/*

 * Copyright (c) 2015, 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 "classfile/classFileParser.hpp"

#include "classfile/classFileStream.hpp"

#include "classfile/classLoader.inline.hpp"

#include "classfile/classLoaderExt.hpp"

#include "classfile/classLoaderData.inline.hpp"

#include "classfile/klassFactory.hpp"

#include "classfile/modules.hpp"

#include "classfile/systemDictionaryShared.hpp"

#include "classfile/vmSymbols.hpp"

#include "logging/log.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/filemap.hpp"

#include "memory/resourceArea.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/oop.inline.hpp"

#include "oops/symbol.hpp"

#include "runtime/arguments.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/java.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/os.hpp"

#include "services/threadService.hpp"

#include "utilities/stringUtils.hpp"

jshort ClassLoaderExt::_app_class_paths_start_index = ClassLoaderExt::max_classpath_index;

jshort ClassLoaderExt::_app_module_paths_start_index = ClassLoaderExt::max_classpath_index;

jshort ClassLoaderExt::_max_used_path_index = 0;

bool ClassLoaderExt::_has_app_classes = false;

bool ClassLoaderExt::_has_platform_classes = false;

void ClassLoaderExt::append_boot_classpath(ClassPathEntry* new_entry) {

  if (UseSharedSpaces) {

    warning("Sharing is only supported for boot loader classes because bootstrap classpath has been appended");

    FileMapInfo::current_info()->set_has_platform_or_app_classes(false);

  }

  ClassLoader::add_to_boot_append_entries(new_entry);

}

void ClassLoaderExt::setup_app_search_path() {

  _app_class_paths_start_index = ClassLoader::num_boot_classpath_entries();

  char* app_class_path = os::strdup(Arguments::get_appclasspath());

  if (strcmp(app_class_path, ".") == 0) {

    // This doesn't make any sense, even for AppCDS, so let's skip it. We

    // don't want to throw an error here because -cp "." is usually assigned

    // by the launcher when classpath is not specified.

    trace_class_path("app loader class path (skipped)=", app_class_path);

  } else {

    trace_class_path("app loader class path=", app_class_path);

    ClassLoader::setup_app_search_path(app_class_path);

  }

}

void ClassLoaderExt::process_module_table(ModuleEntryTable* met, TRAPS) {

  ResourceMark rm(THREAD);

  for (int i = 0; i < met->table_size(); i++) {

    for (ModuleEntry* m = met->bucket(i); m != NULL;) {

      char* path = m->location()->as_C_string();

      if (strncmp(path, "file:", 5) == 0) {

        path = ClassLoader::skip_uri_protocol(path);

        ClassLoader::setup_module_search_path(path, THREAD);

      }

      m = m->next();

    }

  }

}

void ClassLoaderExt::setup_module_paths(TRAPS) {

  _app_module_paths_start_index = ClassLoader::num_boot_classpath_entries() +

                              ClassLoader::num_app_classpath_entries();

  Handle system_class_loader (THREAD, SystemDictionary::java_system_loader());

  ModuleEntryTable* met = Modules::get_module_entry_table(system_class_loader);

  process_module_table(met, THREAD);

}

char* ClassLoaderExt::read_manifest(ClassPathEntry* entry, jint *manifest_size, bool clean_text, TRAPS) {

  const char* name = "META-INF/MANIFEST.MF";

  char* manifest;

  jint size;

  assert(entry->is_jar_file(), "must be");

  manifest = (char*) ((ClassPathZipEntry*)entry )->open_entry(name, &size, true, CHECK_NULL);

  if (manifest == NULL) { // No Manifest

    *manifest_size = 0;

    return NULL;

  }

  if (clean_text) {

    // See http://docs.oracle.com/javase/6/docs/technotes/guides/jar/jar.html#JAR%20Manifest

    // (1): replace all CR/LF and CR with LF

    StringUtils::replace_no_expand(manifest, "\r\n", "\n");

