/*

 * Copyright (c) 1997, 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 "jvm.h"

#include "classfile/symbolTable.hpp"

#include "classfile/vmSymbols.hpp"

#include "compiler/compilerDirectives.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/oopFactory.hpp"

#include "memory/metaspaceClosure.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "utilities/xmlstream.hpp"

Symbol* vmSymbols::_symbols[vmSymbols::SID_LIMIT];

Symbol* vmSymbols::_type_signatures[T_VOID+1] = { NULL /*, NULL...*/ };

inline int compare_symbol(const Symbol* a, const Symbol* b) {

  if (a == b)  return 0;

  // follow the natural address order:

  return (address)a > (address)b ? +1 : -1;

}

static vmSymbols::SID vm_symbol_index[vmSymbols::SID_LIMIT];

extern "C" {

  static int compare_vmsymbol_sid(const void* void_a, const void* void_b) {

    const Symbol* a = vmSymbols::symbol_at(*((vmSymbols::SID*) void_a));

    const Symbol* b = vmSymbols::symbol_at(*((vmSymbols::SID*) void_b));

    return compare_symbol(a, b);

  }

}

#ifdef ASSERT

#define VM_SYMBOL_ENUM_NAME_BODY(name, string) #name "\0"

static const char* vm_symbol_enum_names =

  VM_SYMBOLS_DO(VM_SYMBOL_ENUM_NAME_BODY, VM_ALIAS_IGNORE)

  "\0";

static const char* vm_symbol_enum_name(vmSymbols::SID sid) {

  const char* string = &vm_symbol_enum_names[0];

  int skip = (int)sid - (int)vmSymbols::FIRST_SID;

  for (; skip != 0; skip--) {

    size_t skiplen = strlen(string);

    if (skiplen == 0)  return "<unknown>";  // overflow

    string += skiplen+1;

  }

  return string;

}

#endif //ASSERT

// Put all the VM symbol strings in one place.

// Makes for a more compact libjvm.

#define VM_SYMBOL_BODY(name, string) string "\0"

static const char* vm_symbol_bodies = VM_SYMBOLS_DO(VM_SYMBOL_BODY, VM_ALIAS_IGNORE);

void vmSymbols::initialize(TRAPS) {

  assert((int)SID_LIMIT <= (1<<log2_SID_LIMIT), "must fit in this bitfield");

  assert((int)SID_LIMIT*5 > (1<<log2_SID_LIMIT), "make the bitfield smaller, please");

  assert(vmIntrinsics::FLAG_LIMIT <= (1 << vmIntrinsics::log2_FLAG_LIMIT), "must fit in this bitfield");

  if (!UseSharedSpaces) {

    const char* string = &vm_symbol_bodies[0];

    for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

      Symbol* sym = SymbolTable::new_permanent_symbol(string);

      _symbols[index] = sym;

      string += strlen(string); // skip string body

      string += 1;              // skip trailing null

    }

    _type_signatures[T_BYTE]    = byte_signature();

    _type_signatures[T_CHAR]    = char_signature();

    _type_signatures[T_DOUBLE]  = double_signature();

    _type_signatures[T_FLOAT]   = float_signature();

    _type_signatures[T_INT]     = int_signature();

    _type_signatures[T_LONG]    = long_signature();

    _type_signatures[T_SHORT]   = short_signature();

    _type_signatures[T_BOOLEAN] = bool_signature();

    _type_signatures[T_VOID]    = void_signature();

    // no single signatures for T_OBJECT or T_ARRAY

#ifdef ASSERT

    for (int i = (int)T_BOOLEAN; i < (int)T_VOID+1; i++) {

      Symbol* s = _type_signatures[i];

      if (s == NULL)  continue;

      BasicType st = signature_type(s);

      assert(st == i, "");

