1 /*
   2  * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "cds/filemap.hpp"
  28 #include "classfile/classLoader.hpp"
  29 #include "classfile/javaAssertions.hpp"
  30 #include "classfile/moduleEntry.hpp"
  31 #include "classfile/stringTable.hpp"
  32 #include "classfile/symbolTable.hpp"
  33 #include "compiler/compilerDefinitions.hpp"
  34 #include "gc/shared/gcArguments.hpp"
  35 #include "gc/shared/gcConfig.hpp"
  36 #include "gc/shared/stringdedup/stringDedup.hpp"
  37 #include "gc/shared/tlab_globals.hpp"
  38 #include "logging/log.hpp"
  39 #include "logging/logConfiguration.hpp"
  40 #include "logging/logStream.hpp"
  41 #include "logging/logTag.hpp"
  42 #include "memory/allocation.inline.hpp"
  43 #include "metaprogramming/enableIf.hpp"
  44 #include "oops/instanceKlass.hpp"
  45 #include "oops/oop.inline.hpp"
  46 #include "prims/jvmtiExport.hpp"
  47 #include "runtime/arguments.hpp"
  48 #include "runtime/flags/jvmFlag.hpp"
  49 #include "runtime/flags/jvmFlagAccess.hpp"
  50 #include "runtime/flags/jvmFlagLimit.hpp"
  51 #include "runtime/globals_extension.hpp"
  52 #include "runtime/java.hpp"
  53 #include "runtime/os.hpp"
  54 #include "runtime/safepoint.hpp"
  55 #include "runtime/safepointMechanism.hpp"
  56 #include "runtime/vm_version.hpp"
  57 #include "services/management.hpp"
  58 #include "services/nmtCommon.hpp"
  59 #include "utilities/align.hpp"
  60 #include "utilities/debug.hpp"
  61 #include "utilities/defaultStream.hpp"
  62 #include "utilities/macros.hpp"
  63 #include "utilities/powerOfTwo.hpp"
  64 #include "utilities/stringUtils.hpp"
  65 #if INCLUDE_JFR
  66 #include "jfr/jfr.hpp"
  67 #endif
  68 #include <limits>
  69 
  70 #define DEFAULT_JAVA_LAUNCHER  "generic"
  71 
  72 char*  Arguments::_jvm_flags_file               = NULL;
  73 char** Arguments::_jvm_flags_array              = NULL;
  74 int    Arguments::_num_jvm_flags                = 0;
  75 char** Arguments::_jvm_args_array               = NULL;
  76 int    Arguments::_num_jvm_args                 = 0;
  77 char*  Arguments::_java_command                 = NULL;
  78 SystemProperty* Arguments::_system_properties   = NULL;
  79 size_t Arguments::_conservative_max_heap_alignment = 0;
  80 Arguments::Mode Arguments::_mode                = _mixed;
  81 bool   Arguments::_java_compiler                = false;
  82 bool   Arguments::_xdebug_mode                  = false;
  83 const char*  Arguments::_java_vendor_url_bug    = NULL;
  84 const char*  Arguments::_sun_java_launcher      = DEFAULT_JAVA_LAUNCHER;
  85 bool   Arguments::_sun_java_launcher_is_altjvm  = false;
  86 
  87 // These parameters are reset in method parse_vm_init_args()
  88 bool   Arguments::_AlwaysCompileLoopMethods     = AlwaysCompileLoopMethods;
  89 bool   Arguments::_UseOnStackReplacement        = UseOnStackReplacement;
  90 bool   Arguments::_BackgroundCompilation        = BackgroundCompilation;
  91 bool   Arguments::_ClipInlining                 = ClipInlining;
  92 size_t Arguments::_default_SharedBaseAddress    = SharedBaseAddress;
  93 
  94 bool   Arguments::_enable_preview               = false;
  95 
  96 char*  Arguments::SharedArchivePath             = NULL;
  97 char*  Arguments::SharedDynamicArchivePath      = NULL;
  98 
  99 LegacyGCLogging Arguments::_legacyGCLogging     = { 0, 0 };
 100 
 101 AgentLibraryList Arguments::_libraryList;
 102 AgentLibraryList Arguments::_agentList;
 103 
 104 // These are not set by the JDK's built-in launchers, but they can be set by
 105 // programs that embed the JVM using JNI_CreateJavaVM. See comments around
 106 // JavaVMOption in jni.h.
 107 abort_hook_t     Arguments::_abort_hook         = NULL;
 108 exit_hook_t      Arguments::_exit_hook          = NULL;
 109 vfprintf_hook_t  Arguments::_vfprintf_hook      = NULL;
 110 
 111 
 112 SystemProperty *Arguments::_sun_boot_library_path = NULL;
 113 SystemProperty *Arguments::_java_library_path = NULL;
 114 SystemProperty *Arguments::_java_home = NULL;
 115 SystemProperty *Arguments::_java_class_path = NULL;
 116 SystemProperty *Arguments::_jdk_boot_class_path_append = NULL;
 117 SystemProperty *Arguments::_vm_info = NULL;
 118 
 119 GrowableArray<ModulePatchPath*> *Arguments::_patch_mod_prefix = NULL;
 120 PathString *Arguments::_system_boot_class_path = NULL;
 121 bool Arguments::_has_jimage = false;
 122 
 123 char* Arguments::_ext_dirs = NULL;
 124 
 125 // True if -Xshare:auto option was specified.
 126 static bool xshare_auto_cmd_line = false;
 127 
 128 bool PathString::set_value(const char *value, AllocFailType alloc_failmode) {
 129   char* new_value = AllocateHeap(strlen(value)+1, mtArguments, alloc_failmode);
 130   if (new_value == NULL) {
 131     assert(alloc_failmode == AllocFailStrategy::RETURN_NULL, "must be");
 132     return false;
 133   }
 134   if (_value != NULL) {
 135     FreeHeap(_value);
 136   }
 137   _value = new_value;
 138   strcpy(_value, value);
 139   return true;
 140 }
 141 
 142 void PathString::append_value(const char *value) {
 143   char *sp;
 144   size_t len = 0;
 145   if (value != NULL) {
 146     len = strlen(value);
 147     if (_value != NULL) {
 148       len += strlen(_value);
 149     }
 150     sp = AllocateHeap(len+2, mtArguments);
 151     assert(sp != NULL, "Unable to allocate space for new append path value");
 152     if (sp != NULL) {
 153       if (_value != NULL) {
 154         strcpy(sp, _value);
 155         strcat(sp, os::path_separator());
 156         strcat(sp, value);
 157         FreeHeap(_value);
 158       } else {
 159         strcpy(sp, value);
 160       }
 161       _value = sp;
 162     }
 163   }
 164 }
 165 
 166 PathString::PathString(const char* value) {
 167   if (value == NULL) {
 168     _value = NULL;
 169   } else {
 170     _value = AllocateHeap(strlen(value)+1, mtArguments);
 171     strcpy(_value, value);
 172   }
 173 }
 174 
 175 PathString::~PathString() {
 176   if (_value != NULL) {
 177     FreeHeap(_value);
 178     _value = NULL;
 179   }
 180 }
 181 
 182 ModulePatchPath::ModulePatchPath(const char* module_name, const char* path) {
 183   assert(module_name != NULL && path != NULL, "Invalid module name or path value");
 184   size_t len = strlen(module_name) + 1;
 185   _module_name = AllocateHeap(len, mtInternal);
 186   strncpy(_module_name, module_name, len); // copy the trailing null
 187   _path =  new PathString(path);
 188 }
 189 
 190 ModulePatchPath::~ModulePatchPath() {
 191   if (_module_name != NULL) {
 192     FreeHeap(_module_name);
 193     _module_name = NULL;
 194   }
 195   if (_path != NULL) {
 196     delete _path;
 197     _path = NULL;
 198   }
 199 }
 200 
 201 SystemProperty::SystemProperty(const char* key, const char* value, bool writeable, bool internal) : PathString(value) {
 202   if (key == NULL) {
 203     _key = NULL;
 204   } else {
 205     _key = AllocateHeap(strlen(key)+1, mtArguments);
 206     strcpy(_key, key);
 207   }
 208   _next = NULL;
 209   _internal = internal;
 210   _writeable = writeable;
 211 }
 212 
 213 AgentLibrary::AgentLibrary(const char* name, const char* options,
 214                bool is_absolute_path, void* os_lib,
 215                bool instrument_lib) {
 216   _name = AllocateHeap(strlen(name)+1, mtArguments);
 217   strcpy(_name, name);
 218   if (options == NULL) {
 219     _options = NULL;
 220   } else {
 221     _options = AllocateHeap(strlen(options)+1, mtArguments);
 222     strcpy(_options, options);
 223   }
 224   _is_absolute_path = is_absolute_path;
 225   _os_lib = os_lib;
 226   _next = NULL;
 227   _state = agent_invalid;
 228   _is_static_lib = false;
 229   _is_instrument_lib = instrument_lib;
 230 }
 231 
 232 // Check if head of 'option' matches 'name', and sets 'tail' to the remaining
 233 // part of the option string.
 234 static bool match_option(const JavaVMOption *option, const char* name,
 235                          const char** tail) {
 236   size_t len = strlen(name);
 237   if (strncmp(option->optionString, name, len) == 0) {
 238     *tail = option->optionString + len;
 239     return true;
 240   } else {
 241     return false;
 242   }
 243 }
 244 
 245 // Check if 'option' matches 'name'. No "tail" is allowed.
 246 static bool match_option(const JavaVMOption *option, const char* name) {
 247   const char* tail = NULL;
 248   bool result = match_option(option, name, &tail);
 249   if (tail != NULL && *tail == '\0') {
 250     return result;
 251   } else {
 252     return false;
 253   }
 254 }
 255 
 256 // Return true if any of the strings in null-terminated array 'names' matches.
 257 // If tail_allowed is true, then the tail must begin with a colon; otherwise,
 258 // the option must match exactly.
 259 static bool match_option(const JavaVMOption* option, const char** names, const char** tail,
 260   bool tail_allowed) {
 261   for (/* empty */; *names != NULL; ++names) {
 262   if (match_option(option, *names, tail)) {
 263       if (**tail == '\0' || (tail_allowed && **tail == ':')) {
 264         return true;
 265       }
 266     }
 267   }
 268   return false;
 269 }
 270 
 271 #if INCLUDE_JFR
 272 static bool _has_jfr_option = false;  // is using JFR
 273 
 274 // return true on failure
 275 static bool match_jfr_option(const JavaVMOption** option) {
 276   assert((*option)->optionString != NULL, "invariant");
 277   char* tail = NULL;
 278   if (match_option(*option, "-XX:StartFlightRecording", (const char**)&tail)) {
 279     _has_jfr_option = true;
 280     return Jfr::on_start_flight_recording_option(option, tail);
 281   } else if (match_option(*option, "-XX:FlightRecorderOptions", (const char**)&tail)) {
 282     _has_jfr_option = true;
 283     return Jfr::on_flight_recorder_option(option, tail);
 284   }
 285   return false;
 286 }
 287 
 288 bool Arguments::has_jfr_option() {
 289   return _has_jfr_option;
 290 }
 291 #endif
 292 
 293 static void logOption(const char* opt) {
 294   if (PrintVMOptions) {
 295     jio_fprintf(defaultStream::output_stream(), "VM option '%s'\n", opt);
 296   }
 297 }
 298 
 299 bool needs_module_property_warning = false;
 300 
 301 #define MODULE_PROPERTY_PREFIX "jdk.module."
 302 #define MODULE_PROPERTY_PREFIX_LEN 11
 303 #define ADDEXPORTS "addexports"
 304 #define ADDEXPORTS_LEN 10
 305 #define ADDREADS "addreads"
 306 #define ADDREADS_LEN 8
 307 #define ADDOPENS "addopens"
 308 #define ADDOPENS_LEN 8
 309 #define PATCH "patch"
 310 #define PATCH_LEN 5
 311 #define ADDMODS "addmods"
 312 #define ADDMODS_LEN 7
 313 #define LIMITMODS "limitmods"
 314 #define LIMITMODS_LEN 9
 315 #define PATH "path"
 316 #define PATH_LEN 4
 317 #define UPGRADE_PATH "upgrade.path"
 318 #define UPGRADE_PATH_LEN 12
 319 #define ENABLE_NATIVE_ACCESS "enable.native.access"
 320 #define ENABLE_NATIVE_ACCESS_LEN 20
 321 
 322 void Arguments::add_init_library(const char* name, char* options) {
 323   _libraryList.add(new AgentLibrary(name, options, false, NULL));
 324 }
 325 
 326 void Arguments::add_init_agent(const char* name, char* options, bool absolute_path) {
 327   _agentList.add(new AgentLibrary(name, options, absolute_path, NULL));
 328 }
 329 
 330 void Arguments::add_instrument_agent(const char* name, char* options, bool absolute_path) {
 331   _agentList.add(new AgentLibrary(name, options, absolute_path, NULL, true));
 332 }
 333 
 334 // Late-binding agents not started via arguments
 335 void Arguments::add_loaded_agent(AgentLibrary *agentLib) {
 336   _agentList.add(agentLib);
 337 }
 338 
 339 // Return TRUE if option matches 'property', or 'property=', or 'property.'.
 340 static bool matches_property_suffix(const char* option, const char* property, size_t len) {
 341   return ((strncmp(option, property, len) == 0) &&
 342           (option[len] == '=' || option[len] == '.' || option[len] == '\0'));
 343 }
 344 
 345 // Return true if property starts with "jdk.module." and its ensuing chars match
 346 // any of the reserved module properties.
 347 // property should be passed without the leading "-D".
 348 bool Arguments::is_internal_module_property(const char* property) {
 349   assert((strncmp(property, "-D", 2) != 0), "Unexpected leading -D");
 350   if  (strncmp(property, MODULE_PROPERTY_PREFIX, MODULE_PROPERTY_PREFIX_LEN) == 0) {
 351     const char* property_suffix = property + MODULE_PROPERTY_PREFIX_LEN;
 352     if (matches_property_suffix(property_suffix, ADDEXPORTS, ADDEXPORTS_LEN) ||
 353         matches_property_suffix(property_suffix, ADDREADS, ADDREADS_LEN) ||
 354         matches_property_suffix(property_suffix, ADDOPENS, ADDOPENS_LEN) ||
 355         matches_property_suffix(property_suffix, PATCH, PATCH_LEN) ||
 356         matches_property_suffix(property_suffix, ADDMODS, ADDMODS_LEN) ||
 357         matches_property_suffix(property_suffix, LIMITMODS, LIMITMODS_LEN) ||
 358         matches_property_suffix(property_suffix, PATH, PATH_LEN) ||
 359         matches_property_suffix(property_suffix, UPGRADE_PATH, UPGRADE_PATH_LEN) ||
 360         matches_property_suffix(property_suffix, ENABLE_NATIVE_ACCESS, ENABLE_NATIVE_ACCESS_LEN)) {
 361       return true;
 362     }
 363   }
 364   return false;
 365 }
 366 
 367 // Process java launcher properties.
 368 void Arguments::process_sun_java_launcher_properties(JavaVMInitArgs* args) {
 369   // See if sun.java.launcher or sun.java.launcher.is_altjvm is defined.
 370   // Must do this before setting up other system properties,
 371   // as some of them may depend on launcher type.
 372   for (int index = 0; index < args->nOptions; index++) {
 373     const JavaVMOption* option = args->options + index;
 374     const char* tail;
 375 
 376     if (match_option(option, "-Dsun.java.launcher=", &tail)) {
 377       process_java_launcher_argument(tail, option->extraInfo);
 378       continue;
 379     }
 380     if (match_option(option, "-Dsun.java.launcher.is_altjvm=", &tail)) {
 381       if (strcmp(tail, "true") == 0) {
 382         _sun_java_launcher_is_altjvm = true;
 383       }
 384       continue;
 385     }
 386   }
 387 }
 388 
 389 // Initialize system properties key and value.
 390 void Arguments::init_system_properties() {
 391 
 392   // Set up _system_boot_class_path which is not a property but
 393   // relies heavily on argument processing and the jdk.boot.class.path.append
 394   // property. It is used to store the underlying system boot class path.
 395   _system_boot_class_path = new PathString(NULL);
 396 
 397   PropertyList_add(&_system_properties, new SystemProperty("java.vm.specification.name",
 398                                                            "Java Virtual Machine Specification",  false));
 399   PropertyList_add(&_system_properties, new SystemProperty("java.vm.version", VM_Version::vm_release(),  false));
 400   PropertyList_add(&_system_properties, new SystemProperty("java.vm.name", VM_Version::vm_name(),  false));
 401   PropertyList_add(&_system_properties, new SystemProperty("jdk.debug", VM_Version::jdk_debug_level(),  false));
 402 
 403   // Initialize the vm.info now, but it will need updating after argument parsing.
 404   _vm_info = new SystemProperty("java.vm.info", VM_Version::vm_info_string(), true);
 405 
 406   // Following are JVMTI agent writable properties.
 407   // Properties values are set to NULL and they are
 408   // os specific they are initialized in os::init_system_properties_values().
 409   _sun_boot_library_path = new SystemProperty("sun.boot.library.path", NULL,  true);
 410   _java_library_path = new SystemProperty("java.library.path", NULL,  true);
 411   _java_home =  new SystemProperty("java.home", NULL,  true);
 412   _java_class_path = new SystemProperty("java.class.path", "",  true);
 413   // jdk.boot.class.path.append is a non-writeable, internal property.
 414   // It can only be set by either:
 415   //    - -Xbootclasspath/a:
 416   //    - AddToBootstrapClassLoaderSearch during JVMTI OnLoad phase
 417   _jdk_boot_class_path_append = new SystemProperty("jdk.boot.class.path.append", NULL, false, true);
 418 
 419   // Add to System Property list.
 420   PropertyList_add(&_system_properties, _sun_boot_library_path);
 421   PropertyList_add(&_system_properties, _java_library_path);
 422   PropertyList_add(&_system_properties, _java_home);
 423   PropertyList_add(&_system_properties, _java_class_path);
 424   PropertyList_add(&_system_properties, _jdk_boot_class_path_append);
 425   PropertyList_add(&_system_properties, _vm_info);
 426 
 427   // Set OS specific system properties values
 428   os::init_system_properties_values();
 429 }
 430 
 431 // Update/Initialize System properties after JDK version number is known
 432 void Arguments::init_version_specific_system_properties() {
 433   enum { bufsz = 16 };
 434   char buffer[bufsz];
 435   const char* spec_vendor = "Oracle Corporation";
 436   uint32_t spec_version = JDK_Version::current().major_version();
 437 
 438   jio_snprintf(buffer, bufsz, UINT32_FORMAT, spec_version);
 439 
 440   PropertyList_add(&_system_properties,
 441       new SystemProperty("java.vm.specification.vendor",  spec_vendor, false));
 442   PropertyList_add(&_system_properties,
 443       new SystemProperty("java.vm.specification.version", buffer, false));
 444   PropertyList_add(&_system_properties,
 445       new SystemProperty("java.vm.vendor", VM_Version::vm_vendor(),  false));
 446 }
 447 
 448 /*
 449  *  -XX argument processing:
 450  *
 451  *  -XX arguments are defined in several places, such as:
 452  *      globals.hpp, globals_<cpu>.hpp, globals_<os>.hpp, <compiler>_globals.hpp, or <gc>_globals.hpp.
 453  *  -XX arguments are parsed in parse_argument().
 454  *  -XX argument bounds checking is done in check_vm_args_consistency().
 455  *
 456  * Over time -XX arguments may change. There are mechanisms to handle common cases:
 457  *
 458  *      ALIASED: An option that is simply another name for another option. This is often
 459  *               part of the process of deprecating a flag, but not all aliases need
 460  *               to be deprecated.
 461  *
 462  *               Create an alias for an option by adding the old and new option names to the
 463  *               "aliased_jvm_flags" table. Delete the old variable from globals.hpp (etc).
 464  *
 465  *   DEPRECATED: An option that is supported, but a warning is printed to let the user know that
 466  *               support may be removed in the future. Both regular and aliased options may be
 467  *               deprecated.
 468  *
 469  *               Add a deprecation warning for an option (or alias) by adding an entry in the
 470  *               "special_jvm_flags" table and setting the "deprecated_in" field.
 471  *               Often an option "deprecated" in one major release will
 472  *               be made "obsolete" in the next. In this case the entry should also have its
 473  *               "obsolete_in" field set.
 474  *
 475  *     OBSOLETE: An option that has been removed (and deleted from globals.hpp), but is still accepted
 476  *               on the command line. A warning is printed to let the user know that option might not
 477  *               be accepted in the future.
 478  *
 479  *               Add an obsolete warning for an option by adding an entry in the "special_jvm_flags"
 480  *               table and setting the "obsolete_in" field.
 481  *
 482  *      EXPIRED: A deprecated or obsolete option that has an "accept_until" version less than or equal
 483  *               to the current JDK version. The system will flatly refuse to admit the existence of
 484  *               the flag. This allows a flag to die automatically over JDK releases.
 485  *
 486  *               Note that manual cleanup of expired options should be done at major JDK version upgrades:
 487  *                  - Newly expired options should be removed from the special_jvm_flags and aliased_jvm_flags tables.
 488  *                  - Newly obsolete or expired deprecated options should have their global variable
 489  *                    definitions removed (from globals.hpp, etc) and related implementations removed.
 490  *
 491  * Recommended approach for removing options:
 492  *
 493  * To remove options commonly used by customers (e.g. product -XX options), use
 494  * the 3-step model adding major release numbers to the deprecate, obsolete and expire columns.
 495  *
 496  * To remove internal options (e.g. diagnostic, experimental, develop options), use
 497  * a 2-step model adding major release numbers to the obsolete and expire columns.
 498  *
 499  * To change the name of an option, use the alias table as well as a 2-step
 500  * model adding major release numbers to the deprecate and expire columns.
 501  * Think twice about aliasing commonly used customer options.
 502  *
 503  * There are times when it is appropriate to leave a future release number as undefined.
 504  *
 505  * Tests:  Aliases should be tested in VMAliasOptions.java.
 506  *         Deprecated options should be tested in VMDeprecatedOptions.java.
 507  */
 508 
 509 // The special_jvm_flags table declares options that are being deprecated and/or obsoleted. The
 510 // "deprecated_in" or "obsolete_in" fields may be set to "undefined", but not both.
 511 // When the JDK version reaches 'deprecated_in' limit, the JVM will process this flag on
 512 // the command-line as usual, but will issue a warning.
 513 // When the JDK version reaches 'obsolete_in' limit, the JVM will continue accepting this flag on
 514 // the command-line, while issuing a warning and ignoring the flag value.
 515 // Once the JDK version reaches 'expired_in' limit, the JVM will flatly refuse to admit the
 516 // existence of the flag.
 517 //
 518 // MANUAL CLEANUP ON JDK VERSION UPDATES:
 519 // This table ensures that the handling of options will update automatically when the JDK
 520 // version is incremented, but the source code needs to be cleanup up manually:
 521 // - As "deprecated" options age into "obsolete" or "expired" options, the associated "globals"
 522 //   variable should be removed, as well as users of the variable.
 523 // - As "deprecated" options age into "obsolete" options, move the entry into the
 524 //   "Obsolete Flags" section of the table.
 525 // - All expired options should be removed from the table.
