/*

 * Copyright (c) 1998, 2014, 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 "code/codeBlob.hpp"

#include "code/codeCache.hpp"

#include "code/nmethod.hpp"

#include "code/scopeDesc.hpp"

#include "compiler/oopMap.hpp"

#include "gc_interface/collectedHeap.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/frame.inline.hpp"

#include "runtime/signature.hpp"

#ifdef COMPILER1

#include "c1/c1_Defs.hpp"

#endif

#ifdef COMPILER2

#include "opto/optoreg.hpp"

#endif

// OopMapStream

  _size = oop_map->omv_count();

  _position = 0;

  _valid_omv = false;

}

  _mask = oop_types_mask;

  _position = 0;

  _valid_omv = false;

}

void OopMapStream::find_next() {

  while(_position++ < _size) {

    _omv.read_from(_stream);

    if(((int)_omv.type() & _mask) > 0) {

      _valid_omv = true;

      return;

    }

  }

  _valid_omv = false;

}

// OopMap

// frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd

// slots to hold 4-byte values like ints and floats in the LP64 build.

OopMap::OopMap(int frame_size, int arg_count) {

  // OopMaps are usually quite so small, so pick a small initial size

  set_write_stream(new CompressedWriteStream(32));

  set_omv_count(0);

#ifdef ASSERT

  _locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count;

  _locs_used   = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);

  for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;

#endif

}

OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) {

  // This constructor does a deep copy

  // of the source OopMap.

  set_write_stream(new CompressedWriteStream(source->omv_count() * 2));

  set_omv_count(0);

  set_offset(source->offset());

#ifdef ASSERT

  _locs_length = source->_locs_length;

  _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);

  for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;

#endif

  // We need to copy the entries too.

  for (OopMapStream oms(source); !oms.is_done(); oms.next()) {

    OopMapValue omv = oms.current();

    omv.write_on(write_stream());

    increment_count();

  }

}

OopMap* OopMap::deep_copy() {

  return new OopMap(_deep_copy_token, this);

}

}

int OopMap::heap_size() const {

  int size = sizeof(OopMap);

  int align = sizeof(void *) - 1;

  // Align to a reasonable ending point

  size = ((size+align) & ~align);

  return size;

}

// frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd

// slots to hold 4-byte values like ints and floats in the LP64 build.

void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {

  assert(reg->value() < _locs_length, "too big reg value for stack size");

  assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );

  debug_only( _locs_used[reg->value()] = x; )

  OopMapValue o(reg, x);

  if(x == OopMapValue::callee_saved_value) {

    // This can never be a stack location, so we don't need to transform it.

    assert(optional->is_reg(), "Trying to callee save a stack location");

    o.set_content_reg(optional);

  } else if(x == OopMapValue::derived_oop_value) {

    o.set_content_reg(optional);

  }

  o.write_on(write_stream());

  increment_count();

}

void OopMap::set_oop(VMReg reg) {

  set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad());

}

void OopMap::set_value(VMReg reg) {

  // At this time, we only need value entries in our OopMap when ZapDeadCompiledLocals is active.

  if (ZapDeadCompiledLocals)

    set_xxx(reg, OopMapValue::value_value, VMRegImpl::Bad());

}

void OopMap::set_narrowoop(VMReg reg) {

  set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad());

}

void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) {

  set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register);

}

void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) {

  if( reg == derived_from_local_register ) {

    // Actually an oop, derived shares storage with base,

    set_oop(reg);

  } else {

    set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register);

  }

}

// OopMapSet

OopMapSet::OopMapSet() {

  set_om_size(MinOopMapAllocation);

  set_om_count(0);

  OopMap** temp = NEW_RESOURCE_ARRAY(OopMap*, om_size());

  set_om_data(temp);

}

void OopMapSet::grow_om_data() {

  int new_size = om_size() * 2;

  OopMap** new_data = NEW_RESOURCE_ARRAY(OopMap*, new_size);

  memcpy(new_data,om_data(),om_size() * sizeof(OopMap*));

  set_om_size(new_size);

  set_om_data(new_data);

}

void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) {

  assert(om_size() != -1,"Cannot grow a fixed OopMapSet");

  if(om_count() >= om_size()) {

    grow_om_data();

  }

  map->set_offset(pc_offset);

#ifdef ASSERT

  if(om_count() > 0) {

    OopMap* last = at(om_count()-1);

    if (last->offset() == map->offset() ) {

      fatal("OopMap inserted twice");

