/*

 * Copyright (c) 1999, 2019, 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 "ci/ciCallProfile.hpp"

#include "ci/ciExceptionHandler.hpp"

#include "ci/ciInstanceKlass.hpp"

#include "ci/ciMethod.hpp"

#include "ci/ciMethodBlocks.hpp"

#include "ci/ciMethodData.hpp"

#include "ci/ciStreams.hpp"

#include "ci/ciSymbol.hpp"

#include "ci/ciReplay.hpp"

#include "ci/ciUtilities.inline.hpp"

#include "classfile/systemDictionary.hpp"

#include "compiler/abstractCompiler.hpp"

#include "compiler/methodLiveness.hpp"

#include "interpreter/interpreter.hpp"

#include "interpreter/linkResolver.hpp"

#include "interpreter/oopMapCache.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/resourceArea.hpp"

#include "oops/generateOopMap.hpp"

#include "oops/method.inline.hpp"

#include "oops/oop.inline.hpp"

#include "prims/nativeLookup.hpp"

#include "runtime/deoptimization.hpp"

#include "runtime/handles.inline.hpp"

#include "utilities/bitMap.inline.hpp"

#include "utilities/xmlstream.hpp"

#ifdef COMPILER2

#include "ci/bcEscapeAnalyzer.hpp"

#include "ci/ciTypeFlow.hpp"

#include "oops/method.hpp"

#endif

// ciMethod

//

// This class represents a Method* in the HotSpot virtual

// machine.

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

// ciMethod::ciMethod

//

// Loaded method.

ciMethod::ciMethod(const methodHandle& h_m, ciInstanceKlass* holder) :

  ciMetadata(h_m()),

  _holder(holder)

{

  assert(h_m() != NULL, "no null method");

  if (LogTouchedMethods) {

  }

  // These fields are always filled in in loaded methods.

  // Easy to compute, so fill them in now.

  _can_be_parsed      = true;

  // Lazy fields, filled in on demand.  Require allocation.

  _code               = NULL;

  _exception_handlers = NULL;

  _liveness           = NULL;

  _method_blocks = NULL;

#if defined(COMPILER2)

  _flow               = NULL;

  _bcea               = NULL;

#endif // COMPILER2

  ciEnv *env = CURRENT_ENV;

  if (env->jvmti_can_hotswap_or_post_breakpoint()) {

    // 6328518 check hotswap conditions under the right lock.

    MutexLocker locker(Compile_lock);

    if (Dependencies::check_evol_method(h_m()) != NULL) {

      _is_c1_compilable = false;

      _is_c2_compilable = false;

      _can_be_parsed = false;

    }

  } else {

    DEBUG_ONLY(CompilerThread::current()->check_possible_safepoint());

  }

  } else {

    // Have to use a conservative value in this case.

    _can_be_statically_bound = false;

  }

  // Adjust the definition of this condition to be more useful:

  // %%% take these conditions into account in vtable generation

    _can_be_statically_bound = true;

    _can_be_statically_bound = false;

  // generating _signature may allow GC and therefore move m.

  // These fields are always filled in.

  _signature = new (env->arena()) ciSignature(_holder, cpool, sig_symbol);

  _method_data = NULL;

  // Take a snapshot of these values, so they will be commensurate with the MDO.

  if (ProfileInterpreter || TieredCompilation) {

    // if the value overflowed report it as max int

    _interpreter_invocation_count = invcnt < 0 ? max_jint : invcnt ;

  } else {

    _interpreter_invocation_count = 0;

    _interpreter_throwout_count = 0;

  }

  if (_interpreter_invocation_count == 0)

    _interpreter_invocation_count = 1;

  _instructions_size = -1;

#ifdef ASSERT

  if (ReplayCompiles) {

    ciReplay::initialize(this);

  }

#endif

}

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

// ciMethod::ciMethod

//

// Unloaded method.

ciMethod::ciMethod(ciInstanceKlass* holder,

                   ciSymbol*        name,

                   ciSymbol*        signature,

                   ciInstanceKlass* accessor) :

  ciMetadata((Metadata*)NULL),

  _name(                   name),

  _holder(                 holder),

  _method_data(            NULL),

  _method_blocks(          NULL),

  _intrinsic_id(           vmIntrinsics::_none),

  _instructions_size(-1),

  _can_be_statically_bound(false),

  _liveness(               NULL)

#if defined(COMPILER2)

  ,

  _flow(                   NULL),

  _bcea(                   NULL)

#endif // COMPILER2

{

  // Usually holder and accessor are the same type but in some cases

  // the holder has the wrong class loader (e.g. invokedynamic call

  // sites) so we pass the accessor.

  _signature = new (CURRENT_ENV->arena()) ciSignature(accessor, constantPoolHandle(), signature);

}

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

// ciMethod::load_code

//

// Load the bytecodes and exception handler table for this method.

void ciMethod::load_code() {

  VM_ENTRY_MARK;

  assert(is_loaded(), "only loaded methods have code");

  Method* me = get_Method();

  Arena* arena = CURRENT_THREAD_ENV->arena();

  // Load the bytecodes.

