1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // This file defines all of the flags.  It is separated into different section,
6 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
7 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
8 //
9 // This include does not have a guard, because it is a template-style include,
10 // which can be included multiple times in different modes.  It expects to have
11 // a mode defined before it's included.  The modes are FLAG_MODE_... below:
12 //
13 // PRESUBMIT_INTENTIONALLY_MISSING_INCLUDE_GUARD
14 
15 #define DEFINE_IMPLICATION(whenflag, thenflag) \
16   DEFINE_VALUE_IMPLICATION(whenflag, thenflag, true)
17 
18 #define DEFINE_NEG_IMPLICATION(whenflag, thenflag) \
19   DEFINE_VALUE_IMPLICATION(whenflag, thenflag, false)
20 
21 #define DEFINE_NEG_NEG_IMPLICATION(whenflag, thenflag) \
22   DEFINE_NEG_VALUE_IMPLICATION(whenflag, thenflag, false)
23 
24 // We want to declare the names of the variables for the header file.  Normally
25 // this will just be an extern declaration, but for a readonly flag we let the
26 // compiler make better optimizations by giving it the value.
27 #if defined(FLAG_MODE_DECLARE)
28 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
29   V8_EXPORT_PRIVATE extern ctype FLAG_##nam;
30 #define FLAG_READONLY(ftype, ctype, nam, def, cmt) \
31   static constexpr ctype FLAG_##nam = def;
32 
33 // We want to supply the actual storage and value for the flag variable in the
34 // .cc file.  We only do this for writable flags.
35 #elif defined(FLAG_MODE_DEFINE)
36 #ifdef USING_V8_SHARED
37 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
38   V8_EXPORT_PRIVATE extern ctype FLAG_##nam;
39 #else
40 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
41   V8_EXPORT_PRIVATE ctype FLAG_##nam = def;
42 #endif
43 
44 // We need to define all of our default values so that the Flag structure can
45 // access them by pointer.  These are just used internally inside of one .cc,
46 // for MODE_META, so there is no impact on the flags interface.
47 #elif defined(FLAG_MODE_DEFINE_DEFAULTS)
48 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
49   static constexpr ctype FLAGDEFAULT_##nam = def;
50 
51 // We want to write entries into our meta data table, for internal parsing and
52 // printing / etc in the flag parser code.  We only do this for writable flags.
53 #elif defined(FLAG_MODE_META)
54 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
55   {Flag::TYPE_##ftype, #nam, &FLAG_##nam, &FLAGDEFAULT_##nam, cmt, false},
56 #define FLAG_ALIAS(ftype, ctype, alias, nam)                     \
57   {Flag::TYPE_##ftype,  #alias, &FLAG_##nam, &FLAGDEFAULT_##nam, \
58     "alias for --" #nam, false},
59 
60 // We produce the code to set flags when it is implied by another flag.
61 #elif defined(FLAG_MODE_DEFINE_IMPLICATIONS)
62 #define DEFINE_VALUE_IMPLICATION(whenflag, thenflag, value) \
63   if (FLAG_##whenflag) FLAG_##thenflag = value;
64 
65 #define DEFINE_GENERIC_IMPLICATION(whenflag, statement) \
66   if (FLAG_##whenflag) statement;
67 
68 #define DEFINE_NEG_VALUE_IMPLICATION(whenflag, thenflag, value) \
69   if (!FLAG_##whenflag) FLAG_##thenflag = value;
70 
71 // We apply a generic macro to the flags.
72 #elif defined(FLAG_MODE_APPLY)
73 
74 #define FLAG_FULL FLAG_MODE_APPLY
75 
76 #else
77 #error No mode supplied when including flags.defs
78 #endif
79 
80 // Dummy defines for modes where it is not relevant.
81 #ifndef FLAG_FULL
82 #define FLAG_FULL(ftype, ctype, nam, def, cmt)
83 #endif
84 
85 #ifndef FLAG_READONLY
86 #define FLAG_READONLY(ftype, ctype, nam, def, cmt)
87 #endif
88 
89 #ifndef FLAG_ALIAS
90 #define FLAG_ALIAS(ftype, ctype, alias, nam)
91 #endif
92 
93 #ifndef DEFINE_VALUE_IMPLICATION
94 #define DEFINE_VALUE_IMPLICATION(whenflag, thenflag, value)
95 #endif
96 
97 #ifndef DEFINE_GENERIC_IMPLICATION
98 #define DEFINE_GENERIC_IMPLICATION(whenflag, statement)
99 #endif
100 
101 #ifndef DEFINE_NEG_VALUE_IMPLICATION
102 #define DEFINE_NEG_VALUE_IMPLICATION(whenflag, thenflag, value)
103 #endif
104 
105 #define COMMA ,
106 
107 #ifdef FLAG_MODE_DECLARE
108 
109 struct MaybeBoolFlag {
CreateMaybeBoolFlag110   static MaybeBoolFlag Create(bool has_value, bool value) {
111     MaybeBoolFlag flag;
112     flag.has_value = has_value;
113     flag.value = value;
114     return flag;
115   }
116   bool has_value;
117   bool value;
118 
119   bool operator!=(const MaybeBoolFlag& other) const {
120     return has_value != other.has_value || value != other.value;
121   }
122 };
123 #endif
124 
125 #ifdef DEBUG
126 #define DEBUG_BOOL true
127 #else
128 #define DEBUG_BOOL false
129 #endif
130 
131 #ifdef V8_COMPRESS_POINTERS
132 #define COMPRESS_POINTERS_BOOL true
133 #else
134 #define COMPRESS_POINTERS_BOOL false
135 #endif
136 
137 #ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
138 #define ENABLE_CONTROL_FLOW_INTEGRITY_BOOL true
139 #else
140 #define ENABLE_CONTROL_FLOW_INTEGRITY_BOOL false
141 #endif
142 
143 // Supported ARM configurations are:
144 //  "armv6":       ARMv6 + VFPv2
145 //  "armv7":       ARMv7 + VFPv3-D32 + NEON
146 //  "armv7+sudiv": ARMv7 + VFPv4-D32 + NEON + SUDIV
147 //  "armv8":       ARMv8 (including all of the above)
148 #if !defined(ARM_TEST_NO_FEATURE_PROBE) ||                            \
149     (defined(CAN_USE_ARMV8_INSTRUCTIONS) &&                           \
150      defined(CAN_USE_ARMV7_INSTRUCTIONS) && defined(CAN_USE_SUDIV) && \
151      defined(CAN_USE_NEON) && defined(CAN_USE_VFP3_INSTRUCTIONS))
152 #define ARM_ARCH_DEFAULT "armv8"
153 #elif defined(CAN_USE_ARMV7_INSTRUCTIONS) && defined(CAN_USE_SUDIV) && \
154     defined(CAN_USE_NEON) && defined(CAN_USE_VFP3_INSTRUCTIONS)
155 #define ARM_ARCH_DEFAULT "armv7+sudiv"
156 #elif defined(CAN_USE_ARMV7_INSTRUCTIONS) && defined(CAN_USE_NEON) && \
157     defined(CAN_USE_VFP3_INSTRUCTIONS)
158 #define ARM_ARCH_DEFAULT "armv7"
159 #else
160 #define ARM_ARCH_DEFAULT "armv6"
161 #endif
162 
163 #ifdef V8_OS_WIN
164 #define ENABLE_LOG_COLOUR false
165 #else
166 #define ENABLE_LOG_COLOUR true
167 #endif
168 
169 #define DEFINE_BOOL(nam, def, cmt) FLAG(BOOL, bool, nam, def, cmt)
170 #define DEFINE_BOOL_READONLY(nam, def, cmt) \
171   FLAG_READONLY(BOOL, bool, nam, def, cmt)
172 #define DEFINE_MAYBE_BOOL(nam, cmt) \
173   FLAG(MAYBE_BOOL, MaybeBoolFlag, nam, {false COMMA false}, cmt)
174 #define DEFINE_INT(nam, def, cmt) FLAG(INT, int, nam, def, cmt)
175 #define DEFINE_UINT(nam, def, cmt) FLAG(UINT, unsigned int, nam, def, cmt)
176 #define DEFINE_UINT_READONLY(nam, def, cmt) \
177   FLAG_READONLY(UINT, unsigned int, nam, def, cmt)
178 #define DEFINE_UINT64(nam, def, cmt) FLAG(UINT64, uint64_t, nam, def, cmt)
179 #define DEFINE_FLOAT(nam, def, cmt) FLAG(FLOAT, double, nam, def, cmt)
180 #define DEFINE_SIZE_T(nam, def, cmt) FLAG(SIZE_T, size_t, nam, def, cmt)
181 #define DEFINE_STRING(nam, def, cmt) FLAG(STRING, const char*, nam, def, cmt)
182 #define DEFINE_ALIAS_BOOL(alias, nam) FLAG_ALIAS(BOOL, bool, alias, nam)
183 #define DEFINE_ALIAS_INT(alias, nam) FLAG_ALIAS(INT, int, alias, nam)
184 #define DEFINE_ALIAS_FLOAT(alias, nam) FLAG_ALIAS(FLOAT, double, alias, nam)
185 #define DEFINE_ALIAS_SIZE_T(alias, nam) FLAG_ALIAS(SIZE_T, size_t, alias, nam)
186 #define DEFINE_ALIAS_STRING(alias, nam) \
187   FLAG_ALIAS(STRING, const char*, alias, nam)
188 
189 #ifdef DEBUG
190 #define DEFINE_DEBUG_BOOL DEFINE_BOOL
191 #else
192 #define DEFINE_DEBUG_BOOL DEFINE_BOOL_READONLY
193 #endif
194 
195 //
196 // Flags in all modes.
197 //
198 #define FLAG FLAG_FULL
199 
200 // Flags for language modes and experimental language features.
201 DEFINE_BOOL(use_strict, false, "enforce strict mode")
202 
203 DEFINE_BOOL(es_staging, false,
204             "enable test-worthy harmony features (for internal use only)")
205 DEFINE_BOOL(harmony, false, "enable all completed harmony features")
206 DEFINE_BOOL(harmony_shipping, true, "enable all shipped harmony features")
207 DEFINE_IMPLICATION(es_staging, harmony)
208 // Enabling import.meta requires to also enable import()
209 DEFINE_IMPLICATION(harmony_import_meta, harmony_dynamic_import)
210 
211 // Update bootstrapper.cc whenever adding a new feature flag.
212 
213 // Features that are still work in progress (behind individual flags).
214 #define HARMONY_INPROGRESS_BASE(V)                                    \
215   V(harmony_string_replaceall, "harmony String.prototype.replaceAll") \
216   V(harmony_regexp_sequence, "RegExp Unicode sequence properties")    \
217   V(harmony_weak_refs, "harmony weak references")                     \
218   V(harmony_regexp_match_indices, "harmony regexp match indices")     \
219   V(harmony_top_level_await, "harmony top level await")
220 
221 #ifdef V8_INTL_SUPPORT
222 #define HARMONY_INPROGRESS(V)                       \
223   HARMONY_INPROGRESS_BASE(V)                        \
224   V(harmony_intl_displaynames_date_types, "Intl.DisplayNames date types")
225 #else
226 #define HARMONY_INPROGRESS(V) HARMONY_INPROGRESS_BASE(V)
227 #endif
228 
229 // Features that are complete (but still behind --harmony/es-staging flag).
230 #define HARMONY_STAGED_BASE(V)                                     \
231   V(harmony_private_methods, "harmony private methods in class literals")
232 
233 #ifdef V8_INTL_SUPPORT
234 #define HARMONY_STAGED(V)                                  \
235   HARMONY_STAGED_BASE(V)                                   \
236   V(harmony_intl_dateformat_day_period,                    \
237     "Add dayPeriod option to DateTimeFormat")              \
238   V(harmony_intl_dateformat_fractional_second_digits,      \
239     "Add fractionalSecondDigits option to DateTimeFormat") \
240   V(harmony_intl_segmenter, "Intl.Segmenter")
241 #else
242 #define HARMONY_STAGED(V) HARMONY_STAGED_BASE(V)
243 #endif
244 
245 // Features that are shipping (turned on by default, but internal flag remains).
