1 /*
2 * Copyright (c) 1997, 2024, 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 "jfr/jfrEvents.hpp"
27 #include "jvm_io.h"
28 #include "memory/allocation.inline.hpp"
29 #include "runtime/arguments.hpp"
30 #include "runtime/flags/jvmFlag.hpp"
31 #include "runtime/flags/jvmFlagAccess.hpp"
32 #include "runtime/flags/jvmFlagLookup.hpp"
33 #include "runtime/globals_extension.hpp"
34 #include "utilities/defaultStream.hpp"
35 #include "utilities/stringUtils.hpp"
36
37 static bool is_product_build() {
38 #ifdef PRODUCT
39 return true;
40 #else
41 return false;
42 #endif
43 }
44
45 void JVMFlag::set_origin(JVMFlagOrigin new_origin) {
46 int old_flags = _flags;
47 int origin = static_cast<int>(new_origin);
48 assert((origin & VALUE_ORIGIN_MASK) == origin, "sanity");
49 int was_in_cmdline = (new_origin == JVMFlagOrigin::COMMAND_LINE) ? WAS_SET_ON_COMMAND_LINE : 0;
50 _flags = Flags((_flags & ~VALUE_ORIGIN_MASK) | origin | was_in_cmdline);
51 if ((old_flags & WAS_SET_ON_COMMAND_LINE) != 0) {
52 assert((_flags & WAS_SET_ON_COMMAND_LINE) != 0, "once initialized, should never change");
53 }
54 }
55
56 /**
57 * Returns if this flag is a constant in the binary. Right now this is
58 * true for develop flags in product builds.
59 */
60 bool JVMFlag::is_constant_in_binary() const {
61 #ifdef PRODUCT
62 return is_develop();
63 #else
64 return false;
65 #endif
66 }
67
68 bool JVMFlag::is_unlocker() const {
69 return strcmp(_name, "UnlockDiagnosticVMOptions") == 0 ||
70 strcmp(_name, "UnlockExperimentalVMOptions") == 0;
71 }
72
73 bool JVMFlag::is_unlocked() const {
74 if (is_diagnostic()) {
75 return UnlockDiagnosticVMOptions;
76 }
77 if (is_experimental()) {
78 return UnlockExperimentalVMOptions;
79 }
80 return true;
81 }
82
83 void JVMFlag::clear_diagnostic() {
84 assert(is_diagnostic(), "sanity");
85 _flags = Flags(_flags & ~KIND_DIAGNOSTIC);
86 assert(!is_diagnostic(), "sanity");
87 }
88
89 void JVMFlag::clear_experimental() {
90 assert(is_experimental(), "sanity");
91 _flags = Flags(_flags & ~KIND_EXPERIMENTAL);
92 assert(!is_experimental(), "sanity");
93 }
94
95 void JVMFlag::set_product() {
96 assert(!is_product(), "sanity");
97 _flags = Flags(_flags | KIND_PRODUCT);
98 assert(is_product(), "sanity");
99 }
100
101 // Get custom message for this locked flag, or null if
102 // none is available. Returns message type produced.
103 JVMFlag::MsgType JVMFlag::get_locked_message(char* buf, int buflen) const {
104 buf[0] = '\0';
105 if (is_diagnostic() && !is_unlocked()) {
106 jio_snprintf(buf, buflen,
107 "Error: VM option '%s' is diagnostic and must be enabled via -XX:+UnlockDiagnosticVMOptions.\n"
108 "Error: The unlock option must precede '%s'.\n",
109 _name, _name);
110 return JVMFlag::DIAGNOSTIC_FLAG_BUT_LOCKED;
111 }
112 if (is_experimental() && !is_unlocked()) {
113 jio_snprintf(buf, buflen,
114 "Error: VM option '%s' is experimental and must be enabled via -XX:+UnlockExperimentalVMOptions.\n"
115 "Error: The unlock option must precede '%s'.\n",
116 _name, _name);
117 return JVMFlag::EXPERIMENTAL_FLAG_BUT_LOCKED;
118 }
119 if (is_develop() && is_product_build()) {
120 jio_snprintf(buf, buflen, "Error: VM option '%s' is develop and is available only in debug version of VM.\n",
121 _name);
122 return JVMFlag::DEVELOPER_FLAG_BUT_PRODUCT_BUILD;
123 }
124 return JVMFlag::NONE;
125 }
126
127 // Helper function for JVMFlag::print_on().
