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android / toolchain / jdk / jdk21 / HEAD / . / src / hotspot / share / oops / constantPool.cpp
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/*
* Copyright (c) 1997, 2023, 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 "cds/archiveHeapWriter.hpp"
#include "cds/archiveHeapLoader.hpp"
#include "cds/archiveBuilder.hpp"
#include "cds/classPrelinker.hpp"
#include "cds/heapShared.hpp"
#include "classfile/classLoaderData.hpp"
#include "classfile/javaClasses.inline.hpp"
#include "classfile/metadataOnStackMark.hpp"
#include "classfile/stringTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmClasses.hpp"
#include "classfile/vmSymbols.hpp"
#include "code/codeCache.hpp"
#include "interpreter/bootstrapInfo.hpp"
#include "interpreter/linkResolver.hpp"
#include "jvm.h"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/metaspaceClosure.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/array.hpp"
#include "oops/constantPool.inline.hpp"
#include "oops/cpCache.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klass.inline.hpp"
#include "oops/objArrayKlass.hpp"
#include "oops/objArrayOop.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/typeArrayOop.inline.hpp"
#include "prims/jvmtiExport.hpp"
#include "runtime/atomic.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/init.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/signature.hpp"
#include "runtime/vframe.inline.hpp"
#include "utilities/copy.hpp"
ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
int size = ConstantPool::size(length);
return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
}
void ConstantPool::copy_fields(const ConstantPool* orig) {
// Preserve dynamic constant information from the original pool
if (orig->has_dynamic_constant()) {
set_has_dynamic_constant();
}
set_major_version(orig->major_version());
set_minor_version(orig->minor_version());
set_source_file_name_index(orig->source_file_name_index());
set_generic_signature_index(orig->generic_signature_index());
}
#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<u1>* tags) {
assert(tags != nullptr, "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<u1>* tags) :
_tags(tags),
_length(tags->length()) {
assert(_tags != nullptr, "invariant");
assert(tags->length() == _length, "invariant");
assert(tag_array_is_zero_initialized(tags), "invariant");
assert(0 == flags(), "invariant");
assert(0 == version(), "invariant");
assert(nullptr == _pool_holder, "invariant");
}
void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
if (cache() != nullptr) {
MetadataFactory::free_metadata(loader_data, cache());
set_cache(nullptr);
}
MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
set_resolved_klasses(nullptr);
MetadataFactory::free_array<jushort>(loader_data, operands());
set_operands(nullptr);
release_C_heap_structures();
// free tag array
MetadataFactory::free_array<u1>(loader_data, tags());
set_tags(nullptr);
}
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 _cache->resolved_references();
}
// Called from outside constant pool resolution where a resolved_reference array
// may not be present.
objArrayOop ConstantPool::resolved_references_or_null() const {
if (_cache == nullptr) {
return nullptr;
} else {
return _cache->resolved_references();
}
}
oop ConstantPool::resolved_reference_at(int index) const {
oop result = resolved_references()->obj_at(index);
assert(oopDesc::is_oop_or_null(result), "Must be oop");
return result;
}
// Use a CAS for multithreaded access
oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
return resolved_references()->replace_if_null(index, new_result);
}
// 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<u2>* om = MetadataFactory::new_array<u2>(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(vmClasses::Object_klass(), map_length, CHECK);
HandleMark hm(THREAD);
Handle refs_handle (THREAD, 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() == nullptr, "sanity");
Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(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 <len; i++) {
switch (tag_at(i).value()) {
case JVM_CONSTANT_ClassIndex:
{
const int class_index = klass_index_at(i);
unresolved_klass_at_put(i, class_index, num_klasses++);
}
break;
#ifndef PRODUCT
case JVM_CONSTANT_Class:
case JVM_CONSTANT_UnresolvedClass:
case JVM_CONSTANT_UnresolvedClassInError:
// All of these should have been reverted back to ClassIndex before calling
// this function.
