1 /*
  2  * Copyright (c) 1997, 2026, 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 #ifndef SHARE_RUNTIME_ARGUMENTS_HPP
 26 #define SHARE_RUNTIME_ARGUMENTS_HPP
 27 
 28 #include "jni.h"
 29 #include "memory/allocation.hpp"
 30 #include "memory/allStatic.hpp"
 31 #include "runtime/flags/jvmFlag.hpp"
 32 #include "runtime/java.hpp"
 33 #include "utilities/globalDefinitions.hpp"
 34 
 35 // Arguments parses the command line and recognizes options
 36 
 37 template <typename E>
 38 class GrowableArray;
 39 class JVMFlag;
 40 
 41 // Invocation API hook typedefs (these should really be defined in jni.h)
 42 extern "C" {
 43   typedef void (JNICALL *abort_hook_t)(void);
 44   typedef void (JNICALL *exit_hook_t)(jint code);
 45   typedef jint (JNICALL *vfprintf_hook_t)(FILE *fp, const char *format, va_list args)  ATTRIBUTE_PRINTF(2, 0);
 46 }
 47 
 48 // Obsolete or deprecated -XX flag.
 49 struct SpecialFlag {
 50   const char* name;
 51   JDK_Version deprecated_in; // When the deprecation warning started (or "undefined").
 52   JDK_Version obsolete_in;   // When the obsolete warning started (or "undefined").
 53   JDK_Version expired_in;    // When the option expires (or "undefined").
 54 };
 55 
 56 struct LegacyGCLogging {
 57     const char* file;        // null -> stdout
 58     int lastFlag;            // 0 not set; 1 -> -verbose:gc; 2 -> -Xloggc
 59 };
 60 
 61 // PathString is used as:
 62 //  - the underlying value for a SystemProperty
 63 //  - the path portion of an --patch-module module/path pair
 64 //  - the string that represents the boot class path, Arguments::_boot_class_path.
 65 class PathString : public CHeapObj<mtArguments> {
 66  protected:
 67   char* _value;
 68  public:
 69   char* value() const { return _value; }
 70 
 71   // return false iff OOM && alloc_failmode == AllocFailStrategy::RETURN_NULL
 72   bool set_value(const char *value, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
 73   void append_value(const char *value);
 74 
 75   PathString(const char* value);
 76   ~PathString();
 77 
 78   // for JVM_ReadSystemPropertiesInfo
 79   static int value_offset_in_bytes()  { return (int)offset_of(PathString, _value);  }
 80 };
 81 
 82 // ModulePatchPath records the module/path pair as specified to --patch-module.
 83 class ModulePatchPath : public CHeapObj<mtInternal> {
 84 private:
 85   char* _module_name;
 86   PathString* _path;
 87 public:
 88   ModulePatchPath(const char* module_name, const char* path);
 89   ~ModulePatchPath();
 90 
 91   inline const char* module_name() const { return _module_name; }
 92   inline char* path_string() const { return _path->value(); }
 93   inline void append_path(const char* path) { _path->append_value(path); }
 94 };
 95 
 96 // Element describing System and User (-Dkey=value flags) defined property.
 97 //
 98 // An internal SystemProperty is one that has been removed in
 99 // jdk.internal.VM.saveAndRemoveProperties, like jdk.boot.class.path.append.
100 //
101 class SystemProperty : public PathString {
102  private:
103   char*           _key;
104   SystemProperty* _next;
105   bool            _internal;
106   bool            _writeable;
107 
108  public:
109   // Accessors
110   char* value() const                 { return PathString::value(); }
111   const char* key() const             { return _key; }
112   bool internal() const               { return _internal; }
113   SystemProperty* next() const        { return _next; }
114   void set_next(SystemProperty* next) { _next = next; }
115   bool writeable() const              { return _writeable; }
116 
117   bool readable() const {
118     return !_internal || (strcmp(_key, "jdk.boot.class.path.append") == 0 &&
119                           value() != nullptr);
120   }
121 
122   // A system property should only have its value set
123   // via an external interface if it is a writeable property.