128 // Fills current line up to requested position.
129 // Should the current position already be past the requested position,
130 // one separator blank is enforced.
131 static void fill_to_pos(outputStream* st, unsigned int req_pos) {
132 if ((unsigned int)st->position() < req_pos) {
133 st->fill_to(req_pos); // need to fill with blanks to reach req_pos
134 } else {
135 st->print(" "); // enforce blank separation. Previous field too long.
136 }
137 }
138
139 void JVMFlag::print_on(outputStream* st, bool withComments, bool printRanges) const {
140 // Don't print develop flags in a product build.
141 if (is_constant_in_binary()) {
142 return;
143 }
144
145 if (!printRanges) {
146 // The command line options -XX:+PrintFlags* cause this function to be called
147 // for each existing flag to print information pertinent to this flag. The data
148 // is displayed in columnar form, with the following layout:
149 // col1 - data type, right-justified
150 // col2 - name, left-justified
151 // col3 - ' =' double-char, leading space to align with possible '+='
152 // col4 - value left-justified
153 // col5 - kind right-justified
154 // col6 - origin left-justified
155 // col7 - comments left-justified
156 //
157 // The column widths are fixed. They are defined such that, for most cases,
158 // an eye-pleasing tabular output is created.
159 //
160 // Sample output:
161 // bool ThreadPriorityVerbose = false {product} {default}
162 // uintx ThresholdTolerance = 10 {product} {default}
163 // size_t TLABSize = 0 {product} {default}
164 // uintx SurvivorRatio = 8 {product} {default}
165 // double InitialRAMPercentage = 1.562500 {product} {default}
166 // ccstr CompileCommandFile = MyFile.cmd {product} {command line}
167 // ccstrlist CompileOnly = Method1
168 // CompileOnly += Method2 {product} {command line}
169 // | | | | | | |
170 // | | | | | | +-- col7
171 // | | | | | +-- col6
172 // | | | | +-- col5
173 // | | | +-- col4
174 // | | +-- col3
175 // | +-- col2
176 // +-- col1
177
178 const unsigned int col_spacing = 1;
179 const unsigned int col1_pos = 0;
180 const unsigned int col1_width = 9;
181 const unsigned int col2_pos = col1_pos + col1_width + col_spacing;
182 const unsigned int col2_width = 39;
183 const unsigned int col3_pos = col2_pos + col2_width + col_spacing;
184 const unsigned int col3_width = 2;
185 const unsigned int col4_pos = col3_pos + col3_width + col_spacing;
186 const unsigned int col4_width = 30;
187 const unsigned int col5_pos = col4_pos + col4_width + col_spacing;
188 const unsigned int col5_width = 20;
189 const unsigned int col6_pos = col5_pos + col5_width + col_spacing;
190 const unsigned int col6_width = 15;
191 const unsigned int col7_pos = col6_pos + col6_width + col_spacing;
192 const unsigned int col7_width = 1;
193
194 st->fill_to(col1_pos);
195 st->print("%*s", col1_width, type_string()); // right-justified, therefore width is required.
196
197 fill_to_pos(st, col2_pos);
198 st->print("%s", _name);
199
200 fill_to_pos(st, col3_pos);
201 st->print(" ="); // use " =" for proper alignment with multiline ccstr output.
202
203 fill_to_pos(st, col4_pos);
204 if (is_bool()) {
205 st->print("%s", get_bool() ? "true" : "false");
206 } else if (is_int()) {
207 st->print("%d", get_int());
208 } else if (is_uint()) {
209 st->print("%u", get_uint());
210 } else if (is_intx()) {
211 st->print(INTX_FORMAT, get_intx());
212 } else if (is_uintx()) {
213 st->print(UINTX_FORMAT, get_uintx());
214 } else if (is_uint64_t()) {
215 st->print(UINT64_FORMAT, get_uint64_t());
216 } else if (is_size_t()) {
217 st->print(SIZE_FORMAT, get_size_t());
218 } else if (is_double()) {
219 st->print("%f", get_double());
220 } else if (is_ccstr()) {
221 // Honor <newline> characters in ccstr: print multiple lines.
