/*

 * Copyright (c) 2015, 2018, 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 "jimage.hpp"

#include "classfile/classListParser.hpp"

#include "classfile/classLoaderExt.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/systemDictionaryShared.hpp"

#include "logging/log.hpp"

#include "logging/logTag.hpp"

#include "memory/metaspaceShared.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/fieldType.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/javaCalls.hpp"

#include "utilities/defaultStream.hpp"

#include "utilities/hashtable.inline.hpp"

#include "utilities/macros.hpp"

ClassListParser* ClassListParser::_instance = NULL;

ClassListParser::ClassListParser(const char* file) {

  assert(_instance == NULL, "must be singleton");

  _instance = this;

  _classlist_file = file;

  _file = fopen(file, "r");

  if (_file == NULL) {

    char errmsg[JVM_MAXPATHLEN];

    os::lasterror(errmsg, JVM_MAXPATHLEN);

    vm_exit_during_initialization("Loading classlist failed", errmsg);

  }

}

ClassListParser::~ClassListParser() {

  if (_file) {

    fclose(_file);

  }

  _instance = NULL;

}

bool ClassListParser::parse_one_line() {

  for (;;) {

    if (fgets(_line, sizeof(_line), _file) == NULL) {

      return false;

    }

    ++ _line_no;

    _line_len = (int)strlen(_line);

    if (_line_len > _max_allowed_line_len) {

      error("input line too long (must be no longer than %d chars)", _max_allowed_line_len);

    }

    if (*_line == '#') { // comment

      continue;

    }

    break;

  }

  _id = _unspecified;

  _super = _unspecified;

  _interfaces->clear();

  _source = NULL;

  _interfaces_specified = false;

  {

    int len = (int)strlen(_line);

    int i;

    // Replace \t\r\n with ' '

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

      if (_line[i] == '\t' || _line[i] == '\r' || _line[i] == '\n') {

        _line[i] = ' ';

      }

    }

    // Remove trailing newline/space

    while (len > 0) {

      if (_line[len-1] == ' ') {

        _line[len-1] = '\0';

        len --;

      } else {

        break;

      }

    }

    _line_len = len;

    _class_name = _line;

  }

  if ((_token = strchr(_line, ' ')) == NULL) {

    // No optional arguments are specified.

    return true;

  }

  // Mark the end of the name, and go to the next input char

  *_token++ = '\0';

  while (*_token) {

    skip_whitespaces();

    if (parse_int_option("id:", &_id)) {

      continue;

    } else if (parse_int_option("super:", &_super)) {

      check_already_loaded("Super class", _super);

      continue;

    } else if (skip_token("interfaces:")) {

      int i;

      while (try_parse_int(&i)) {

        check_already_loaded("Interface", i);

        _interfaces->append(i);

      }

    } else if (skip_token("source:")) {

      skip_whitespaces();

      _source = _token;

      char* s = strchr(_token, ' ');

      if (s == NULL) {

        break; // end of input line

      } else {

        *s = '\0'; // mark the end of _source

        _token = s+1;

      }

    } else {

      error("Unknown input");

    }

  }

  // if src is specified

  //     id super interfaces must all be specified

  //     loader may be specified

  // else

  //     # the class is loaded from classpath

  //     id may be specified

  //     super, interfaces, loader must not be specified

  return true;

}

void ClassListParser::skip_whitespaces() {

  while (*_token == ' ' || *_token == '\t') {

    _token ++;

  }

}

void ClassListParser::skip_non_whitespaces() {

  while (*_token && *_token != ' ' && *_token != '\t') {

    _token ++;

  }

}

void ClassListParser::parse_int(int* value) {

  skip_whitespaces();

  if (sscanf(_token, "%i", value) == 1) {

    skip_non_whitespaces();

    if (*value < 0) {

      error("Error: negative integers not allowed (%d)", *value);

    }

  } else {

    error("Error: expected integer");

  }

}

bool ClassListParser::try_parse_int(int* value) {

  skip_whitespaces();

  if (sscanf(_token, "%i", value) == 1) {

    skip_non_whitespaces();

    return true;

  }

  return false;

}

bool ClassListParser::skip_token(const char* option_name) {

  size_t len = strlen(option_name);

  if (strncmp(_token, option_name, len) == 0) {

    _token += len;

    return true;

  } else {

    return false;

  }

}

bool ClassListParser::parse_int_option(const char* option_name, int* value) {

  if (skip_token(option_name)) {

    if (*value != _unspecified) {

      error("%s specified twice", option_name);

