/*

 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.

 * Copyright 2009, 2010, 2011 Red Hat, Inc.

 * 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/interpreter.hpp"

#include "memory/allocation.inline.hpp"

#include "oops/oop.inline.hpp"

#include "prims/methodHandles.hpp"

void MethodHandles::invoke_target(Method* method, TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;

  ZeroStack *stack = thread->zero_stack();

  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();

  interpreterState istate = frame->interpreter_state();

  // Trim back the stack to put the parameters at the top

  stack->set_sp(istate->stack() + 1);

  Interpreter::invoke_method(method, method->from_interpreted_entry(), THREAD);

  // Convert the result

  istate->set_stack(stack->sp() - 1);

}

oop MethodHandles::popFromStack(TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;

  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();

  interpreterState istate = frame->interpreter_state();

  intptr_t* topOfStack = istate->stack();

  oop top = STACK_OBJECT(-1);

  MORE_STACK(-1);

  istate->set_stack(topOfStack);

  return top;

}

int MethodHandles::method_handle_entry_invokeBasic(Method* method, intptr_t UNUSED, TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;

  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();

  interpreterState istate = frame->interpreter_state();

  intptr_t* topOfStack = istate->stack();

  // 'this' is a MethodHandle. We resolve the target method by accessing this.form.vmentry.vmtarget.

  int numArgs = method->size_of_parameters();

  oop lform1 = java_lang_invoke_MethodHandle::form(STACK_OBJECT(-numArgs)); // this.form

  oop vmEntry1 = java_lang_invoke_LambdaForm::vmentry(lform1);

  Method* vmtarget = (Method*) java_lang_invoke_MemberName::vmtarget(vmEntry1);

  invoke_target(vmtarget, THREAD);

  // No deoptimized frames on the stack

  return 0;

}

int MethodHandles::method_handle_entry_linkToStaticOrSpecial(Method* method, intptr_t UNUSED, TRAPS) {

  // Pop appendix argument from stack. This is a MemberName which we resolve to the

  // target method.

  oop vmentry = popFromStack(THREAD);

  Method* vmtarget = (Method*) java_lang_invoke_MemberName::vmtarget(vmentry);

  invoke_target(vmtarget, THREAD);

  return 0;

}

int MethodHandles::method_handle_entry_linkToInterface(Method* method, intptr_t UNUSED, TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;

  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();

  interpreterState istate = frame->interpreter_state();

  // Pop appendix argument from stack. This is a MemberName which we resolve to the

  // target method.

  oop vmentry = popFromStack(THREAD);

  intptr_t* topOfStack = istate->stack();

  // Resolve target method by looking up in the receiver object's itable.

  Klass* clazz = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(vmentry));

  intptr_t vmindex = java_lang_invoke_MemberName::vmindex(vmentry);

  Method* target = (Method*) java_lang_invoke_MemberName::vmtarget(vmentry);

  int numArgs = target->size_of_parameters();

  oop recv = STACK_OBJECT(-numArgs);

  InstanceKlass* klass_part = InstanceKlass::cast(recv->klass());

  itableOffsetEntry* ki = (itableOffsetEntry*) klass_part->start_of_itable();

  int i;

  for ( i = 0 ; i < klass_part->itable_length() ; i++, ki++ ) {

    if (ki->interface_klass() == clazz) break;

  }

  itableMethodEntry* im = ki->first_method_entry(recv->klass());

  Method* vmtarget = im[vmindex].method();

  invoke_target(vmtarget, THREAD);

  return 0;

}

int MethodHandles::method_handle_entry_linkToVirtual(Method* method, intptr_t UNUSED, TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;

  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();

  interpreterState istate = frame->interpreter_state();

  // Pop appendix argument from stack. This is a MemberName which we resolve to the

  // target method.

  oop vmentry = popFromStack(THREAD);

  intptr_t* topOfStack = istate->stack();

  // Resolve target method by looking up in the receiver object's vtable.

  intptr_t vmindex = java_lang_invoke_MemberName::vmindex(vmentry);

  Method* target = (Method*) java_lang_invoke_MemberName::vmtarget(vmentry);

  int numArgs = target->size_of_parameters();

  oop recv = STACK_OBJECT(-numArgs);

  Klass* clazz = recv->klass();

  Klass* klass_part = InstanceKlass::cast(clazz);

  ResourceMark rm(THREAD);

  klassVtable* vtable = klass_part->vtable();

  Method* vmtarget = vtable->method_at(vmindex);

  invoke_target(vmtarget, THREAD);

  return 0;

}

int MethodHandles::method_handle_entry_invalid(Method* method, intptr_t UNUSED, TRAPS) {

  ShouldNotReachHere();

  return 0;

}

address MethodHandles::generate_method_handle_interpreter_entry(MacroAssembler* masm,

                                                                vmIntrinsics::ID iid) {

  switch (iid) {

  case vmIntrinsics::_invokeGeneric:

  case vmIntrinsics::_compiledLambdaForm:

    // Perhaps surprisingly, the symbolic references visible to Java are not directly used.

    // They are linked to Java-generated adapters via MethodHandleNatives.linkMethod.

    // They all allow an appendix argument.

  case vmIntrinsics::_invokeBasic:

  case vmIntrinsics::_linkToStatic:

  case vmIntrinsics::_linkToSpecial:

  case vmIntrinsics::_linkToInterface:

  case vmIntrinsics::_linkToVirtual:

  default:

    ShouldNotReachHere();

    return NULL;

  }

}