    }

    if(last->offset() > map->offset()) {

      tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d",

                      om_count(),last->offset(),om_count()+1,map->offset());

    }

  }

#endif // ASSERT

  set(om_count(),map);

  increment_count();

}

int OopMapSet::heap_size() const {

  // The space we use

  int size = sizeof(OopMap);

  int align = sizeof(void *) - 1;

  size = ((size+align) & ~align);

  size += om_count() * sizeof(OopMap*);

  // Now add in the space needed for the indivdiual OopMaps

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

    size += at(i)->heap_size();

  }

  // We don't need to align this, it will be naturally pointer aligned

  return size;

}

OopMap* OopMapSet::singular_oop_map() {

  guarantee(om_count() == 1, "Make sure we only have a single gc point");

  return at(0);

}

OopMap* OopMapSet::find_map_at_offset(int pc_offset) const {

  int i, len = om_count();

  assert( len > 0, "must have pointer maps" );

  // Scan through oopmaps. Stop when current offset is either equal or greater

  // than the one we are looking for.

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

    if( at(i)->offset() >= pc_offset )

      break;

  }

  assert( i < len, "oopmap not found" );

  OopMap* m = at(i);

  assert( m->offset() == pc_offset, "oopmap not found" );

  return m;

}

class DoNothingClosure: public OopClosure {

 public:

  void do_oop(oop* p)       {}

  void do_oop(narrowOop* p) {}

};

static DoNothingClosure do_nothing;

static void add_derived_oop(oop* base, oop* derived) {

#ifndef TIERED

  COMPILER1_PRESENT(ShouldNotReachHere();)

#endif // TIERED

#ifdef COMPILER2

  DerivedPointerTable::add(derived, base);

#endif // COMPILER2

}

#ifndef PRODUCT

static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) {

  // Print oopmap and regmap

  tty->print_cr("------ ");

  CodeBlob* cb = fr->cb();

  map->print();

  if( cb->is_nmethod() ) {

    nmethod* nm = (nmethod*)cb;

    // native wrappers have no scope data, it is implied

    if (nm->is_native_method()) {

      tty->print("bci: 0 (native)");

    } else {

      ScopeDesc* scope  = nm->scope_desc_at(fr->pc());

      tty->print("bci: %d ",scope->bci());

    }

  }

  tty->cr();

  fr->print_on(tty);

  tty->print("     ");

  cb->print_value_on(tty);  tty->cr();

  reg_map->print();

  tty->print_cr("------ ");

}

#endif // PRODUCT

void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) {

  // add derived oops to a table

  all_do(fr, reg_map, f, add_derived_oop, &do_nothing);

}

void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,

                       OopClosure* oop_fn, void derived_oop_fn(oop*, oop*),

                       OopClosure* value_fn) {

  CodeBlob* cb = fr->cb();

  assert(cb != NULL, "no codeblob");

  NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);)

  assert(map != NULL, "no ptr map found");

  // handle derived pointers first (otherwise base pointer may be

  // changed before derived pointer offset has been collected)

  OopMapValue omv;

  {

    OopMapStream oms(map,OopMapValue::derived_oop_value);

    if (!oms.is_done()) {

#ifndef TIERED

      COMPILER1_PRESENT(ShouldNotReachHere();)

#endif // !TIERED

      // Protect the operation on the derived pointers.  This

      // protects the addition of derived pointers to the shared

      // derived pointer table in DerivedPointerTable::add().

      MutexLockerEx x(DerivedPointerTableGC_lock, Mutex::_no_safepoint_check_flag);

      do {

        omv = oms.current();

        oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);

        if ( loc != NULL ) {

          oop *base_loc    = fr->oopmapreg_to_location(omv.content_reg(), reg_map);

          oop *derived_loc = loc;

          oop val = *base_loc;

          if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {

            // Ignore NULL oops and decoded NULL narrow oops which

            // equal to Universe::narrow_oop_base when a narrow oop

            // implicit null check is used in compiled code.

            // The narrow_oop_base could be NULL or be the address

            // of the page below heap depending on compressed oops mode.

          } else

            derived_oop_fn(base_loc, derived_loc);

        }

        oms.next();

      }  while (!oms.is_done());

    }

  }

  // We want coop, value and oop oop_types

  int mask = OopMapValue::oop_value | OopMapValue::value_value | OopMapValue::narrowoop_value;

  {

    for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) {

      omv = oms.current();

      oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);

      if ( loc != NULL ) {

        if ( omv.type() == OopMapValue::oop_value ) {

          oop val = *loc;

          if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {

            // Ignore NULL oops and decoded NULL narrow oops which

            // equal to Universe::narrow_oop_base when a narrow oop

            // implicit null check is used in compiled code.