    // (2) remove all new-line continuation (remove all "\n " substrings)

    StringUtils::replace_no_expand(manifest, "\n ", "");

  }

  *manifest_size = (jint)strlen(manifest);

  return manifest;

}

char* ClassLoaderExt::get_class_path_attr(const char* jar_path, char* manifest, jint manifest_size) {

  const char* tag = "Class-Path: ";

  const int tag_len = (int)strlen(tag);

  char* found = NULL;

  char* line_start = manifest;

  char* end = manifest + manifest_size;

  assert(*end == 0, "must be nul-terminated");

  while (line_start < end) {

    char* line_end = strchr(line_start, '\n');

    if (line_end == NULL) {

      // JAR spec require the manifest file to be terminated by a new line.

      break;

    }

    if (strncmp(tag, line_start, tag_len) == 0) {

      if (found != NULL) {

        // Same behavior as jdk/src/share/classes/java/util/jar/Attributes.java

        // If duplicated entries are found, the last one is used.

        log_warning(cds)("Warning: Duplicate name in Manifest: %s.\n"

                      "Ensure that the manifest does not have duplicate entries, and\n"

                      "that blank lines separate individual sections in both your\n"

                      "manifest and in the META-INF/MANIFEST.MF entry in the jar file:\n%s\n", tag, jar_path);

      }

      found = line_start + tag_len;

      assert(found <= line_end, "sanity");

      *line_end = '\0';

    }

    line_start = line_end + 1;

  }

  return found;

}

void ClassLoaderExt::process_jar_manifest(ClassPathEntry* entry,

                                          bool check_for_duplicates) {

  Thread* THREAD = Thread::current();

  ResourceMark rm(THREAD);

  jint manifest_size;

  char* manifest = read_manifest(entry, &manifest_size, CHECK);

  if (manifest == NULL) {

    return;

  }

  if (strstr(manifest, "Extension-List:") != NULL) {

    vm_exit_during_cds_dumping(err_msg("-Xshare:dump does not support Extension-List in JAR manifest: %s", entry->name()));

  }

  char* cp_attr = get_class_path_attr(entry->name(), manifest, manifest_size);

  if (cp_attr != NULL && strlen(cp_attr) > 0) {

    trace_class_path("found Class-Path: ", cp_attr);

    char sep = os::file_separator()[0];

    const char* dir_name = entry->name();

    const char* dir_tail = strrchr(dir_name, sep);

    int dir_len;

    if (dir_tail == NULL) {

      dir_len = 0;

    } else {

      dir_len = dir_tail - dir_name + 1;

    }

    // Split the cp_attr by spaces, and add each file

    char* file_start = cp_attr;

    char* end = file_start + strlen(file_start);

    while (file_start < end) {

      char* file_end = strchr(file_start, ' ');

      if (file_end != NULL) {

        *file_end = 0;

        file_end += 1;

      } else {

        file_end = end;

      }

      size_t name_len = strlen(file_start);

      if (name_len > 0) {

        ResourceMark rm(THREAD);

        size_t libname_len = dir_len + name_len;

        char* libname = NEW_RESOURCE_ARRAY(char, libname_len + 1);

        int n = os::snprintf(libname, libname_len + 1, "%.*s%s", dir_len, dir_name, file_start);

        assert((size_t)n == libname_len, "Unexpected number of characters in string");

        if (ClassLoader::update_class_path_entry_list(libname, true, false, true /* from_class_path_attr */)) {

          trace_class_path("library = ", libname);

        } else {

          trace_class_path("library (non-existent) = ", libname);

          FileMapInfo::record_non_existent_class_path_entry(libname);

        }

      }

      file_start = file_end;

    }

  }

}

void ClassLoaderExt::setup_search_paths() {

  ClassLoaderExt::setup_app_search_path();

}

void ClassLoaderExt::record_result(const s2 classpath_index,

                                   InstanceKlass* result,

                                   TRAPS) {

  // We need to remember where the class comes from during dumping.

