jdk

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/*
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 * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#include "cds/cdsConfig.hpp"
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#include "cds/metaspaceShared.hpp"
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#include "classfile/vmClasses.hpp"
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#include "interpreter/bytecodes.hpp"
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#include "interpreter/bytecodeStream.hpp"
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#include "interpreter/interpreter.hpp"
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#include "interpreter/rewriter.hpp"
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#include "memory/metadataFactory.hpp"
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#include "memory/resourceArea.hpp"
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#include "oops/generateOopMap.hpp"
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#include "oops/resolvedFieldEntry.hpp"
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#include "oops/resolvedIndyEntry.hpp"
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#include "oops/resolvedMethodEntry.hpp"
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#include "prims/methodHandles.hpp"
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#include "runtime/fieldDescriptor.inline.hpp"
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#include "runtime/handles.inline.hpp"
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#include "utilities/checkedCast.hpp"
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// Computes a CPC map (new_index -> original_index) for constant pool entries
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// that are referred to by the interpreter at runtime via the constant pool cache.
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// Also computes a CP map (original_index -> new_index).
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// Marks entries in CP which require additional processing.
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void Rewriter::compute_index_maps() {
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  const int length  = _pool->length();
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  init_maps(length);
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  bool saw_mh_symbol = false;
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  for (int i = 0; i < length; i++) {
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    int tag = _pool->tag_at(i).value();
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    switch (tag) {
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      case JVM_CONSTANT_Fieldref          :
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        _cp_map.at_put(i, _field_entry_index);
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        _field_entry_index++;
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        _initialized_field_entries.push(ResolvedFieldEntry((u2)i));
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        break;
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      case JVM_CONSTANT_InterfaceMethodref: // fall through
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      case JVM_CONSTANT_Methodref         :
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        _cp_map.at_put(i, _method_entry_index);
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        _method_entry_index++;
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        _initialized_method_entries.push(ResolvedMethodEntry((u2)i));
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        break;
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      case JVM_CONSTANT_Dynamic:
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        assert(_pool->has_dynamic_constant(), "constant pool's _has_dynamic_constant flag not set");
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        add_resolved_references_entry(i);
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        break;
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      case JVM_CONSTANT_String            : // fall through
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      case JVM_CONSTANT_MethodHandle      : // fall through
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      case JVM_CONSTANT_MethodType        : // fall through
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        add_resolved_references_entry(i);
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        break;
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      case JVM_CONSTANT_Utf8:
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        if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle() ||
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            _pool->symbol_at(i) == vmSymbols::java_lang_invoke_VarHandle()) {
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          saw_mh_symbol = true;
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        }
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        break;
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    }
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  }
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  // Record limits of resolved reference map for constant pool cache indices
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  record_map_limits();
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  guarantee(_initialized_field_entries.length() - 1 <= (int)((u2)-1), "All resolved field indices fit in a u2");
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  guarantee(_initialized_method_entries.length() - 1 <= (int)((u2)-1), "All resolved method indices fit in a u2");
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  if (saw_mh_symbol) {
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    _method_handle_invokers.at_grow(length, 0);
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  }
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}
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// Unrewrite the bytecodes if an error occurs.
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void Rewriter::restore_bytecodes(Thread* thread) {
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  int len = _methods->length();
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  bool invokespecial_error = false;
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  for (int i = len-1; i >= 0; i--) {
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    Method* method = _methods->at(i);
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    scan_method(thread, method, true, &invokespecial_error);
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    assert(!invokespecial_error, "reversing should not get an invokespecial error");
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  }
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}
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// Creates a constant pool cache given a CPC map
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void Rewriter::make_constant_pool_cache(TRAPS) {
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  ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data();
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  assert(_field_entry_index == _initialized_field_entries.length(), "Field entry size mismatch");
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  assert(_method_entry_index == _initialized_method_entries.length(), "Method entry size mismatch");
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  ConstantPoolCache* cache =
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      ConstantPoolCache::allocate(loader_data, _invokedynamic_references_map,
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                                  _initialized_indy_entries, _initialized_field_entries, _initialized_method_entries,
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                                  CHECK);
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  // initialize object cache in constant pool
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  _pool->set_cache(cache);
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  cache->set_constant_pool(_pool());
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  // _resolved_references is stored in pool->cache(), so need to be done after
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  // the above lines.
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  _pool->initialize_resolved_references(loader_data, _resolved_references_map,
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                                        _resolved_reference_limit,
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                                        THREAD);
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#if INCLUDE_CDS
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  if (!HAS_PENDING_EXCEPTION && CDSConfig::is_dumping_archive()) {
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    if (_pool->pool_holder()->is_shared()) {
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      assert(CDSConfig::is_dumping_dynamic_archive(), "must be");
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      // We are linking a shared class from the base archive. This
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      // class won't be written into the dynamic archive, so there's no
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      // need to save its CpCaches.
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    }
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  }
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#endif
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  // Clean up constant pool cache if initialize_resolved_references() failed.
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  if (HAS_PENDING_EXCEPTION) {
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    MetadataFactory::free_metadata(loader_data, cache);
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    _pool->set_cache(nullptr);  // so the verifier isn't confused
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  }
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}
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// The new finalization semantics says that registration of
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// finalizable objects must be performed on successful return from the
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// Object.<init> constructor.  We could implement this trivially if
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// <init> were never rewritten but since JVMTI allows this to occur, a
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// more complicated solution is required.  A special return bytecode
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// is used only by Object.<init> to signal the finalization
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// registration point.  Additionally local 0 must be preserved so it's
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// available to pass to the registration function.  For simplicity we
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// require that local 0 is never overwritten so it's available as an
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// argument for registration.
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void Rewriter::rewrite_Object_init(const methodHandle& method, TRAPS) {
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  RawBytecodeStream bcs(method);
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  while (!bcs.is_last_bytecode()) {
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    Bytecodes::Code opcode = bcs.raw_next();
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    switch (opcode) {
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      case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
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      case Bytecodes::_istore:
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      case Bytecodes::_lstore:
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      case Bytecodes::_fstore:
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      case Bytecodes::_dstore:
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      case Bytecodes::_astore:
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        if (bcs.get_index() != 0) continue;
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        // fall through
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      case Bytecodes::_istore_0:
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      case Bytecodes::_lstore_0:
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      case Bytecodes::_fstore_0:
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      case Bytecodes::_dstore_0:
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      case Bytecodes::_astore_0:
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        THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
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                  "can't overwrite local 0 in Object.<init>");
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        break;
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      default:
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        break;
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    }
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  }
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}
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187

