/*

 * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "classfile/symbolTable.hpp"

#include "interpreter/bytecodeStream.hpp"

#include "oops/fieldStreams.hpp"

#include "prims/jvmtiClassFileReconstituter.hpp"

#include "runtime/signature.hpp"

#include "utilities/bytes.hpp"

// FIXME: add Deprecated attribute

// FIXME: fix Synthetic attribute

// FIXME: per Serguei, add error return handling for ConstantPool::copy_cpool_bytes()

// Write the field information portion of ClassFile structure

// JVMSpec|     u2 fields_count;

// JVMSpec|     field_info fields[fields_count];

void JvmtiClassFileReconstituter::write_field_infos() {

  HandleMark hm(thread());

  Array<AnnotationArray*>* fields_anno = ik()->fields_annotations();

  Array<AnnotationArray*>* fields_type_anno = ik()->fields_type_annotations();

  // Compute the real number of Java fields

  int java_fields = ik()->java_fields_count();

  write_u2(java_fields);

  for (JavaFieldStream fs(ik()); !fs.done(); fs.next()) {

    AccessFlags access_flags = fs.access_flags();

    int name_index = fs.name_index();

    int signature_index = fs.signature_index();

    int initial_value_index = fs.initval_index();

    guarantee(name_index != 0 && signature_index != 0, "bad constant pool index for field");

    // int offset = ik()->field_offset( index );

    int generic_signature_index = fs.generic_signature_index();

    AnnotationArray* anno = fields_anno == NULL ? NULL : fields_anno->at(fs.index());

    AnnotationArray* type_anno = fields_type_anno == NULL ? NULL : fields_type_anno->at(fs.index());

    // JVMSpec|   field_info {

    // JVMSpec|         u2 access_flags;

    // JVMSpec|         u2 name_index;

    // JVMSpec|         u2 descriptor_index;

    // JVMSpec|         u2 attributes_count;

    // JVMSpec|         attribute_info attributes[attributes_count];

    // JVMSpec|   }

    write_u2(access_flags.as_int() & JVM_RECOGNIZED_FIELD_MODIFIERS);

    write_u2(name_index);

    write_u2(signature_index);

    int attr_count = 0;

    if (initial_value_index != 0) {

      ++attr_count;

    }

    if (access_flags.is_synthetic()) {

      // ++attr_count;

    }

    if (generic_signature_index != 0) {

      ++attr_count;

    }

    if (anno != NULL) {

      ++attr_count;     // has RuntimeVisibleAnnotations attribute

    }

    if (type_anno != NULL) {

      ++attr_count;     // has RuntimeVisibleTypeAnnotations attribute

    }

    write_u2(attr_count);

    if (initial_value_index != 0) {

      write_attribute_name_index("ConstantValue");

      write_u4(2); //length always 2

      write_u2(initial_value_index);

    }

    if (access_flags.is_synthetic()) {

      // write_synthetic_attribute();

    }

    if (generic_signature_index != 0) {

      write_signature_attribute(generic_signature_index);

    }

    if (anno != NULL) {

      write_annotations_attribute("RuntimeVisibleAnnotations", anno);

    }

    if (type_anno != NULL) {

      write_annotations_attribute("RuntimeVisibleTypeAnnotations", type_anno);

    }

  }

}

// Write Code attribute

// JVMSpec|   Code_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 max_stack;

// JVMSpec|     u2 max_locals;

// JVMSpec|     u4 code_length;

// JVMSpec|     u1 code[code_length];

// JVMSpec|     u2 exception_table_length;

// JVMSpec|     {       u2 start_pc;

// JVMSpec|             u2 end_pc;

// JVMSpec|             u2  handler_pc;

// JVMSpec|             u2  catch_type;

// JVMSpec|     }       exception_table[exception_table_length];

// JVMSpec|     u2 attributes_count;

// JVMSpec|     attribute_info attributes[attributes_count];

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_code_attribute(const methodHandle& method) {

  ConstMethod* const_method = method->constMethod();

  u2 line_num_cnt = 0;

  int stackmap_len = 0;

  int local_variable_table_length = 0;

  int local_variable_type_table_length = 0;

