/*

 * Copyright (c) 1997, 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 "interpreter/bytecode.hpp"

#include "interpreter/linkResolver.hpp"

#include "oops/constantPool.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/fieldType.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/safepoint.hpp"

#include "runtime/signature.hpp"

// Implementation of Bytecode

#ifdef ASSERT

void Bytecode::assert_same_format_as(Bytecodes::Code testbc, bool is_wide) const {

  Bytecodes::Code thisbc = Bytecodes::cast(byte_at(0));

  if (thisbc == Bytecodes::_breakpoint)  return;  // let the assertion fail silently

  if (is_wide) {

    assert(thisbc == Bytecodes::_wide, "expected a wide instruction");

    thisbc = Bytecodes::cast(byte_at(1));

    if (thisbc == Bytecodes::_breakpoint)  return;

  }

  int thisflags = Bytecodes::flags(testbc, is_wide) & Bytecodes::_all_fmt_bits;

  int testflags = Bytecodes::flags(thisbc, is_wide) & Bytecodes::_all_fmt_bits;

  if (thisflags != testflags)

    tty->print_cr("assert_same_format_as(%d) failed on bc=%d%s; %d != %d",

                  (int)testbc, (int)thisbc, (is_wide?"/wide":""), testflags, thisflags);

  assert(thisflags == testflags, "expected format");

}

void Bytecode::assert_index_size(int size, Bytecodes::Code bc, bool is_wide) {

  int have_fmt = (Bytecodes::flags(bc, is_wide)

                  & (Bytecodes::_fmt_has_u2 | Bytecodes::_fmt_has_u4 |

                     Bytecodes::_fmt_not_simple |

                     // Not an offset field:

                     Bytecodes::_fmt_has_o));

  int need_fmt = -1;

  switch (size) {

  case 1: need_fmt = 0;                      break;

  case 2: need_fmt = Bytecodes::_fmt_has_u2; break;

  case 4: need_fmt = Bytecodes::_fmt_has_u4; break;

  }

  if (is_wide)  need_fmt |= Bytecodes::_fmt_not_simple;

  if (have_fmt != need_fmt) {

    tty->print_cr("assert_index_size %d: bc=%d%s %d != %d", size, bc, (is_wide?"/wide":""), have_fmt, need_fmt);

    assert(have_fmt == need_fmt, "assert_index_size");

  }

}

void Bytecode::assert_offset_size(int size, Bytecodes::Code bc, bool is_wide) {

  int have_fmt = Bytecodes::flags(bc, is_wide) & Bytecodes::_all_fmt_bits;

  int need_fmt = -1;

  switch (size) {

  case 2: need_fmt = Bytecodes::_fmt_bo2; break;

  case 4: need_fmt = Bytecodes::_fmt_bo4; break;

  }

  if (is_wide)  need_fmt |= Bytecodes::_fmt_not_simple;

  if (have_fmt != need_fmt) {

    tty->print_cr("assert_offset_size %d: bc=%d%s %d != %d", size, bc, (is_wide?"/wide":""), have_fmt, need_fmt);

    assert(have_fmt == need_fmt, "assert_offset_size");

  }

}

void Bytecode::assert_constant_size(int size, int where, Bytecodes::Code bc, bool is_wide) {

  int have_fmt = Bytecodes::flags(bc, is_wide) & (Bytecodes::_all_fmt_bits

                                                  // Ignore any 'i' field (for iinc):

                                                  & ~Bytecodes::_fmt_has_i);

  int need_fmt = -1;

  switch (size) {

  case 1: need_fmt = Bytecodes::_fmt_bc;                          break;

  case 2: need_fmt = Bytecodes::_fmt_bc | Bytecodes::_fmt_has_u2; break;

  }

  if (is_wide)  need_fmt |= Bytecodes::_fmt_not_simple;

  int length = is_wide ? Bytecodes::wide_length_for(bc) : Bytecodes::length_for(bc);

  if (have_fmt != need_fmt || where + size != length) {

    tty->print_cr("assert_constant_size %d @%d: bc=%d%s %d != %d", size, where, bc, (is_wide?"/wide":""), have_fmt, need_fmt);

  }

  assert(have_fmt == need_fmt, "assert_constant_size");

  assert(where + size == length, "assert_constant_size oob");