246 #define HARMONY_SHIPPING_BASE(V)                               \
247   V(harmony_namespace_exports,                                 \
248     "harmony namespace exports (export * as foo from 'bar')")  \
249   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")    \
250   V(harmony_import_meta, "harmony import.meta property")       \
251   V(harmony_dynamic_import, "harmony dynamic import")          \
252   V(harmony_promise_all_settled, "harmony Promise.allSettled") \
253   V(harmony_nullish, "harmony nullish operator")               \
254   V(harmony_optional_chaining, "harmony optional chaining syntax")
255 
256 #ifdef V8_INTL_SUPPORT
257 #define HARMONY_SHIPPING(V)                               \
258   HARMONY_SHIPPING_BASE(V)                                \
259   V(harmony_intl_add_calendar_numbering_system,           \
260     "Add calendar and numberingSystem to DateTimeFormat") \
261   V(harmony_intl_displaynames, "Intl.DisplayNames")       \
262   V(harmony_intl_other_calendars, "DateTimeFormat other calendars")
263 #else
264 #define HARMONY_SHIPPING(V) HARMONY_SHIPPING_BASE(V)
265 #endif
266 
267 // Once a shipping feature has proved stable in the wild, it will be dropped
268 // from HARMONY_SHIPPING, all occurrences of the FLAG_ variable are removed,
269 // and associated tests are moved from the harmony directory to the appropriate
270 // esN directory.
271 
272 #define FLAG_INPROGRESS_FEATURES(id, description) \
273   DEFINE_BOOL(id, false, "enable " #description " (in progress)")
274 HARMONY_INPROGRESS(FLAG_INPROGRESS_FEATURES)
275 #undef FLAG_INPROGRESS_FEATURES
276 
277 #define FLAG_STAGED_FEATURES(id, description)    \
278   DEFINE_BOOL(id, false, "enable " #description) \
279   DEFINE_IMPLICATION(harmony, id)
280 HARMONY_STAGED(FLAG_STAGED_FEATURES)
281 #undef FLAG_STAGED_FEATURES
282 
283 #define FLAG_SHIPPING_FEATURES(id, description) \
284   DEFINE_BOOL(id, true, "enable " #description) \
285   DEFINE_NEG_NEG_IMPLICATION(harmony_shipping, id)
286 HARMONY_SHIPPING(FLAG_SHIPPING_FEATURES)
287 #undef FLAG_SHIPPING_FEATURES
288 
289 #ifdef V8_INTL_SUPPORT
290 DEFINE_BOOL(icu_timezone_data, true, "get information about timezones from ICU")
291 #endif
292 
293 #ifdef V8_ENABLE_DOUBLE_CONST_STORE_CHECK
294 #define V8_ENABLE_DOUBLE_CONST_STORE_CHECK_BOOL true
295 #else
296 #define V8_ENABLE_DOUBLE_CONST_STORE_CHECK_BOOL false
297 #endif
298 
299 #ifdef V8_LITE_MODE
300 #define V8_LITE_BOOL true
301 #else
302 #define V8_LITE_BOOL false
303 #endif
304 
305 #ifdef V8_ENABLE_LAZY_SOURCE_POSITIONS
306 #define V8_LAZY_SOURCE_POSITIONS_BOOL true
307 #else
308 #define V8_LAZY_SOURCE_POSITIONS_BOOL false
309 #endif
310 
311 #ifdef V8_SHARED_RO_HEAP
312 #define V8_SHARED_RO_HEAP_BOOL true
313 #else
314 #define V8_SHARED_RO_HEAP_BOOL false
315 #endif
316 
317 DEFINE_BOOL(lite_mode, V8_LITE_BOOL,
318             "enables trade-off of performance for memory savings")
319 
320 // Lite mode implies other flags to trade-off performance for memory.
321 DEFINE_IMPLICATION(lite_mode, jitless)
322 DEFINE_IMPLICATION(lite_mode, lazy_feedback_allocation)
323 DEFINE_IMPLICATION(lite_mode, optimize_for_size)
324 
325 #ifdef V8_ENABLE_THIRD_PARTY_HEAP
326 #define V8_ENABLE_THIRD_PARTY_HEAP_BOOL true
327 #else
328 #define V8_ENABLE_THIRD_PARTY_HEAP_BOOL false
329 #endif
330 
331 DEFINE_BOOL_READONLY(enable_third_party_heap, V8_ENABLE_THIRD_PARTY_HEAP_BOOL,
332                      "Use third-party heap")
333 
334 #ifdef V8_DISABLE_WRITE_BARRIERS
335 #define V8_DISABLE_WRITE_BARRIERS_BOOL true
336 #else
337 #define V8_DISABLE_WRITE_BARRIERS_BOOL false
338 #endif
339 
340 DEFINE_BOOL_READONLY(disable_write_barriers, V8_DISABLE_WRITE_BARRIERS_BOOL,
341                      "disable write barriers when GC is non-incremental "
342                      "and heap contains single generation.")
343 
344 // Disable incremental marking barriers
345 DEFINE_NEG_IMPLICATION(disable_write_barriers, incremental_marking)
346 
347 #ifdef V8_ENABLE_SINGLE_GENERATION
348 #define V8_GENERATION_BOOL true
349 #else
350 #define V8_GENERATION_BOOL false
351 #endif
352 
353 DEFINE_BOOL_READONLY(
354     single_generation, V8_GENERATION_BOOL,
355     "allocate all objects from young generation to old generation")
356 
357 // Prevent inline allocation into new space
358 DEFINE_NEG_IMPLICATION(single_generation, inline_new)
359 DEFINE_NEG_IMPLICATION(single_generation, turbo_allocation_folding)
360 
361 #ifdef V8_ENABLE_FUTURE
362 #define FUTURE_BOOL true
363 #else
364 #define FUTURE_BOOL false
365 #endif
366 DEFINE_BOOL(future, FUTURE_BOOL,
367             "Implies all staged features that we want to ship in the "
368             "not-too-far future")
369 
370 DEFINE_IMPLICATION(future, write_protect_code_memory)
371 
372 DEFINE_BOOL(assert_types, false,
373             "generate runtime type assertions to test the typer")
374 
375 // Flags for experimental implementation features.
376 DEFINE_BOOL(allocation_site_pretenuring, true,
377             "pretenure with allocation sites")
378 DEFINE_BOOL(page_promotion, true, "promote pages based on utilization")
379 DEFINE_BOOL(always_promote_young_mc, true,
380             "always promote young objects during mark-compact")
381 DEFINE_INT(page_promotion_threshold, 70,
382            "min percentage of live bytes on a page to enable fast evacuation")
383 DEFINE_BOOL(trace_pretenuring, false,
384             "trace pretenuring decisions of HAllocate instructions")
385 DEFINE_BOOL(trace_pretenuring_statistics, false,
386             "trace allocation site pretenuring statistics")
387 DEFINE_BOOL(track_fields, true, "track fields with only smi values")
388 DEFINE_BOOL(track_double_fields, true, "track fields with double values")
389 DEFINE_BOOL(track_heap_object_fields, true, "track fields with heap values")
390 DEFINE_BOOL(track_computed_fields, true, "track computed boilerplate fields")
391 DEFINE_IMPLICATION(track_double_fields, track_fields)
392 DEFINE_IMPLICATION(track_heap_object_fields, track_fields)
393 DEFINE_IMPLICATION(track_computed_fields, track_fields)
394 DEFINE_BOOL(track_field_types, true, "track field types")
395 DEFINE_IMPLICATION(track_field_types, track_fields)
396 DEFINE_IMPLICATION(track_field_types, track_heap_object_fields)
397 DEFINE_BOOL(trace_block_coverage, false,
398             "trace collected block coverage information")
399 DEFINE_BOOL(trace_protector_invalidation, false,
400             "trace protector cell invalidations")
401 DEFINE_BOOL(feedback_normalization, false,
402             "feed back normalization to constructors")
403 // TODO(jkummerow): This currently adds too much load on the stub cache.
404 DEFINE_BOOL_READONLY(internalize_on_the_fly, true,
405                      "internalize string keys for generic keyed ICs on the fly")
406 
407 // Flag for one shot optimiztions.
408 DEFINE_BOOL(enable_one_shot_optimization, false,
409             "Enable size optimizations for the code that will "
410             "only be executed once")
411 
412 // Flag for sealed, frozen elements kind instead of dictionary elements kind
413 DEFINE_BOOL_READONLY(enable_sealed_frozen_elements_kind, true,
414                      "Enable sealed, frozen elements kind")
415 
416 // Flags for data representation optimizations
417 DEFINE_BOOL(unbox_double_arrays, true, "automatically unbox arrays of doubles")
418 DEFINE_BOOL_READONLY(string_slices, true, "use string slices")
419 
420 DEFINE_INT(interrupt_budget, 144 * KB,
421            "interrupt budget which should be used for the profiler counter")
422 
423 // Flags for jitless
424 DEFINE_BOOL(jitless, V8_LITE_BOOL,
425             "Disable runtime allocation of executable memory.")
426 
427 // Jitless V8 has a few implications:
428 DEFINE_NEG_IMPLICATION(jitless, opt)
429 // Field representation tracking is only used by TurboFan.
430 DEFINE_NEG_IMPLICATION(jitless, track_field_types)
431 DEFINE_NEG_IMPLICATION(jitless, track_heap_object_fields)
432 // Regexps are interpreted.
433 DEFINE_IMPLICATION(jitless, regexp_interpret_all)
434 // asm.js validation is disabled since it triggers wasm code generation.
435 DEFINE_NEG_IMPLICATION(jitless, validate_asm)
436 // Wasm is put into interpreter-only mode. We repeat flag implications down
437 // here to ensure they're applied correctly by setting the --jitless flag.
438 DEFINE_IMPLICATION(jitless, wasm_interpret_all)
439 DEFINE_NEG_IMPLICATION(jitless, asm_wasm_lazy_compilation)
440 DEFINE_NEG_IMPLICATION(jitless, wasm_lazy_compilation)
441 // --jitless also implies --no-expose-wasm, see InitializeOncePerProcessImpl.
442 
443 // Flags for inline caching and feedback vectors.
444 DEFINE_BOOL(use_ic, true, "use inline caching")
445 DEFINE_INT(budget_for_feedback_vector_allocation, 1 * KB,
446            "The budget in amount of bytecode executed by a function before we "
447            "decide to allocate feedback vectors")
448 DEFINE_BOOL(lazy_feedback_allocation, true, "Allocate feedback vectors lazily")
449 
450 // Flags for Ignition.
451 DEFINE_BOOL(ignition_elide_noneffectful_bytecodes, true,
452             "elide bytecodes which won't have any external effect")
453 DEFINE_BOOL(ignition_reo, true, "use ignition register equivalence optimizer")
454 DEFINE_BOOL(ignition_filter_expression_positions, true,
455             "filter expression positions before the bytecode pipeline")
456 DEFINE_BOOL(ignition_share_named_property_feedback, true,
457             "share feedback slots when loading the same named property from "
458             "the same object")
459 DEFINE_BOOL(print_bytecode, false,
460             "print bytecode generated by ignition interpreter")
461 DEFINE_BOOL(enable_lazy_source_positions, V8_LAZY_SOURCE_POSITIONS_BOOL,
462             "skip generating source positions during initial compile but "
463             "regenerate when actually required")
464 DEFINE_BOOL(stress_lazy_source_positions, false,
465             "collect lazy source positions immediately after lazy compile")
466 DEFINE_STRING(print_bytecode_filter, "*",
467               "filter for selecting which functions to print bytecode")
468 #ifdef V8_TRACE_IGNITION
469 DEFINE_BOOL(trace_ignition, false,
470             "trace the bytecodes executed by the ignition interpreter")
471 #endif
472 #ifdef V8_TRACE_FEEDBACK_UPDATES
473 DEFINE_BOOL(
474     trace_feedback_updates, false,
475     "trace updates to feedback vectors during ignition interpreter execution.")