  _code = (address)arena->Amalloc(code_size());

  memcpy(_code, me->code_base(), code_size());

#if INCLUDE_JVMTI

  // Revert any breakpoint bytecodes in ci's copy

  if (me->number_of_breakpoints() > 0) {

    BreakpointInfo* bp = me->method_holder()->breakpoints();

    for (; bp != NULL; bp = bp->next()) {

      if (bp->match(me)) {

        code_at_put(bp->bci(), bp->orig_bytecode());

      }

    }

  }

#endif

  // And load the exception table.

  ExceptionTable exc_table(me);

  // Allocate one extra spot in our list of exceptions.  This

  // last entry will be used to represent the possibility that

  // an exception escapes the method.  See ciExceptionHandlerStream

  // for details.

  _exception_handlers =

    (ciExceptionHandler**)arena->Amalloc(sizeof(ciExceptionHandler*)

                                         * (_handler_count + 1));

  if (_handler_count > 0) {

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

      _exception_handlers[i] = new (arena) ciExceptionHandler(

                                holder(),

            /* start    */      exc_table.start_pc(i),

            /* limit    */      exc_table.end_pc(i),

            /* goto pc  */      exc_table.handler_pc(i),

            /* cp index */      exc_table.catch_type_index(i));

    }

  }

  // Put an entry at the end of our list to represent the possibility

  // of exceptional exit.

  _exception_handlers[_handler_count] =

    new (arena) ciExceptionHandler(holder(), 0, code_size(), -1, 0);

  if (CIPrintMethodCodes) {

    print_codes();

  }

}

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

// ciMethod::has_linenumber_table

//

// length unknown until decompression

bool    ciMethod::has_linenumber_table() const {

  check_is_loaded();

  VM_ENTRY_MARK;

  return get_Method()->has_linenumber_table();

}

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

// ciMethod::compressed_linenumber_table

u_char* ciMethod::compressed_linenumber_table() const {

  check_is_loaded();

  VM_ENTRY_MARK;

  return get_Method()->compressed_linenumber_table();

}

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

// ciMethod::line_number_from_bci

int ciMethod::line_number_from_bci(int bci) const {

  check_is_loaded();

  VM_ENTRY_MARK;

  return get_Method()->line_number_from_bci(bci);

}

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

// ciMethod::vtable_index

//

// Get the position of this method's entry in the vtable, if any.

int ciMethod::vtable_index() {

  check_is_loaded();

  assert(holder()->is_linked(), "must be linked");

  VM_ENTRY_MARK;

  return get_Method()->vtable_index();

}

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

// ciMethod::native_entry

//

// Get the address of this method's native code, if any.

address ciMethod::native_entry() {

  check_is_loaded();

  assert(flags().is_native(), "must be native method");

  VM_ENTRY_MARK;

  Method* method = get_Method();

  address entry = method->native_function();

  assert(entry != NULL, "must be valid entry point");

  return entry;

}

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

// ciMethod::interpreter_entry

//

// Get the entry point for running this method in the interpreter.

address ciMethod::interpreter_entry() {

  check_is_loaded();

  VM_ENTRY_MARK;

  methodHandle mh(THREAD, get_Method());

  return Interpreter::entry_for_method(mh);

}

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

// ciMethod::uses_balanced_monitors

//

// Does this method use monitors in a strict stack-disciplined manner?

bool ciMethod::has_balanced_monitors() {

  check_is_loaded();

  if (_balanced_monitors) return true;

  // Analyze the method to see if monitors are used properly.

  VM_ENTRY_MARK;

  methodHandle method(THREAD, get_Method());

  assert(method->has_monitor_bytecodes(), "should have checked this");

  // Check to see if a previous compilation computed the

  // monitor-matching analysis.

  if (method->guaranteed_monitor_matching()) {

    _balanced_monitors = true;

    return true;

  }

  {

    EXCEPTION_MARK;

    ResourceMark rm(THREAD);

    GeneratePairingInfo gpi(method);

    gpi.compute_map(CATCH);

    if (!gpi.monitor_safe()) {

      return false;

    }

    method->set_guaranteed_monitor_matching();

    _balanced_monitors = true;

  }

  return true;

}

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

// ciMethod::get_flow_analysis

ciTypeFlow* ciMethod::get_flow_analysis() {

#if defined(COMPILER2)

  if (_flow == NULL) {

    ciEnv* env = CURRENT_ENV;

    _flow = new (env->arena()) ciTypeFlow(env, this);

    _flow->do_flow();

  }

  return _flow;

#else // COMPILER2

  ShouldNotReachHere();

  return NULL;

#endif // COMPILER2

}

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

// ciMethod::get_osr_flow_analysis

ciTypeFlow* ciMethod::get_osr_flow_analysis(int osr_bci) {

#if defined(COMPILER2)

  // OSR entry points are always place after a call bytecode of some sort

  assert(osr_bci >= 0, "must supply valid OSR entry point");

  ciEnv* env = CURRENT_ENV;

  ciTypeFlow* flow = new (env->arena()) ciTypeFlow(env, this, osr_bci);

  flow->do_flow();

  return flow;

#else // COMPILER2

  ShouldNotReachHere();

  return NULL;

#endif // COMPILER2

}

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

// ciMethod::raw_liveness_at_bci

//

// Which local variables are live at a specific bci?