222 const char* cp = get_ccstr();
223 if (cp != nullptr) {
224 const char* eol;
225 while ((eol = strchr(cp, '\n')) != nullptr) {
226 size_t llen = pointer_delta(eol, cp, sizeof(char));
227 st->print("%.*s", (int)llen, cp);
228 st->cr();
229 cp = eol+1;
230 fill_to_pos(st, col2_pos);
231 st->print("%s", _name);
232 fill_to_pos(st, col3_pos);
233 st->print("+=");
234 fill_to_pos(st, col4_pos);
235 }
236 st->print("%s", cp);
237 }
238 } else {
239 st->print("unhandled type %s", type_string());
240 st->cr();
241 return;
242 }
243
244 fill_to_pos(st, col5_pos);
245 print_kind(st, col5_width);
246
247 fill_to_pos(st, col6_pos);
248 print_origin(st, col6_width);
249
250 #ifndef PRODUCT
251 if (withComments) {
252 fill_to_pos(st, col7_pos);
253 st->print("%s", _doc);
254 }
255 #endif
256 st->cr();
257 } else if (!is_bool() && !is_ccstr()) {
258 // The command line options -XX:+PrintFlags* cause this function to be called
259 // for each existing flag to print information pertinent to this flag. The data
260 // is displayed in columnar form, with the following layout:
261 // col1 - data type, right-justified
262 // col2 - name, left-justified
263 // col4 - range [ min ... max]
264 // col5 - kind right-justified
265 // col6 - origin left-justified
266 // col7 - comments left-justified
267 //
268 // The column widths are fixed. They are defined such that, for most cases,
269 // an eye-pleasing tabular output is created.
270 //
271 // Sample output:
272 // intx MinPassesBeforeFlush [ 0 ... 9223372036854775807 ] {diagnostic} {default}
273 // double MinRAMPercentage [ 0.000 ... 100.000 ] {product} {default}
274 // uintx MinSurvivorRatio [ 3 ... 18446744073709551615 ] {product} {default}
275 // size_t MinTLABSize [ 1 ... 9223372036854775807 ] {product} {default}
276 // intx MaxInlineSize [ 0 ... 2147483647 ] {product} {default}
277 // | | | | | |
278 // | | | | | +-- col7
279 // | | | | +-- col6
280 // | | | +-- col5
281 // | | +-- col4
282 // | +-- col2
283 // +-- col1
284
285 const unsigned int col_spacing = 1;
286 const unsigned int col1_pos = 0;
287 const unsigned int col1_width = 9;
288 const unsigned int col2_pos = col1_pos + col1_width + col_spacing;
289 const unsigned int col2_width = 49;
290 const unsigned int col3_pos = col2_pos + col2_width + col_spacing;
291 const unsigned int col3_width = 0;
292 const unsigned int col4_pos = col3_pos + col3_width + col_spacing;
293 const unsigned int col4_width = 60;
294 const unsigned int col5_pos = col4_pos + col4_width + col_spacing;
295 const unsigned int col5_width = 35;
296 const unsigned int col6_pos = col5_pos + col5_width + col_spacing;
297 const unsigned int col6_width = 15;
298 const unsigned int col7_pos = col6_pos + col6_width + col_spacing;
299 const unsigned int col7_width = 1;
300
301 st->fill_to(col1_pos);
302 st->print("%*s", col1_width, type_string()); // right-justified, therefore width is required.
