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products/sources/formale Sprachen/Java/Openjdk/src/hotspot/share/runtime/ (Sun/Oracle ^©) Datei vom 13.11.2022 mit Größe 159 kB

SSL arguments.cpp Sprache: C

/*
* Copyright (c) 1997, 2022, 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 "cds/cds_globals.hpp"
#include "cds/filemap.hpp"
#include "classfile/classLoader.hpp"
#include "classfile/javaAssertions.hpp"
#include "classfile/moduleEntry.hpp"
#include "classfile/stringTable.hpp"
#include "classfile/symbolTable.hpp"
#include "compiler/compilerDefinitions.hpp"
#include "gc/shared/gcArguments.hpp"
#include "gc/shared/gcConfig.hpp"
#include "gc/shared/stringdedup/stringDedup.hpp"
#include "gc/shared/tlab_globals.hpp"
#include "jvm.h"
#include "logging/log.hpp"
#include "logging/logConfiguration.hpp"
#include "logging/logStream.hpp"
#include "logging/logTag.hpp"
#include "memory/allocation.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvmtiExport.hpp"
#include "runtime/arguments.hpp"
#include "runtime/flags/jvmFlag.hpp"
#include "runtime/flags/jvmFlagAccess.hpp"
#include "runtime/flags/jvmFlagLimit.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/java.hpp"
#include "runtime/os.hpp"
#include "runtime/safepoint.hpp"
#include "runtime/safepointMechanism.hpp"
#include "runtime/synchronizer.hpp"
#include "runtime/vm_version.hpp"
#include "services/management.hpp"
#include "services/nmtCommon.hpp"
#include "utilities/align.hpp"
#include "utilities/debug.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/macros.hpp"
#include "utilities/parseInteger.hpp"
#include "utilities/powerOfTwo.hpp"
#include "utilities/stringUtils.hpp"
#if INCLUDE_JFR
#include "jfr/jfr.hpp"
#endif

#include <limits>

#define DEFAULT_JAVA_LAUNCHER  "generic"

char*  Arguments::_jvm_flags_file               = NULL;
char** Arguments::_jvm_flags_array              = NULL;
int    Arguments::_num_jvm_flags                = 0;
char** Arguments::_jvm_args_array               = NULL;
int    Arguments::_num_jvm_args                 = 0;
char*  Arguments::_java_command                 = NULL;
SystemProperty* Arguments::_system_properties   = NULL;
size_t Arguments::_conservative_max_heap_alignment = 0;
Arguments::Mode Arguments::_mode                = _mixed;
bool   Arguments::_java_compiler                = false;
bool   Arguments::_xdebug_mode                  = false;
const char*  Arguments::_java_vendor_url_bug    = NULL;
const char*  Arguments::_sun_java_launcher      = DEFAULT_JAVA_LAUNCHER;
bool   Arguments::_sun_java_launcher_is_altjvm  = false;

// These parameters are reset in method parse_vm_init_args()
bool   Arguments::_AlwaysCompileLoopMethods     = AlwaysCompileLoopMethods;
bool   Arguments::_UseOnStackReplacement        = UseOnStackReplacement;
bool   Arguments::_BackgroundCompilation        = BackgroundCompilation;
bool   Arguments::_ClipInlining                 = ClipInlining;
size_t Arguments::_default_SharedBaseAddress    = SharedBaseAddress;

bool   Arguments::_enable_preview               = false;

char*  Arguments::SharedArchivePath             = NULL;
char*  Arguments::SharedDynamicArchivePath      = NULL;

LegacyGCLogging Arguments::_legacyGCLogging     = { 0, 0 };

AgentLibraryList Arguments::_libraryList;
AgentLibraryList Arguments::_agentList;

// These are not set by the JDK's built-in launchers, but they can be set by
// programs that embed the JVM using JNI_CreateJavaVM. See comments around
// JavaVMOption in jni.h.
abort_hook_t     Arguments::_abort_hook         = NULL;
exit_hook_t      Arguments::_exit_hook          = NULL;
vfprintf_hook_t  Arguments::_vfprintf_hook      = NULL;

SystemProperty *Arguments::_sun_boot_library_path = NULL;
SystemProperty *Arguments::_java_library_path = NULL;
SystemProperty *Arguments::_java_home = NULL;
SystemProperty *Arguments::_java_class_path = NULL;
SystemProperty *Arguments::_jdk_boot_class_path_append = NULL;
SystemProperty *Arguments::_vm_info = NULL;

GrowableArray<ModulePatchPath*> *Arguments::_patch_mod_prefix = NULL;
PathString *Arguments::_boot_class_path = NULL;
bool Arguments::_has_jimage = false;

char* Arguments::_ext_dirs = NULL;

// True if -Xshare:auto option was specified.
static bool xshare_auto_cmd_line = false;

bool PathString::set_value(const char *value, AllocFailType alloc_failmode) {
  char* new_value = AllocateHeap(strlen(value)+1, mtArguments, alloc_failmode);
  if (new_value == NULL) {
    assert(alloc_failmode == AllocFailStrategy::RETURN_NULL, "must be");
    return false;
  }
  if (_value != NULL) {
    FreeHeap(_value);
  }
  _value = new_value;
  strcpy(_value, value);
  return true;
}

void PathString::append_value(const char *value) {
  char *sp;
  size_t len = 0;
  if (value != NULL) {
    len = strlen(value);
    if (_value != NULL) {
      len += strlen(_value);
    }
    sp = AllocateHeap(len+2, mtArguments);
    assert(sp != NULL, "Unable to allocate space for new append path value");
    if (sp != NULL) {
      if (_value != NULL) {
        strcpy(sp, _value);
        strcat(sp, os::path_separator());
        strcat(sp, value);
        FreeHeap(_value);
      } else {
        strcpy(sp, value);
      }
      _value = sp;
    }
  }
}

PathString::PathString(const char* value) {
  if (value == NULL) {
    _value = NULL;
  } else {
    _value = AllocateHeap(strlen(value)+1, mtArguments);
    strcpy(_value, value);
  }
}

PathString::~PathString() {
  if (_value != NULL) {
    FreeHeap(_value);
    _value = NULL;
  }
}

ModulePatchPath::ModulePatchPath(const char* module_name, const char* path) {
  assert(module_name != NULL && path != NULL, "Invalid module name or path value");
  size_t len = strlen(module_name) + 1;
  _module_name = AllocateHeap(len, mtInternal);
  strncpy(_module_name, module_name, len); // copy the trailing null
  _path =  new PathString(path);
}

ModulePatchPath::~ModulePatchPath() {
  if (_module_name != NULL) {
    FreeHeap(_module_name);
    _module_name = NULL;
  }
  if (_path != NULL) {
    delete _path;
    _path = NULL;
  }
}

SystemProperty::SystemProperty(const char* key, const char* value, bool writeable, bool internal) : PathString(value) {
  if (key == NULL) {
    _key = NULL;
  } else {
    _key = AllocateHeap(strlen(key)+1, mtArguments);
    strcpy(_key, key);
  }
  _next = NULL;
  _internal = internal;
  _writeable = writeable;
}

AgentLibrary::AgentLibrary(const char* name, const char* options,
               bool is_absolute_path, void* os_lib,
               bool instrument_lib) {
  _name = AllocateHeap(strlen(name)+1, mtArguments);
  strcpy(_name, name);
  if (options == NULL) {
    _options = NULL;
  } else {
    _options = AllocateHeap(strlen(options)+1, mtArguments);
    strcpy(_options, options);
  }
  _is_absolute_path = is_absolute_path;
  _os_lib = os_lib;
  _next = NULL;
  _state = agent_invalid;
  _is_static_lib = false;
  _is_instrument_lib = instrument_lib;
}

// Check if head of 'option' matches 'name', and sets 'tail' to the remaining
// part of the option string.
static bool match_option(const JavaVMOption *option, const char* name,
                         const char** tail) {
  size_t len = strlen(name);
  if (strncmp(option->optionString, name, len) == 0) {
    *tail = option->optionString + len;
    return true;
  } else {
    return false;
  }
}

// Check if 'option' matches 'name'. No "tail" is allowed.
static bool match_option(const JavaVMOption *option, const char* name) {
  const char* tail = NULL;
  bool result = match_option(option, name, &tail);
  if (tail != NULL && *tail == '\0') {
    return result;
  } else {
    return false;
  }
}