476 #endif
477 DEFINE_BOOL(trace_ignition_codegen, false,
478             "trace the codegen of ignition interpreter bytecode handlers")
479 DEFINE_BOOL(trace_ignition_dispatches, false,
480             "traces the dispatches to bytecode handlers by the ignition "
481             "interpreter")
482 DEFINE_STRING(trace_ignition_dispatches_output_file, nullptr,
483               "the file to which the bytecode handler dispatch table is "
484               "written (by default, the table is not written to a file)")
485 
486 DEFINE_BOOL(fast_math, true, "faster (but maybe less accurate) math functions")
487 DEFINE_BOOL(trace_track_allocation_sites, false,
488             "trace the tracking of allocation sites")
489 DEFINE_BOOL(trace_migration, false, "trace object migration")
490 DEFINE_BOOL(trace_generalization, false, "trace map generalization")
491 
492 // Flags for TurboProp.
493 DEFINE_BOOL(turboprop, false,
494             "enable experimental turboprop mid-tier compiler.")
495 DEFINE_NEG_IMPLICATION(turboprop, turbo_inlining)
496 DEFINE_IMPLICATION(turboprop, concurrent_inlining)
497 DEFINE_VALUE_IMPLICATION(turboprop, interrupt_budget, 15 * KB)
498 
499 // Flags for concurrent recompilation.
500 DEFINE_BOOL(concurrent_recompilation, true,
501             "optimizing hot functions asynchronously on a separate thread")
502 DEFINE_BOOL(trace_concurrent_recompilation, false,
503             "track concurrent recompilation")
504 DEFINE_INT(concurrent_recompilation_queue_length, 8,
505            "the length of the concurrent compilation queue")
506 DEFINE_INT(concurrent_recompilation_delay, 0,
507            "artificial compilation delay in ms")
508 DEFINE_BOOL(block_concurrent_recompilation, false,
509             "block queued jobs until released")
510 DEFINE_BOOL(concurrent_inlining, false,
511             "run optimizing compiler's inlining phase on a separate thread")
512 DEFINE_INT(max_serializer_nesting, 25,
513            "maximum levels for nesting child serializers")
514 DEFINE_IMPLICATION(future, concurrent_inlining)
515 DEFINE_BOOL(trace_heap_broker_verbose, false,
516             "trace the heap broker verbosely (all reports)")
517 DEFINE_BOOL(trace_heap_broker_memory, false,
518             "trace the heap broker memory (refs analysis and zone numbers)")
519 DEFINE_BOOL(trace_heap_broker, false,
520             "trace the heap broker (reports on missing data only)")
521 DEFINE_IMPLICATION(trace_heap_broker_verbose, trace_heap_broker)
522 DEFINE_IMPLICATION(trace_heap_broker_memory, trace_heap_broker)
523 
524 // Flags for stress-testing the compiler.
525 DEFINE_INT(stress_runs, 0, "number of stress runs")
526 DEFINE_INT(deopt_every_n_times, 0,
527            "deoptimize every n times a deopt point is passed")
528 DEFINE_BOOL(print_deopt_stress, false, "print number of possible deopt points")
529 
530 // Flags for TurboFan.
531 DEFINE_BOOL(opt, true, "use adaptive optimizations")
532 DEFINE_BOOL(turbo_sp_frame_access, false,
533             "use stack pointer-relative access to frame wherever possible")
534 DEFINE_BOOL(turbo_control_flow_aware_allocation, true,
535             "consider control flow while allocating registers")
536 
537 DEFINE_STRING(turbo_filter, "*", "optimization filter for TurboFan compiler")
538 DEFINE_BOOL(trace_turbo, false, "trace generated TurboFan IR")
539 DEFINE_STRING(trace_turbo_path, nullptr,
540               "directory to dump generated TurboFan IR to")
541 DEFINE_STRING(trace_turbo_filter, "*",
542               "filter for tracing turbofan compilation")
543 DEFINE_BOOL(trace_turbo_graph, false, "trace generated TurboFan graphs")
544 DEFINE_BOOL(trace_turbo_scheduled, false, "trace TurboFan IR with schedule")
545 DEFINE_IMPLICATION(trace_turbo_scheduled, trace_turbo_graph)
546 DEFINE_STRING(trace_turbo_cfg_file, nullptr,
547               "trace turbo cfg graph (for C1 visualizer) to a given file name")
548 DEFINE_BOOL(trace_turbo_types, true, "trace TurboFan's types")
549 DEFINE_BOOL(trace_turbo_scheduler, false, "trace TurboFan's scheduler")
550 DEFINE_BOOL(trace_turbo_reduction, false, "trace TurboFan's various reducers")
551 DEFINE_BOOL(trace_turbo_trimming, false, "trace TurboFan's graph trimmer")
552 DEFINE_BOOL(trace_turbo_jt, false, "trace TurboFan's jump threading")
553 DEFINE_BOOL(trace_turbo_ceq, false, "trace TurboFan's control equivalence")
554 DEFINE_BOOL(trace_turbo_loop, false, "trace TurboFan's loop optimizations")
555 DEFINE_BOOL(trace_turbo_alloc, false, "trace TurboFan's register allocator")
556 DEFINE_BOOL(trace_all_uses, false, "trace all use positions")
557 DEFINE_BOOL(trace_representation, false, "trace representation types")
558 DEFINE_BOOL(turbo_verify, DEBUG_BOOL, "verify TurboFan graphs at each phase")
559 DEFINE_STRING(turbo_verify_machine_graph, nullptr,
560               "verify TurboFan machine graph before instruction selection")
561 #ifdef ENABLE_VERIFY_CSA
562 DEFINE_BOOL(verify_csa, DEBUG_BOOL,
563             "verify TurboFan machine graph of code stubs")
564 #else
565 // Define the flag as read-only-false so that code still compiles even in the
566 // non-ENABLE_VERIFY_CSA configuration.
567 DEFINE_BOOL_READONLY(verify_csa, false,
568                      "verify TurboFan machine graph of code stubs")
569 #endif
570 DEFINE_BOOL(trace_verify_csa, false, "trace code stubs verification")
571 DEFINE_STRING(csa_trap_on_node, nullptr,
572               "trigger break point when a node with given id is created in "
573               "given stub. The format is: StubName,NodeId")
574 DEFINE_BOOL_READONLY(fixed_array_bounds_checks, true,
575                      "enable FixedArray bounds checks")
576 DEFINE_BOOL(turbo_stats, false, "print TurboFan statistics")
577 DEFINE_BOOL(turbo_stats_nvp, false,
578             "print TurboFan statistics in machine-readable format")
579 DEFINE_BOOL(turbo_stats_wasm, false,
580             "print TurboFan statistics of wasm compilations")
581 DEFINE_BOOL(turbo_splitting, true, "split nodes during scheduling in TurboFan")
582 DEFINE_BOOL(function_context_specialization, false,
583             "enable function context specialization in TurboFan")
584 DEFINE_BOOL(turbo_inlining, true, "enable inlining in TurboFan")
585 DEFINE_INT(max_inlined_bytecode_size, 500,
586            "maximum size of bytecode for a single inlining")
587 DEFINE_INT(max_inlined_bytecode_size_cumulative, 1000,
588            "maximum cumulative size of bytecode considered for inlining")
589 DEFINE_INT(max_inlined_bytecode_size_absolute, 5000,
590            "maximum cumulative size of bytecode considered for inlining")
591 DEFINE_FLOAT(reserve_inline_budget_scale_factor, 1.2,
592              "maximum cumulative size of bytecode considered for inlining")
593 DEFINE_INT(max_inlined_bytecode_size_small, 30,
594            "maximum size of bytecode considered for small function inlining")
595 DEFINE_INT(max_optimized_bytecode_size, 60 * KB,
596            "maximum bytecode size to "
597            "be considered for optimization; too high values may cause "
598            "the compiler to hit (release) assertions")
599 DEFINE_FLOAT(min_inlining_frequency, 0.15, "minimum frequency for inlining")
600 DEFINE_BOOL(polymorphic_inlining, true, "polymorphic inlining")
601 DEFINE_BOOL(stress_inline, false,
602             "set high thresholds for inlining to inline as much as possible")
603 DEFINE_VALUE_IMPLICATION(stress_inline, max_inlined_bytecode_size, 999999)
604 DEFINE_VALUE_IMPLICATION(stress_inline, max_inlined_bytecode_size_cumulative,
605                          999999)
606 DEFINE_VALUE_IMPLICATION(stress_inline, max_inlined_bytecode_size_absolute,
607                          999999)
608 DEFINE_VALUE_IMPLICATION(stress_inline, min_inlining_frequency, 0)
609 DEFINE_IMPLICATION(stress_inline, polymorphic_inlining)
610 DEFINE_BOOL(trace_turbo_inlining, false, "trace TurboFan inlining")
611 DEFINE_BOOL(turbo_inline_array_builtins, true,
612             "inline array builtins in TurboFan code")
613 DEFINE_BOOL(use_osr, true, "use on-stack replacement")
614 DEFINE_BOOL(trace_osr, false, "trace on-stack replacement")
615 DEFINE_BOOL(analyze_environment_liveness, true,
616             "analyze liveness of environment slots and zap dead values")
617 DEFINE_BOOL(trace_environment_liveness, false,
618             "trace liveness of local variable slots")
619 DEFINE_BOOL(turbo_load_elimination, true, "enable load elimination in TurboFan")
620 DEFINE_BOOL(trace_turbo_load_elimination, false,
621             "trace TurboFan load elimination")
622 DEFINE_BOOL(turbo_profiling, false, "enable profiling in TurboFan")
623 DEFINE_BOOL(turbo_verify_allocation, DEBUG_BOOL,
624             "verify register allocation in TurboFan")
625 DEFINE_BOOL(turbo_move_optimization, true, "optimize gap moves in TurboFan")
626 DEFINE_BOOL(turbo_jt, true, "enable jump threading in TurboFan")
627 DEFINE_BOOL(turbo_loop_peeling, true, "Turbofan loop peeling")
628 DEFINE_BOOL(turbo_loop_variable, true, "Turbofan loop variable optimization")
629 DEFINE_BOOL(turbo_loop_rotation, true, "Turbofan loop rotation")
630 DEFINE_BOOL(turbo_cf_optimization, true, "optimize control flow in TurboFan")
631 DEFINE_BOOL(turbo_escape, true, "enable escape analysis")
632 DEFINE_BOOL(turbo_allocation_folding, true, "Turbofan allocation folding")
633 DEFINE_BOOL(turbo_instruction_scheduling, false,
634             "enable instruction scheduling in TurboFan")
635 DEFINE_BOOL(turbo_stress_instruction_scheduling, false,
636             "randomly schedule instructions to stress dependency tracking")
637 DEFINE_IMPLICATION(turbo_stress_instruction_scheduling,
638                    turbo_instruction_scheduling)
639 DEFINE_BOOL(turbo_store_elimination, true,
640             "enable store-store elimination in TurboFan")
641 DEFINE_BOOL(trace_store_elimination, false, "trace store elimination")
642 DEFINE_BOOL(turbo_rewrite_far_jumps, true,
643             "rewrite far to near jumps (ia32,x64)")
644 DEFINE_BOOL(
645     stress_gc_during_compilation, false,
646     "simulate GC/compiler thread race related to https://crbug.com/v8/8520")
647 DEFINE_BOOL(turbo_fast_api_calls, false, "enable fast API calls from TurboFan")
648 
649 // Favor memory over execution speed.
650 DEFINE_BOOL(optimize_for_size, false,
651             "Enables optimizations which favor memory size over execution "
652             "speed")
653 DEFINE_VALUE_IMPLICATION(optimize_for_size, max_semi_space_size, 1)
654 
655 #ifdef DISABLE_UNTRUSTED_CODE_MITIGATIONS
656 #define V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS false
657 #else
658 #define V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS true
659 #endif
660 DEFINE_BOOL(untrusted_code_mitigations, V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS,
661             "Enable mitigations for executing untrusted code")
662 #undef V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS
663 
664 // Flags for native WebAssembly.
