic_archive()) { // This is difficult to handle. See JDK-8374639 return false; } Klass* elem = ObjArrayKlass::cast(resolved_class)->bottom_klass(); if (elem->is_instance_klass()) { return is_class_resolution_deterministic(cp_holder, InstanceKlass::cast(elem)); } else if (elem->is_typeArray_klass()) { return true; } else { return false; } } else if (resolved_class->is_typeArray_klass()) { return true; } else { return false; } } void AOTConstantPoolResolver::preresolve_string_cp_entries(InstanceKlass* ik, TRAPS) { if (!ik->is_linked()) { // The cp->resolved_referenced() array is not ready yet, so we can't call resolve_string(). return; } constantPoolHandle cp(THREAD, ik->constants()); for (int cp_index = 1; cp_index < cp->length(); cp_index++) { // Index 0 is unused switch (cp->tag_at(cp_index).value()) { case JVM_CONSTANT_String: resolve_string(cp, cp_index, CHECK); // may throw OOM when interning strings. break; } } } // This works only for the boot/platform/app loaders Klass* AOTConstantPoolResolver::find_loaded_class(Thread* current, oop class_loader, Symbol* name) { HandleMark hm(current); Handle h_loader(current, class_loader); Klass* k = SystemDictionary::find_instance_or_array_klass(current, name, h_loader); if (k != nullptr) { return k; } if (h_loader() == SystemDictionary::java_system_loader()) { return find_loaded_class(current, SystemDictionary::java_platform_loader(), name); } else if (h_loader() == SystemDictionary::java_platform_loader()) { return find_loaded_class(current, nullptr, name); } else { assert(h_loader() == nullptr, "This function only works for boot/platform/app loaders %p %p %p", cast_from_oop
(h_loader()), cast_from_oop
(SystemDictionary::java_system_loader()), cast_from_oop
(SystemDictionary::java_platform_loader())); } return nullptr; } Klass* AOTConstantPoolResolver::find_loaded_class(Thread* current, ConstantPool* cp, int class_cp_index) { Symbol* name = cp->klass_name_at(class_cp_index); return find_loaded_class(current, cp->pool_holder()->class_loader(), name); } #if INCLUDE_CDS_JAVA_HEAP void AOTConstantPoolResolver::resolve_string(constantPoolHandle cp, int cp_index, TRAPS) { if (CDSConfig::is_dumping_heap()) { int cache_index = cp->cp_to_object_index(cp_index); ConstantPool::string_at_impl(cp, cp_index, cache_index, CHECK); } } #endif void AOTConstantPoolResolver::preresolve_class_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray* preresolve_list) { if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) { return; } JavaThread* THREAD = current; constantPoolHandle cp(THREAD, ik->constants()); for (int cp_index = 1; cp_index < cp->length(); cp_index++) { if (cp->tag_at(cp_index).value() == JVM_CONSTANT_UnresolvedClass) { if (preresolve_list != nullptr && preresolve_list->at(cp_index) == false) { // This class was not resolved during trial run. Don't attempt to resolve it. Otherwise // the compiler may generate less efficient code. continue; } if (find_loaded_class(current, cp(), cp_index) == nullptr) { // Do not resolve any class that has not been loaded yet continue; } Klass* resolved_klass = cp->klass_at(cp_index, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; // just ignore } else { log_trace(aot, resolve)("Resolved class [%3d] %s -> %s", cp_index, ik->external_name(), resolved_klass->external_name()); } } } } void AOTConstantPoolResolver::preresolve_field_and_method_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray* preresolve_list) { JavaThread* THREAD = current; constantPoolHandle cp(THREAD, ik->constants()); if (cp->cache() == nullptr) { return; } for (int i = 0; i < ik->methods()->length(); i++) { Method* m = ik->methods()->at(i); BytecodeStream bcs(methodHandle(THREAD, m)); while (!bcs.is_last_bytecode()) { bcs.next(); Bytecodes::Code raw_bc = bcs.raw_code(); switch (raw_bc) { case Bytecodes::_getstatic: case Bytecodes::_putstatic: maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; // just ignore } break; case Bytecodes::_getfield: // no-fast bytecode case Bytecodes::_nofast_getfield: // fast bytecodes case Bytecodes::_fast_agetfield: case Bytecodes::_fast_bgetfield: case Bytecodes::_fast_cgetfield: case Bytecodes::_fast_dgetfield: case Bytecodes::_fast_fgetfield: case Bytecodes::_fast_igetfield: case Bytecodes::_fast_lgetfield: case Bytecodes::_fast_sgetfield: raw_bc = Bytecodes::_getfield; maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; // just ignore } break; case Bytecodes::_putfield: // no-fast bytecode case Bytecodes::_nofast_putfield: // fast bytecodes case Bytecodes::_fast_aputfield: case Bytecodes::_fast_bputfield: case Bytecodes::_fast_zputfield: case Bytecodes::_fast_cputfield: case Bytecodes::_fast_dputfield: case Bytecodes::_fast_fputfield: case Bytecodes::_fast_iputfield: case Bytecodes::_fast_lputfield: case Bytecodes::_fast_sputfield: raw_bc = Bytecodes::_putfield; maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; // just ignore } break; case Bytecodes::_invokehandle: case Bytecodes::_invokespecial: case Bytecodes::_invokevirtual: case Bytecodes::_invokeinterface: case Bytecodes::_invokestatic: maybe_resolve_fmi_ref(ik, m, raw_bc, bcs.get_index_u2(), preresolve_list, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; // just ignore } break; default: break; } } } } void AOTConstantPoolResolver::maybe_resolve_fmi_ref(InstanceKlass* ik, Method* m, Bytecodes::Code bc, int raw_index, GrowableArray* preresolve_list, TRAPS) { methodHandle mh(THREAD, m); constantPoolHandle cp(THREAD, ik->constants()); HandleMark hm(THREAD); int cp_index = cp->to_cp_index(raw_index, bc); if (cp->is_resolved(raw_index, bc)) { return; } if (preresolve_list != nullptr && preresolve_list->at(cp_index) == false) { // This field wasn't resolved during the trial run. Don't attempt to resolve it. Otherwise // the compiler may generate less efficient code. return; } int klass_cp_index = cp->uncached_klass_ref_index_at(cp_index); if (find_loaded_class(THREAD, cp(), klass_cp_index) == nullptr) { // Do not resolve any field/methods from a class that has not been loaded yet. return; } Klass* resolved_klass = cp->klass_ref_at(raw_index, bc, CHECK); const char* is_static = ""; switch (bc) { case Bytecodes::_getstatic: case Bytecodes::_putstatic: if (!VM_Version::supports_fast_class_init_checks()) { return; // Do not resolve since interpreter lacks fast clinit barriers support } InterpreterRuntime::resolve_get_put(bc, raw_index, mh, cp, ClassInitMode::dont_init, CHECK); is_static = " *** static"; break; case Bytecodes::_getfield: case Bytecodes::_putfield: InterpreterRuntime::resolve_get_put(bc, raw_index, mh, cp, ClassInitMode::dont_init, CHECK); break; case Bytecodes::_invokestatic: if (!VM_Version::supports_fast_class_init_checks()) { return; // Do not resolve since interpreter lacks fast clinit barriers support } InterpreterRuntime::cds_resolve_invoke(bc, raw_index, cp, CHECK); is_static = " *** static"; break; case Bytecodes::_invokevirtual: case Bytecodes::_invokespecial: case Bytecodes::_invokeinterface: InterpreterRuntime::cds_resolve_invoke(bc, raw_index, cp, CHECK); break; case Bytecodes::_invokehandle: InterpreterRuntime::cds_resolve_invokehandle(raw_index, cp, CHECK); break; default: ShouldNotReachHere(); } if (log_is_enabled(Trace, aot, resolve)) { ResourceMark rm(THREAD); bool resolved = cp->is_resolved(raw_index, bc); Symbol* name = cp->name_ref_at(raw_index, bc); Symbol* signature = cp->signature_ref_at(raw_index, bc); log_trace(aot, resolve)("%s %s [%3d] %s -> %s.