jdk

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/*
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 * Copyright (c) 2005, 2024, 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 "classfile/symbolTable.hpp"
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#include "interpreter/bytecodeStream.hpp"
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#include "memory/universe.hpp"
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#include "oops/constantPool.inline.hpp"
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#include "oops/fieldStreams.inline.hpp"
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#include "oops/instanceKlass.inline.hpp"
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#include "oops/recordComponent.hpp"
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#include "prims/jvmtiClassFileReconstituter.hpp"
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#include "runtime/handles.inline.hpp"
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#include "runtime/signature.hpp"
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#include "utilities/bytes.hpp"
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#include "utilities/checkedCast.hpp"
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// FIXME: add Deprecated attribute
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// FIXME: fix Synthetic attribute
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// FIXME: per Serguei, add error return handling for ConstantPool::copy_cpool_bytes()
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JvmtiConstantPoolReconstituter::JvmtiConstantPoolReconstituter(InstanceKlass* ik) {
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  set_error(JVMTI_ERROR_NONE);
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  _ik = ik;
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  _cpool = constantPoolHandle(Thread::current(), ik->constants());
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  _symmap = new ConstantPool::SymbolHash();
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  _classmap = new ConstantPool::SymbolHash();
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  _cpool_size = _cpool->hash_entries_to(_symmap, _classmap);
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  if (_cpool_size == 0) {
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    set_error(JVMTI_ERROR_OUT_OF_MEMORY);
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  } else if (_cpool_size < 0) {
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    set_error(JVMTI_ERROR_INTERNAL);
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  }
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}
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// Write the field information portion of ClassFile structure
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// JVMSpec|     u2 fields_count;
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// JVMSpec|     field_info fields[fields_count];
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void JvmtiClassFileReconstituter::write_field_infos() {
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  HandleMark hm(thread());
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  Array<AnnotationArray*>* fields_anno = ik()->fields_annotations();
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  Array<AnnotationArray*>* fields_type_anno = ik()->fields_type_annotations();
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  // Compute the real number of Java fields
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  int java_fields = ik()->java_fields_count();
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  write_u2(checked_cast<u2>(java_fields));
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  for (JavaFieldStream fs(ik()); !fs.done(); fs.next()) {
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    AccessFlags access_flags = fs.access_flags();
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    u2 name_index = fs.name_index();
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    u2 signature_index = fs.signature_index();
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    u2 initial_value_index = fs.initval_index();
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    guarantee(name_index != 0 && signature_index != 0, "bad constant pool index for field");
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    // int offset = ik()->field_offset( index );
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    u2 generic_signature_index = fs.generic_signature_index();
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    AnnotationArray* anno = fields_anno == nullptr ? nullptr : fields_anno->at(fs.index());
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    AnnotationArray* type_anno = fields_type_anno == nullptr ? nullptr : fields_type_anno->at(fs.index());
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    // JVMSpec|   field_info {
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    // JVMSpec|         u2 access_flags;
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    // JVMSpec|         u2 name_index;
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    // JVMSpec|         u2 descriptor_index;
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    // JVMSpec|         u2 attributes_count;
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    // JVMSpec|         attribute_info attributes[attributes_count];
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    // JVMSpec|   }
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    write_u2(access_flags.get_flags() & JVM_RECOGNIZED_FIELD_MODIFIERS);
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    write_u2(name_index);
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    write_u2(signature_index);
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    u2 attr_count = 0;
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    if (initial_value_index != 0) {
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      ++attr_count;
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    }
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    if (access_flags.is_synthetic()) {
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      // ++attr_count;
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    }
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    if (generic_signature_index != 0) {
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      ++attr_count;
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    }
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    if (anno != nullptr) {
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      ++attr_count;     // has RuntimeVisibleAnnotations attribute
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    }
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    if (type_anno != nullptr) {
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      ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
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    }
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    write_u2(attr_count);
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    if (initial_value_index != 0) {
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      write_attribute_name_index("ConstantValue");
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      write_u4(2); //length always 2
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      write_u2(initial_value_index);
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    }
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    if (access_flags.is_synthetic()) {
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      // write_synthetic_attribute();
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    }
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    if (generic_signature_index != 0) {
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      write_signature_attribute(generic_signature_index);
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    }
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    if (anno != nullptr) {
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      write_annotations_attribute("RuntimeVisibleAnnotations", anno);
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    }
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    if (type_anno != nullptr) {
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      write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
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    }
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  }
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}
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// Write Code attribute
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// JVMSpec|   Code_attribute {
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// JVMSpec|     u2 attribute_name_index;
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// JVMSpec|     u4 attribute_length;
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// JVMSpec|     u2 max_stack;
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// JVMSpec|     u2 max_locals;
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// JVMSpec|     u4 code_length;
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// JVMSpec|     u1 code[code_length];
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// JVMSpec|     u2 exception_table_length;
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// JVMSpec|     {       u2 start_pc;
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// JVMSpec|             u2 end_pc;
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// JVMSpec|             u2  handler_pc;
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// JVMSpec|             u2  catch_type;
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// JVMSpec|     }       exception_table[exception_table_length];
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// JVMSpec|     u2 attributes_count;
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// JVMSpec|     attribute_info attributes[attributes_count];
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// JVMSpec|   }
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void JvmtiClassFileReconstituter::write_code_attribute(const methodHandle& method) {
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  ConstMethod* const_method = method->constMethod();
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  u2 line_num_cnt = 0;
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  int stackmap_len = 0;
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  u2 local_variable_table_length = 0;
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  u2 local_variable_type_table_length = 0;
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  // compute number and length of attributes
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  u2 attr_count = 0;
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  int attr_size = 0;
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  if (const_method->has_linenumber_table()) {
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    line_num_cnt = line_number_table_entries(method);
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    if (line_num_cnt != 0) {
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      ++attr_count;
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      // Compute the complete size of the line number table attribute:
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      //      LineNumberTable_attribute {
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      //        u2 attribute_name_index;
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      //        u4 attribute_length;
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      //        u2 line_number_table_length;
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      //        {  u2 start_pc;
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      //           u2 line_number;
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      //        } line_number_table[line_number_table_length];
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      //      }
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      attr_size += 2 + 4 + 2 + line_num_cnt * (2 + 2);
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    }
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  }
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  if (method->has_stackmap_table()) {
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    stackmap_len = method->stackmap_data()->length();
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    if (stackmap_len != 0) {
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      ++attr_count;
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      // Compute the  size of the stack map table attribute (VM stores raw):
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      //      StackMapTable_attribute {
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      //        u2 attribute_name_index;
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      //        u4 attribute_length;
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      //        u2 number_of_entries;
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      //        stack_map_frame_entries[number_of_entries];
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      //      }
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      attr_size += 2 + 4 + stackmap_len;
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    }
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  }
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  if (method->has_localvariable_table()) {
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    local_variable_table_length = method->localvariable_table_length();
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    if (local_variable_table_length != 0) {
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      ++attr_count;
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      // Compute the size of the local variable table attribute (VM stores raw):
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      // LocalVariableTable_attribute {