ShouldNotReachHere();
#endif
}
}
allocate_resolved_klasses(loader_data, num_klasses, THREAD);
}
// Hidden class support:
void ConstantPool::klass_at_put(int class_index, Klass* k) {
assert(k != nullptr, "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);
Atomic::release_store(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);
}
#if INCLUDE_CDS_JAVA_HEAP
// Returns the _resolved_reference array after removing unarchivable items from it.
// Returns null if this class is not supported, or _resolved_reference doesn't exist.
objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
if (_cache == nullptr) {
return nullptr; // nothing to do
}
InstanceKlass *ik = pool_holder();
if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
ik->is_shared_app_class())) {
// Archiving resolved references for classes from non-builtin loaders
// is not yet supported.
return nullptr;
}
objArrayOop rr = resolved_references();
if (rr != nullptr) {
Array<u2>* ref_map = reference_map();
int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
int rr_len = rr->length();
for (int i = 0; i < rr_len; i++) {
oop obj = rr->obj_at(i);
rr->obj_at_put(i, nullptr);
if (obj != nullptr && i < ref_map_len) {
int index = object_to_cp_index(i);
if (tag_at(index).is_string()) {
assert(java_lang_String::is_instance(obj), "must be");
if (!ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
rr->obj_at_put(i, obj);
}
}
}
}
}
return rr;
}
void ConstantPool::add_dumped_interned_strings() {
objArrayOop rr = resolved_references();
if (rr != nullptr) {
int rr_len = rr->length();
for (int i = 0; i < rr_len; i++) {
oop p = rr->obj_at(i);
if (java_lang_String::is_instance(p) &&
!ArchiveHeapWriter::is_string_too_large_to_archive(p)) {
HeapShared::add_to_dumped_interned_strings(p);
}
}
}
}
#endif
#if INCLUDE_CDS
// CDS support. Create a new resolved_references array.
void ConstantPool::restore_unshareable_info(TRAPS) {
if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
return;
}
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");
assert(_cache != nullptr, "constant pool _cache should not be null");
// Only create the new resolved references array if it hasn't been attempted before
if (resolved_references() != nullptr) return;
if (vmClasses::Object_klass_loaded()) {
ClassLoaderData* loader_data = pool_holder()->class_loader_data();
#if INCLUDE_CDS_JAVA_HEAP
if (ArchiveHeapLoader::is_in_use() &&
_cache->archived_references() != nullptr) {
oop archived = _cache->archived_references();
// Create handle for the archived resolved reference array object
HandleMark hm(THREAD);
Handle refs_handle(THREAD, archived);
set_resolved_references(loader_data->add_handle(refs_handle));
_cache->clear_archived_references();
} else
#endif
{
// No mapped archived resolved reference array
// Recreate the object array and add to ClassLoaderData.
int map_length = resolved_reference_length();
if (map_length > 0) {
objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
HandleMark hm(THREAD);
Handle refs_handle(THREAD, stom); // must handleize.
set_resolved_references(loader_data->add_handle(refs_handle));
}
}
}
}
void ConstantPool::remove_unshareable_info() {
// 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);
if (!_pool_holder->is_linked() && !_pool_holder->verified_at_dump_time()) {
return;
}
// 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. It is needed when
// re-creating the resolved reference array if archived heap data cannot be map
// at runtime.
set_resolved_reference_length(
resolved_references() != nullptr ? resolved_references()->length() : 0);
set_resolved_references(OopHandle());
bool archived = false;
for (int index = 1; index < length(); index++) { // Index 0 is unused
switch (tag_at(index).value()) {
case JVM_CONSTANT_UnresolvedClassInError:
tag_at_put(index, JVM_CONSTANT_UnresolvedClass);
break;
case JVM_CONSTANT_MethodHandleInError:
tag_at_put(index, JVM_CONSTANT_MethodHandle);
break;
case JVM_CONSTANT_MethodTypeInError:
tag_at_put(index, JVM_CONSTANT_MethodType);
break;
case JVM_CONSTANT_DynamicInError:
tag_at_put(index, JVM_CONSTANT_Dynamic);
break;
case JVM_CONSTANT_Class:
archived = maybe_archive_resolved_klass_at(index);
ArchiveBuilder::alloc_stats()->record_klass_cp_entry(archived);
break;
}
}
if (cache() != nullptr) {
// cache() is null if this class is not yet linked.
