/*

 * Copyright (c) 1997, 2012, 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/classFileParser.hpp"

#include "classfile/classLoader.hpp"

#include "classfile/javaClasses.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/verificationType.hpp"

#include "classfile/verifier.hpp"

#include "classfile/vmSymbols.hpp"

#include "memory/allocation.hpp"

#include "memory/gcLocker.hpp"

#include "memory/oopFactory.hpp"

#include "memory/universe.inline.hpp"

#include "oops/constantPoolOop.hpp"

#include "oops/fieldStreams.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/instanceMirrorKlass.hpp"

#include "oops/klass.inline.hpp"

#include "oops/klassOop.hpp"

#include "oops/klassVtable.hpp"

#include "oops/methodOop.hpp"

#include "oops/symbol.hpp"

#include "prims/jvmtiExport.hpp"

#include "prims/jvmtiThreadState.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/perfData.hpp"

#include "runtime/reflection.hpp"

#include "runtime/signature.hpp"

#include "runtime/timer.hpp"

#include "services/classLoadingService.hpp"

#include "services/threadService.hpp"

// We generally try to create the oops directly when parsing, rather than

// allocating temporary data structures and copying the bytes twice. A

// temporary area is only needed when parsing utf8 entries in the constant

// pool and when parsing line number tables.

// We add assert in debug mode when class format is not checked.

#define JAVA_CLASSFILE_MAGIC              0xCAFEBABE

#define JAVA_MIN_SUPPORTED_VERSION        45

#define JAVA_MAX_SUPPORTED_VERSION        51

#define JAVA_MAX_SUPPORTED_MINOR_VERSION  0

// Used for two backward compatibility reasons:

// - to check for new additions to the class file format in JDK1.5

// - to check for bug fixes in the format checker in JDK1.5

#define JAVA_1_5_VERSION                  49

// Used for backward compatibility reasons:

// - to check for javac bug fixes that happened after 1.5

// - also used as the max version when running in jdk6

#define JAVA_6_VERSION                    50

// Used for backward compatibility reasons:

// - to check NameAndType_info signatures more aggressively

#define JAVA_7_VERSION                    51

void ClassFileParser::parse_constant_pool_entries(Handle class_loader, constantPoolHandle cp, int length, TRAPS) {

  // Use a local copy of ClassFileStream. It helps the C++ compiler to optimize

  // this function (_current can be allocated in a register, with scalar

  // replacement of aggregates). The _current pointer is copied back to

  // stream() when this function returns. DON'T call another method within

  // this method that uses stream().

  ClassFileStream* cfs0 = stream();

  ClassFileStream cfs1 = *cfs0;

  ClassFileStream* cfs = &cfs1;

#ifdef ASSERT

  assert(cfs->allocated_on_stack(),"should be local");

  u1* old_current = cfs0->current();

#endif

  // Used for batching symbol allocations.

  const char* names[SymbolTable::symbol_alloc_batch_size];

  int lengths[SymbolTable::symbol_alloc_batch_size];

  int indices[SymbolTable::symbol_alloc_batch_size];

  unsigned int hashValues[SymbolTable::symbol_alloc_batch_size];

  int names_count = 0;

  // parsing  Index 0 is unused

  for (int index = 1; index < length; index++) {

    // Each of the following case guarantees one more byte in the stream

    // for the following tag or the access_flags following constant pool,

    // so we don't need bounds-check for reading tag.

    u1 tag = cfs->get_u1_fast();

    switch (tag) {

      case JVM_CONSTANT_Class :

        {

          cfs->guarantee_more(3, CHECK);  // name_index, tag/access_flags

          u2 name_index = cfs->get_u2_fast();

          cp->klass_index_at_put(index, name_index);

        }

        break;

      case JVM_CONSTANT_Fieldref :

        {

          cfs->guarantee_more(5, CHECK);  // class_index, name_and_type_index, tag/access_flags

          u2 class_index = cfs->get_u2_fast();

          u2 name_and_type_index = cfs->get_u2_fast();

          cp->field_at_put(index, class_index, name_and_type_index);