124   // The internal, non-writeable property jdk.boot.class.path.append
125   // is the only exception to this rule.  It can be set externally
126   // via -Xbootclasspath/a or JVMTI OnLoad phase call to AddToBootstrapClassLoaderSearch.
127   // In those cases for jdk.boot.class.path.append, the base class
128   // set_value and append_value methods are called directly.
129   void set_writeable_value(const char *value) {
130     if (writeable()) {
131       set_value(value);
132     }
133   }
134   void append_writeable_value(const char *value) {
135     if (writeable()) {
136       append_value(value);
137     }
138   }
139 
140   // Constructor
141   SystemProperty(const char* key, const char* value, bool writeable, bool internal = false);
142 
143   // for JVM_ReadSystemPropertiesInfo
144   static int key_offset_in_bytes()  { return (int)offset_of(SystemProperty, _key);  }
145   static int next_offset_in_bytes() { return (int)offset_of(SystemProperty, _next); }
146 };
147 
148 // Helper class for controlling the lifetime of JavaVMInitArgs objects.
149 class ScopedVMInitArgs;
150 
151 struct VMInitArgsGroup;
152 template <typename E, MemTag MT> class GrowableArrayCHeap;
153 
154 class Arguments : AllStatic {
155   friend class VMStructs;
156   friend class JvmtiExport;
157   friend class ArgumentsTest;
158   friend class LargeOptionsTest;
159  public:
160   // Operation modi
161   enum Mode {
162     _int,       // corresponds to -Xint
163     _mixed,     // corresponds to -Xmixed
164     _comp       // corresponds to -Xcomp
165   };
166 
167   enum ArgsRange {
168     arg_unreadable = -3,
169     arg_too_small  = -2,
170     arg_too_big    = -1,
171     arg_in_range   = 0
172   };
173 
174   enum PropertyAppendable {
175     AppendProperty,
176     AddProperty
177   };
178 
179   enum PropertyWriteable {
180     WriteableProperty,
181     UnwriteableProperty
182   };
183 
184   enum PropertyInternal {
185     InternalProperty,
186     ExternalProperty
187   };
188 
189  private:
190 
191   // a pointer to the flags file name if it is specified
192   static char*  _jvm_flags_file;
193   // an array containing all flags specified in the .hotspotrc file
194   static char** _jvm_flags_array;
195   static int    _num_jvm_flags;
196   // an array containing all jvm arguments specified in the command line
197   static char** _jvm_args_array;
198   static int    _num_jvm_args;
199   // string containing all java command (class/jarfile name and app args)
200   static char* _java_command;
201   // number of unique modules specified in the --add-modules option
202   static unsigned int _addmods_count;
203 #if INCLUDE_JVMCI
204   // was jdk.internal.vm.ci module specified in the --add-modules option?
205   static bool _jvmci_module_added;
206 #endif
207 
208   // Property list
209   static SystemProperty* _system_properties;
210 
211   // Quick accessor to System properties in the list:
212   static SystemProperty *_sun_boot_library_path;
213   static SystemProperty *_java_library_path;
214   static SystemProperty *_java_home;
215   static SystemProperty *_java_class_path;
216   static SystemProperty *_jdk_boot_class_path_append;
217   static SystemProperty *_vm_info;
218 
219   // --patch-module=module=<file>(<pathsep><file>)*
220   // Each element contains the associated module name, path
221   // string pair as specified to --patch-module.
222   static GrowableArray<ModulePatchPath*>* _patch_mod_prefix;
223 
224   // The constructed value of the system class path after
225   // argument processing and JVMTI OnLoad additions via
226   // calls to AddToBootstrapClassLoaderSearch.  This is the
227   // final form before ClassLoader::setup_bootstrap_search().
228   // Note: since --patch-module is a module name/path pair, the
229   // boot class path string no longer contains the "prefix"
230   // to the boot class path base piece as it did when
231   // -Xbootclasspath/p was supported.