665 DEFINE_BOOL(expose_wasm, true, "expose wasm interface to JavaScript")
666 DEFINE_BOOL(assume_asmjs_origin, false,
667             "force wasm decoder to assume input is internal asm-wasm format")
668 DEFINE_INT(wasm_num_compilation_tasks, 128,
669            "maximum number of parallel compilation tasks for wasm")
670 DEFINE_DEBUG_BOOL(trace_wasm_native_heap, false,
671                   "trace wasm native heap events")
672 DEFINE_BOOL(wasm_write_protect_code_memory, false,
673             "write protect code memory on the wasm native heap")
674 DEFINE_DEBUG_BOOL(trace_wasm_serialization, false,
675                   "trace serialization/deserialization")
676 DEFINE_BOOL(wasm_async_compilation, true,
677             "enable actual asynchronous compilation for WebAssembly.compile")
678 DEFINE_BOOL(wasm_test_streaming, false,
679             "use streaming compilation instead of async compilation for tests")
680 DEFINE_UINT(wasm_max_mem_pages,
681             v8::internal::wasm::kSpecMaxWasmInitialMemoryPages,
682             "maximum initial number of 64KiB memory pages of a wasm instance")
683 DEFINE_UINT(wasm_max_mem_pages_growth,
684             v8::internal::wasm::kSpecMaxWasmMaximumMemoryPages,
685             "maximum number of 64KiB pages a Wasm memory can grow to")
686 DEFINE_UINT(wasm_max_table_size, v8::internal::wasm::kV8MaxWasmTableSize,
687             "maximum table size of a wasm instance")
688 DEFINE_UINT(wasm_max_code_space, v8::internal::kMaxWasmCodeMB,
689             "maximum committed code space for wasm (in MB)")
690 DEFINE_BOOL(wasm_tier_up, true,
691             "enable tier up to the optimizing compiler (requires --liftoff to "
692             "have an effect)")
693 DEFINE_DEBUG_BOOL(trace_wasm_decoder, false, "trace decoding of wasm code")
694 DEFINE_DEBUG_BOOL(trace_wasm_compiler, false, "trace compiling of wasm code")
695 DEFINE_DEBUG_BOOL(trace_wasm_interpreter, false,
696                   "trace interpretation of wasm code")
697 DEFINE_DEBUG_BOOL(trace_wasm_streaming, false,
698                   "trace streaming compilation of wasm code")
699 DEFINE_INT(trace_wasm_ast_start, 0,
700            "start function for wasm AST trace (inclusive)")
701 DEFINE_INT(trace_wasm_ast_end, 0, "end function for wasm AST trace (exclusive)")
702 // Enable Liftoff by default on ia32 and x64. More architectures will follow
703 // once they are implemented and sufficiently tested.
704 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64
705 DEFINE_BOOL(liftoff, true,
706             "enable Liftoff, the baseline compiler for WebAssembly")
707 #else
708 DEFINE_BOOL(liftoff, false,
709             "enable Liftoff, the baseline compiler for WebAssembly")
710 DEFINE_IMPLICATION(future, liftoff)
711 #endif
712 DEFINE_DEBUG_BOOL(trace_liftoff, false,
713                   "trace Liftoff, the baseline compiler for WebAssembly")
714 DEFINE_BOOL(trace_wasm_memory, false,
715             "print all memory updates performed in wasm code")
716 // Fuzzers use {wasm_tier_mask_for_testing} together with {liftoff} and
717 // {no_wasm_tier_up} to force some functions to be compiled with Turbofan.
718 DEFINE_INT(wasm_tier_mask_for_testing, 0,
719            "bitmask of functions to compile with TurboFan instead of Liftoff")
720 
721 DEFINE_BOOL(debug_in_liftoff, false,
722             "use Liftoff instead of the C++ interpreter for debugging "
723             "WebAssembly (experimental)")
724 DEFINE_IMPLICATION(future, debug_in_liftoff)
725 
726 DEFINE_BOOL(validate_asm, true, "validate asm.js modules before compiling")
727 DEFINE_BOOL(suppress_asm_messages, false,
728             "don't emit asm.js related messages (for golden file testing)")
729 DEFINE_BOOL(trace_asm_time, false, "log asm.js timing info to the console")
730 DEFINE_BOOL(trace_asm_scanner, false,
731             "log tokens encountered by asm.js scanner")
732 DEFINE_BOOL(trace_asm_parser, false, "verbose logging of asm.js parse failures")
733 DEFINE_BOOL(stress_validate_asm, false, "try to validate everything as asm.js")
734 
735 DEFINE_DEBUG_BOOL(dump_wasm_module, false, "dump wasm module bytes")
736 DEFINE_STRING(dump_wasm_module_path, nullptr,
737               "directory to dump wasm modules to")
738 
739 // Declare command-line flags for Wasm features. Warning: avoid using these
740 // flags directly in the implementation. Instead accept wasm::WasmFeatures
741 // for configurability.
742 #include "src/wasm/wasm-feature-flags.h"
743 
744 #define DECL_WASM_FLAG(feat, desc, val)      \
745   DEFINE_BOOL(experimental_wasm_##feat, val, \
746               "enable prototype " desc " for wasm")
747 FOREACH_WASM_FEATURE_FLAG(DECL_WASM_FLAG)
748 #undef DECL_WASM_FLAG
749 
750 DEFINE_BOOL(wasm_staging, false, "enable staged wasm features")
751 
752 #define WASM_STAGING_IMPLICATION(feat, desc, val) \
753   DEFINE_IMPLICATION(wasm_staging, experimental_wasm_##feat)
754 FOREACH_WASM_STAGING_FEATURE_FLAG(WASM_STAGING_IMPLICATION)
755 #undef WASM_STAGING_IMPLICATION
756 
757 DEFINE_BOOL(wasm_opt, false, "enable wasm optimization")
758 DEFINE_BOOL(
759     wasm_bounds_checks, true,
760     "enable bounds checks (disable for performance testing only)")
761 DEFINE_BOOL(wasm_stack_checks, true,
762             "enable stack checks (disable for performance testing only)")
763 DEFINE_BOOL(wasm_math_intrinsics, true,
764             "intrinsify some Math imports into wasm")
765 
766 DEFINE_BOOL(wasm_trap_handler, true,
767             "use signal handlers to catch out of bounds memory access in wasm"
768             " (currently Linux x86_64 only)")
769 DEFINE_BOOL(wasm_fuzzer_gen_test, false,
770             "generate a test case when running a wasm fuzzer")
771 DEFINE_IMPLICATION(wasm_fuzzer_gen_test, single_threaded)
772 DEFINE_BOOL(print_wasm_code, false, "Print WebAssembly code")
773 DEFINE_BOOL(print_wasm_stub_code, false, "Print WebAssembly stub code")
774 DEFINE_BOOL(wasm_interpret_all, false,
775             "execute all wasm code in the wasm interpreter")
776 DEFINE_BOOL(asm_wasm_lazy_compilation, false,
777             "enable lazy compilation for asm-wasm modules")
778 DEFINE_IMPLICATION(validate_asm, asm_wasm_lazy_compilation)
779 DEFINE_BOOL(wasm_lazy_compilation, false,
780             "enable lazy compilation for all wasm modules")
781 DEFINE_DEBUG_BOOL(trace_wasm_lazy_compilation, false,
782                   "trace lazy compilation of wasm functions")
783 DEFINE_BOOL(wasm_lazy_validation, false,
784             "enable lazy validation for lazily compiled wasm functions")
785 
786 // Flags for wasm prototyping that are not strictly features i.e., part of
787 // an existing proposal that may be conditionally enabled.
788 DEFINE_BOOL(wasm_atomics_on_non_shared_memory, false,
789             "allow atomic operations on non-shared WebAssembly memory")
790 DEFINE_BOOL(wasm_grow_shared_memory, true,
791             "allow growing shared WebAssembly memory objects")
792 DEFINE_BOOL(wasm_simd_post_mvp, false,
793             "allow experimental SIMD operations for prototyping that are not "
794             "included in the current proposal")
795 DEFINE_IMPLICATION(wasm_simd_post_mvp, experimental_wasm_simd)
796 
797 // wasm-interpret-all resets {asm-,}wasm-lazy-compilation.
798 DEFINE_NEG_IMPLICATION(wasm_interpret_all, asm_wasm_lazy_compilation)
799 DEFINE_NEG_IMPLICATION(wasm_interpret_all, wasm_lazy_compilation)
800 DEFINE_NEG_IMPLICATION(wasm_interpret_all, wasm_tier_up)
801 DEFINE_BOOL(wasm_code_gc, true, "enable garbage collection of wasm code")
802 DEFINE_BOOL(trace_wasm_code_gc, false, "trace garbage collection of wasm code")
803 DEFINE_BOOL(stress_wasm_code_gc, false,
804             "stress test garbage collection of wasm code")
805 DEFINE_INT(wasm_max_initial_code_space_reservation, 0,
806            "maximum size of the initial wasm code space reservation (in MB)")
807 
808 // Profiler flags.
809 DEFINE_INT(frame_count, 1, "number of stack frames inspected by the profiler")
810 
811 DEFINE_INT(stress_sampling_allocation_profiler, 0,
812            "Enables sampling allocation profiler with X as a sample interval")
813 
814 // Garbage collections flags.
815 DEFINE_SIZE_T(min_semi_space_size, 0,
816               "min size of a semi-space (in MBytes), the new space consists of "
817               "two semi-spaces")
818 DEFINE_SIZE_T(max_semi_space_size, 0,
819               "max size of a semi-space (in MBytes), the new space consists of "
820               "two semi-spaces")
821 DEFINE_INT(semi_space_growth_factor, 2, "factor by which to grow the new space")
822 DEFINE_SIZE_T(max_old_space_size, 0, "max size of the old space (in Mbytes)")
823 DEFINE_SIZE_T(
824     max_heap_size, 0,
825     "max size of the heap (in Mbytes) "
826     "both max_semi_space_size and max_old_space_size take precedence. "
827     "All three flags cannot be specified at the same time.")
828 DEFINE_SIZE_T(initial_heap_size, 0, "initial size of the heap (in Mbytes)")
829 DEFINE_BOOL(huge_max_old_generation_size, true,
830             "Increase max size of the old space to 4 GB for x64 systems with"
831             "the physical memory bigger than 16 GB")
832 DEFINE_SIZE_T(initial_old_space_size, 0, "initial old space size (in Mbytes)")
833 DEFINE_BOOL(global_gc_scheduling, true,
834             "enable GC scheduling based on global memory")
835 DEFINE_BOOL(gc_global, false, "always perform global GCs")
836 DEFINE_INT(random_gc_interval, 0,
837            "Collect garbage after random(0, X) allocations. It overrides "
838            "gc_interval.")