        }

        break;

      case JVM_CONSTANT_Methodref :

        {

          cfs->guarantee_more(5, CHECK);  // class_index, name_and_type_index, tag/access_flags

          u2 class_index = cfs->get_u2_fast();

          u2 name_and_type_index = cfs->get_u2_fast();

          cp->method_at_put(index, class_index, name_and_type_index);

        }

        break;

      case JVM_CONSTANT_InterfaceMethodref :

        {

          cfs->guarantee_more(5, CHECK);  // class_index, name_and_type_index, tag/access_flags

          u2 class_index = cfs->get_u2_fast();

          u2 name_and_type_index = cfs->get_u2_fast();

          cp->interface_method_at_put(index, class_index, name_and_type_index);

        }

        break;

      case JVM_CONSTANT_String :

        {

          cfs->guarantee_more(3, CHECK);  // string_index, tag/access_flags

          u2 string_index = cfs->get_u2_fast();

          cp->string_index_at_put(index, string_index);

        }

        break;

      case JVM_CONSTANT_MethodHandle :

      case JVM_CONSTANT_MethodType :

        if (_major_version < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {

          classfile_parse_error(

            "Class file version does not support constant tag %u in class file %s",

            tag, CHECK);

        }

        if (!EnableInvokeDynamic) {

          classfile_parse_error(

            "This JVM does not support constant tag %u in class file %s",

            tag, CHECK);

        }

        if (tag == JVM_CONSTANT_MethodHandle) {

          cfs->guarantee_more(4, CHECK);  // ref_kind, method_index, tag/access_flags

          u1 ref_kind = cfs->get_u1_fast();

          u2 method_index = cfs->get_u2_fast();

          cp->method_handle_index_at_put(index, ref_kind, method_index);

        } else if (tag == JVM_CONSTANT_MethodType) {

          cfs->guarantee_more(3, CHECK);  // signature_index, tag/access_flags

          u2 signature_index = cfs->get_u2_fast();

          cp->method_type_index_at_put(index, signature_index);

        } else {

          ShouldNotReachHere();

        }

        break;

      case JVM_CONSTANT_InvokeDynamic :

        {

          if (_major_version < Verifier::INVOKEDYNAMIC_MAJOR_VERSION) {

            classfile_parse_error(

              "Class file version does not support constant tag %u in class file %s",

              tag, CHECK);

          }

          if (!EnableInvokeDynamic) {

            classfile_parse_error(

              "This JVM does not support constant tag %u in class file %s",

              tag, CHECK);

          }

          cfs->guarantee_more(5, CHECK);  // bsm_index, nt, tag/access_flags

          u2 bootstrap_specifier_index = cfs->get_u2_fast();

          u2 name_and_type_index = cfs->get_u2_fast();

          if (_max_bootstrap_specifier_index < (int) bootstrap_specifier_index)

            _max_bootstrap_specifier_index = (int) bootstrap_specifier_index;  // collect for later

          cp->invoke_dynamic_at_put(index, bootstrap_specifier_index, name_and_type_index);

        }

        break;

      case JVM_CONSTANT_Integer :

        {

          cfs->guarantee_more(5, CHECK);  // bytes, tag/access_flags

          u4 bytes = cfs->get_u4_fast();

          cp->int_at_put(index, (jint) bytes);

        }

        break;

      case JVM_CONSTANT_Float :

        {

          cfs->guarantee_more(5, CHECK);  // bytes, tag/access_flags

          u4 bytes = cfs->get_u4_fast();

          cp->float_at_put(index, *(jfloat*)&bytes);

        }

        break;

      case JVM_CONSTANT_Long :

        // A mangled type might cause you to overrun allocated memory

        guarantee_property(index+1 < length,

                           "Invalid constant pool entry %u in class file %s",

                           index, CHECK);

