/*

 * 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 "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "code/nmethod.hpp"

#include "compiler/compileBroker.hpp"

#include "interpreter/interpreter.hpp"

#include "interpreter/linkResolver.hpp"

#include "memory/universe.inline.hpp"

#include "oops/oop.inline.hpp"

#include "prims/jniCheck.hpp"

#include "runtime/compilationPolicy.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/interfaceSupport.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/os.inline.hpp"

#include "runtime/signature.hpp"

#include "runtime/stubRoutines.hpp"

#include "runtime/thread.inline.hpp"

#if INCLUDE_JVMCI

#include "jvmci/jvmciJavaClasses.hpp"

#include "jvmci/jvmciRuntime.hpp"

#endif

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

// Implementation of JavaCallWrapper

JavaCallWrapper::JavaCallWrapper(const methodHandle& callee_method, Handle receiver, JavaValue* result, TRAPS) {

  JavaThread* thread = (JavaThread *)THREAD;

  bool clear_pending_exception = true;

  guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");

  assert(!thread->owns_locks(), "must release all locks when leaving VM");

  guarantee(thread->can_call_java(), "cannot make java calls from the native compiler");

  _result   = result;

  // Allocate handle block for Java code. This must be done before we change thread_state to _thread_in_Java_or_stub,

  // since it can potentially block.

  JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(thread);

  // After this, we are official in JavaCode. This needs to be done before we change any of the thread local

  // info, since we cannot find oops before the new information is set up completely.

  ThreadStateTransition::transition(thread, _thread_in_vm, _thread_in_Java);

  // Make sure that we handle asynchronous stops and suspends _before_ we clear all thread state

  // in JavaCallWrapper::JavaCallWrapper(). This way, we can decide if we need to do any pd actions

  // to prepare for stop/suspend (flush register windows on sparcs, cache sp, or other state).

  if (thread->has_special_runtime_exit_condition()) {

    thread->handle_special_runtime_exit_condition();

    if (HAS_PENDING_EXCEPTION) {

      clear_pending_exception = false;

    }

  }

  // Make sure to set the oop's after the thread transition - since we can block there. No one is GC'ing

  // the JavaCallWrapper before the entry frame is on the stack.

  _callee_method = callee_method();

  _receiver = receiver();

#ifdef CHECK_UNHANDLED_OOPS

  THREAD->allow_unhandled_oop(&_receiver);

#endif // CHECK_UNHANDLED_OOPS

  _thread       = (JavaThread *)thread;

  _handles      = _thread->active_handles();    // save previous handle block & Java frame linkage

  // For the profiler, the last_Java_frame information in thread must always be in

  // legal state. We have no last Java frame if last_Java_sp == NULL so

  // the valid transition is to clear _last_Java_sp and then reset the rest of

  // the (platform specific) state.

  _anchor.copy(_thread->frame_anchor());

  _thread->frame_anchor()->clear();

  debug_only(_thread->inc_java_call_counter());

  _thread->set_active_handles(new_handles);     // install new handle block and reset Java frame linkage

  assert (_thread->thread_state() != _thread_in_native, "cannot set native pc to NULL");

  // clear any pending exception in thread (native calls start with no exception pending)

  if(clear_pending_exception) {

    _thread->clear_pending_exception();

  }

  if (_anchor.last_Java_sp() == NULL) {

    _thread->record_base_of_stack_pointer();

  }

}

JavaCallWrapper::~JavaCallWrapper() {

  assert(_thread == JavaThread::current(), "must still be the same thread");

  // restore previous handle block & Java frame linkage

  JNIHandleBlock *_old_handles = _thread->active_handles();

  _thread->set_active_handles(_handles);

  _thread->frame_anchor()->zap();

  debug_only(_thread->dec_java_call_counter());

  if (_anchor.last_Java_sp() == NULL) {

    _thread->set_base_of_stack_pointer(NULL);

  }

  // Old thread-local info. has been restored. We are not back in the VM.

  ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);

  // State has been restored now make the anchor frame visible for the profiler.

  // Do this after the transition because this allows us to put an assert

  // the Java->vm transition which checks to see that stack is not walkable

  // on sparc/ia64 which will catch violations of the reseting of last_Java_frame

  // invariants (i.e. _flags always cleared on return to Java)

  _thread->frame_anchor()->copy(&_anchor);

  // Release handles after we are marked as being inside the VM again, since this

  // operation might block

  JNIHandleBlock::release_block(_old_handles, _thread);

}

void JavaCallWrapper::oops_do(OopClosure* f) {

  f->do_oop((oop*)&_receiver);

  handles()->oops_do(f);

}

// Helper methods

static BasicType runtime_type_from(JavaValue* result) {

  switch (result->get_type()) {

    case T_BOOLEAN: // fall through

    case T_CHAR   : // fall through

    case T_SHORT  : // fall through

    case T_INT    : // fall through

#ifndef _LP64

    case T_OBJECT : // fall through

    case T_ARRAY  : // fall through

#endif

    case T_BYTE   : // fall through

    case T_VOID   : return T_INT;

    case T_LONG   : return T_LONG;

    case T_FLOAT  : return T_FLOAT;

    case T_DOUBLE : return T_DOUBLE;