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void Rewriter::rewrite_field_reference(address bcp, int offset, bool reverse) {
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  address p = bcp + offset;
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  if (!reverse) {
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    int cp_index = Bytes::get_Java_u2(p);
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    int field_entry_index = _cp_map.at(cp_index);
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    Bytes::put_native_u2(p, checked_cast<u2>(field_entry_index));
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  } else {
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    int field_entry_index = Bytes::get_native_u2(p);
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    int pool_index = _initialized_field_entries.at(field_entry_index).constant_pool_index();
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    Bytes::put_Java_u2(p, checked_cast<u2>(pool_index));
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  }
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}
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void Rewriter::rewrite_method_reference(address bcp, int offset, bool reverse) {
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  address p = bcp + offset;
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  if (!reverse) {
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    int  cp_index    = Bytes::get_Java_u2(p);
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    int  method_entry_index = _cp_map.at(cp_index);
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    Bytes::put_native_u2(p, (u2)method_entry_index);
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    if (!_method_handle_invokers.is_empty()) {
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      maybe_rewrite_invokehandle(p - 1, cp_index, method_entry_index, reverse);
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    }
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  } else {
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    int method_entry_index = Bytes::get_native_u2(p);
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    int pool_index = _initialized_method_entries.at(method_entry_index).constant_pool_index();
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    Bytes::put_Java_u2(p, (u2)pool_index);
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    if (!_method_handle_invokers.is_empty()) {
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      maybe_rewrite_invokehandle(p - 1, pool_index, method_entry_index, reverse);
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    }
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  }
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}
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// If the constant pool entry for invokespecial is InterfaceMethodref,
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// we need to add a separate cpCache entry for its resolution, because it is
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// different than the resolution for invokeinterface with InterfaceMethodref.
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// These cannot share cpCache entries.
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void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) {
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  address p = bcp + offset;
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  if (!reverse) {
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    int cp_index = Bytes::get_Java_u2(p);
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    if (_pool->tag_at(cp_index).is_interface_method()) {
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      _initialized_method_entries.push(ResolvedMethodEntry((u2)cp_index));
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      Bytes::put_native_u2(p, (u2)_method_entry_index);
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      _method_entry_index++;
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      if (_method_entry_index != (int)(u2)_method_entry_index) {
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        *invokespecial_error = true;
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      }
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    } else {
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      rewrite_method_reference(bcp, offset, reverse);
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    }
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  } else {
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    rewrite_method_reference(bcp, offset, reverse);
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  }
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}
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// Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.)
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void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) {
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  if (!reverse) {
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    if ((*opc) == (u1)Bytecodes::_invokevirtual ||
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        // allow invokespecial as an alias, although it would be very odd:
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        ((*opc) == (u1)Bytecodes::_invokespecial)) {
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          assert(_pool->tag_at(cp_index).is_method(), "wrong index");
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      // Determine whether this is a signature-polymorphic method.
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      if (cp_index >= _method_handle_invokers.length())  return;
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      int status = _method_handle_invokers.at(cp_index);
253
      assert(status >= -1 && status <= 1, "oob tri-state");
254
      if (status == 0) {
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        if (_pool->uncached_klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() &&
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            MethodHandles::is_signature_polymorphic_name(vmClasses::MethodHandle_klass(),
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                                                         _pool->uncached_name_ref_at(cp_index))) {
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          // we may need a resolved_refs entry for the appendix
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          int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, cache_index);
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          _initialized_method_entries.at(cache_index).set_resolved_references_index((u2)resolved_index);
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          status = +1;
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        } else if (_pool->uncached_klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_VarHandle() &&
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                   MethodHandles::is_signature_polymorphic_name(vmClasses::VarHandle_klass(),
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                                                                _pool->uncached_name_ref_at(cp_index))) {
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          // we may need a resolved_refs entry for the appendix
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          int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, cache_index);
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          _initialized_method_entries.at(cache_index).set_resolved_references_index((u2)resolved_index);
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          status = +1;
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        } else {
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          status = -1;
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        }
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        _method_handle_invokers.at(cp_index) = status;
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      }
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      // We use a special internal bytecode for such methods (if non-static).
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      // The basic reason for this is that such methods need an extra "appendix" argument
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      // to transmit the call site's intended call type.
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      if (status > 0) {
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        (*opc) = (u1)Bytecodes::_invokehandle;
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      }
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    }
281
  } else {
282
    // Do not need to look at cp_index.
283
    if ((*opc) == (u1)Bytecodes::_invokehandle) {
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      (*opc) = (u1)Bytecodes::_invokevirtual;
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      // Ignore corner case of original _invokespecial instruction.
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      // This is safe because (a) the signature polymorphic method was final, and
287
      // (b) the implementation of MethodHandle will not call invokespecial on it.
288
    }
289
  }
290
}
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292