cache()->remove_unshareable_info();
}
}
bool ConstantPool::maybe_archive_resolved_klass_at(int cp_index) {
assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
assert(tag_at(cp_index).is_klass(), "must be resolved");
if (pool_holder()->is_hidden() && cp_index == pool_holder()->this_class_index()) {
// All references to a hidden class's own field/methods are through this
// index, which was resolved in ClassFileParser::fill_instance_klass. We
// must preserve it.
return true;
}
CPKlassSlot kslot = klass_slot_at(cp_index);
int resolved_klass_index = kslot.resolved_klass_index();
Klass* k = resolved_klasses()->at(resolved_klass_index);
// k could be null if the referenced class has been excluded via
// SystemDictionaryShared::is_excluded_class().
if (k != nullptr) {
ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
if (ClassPrelinker::can_archive_resolved_klass(src_cp, cp_index)) {
if (log_is_enabled(Debug, cds, resolve)) {
ResourceMark rm;
log_debug(cds, resolve)("Resolved klass CP entry [%d]: %s => %s", cp_index,
pool_holder()->external_name(), k->external_name());
}
return true;
}
}
// This referenced class cannot be archived. Revert the tag to UnresolvedClass,
// so that the proper class loading and initialization can happen at runtime.
resolved_klasses()->at_put(resolved_klass_index, nullptr);
tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
return false;
}
#endif // INCLUDE_CDS
int ConstantPool::cp_to_object_index(int cp_index) {
// this is harder don't do this so much.
int i = reference_map()->find(checked_cast<u2>(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) {
oop result = set_resolved_reference_at(obj_index, str);
assert(result == nullptr || result == str, "Only set once or to the same string.");
}
void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
ResourceMark rm;
int line_number = -1;
const char * source_file = nullptr;
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 != nullptr) {
source_file = s->as_C_string();
}
}
}
if (k != this_cp->pool_holder()) {
// only print something if the classes are different
if (source_file != nullptr) {
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,
TRAPS) {
JavaThread* javaThread = 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 atomically.
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");
// The tag must be JVM_CONSTANT_Class in order to read the correct value from
// the unresolved_klasses() array.
if (this_cp->tag_at(which).is_klass()) {
Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
if (klass != nullptr) {
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_NULL);
ShouldNotReachHere();
}
HandleMark hm(THREAD);
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;
{
// Turn off the single stepping while doing class resolution
JvmtiHideSingleStepping jhss(javaThread);
k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
} // JvmtiHideSingleStepping jhss(javaThread);
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) {
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* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
assert(klass != nullptr, "must be resolved if exception was cleared");
return klass;
}
// 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);
Atomic::release_store(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.
// We also need to CAS to not overwrite an error from a racing thread.
jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(which),
(jbyte)JVM_CONSTANT_UnresolvedClass,
(jbyte)JVM_CONSTANT_Class);
// We need to recheck exceptions from racing thread and return the same.
if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
// Remove klass.
this_cp->resolved_klasses()->at_put(resolved_klass_index, nullptr);
throw_resolution_error(this_cp, which, CHECK_NULL);
}
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");
if (this_cp->tag_at(which).is_klass()) {
Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
assert(k != nullptr, "should be resolved");
return k;
} else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
return nullptr;
} else {
Thread* current = Thread::current();
HandleMark hm(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 (current, protection_domain);
Handle h_loader (current, loader);
Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader, h_prot);
// Avoid constant pool verification at a safepoint, as it takes the Module_lock.