// Return true if any of the strings in null-terminated array 'names' matches.
// If tail_allowed is true, then the tail must begin with a colon; otherwise,
// the option must match exactly.
static bool match_option(const JavaVMOption* option, const char** names, const char** tail,
  bool tail_allowed) {
  for (/* empty */; *names != NULL; ++names) {
  if (match_option(option, *names, tail)) {
      if (**tail == '\0' || (tail_allowed && **tail == ':')) {
        return true;
      }
    }
  }
  return false;
}

#if INCLUDE_JFR
static bool _has_jfr_option = false;  // is using JFR

// return true on failure
static bool match_jfr_option(const JavaVMOption** option) {
  assert((*option)->optionString != NULL, "invariant");
  char* tail = NULL;
  if (match_option(*option, "-XX:StartFlightRecording", (const char**)&tail)) {
    _has_jfr_option = true;
    return Jfr::on_start_flight_recording_option(option, tail);
  } else if (match_option(*option, "-XX:FlightRecorderOptions", (const char**)&tail)) {
    _has_jfr_option = true;
    return Jfr::on_flight_recorder_option(option, tail);
  }
  return false;
}

bool Arguments::has_jfr_option() {
  return _has_jfr_option;
}
#endif

static void logOption(const char* opt) {
  if (PrintVMOptions) {
    jio_fprintf(defaultStream::output_stream(), "VM option '%s'\n", opt);
  }
}

bool needs_module_property_warning = false;

#define MODULE_PROPERTY_PREFIX "jdk.module."
#define MODULE_PROPERTY_PREFIX_LEN 11
#define ADDEXPORTS "addexports"
#define ADDEXPORTS_LEN 10
#define ADDREADS "addreads"
#define ADDREADS_LEN 8
#define ADDOPENS "addopens"
#define ADDOPENS_LEN 8
#define PATCH "patch"
#define PATCH_LEN 5
#define ADDMODS "addmods"
#define ADDMODS_LEN 7
#define LIMITMODS "limitmods"
#define LIMITMODS_LEN 9
#define PATH "path"
#define PATH_LEN 4
#define UPGRADE_PATH "upgrade.path"
#define UPGRADE_PATH_LEN 12
#define ENABLE_NATIVE_ACCESS "enable.native.access"
#define ENABLE_NATIVE_ACCESS_LEN 20

void Arguments::add_init_library(const char* name, char* options) {
  _libraryList.add(new AgentLibrary(name, options, false, NULL));
}

void Arguments::add_init_agent(const char* name, char* options, bool absolute_path) {
  _agentList.add(new AgentLibrary(name, options, absolute_path, NULL));
}

void Arguments::add_instrument_agent(const char* name, char* options, bool absolute_path) {
  _agentList.add(new AgentLibrary(name, options, absolute_path, NULL, true));
}

// Late-binding agents not started via arguments
void Arguments::add_loaded_agent(AgentLibrary *agentLib) {
  _agentList.add(agentLib);
}

// Return TRUE if option matches 'property', or 'property=', or 'property.'.
static bool matches_property_suffix(const char* option, const char* property, size_t len) {
  return ((strncmp(option, property, len) == 0) &&
          (option[len] == '=' || option[len] == '.' || option[len] == '\0'));
}

// Return true if property starts with "jdk.module." and its ensuing chars match
// any of the reserved module properties.
// property should be passed without the leading "-D".
bool Arguments::is_internal_module_property(const char* property) {
  assert((strncmp(property, "-D", 2) != 0), "Unexpected leading -D");
  if  (strncmp(property, MODULE_PROPERTY_PREFIX, MODULE_PROPERTY_PREFIX_LEN) == 0) {
    const char* property_suffix = property + MODULE_PROPERTY_PREFIX_LEN;
    if (matches_property_suffix(property_suffix, ADDEXPORTS, ADDEXPORTS_LEN) ||
        matches_property_suffix(property_suffix, ADDREADS, ADDREADS_LEN) ||
        matches_property_suffix(property_suffix, ADDOPENS, ADDOPENS_LEN) ||
        matches_property_suffix(property_suffix, PATCH, PATCH_LEN) ||
        matches_property_suffix(property_suffix, ADDMODS, ADDMODS_LEN) ||
        matches_property_suffix(property_suffix, LIMITMODS, LIMITMODS_LEN) ||
        matches_property_suffix(property_suffix, PATH, PATH_LEN) ||
        matches_property_suffix(property_suffix, UPGRADE_PATH, UPGRADE_PATH_LEN) ||
        matches_property_suffix(property_suffix, ENABLE_NATIVE_ACCESS, ENABLE_NATIVE_ACCESS_LEN)) {
      return true;
    }
  }
  return false;
}

// Process java launcher properties.
void Arguments::process_sun_java_launcher_properties(JavaVMInitArgs* args) {
  // See if sun.java.launcher or sun.java.launcher.is_altjvm is defined.
  // Must do this before setting up other system properties,
  // as some of them may depend on launcher type.
  for (int index = 0; index < args->nOptions; index++) {
    const JavaVMOption* option = args->options + index;
    const char* tail;

    if (match_option(option, "-Dsun.java.launcher=", &tail)) {
      process_java_launcher_argument(tail, option->extraInfo);
      continue;
    }
    if (match_option(option, "-Dsun.java.launcher.is_altjvm=", &tail)) {
      if (strcmp(tail, "true") == 0) {
        _sun_java_launcher_is_altjvm = true;
      }
      continue;
    }
  }
}

// Initialize system properties key and value.
void Arguments::init_system_properties() {

  // Set up _boot_class_path which is not a property but
  // relies heavily on argument processing and the jdk.boot.class.path.append
  // property. It is used to store the underlying boot class path.
  _boot_class_path = new PathString(NULL);

  PropertyList_add(&_system_properties, new SystemProperty("java.vm.specification.name",
                                                           "Java Virtual Machine Specification",  false));
  PropertyList_add(&_system_properties, new SystemProperty("java.vm.version", VM_Version::vm_release(),  false));
  PropertyList_add(&_system_properties, new SystemProperty("java.vm.name", VM_Version::vm_name(),  false));
  PropertyList_add(&_system_properties, new SystemProperty("jdk.debug", VM_Version::jdk_debug_level(),  false));

  // Initialize the vm.info now, but it will need updating after argument parsing.
  _vm_info = new SystemProperty("java.vm.info", VM_Version::vm_info_string(), true);

  // Following are JVMTI agent writable properties.
  // Properties values are set to NULL and they are
  // os specific they are initialized in os::init_system_properties_values().
  _sun_boot_library_path = new SystemProperty("sun.boot.library.path", NULL,  true);
  _java_library_path = new SystemProperty("java.library.path", NULL,  true);
  _java_home =  new SystemProperty("java.home", NULL,  true);
  _java_class_path = new SystemProperty("java.class.path", "",  true);
  // jdk.boot.class.path.append is a non-writeable, internal property.
  // It can only be set by either:
  //    - -Xbootclasspath/a:
  //    - AddToBootstrapClassLoaderSearch during JVMTI OnLoad phase
  _jdk_boot_class_path_append = new SystemProperty("jdk.boot.class.path.append", NULL, false, true);

  // Add to System Property list.
  PropertyList_add(&_system_properties, _sun_boot_library_path);
  PropertyList_add(&_system_properties, _java_library_path);
  PropertyList_add(&_system_properties, _java_home);
  PropertyList_add(&_system_properties, _java_class_path);
  PropertyList_add(&_system_properties, _jdk_boot_class_path_append);
  PropertyList_add(&_system_properties, _vm_info);

  // Set OS specific system properties values
  os::init_system_properties_values();
}

// Update/Initialize System properties after JDK version number is known
void Arguments::init_version_specific_system_properties() {
  enum { bufsz = 16 };
  char buffer[bufsz];
  const char* spec_vendor = "Oracle Corporation";
  uint32_t spec_version = JDK_Version::current().major_version();

  jio_snprintf(buffer, bufsz, UINT32_FORMAT, spec_version);

  PropertyList_add(&_system_properties,
      new SystemProperty("java.vm.specification.vendor",  spec_vendor, false));
  PropertyList_add(&_system_properties,
      new SystemProperty("java.vm.specification.version", buffer, false));
  PropertyList_add(&_system_properties,
      new SystemProperty("java.vm.vendor", VM_Version::vm_vendor(),  false));
}