 526 static SpecialFlag const special_jvm_flags[] = {
 527   // -------------- Deprecated Flags --------------
 528   // --- Non-alias flags - sorted by obsolete_in then expired_in:
 529   { "MaxGCMinorPauseMillis",        JDK_Version::jdk(8), JDK_Version::undefined(), JDK_Version::undefined() },
 530   { "MaxRAMFraction",               JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
 531   { "MinRAMFraction",               JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
 532   { "InitialRAMFraction",           JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
 533   { "AllowRedefinitionToAddDeleteMethods", JDK_Version::jdk(13), JDK_Version::undefined(), JDK_Version::undefined() },
 534   { "FlightRecorder",               JDK_Version::jdk(13), JDK_Version::undefined(), JDK_Version::undefined() },
 535   { "DumpSharedSpaces",             JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
 536   { "DynamicDumpSharedSpaces",      JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
 537   { "RequireSharedSpaces",          JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
 538   { "UseSharedSpaces",              JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::undefined() },
 539 #ifdef PRODUCT
 540   { "UseHeavyMonitors",             JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::jdk(20) },
 541 #endif
 542   { "ExtendedDTraceProbes",         JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
 543   { "UseContainerCpuShares",        JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
 544   { "PreferContainerQuotaForCPUCount", JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
 545   { "AliasLevel",                   JDK_Version::jdk(19), JDK_Version::jdk(20), JDK_Version::jdk(21) },
 546 
 547   // --- Deprecated alias flags (see also aliased_jvm_flags) - sorted by obsolete_in then expired_in:
 548   { "DefaultMaxRAMFraction",        JDK_Version::jdk(8),  JDK_Version::undefined(), JDK_Version::undefined() },
 549   { "CreateMinidumpOnCrash",        JDK_Version::jdk(9),  JDK_Version::undefined(), JDK_Version::undefined() },
 550   { "TLABStats",                    JDK_Version::jdk(12), JDK_Version::undefined(), JDK_Version::undefined() },
 551 
 552   // -------------- Obsolete Flags - sorted by expired_in --------------
 553 
 554   { "FilterSpuriousWakeups",        JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::jdk(20) },
 555   { "MinInliningThreshold",         JDK_Version::jdk(18), JDK_Version::jdk(19), JDK_Version::jdk(20) },
 556   { "PrefetchFieldsAhead",          JDK_Version::undefined(), JDK_Version::jdk(19), JDK_Version::jdk(20) },
 557 #ifdef ASSERT
 558   { "DummyObsoleteTestFlag",        JDK_Version::undefined(), JDK_Version::jdk(18), JDK_Version::undefined() },
 559 #endif
 560 
 561 #ifdef TEST_VERIFY_SPECIAL_JVM_FLAGS
 562   // These entries will generate build errors.  Their purpose is to test the macros.
 563   { "dep > obs",                    JDK_Version::jdk(9), JDK_Version::jdk(8), JDK_Version::undefined() },
 564   { "dep > exp ",                   JDK_Version::jdk(9), JDK_Version::undefined(), JDK_Version::jdk(8) },
 565   { "obs > exp ",                   JDK_Version::undefined(), JDK_Version::jdk(9), JDK_Version::jdk(8) },
 566   { "obs > exp",                    JDK_Version::jdk(8), JDK_Version::undefined(), JDK_Version::jdk(10) },
 567   { "not deprecated or obsolete",   JDK_Version::undefined(), JDK_Version::undefined(), JDK_Version::jdk(9) },
 568   { "dup option",                   JDK_Version::jdk(9), JDK_Version::undefined(), JDK_Version::undefined() },
 569   { "dup option",                   JDK_Version::jdk(9), JDK_Version::undefined(), JDK_Version::undefined() },
 570 #endif
 571 
 572   { NULL, JDK_Version(0), JDK_Version(0) }
 573 };
 574 
 575 // Flags that are aliases for other flags.
 576 typedef struct {
 577   const char* alias_name;
 578   const char* real_name;
 579 } AliasedFlag;
 580 
 581 static AliasedFlag const aliased_jvm_flags[] = {
 582   { "DefaultMaxRAMFraction",    "MaxRAMFraction"    },
 583   { "CreateMinidumpOnCrash",    "CreateCoredumpOnCrash" },
 584   { NULL, NULL}
 585 };
 586 
 587 // Return true if "v" is less than "other", where "other" may be "undefined".
 588 static bool version_less_than(JDK_Version v, JDK_Version other) {
 589   assert(!v.is_undefined(), "must be defined");
 590   if (!other.is_undefined() && v.compare(other) >= 0) {
 591     return false;
 592   } else {
 593     return true;
 594   }
 595 }
 596 
 597 static bool lookup_special_flag(const char *flag_name, SpecialFlag& flag) {
 598   for (size_t i = 0; special_jvm_flags[i].name != NULL; i++) {
 599     if ((strcmp(special_jvm_flags[i].name, flag_name) == 0)) {
 600       flag = special_jvm_flags[i];
 601       return true;
 602     }
 603   }
 604   return false;
 605 }
 606 
 607 bool Arguments::is_obsolete_flag(const char *flag_name, JDK_Version* version) {
 608   assert(version != NULL, "Must provide a version buffer");
 609   SpecialFlag flag;
 610   if (lookup_special_flag(flag_name, flag)) {
 611     if (!flag.obsolete_in.is_undefined()) {
 612       if (!version_less_than(JDK_Version::current(), flag.obsolete_in)) {
 613         *version = flag.obsolete_in;
 614         // This flag may have been marked for obsoletion in this version, but we may not
 615         // have actually removed it yet. Rather than ignoring it as soon as we reach
 616         // this version we allow some time for the removal to happen. So if the flag
 617         // still actually exists we process it as normal, but issue an adjusted warning.
 618         const JVMFlag *real_flag = JVMFlag::find_declared_flag(flag_name);
 619         if (real_flag != NULL) {
 620           char version_str[256];
 621           version->to_string(version_str, sizeof(version_str));
 622           warning("Temporarily processing option %s; support is scheduled for removal in %s",
 623                   flag_name, version_str);
 624           return false;
 625         }
 626         return true;
 627       }
 628     }
 629   }
 630   return false;
 631 }
 632 
 633 int Arguments::is_deprecated_flag(const char *flag_name, JDK_Version* version) {
 634   assert(version != NULL, "Must provide a version buffer");
 635   SpecialFlag flag;
 636   if (lookup_special_flag(flag_name, flag)) {
 637     if (!flag.deprecated_in.is_undefined()) {
 638       if (version_less_than(JDK_Version::current(), flag.obsolete_in) &&
 639           version_less_than(JDK_Version::current(), flag.expired_in)) {
 640         *version = flag.deprecated_in;
 641         return 1;
 642       } else {
 643         return -1;
 644       }
 645     }
 646   }
 647   return 0;
 648 }
 649 
 650 const char* Arguments::real_flag_name(const char *flag_name) {
 651   for (size_t i = 0; aliased_jvm_flags[i].alias_name != NULL; i++) {
 652     const AliasedFlag& flag_status = aliased_jvm_flags[i];
 653     if (strcmp(flag_status.alias_name, flag_name) == 0) {
 654         return flag_status.real_name;
 655     }
 656   }
 657   return flag_name;
 658 }
 659 
 660 #ifdef ASSERT
 661 static bool lookup_special_flag(const char *flag_name, size_t skip_index) {
 662   for (size_t i = 0; special_jvm_flags[i].name != NULL; i++) {
 663     if ((i != skip_index) && (strcmp(special_jvm_flags[i].name, flag_name) == 0)) {
 664       return true;
 665     }
 666   }
 667   return false;
 668 }
 669 
 670 // Verifies the correctness of the entries in the special_jvm_flags table.
 671 // If there is a semantic error (i.e. a bug in the table) such as the obsoletion
 672 // version being earlier than the deprecation version, then a warning is issued
 673 // and verification fails - by returning false. If it is detected that the table
 674 // is out of date, with respect to the current version, then ideally a warning is
 675 // issued but verification does not fail. This allows the VM to operate when the
 676 // version is first updated, without needing to update all the impacted flags at
 677 // the same time. In practice we can't issue the warning immediately when the version
 678 // is updated as it occurs for every test and some tests are not prepared to handle
 679 // unexpected output - see 8196739. Instead we only check if the table is up-to-date
 680 // if the check_globals flag is true, and in addition allow a grace period and only
 681 // check for stale flags when we hit build 25 (which is far enough into the 6 month
 682 // release cycle that all flag updates should have been processed, whilst still
 683 // leaving time to make the change before RDP2).
 684 // We use a gtest to call this, passing true, so that we can detect stale flags before
 685 // the end of the release cycle.
 686 
 687 static const int SPECIAL_FLAG_VALIDATION_BUILD = 25;
 688 
 689 bool Arguments::verify_special_jvm_flags(bool check_globals) {
 690   bool success = true;
 691   for (size_t i = 0; special_jvm_flags[i].name != NULL; i++) {
 692     const SpecialFlag& flag = special_jvm_flags[i];
 693     if (lookup_special_flag(flag.name, i)) {
 694       warning("Duplicate special flag declaration \"%s\"", flag.name);
 695       success = false;
 696     }
 697     if (flag.deprecated_in.is_undefined() &&
 698         flag.obsolete_in.is_undefined()) {
 699       warning("Special flag entry \"%s\" must declare version deprecated and/or obsoleted in.", flag.name);
 700       success = false;
 701     }
 702 
 703     if (!flag.deprecated_in.is_undefined()) {
 704       if (!version_less_than(flag.deprecated_in, flag.obsolete_in)) {
 705         warning("Special flag entry \"%s\" must be deprecated before obsoleted.", flag.name);
 706         success = false;
 707       }
 708 
 709       if (!version_less_than(flag.deprecated_in, flag.expired_in)) {
 710         warning("Special flag entry \"%s\" must be deprecated before expired.", flag.name);
 711         success = false;
 712       }
 713     }
 714 
 715     if (!flag.obsolete_in.is_undefined()) {
 716       if (!version_less_than(flag.obsolete_in, flag.expired_in)) {
 717         warning("Special flag entry \"%s\" must be obsoleted before expired.", flag.name);
 718         success = false;
 719       }
 720 
 721       // if flag has become obsolete it should not have a "globals" flag defined anymore.
 722       if (check_globals && VM_Version::vm_build_number() >= SPECIAL_FLAG_VALIDATION_BUILD &&
 723           !version_less_than(JDK_Version::current(), flag.obsolete_in)) {
 724         if (JVMFlag::find_declared_flag(flag.name) != NULL) {
 725           warning("Global variable for obsolete special flag entry \"%s\" should be removed", flag.name);
 726           success = false;
 727         }
 728       }
 729 
 730     } else if (!flag.expired_in.is_undefined()) {
 731       warning("Special flag entry \"%s\" must be explicitly obsoleted before expired.", flag.name);
 732       success = false;
 733     }
 734 
 735     if (!flag.expired_in.is_undefined()) {
 736       // if flag has become expired it should not have a "globals" flag defined anymore.
 737       if (check_globals && VM_Version::vm_build_number() >= SPECIAL_FLAG_VALIDATION_BUILD &&
 738           !version_less_than(JDK_Version::current(), flag.expired_in)) {
 739         if (JVMFlag::find_declared_flag(flag.name) != NULL) {
 740           warning("Global variable for expired flag entry \"%s\" should be removed", flag.name);
 741           success = false;
 742         }
 743       }
 744     }
 745   }
 746   return success;
 747 }
 748 #endif
 749 
 750 template <typename T, ENABLE_IF(std::is_signed<T>::value), ENABLE_IF(sizeof(T) == 4)> // signed 32-bit
 751 static bool parse_integer_impl(const char *s, char **endptr, int base, T* result) {
 752   // Don't use strtol -- on 64-bit builds, "long" could be either 32- or 64-bits
 753   // so the range tests could be tautological and might cause compiler warnings.
 754   STATIC_ASSERT(sizeof(long long) >= 8); // C++ specification
 755   errno = 0; // errno is thread safe
 756   long long v = strtoll(s, endptr, base);
 757   if (errno != 0 || v < min_jint || v > max_jint) {
 758     return false;
 759   }
 760   *result = static_cast<T>(v);
 761   return true;
 762 }
 763 
 764 template <typename T, ENABLE_IF(!std::is_signed<T>::value), ENABLE_IF(sizeof(T) == 4)> // unsigned 32-bit
 765 static bool parse_integer_impl(const char *s, char **endptr, int base, T* result) {
 766   if (s[0] == '-') {
 767     return false;
 768   }
 769   // Don't use strtoul -- same reason as above.
 770   STATIC_ASSERT(sizeof(unsigned long long) >= 8); // C++ specification
 771   errno = 0; // errno is thread safe
 772   unsigned long long v = strtoull(s, endptr, base);
 773   if (errno != 0 || v > max_juint) {
 774     return false;
 775   }
 776   *result = static_cast<T>(v);
 777   return true;
 778 }
 779 
 780 template <typename T, ENABLE_IF(std::is_signed<T>::value), ENABLE_IF(sizeof(T) == 8)> // signed 64-bit
 781 static bool parse_integer_impl(const char *s, char **endptr, int base, T* result) {
 782   errno = 0; // errno is thread safe
 783   *result = strtoll(s, endptr, base);
 784   return errno == 0;
 785 }
 786 
 787 template <typename T, ENABLE_IF(!std::is_signed<T>::value), ENABLE_IF(sizeof(T) == 8)> // unsigned 64-bit
 788 static bool parse_integer_impl(const char *s, char **endptr, int base, T* result) {
 789   if (s[0] == '-') {
 790     return false;
 791   }
 792   errno = 0; // errno is thread safe
 793   *result = strtoull(s, endptr, base);
 794   return errno == 0;
 795 }
 796 
 797 template<typename T>
 798 static bool multiply_by_1k(T& n) {
 799   if (n >= std::numeric_limits<T>::min() / 1024 &&
 800       n <= std::numeric_limits<T>::max() / 1024) {
 801     n *= 1024;
 802     return true;
 803   } else {
 804     return false;
 805   }
 806 }
 807 
 808 // All of the integral types that can be used for command line options:
 809 //   int, uint, intx, uintx, uint64_t, size_t
 810 //
 811 // In all supported platforms, these types can be mapped to only 4 native types:
 812 //    {signed, unsigned} x {32-bit, 64-bit}
 813 //
 814 // We use SFINAE to pick the correct parse_integer_impl() function
 815 template<typename T>
 816 static bool parse_integer(const char *s, T* result) {
 817   if (!isdigit(s[0]) && s[0] != '-') {
 818     // strtoll/strtoull may allow leading spaces. Forbid it.
 819     return false;
 820   }
 821 
 822   T n = 0;
 823   bool is_hex = (s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) ||
 824                 (s[0] == '-' && s[1] == '0' && (s[2] == 'x' || s[3] == 'X'));
 825   char* remainder;
 826 
 827   if (!parse_integer_impl(s, &remainder, (is_hex ? 16 : 10), &n)) {
 828     return false;
 829   }
 830 
 831   // Fail if no number was read at all or if the remainder contains more than a single non-digit character.
 832   if (remainder == s || strlen(remainder) > 1) {
 833     return false;
 834   }
 835 
 836   switch (*remainder) {
 837     case 'T': case 't':
 838       if (!multiply_by_1k(n)) return false;
 839       // fall-through
 840     case 'G': case 'g':
 841       if (!multiply_by_1k(n)) return false;
 842       // fall-through
 843     case 'M': case 'm':
 844       if (!multiply_by_1k(n)) return false;
 845       // fall-through
 846     case 'K': case 'k':
 847       if (!multiply_by_1k(n)) return false;
 848       break;
 849     case '\0':
 850       break;
 851     default:
 852       return false;
 853   }
 854 
 855   *result = n;
 856   return true;
 857 }
 858 
 859 bool Arguments::atojulong(const char *s, julong* result) {
 860   return parse_integer(s, result);
 861 }
 862 
 863 Arguments::ArgsRange Arguments::check_memory_size(julong size, julong min_size, julong max_size) {
 864   if (size < min_size) return arg_too_small;
 865   if (size > max_size) return arg_too_big;
 866   return arg_in_range;
 867 }
 868 
 869 // Describe an argument out of range error
 870 void Arguments::describe_range_error(ArgsRange errcode) {
 871   switch(errcode) {
 872   case arg_too_big:
 873     jio_fprintf(defaultStream::error_stream(),
 874                 "The specified size exceeds the maximum "
 875                 "representable size.\n");
 876     break;
 877   case arg_too_small:
 878   case arg_unreadable:
 879   case arg_in_range:
 880     // do nothing for now
 881     break;
 882   default:
 883     ShouldNotReachHere();
 884   }
 885 }
 886 
 887 static bool set_bool_flag(JVMFlag* flag, bool value, JVMFlagOrigin origin) {
 888   if (JVMFlagAccess::set_bool(flag, &value, origin) == JVMFlag::SUCCESS) {
 889     return true;
 890   } else {
 891     return false;
 892   }
 893 }
 894 
 895 static bool set_fp_numeric_flag(JVMFlag* flag, const char* value, JVMFlagOrigin origin) {
 896   // strtod allows leading whitespace, but our flag format does not.
 897   if (*value == '\0' || isspace(*value)) {
 898     return false;
 899   }
 900   char* end;
 901   errno = 0;
 902   double v = strtod(value, &end);
 903   if ((errno != 0) || (*end != 0)) {
 904     return false;
 905   }
 906   if (g_isnan(v) || !g_isfinite(v)) {
 907     // Currently we cannot handle these special values.
 908     return false;
 909   }
 910 
 911   if (JVMFlagAccess::set_double(flag, &v, origin) == JVMFlag::SUCCESS) {
 912     return true;
 913   }
 914   return false;
 915 }
 916 
 917 static bool set_numeric_flag(JVMFlag* flag, const char* value, JVMFlagOrigin origin) {
 918   JVMFlag::Error result = JVMFlag::WRONG_FORMAT;
 919 
 920   if (flag->is_int()) {
 921     int v;
 922     if (parse_integer(value, &v)) {
 923       result = JVMFlagAccess::set_int(flag, &v, origin);
 924     }
 925   } else if (flag->is_uint()) {
 926     uint v;
 927     if (parse_integer(value, &v)) {
 928       result = JVMFlagAccess::set_uint(flag, &v, origin);
 929     }
 930   } else if (flag->is_intx()) {
 931     intx v;
 932     if (parse_integer(value, &v)) {
 933       result = JVMFlagAccess::set_intx(flag, &v, origin);
 934     }
 935   } else if (flag->is_uintx()) {
 936     uintx v;
 937     if (parse_integer(value, &v)) {
 938       result = JVMFlagAccess::set_uintx(flag, &v, origin);
 939     }
 940   } else if (flag->is_uint64_t()) {
 941     uint64_t v;
 942     if (parse_integer(value, &v)) {
 943       result = JVMFlagAccess::set_uint64_t(flag, &v, origin);
 944     }
 945   } else if (flag->is_size_t()) {
 946     size_t v;
 947     if (parse_integer(value, &v)) {
 948       result = JVMFlagAccess::set_size_t(flag, &v, origin);
 949     }
 950   }
 951 
 952   return result == JVMFlag::SUCCESS;
 953 }
 954 
 955 static bool set_string_flag(JVMFlag* flag, const char* value, JVMFlagOrigin origin) {
 956   if (value[0] == '\0') {
 957     value = NULL;
 958   }
 959   if (JVMFlagAccess::set_ccstr(flag, &value, origin) != JVMFlag::SUCCESS) return false;
 960   // Contract:  JVMFlag always returns a pointer that needs freeing.
 961   FREE_C_HEAP_ARRAY(char, value);
 962   return true;
 963 }
 964 
 965 static bool append_to_string_flag(JVMFlag* flag, const char* new_value, JVMFlagOrigin origin) {
 966   const char* old_value = "";
 967   if (JVMFlagAccess::get_ccstr(flag, &old_value) != JVMFlag::SUCCESS) return false;
 968   size_t old_len = old_value != NULL ? strlen(old_value) : 0;
 969   size_t new_len = strlen(new_value);
 970   const char* value;
 971   char* free_this_too = NULL;
 972   if (old_len == 0) {
 973     value = new_value;
 974   } else if (new_len == 0) {
 975     value = old_value;
 976   } else {
 977      size_t length = old_len + 1 + new_len + 1;
 978      char* buf = NEW_C_HEAP_ARRAY(char, length, mtArguments);
 979     // each new setting adds another LINE to the switch:
 980     jio_snprintf(buf, length, "%s\n%s", old_value, new_value);
 981     value = buf;
 982     free_this_too = buf;
 983   }
 984   (void) JVMFlagAccess::set_ccstr(flag, &value, origin);
 985   // JVMFlag always returns a pointer that needs freeing.
 986   FREE_C_HEAP_ARRAY(char, value);
 987   // JVMFlag made its own copy, so I must delete my own temp. buffer.
 988   FREE_C_HEAP_ARRAY(char, free_this_too);
 989   return true;
 990 }
 991 
 992 const char* Arguments::handle_aliases_and_deprecation(const char* arg) {
 993   const char* real_name = real_flag_name(arg);
 994   JDK_Version since = JDK_Version();
 995   switch (is_deprecated_flag(arg, &since)) {
 996   case -1: {
 997       // Obsolete or expired, so don't process normally,
 998       // but allow for an obsolete flag we're still
 999       // temporarily allowing.
1000       if (!is_obsolete_flag(arg, &since)) {
1001         return real_name;
1002       }
1003       // Note if we're not considered obsolete then we can't be expired either
1004       // as obsoletion must come first.
1005       return NULL;
1006     }
1007     case 0:
1008       return real_name;
1009     case 1: {
1010       char version[256];
1011       since.to_string(version, sizeof(version));
1012       if (real_name != arg) {
1013         warning("Option %s was deprecated in version %s and will likely be removed in a future release. Use option %s instead.",
1014                 arg, version, real_name);
1015       } else {
1016         warning("Option %s was deprecated in version %s and will likely be removed in a future release.",
1017                 arg, version);
1018       }
1019       return real_name;
1020     }
1021   }
1022   ShouldNotReachHere();
1023   return NULL;
1024 }
1025 
1026 #define BUFLEN 255
1027 
1028 JVMFlag* Arguments::find_jvm_flag(const char* name, size_t name_length) {
1029   char name_copied[BUFLEN+1];
1030   if (name[name_length] != 0) {
1031     if (name_length > BUFLEN) {
1032       return NULL;
1033     } else {
1034       strncpy(name_copied, name, name_length);
1035       name_copied[name_length] = '\0';
1036       name = name_copied;
1037     }
1038   }
1039 
1040   const char* real_name = Arguments::handle_aliases_and_deprecation(name);
1041   if (real_name == NULL) {
1042     return NULL;
1043   }
1044   JVMFlag* flag = JVMFlag::find_flag(real_name);
1045   return flag;
1046 }
1047 
1048 bool Arguments::parse_argument(const char* arg, JVMFlagOrigin origin) {
1049   bool is_bool = false;
1050   bool bool_val = false;
1051   char c = *arg;
1052   if (c == '+' || c == '-') {
1053     is_bool = true;
1054     bool_val = (c == '+');
1055     arg++;
1056   }
1057 
1058   const char* name = arg;
1059   while (true) {
1060     c = *arg;
1061     if (isalnum(c) || (c == '_')) {
1062       ++arg;
1063     } else {
1064       break;
1065     }
1066   }
1067 
1068   size_t name_len = size_t(arg - name);
1069   if (name_len == 0) {
1070     return false;
1071   }
1072 
1073   JVMFlag* flag = find_jvm_flag(name, name_len);
1074   if (flag == NULL) {
1075     return false;
1076   }
1077 
1078   if (is_bool) {
1079     if (*arg != 0) {
1080       // Error -- extra characters such as -XX:+BoolFlag=123
1081       return false;
1082     }
1083     return set_bool_flag(flag, bool_val, origin);
1084   }
1085 
1086   if (arg[0] == '=') {
1087     const char* value = arg + 1;
1088     if (flag->is_ccstr()) {
1089       if (flag->ccstr_accumulates()) {
1090         return append_to_string_flag(flag, value, origin);
1091       } else {
1092         return set_string_flag(flag, value, origin);
1093       }
1094     } else if (flag->is_double()) {
1095       return set_fp_numeric_flag(flag, value, origin);
1096     } else {
1097       return set_numeric_flag(flag, value, origin);
1098     }
1099   }
1100 
1101   if (arg[0] == ':' && arg[1] == '=') {
1102     // -XX:Foo:=xxx will reset the string flag to the given value.