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      //   u2 attribute_name_index;
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      //   u4 attribute_length;
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      //   u2 local_variable_table_length;
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      //   {
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      //     u2 start_pc;
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      //     u2 length;
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      //     u2 name_index;
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      //     u2 descriptor_index;
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      //     u2 index;
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      //   }
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      attr_size += 2 + 4 + 2 + local_variable_table_length * (2 + 2 + 2 + 2 + 2);
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      // Local variables with generic signatures must have LVTT entries
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      LocalVariableTableElement *elem = method->localvariable_table_start();
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      for (int idx = 0; idx < local_variable_table_length; idx++) {
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        if (elem[idx].signature_cp_index != 0) {
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          local_variable_type_table_length++;
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        }
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      }
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      if (local_variable_type_table_length != 0) {
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        ++attr_count;
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        // Compute the size of the local variable type table attribute (VM stores raw):
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        // LocalVariableTypeTable_attribute {
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        //   u2 attribute_name_index;
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        //   u4 attribute_length;
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        //   u2 local_variable_type_table_length;
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        //   {
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        //     u2 start_pc;
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        //     u2 length;
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        //     u2 name_index;
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        //     u2 signature_index;
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        //     u2 index;
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        //   }
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        attr_size += 2 + 4 + 2 + local_variable_type_table_length * (2 + 2 + 2 + 2 + 2);
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      }
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    }
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  }
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  ExceptionTable exception_table(method());
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  u2 exception_table_length = exception_table.length();
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  int code_size = const_method->code_size();
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  int size =
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    2+2+4 +                                // max_stack, max_locals, code_length
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    code_size +                            // code
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    2 +                                    // exception_table_length
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    (2+2+2+2) * exception_table_length +   // exception_table
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    2 +                                    // attributes_count
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    attr_size;                             // attributes
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  write_attribute_name_index("Code");
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  write_u4(size);
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  write_u2(method->verifier_max_stack());
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  write_u2(method->max_locals());
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  write_u4(code_size);
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  copy_bytecodes(method, (unsigned char*)writeable_address(code_size));
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  write_u2(exception_table_length);
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  for (int index = 0; index < exception_table_length; index++) {
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    write_u2(exception_table.start_pc(index));
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    write_u2(exception_table.end_pc(index));
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    write_u2(exception_table.handler_pc(index));
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    write_u2(exception_table.catch_type_index(index));
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  }
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  write_u2(attr_count);
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  if (line_num_cnt != 0) {
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    write_line_number_table_attribute(method, line_num_cnt);
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  }
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  if (stackmap_len != 0) {
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    write_stackmap_table_attribute(method, stackmap_len);
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  }
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  if (local_variable_table_length != 0) {
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    write_local_variable_table_attribute(method, local_variable_table_length);
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  }
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  if (local_variable_type_table_length != 0) {
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    write_local_variable_type_table_attribute(method, local_variable_type_table_length);
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  }
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}
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// Write Exceptions attribute
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// JVMSpec|   Exceptions_attribute {
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// JVMSpec|     u2 attribute_name_index;
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// JVMSpec|     u4 attribute_length;
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// JVMSpec|     u2 number_of_exceptions;
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// JVMSpec|     u2 exception_index_table[number_of_exceptions];
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// JVMSpec|   }
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void JvmtiClassFileReconstituter::write_exceptions_attribute(ConstMethod* const_method) {
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  CheckedExceptionElement* checked_exceptions = const_method->checked_exceptions_start();
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  u2 checked_exceptions_length = const_method->checked_exceptions_length();
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  int size =
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    2 +                                    // number_of_exceptions
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    2 * checked_exceptions_length;         // exception_index_table
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  write_attribute_name_index("Exceptions");
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  write_u4(size);
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  write_u2(checked_exceptions_length);
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  for (int index = 0; index < checked_exceptions_length; index++) {
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    write_u2(checked_exceptions[index].class_cp_index);
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  }
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}
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// Write MethodParameters attribute
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// JVMSpec|   MethodParameters_attribute {
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// JVMSpec|     u2 attribute_name_index;
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// JVMSpec|     u4 attribute_length;
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// JVMSpec|     u1 parameters_count;
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// JVMSpec|     {   u2 name_index;
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// JVMSpec|         u2 access_flags;
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// JVMSpec|     } parameters[parameters_count];
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// JVMSpec|   }
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void JvmtiClassFileReconstituter::write_method_parameter_attribute(const ConstMethod* const_method) {
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  const MethodParametersElement *parameters = const_method->method_parameters_start();
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  int length = const_method->method_parameters_length();
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  assert(length <= max_jubyte, "must fit u1");
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  int size = 1                  // parameters_count
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           + (2 + 2) * length;  // parameters
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  write_attribute_name_index("MethodParameters");
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  write_u4(size);
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  write_u1((u1)length);
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  for (int index = 0; index < length; index++) {
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    write_u2(parameters[index].name_cp_index);
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    write_u2(parameters[index].flags);
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  }
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}
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// Write SourceFile attribute
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// JVMSpec|   SourceFile_attribute {
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// JVMSpec|     u2 attribute_name_index;
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// JVMSpec|     u4 attribute_length;
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// JVMSpec|     u2 sourcefile_index;
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// JVMSpec|   }
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void JvmtiClassFileReconstituter::write_source_file_attribute() {
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  assert(ik()->source_file_name() != nullptr, "caller must check");
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  write_attribute_name_index("SourceFile");
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  write_u4(2);  // always length 2
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  write_u2(symbol_to_cpool_index(ik()->source_file_name()));
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}
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// Write SourceDebugExtension attribute
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// JSR45|   SourceDebugExtension_attribute {
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// JSR45|       u2 attribute_name_index;
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// JSR45|       u4 attribute_length;
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// JSR45|       u1 debug_extension[attribute_length];
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// JSR45|   }
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void JvmtiClassFileReconstituter::write_source_debug_extension_attribute() {
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  assert(ik()->source_debug_extension() != nullptr, "caller must check");
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  write_attribute_name_index("SourceDebugExtension");
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  int len = (int)strlen(ik()->source_debug_extension());
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  write_u4(len);
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  u1* ext = (u1*)ik()->source_debug_extension();
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  for (int i=0; i<len; i++) {
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    write_u1(ext[i]);
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  }
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}
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// Write (generic) Signature attribute
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// JVMSpec|   Signature_attribute {
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// JVMSpec|     u2 attribute_name_index;
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// JVMSpec|     u4 attribute_length;
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// JVMSpec|     u2 signature_index;
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// JVMSpec|   }
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void JvmtiClassFileReconstituter::write_signature_attribute(u2 generic_signature_index) {
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  write_attribute_name_index("Signature");
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  write_u4(2);  // always length 2
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  write_u2(generic_signature_index);
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}
361

