/*

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

#include "code/nmethod.hpp"

#include "memory/allocation.inline.hpp"

void ExceptionHandlerTable::add_entry(HandlerTableEntry entry) {

  _nesting.check();

  if (_length >= _size) {

    // not enough space => grow the table (amortized growth, double its size)

    guarantee(_size > 0, "no space allocated => cannot grow the table since it is part of nmethod");

    int new_size = _size * 2;

    _table = REALLOC_RESOURCE_ARRAY(HandlerTableEntry, _table, _size, new_size);

    _size = new_size;

  }

  assert(_length < _size, "sanity check");

  _table[_length++] = entry;

}

HandlerTableEntry* ExceptionHandlerTable::subtable_for(int catch_pco) const {

  int i = 0;

  while (i < _length) {

    HandlerTableEntry* t = _table + i;

    if (t->pco() == catch_pco) {

      // found subtable matching the catch_pco

      return t;

    } else {

      // advance to next subtable

      i += t->len() + 1; // +1 for header

    }

  }

  return NULL;

}

ExceptionHandlerTable::ExceptionHandlerTable(int initial_size) {

  guarantee(initial_size > 0, "initial size must be > 0");

  _table  = NEW_RESOURCE_ARRAY(HandlerTableEntry, initial_size);

  _length = 0;

  _size   = initial_size;

}

ExceptionHandlerTable::ExceptionHandlerTable(const CompiledMethod* cm) {

  _table  = (HandlerTableEntry*)cm->handler_table_begin();

  _length = cm->handler_table_size() / sizeof(HandlerTableEntry);

  _size   = 0; // no space allocated by ExeptionHandlerTable!

}

void ExceptionHandlerTable::add_subtable(

  int                 catch_pco,

  GrowableArray<intptr_t>* handler_bcis,

  GrowableArray<intptr_t>* scope_depths_from_top_scope,

  GrowableArray<intptr_t>* handler_pcos

) {

  assert(subtable_for(catch_pco) == NULL, "catch handlers for this catch_pco added twice");

  assert(handler_bcis->length() == handler_pcos->length(), "bci & pc table have different length");

  assert(scope_depths_from_top_scope == NULL || handler_bcis->length() == scope_depths_from_top_scope->length(), "bci & scope_depths table have different length");

  if (handler_bcis->length() > 0) {

    // add subtable header

    add_entry(HandlerTableEntry(handler_bcis->length(), catch_pco, 0));

    // add individual entries

    for (int i = 0; i < handler_bcis->length(); i++) {

      intptr_t scope_depth = 0;

      if (scope_depths_from_top_scope != NULL) {

        scope_depth = scope_depths_from_top_scope->at(i);

      }

      add_entry(HandlerTableEntry(handler_bcis->at(i), handler_pcos->at(i), scope_depth));

      assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->pco() == handler_pcos->at(i), "entry not added correctly (1)");

      assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->scope_depth() == scope_depth, "entry not added correctly (2)");

    }

  }

}

void ExceptionHandlerTable::copy_to(CompiledMethod* cm) {

  assert(size_in_bytes() == cm->handler_table_size(), "size of space allocated in compiled method incorrect");

  copy_bytes_to(cm->handler_table_begin());

}

void ExceptionHandlerTable::copy_bytes_to(address addr) {

  memmove(addr, _table, size_in_bytes());

}

HandlerTableEntry* ExceptionHandlerTable::entry_for(int catch_pco, int handler_bci, int scope_depth) const {

  HandlerTableEntry* t = subtable_for(catch_pco);

  if (t != NULL) {

    int l = t->len();

    while (l-- > 0) {

      t++;

      if (t->bci() == handler_bci && t->scope_depth() == scope_depth) return t;

    }

  }

  return NULL;

}

void ExceptionHandlerTable::print_subtable(HandlerTableEntry* t) const {

  int l = t->len();

  tty->print_cr("catch_pco = %d (%d entries)", t->pco(), l);

  while (l-- > 0) {

    t++;

    tty->print_cr("  bci %d at scope depth %d -> pco %d", t->bci(), t->scope_depth(), t->pco());

  }

}

void ExceptionHandlerTable::print() const {

  tty->print_cr("ExceptionHandlerTable (size = %d bytes)", size_in_bytes());

  int i = 0;

  while (i < _length) {

    HandlerTableEntry* t = _table + i;

    print_subtable(t);