303
304 fill_to_pos(st, col2_pos);
305 st->print("%s", _name);
306
307 fill_to_pos(st, col4_pos);
308 JVMFlagAccess::print_range(st, this);
309
310 fill_to_pos(st, col5_pos);
311 print_kind(st, col5_width);
312
313 fill_to_pos(st, col6_pos);
314 print_origin(st, col6_width);
315
316 #ifndef PRODUCT
317 if (withComments) {
318 fill_to_pos(st, col7_pos);
319 st->print("%s", _doc);
320 }
321 #endif
322 st->cr();
323 }
324 }
325
326 void JVMFlag::print_kind(outputStream* st, unsigned int width) const {
327 struct Data {
328 int flag;
329 const char* name;
330 };
331
332 Data data[] = {
333 { KIND_JVMCI, "JVMCI" },
334 { KIND_C1, "C1" },
335 { KIND_C2, "C2" },
336 { KIND_ARCH, "ARCH" },
337 { KIND_PLATFORM_DEPENDENT, "pd" },
338 { KIND_PRODUCT, "product" },
339 { KIND_MANAGEABLE, "manageable" },
340 { KIND_DIAGNOSTIC, "diagnostic" },
341 { KIND_EXPERIMENTAL, "experimental" },
342 { KIND_DEVELOP, "develop" },
343 { KIND_LP64_PRODUCT, "lp64_product" },
344 { -1, "" }
345 };
346
347 if ((_flags & KIND_MASK) != 0) {
348 bool is_first = true;
349 const size_t buffer_size = 64;
350 size_t buffer_used = 0;
351 char kind[buffer_size];
352
353 jio_snprintf(kind, buffer_size, "{");
354 buffer_used++;
355 for (int i = 0; data[i].flag != -1; i++) {
356 Data d = data[i];
357 if ((_flags & d.flag) != 0) {
358 if (is_first) {
359 is_first = false;
360 } else {
361 assert(buffer_used + 1 < buffer_size, "Too small buffer");
362 jio_snprintf(kind + buffer_used, buffer_size - buffer_used, " ");
363 buffer_used++;
364 }
365 size_t length = strlen(d.name);
366 assert(buffer_used + length < buffer_size, "Too small buffer");
367 jio_snprintf(kind + buffer_used, buffer_size - buffer_used, "%s", d.name);
368 buffer_used += length;
369 }
370 }
371 assert(buffer_used + 2 <= buffer_size, "Too small buffer");
372 jio_snprintf(kind + buffer_used, buffer_size - buffer_used, "}");
373 st->print("%*s", width, kind);
374 }
375 }
376
377 void JVMFlag::print_origin(outputStream* st, unsigned int width) const {
378 st->print("{");
379 switch(get_origin()) {
380 case JVMFlagOrigin::DEFAULT:
381 st->print("default"); break;
382 case JVMFlagOrigin::COMMAND_LINE:
383 st->print("command line"); break;
384 case JVMFlagOrigin::ENVIRON_VAR:
385 st->print("environment"); break;
386 case JVMFlagOrigin::CONFIG_FILE:
387 st->print("config file"); break;
388 case JVMFlagOrigin::MANAGEMENT:
389 st->print("management"); break;
390 case JVMFlagOrigin::ERGONOMIC:
391 if (_flags & WAS_SET_ON_COMMAND_LINE) {
392 st->print("command line, ");
393 }
394 st->print("ergonomic"); break;
395 case JVMFlagOrigin::ATTACH_ON_DEMAND:
396 st->print("attach"); break;
397 case JVMFlagOrigin::INTERNAL:
398 st->print("internal"); break;
399 case JVMFlagOrigin::JIMAGE_RESOURCE:
400 st->print("jimage"); break;
401 }
402 st->print("}");
403 }
404
405 void JVMFlag::print_as_flag(outputStream* st) const {
406 if (is_bool()) {
407 st->print("-XX:%s%s", get_bool() ? "+" : "-", _name);
408 } else if (is_int()) {
409 st->print("-XX:%s=%d", _name, get_int());
410 } else if (is_uint()) {
411 st->print("-XX:%s=%u", _name, get_uint());
412 } else if (is_intx()) {
413 st->print("-XX:%s=" INTX_FORMAT, _name, get_intx());
414 } else if (is_uintx()) {
415 st->print("-XX:%s=" UINTX_FORMAT, _name, get_uintx());
416 } else if (is_uint64_t()) {
417 st->print("-XX:%s=" UINT64_FORMAT, _name, get_uint64_t());
418 } else if (is_size_t()) {
419 st->print("-XX:%s=" SIZE_FORMAT, _name, get_size_t());
420 } else if (is_double()) {
421 st->print("-XX:%s=%f", _name, get_double());
422 } else if (is_ccstr()) {
423 st->print("-XX:%s=", _name);
424 const char* cp = get_ccstr();
425 if (cp != nullptr) {
426 // Need to turn embedded '\n's back into separate arguments
427 // Not so efficient to print one character at a time,
428 // but the choice is to do the transformation to a buffer
429 // and print that. And this need not be efficient.