if (k != nullptr && current->is_Java_thread()) {
// Make sure that resolving is legal
JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
ExceptionMark em(THREAD);
// return null if verification fails
verify_constant_pool_resolve(this_cp, k, THREAD);
if (HAS_PENDING_EXCEPTION) {
CLEAR_PENDING_EXCEPTION;
return nullptr;
}
return k;
} else {
return k;
}
}
}
Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
int which) {
if (cpool->cache() == nullptr) return nullptr; // 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 nullptr;
}
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() == nullptr) return false; // nothing to load yet
if (is_invokedynamic_index(which)) {
int indy_index = decode_invokedynamic_index(which);
return cpool->resolved_indy_entry_at(indy_index)->has_appendix();
} else {
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() == nullptr) return nullptr; // nothing to load yet
if (is_invokedynamic_index(which)) {
int indy_index = decode_invokedynamic_index(which);
return cpool->resolved_reference_from_indy(indy_index);
} else {
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_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which) {
if (cpool->cache() == nullptr) return false; // nothing to load yet
int cache_index = decode_cpcache_index(which, true);
if (is_invokedynamic_index(which)) {
return cpool->resolved_indy_entry_at(cache_index)->has_local_signature();
} else {
ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
return e->has_local_signature();
}
}
// Translate index, which could be CPCache index or Indy index, to a constant pool index
int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
switch(code) {
case Bytecodes::_invokedynamic:
return invokedynamic_bootstrap_ref_index_at(index);
case Bytecodes::_getfield:
case Bytecodes::_getstatic:
case Bytecodes::_putfield:
case Bytecodes::_putstatic:
// TODO: handle resolved field entries with new structure
// i = ....
case Bytecodes::_invokeinterface:
case Bytecodes::_invokehandle:
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
case Bytecodes::_invokevirtual:
// TODO: handle resolved method entries with new structure
default:
// change byte-ordering and go via cache
return remap_instruction_operand_from_cache(index);
}
}
u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
if (tag_at(cp_index).has_bootstrap()) {
u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
assert(tag_at(pool_index).is_name_and_type(), "");
return pool_index;
}
assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
jint ref_index = *int_at_addr(cp_index);
return extract_high_short_from_int(ref_index);
}
u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
}
constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
// which may be either a Constant Pool index or a rewritten index
int pool_index = which;
assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
pool_index = to_cp_index(which, code);
return tag_at(pool_index);
}
u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
jint ref_index = *int_at_addr(cp_index);
return extract_low_short_from_int(ref_index);
}
u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
guarantee(!ConstantPool::is_invokedynamic_index(index),
"an invokedynamic instruction does not have a klass");
assert(code != Bytecodes::_invokedynamic,
"an invokedynamic instruction does not have a klass");
return uncached_klass_ref_index_at(to_cp_index(index, code));
}
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())) {
return; // short cut, typeArray klass is always accessible
}
Klass* holder = this_cp->pool_holder();
LinkResolver::check_klass_accessibility(holder, k, CHECK);
}
u2 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);
}
u2 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, Bytecodes::Code code, TRAPS) {
return klass_at(klass_ref_index_at(which, code), 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, Bytecodes::Code code) {
jint ref_index = klass_ref_index_at(which, code);
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 Signature::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);
}
}
}
static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
// Note: caller needs ResourceMark
// Dig out the detailed message to reuse if possible
const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
if (msg != nullptr) {
return msg;
}
Symbol* message = nullptr;
// 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;
case JVM_CONSTANT_Dynamic:
// return the name of the condy in the error message
message = this_cp->uncached_name_ref_at(which);
break;
default:
ShouldNotReachHere();
}
return message != nullptr ? message->as_C_string() : nullptr;
}
static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
constantTag tag, oop pending_exception) {
ResourceMark rm(current);
Symbol* error = pending_exception->klass()->name();
oop cause = java_lang_Throwable::cause(pending_exception);
// Also dig out the exception cause, if present.