1103     const char* value = arg + 2;
1104     return set_string_flag(flag, value, origin);
1105   }
1106 
1107   return false;
1108 }
1109 
1110 void Arguments::add_string(char*** bldarray, int* count, const char* arg) {
1111   assert(bldarray != NULL, "illegal argument");
1112 
1113   if (arg == NULL) {
1114     return;
1115   }
1116 
1117   int new_count = *count + 1;
1118 
1119   // expand the array and add arg to the last element
1120   if (*bldarray == NULL) {
1121     *bldarray = NEW_C_HEAP_ARRAY(char*, new_count, mtArguments);
1122   } else {
1123     *bldarray = REALLOC_C_HEAP_ARRAY(char*, *bldarray, new_count, mtArguments);
1124   }
1125   (*bldarray)[*count] = os::strdup_check_oom(arg);
1126   *count = new_count;
1127 }
1128 
1129 void Arguments::build_jvm_args(const char* arg) {
1130   add_string(&_jvm_args_array, &_num_jvm_args, arg);
1131 }
1132 
1133 void Arguments::build_jvm_flags(const char* arg) {
1134   add_string(&_jvm_flags_array, &_num_jvm_flags, arg);
1135 }
1136 
1137 // utility function to return a string that concatenates all
1138 // strings in a given char** array
1139 const char* Arguments::build_resource_string(char** args, int count) {
1140   if (args == NULL || count == 0) {
1141     return NULL;
1142   }
1143   size_t length = 0;
1144   for (int i = 0; i < count; i++) {
1145     length += strlen(args[i]) + 1; // add 1 for a space or NULL terminating character
1146   }
1147   char* s = NEW_RESOURCE_ARRAY(char, length);
1148   char* dst = s;
1149   for (int j = 0; j < count; j++) {
1150     size_t offset = strlen(args[j]) + 1; // add 1 for a space or NULL terminating character
1151     jio_snprintf(dst, length, "%s ", args[j]); // jio_snprintf will replace the last space character with NULL character
1152     dst += offset;
1153     length -= offset;
1154   }
1155   return (const char*) s;
1156 }
1157 
1158 void Arguments::print_on(outputStream* st) {
1159   st->print_cr("VM Arguments:");
1160   if (num_jvm_flags() > 0) {
1161     st->print("jvm_flags: "); print_jvm_flags_on(st);
1162     st->cr();
1163   }
1164   if (num_jvm_args() > 0) {
1165     st->print("jvm_args: "); print_jvm_args_on(st);
1166     st->cr();
1167   }
1168   st->print_cr("java_command: %s", java_command() ? java_command() : "<unknown>");
1169   if (_java_class_path != NULL) {
1170     char* path = _java_class_path->value();
1171     size_t len = strlen(path);
1172     st->print("java_class_path (initial): ");
1173     // Avoid using st->print_cr() because path length maybe longer than O_BUFLEN.
1174     if (len == 0) {
1175       st->print_raw_cr("<not set>");
1176     } else {
1177       st->print_raw_cr(path, len);
1178     }
1179   }
1180   st->print_cr("Launcher Type: %s", _sun_java_launcher);
1181 }
1182 
1183 void Arguments::print_summary_on(outputStream* st) {
1184   // Print the command line.  Environment variables that are helpful for
1185   // reproducing the problem are written later in the hs_err file.
1186   // flags are from setting file
1187   if (num_jvm_flags() > 0) {
1188     st->print_raw("Settings File: ");
1189     print_jvm_flags_on(st);
1190     st->cr();
1191   }
1192   // args are the command line and environment variable arguments.
1193   st->print_raw("Command Line: ");
1194   if (num_jvm_args() > 0) {
1195     print_jvm_args_on(st);
1196   }
1197   // this is the classfile and any arguments to the java program
1198   if (java_command() != NULL) {
1199     st->print("%s", java_command());
1200   }
1201   st->cr();
1202 }
1203 
1204 void Arguments::print_jvm_flags_on(outputStream* st) {
1205   if (_num_jvm_flags > 0) {
1206     for (int i=0; i < _num_jvm_flags; i++) {
1207       st->print("%s ", _jvm_flags_array[i]);
1208     }
1209   }
1210 }
1211 
1212 void Arguments::print_jvm_args_on(outputStream* st) {
1213   if (_num_jvm_args > 0) {
1214     for (int i=0; i < _num_jvm_args; i++) {
1215       st->print("%s ", _jvm_args_array[i]);
1216     }
1217   }
1218 }
1219 
1220 bool Arguments::process_argument(const char* arg,
1221                                  jboolean ignore_unrecognized,
1222                                  JVMFlagOrigin origin) {
1223   JDK_Version since = JDK_Version();
1224 
1225   if (parse_argument(arg, origin)) {
1226     return true;
1227   }
1228 
1229   // Determine if the flag has '+', '-', or '=' characters.
1230   bool has_plus_minus = (*arg == '+' || *arg == '-');
1231   const char* const argname = has_plus_minus ? arg + 1 : arg;
1232 
1233   size_t arg_len;
1234   const char* equal_sign = strchr(argname, '=');
1235   if (equal_sign == NULL) {
1236     arg_len = strlen(argname);
1237   } else {
1238     arg_len = equal_sign - argname;
1239   }
1240 
1241   // Only make the obsolete check for valid arguments.
1242   if (arg_len <= BUFLEN) {
1243     // Construct a string which consists only of the argument name without '+', '-', or '='.
1244     char stripped_argname[BUFLEN+1]; // +1 for '\0'
1245     jio_snprintf(stripped_argname, arg_len+1, "%s", argname); // +1 for '\0'
1246     if (is_obsolete_flag(stripped_argname, &since)) {
1247       char version[256];
1248       since.to_string(version, sizeof(version));
1249       warning("Ignoring option %s; support was removed in %s", stripped_argname, version);
1250       return true;
1251     }
1252   }
1253 
1254   // For locked flags, report a custom error message if available.
1255   // Otherwise, report the standard unrecognized VM option.
1256   const JVMFlag* found_flag = JVMFlag::find_declared_flag((const char*)argname, arg_len);
1257   if (found_flag != NULL) {
1258     char locked_message_buf[BUFLEN];
1259     JVMFlag::MsgType msg_type = found_flag->get_locked_message(locked_message_buf, BUFLEN);
1260     if (strlen(locked_message_buf) == 0) {
1261       if (found_flag->is_bool() && !has_plus_minus) {
1262         jio_fprintf(defaultStream::error_stream(),
1263           "Missing +/- setting for VM option '%s'\n", argname);
1264       } else if (!found_flag->is_bool() && has_plus_minus) {
1265         jio_fprintf(defaultStream::error_stream(),
1266           "Unexpected +/- setting in VM option '%s'\n", argname);
1267       } else {
1268         jio_fprintf(defaultStream::error_stream(),
1269           "Improperly specified VM option '%s'\n", argname);
1270       }
1271     } else {
1272 #ifdef PRODUCT
1273       bool mismatched = ((msg_type == JVMFlag::NOTPRODUCT_FLAG_BUT_PRODUCT_BUILD) ||
1274                          (msg_type == JVMFlag::DEVELOPER_FLAG_BUT_PRODUCT_BUILD));
1275       if (ignore_unrecognized && mismatched) {
1276         return true;
1277       }
1278 #endif
1279       jio_fprintf(defaultStream::error_stream(), "%s", locked_message_buf);
1280     }
1281   } else {
1282     if (ignore_unrecognized) {
1283       return true;
1284     }
1285     jio_fprintf(defaultStream::error_stream(),
1286                 "Unrecognized VM option '%s'\n", argname);
1287     JVMFlag* fuzzy_matched = JVMFlag::fuzzy_match((const char*)argname, arg_len, true);
1288     if (fuzzy_matched != NULL) {
1289       jio_fprintf(defaultStream::error_stream(),
1290                   "Did you mean '%s%s%s'? ",
1291                   (fuzzy_matched->is_bool()) ? "(+/-)" : "",
1292                   fuzzy_matched->name(),
1293                   (fuzzy_matched->is_bool()) ? "" : "=<value>");
1294     }
1295   }
1296 
1297   // allow for commandline "commenting out" options like -XX:#+Verbose
1298   return arg[0] == '#';
1299 }
1300 
1301 bool Arguments::process_settings_file(const char* file_name, bool should_exist, jboolean ignore_unrecognized) {
1302   FILE* stream = os::fopen(file_name, "rb");
1303   if (stream == NULL) {
1304     if (should_exist) {
1305       jio_fprintf(defaultStream::error_stream(),
1306                   "Could not open settings file %s\n", file_name);
1307       return false;
1308     } else {
1309       return true;
1310     }
1311   }
1312 
1313   char token[1024];
1314   int  pos = 0;
1315 
1316   bool in_white_space = true;
1317   bool in_comment     = false;
1318   bool in_quote       = false;
1319   char quote_c        = 0;
1320   bool result         = true;
1321 
1322   int c = getc(stream);
1323   while(c != EOF && pos < (int)(sizeof(token)-1)) {
1324     if (in_white_space) {
1325       if (in_comment) {
1326         if (c == '\n') in_comment = false;
1327       } else {
1328         if (c == '#') in_comment = true;
1329         else if (!isspace(c)) {
1330           in_white_space = false;
1331           token[pos++] = c;
1332         }
1333       }
1334     } else {
1335       if (c == '\n' || (!in_quote && isspace(c))) {
1336         // token ends at newline, or at unquoted whitespace
1337         // this allows a way to include spaces in string-valued options
1338         token[pos] = '\0';
1339         logOption(token);
1340         result &= process_argument(token, ignore_unrecognized, JVMFlagOrigin::CONFIG_FILE);
1341         build_jvm_flags(token);
1342         pos = 0;
1343         in_white_space = true;
1344         in_quote = false;
1345       } else if (!in_quote && (c == '\'' || c == '"')) {
1346         in_quote = true;
1347         quote_c = c;
1348       } else if (in_quote && (c == quote_c)) {
1349         in_quote = false;
1350       } else {
1351         token[pos++] = c;
1352       }
1353     }
1354     c = getc(stream);
1355   }
1356   if (pos > 0) {
1357     token[pos] = '\0';
1358     result &= process_argument(token, ignore_unrecognized, JVMFlagOrigin::CONFIG_FILE);
1359     build_jvm_flags(token);
1360   }
1361   fclose(stream);
1362   return result;
1363 }
1364 
1365 //=============================================================================================================
1366 // Parsing of properties (-D)
1367 
1368 const char* Arguments::get_property(const char* key) {
1369   return PropertyList_get_value(system_properties(), key);
1370 }
1371 
1372 bool Arguments::add_property(const char* prop, PropertyWriteable writeable, PropertyInternal internal) {
1373   const char* eq = strchr(prop, '=');
1374   const char* key;
1375   const char* value = "";
1376 
1377   if (eq == NULL) {
1378     // property doesn't have a value, thus use passed string
1379     key = prop;
1380   } else {
1381     // property have a value, thus extract it and save to the
1382     // allocated string
1383     size_t key_len = eq - prop;
1384     char* tmp_key = AllocateHeap(key_len + 1, mtArguments);
1385 
1386     jio_snprintf(tmp_key, key_len + 1, "%s", prop);
1387     key = tmp_key;
1388 
1389     value = &prop[key_len + 1];
1390   }
1391 
1392 #if INCLUDE_CDS
1393   if (is_internal_module_property(key) ||
1394       strcmp(key, "jdk.module.main") == 0) {
1395     MetaspaceShared::disable_optimized_module_handling();
1396     log_info(cds)("optimized module handling: disabled due to incompatible property: %s=%s", key, value);
1397   }
1398   if (strcmp(key, "jdk.module.showModuleResolution") == 0 ||
1399       strcmp(key, "jdk.module.validation") == 0 ||
1400       strcmp(key, "java.system.class.loader") == 0) {
1401     MetaspaceShared::disable_full_module_graph();
1402     log_info(cds)("full module graph: disabled due to incompatible property: %s=%s", key, value);
1403   }
1404 #endif
1405 
1406   if (strcmp(key, "java.compiler") == 0) {
1407     process_java_compiler_argument(value);
1408     // Record value in Arguments, but let it get passed to Java.
1409   } else if (strcmp(key, "sun.java.launcher.is_altjvm") == 0) {
1410     // sun.java.launcher.is_altjvm property is
1411     // private and is processed in process_sun_java_launcher_properties();
1412     // the sun.java.launcher property is passed on to the java application
1413   } else if (strcmp(key, "sun.boot.library.path") == 0) {
1414     // append is true, writable is true, internal is false
1415     PropertyList_unique_add(&_system_properties, key, value, AppendProperty,
1416                             WriteableProperty, ExternalProperty);
1417   } else {
1418     if (strcmp(key, "sun.java.command") == 0) {
1419       char *old_java_command = _java_command;
1420       _java_command = os::strdup_check_oom(value, mtArguments);
1421       if (old_java_command != NULL) {
1422         os::free(old_java_command);
1423       }
1424     } else if (strcmp(key, "java.vendor.url.bug") == 0) {
1425       // If this property is set on the command line then its value will be
1426       // displayed in VM error logs as the URL at which to submit such logs.
1427       // Normally the URL displayed in error logs is different from the value
1428       // of this system property, so a different property should have been
1429       // used here, but we leave this as-is in case someone depends upon it.
1430       const char* old_java_vendor_url_bug = _java_vendor_url_bug;
1431       // save it in _java_vendor_url_bug, so JVM fatal error handler can access
1432       // its value without going through the property list or making a Java call.
1433       _java_vendor_url_bug = os::strdup_check_oom(value, mtArguments);
1434       if (old_java_vendor_url_bug != NULL) {
1435         os::free((void *)old_java_vendor_url_bug);
1436       }
1437     }
1438 
1439     // Create new property and add at the end of the list
1440     PropertyList_unique_add(&_system_properties, key, value, AddProperty, writeable, internal);
1441   }
1442 
1443   if (key != prop) {
1444     // SystemProperty copy passed value, thus free previously allocated
1445     // memory
1446     FreeHeap((void *)key);
1447   }
1448 
1449   return true;
1450 }
1451 
1452 #if INCLUDE_CDS
1453 const char* unsupported_properties[] = { "jdk.module.limitmods",
1454                                          "jdk.module.upgrade.path",
1455                                          "jdk.module.patch.0" };
1456 const char* unsupported_options[] = { "--limit-modules",
1457                                       "--upgrade-module-path",
1458                                       "--patch-module"
1459                                     };
1460 void Arguments::check_unsupported_dumping_properties() {
1461   assert(is_dumping_archive(),
1462          "this function is only used with CDS dump time");
1463   assert(ARRAY_SIZE(unsupported_properties) == ARRAY_SIZE(unsupported_options), "must be");
1464   // If a vm option is found in the unsupported_options array, vm will exit with an error message.
1465   SystemProperty* sp = system_properties();
1466   while (sp != NULL) {
1467     for (uint i = 0; i < ARRAY_SIZE(unsupported_properties); i++) {
1468       if (strcmp(sp->key(), unsupported_properties[i]) == 0) {
1469         vm_exit_during_initialization(
1470           "Cannot use the following option when dumping the shared archive", unsupported_options[i]);
1471       }
1472     }
1473     sp = sp->next();
1474   }
1475 
1476   // Check for an exploded module build in use with -Xshare:dump.
1477   if (!has_jimage()) {
1478     vm_exit_during_initialization("Dumping the shared archive is not supported with an exploded module build");
1479   }
1480 }
1481 
1482 bool Arguments::check_unsupported_cds_runtime_properties() {
1483   assert(UseSharedSpaces, "this function is only used with -Xshare:{on,auto}");
1484   assert(ARRAY_SIZE(unsupported_properties) == ARRAY_SIZE(unsupported_options), "must be");
1485   if (ArchiveClassesAtExit != NULL) {
1486     // dynamic dumping, just return false for now.
1487     // check_unsupported_dumping_properties() will be called later to check the same set of
1488     // properties, and will exit the VM with the correct error message if the unsupported properties
1489     // are used.
1490     return false;
1491   }
1492   for (uint i = 0; i < ARRAY_SIZE(unsupported_properties); i++) {
1493     if (get_property(unsupported_properties[i]) != NULL) {
1494       if (RequireSharedSpaces) {
1495         warning("CDS is disabled when the %s option is specified.", unsupported_options[i]);
1496       } else {
1497         log_info(cds)("CDS is disabled when the %s option is specified.", unsupported_options[i]);
1498       }
1499       return true;
1500     }
1501   }
1502   return false;
1503 }
1504 #endif
1505 
1506 //===========================================================================================================
1507 // Setting int/mixed/comp mode flags
1508 
1509 void Arguments::set_mode_flags(Mode mode) {
1510   // Set up default values for all flags.
1511   // If you add a flag to any of the branches below,
1512   // add a default value for it here.
1513   set_java_compiler(false);
1514   _mode                      = mode;
1515 
1516   // Ensure Agent_OnLoad has the correct initial values.
1517   // This may not be the final mode; mode may change later in onload phase.
1518   PropertyList_unique_add(&_system_properties, "java.vm.info",
1519                           VM_Version::vm_info_string(), AddProperty, UnwriteableProperty, ExternalProperty);
1520 
1521   UseInterpreter             = true;
1522   UseCompiler                = true;
1523   UseLoopCounter             = true;
1524 
1525   // Default values may be platform/compiler dependent -
1526   // use the saved values
1527   ClipInlining               = Arguments::_ClipInlining;
1528   AlwaysCompileLoopMethods   = Arguments::_AlwaysCompileLoopMethods;
1529   UseOnStackReplacement      = Arguments::_UseOnStackReplacement;
1530   BackgroundCompilation      = Arguments::_BackgroundCompilation;
1531 
1532   // Change from defaults based on mode
1533   switch (mode) {
1534   default:
1535     ShouldNotReachHere();
1536     break;
1537   case _int:
1538     UseCompiler              = false;
1539     UseLoopCounter           = false;
1540     AlwaysCompileLoopMethods = false;
1541     UseOnStackReplacement    = false;
1542     break;
1543   case _mixed:
1544     // same as default
1545     break;
1546   case _comp:
1547     UseInterpreter           = false;
1548     BackgroundCompilation    = false;
1549     ClipInlining             = false;
1550     break;
1551   }
1552 }
1553 
1554 // Conflict: required to use shared spaces (-Xshare:on), but
1555 // incompatible command line options were chosen.
1556 static void no_shared_spaces(const char* message) {
1557   if (RequireSharedSpaces) {
1558     jio_fprintf(defaultStream::error_stream(),
1559       "Class data sharing is inconsistent with other specified options.\n");
1560     vm_exit_during_initialization("Unable to use shared archive", message);
1561   } else {
1562     log_info(cds)("Unable to use shared archive: %s", message);
1563     UseSharedSpaces = false;
1564   }
1565 }
1566 
1567 void set_object_alignment() {
1568   // Object alignment.
1569   assert(is_power_of_2(ObjectAlignmentInBytes), "ObjectAlignmentInBytes must be power of 2");
1570   MinObjAlignmentInBytes     = ObjectAlignmentInBytes;
1571   assert(MinObjAlignmentInBytes >= HeapWordsPerLong * HeapWordSize, "ObjectAlignmentInBytes value is too small");
1572   MinObjAlignment            = MinObjAlignmentInBytes / HeapWordSize;
1573   assert(MinObjAlignmentInBytes == MinObjAlignment * HeapWordSize, "ObjectAlignmentInBytes value is incorrect");
1574   MinObjAlignmentInBytesMask = MinObjAlignmentInBytes - 1;
1575 
1576   LogMinObjAlignmentInBytes  = exact_log2(ObjectAlignmentInBytes);
1577   LogMinObjAlignment         = LogMinObjAlignmentInBytes - LogHeapWordSize;
1578 
1579   // Oop encoding heap max
1580   OopEncodingHeapMax = (uint64_t(max_juint) + 1) << LogMinObjAlignmentInBytes;
1581 }
1582 
1583 size_t Arguments::max_heap_for_compressed_oops() {
1584   // Avoid sign flip.
1585   assert(OopEncodingHeapMax > (uint64_t)os::vm_page_size(), "Unusual page size");
1586   // We need to fit both the NULL page and the heap into the memory budget, while
1587   // keeping alignment constraints of the heap. To guarantee the latter, as the
1588   // NULL page is located before the heap, we pad the NULL page to the conservative
1589   // maximum alignment that the GC may ever impose upon the heap.
1590   size_t displacement_due_to_null_page = align_up((size_t)os::vm_page_size(),
1591                                                   _conservative_max_heap_alignment);
1592 
1593   LP64_ONLY(return OopEncodingHeapMax - displacement_due_to_null_page);
1594   NOT_LP64(ShouldNotReachHere(); return 0);
1595 }
1596 
1597 void Arguments::set_use_compressed_oops() {
1598 #ifdef _LP64
1599   // MaxHeapSize is not set up properly at this point, but
1600   // the only value that can override MaxHeapSize if we are
1601   // to use UseCompressedOops are InitialHeapSize and MinHeapSize.
1602   size_t max_heap_size = MAX3(MaxHeapSize, InitialHeapSize, MinHeapSize);
1603 
1604   if (max_heap_size <= max_heap_for_compressed_oops()) {
1605     if (FLAG_IS_DEFAULT(UseCompressedOops)) {
1606       FLAG_SET_ERGO(UseCompressedOops, true);
1607     }
1608   } else {
1609     if (UseCompressedOops && !FLAG_IS_DEFAULT(UseCompressedOops)) {
1610       warning("Max heap size too large for Compressed Oops");
1611       FLAG_SET_DEFAULT(UseCompressedOops, false);
1612       if (COMPRESSED_CLASS_POINTERS_DEPENDS_ON_COMPRESSED_OOPS) {
1613         FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
1614       }
1615     }
1616   }
1617 #endif // _LP64
1618 }
1619 
1620 
1621 // NOTE: set_use_compressed_klass_ptrs() must be called after calling
1622 // set_use_compressed_oops().
1623 void Arguments::set_use_compressed_klass_ptrs() {
1624 #ifdef _LP64
1625   // On some architectures, the use of UseCompressedClassPointers implies the use of
1626   // UseCompressedOops. The reason is that the rheap_base register of said platforms
1627   // is reused to perform some optimized spilling, in order to use rheap_base as a
1628   // temp register. But by treating it as any other temp register, spilling can typically
1629   // be completely avoided instead. So it is better not to perform this trick. And by
1630   // not having that reliance, large heaps, or heaps not supporting compressed oops,
1631   // can still use compressed class pointers.
1632   if (COMPRESSED_CLASS_POINTERS_DEPENDS_ON_COMPRESSED_OOPS && !UseCompressedOops) {
1633     if (UseCompressedClassPointers) {
1634       warning("UseCompressedClassPointers requires UseCompressedOops");
1635     }
1636     FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
1637   } else {
1638     // Turn on UseCompressedClassPointers too
1639     if (FLAG_IS_DEFAULT(UseCompressedClassPointers)) {
1640       FLAG_SET_ERGO(UseCompressedClassPointers, true);
1641     }
1642     // Check the CompressedClassSpaceSize to make sure we use compressed klass ptrs.
1643     if (UseCompressedClassPointers) {
1644       if (CompressedClassSpaceSize > KlassEncodingMetaspaceMax) {
1645         warning("CompressedClassSpaceSize is too large for UseCompressedClassPointers");
1646         FLAG_SET_DEFAULT(UseCompressedClassPointers, false);
1647       }
1648     }
1649   }
1650 #endif // _LP64
1651 }
1652 
1653 void Arguments::set_conservative_max_heap_alignment() {
1654   // The conservative maximum required alignment for the heap is the maximum of
1655   // the alignments imposed by several sources: any requirements from the heap
1656   // itself and the maximum page size we may run the VM with.
1657   size_t heap_alignment = GCConfig::arguments()->conservative_max_heap_alignment();
1658   _conservative_max_heap_alignment = MAX4(heap_alignment,
1659                                           (size_t)os::vm_allocation_granularity(),
1660                                           os::max_page_size(),
1661                                           GCArguments::compute_heap_alignment());
1662 }
1663 
1664 jint Arguments::set_ergonomics_flags() {
1665   GCConfig::initialize();
1666 
1667   set_conservative_max_heap_alignment();
1668 
1669 #ifdef _LP64
1670   set_use_compressed_oops();
1671 
1672   // set_use_compressed_klass_ptrs() must be called after calling
1673   // set_use_compressed_oops().
1674   set_use_compressed_klass_ptrs();
1675 
1676   // Also checks that certain machines are slower with compressed oops
1677   // in vm_version initialization code.
1678 #endif // _LP64
1679 
1680   return JNI_OK;
1681 }
1682 
1683 size_t Arguments::limit_heap_by_allocatable_memory(size_t limit) {
1684   size_t max_allocatable;
1685   size_t result = limit;
1686   if (os::has_allocatable_memory_limit(&max_allocatable)) {
1687     // The AggressiveHeap check is a temporary workaround to avoid calling
1688     // GCarguments::heap_virtual_to_physical_ratio() before a GC has been
1689     // selected. This works because AggressiveHeap implies UseParallelGC
1690     // where we know the ratio will be 1. Once the AggressiveHeap option is
1691     // removed, this can be cleaned up.
1692     size_t heap_virtual_to_physical_ratio = (AggressiveHeap ? 1 : GCConfig::arguments()->heap_virtual_to_physical_ratio());
1693     size_t fraction = MaxVirtMemFraction * heap_virtual_to_physical_ratio;
1694     result = MIN2(result, max_allocatable / fraction);
1695   }
1696   return result;
1697 }
1698 
1699 // Use static initialization to get the default before parsing
1700 static const size_t DefaultHeapBaseMinAddress = HeapBaseMinAddress;
1701 
1702 void Arguments::set_heap_size() {
1703   julong phys_mem;
1704 
1705   // If the user specified one of these options, they
1706   // want specific memory sizing so do not limit memory
1707   // based on compressed oops addressability.
