/*

 * Copyright 1997-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_classFileParser.cpp.incl"

// 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

void ClassFileParser::parse_constant_pool_entries(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

  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_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 (AnonymousClasses && 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;

          symbolOop 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) {

              oopFactory::new_symbols(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) {

    oopFactory::new_symbols(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());

}

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

constantPoolHandle ClassFileParser::parse_constant_pool(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,

                                                   methodOopDesc::IsSafeConc,

                                                   CHECK_(nullHandle));

  constantPoolHandle cp (THREAD, constant_pool);

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

  // parsing constant pool entries

  parse_constant_pool_entries(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

    switch (cp->tag_at(index).value()) {

      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));

          symbolOop sym = cp->symbol_at(string_index);

          cp->unresolved_string_at_put(index, sym);

        }

        break;

      default:

        fatal1("bad constant pool tag value %u", cp->tag_at(index).value());

        ShouldNotReachHere();

        break;

    } // end of switch

  } // end of for

  if (_cp_patches != NULL) {

    // need to treat this_class specially...

    assert(AnonymousClasses, "");

    int this_class_index;

    {

      cfs->guarantee_more(8, CHECK_(nullHandle));  // flags, this_class, super_class, infs_len

      u1* mark = cfs->current();

      u2 flags         = cfs->get_u2_fast();

      this_class_index = cfs->get_u2_fast();

      cfs->set_current(mark);  // revert to mark

    }

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

      if (has_cp_patch_at(index)) {

        guarantee_property(index != this_class_index,

                           "Illegal constant pool patch to self at %d in class file %s",

                           index, CHECK_(nullHandle));

        patch_constant_pool(cp, index, cp_patch_at(index), CHECK_(nullHandle));

      }

    }

    // Ensure that all the patches have been used.

    for (index = 0; index < _cp_patches->length(); index++) {

      guarantee_property(!has_cp_patch_at(index),

                         "Unused constant pool patch at %d in class file %s",

                         index, CHECK_(nullHandle));

    }

  }

  if (!_need_verify) {

    return cp;

  }

  // second verification pass - checks the strings are of the right format.

  // but not yet to the other entries

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

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

    switch (tag) {

      case JVM_CONSTANT_UnresolvedClass: {

        symbolHandle class_name(THREAD, cp->unresolved_klass_at(index));

        // check the name, even if _cp_patches will overwrite it

        verify_legal_class_name(class_name, CHECK_(nullHandle));

        break;

      }

      case JVM_CONSTANT_Fieldref:

      case JVM_CONSTANT_Methodref:

      case JVM_CONSTANT_InterfaceMethodref: {

        int name_and_type_ref_index = cp->name_and_type_ref_index_at(index);

        // already verified to be utf8

        int name_ref_index = cp->name_ref_index_at(name_and_type_ref_index);

        // already verified to be utf8

        int signature_ref_index = cp->signature_ref_index_at(name_and_type_ref_index);

        symbolHandle name(THREAD, cp->symbol_at(name_ref_index));

        symbolHandle signature(THREAD, cp->symbol_at(signature_ref_index));

        if (tag == JVM_CONSTANT_Fieldref) {

          verify_legal_field_name(name, CHECK_(nullHandle));

          verify_legal_field_signature(name, signature, CHECK_(nullHandle));

        } else {

          verify_legal_method_name(name, CHECK_(nullHandle));

          verify_legal_method_signature(name, signature, CHECK_(nullHandle));

          if (tag == JVM_CONSTANT_Methodref) {

            // 4509014: If a class method name begins with '<', it must be "<init>".

            assert(!name.is_null(), "method name in constant pool is null");

            unsigned int name_len = name->utf8_length();

            assert(name_len > 0, "bad method name");  // already verified as legal name

            if (name->byte_at(0) == '<') {

              if (name() != vmSymbols::object_initializer_name()) {

                classfile_parse_error(

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

                  name_ref_index, CHECK_(nullHandle));

              }

            }

          }

        }

        break;

      }

    }  // end of switch

  }  // end of for

  return cp;

}

void ClassFileParser::patch_constant_pool(constantPoolHandle cp, int index, Handle patch, TRAPS) {

  assert(AnonymousClasses, "");

  BasicType patch_type = T_VOID;

  switch (cp->tag_at(index).value()) {

  case JVM_CONSTANT_UnresolvedClass :

    // Patching a class means pre-resolving it.

    // The name in the constant pool is ignored.

      guarantee_property(!java_lang_Class::is_primitive(patch()),

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

                         index, CHECK);

      cp->klass_at_put(index, java_lang_Class::as_klassOop(patch()));

    } else {

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

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

                         index, CHECK);

      symbolHandle name = java_lang_String::as_symbol(patch(), CHECK);

      cp->unresolved_klass_at_put(index, name());

    }

    break;

  case JVM_CONSTANT_UnresolvedString :

    // Patching a string means pre-resolving it.

    // The spelling in the constant pool is ignored.

    // The constant reference may be any object whatever.

    // If it is not a real interned string, the constant is referred

    // to as a "pseudo-string", and must be presented to the CP

    // explicitly, because it may require scavenging.

    cp->pseudo_string_at_put(index, patch());

    break;

  case JVM_CONSTANT_Integer : patch_type = T_INT;    goto patch_prim;

  case JVM_CONSTANT_Float :   patch_type = T_FLOAT;  goto patch_prim;

  case JVM_CONSTANT_Long :    patch_type = T_LONG;   goto patch_prim;

  case JVM_CONSTANT_Double :  patch_type = T_DOUBLE; goto patch_prim;

  patch_prim:

    {

      jvalue value;

      BasicType value_type = java_lang_boxing_object::get_value(patch(), &value);

      guarantee_property(value_type == patch_type,

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

                         index, CHECK);

      switch (value_type) {

      case T_INT:    cp->int_at_put(index,   value.i); break;

      case T_FLOAT:  cp->float_at_put(index, value.f); break;

      case T_LONG:   cp->long_at_put(index,  value.j); break;

      case T_DOUBLE: cp->double_at_put(index, value.d); break;

      default:       assert(false, "");

      }

    }

    break;

  default:

    // %%% TODO: put method handles into CONSTANT_InterfaceMethodref, etc.

    guarantee_property(!has_cp_patch_at(index),

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

                       index, CHECK);

    return;

  }

  // On fall-through, mark the patch as used.

  clear_cp_patch_at(index);

}

class NameSigHash: public ResourceObj {

 public:

  symbolOop     _name;       // name

  symbolOop     _sig;        // signature

  NameSigHash*  _next;       // Next entry in hash table

};

#define HASH_ROW_SIZE 256

unsigned int hash(symbolOop name, symbolOop sig) {

  unsigned int raw_hash = 0;

  raw_hash += ((unsigned int)(uintptr_t)name) >> (LogHeapWordSize + 2);

  raw_hash += ((unsigned int)(uintptr_t)sig) >> LogHeapWordSize;

  return (raw_hash + (unsigned int)(uintptr_t)name) % HASH_ROW_SIZE;

}

void initialize_hashtable(NameSigHash** table) {

  memset((void*)table, 0, sizeof(NameSigHash*) * HASH_ROW_SIZE);

}

// Return false if the name/sig combination is found in table.

// Return true if no duplicate is found. And name/sig is added as a new entry in table.

// The old format checker uses heap sort to find duplicates.

// NOTE: caller should guarantee that GC doesn't happen during the life cycle

// of table since we don't expect symbolOop's to move.