/*

 * 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 "aot/aotLoader.hpp"

#include "classfile/classFileParser.hpp"

#include "classfile/classFileStream.hpp"

#include "classfile/classLoader.hpp"

#include "classfile/classLoaderData.inline.hpp"

#include "classfile/defaultMethods.hpp"

#include "classfile/dictionary.hpp"

#include "classfile/javaClasses.inline.hpp"

#include "classfile/moduleEntry.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/verificationType.hpp"

#include "classfile/verifier.hpp"

#include "classfile/vmSymbols.hpp"

#include "logging/log.hpp"

#include "logging/logStream.hpp"

#include "memory/allocation.hpp"

#include "memory/metadataFactory.hpp"

#include "memory/oopFactory.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.hpp"

#include "oops/annotations.hpp"

#include "oops/constantPool.inline.hpp"

#include "oops/fieldStreams.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/instanceMirrorKlass.hpp"

#include "oops/klass.inline.hpp"

#include "oops/klassVtable.hpp"

#include "oops/metadata.hpp"

#include "oops/method.hpp"

#include "oops/oop.inline.hpp"

#include "oops/symbol.hpp"

#include "prims/jvmtiExport.hpp"

#include "prims/jvmtiThreadState.hpp"

#include "runtime/arguments.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/perfData.hpp"

#include "runtime/reflection.hpp"

#include "runtime/safepointVerifiers.hpp"

#include "runtime/signature.hpp"

#include "runtime/timer.hpp"

#include "services/classLoadingService.hpp"

#include "services/threadService.hpp"

#include "utilities/align.hpp"

#include "utilities/bitMap.inline.hpp"

#include "utilities/copy.hpp"

#include "utilities/exceptions.hpp"

#include "utilities/globalDefinitions.hpp"

#include "utilities/growableArray.hpp"

#include "utilities/macros.hpp"

#include "utilities/ostream.hpp"

#include "utilities/resourceHash.hpp"

#if INCLUDE_CDS

#include "classfile/systemDictionaryShared.hpp"

#endif

#if INCLUDE_JFR

#include "jfr/support/jfrTraceIdExtension.hpp"

#endif

// 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_PREVIEW_MINOR_VERSION        65535

// 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 disallow argument and require ACC_STATIC for <clinit> methods

#define JAVA_7_VERSION                    51

// Extension method support.

#define JAVA_8_VERSION                    52

#define JAVA_9_VERSION                    53

#define JAVA_10_VERSION                   54

#define JAVA_11_VERSION                   55

#define JAVA_12_VERSION                   56

#define JAVA_13_VERSION                   57

void ClassFileParser::set_class_bad_constant_seen(short bad_constant) {

  assert((bad_constant == 19 || bad_constant == 20) && _major_version >= JAVA_9_VERSION,

         "Unexpected bad constant pool entry");

  if (_bad_constant_seen == 0) _bad_constant_seen = bad_constant;

}

void ClassFileParser::parse_constant_pool_entries(const ClassFileStream* const stream,

                                                  ConstantPool* cp,

                                                  const int length,

                                                  TRAPS) {

  assert(stream != NULL, "invariant");

  assert(cp != NULL, "invariant");

  // 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().

  const ClassFileStream cfs1 = *stream;

  const ClassFileStream* const cfs = &cfs1;

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

  debug_only(const u1* const old_current = stream->current();)

  // 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.

    const u1 tag = cfs->get_u1_fast();

    switch (tag) {

      case JVM_CONSTANT_Class : {

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

        const 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

        const u2 class_index = cfs->get_u2_fast();

        const 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

        const u2 class_index = cfs->get_u2_fast();

        const 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

        const u2 class_index = cfs->get_u2_fast();

        const 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

        const 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 (tag == JVM_CONSTANT_MethodHandle) {

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

          const u1 ref_kind = cfs->get_u1_fast();

          const 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

          const u2 signature_index = cfs->get_u2_fast();

          cp->method_type_index_at_put(index, signature_index);

        }

        else {

          ShouldNotReachHere();

        }

        break;

      }

      case JVM_CONSTANT_Dynamic : {

        if (_major_version < Verifier::DYNAMICCONSTANT_MAJOR_VERSION) {

          classfile_parse_error(

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

              tag, CHECK);