%s:%s%s", (resolved ? "Resolved" : "Failed to resolve"), Bytecodes::name(bc), cp_index, ik->external_name(), resolved_klass->external_name(), name->as_C_string(), signature->as_C_string(), is_static); } } void AOTConstantPoolResolver::preresolve_indy_cp_entries(JavaThread* current, InstanceKlass* ik, GrowableArray* preresolve_list) { JavaThread* THREAD = current; constantPoolHandle cp(THREAD, ik->constants()); if (!CDSConfig::is_dumping_invokedynamic() || cp->cache() == nullptr) { return; } assert(preresolve_list != nullptr, "preresolve_indy_cp_entries() should not be called for " "regenerated LambdaForm Invoker classes, which should not have indys anyway."); Array* indy_entries = cp->cache()->resolved_indy_entries(); for (int i = 0; i < indy_entries->length(); i++) { ResolvedIndyEntry* rie = indy_entries->adr_at(i); int cp_index = rie->constant_pool_index(); if (preresolve_list->at(cp_index) == true) { if (!rie->is_resolved() && is_indy_resolution_deterministic(cp(), cp_index)) { InterpreterRuntime::cds_resolve_invokedynamic(i, cp, THREAD); if (HAS_PENDING_EXCEPTION) { CLEAR_PENDING_EXCEPTION; // just ignore } } if (log_is_enabled(Trace, aot, resolve)) { ResourceMark rm(THREAD); log_trace(aot, resolve)("%s indy [%3d] %s", rie->is_resolved() ? "Resolved" : "Failed to resolve", cp_index, ik->external_name()); } } } } // Check the MethodType signatures used by parameters to the indy BSMs. Make sure we don't // use types that have been excluded, or else we might end up creating MethodTypes that cannot be stored // in the AOT cache. bool AOTConstantPoolResolver::check_methodtype_signature(ConstantPool* cp, Symbol* sig, Klass** return_type_ret) { ResourceMark rm; for (SignatureStream ss(sig); !ss.is_done(); ss.next()) { if (ss.is_reference()) { Symbol* type = ss.as_symbol(); Klass* k = find_loaded_class(Thread::current(), cp->pool_holder()->class_loader(), type); if (k == nullptr) { return false; } if (SystemDictionaryShared::should_be_excluded(k)) { if (log_is_enabled(Warning, aot, resolve)) { ResourceMark rm; log_warning(aot, resolve)("Cannot aot-resolve Lambda proxy because %s is excluded", k->external_name()); } return false; } if (ss.at_return_type() && return_type_ret != nullptr) { *return_type_ret = k; } } } return true; } bool AOTConstantPoolResolver::check_lambda_metafactory_signature(ConstantPool* cp, Symbol* sig) { Klass* k; if (!check_methodtype_signature(cp, sig, &k)) { return false; } // is the interface type implemented by the lambda proxy if (!k->is_interface()) { // cp->pool_holder() doesn't look like a valid class generated by javac return false; } // The linked lambda callsite has an instance of the interface implemented by this lambda. If this // interface requires its to be executed, then we must delay the execution to the production run // as can have side effects ==> exclude such cases. InstanceKlass* intf = InstanceKlass::cast(k); bool exclude = intf->interface_needs_clinit_execution_as_super(); if (log_is_enabled(Debug, aot, resolve)) { ResourceMark rm; log_debug(aot, resolve)("%s aot-resolve Lambda proxy of interface type %s", exclude ? "Cannot" : "Can", k->external_name()); } return !exclude; } bool AOTConstantPoolResolver::check_lambda_metafactory_methodtype_arg(ConstantPool* cp, int bsms_attribute_index, int arg_i) { int mt_index = cp->bsm_attribute_entry(bsms_attribute_index)->argument(arg_i); if (!cp->tag_at(mt_index).is_method_type()) { // malformed class? return false; } Symbol* sig = cp->method_type_signature_at(mt_index); if (log_is_enabled(Debug, aot, resolve)) { ResourceMark rm; log_debug(aot, resolve)("Checking MethodType for LambdaMetafactory BSM arg %d: %s", arg_i, sig->as_C_string()); } return check_methodtype_signature(cp, sig); } bool AOTConstantPoolResolver::check_lambda_metafactory_methodhandle_arg(ConstantPool* cp, int bsms_attribute_index, int arg_i) { int mh_index = cp->bsm_attribute_entry(bsms_attribute_index)->argument(arg_i); if (!cp->tag_at(mh_index).is_method_handle()) { // malformed class? return false; } Symbol* sig = cp->method_handle_signature_ref_at(mh_index); if (log_is_enabled(Debug, aot, resolve)) { ResourceMark rm; log_debug(aot, resolve)("Checking MethodType of MethodHandle for LambdaMetafactory BSM arg %d: %s", arg_i, sig->as_C_string()); } return check_methodtype_signature(cp, sig); } bool AOTConstantPoolResolver::is_indy_resolution_deterministic(ConstantPool* cp, int cp_index) { assert(cp->tag_at(cp_index).is_invoke_dynamic(), "sanity"); if (!CDSConfig::is_dumping_invokedynamic()) { return false; } InstanceKlass* pool_holder = cp->pool_holder(); if (!SystemDictionaryShared::is_builtin(pool_holder)) { return false; } int bsm = cp->bootstrap_method_ref_index_at(cp_index); int bsm_ref = cp->method_handle_index_at(bsm); Symbol* bsm_name = cp->uncached_name_ref_at(bsm_ref); Symbol* bsm_signature = cp->uncached_signature_ref_at(bsm_ref); Symbol* bsm_klass = cp->klass_name_at(cp->uncached_klass_ref_index_at(bsm_ref)); // We currently support only StringConcatFactory::makeConcatWithConstants() and LambdaMetafactory::metafactory() // We should mark the allowed BSMs in the JDK code using a private annotation. // See notes on RFE JDK-8342481. if (bsm_klass->equals("java/lang/invoke/StringConcatFactory") && bsm_name->equals("makeConcatWithConstants") && bsm_signature->equals("(Ljava/lang/invoke/MethodHandles$Lookup;" "Ljava/lang/String;" "Ljava/lang/invoke/MethodType;" "Ljava/lang/String;" "[Ljava/lang/Object;" ")Ljava/lang/invoke/CallSite;")) { Symbol* factory_type_sig = cp->uncached_signature_ref_at(cp_index); if (log_is_enabled(Debug, aot, resolve)) { ResourceMark rm; log_debug(aot, resolve)("Checking StringConcatFactory callsite signature [%d]: %s", cp_index, factory_type_sig->as_C_string()); } Klass* k; if (!check_methodtype_signature(cp, factory_type_sig, &k)) { return false; } if (k != vmClasses::String_klass()) { // bad class file? return false; } return true; } if (bsm_klass->equals("java/lang/invoke/LambdaMetafactory") && bsm_name->equals("metafactory") && bsm_signature->equals("(Ljava/lang/invoke/MethodHandles$Lookup;" "Ljava/lang/String;" "Ljava/lang/invoke/MethodType;" "Ljava/lang/invoke/MethodType;" "Ljava/lang/invoke/MethodHandle;" "Ljava/lang/invoke/MethodType;" ")Ljava/lang/invoke/CallSite;")) { /* * An indy callsite is associated with the following MethodType and MethodHandles: * * https://github.com/openjdk/jdk/blob/580eb62dc097efeb51c76b095c1404106859b673/src/java.base/share/classes/java/lang/invoke/LambdaMetafactory.java#L293-L309 * * MethodType factoryType The expected signature of the {@code CallSite}. The * parameter types represent the types of capture variables; * the return type is the interface to implement. When * used with {@code invokedynamic}, this is provided by * the {@code NameAndType} of the {@code InvokeDynamic} * * MethodType interfaceMethodType Signature and return type of method to be * implemented by the function object. * * MethodHandle implementation A direct method handle describing the implementation * method which should be called (with suitable adaptation * of argument types and return types, and with captured * arguments prepended to the invocation arguments) at * invocation time. * * MethodType dynamicMethodType The signature and return type that should * be enforced dynamically at invocation time. * In simple use cases this is the same as * {@code interfaceMethodType}. */ Symbol* factory_type_sig = cp->uncached_signature_ref_at(cp_index); if (log_is_enabled(Debug, aot, resolve)) { ResourceMark rm; log_debug(aot, resolve)("Checking lambda callsite signature [%d]: %s", cp_index, factory_type_sig->as_C_string()); } if (!check_lambda_metafactory_signature(cp, factory_type_sig)) { return false; } int bsms_attribute_index = cp->bootstrap_methods_attribute_index(cp_index); int arg_count = cp->bsm_attribute_entry(bsms_attribute_index)->argument_count(); if (arg_count != 3) { // Malformed class? return false; } // interfaceMethodType if (!check_lambda_metafactory_methodtype_arg(cp, bsms_attribute_index, 0)) { return false; } // implementation if (!check_lambda_metafactory_methodhandle_arg(cp, bsms_attribute_index, 1)) { return false; } // dynamicMethodType if (!check_lambda_metafactory_methodtype_arg(cp, bsms_attribute_index, 2)) { return false; } return true; } return false; } #ifdef ASSERT bool AOTConstantPoolResolver::is_in_archivebuilder_buffer(address p) { if (!Thread::current()->is_VM_thread() || ArchiveBuilder::current() == nullptr) { return false; } else { return ArchiveBuilder::current()->is_in_buffer_space(p); } } #endif