362
// Compute the number of entries in the InnerClasses attribute
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u2 JvmtiClassFileReconstituter::inner_classes_attribute_length() {
364
  InnerClassesIterator iter(ik());
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  return checked_cast<u2>(iter.length());
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}
367

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// Write an annotation attribute.  The VM stores them in raw form, so all we need
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// to do is add the attribute name and fill in the length.
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// JSR202|   *Annotations_attribute {
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// JSR202|     u2 attribute_name_index;
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// JSR202|     u4 attribute_length;
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// JSR202|     ...
374
// JSR202|   }
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void JvmtiClassFileReconstituter::write_annotations_attribute(const char* attr_name,
376
                                                              AnnotationArray* annos) {
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  u4 length = annos->length();
378
  write_attribute_name_index(attr_name);
379
  write_u4(length);
380
  memcpy(writeable_address(length), annos->adr_at(0), length);
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}
382

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//  BootstrapMethods_attribute {
384
//    u2 attribute_name_index;
385
//    u4 attribute_length;
386
//    u2 num_bootstrap_methods;
387
//    {   u2 bootstrap_method_ref;
388
//        u2 num_bootstrap_arguments;
389
//        u2 bootstrap_arguments[num_bootstrap_arguments];
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//    } bootstrap_methods[num_bootstrap_methods];
391
//  }
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void JvmtiClassFileReconstituter::write_bootstrapmethod_attribute() {
393
  Array<u2>* operands = cpool()->operands();
394
  write_attribute_name_index("BootstrapMethods");
395
  int num_bootstrap_methods = ConstantPool::operand_array_length(operands);
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397
  // calculate length of attribute
398
  u4 length = sizeof(u2); // num_bootstrap_methods
399
  for (int n = 0; n < num_bootstrap_methods; n++) {
400
    u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);
401
    length += sizeof(u2); // bootstrap_method_ref
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    length += sizeof(u2); // num_bootstrap_arguments
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    length += (u4)sizeof(u2) * num_bootstrap_arguments; // bootstrap_arguments[num_bootstrap_arguments]
404
  }
405
  write_u4(length);
406

407
  // write attribute
408
  write_u2(checked_cast<u2>(num_bootstrap_methods));
409
  for (int n = 0; n < num_bootstrap_methods; n++) {
410
    u2 bootstrap_method_ref = cpool()->operand_bootstrap_method_ref_index_at(n);
411
    u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);
412
    write_u2(bootstrap_method_ref);
413
    write_u2(num_bootstrap_arguments);
414
    for (int arg = 0; arg < num_bootstrap_arguments; arg++) {
415
      u2 bootstrap_argument = cpool()->operand_argument_index_at(n, arg);
416
      write_u2(bootstrap_argument);
417
    }
418
  }
419
}
420

421
//  NestHost_attribute {
422
//    u2 attribute_name_index;
423
//    u4 attribute_length;
424
//    u2 host_class_index;
425
//  }
426
void JvmtiClassFileReconstituter::write_nest_host_attribute() {
427
  int length = sizeof(u2);
428
  u2 host_class_index = ik()->nest_host_index();
429