Symbol* cause_sym = nullptr;
const char* cause_msg = nullptr;
if (cause != nullptr && cause != pending_exception) {
cause_sym = cause->klass()->name();
cause_msg = java_lang_Throwable::message_as_utf8(cause);
}
const char* message = exception_message(this_cp, which, tag, pending_exception);
SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
}
void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
ResourceMark rm(THREAD);
const char* message = nullptr;
Symbol* cause = nullptr;
const char* cause_msg = nullptr;
Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
assert(error != nullptr, "checking");
CLEAR_PENDING_EXCEPTION;
if (message != nullptr) {
if (cause != nullptr) {
Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
THROW_MSG_CAUSE(error, message, h_cause);
} else {
THROW_MSG(error, message);
}
} else {
if (cause != nullptr) {
Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
THROW_CAUSE(error, h_cause);
} else {
THROW(error);
}
}
}
// If resolution for Class, Dynamic constant, 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) {
int error_tag = tag.error_value();
if (!PENDING_EXCEPTION->
is_a(vmClasses::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) {
add_resolution_error(THREAD, this_cp, which, tag, PENDING_EXCEPTION);
// 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*)this_cp->tag_addr_at(which),
(jbyte)tag.value(),
(jbyte)error_tag);
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);
}
}
constantTag ConstantPool::constant_tag_at(int which) {
constantTag tag = tag_at(which);
if (tag.is_dynamic_constant()) {
BasicType bt = basic_type_for_constant_at(which);
return constantTag(constantTag::type2tag(bt));
}
return tag;
}
BasicType ConstantPool::basic_type_for_constant_at(int which) {
constantTag tag = tag_at(which);
if (tag.is_dynamic_constant() ||
tag.is_dynamic_constant_in_error()) {
// have to look at the signature for this one
Symbol* constant_type = uncached_signature_ref_at(which);
return Signature::basic_type(constant_type);
}
return tag.basic_type();
}
// 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,
bool* status_return, TRAPS) {
oop result_oop = nullptr;
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.
// FIXME: If bootstrap specifiers stress this code, consider putting in
// a reverse index. Binary search over a short array should do it.
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_reference_at(cache_index);
if (result_oop != nullptr) {
if (result_oop == Universe::the_null_sentinel()) {
DEBUG_ONLY(int temp_index = (index >= 0 ? index : this_cp->object_to_cp_index(cache_index)));
assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
result_oop = nullptr;
}
if (status_return != nullptr) (*status_return) = true;
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);
if (status_return != nullptr) {
// don't trigger resolution if the constant might need it
switch (tag.value()) {
case JVM_CONSTANT_Class:
{
CPKlassSlot kslot = this_cp->klass_slot_at(index);
int resolved_klass_index = kslot.resolved_klass_index();
if (this_cp->resolved_klasses()->at(resolved_klass_index) == nullptr) {
(*status_return) = false;
return nullptr;
}
// the klass is waiting in the CP; go get it
break;
}
case JVM_CONSTANT_String:
case JVM_CONSTANT_Integer:
case JVM_CONSTANT_Float:
case JVM_CONSTANT_Long:
case JVM_CONSTANT_Double:
// these guys trigger OOM at worst
break;
default:
(*status_return) = false;
return nullptr;
}
// from now on there is either success or an OOME
(*status_return) = true;
}
switch (tag.value()) {
case JVM_CONSTANT_UnresolvedClass:
case JVM_CONSTANT_Class:
{
assert(cache_index == _no_index_sentinel, "should not have been set");
Klass* resolved = klass_at_impl(this_cp, index, CHECK_NULL);
// ldc wants the java mirror.
result_oop = resolved->java_mirror();
break;
}
case JVM_CONSTANT_Dynamic:
{
// Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
BootstrapInfo bootstrap_specifier(this_cp, index);
// The initial step in resolving an unresolved symbolic reference to a
// dynamically-computed constant is to resolve the symbolic reference to a
// method handle which will be the bootstrap method for the dynamically-computed
// constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
// method fails, then a MethodHandleInError is stored at the corresponding
// bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
// set a DynamicConstantInError here since any subsequent use of this
// bootstrap method will encounter the resolution of MethodHandleInError.