1708   // Also, memory limits will be calculated based on
1709   // available os physical memory, not our MaxRAM limit,
1710   // unless MaxRAM is also specified.
1711   bool override_coop_limit = (!FLAG_IS_DEFAULT(MaxRAMPercentage) ||
1712                            !FLAG_IS_DEFAULT(MaxRAMFraction) ||
1713                            !FLAG_IS_DEFAULT(MinRAMPercentage) ||
1714                            !FLAG_IS_DEFAULT(MinRAMFraction) ||
1715                            !FLAG_IS_DEFAULT(InitialRAMPercentage) ||
1716                            !FLAG_IS_DEFAULT(InitialRAMFraction) ||
1717                            !FLAG_IS_DEFAULT(MaxRAM));
1718   if (override_coop_limit) {
1719     if (FLAG_IS_DEFAULT(MaxRAM)) {
1720       phys_mem = os::physical_memory();
1721       FLAG_SET_ERGO(MaxRAM, (uint64_t)phys_mem);
1722     } else {
1723       phys_mem = (julong)MaxRAM;
1724     }
1725   } else {
1726     phys_mem = FLAG_IS_DEFAULT(MaxRAM) ? MIN2(os::physical_memory(), (julong)MaxRAM)
1727                                        : (julong)MaxRAM;
1728   }
1729 
1730 
1731   // Convert deprecated flags
1732   if (FLAG_IS_DEFAULT(MaxRAMPercentage) &&
1733       !FLAG_IS_DEFAULT(MaxRAMFraction))
1734     MaxRAMPercentage = 100.0 / MaxRAMFraction;
1735 
1736   if (FLAG_IS_DEFAULT(MinRAMPercentage) &&
1737       !FLAG_IS_DEFAULT(MinRAMFraction))
1738     MinRAMPercentage = 100.0 / MinRAMFraction;
1739 
1740   if (FLAG_IS_DEFAULT(InitialRAMPercentage) &&
1741       !FLAG_IS_DEFAULT(InitialRAMFraction))
1742     InitialRAMPercentage = 100.0 / InitialRAMFraction;
1743 
1744   // If the maximum heap size has not been set with -Xmx,
1745   // then set it as fraction of the size of physical memory,
1746   // respecting the maximum and minimum sizes of the heap.
1747   if (FLAG_IS_DEFAULT(MaxHeapSize)) {
1748     julong reasonable_max = (julong)((phys_mem * MaxRAMPercentage) / 100);
1749     const julong reasonable_min = (julong)((phys_mem * MinRAMPercentage) / 100);
1750     if (reasonable_min < MaxHeapSize) {
1751       // Small physical memory, so use a minimum fraction of it for the heap
1752       reasonable_max = reasonable_min;
1753     } else {
1754       // Not-small physical memory, so require a heap at least
1755       // as large as MaxHeapSize
1756       reasonable_max = MAX2(reasonable_max, (julong)MaxHeapSize);
1757     }
1758 
1759     if (!FLAG_IS_DEFAULT(ErgoHeapSizeLimit) && ErgoHeapSizeLimit != 0) {
1760       // Limit the heap size to ErgoHeapSizeLimit
1761       reasonable_max = MIN2(reasonable_max, (julong)ErgoHeapSizeLimit);
1762     }
1763 
1764     reasonable_max = limit_heap_by_allocatable_memory(reasonable_max);
1765 
1766     if (!FLAG_IS_DEFAULT(InitialHeapSize)) {
1767       // An initial heap size was specified on the command line,
1768       // so be sure that the maximum size is consistent.  Done
1769       // after call to limit_heap_by_allocatable_memory because that
1770       // method might reduce the allocation size.
1771       reasonable_max = MAX2(reasonable_max, (julong)InitialHeapSize);
1772     } else if (!FLAG_IS_DEFAULT(MinHeapSize)) {
1773       reasonable_max = MAX2(reasonable_max, (julong)MinHeapSize);
1774     }
1775 
1776 #ifdef _LP64
1777     if (UseCompressedOops || UseCompressedClassPointers) {
1778       // HeapBaseMinAddress can be greater than default but not less than.
1779       if (!FLAG_IS_DEFAULT(HeapBaseMinAddress)) {
1780         if (HeapBaseMinAddress < DefaultHeapBaseMinAddress) {
1781           // matches compressed oops printing flags
1782           log_debug(gc, heap, coops)("HeapBaseMinAddress must be at least " SIZE_FORMAT
1783                                      " (" SIZE_FORMAT "G) which is greater than value given " SIZE_FORMAT,
1784                                      DefaultHeapBaseMinAddress,
1785                                      DefaultHeapBaseMinAddress/G,
1786                                      HeapBaseMinAddress);
1787           FLAG_SET_ERGO(HeapBaseMinAddress, DefaultHeapBaseMinAddress);
1788         }
1789       }
1790     }
1791     if (UseCompressedOops) {
1792       // Limit the heap size to the maximum possible when using compressed oops
1793       julong max_coop_heap = (julong)max_heap_for_compressed_oops();
1794 
1795       if (HeapBaseMinAddress + MaxHeapSize < max_coop_heap) {
1796         // Heap should be above HeapBaseMinAddress to get zero based compressed oops
1797         // but it should be not less than default MaxHeapSize.
1798         max_coop_heap -= HeapBaseMinAddress;
1799       }
1800 
1801       // If user specified flags prioritizing os physical
1802       // memory limits, then disable compressed oops if
1803       // limits exceed max_coop_heap and UseCompressedOops
1804       // was not specified.
1805       if (reasonable_max > max_coop_heap) {
1806         if (FLAG_IS_ERGO(UseCompressedOops) && override_coop_limit) {
1807           log_info(cds)("UseCompressedOops and UseCompressedClassPointers have been disabled due to"
1808             " max heap " SIZE_FORMAT " > compressed oop heap " SIZE_FORMAT ". "
1809             "Please check the setting of MaxRAMPercentage %5.2f."
1810             ,(size_t)reasonable_max, (size_t)max_coop_heap, MaxRAMPercentage);
1811           FLAG_SET_ERGO(UseCompressedOops, false);
1812           if (COMPRESSED_CLASS_POINTERS_DEPENDS_ON_COMPRESSED_OOPS) {
1813             FLAG_SET_ERGO(UseCompressedClassPointers, false);
1814           }
1815         } else {
1816           reasonable_max = MIN2(reasonable_max, max_coop_heap);
1817         }
1818       }
1819     }
1820 #endif // _LP64
1821 
1822     log_trace(gc, heap)("  Maximum heap size " SIZE_FORMAT, (size_t) reasonable_max);
1823     FLAG_SET_ERGO(MaxHeapSize, (size_t)reasonable_max);
1824   }
1825 
1826   // If the minimum or initial heap_size have not been set or requested to be set
1827   // ergonomically, set them accordingly.
1828   if (InitialHeapSize == 0 || MinHeapSize == 0) {
1829     julong reasonable_minimum = (julong)(OldSize + NewSize);
1830 
1831     reasonable_minimum = MIN2(reasonable_minimum, (julong)MaxHeapSize);
1832 
1833     reasonable_minimum = limit_heap_by_allocatable_memory(reasonable_minimum);
1834 
1835     if (InitialHeapSize == 0) {
1836       julong reasonable_initial = (julong)((phys_mem * InitialRAMPercentage) / 100);
1837       reasonable_initial = limit_heap_by_allocatable_memory(reasonable_initial);
1838 
1839       reasonable_initial = MAX3(reasonable_initial, reasonable_minimum, (julong)MinHeapSize);
1840       reasonable_initial = MIN2(reasonable_initial, (julong)MaxHeapSize);
1841 
1842       FLAG_SET_ERGO(InitialHeapSize, (size_t)reasonable_initial);
1843       log_trace(gc, heap)("  Initial heap size " SIZE_FORMAT, InitialHeapSize);
1844     }
1845     // If the minimum heap size has not been set (via -Xms or -XX:MinHeapSize),
1846     // synchronize with InitialHeapSize to avoid errors with the default value.
1847     if (MinHeapSize == 0) {
1848       FLAG_SET_ERGO(MinHeapSize, MIN2((size_t)reasonable_minimum, InitialHeapSize));
1849       log_trace(gc, heap)("  Minimum heap size " SIZE_FORMAT, MinHeapSize);
1850     }
1851   }
1852 }
1853 
1854 // This option inspects the machine and attempts to set various
1855 // parameters to be optimal for long-running, memory allocation
1856 // intensive jobs.  It is intended for machines with large
1857 // amounts of cpu and memory.
1858 jint Arguments::set_aggressive_heap_flags() {
1859   // initHeapSize is needed since _initial_heap_size is 4 bytes on a 32 bit
1860   // VM, but we may not be able to represent the total physical memory
1861   // available (like having 8gb of memory on a box but using a 32bit VM).
1862   // Thus, we need to make sure we're using a julong for intermediate
1863   // calculations.
1864   julong initHeapSize;
1865   julong total_memory = os::physical_memory();
1866 
1867   if (total_memory < (julong) 256 * M) {
1868     jio_fprintf(defaultStream::error_stream(),
1869             "You need at least 256mb of memory to use -XX:+AggressiveHeap\n");
1870     vm_exit(1);
1871   }
1872 
1873   // The heap size is half of available memory, or (at most)
1874   // all of possible memory less 160mb (leaving room for the OS
1875   // when using ISM).  This is the maximum; because adaptive sizing
1876   // is turned on below, the actual space used may be smaller.
1877 
1878   initHeapSize = MIN2(total_memory / (julong) 2,
1879           total_memory - (julong) 160 * M);
1880 
1881   initHeapSize = limit_heap_by_allocatable_memory(initHeapSize);
1882 
1883   if (FLAG_IS_DEFAULT(MaxHeapSize)) {
1884     if (FLAG_SET_CMDLINE(MaxHeapSize, initHeapSize) != JVMFlag::SUCCESS) {
1885       return JNI_EINVAL;
1886     }
1887     if (FLAG_SET_CMDLINE(InitialHeapSize, initHeapSize) != JVMFlag::SUCCESS) {
1888       return JNI_EINVAL;
1889     }
1890     if (FLAG_SET_CMDLINE(MinHeapSize, initHeapSize) != JVMFlag::SUCCESS) {
1891       return JNI_EINVAL;
1892     }
1893   }
1894   if (FLAG_IS_DEFAULT(NewSize)) {
1895     // Make the young generation 3/8ths of the total heap.
1896     if (FLAG_SET_CMDLINE(NewSize,
1897             ((julong) MaxHeapSize / (julong) 8) * (julong) 3) != JVMFlag::SUCCESS) {
1898       return JNI_EINVAL;
1899     }
1900     if (FLAG_SET_CMDLINE(MaxNewSize, NewSize) != JVMFlag::SUCCESS) {
1901       return JNI_EINVAL;
1902     }
1903   }
1904 
1905 #if !defined(_ALLBSD_SOURCE) && !defined(AIX)  // UseLargePages is not yet supported on BSD and AIX.
1906   FLAG_SET_DEFAULT(UseLargePages, true);
1907 #endif
1908 
1909   // Increase some data structure sizes for efficiency
1910   if (FLAG_SET_CMDLINE(BaseFootPrintEstimate, MaxHeapSize) != JVMFlag::SUCCESS) {
1911     return JNI_EINVAL;
1912   }
1913   if (FLAG_SET_CMDLINE(ResizeTLAB, false) != JVMFlag::SUCCESS) {
1914     return JNI_EINVAL;
1915   }
1916   if (FLAG_SET_CMDLINE(TLABSize, 256 * K) != JVMFlag::SUCCESS) {
1917     return JNI_EINVAL;
1918   }
1919 
1920   // See the OldPLABSize comment below, but replace 'after promotion'
1921   // with 'after copying'.  YoungPLABSize is the size of the survivor
1922   // space per-gc-thread buffers.  The default is 4kw.
1923   if (FLAG_SET_CMDLINE(YoungPLABSize, 256 * K) != JVMFlag::SUCCESS) { // Note: this is in words
1924     return JNI_EINVAL;
1925   }
1926 
1927   // OldPLABSize is the size of the buffers in the old gen that
1928   // UseParallelGC uses to promote live data that doesn't fit in the
1929   // survivor spaces.  At any given time, there's one for each gc thread.
1930   // The default size is 1kw. These buffers are rarely used, since the
1931   // survivor spaces are usually big enough.  For specjbb, however, there
1932   // are occasions when there's lots of live data in the young gen
1933   // and we end up promoting some of it.  We don't have a definite
1934   // explanation for why bumping OldPLABSize helps, but the theory
1935   // is that a bigger PLAB results in retaining something like the
1936   // original allocation order after promotion, which improves mutator
1937   // locality.  A minor effect may be that larger PLABs reduce the
1938   // number of PLAB allocation events during gc.  The value of 8kw
1939   // was arrived at by experimenting with specjbb.
1940   if (FLAG_SET_CMDLINE(OldPLABSize, 8 * K) != JVMFlag::SUCCESS) { // Note: this is in words
1941     return JNI_EINVAL;
1942   }
1943 
1944   // Enable parallel GC and adaptive generation sizing
1945   if (FLAG_SET_CMDLINE(UseParallelGC, true) != JVMFlag::SUCCESS) {
1946     return JNI_EINVAL;
1947   }
1948 
1949   // Encourage steady state memory management
1950   if (FLAG_SET_CMDLINE(ThresholdTolerance, 100) != JVMFlag::SUCCESS) {
1951     return JNI_EINVAL;
1952   }
1953 
1954   // This appears to improve mutator locality
1955   if (FLAG_SET_CMDLINE(ScavengeBeforeFullGC, false) != JVMFlag::SUCCESS) {
1956     return JNI_EINVAL;
1957   }
1958 
1959   return JNI_OK;
1960 }
1961 
1962 // This must be called after ergonomics.
1963 void Arguments::set_bytecode_flags() {
1964   if (!RewriteBytecodes) {
1965     FLAG_SET_DEFAULT(RewriteFrequentPairs, false);
1966   }
1967 }
1968 
1969 // Aggressive optimization flags
1970 jint Arguments::set_aggressive_opts_flags() {
1971 #ifdef COMPILER2
1972   if (AggressiveUnboxing) {
1973     if (FLAG_IS_DEFAULT(EliminateAutoBox)) {
1974       FLAG_SET_DEFAULT(EliminateAutoBox, true);
1975     } else if (!EliminateAutoBox) {
1976       // warning("AggressiveUnboxing is disabled because EliminateAutoBox is disabled");
1977       AggressiveUnboxing = false;
1978     }
1979     if (FLAG_IS_DEFAULT(DoEscapeAnalysis)) {
1980       FLAG_SET_DEFAULT(DoEscapeAnalysis, true);
1981     } else if (!DoEscapeAnalysis) {
1982       // warning("AggressiveUnboxing is disabled because DoEscapeAnalysis is disabled");
1983       AggressiveUnboxing = false;
1984     }
1985   }
1986   if (!FLAG_IS_DEFAULT(AutoBoxCacheMax)) {
1987     if (FLAG_IS_DEFAULT(EliminateAutoBox)) {
1988       FLAG_SET_DEFAULT(EliminateAutoBox, true);
1989     }
1990     // Feed the cache size setting into the JDK
1991     char buffer[1024];
1992     jio_snprintf(buffer, 1024, "java.lang.Integer.IntegerCache.high=" INTX_FORMAT, AutoBoxCacheMax);
1993     if (!add_property(buffer)) {
1994       return JNI_ENOMEM;
1995     }
1996   }
1997 #endif
1998 
1999   return JNI_OK;
2000 }
2001 
2002 //===========================================================================================================
2003 // Parsing of java.compiler property
2004 
2005 void Arguments::process_java_compiler_argument(const char* arg) {
2006   // For backwards compatibility, Djava.compiler=NONE or ""
2007   // causes us to switch to -Xint mode UNLESS -Xdebug
2008   // is also specified.
2009   if (strlen(arg) == 0 || strcasecmp(arg, "NONE") == 0) {
2010     set_java_compiler(true);    // "-Djava.compiler[=...]" most recently seen.
2011   }
2012 }
2013 
2014 void Arguments::process_java_launcher_argument(const char* launcher, void* extra_info) {
2015   _sun_java_launcher = os::strdup_check_oom(launcher);
2016 }
2017 
2018 bool Arguments::created_by_java_launcher() {
2019   assert(_sun_java_launcher != NULL, "property must have value");
2020   return strcmp(DEFAULT_JAVA_LAUNCHER, _sun_java_launcher) != 0;
2021 }
2022 
2023 bool Arguments::sun_java_launcher_is_altjvm() {
2024   return _sun_java_launcher_is_altjvm;
2025 }
2026 
2027 //===========================================================================================================
2028 // Parsing of main arguments
2029 
2030 unsigned int addreads_count = 0;
2031 unsigned int addexports_count = 0;
2032 unsigned int addopens_count = 0;
2033 unsigned int addmods_count = 0;
2034 unsigned int patch_mod_count = 0;
2035 unsigned int enable_native_access_count = 0;
2036 
2037 // Check the consistency of vm_init_args
2038 bool Arguments::check_vm_args_consistency() {
2039   // Method for adding checks for flag consistency.
2040   // The intent is to warn the user of all possible conflicts,
2041   // before returning an error.
2042   // Note: Needs platform-dependent factoring.
2043   bool status = true;
2044 
2045   if (TLABRefillWasteFraction == 0) {
2046     jio_fprintf(defaultStream::error_stream(),
2047                 "TLABRefillWasteFraction should be a denominator, "
2048                 "not " SIZE_FORMAT "\n",
2049                 TLABRefillWasteFraction);
2050     status = false;
2051   }
2052 
2053   status = CompilerConfig::check_args_consistency(status);
2054 #if INCLUDE_JVMCI
2055   if (status && EnableJVMCI) {
2056     PropertyList_unique_add(&_system_properties, "jdk.internal.vm.ci.enabled", "true",
2057         AddProperty, UnwriteableProperty, InternalProperty);
2058     if (!create_numbered_module_property("jdk.module.addmods", "jdk.internal.vm.ci", addmods_count++)) {
2059       return false;
2060     }
2061   }
2062 #endif
2063 
2064 #ifndef SUPPORT_RESERVED_STACK_AREA
2065   if (StackReservedPages != 0) {
2066     FLAG_SET_CMDLINE(StackReservedPages, 0);
2067     warning("Reserved Stack Area not supported on this platform");
2068   }
2069 #endif
2070 
2071 #if !defined(X86) && !defined(AARCH64) && !defined(PPC64) && !defined(RISCV64)
2072   if (UseHeavyMonitors) {
2073     jio_fprintf(defaultStream::error_stream(),
2074                 "UseHeavyMonitors is not fully implemented on this architecture");
2075     return false;
2076   }
2077 #endif
2078 #if (defined(X86) || defined(PPC64)) && !defined(ZERO)
2079   if (UseHeavyMonitors && UseRTMForStackLocks) {
2080     jio_fprintf(defaultStream::error_stream(),
2081                 "-XX:+UseHeavyMonitors and -XX:+UseRTMForStackLocks are mutually exclusive");
2082 
2083     return false;
2084   }
2085 #endif
2086   if (VerifyHeavyMonitors && !UseHeavyMonitors) {
2087     jio_fprintf(defaultStream::error_stream(),
2088                 "-XX:+VerifyHeavyMonitors requires -XX:+UseHeavyMonitors");
2089     return false;
2090   }
2091 
2092   return status;
2093 }
2094 
2095 bool Arguments::is_bad_option(const JavaVMOption* option, jboolean ignore,
2096   const char* option_type) {
2097   if (ignore) return false;
2098 
2099   const char* spacer = " ";
2100   if (option_type == NULL) {
2101     option_type = ++spacer; // Set both to the empty string.
2102   }
2103 
2104   jio_fprintf(defaultStream::error_stream(),
2105               "Unrecognized %s%soption: %s\n", option_type, spacer,
2106               option->optionString);
2107   return true;
2108 }
2109 
2110 static const char* user_assertion_options[] = {
2111   "-da", "-ea", "-disableassertions", "-enableassertions", 0
2112 };
2113 
2114 static const char* system_assertion_options[] = {
2115   "-dsa", "-esa", "-disablesystemassertions", "-enablesystemassertions", 0
2116 };
2117 
2118 bool Arguments::parse_uintx(const char* value,
2119                             uintx* uintx_arg,
2120                             uintx min_size) {
2121   uintx n;
2122   if (!parse_integer(value, &n)) {
2123     return false;
2124   }
2125   if (n >= min_size) {
2126     *uintx_arg = n;
2127     return true;
2128   } else {
2129     return false;
2130   }
2131 }
2132 
2133 bool Arguments::create_module_property(const char* prop_name, const char* prop_value, PropertyInternal internal) {
2134   assert(is_internal_module_property(prop_name), "unknown module property: '%s'", prop_name);
2135   size_t prop_len = strlen(prop_name) + strlen(prop_value) + 2;
2136   char* property = AllocateHeap(prop_len, mtArguments);
2137   int ret = jio_snprintf(property, prop_len, "%s=%s", prop_name, prop_value);
2138   if (ret < 0 || ret >= (int)prop_len) {
2139     FreeHeap(property);
2140     return false;
2141   }
2142   // These are not strictly writeable properties as they cannot be set via -Dprop=val. But that
2143   // is enforced by checking is_internal_module_property(). We need the property to be writeable so
2144   // that multiple occurrences of the associated flag just causes the existing property value to be
2145   // replaced ("last option wins"). Otherwise we would need to keep track of the flags and only convert
2146   // to a property after we have finished flag processing.
2147   bool added = add_property(property, WriteableProperty, internal);
2148   FreeHeap(property);
2149   return added;
2150 }
2151 
2152 bool Arguments::create_numbered_module_property(const char* prop_base_name, const char* prop_value, unsigned int count) {
2153   assert(is_internal_module_property(prop_base_name), "unknown module property: '%s'", prop_base_name);
2154   const unsigned int props_count_limit = 1000;
2155   const int max_digits = 3;
2156   const int extra_symbols_count = 3; // includes '.', '=', '\0'
2157 
2158   // Make sure count is < props_count_limit. Otherwise, memory allocation will be too small.
2159   if (count < props_count_limit) {
2160     size_t prop_len = strlen(prop_base_name) + strlen(prop_value) + max_digits + extra_symbols_count;
2161     char* property = AllocateHeap(prop_len, mtArguments);
2162     int ret = jio_snprintf(property, prop_len, "%s.%d=%s", prop_base_name, count, prop_value);
2163     if (ret < 0 || ret >= (int)prop_len) {
2164       FreeHeap(property);
2165       jio_fprintf(defaultStream::error_stream(), "Failed to create property %s.%d=%s\n", prop_base_name, count, prop_value);
2166       return false;
2167     }
2168     bool added = add_property(property, UnwriteableProperty, InternalProperty);
2169     FreeHeap(property);
2170     return added;
2171   }
2172 
2173   jio_fprintf(defaultStream::error_stream(), "Property count limit exceeded: %s, limit=%d\n", prop_base_name, props_count_limit);
2174   return false;
2175 }
2176 
2177 Arguments::ArgsRange Arguments::parse_memory_size(const char* s,
2178                                                   julong* long_arg,
2179                                                   julong min_size,
2180                                                   julong max_size) {
2181   if (!parse_integer(s, long_arg)) return arg_unreadable;
2182   return check_memory_size(*long_arg, min_size, max_size);
2183 }
2184 
2185 // Parse JavaVMInitArgs structure
2186 
2187 jint Arguments::parse_vm_init_args(const JavaVMInitArgs *vm_options_args,
2188                                    const JavaVMInitArgs *java_tool_options_args,
2189                                    const JavaVMInitArgs *java_options_args,
2190                                    const JavaVMInitArgs *cmd_line_args) {
2191   bool patch_mod_javabase = false;
2192 
2193   // Save default settings for some mode flags
2194   Arguments::_AlwaysCompileLoopMethods = AlwaysCompileLoopMethods;
2195   Arguments::_UseOnStackReplacement    = UseOnStackReplacement;
2196   Arguments::_ClipInlining             = ClipInlining;
2197   Arguments::_BackgroundCompilation    = BackgroundCompilation;
2198 
2199   // Remember the default value of SharedBaseAddress.
2200   Arguments::_default_SharedBaseAddress = SharedBaseAddress;
2201 
2202   // Setup flags for mixed which is the default
2203   set_mode_flags(_mixed);
2204 
2205   // Parse args structure generated from java.base vm options resource
2206   jint result = parse_each_vm_init_arg(vm_options_args, &patch_mod_javabase, JVMFlagOrigin::JIMAGE_RESOURCE);
2207   if (result != JNI_OK) {
2208     return result;
2209   }
2210 
2211   // Parse args structure generated from JAVA_TOOL_OPTIONS environment
2212   // variable (if present).