430 for (; *cp != '\0'; cp += 1) {
431 switch (*cp) {
432 default:
433 st->print("%c", *cp);
434 break;
435 case '\n':
436 st->print(" -XX:%s=", _name);
437 break;
438 }
439 }
440 }
441 } else {
442 ShouldNotReachHere();
443 }
444 }
445
446 //----------------------------------------------------------------------
447 // Build flagTable[]
448
449 // Find out the number of LP64/ARCH/JVMCI/COMPILER1/COMPILER2 flags,
450 // for JVMFlag::flag_group()
451
452 #define ENUM_F(type, name, ...) enum_##name,
453 #define IGNORE_F(...)
454
455 // dev dev-pd pro pro-pd range constraint
456 enum FlagCounter_LP64 { LP64_RUNTIME_FLAGS( ENUM_F, ENUM_F, ENUM_F, ENUM_F, IGNORE_F, IGNORE_F) num_flags_LP64 };
457 enum FlagCounter_ARCH { ARCH_FLAGS( ENUM_F, ENUM_F, IGNORE_F, IGNORE_F) num_flags_ARCH };
458 enum FlagCounter_JVMCI { JVMCI_ONLY(JVMCI_FLAGS( ENUM_F, ENUM_F, ENUM_F, ENUM_F, IGNORE_F, IGNORE_F)) num_flags_JVMCI };
459 enum FlagCounter_C1 { COMPILER1_PRESENT(C1_FLAGS(ENUM_F, ENUM_F, ENUM_F, ENUM_F, IGNORE_F, IGNORE_F)) num_flags_C1 };
460 enum FlagCounter_C2 { COMPILER2_PRESENT(C2_FLAGS(ENUM_F, ENUM_F, ENUM_F, ENUM_F, IGNORE_F, IGNORE_F)) num_flags_C2 };
461
462 const int first_flag_enum_LP64 = 0;
463 const int first_flag_enum_ARCH = first_flag_enum_LP64 + num_flags_LP64;
464 const int first_flag_enum_JVMCI = first_flag_enum_ARCH + num_flags_ARCH;
465 const int first_flag_enum_C1 = first_flag_enum_JVMCI + num_flags_JVMCI;
466 const int first_flag_enum_C2 = first_flag_enum_C1 + num_flags_C1;
467 const int first_flag_enum_other = first_flag_enum_C2 + num_flags_C2;
468
469 static constexpr int flag_group(int flag_enum) {
470 if (flag_enum < first_flag_enum_ARCH) return JVMFlag::KIND_LP64_PRODUCT;
471 if (flag_enum < first_flag_enum_JVMCI) return JVMFlag::KIND_ARCH;
472 if (flag_enum < first_flag_enum_C1) return JVMFlag::KIND_JVMCI;
473 if (flag_enum < first_flag_enum_C2) return JVMFlag::KIND_C1;
474 if (flag_enum < first_flag_enum_other) return JVMFlag::KIND_C2;
475
476 return 0;
477 }
478
479 constexpr JVMFlag::JVMFlag(int flag_enum, FlagType type, const char* name,
480 void* addr, int flags, int extra_flags, const char* doc) :
481 _addr(addr), _name(name), _flags(), _type(type) NOT_PRODUCT(COMMA _doc(doc)) {
482 flags = flags | extra_flags | static_cast<int>(JVMFlagOrigin::DEFAULT) | flag_group(flag_enum);
483 if ((flags & JVMFlag::KIND_PRODUCT) != 0) {
484 if (flags & (JVMFlag::KIND_DIAGNOSTIC | JVMFlag::KIND_MANAGEABLE | JVMFlag::KIND_EXPERIMENTAL)) {
485 // Backwards compatibility. This will be relaxed in JDK-7123237.