    }

#endif

  }

#ifdef ASSERT

  // Check for duplicates:

  for (int i1 = (int)FIRST_SID; i1 < (int)SID_LIMIT; i1++) {

    Symbol* sym = symbol_at((SID)i1);

    for (int i2 = (int)FIRST_SID; i2 < i1; i2++) {

      if (symbol_at((SID)i2) == sym) {

        tty->print("*** Duplicate VM symbol SIDs %s(%d) and %s(%d): \"",

                   vm_symbol_enum_name((SID)i2), i2,

                   vm_symbol_enum_name((SID)i1), i1);

        sym->print_symbol_on(tty);

        tty->print_cr("\"");

      }

    }

  }

#endif //ASSERT

  // Create an index for find_id:

  {

    for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

      vm_symbol_index[index] = (SID)index;

    }

    int num_sids = SID_LIMIT-FIRST_SID;

    qsort(&vm_symbol_index[FIRST_SID], num_sids, sizeof(vm_symbol_index[0]),

          compare_vmsymbol_sid);

  }

#ifdef ASSERT

  {

    // Spot-check correspondence between strings, symbols, and enums:

    assert(_symbols[NO_SID] == NULL, "must be");

    const char* str = "java/lang/Object";

    TempNewSymbol jlo = SymbolTable::new_permanent_symbol(str);

    assert(strncmp(str, (char*)jlo->base(), jlo->utf8_length()) == 0, "");

    assert(jlo == java_lang_Object(), "");

    SID sid = VM_SYMBOL_ENUM_NAME(java_lang_Object);

    assert(find_sid(jlo) == sid, "");

    assert(symbol_at(sid) == jlo, "");

    // Make sure find_sid produces the right answer in each case.

    for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

      Symbol* sym = symbol_at((SID)index);

      sid = find_sid(sym);

      assert(sid == (SID)index, "symbol index works");

      // Note:  If there are duplicates, this assert will fail.

      // A "Duplicate VM symbol" message will have already been printed.

    }

    // The string "format" happens (at the moment) not to be a vmSymbol,

    // though it is a method name in java.lang.String.

    str = "format";

    TempNewSymbol fmt = SymbolTable::new_permanent_symbol(str);

    sid = find_sid(fmt);

    assert(sid == NO_SID, "symbol index works (negative test)");

  }

#endif

}

#ifndef PRODUCT

const char* vmSymbols::name_for(vmSymbols::SID sid) {

  if (sid == NO_SID)

    return "NO_SID";

  const char* string = &vm_symbol_bodies[0];

  for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

    if (index == (int)sid)

      return string;

    string += strlen(string); // skip string body

    string += 1;              // skip trailing null

  }

  return "BAD_SID";

}

#endif

void vmSymbols::symbols_do(SymbolClosure* f) {

  for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

    f->do_symbol(&_symbols[index]);

  }

  for (int i = 0; i < T_VOID+1; i++) {

    f->do_symbol(&_type_signatures[i]);

  }

}

void vmSymbols::metaspace_pointers_do(MetaspaceClosure *it) {

  for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

    it->push(&_symbols[index]);

  }

  for (int i = 0; i < T_VOID+1; i++) {

    it->push(&_type_signatures[i]);

  }

}

void vmSymbols::serialize(SerializeClosure* soc) {

  soc->do_region((u_char*)&_symbols[FIRST_SID],

                 (SID_LIMIT - FIRST_SID) * sizeof(_symbols[0]));

  soc->do_region((u_char*)_type_signatures, sizeof(_type_signatures));

}

BasicType vmSymbols::signature_type(const Symbol* s) {

  assert(s != NULL, "checking");

  if (s->utf8_length() == 1) {

    BasicType result = char2type(s->char_at(0));

    if (is_java_primitive(result) || result == T_VOID) {

      assert(s == _type_signatures[result], "");

      return result;

    }

  }

  return T_OBJECT;

}

static int mid_hint = (int)vmSymbols::FIRST_SID+1;

#ifndef PRODUCT

static int find_sid_calls, find_sid_probes;

// (Typical counts are calls=7000 and probes=17000.)