  // compute number and length of attributes

  int attr_count = 0;

  int attr_size = 0;

  if (const_method->has_linenumber_table()) {

    line_num_cnt = line_number_table_entries(method);

    if (line_num_cnt != 0) {

      ++attr_count;

      // Compute the complete size of the line number table attribute:

      //      LineNumberTable_attribute {

      //        u2 attribute_name_index;

      //        u4 attribute_length;

      //        u2 line_number_table_length;

      //        {  u2 start_pc;

      //           u2 line_number;

      //        } line_number_table[line_number_table_length];

      //      }

      attr_size += 2 + 4 + 2 + line_num_cnt * (2 + 2);

    }

  }

  if (method->has_stackmap_table()) {

    stackmap_len = method->stackmap_data()->length();

    if (stackmap_len != 0) {

      ++attr_count;

      // Compute the  size of the stack map table attribute (VM stores raw):

      //      StackMapTable_attribute {

      //        u2 attribute_name_index;

      //        u4 attribute_length;

      //        u2 number_of_entries;

      //        stack_map_frame_entries[number_of_entries];

      //      }

      attr_size += 2 + 4 + stackmap_len;

    }

  }

  if (method->has_localvariable_table()) {

    local_variable_table_length = method->localvariable_table_length();

    if (local_variable_table_length != 0) {

      ++attr_count;

      // Compute the size of the local variable table attribute (VM stores raw):

      // LocalVariableTable_attribute {

      //   u2 attribute_name_index;

      //   u4 attribute_length;

      //   u2 local_variable_table_length;

      //   {

      //     u2 start_pc;

      //     u2 length;

      //     u2 name_index;

      //     u2 descriptor_index;

      //     u2 index;

      //   }

      attr_size += 2 + 4 + 2 + local_variable_table_length * (2 + 2 + 2 + 2 + 2);

      // Local variables with generic signatures must have LVTT entries

      LocalVariableTableElement *elem = method->localvariable_table_start();

      for (int idx = 0; idx < local_variable_table_length; idx++) {

        if (elem[idx].signature_cp_index != 0) {

          local_variable_type_table_length++;

        }

      }

      if (local_variable_type_table_length != 0) {

        ++attr_count;

        // Compute the size of the local variable type table attribute (VM stores raw):

        // LocalVariableTypeTable_attribute {

        //   u2 attribute_name_index;

        //   u4 attribute_length;

        //   u2 local_variable_type_table_length;

        //   {

        //     u2 start_pc;

        //     u2 length;

        //     u2 name_index;

        //     u2 signature_index;

        //     u2 index;

        //   }

        attr_size += 2 + 4 + 2 + local_variable_type_table_length * (2 + 2 + 2 + 2 + 2);

      }

    }

  }

  ExceptionTable exception_table(method());

  int exception_table_length = exception_table.length();

  int code_size = const_method->code_size();

  int size =

    2+2+4 +                                // max_stack, max_locals, code_length

    code_size +                            // code

    2 +                                    // exception_table_length

    (2+2+2+2) * exception_table_length +   // exception_table

    2 +                                    // attributes_count

    attr_size;                             // attributes

  write_attribute_name_index("Code");

  write_u4(size);

  write_u2(method->verifier_max_stack());

  write_u2(method->max_locals());

  write_u4(code_size);

  copy_bytecodes(method, (unsigned char*)writeable_address(code_size));

  write_u2(exception_table_length);

  for (int index = 0; index < exception_table_length; index++) {

    write_u2(exception_table.start_pc(index));

    write_u2(exception_table.end_pc(index));

    write_u2(exception_table.handler_pc(index));

    write_u2(exception_table.catch_type_index(index));

  }

  write_u2(attr_count);

  if (line_num_cnt != 0) {

    write_line_number_table_attribute(method, line_num_cnt);

  }

  if (stackmap_len != 0) {

    write_stackmap_table_attribute(method, stackmap_len);

  }

  if (local_variable_table_length != 0) {

    write_local_variable_table_attribute(method, local_variable_table_length);

  }

  if (local_variable_type_table_length != 0) {

    write_local_variable_type_table_attribute(method, local_variable_type_table_length);

  }

}

// Write Exceptions attribute

// JVMSpec|   Exceptions_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 number_of_exceptions;

// JVMSpec|     u2 exception_index_table[number_of_exceptions];