    // advance to next subtable

    i += t->len() + 1; // +1 for header

  }

}

void ExceptionHandlerTable::print_subtable_for(int catch_pco) const {

  HandlerTableEntry* subtable = subtable_for(catch_pco);

  if( subtable != NULL ) { print_subtable( subtable ); }

}

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

// Implicit null exception tables.  Maps an exception PC offset to a

// continuation PC offset.  During construction it's a variable sized

// array with a max size and current length.  When stored inside an

// nmethod a zero length table takes no space.  This is detected by

// nul_chk_table_size() == 0.  Otherwise the table has a length word

// followed by pairs of <excp-offset, const-offset>.

void ImplicitExceptionTable::set_size( uint size ) {

  _size = size;

  _data = NEW_RESOURCE_ARRAY(implicit_null_entry, (size*2));

  _len = 0;

}

void ImplicitExceptionTable::append( uint exec_off, uint cont_off ) {

  assert( (sizeof(implicit_null_entry) >= 4) || (exec_off < 65535), "" );

  assert( (sizeof(implicit_null_entry) >= 4) || (cont_off < 65535), "" );

  uint l = len();

  if (l == _size) {

    uint old_size_in_elements = _size*2;

    if (_size == 0) _size = 4;

    _size *= 2;

    uint new_size_in_elements = _size*2;

    _data = REALLOC_RESOURCE_ARRAY(uint, _data, old_size_in_elements, new_size_in_elements);

  }

  *(adr(l)  ) = exec_off;

  *(adr(l)+1) = cont_off;

  _len = l+1;

};

uint ImplicitExceptionTable::continuation_offset( uint exec_off ) const {

  uint l = len();

  for( uint i=0; i<l; i++ )

    if( *adr(i) == exec_off )

      return *(adr(i)+1);

  return 0;                     // Failed to find any execption offset

}

void ImplicitExceptionTable::print(address base) const {

  const uint n = len();

  if (n > 0) {

    const uint items_per_line = 3;

    uint i;

    tty->print_cr("ImplicitExceptionTable (size = %d entries, %d bytes):", n, size_in_bytes());

    tty->print("{");

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

      if (i%items_per_line == 0) {

        tty->cr();

        tty->fill_to(3);

      }

      tty->print("< " INTPTR_FORMAT ", " INTPTR_FORMAT " > ", p2i(base + *adr(i)), p2i(base + *(adr(i)+1)));

    }

    tty->bol();

    tty->print_cr("}");

  } else {

    tty->print_cr("ImplicitExceptionTable is empty");

  }

}

ImplicitExceptionTable::ImplicitExceptionTable(const CompiledMethod* nm) {

  if (nm->nul_chk_table_size() == 0) {

    _len = 0;

    _data = NULL;

  } else {

    // the first word is the length if non-zero, so read it out and

    // skip to the next word to get the table.

    _data  = (implicit_null_entry*)nm->nul_chk_table_begin();

    _len = _data[0];

    _data++;

  }

  _size = len();

  assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");

}

void ImplicitExceptionTable::copy_to( nmethod* nm ) {

  copy_bytes_to(nm->nul_chk_table_begin(), nm->nul_chk_table_size());

}

void ImplicitExceptionTable::copy_bytes_to(address addr, int size) {

  assert(size_in_bytes() <= size, "size of space allocated in nmethod incorrect");

  if (len() != 0) {

    implicit_null_entry* nmdata = (implicit_null_entry*)addr;

    // store the length in the first uint

    nmdata[0] = _len;

    nmdata++;

    // copy the table after the length

    memmove( nmdata, _data, 2 * len() * sizeof(implicit_null_entry));

  } else {

    // zero length table takes zero bytes

    assert(size_in_bytes() == 0, "bad size");

    assert(size == 0, "bad size");

  }

}

void ImplicitExceptionTable::verify(nmethod *nm) const {

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

     if ((*adr(i) > (unsigned int)nm->insts_size()) ||

         (*(adr(i)+1) > (unsigned int)nm->insts_size()))

       fatal("Invalid offset in ImplicitExceptionTable at " PTR_FORMAT, p2i(_data));

  }

}