#endif

vmSymbols::SID vmSymbols::find_sid(const Symbol* symbol) {

  // Handle the majority of misses by a bounds check.

  // Then, use a binary search over the index.

  // Expected trip count is less than log2_SID_LIMIT, about eight.

  // This is slow but acceptable, given that calls are not

  // dynamically common.  (Method*::intrinsic_id has a cache.)

  NOT_PRODUCT(find_sid_calls++);

  int min = (int)FIRST_SID, max = (int)SID_LIMIT - 1;

  SID sid = NO_SID, sid1;

  int cmp1;

  sid1 = vm_symbol_index[min];

  cmp1 = compare_symbol(symbol, symbol_at(sid1));

  if (cmp1 <= 0) {              // before the first

    if (cmp1 == 0)  sid = sid1;

  } else {

    sid1 = vm_symbol_index[max];

    cmp1 = compare_symbol(symbol, symbol_at(sid1));

    if (cmp1 >= 0) {            // after the last

      if (cmp1 == 0)  sid = sid1;

    } else {

      // After checking the extremes, do a binary search.

      ++min; --max;             // endpoints are done

      int mid = mid_hint;       // start at previous success

      while (max >= min) {

        assert(mid >= min && mid <= max, "");

        NOT_PRODUCT(find_sid_probes++);

        sid1 = vm_symbol_index[mid];

        cmp1 = compare_symbol(symbol, symbol_at(sid1));

        if (cmp1 == 0) {

          mid_hint = mid;

          sid = sid1;

          break;

        }

        if (cmp1 < 0)

          max = mid - 1;        // symbol < symbol_at(sid)

        else

          min = mid + 1;

        // Pick a new probe point:

        mid = (max + min) / 2;

      }

    }

  }

#ifdef ASSERT

  // Perform the exhaustive self-check the first 1000 calls,

  // and every 100 calls thereafter.

  static int find_sid_check_count = -2000;

  if ((uint)++find_sid_check_count > (uint)100) {

    if (find_sid_check_count > 0)  find_sid_check_count = 0;

    // Make sure this is the right answer, using linear search.

    // (We have already proven that there are no duplicates in the list.)

    SID sid2 = NO_SID;

    for (int index = (int)FIRST_SID; index < (int)SID_LIMIT; index++) {

      Symbol* sym2 = symbol_at((SID)index);

      if (sym2 == symbol) {

        sid2 = (SID)index;

        break;

      }

    }

    // Unless it's a duplicate, assert that the sids are the same.

    if (_symbols[sid] != _symbols[sid2]) {

      assert(sid == sid2, "binary same as linear search");

    }

  }

#endif //ASSERT

  return sid;

}

vmSymbols::SID vmSymbols::find_sid(const char* symbol_name) {

  Symbol* symbol = SymbolTable::probe(symbol_name, (int) strlen(symbol_name));

  if (symbol == NULL)  return NO_SID;

  return find_sid(symbol);

}

static vmIntrinsics::ID wrapper_intrinsic(BasicType type, bool unboxing) {

#define TYPE2(type, unboxing) ((int)(type)*2 + ((unboxing) ? 1 : 0))

  switch (TYPE2(type, unboxing)) {

#define BASIC_TYPE_CASE(type, box, unbox) \

    case TYPE2(type, false):  return vmIntrinsics::box; \

    case TYPE2(type, true):   return vmIntrinsics::unbox

    BASIC_TYPE_CASE(T_BOOLEAN, _Boolean_valueOf,   _booleanValue);

    BASIC_TYPE_CASE(T_BYTE,    _Byte_valueOf,      _byteValue);

    BASIC_TYPE_CASE(T_CHAR,    _Character_valueOf, _charValue);

    BASIC_TYPE_CASE(T_SHORT,   _Short_valueOf,     _shortValue);