        {

          cfs->guarantee_more(9, CHECK);  // bytes, tag/access_flags

          u8 bytes = cfs->get_u8_fast();

          cp->long_at_put(index, bytes);

        }

        index++;   // Skip entry following eigth-byte constant, see JVM book p. 98

        break;

      case JVM_CONSTANT_Double :

        // A mangled type might cause you to overrun allocated memory

        guarantee_property(index+1 < length,

                           "Invalid constant pool entry %u in class file %s",

                           index, CHECK);

        {

          cfs->guarantee_more(9, CHECK);  // bytes, tag/access_flags

          u8 bytes = cfs->get_u8_fast();

          cp->double_at_put(index, *(jdouble*)&bytes);

        }

        index++;   // Skip entry following eigth-byte constant, see JVM book p. 98

        break;

      case JVM_CONSTANT_NameAndType :

        {

          cfs->guarantee_more(5, CHECK);  // name_index, signature_index, tag/access_flags

          u2 name_index = cfs->get_u2_fast();

          u2 signature_index = cfs->get_u2_fast();

          cp->name_and_type_at_put(index, name_index, signature_index);

        }

        break;

      case JVM_CONSTANT_Utf8 :

        {

          cfs->guarantee_more(2, CHECK);  // utf8_length

          u2  utf8_length = cfs->get_u2_fast();

          u1* utf8_buffer = cfs->get_u1_buffer();

          assert(utf8_buffer != NULL, "null utf8 buffer");

          // Got utf8 string, guarantee utf8_length+1 bytes, set stream position forward.

          cfs->guarantee_more(utf8_length+1, CHECK);  // utf8 string, tag/access_flags

          cfs->skip_u1_fast(utf8_length);

          // Before storing the symbol, make sure it's legal

          if (_need_verify) {

            verify_legal_utf8((unsigned char*)utf8_buffer, utf8_length, CHECK);

          }

          if (EnableInvokeDynamic && has_cp_patch_at(index)) {

            Handle patch = clear_cp_patch_at(index);

            guarantee_property(java_lang_String::is_instance(patch()),

                               "Illegal utf8 patch at %d in class file %s",

                               index, CHECK);

            char* str = java_lang_String::as_utf8_string(patch());

            // (could use java_lang_String::as_symbol instead, but might as well batch them)

            utf8_buffer = (u1*) str;

            utf8_length = (int) strlen(str);

          }

          unsigned int hash;

          Symbol* result = SymbolTable::lookup_only((char*)utf8_buffer, utf8_length, hash);

          if (result == NULL) {

            names[names_count] = (char*)utf8_buffer;

            lengths[names_count] = utf8_length;

            indices[names_count] = index;

            hashValues[names_count++] = hash;

            if (names_count == SymbolTable::symbol_alloc_batch_size) {

              SymbolTable::new_symbols(class_loader, cp, names_count, names, lengths, indices, hashValues, CHECK);

              names_count = 0;

            }

          } else {

            cp->symbol_at_put(index, result);

          }

        }

        break;

      default:

        classfile_parse_error(

          "Unknown constant tag %u in class file %s", tag, CHECK);

        break;

    }

  }

  // Allocate the remaining symbols

  if (names_count > 0) {

    SymbolTable::new_symbols(class_loader, cp, names_count, names, lengths, indices, hashValues, CHECK);

  }

  // Copy _current pointer of local copy back to stream().

#ifdef ASSERT

  assert(cfs0->current() == old_current, "non-exclusive use of stream()");

#endif

  cfs0->set_current(cfs1.current());

}

// This class unreferences constant pool symbols if an error has occurred

// while parsing the class before it is assigned into the class.

