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