232   static PathString* _boot_class_path;
233 
234   // Set if a modular java runtime image is present vs. a build with exploded modules
235   static bool _has_jimage;
236 
237   // temporary: to emit warning if the default ext dirs are not empty.
238   // remove this variable when the warning is no longer needed.
239   static char* _ext_dirs;
240 
241   // java.vendor.url.bug, bug reporting URL for fatal errors.
242   static const char* _java_vendor_url_bug;
243 
244   // sun.java.launcher, private property to provide information about
245   // java launcher
246   static const char* _sun_java_launcher;
247 
248   // was this VM created with the -XX:+ExecutingUnitTests option
249   static bool _executing_unit_tests;
250 
251   // for legacy gc options (-verbose:gc and -Xloggc:)
252   static LegacyGCLogging _legacyGCLogging;
253 
254   // Value of the conservative maximum heap alignment needed
255   static size_t  _conservative_max_heap_alignment;
256 
257   // Operation modi
258   static Mode _mode;
259 
260   // preview features
261   static bool _enable_preview;
262 
263   // jdwp
264   static bool _has_jdwp_agent;
265 
266   // Used to save default settings
267   static bool _AlwaysCompileLoopMethods;
268   static bool _UseOnStackReplacement;
269   static bool _BackgroundCompilation;
270   static bool _ClipInlining;
271 
272   // GC ergonomics
273   static void set_conservative_max_heap_alignment();
274   static void set_use_compressed_oops();
275   static jint set_ergonomics_flags();
276   static void set_compact_headers_flags();
277   // Limits the given heap size by the maximum amount of virtual
278   // memory this process is currently allowed to use. It also takes
279   // the virtual-to-physical ratio of the current GC into account.
280   static size_t limit_heap_by_allocatable_memory(size_t size);
281   // Setup heap size
282   static void set_heap_size();
283 
284   // Bytecode rewriting
285   static void set_bytecode_flags();
286 
287   // Invocation API hooks
288   static abort_hook_t     _abort_hook;
289   static exit_hook_t      _exit_hook;
290   static vfprintf_hook_t  _vfprintf_hook;
291 
292   // System properties
293   static bool add_property(const char* prop, PropertyWriteable writeable=WriteableProperty,
294                            PropertyInternal internal=ExternalProperty);
295 
296   // Used for module system related properties: converted from command-line flags.
297   // Basic properties are writeable as they operate as "last one wins" and will get overwritten.
298   // Numbered properties are never writeable, and always internal.
299   static bool create_module_property(const char* prop_name, const char* prop_value, PropertyInternal internal);
300   static bool create_numbered_module_property(const char* prop_base_name, const char* prop_value, unsigned int count);
301 
302   static int process_patch_mod_option(const char* patch_mod_tail);
303 
304   // Aggressive optimization flags.