486 flags &= ~(JVMFlag::KIND_PRODUCT);
487 }
488 }
489 _flags = static_cast<Flags>(flags);
490 }
491
492 constexpr JVMFlag::JVMFlag(int flag_enum, FlagType type, const char* name,
493 void* addr, int flags, const char* doc) :
494 JVMFlag(flag_enum, type, name, addr, flags, /*extra_flags*/0, doc) {}
495
496 const int PRODUCT_KIND = JVMFlag::KIND_PRODUCT;
497 const int PRODUCT_KIND_PD = JVMFlag::KIND_PRODUCT | JVMFlag::KIND_PLATFORM_DEPENDENT;
498 const int DEVELOP_KIND = JVMFlag::KIND_DEVELOP;
499 const int DEVELOP_KIND_PD = JVMFlag::KIND_DEVELOP | JVMFlag::KIND_PLATFORM_DEPENDENT;
500
501 #define FLAG_TYPE(type) (JVMFlag::TYPE_ ## type)
502 #define INITIALIZE_DEVELOP_FLAG( type, name, value, ...) JVMFlag(FLAG_MEMBER_ENUM(name), FLAG_TYPE(type), XSTR(name), (void*)&name, DEVELOP_KIND, __VA_ARGS__),
503 #define INITIALIZE_DEVELOP_FLAG_PD(type, name, ...) JVMFlag(FLAG_MEMBER_ENUM(name), FLAG_TYPE(type), XSTR(name), (void*)&name, DEVELOP_KIND_PD, __VA_ARGS__),
504 #define INITIALIZE_PRODUCT_FLAG( type, name, value, ...) JVMFlag(FLAG_MEMBER_ENUM(name), FLAG_TYPE(type), XSTR(name), (void*)&name, PRODUCT_KIND, __VA_ARGS__),
505 #define INITIALIZE_PRODUCT_FLAG_PD(type, name, ...) JVMFlag(FLAG_MEMBER_ENUM(name), FLAG_TYPE(type), XSTR(name), (void*)&name, PRODUCT_KIND_PD, __VA_ARGS__),
506
507 // Handy aliases to match the symbols used in the flag specification macros.
508 const int DIAGNOSTIC = JVMFlag::KIND_DIAGNOSTIC;
509 const int MANAGEABLE = JVMFlag::KIND_MANAGEABLE;
510 const int EXPERIMENTAL = JVMFlag::KIND_EXPERIMENTAL;
511
512 #define MATERIALIZE_ALL_FLAGS \
513 ALL_FLAGS(INITIALIZE_DEVELOP_FLAG, \
514 INITIALIZE_DEVELOP_FLAG_PD, \
515 INITIALIZE_PRODUCT_FLAG, \
516 INITIALIZE_PRODUCT_FLAG_PD, \
517 IGNORE_RANGE, \
518 IGNORE_CONSTRAINT)
519
520 static JVMFlag flagTable[NUM_JVMFlagsEnum + 1] = {
521 MATERIALIZE_ALL_FLAGS
522 JVMFlag() // The iteration code wants a flag with a null name at the end of the table.
523 };
524
525 // We want flagTable[] to be completely initialized at C++ compilation time, which requires
526 // that all arguments passed to JVMFlag() constructors be constexpr. The following line
527 // checks for this -- if any non-constexpr arguments are passed, the C++ compiler will
528 // generate an error.
529 //
530 // constexpr implies internal linkage. This means the flagTable_verify_constexpr[] variable
531 // will not be included in jvmFlag.o, so there's no footprint cost for having this variable.