293
void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
294
  address p = bcp + offset;
295
  assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
296
  if (!reverse) {
297
    int cp_index = Bytes::get_Java_u2(p);
298
    int resolved_index = add_invokedynamic_resolved_references_entry(cp_index, -1); // Indy no longer has a CPCE
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    // Replace the trailing four bytes with an index to the array of
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    // indy resolution information in the CPC. There is one entry for
301
    // each bytecode, even if they make the same call. In other words,
302
    // the CPC-to-CP relation is many-to-one for invokedynamic entries.
303
    // This means we must use a larger index size than u2 to address
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    // all these entries.  That is the main reason invokedynamic
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    // must have a five-byte instruction format.  (Of course, other JVM
306
    // implementations can use the bytes for other purposes.)
307
    // Note: We use native_u4 format exclusively for 4-byte indexes.
308
    Bytes::put_native_u4(p, (u2)_invokedynamic_index);
309
    _invokedynamic_index++;
310

311
    // Collect invokedynamic information before creating ResolvedInvokeDynamicInfo array
312
    _initialized_indy_entries.push(ResolvedIndyEntry((u2)resolved_index, (u2)cp_index));
313
  } else {
314
    // Should do nothing since we are not patching this bytecode
315
    int cache_index = Bytes::get_native_u4(p);
316
    int cp_index = _initialized_indy_entries.at(cache_index).constant_pool_index();
317
    assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index");
318
    // zero out 4 bytes
319
    Bytes::put_Java_u4(p, 0);
320
    Bytes::put_Java_u2(p, (u2)cp_index);
321
  }
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}
323

