C++ ConstantPool类代码示例

bool BytecodePrinter::check_index(int i, int& cp_index, outputStream* st) {
  ConstantPool* constants = method()->constants();
  int ilimit = constants->length();
  Bytecodes::Code code = raw_code();

  ConstantPoolCache* cache = NULL;
  if (Bytecodes::uses_cp_cache(code)) {
    bool okay = true;
    switch (code) {
    case Bytecodes::_fast_aldc:
    case Bytecodes::_fast_aldc_w:
      okay = check_obj_index(i, cp_index, st);
      break;
    case Bytecodes::_invokedynamic:
      okay = check_invokedynamic_index(i, cp_index, st);
      break;
    default:
      okay = check_cp_cache_index(i, cp_index, st);
      break;
    }
    if (!okay) return false;
  }


  // check cp index
  if (cp_index >= 0 && cp_index < ilimit) {
    if (WizardMode)  st->print(" cp[%d]", cp_index);
    return true;
  }

  st->print_cr(" CP[%d] not in CP", cp_index);
  return false;
}

static void emitConstantPool(MCStreamer &Streamer, const MCSection *Section,
                             ConstantPool &CP) {
  if (!CP.empty()) {
    Streamer.SwitchSection(Section);
    CP.emitEntries(Streamer);
  }
}

void InterpretTest::gcTest()
{
	ConstantPool * pool = new ConstantPool();
	Class * cls = initClass("GCTest", pool);
	const char code[] = 
	{
		PUSH, 0x00, 0x00,
		STORE_LOCAL, 0x00,
		PUSH, 0x01, 0x00, //label1
		LOAD_LOCAL, 0x00,
		SUB,
		IF_GE, 0x0D,//if(i < 1000)
		PUSH, 0x01, 0x00,
		NEW_ARRAY,
		STORE_LOCAL, 0x01,
		LOAD_LOCAL, 0x00,
		INC,
		STORE_LOCAL, 0x00,
		JMP, -21,
		RET_VOID
	};
	Method * m = initMethod("gcTest", code, sizeof(code), 0, 2, 0);
	ClassLoader cl("");
	Interpret instance(&cl);
	IntConst i;
	i.value = 0;
	pool->addItem(&i, INT_CONST);//0
	i.value = 1000;
	pool->addItem(&i, INT_CONST);//1
	cls->addMethod(m);
	cl.addClass(cls);
	instance.run(cls->getName().c_str(), m->getName().c_str());
}

  //interpreteur put fast_invoke_virtual_final not only for 
  //static methods but also for final methods of Object class!
  void check_uncommon_or_static_method(int index JVM_TRAPS) {
    ConstantPool cp = method()->constants();

    if (!cp.tag_at(index).is_resolved_final_uncommon_interface_method()) {
      check_static(index JVM_CHECK);
    }
  }

oop Bytecode_loadconstant::resolve_constant(TRAPS) const {
  assert(_method.not_null(), "must supply method to resolve constant");
  int index = raw_index();
  ConstantPool* constants = _method->constants();
  if (has_cache_index()) {
    return constants->resolve_cached_constant_at(index, THREAD);
  } else {
    return constants->resolve_constant_at(index, THREAD);
  }
}

static void switchover_constant_pool(BytecodeConstantPool* bpool,
    InstanceKlass* klass, GrowableArray<Method*>* new_methods, TRAPS) {

  if (new_methods->length() > 0) {
    ConstantPool* cp = bpool->create_constant_pool(CHECK);
    if (cp != klass->constants()) {
      klass->class_loader_data()->add_to_deallocate_list(klass->constants());
      klass->set_constants(cp);
      cp->set_pool_holder(klass);

      for (int i = 0; i < new_methods->length(); ++i) {
        new_methods->at(i)->set_constants(cp);
      }
      for (int i = 0; i < klass->methods()->length(); ++i) {
        Method* mo = klass->methods()->at(i);
        mo->set_constants(cp);
      }
    }
  }
}

ConstantPool* BytecodeConstantPool::create_constant_pool(TRAPS) const {
  if (_entries.length() == 0) {
    return _orig;
  }