/*
*  -XX argument processing:
*
*  -XX arguments are defined in several places, such as:
*      globals.hpp, globals_<cpu>.hpp, globals_<os>.hpp, <compiler>_globals.hpp, or <gc>_globals.hpp.
*  -XX arguments are parsed in parse_argument().
*  -XX argument bounds checking is done in check_vm_args_consistency().
*
* Over time -XX arguments may change. There are mechanisms to handle common cases:
*
*      ALIASED: An option that is simply another name for another option. This is often
*               part of the process of deprecating a flag, but not all aliases need
*               to be deprecated.
*
*               Create an alias for an option by adding the old and new option names to the
*               "aliased_jvm_flags" table. Delete the old variable from globals.hpp (etc).
*
*   DEPRECATED: An option that is supported, but a warning is printed to let the user know that
*               support may be removed in the future. Both regular and aliased options may be
*               deprecated.
*
*               Add a deprecation warning for an option (or alias) by adding an entry in the
*               "special_jvm_flags" table and setting the "deprecated_in" field.
*               Often an option "deprecated" in one major release will
*               be made "obsolete" in the next. In this case the entry should also have its
*               "obsolete_in" field set.
*
*     OBSOLETE: An option that has been removed (and deleted from globals.hpp), but is still accepted
*               on the command line. A warning is printed to let the user know that option might not
*               be accepted in the future.
*
*               Add an obsolete warning for an option by adding an entry in the "special_jvm_flags"
*               table and setting the "obsolete_in" field.
*
*      EXPIRED: A deprecated or obsolete option that has an "accept_until" version less than or equal
*               to the current JDK version. The system will flatly refuse to admit the existence of
*               the flag. This allows a flag to die automatically over JDK releases.
*
*               Note that manual cleanup of expired options should be done at major JDK version upgrades:
*                  - Newly expired options should be removed from the special_jvm_flags and aliased_jvm_flags tables.
*                  - Newly obsolete or expired deprecated options should have their global variable
*                    definitions removed (from globals.hpp, etc) and related implementations removed.
*
* Recommended approach for removing options:
*
* To remove options commonly used by customers (e.g. product -XX options), use
* the 3-step model adding major release numbers to the deprecate, obsolete and expire columns.
*
* To remove internal options (e.g. diagnostic, experimental, develop options), use
* a 2-step model adding major release numbers to the obsolete and expire columns.
*
* To change the name of an option, use the alias table as well as a 2-step
* model adding major release numbers to the deprecate and expire columns.
* Think twice about aliasing commonly used customer options.
*
* There are times when it is appropriate to leave a future release number as undefined.
*
* Tests:  Aliases should be tested in VMAliasOptions.java.
*         Deprecated options should be tested in VMDeprecatedOptions.java.
*/

// The special_jvm_flags table declares options that are being deprecated and/or obsoleted. The
// "deprecated_in" or "obsolete_in" fields may be set to "undefined", but not both.
// When the JDK version reaches 'deprecated_in' limit, the JVM will process this flag on
// the command-line as usual, but will issue a warning.
// When the JDK version reaches 'obsolete_in' limit, the JVM will continue accepting this flag on
// the command-line, while issuing a warning and ignoring the flag value.
// Once the JDK version reaches 'expired_in' limit, the JVM will flatly refuse to admit the
// existence of the flag.
//
// MANUAL CLEANUP ON JDK VERSION UPDATES:
// This table ensures that the handling of options will update automatically when the JDK
// version is incremented, but the source code needs to be cleanup up manually:
// - As "deprecated" options age into "obsolete" or "expired" options, the associated "globals"
//   variable should be removed, as well as users of the variable.
// - As "deprecated" options age into "obsolete" options, move the entry into the
//   "Obsolete Flags" section of the table.
// - All expired options should be removed from the table.
static SpecialFlag const special_jvm_flags[] = {
  // -------------- Deprecated Flags --------------
  // --- Non-alias flags - sorted by obsolete_in then expired_in:
  { "MaxGCMinorPauseMillis",        JDK_Version::jdk(8), JDK_Version::undefined(), JDK_Version::undefined() },
  { "MaxRAMFraction",               JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
  { "MinRAMFraction",               JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
  { "InitialRAMFraction",           JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
  { "AllowRedefinitionToAddDeleteMethods", JDK_Version::jdk(13), JDK_Version::undefined(), JDK_Version::undefined() },
  { "FlightRecorder",               JDK_Version::jdk(13), JDK_Version::undefined(), JDK_Version::undefined() },
  { "DumpSharedSpaces",             JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
  { "DynamicDumpSharedSpaces",      JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
  { "RequireSharedSpaces",          JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
  { "UseSharedSpaces",              JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
  { "EnableWaitForParallelLoad",    JDK_Version::jdk(20), JDK_Version::jdk(21), JDK_Version::jdk(22) },

  // --- Deprecated alias flags (see also aliased_jvm_flags) - sorted by obsolete_in then expired_in:
  { "DefaultMaxRAMFraction",        JDK_Version::jdk(8),  JDK_Version::undefined(), JDK_Version::undefined() },
  { "CreateMinidumpOnCrash",        JDK_Version::jdk(9),  JDK_Version::undefined(), JDK_Version::undefined() },
  { "TLABStats",                    JDK_Version::jdk(12), JDK_Version::undefined(), JDK_Version::undefined() },

  // -------------- Obsolete Flags - sorted by expired_in --------------

  { "ExtendedDTraceProbes",         JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
  { "UseContainerCpuShares",        JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
  { "PreferContainerQuotaForCPUCount", JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
  { "AliasLevel",                   JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
  { "UseCodeAging",                 JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::jdk(21) },
  { "PrintSharedDictionary",          JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::jdk(21) },

  { "G1ConcRefinementGreenZone",    JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::undefined() },
  { "G1ConcRefinementYellowZone",   JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::undefined() },
  { "G1ConcRefinementRedZone",      JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::undefined() },
  { "G1ConcRefinementThresholdStep", JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::undefined() },
  { "G1UseAdaptiveConcRefinement",  JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::undefined() },
  { "G1ConcRefinementServiceIntervalMillis", JDK_Version::undefined(), JDK_Version::jdk(20), JDK_Version::undefined() },

#ifdef ASSERT
  { "DummyObsoleteTestFlag",        JDK_Version::undefined(), JDK_Version::jdk(18), JDK_Version::undefined() },
#endif

#ifdef TEST_VERIFY_SPECIAL_JVM_FLAGS
  // These entries will generate build errors.  Their purpose is to test the macros.
  { "dep > obs",                    JDK_Version::jdk(9), JDK_Version::jdk(8), JDK_Version::undefined() },
  { "dep > exp ",                   JDK_Version::jdk(9), JDK_Version::undefined(), JDK_Version::jdk(8) },
  { "obs > exp ",                   JDK_Version::undefined(), JDK_Version::jdk(9), JDK_Version::jdk(8) },
  { "obs > exp",                    JDK_Version::jdk(8), JDK_Version::undefined(), JDK_Version::jdk(10) },
  { "not deprecated or obsolete",   JDK_Version::undefined(), JDK_Version::undefined(), JDK_Version::jdk(9) },
  { "dup option",                   JDK_Version::jdk(9), JDK_Version::undefined(), JDK_Version::undefined() },
  { "dup option",                   JDK_Version::jdk(9), JDK_Version::undefined(), JDK_Version::undefined() },
#endif

  { NULL, JDK_Version(0), JDK_Version(0) }
};

// Flags that are aliases for other flags.
typedef struct {
  const char* alias_name;
  const char* real_name;
} AliasedFlag;

static AliasedFlag const aliased_jvm_flags[] = {
  { "DefaultMaxRAMFraction",    "MaxRAMFraction"    },
  { "CreateMinidumpOnCrash",    "CreateCoredumpOnCrash" },
  { NULL, NULL}
};