#ifdef _LP64

    case T_ARRAY  : // fall through

    case T_OBJECT:  return T_OBJECT;

#endif

    default:

      ShouldNotReachHere();

      return T_ILLEGAL;

  }

}

// ============ Virtual calls ============

void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {

  CallInfo callinfo;

  Handle receiver = args->receiver();

  Klass* recvrKlass = receiver.is_null() ? (Klass*)NULL : receiver->klass();

  LinkInfo link_info(spec_klass, name, signature);

  LinkResolver::resolve_virtual_call(

          callinfo, receiver, recvrKlass, link_info, true, CHECK);

  methodHandle method = callinfo.selected_method();

  assert(method.not_null(), "should have thrown exception");

  // Invoke the method

  JavaCalls::call(result, method, args, CHECK);

}

void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {

  JavaCallArguments args(receiver); // One oop argument

  call_virtual(result, spec_klass, name, signature, &args, CHECK);

}

void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {

  JavaCallArguments args(receiver); // One oop argument

  args.push_oop(arg1);

  call_virtual(result, spec_klass, name, signature, &args, CHECK);

}

void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {

  JavaCallArguments args(receiver); // One oop argument

  args.push_oop(arg1);

  args.push_oop(arg2);

  call_virtual(result, spec_klass, name, signature, &args, CHECK);

}

// ============ Special calls ============

void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {

  CallInfo callinfo;

  LinkInfo link_info(klass, name, signature);

  LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);

  methodHandle method = callinfo.selected_method();

  assert(method.not_null(), "should have thrown exception");

  // Invoke the method

  JavaCalls::call(result, method, args, CHECK);

}

void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {

  JavaCallArguments args(receiver); // One oop argument

  call_special(result, klass, name, signature, &args, CHECK);

}

void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {

  JavaCallArguments args(receiver); // One oop argument

  args.push_oop(arg1);

  call_special(result, klass, name, signature, &args, CHECK);

}

void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {

  JavaCallArguments args(receiver); // One oop argument

  args.push_oop(arg1);

  args.push_oop(arg2);

  call_special(result, klass, name, signature, &args, CHECK);

}

// ============ Static calls ============

void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {

  CallInfo callinfo;

  LinkInfo link_info(klass, name, signature);

  LinkResolver::resolve_static_call(callinfo, link_info, true, CHECK);

  methodHandle method = callinfo.selected_method();

  assert(method.not_null(), "should have thrown exception");

  // Invoke the method

  JavaCalls::call(result, method, args, CHECK);

}

void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {

  JavaCallArguments args; // No argument

  call_static(result, klass, name, signature, &args, CHECK);

}

void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {

  JavaCallArguments args(arg1); // One oop argument

  call_static(result, klass, name, signature, &args, CHECK);

}

void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {

  JavaCallArguments args; // One oop argument

  args.push_oop(arg1);

  args.push_oop(arg2);

  call_static(result, klass, name, signature, &args, CHECK);

}

void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {

  JavaCallArguments args; // One oop argument

  args.push_oop(arg1);

  args.push_oop(arg2);

  args.push_oop(arg3);

  call_static(result, klass, name, signature, &args, CHECK);

}

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

// Implementation of JavaCalls (low level)

void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {

  // Check if we need to wrap a potential OS exception handler around thread

  // This is used for e.g. Win32 structured exception handlers

  assert(THREAD->is_Java_thread(), "only JavaThreads can make JavaCalls");

  // Need to wrap each and every time, since there might be native code down the

  // stack that has installed its own exception handlers

  os::os_exception_wrapper(call_helper, result, method, args, THREAD);

}

void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {

  JavaThread* thread = (JavaThread*)THREAD;

  assert(thread->is_Java_thread(), "must be called by a java thread");

  assert(method.not_null(), "must have a method to call");

  assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");

  assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");

  CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)

#if INCLUDE_JVMCI

  // Gets the nmethod (if any) that should be called instead of normal target

  nmethod* alternative_target = args->alternative_target();

  if (alternative_target == NULL) {

#endif

// Verify the arguments

  if (CheckJNICalls)  {

    args->verify(method, result->get_type());

  }

  else debug_only(args->verify(method, result->get_type()));

#if INCLUDE_JVMCI

  }

#else

  // Ignore call if method is empty

  if (method->is_empty_method()) {

    assert(result->get_type() == T_VOID, "an empty method must return a void value");

    return;

  }

#endif

#ifdef ASSERT

  { InstanceKlass* holder = method->method_holder();

    // A klass might not be initialized since JavaCall's might be used during the executing of

    // the <clinit>. For example, a Thread.start might start executing on an object that is