            // The narrow_oop_base could be NULL or be the address

            // of the page below heap depending on compressed oops mode.

            continue;

          }

#ifdef ASSERT

          if ((((uintptr_t)loc & (sizeof(*loc)-1)) != 0) ||

             !Universe::heap()->is_in_or_null(*loc)) {

            tty->print_cr("# Found non oop pointer.  Dumping state at failure");

            // try to dump out some helpful debugging information

            trace_codeblob_maps(fr, reg_map);

            omv.print();

            tty->print_cr("register r");

            omv.reg()->print();

            tty->print_cr("loc = %p *loc = %p\n", loc, (address)*loc);

            // do the real assert.

            assert(Universe::heap()->is_in_or_null(*loc), "found non oop pointer");

          }

#endif // ASSERT

          oop_fn->do_oop(loc);

        } else if ( omv.type() == OopMapValue::value_value ) {

          assert((*loc) == (oop)NULL || !Universe::is_narrow_oop_base(*loc),

                 "found invalid value pointer");

          value_fn->do_oop(loc);

        } else if ( omv.type() == OopMapValue::narrowoop_value ) {

          narrowOop *nl = (narrowOop*)loc;

#ifndef VM_LITTLE_ENDIAN

          if (!omv.reg()->is_stack()) {

            // compressed oops in registers only take up 4 bytes of an

            // 8 byte register but they are in the wrong part of the

            // word so adjust loc to point at the right place.

            nl = (narrowOop*)((address)nl + 4);

          }

#endif

          oop_fn->do_oop(nl);

        }

      }

    }

  }

}

// Update callee-saved register info for the following frame

void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {

  ResourceMark rm;

  CodeBlob* cb = fr->cb();

  assert(cb != NULL, "no codeblob");

  // Any reg might be saved by a safepoint handler (see generate_handler_blob).

  assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id),

         "already updated this map; do not 'update' it twice!" );

  debug_only(reg_map->_update_for_id = fr->id());

  // Check if caller must update oop argument

  assert((reg_map->include_argument_oops() ||

          !cb->caller_must_gc_arguments(reg_map->thread())),

         "include_argument_oops should already be set");

  // Scan through oopmap and find location of all callee-saved registers

  // (we do not do update in place, since info could be overwritten)

  address pc = fr->pc();

  assert(map != NULL, "no ptr map found");

  DEBUG_ONLY(int nof_callee = 0;)

  for (OopMapStream oms(map, OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) {

    OopMapValue omv = oms.current();

    VMReg reg = omv.content_reg();

    oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);

    reg_map->set_location(reg, (address) loc);

    DEBUG_ONLY(nof_callee++;)

  }

  // Check that runtime stubs save all callee-saved registers

#ifdef COMPILER2

  assert(cb->is_compiled_by_c1() || !cb->is_runtime_stub() ||

         (nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),

         "must save all");

#endif // COMPILER2

}

//=============================================================================

// Non-Product code

#ifndef PRODUCT

#ifndef TIERED

  COMPILER1_PRESENT(return false);

#endif // !TIERED

#ifdef COMPILER2

  OopMapStream oms((OopMap*)this,OopMapValue::derived_oop_value);

  return oms.is_done();

#else

  return false;

#endif // COMPILER2

}

#endif //PRODUCT

// Printing code is present in product build for -XX:+PrintAssembly.

static

void print_register_type(OopMapValue::oop_types x, VMReg optional,

                         outputStream* st) {

  switch( x ) {

  case OopMapValue::oop_value:

    st->print("Oop");

    break;

  case OopMapValue::value_value:

    st->print("Value");

    break;

  case OopMapValue::narrowoop_value:

    st->print("NarrowOop");

    break;

  case OopMapValue::callee_saved_value:

    st->print("Callers_");

    optional->print_on(st);

    break;

  case OopMapValue::derived_oop_value:

    st->print("Derived_oop_");

    optional->print_on(st);

    break;

  default:

    ShouldNotReachHere();

  }

}

void OopMapValue::print_on(outputStream* st) const {

  reg()->print_on(st);

  st->print("=");

  print_register_type(type(),content_reg(),st);

  st->print(" ");

}