// Return true if "v" is less than "other", where "other" may be "undefined".
static bool version_less_than(JDK_Version v, JDK_Version other) {
  assert(!v.is_undefined(), "must be defined");
  if (!other.is_undefined() && v.compare(other) >= 0) {
    return false;
  } else {
    return true;
  }
}

static bool lookup_special_flag(const char *flag_name, SpecialFlag& flag) {
  for (size_t i = 0; special_jvm_flags[i].name != NULL; i++) {
    if ((strcmp(special_jvm_flags[i].name, flag_name) == 0)) {
      flag = special_jvm_flags[i];
      return true;
    }
  }
  return false;
}

bool Arguments::is_obsolete_flag(const char *flag_name, JDK_Version* version) {
  assert(version != NULL, "Must provide a version buffer");
  SpecialFlag flag;
  if (lookup_special_flag(flag_name, flag)) {
    if (!flag.obsolete_in.is_undefined()) {
      if (!version_less_than(JDK_Version::current(), flag.obsolete_in)) {
        *version = flag.obsolete_in;
        // This flag may have been marked for obsoletion in this version, but we may not
        // have actually removed it yet. Rather than ignoring it as soon as we reach
        // this version we allow some time for the removal to happen. So if the flag
        // still actually exists we process it as normal, but issue an adjusted warning.
        const JVMFlag *real_flag = JVMFlag::find_declared_flag(flag_name);
        if (real_flag != NULL) {
          char version_str[256];
          version->to_string(version_str, sizeof(version_str));
          warning("Temporarily processing option %s; support is scheduled for removal in %s",
                  flag_name, version_str);
          return false;
        }
        return true;
      }
    }
  }
  return false;
}

int Arguments::is_deprecated_flag(const char *flag_name, JDK_Version* version) {
  assert(version != NULL, "Must provide a version buffer");
  SpecialFlag flag;
  if (lookup_special_flag(flag_name, flag)) {
    if (!flag.deprecated_in.is_undefined()) {
      if (version_less_than(JDK_Version::current(), flag.obsolete_in) &&
          version_less_than(JDK_Version::current(), flag.expired_in)) {
        *version = flag.deprecated_in;
        return 1;
      } else {
        return -1;
      }
    }
  }
  return 0;
}

const char* Arguments::real_flag_name(const char *flag_name) {
  for (size_t i = 0; aliased_jvm_flags[i].alias_name != NULL; i++) {
    const AliasedFlag& flag_status = aliased_jvm_flags[i];
    if (strcmp(flag_status.alias_name, flag_name) == 0) {
        return flag_status.real_name;
    }
  }
  return flag_name;
}

#ifdef ASSERT
static bool lookup_special_flag(const char *flag_name, size_t skip_index) {
  for (size_t i = 0; special_jvm_flags[i].name != NULL; i++) {
    if ((i != skip_index) && (strcmp(special_jvm_flags[i].name, flag_name) == 0)) {
      return true;
    }
  }
  return false;
}

// Verifies the correctness of the entries in the special_jvm_flags table.
// If there is a semantic error (i.e. a bug in the table) such as the obsoletion
// version being earlier than the deprecation version, then a warning is issued
// and verification fails - by returning false. If it is detected that the table
// is out of date, with respect to the current version, then ideally a warning is
// issued but verification does not fail. This allows the VM to operate when the
// version is first updated, without needing to update all the impacted flags at
// the same time. In practice we can't issue the warning immediately when the version
// is updated as it occurs for every test and some tests are not prepared to handle
// unexpected output - see 8196739. Instead we only check if the table is up-to-date
// if the check_globals flag is true, and in addition allow a grace period and only
// check for stale flags when we hit build 25 (which is far enough into the 6 month
// release cycle that all flag updates should have been processed, whilst still
// leaving time to make the change before RDP2).
// We use a gtest to call this, passing true, so that we can detect stale flags before
// the end of the release cycle.

static const int SPECIAL_FLAG_VALIDATION_BUILD = 25;

bool Arguments::verify_special_jvm_flags(bool check_globals) {
  bool success = true;
  for (size_t i = 0; special_jvm_flags[i].name != NULL; i++) {
    const SpecialFlag& flag = special_jvm_flags[i];
    if (lookup_special_flag(flag.name, i)) {
      warning("Duplicate special flag declaration \"%s\"", flag.name);
      success = false;
    }
    if (flag.deprecated_in.is_undefined() &&
        flag.obsolete_in.is_undefined()) {
      warning("Special flag entry \"%s\" must declare version deprecated and/or obsoleted in.", flag.name);
      success = false;
    }

    if (!flag.deprecated_in.is_undefined()) {
      if (!version_less_than(flag.deprecated_in, flag.obsolete_in)) {
        warning("Special flag entry \"%s\" must be deprecated before obsoleted.", flag.name);
        success = false;
      }

      if (!version_less_than(flag.deprecated_in, flag.expired_in)) {
        warning("Special flag entry \"%s\" must be deprecated before expired.", flag.name);
        success = false;
      }
    }

    if (!flag.obsolete_in.is_undefined()) {
      if (!version_less_than(flag.obsolete_in, flag.expired_in)) {
        warning("Special flag entry \"%s\" must be obsoleted before expired.", flag.name);
        success = false;
      }

      // if flag has become obsolete it should not have a "globals" flag defined anymore.
      if (check_globals && VM_Version::vm_build_number() >= SPECIAL_FLAG_VALIDATION_BUILD &&
          !version_less_than(JDK_Version::current(), flag.obsolete_in)) {
        if (JVMFlag::find_declared_flag(flag.name) != NULL) {
          warning("Global variable for obsolete special flag entry \"%s\" should be removed", flag.name);
          success = false;
        }
      }

    } else if (!flag.expired_in.is_undefined()) {
      warning("Special flag entry \"%s\" must be explicitly obsoleted before expired.", flag.name);
      success = false;
    }

    if (!flag.expired_in.is_undefined()) {
      // if flag has become expired it should not have a "globals" flag defined anymore.
      if (check_globals && VM_Version::vm_build_number() >= SPECIAL_FLAG_VALIDATION_BUILD &&
          !version_less_than(JDK_Version::current(), flag.expired_in)) {
        if (JVMFlag::find_declared_flag(flag.name) != NULL) {
          warning("Global variable for expired flag entry \"%s\" should be removed", flag.name);
          success = false;
        }
      }
    }
  }
  return success;
}
#endif

bool Arguments::atojulong(const char *s, julong* result) {
  return parse_integer(s, result);
}

Arguments::ArgsRange Arguments::check_memory_size(julong size, julong min_size, julong max_size) {
  if (size < min_size) return arg_too_small;
  if (size > max_size) return arg_too_big;
  return arg_in_range;
}

// Describe an argument out of range error
void Arguments::describe_range_error(ArgsRange errcode) {
  switch(errcode) {
  case arg_too_big:
    jio_fprintf(defaultStream::error_stream(),
                "The specified size exceeds the maximum "
                "representable size.\n");
    break;
  case arg_too_small:
  case arg_unreadable:
  case arg_in_range:
    // do nothing for now
    break;
  default:
    ShouldNotReachHere();
  }
}

static bool set_bool_flag(JVMFlag* flag, bool value, JVMFlagOrigin origin) {
  if (JVMFlagAccess::set_bool(flag, &value, origin) == JVMFlag::SUCCESS) {
    return true;
  } else {
    return false;
  }
}

static bool set_fp_numeric_flag(JVMFlag* flag, const char* value, JVMFlagOrigin origin) {
  // strtod allows leading whitespace, but our flag format does not.
  if (*value == '\0' || isspace(*value)) {
    return false;
  }
  char* end;
  errno = 0;
  double v = strtod(value, &end);
  if ((errno != 0) || (*end != 0)) {
    return false;
  }
  if (g_isnan(v) || !g_isfinite(v)) {
    // Currently we cannot handle these special values.
    return false;
  }

  if (JVMFlagAccess::set_double(flag, &v, origin) == JVMFlag::SUCCESS) {
    return true;
  }
  return false;
}

static bool set_numeric_flag(JVMFlag* flag, const char* value, JVMFlagOrigin origin) {
  JVMFlag::Error result = JVMFlag::WRONG_FORMAT;