839 DEFINE_INT(gc_interval, -1, "garbage collect after <n> allocations")
840 DEFINE_INT(retain_maps_for_n_gc, 2,
841            "keeps maps alive for <n> old space garbage collections")
842 DEFINE_BOOL(trace_gc, false,
843             "print one trace line following each garbage collection")
844 DEFINE_BOOL(trace_gc_nvp, false,
845             "print one detailed trace line in name=value format "
846             "after each garbage collection")
847 DEFINE_BOOL(trace_gc_ignore_scavenger, false,
848             "do not print trace line after scavenger collection")
849 DEFINE_BOOL(trace_idle_notification, false,
850             "print one trace line following each idle notification")
851 DEFINE_BOOL(trace_idle_notification_verbose, false,
852             "prints the heap state used by the idle notification")
853 DEFINE_BOOL(trace_gc_verbose, false,
854             "print more details following each garbage collection")
855 DEFINE_IMPLICATION(trace_gc_verbose, trace_gc)
856 DEFINE_BOOL(trace_gc_freelists, false,
857             "prints details of each freelist before and after "
858             "each major garbage collection")
859 DEFINE_BOOL(trace_gc_freelists_verbose, false,
860             "prints details of freelists of each page before and after "
861             "each major garbage collection")
862 DEFINE_IMPLICATION(trace_gc_freelists_verbose, trace_gc_freelists)
863 DEFINE_BOOL(trace_evacuation_candidates, false,
864             "Show statistics about the pages evacuation by the compaction")
865 DEFINE_BOOL(
866     trace_allocations_origins, false,
867     "Show statistics about the origins of allocations. "
868     "Combine with --no-inline-new to track allocations from generated code")
869 DEFINE_INT(gc_freelist_strategy, 5,
870            "Freelist strategy to use: "
871            "0:FreeListLegacy. "
872            "1:FreeListFastAlloc. "
873            "2:FreeListMany. "
874            "3:FreeListManyCached. "
875            "4:FreeListManyCachedFastPath. "
876            "5:FreeListManyCachedOrigin. ")
877 
878 DEFINE_INT(trace_allocation_stack_interval, -1,
879            "print stack trace after <n> free-list allocations")
880 DEFINE_INT(trace_duplicate_threshold_kb, 0,
881            "print duplicate objects in the heap if their size is more than "
882            "given threshold")
883 DEFINE_BOOL(trace_fragmentation, false, "report fragmentation for old space")
884 DEFINE_BOOL(trace_fragmentation_verbose, false,
885             "report fragmentation for old space (detailed)")
886 DEFINE_BOOL(trace_evacuation, false, "report evacuation statistics")
887 DEFINE_BOOL(trace_mutator_utilization, false,
888             "print mutator utilization, allocation speed, gc speed")
889 DEFINE_BOOL(incremental_marking, true, "use incremental marking")
890 DEFINE_BOOL(incremental_marking_wrappers, true,
891             "use incremental marking for marking wrappers")
892 DEFINE_BOOL(trace_unmapper, false, "Trace the unmapping")
893 DEFINE_BOOL(parallel_scavenge, true, "parallel scavenge")
894 DEFINE_BOOL(trace_parallel_scavenge, false, "trace parallel scavenge")
895 DEFINE_BOOL(write_protect_code_memory, true, "write protect code memory")
896 #ifdef V8_CONCURRENT_MARKING
897 #define V8_CONCURRENT_MARKING_BOOL true
898 #else
899 #define V8_CONCURRENT_MARKING_BOOL false
900 #endif
901 DEFINE_BOOL(concurrent_marking, V8_CONCURRENT_MARKING_BOOL,
902             "use concurrent marking")
903 #ifdef V8_ARRAY_BUFFER_EXTENSION
904 #define V8_ARRAY_BUFFER_EXTENSION_BOOL true
905 #else
906 #define V8_ARRAY_BUFFER_EXTENSION_BOOL false
907 #endif
908 DEFINE_BOOL_READONLY(array_buffer_extension, V8_ARRAY_BUFFER_EXTENSION_BOOL,
909                      "enable array buffer tracking using extension objects")
910 DEFINE_IMPLICATION(array_buffer_extension, always_promote_young_mc)
911 DEFINE_BOOL(concurrent_array_buffer_sweeping, true,
912             "concurrently sweep array buffers")
913 DEFINE_BOOL(local_heaps, false, "allow heap access from background tasks")
914 DEFINE_BOOL(parallel_marking, true, "use parallel marking in atomic pause")
915 DEFINE_INT(ephemeron_fixpoint_iterations, 10,
916            "number of fixpoint iterations it takes to switch to linear "
917            "ephemeron algorithm")
918 DEFINE_BOOL(trace_concurrent_marking, false, "trace concurrent marking")
919 DEFINE_BOOL(concurrent_store_buffer, true,
920             "use concurrent store buffer processing")
921 DEFINE_BOOL(concurrent_sweeping, true, "use concurrent sweeping")
922 DEFINE_BOOL(parallel_compaction, true, "use parallel compaction")
923 DEFINE_BOOL(parallel_pointer_update, true,
924             "use parallel pointer update during compaction")
925 DEFINE_BOOL(detect_ineffective_gcs_near_heap_limit, true,
926             "trigger out-of-memory failure to avoid GC storm near heap limit")
927 DEFINE_BOOL(trace_incremental_marking, false,
928             "trace progress of the incremental marking")
929 DEFINE_BOOL(trace_stress_marking, false, "trace stress marking progress")
930 DEFINE_BOOL(trace_stress_scavenge, false, "trace stress scavenge progress")
931 DEFINE_BOOL(track_gc_object_stats, false,
932             "track object counts and memory usage")
933 DEFINE_BOOL(trace_gc_object_stats, false,
934             "trace object counts and memory usage")
935 DEFINE_BOOL(trace_zone_stats, false, "trace zone memory usage")
936 DEFINE_BOOL(track_retaining_path, false,
937             "enable support for tracking retaining path")
938 DEFINE_DEBUG_BOOL(trace_backing_store, false, "trace backing store events")
939 DEFINE_BOOL(concurrent_array_buffer_freeing, true,
940             "free array buffer allocations on a background thread")
941 DEFINE_INT(gc_stats, 0, "Used by tracing internally to enable gc statistics")
942 DEFINE_IMPLICATION(trace_gc_object_stats, track_gc_object_stats)
943 DEFINE_GENERIC_IMPLICATION(
944     track_gc_object_stats,
945     TracingFlags::gc_stats.store(
946         v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE))
947 DEFINE_GENERIC_IMPLICATION(
948     trace_gc_object_stats,
949     TracingFlags::gc_stats.store(
950         v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE))
951 DEFINE_NEG_IMPLICATION(trace_gc_object_stats, incremental_marking)
952 DEFINE_NEG_IMPLICATION(track_retaining_path, incremental_marking)
953 DEFINE_NEG_IMPLICATION(track_retaining_path, parallel_marking)
954 DEFINE_NEG_IMPLICATION(track_retaining_path, concurrent_marking)
955 DEFINE_BOOL(track_detached_contexts, true,
956             "track native contexts that are expected to be garbage collected")
957 DEFINE_BOOL(trace_detached_contexts, false,
958             "trace native contexts that are expected to be garbage collected")
959 DEFINE_IMPLICATION(trace_detached_contexts, track_detached_contexts)
960 #ifdef VERIFY_HEAP
961 DEFINE_BOOL(verify_heap, false, "verify heap pointers before and after GC")
962 DEFINE_BOOL(verify_heap_skip_remembered_set, false,
963             "disable remembered set verification")
964 #endif
965 DEFINE_BOOL(move_object_start, true, "enable moving of object starts")
966 DEFINE_BOOL(memory_reducer, true, "use memory reducer")
967 DEFINE_BOOL(memory_reducer_for_small_heaps, true,
968             "use memory reducer for small heaps")
969 DEFINE_INT(heap_growing_percent, 0,
970            "specifies heap growing factor as (1 + heap_growing_percent/100)")
971 DEFINE_INT(v8_os_page_size, 0, "override OS page size (in KBytes)")
972 DEFINE_BOOL(always_compact, false, "Perform compaction on every full GC")
973 DEFINE_BOOL(never_compact, false,
974             "Never perform compaction on full GC - testing only")
975 DEFINE_BOOL(compact_code_space, true, "Compact code space on full collections")
976 DEFINE_BOOL(flush_bytecode, true,
977             "flush of bytecode when it has not been executed recently")
978 DEFINE_BOOL(stress_flush_bytecode, false, "stress bytecode flushing")
979 DEFINE_IMPLICATION(stress_flush_bytecode, flush_bytecode)
980 DEFINE_BOOL(use_marking_progress_bar, true,
981             "Use a progress bar to scan large objects in increments when "
982             "incremental marking is active.")
983 DEFINE_BOOL(stress_per_context_marking_worklist, false,
984             "Use per-context worklist for marking")
985 DEFINE_BOOL(force_marking_deque_overflows, false,
986             "force overflows of marking deque by reducing it's size "
987             "to 64 words")
988 DEFINE_BOOL(stress_compaction, false,
989             "stress the GC compactor to flush out bugs (implies "
990             "--force_marking_deque_overflows)")
991 DEFINE_BOOL(stress_compaction_random, false,
992             "Stress GC compaction by selecting random percent of pages as "
993             "evacuation candidates. It overrides stress_compaction.")
994 DEFINE_BOOL(stress_incremental_marking, false,
995             "force incremental marking for small heaps and run it more often")
996 
997 DEFINE_BOOL(fuzzer_gc_analysis, false,
998             "prints number of allocations and enables analysis mode for gc "
999             "fuzz testing, e.g. --stress-marking, --stress-scavenge")
1000 DEFINE_INT(stress_marking, 0,
1001            "force marking at random points between 0 and X (inclusive) percent "
1002            "of the regular marking start limit")
1003 DEFINE_INT(stress_scavenge, 0,
1004            "force scavenge at random points between 0 and X (inclusive) "
1005            "percent of the new space capacity")
1006 DEFINE_IMPLICATION(fuzzer_gc_analysis, stress_marking)
1007 DEFINE_IMPLICATION(fuzzer_gc_analysis, stress_scavenge)
1008 
1009 // These flags will be removed after experiments. Do not rely on them.
1010 DEFINE_BOOL(gc_experiment_background_schedule, false,
1011             "new background GC schedule heuristics")
1012 DEFINE_BOOL(gc_experiment_less_compaction, false,
1013             "less compaction in non-memory reducing mode")
1014 
1015 DEFINE_BOOL(disable_abortjs, false, "disables AbortJS runtime function")
1016 
1017 DEFINE_BOOL(randomize_all_allocations, false,
1018             "randomize virtual memory reservations by ignoring any hints "
1019             "passed when allocating pages")
1020 
1021 DEFINE_BOOL(manual_evacuation_candidates_selection, false,
1022             "Test mode only flag. It allows an unit test to select evacuation "
1023             "candidates pages (requires --stress_compaction).")
1024 DEFINE_BOOL(fast_promotion_new_space, false,
1025             "fast promote new space on high survival rates")
1026 
1027 DEFINE_BOOL(clear_free_memory, false, "initialize free memory with 0")
1028 
1029 DEFINE_BOOL(young_generation_large_objects, true,
1030             "allocates large objects by default in the young generation large "
1031             "object space")
1032 
1033 // assembler-ia32.cc / assembler-arm.cc / assembler-x64.cc
1034 DEFINE_BOOL(debug_code, DEBUG_BOOL,
1035             "generate extra code (assertions) for debugging")
1036 DEFINE_BOOL(code_comments, false,
1037             "emit comments in code disassembly; for more readable source "
1038             "positions you should add --no-concurrent_recompilation")
1039 DEFINE_BOOL(enable_sse3, true, "enable use of SSE3 instructions if available")
1040 DEFINE_BOOL(enable_ssse3, true, "enable use of SSSE3 instructions if available")
1041 DEFINE_BOOL(enable_sse4_1, true,
1042             "enable use of SSE4.1 instructions if available")
1043 DEFINE_BOOL(enable_sse4_2, true,
1044             "enable use of SSE4.2 instructions if available")
1045 DEFINE_BOOL(enable_sahf, true,
1046             "enable use of SAHF instruction if available (X64 only)")
1047 DEFINE_BOOL(enable_avx, true, "enable use of AVX instructions if available")
1048 DEFINE_BOOL(enable_fma3, true, "enable use of FMA3 instructions if available")
1049 DEFINE_BOOL(enable_bmi1, true, "enable use of BMI1 instructions if available")
1050 DEFINE_BOOL(enable_bmi2, true, "enable use of BMI2 instructions if available")
1051 DEFINE_BOOL(enable_lzcnt, true, "enable use of LZCNT instruction if available")
1052 DEFINE_BOOL(enable_popcnt, true,
1053             "enable use of POPCNT instruction if available")
1054 DEFINE_STRING(arm_arch, ARM_ARCH_DEFAULT,
1055               "generate instructions for the selected ARM architecture if "
1056               "available: armv6, armv7, armv7+sudiv or armv8")
1057 DEFINE_BOOL(force_long_branches, false,
1058             "force all emitted branches to be in long mode (MIPS/PPC only)")
1059 DEFINE_STRING(mcpu, "auto", "enable optimization for specific cpu")
1060 DEFINE_BOOL(partial_constant_pool, true,
1061             "enable use of partial constant pools (X64 only)")
1062 
1063 // Controlling source positions for Torque/CSA code.
1064 DEFINE_BOOL(enable_source_at_csa_bind, false,
1065             "Include source information in the binary at CSA bind locations.")
1066 
1067 // Deprecated ARM flags (replaced by arm_arch).