// If it gets an error after that it is unloaded and the constant pool will

// be cleaned up then.

class ConstantPoolCleaner : public StackObj {

  constantPoolHandle _cphandle;

  bool               _in_error;

 public:

  ConstantPoolCleaner(constantPoolHandle cp) : _cphandle(cp), _in_error(true) {}

  ~ConstantPoolCleaner() {

    if (_in_error && _cphandle.not_null()) {

      _cphandle->unreference_symbols();

    }

  }

  void set_in_error(bool clean) { _in_error = clean; }

};

bool inline valid_cp_range(int index, int length) { return (index > 0 && index < length); }

inline Symbol* check_symbol_at(constantPoolHandle cp, int index) {

  if (valid_cp_range(index, cp->length()) && cp->tag_at(index).is_utf8())

    return cp->symbol_at(index);

  else

    return NULL;

}

constantPoolHandle ClassFileParser::parse_constant_pool(Handle class_loader, TRAPS) {

  ClassFileStream* cfs = stream();

  constantPoolHandle nullHandle;

  cfs->guarantee_more(3, CHECK_(nullHandle)); // length, first cp tag

  u2 length = cfs->get_u2_fast();

  guarantee_property(

    length >= 1, "Illegal constant pool size %u in class file %s",

    length, CHECK_(nullHandle));

  constantPoolOop constant_pool =

                      oopFactory::new_constantPool(length,

                                                   oopDesc::IsSafeConc,

                                                   CHECK_(nullHandle));

  constantPoolHandle cp (THREAD, constant_pool);

  cp->set_partially_loaded();    // Enables heap verify to work on partial constantPoolOops

  ConstantPoolCleaner cp_in_error(cp); // set constant pool to be cleaned up.

  // parsing constant pool entries

  parse_constant_pool_entries(class_loader, cp, length, CHECK_(nullHandle));

  int index = 1;  // declared outside of loops for portability

  // first verification pass - validate cross references and fixup class and string constants

  for (index = 1; index < length; index++) {          // Index 0 is unused

    jbyte tag = cp->tag_at(index).value();

    switch (tag) {

      case JVM_CONSTANT_Class :

        ShouldNotReachHere();     // Only JVM_CONSTANT_ClassIndex should be present

        break;

      case JVM_CONSTANT_Fieldref :

        // fall through

      case JVM_CONSTANT_Methodref :

        // fall through

      case JVM_CONSTANT_InterfaceMethodref : {

        if (!_need_verify) break;

        int klass_ref_index = cp->klass_ref_index_at(index);

        int name_and_type_ref_index = cp->name_and_type_ref_index_at(index);

        check_property(valid_cp_range(klass_ref_index, length) &&

                       is_klass_reference(cp, klass_ref_index),

                       "Invalid constant pool index %u in class file %s",

                       klass_ref_index,

                       CHECK_(nullHandle));

        check_property(valid_cp_range(name_and_type_ref_index, length) &&

                       cp->tag_at(name_and_type_ref_index).is_name_and_type(),

                       "Invalid constant pool index %u in class file %s",

                       name_and_type_ref_index,

                       CHECK_(nullHandle));

        break;

      }

      case JVM_CONSTANT_String :

        ShouldNotReachHere();     // Only JVM_CONSTANT_StringIndex should be present

        break;

      case JVM_CONSTANT_Integer :

        break;

      case JVM_CONSTANT_Float :

        break;

      case JVM_CONSTANT_Long :

      case JVM_CONSTANT_Double :

        index++;

        check_property(

          (index < length && cp->tag_at(index).is_invalid()),

          "Improper constant pool long/double index %u in class file %s",

          index, CHECK_(nullHandle));

        break;

      case JVM_CONSTANT_NameAndType : {

        if (!_need_verify) break;

        int name_ref_index = cp->name_ref_index_at(index);

        int signature_ref_index = cp->signature_ref_index_at(index);

        check_property(

          valid_cp_range(name_ref_index, length) &&

            cp->tag_at(name_ref_index).is_utf8(),

          "Invalid constant pool index %u in class file %s",

          name_ref_index, CHECK_(nullHandle));

        check_property(

          valid_cp_range(signature_ref_index, length) &&

            cp->tag_at(signature_ref_index).is_utf8(),

          "Invalid constant pool index %u in class file %s",

          signature_ref_index, CHECK_(nullHandle));

        break;