    BASIC_TYPE_CASE(T_INT,     _Integer_valueOf,   _intValue);

    BASIC_TYPE_CASE(T_LONG,    _Long_valueOf,      _longValue);

    BASIC_TYPE_CASE(T_FLOAT,   _Float_valueOf,     _floatValue);

    BASIC_TYPE_CASE(T_DOUBLE,  _Double_valueOf,    _doubleValue);

#undef BASIC_TYPE_CASE

  }

#undef TYPE2

  return vmIntrinsics::_none;

}

vmIntrinsics::ID vmIntrinsics::for_boxing(BasicType type) {

  return wrapper_intrinsic(type, false);

}

vmIntrinsics::ID vmIntrinsics::for_unboxing(BasicType type) {

  return wrapper_intrinsic(type, true);

}

vmIntrinsics::ID vmIntrinsics::for_raw_conversion(BasicType src, BasicType dest) {

#define SRC_DEST(s,d) (((int)(s) << 4) + (int)(d))

  switch (SRC_DEST(src, dest)) {

  case SRC_DEST(T_INT, T_FLOAT):   return vmIntrinsics::_intBitsToFloat;

  case SRC_DEST(T_FLOAT, T_INT):   return vmIntrinsics::_floatToRawIntBits;

  case SRC_DEST(T_LONG, T_DOUBLE): return vmIntrinsics::_longBitsToDouble;

  case SRC_DEST(T_DOUBLE, T_LONG): return vmIntrinsics::_doubleToRawLongBits;

  }

#undef SRC_DEST

  return vmIntrinsics::_none;

}

bool vmIntrinsics::preserves_state(vmIntrinsics::ID id) {

  assert(id != vmIntrinsics::_none, "must be a VM intrinsic");

  switch(id) {

#ifdef JFR_HAVE_INTRINSICS

  case vmIntrinsics::_counterTime:

#endif

  case vmIntrinsics::_currentTimeMillis:

  case vmIntrinsics::_nanoTime:

  case vmIntrinsics::_floatToRawIntBits:

  case vmIntrinsics::_intBitsToFloat:

  case vmIntrinsics::_doubleToRawLongBits:

  case vmIntrinsics::_longBitsToDouble:

  case vmIntrinsics::_getClass:

  case vmIntrinsics::_isInstance:

  case vmIntrinsics::_currentThread:

  case vmIntrinsics::_dabs:

  case vmIntrinsics::_fabs:

  case vmIntrinsics::_iabs:

  case vmIntrinsics::_labs:

  case vmIntrinsics::_dsqrt:

  case vmIntrinsics::_dsin:

  case vmIntrinsics::_dcos:

  case vmIntrinsics::_dtan:

  case vmIntrinsics::_dlog:

  case vmIntrinsics::_dlog10:

  case vmIntrinsics::_dexp:

  case vmIntrinsics::_dpow:

  case vmIntrinsics::_checkIndex:

  case vmIntrinsics::_Reference_get:

  case vmIntrinsics::_updateCRC32:

  case vmIntrinsics::_updateBytesCRC32:

  case vmIntrinsics::_updateByteBufferCRC32:

  case vmIntrinsics::_vectorizedMismatch:

  case vmIntrinsics::_fmaD:

  case vmIntrinsics::_fmaF:

  case vmIntrinsics::_isDigit:

  case vmIntrinsics::_isLowerCase:

  case vmIntrinsics::_isUpperCase:

  case vmIntrinsics::_isWhitespace:

    return true;

  default:

    return false;

  }

}

bool vmIntrinsics::can_trap(vmIntrinsics::ID id) {

  assert(id != vmIntrinsics::_none, "must be a VM intrinsic");

  switch(id) {

#ifdef JFR_HAVE_INTRINSICS

  case vmIntrinsics::_counterTime:

  case vmIntrinsics::_getClassId:

#endif

  case vmIntrinsics::_currentTimeMillis:

  case vmIntrinsics::_nanoTime:

  case vmIntrinsics::_floatToRawIntBits:

  case vmIntrinsics::_intBitsToFloat:

  case vmIntrinsics::_doubleToRawLongBits:

  case vmIntrinsics::_longBitsToDouble:

  case vmIntrinsics::_currentThread:

  case vmIntrinsics::_dabs:

  case vmIntrinsics::_fabs:

  case vmIntrinsics::_iabs:

  case vmIntrinsics::_labs:

  case vmIntrinsics::_dsqrt:

  case vmIntrinsics::_dsin:

  case vmIntrinsics::_dcos:

  case vmIntrinsics::_dtan:

  case vmIntrinsics::_dlog:

  case vmIntrinsics::_dlog10:

  case vmIntrinsics::_dexp:

  case vmIntrinsics::_dpow:

  case vmIntrinsics::_updateCRC32:

  case vmIntrinsics::_updateBytesCRC32:

  case vmIntrinsics::_updateByteBufferCRC32:

  case vmIntrinsics::_vectorizedMismatch:

  case vmIntrinsics::_fmaD:

  case vmIntrinsics::_fmaF:

    return false;

  default:

    return true;

  }

}

// Some intrinsics produce different results if they are not pinned

bool vmIntrinsics::should_be_pinned(vmIntrinsics::ID id) {

  assert(id != vmIntrinsics::_none, "must be a VM intrinsic");

  switch(id) {

#ifdef JFR_HAVE_INTRINSICS

  case vmIntrinsics::_counterTime:

#endif

  case vmIntrinsics::_currentTimeMillis:

  case vmIntrinsics::_nanoTime:

    return true;

  default:

    return false;

  }

}

bool vmIntrinsics::does_virtual_dispatch(vmIntrinsics::ID id) {

  assert(id != vmIntrinsics::_none, "must be a VM intrinsic");

  switch(id) {

  case vmIntrinsics::_hashCode:

  case vmIntrinsics::_clone:

    return true;

    break;

  default:

    return false;

  }

}

int vmIntrinsics::predicates_needed(vmIntrinsics::ID id) {

  assert(id != vmIntrinsics::_none, "must be a VM intrinsic");

  switch (id) {

  case vmIntrinsics::_cipherBlockChaining_encryptAESCrypt:

  case vmIntrinsics::_cipherBlockChaining_decryptAESCrypt:

  case vmIntrinsics::_electronicCodeBook_encryptAESCrypt:

  case vmIntrinsics::_electronicCodeBook_decryptAESCrypt:

  case vmIntrinsics::_counterMode_AESCrypt:

    return 1;

  case vmIntrinsics::_digestBase_implCompressMB:

    return 3;

  default:

    return 0;

  }

}

bool vmIntrinsics::is_intrinsic_available(vmIntrinsics::ID id) {

  return !vmIntrinsics::is_intrinsic_disabled(id) &&

    !vmIntrinsics::is_disabled_by_flags(id);

}

bool vmIntrinsics::is_intrinsic_disabled(vmIntrinsics::ID id) {

  assert(id != vmIntrinsics::_none, "must be a VM intrinsic");

  // Canonicalize DisableIntrinsic to contain only ',' as a separator.

  // Note, DirectiveSet may not be created at this point yet since this code

  // is called from initial stub geenration code.

  char* local_list = (char*)DirectiveSet::canonicalize_disableintrinsic(DisableIntrinsic);

  char* save_ptr;

  bool found = false;

  char* token = strtok_r(local_list, ",", &save_ptr);

  while (token != NULL) {

    if (strcmp(token, vmIntrinsics::name_at(id)) == 0) {

      found = true;

      break;

    } else {

      token = strtok_r(NULL, ",", &save_ptr);

    }

  }

  FREE_C_HEAP_ARRAY(char, local_list);

  return found;

}