  oop loader = result->class_loader();

  s2 classloader_type = ClassLoader::BOOT_LOADER;

  if (SystemDictionary::is_system_class_loader(loader)) {

    classloader_type = ClassLoader::APP_LOADER;

    ClassLoaderExt::set_has_app_classes();

  } else if (SystemDictionary::is_platform_class_loader(loader)) {

    classloader_type = ClassLoader::PLATFORM_LOADER;

    ClassLoaderExt::set_has_platform_classes();

  }

  if (classpath_index > ClassLoaderExt::max_used_path_index()) {

    ClassLoaderExt::set_max_used_path_index(classpath_index);

  }

  result->set_shared_classpath_index(classpath_index);

  result->set_class_loader_type(classloader_type);

}

// Load the class of the given name from the location given by path. The path is specified by

// the "source:" in the class list file (see classListParser.cpp), and can be a directory or

// a JAR file.

InstanceKlass* ClassLoaderExt::load_class(Symbol* name, const char* path, TRAPS) {

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

  assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");

  ResourceMark rm(THREAD);

  const char* class_name = name->as_C_string();

  const char* file_name = file_name_for_class_name(class_name,

                                                   name->utf8_length());

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

  // Lookup stream for parsing .class file

  ClassFileStream* stream = NULL;

  ClassPathEntry* e = find_classpath_entry_from_cache(path, CHECK_NULL);

  if (e == NULL) {

    return NULL;

  }

  {

    PerfClassTraceTime vmtimer(perf_sys_class_lookup_time(),

                               ((JavaThread*) THREAD)->get_thread_stat()->perf_timers_addr(),

                               PerfClassTraceTime::CLASS_LOAD);

    stream = e->open_stream(file_name, CHECK_NULL);

  }

  if (NULL == stream) {

    log_warning(cds)("Preload Warning: Cannot find %s", class_name);

    return NULL;

  }

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

  stream->set_verify(true);

  ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();

  Handle protection_domain;

  InstanceKlass* result = KlassFactory::create_from_stream(stream,

                                                           name,

                                                           loader_data,

                                                           protection_domain,

                                                           NULL, // unsafe_anonymous_host

                                                           NULL, // cp_patches

                                                           THREAD);

  if (HAS_PENDING_EXCEPTION) {

    log_error(cds)("Preload Error: Failed to load %s", class_name);

    return NULL;

  }

  return result;

}

struct CachedClassPathEntry {

  const char* _path;

  ClassPathEntry* _entry;

};

static GrowableArray<CachedClassPathEntry>* cached_path_entries = NULL;

ClassPathEntry* ClassLoaderExt::find_classpath_entry_from_cache(const char* path, TRAPS) {

  // This is called from dump time so it's single threaded and there's no need for a lock.

  assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");

  if (cached_path_entries == NULL) {

    cached_path_entries = new (ResourceObj::C_HEAP, mtClass) GrowableArray<CachedClassPathEntry>(20, /*c heap*/ true);

  }

  CachedClassPathEntry ccpe;

  for (int i=0; i<cached_path_entries->length(); i++) {

    ccpe = cached_path_entries->at(i);

    if (strcmp(ccpe._path, path) == 0) {

      if (i != 0) {

        // Put recent entries at the beginning to speed up searches.

        cached_path_entries->remove_at(i);

        cached_path_entries->insert_before(0, ccpe);

      }

      return ccpe._entry;

    }

  }

  struct stat st;

  if (os::stat(path, &st) != 0) {

    // File or directory not found

    return NULL;

  }

  ClassPathEntry* new_entry = NULL;

  new_entry = create_class_path_entry(path, &st, false, false, false, CHECK_NULL);

  if (new_entry == NULL) {

    return NULL;

  }

  ccpe._path = strdup(path);

  ccpe._entry = new_entry;

  cached_path_entries->insert_before(0, ccpe);

  return new_entry;

}