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// Rewrite some ldc bytecodes to _fast_aldc
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void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide,
326
                                 bool reverse) {
327
  if (!reverse) {
328
    assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode");
329
    address p = bcp + offset;
330
    int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p);
331
    constantTag tag = _pool->tag_at(cp_index).value();
332

333
    if (tag.is_method_handle() ||
334
        tag.is_method_type() ||
335
        tag.is_string() ||
336
        (tag.is_dynamic_constant() &&
337
         // keep regular ldc interpreter logic for condy primitives
338
         is_reference_type(Signature::basic_type(_pool->uncached_signature_ref_at(cp_index))))
339
        ) {
340
      int ref_index = cp_entry_to_resolved_references(cp_index);
341
      if (is_wide) {
342
        (*bcp) = Bytecodes::_fast_aldc_w;
343
        assert(ref_index == (u2)ref_index, "index overflow");
344
        Bytes::put_native_u2(p, (u2)ref_index);
345
      } else {
346
        (*bcp) = Bytecodes::_fast_aldc;
347
        assert(ref_index == (u1)ref_index, "index overflow");
348
        (*p) = (u1)ref_index;
349
      }
350
    }
351
  } else {
352
    Bytecodes::Code rewritten_bc =
353
              (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
354
    if ((*bcp) == rewritten_bc) {
355
      address p = bcp + offset;
356
      int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
357
      int pool_index = resolved_references_entry_to_pool_index(ref_index);
358
      if (is_wide) {
359
        (*bcp) = Bytecodes::_ldc_w;
360
        assert(pool_index == (u2)pool_index, "index overflow");
361
        Bytes::put_Java_u2(p, (u2)pool_index);
362
      } else {
363
        (*bcp) = Bytecodes::_ldc;
364
        assert(pool_index == (u1)pool_index, "index overflow");
365
        (*p) = (u1)pool_index;
366
      }
367
    }
368
  }
369
}
370

371

372
// Rewrites a method given the index_map information
373
void Rewriter::scan_method(Thread* thread, Method* method, bool reverse, bool* invokespecial_error) {
374

375
  int nof_jsrs = 0;
376
  bool has_monitor_bytecodes = false;
377
  Bytecodes::Code c;
378

379
  // Bytecodes and their length
380
  const address code_base = method->code_base();
381
  const int code_length = method->code_size();
382

383
  int bc_length;
384
  for (int bci = 0; bci < code_length; bci += bc_length) {
385
    address bcp = code_base + bci;
386
    int prefix_length = 0;
387
    c = (Bytecodes::Code)(*bcp);
388

389
    // Since we have the code, see if we can get the length
390
    // directly. Some more complicated bytecodes will report
391
    // a length of zero, meaning we need to make another method
392
    // call to calculate the length.
393
    bc_length = Bytecodes::length_for(c);
394
    if (bc_length == 0) {
395
      bc_length = Bytecodes::length_at(method, bcp);
396

397
      // length_at will put us at the bytecode after the one modified
398
      // by 'wide'. We don't currently examine any of the bytecodes
399
      // modified by wide, but in case we do in the future...
400
      if (c == Bytecodes::_wide) {
401
        prefix_length = 1;
402
        c = (Bytecodes::Code)bcp[1];
403
      }
404
    }
405

406
    // Continuing with an invalid bytecode will fail in the loop below.
407
    // So guarantee here.
408
    guarantee(bc_length > 0, "Verifier should have caught this invalid bytecode");
409

410
    switch (c) {
411
      case Bytecodes::_lookupswitch   : {
412
#ifndef ZERO
413
        Bytecode_lookupswitch bc(method, bcp);
414
        (*bcp) = (
415
          bc.number_of_pairs() < BinarySwitchThreshold
416
          ? Bytecodes::_fast_linearswitch
417
          : Bytecodes::_fast_binaryswitch
418
        );
419
#endif
420
        break;
421
      }
422
      case Bytecodes::_fast_linearswitch:
423
      case Bytecodes::_fast_binaryswitch: {
424
#ifndef ZERO
425
        (*bcp) = Bytecodes::_lookupswitch;
426
#endif
427
        break;
428
      }
429