2213   result = parse_each_vm_init_arg(java_tool_options_args, &patch_mod_javabase, JVMFlagOrigin::ENVIRON_VAR);
2214   if (result != JNI_OK) {
2215     return result;
2216   }
2217 
2218   // Parse args structure generated from the command line flags.
2219   result = parse_each_vm_init_arg(cmd_line_args, &patch_mod_javabase, JVMFlagOrigin::COMMAND_LINE);
2220   if (result != JNI_OK) {
2221     return result;
2222   }
2223 
2224   // Parse args structure generated from the _JAVA_OPTIONS environment
2225   // variable (if present) (mimics classic VM)
2226   result = parse_each_vm_init_arg(java_options_args, &patch_mod_javabase, JVMFlagOrigin::ENVIRON_VAR);
2227   if (result != JNI_OK) {
2228     return result;
2229   }
2230 
2231   // We need to ensure processor and memory resources have been properly
2232   // configured - which may rely on arguments we just processed - before
2233   // doing the final argument processing. Any argument processing that
2234   // needs to know about processor and memory resources must occur after
2235   // this point.
2236 
2237   os::init_container_support();
2238 
2239   // Do final processing now that all arguments have been parsed
2240   result = finalize_vm_init_args(patch_mod_javabase);
2241   if (result != JNI_OK) {
2242     return result;
2243   }
2244 
2245   return JNI_OK;
2246 }
2247 
2248 // Checks if name in command-line argument -agent{lib,path}:name[=options]
2249 // represents a valid JDWP agent.  is_path==true denotes that we
2250 // are dealing with -agentpath (case where name is a path), otherwise with
2251 // -agentlib
2252 bool valid_jdwp_agent(char *name, bool is_path) {
2253   char *_name;
2254   const char *_jdwp = "jdwp";
2255   size_t _len_jdwp, _len_prefix;
2256 
2257   if (is_path) {
2258     if ((_name = strrchr(name, (int) *os::file_separator())) == NULL) {
2259       return false;
2260     }
2261 
2262     _name++;  // skip past last path separator
2263     _len_prefix = strlen(JNI_LIB_PREFIX);
2264 
2265     if (strncmp(_name, JNI_LIB_PREFIX, _len_prefix) != 0) {
2266       return false;
2267     }
2268 
2269     _name += _len_prefix;
2270     _len_jdwp = strlen(_jdwp);
2271 
2272     if (strncmp(_name, _jdwp, _len_jdwp) == 0) {
2273       _name += _len_jdwp;
2274     }
2275     else {
2276       return false;
2277     }
2278 
2279     if (strcmp(_name, JNI_LIB_SUFFIX) != 0) {
2280       return false;
2281     }
2282 
2283     return true;
2284   }
2285 
2286   if (strcmp(name, _jdwp) == 0) {
2287     return true;
2288   }
2289 
2290   return false;
2291 }
2292 
2293 int Arguments::process_patch_mod_option(const char* patch_mod_tail, bool* patch_mod_javabase) {
2294   // --patch-module=<module>=<file>(<pathsep><file>)*
2295   assert(patch_mod_tail != NULL, "Unexpected NULL patch-module value");
2296   // Find the equal sign between the module name and the path specification
2297   const char* module_equal = strchr(patch_mod_tail, '=');
2298   if (module_equal == NULL) {
2299     jio_fprintf(defaultStream::output_stream(), "Missing '=' in --patch-module specification\n");
2300     return JNI_ERR;
2301   } else {
2302     // Pick out the module name
2303     size_t module_len = module_equal - patch_mod_tail;
2304     char* module_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, module_len+1, mtArguments);
2305     if (module_name != NULL) {
2306       memcpy(module_name, patch_mod_tail, module_len);
2307       *(module_name + module_len) = '\0';
2308       // The path piece begins one past the module_equal sign
2309       add_patch_mod_prefix(module_name, module_equal + 1, patch_mod_javabase);
2310       FREE_C_HEAP_ARRAY(char, module_name);
2311       if (!create_numbered_module_property("jdk.module.patch", patch_mod_tail, patch_mod_count++)) {
2312         return JNI_ENOMEM;
2313       }
2314     } else {
2315       return JNI_ENOMEM;
2316     }
2317   }
2318   return JNI_OK;
2319 }
2320 
2321 // Parse -Xss memory string parameter and convert to ThreadStackSize in K.
2322 jint Arguments::parse_xss(const JavaVMOption* option, const char* tail, intx* out_ThreadStackSize) {
2323   // The min and max sizes match the values in globals.hpp, but scaled
2324   // with K. The values have been chosen so that alignment with page
2325   // size doesn't change the max value, which makes the conversions
2326   // back and forth between Xss value and ThreadStackSize value easier.
2327   // The values have also been chosen to fit inside a 32-bit signed type.
2328   const julong min_ThreadStackSize = 0;
2329   const julong max_ThreadStackSize = 1 * M;
2330 
2331   // Make sure the above values match the range set in globals.hpp
2332   const JVMTypedFlagLimit<intx>* limit = JVMFlagLimit::get_range_at(FLAG_MEMBER_ENUM(ThreadStackSize))->cast<intx>();
2333   assert(min_ThreadStackSize == static_cast<julong>(limit->min()), "must be");
2334   assert(max_ThreadStackSize == static_cast<julong>(limit->max()), "must be");
2335 
2336   const julong min_size = min_ThreadStackSize * K;
2337   const julong max_size = max_ThreadStackSize * K;
2338 
2339   assert(is_aligned(max_size, os::vm_page_size()), "Implementation assumption");
2340 
2341   julong size = 0;
2342   ArgsRange errcode = parse_memory_size(tail, &size, min_size, max_size);
2343   if (errcode != arg_in_range) {
2344     bool silent = (option == NULL); // Allow testing to silence error messages
2345     if (!silent) {
2346       jio_fprintf(defaultStream::error_stream(),
2347                   "Invalid thread stack size: %s\n", option->optionString);
2348       describe_range_error(errcode);
2349     }
2350     return JNI_EINVAL;
2351   }
2352 
2353   // Internally track ThreadStackSize in units of 1024 bytes.
2354   const julong size_aligned = align_up(size, K);
2355   assert(size <= size_aligned,
2356          "Overflow: " JULONG_FORMAT " " JULONG_FORMAT,
2357          size, size_aligned);
2358 
2359   const julong size_in_K = size_aligned / K;
2360   assert(size_in_K < (julong)max_intx,
2361          "size_in_K doesn't fit in the type of ThreadStackSize: " JULONG_FORMAT,
2362          size_in_K);
2363 
2364   // Check that code expanding ThreadStackSize to a page aligned number of bytes won't overflow.
2365   const julong max_expanded = align_up(size_in_K * K, os::vm_page_size());
2366   assert(max_expanded < max_uintx && max_expanded >= size_in_K,
2367          "Expansion overflowed: " JULONG_FORMAT " " JULONG_FORMAT,
2368          max_expanded, size_in_K);
2369 
2370   *out_ThreadStackSize = (intx)size_in_K;
2371 
2372   return JNI_OK;
2373 }
2374 
2375 jint Arguments::parse_each_vm_init_arg(const JavaVMInitArgs* args, bool* patch_mod_javabase, JVMFlagOrigin origin) {
2376   // For match_option to return remaining or value part of option string
2377   const char* tail;
2378 
2379   // iterate over arguments
2380   for (int index = 0; index < args->nOptions; index++) {
2381     bool is_absolute_path = false;  // for -agentpath vs -agentlib
2382 
2383     const JavaVMOption* option = args->options + index;
2384 
2385     if (!match_option(option, "-Djava.class.path", &tail) &&
2386         !match_option(option, "-Dsun.java.command", &tail) &&
2387         !match_option(option, "-Dsun.java.launcher", &tail)) {
2388 
2389         // add all jvm options to the jvm_args string. This string
2390         // is used later to set the java.vm.args PerfData string constant.
2391         // the -Djava.class.path and the -Dsun.java.command options are
2392         // omitted from jvm_args string as each have their own PerfData
2393         // string constant object.
2394         build_jvm_args(option->optionString);
2395     }
2396 
2397     // -verbose:[class/module/gc/jni]
2398     if (match_option(option, "-verbose", &tail)) {
2399       if (!strcmp(tail, ":class") || !strcmp(tail, "")) {
2400         LogConfiguration::configure_stdout(LogLevel::Info, true, LOG_TAGS(class, load));
2401         LogConfiguration::configure_stdout(LogLevel::Info, true, LOG_TAGS(class, unload));
2402       } else if (!strcmp(tail, ":module")) {
2403         LogConfiguration::configure_stdout(LogLevel::Info, true, LOG_TAGS(module, load));
2404         LogConfiguration::configure_stdout(LogLevel::Info, true, LOG_TAGS(module, unload));
2405       } else if (!strcmp(tail, ":gc")) {
2406         if (_legacyGCLogging.lastFlag == 0) {
2407           _legacyGCLogging.lastFlag = 1;
2408         }
2409       } else if (!strcmp(tail, ":jni")) {
2410         LogConfiguration::configure_stdout(LogLevel::Debug, true, LOG_TAGS(jni, resolve));
2411       }
2412     // -da / -ea / -disableassertions / -enableassertions
2413     // These accept an optional class/package name separated by a colon, e.g.,
2414     // -da:java.lang.Thread.
2415     } else if (match_option(option, user_assertion_options, &tail, true)) {
2416       bool enable = option->optionString[1] == 'e';     // char after '-' is 'e'
2417       if (*tail == '\0') {
2418         JavaAssertions::setUserClassDefault(enable);
2419       } else {
2420         assert(*tail == ':', "bogus match by match_option()");
2421         JavaAssertions::addOption(tail + 1, enable);
2422       }
2423     // -dsa / -esa / -disablesystemassertions / -enablesystemassertions
2424     } else if (match_option(option, system_assertion_options, &tail, false)) {
2425       bool enable = option->optionString[1] == 'e';     // char after '-' is 'e'
2426       JavaAssertions::setSystemClassDefault(enable);
2427     // -bootclasspath:
2428     } else if (match_option(option, "-Xbootclasspath:", &tail)) {
2429         jio_fprintf(defaultStream::output_stream(),
2430           "-Xbootclasspath is no longer a supported option.\n");
2431         return JNI_EINVAL;
2432     // -bootclasspath/a:
2433     } else if (match_option(option, "-Xbootclasspath/a:", &tail)) {
2434       Arguments::append_sysclasspath(tail);
2435 #if INCLUDE_CDS
2436       MetaspaceShared::disable_optimized_module_handling();
2437       log_info(cds)("optimized module handling: disabled because bootclasspath was appended");
2438 #endif
2439     // -bootclasspath/p:
2440     } else if (match_option(option, "-Xbootclasspath/p:", &tail)) {
2441         jio_fprintf(defaultStream::output_stream(),
2442           "-Xbootclasspath/p is no longer a supported option.\n");
2443         return JNI_EINVAL;
2444     // -Xrun
2445     } else if (match_option(option, "-Xrun", &tail)) {
2446       if (tail != NULL) {
2447         const char* pos = strchr(tail, ':');
2448         size_t len = (pos == NULL) ? strlen(tail) : pos - tail;
2449         char* name = NEW_C_HEAP_ARRAY(char, len + 1, mtArguments);
2450         jio_snprintf(name, len + 1, "%s", tail);
2451 
2452         char *options = NULL;
2453         if(pos != NULL) {
2454           size_t len2 = strlen(pos+1) + 1; // options start after ':'.  Final zero must be copied.
2455           options = (char*)memcpy(NEW_C_HEAP_ARRAY(char, len2, mtArguments), pos+1, len2);
2456         }
2457 #if !INCLUDE_JVMTI
2458         if (strcmp(name, "jdwp") == 0) {
2459           jio_fprintf(defaultStream::error_stream(),
2460             "Debugging agents are not supported in this VM\n");
2461           return JNI_ERR;
2462         }
2463 #endif // !INCLUDE_JVMTI
2464         add_init_library(name, options);
2465       }
2466     } else if (match_option(option, "--add-reads=", &tail)) {
2467       if (!create_numbered_module_property("jdk.module.addreads", tail, addreads_count++)) {
2468         return JNI_ENOMEM;
2469       }
2470     } else if (match_option(option, "--add-exports=", &tail)) {
2471       if (!create_numbered_module_property("jdk.module.addexports", tail, addexports_count++)) {
2472         return JNI_ENOMEM;
2473       }
2474     } else if (match_option(option, "--add-opens=", &tail)) {
2475       if (!create_numbered_module_property("jdk.module.addopens", tail, addopens_count++)) {
2476         return JNI_ENOMEM;
2477       }
2478     } else if (match_option(option, "--add-modules=", &tail)) {
2479       if (!create_numbered_module_property("jdk.module.addmods", tail, addmods_count++)) {
2480         return JNI_ENOMEM;
2481       }
2482     } else if (match_option(option, "--enable-native-access=", &tail)) {
2483       if (!create_numbered_module_property("jdk.module.enable.native.access", tail, enable_native_access_count++)) {
2484         return JNI_ENOMEM;
2485       }
2486     } else if (match_option(option, "--limit-modules=", &tail)) {
2487       if (!create_module_property("jdk.module.limitmods", tail, InternalProperty)) {
2488         return JNI_ENOMEM;
2489       }
2490     } else if (match_option(option, "--module-path=", &tail)) {
2491       if (!create_module_property("jdk.module.path", tail, ExternalProperty)) {
2492         return JNI_ENOMEM;
2493       }
2494     } else if (match_option(option, "--upgrade-module-path=", &tail)) {
2495       if (!create_module_property("jdk.module.upgrade.path", tail, ExternalProperty)) {
2496         return JNI_ENOMEM;
2497       }
2498     } else if (match_option(option, "--patch-module=", &tail)) {
2499       // --patch-module=<module>=<file>(<pathsep><file>)*
2500       int res = process_patch_mod_option(tail, patch_mod_javabase);
2501       if (res != JNI_OK) {
2502         return res;
2503       }
2504     } else if (match_option(option, "--illegal-access=", &tail)) {
2505       char version[256];
2506       JDK_Version::jdk(17).to_string(version, sizeof(version));
2507       warning("Ignoring option %s; support was removed in %s", option->optionString, version);
2508     // -agentlib and -agentpath
2509     } else if (match_option(option, "-agentlib:", &tail) ||
2510           (is_absolute_path = match_option(option, "-agentpath:", &tail))) {
2511       if(tail != NULL) {
2512         const char* pos = strchr(tail, '=');
2513         char* name;
2514         if (pos == NULL) {
2515           name = os::strdup_check_oom(tail, mtArguments);
2516         } else {
2517           size_t len = pos - tail;
2518           name = NEW_C_HEAP_ARRAY(char, len + 1, mtArguments);
2519           memcpy(name, tail, len);
2520           name[len] = '\0';
2521         }
2522 
2523         char *options = NULL;
2524         if(pos != NULL) {
2525           options = os::strdup_check_oom(pos + 1, mtArguments);
2526         }
2527 #if !INCLUDE_JVMTI
2528         if (valid_jdwp_agent(name, is_absolute_path)) {
2529           jio_fprintf(defaultStream::error_stream(),
2530             "Debugging agents are not supported in this VM\n");
2531           return JNI_ERR;
2532         }
2533 #endif // !INCLUDE_JVMTI
2534         add_init_agent(name, options, is_absolute_path);
2535       }
2536     // -javaagent
2537     } else if (match_option(option, "-javaagent:", &tail)) {
2538 #if !INCLUDE_JVMTI
2539       jio_fprintf(defaultStream::error_stream(),
2540         "Instrumentation agents are not supported in this VM\n");
2541       return JNI_ERR;
2542 #else
2543       if (tail != NULL) {
2544         size_t length = strlen(tail) + 1;
2545         char *options = NEW_C_HEAP_ARRAY(char, length, mtArguments);
2546         jio_snprintf(options, length, "%s", tail);
2547         add_instrument_agent("instrument", options, false);
2548         // java agents need module java.instrument
2549         if (!create_numbered_module_property("jdk.module.addmods", "java.instrument", addmods_count++)) {
2550           return JNI_ENOMEM;
2551         }
2552       }
2553 #endif // !INCLUDE_JVMTI
2554     // --enable_preview
2555     } else if (match_option(option, "--enable-preview")) {
2556       set_enable_preview();
2557     // -Xnoclassgc
2558     } else if (match_option(option, "-Xnoclassgc")) {
2559       if (FLAG_SET_CMDLINE(ClassUnloading, false) != JVMFlag::SUCCESS) {
2560         return JNI_EINVAL;
2561       }
2562     // -Xbatch
2563     } else if (match_option(option, "-Xbatch")) {
2564       if (FLAG_SET_CMDLINE(BackgroundCompilation, false) != JVMFlag::SUCCESS) {
2565         return JNI_EINVAL;
2566       }
2567     // -Xmn for compatibility with other JVM vendors
2568     } else if (match_option(option, "-Xmn", &tail)) {
2569       julong long_initial_young_size = 0;
2570       ArgsRange errcode = parse_memory_size(tail, &long_initial_young_size, 1);
2571       if (errcode != arg_in_range) {
2572         jio_fprintf(defaultStream::error_stream(),
2573                     "Invalid initial young generation size: %s\n", option->optionString);
2574         describe_range_error(errcode);
2575         return JNI_EINVAL;
2576       }
2577       if (FLAG_SET_CMDLINE(MaxNewSize, (size_t)long_initial_young_size) != JVMFlag::SUCCESS) {
2578         return JNI_EINVAL;
2579       }
2580       if (FLAG_SET_CMDLINE(NewSize, (size_t)long_initial_young_size) != JVMFlag::SUCCESS) {
2581         return JNI_EINVAL;
2582       }
2583     // -Xms
2584     } else if (match_option(option, "-Xms", &tail)) {
2585       julong size = 0;
2586       // an initial heap size of 0 means automatically determine
2587       ArgsRange errcode = parse_memory_size(tail, &size, 0);
2588       if (errcode != arg_in_range) {
2589         jio_fprintf(defaultStream::error_stream(),
2590                     "Invalid initial heap size: %s\n", option->optionString);
2591         describe_range_error(errcode);
2592         return JNI_EINVAL;
2593       }
2594       if (FLAG_SET_CMDLINE(MinHeapSize, (size_t)size) != JVMFlag::SUCCESS) {
2595         return JNI_EINVAL;
2596       }
2597       if (FLAG_SET_CMDLINE(InitialHeapSize, (size_t)size) != JVMFlag::SUCCESS) {
2598         return JNI_EINVAL;
2599       }
2600     // -Xmx
2601     } else if (match_option(option, "-Xmx", &tail) || match_option(option, "-XX:MaxHeapSize=", &tail)) {
2602       julong long_max_heap_size = 0;
2603       ArgsRange errcode = parse_memory_size(tail, &long_max_heap_size, 1);
2604       if (errcode != arg_in_range) {
2605         jio_fprintf(defaultStream::error_stream(),
2606                     "Invalid maximum heap size: %s\n", option->optionString);
2607         describe_range_error(errcode);
2608         return JNI_EINVAL;
2609       }
2610       if (FLAG_SET_CMDLINE(MaxHeapSize, (size_t)long_max_heap_size) != JVMFlag::SUCCESS) {
2611         return JNI_EINVAL;
2612       }
2613     // Xmaxf
2614     } else if (match_option(option, "-Xmaxf", &tail)) {
2615       char* err;
2616       int maxf = (int)(strtod(tail, &err) * 100);
2617       if (*err != '\0' || *tail == '\0') {
2618         jio_fprintf(defaultStream::error_stream(),
2619                     "Bad max heap free percentage size: %s\n",
2620                     option->optionString);
2621         return JNI_EINVAL;
2622       } else {
2623         if (FLAG_SET_CMDLINE(MaxHeapFreeRatio, maxf) != JVMFlag::SUCCESS) {
2624             return JNI_EINVAL;
2625         }
2626       }
2627     // Xminf
2628     } else if (match_option(option, "-Xminf", &tail)) {
2629       char* err;
2630       int minf = (int)(strtod(tail, &err) * 100);
2631       if (*err != '\0' || *tail == '\0') {
2632         jio_fprintf(defaultStream::error_stream(),
2633                     "Bad min heap free percentage size: %s\n",
2634                     option->optionString);
2635         return JNI_EINVAL;
2636       } else {
2637         if (FLAG_SET_CMDLINE(MinHeapFreeRatio, minf) != JVMFlag::SUCCESS) {
2638           return JNI_EINVAL;
2639         }
2640       }
2641     // -Xss
2642     } else if (match_option(option, "-Xss", &tail)) {
2643       intx value = 0;
2644       jint err = parse_xss(option, tail, &value);
2645       if (err != JNI_OK) {
2646         return err;
2647       }
2648       if (FLAG_SET_CMDLINE(ThreadStackSize, value) != JVMFlag::SUCCESS) {
2649         return JNI_EINVAL;
2650       }
2651     } else if (match_option(option, "-Xmaxjitcodesize", &tail) ||
2652                match_option(option, "-XX:ReservedCodeCacheSize=", &tail)) {
2653       julong long_ReservedCodeCacheSize = 0;
2654 
2655       ArgsRange errcode = parse_memory_size(tail, &long_ReservedCodeCacheSize, 1);
2656       if (errcode != arg_in_range) {
2657         jio_fprintf(defaultStream::error_stream(),
2658                     "Invalid maximum code cache size: %s.\n", option->optionString);
2659         return JNI_EINVAL;
2660       }
2661       if (FLAG_SET_CMDLINE(ReservedCodeCacheSize, (uintx)long_ReservedCodeCacheSize) != JVMFlag::SUCCESS) {
2662         return JNI_EINVAL;
2663       }
2664     // -green
2665     } else if (match_option(option, "-green")) {
2666       jio_fprintf(defaultStream::error_stream(),
2667                   "Green threads support not available\n");
2668           return JNI_EINVAL;
2669     // -native
2670     } else if (match_option(option, "-native")) {
2671           // HotSpot always uses native threads, ignore silently for compatibility
2672     // -Xrs
2673     } else if (match_option(option, "-Xrs")) {
2674           // Classic/EVM option, new functionality
2675       if (FLAG_SET_CMDLINE(ReduceSignalUsage, true) != JVMFlag::SUCCESS) {
2676         return JNI_EINVAL;
2677       }
2678       // -Xprof
2679     } else if (match_option(option, "-Xprof")) {
2680       char version[256];
2681       // Obsolete in JDK 10
2682       JDK_Version::jdk(10).to_string(version, sizeof(version));
2683       warning("Ignoring option %s; support was removed in %s", option->optionString, version);
2684     // -Xinternalversion
2685     } else if (match_option(option, "-Xinternalversion")) {
2686       jio_fprintf(defaultStream::output_stream(), "%s\n",
2687                   VM_Version::internal_vm_info_string());
2688       vm_exit(0);
2689 #ifndef PRODUCT
2690     // -Xprintflags
2691     } else if (match_option(option, "-Xprintflags")) {
2692       JVMFlag::printFlags(tty, false);
2693       vm_exit(0);
2694 #endif
2695     // -D
2696     } else if (match_option(option, "-D", &tail)) {
2697       const char* value;
2698       if (match_option(option, "-Djava.endorsed.dirs=", &value) &&
2699             *value!= '\0' && strcmp(value, "\"\"") != 0) {
2700         // abort if -Djava.endorsed.dirs is set
2701         jio_fprintf(defaultStream::output_stream(),
2702           "-Djava.endorsed.dirs=%s is not supported. Endorsed standards and standalone APIs\n"
2703           "in modular form will be supported via the concept of upgradeable modules.\n", value);
2704         return JNI_EINVAL;
2705       }
2706       if (match_option(option, "-Djava.ext.dirs=", &value) &&
2707             *value != '\0' && strcmp(value, "\"\"") != 0) {
2708         // abort if -Djava.ext.dirs is set
2709         jio_fprintf(defaultStream::output_stream(),
2710           "-Djava.ext.dirs=%s is not supported.  Use -classpath instead.\n", value);
2711         return JNI_EINVAL;
2712       }
2713       // Check for module related properties.  They must be set using the modules
2714       // options. For example: use "--add-modules=java.sql", not
2715       // "-Djdk.module.addmods=java.sql"
2716       if (is_internal_module_property(option->optionString + 2)) {
2717         needs_module_property_warning = true;
2718         continue;
2719       }
2720       if (!add_property(tail)) {
2721         return JNI_ENOMEM;
2722       }
2723       // Out of the box management support
2724       if (match_option(option, "-Dcom.sun.management", &tail)) {
2725 #if INCLUDE_MANAGEMENT
2726         if (FLAG_SET_CMDLINE(ManagementServer, true) != JVMFlag::SUCCESS) {
2727           return JNI_EINVAL;
2728         }
2729         // management agent in module jdk.management.agent
2730         if (!create_numbered_module_property("jdk.module.addmods", "jdk.management.agent", addmods_count++)) {
2731           return JNI_ENOMEM;
2732         }
2733 #else
2734         jio_fprintf(defaultStream::output_stream(),
2735           "-Dcom.sun.management is not supported in this VM.\n");
2736         return JNI_ERR;
2737 #endif
2738       }
2739     // -Xint
2740     } else if (match_option(option, "-Xint")) {
2741           set_mode_flags(_int);
2742     // -Xmixed
2743     } else if (match_option(option, "-Xmixed")) {
2744           set_mode_flags(_mixed);
2745     // -Xcomp
2746     } else if (match_option(option, "-Xcomp")) {
2747       // for testing the compiler; turn off all flags that inhibit compilation
2748           set_mode_flags(_comp);
2749     // -Xshare:dump
2750     } else if (match_option(option, "-Xshare:dump")) {
2751       DumpSharedSpaces = true;
2752     // -Xshare:on
2753     } else if (match_option(option, "-Xshare:on")) {
2754       UseSharedSpaces = true;
2755       RequireSharedSpaces = true;
2756     // -Xshare:auto || -XX:ArchiveClassesAtExit=<archive file>
2757     } else if (match_option(option, "-Xshare:auto")) {
2758       UseSharedSpaces = true;
2759       RequireSharedSpaces = false;
2760       xshare_auto_cmd_line = true;
2761     // -Xshare:off
2762     } else if (match_option(option, "-Xshare:off")) {
2763       UseSharedSpaces = false;
2764       RequireSharedSpaces = false;
2765     // -Xverify
2766     } else if (match_option(option, "-Xverify", &tail)) {
2767       if (strcmp(tail, ":all") == 0 || strcmp(tail, "") == 0) {
2768         if (FLAG_SET_CMDLINE(BytecodeVerificationLocal, true) != JVMFlag::SUCCESS) {
2769           return JNI_EINVAL;
2770         }
2771         if (FLAG_SET_CMDLINE(BytecodeVerificationRemote, true) != JVMFlag::SUCCESS) {
2772           return JNI_EINVAL;
2773         }
2774       } else if (strcmp(tail, ":remote") == 0) {
2775         if (FLAG_SET_CMDLINE(BytecodeVerificationLocal, false) != JVMFlag::SUCCESS) {
2776           return JNI_EINVAL;
2777         }
2778         if (FLAG_SET_CMDLINE(BytecodeVerificationRemote, true) != JVMFlag::SUCCESS) {
2779           return JNI_EINVAL;
2780         }
2781       } else if (strcmp(tail, ":none") == 0) {
2782         if (FLAG_SET_CMDLINE(BytecodeVerificationLocal, false) != JVMFlag::SUCCESS) {
2783           return JNI_EINVAL;
2784         }
2785         if (FLAG_SET_CMDLINE(BytecodeVerificationRemote, false) != JVMFlag::SUCCESS) {
2786           return JNI_EINVAL;
2787         }
2788         warning("Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release.");
2789       } else if (is_bad_option(option, args->ignoreUnrecognized, "verification")) {
2790         return JNI_EINVAL;
2791       }
2792     // -Xdebug
2793     } else if (match_option(option, "-Xdebug")) {
2794       // note this flag has been used, then ignore
2795       set_xdebug_mode(true);
2796     // -Xnoagent
2797     } else if (match_option(option, "-Xnoagent")) {
2798       // For compatibility with classic. HotSpot refuses to load the old style agent.dll.