1068 DEFINE_MAYBE_BOOL(enable_armv7, "deprecated (use --arm_arch instead)")
1069 DEFINE_MAYBE_BOOL(enable_vfp3, "deprecated (use --arm_arch instead)")
1070 DEFINE_MAYBE_BOOL(enable_32dregs, "deprecated (use --arm_arch instead)")
1071 DEFINE_MAYBE_BOOL(enable_neon, "deprecated (use --arm_arch instead)")
1072 DEFINE_MAYBE_BOOL(enable_sudiv, "deprecated (use --arm_arch instead)")
1073 DEFINE_MAYBE_BOOL(enable_armv8, "deprecated (use --arm_arch instead)")
1074 
1075 // regexp-macro-assembler-*.cc
1076 DEFINE_BOOL(enable_regexp_unaligned_accesses, true,
1077             "enable unaligned accesses for the regexp engine")
1078 
1079 // api.cc
1080 DEFINE_BOOL(script_streaming, true, "enable parsing on background")
1081 DEFINE_BOOL(
1082     finalize_streaming_on_background, false,
1083     "perform the script streaming finalization on the background thread")
1084 DEFINE_BOOL(disable_old_api_accessors, false,
1085             "Disable old-style API accessors whose setters trigger through the "
1086             "prototype chain")
1087 
1088 // bootstrapper.cc
1089 DEFINE_BOOL(expose_gc, false, "expose gc extension")
1090 DEFINE_STRING(expose_gc_as, nullptr,
1091               "expose gc extension under the specified name")
1092 DEFINE_IMPLICATION(expose_gc_as, expose_gc)
1093 DEFINE_BOOL(expose_externalize_string, false,
1094             "expose externalize string extension")
1095 DEFINE_BOOL(expose_trigger_failure, false, "expose trigger-failure extension")
1096 DEFINE_INT(stack_trace_limit, 10, "number of stack frames to capture")
1097 DEFINE_BOOL(builtins_in_stack_traces, false,
1098             "show built-in functions in stack traces")
1099 DEFINE_BOOL(experimental_stack_trace_frames, false,
1100             "enable experimental frames (API/Builtins) and stack trace layout")
1101 DEFINE_BOOL(disallow_code_generation_from_strings, false,
1102             "disallow eval and friends")
1103 DEFINE_BOOL(expose_async_hooks, false, "expose async_hooks object")
1104 DEFINE_STRING(expose_cputracemark_as, nullptr,
1105               "expose cputracemark extension under the specified name")
1106 #ifdef ENABLE_VTUNE_TRACEMARK
1107 DEFINE_BOOL(enable_vtune_domain_support, true, "enable vtune domain support")
1108 #endif  // ENABLE_VTUNE_TRACEMARK
1109 
1110 // builtins.cc
1111 DEFINE_BOOL(allow_unsafe_function_constructor, false,
1112             "allow invoking the function constructor without security checks")
1113 DEFINE_BOOL(force_slow_path, false, "always take the slow path for builtins")
1114 DEFINE_BOOL(test_small_max_function_context_stub_size, false,
1115             "enable testing the function context size overflow path "
1116             "by making the maximum size smaller")
1117 
1118 DEFINE_BOOL(inline_new, true, "use fast inline allocation")
1119 DEFINE_NEG_NEG_IMPLICATION(inline_new, turbo_allocation_folding)
1120 
1121 // codegen-ia32.cc / codegen-arm.cc
1122 DEFINE_BOOL(trace, false, "trace function calls")
1123 
1124 // codegen.cc
1125 DEFINE_BOOL(lazy, true, "use lazy compilation")
1126 DEFINE_BOOL(max_lazy, false, "ignore eager compilation hints")
1127 DEFINE_IMPLICATION(max_lazy, lazy)
1128 DEFINE_BOOL(trace_opt, false, "trace lazy optimization")
1129 DEFINE_BOOL(trace_opt_verbose, false, "extra verbose compilation tracing")
1130 DEFINE_IMPLICATION(trace_opt_verbose, trace_opt)
1131 DEFINE_BOOL(trace_opt_stats, false, "trace lazy optimization statistics")
1132 DEFINE_BOOL(trace_deopt, false, "trace optimize function deoptimization")
1133 DEFINE_BOOL(trace_file_names, false,
1134             "include file names in trace-opt/trace-deopt output")
1135 DEFINE_BOOL(always_opt, false, "always try to optimize functions")
1136 DEFINE_BOOL(always_osr, false, "always try to OSR functions")
1137 DEFINE_BOOL(prepare_always_opt, false, "prepare for turning on always opt")
1138 
1139 DEFINE_BOOL(trace_serializer, false, "print code serializer trace")
1140 #ifdef DEBUG
1141 DEFINE_BOOL(external_reference_stats, false,
1142             "print statistics on external references used during serialization")
1143 #endif  // DEBUG
1144 
1145 // compilation-cache.cc
1146 DEFINE_BOOL(compilation_cache, true, "enable compilation cache")
1147 
1148 DEFINE_BOOL(cache_prototype_transitions, true, "cache prototype transitions")
1149 
1150 // compiler-dispatcher.cc
1151 DEFINE_BOOL(parallel_compile_tasks, false, "enable parallel compile tasks")
1152 DEFINE_BOOL(compiler_dispatcher, false, "enable compiler dispatcher")
1153 DEFINE_IMPLICATION(parallel_compile_tasks, compiler_dispatcher)
1154 DEFINE_BOOL(trace_compiler_dispatcher, false,
1155             "trace compiler dispatcher activity")
1156 
1157 // cpu-profiler.cc
1158 DEFINE_INT(cpu_profiler_sampling_interval, 1000,
1159            "CPU profiler sampling interval in microseconds")
1160 
1161 // debugger
1162 DEFINE_BOOL(
1163     trace_side_effect_free_debug_evaluate, false,
1164     "print debug messages for side-effect-free debug-evaluate for testing")
1165 DEFINE_BOOL(hard_abort, true, "abort by crashing")
1166 
1167 // inspector
1168 DEFINE_BOOL(expose_inspector_scripts, false,
1169             "expose injected-script-source.js for debugging")
1170 
1171 // execution.cc
1172 DEFINE_INT(stack_size, V8_DEFAULT_STACK_SIZE_KB,
1173            "default size of stack region v8 is allowed to use (in kBytes)")
1174 
1175 // frames.cc
1176 DEFINE_INT(max_stack_trace_source_length, 300,
1177            "maximum length of function source code printed in a stack trace.")
1178 
1179 // execution.cc, messages.cc
1180 DEFINE_BOOL(clear_exceptions_on_js_entry, false,
1181             "clear pending exceptions when entering JavaScript")
1182 
1183 // counters.cc
1184 DEFINE_INT(histogram_interval, 600000,
1185            "time interval in ms for aggregating memory histograms")
1186 
1187 // heap-snapshot-generator.cc
1188 DEFINE_BOOL(heap_profiler_trace_objects, false,
1189             "Dump heap object allocations/movements/size_updates")
1190 DEFINE_BOOL(heap_profiler_use_embedder_graph, true,
1191             "Use the new EmbedderGraph API to get embedder nodes")
1192 DEFINE_INT(heap_snapshot_string_limit, 1024,
1193            "truncate strings to this length in the heap snapshot")
1194 
1195 // sampling-heap-profiler.cc
1196 DEFINE_BOOL(sampling_heap_profiler_suppress_randomness, false,
1197             "Use constant sample intervals to eliminate test flakiness")
1198 
1199 // v8.cc
1200 DEFINE_BOOL(use_idle_notification, true,
1201             "Use idle notification to reduce memory footprint.")
1202 // ic.cc
1203 DEFINE_BOOL(trace_ic, false,
1204             "trace inline cache state transitions for tools/ic-processor")
1205 DEFINE_IMPLICATION(trace_ic, log_code)
1206 DEFINE_GENERIC_IMPLICATION(
1207     trace_ic, TracingFlags::ic_stats.store(
1208                   v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE))
1209 DEFINE_BOOL_READONLY(fast_map_update, false,
1210                      "enable fast map update by caching the migration target")
1211 DEFINE_BOOL(modify_field_representation_inplace, true,
1212             "enable in-place field representation updates")
1213 DEFINE_INT(max_polymorphic_map_count, 4,
1214            "maximum number of maps to track in POLYMORPHIC state")
1215 
1216 DEFINE_BOOL(native_code_counters, DEBUG_BOOL,
1217             "generate extra code for manipulating stats counters")
1218 
1219 // objects.cc
1220 DEFINE_BOOL(thin_strings, true, "Enable ThinString support")
1221 DEFINE_BOOL(trace_prototype_users, false,
1222             "Trace updates to prototype user tracking")
1223 DEFINE_BOOL(use_verbose_printer, true, "allows verbose printing")
1224 DEFINE_BOOL(trace_for_in_enumerate, false, "Trace for-in enumerate slow-paths")
1225 DEFINE_BOOL(trace_maps, false, "trace map creation")
1226 DEFINE_BOOL(trace_maps_details, true, "also log map details")
1227 DEFINE_IMPLICATION(trace_maps, log_code)
1228 
1229 // parser.cc
1230 DEFINE_BOOL(allow_natives_syntax, false, "allow natives syntax")
1231 DEFINE_BOOL(allow_natives_for_fuzzing, false,
1232             "allow only natives explicitly whitelisted for fuzzers")
1233 DEFINE_BOOL(allow_natives_for_differential_fuzzing, false,
1234             "allow only natives explicitly whitelisted for differential "
1235             "fuzzers")
1236 DEFINE_IMPLICATION(allow_natives_for_differential_fuzzing, allow_natives_syntax)
1237 DEFINE_IMPLICATION(allow_natives_for_fuzzing, allow_natives_syntax)
1238 DEFINE_IMPLICATION(allow_natives_for_differential_fuzzing,
1239                    allow_natives_for_fuzzing)
1240 DEFINE_BOOL(parse_only, false, "only parse the sources")
1241 
1242 // simulator-arm.cc, simulator-arm64.cc and simulator-mips.cc
1243 DEFINE_BOOL(trace_sim, false, "Trace simulator execution")
1244 DEFINE_BOOL(debug_sim, false, "Enable debugging the simulator")
1245 DEFINE_BOOL(check_icache, false,
1246             "Check icache flushes in ARM and MIPS simulator")
1247 DEFINE_INT(stop_sim_at, 0, "Simulator stop after x number of instructions")
1248 #if defined(V8_TARGET_ARCH_ARM64) || defined(V8_TARGET_ARCH_MIPS64) || \
1249     defined(V8_TARGET_ARCH_PPC64)
1250 DEFINE_INT(sim_stack_alignment, 16,
1251            "Stack alignment in bytes in simulator. This must be a power of two "
1252            "and it must be at least 16. 16 is default.")
1253 #else
1254 DEFINE_INT(sim_stack_alignment, 8,
1255            "Stack alingment in bytes in simulator (4 or 8, 8 is default)")
1256 #endif
1257 DEFINE_INT(sim_stack_size, 2 * MB / KB,
1258            "Stack size of the ARM64, MIPS64 and PPC64 simulator "
1259            "in kBytes (default is 2 MB)")
1260 DEFINE_BOOL(log_colour, ENABLE_LOG_COLOUR,
1261             "When logging, try to use coloured output.")
1262 DEFINE_BOOL(trace_sim_messages, false,
1263             "Trace simulator debug messages. Implied by --trace-sim.")
1264 
1265 // isolate.cc
1266 DEFINE_BOOL(async_stack_traces, true,
1267             "include async stack traces in Error.stack")
1268 DEFINE_BOOL(stack_trace_on_illegal, false,
1269             "print stack trace when an illegal exception is thrown")
1270 DEFINE_BOOL(abort_on_uncaught_exception, false,
1271             "abort program (dump core) when an uncaught exception is thrown")
1272 DEFINE_BOOL(correctness_fuzzer_suppressions, false,
1273             "Suppress certain unspecified behaviors to ease correctness "
1274             "fuzzing: Abort program when the stack overflows or a string "
1275             "exceeds maximum length (as opposed to throwing RangeError). "
1276             "Use a fixed suppression string for error messages.")
1277 DEFINE_BOOL(randomize_hashes, true,
1278             "randomize hashes to avoid predictable hash collisions "
1279             "(with snapshots this option cannot override the baked-in seed)")
1280 DEFINE_BOOL(rehash_snapshot, true,
1281             "rehash strings from the snapshot to override the baked-in seed")
1282 DEFINE_UINT64(hash_seed, 0,
1283               "Fixed seed to use to hash property keys (0 means random)"
1284               "(with snapshots this option cannot override the baked-in seed)")
1285 DEFINE_INT(random_seed, 0,
1286            "Default seed for initializing random generator "
1287            "(0, the default, means to use system random).")