430
      case Bytecodes::_invokespecial  : {
431
        rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error);
432
        break;
433
      }
434

435
      case Bytecodes::_putstatic      :
436
      case Bytecodes::_putfield       : {
437
        if (!reverse) {
438
          // Check if any final field of the class given as parameter is modified
439
          // outside of initializer methods of the class. Fields that are modified
440
          // are marked with a flag. For marked fields, the compilers do not perform
441
          // constant folding (as the field can be changed after initialization).
442
          //
443
          // The check is performed after verification and only if verification has
444
          // succeeded. Therefore, the class is guaranteed to be well-formed.
445
          InstanceKlass* klass = method->method_holder();
446
          u2 bc_index = Bytes::get_Java_u2(bcp + prefix_length + 1);
447
          constantPoolHandle cp(thread, method->constants());
448
          Symbol* ref_class_name = cp->klass_name_at(cp->uncached_klass_ref_index_at(bc_index));
449

450
          if (klass->name() == ref_class_name) {
451
            Symbol* field_name = cp->uncached_name_ref_at(bc_index);
452
            Symbol* field_sig = cp->uncached_signature_ref_at(bc_index);
453

454
            fieldDescriptor fd;
455
            if (klass->find_field(field_name, field_sig, &fd) != nullptr) {
456
              if (fd.access_flags().is_final()) {
457
                if (fd.access_flags().is_static()) {
458
                  if (!method->is_static_initializer()) {
459
                    fd.set_has_initialized_final_update(true);
460
                  }
461
                } else {
462
                  if (!method->is_object_initializer()) {
463
                    fd.set_has_initialized_final_update(true);
464
                  }
465
                }
466
              }
467
            }
468
          }
469
        }
470
      }
471
      // fall through
472
      case Bytecodes::_getstatic      : // fall through
473
      case Bytecodes::_getfield       : // fall through
474
        rewrite_field_reference(bcp, prefix_length+1, reverse);
475
        break;
476
      case Bytecodes::_invokevirtual  : // fall through
477
      case Bytecodes::_invokestatic   :
478
      case Bytecodes::_invokeinterface:
479
      case Bytecodes::_invokehandle   : // if reverse=true
480
        rewrite_method_reference(bcp, prefix_length+1, reverse);
481
        break;
482
      case Bytecodes::_invokedynamic:
483
        rewrite_invokedynamic(bcp, prefix_length+1, reverse);
484
        break;
485
      case Bytecodes::_ldc:
486
      case Bytecodes::_fast_aldc:  // if reverse=true
487
        maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
488
        break;
489
      case Bytecodes::_ldc_w:
490
      case Bytecodes::_fast_aldc_w:  // if reverse=true
491
        maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
492
        break;
493
      case Bytecodes::_jsr            : // fall through
494
      case Bytecodes::_jsr_w          : nof_jsrs++;                   break;
495
      case Bytecodes::_monitorenter   : // fall through
496
      case Bytecodes::_monitorexit    : has_monitor_bytecodes = true; break;
497

498
      default: break;
499
    }
500
  }
501

502
  // Update flags
503
  if (has_monitor_bytecodes) {
504
    method->set_has_monitor_bytecodes();
505
  }
506

507
  // The present of a jsr bytecode implies that the method might potentially
508
  // have to be rewritten, so we run the oopMapGenerator on the method
509
  if (nof_jsrs > 0) {
510
    method->set_has_jsrs();
511
  }
512
}
513

514
// After constant pool is created, revisit methods containing jsrs.
515
methodHandle Rewriter::rewrite_jsrs(const methodHandle& method, TRAPS) {
516
  ResourceMark rm(THREAD);
517
  ResolveOopMapConflicts romc(method);
518
  methodHandle new_method = romc.do_potential_rewrite(CHECK_(methodHandle()));
519
  // Update monitor matching info.
520
  if (romc.monitor_safe()) {
521
    new_method->set_guaranteed_monitor_matching();
522
  }
523