      }

      case JVM_CONSTANT_Utf8 :

        break;

      case JVM_CONSTANT_UnresolvedClass :         // fall-through

      case JVM_CONSTANT_UnresolvedClassInError:

        ShouldNotReachHere();     // Only JVM_CONSTANT_ClassIndex should be present

        break;

      case JVM_CONSTANT_ClassIndex :

        {

          int class_index = cp->klass_index_at(index);

          check_property(

            valid_cp_range(class_index, length) &&

              cp->tag_at(class_index).is_utf8(),

            "Invalid constant pool index %u in class file %s",

            class_index, CHECK_(nullHandle));

          cp->unresolved_klass_at_put(index, cp->symbol_at(class_index));

        }

        break;

      case JVM_CONSTANT_UnresolvedString :

        ShouldNotReachHere();     // Only JVM_CONSTANT_StringIndex should be present

        break;

      case JVM_CONSTANT_StringIndex :

        {

          int string_index = cp->string_index_at(index);

          check_property(

            valid_cp_range(string_index, length) &&

              cp->tag_at(string_index).is_utf8(),

            "Invalid constant pool index %u in class file %s",

            string_index, CHECK_(nullHandle));

          Symbol* sym = cp->symbol_at(string_index);

          cp->unresolved_string_at_put(index, sym);

        }

        break;

      case JVM_CONSTANT_MethodHandle :

        {

          int ref_index = cp->method_handle_index_at(index);

          check_property(

            valid_cp_range(ref_index, length) &&

                EnableInvokeDynamic,

              "Invalid constant pool index %u in class file %s",

              ref_index, CHECK_(nullHandle));

          constantTag tag = cp->tag_at(ref_index);

          int ref_kind  = cp->method_handle_ref_kind_at(index);

          switch (ref_kind) {

          case JVM_REF_getField:

          case JVM_REF_getStatic:

          case JVM_REF_putField:

          case JVM_REF_putStatic:

            check_property(

              tag.is_field(),

              "Invalid constant pool index %u in class file %s (not a field)",

              ref_index, CHECK_(nullHandle));

            break;

          case JVM_REF_invokeVirtual:

          case JVM_REF_invokeStatic:

          case JVM_REF_invokeSpecial:

          case JVM_REF_newInvokeSpecial:

            check_property(

              tag.is_method(),

              "Invalid constant pool index %u in class file %s (not a method)",

              ref_index, CHECK_(nullHandle));

            break;

          case JVM_REF_invokeInterface:

            check_property(

              tag.is_interface_method(),

              "Invalid constant pool index %u in class file %s (not an interface method)",

              ref_index, CHECK_(nullHandle));

            break;

          default:

            classfile_parse_error(

              "Bad method handle kind at constant pool index %u in class file %s",

              index, CHECK_(nullHandle));

          }

          // Keep the ref_index unchanged.  It will be indirected at link-time.

        }

        break;

      case JVM_CONSTANT_MethodType :

        {

          int ref_index = cp->method_type_index_at(index);

          check_property(

            valid_cp_range(ref_index, length) &&

                cp->tag_at(ref_index).is_utf8() &&

                EnableInvokeDynamic,

              "Invalid constant pool index %u in class file %s",

              ref_index, CHECK_(nullHandle));

        }

        break;

      case JVM_CONSTANT_InvokeDynamic :

        {

          int name_and_type_ref_index = cp->invoke_dynamic_name_and_type_ref_index_at(index);

          check_property(valid_cp_range(name_and_type_ref_index, length) &&

                         cp->tag_at(name_and_type_ref_index).is_name_and_type(),

                         "Invalid constant pool index %u in class file %s",

                         name_and_type_ref_index,

                         CHECK_(nullHandle));

          // bootstrap specifier index must be checked later, when BootstrapMethods attr is available

          break;

        }

      default:

        fatal(err_msg("bad constant pool tag value %u",

                      cp->tag_at(index).value()));

        ShouldNotReachHere();