305   static jint set_aggressive_opts_flags();
306 
307   // Argument parsing
308   static bool parse_argument(const char* arg, JVMFlagOrigin origin);
309   static bool process_argument(const char* arg, jboolean ignore_unrecognized, JVMFlagOrigin origin);
310   static void process_java_launcher_argument(const char*, void*);
311   static jint parse_options_environment_variable(const char* name, ScopedVMInitArgs* vm_args);
312   static jint parse_java_tool_options_environment_variable(ScopedVMInitArgs* vm_args);
313   static jint parse_java_options_environment_variable(ScopedVMInitArgs* vm_args);
314   static jint parse_jdk_aot_vm_options_environment_variable(GrowableArrayCHeap<VMInitArgsGroup, mtArguments>* all_args,
315                                                             ScopedVMInitArgs* jdk_aot_vm_options_args);
316   static jint parse_vm_options_file(const char* file_name, ScopedVMInitArgs* vm_args);
317   static jint parse_options_buffer(const char* name, char* buffer, const size_t buf_len, ScopedVMInitArgs* vm_args);
318   static jint parse_xss(const JavaVMOption* option, const char* tail, intx* out_ThreadStackSize);
319   static jint insert_vm_options_file(const JavaVMInitArgs* args,
320                                      const char* vm_options_file,
321                                      const int vm_options_file_pos,
322                                      ScopedVMInitArgs* vm_options_file_args,
323                                      ScopedVMInitArgs* args_out);
324   static bool args_contains_vm_options_file_arg(const JavaVMInitArgs* args);
325   static jint expand_vm_options_as_needed(const JavaVMInitArgs* args_in,
326                                           ScopedVMInitArgs* mod_args,
327                                           JavaVMInitArgs** args_out);
328   static jint match_special_option_and_act(const JavaVMInitArgs* args,
329                                            ScopedVMInitArgs* args_out);
330 
331   static bool handle_deprecated_print_gc_flags();
332 
333   static jint parse_vm_init_args(GrowableArrayCHeap<VMInitArgsGroup, mtArguments>* all_args);
334   static jint parse_each_vm_init_arg(const JavaVMInitArgs* args, JVMFlagOrigin origin);
335   static jint finalize_vm_init_args();
336   static bool is_bad_option(const JavaVMOption* option, jboolean ignore, const char* option_type);
337 
338   static bool is_bad_option(const JavaVMOption* option, jboolean ignore) {
339     return is_bad_option(option, ignore, nullptr);
340   }
341 
342   static void describe_range_error(ArgsRange errcode);
343   static ArgsRange check_memory_size(julong size, julong min_size, julong max_size);
344   static ArgsRange parse_memory_size(const char* s, julong* long_arg,
345                                      julong min_size, julong max_size = max_uintx);
346 
347   // methods to build strings from individual args
348   static void build_jvm_args(const char* arg);
349   static void build_jvm_flags(const char* arg);
350   static void add_string(char*** bldarray, int* count, const char* arg);
351   static const char* build_resource_string(char** args, int count);
352 
353   // Returns true if the flag is obsolete (and not yet expired).
354   // In this case the 'version' buffer is filled in with
355   // the version number when the flag became obsolete.
356   static bool is_obsolete_flag(const char* flag_name, JDK_Version* version);
357 
358   // Returns 1 if the flag is deprecated (and not yet obsolete or expired).
359   //     In this case the 'version' buffer is filled in with the version number when
360   //     the flag became deprecated.
361   // Returns -1 if the flag is expired or obsolete.
362   // Returns 0 otherwise.
363   static int is_deprecated_flag(const char* flag_name, JDK_Version* version);
364 
365   // Return the real name for the flag passed on the command line (either an alias name or "flag_name").
366   static const char* real_flag_name(const char *flag_name);
367   static JVMFlag* find_jvm_flag(const char* name, size_t name_length);
368 
369   // Return the "real" name for option arg if arg is an alias, and print a warning if arg is deprecated.
370   // Return nullptr if the arg has expired.
371   static const char* handle_aliases_and_deprecation(const char* arg);
372   static size_t _default_SharedBaseAddress; // The default value specified in globals.hpp
373 
374   static bool internal_module_property_helper(const char* property, bool check_for_cds);
375 
376  public:
377   // Parses the arguments, first phase
378   static jint parse(const JavaVMInitArgs* args);
379   // Parse a string for a unsigned integer.  Returns true if value
380   // is an unsigned integer greater than or equal to the minimum
381   // parameter passed and returns the value in uint_arg.  Returns
382   // false otherwise, with uint_arg undefined.