  if (flag->is_int()) {
    int v;
    if (parse_integer(value, &v)) {
      result = JVMFlagAccess::set_int(flag, &v, origin);
    }
  } else if (flag->is_uint()) {
    uint v;
    if (parse_integer(value, &v)) {
      result = JVMFlagAccess::set_uint(flag, &v, origin);
    }
  } else if (flag->is_intx()) {
    intx v;
    if (parse_integer(value, &v)) {
      result = JVMFlagAccess::set_intx(flag, &v, origin);
    }
  } else if (flag->is_uintx()) {
    uintx v;
    if (parse_integer(value, &v)) {
      result = JVMFlagAccess::set_uintx(flag, &v, origin);
    }
  } else if (flag->is_uint64_t()) {
    uint64_t v;
    if (parse_integer(value, &v)) {
      result = JVMFlagAccess::set_uint64_t(flag, &v, origin);
    }
  } else if (flag->is_size_t()) {
    size_t v;
    if (parse_integer(value, &v)) {
      result = JVMFlagAccess::set_size_t(flag, &v, origin);
    }
  }

  return result == JVMFlag::SUCCESS;
}

static bool set_string_flag(JVMFlag* flag, const char* value, JVMFlagOrigin origin) {
  if (value[0] == '\0') {
    value = NULL;
  }
  if (JVMFlagAccess::set_ccstr(flag, &value, origin) != JVMFlag::SUCCESS) return false;
  // Contract:  JVMFlag always returns a pointer that needs freeing.
  FREE_C_HEAP_ARRAY(char, value);
  return true;
}

static bool append_to_string_flag(JVMFlag* flag, const char* new_value, JVMFlagOrigin origin) {
  const char* old_value = "";
  if (JVMFlagAccess::get_ccstr(flag, &old_value) != JVMFlag::SUCCESS) return false;
  size_t old_len = old_value != NULL ? strlen(old_value) : 0;
  size_t new_len = strlen(new_value);
  const char* value;
  char* free_this_too = NULL;
  if (old_len == 0) {
    value = new_value;
  } else if (new_len == 0) {
    value = old_value;
  } else {
     size_t length = old_len + 1 + new_len + 1;
     char* buf = NEW_C_HEAP_ARRAY(char, length, mtArguments);
    // each new setting adds another LINE to the switch:
    jio_snprintf(buf, length, "%s\n%s", old_value, new_value);
    value = buf;
    free_this_too = buf;
  }
  (void) JVMFlagAccess::set_ccstr(flag, &value, origin);
  // JVMFlag always returns a pointer that needs freeing.
  FREE_C_HEAP_ARRAY(char, value);
  // JVMFlag made its own copy, so I must delete my own temp. buffer.
  FREE_C_HEAP_ARRAY(char, free_this_too);
  return true;
}

const char* Arguments::handle_aliases_and_deprecation(const char* arg) {
  const char* real_name = real_flag_name(arg);
  JDK_Version since = JDK_Version();
  switch (is_deprecated_flag(arg, &since)) {
  case -1: {
      // Obsolete or expired, so don't process normally,
      // but allow for an obsolete flag we're still
      // temporarily allowing.
      if (!is_obsolete_flag(arg, &since)) {
        return real_name;
      }
      // Note if we're not considered obsolete then we can't be expired either
      // as obsoletion must come first.
      return NULL;
    }
    case 0:
      return real_name;
    case 1: {
      char version[256];
      since.to_string(version, sizeof(version));
      if (real_name != arg) {
        warning("Option %s was deprecated in version %s and will likely be removed in a future release. Use option %s instead.",
                arg, version, real_name);
      } else {
        warning("Option %s was deprecated in version %s and will likely be removed in a future release.",
                arg, version);
      }
      return real_name;
    }
  }
  ShouldNotReachHere();
  return NULL;
}

#define BUFLEN 255

JVMFlag* Arguments::find_jvm_flag(const char* name, size_t name_length) {
  char name_copied[BUFLEN+1];
  if (name[name_length] != 0) {
    if (name_length > BUFLEN) {
      return NULL;
    } else {
      strncpy(name_copied, name, name_length);
      name_copied[name_length] = '\0';
      name = name_copied;
    }
  }

  const char* real_name = Arguments::handle_aliases_and_deprecation(name);
  if (real_name == NULL) {
    return NULL;
  }
  JVMFlag* flag = JVMFlag::find_flag(real_name);
  return flag;
}

bool Arguments::parse_argument(const char* arg, JVMFlagOrigin origin) {
  bool is_bool = false;
  bool bool_val = false;
  char c = *arg;
  if (c == '+' || c == '-') {
    is_bool = true;
    bool_val = (c == '+');
    arg++;
  }

  const char* name = arg;
  while (true) {
    c = *arg;
    if (isalnum(c) || (c == '_')) {
      ++arg;
    } else {
      break;
    }
  }

  size_t name_len = size_t(arg - name);
  if (name_len == 0) {
    return false;
  }

  JVMFlag* flag = find_jvm_flag(name, name_len);
  if (flag == NULL) {
    return false;
  }

  if (is_bool) {
    if (*arg != 0) {
      // Error -- extra characters such as -XX:+BoolFlag=123
      return false;
    }
    return set_bool_flag(flag, bool_val, origin);
  }

  if (arg[0] == '=') {
    const char* value = arg + 1;
    if (flag->is_ccstr()) {
      if (flag->ccstr_accumulates()) {
        return append_to_string_flag(flag, value, origin);
      } else {
        return set_string_flag(flag, value, origin);
      }
    } else if (flag->is_double()) {
      return set_fp_numeric_flag(flag, value, origin);
    } else {
      return set_numeric_flag(flag, value, origin);
    }
  }

  if (arg[0] == ':' && arg[1] == '=') {
    // -XX:Foo:=xxx will reset the string flag to the given value.
    const char* value = arg + 2;
    return set_string_flag(flag, value, origin);
  }

  return false;
}

void Arguments::add_string(char*** bldarray, int* count, const char* arg) {
  assert(bldarray != NULL, "illegal argument");

  if (arg == NULL) {
    return;
  }

  int new_count = *count + 1;

  // expand the array and add arg to the last element
  if (*bldarray == NULL) {
    *bldarray = NEW_C_HEAP_ARRAY(char*, new_count, mtArguments);
  } else {
    *bldarray = REALLOC_C_HEAP_ARRAY(char*, *bldarray, new_count, mtArguments);
  }
  (*bldarray)[*count] = os::strdup_check_oom(arg);
  *count = new_count;
}

void Arguments::build_jvm_args(const char* arg) {
  add_string(&_jvm_args_array, &_num_jvm_args, arg);
}

void Arguments::build_jvm_flags(const char* arg) {
  add_string(&_jvm_flags_array, &_num_jvm_flags, arg);
}

// utility function to return a string that concatenates all
// strings in a given char** array
const char* Arguments::build_resource_string(char** args, int count) {
  if (args == NULL || count == 0) {
    return NULL;
  }
  size_t length = 0;
  for (int i = 0; i < count; i++) {
    length += strlen(args[i]) + 1; // add 1 for a space or NULL terminating character
  }
  char* s = NEW_RESOURCE_ARRAY(char, length);
  char* dst = s;
  for (int j = 0; j < count; j++) {
    size_t offset = strlen(args[j]) + 1; // add 1 for a space or NULL terminating character
    jio_snprintf(dst, length, "%s ", args[j]); // jio_snprintf will replace the last space character with NULL character
    dst += offset;
    length -= offset;
  }
  return (const char*) s;
}

void Arguments::print_on(outputStream* st) {
  st->print_cr("VM Arguments:");
  if (num_jvm_flags() > 0) {
    st->print("jvm_flags: "); print_jvm_flags_on(st);
    st->cr();
  }
  if (num_jvm_args() > 0) {
    st->print("jvm_args: "); print_jvm_args_on(st);
    st->cr();
  }
  st->print_cr("java_command: %s", java_command() ? java_command() : "");
  if (_java_class_path != NULL) {
    char* path = _java_class_path->value();
    size_t len = strlen(path);
    st->print("java_class_path (initial): ");
    // Avoid using st->print_cr() because path length maybe longer than O_BUFLEN.
    if (len == 0) {
      st->print_raw_cr("");
    } else {
      st->print_raw_cr(path, len);
    }
  }
  st->print_cr("Launcher Type: %s", _sun_java_launcher);
}