430
  write_attribute_name_index("NestHost");
431
  write_u4(length);
432
  write_u2(host_class_index);
433
}
434

435
//  NestMembers_attribute {
436
//    u2 attribute_name_index;
437
//    u4 attribute_length;
438
//    u2 number_of_classes;
439
//    u2 classes[number_of_classes];
440
//  }
441
void JvmtiClassFileReconstituter::write_nest_members_attribute() {
442
  Array<u2>* nest_members = ik()->nest_members();
443
  int number_of_classes = nest_members->length();
444
  int length = sizeof(u2) * (1 + number_of_classes);
445

446
  write_attribute_name_index("NestMembers");
447
  write_u4(length);
448
  write_u2(checked_cast<u2>(number_of_classes));
449
  for (int i = 0; i < number_of_classes; i++) {
450
    u2 class_cp_index = nest_members->at(i);
451
    write_u2(class_cp_index);
452
  }
453
}
454

455
//  PermittedSubclasses {
456
//    u2 attribute_name_index;
457
//    u4 attribute_length;
458
//    u2 number_of_classes;
459
//    u2 classes[number_of_classes];
460
//  }
461
void JvmtiClassFileReconstituter::write_permitted_subclasses_attribute() {
462
  Array<u2>* permitted_subclasses = ik()->permitted_subclasses();
463
  int number_of_classes = permitted_subclasses->length();
464
  int length = sizeof(u2) * (1 + number_of_classes); // '1 +' is for number_of_classes field
465

466
  write_attribute_name_index("PermittedSubclasses");
467
  write_u4(length);
468
  write_u2(checked_cast<u2>(number_of_classes));
469
  for (int i = 0; i < number_of_classes; i++) {
470
    u2 class_cp_index = permitted_subclasses->at(i);
471
    write_u2(class_cp_index);
472
  }
473
}
474

475
//  Record {
476
//    u2 attribute_name_index;
477
//    u4 attribute_length;
478
//    u2 components_count;
479
//    component_info components[components_count];
480
//  }
481
//  component_info {
482
//    u2 name_index;
483
//    u2 descriptor_index
484
//    u2 attributes_count;
485
//    attribute_info_attributes[attributes_count];
486
//  }
487
void JvmtiClassFileReconstituter::write_record_attribute() {
488
  Array<RecordComponent*>* components = ik()->record_components();
489
  int number_of_components = components->length();
490

491
  // Each component has a u2 for name, descr, attribute count
492
  u4 length = checked_cast<u4>(sizeof(u2) + (sizeof(u2) * 3 * number_of_components));
493
  for (int x = 0; x < number_of_components; x++) {
494
    RecordComponent* component = components->at(x);
495
    if (component->generic_signature_index() != 0) {
496
      length += 8; // Signature attribute size
497
    }
498
    if (component->annotations() != nullptr) {
499
      length += 6 + component->annotations()->length();
500
    }
501
    if (component->type_annotations() != nullptr) {
502
      length += 6 + component->type_annotations()->length();
503
    }
504
  }
505

506
  write_attribute_name_index("Record");
507
  write_u4(length);
508
  write_u2(checked_cast<u2>(number_of_components));
509
  for (int i = 0; i < number_of_components; i++) {
510
    RecordComponent* component = components->at(i);
511
    write_u2(component->name_index());
512
    write_u2(component->descriptor_index());
513
    u2 attributes_count = (component->generic_signature_index() != 0 ? 1 : 0)
514
                        + (component->annotations() != nullptr ? 1 : 0)
515
                        + (component->type_annotations() != nullptr ? 1 : 0);
516

517
    write_u2(attributes_count);
518
    if (component->generic_signature_index() != 0) {
519
      write_signature_attribute(component->generic_signature_index());
520
    }
521
    if (component->annotations() != nullptr) {
522
      write_annotations_attribute("RuntimeVisibleAnnotations", component->annotations());
523
    }
524
    if (component->type_annotations() != nullptr) {
525
      write_annotations_attribute("RuntimeVisibleTypeAnnotations", component->type_annotations());
526
    }
527
  }
528
}
529

530
// Write InnerClasses attribute
531
// JVMSpec|   InnerClasses_attribute {
532
// JVMSpec|     u2 attribute_name_index;
533
// JVMSpec|     u4 attribute_length;
534
// JVMSpec|     u2 number_of_classes;
535
// JVMSpec|     {  u2 inner_class_info_index;
536
// JVMSpec|        u2 outer_class_info_index;
537
// JVMSpec|        u2 inner_name_index;
538
// JVMSpec|        u2 inner_class_access_flags;
539
// JVMSpec|     } classes[number_of_classes];
540
// JVMSpec|   }
541
void JvmtiClassFileReconstituter::write_inner_classes_attribute(int length) {
542
  InnerClassesIterator iter(ik());
543
  guarantee(iter.length() != 0 && iter.length() == length,
544
            "caller must check");
545
  u2 entry_count = checked_cast<u2>(length / InstanceKlass::inner_class_next_offset);
546
  u4 size = 2 + entry_count * (2+2+2+2);
547

548
  write_attribute_name_index("InnerClasses");
549
  write_u4(size);
550
  write_u2(entry_count);
551
  for (; !iter.done(); iter.next()) {
552
    write_u2(iter.inner_class_info_index());
553
    write_u2(iter.outer_class_info_index());
554
    write_u2(iter.inner_name_index());
555
    write_u2(iter.inner_access_flags());
556
  }
557
}
558