    } else {

      parse_int(value);

      return true;

    }

  }

  return false;

}

void ClassListParser::print_specified_interfaces() {

  const int n = _interfaces->length();

  jio_fprintf(defaultStream::error_stream(), "Currently specified interfaces[%d] = {\n", n);

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

    InstanceKlass* k = lookup_class_by_id(_interfaces->at(i));

    jio_fprintf(defaultStream::error_stream(), "  %4d = %s\n", _interfaces->at(i), k->name()->as_klass_external_name());

  }

  jio_fprintf(defaultStream::error_stream(), "}\n");

}

void ClassListParser::print_actual_interfaces(InstanceKlass *ik) {

  int n = ik->local_interfaces()->length();

  jio_fprintf(defaultStream::error_stream(), "Actual interfaces[%d] = {\n", n);

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

    InstanceKlass* e = InstanceKlass::cast(ik->local_interfaces()->at(i));

    jio_fprintf(defaultStream::error_stream(), "  %s\n", e->name()->as_klass_external_name());

  }

  jio_fprintf(defaultStream::error_stream(), "}\n");

}

void ClassListParser::error(const char *msg, ...) {

  va_list ap;

  va_start(ap, msg);

  int error_index = _token - _line;

  if (error_index >= _line_len) {

    error_index = _line_len - 1;

  }

  if (error_index < 0) {

    error_index = 0;

  }

  jio_fprintf(defaultStream::error_stream(),

              "An error has occurred while processing class list file %s %d:%d.\n",

              _classlist_file, _line_no, (error_index + 1));

  jio_vfprintf(defaultStream::error_stream(), msg, ap);

  if (_line_len <= 0) {

    jio_fprintf(defaultStream::error_stream(), "\n");

  } else {

    jio_fprintf(defaultStream::error_stream(), ":\n");

    for (int i=0; i<_line_len; i++) {

      char c = _line[i];

      if (c == '\0') {

        jio_fprintf(defaultStream::error_stream(), "%s", " ");

      } else {

        jio_fprintf(defaultStream::error_stream(), "%c", c);

      }

    }

    jio_fprintf(defaultStream::error_stream(), "\n");

    for (int i=0; i<error_index; i++) {

      jio_fprintf(defaultStream::error_stream(), "%s", " ");

    }

    jio_fprintf(defaultStream::error_stream(), "^\n");

  }

  vm_exit_during_initialization("class list format error.", NULL);

  va_end(ap);

}

// This function is used for loading classes for customized class loaders

// during archive dumping.

InstanceKlass* ClassListParser::load_class_from_source(Symbol* class_name, TRAPS) {

#if !(defined(_LP64) && (defined(LINUX)|| defined(SOLARIS)))

  // The only supported platforms are: (1) Linux/64-bit and (2) Solaris/64-bit

  //

  // This #if condition should be in sync with the areCustomLoadersSupportedForCDS

  // method in test/lib/jdk/test/lib/Platform.java.

  error("AppCDS custom class loaders not supported on this platform");

#endif

  if (!is_super_specified()) {

    error("If source location is specified, super class must be also specified");

  }

  if (!is_id_specified()) {

    error("If source location is specified, id must be also specified");

  }

  InstanceKlass* k = ClassLoaderExt::load_class(class_name, _source, THREAD);

  if (strncmp(_class_name, "java/", 5) == 0) {

    log_info(cds)("Prohibited package for non-bootstrap classes: %s.class from %s",

          _class_name, _source);

    return NULL;

  }

  if (k != NULL) {

    if (k->local_interfaces()->length() != _interfaces->length()) {

      print_specified_interfaces();

      print_actual_interfaces(k);

      error("The number of interfaces (%d) specified in class list does not match the class file (%d)",

            _interfaces->length(), k->local_interfaces()->length());

    }

    if (!SystemDictionaryShared::add_non_builtin_klass(class_name, ClassLoaderData::the_null_class_loader_data(),

                                                       k, THREAD)) {

      error("Duplicated class %s", _class_name);

    }

    // This tells JVM_FindLoadedClass to not find this class.

    k->set_shared_classpath_index(UNREGISTERED_INDEX);

    k->clear_class_loader_type();

  }

  return k;

}

Klass* ClassListParser::load_current_class(TRAPS) {

  TempNewSymbol class_name_symbol = SymbolTable::new_symbol(_class_name, THREAD);

  guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");

  Klass *klass = NULL;

  if (!is_loading_from_source()) {

    // Load classes for the boot/platform/app loaders only.

    if (is_super_specified()) {

      error("If source location is not specified, super class must not be specified");

    }

    if (are_interfaces_specified()) {

      error("If source location is not specified, interface(s) must not be specified");

    }

    bool non_array = !FieldType::is_array(class_name_symbol);

    JavaValue result(T_OBJECT);

    if (non_array) {

      // At this point, we are executing in the context of the boot loader. We

      // cannot call Class.forName because that is context dependent and

      // would load only classes for the boot loader.