532 //
533 // Note that we cannot declare flagTable[] as constexpr because JVMFlag::_flags is modified
534 // at runtime.
535 constexpr JVMFlag flagTable_verify_constexpr[] = { MATERIALIZE_ALL_FLAGS };
536
537 JVMFlag* JVMFlag::flags = flagTable;
538 size_t JVMFlag::numFlags = (sizeof(flagTable) / sizeof(JVMFlag));
539
540 #define JVM_FLAG_TYPE_SIGNATURE(t) JVMFlag::type_signature<t>(),
541
542 const int JVMFlag::type_signatures[] = {
543 JVM_FLAG_NON_STRING_TYPES_DO(JVM_FLAG_TYPE_SIGNATURE)
544 JVMFlag::type_signature<ccstr>(),
545 JVMFlag::type_signature<ccstr>()
546 };
547
548 // Search the flag table for a named flag
549 JVMFlag* JVMFlag::find_flag(const char* name, size_t length, bool allow_locked, bool return_flag) {
550 JVMFlag* flag = JVMFlagLookup::find(name, length);
551 if (flag != nullptr) {
552 // Found a matching entry.
553 // Don't report develop flags in product builds.
554 if (flag->is_constant_in_binary()) {
555 return (return_flag ? flag : nullptr);
556 }
557 // Report locked flags only if allowed.
558 if (!(flag->is_unlocked() || flag->is_unlocker())) {
559 if (!allow_locked) {
560 // disable use of locked flags, e.g. diagnostic, experimental,
561 // etc. until they are explicitly unlocked
562 return nullptr;
563 }
564 }
565 return flag;
566 }
567 // JVMFlag name is not in the flag table
568 return nullptr;
569 }
570
571 JVMFlag* JVMFlag::fuzzy_match(const char* name, size_t length, bool allow_locked) {
572 double VMOptionsFuzzyMatchSimilarity = 0.7;
573 JVMFlag* match = nullptr;
574 double score;
575 double max_score = -1;
576
577 for (JVMFlag* current = &flagTable[0]; current->_name != nullptr; current++) {
578 score = StringUtils::similarity(current->_name, strlen(current->_name), name, length);
579 if (score > max_score) {
580 max_score = score;
581 match = current;
582 }
583 }
584
585 if (match == nullptr) {
586 return nullptr;
587 }
588
589 if (!(match->is_unlocked() || match->is_unlocker())) {
590 if (!allow_locked) {
591 return nullptr;
592 }
593 }
594
595 if (max_score < VMOptionsFuzzyMatchSimilarity) {
596 return nullptr;
597 }
598
599 return match;
600 }
601
602 bool JVMFlag::is_default(JVMFlagsEnum flag) {
603 return flag_from_enum(flag)->is_default();
604 }
605
606 bool JVMFlag::is_ergo(JVMFlagsEnum flag) {
607 return flag_from_enum(flag)->is_ergonomic();
608 }
609
610 bool JVMFlag::is_cmdline(JVMFlagsEnum flag) {
611 return flag_from_enum(flag)->is_command_line();
612 }
613
614 bool JVMFlag::is_jimage_resource(JVMFlagsEnum flag) {
615 return flag_from_enum(flag)->is_jimage_resource();
616 }
617
618 void JVMFlag::setOnCmdLine(JVMFlagsEnum flag) {
619 flag_from_enum(flag)->set_command_line();
620 }
621
622 extern "C" {
623 static int compare_flags(const void* void_a, const void* void_b) {
624 return strcmp((*((JVMFlag**) void_a))->name(), (*((JVMFlag**) void_b))->name());
625 }
626 }
627
628 void JVMFlag::printSetFlags(outputStream* out) {
629 // Print which flags were set on the command line
630 // note: this method is called before the thread structure is in place
631 // which means resource allocation cannot be used.
632
633 // The last entry is the null entry.