2799     } else if (match_option(option, "-Xloggc:", &tail)) {
2800       // Deprecated flag to redirect GC output to a file. -Xloggc:<filename>
2801       log_warning(gc)("-Xloggc is deprecated. Will use -Xlog:gc:%s instead.", tail);
2802       _legacyGCLogging.lastFlag = 2;
2803       _legacyGCLogging.file = os::strdup_check_oom(tail);
2804     } else if (match_option(option, "-Xlog", &tail)) {
2805       bool ret = false;
2806       if (strcmp(tail, ":help") == 0) {
2807         fileStream stream(defaultStream::output_stream());
2808         LogConfiguration::print_command_line_help(&stream);
2809         vm_exit(0);
2810       } else if (strcmp(tail, ":disable") == 0) {
2811         LogConfiguration::disable_logging();
2812         ret = true;
2813       } else if (strcmp(tail, ":async") == 0) {
2814         LogConfiguration::set_async_mode(true);
2815         ret = true;
2816       } else if (*tail == '\0') {
2817         ret = LogConfiguration::parse_command_line_arguments();
2818         assert(ret, "-Xlog without arguments should never fail to parse");
2819       } else if (*tail == ':') {
2820         ret = LogConfiguration::parse_command_line_arguments(tail + 1);
2821       }
2822       if (ret == false) {
2823         jio_fprintf(defaultStream::error_stream(),
2824                     "Invalid -Xlog option '-Xlog%s', see error log for details.\n",
2825                     tail);
2826         return JNI_EINVAL;
2827       }
2828     // JNI hooks
2829     } else if (match_option(option, "-Xcheck", &tail)) {
2830       if (!strcmp(tail, ":jni")) {
2831 #if !INCLUDE_JNI_CHECK
2832         warning("JNI CHECKING is not supported in this VM");
2833 #else
2834         CheckJNICalls = true;
2835 #endif // INCLUDE_JNI_CHECK
2836       } else if (is_bad_option(option, args->ignoreUnrecognized,
2837                                      "check")) {
2838         return JNI_EINVAL;
2839       }
2840     } else if (match_option(option, "vfprintf")) {
2841       _vfprintf_hook = CAST_TO_FN_PTR(vfprintf_hook_t, option->extraInfo);
2842     } else if (match_option(option, "exit")) {
2843       _exit_hook = CAST_TO_FN_PTR(exit_hook_t, option->extraInfo);
2844     } else if (match_option(option, "abort")) {
2845       _abort_hook = CAST_TO_FN_PTR(abort_hook_t, option->extraInfo);
2846     // Need to keep consistency of MaxTenuringThreshold and AlwaysTenure/NeverTenure;
2847     // and the last option wins.
2848     } else if (match_option(option, "-XX:+NeverTenure")) {
2849       if (FLAG_SET_CMDLINE(NeverTenure, true) != JVMFlag::SUCCESS) {
2850         return JNI_EINVAL;
2851       }
2852       if (FLAG_SET_CMDLINE(AlwaysTenure, false) != JVMFlag::SUCCESS) {
2853         return JNI_EINVAL;
2854       }
2855       if (FLAG_SET_CMDLINE(MaxTenuringThreshold, markWord::max_age + 1) != JVMFlag::SUCCESS) {
2856         return JNI_EINVAL;
2857       }
2858     } else if (match_option(option, "-XX:+AlwaysTenure")) {
2859       if (FLAG_SET_CMDLINE(NeverTenure, false) != JVMFlag::SUCCESS) {
2860         return JNI_EINVAL;
2861       }
2862       if (FLAG_SET_CMDLINE(AlwaysTenure, true) != JVMFlag::SUCCESS) {
2863         return JNI_EINVAL;
2864       }
2865       if (FLAG_SET_CMDLINE(MaxTenuringThreshold, 0) != JVMFlag::SUCCESS) {
2866         return JNI_EINVAL;
2867       }
2868     } else if (match_option(option, "-XX:MaxTenuringThreshold=", &tail)) {
2869       uintx max_tenuring_thresh = 0;
2870       if (!parse_uintx(tail, &max_tenuring_thresh, 0)) {
2871         jio_fprintf(defaultStream::error_stream(),
2872                     "Improperly specified VM option \'MaxTenuringThreshold=%s\'\n", tail);
2873         return JNI_EINVAL;
2874       }
2875 
2876       if (FLAG_SET_CMDLINE(MaxTenuringThreshold, max_tenuring_thresh) != JVMFlag::SUCCESS) {
2877         return JNI_EINVAL;
2878       }
2879 
2880       if (MaxTenuringThreshold == 0) {
2881         if (FLAG_SET_CMDLINE(NeverTenure, false) != JVMFlag::SUCCESS) {
2882           return JNI_EINVAL;
2883         }
2884         if (FLAG_SET_CMDLINE(AlwaysTenure, true) != JVMFlag::SUCCESS) {
2885           return JNI_EINVAL;
2886         }
2887       } else {
2888         if (FLAG_SET_CMDLINE(NeverTenure, false) != JVMFlag::SUCCESS) {
2889           return JNI_EINVAL;
2890         }
2891         if (FLAG_SET_CMDLINE(AlwaysTenure, false) != JVMFlag::SUCCESS) {
2892           return JNI_EINVAL;
2893         }
2894       }
2895     } else if (match_option(option, "-XX:+DisplayVMOutputToStderr")) {
2896       if (FLAG_SET_CMDLINE(DisplayVMOutputToStdout, false) != JVMFlag::SUCCESS) {
2897         return JNI_EINVAL;
2898       }
2899       if (FLAG_SET_CMDLINE(DisplayVMOutputToStderr, true) != JVMFlag::SUCCESS) {
2900         return JNI_EINVAL;
2901       }
2902     } else if (match_option(option, "-XX:+DisplayVMOutputToStdout")) {
2903       if (FLAG_SET_CMDLINE(DisplayVMOutputToStderr, false) != JVMFlag::SUCCESS) {
2904         return JNI_EINVAL;
2905       }
2906       if (FLAG_SET_CMDLINE(DisplayVMOutputToStdout, true) != JVMFlag::SUCCESS) {
2907         return JNI_EINVAL;
2908       }
2909     } else if (match_option(option, "-XX:+ErrorFileToStderr")) {
2910       if (FLAG_SET_CMDLINE(ErrorFileToStdout, false) != JVMFlag::SUCCESS) {
2911         return JNI_EINVAL;
2912       }
2913       if (FLAG_SET_CMDLINE(ErrorFileToStderr, true) != JVMFlag::SUCCESS) {
2914         return JNI_EINVAL;
2915       }
2916     } else if (match_option(option, "-XX:+ErrorFileToStdout")) {
2917       if (FLAG_SET_CMDLINE(ErrorFileToStderr, false) != JVMFlag::SUCCESS) {
2918         return JNI_EINVAL;
2919       }
2920       if (FLAG_SET_CMDLINE(ErrorFileToStdout, true) != JVMFlag::SUCCESS) {
2921         return JNI_EINVAL;
2922       }
2923     } else if (match_option(option, "--finalization=", &tail)) {
2924       if (strcmp(tail, "enabled") == 0) {
2925         InstanceKlass::set_finalization_enabled(true);
2926       } else if (strcmp(tail, "disabled") == 0) {
2927         InstanceKlass::set_finalization_enabled(false);
2928       } else {
2929         jio_fprintf(defaultStream::error_stream(),
2930                     "Invalid finalization value '%s', must be 'disabled' or 'enabled'.\n",
2931                     tail);
2932         return JNI_EINVAL;
2933       }
2934     } else if (match_option(option, "-XX:+ExtendedDTraceProbes")) {
2935 #if defined(DTRACE_ENABLED)
2936       warning("Option ExtendedDTraceProbes was deprecated in version 19 and will likely be removed in a future release.");
2937       warning("Use the combination of -XX:+DTraceMethodProbes, -XX:+DTraceAllocProbes and -XX:+DTraceMonitorProbes instead.");
2938       if (FLAG_SET_CMDLINE(ExtendedDTraceProbes, true) != JVMFlag::SUCCESS) {
2939         return JNI_EINVAL;
2940       }
2941       if (FLAG_SET_CMDLINE(DTraceMethodProbes, true) != JVMFlag::SUCCESS) {
2942         return JNI_EINVAL;
2943       }
2944       if (FLAG_SET_CMDLINE(DTraceAllocProbes, true) != JVMFlag::SUCCESS) {
2945         return JNI_EINVAL;
2946       }
2947       if (FLAG_SET_CMDLINE(DTraceMonitorProbes, true) != JVMFlag::SUCCESS) {
2948         return JNI_EINVAL;
2949       }
2950 #else // defined(DTRACE_ENABLED)
2951       jio_fprintf(defaultStream::error_stream(),
2952                   "ExtendedDTraceProbes flag is not applicable for this configuration\n");
2953       return JNI_EINVAL;
2954     } else if (match_option(option, "-XX:+DTraceMethodProbes")) {
2955       jio_fprintf(defaultStream::error_stream(),
2956                   "DTraceMethodProbes flag is not applicable for this configuration\n");
2957       return JNI_EINVAL;
2958     } else if (match_option(option, "-XX:+DTraceAllocProbes")) {
2959       jio_fprintf(defaultStream::error_stream(),
2960                   "DTraceAllocProbes flag is not applicable for this configuration\n");
2961       return JNI_EINVAL;
2962     } else if (match_option(option, "-XX:+DTraceMonitorProbes")) {
2963       jio_fprintf(defaultStream::error_stream(),
2964                   "DTraceMonitorProbes flag is not applicable for this configuration\n");
2965       return JNI_EINVAL;
2966 #endif // defined(DTRACE_ENABLED)
2967 #ifdef ASSERT
2968     } else if (match_option(option, "-XX:+FullGCALot")) {
2969       if (FLAG_SET_CMDLINE(FullGCALot, true) != JVMFlag::SUCCESS) {
2970         return JNI_EINVAL;
2971       }
2972       // disable scavenge before parallel mark-compact
2973       if (FLAG_SET_CMDLINE(ScavengeBeforeFullGC, false) != JVMFlag::SUCCESS) {
2974         return JNI_EINVAL;
2975       }
2976 #endif
2977 #if !INCLUDE_MANAGEMENT
2978     } else if (match_option(option, "-XX:+ManagementServer")) {
2979         jio_fprintf(defaultStream::error_stream(),
2980           "ManagementServer is not supported in this VM.\n");
2981         return JNI_ERR;
2982 #endif // INCLUDE_MANAGEMENT
2983 #if INCLUDE_JVMCI
2984     } else if (match_option(option, "-XX:-EnableJVMCIProduct")) {
2985       if (EnableJVMCIProduct) {
2986         jio_fprintf(defaultStream::error_stream(),
2987                   "-XX:-EnableJVMCIProduct cannot come after -XX:+EnableJVMCIProduct\n");
2988         return JNI_EINVAL;
2989       }
2990     } else if (match_option(option, "-XX:+EnableJVMCIProduct")) {
2991       // Just continue, since "-XX:+EnableJVMCIProduct" has been specified before
2992       if (EnableJVMCIProduct) {
2993         continue;
2994       }
2995       JVMFlag *jvmciFlag = JVMFlag::find_flag("EnableJVMCIProduct");
2996       // Allow this flag if it has been unlocked.
2997       if (jvmciFlag != NULL && jvmciFlag->is_unlocked()) {
2998         if (!JVMCIGlobals::enable_jvmci_product_mode(origin)) {
2999           jio_fprintf(defaultStream::error_stream(),
3000             "Unable to enable JVMCI in product mode");
3001           return JNI_ERR;
3002         }
3003       }
3004       // The flag was locked so process normally to report that error
3005       else if (!process_argument("EnableJVMCIProduct", args->ignoreUnrecognized, origin)) {
3006         return JNI_EINVAL;
3007       }
3008 #endif // INCLUDE_JVMCI
3009 #if INCLUDE_JFR
3010     } else if (match_jfr_option(&option)) {
3011       return JNI_EINVAL;
3012 #endif
3013     } else if (match_option(option, "-XX:", &tail)) { // -XX:xxxx
3014       // Skip -XX:Flags= and -XX:VMOptionsFile= since those cases have
3015       // already been handled
3016       if ((strncmp(tail, "Flags=", strlen("Flags=")) != 0) &&
3017           (strncmp(tail, "VMOptionsFile=", strlen("VMOptionsFile=")) != 0)) {
3018         if (!process_argument(tail, args->ignoreUnrecognized, origin)) {
3019           return JNI_EINVAL;
3020         }
3021       }
3022     // Unknown option
3023     } else if (is_bad_option(option, args->ignoreUnrecognized)) {
3024       return JNI_ERR;
3025     }
3026   }
3027 
3028   // PrintSharedArchiveAndExit will turn on
3029   //   -Xshare:on
3030   //   -Xlog:class+path=info
3031   if (PrintSharedArchiveAndExit) {
3032     UseSharedSpaces = true;
3033     RequireSharedSpaces = true;
3034     LogConfiguration::configure_stdout(LogLevel::Info, true, LOG_TAGS(class, path));
3035   }
3036 
3037   fix_appclasspath();
3038 
3039   return JNI_OK;
3040 }
3041 
3042 void Arguments::add_patch_mod_prefix(const char* module_name, const char* path, bool* patch_mod_javabase) {
3043   // For java.base check for duplicate --patch-module options being specified on the command line.
3044   // This check is only required for java.base, all other duplicate module specifications
3045   // will be checked during module system initialization.  The module system initialization
3046   // will throw an ExceptionInInitializerError if this situation occurs.
3047   if (strcmp(module_name, JAVA_BASE_NAME) == 0) {
3048     if (*patch_mod_javabase) {
3049       vm_exit_during_initialization("Cannot specify " JAVA_BASE_NAME " more than once to --patch-module");
3050     } else {
3051       *patch_mod_javabase = true;
3052     }
3053   }
3054 
3055   // Create GrowableArray lazily, only if --patch-module has been specified
3056   if (_patch_mod_prefix == NULL) {
3057     _patch_mod_prefix = new (ResourceObj::C_HEAP, mtArguments) GrowableArray<ModulePatchPath*>(10, mtArguments);
3058   }
3059 
3060   _patch_mod_prefix->push(new ModulePatchPath(module_name, path));
3061 }
3062 
3063 // Remove all empty paths from the app classpath (if IgnoreEmptyClassPaths is enabled)
3064 //
3065 // This is necessary because some apps like to specify classpath like -cp foo.jar:${XYZ}:bar.jar
3066 // in their start-up scripts. If XYZ is empty, the classpath will look like "-cp foo.jar::bar.jar".
3067 // Java treats such empty paths as if the user specified "-cp foo.jar:.:bar.jar". I.e., an empty
3068 // path is treated as the current directory.
3069 //
3070 // This causes problems with CDS, which requires that all directories specified in the classpath
3071 // must be empty. In most cases, applications do NOT want to load classes from the current
3072 // directory anyway. Adding -XX:+IgnoreEmptyClassPaths will make these applications' start-up
3073 // scripts compatible with CDS.
3074 void Arguments::fix_appclasspath() {
3075   if (IgnoreEmptyClassPaths) {
3076     const char separator = *os::path_separator();
3077     const char* src = _java_class_path->value();
3078 
3079     // skip over all the leading empty paths
3080     while (*src == separator) {
3081       src ++;
3082     }
3083 
3084     char* copy = os::strdup_check_oom(src, mtArguments);
3085 
3086     // trim all trailing empty paths
3087     for (char* tail = copy + strlen(copy) - 1; tail >= copy && *tail == separator; tail--) {
3088       *tail = '\0';
3089     }
3090 
3091     char from[3] = {separator, separator, '\0'};
3092     char to  [2] = {separator, '\0'};
3093     while (StringUtils::replace_no_expand(copy, from, to) > 0) {
3094       // Keep replacing "::" -> ":" until we have no more "::" (non-windows)
3095       // Keep replacing ";;" -> ";" until we have no more ";;" (windows)
3096     }
3097 
3098     _java_class_path->set_writeable_value(copy);
3099     FreeHeap(copy); // a copy was made by set_value, so don't need this anymore
3100   }
3101 }
3102 
3103 jint Arguments::finalize_vm_init_args(bool patch_mod_javabase) {
3104   // check if the default lib/endorsed directory exists; if so, error
3105   char path[JVM_MAXPATHLEN];
3106   const char* fileSep = os::file_separator();
3107   jio_snprintf(path, JVM_MAXPATHLEN, "%s%slib%sendorsed", Arguments::get_java_home(), fileSep, fileSep);
3108 
3109   DIR* dir = os::opendir(path);
3110   if (dir != NULL) {
3111     jio_fprintf(defaultStream::output_stream(),
3112       "<JAVA_HOME>/lib/endorsed is not supported. Endorsed standards and standalone APIs\n"
3113       "in modular form will be supported via the concept of upgradeable modules.\n");
3114     os::closedir(dir);
3115     return JNI_ERR;
3116   }
3117 
3118   jio_snprintf(path, JVM_MAXPATHLEN, "%s%slib%sext", Arguments::get_java_home(), fileSep, fileSep);
3119   dir = os::opendir(path);
3120   if (dir != NULL) {
3121     jio_fprintf(defaultStream::output_stream(),
3122       "<JAVA_HOME>/lib/ext exists, extensions mechanism no longer supported; "
3123       "Use -classpath instead.\n.");
3124     os::closedir(dir);
3125     return JNI_ERR;
3126   }
3127 
3128   // This must be done after all arguments have been processed
3129   // and the container support has been initialized since AggressiveHeap
3130   // relies on the amount of total memory available.
3131   if (AggressiveHeap) {
3132     jint result = set_aggressive_heap_flags();
3133     if (result != JNI_OK) {
3134       return result;
3135     }
3136   }
3137 
3138   // This must be done after all arguments have been processed.
3139   // java_compiler() true means set to "NONE" or empty.
3140   if (java_compiler() && !xdebug_mode()) {
3141     // For backwards compatibility, we switch to interpreted mode if
3142     // -Djava.compiler="NONE" or "" is specified AND "-Xdebug" was
3143     // not specified.
3144     set_mode_flags(_int);
3145   }
3146 
3147   // CompileThresholdScaling == 0.0 is same as -Xint: Disable compilation (enable interpreter-only mode),
3148   // but like -Xint, leave compilation thresholds unaffected.
3149   // With tiered compilation disabled, setting CompileThreshold to 0 disables compilation as well.
3150   if ((CompileThresholdScaling == 0.0) || (!TieredCompilation && CompileThreshold == 0)) {
3151     set_mode_flags(_int);
3152   }
3153 
3154 #ifdef ZERO
3155   // Zero always runs in interpreted mode
3156   set_mode_flags(_int);
3157 #endif
3158 
3159   // eventually fix up InitialTenuringThreshold if only MaxTenuringThreshold is set
3160   if (FLAG_IS_DEFAULT(InitialTenuringThreshold) && (InitialTenuringThreshold > MaxTenuringThreshold)) {
3161     FLAG_SET_ERGO(InitialTenuringThreshold, MaxTenuringThreshold);
3162   }
3163 
3164 #if !COMPILER2_OR_JVMCI
3165   // Don't degrade server performance for footprint
3166   if (FLAG_IS_DEFAULT(UseLargePages) &&
3167       MaxHeapSize < LargePageHeapSizeThreshold) {
3168     // No need for large granularity pages w/small heaps.
3169     // Note that large pages are enabled/disabled for both the
3170     // Java heap and the code cache.
3171     FLAG_SET_DEFAULT(UseLargePages, false);
3172   }
3173 
3174   UNSUPPORTED_OPTION(ProfileInterpreter);
3175 #endif
3176 
3177   // Parse the CompilationMode flag
3178   if (!CompilationModeFlag::initialize()) {
3179     return JNI_ERR;
3180   }
3181 
3182   if (!check_vm_args_consistency()) {
3183     return JNI_ERR;
3184   }
3185 
3186 #if INCLUDE_CDS
3187   if (DumpSharedSpaces) {
3188     // Compiler threads may concurrently update the class metadata (such as method entries), so it's
3189     // unsafe with -Xshare:dump (which modifies the class metadata in place). Let's disable
3190     // compiler just to be safe.
3191     //
3192     // Note: this is not a concern for dynamically dumping shared spaces, which makes a copy of the
3193     // class metadata instead of modifying them in place. The copy is inaccessible to the compiler.
3194     // TODO: revisit the following for the static archive case.