559
// Write Synthetic attribute
560
// JVMSpec|   Synthetic_attribute {
561
// JVMSpec|     u2 attribute_name_index;
562
// JVMSpec|     u4 attribute_length;
563
// JVMSpec|   }
564
void JvmtiClassFileReconstituter::write_synthetic_attribute() {
565
  write_attribute_name_index("Synthetic");
566
  write_u4(0); //length always zero
567
}
568

569
// Compute size of LineNumberTable
570
u2 JvmtiClassFileReconstituter::line_number_table_entries(const methodHandle& method) {
571
  // The line number table is compressed so we don't know how big it is until decompressed.
572
  // Decompression is really fast so we just do it twice.
573
  u2 num_entries = 0;
574
  CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
575
  while (stream.read_pair()) {
576
    num_entries++;
577
  }
578
  return num_entries;
579
}
580

581
// Write LineNumberTable attribute
582
// JVMSpec|   LineNumberTable_attribute {
583
// JVMSpec|     u2 attribute_name_index;
584
// JVMSpec|     u4 attribute_length;
585
// JVMSpec|     u2 line_number_table_length;
586
// JVMSpec|     {  u2 start_pc;
587
// JVMSpec|        u2 line_number;
588
// JVMSpec|     } line_number_table[line_number_table_length];
589
// JVMSpec|   }
590
void JvmtiClassFileReconstituter::write_line_number_table_attribute(const methodHandle& method,
591
                                                                    u2 num_entries) {
592

593
  write_attribute_name_index("LineNumberTable");
594
  write_u4(2 + num_entries * (2 + 2));
595
  write_u2(num_entries);
596

597
  CompressedLineNumberReadStream stream(method->compressed_linenumber_table());
598
  while (stream.read_pair()) {
599
    write_u2(checked_cast<u2>(stream.bci()));
600
    write_u2(checked_cast<u2>(stream.line()));
601
  }
602
}
603

604
// Write LocalVariableTable attribute
605
// JVMSpec|   LocalVariableTable_attribute {
606
// JVMSpec|     u2 attribute_name_index;
607
// JVMSpec|     u4 attribute_length;
608
// JVMSpec|     u2 local_variable_table_length;
609
// JVMSpec|     {  u2 start_pc;
610
// JVMSpec|       u2 length;
611
// JVMSpec|       u2 name_index;
612
// JVMSpec|       u2 descriptor_index;
613
// JVMSpec|       u2 index;
614
// JVMSpec|     } local_variable_table[local_variable_table_length];
615
// JVMSpec|   }
616
void JvmtiClassFileReconstituter::write_local_variable_table_attribute(const methodHandle& method, u2 num_entries) {
617
    write_attribute_name_index("LocalVariableTable");
618
    write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));
619
    write_u2(num_entries);
620

621
    assert(method->localvariable_table_length() == num_entries, "just checking");
622

623
    LocalVariableTableElement *elem = method->localvariable_table_start();
624
    for (int j=0; j<method->localvariable_table_length(); j++) {
625
      write_u2(elem->start_bci);
626
      write_u2(elem->length);
627
      write_u2(elem->name_cp_index);
628
      write_u2(elem->descriptor_cp_index);
629
      write_u2(elem->slot);
630
      elem++;
631
    }
632
}
633

634
// Write LocalVariableTypeTable attribute
635
// JVMSpec|   LocalVariableTypeTable_attribute {
636
// JVMSpec|     u2 attribute_name_index;
637
// JVMSpec|     u4 attribute_length;
638
// JVMSpec|     u2 local_variable_type_table_length;
639
// JVMSpec|     { u2 start_pc;
640
// JVMSpec|       u2 length;
641
// JVMSpec|       u2 name_index;
642
// JVMSpec|       u2 signature_index;
643
// JVMSpec|       u2 index;
644
// JVMSpec|     } local_variable_type_table[local_variable_type_table_length];
645
// JVMSpec|   }
646
void JvmtiClassFileReconstituter::write_local_variable_type_table_attribute(const methodHandle& method, u2 num_entries) {
647
    write_attribute_name_index("LocalVariableTypeTable");
648
    write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));
649
    write_u2(num_entries);
650

651
    LocalVariableTableElement *elem = method->localvariable_table_start();
652
    for (int j=0; j<method->localvariable_table_length(); j++) {
653
      if (elem->signature_cp_index > 0) {
654
        // Local variable has a generic signature - write LVTT attribute entry
655
        write_u2(elem->start_bci);
656
        write_u2(elem->length);
657
        write_u2(elem->name_cp_index);
658
        write_u2(elem->signature_cp_index);
659
        write_u2(elem->slot);
660
        num_entries--;
661
      }
662
      elem++;
663
    }
664
    assert(num_entries == 0, "just checking");
665
}
666

667
// Write stack map table attribute
668
// JSR-202|   StackMapTable_attribute {
669
// JSR-202|     u2 attribute_name_index;
670
// JSR-202|     u4 attribute_length;
671
// JSR-202|     u2 number_of_entries;
672
// JSR-202|     stack_map_frame_entries[number_of_entries];
673
// JSR-202|   }
674
void JvmtiClassFileReconstituter::write_stackmap_table_attribute(const methodHandle& method,
675
                                                                 int stackmap_len) {
676

677
  write_attribute_name_index("StackMapTable");
678
  write_u4(stackmap_len);
679
  memcpy(
680
    writeable_address(stackmap_len),
681
    (void*)(method->stackmap_data()->adr_at(0)),
682
    stackmap_len);
683
}
684