634 const size_t length = JVMFlag::numFlags - 1;
635
636 // Sort
637 JVMFlag** array = NEW_C_HEAP_ARRAY(JVMFlag*, length, mtArguments);
638 for (size_t i = 0; i < length; i++) {
639 array[i] = &flagTable[i];
640 }
641 qsort(array, length, sizeof(JVMFlag*), compare_flags);
642
643 // Print
644 for (size_t i = 0; i < length; i++) {
645 if (array[i]->get_origin() != JVMFlagOrigin::DEFAULT) {
646 array[i]->print_as_flag(out);
647 out->print(" ");
648 }
649 }
650 out->cr();
651 FREE_C_HEAP_ARRAY(JVMFlag*, array);
652 }
653
654 #ifndef PRODUCT
655
656 void JVMFlag::verify() {
657 assert(Arguments::check_vm_args_consistency(), "Some flag settings conflict");
658 }
659
660 #endif // PRODUCT
661
662 #ifdef ASSERT
663
664 void JVMFlag::assert_valid_flag_enum(JVMFlagsEnum i) {
665 assert(0 <= int(i) && int(i) < NUM_JVMFlagsEnum, "must be");
666 }
667
668 void JVMFlag::check_all_flag_declarations() {
669 for (JVMFlag* current = &flagTable[0]; current->_name != nullptr; current++) {
670 int flags = static_cast<int>(current->_flags);
671 // Backwards compatibility. This will be relaxed/removed in JDK-7123237.
672 int mask = JVMFlag::KIND_DIAGNOSTIC | JVMFlag::KIND_MANAGEABLE | JVMFlag::KIND_EXPERIMENTAL;
673 if ((flags & mask) != 0) {
674 assert((flags & mask) == JVMFlag::KIND_DIAGNOSTIC ||
675 (flags & mask) == JVMFlag::KIND_MANAGEABLE ||
676 (flags & mask) == JVMFlag::KIND_EXPERIMENTAL,
677 "%s can be declared with at most one of "
678 "DIAGNOSTIC, MANAGEABLE or EXPERIMENTAL", current->_name);
679 assert((flags & KIND_DEVELOP) == 0,
680 "%s has an optional DIAGNOSTIC, MANAGEABLE or EXPERIMENTAL "
681 "attribute; it must be declared as a product flag", current->_name);
682 }
683 }
684 }
685
686 #endif // ASSERT
687
688 void JVMFlag::printFlags(outputStream* out, bool withComments, bool printRanges, bool skipDefaults) {
689 // Print the flags sorted by name
690 // Note: This method may be called before the thread structure is in place
691 // which means resource allocation cannot be used. Also, it may be
692 // called as part of error reporting, so handle native OOMs gracefully.
693
694 // The last entry is the null entry.
695 const size_t length = JVMFlag::numFlags - 1;
696
697 // Print
698 if (!printRanges) {
699 out->print_cr("[Global flags]");
700 } else {
701 out->print_cr("[Global flags ranges]");
702 }
703
704 // Sort
705 JVMFlag** array = NEW_C_HEAP_ARRAY_RETURN_NULL(JVMFlag*, length, mtArguments);
706 if (array != nullptr) {
707 for (size_t i = 0; i < length; i++) {
708 array[i] = &flagTable[i];
709 }
710 qsort(array, length, sizeof(JVMFlag*), compare_flags);
711
712 for (size_t i = 0; i < length; i++) {
713 if (array[i]->is_unlocked() && !(skipDefaults && array[i]->is_default())) {
714 array[i]->print_on(out, withComments, printRanges);
715 }
716 }
717 FREE_C_HEAP_ARRAY(JVMFlag*, array);
718 } else {
719 // OOM? Print unsorted.
720 for (size_t i = 0; i < length; i++) {
721 if (flagTable[i].is_unlocked() && !(skipDefaults && flagTable[i].is_default())) {
722 flagTable[i].print_on(out, withComments, printRanges);
723 }
724 }
725 }
726 }
727
728 void JVMFlag::printError(bool verbose, const char* msg, ...) {
729 if (verbose) {
730 va_list listPointer;
731 va_start(listPointer, msg);
732 jio_vfprintf(defaultStream::error_stream(), msg, listPointer);
733 va_end(listPointer);
734 }
735 }