// Both the first, (resolution of the BSM and its static arguments), and the second tasks,
// (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
// for the bootstrap_specifier created above.
SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
if (HAS_PENDING_EXCEPTION) {
// Resolution failure of the dynamically-computed constant, save_and_throw_exception
// will check for a LinkageError and store a DynamicConstantInError.
save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
}
result_oop = bootstrap_specifier.resolved_value()();
BasicType type = Signature::basic_type(bootstrap_specifier.signature());
if (!is_reference_type(type)) {
// Make sure the primitive value is properly boxed.
// This is a JDK responsibility.
const char* fail = nullptr;
if (result_oop == nullptr) {
fail = "null result instead of box";
} else if (!is_java_primitive(type)) {
// FIXME: support value types via unboxing
fail = "can only handle references and primitives";
} else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
fail = "primitive is not properly boxed";
}
if (fail != nullptr) {
// Since this exception is not a LinkageError, throw exception
// but do not save a DynamicInError resolution result.
// See section 5.4.3 of the VM spec.
THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
}
}
LogTarget(Debug, methodhandles, condy) lt_condy;
if (lt_condy.is_enabled()) {
LogStream ls(lt_condy);
bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
}
break;
}
case JVM_CONSTANT_String:
assert(cache_index != _no_index_sentinel, "should have been set");
result_oop = string_at_impl(this_cp, index, cache_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, THREAD);
if (HAS_PENDING_EXCEPTION) {
save_and_throw_exception(this_cp, index, tag, 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);
stringStream ss;
ss.print("Inconsistent constant pool data in classfile for class %s. "
"Method '", callee->name()->as_C_string());
signature->print_as_signature_external_return_type(&ss);
ss.print(" %s(", name->as_C_string());
signature->print_as_signature_external_parameters(&ss);
ss.print(")' at index %d is %s and should be %s",
index,
callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
}
Klass* klass = this_cp->pool_holder();
HandleMark hm(THREAD);
Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
callee, name, signature,
THREAD);
if (HAS_PENDING_EXCEPTION) {
save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
}
result_oop = value();
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();
HandleMark hm(THREAD);
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;
case JVM_CONSTANT_UnresolvedClassInError:
case JVM_CONSTANT_DynamicInError:
case JVM_CONSTANT_MethodHandleInError:
case JVM_CONSTANT_MethodTypeInError:
throw_resolution_error(this_cp, index, CHECK_NULL);
break;
default:
fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), index, cache_index, tag.value());
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 new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
if (old_result == nullptr) {
return result_oop; // was installed
} else {
// Return the winning thread's result. This can be different than
// the result here for MethodHandles.
if (old_result == Universe::the_null_sentinel())
old_result = nullptr;
return old_result;
}
} else {
assert(result_oop != Universe::the_null_sentinel(), "");
return result_oop;
}
}
oop ConstantPool::uncached_string_at(int which, TRAPS) {
Symbol* sym = unresolved_string_at(which);
oop str = StringTable::intern(sym, CHECK_(nullptr));
assert(java_lang_String::is_instance(str), "must be string");
return str;
}
void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
int start_arg, int end_arg,
objArrayHandle info, int pos,
bool must_resolve, Handle if_not_available,
TRAPS) {
int limit = pos + end_arg - start_arg;
// checks: index in range [0..this_cp->length),
// tag at index, start..end in range [0..this_cp->bootstrap_argument_count],
// info array non-null, pos..limit in [0..info.length]
if ((0 >= index || index >= this_cp->length()) ||
!(this_cp->tag_at(index).is_invoke_dynamic() ||
this_cp->tag_at(index).is_dynamic_constant()) ||
(0 > start_arg || start_arg > end_arg) ||
(end_arg > this_cp->bootstrap_argument_count_at(index)) ||
(0 > pos || pos > limit) ||
(info.is_null() || limit > info->length())) {
// An index or something else went wrong; throw an error.