685
// Write one method_info structure
686
// JVMSpec|   method_info {
687
// JVMSpec|     u2 access_flags;
688
// JVMSpec|     u2 name_index;
689
// JVMSpec|     u2 descriptor_index;
690
// JVMSpec|     u2 attributes_count;
691
// JVMSpec|     attribute_info attributes[attributes_count];
692
// JVMSpec|   }
693
void JvmtiClassFileReconstituter::write_method_info(const methodHandle& method) {
694
  AccessFlags access_flags = method->access_flags();
695
  ConstMethod* const_method = method->constMethod();
696
  u2 generic_signature_index = const_method->generic_signature_index();
697
  AnnotationArray* anno = method->annotations();
698
  AnnotationArray* param_anno = method->parameter_annotations();
699
  AnnotationArray* default_anno = method->annotation_default();
700
  AnnotationArray* type_anno = method->type_annotations();
701

702
  // skip generated default interface methods
703
  if (method->is_overpass()) {
704
    return;
705
  }
706

707
  write_u2(access_flags.get_flags() & JVM_RECOGNIZED_METHOD_MODIFIERS);
708
  write_u2(const_method->name_index());
709
  write_u2(const_method->signature_index());
710

711
  // write attributes in the same order javac does, so we can test with byte for
712
  // byte comparison
713
  int attr_count = 0;
714
  if (const_method->code_size() != 0) {
715
    ++attr_count;     // has Code attribute
716
  }
717
  if (const_method->has_checked_exceptions()) {
718
    ++attr_count;     // has Exceptions attribute
719
  }
720
  if (default_anno != nullptr) {
721
    ++attr_count;     // has AnnotationDefault attribute
722
  }
723
  if (const_method->has_method_parameters()) {
724
    ++attr_count;     // has MethodParameters attribute
725
  }
726
  // Deprecated attribute would go here
727
  if (access_flags.is_synthetic()) { // FIXME
728
    // ++attr_count;
729
  }
730
  if (generic_signature_index != 0) {
731
    ++attr_count;
732
  }
733
  if (anno != nullptr) {
734
    ++attr_count;     // has RuntimeVisibleAnnotations attribute
735
  }
736
  if (param_anno != nullptr) {
737
    ++attr_count;     // has RuntimeVisibleParameterAnnotations attribute
738
  }
739
  if (type_anno != nullptr) {
740
    ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
741
  }
742

743
  write_u2(checked_cast<u2>(attr_count));
744
  if (const_method->code_size() > 0) {
745
    write_code_attribute(method);
746
  }
747
  if (const_method->has_checked_exceptions()) {
748
    write_exceptions_attribute(const_method);
749
  }
750
  if (default_anno != nullptr) {
751
    write_annotations_attribute("AnnotationDefault", default_anno);
752
  }
753
  if (const_method->has_method_parameters()) {
754
    write_method_parameter_attribute(const_method);
755
  }
756
  // Deprecated attribute would go here
757
  if (access_flags.is_synthetic()) {
758
    // write_synthetic_attribute();
759
  }
760
  if (generic_signature_index != 0) {
761
    write_signature_attribute(generic_signature_index);
762
  }
763
  if (anno != nullptr) {
764
    write_annotations_attribute("RuntimeVisibleAnnotations", anno);
765
  }
766
  if (param_anno != nullptr) {
767
    write_annotations_attribute("RuntimeVisibleParameterAnnotations", param_anno);
768
  }
769
  if (type_anno != nullptr) {
770
    write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
771
  }
772
}
773

774
// Write the class attributes portion of ClassFile structure
775
// JVMSpec|     u2 attributes_count;
776
// JVMSpec|     attribute_info attributes[attributes_count];
777
void JvmtiClassFileReconstituter::write_class_attributes() {
778
  u2 inner_classes_length = inner_classes_attribute_length();
779
  Symbol* generic_signature = ik()->generic_signature();
780
  AnnotationArray* anno = ik()->class_annotations();
781
  AnnotationArray* type_anno = ik()->class_type_annotations();
782

783
  u2 attr_count = 0;
784
  if (generic_signature != nullptr) {
785
    ++attr_count;
786
  }
787
  if (ik()->source_file_name() != nullptr) {
788
    ++attr_count;
789
  }
790
  if (ik()->source_debug_extension() != nullptr) {
791
    ++attr_count;
792
  }
793
  if (inner_classes_length > 0) {
794
    ++attr_count;
795
  }
796
  if (anno != nullptr) {
797
    ++attr_count;     // has RuntimeVisibleAnnotations attribute
798
  }
799
  if (type_anno != nullptr) {
800
    ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute
801
  }
802
  if (cpool()->operands() != nullptr) {
803
    ++attr_count;
804
  }
805
  if (ik()->nest_host_index() != 0) {
806
    ++attr_count;
807
  }
808
  if (ik()->nest_members() != Universe::the_empty_short_array()) {
809
    ++attr_count;
810
  }
811
  if (ik()->permitted_subclasses() != Universe::the_empty_short_array()) {
812
    ++attr_count;
813
  }
814
  if (ik()->record_components() != nullptr) {
815
    ++attr_count;
816
  }
817

818
  write_u2(attr_count);
819

820
  if (generic_signature != nullptr) {
821
    write_signature_attribute(symbol_to_cpool_index(generic_signature));
822
  }
823
  if (ik()->source_file_name() != nullptr) {
824
    write_source_file_attribute();
825
  }
826
  if (ik()->source_debug_extension() != nullptr) {
827
    write_source_debug_extension_attribute();
828
  }
829
  if (anno != nullptr) {
830
    write_annotations_attribute("RuntimeVisibleAnnotations", anno);
831
  }
832
  if (type_anno != nullptr) {
833
    write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);
834
  }
835
  if (ik()->nest_host_index() != 0) {
836
    write_nest_host_attribute();
837
  }
838
  if (ik()->nest_members() != Universe::the_empty_short_array()) {
839
    write_nest_members_attribute();
840
  }
841
  if (ik()->permitted_subclasses() != Universe::the_empty_short_array()) {
842
    write_permitted_subclasses_attribute();
843
  }
844
  if (ik()->record_components() != nullptr) {
845
    write_record_attribute();
846
  }
847
  if (cpool()->operands() != nullptr) {
848
    write_bootstrapmethod_attribute();
849
  }
850
  if (inner_classes_length > 0) {
851
    write_inner_classes_attribute(inner_classes_length);
852
  }
853
}
854