MethodLivenessResult ciMethod::raw_liveness_at_bci(int bci) {

  check_is_loaded();

  if (_liveness == NULL) {

    // Create the liveness analyzer.

    Arena* arena = CURRENT_ENV->arena();

    _liveness = new (arena) MethodLiveness(arena, this);

    _liveness->compute_liveness();

  }

  return _liveness->get_liveness_at(bci);

}

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

// ciMethod::liveness_at_bci

//

// Which local variables are live at a specific bci?  When debugging

// will return true for all locals in some cases to improve debug

// information.

MethodLivenessResult ciMethod::liveness_at_bci(int bci) {

  if (CURRENT_ENV->should_retain_local_variables() || DeoptimizeALot) {

    // Keep all locals live for the user's edification and amusement.

    MethodLivenessResult result(_max_locals);

    result.set_range(0, _max_locals);

    result.set_is_valid();

    return result;

  }

  return raw_liveness_at_bci(bci);

}

// ciMethod::live_local_oops_at_bci

//

// find all the live oops in the locals array for a particular bci

// Compute what the interpreter believes by using the interpreter

// oopmap generator. This is used as a double check during osr to

// guard against conservative result from MethodLiveness making us

// think a dead oop is live.  MethodLiveness is conservative in the

// sense that it may consider locals to be live which cannot be live,

// like in the case where a local could contain an oop or  a primitive

// along different paths.  In that case the local must be dead when

// those paths merge. Since the interpreter's viewpoint is used when

// gc'ing an interpreter frame we need to use its viewpoint  during

// OSR when loading the locals.

ResourceBitMap ciMethod::live_local_oops_at_bci(int bci) {

  VM_ENTRY_MARK;

  InterpreterOopMap mask;

  int mask_size = max_locals();

  ResourceBitMap result(mask_size);

  int i;

  for (i = 0; i < mask_size ; i++ ) {

    if (mask.is_oop(i)) result.set_bit(i);

  }

  return result;

}

#ifdef COMPILER1

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

// ciMethod::bci_block_start

//

// Marks all bcis where a new basic block starts

const BitMap& ciMethod::bci_block_start() {

  check_is_loaded();

  if (_liveness == NULL) {

    // Create the liveness analyzer.

    Arena* arena = CURRENT_ENV->arena();

    _liveness = new (arena) MethodLiveness(arena, this);

    _liveness->compute_liveness();

  }

  return _liveness->get_bci_block_start();

}

#endif // COMPILER1

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

// ciMethod::check_overflow

//

// Check whether the profile counter is overflowed and adjust if true.

// For invoke* it will turn negative values into max_jint,

// and for checkcast/aastore/instanceof turn positive values into min_jint.

int ciMethod::check_overflow(int c, Bytecodes::Code code) {

  switch (code) {

    case Bytecodes::_aastore:    // fall-through

    case Bytecodes::_checkcast:  // fall-through

    case Bytecodes::_instanceof: {

      return (c > 0 ? min_jint : c); // always non-positive

    }

    default: {

      assert(Bytecodes::is_invoke(code), "%s", Bytecodes::name(code));

      return (c < 0 ? max_jint : c); // always non-negative

    }

  }

}

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

// ciMethod::call_profile_at_bci

//

// Get the ciCallProfile for the invocation of this method.

// Also reports receiver types for non-call type checks (if TypeProfileCasts).

ciCallProfile ciMethod::call_profile_at_bci(int bci) {

  ResourceMark rm;

  ciCallProfile result;

  if (method_data() != NULL && method_data()->is_mature()) {

    ciProfileData* data = method_data()->bci_to_data(bci);

    if (data != NULL && data->is_CounterData()) {

      // Every profiled call site has a counter.

      int count = check_overflow(data->as_CounterData()->count(), java_code_at_bci(bci));

      if (!data->is_ReceiverTypeData()) {

        result._receiver_count[0] = 0;  // that's a definite zero

      } else { // ReceiverTypeData is a subclass of CounterData

        ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();

        // In addition, virtual call sites have receiver type information

        int receivers_count_total = 0;

        int morphism = 0;

        // Precompute morphism for the possible fixup

        for (uint i = 0; i < call->row_limit(); i++) {

          ciKlass* receiver = call->receiver(i);