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_exceptions_attribute(ConstMethod* const_method) {

  CheckedExceptionElement* checked_exceptions = const_method->checked_exceptions_start();

  int checked_exceptions_length = const_method->checked_exceptions_length();

  int size =

    2 +                                    // number_of_exceptions

    2 * checked_exceptions_length;         // exception_index_table

  write_attribute_name_index("Exceptions");

  write_u4(size);

  write_u2(checked_exceptions_length);

  for (int index = 0; index < checked_exceptions_length; index++) {

    write_u2(checked_exceptions[index].class_cp_index);

  }

}

// Write SourceFile attribute

// JVMSpec|   SourceFile_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 sourcefile_index;

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_source_file_attribute() {

  assert(ik()->source_file_name() != NULL, "caller must check");

  write_attribute_name_index("SourceFile");

  write_u4(2);  // always length 2

  write_u2(symbol_to_cpool_index(ik()->source_file_name()));

}

// Write SourceDebugExtension attribute

// JSR45|   SourceDebugExtension_attribute {

// JSR45|       u2 attribute_name_index;

// JSR45|       u4 attribute_length;

// JSR45|       u1 debug_extension[attribute_length];

// JSR45|   }

void JvmtiClassFileReconstituter::write_source_debug_extension_attribute() {

  assert(ik()->source_debug_extension() != NULL, "caller must check");

  write_attribute_name_index("SourceDebugExtension");

  int len = (int)strlen(ik()->source_debug_extension());

  write_u4(len);

  u1* ext = (u1*)ik()->source_debug_extension();

  for (int i=0; i<len; i++) {

    write_u1(ext[i]);

  }

}

// Write (generic) Signature attribute

// JVMSpec|   Signature_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 signature_index;

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_signature_attribute(u2 generic_signature_index) {

  write_attribute_name_index("Signature");

  write_u4(2);  // always length 2

  write_u2(generic_signature_index);

}

// Compute the number of entries in the InnerClasses attribute

u2 JvmtiClassFileReconstituter::inner_classes_attribute_length() {

  InnerClassesIterator iter(ik());

  return iter.length();

}

// Write an annotation attribute.  The VM stores them in raw form, so all we need

// to do is add the attrubute name and fill in the length.

// JSR202|   *Annotations_attribute {

// JSR202|     u2 attribute_name_index;

// JSR202|     u4 attribute_length;

// JSR202|     ...

// JSR202|   }

void JvmtiClassFileReconstituter::write_annotations_attribute(const char* attr_name,

                                                              AnnotationArray* annos) {

  u4 length = annos->length();

  write_attribute_name_index(attr_name);

  write_u4(length);

  memcpy(writeable_address(length), annos->adr_at(0), length);

}

//  BootstrapMethods_attribute {

//    u2 attribute_name_index;

//    u4 attribute_length;

//    u2 num_bootstrap_methods;

//    {   u2 bootstrap_method_ref;

//        u2 num_bootstrap_arguments;

//        u2 bootstrap_arguments[num_bootstrap_arguments];

//    } bootstrap_methods[num_bootstrap_methods];

//  }

void JvmtiClassFileReconstituter::write_bootstrapmethod_attribute() {

  Array<u2>* operands = cpool()->operands();

  write_attribute_name_index("BootstrapMethods");

  int num_bootstrap_methods = ConstantPool::operand_array_length(operands);

  // calculate length of attribute

  int length = sizeof(u2); // num_bootstrap_methods

  for (int n = 0; n < num_bootstrap_methods; n++) {

    u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);

    length += sizeof(u2); // bootstrap_method_ref

    length += sizeof(u2); // num_bootstrap_arguments

    length += sizeof(u2) * num_bootstrap_arguments; // bootstrap_arguments[num_bootstrap_arguments]

  }

  write_u4(length);

  // write attribute

  write_u2(num_bootstrap_methods);

  for (int n = 0; n < num_bootstrap_methods; n++) {

    u2 bootstrap_method_ref = cpool()->operand_bootstrap_method_ref_index_at(n);

    u2 num_bootstrap_arguments = cpool()->operand_argument_count_at(n);

    write_u2(bootstrap_method_ref);

    write_u2(num_bootstrap_arguments);

    for (int arg = 0; arg < num_bootstrap_arguments; arg++) {

      u2 bootstrap_argument = cpool()->operand_argument_index_at(n, arg);

      write_u2(bootstrap_argument);