void Arguments::print_summary_on(outputStream* st) {
  // Print the command line.  Environment variables that are helpful for
  // reproducing the problem are written later in the hs_err file.
  // flags are from setting file
  if (num_jvm_flags() > 0) {
    st->print_raw("Settings File: ");
    print_jvm_flags_on(st);
    st->cr();
  }
  // args are the command line and environment variable arguments.
  st->print_raw("Command Line: ");
  if (num_jvm_args() > 0) {
    print_jvm_args_on(st);
  }
  // this is the classfile and any arguments to the java program
  if (java_command() != NULL) {
    st->print("%s", java_command());
  }
  st->cr();
}

void Arguments::print_jvm_flags_on(outputStream* st) {
  if (_num_jvm_flags > 0) {
    for (int i=0; i < _num_jvm_flags; i++) {
      st->print("%s ", _jvm_flags_array[i]);
    }
  }
}

void Arguments::print_jvm_args_on(outputStream* st) {
  if (_num_jvm_args > 0) {
    for (int i=0; i < _num_jvm_args; i++) {
      st->print("%s ", _jvm_args_array[i]);
    }
  }
}

bool Arguments::process_argument(const char* arg,
                                 jboolean ignore_unrecognized,
                                 JVMFlagOrigin origin) {
  JDK_Version since = JDK_Version();

  if (parse_argument(arg, origin)) {
    return true;
  }

  // Determine if the flag has '+', '-', or '=' characters.
  bool has_plus_minus = (*arg == '+' || *arg == '-');
  const char* const argname = has_plus_minus ? arg + 1 : arg;

  size_t arg_len;
  const char* equal_sign = strchr(argname, '=');
  if (equal_sign == NULL) {
    arg_len = strlen(argname);
  } else {
    arg_len = equal_sign - argname;
  }

  // Only make the obsolete check for valid arguments.
  if (arg_len <= BUFLEN) {
    // Construct a string which consists only of the argument name without '+', '-', or '='.
    char stripped_argname[BUFLEN+1]; // +1 for '\0'
    jio_snprintf(stripped_argname, arg_len+1, "%s", argname); // +1 for '\0'
    if (is_obsolete_flag(stripped_argname, &since)) {
      char version[256];
      since.to_string(version, sizeof(version));
      warning("Ignoring option %s; support was removed in %s", stripped_argname, version);
      return true;
    }
  }

  // For locked flags, report a custom error message if available.
  // Otherwise, report the standard unrecognized VM option.
  const JVMFlag* found_flag = JVMFlag::find_declared_flag((const char*)argname, arg_len);
  if (found_flag != NULL) {
    char locked_message_buf[BUFLEN];
    JVMFlag::MsgType msg_type = found_flag->get_locked_message(locked_message_buf, BUFLEN);
    if (strlen(locked_message_buf) == 0) {
      if (found_flag->is_bool() && !has_plus_minus) {
        jio_fprintf(defaultStream::error_stream(),
          "Missing +/- setting for VM option '%s'\n", argname);
      } else if (!found_flag->is_bool() && has_plus_minus) {
        jio_fprintf(defaultStream::error_stream(),
          "Unexpected +/- setting in VM option '%s'\n", argname);
      } else {
        jio_fprintf(defaultStream::error_stream(),
          "Improperly specified VM option '%s'\n", argname);
      }
    } else {
#ifdef PRODUCT
      bool mismatched = ((msg_type == JVMFlag::NOTPRODUCT_FLAG_BUT_PRODUCT_BUILD) ||
                         (msg_type == JVMFlag::DEVELOPER_FLAG_BUT_PRODUCT_BUILD));
      if (ignore_unrecognized && mismatched) {
        return true;
      }
#endif
      jio_fprintf(defaultStream::error_stream(), "%s", locked_message_buf);
    }
  } else {
    if (ignore_unrecognized) {
      return true;
    }
    jio_fprintf(defaultStream::error_stream(),
                "Unrecognized VM option '%s'\n", argname);
    JVMFlag* fuzzy_matched = JVMFlag::fuzzy_match((const char*)argname, arg_len, true);
    if (fuzzy_matched != NULL) {
      jio_fprintf(defaultStream::error_stream(),
                  "Did you mean '%s%s%s'? ",
                  (fuzzy_matched->is_bool()) ? "(+/-)" : "",
                  fuzzy_matched->name(),
                  (fuzzy_matched->is_bool()) ? "" : "=");
    }
  }

  // allow for commandline "commenting out" options like -XX:#+Verbose
  return arg[0] == '#';
}

bool Arguments::process_settings_file(const char* file_name, bool should_exist, jboolean ignore_unrecognized) {
  FILE* stream = os::fopen(file_name, "rb");
  if (stream == NULL) {
    if (should_exist) {
      jio_fprintf(defaultStream::error_stream(),
                  "Could not open settings file %s\n", file_name);
      return false;
    } else {
      return true;
    }
  }

  char token[1024];
  int  pos = 0;

  bool in_white_space = true;
  bool in_comment     = false;
  bool in_quote       = false;
  char quote_c        = 0;
  bool result         = true;

  int c = getc(stream);
  while(c != EOF && pos < (int)(sizeof(token)-1)) {
    if (in_white_space) {
      if (in_comment) {
        if (c == '\n') in_comment = false;
      } else {
        if (c == '#') in_comment = true;
        else if (!isspace(c)) {
          in_white_space = false;
          token[pos++] = c;
        }
      }
    } else {
      if (c == '\n' || (!in_quote && isspace(c))) {
        // token ends at newline, or at unquoted whitespace
        // this allows a way to include spaces in string-valued options
        token[pos] = '\0';
        logOption(token);
        result &= process_argument(token, ignore_unrecognized, JVMFlagOrigin::CONFIG_FILE);
        build_jvm_flags(token);
        pos = 0;
        in_white_space = true;
        in_quote = false;
      } else if (!in_quote && (c == '\'' || c == '"')) {
        in_quote = true;
        quote_c = c;
      } else if (in_quote && (c == quote_c)) {
        in_quote = false;
      } else {
        token[pos++] = c;
      }
    }
    c = getc(stream);
  }
  if (pos > 0) {
    token[pos] = '\0';
    result &= process_argument(token, ignore_unrecognized, JVMFlagOrigin::CONFIG_FILE);
    build_jvm_flags(token);
  }
  fclose(stream);
  return result;
}

//=============================================================================================================
// Parsing of properties (-D)

const char* Arguments::get_property(const char* key) {
  return PropertyList_get_value(system_properties(), key);
}

bool Arguments::add_property(const char* prop, PropertyWriteable writeable, PropertyInternal internal) {
  const char* eq = strchr(prop, '=');
  const char* key;
  const char* value = "";

  if (eq == NULL) {
    // property doesn't have a value, thus use passed string
    key = prop;
  } else {
    // property have a value, thus extract it and save to the
    // allocated string
    size_t key_len = eq - prop;
    char* tmp_key = AllocateHeap(key_len + 1, mtArguments);

    jio_snprintf(tmp_key, key_len + 1, "%s", prop);
    key = tmp_key;

    value = &prop[key_len + 1];
  }

#if INCLUDE_CDS
  if (is_internal_module_property(key) ||
      strcmp(key, "jdk.module.main") == 0) {
    MetaspaceShared::disable_optimized_module_handling();
    log_info(cds)("optimized module handling: disabled due to incompatible property: %s=%s", key, value);
  }
  if (strcmp(key, "jdk.module.showModuleResolution") == 0 ||
      strcmp(key, "jdk.module.validation") == 0 ||
      strcmp(key, "java.system.class.loader") == 0) {
    MetaspaceShared::disable_full_module_graph();
    log_info(cds)("full module graph: disabled due to incompatible property: %s=%s", key, value);
  }
#endif

  if (strcmp(key, "java.compiler") == 0) {
    process_java_compiler_argument(value);
    // Record value in Arguments, but let it get passed to Java.
  } else if (strcmp(key, "sun.java.launcher.is_altjvm") == 0) {
    // sun.java.launcher.is_altjvm property is
    // private and is processed in process_sun_java_launcher_properties();
    // the sun.java.launcher property is passed on to the java application
  } else if (strcmp(key, "sun.boot.library.path") == 0) {
    // append is true, writable is true, internal is false
    PropertyList_unique_add(&_system_properties, key, value, AppendProperty,
                            WriteableProperty, ExternalProperty);
  } else {
    if (strcmp(key, "sun.java.command") == 0) {
      char *old_java_command = _java_command;
      _java_command = os::strdup_check_oom(value, mtArguments);
      if (old_java_command != NULL) {
        os::free(old_java_command);
      }
    } else if (strcmp(key, "java.vendor.url.bug") == 0) {
      // If this property is set on the command line then its value will be
      // displayed in VM error logs as the URL at which to submit such logs.
      // Normally the URL displayed in error logs is different from the value
      // of this system property, so a different property should have been
      // used here, but we leave this as-is in case someone depends upon it.
      const char* old_java_vendor_url_bug = _java_vendor_url_bug;
      // save it in _java_vendor_url_bug, so JVM fatal error handler can access
      // its value without going through the property list or making a Java call.
      _java_vendor_url_bug = os::strdup_check_oom(value, mtArguments);
      if (old_java_vendor_url_bug != NULL) {
        os::free((void *)old_java_vendor_url_bug);
      }
    }