1288 DEFINE_INT(fuzzer_random_seed, 0,
1289            "Default seed for initializing fuzzer random generator "
1290            "(0, the default, means to use v8's random number generator seed).")
1291 DEFINE_BOOL(trace_rail, false, "trace RAIL mode")
1292 DEFINE_BOOL(print_all_exceptions, false,
1293             "print exception object and stack trace on each thrown exception")
1294 DEFINE_BOOL(
1295     detailed_error_stack_trace, false,
1296     "includes arguments for each function call in the error stack frames array")
1297 DEFINE_BOOL(adjust_os_scheduling_parameters, true,
1298             "adjust OS specific scheduling params for the isolate")
1299 
1300 // runtime.cc
1301 DEFINE_BOOL(runtime_call_stats, false, "report runtime call counts and times")
1302 DEFINE_GENERIC_IMPLICATION(
1303     runtime_call_stats,
1304     TracingFlags::runtime_stats.store(
1305         v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE))
1306 DEFINE_BOOL(rcs, false, "report runtime call counts and times")
1307 DEFINE_IMPLICATION(rcs, runtime_call_stats)
1308 
1309 DEFINE_BOOL(rcs_cpu_time, false,
1310             "report runtime times in cpu time (the default is wall time)")
1311 DEFINE_IMPLICATION(rcs_cpu_time, rcs)
1312 
1313 // snapshot-common.cc
1314 DEFINE_BOOL(profile_deserialization, false,
1315             "Print the time it takes to deserialize the snapshot.")
1316 DEFINE_BOOL(serialization_statistics, false,
1317             "Collect statistics on serialized objects.")
1318 #ifdef V8_ENABLE_THIRD_PARTY_HEAP
1319 DEFINE_UINT_READONLY(serialization_chunk_size, 1,
1320                      "Custom size for serialization chunks")
1321 #else
1322 DEFINE_UINT(serialization_chunk_size, 4096,
1323             "Custom size for serialization chunks")
1324 #endif
1325 // Regexp
1326 DEFINE_BOOL(regexp_optimization, true, "generate optimized regexp code")
1327 DEFINE_BOOL(regexp_mode_modifiers, false, "enable inline flags in regexp.")
1328 DEFINE_BOOL(regexp_interpret_all, false, "interpret all regexp code")
1329 #ifdef V8_TARGET_BIG_ENDIAN
1330 #define REGEXP_PEEPHOLE_OPTIMIZATION_BOOL false
1331 #else
1332 #define REGEXP_PEEPHOLE_OPTIMIZATION_BOOL true
1333 #endif
1334 DEFINE_BOOL(regexp_tier_up, true,
1335             "enable regexp interpreter and tier up to the compiler after the "
1336             "number of executions set by the tier up ticks flag")
1337 DEFINE_INT(regexp_tier_up_ticks, 1,
1338            "set the number of executions for the regexp interpreter before "
1339            "tiering-up to the compiler")
1340 DEFINE_BOOL(regexp_peephole_optimization, REGEXP_PEEPHOLE_OPTIMIZATION_BOOL,
1341             "enable peephole optimization for regexp bytecode")
1342 DEFINE_BOOL(trace_regexp_peephole_optimization, false,
1343             "trace regexp bytecode peephole optimization")
1344 DEFINE_BOOL(trace_regexp_bytecodes, false, "trace regexp bytecode execution")
1345 DEFINE_BOOL(trace_regexp_assembler, false,
1346             "trace regexp macro assembler calls.")
1347 DEFINE_BOOL(trace_regexp_parser, false, "trace regexp parsing")
1348 DEFINE_BOOL(trace_regexp_tier_up, false, "trace regexp tiering up execution")
1349 
1350 // Testing flags test/cctest/test-{flags,api,serialization}.cc
1351 DEFINE_BOOL(testing_bool_flag, true, "testing_bool_flag")
1352 DEFINE_MAYBE_BOOL(testing_maybe_bool_flag, "testing_maybe_bool_flag")
1353 DEFINE_INT(testing_int_flag, 13, "testing_int_flag")
1354 DEFINE_FLOAT(testing_float_flag, 2.5, "float-flag")
1355 DEFINE_STRING(testing_string_flag, "Hello, world!", "string-flag")
1356 DEFINE_INT(testing_prng_seed, 42, "Seed used for threading test randomness")
1357 
1358 // Test flag for a check in %OptimizeFunctionOnNextCall
1359 DEFINE_BOOL(
1360     testing_d8_test_runner, false,
1361     "test runner turns on this flag to enable a check that the funciton was "
1362     "prepared for optimization before marking it for optimization")
1363 
1364 // mksnapshot.cc
1365 DEFINE_STRING(embedded_src, nullptr,
1366               "Path for the generated embedded data file. (mksnapshot only)")
1367 DEFINE_STRING(
1368     embedded_variant, nullptr,
1369     "Label to disambiguate symbols in embedded data file. (mksnapshot only)")
1370 DEFINE_STRING(startup_src, nullptr,
1371               "Write V8 startup as C++ src. (mksnapshot only)")
1372 DEFINE_STRING(startup_blob, nullptr,
1373               "Write V8 startup blob file. (mksnapshot only)")
1374 DEFINE_STRING(target_arch, nullptr,
1375               "The mksnapshot target arch. (mksnapshot only)")
1376 DEFINE_STRING(target_os, nullptr, "The mksnapshot target os. (mksnapshot only)")
1377 DEFINE_BOOL(target_is_simulator, false,
1378             "Instruct mksnapshot that the target is meant to run in the "
1379             "simulator and it can generate simulator-specific instructions. "
1380             "(mksnapshot only)")
1381 
1382 //
1383 // Minor mark compact collector flags.
1384 //
1385 #ifdef ENABLE_MINOR_MC
1386 DEFINE_BOOL(minor_mc_parallel_marking, true,
1387             "use parallel marking for the young generation")
1388 DEFINE_BOOL(trace_minor_mc_parallel_marking, false,
1389             "trace parallel marking for the young generation")
1390 DEFINE_BOOL(minor_mc, false, "perform young generation mark compact GCs")
1391 #else
1392 DEFINE_BOOL_READONLY(minor_mc, false,
1393                      "perform young generation mark compact GCs")
1394 #endif  // ENABLE_MINOR_MC
1395 
1396 //
1397 // Dev shell flags
1398 //
1399 
1400 DEFINE_BOOL(help, false, "Print usage message, including flags, on console")
1401 DEFINE_BOOL(dump_counters, false, "Dump counters on exit")
1402 DEFINE_BOOL(dump_counters_nvp, false,
1403             "Dump counters as name-value pairs on exit")
1404 DEFINE_BOOL(use_external_strings, false, "Use external strings for source code")
1405 
1406 DEFINE_STRING(map_counters, "", "Map counters to a file")
1407 DEFINE_BOOL(mock_arraybuffer_allocator, false,
1408             "Use a mock ArrayBuffer allocator for testing.")
1409 DEFINE_SIZE_T(mock_arraybuffer_allocator_limit, 0,
1410               "Memory limit for mock ArrayBuffer allocator used to simulate "
1411               "OOM for testing.")
1412 #if V8_OS_LINUX
1413 DEFINE_BOOL(multi_mapped_mock_allocator, false,
1414             "Use a multi-mapped mock ArrayBuffer allocator for testing.")
1415 #endif
1416 
1417 // Flags for Wasm GDB remote debugging.
1418 #ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
1419 #define DEFAULT_WASM_GDB_REMOTE_PORT 8765
1420 DEFINE_BOOL(wasm_gdb_remote, false,
1421             "enable GDB-remote for WebAssembly debugging")
1422 DEFINE_INT(wasm_gdb_remote_port, DEFAULT_WASM_GDB_REMOTE_PORT,
1423            "default port for WebAssembly debugging with LLDB.")
1424 DEFINE_BOOL(wasm_pause_waiting_for_debugger, false,
1425             "pause at the first Webassembly instruction waiting for a debugger "
1426             "to attach")
1427 #endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
1428 
1429 //
1430 // GDB JIT integration flags.
1431 //
1432 #undef FLAG
1433 #ifdef ENABLE_GDB_JIT_INTERFACE
1434 #define FLAG FLAG_FULL
1435 #else
1436 #define FLAG FLAG_READONLY
1437 #endif
1438 
1439 DEFINE_BOOL(gdbjit, false, "enable GDBJIT interface")
1440 DEFINE_BOOL(gdbjit_full, false, "enable GDBJIT interface for all code objects")
1441 DEFINE_BOOL(gdbjit_dump, false, "dump elf objects with debug info to disk")
1442 DEFINE_STRING(gdbjit_dump_filter, "",
1443               "dump only objects containing this substring")
1444 
1445 #ifdef ENABLE_GDB_JIT_INTERFACE
1446 DEFINE_IMPLICATION(gdbjit_full, gdbjit)
1447 DEFINE_IMPLICATION(gdbjit_dump, gdbjit)
1448 #endif
1449 DEFINE_NEG_IMPLICATION(gdbjit, compact_code_space)
1450 
1451 //
1452 // Debug only flags
1453 //
1454 #undef FLAG
1455 #ifdef DEBUG
1456 #define FLAG FLAG_FULL
1457 #else
1458 #define FLAG FLAG_READONLY
1459 #endif
1460 
1461 // checks.cc
1462 #ifdef ENABLE_SLOW_DCHECKS
1463 DEFINE_BOOL(enable_slow_asserts, true,
1464             "enable asserts that are slow to execute")
1465 #endif
1466 
1467 // codegen-ia32.cc / codegen-arm.cc / macro-assembler-*.cc
1468 DEFINE_BOOL(print_ast, false, "print source AST")
1469 DEFINE_BOOL(trap_on_abort, false, "replace aborts by breakpoints")
1470 
1471 // compiler.cc
1472 DEFINE_BOOL(print_scopes, false, "print scopes")
1473 
1474 // contexts.cc
1475 DEFINE_BOOL(trace_contexts, false, "trace contexts operations")
1476 
1477 // heap.cc
1478 DEFINE_BOOL(gc_verbose, false, "print stuff during garbage collection")
1479 DEFINE_BOOL(code_stats, false, "report code statistics after GC")
1480 DEFINE_BOOL(print_handles, false, "report handles after GC")
1481 DEFINE_BOOL(check_handle_count, false,
1482             "Check that there are not too many handles at GC")
1483 DEFINE_BOOL(print_global_handles, false, "report global handles after GC")
1484 
1485 // TurboFan debug-only flags.
1486 DEFINE_BOOL(trace_turbo_escape, false, "enable tracing in escape analysis")
1487 
1488 // objects.cc
1489 DEFINE_BOOL(trace_module_status, false,
1490             "Trace status transitions of ECMAScript modules")
1491 DEFINE_BOOL(trace_normalization, false,
1492             "prints when objects are turned into dictionaries.")
1493 
1494 // runtime.cc
1495 DEFINE_BOOL(trace_lazy, false, "trace lazy compilation")
1496 
1497 // spaces.cc
1498 DEFINE_BOOL(collect_heap_spill_statistics, false,
1499             "report heap spill statistics along with heap_stats "
1500             "(requires heap_stats)")
1501 DEFINE_BOOL(trace_isolates, false, "trace isolate state changes")
1502 
1503 // Regexp
1504 DEFINE_BOOL(regexp_possessive_quantifier, false,
1505             "enable possessive quantifier syntax for testing")
1506 
1507 // Debugger
1508 DEFINE_BOOL(print_break_location, false, "print source location on debug break")
1509 
1510 // wasm instance management
1511 DEFINE_DEBUG_BOOL(trace_wasm_instances, false,
1512                   "trace creation and collection of wasm instances")
1513 
1514 #ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
1515 DEFINE_BOOL(trace_wasm_gdb_remote, false, "trace Webassembly GDB-remote server")
1516 #endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
1517 
1518 //
1519 // Logging and profiling flags
1520 //
1521 #undef FLAG
1522 #define FLAG FLAG_FULL
1523 
1524 // log.cc
1525 DEFINE_BOOL(log, false,
1526             "Minimal logging (no API, code, GC, suspect, or handles samples).")