3195     set_mode_flags(_int);
3196   }
3197 
3198   // RecordDynamicDumpInfo is not compatible with ArchiveClassesAtExit
3199   if (ArchiveClassesAtExit != NULL && RecordDynamicDumpInfo) {
3200     jio_fprintf(defaultStream::output_stream(),
3201                 "-XX:+RecordDynamicDumpInfo cannot be used with -XX:ArchiveClassesAtExit.\n");
3202     return JNI_ERR;
3203   }
3204 
3205   if (ArchiveClassesAtExit == NULL && !RecordDynamicDumpInfo) {
3206     DynamicDumpSharedSpaces = false;
3207   } else {
3208     DynamicDumpSharedSpaces = true;
3209   }
3210 
3211   if (AutoCreateSharedArchive) {
3212     if (SharedArchiveFile == NULL) {
3213       log_warning(cds)("-XX:+AutoCreateSharedArchive requires -XX:SharedArchiveFile");
3214       return JNI_ERR;
3215     }
3216     if (ArchiveClassesAtExit != NULL) {
3217       log_warning(cds)("-XX:+AutoCreateSharedArchive does not work with ArchiveClassesAtExit");
3218       return JNI_ERR;
3219     }
3220   }
3221 
3222   if (UseSharedSpaces && patch_mod_javabase) {
3223     no_shared_spaces("CDS is disabled when " JAVA_BASE_NAME " module is patched.");
3224   }
3225   if (UseSharedSpaces && !DumpSharedSpaces && check_unsupported_cds_runtime_properties()) {
3226     UseSharedSpaces = false;
3227   }
3228 
3229   if (DumpSharedSpaces || DynamicDumpSharedSpaces) {
3230     // Always verify non-system classes during CDS dump
3231     if (!BytecodeVerificationRemote) {
3232       BytecodeVerificationRemote = true;
3233       log_info(cds)("All non-system classes will be verified (-Xverify:remote) during CDS dump time.");
3234     }
3235   }
3236 #endif
3237 
3238 #ifndef CAN_SHOW_REGISTERS_ON_ASSERT
3239   UNSUPPORTED_OPTION(ShowRegistersOnAssert);
3240 #endif // CAN_SHOW_REGISTERS_ON_ASSERT
3241 
3242   return JNI_OK;
3243 }
3244 
3245 // Helper class for controlling the lifetime of JavaVMInitArgs
3246 // objects.  The contents of the JavaVMInitArgs are guaranteed to be
3247 // deleted on the destruction of the ScopedVMInitArgs object.
3248 class ScopedVMInitArgs : public StackObj {
3249  private:
3250   JavaVMInitArgs _args;
3251   char*          _container_name;
3252   bool           _is_set;
3253   char*          _vm_options_file_arg;
3254 
3255  public:
3256   ScopedVMInitArgs(const char *container_name) {
3257     _args.version = JNI_VERSION_1_2;
3258     _args.nOptions = 0;
3259     _args.options = NULL;
3260     _args.ignoreUnrecognized = false;
3261     _container_name = (char *)container_name;
3262     _is_set = false;
3263     _vm_options_file_arg = NULL;
3264   }
3265 
3266   // Populates the JavaVMInitArgs object represented by this
3267   // ScopedVMInitArgs object with the arguments in options.  The
3268   // allocated memory is deleted by the destructor.  If this method
3269   // returns anything other than JNI_OK, then this object is in a
3270   // partially constructed state, and should be abandoned.
3271   jint set_args(const GrowableArrayView<JavaVMOption>* options) {
3272     _is_set = true;
3273     JavaVMOption* options_arr = NEW_C_HEAP_ARRAY_RETURN_NULL(
3274         JavaVMOption, options->length(), mtArguments);
3275     if (options_arr == NULL) {
3276       return JNI_ENOMEM;
3277     }
3278     _args.options = options_arr;
3279 
3280     for (int i = 0; i < options->length(); i++) {
3281       options_arr[i] = options->at(i);
3282       options_arr[i].optionString = os::strdup(options_arr[i].optionString);
3283       if (options_arr[i].optionString == NULL) {
3284         // Rely on the destructor to do cleanup.
3285         _args.nOptions = i;
3286         return JNI_ENOMEM;
3287       }
3288     }
3289 
3290     _args.nOptions = options->length();
3291     _args.ignoreUnrecognized = IgnoreUnrecognizedVMOptions;
3292     return JNI_OK;
3293   }
3294 
3295   JavaVMInitArgs* get()             { return &_args; }
3296   char* container_name()            { return _container_name; }
3297   bool  is_set()                    { return _is_set; }
3298   bool  found_vm_options_file_arg() { return _vm_options_file_arg != NULL; }
3299   char* vm_options_file_arg()       { return _vm_options_file_arg; }
3300 
3301   void set_vm_options_file_arg(const char *vm_options_file_arg) {
3302     if (_vm_options_file_arg != NULL) {
3303       os::free(_vm_options_file_arg);
3304     }
3305     _vm_options_file_arg = os::strdup_check_oom(vm_options_file_arg);
3306   }
3307 
3308   ~ScopedVMInitArgs() {
3309     if (_vm_options_file_arg != NULL) {
3310       os::free(_vm_options_file_arg);
3311     }
3312     if (_args.options == NULL) return;
3313     for (int i = 0; i < _args.nOptions; i++) {
3314       os::free(_args.options[i].optionString);
3315     }
3316     FREE_C_HEAP_ARRAY(JavaVMOption, _args.options);
3317   }
3318 
3319   // Insert options into this option list, to replace option at
3320   // vm_options_file_pos (-XX:VMOptionsFile)
3321   jint insert(const JavaVMInitArgs* args,
3322               const JavaVMInitArgs* args_to_insert,
3323               const int vm_options_file_pos) {
3324     assert(_args.options == NULL, "shouldn't be set yet");
3325     assert(args_to_insert->nOptions != 0, "there should be args to insert");
3326     assert(vm_options_file_pos != -1, "vm_options_file_pos should be set");
3327 
3328     int length = args->nOptions + args_to_insert->nOptions - 1;
3329     // Construct new option array
3330     GrowableArrayCHeap<JavaVMOption, mtArguments> options(length);
3331     for (int i = 0; i < args->nOptions; i++) {
3332       if (i == vm_options_file_pos) {
3333         // insert the new options starting at the same place as the
3334         // -XX:VMOptionsFile option
3335         for (int j = 0; j < args_to_insert->nOptions; j++) {
3336           options.push(args_to_insert->options[j]);
3337         }
3338       } else {
3339         options.push(args->options[i]);
3340       }
3341     }
3342     // make into options array
3343     return set_args(&options);
3344   }
3345 };
3346 
3347 jint Arguments::parse_java_options_environment_variable(ScopedVMInitArgs* args) {
3348   return parse_options_environment_variable("_JAVA_OPTIONS", args);
3349 }
3350 
3351 jint Arguments::parse_java_tool_options_environment_variable(ScopedVMInitArgs* args) {
3352   return parse_options_environment_variable("JAVA_TOOL_OPTIONS", args);
3353 }
3354 
3355 jint Arguments::parse_options_environment_variable(const char* name,
3356                                                    ScopedVMInitArgs* vm_args) {
3357   char *buffer = ::getenv(name);
3358 
3359   // Don't check this environment variable if user has special privileges
3360   // (e.g. unix su command).
3361   if (buffer == NULL || os::have_special_privileges()) {
3362     return JNI_OK;
3363   }
3364 
3365   if ((buffer = os::strdup(buffer)) == NULL) {
3366     return JNI_ENOMEM;
3367   }
3368 
3369   jio_fprintf(defaultStream::error_stream(),
3370               "Picked up %s: %s\n", name, buffer);
3371 
3372   int retcode = parse_options_buffer(name, buffer, strlen(buffer), vm_args);
3373 
3374   os::free(buffer);
3375   return retcode;
3376 }
3377 
3378 jint Arguments::parse_vm_options_file(const char* file_name, ScopedVMInitArgs* vm_args) {
3379   // read file into buffer
3380   int fd = ::open(file_name, O_RDONLY);
3381   if (fd < 0) {
3382     jio_fprintf(defaultStream::error_stream(),
3383                 "Could not open options file '%s'\n",
3384                 file_name);
3385     return JNI_ERR;
3386   }
3387 
3388   struct stat stbuf;
3389   int retcode = os::stat(file_name, &stbuf);
3390   if (retcode != 0) {
3391     jio_fprintf(defaultStream::error_stream(),
3392                 "Could not stat options file '%s'\n",
3393                 file_name);
3394     ::close(fd);
3395     return JNI_ERR;
3396   }
3397 
3398   if (stbuf.st_size == 0) {
3399     // tell caller there is no option data and that is ok
3400     ::close(fd);
3401     return JNI_OK;
3402   }
3403 
3404   // '+ 1' for NULL termination even with max bytes
3405   size_t bytes_alloc = stbuf.st_size + 1;
3406 
3407   char *buf = NEW_C_HEAP_ARRAY_RETURN_NULL(char, bytes_alloc, mtArguments);
3408   if (NULL == buf) {
3409     jio_fprintf(defaultStream::error_stream(),
3410                 "Could not allocate read buffer for options file parse\n");
3411     ::close(fd);
3412     return JNI_ENOMEM;
3413   }
3414 
3415   memset(buf, 0, bytes_alloc);
3416 
3417   // Fill buffer
3418   ssize_t bytes_read = ::read(fd, (void *)buf, (unsigned)bytes_alloc);
3419   ::close(fd);
3420   if (bytes_read < 0) {
3421     FREE_C_HEAP_ARRAY(char, buf);
3422     jio_fprintf(defaultStream::error_stream(),
3423                 "Could not read options file '%s'\n", file_name);
3424     return JNI_ERR;
3425   }
3426 
3427   if (bytes_read == 0) {
3428     // tell caller there is no option data and that is ok
3429     FREE_C_HEAP_ARRAY(char, buf);
3430     return JNI_OK;
3431   }
3432 
3433   retcode = parse_options_buffer(file_name, buf, bytes_read, vm_args);
3434 
3435   FREE_C_HEAP_ARRAY(char, buf);
3436   return retcode;
3437 }
3438 
3439 jint Arguments::parse_options_buffer(const char* name, char* buffer, const size_t buf_len, ScopedVMInitArgs* vm_args) {
3440   // Construct option array
3441   GrowableArrayCHeap<JavaVMOption, mtArguments> options(2);
3442 
3443   // some pointers to help with parsing
3444   char *buffer_end = buffer + buf_len;
3445   char *opt_hd = buffer;
3446   char *wrt = buffer;
3447   char *rd = buffer;
3448 
3449   // parse all options
3450   while (rd < buffer_end) {
3451     // skip leading white space from the input string
3452     while (rd < buffer_end && isspace(*rd)) {
3453       rd++;
3454     }
3455 
3456     if (rd >= buffer_end) {
3457       break;
3458     }
3459 
3460     // Remember this is where we found the head of the token.
3461     opt_hd = wrt;
3462 
3463     // Tokens are strings of non white space characters separated
3464     // by one or more white spaces.
3465     while (rd < buffer_end && !isspace(*rd)) {
3466       if (*rd == '\'' || *rd == '"') {      // handle a quoted string
3467         int quote = *rd;                    // matching quote to look for
3468         rd++;                               // don't copy open quote
3469         while (rd < buffer_end && *rd != quote) {
3470                                             // include everything (even spaces)
3471                                             // up until the close quote
3472           *wrt++ = *rd++;                   // copy to option string
3473         }
3474 
3475         if (rd < buffer_end) {
3476           rd++;                             // don't copy close quote
3477         } else {
3478                                             // did not see closing quote
3479           jio_fprintf(defaultStream::error_stream(),
3480                       "Unmatched quote in %s\n", name);
3481           return JNI_ERR;
3482         }
3483       } else {
3484         *wrt++ = *rd++;                     // copy to option string
3485       }
3486     }
3487 
3488     // steal a white space character and set it to NULL
3489     *wrt++ = '\0';
3490     // We now have a complete token
3491 
3492     JavaVMOption option;
3493     option.optionString = opt_hd;
3494     option.extraInfo = NULL;
3495 
3496     options.append(option);                // Fill in option
3497 
3498     rd++;  // Advance to next character
3499   }
3500 
3501   // Fill out JavaVMInitArgs structure.
3502   return vm_args->set_args(&options);
3503 }
3504 
3505 void Arguments::set_shared_spaces_flags_and_archive_paths() {
3506   if (DumpSharedSpaces) {
3507     if (RequireSharedSpaces) {
3508       warning("Cannot dump shared archive while using shared archive");
3509     }
3510     UseSharedSpaces = false;
3511   }
3512 #if INCLUDE_CDS
3513   // Initialize shared archive paths which could include both base and dynamic archive paths
3514   // This must be after set_ergonomics_flags() called so flag UseCompressedOops is set properly.
3515   //
3516   // UseSharedSpaces may be disabled if -XX:SharedArchiveFile is invalid.
3517   if (DumpSharedSpaces || UseSharedSpaces) {
3518     init_shared_archive_paths();
3519   }
3520 #endif  // INCLUDE_CDS
3521 }
3522 
3523 #if INCLUDE_CDS
3524 // Sharing support
3525 // Construct the path to the archive
3526 char* Arguments::get_default_shared_archive_path() {
3527   char *default_archive_path;
3528   char jvm_path[JVM_MAXPATHLEN];
3529   os::jvm_path(jvm_path, sizeof(jvm_path));
3530   char *end = strrchr(jvm_path, *os::file_separator());
3531   if (end != NULL) *end = '\0';
3532   size_t jvm_path_len = strlen(jvm_path);
3533   size_t file_sep_len = strlen(os::file_separator());
3534   const size_t len = jvm_path_len + file_sep_len + 20;
3535   default_archive_path = NEW_C_HEAP_ARRAY(char, len, mtArguments);
3536   jio_snprintf(default_archive_path, len,
3537                LP64_ONLY(!UseCompressedOops ? "%s%sclasses_nocoops.jsa":) "%s%sclasses.jsa",
3538                jvm_path, os::file_separator());
3539   return default_archive_path;
3540 }
3541 
3542 int Arguments::num_archives(const char* archive_path) {
3543   if (archive_path == NULL) {
3544     return 0;
3545   }
3546   int npaths = 1;
3547   char* p = (char*)archive_path;
3548   while (*p != '\0') {
3549     if (*p == os::path_separator()[0]) {
3550       npaths++;
3551     }
3552     p++;
3553   }
3554   return npaths;
3555 }
3556 
3557 void Arguments::extract_shared_archive_paths(const char* archive_path,
3558                                          char** base_archive_path,
3559                                          char** top_archive_path) {
3560   char* begin_ptr = (char*)archive_path;
3561   char* end_ptr = strchr((char*)archive_path, os::path_separator()[0]);
3562   if (end_ptr == NULL || end_ptr == begin_ptr) {
3563     vm_exit_during_initialization("Base archive was not specified", archive_path);
3564   }
3565   size_t len = end_ptr - begin_ptr;
3566   char* cur_path = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
3567   strncpy(cur_path, begin_ptr, len);
3568   cur_path[len] = '\0';
3569   *base_archive_path = cur_path;
3570 
3571   begin_ptr = ++end_ptr;
3572   if (*begin_ptr == '\0') {
3573     vm_exit_during_initialization("Top archive was not specified", archive_path);
3574   }
3575   end_ptr = strchr(begin_ptr, '\0');
3576   assert(end_ptr != NULL, "sanity");
3577   len = end_ptr - begin_ptr;
3578   cur_path = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
3579   strncpy(cur_path, begin_ptr, len + 1);
3580   *top_archive_path = cur_path;
3581 }
3582 
3583 void Arguments::init_shared_archive_paths() {
3584   if (ArchiveClassesAtExit != nullptr) {
3585     assert(!RecordDynamicDumpInfo, "already checked");
3586     if (DumpSharedSpaces) {
3587       vm_exit_during_initialization("-XX:ArchiveClassesAtExit cannot be used with -Xshare:dump");
3588     }
3589     check_unsupported_dumping_properties();
3590 
3591     if (os::same_files((const char*)get_default_shared_archive_path(), ArchiveClassesAtExit)) {
3592       vm_exit_during_initialization(
3593         "Cannot specify the default CDS archive for -XX:ArchiveClassesAtExit", get_default_shared_archive_path());
3594     }
3595   }
3596 
3597   if (SharedArchiveFile == nullptr) {
3598     SharedArchivePath = get_default_shared_archive_path();
3599   } else {
3600     int archives = num_archives(SharedArchiveFile);
3601     assert(archives > 0, "must be");
3602 
3603     if (is_dumping_archive() && archives > 1) {
3604       vm_exit_during_initialization(
3605         "Cannot have more than 1 archive file specified in -XX:SharedArchiveFile during CDS dumping");
3606     }
3607 
3608     if (DumpSharedSpaces) {
3609       assert(archives == 1, "must be");
3610       // Static dump is simple: only one archive is allowed in SharedArchiveFile. This file
3611       // will be overwritten no matter regardless of its contents
3612       SharedArchivePath = os::strdup_check_oom(SharedArchiveFile, mtArguments);
3613     } else {
3614       // SharedArchiveFile may specify one or two files. In case (c), the path for base.jsa
3615       // is read from top.jsa
3616       //    (a) 1 file:  -XX:SharedArchiveFile=base.jsa
3617       //    (b) 2 files: -XX:SharedArchiveFile=base.jsa:top.jsa
3618       //    (c) 2 files: -XX:SharedArchiveFile=top.jsa
3619       //
3620       // However, if either RecordDynamicDumpInfo or ArchiveClassesAtExit is used, we do not
3621       // allow cases (b) and (c). Case (b) is already checked above.
3622 
3623       if (archives > 2) {
3624         vm_exit_during_initialization(
3625           "Cannot have more than 2 archive files specified in the -XX:SharedArchiveFile option");
3626       }
3627       if (archives == 1) {
3628         char* base_archive_path = NULL;
3629         bool success =
3630           FileMapInfo::get_base_archive_name_from_header(SharedArchiveFile, &base_archive_path);
3631         if (!success) {
3632           // If +AutoCreateSharedArchive and the specified shared archive does not exist,
3633           // regenerate the dynamic archive base on default archive.
3634           if (AutoCreateSharedArchive && !os::file_exists(SharedArchiveFile)) {
3635             DynamicDumpSharedSpaces = true;
3636             ArchiveClassesAtExit = const_cast<char *>(SharedArchiveFile);
3637             SharedArchivePath = get_default_shared_archive_path();
3638             SharedArchiveFile = nullptr;
3639           } else {
3640             if (AutoCreateSharedArchive) {
3641               warning("-XX:+AutoCreateSharedArchive is unsupported when base CDS archive is not loaded. Run with -Xlog:cds for more info.");
3642               AutoCreateSharedArchive = false;
3643             }
3644             no_shared_spaces("invalid archive");
3645           }
3646         } else if (base_archive_path == NULL) {
3647           // User has specified a single archive, which is a static archive.
3648           SharedArchivePath = const_cast<char *>(SharedArchiveFile);
3649         } else {
3650           // User has specified a single archive, which is a dynamic archive.
3651           SharedDynamicArchivePath = const_cast<char *>(SharedArchiveFile);
3652           SharedArchivePath = base_archive_path; // has been c-heap allocated.
3653         }
3654       } else {
3655         extract_shared_archive_paths((const char*)SharedArchiveFile,
3656                                       &SharedArchivePath, &SharedDynamicArchivePath);
3657         if (SharedArchivePath == NULL) {
3658           assert(SharedDynamicArchivePath == NULL, "must be");
3659           no_shared_spaces("invalid archive");
3660         }
3661       }
3662 
3663       if (SharedDynamicArchivePath != nullptr) {
3664         // Check for case (c)
3665         if (RecordDynamicDumpInfo) {
3666           vm_exit_during_initialization("-XX:+RecordDynamicDumpInfo is unsupported when a dynamic CDS archive is specified in -XX:SharedArchiveFile",
3667                                         SharedArchiveFile);
3668         }
3669         if (ArchiveClassesAtExit != nullptr) {
3670           vm_exit_during_initialization("-XX:ArchiveClassesAtExit is unsupported when a dynamic CDS archive is specified in -XX:SharedArchiveFile",
3671                                         SharedArchiveFile);
3672         }
3673       }
3674 
3675       if (ArchiveClassesAtExit != nullptr && os::same_files(SharedArchiveFile, ArchiveClassesAtExit)) {
3676           vm_exit_during_initialization(
3677             "Cannot have the same archive file specified for -XX:SharedArchiveFile and -XX:ArchiveClassesAtExit",
3678             SharedArchiveFile);
3679       }
3680     }
3681   }
3682 }
3683 #endif // INCLUDE_CDS
3684 
3685 #ifndef PRODUCT
3686 // Determine whether LogVMOutput should be implicitly turned on.
3687 static bool use_vm_log() {
3688   if (LogCompilation || !FLAG_IS_DEFAULT(LogFile) ||
3689       PrintCompilation || PrintInlining || PrintDependencies || PrintNativeNMethods ||
3690       PrintDebugInfo || PrintRelocations || PrintNMethods || PrintExceptionHandlers ||
3691       PrintAssembly || TraceDeoptimization || TraceDependencies ||
3692       (VerifyDependencies && FLAG_IS_CMDLINE(VerifyDependencies))) {
3693     return true;
3694   }
3695 
3696 #ifdef COMPILER1
3697   if (PrintC1Statistics) {
3698     return true;
3699   }
3700 #endif // COMPILER1
3701 
3702 #ifdef COMPILER2
3703   if (PrintOptoAssembly || PrintOptoStatistics) {
3704     return true;
3705   }
3706 #endif // COMPILER2
3707 
3708   return false;
3709 }
3710 
3711 #endif // PRODUCT
3712 
3713 bool Arguments::args_contains_vm_options_file_arg(const JavaVMInitArgs* args) {
3714   for (int index = 0; index < args->nOptions; index++) {
3715     const JavaVMOption* option = args->options + index;
3716     const char* tail;
3717     if (match_option(option, "-XX:VMOptionsFile=", &tail)) {
3718       return true;
3719     }
3720   }
3721   return false;
3722 }
3723 
3724 jint Arguments::insert_vm_options_file(const JavaVMInitArgs* args,
3725                                        const char* vm_options_file,
3726                                        const int vm_options_file_pos,
3727                                        ScopedVMInitArgs* vm_options_file_args,
3728                                        ScopedVMInitArgs* args_out) {
3729   jint code = parse_vm_options_file(vm_options_file, vm_options_file_args);
3730   if (code != JNI_OK) {
3731     return code;
3732   }
3733 
3734   if (vm_options_file_args->get()->nOptions < 1) {
3735     return JNI_OK;
3736   }
3737 
3738   if (args_contains_vm_options_file_arg(vm_options_file_args->get())) {
3739     jio_fprintf(defaultStream::error_stream(),
3740                 "A VM options file may not refer to a VM options file. "
3741                 "Specification of '-XX:VMOptionsFile=<file-name>' in the "
3742                 "options file '%s' in options container '%s' is an error.\n",
3743                 vm_options_file_args->vm_options_file_arg(),
3744                 vm_options_file_args->container_name());
3745     return JNI_EINVAL;
3746   }
3747 
3748   return args_out->insert(args, vm_options_file_args->get(),
3749                           vm_options_file_pos);
3750 }
3751 
3752 // Expand -XX:VMOptionsFile found in args_in as needed.
3753 // mod_args and args_out parameters may return values as needed.
3754 jint Arguments::expand_vm_options_as_needed(const JavaVMInitArgs* args_in,
3755                                             ScopedVMInitArgs* mod_args,
3756                                             JavaVMInitArgs** args_out) {
3757   jint code = match_special_option_and_act(args_in, mod_args);
3758   if (code != JNI_OK) {
3759     return code;
3760   }
3761 
3762   if (mod_args->is_set()) {
3763     // args_in contains -XX:VMOptionsFile and mod_args contains the
3764     // original options from args_in along with the options expanded
3765     // from the VMOptionsFile. Return a short-hand to the caller.
3766     *args_out = mod_args->get();
3767   } else {
3768     *args_out = (JavaVMInitArgs *)args_in;  // no changes so use args_in
3769   }
3770   return JNI_OK;
3771 }
3772 
3773 jint Arguments::match_special_option_and_act(const JavaVMInitArgs* args,
3774                                              ScopedVMInitArgs* args_out) {
3775   // Remaining part of option string
3776   const char* tail;
3777   ScopedVMInitArgs vm_options_file_args(args_out->container_name());
3778 
3779   for (int index = 0; index < args->nOptions; index++) {
3780     const JavaVMOption* option = args->options + index;
3781     if (match_option(option, "-XX:Flags=", &tail)) {
3782       Arguments::set_jvm_flags_file(tail);
3783       continue;
3784     }
3785     if (match_option(option, "-XX:VMOptionsFile=", &tail)) {
3786       if (vm_options_file_args.found_vm_options_file_arg()) {
3787         jio_fprintf(defaultStream::error_stream(),
3788                     "The option '%s' is already specified in the options "
3789                     "container '%s' so the specification of '%s' in the "
3790                     "same options container is an error.\n",
3791                     vm_options_file_args.vm_options_file_arg(),
3792                     vm_options_file_args.container_name(),
3793                     option->optionString);
3794         return JNI_EINVAL;
3795       }
3796       vm_options_file_args.set_vm_options_file_arg(option->optionString);
3797       // If there's a VMOptionsFile, parse that
3798       jint code = insert_vm_options_file(args, tail, index,
3799                                          &vm_options_file_args, args_out);
3800       if (code != JNI_OK) {
3801         return code;
3802       }
3803       args_out->set_vm_options_file_arg(vm_options_file_args.vm_options_file_arg());
3804       if (args_out->is_set()) {
3805         // The VMOptions file inserted some options so switch 'args'
3806         // to the new set of options, and continue processing which
3807         // preserves "last option wins" semantics.