    // Create new property and add at the end of the list
    PropertyList_unique_add(&_system_properties, key, value, AddProperty, writeable, internal);
  }

  if (key != prop) {
    // SystemProperty copy passed value, thus free previously allocated
    // memory
    FreeHeap((void *)key);
  }

  return true;
}

#if INCLUDE_CDS
const char* unsupported_properties[] = { "jdk.module.limitmods",
                                         "jdk.module.upgrade.path",
                                         "jdk.module.patch.0" };
const char* unsupported_options[] = { "--limit-modules",
                                      "--upgrade-module-path",
                                      "--patch-module"
                                    };
void Arguments::check_unsupported_dumping_properties() {
  assert(is_dumping_archive(),
         "this function is only used with CDS dump time");
  assert(ARRAY_SIZE(unsupported_properties) == ARRAY_SIZE(unsupported_options), "must be");
  // If a vm option is found in the unsupported_options array, vm will exit with an error message.
  SystemProperty* sp = system_properties();
  while (sp != NULL) {
    for (uint i = 0; i < ARRAY_SIZE(unsupported_properties); i++) {
      if (strcmp(sp->key(), unsupported_properties[i]) == 0) {
        vm_exit_during_initialization(
          "Cannot use the following option when dumping the shared archive", unsupported_options[i]);
      }
    }
    sp = sp->next();
  }

  // Check for an exploded module build in use with -Xshare:dump.
  if (!has_jimage()) {
    vm_exit_during_initialization("Dumping the shared archive is not supported with an exploded module build");
  }
}

bool Arguments::check_unsupported_cds_runtime_properties() {
  assert(UseSharedSpaces, "this function is only used with -Xshare:{on,auto}");
  assert(ARRAY_SIZE(unsupported_properties) == ARRAY_SIZE(unsupported_options), "must be");
  if (ArchiveClassesAtExit != NULL) {
    // dynamic dumping, just return false for now.
    // check_unsupported_dumping_properties() will be called later to check the same set of
    // properties, and will exit the VM with the correct error message if the unsupported properties
    // are used.
    return false;
  }
  for (uint i = 0; i < ARRAY_SIZE(unsupported_properties); i++) {
    if (get_property(unsupported_properties[i]) != NULL) {
      if (RequireSharedSpaces) {
        warning("CDS is disabled when the %s option is specified.", unsupported_options[i]);
      } else {
        log_info(cds)("CDS is disabled when the %s option is specified.", unsupported_options[i]);
      }
      return true;
    }
  }
  return false;
}
#endif

//===========================================================================================================
// Setting int/mixed/comp mode flags

void Arguments::set_mode_flags(Mode mode) {
  // Set up default values for all flags.
  // If you add a flag to any of the branches below,
  // add a default value for it here.
  set_java_compiler(false);
  _mode                      = mode;

  // Ensure Agent_OnLoad has the correct initial values.
  // This may not be the final mode; mode may change later in onload phase.
  PropertyList_unique_add(&_system_properties, "java.vm.info",
                          VM_Version::vm_info_string(), AddProperty, UnwriteableProperty, ExternalProperty);

  UseInterpreter             = true;
  UseCompiler                = true;
  UseLoopCounter             = true;

  // Default values may be platform/compiler dependent -
  // use the saved values
  ClipInlining               = Arguments::_ClipInlining;
  AlwaysCompileLoopMethods   = Arguments::_AlwaysCompileLoopMethods;
  UseOnStackReplacement      = Arguments::_UseOnStackReplacement;
  BackgroundCompilation      = Arguments::_BackgroundCompilation;

  // Change from defaults based on mode
  switch (mode) {
  default:
    ShouldNotReachHere();
    break;
  case _int:
    UseCompiler              = false;
    UseLoopCounter           = false;
    AlwaysCompileLoopMethods = false;
    UseOnStackReplacement    = false;
    break;
  case _mixed:
    // same as default
    break;
  case _comp:
    UseInterpreter           = false;
    BackgroundCompilation    = false;
    ClipInlining             = false;
    break;
  }
}

// Conflict: required to use shared spaces (-Xshare:on), but
// incompatible command line options were chosen.
static void no_shared_spaces(const char* message) {
  if (RequireSharedSpaces) {
    jio_fprintf(defaultStream::error_stream(),
      "Class data sharing is inconsistent with other specified options.\n");
    vm_exit_during_initialization("Unable to use shared archive", message);
  } else {
    log_info(cds)("Unable to use shared archive: %s", message);
    UseSharedSpaces = false;
  }
}

void set_object_alignment() {
  // Object alignment.
  assert(is_power_of_2(ObjectAlignmentInBytes), "ObjectAlignmentInBytes must be power of 2");
  MinObjAlignmentInBytes     = ObjectAlignmentInBytes;
  assert(MinObjAlignmentInBytes >= HeapWordsPerLong * HeapWordSize, "ObjectAlignmentInBytes value is too small");
  MinObjAlignment            = MinObjAlignmentInBytes / HeapWordSize;
  assert(MinObjAlignmentInBytes == MinObjAlignment * HeapWordSize, "ObjectAlignmentInBytes value is incorrect");
  MinObjAlignmentInBytesMask = MinObjAlignmentInBytes - 1;

  LogMinObjAlignmentInBytes  = exact_log2(ObjectAlignmentInBytes);
  LogMinObjAlignment         = LogMinObjAlignmentInBytes - LogHeapWordSize;

  // Oop encoding heap max
  OopEncodingHeapMax = (uint64_t(max_juint) + 1) << LogMinObjAlignmentInBytes;
}

size_t Arguments::max_heap_for_compressed_oops() {
  // Avoid sign flip.
  assert(OopEncodingHeapMax > (uint64_t)os::vm_page_size(), "Unusual page size");
  // We need to fit both the NULL page and the heap into the memory budget, while
  // keeping alignment constraints of the heap. To guarantee the latter, as the
  // NULL page is located before the heap, we pad the NULL page to the conservative
  // maximum alignment that the GC may ever impose upon the heap.
  size_t displacement_due_to_null_page = align_up((size_t)os::vm_page_size(),
                                                  _conservative_max_heap_alignment);

  LP64_ONLY(return OopEncodingHeapMax - displacement_due_to_null_page);
  NOT_LP64(ShouldNotReachHere(); return 0);
}

void Arguments::set_use_compressed_oops() {
#ifdef _LP64
  // MaxHeapSize is not set up properly at this point, but
  // the only value that can override MaxHeapSize if we are
  // to use UseCompressedOops are InitialHeapSize and MinHeapSize.
  size_t max_heap_size = MAX3(MaxHeapSize, InitialHeapSize, MinHeapSize);

  if (max_heap_size <= max_heap_for_compressed_oops()) {
    if (FLAG_IS_DEFAULT(UseCompressedOops)) {
      FLAG_SET_ERGO(UseCompressedOops, true);
    }
  } else {
    if (UseCompressedOops && !FLAG_IS_DEFAULT(UseCompressedOops)) {
      warning("Max heap size too large for Compressed Oops");
      FLAG_SET_DEFAULT(UseCompressedOops, false);
      if (COMPRESSED_CLASS_POINTERS_DEPENDS_ON_COMPRESSED_OOPS) {
        FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
      }
    }
  }
#endif // _LP64
}