// Since this is an internal API, we don't expect this,
// so we don't bother to craft a nice message.
THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
}
// now we can loop safely
int info_i = pos;
for (int i = start_arg; i < end_arg; i++) {
int arg_index = this_cp->bootstrap_argument_index_at(index, i);
oop arg_oop;
if (must_resolve) {
arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
} else {
bool found_it = false;
arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
if (!found_it) arg_oop = if_not_available();
}
info->obj_at_put(info_i++, arg_oop);
}
}
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_reference_at(obj_index);
assert(str != Universe::the_null_sentinel(), "");
if (str != nullptr) return str;
Symbol* sym = this_cp->unresolved_string_at(which);
str = StringTable::intern(sym, CHECK_(nullptr));
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) {
// 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 = resolved_klass_at(index1);
Klass* k2 = cp2->resolved_klass_at(index2);
if (k1 == k2) {
return true;
}
} break;
case JVM_CONSTANT_ClassIndex:
{
int recur1 = klass_index_at(index1);
int recur2 = cp2->klass_index_at(index2);
if (compare_entry_to(recur1, cp2, recur2)) {
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);
if (match) {
recur1 = uncached_name_and_type_ref_index_at(index1);
recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
if (compare_entry_to(recur1, cp2, recur2)) {
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);
if (compare_entry_to(recur1, cp2, recur2)) {
recur1 = signature_ref_index_at(index1);
recur2 = cp2->signature_ref_index_at(index2);
if (compare_entry_to(recur1, cp2, recur2)) {
return true;
}
}
} break;
case JVM_CONSTANT_StringIndex:
{
int recur1 = string_index_at(index1);
int recur2 = cp2->string_index_at(index2);
if (compare_entry_to(recur1, cp2, recur2)) {
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);
if (compare_entry_to(k1, cp2, k2)) {
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);
if (compare_entry_to(i1, cp2, i2)) {
return true;
}
}
} break;
case JVM_CONSTANT_Dynamic:
{
int k1 = bootstrap_name_and_type_ref_index_at(index1);
int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
int i1 = bootstrap_methods_attribute_index(index1);
int i2 = cp2->bootstrap_methods_attribute_index(index2);
bool match_entry = compare_entry_to(k1, cp2, k2);
bool match_operand = compare_operand_to(i1, cp2, i2);
return (match_entry && match_operand);
} break;
case JVM_CONSTANT_InvokeDynamic:
{
int k1 = bootstrap_name_and_type_ref_index_at(index1);
int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
int i1 = bootstrap_methods_attribute_index(index1);
int i2 = cp2->bootstrap_methods_attribute_index(index2);
bool match_entry = compare_entry_to(k1, cp2, k2);
bool match_operand = compare_operand_to(i1, cp2, i2);
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<u2>* new_ops = MetadataFactory::new_array<u2>(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() != nullptr) { // the safety check
MetadataFactory::free_array<u2>(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<u2>* new_ops = MetadataFactory::new_array<u2>(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<u2>* new_ops = MetadataFactory::new_array<u2>(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<u2>* new_operands = MetadataFactory::new_array<u2>(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);
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) {
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_Dynamic:
case JVM_CONSTANT_DynamicInError:
{
int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
to_cp->dynamic_constant_at_put(to_i, k1, k2);
} break;
case JVM_CONSTANT_InvokeDynamic:
{
int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
int k2 = from_cp->bootstrap_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) {
// 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);
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) {
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);
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);
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 data at pattern_i index.