        }

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

        const u2 bootstrap_specifier_index = cfs->get_u2_fast();

        const 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->dynamic_constant_at_put(index, bootstrap_specifier_index, name_and_type_index);

        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);

        }

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

        const u2 bootstrap_specifier_index = cfs->get_u2_fast();

        const 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

        const 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

        const 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

        const 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

        const 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

        const u2 name_index = cfs->get_u2_fast();

        const 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();

        const u1* utf8_buffer = cfs->current();

        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(utf8_buffer, utf8_length, CHECK);

        }

        if (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);

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

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

          utf8_buffer = (const u1*) str;

          utf8_length = (int) strlen(str);

        }

        unsigned int hash;

        Symbol* const result = SymbolTable::lookup_only((const char*)utf8_buffer,

                                                        utf8_length,

                                                        hash);

        if (result == NULL) {

          names[names_count] = (const 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(_loader_data,

                                     cp,

                                     names_count,

                                     names,

                                     lengths,

                                     indices,

                                     hashValues,

                                     CHECK);

            names_count = 0;

          }

        } else {

          cp->symbol_at_put(index, result);

        }

        break;

      }

      case 19:

      case 20: {

        // Record that an error occurred in these two cases but keep parsing so

        // that ACC_Module can be checked for in the access_flags.  Need to

        // throw NoClassDefFoundError in that case.

        if (_major_version >= JAVA_9_VERSION) {

          cfs->guarantee_more(3, CHECK);

          cfs->get_u2_fast();

          set_class_bad_constant_seen(tag);

          break;

        }

      }

      default: {

        classfile_parse_error("Unknown constant tag %u in class file %s",

                              tag,

                              CHECK);

        break;

      }

    } // end of switch(tag)

  } // end of for

  // Allocate the remaining symbols

  if (names_count > 0) {

    SymbolTable::new_symbols(_loader_data,

                             cp,

                             names_count,

                             names,

                             lengths,

                             indices,

                             hashValues,

                             CHECK);

  }

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

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

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

}

static inline bool valid_cp_range(int index, int length) {

  return (index > 0 && index < length);

}

static inline Symbol* check_symbol_at(const ConstantPool* cp, int index) {

  assert(cp != NULL, "invariant");

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

    return cp->symbol_at(index);

  }

  return NULL;

}

#ifdef ASSERT

PRAGMA_DIAG_PUSH

PRAGMA_FORMAT_NONLITERAL_IGNORED

void ClassFileParser::report_assert_property_failure(const char* msg, TRAPS) const {

  ResourceMark rm(THREAD);

  fatal(msg, _class_name->as_C_string());

}

void ClassFileParser::report_assert_property_failure(const char* msg,

                                                     int index,

                                                     TRAPS) const {

  ResourceMark rm(THREAD);

  fatal(msg, index, _class_name->as_C_string());

}

PRAGMA_DIAG_POP

#endif

void ClassFileParser::parse_constant_pool(const ClassFileStream* const stream,

                                         ConstantPool* const cp,

                                         const int length,

                                         TRAPS) {

  assert(cp != NULL, "invariant");

  assert(stream != NULL, "invariant");

  // parsing constant pool entries

  parse_constant_pool_entries(stream, cp, length, CHECK);

  if (class_bad_constant_seen() != 0) {

    // a bad CP entry has been detected previously so stop parsing and just return.

    return;

  }

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

  int num_klasses = 0;

  // first verification pass - validate cross references

  // and fixup class and string constants

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

    const 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;

        const int klass_ref_index = cp->klass_ref_index_at(index);

        const int name_and_type_ref_index = cp->name_and_type_ref_index_at(index);

        check_property(valid_klass_reference_at(klass_ref_index),

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

                       klass_ref_index, CHECK);

        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);

        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);

        break;

      }

      case JVM_CONSTANT_NameAndType: {

        if (!_need_verify) break;

        const int name_ref_index = cp->name_ref_index_at(index);

        const int signature_ref_index = cp->signature_ref_index_at(index);

        check_property(valid_symbol_at(name_ref_index),

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

          name_ref_index, CHECK);

        check_property(valid_symbol_at(signature_ref_index),

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

          signature_ref_index, CHECK);

        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: {