    }

  }

}

// Write InnerClasses attribute

// JVMSpec|   InnerClasses_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 number_of_classes;

// JVMSpec|     {  u2 inner_class_info_index;

// JVMSpec|        u2 outer_class_info_index;

// JVMSpec|        u2 inner_name_index;

// JVMSpec|        u2 inner_class_access_flags;

// JVMSpec|     } classes[number_of_classes];

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_inner_classes_attribute(int length) {

  InnerClassesIterator iter(ik());

  guarantee(iter.length() != 0 && iter.length() == length,

            "caller must check");

  u2 entry_count = length / InstanceKlass::inner_class_next_offset;

  u4 size = 2 + entry_count * (2+2+2+2);

  write_attribute_name_index("InnerClasses");

  write_u4(size);

  write_u2(entry_count);

  for (; !iter.done(); iter.next()) {

    write_u2(iter.inner_class_info_index());

    write_u2(iter.outer_class_info_index());

    write_u2(iter.inner_name_index());

    write_u2(iter.inner_access_flags());

  }

}

// Write Synthetic attribute

// JVMSpec|   Synthetic_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_synthetic_attribute() {

  write_attribute_name_index("Synthetic");

  write_u4(0); //length always zero

}

// Compute size of LineNumberTable

u2 JvmtiClassFileReconstituter::line_number_table_entries(const methodHandle& method) {

  // The line number table is compressed so we don't know how big it is until decompressed.

  // Decompression is really fast so we just do it twice.

  u2 num_entries = 0;

  CompressedLineNumberReadStream stream(method->compressed_linenumber_table());

  while (stream.read_pair()) {

    num_entries++;

  }

  return num_entries;

}

// Write LineNumberTable attribute

// JVMSpec|   LineNumberTable_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 line_number_table_length;

// JVMSpec|     {  u2 start_pc;

// JVMSpec|        u2 line_number;

// JVMSpec|     } line_number_table[line_number_table_length];

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_line_number_table_attribute(const methodHandle& method,

                                                                    u2 num_entries) {

  write_attribute_name_index("LineNumberTable");

  write_u4(2 + num_entries * (2 + 2));

  write_u2(num_entries);

  CompressedLineNumberReadStream stream(method->compressed_linenumber_table());

  while (stream.read_pair()) {

    write_u2(stream.bci());

    write_u2(stream.line());

  }

}

// Write LocalVariableTable attribute

// JVMSpec|   LocalVariableTable_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 local_variable_table_length;

// JVMSpec|     {  u2 start_pc;

// JVMSpec|       u2 length;

// JVMSpec|       u2 name_index;

// JVMSpec|       u2 descriptor_index;

// JVMSpec|       u2 index;

// JVMSpec|     } local_variable_table[local_variable_table_length];

// JVMSpec|   }

void JvmtiClassFileReconstituter::write_local_variable_table_attribute(const methodHandle& method, u2 num_entries) {

    write_attribute_name_index("LocalVariableTable");

    write_u4(2 + num_entries * (2 + 2 + 2 + 2 + 2));

    write_u2(num_entries);

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

    LocalVariableTableElement *elem = method->localvariable_table_start();

    for (int j=0; j<method->localvariable_table_length(); j++) {

      write_u2(elem->start_bci);

      write_u2(elem->length);

      write_u2(elem->name_cp_index);

      write_u2(elem->descriptor_cp_index);

      write_u2(elem->slot);

      elem++;

    }

}

// Write LocalVariableTypeTable attribute

// JVMSpec|   LocalVariableTypeTable_attribute {

// JVMSpec|     u2 attribute_name_index;

// JVMSpec|     u4 attribute_length;

// JVMSpec|     u2 local_variable_type_table_length;

// JVMSpec|     { u2 start_pc;

// JVMSpec|       u2 length;

// JVMSpec|       u2 name_index;

// JVMSpec|       u2 signature_index;

// JVMSpec|       u2 index;

// JVMSpec|     } local_variable_type_table[local_variable_type_table_length];

// JVMSpec|   }