// NOTE: set_use_compressed_klass_ptrs() must be called after calling
// set_use_compressed_oops().
void Arguments::set_use_compressed_klass_ptrs() {
#ifdef _LP64
  // On some architectures, the use of UseCompressedClassPointers implies the use of
  // UseCompressedOops. The reason is that the rheap_base register of said platforms
  // is reused to perform some optimized spilling, in order to use rheap_base as a
  // temp register. But by treating it as any other temp register, spilling can typically
  // be completely avoided instead. So it is better not to perform this trick. And by
  // not having that reliance, large heaps, or heaps not supporting compressed oops,
  // can still use compressed class pointers.
  if (COMPRESSED_CLASS_POINTERS_DEPENDS_ON_COMPRESSED_OOPS && !UseCompressedOops) {
    if (UseCompressedClassPointers) {
      warning("UseCompressedClassPointers requires UseCompressedOops");
    }
    FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
  } else {
    // Turn on UseCompressedClassPointers too
    if (FLAG_IS_DEFAULT(UseCompressedClassPointers)) {
      FLAG_SET_ERGO(UseCompressedClassPointers, true);
    }
    // Check the CompressedClassSpaceSize to make sure we use compressed klass ptrs.
    if (UseCompressedClassPointers) {
      if (CompressedClassSpaceSize > KlassEncodingMetaspaceMax) {
        warning("CompressedClassSpaceSize is too large for UseCompressedClassPointers");
        FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
      }
    }
  }
#endif // _LP64
}

void Arguments::set_conservative_max_heap_alignment() {
  // The conservative maximum required alignment for the heap is the maximum of
  // the alignments imposed by several sources: any requirements from the heap
  // itself and the maximum page size we may run the VM with.
  size_t heap_alignment = GCConfig::arguments()->conservative_max_heap_alignment();
  _conservative_max_heap_alignment = MAX4(heap_alignment,
                                          (size_t)os::vm_allocation_granularity(),
                                          os::max_page_size(),
                                          GCArguments::compute_heap_alignment());
}

jint Arguments::set_ergonomics_flags() {
  GCConfig::initialize();

  set_conservative_max_heap_alignment();

#ifdef _LP64
  set_use_compressed_oops();

  // set_use_compressed_klass_ptrs() must be called after calling
  // set_use_compressed_oops().
  set_use_compressed_klass_ptrs();

  // Also checks that certain machines are slower with compressed oops
  // in vm_version initialization code.
#endif // _LP64

  return JNI_OK;
}

size_t Arguments::limit_heap_by_allocatable_memory(size_t limit) {
  size_t max_allocatable;
  size_t result = limit;
  if (os::has_allocatable_memory_limit(&max_allocatable)) {
    // The AggressiveHeap check is a temporary workaround to avoid calling
    // GCarguments::heap_virtual_to_physical_ratio() before a GC has been
    // selected. This works because AggressiveHeap implies UseParallelGC
    // where we know the ratio will be 1. Once the AggressiveHeap option is
    // removed, this can be cleaned up.
    size_t heap_virtual_to_physical_ratio = (AggressiveHeap ? 1 : GCConfig::arguments()->heap_virtual_to_physical_ratio());
    size_t fraction = MaxVirtMemFraction * heap_virtual_to_physical_ratio;
    result = MIN2(result, max_allocatable / fraction);
  }
  return result;
}

// Use static initialization to get the default before parsing
static const size_t DefaultHeapBaseMinAddress = HeapBaseMinAddress;

void Arguments::set_heap_size() {
  julong phys_mem;

  // If the user specified one of these options, they
  // want specific memory sizing so do not limit memory
  // based on compressed oops addressability.
  // Also, memory limits will be calculated based on
  // available os physical memory, not our MaxRAM limit,
  // unless MaxRAM is also specified.
  bool override_coop_limit = (!FLAG_IS_DEFAULT(MaxRAMPercentage) ||
                           !FLAG_IS_DEFAULT(MaxRAMFraction) ||
                           !FLAG_IS_DEFAULT(MinRAMPercentage) ||
                           !FLAG_IS_DEFAULT(MinRAMFraction) ||
                           !FLAG_IS_DEFAULT(InitialRAMPercentage) ||
                           !FLAG_IS_DEFAULT(InitialRAMFraction) ||
                           !FLAG_IS_DEFAULT(MaxRAM));
  if (override_coop_limit) {
    if (FLAG_IS_DEFAULT(MaxRAM)) {
      phys_mem = os::physical_memory();
      FLAG_SET_ERGO(MaxRAM, (uint64_t)phys_mem);
    } else {
      phys_mem = (julong)MaxRAM;
    }
  } else {
    phys_mem = FLAG_IS_DEFAULT(MaxRAM) ? MIN2(os::physical_memory(), (julong)MaxRAM)
                                       : (julong)MaxRAM;
  }

  // Convert deprecated flags
  if (FLAG_IS_DEFAULT(MaxRAMPercentage) &&
      !FLAG_IS_DEFAULT(MaxRAMFraction))
    MaxRAMPercentage = 100.0 / MaxRAMFraction;

  if (FLAG_IS_DEFAULT(MinRAMPercentage) &&
      !FLAG_IS_DEFAULT(MinRAMFraction))
    MinRAMPercentage = 100.0 / MinRAMFraction;

  if (FLAG_IS_DEFAULT(InitialRAMPercentage) &&
      !FLAG_IS_DEFAULT(InitialRAMFraction))
    InitialRAMPercentage = 100.0 / InitialRAMFraction;

  // If the maximum heap size has not been set with -Xmx,
  // then set it as fraction of the size of physical memory,
  // respecting the maximum and minimum sizes of the heap.
  if (FLAG_IS_DEFAULT(MaxHeapSize)) {
    julong reasonable_max = (julong)((phys_mem * MaxRAMPercentage) / 100);
    const julong reasonable_min = (julong)((phys_mem * MinRAMPercentage) / 100);
    if (reasonable_min < MaxHeapSize) {
      // Small physical memory, so use a minimum fraction of it for the heap
      reasonable_max = reasonable_min;
    } else {
      // Not-small physical memory, so require a heap at least
      // as large as MaxHeapSize
      reasonable_max = MAX2(reasonable_max, (julong)MaxHeapSize);
    }

    if (!FLAG_IS_DEFAULT(ErgoHeapSizeLimit) && ErgoHeapSizeLimit != 0) {
      // Limit the heap size to ErgoHeapSizeLimit
      reasonable_max = MIN2(reasonable_max, (julong)ErgoHeapSizeLimit);
    }

    reasonable_max = limit_heap_by_allocatable_memory(reasonable_max);

    if (!FLAG_IS_DEFAULT(InitialHeapSize)) {
      // An initial heap size was specified on the command line,
      // so be sure that the maximum size is consistent.  Done
      // after call to limit_heap_by_allocatable_memory because that
      // method might reduce the allocation size.
      reasonable_max = MAX2(reasonable_max, (julong)InitialHeapSize);
    } else if (!FLAG_IS_DEFAULT(MinHeapSize)) {
      reasonable_max = MAX2(reasonable_max, (julong)MinHeapSize);
    }

#ifdef _LP64
    if (UseCompressedOops || UseCompressedClassPointers) {
      // HeapBaseMinAddress can be greater than default but not less than.
      if (!FLAG_IS_DEFAULT(HeapBaseMinAddress)) {
        if (HeapBaseMinAddress < DefaultHeapBaseMinAddress) {
          // matches compressed oops printing flags
          log_debug(gc, heap, coops)("HeapBaseMinAddress must be at least " SIZE_FORMAT
                                     " (" SIZE_FORMAT "G) which is greater than value given " SIZE_FORMAT,
                                     DefaultHeapBaseMinAddress,
                                     DefaultHeapBaseMinAddress/G,
                                     HeapBaseMinAddress);
          FLAG_SET_ERGO(HeapBaseMinAddress, DefaultHeapBaseMinAddress);
        }
      }
    }
    if (UseCompressedOops) {
      // Limit the heap size to the maximum possible when using compressed oops
      julong max_coop_heap = (julong)max_heap_for_compressed_oops();

      if (HeapBaseMinAddress + MaxHeapSize < max_coop_heap) {
        // Heap should be above HeapBaseMinAddress to get zero based compressed oops
        // but it should be not less than default MaxHeapSize.
--> --------------------

--> maximum size reached

--> --------------------

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