383   static bool parse_uint(const char* value, uint* uintx_arg,
384                          uint min_size);
385   // Apply ergonomics
386   static jint apply_ergo();
387   // Adjusts the arguments after the OS have adjusted the arguments
388   static jint adjust_after_os();
389 
390   // Check consistency or otherwise of VM argument settings
391   static bool check_vm_args_consistency();
392   // Used by os_solaris
393   static bool process_settings_file(const char* file_name, bool should_exist, jboolean ignore_unrecognized);
394 
395   static size_t conservative_max_heap_alignment() { return _conservative_max_heap_alignment; }
396   // Return the maximum size a heap with compressed oops can take
397   static size_t max_heap_for_compressed_oops();
398 
399   // return a char* array containing all options
400   static char** jvm_flags_array()          { return _jvm_flags_array; }
401   static char** jvm_args_array()           { return _jvm_args_array; }
402   static int num_jvm_flags()               { return _num_jvm_flags; }
403   static int num_jvm_args()                { return _num_jvm_args; }
404   // return the arguments passed to the Java application
405   static const char* java_command()        { return _java_command; }
406 
407   // print jvm_flags, jvm_args and java_command
408   static void print_on(outputStream* st);
409   static void print_summary_on(outputStream* st);
410 
411   // convenient methods to get and set jvm_flags_file
412   static const char* get_jvm_flags_file()  { return _jvm_flags_file; }
413   static void set_jvm_flags_file(const char *value);
414 
415   // convenient methods to obtain / print jvm_flags and jvm_args
416   static const char* jvm_flags()           { return build_resource_string(_jvm_flags_array, _num_jvm_flags); }
417   static const char* jvm_args()            { return build_resource_string(_jvm_args_array, _num_jvm_args); }
418   static void print_jvm_flags_on(outputStream* st);
419   static void print_jvm_args_on(outputStream* st);
420 
421   // -Dkey=value flags
422   static SystemProperty*  system_properties()   { return _system_properties; }
423   static const char*    get_property(const char* key);
424 
425   // -Djava.vendor.url.bug
426   static const char* java_vendor_url_bug()  { return _java_vendor_url_bug; }
427 
428   // -Dsun.java.launcher
429   static const char* sun_java_launcher()    { return _sun_java_launcher; }
430   // Was VM created by a Java launcher?
431   static bool created_by_java_launcher();
432   // -XX:+ExecutingUnitTests
433   static bool executing_unit_tests();
434 
435   // abort, exit, vfprintf hooks
436   static abort_hook_t    abort_hook()       { return _abort_hook; }
437   static exit_hook_t     exit_hook()        { return _exit_hook; }
438   static vfprintf_hook_t vfprintf_hook()    { return _vfprintf_hook; }
439 
440   static void no_shared_spaces(const char* message);
441   static size_t default_SharedBaseAddress() { return _default_SharedBaseAddress; }
442   // Java launcher properties
443   static void process_sun_java_launcher_properties(JavaVMInitArgs* args);
444 
445   // System properties
446   static void init_system_properties();
447 
448   // Update/Initialize System properties after JDK version number is known
449   static void init_version_specific_system_properties();
450 
451   // Update VM info property - called after argument parsing
452   static void update_vm_info_property(const char* vm_info) {
453     _vm_info->set_value(vm_info);
454   }
455 
456   // Property List manipulation
457   static void PropertyList_add(SystemProperty *element);
458   static void PropertyList_add(SystemProperty** plist, SystemProperty *element);
459   static void PropertyList_add(SystemProperty** plist, const char* k, const char* v, bool writeable, bool internal);
460 
461   static void PropertyList_unique_add(SystemProperty** plist, const char* k, const char* v,
462                                       PropertyAppendable append, PropertyWriteable writeable,
463                                       PropertyInternal internal);
464   static const char* PropertyList_get_value(SystemProperty* plist, const char* key);
465   static const char* PropertyList_get_readable_value(SystemProperty* plist, const char* key);
466   static int  PropertyList_count(SystemProperty* pl);
467   static int  PropertyList_readable_count(SystemProperty* pl);
468 
469   static bool is_internal_module_property(const char* option);
470   static bool is_incompatible_cds_internal_module_property(const char* property);
471 
472   // Miscellaneous System property value getter and setters.