    // not fully initialized! (bad Java programming style)

    assert(holder->is_linked(), "rewriting must have taken place");

  }

#endif

  CompilationPolicy::compile_if_required(method, CHECK);

  // Since the call stub sets up like the interpreter we call the from_interpreted_entry

  // so we can go compiled via a i2c. Otherwise initial entry method will always

  // run interpreted.

  address entry_point = method->from_interpreted_entry();

  if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {

    entry_point = method->interpreter_entry();

  }

  // Figure out if the result value is an oop or not (Note: This is a different value

  // than result_type. result_type will be T_INT of oops. (it is about size)

  BasicType result_type = runtime_type_from(result);

  bool oop_result_flag = (result->get_type() == T_OBJECT || result->get_type() == T_ARRAY);

  // NOTE: if we move the computation of the result_val_address inside

  // the call to call_stub, the optimizer produces wrong code.

  intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());

  // Find receiver

  Handle receiver = (!method->is_static()) ? args->receiver() : Handle();

  // When we reenter Java, we need to reenable the reserved/yellow zone which

  // might already be disabled when we are in VM.

  if (!thread->stack_guards_enabled()) {

    thread->reguard_stack();

  }

  // Check that there are shadow pages available before changing thread state

  // to Java. Calculate current_stack_pointer here to make sure

  // stack_shadow_pages_available() and bang_stack_shadow_pages() use the same sp.

  address sp = os::current_stack_pointer();

  if (!os::stack_shadow_pages_available(THREAD, method, sp)) {

    // Throw stack overflow exception with preinitialized exception.

    Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);

    return;

  } else {

    // Touch pages checked if the OS needs them to be touched to be mapped.

    os::map_stack_shadow_pages(sp);

  }

#if INCLUDE_JVMCI

  if (alternative_target != NULL) {

    if (alternative_target->is_alive()) {

      thread->set_jvmci_alternate_call_target(alternative_target->verified_entry_point());

      entry_point = method->adapter()->get_i2c_entry();

    } else {

      THROW(vmSymbols::jdk_vm_ci_code_InvalidInstalledCodeException());

    }

  }

#endif

  // do call

  { JavaCallWrapper link(method, receiver, result, CHECK);

    { HandleMark hm(thread);  // HandleMark used by HandleMarkCleaner

      StubRoutines::call_stub()(

        (address)&link,

        // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)

        result_val_address,          // see NOTE above (compiler problem)

        result_type,

        method(),

        entry_point,

        args->parameters(),

        args->size_of_parameters(),

        CHECK

      );

      result = link.result();  // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)

      // Preserve oop return value across possible gc points

      if (oop_result_flag) {

        thread->set_vm_result((oop) result->get_jobject());

      }

    }

  } // Exit JavaCallWrapper (can block - potential return oop must be preserved)

  // Check if a thread stop or suspend should be executed

  // The following assert was not realistic.  Thread.stop can set that bit at any moment.

  //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");

  // Restore possible oop return

  if (oop_result_flag) {

    result->set_jobject((jobject)thread->vm_result());

    thread->set_vm_result(NULL);

  }

}

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

// Implementation of JavaCallArguments

inline bool is_value_state_indirect_oop(uint state) {

  assert(state != JavaCallArguments::value_state_oop,

         "Checking for handles after removal");

  assert(state < JavaCallArguments::value_state_limit,

         "Invalid value state %u", state);

  return state != JavaCallArguments::value_state_primitive;

}

inline oop resolve_indirect_oop(intptr_t value, uint state) {

  switch (state) {

  case JavaCallArguments::value_state_handle:

  {

    oop* ptr = reinterpret_cast<oop*>(value);

    return Handle::raw_resolve(ptr);

  }

  case JavaCallArguments::value_state_jobject:

  {

    jobject obj = reinterpret_cast<jobject>(value);

    return JNIHandles::resolve(obj);

  }

  default:

    ShouldNotReachHere();

    return NULL;

  }

}

intptr_t* JavaCallArguments::parameters() {

  // First convert all handles to oops

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

    uint state = _value_state[i];

    assert(state != value_state_oop, "Multiple handle conversions");

    if (is_value_state_indirect_oop(state)) {

      oop obj = resolve_indirect_oop(_value[i], state);

      _value[i] = cast_from_oop<intptr_t>(obj);

      _value_state[i] = value_state_oop;

    }

  }

  // Return argument vector

  return _value;

}

class SignatureChekker : public SignatureIterator {

 private:

   int _pos;

   BasicType _return_type;

   u_char* _value_state;

   intptr_t* _value;

 public:

  bool _is_return;

  SignatureChekker(Symbol* signature,

                   BasicType return_type,

                   bool is_static,

                   u_char* value_state,

                   intptr_t* value) :

    SignatureIterator(signature),

    _pos(0),

    _return_type(return_type),

    _value_state(value_state),

    _value(value),

    _is_return(false)

  {

    if (!is_static) {

      check_value(true); // Receiver must be an oop

    }

  }