855
// Write the method information portion of ClassFile structure
856
// JVMSpec|     u2 methods_count;
857
// JVMSpec|     method_info methods[methods_count];
858
void JvmtiClassFileReconstituter::write_method_infos() {
859
  HandleMark hm(thread());
860
  Array<Method*>* methods = ik()->methods();
861
  int num_methods = methods->length();
862
  int num_overpass = 0;
863

864
  // count the generated default interface methods
865
  // these will not be re-created by write_method_info
866
  // and should not be included in the total count
867
  for (int index = 0; index < num_methods; index++) {
868
    Method* method = methods->at(index);
869
    if (method->is_overpass()) {
870
      num_overpass++;
871
    }
872
  }
873

874
  write_u2(checked_cast<u2>(num_methods - num_overpass));
875
  if (JvmtiExport::can_maintain_original_method_order()) {
876
    int index;
877
    int original_index;
878
    intArray method_order(num_methods, num_methods, 0);
879

880
    // invert the method order mapping
881
    for (index = 0; index < num_methods; index++) {
882
      original_index = ik()->method_ordering()->at(index);
883
      assert(original_index >= 0 && original_index < num_methods,
884
             "invalid original method index");
885
      method_order.at_put(original_index, index);
886
    }
887

888
    // write in original order
889
    for (original_index = 0; original_index < num_methods; original_index++) {
890
      index = method_order.at(original_index);
891
      methodHandle method(thread(), methods->at(index));
892
      write_method_info(method);
893
    }
894
  } else {
895
    // method order not preserved just dump the method infos
896
    for (int index = 0; index < num_methods; index++) {
897
      methodHandle method(thread(), methods->at(index));
898
      write_method_info(method);
899
    }
900
  }
901
}
902

903
void JvmtiClassFileReconstituter::write_class_file_format() {
904
  ReallocMark();
905

906
  // JVMSpec|   ClassFile {
907
  // JVMSpec|           u4 magic;
908
  write_u4(0xCAFEBABE);
909

910
  // JVMSpec|           u2 minor_version;
911
  // JVMSpec|           u2 major_version;
912
  write_u2(ik()->minor_version());
913
  u2 major = ik()->major_version();
914
  write_u2(major);
915

916
  // JVMSpec|           u2 constant_pool_count;
917
  // JVMSpec|           cp_info constant_pool[constant_pool_count-1];
918
  write_u2(checked_cast<u2>(cpool()->length()));
919
  copy_cpool_bytes(writeable_address(cpool_size()));
920

921
  // JVMSpec|           u2 access_flags;
922
  write_u2(ik()->access_flags().get_flags() & JVM_RECOGNIZED_CLASS_MODIFIERS);
923

924
  // JVMSpec|           u2 this_class;
925
  // JVMSpec|           u2 super_class;
926
  write_u2(class_symbol_to_cpool_index(ik()->name()));
927
  Klass* super_class = ik()->super();
928
  write_u2(super_class == nullptr? 0 :  // zero for java.lang.Object
929
                class_symbol_to_cpool_index(super_class->name()));
930

931
  // JVMSpec|           u2 interfaces_count;
932
  // JVMSpec|           u2 interfaces[interfaces_count];
933
  Array<InstanceKlass*>* interfaces =  ik()->local_interfaces();
934
  int num_interfaces = interfaces->length();
935
  write_u2(checked_cast<u2>(num_interfaces));
936
  for (int index = 0; index < num_interfaces; index++) {
937
    HandleMark hm(thread());
938
    InstanceKlass* iik = interfaces->at(index);
939
    write_u2(class_symbol_to_cpool_index(iik->name()));
940
  }
941

942
  // JVMSpec|           u2 fields_count;
943
  // JVMSpec|           field_info fields[fields_count];
944
  write_field_infos();
945

946
  // JVMSpec|           u2 methods_count;
947
  // JVMSpec|           method_info methods[methods_count];
948
  write_method_infos();
949

950
  // JVMSpec|           u2 attributes_count;
951
  // JVMSpec|           attribute_info attributes[attributes_count];
952
  // JVMSpec|   } /* end ClassFile 8?
953
  write_class_attributes();
954
}
955

956
address JvmtiClassFileReconstituter::writeable_address(size_t size) {
957
  size_t used_size = _buffer_ptr - _buffer;
958
  if (size + used_size >= _buffer_size) {
959
    // compute the new buffer size: must be at least twice as big as before
960
    // plus whatever new is being used; then convert to nice clean block boundary
961
    size_t new_buffer_size = (size + _buffer_size*2 + 1) / initial_buffer_size
962
                                                         * initial_buffer_size;
963

964
    // VM goes belly-up if the memory isn't available, so cannot do OOM processing
965
    _buffer = REALLOC_RESOURCE_ARRAY(u1, _buffer, _buffer_size, new_buffer_size);
966
    _buffer_size = new_buffer_size;
967
    _buffer_ptr = _buffer + used_size;
968
  }
969
  u1* ret_ptr = _buffer_ptr;
970
  _buffer_ptr += size;
971
  return ret_ptr;
972
}
973