473   static void set_dll_dir(const char *value) { _sun_boot_library_path->set_value(value); }
474   static void set_java_home(const char *value) { _java_home->set_value(value); }
475   static void set_library_path(const char *value) { _java_library_path->set_value(value); }
476   static void set_ext_dirs(char *value);
477 
478   // Set up the underlying pieces of the boot class path
479   static void add_patch_mod_prefix(const char *module_name, const char *path);
480   static int finalize_patch_module();
481 
482   static void set_boot_class_path(const char *value, bool has_jimage) {
483     // During start up, set by os::set_boot_path()
484     assert(get_boot_class_path() == nullptr, "Boot class path previously set");
485     _boot_class_path->set_value(value);
486     _has_jimage = has_jimage;
487   }
488   static void append_sysclasspath(const char *value) {
489     _boot_class_path->append_value(value);
490     _jdk_boot_class_path_append->append_value(value);
491   }
492 
493   static GrowableArray<ModulePatchPath*>* get_patch_mod_prefix() { return _patch_mod_prefix; }
494   static char* get_boot_class_path() { return _boot_class_path->value(); }
495   static bool has_jimage() { return _has_jimage; }
496 
497   static char* get_java_home()    { return _java_home->value(); }
498   static char* get_dll_dir()      { return _sun_boot_library_path->value(); }
499   static char* get_appclasspath() { return _java_class_path->value(); }
500   static void  fix_appclasspath();
501 
502   // Operation modi
503   static Mode mode()                { return _mode;           }
504   static void set_mode_flags(Mode mode);
505   static bool is_interpreter_only() { return mode() == _int;  }
506   static bool is_compiler_only()    { return mode() == _comp; }
507 
508 
509   // preview features
510   static void set_enable_preview() { _enable_preview = true; }
511   static bool enable_preview() { return _enable_preview; }
512   static bool is_valhalla_enabled() {
513     // Valhalla is a feature opted-in by --enable-preview
514     return enable_preview();
515   }
516 
517   // jdwp
518   static bool has_jdwp_agent() { return _has_jdwp_agent; }
519 
520   // Utility: copies src into buf, replacing "%%" with "%" and "%p" with pid.
521   static bool copy_expand_pid(const char* src, size_t srclen, char* buf, size_t buflen);
522 
523   static bool atojulong(const char *s, julong* result);
524 
525   static bool has_jfr_option() NOT_JFR_RETURN_(false);
526 
527   DEBUG_ONLY(static bool verify_special_jvm_flags(bool check_globals);)
528 };
529 
530 // Disable options not supported in this release, with a warning if they
531 // were explicitly requested on the command-line
532 #define UNSUPPORTED_OPTION(opt)                          \
533 do {                                                     \
534   if (opt) {                                             \
535     if (FLAG_IS_CMDLINE(opt)) {                          \
536       warning("-XX:+" #opt " not supported in this VM"); \
537     }                                                    \
538     FLAG_SET_DEFAULT(opt, false);                        \
539   }                                                      \
540 } while(0)
541 
542 // similar to UNSUPPORTED_OPTION but sets flag to nullptr
543 #define UNSUPPORTED_OPTION_NULL(opt)                         \
544 do {                                                         \
545   if (opt) {                                                 \
546     if (FLAG_IS_CMDLINE(opt)) {                              \
547       warning("-XX flag " #opt " not supported in this VM"); \
548     }                                                        \
549     FLAG_SET_DEFAULT(opt, nullptr);                          \
550   }                                                          \
551 } while(0)
552 
553 // Initialize options not supported in this release, with a warning
554 // if they were explicitly requested on the command-line
555 #define UNSUPPORTED_OPTION_INIT(opt, value)              \
556 do {                                                     \
557   if (FLAG_IS_CMDLINE(opt)) {                            \
558     warning("-XX flag " #opt " not supported in this VM"); \
559   }                                                      \
560   FLAG_SET_DEFAULT(opt, value);                          \
561 } while(0)
562 
563 #endif // SHARE_RUNTIME_ARGUMENTS_HPP