}

void Bytecode::assert_native_index(Bytecodes::Code bc, bool is_wide) {

  assert((Bytecodes::flags(bc, is_wide) & Bytecodes::_fmt_has_nbo) != 0, "native index");

}

#endif //ASSERT

// Implementation of Bytecode_tableupswitch

int Bytecode_tableswitch::dest_offset_at(int i) const {

  return get_aligned_Java_u4_at(1 + (3 + i)*jintSize);

}

// Implementation of Bytecode_invoke

void Bytecode_invoke::verify() const {

  assert(is_valid(), "check invoke");

  assert(cpcache() != NULL, "do not call this from verifier or rewriter");

}

Symbol* Bytecode_member_ref::klass() const {

  return constants()->klass_ref_at_noresolve(index());

}

Symbol* Bytecode_member_ref::name() const {

  return constants()->name_ref_at(index());

}

Symbol* Bytecode_member_ref::signature() const {

  return constants()->signature_ref_at(index());

}

BasicType Bytecode_member_ref::result_type() const {

  ResultTypeFinder rts(signature());

  rts.iterate();

  return rts.type();

}

methodHandle Bytecode_invoke::static_target(TRAPS) {

  constantPoolHandle constants(THREAD, this->constants());

  Bytecodes::Code bc = invoke_code();

  return LinkResolver::resolve_method_statically(bc, constants, index(), THREAD);

}

Handle Bytecode_invoke::appendix(TRAPS) {

  ConstantPoolCacheEntry* cpce = cpcache_entry();

  if (cpce->has_appendix())

    return Handle(THREAD, cpce->appendix_if_resolved(constants()));

  return Handle();  // usual case

}

int Bytecode_member_ref::index() const {

  // Note:  Rewriter::rewrite changes the Java_u2 of an invokedynamic to a native_u4,

  // at the same time it allocates per-call-site CP cache entries.

  Bytecodes::Code rawc = code();

  if (has_index_u4(rawc))

    return get_index_u4(rawc);

  else

    return get_index_u2_cpcache(rawc);

}

int Bytecode_member_ref::pool_index() const {

  return cpcache_entry()->constant_pool_index();

}

ConstantPoolCacheEntry* Bytecode_member_ref::cpcache_entry() const {

  int index = this->index();

  return cpcache()->entry_at(ConstantPool::decode_cpcache_index(index, true));

}

// Implementation of Bytecode_field

void Bytecode_field::verify() const {

  assert(is_valid(), "check field");

}

// Implementation of Bytecode_loadconstant

int Bytecode_loadconstant::raw_index() const {

  Bytecodes::Code rawc = code();

  assert(rawc != Bytecodes::_wide, "verifier prevents this");

  if (Bytecodes::java_code(rawc) == Bytecodes::_ldc)

    return get_index_u1(rawc);

  else

    return get_index_u2(rawc, false);

}

int Bytecode_loadconstant::pool_index() const {

  int index = raw_index();

  if (has_cache_index()) {

    return _method->constants()->object_to_cp_index(index);

  }

  return index;

}

BasicType Bytecode_loadconstant::result_type() const {

  int index = pool_index();

  constantTag tag = _method->constants()->tag_at(index);

  return tag.basic_type();

}

oop Bytecode_loadconstant::resolve_constant(TRAPS) const {

  assert(_method != 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);

  }

}

//------------------------------------------------------------------------------

// Non-product code

#ifndef PRODUCT

void Bytecode_lookupswitch::verify() const {

  switch (Bytecodes::java_code(code())) {

    case Bytecodes::_lookupswitch:

      { int i = number_of_pairs() - 1;

        while (i-- > 0) {

          assert(pair_at(i).match() < pair_at(i+1).match(), "unsorted table entries");

        }

      }

      break;

    default:

      fatal("not a lookupswitch bytecode");

  }

}

void Bytecode_tableswitch::verify() const {

  switch (Bytecodes::java_code(code())) {

    case Bytecodes::_tableswitch:

      { int lo = low_key();

        int hi = high_key();

        assert (hi >= lo, "incorrect hi/lo values in tableswitch");

        int i  = hi - lo - 1 ;

        while (i-- > 0) {

          // no special check needed

        }

      }

      break;

    default:

      fatal("not a tableswitch bytecode");

  }

}

#endif