524
  return new_method;
525
}
526

527
void Rewriter::rewrite_bytecodes(TRAPS) {
528
  assert(_pool->cache() == nullptr, "constant pool cache must not be set yet");
529

530
  // determine index maps for Method* rewriting
531
  compute_index_maps();
532

533
  if (_klass->name() == vmSymbols::java_lang_Object()) {
534
    bool did_rewrite = false;
535
    int i = _methods->length();
536
    while (i-- > 0) {
537
      Method* method = _methods->at(i);
538
      if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
539
        // rewrite the return bytecodes of Object.<init> to register the
540
        // object for finalization if needed.
541
        methodHandle m(THREAD, method);
542
        rewrite_Object_init(m, CHECK);
543
        did_rewrite = true;
544
        break;
545
      }
546
    }
547
    assert(did_rewrite, "must find Object::<init> to rewrite it");
548
  }
549

550
  // rewrite methods, in two passes
551
  int len = _methods->length();
552
  bool invokespecial_error = false;
553

554
  for (int i = len-1; i >= 0; i--) {
555
    Method* method = _methods->at(i);
556
    scan_method(THREAD, method, false, &invokespecial_error);
557
    if (invokespecial_error) {
558
      // If you get an error here, there is no reversing bytecodes
559
      // This exception is stored for this class and no further attempt is
560
      // made at verifying or rewriting.
561
      THROW_MSG(vmSymbols::java_lang_InternalError(),
562
                "This classfile overflows invokespecial for interfaces "
563
                "and cannot be loaded");
564
      return;
565
     }
566
  }
567
}
568

569
void Rewriter::rewrite(InstanceKlass* klass, TRAPS) {
570
#if INCLUDE_CDS
571
  if (klass->is_shared()) {
572
    assert(!klass->is_rewritten(), "rewritten shared classes cannot be rewritten again");
573
  }
574
#endif // INCLUDE_CDS
575
  ResourceMark rm(THREAD);
576
  constantPoolHandle cpool(THREAD, klass->constants());
577
  Rewriter     rw(klass, cpool, klass->methods(), CHECK);
578
  // (That's all, folks.)
579
}
580

581
Rewriter::Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS)
582
  : _klass(klass),
583
    _pool(cpool),
584
    _methods(methods),
585
    _cp_map(cpool->length()),
586
    _reference_map(cpool->length()),
587
    _resolved_references_map(cpool->length() / 2),
588
    _invokedynamic_references_map(cpool->length() / 2),
589
    _method_handle_invokers(cpool->length()),
590
    _invokedynamic_index(0),
591
    _field_entry_index(0),
592
    _method_entry_index(0)
593
{
594

595
  // Rewrite bytecodes - exception here exits.
596
  rewrite_bytecodes(CHECK);
597

598
  // Stress restoring bytecodes
599
  if (StressRewriter) {
600
    restore_bytecodes(THREAD);
601
    rewrite_bytecodes(CHECK);
602
  }
603

604
  // allocate constant pool cache, now that we've seen all the bytecodes
605
  make_constant_pool_cache(THREAD);
606

607
  // Restore bytecodes to their unrewritten state if there are exceptions
608
  // rewriting bytecodes or allocating the cpCache
609
  if (HAS_PENDING_EXCEPTION) {
610
    restore_bytecodes(THREAD);
611
    return;
612
  }
613

614
  // Relocate after everything, but still do this under the is_rewritten flag,
615
  // so methods with jsrs in custom class lists in aren't attempted to be
616
  // rewritten in the RO section of the shared archive.
617
  // Relocated bytecodes don't have to be restored, only the cp cache entries
618
  int len = _methods->length();
619
  for (int i = len-1; i >= 0; i--) {
620
    methodHandle m(THREAD, _methods->at(i));
621

622
    if (m->has_jsrs()) {
623
      m = rewrite_jsrs(m, THREAD);
624
      // Restore bytecodes to their unrewritten state if there are exceptions
625
      // relocating bytecodes.  If some are relocated, that is ok because that
626
      // doesn't affect constant pool to cpCache rewriting.
627
      if (HAS_PENDING_EXCEPTION) {
628
        restore_bytecodes(THREAD);
629
        return;
630
      }
631
      // Method might have gotten rewritten.
632
      methods->at_put(i, m());
633
    }
634
  }
635
}
636