974
void JvmtiClassFileReconstituter::write_attribute_name_index(const char* name) {
975
  TempNewSymbol sym = SymbolTable::probe(name, (int)strlen(name));
976
  assert(sym != nullptr, "attribute name symbol not found");
977
  u2 attr_name_index = symbol_to_cpool_index(sym);
978
  assert(attr_name_index != 0, "attribute name symbol not in constant pool");
979
  write_u2(attr_name_index);
980
}
981

982
void JvmtiClassFileReconstituter::write_u1(u1 x) {
983
  *writeable_address(1) = x;
984
}
985

986
void JvmtiClassFileReconstituter::write_u2(u2 x) {
987
  Bytes::put_Java_u2(writeable_address(2), x);
988
}
989

990
void JvmtiClassFileReconstituter::write_u4(u4 x) {
991
  Bytes::put_Java_u4(writeable_address(4), x);
992
}
993

994
void JvmtiClassFileReconstituter::write_u8(u8 x) {
995
  Bytes::put_Java_u8(writeable_address(8), x);
996
}
997

998
void JvmtiClassFileReconstituter::copy_bytecodes(const methodHandle& mh,
999
                                                 unsigned char* bytecodes) {
1000
  // use a BytecodeStream to iterate over the bytecodes. JVM/fast bytecodes
1001
  // and the breakpoint bytecode are converted to their original bytecodes.
1002

1003
  BytecodeStream bs(mh);
1004

1005
  unsigned char* p = bytecodes;
1006
  Bytecodes::Code code;
1007
  bool is_rewritten = mh->method_holder()->is_rewritten();
1008

1009
  while ((code = bs.next()) >= 0) {
1010
    assert(Bytecodes::is_java_code(code), "sanity check");
1011
    assert(code != Bytecodes::_breakpoint, "sanity check");
1012

1013
    // length of bytecode (mnemonic + operands)
1014
    address bcp = bs.bcp();
1015
    int     len = bs.instruction_size();
1016
    assert(len > 0, "length must be > 0");
1017

1018
    // copy the bytecodes
1019
    *p = (unsigned char) (bs.is_wide()? Bytecodes::_wide : code);
1020
    if (len > 1) {
1021
      memcpy(p+1, bcp+1, len-1);
1022
    }
1023

1024
    // During linking the get/put and invoke instructions are rewritten
1025
    // with an index into the constant pool cache. The original constant
1026
    // pool index must be returned to caller.  Rewrite the index.
1027
    if (is_rewritten && len > 1) {
1028
      bool is_wide = false;
1029
      switch (code) {
1030
      case Bytecodes::_getstatic       :  // fall through
1031
      case Bytecodes::_putstatic       :  // fall through
1032
      case Bytecodes::_getfield        :  // fall through
1033
      case Bytecodes::_putfield        :  {
1034
        int field_index = Bytes::get_native_u2(bcp+1);
1035
        u2 pool_index = mh->constants()->resolved_field_entry_at(field_index)->constant_pool_index();
1036
        assert(pool_index < mh->constants()->length(), "sanity check");
1037
        Bytes::put_Java_u2((address)(p+1), pool_index);     // java byte ordering
1038
        break;
1039
      }
1040
      case Bytecodes::_invokevirtual   :  // fall through
1041
      case Bytecodes::_invokespecial   :  // fall through
1042
      case Bytecodes::_invokestatic    :  // fall through
1043
      case Bytecodes::_invokedynamic   :  // fall through
1044
      case Bytecodes::_invokeinterface : {
1045
        assert(len == 3 ||
1046
               (code == Bytecodes::_invokeinterface && len == 5) ||
1047
               (code == Bytecodes::_invokedynamic   && len == 5),
1048
               "sanity check");
1049

1050
        int cpci = Bytes::get_native_u2(bcp+1);
1051
        bool is_invokedynamic = (code == Bytecodes::_invokedynamic);
1052
        int pool_index;
1053
        if (is_invokedynamic) {
1054
          cpci = Bytes::get_native_u4(bcp+1);
1055
          pool_index = mh->constants()->resolved_indy_entry_at(cpci)->constant_pool_index();
1056
        } else {
1057
          // cache cannot be pre-fetched since some classes won't have it yet
1058
          pool_index = mh->constants()->resolved_method_entry_at(cpci)->constant_pool_index();
1059
        }
1060
        assert(pool_index < mh->constants()->length(), "sanity check");
1061
        Bytes::put_Java_u2((address)(p+1), (u2)pool_index);     // java byte ordering
1062
        if (is_invokedynamic)  *(p+3) = *(p+4) = 0;
1063
        break;
1064
      }
1065
      case Bytecodes::_ldc_w:
1066
        is_wide = true; // fall through
1067
      case Bytecodes::_ldc: {
1068
        if (bs.raw_code() == Bytecodes::_fast_aldc || bs.raw_code() == Bytecodes::_fast_aldc_w) {
1069
          int cpci = is_wide ? Bytes::get_native_u2(bcp+1) : (u1)(*(bcp+1));
1070
          int i = mh->constants()->object_to_cp_index(cpci);
1071
          assert(i < mh->constants()->length(), "sanity check");
1072
          if (is_wide) {
1073
            Bytes::put_Java_u2((address)(p+1), (u2)i);     // java byte ordering
1074
          } else {
1075
            *(p+1) = (u1)i;
1076
          }
1077
        }
1078
        break;
1079
        }
1080
      default:
1081
        break;
1082
      }
1083
    }
1084

1085
    p += len;
1086
  }
1087
}
1088