// Return the index of a matching bootstrap attribute record or (-1) if there is no match.
int ConstantPool::find_matching_operand(int pattern_i,
const constantPoolHandle& search_cp, int search_len) {
for (int i = 0; i < search_len; i++) {
bool found = compare_operand_to(pattern_i, search_cp, i);
if (found) {
return i;
}
}
return -1; // bootstrap specifier data 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_Dynamic:
case JVM_CONSTANT_DynamicInError:
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 */
// SymbolHash is used to find a constant pool index from a string.
// This function fills in SymbolHashs, one for utf8s and one for
// class names, returns size of the cpool raw bytes.
jint ConstantPool::hash_entries_to(SymbolHash *symmap,
SymbolHash *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_if_absent(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_if_absent(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,
SymbolHash* 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, ", (short)idx, (short)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 = checked_cast<u2>(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 = checked_cast<u2>(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 = checked_cast<u2>(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 = checked_cast<u2>(method_type_index_at(idx));
Bytes::put_Java_u2((address) (bytes+1), idx1);
DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
break;
}
case JVM_CONSTANT_Dynamic:
case JVM_CONSTANT_DynamicInError: {
*bytes = tag;
idx1 = extract_low_short_from_int(*int_at_addr(idx));
idx2 = extract_high_short_from_int(*int_at_addr(idx));
assert(idx2 == bootstrap_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_Dynamic: %hd %hd", idx1, idx2));
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 == bootstrap_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 temporarily for debugging until it's stable.
DBG(print_cpool_bytes(cnt, start_bytes));
return (int)(bytes - start_bytes);
} /* end copy_cpool_bytes */
#undef DBG
bool ConstantPool::is_maybe_on_stack() const {
// This method uses the similar logic as nmethod::is_maybe_on_stack()
if (!Continuations::enabled()) {
return false;
}
// If the condition below is true, it means that the nmethod was found to
// be alive the previous completed marking cycle.
return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
}
// For redefinition, if any methods found in loom stack chunks, the gc_epoch is
// recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
// memory for the method is reclaimed.
bool ConstantPool::on_stack() const {
if ((_flags &_on_stack) != 0) {
return true;
}
if (_cache == nullptr) {
return false;
}
return is_maybe_on_stack();
}
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 &= (u2)(~_on_stack);
}
}
}
// 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() != nullptr) {
st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
}
st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
st->print_cr(" - cp length: %d", length());
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 != nullptr, "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 :
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");
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_Dynamic :
case JVM_CONSTANT_DynamicInError :
{
st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(index));
st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(index));
int argc = bootstrap_argument_count_at(index);
if (argc > 0) {
for (int arg_i = 0; arg_i < argc; arg_i++) {
int arg = bootstrap_argument_index_at(index, arg_i);
st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
}
st->print("}");
}
}
break;
case JVM_CONSTANT_InvokeDynamic :
{
st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(index));
st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(index));
int argc = bootstrap_argument_count_at(index);
if (argc > 0) {
for (int arg_i = 0; arg_i < argc; arg_i++) {
int arg = bootstrap_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() != nullptr) st->print("/operands[%d]", operands()->length());
print_address_on(st);
if (pool_holder() != nullptr) {
st->print(" for ");
pool_holder()->print_value_on(st);
bool extra = (pool_holder()->constants() != this);
if (extra) st->print(" (extra)");
}
if (cache() != nullptr) {
st->print(" cache=" PTR_FORMAT, p2i(cache()));
}
}
// 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()) {
Symbol* entry = symbol_at(i);
guarantee(entry->refcount() != 0, "should have nonzero reference count");
} else if (tag.is_string()) {
Symbol* entry = unresolved_string_at(i);
guarantee(entry->refcount() != 0, "should have nonzero reference count");
}
}
if (pool_holder() != nullptr) {
// Note: pool_holder() can be null in temporary constant pools
// used during constant pool merging
guarantee(pool_holder()->is_klass(), "should be klass");
}
}