      //

      // Instead, let's call java_system_loader().loadClass() directly, which will

      // delegate to the correct loader (boot, platform or app) depending on

      // the class name.

      Handle s = java_lang_String::create_from_symbol(class_name_symbol, CHECK_0);

      // ClassLoader.loadClass() wants external class name format, i.e., convert '/' chars to '.'

      Handle ext_class_name = java_lang_String::externalize_classname(s, CHECK_0);

      Handle loader = Handle(THREAD, SystemDictionary::java_system_loader());

      JavaCalls::call_virtual(&result,

                              loader, //SystemDictionary::java_system_loader(),

                              SystemDictionary::ClassLoader_klass(),

                              vmSymbols::loadClass_name(),

                              vmSymbols::string_class_signature(),

                              ext_class_name,

                              THREAD);

    } else {

      // array classes are not supported in class list.

      THROW_NULL(vmSymbols::java_lang_ClassNotFoundException());

    }

    assert(result.get_type() == T_OBJECT, "just checking");

    oop obj = (oop) result.get_jobject();

    if (!HAS_PENDING_EXCEPTION && (obj != NULL)) {

      klass = java_lang_Class::as_Klass(obj);

    } else { // load classes in bootclasspath/a

      if (HAS_PENDING_EXCEPTION) {

        CLEAR_PENDING_EXCEPTION;

      }

      if (non_array) {

        Klass* k = SystemDictionary::resolve_or_null(class_name_symbol, CHECK_NULL);

        if (k != NULL) {

          klass = k;

        } else {

          if (!HAS_PENDING_EXCEPTION) {

            THROW_NULL(vmSymbols::java_lang_ClassNotFoundException());

          }

        }

      }

    }

  } else {

    // If "source:" tag is specified, all super class and super interfaces must be specified in the

    // class list file.

    klass = load_class_from_source(class_name_symbol, CHECK_NULL);

  }

  if (klass != NULL && klass->is_instance_klass() && is_id_specified()) {

    InstanceKlass* ik = InstanceKlass::cast(klass);

    int id = this->id();

    SystemDictionaryShared::update_shared_entry(ik, id);

    InstanceKlass* old = table()->lookup(id);

    if (old != NULL && old != ik) {

      error("Duplicated ID %d for class %s", id, _class_name);

    }

    table()->add(id, ik);

  }

  return klass;

}

bool ClassListParser::is_loading_from_source() {

  return (_source != NULL);

}

InstanceKlass* ClassListParser::lookup_class_by_id(int id) {

  InstanceKlass* klass = table()->lookup(id);

  if (klass == NULL) {

    error("Class ID %d has not been defined", id);

  }

  return klass;

}

InstanceKlass* ClassListParser::lookup_super_for_current_class(Symbol* super_name) {

  if (!is_loading_from_source()) {

    return NULL;

  }

  InstanceKlass* k = lookup_class_by_id(super());

  if (super_name != k->name()) {

    error("The specified super class %s (id %d) does not match actual super class %s",

          k->name()->as_klass_external_name(), super(),

          super_name->as_klass_external_name());

  }

  return k;

}

InstanceKlass* ClassListParser::lookup_interface_for_current_class(Symbol* interface_name) {

  if (!is_loading_from_source()) {

    return NULL;

  }

  const int n = _interfaces->length();

  if (n == 0) {

    error("Class %s implements the interface %s, but no interface has been specified in the input line",

          _class_name, interface_name->as_klass_external_name());

    ShouldNotReachHere();

  }

  int i;

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

    InstanceKlass* k = lookup_class_by_id(_interfaces->at(i));

    if (interface_name == k->name()) {

      return k;

    }

  }

  // interface_name is not specified by the "interfaces:" keyword.

  print_specified_interfaces();

  error("The interface %s implemented by class %s does not match any of the specified interface IDs",

        interface_name->as_klass_external_name(), _class_name);

  ShouldNotReachHere();

  return NULL;

}