3808         args = args_out->get();
3809         // The first option from the VMOptionsFile replaces the
3810         // current option.  So we back track to process the
3811         // replacement option.
3812         index--;
3813       }
3814       continue;
3815     }
3816     if (match_option(option, "-XX:+PrintVMOptions")) {
3817       PrintVMOptions = true;
3818       continue;
3819     }
3820     if (match_option(option, "-XX:-PrintVMOptions")) {
3821       PrintVMOptions = false;
3822       continue;
3823     }
3824     if (match_option(option, "-XX:+IgnoreUnrecognizedVMOptions")) {
3825       IgnoreUnrecognizedVMOptions = true;
3826       continue;
3827     }
3828     if (match_option(option, "-XX:-IgnoreUnrecognizedVMOptions")) {
3829       IgnoreUnrecognizedVMOptions = false;
3830       continue;
3831     }
3832     if (match_option(option, "-XX:+PrintFlagsInitial")) {
3833       JVMFlag::printFlags(tty, false);
3834       vm_exit(0);
3835     }
3836 
3837 #ifndef PRODUCT
3838     if (match_option(option, "-XX:+PrintFlagsWithComments")) {
3839       JVMFlag::printFlags(tty, true);
3840       vm_exit(0);
3841     }
3842 #endif
3843   }
3844   return JNI_OK;
3845 }
3846 
3847 static void print_options(const JavaVMInitArgs *args) {
3848   const char* tail;
3849   for (int index = 0; index < args->nOptions; index++) {
3850     const JavaVMOption *option = args->options + index;
3851     if (match_option(option, "-XX:", &tail)) {
3852       logOption(tail);
3853     }
3854   }
3855 }
3856 
3857 bool Arguments::handle_deprecated_print_gc_flags() {
3858   if (PrintGC) {
3859     log_warning(gc)("-XX:+PrintGC is deprecated. Will use -Xlog:gc instead.");
3860   }
3861   if (PrintGCDetails) {
3862     log_warning(gc)("-XX:+PrintGCDetails is deprecated. Will use -Xlog:gc* instead.");
3863   }
3864 
3865   if (_legacyGCLogging.lastFlag == 2) {
3866     // -Xloggc was used to specify a filename
3867     const char* gc_conf = PrintGCDetails ? "gc*" : "gc";
3868 
3869     LogTarget(Error, logging) target;
3870     LogStream errstream(target);
3871     return LogConfiguration::parse_log_arguments(_legacyGCLogging.file, gc_conf, NULL, NULL, &errstream);
3872   } else if (PrintGC || PrintGCDetails || (_legacyGCLogging.lastFlag == 1)) {
3873     LogConfiguration::configure_stdout(LogLevel::Info, !PrintGCDetails, LOG_TAGS(gc));
3874   }
3875   return true;
3876 }
3877 
3878 static void apply_debugger_ergo() {
3879   if (ReplayCompiles) {
3880     FLAG_SET_ERGO_IF_DEFAULT(UseDebuggerErgo, true);
3881   }
3882 
3883   if (UseDebuggerErgo) {
3884     // Turn on sub-flags
3885     FLAG_SET_ERGO_IF_DEFAULT(UseDebuggerErgo1, true);
3886     FLAG_SET_ERGO_IF_DEFAULT(UseDebuggerErgo2, true);
3887   }
3888 
3889   if (UseDebuggerErgo2) {
3890     // Debugging with limited number of CPUs
3891     FLAG_SET_ERGO_IF_DEFAULT(UseNUMA, false);
3892     FLAG_SET_ERGO_IF_DEFAULT(ConcGCThreads, 1);
3893     FLAG_SET_ERGO_IF_DEFAULT(ParallelGCThreads, 1);
3894     FLAG_SET_ERGO_IF_DEFAULT(CICompilerCount, 2);
3895   }
3896 }
3897 
3898 // Parse entry point called from JNI_CreateJavaVM
3899 
3900 jint Arguments::parse(const JavaVMInitArgs* initial_cmd_args) {
3901   assert(verify_special_jvm_flags(false), "deprecated and obsolete flag table inconsistent");
3902   JVMFlag::check_all_flag_declarations();
3903 
3904   // If flag "-XX:Flags=flags-file" is used it will be the first option to be processed.
3905   const char* hotspotrc = ".hotspotrc";
3906   bool settings_file_specified = false;
3907   bool needs_hotspotrc_warning = false;
3908   ScopedVMInitArgs initial_vm_options_args("");
3909   ScopedVMInitArgs initial_java_tool_options_args("env_var='JAVA_TOOL_OPTIONS'");
3910   ScopedVMInitArgs initial_java_options_args("env_var='_JAVA_OPTIONS'");
3911 
3912   // Pointers to current working set of containers
3913   JavaVMInitArgs* cur_cmd_args;
3914   JavaVMInitArgs* cur_vm_options_args;
3915   JavaVMInitArgs* cur_java_options_args;
3916   JavaVMInitArgs* cur_java_tool_options_args;
3917 
3918   // Containers for modified/expanded options
3919   ScopedVMInitArgs mod_cmd_args("cmd_line_args");
3920   ScopedVMInitArgs mod_vm_options_args("vm_options_args");
3921   ScopedVMInitArgs mod_java_tool_options_args("env_var='JAVA_TOOL_OPTIONS'");
3922   ScopedVMInitArgs mod_java_options_args("env_var='_JAVA_OPTIONS'");
3923 
3924 
3925   jint code =
3926       parse_java_tool_options_environment_variable(&initial_java_tool_options_args);
3927   if (code != JNI_OK) {
3928     return code;
3929   }
3930 
3931   code = parse_java_options_environment_variable(&initial_java_options_args);
3932   if (code != JNI_OK) {
3933     return code;
3934   }
3935 
3936   // Parse the options in the /java.base/jdk/internal/vm/options resource, if present
3937   char *vmoptions = ClassLoader::lookup_vm_options();
3938   if (vmoptions != NULL) {
3939     code = parse_options_buffer("vm options resource", vmoptions, strlen(vmoptions), &initial_vm_options_args);
3940     FREE_C_HEAP_ARRAY(char, vmoptions);
3941     if (code != JNI_OK) {
3942       return code;
3943     }
3944   }
3945 
3946   code = expand_vm_options_as_needed(initial_java_tool_options_args.get(),
3947                                      &mod_java_tool_options_args,
3948                                      &cur_java_tool_options_args);
3949   if (code != JNI_OK) {
3950     return code;
3951   }
3952 
3953   code = expand_vm_options_as_needed(initial_cmd_args,
3954                                      &mod_cmd_args,
3955                                      &cur_cmd_args);
3956   if (code != JNI_OK) {
3957     return code;
3958   }
3959 
3960   code = expand_vm_options_as_needed(initial_java_options_args.get(),
3961                                      &mod_java_options_args,
3962                                      &cur_java_options_args);
3963   if (code != JNI_OK) {
3964     return code;
3965   }
3966 
3967   code = expand_vm_options_as_needed(initial_vm_options_args.get(),
3968                                      &mod_vm_options_args,
3969                                      &cur_vm_options_args);
3970   if (code != JNI_OK) {
3971     return code;
3972   }
3973 
3974   const char* flags_file = Arguments::get_jvm_flags_file();
3975   settings_file_specified = (flags_file != NULL);
3976 
3977   if (IgnoreUnrecognizedVMOptions) {
3978     cur_cmd_args->ignoreUnrecognized = true;
3979     cur_java_tool_options_args->ignoreUnrecognized = true;
3980     cur_java_options_args->ignoreUnrecognized = true;
3981   }
3982 
3983   // Parse specified settings file
3984   if (settings_file_specified) {
3985     if (!process_settings_file(flags_file, true,
3986                                cur_cmd_args->ignoreUnrecognized)) {
3987       return JNI_EINVAL;
3988     }
3989   } else {
3990 #ifdef ASSERT
3991     // Parse default .hotspotrc settings file
3992     if (!process_settings_file(".hotspotrc", false,
3993                                cur_cmd_args->ignoreUnrecognized)) {
3994       return JNI_EINVAL;
3995     }
3996 #else
3997     struct stat buf;
3998     if (os::stat(hotspotrc, &buf) == 0) {
3999       needs_hotspotrc_warning = true;
4000     }
4001 #endif
4002   }
4003 
4004   if (PrintVMOptions) {
4005     print_options(cur_java_tool_options_args);
4006     print_options(cur_cmd_args);
4007     print_options(cur_java_options_args);
4008   }
4009 
4010   // Parse JavaVMInitArgs structure passed in, as well as JAVA_TOOL_OPTIONS and _JAVA_OPTIONS
4011   jint result = parse_vm_init_args(cur_vm_options_args,
4012                                    cur_java_tool_options_args,
4013                                    cur_java_options_args,
4014                                    cur_cmd_args);
4015 
4016   if (result != JNI_OK) {
4017     return result;
4018   }
4019 
4020   // Delay warning until here so that we've had a chance to process
4021   // the -XX:-PrintWarnings flag
4022   if (needs_hotspotrc_warning) {
4023     warning("%s file is present but has been ignored.  "
4024             "Run with -XX:Flags=%s to load the file.",
4025             hotspotrc, hotspotrc);
4026   }
4027 
4028   if (needs_module_property_warning) {
4029     warning("Ignoring system property options whose names match the '-Djdk.module.*'."
4030             " names that are reserved for internal use.");
4031   }
4032 
4033 #if defined(_ALLBSD_SOURCE) || defined(AIX)  // UseLargePages is not yet supported on BSD and AIX.
4034   UNSUPPORTED_OPTION(UseLargePages);
4035 #endif
4036 
4037 #if defined(AIX)
4038   UNSUPPORTED_OPTION_NULL(AllocateHeapAt);
4039 #endif
4040 
4041 #ifndef PRODUCT
4042   if (TraceBytecodesAt != 0) {
4043     TraceBytecodes = true;
4044   }
4045   if (CountCompiledCalls) {
4046     if (UseCounterDecay) {
4047       warning("UseCounterDecay disabled because CountCalls is set");
4048       UseCounterDecay = false;
4049     }
4050   }
4051 #endif // PRODUCT
4052 
4053   if (ScavengeRootsInCode == 0) {
4054     if (!FLAG_IS_DEFAULT(ScavengeRootsInCode)) {
4055       warning("Forcing ScavengeRootsInCode non-zero");
4056     }
4057     ScavengeRootsInCode = 1;
4058   }
4059 
4060   if (!handle_deprecated_print_gc_flags()) {
4061     return JNI_EINVAL;
4062   }
4063 
4064   // Set object alignment values.
4065   set_object_alignment();
4066 
4067 #if !INCLUDE_CDS
4068   if (DumpSharedSpaces || RequireSharedSpaces) {
4069     jio_fprintf(defaultStream::error_stream(),
4070       "Shared spaces are not supported in this VM\n");
4071     return JNI_ERR;
4072   }
4073   if (DumpLoadedClassList != NULL) {
4074     jio_fprintf(defaultStream::error_stream(),
4075       "DumpLoadedClassList is not supported in this VM\n");
4076     return JNI_ERR;
4077   }
4078   if ((UseSharedSpaces && xshare_auto_cmd_line) ||
4079       log_is_enabled(Info, cds)) {
4080     warning("Shared spaces are not supported in this VM");
4081     UseSharedSpaces = false;
4082     LogConfiguration::configure_stdout(LogLevel::Off, true, LOG_TAGS(cds));
4083   }
4084   no_shared_spaces("CDS Disabled");
4085 #endif // INCLUDE_CDS
4086 
4087   // Verify NMT arguments
4088   const NMT_TrackingLevel lvl = NMTUtil::parse_tracking_level(NativeMemoryTracking);
4089   if (lvl == NMT_unknown) {
4090     jio_fprintf(defaultStream::error_stream(),
4091                 "Syntax error, expecting -XX:NativeMemoryTracking=[off|summary|detail]", NULL);
4092     return JNI_ERR;
4093   }
4094   if (PrintNMTStatistics && lvl == NMT_off) {
4095     warning("PrintNMTStatistics is disabled, because native memory tracking is not enabled");
4096     FLAG_SET_DEFAULT(PrintNMTStatistics, false);
4097   }
4098 
4099   if (TraceDependencies && VerifyDependencies) {
4100     if (!FLAG_IS_DEFAULT(TraceDependencies)) {
4101       warning("TraceDependencies results may be inflated by VerifyDependencies");
4102     }
4103   }
4104 
4105   apply_debugger_ergo();
4106 
4107   if (log_is_enabled(Info, arguments)) {
4108     LogStream st(Log(arguments)::info());
4109     Arguments::print_on(&st);
4110   }
4111 
4112   return JNI_OK;
4113 }
4114 
4115 jint Arguments::apply_ergo() {
4116   // Set flags based on ergonomics.
4117   jint result = set_ergonomics_flags();
4118   if (result != JNI_OK) return result;
4119 
4120   // Set heap size based on available physical memory
4121   set_heap_size();
4122 
4123   GCConfig::arguments()->initialize();
4124 
4125   set_shared_spaces_flags_and_archive_paths();
4126 
4127   // Initialize Metaspace flags and alignments
4128   Metaspace::ergo_initialize();
4129 
4130   if (!StringDedup::ergo_initialize()) {
4131     return JNI_EINVAL;
4132   }
4133 
4134   // Set compiler flags after GC is selected and GC specific
4135   // flags (LoopStripMiningIter) are set.
4136   CompilerConfig::ergo_initialize();
4137 
4138   // Set bytecode rewriting flags
4139   set_bytecode_flags();
4140 
4141   // Set flags if aggressive optimization flags are enabled
4142   jint code = set_aggressive_opts_flags();
4143   if (code != JNI_OK) {
4144     return code;
4145   }
4146 
4147 #ifdef ZERO
4148   // Clear flags not supported on zero.
4149   FLAG_SET_DEFAULT(ProfileInterpreter, false);
4150 
4151   if (LogTouchedMethods) {
4152     warning("LogTouchedMethods is not supported for Zero");
4153     FLAG_SET_DEFAULT(LogTouchedMethods, false);
4154   }
4155 #endif // ZERO
4156 
4157   if (PrintAssembly && FLAG_IS_DEFAULT(DebugNonSafepoints)) {
4158     warning("PrintAssembly is enabled; turning on DebugNonSafepoints to gain additional output");
4159     DebugNonSafepoints = true;
4160   }
4161 
4162   if (FLAG_IS_CMDLINE(CompressedClassSpaceSize) && !UseCompressedClassPointers) {
4163     warning("Setting CompressedClassSpaceSize has no effect when compressed class pointers are not used");
4164   }
4165 
4166   // Treat the odd case where local verification is enabled but remote
4167   // verification is not as if both were enabled.
4168   if (BytecodeVerificationLocal && !BytecodeVerificationRemote) {
4169     log_info(verification)("Turning on remote verification because local verification is on");
4170     FLAG_SET_DEFAULT(BytecodeVerificationRemote, true);
4171   }
4172 
4173 #ifndef PRODUCT
4174   if (!LogVMOutput && FLAG_IS_DEFAULT(LogVMOutput)) {
4175     if (use_vm_log()) {
4176       LogVMOutput = true;
4177     }
4178   }
4179 #endif // PRODUCT
4180 
4181   if (PrintCommandLineFlags) {
4182     JVMFlag::printSetFlags(tty);
4183   }
4184 
4185 #ifdef COMPILER2
4186   if (!FLAG_IS_DEFAULT(EnableVectorSupport) && !EnableVectorSupport) {
4187     if (!FLAG_IS_DEFAULT(EnableVectorReboxing) && EnableVectorReboxing) {
4188       warning("Disabling EnableVectorReboxing since EnableVectorSupport is turned off.");
4189     }
4190     FLAG_SET_DEFAULT(EnableVectorReboxing, false);
4191 
4192     if (!FLAG_IS_DEFAULT(EnableVectorAggressiveReboxing) && EnableVectorAggressiveReboxing) {
4193       if (!EnableVectorReboxing) {
4194         warning("Disabling EnableVectorAggressiveReboxing since EnableVectorReboxing is turned off.");
4195       } else {
4196         warning("Disabling EnableVectorAggressiveReboxing since EnableVectorSupport is turned off.");
4197       }
4198     }
4199     FLAG_SET_DEFAULT(EnableVectorAggressiveReboxing, false);
4200 
4201     if (!FLAG_IS_DEFAULT(UseVectorStubs) && UseVectorStubs) {
4202       warning("Disabling UseVectorStubs since EnableVectorSupport is turned off.");
4203     }
4204     FLAG_SET_DEFAULT(UseVectorStubs, false);
4205   }
4206 #endif // COMPILER2
4207 
4208   if (FLAG_IS_CMDLINE(DiagnoseSyncOnValueBasedClasses)) {
4209     if (DiagnoseSyncOnValueBasedClasses == ObjectSynchronizer::LOG_WARNING && !log_is_enabled(Info, valuebasedclasses)) {
4210       LogConfiguration::configure_stdout(LogLevel::Info, true, LOG_TAGS(valuebasedclasses));
4211     }
4212   }
4213   return JNI_OK;
4214 }
4215 
4216 jint Arguments::adjust_after_os() {
4217   if (UseNUMA) {
4218     if (UseParallelGC) {
4219       if (FLAG_IS_DEFAULT(MinHeapDeltaBytes)) {
4220          FLAG_SET_DEFAULT(MinHeapDeltaBytes, 64*M);
4221       }
4222     }
4223   }
4224   return JNI_OK;
4225 }
4226 
4227 int Arguments::PropertyList_count(SystemProperty* pl) {
4228   int count = 0;
4229   while(pl != NULL) {
4230     count++;
4231     pl = pl->next();
4232   }
4233   return count;
4234 }
4235 
4236 // Return the number of readable properties.
4237 int Arguments::PropertyList_readable_count(SystemProperty* pl) {
4238   int count = 0;
4239   while(pl != NULL) {
4240     if (pl->readable()) {
4241       count++;
4242     }
4243     pl = pl->next();
4244   }
4245   return count;
4246 }
4247 
4248 const char* Arguments::PropertyList_get_value(SystemProperty *pl, const char* key) {
4249   assert(key != NULL, "just checking");
4250   SystemProperty* prop;
4251   for (prop = pl; prop != NULL; prop = prop->next()) {
4252     if (strcmp(key, prop->key()) == 0) return prop->value();
4253   }
4254   return NULL;
4255 }
4256 
4257 // Return the value of the requested property provided that it is a readable property.
4258 const char* Arguments::PropertyList_get_readable_value(SystemProperty *pl, const char* key) {
4259   assert(key != NULL, "just checking");
4260   SystemProperty* prop;
4261   // Return the property value if the keys match and the property is not internal or
4262   // it's the special internal property "jdk.boot.class.path.append".
4263   for (prop = pl; prop != NULL; prop = prop->next()) {
4264     if (strcmp(key, prop->key()) == 0) {
4265       if (!prop->internal()) {
4266         return prop->value();
4267       } else if (strcmp(key, "jdk.boot.class.path.append") == 0) {
4268         return prop->value();
4269       } else {
4270         // Property is internal and not jdk.boot.class.path.append so return NULL.
4271         return NULL;
4272       }
4273     }
4274   }
4275   return NULL;
4276 }
4277 
4278 const char* Arguments::PropertyList_get_key_at(SystemProperty *pl, int index) {
4279   int count = 0;
4280   const char* ret_val = NULL;
4281 
4282   while(pl != NULL) {
4283     if(count >= index) {
4284       ret_val = pl->key();
4285       break;
4286     }
4287     count++;
4288     pl = pl->next();
4289   }
4290 
4291   return ret_val;
4292 }
4293 
4294 char* Arguments::PropertyList_get_value_at(SystemProperty* pl, int index) {
4295   int count = 0;
4296   char* ret_val = NULL;
4297 
4298   while(pl != NULL) {
4299     if(count >= index) {
4300       ret_val = pl->value();
4301       break;
4302     }
4303     count++;
4304     pl = pl->next();
4305   }
4306 
4307   return ret_val;
4308 }
4309 
4310 void Arguments::PropertyList_add(SystemProperty** plist, SystemProperty *new_p) {
4311   SystemProperty* p = *plist;
4312   if (p == NULL) {
4313     *plist = new_p;
4314   } else {
4315     while (p->next() != NULL) {
4316       p = p->next();
4317     }
4318     p->set_next(new_p);
4319   }
4320 }
4321 
4322 void Arguments::PropertyList_add(SystemProperty** plist, const char* k, const char* v,
4323                                  bool writeable, bool internal) {
4324   if (plist == NULL)
4325     return;
4326 
4327   SystemProperty* new_p = new SystemProperty(k, v, writeable, internal);
4328   PropertyList_add(plist, new_p);
4329 }
4330 
4331 void Arguments::PropertyList_add(SystemProperty *element) {
4332   PropertyList_add(&_system_properties, element);
4333 }
4334 
4335 // This add maintains unique property key in the list.
4336 void Arguments::PropertyList_unique_add(SystemProperty** plist, const char* k, const char* v,
4337                                         PropertyAppendable append, PropertyWriteable writeable,
4338                                         PropertyInternal internal) {
4339   if (plist == NULL)
4340     return;
4341 
4342   // If property key exists and is writeable, then update with new value.
4343   // Trying to update a non-writeable property is silently ignored.
4344   SystemProperty* prop;
4345   for (prop = *plist; prop != NULL; prop = prop->next()) {
4346     if (strcmp(k, prop->key()) == 0) {
4347       if (append == AppendProperty) {
4348         prop->append_writeable_value(v);
4349       } else {
4350         prop->set_writeable_value(v);
4351       }
4352       return;
4353     }
4354   }
4355 
4356   PropertyList_add(plist, k, v, writeable == WriteableProperty, internal == InternalProperty);
4357 }
4358 
4359 // Copies src into buf, replacing "%%" with "%" and "%p" with pid
4360 // Returns true if all of the source pointed by src has been copied over to
4361 // the destination buffer pointed by buf. Otherwise, returns false.
4362 // Notes:
4363 // 1. If the length (buflen) of the destination buffer excluding the
4364 // NULL terminator character is not long enough for holding the expanded
4365 // pid characters, it also returns false instead of returning the partially
4366 // expanded one.
4367 // 2. The passed in "buflen" should be large enough to hold the null terminator.
4368 bool Arguments::copy_expand_pid(const char* src, size_t srclen,
4369                                 char* buf, size_t buflen) {
4370   const char* p = src;
4371   char* b = buf;
4372   const char* src_end = &src[srclen];
4373   char* buf_end = &buf[buflen - 1];
4374 
4375   while (p < src_end && b < buf_end) {
4376     if (*p == '%') {
4377       switch (*(++p)) {
4378       case '%':         // "%%" ==> "%"
4379         *b++ = *p++;
4380         break;
4381       case 'p':  {       //  "%p" ==> current process id
4382         // buf_end points to the character before the last character so
4383         // that we could write '\0' to the end of the buffer.
4384         size_t buf_sz = buf_end - b + 1;
4385         int ret = jio_snprintf(b, buf_sz, "%d", os::current_process_id());
4386 
4387         // if jio_snprintf fails or the buffer is not long enough to hold
4388         // the expanded pid, returns false.
4389         if (ret < 0 || ret >= (int)buf_sz) {
4390           return false;
4391         } else {
4392           b += ret;
4393           assert(*b == '\0', "fail in copy_expand_pid");
4394           if (p == src_end && b == buf_end + 1) {
4395             // reach the end of the buffer.
4396             return true;
4397           }
4398         }
4399         p++;
4400         break;
4401       }
4402       default :
4403         *b++ = '%';
4404       }
4405     } else {
4406       *b++ = *p++;
4407     }
4408   }
4409   *b = '\0';
4410   return (p == src_end); // return false if not all of the source was copied
4411 }