  ConstantPool* cp = ConstantPool::allocate(
      _orig->pool_holder()->class_loader_data(),
      _orig->length() + _entries.length(), CHECK_NULL);

  cp->set_pool_holder(_orig->pool_holder());
  _orig->copy_cp_to(1, _orig->length() - 1, cp, 1, CHECK_NULL);

  for (int i = 0; i < _entries.length(); ++i) {
    BytecodeCPEntry entry = _entries.at(i);
    int idx = i + _orig->length();
    switch (entry._tag) {
      case BytecodeCPEntry::UTF8:
        entry._u.utf8->increment_refcount();
        cp->symbol_at_put(idx, entry._u.utf8);
        break;
      case BytecodeCPEntry::KLASS:
        cp->unresolved_klass_at_put(
            idx, cp->symbol_at(entry._u.klass));
        break;
      case BytecodeCPEntry::STRING:
        cp->unresolved_string_at_put(
            idx, cp->symbol_at(entry._u.string));
        break;
      case BytecodeCPEntry::NAME_AND_TYPE:
        cp->name_and_type_at_put(idx,
            entry._u.name_and_type.name_index,
            entry._u.name_and_type.type_index);
        break;
      case BytecodeCPEntry::METHODREF:
        cp->method_at_put(idx,
            entry._u.methodref.class_index,
            entry._u.methodref.name_and_type_index);
        break;
      default:
        ShouldNotReachHere();
    }
  }
  return cp;
}

void BytecodePrinter::print_attributes(int bci, outputStream* st) {
  // Show attributes of pre-rewritten codes
  Bytecodes::Code code = Bytecodes::java_code(raw_code());
  // If the code doesn't have any fields there's nothing to print.
  // note this is ==1 because the tableswitch and lookupswitch are
  // zero size (for some reason) and we want to print stuff out for them.
  if (Bytecodes::length_for(code) == 1) {
    st->cr();
    return;
  }

  switch(code) {
    // Java specific bytecodes only matter.
    case Bytecodes::_bipush:
      st->print_cr(" " INT32_FORMAT, get_byte());
      break;
    case Bytecodes::_sipush:
      st->print_cr(" " INT32_FORMAT, get_short());
      break;
    case Bytecodes::_ldc:
      if (Bytecodes::uses_cp_cache(raw_code())) {
        print_constant(get_index_u1_cpcache(), st);
      } else {
        print_constant(get_index_u1(), st);
      }
      break;

    case Bytecodes::_ldc_w:
    case Bytecodes::_ldc2_w:
      if (Bytecodes::uses_cp_cache(raw_code())) {
        print_constant(get_index_u2_cpcache(), st);
      } else {
        print_constant(get_index_u2(), st);
      }
      break;

    case Bytecodes::_iload:
    case Bytecodes::_lload:
    case Bytecodes::_fload:
    case Bytecodes::_dload:
    case Bytecodes::_aload:
    case Bytecodes::_istore:
    case Bytecodes::_lstore:
    case Bytecodes::_fstore:
    case Bytecodes::_dstore:
    case Bytecodes::_astore:
      st->print_cr(" #%d", get_index_special());
      break;

    case Bytecodes::_iinc:
      { int index = get_index_special();
        jint offset = is_wide() ? get_short(): get_byte();
        st->print_cr(" #%d " INT32_FORMAT, index, offset);
      }
      break;

    case Bytecodes::_newarray: {
        BasicType atype = (BasicType)get_index_u1();
        const char* str = type2name(atype);
        if (str == NULL || atype == T_OBJECT || atype == T_ARRAY) {
          assert(false, "Unidentified basic type");
        }
        st->print_cr(" %s", str);
      }
      break;
    case Bytecodes::_anewarray: {
        int klass_index = get_index_u2();
        ConstantPool* constants = method()->constants();
        Symbol* name = constants->klass_name_at(klass_index);
        st->print_cr(" %s ", name->as_C_string());
      }
      break;
    case Bytecodes::_multianewarray: {
        int klass_index = get_index_u2();
        int nof_dims = get_index_u1();
        ConstantPool* constants = method()->constants();
        Symbol* name = constants->klass_name_at(klass_index);
        st->print_cr(" %s %d", name->as_C_string(), nof_dims);
      }
      break;

    case Bytecodes::_ifeq:
    case Bytecodes::_ifnull:
    case Bytecodes::_iflt:
    case Bytecodes::_ifle:
    case Bytecodes::_ifne:
    case Bytecodes::_ifnonnull:
    case Bytecodes::_ifgt:
    case Bytecodes::_ifge:
    case Bytecodes::_if_icmpeq:
    case Bytecodes::_if_icmpne:
    case Bytecodes::_if_icmplt:
    case Bytecodes::_if_icmpgt:
    case Bytecodes::_if_icmple:
    case Bytecodes::_if_icmpge:
    case Bytecodes::_if_acmpeq:
    case Bytecodes::_if_acmpne:
    case Bytecodes::_goto:
    case Bytecodes::_jsr:
      st->print_cr(" %d", bci + get_short());
//.........这里部分代码省略.........

Struct_CP_Table::Struct_CP_Table(ConstantPool const &constantPool)
{
    CPMaker v(constants);
    constantPool.accept(v);
}