1527 DEFINE_BOOL(log_all, false, "Log all events to the log file.")
1528 DEFINE_BOOL(log_api, false, "Log API events to the log file.")
1529 DEFINE_BOOL(log_code, false,
1530             "Log code events to the log file without profiling.")
1531 DEFINE_BOOL(log_handles, false, "Log global handle events.")
1532 DEFINE_BOOL(log_suspect, false, "Log suspect operations.")
1533 DEFINE_BOOL(log_source_code, false, "Log source code.")
1534 DEFINE_BOOL(log_function_events, false,
1535             "Log function events "
1536             "(parse, compile, execute) separately.")
1537 DEFINE_BOOL(prof, false,
1538             "Log statistical profiling information (implies --log-code).")
1539 
1540 DEFINE_BOOL(detailed_line_info, false,
1541             "Always generate detailed line information for CPU profiling.")
1542 
1543 #if defined(ANDROID)
1544 // Phones and tablets have processors that are much slower than desktop
1545 // and laptop computers for which current heuristics are tuned.
1546 #define DEFAULT_PROF_SAMPLING_INTERVAL 5000
1547 #else
1548 #define DEFAULT_PROF_SAMPLING_INTERVAL 1000
1549 #endif
1550 DEFINE_INT(prof_sampling_interval, DEFAULT_PROF_SAMPLING_INTERVAL,
1551            "Interval for --prof samples (in microseconds).")
1552 #undef DEFAULT_PROF_SAMPLING_INTERVAL
1553 
1554 DEFINE_BOOL(prof_cpp, false, "Like --prof, but ignore generated code.")
1555 DEFINE_IMPLICATION(prof, prof_cpp)
1556 DEFINE_BOOL(prof_browser_mode, true,
1557             "Used with --prof, turns on browser-compatible mode for profiling.")
1558 DEFINE_STRING(logfile, "v8.log", "Specify the name of the log file.")
1559 DEFINE_BOOL(logfile_per_isolate, true, "Separate log files for each isolate.")
1560 DEFINE_BOOL(ll_prof, false, "Enable low-level linux profiler.")
1561 
1562 #if V8_OS_LINUX
1563 #define DEFINE_PERF_PROF_BOOL(nam, cmt) DEFINE_BOOL(nam, false, cmt)
1564 #define DEFINE_PERF_PROF_IMPLICATION DEFINE_IMPLICATION
1565 #else
1566 #define DEFINE_PERF_PROF_BOOL(nam, cmt) DEFINE_BOOL_READONLY(nam, false, cmt)
1567 #define DEFINE_PERF_PROF_IMPLICATION(...)
1568 #endif
1569 
1570 DEFINE_PERF_PROF_BOOL(perf_basic_prof,
1571                       "Enable perf linux profiler (basic support).")
1572 DEFINE_NEG_IMPLICATION(perf_basic_prof, compact_code_space)
1573 DEFINE_PERF_PROF_BOOL(
1574     perf_basic_prof_only_functions,
1575     "Only report function code ranges to perf (i.e. no stubs).")
1576 DEFINE_PERF_PROF_IMPLICATION(perf_basic_prof_only_functions, perf_basic_prof)
1577 DEFINE_PERF_PROF_BOOL(
1578     perf_prof, "Enable perf linux profiler (experimental annotate support).")
1579 DEFINE_PERF_PROF_BOOL(
1580     perf_prof_annotate_wasm,
1581     "Used with --perf-prof, load wasm source map and provide annotate "
1582     "support (experimental).")
1583 DEFINE_PERF_PROF_BOOL(
1584     perf_prof_delete_file,
1585     "Remove the perf file right after creating it (for testing only).")
1586 DEFINE_NEG_IMPLICATION(perf_prof, compact_code_space)
1587 // TODO(v8:8462) Remove implication once perf supports remapping.
1588 DEFINE_NEG_IMPLICATION(perf_prof, write_protect_code_memory)
1589 DEFINE_NEG_IMPLICATION(perf_prof, wasm_write_protect_code_memory)
1590 
1591 // --perf-prof-unwinding-info is available only on selected architectures.
1592 #if !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_X64 && \
1593     !V8_TARGET_ARCH_S390X && !V8_TARGET_ARCH_PPC64
1594 #undef DEFINE_PERF_PROF_BOOL
1595 #define DEFINE_PERF_PROF_BOOL(nam, cmt) DEFINE_BOOL_READONLY(nam, false, cmt)
1596 #undef DEFINE_PERF_PROF_IMPLICATION
1597 #define DEFINE_PERF_PROF_IMPLICATION(...)
1598 #endif
1599 
1600 DEFINE_PERF_PROF_BOOL(
1601     perf_prof_unwinding_info,
1602     "Enable unwinding info for perf linux profiler (experimental).")
1603 DEFINE_PERF_PROF_IMPLICATION(perf_prof, perf_prof_unwinding_info)
1604 
1605 #undef DEFINE_PERF_PROF_BOOL
1606 #undef DEFINE_PERF_PROF_IMPLICATION
1607 
1608 DEFINE_STRING(gc_fake_mmap, "/tmp/__v8_gc__",
1609               "Specify the name of the file for fake gc mmap used in ll_prof")
1610 DEFINE_BOOL(log_internal_timer_events, false, "Time internal events.")
1611 DEFINE_IMPLICATION(log_internal_timer_events, prof)
1612 
1613 DEFINE_BOOL(redirect_code_traces, false,
1614             "output deopt information and disassembly into file "
1615             "code-<pid>-<isolate id>.asm")
1616 DEFINE_STRING(redirect_code_traces_to, nullptr,
1617               "output deopt information and disassembly into the given file")
1618 
1619 DEFINE_BOOL(print_opt_source, false,
1620             "print source code of optimized and inlined functions")
1621 
1622 DEFINE_BOOL(vtune_prof_annotate_wasm, false,
1623             "Used when v8_enable_vtunejit is enabled, load wasm source map and "
1624             "provide annotate support (experimental).")
1625 
1626 DEFINE_BOOL(win64_unwinding_info, true, "Enable unwinding info for Windows/x64")
1627 
1628 #if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_S390X)
1629 // Unsupported on above architectures. See https://crbug.com/v8/8713.
1630 DEFINE_BOOL_READONLY(
1631     interpreted_frames_native_stack, false,
1632     "Show interpreted frames on the native stack (useful for external "
1633     "profilers).")
1634 #else
1635 DEFINE_BOOL(interpreted_frames_native_stack, false,
1636             "Show interpreted frames on the native stack (useful for external "
1637             "profilers).")
1638 #endif
1639 
1640 //
1641 // Disassembler only flags
1642 //
1643 #undef FLAG
1644 #ifdef ENABLE_DISASSEMBLER
1645 #define FLAG FLAG_FULL
1646 #else
1647 #define FLAG FLAG_READONLY
1648 #endif
1649 
1650 // elements.cc
1651 DEFINE_BOOL(trace_elements_transitions, false, "trace elements transitions")
1652 
1653 DEFINE_BOOL(trace_creation_allocation_sites, false,
1654             "trace the creation of allocation sites")
1655 
1656 DEFINE_BOOL(print_code, false, "print generated code")
1657 DEFINE_BOOL(print_opt_code, false, "print optimized code")
1658 DEFINE_STRING(print_opt_code_filter, "*", "filter for printing optimized code")
1659 DEFINE_BOOL(print_code_verbose, false, "print more information for code")
1660 DEFINE_BOOL(print_builtin_code, false, "print generated code for builtins")
1661 DEFINE_STRING(print_builtin_code_filter, "*",
1662               "filter for printing builtin code")
1663 DEFINE_BOOL(print_regexp_code, false, "print generated regexp code")
1664 DEFINE_BOOL(print_regexp_bytecode, false, "print generated regexp bytecode")
1665 DEFINE_BOOL(print_builtin_size, false, "print code size for builtins")
1666 
1667 #ifdef ENABLE_DISASSEMBLER
1668 DEFINE_BOOL(sodium, false,
1669             "print generated code output suitable for use with "
1670             "the Sodium code viewer")
1671 
1672 DEFINE_IMPLICATION(sodium, print_code)
1673 DEFINE_IMPLICATION(sodium, print_opt_code)
1674 DEFINE_IMPLICATION(sodium, code_comments)
1675 
1676 DEFINE_BOOL(print_all_code, false, "enable all flags related to printing code")
1677 DEFINE_IMPLICATION(print_all_code, print_code)
1678 DEFINE_IMPLICATION(print_all_code, print_opt_code)
1679 DEFINE_IMPLICATION(print_all_code, print_code_verbose)
1680 DEFINE_IMPLICATION(print_all_code, print_builtin_code)
1681 DEFINE_IMPLICATION(print_all_code, print_regexp_code)
1682 DEFINE_IMPLICATION(print_all_code, code_comments)
1683 #endif
1684 
1685 #undef FLAG
1686 #define FLAG FLAG_FULL
1687 
1688 //
1689 // Predictable mode related flags.
1690 //
1691 
1692 DEFINE_BOOL(predictable, false, "enable predictable mode")
1693 DEFINE_IMPLICATION(predictable, single_threaded)
1694 DEFINE_NEG_IMPLICATION(predictable, memory_reducer)
1695 DEFINE_VALUE_IMPLICATION(single_threaded, wasm_num_compilation_tasks, 0)
1696 DEFINE_NEG_IMPLICATION(single_threaded, wasm_async_compilation)
1697 
1698 DEFINE_BOOL(predictable_gc_schedule, false,
1699             "Predictable garbage collection schedule. Fixes heap growing, "
1700             "idle, and memory reducing behavior.")
1701 DEFINE_VALUE_IMPLICATION(predictable_gc_schedule, min_semi_space_size, 4)
1702 DEFINE_VALUE_IMPLICATION(predictable_gc_schedule, max_semi_space_size, 4)
1703 DEFINE_VALUE_IMPLICATION(predictable_gc_schedule, heap_growing_percent, 30)
1704 DEFINE_NEG_IMPLICATION(predictable_gc_schedule, memory_reducer)
1705 
1706 //
1707 // Threading related flags.
1708 //
1709 
1710 DEFINE_BOOL(single_threaded, false, "disable the use of background tasks")
1711 DEFINE_IMPLICATION(single_threaded, single_threaded_gc)
1712 DEFINE_NEG_IMPLICATION(single_threaded, concurrent_recompilation)
1713 DEFINE_NEG_IMPLICATION(single_threaded, compiler_dispatcher)
1714 
1715 //
1716 // Parallel and concurrent GC (Orinoco) related flags.
1717 //
1718 DEFINE_BOOL(single_threaded_gc, false, "disable the use of background gc tasks")
1719 DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_marking)
1720 DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_sweeping)
1721 DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_compaction)
1722 DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_marking)
1723 DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_pointer_update)
1724 DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_scavenge)
1725 DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_store_buffer)
1726 #ifdef ENABLE_MINOR_MC
1727 DEFINE_NEG_IMPLICATION(single_threaded_gc, minor_mc_parallel_marking)
1728 #endif  // ENABLE_MINOR_MC
1729 DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_array_buffer_freeing)
1730 DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_array_buffer_sweeping)
1731 
1732 #undef FLAG
1733 
1734 #ifdef VERIFY_PREDICTABLE
1735 #define FLAG FLAG_FULL
1736 #else
1737 #define FLAG FLAG_READONLY
1738 #endif
1739 
1740 DEFINE_BOOL(verify_predictable, false,
1741             "this mode is used for checking that V8 behaves predictably")
1742 DEFINE_INT(dump_allocations_digest_at_alloc, -1,
1743            "dump allocations digest each n-th allocation")
1744 
1745 //
1746 // Read-only flags
1747 //
1748 #undef FLAG
1749 #define FLAG FLAG_READONLY
1750 
1751 // assembler.h
1752 DEFINE_BOOL(enable_embedded_constant_pool, V8_EMBEDDED_CONSTANT_POOL,
1753             "enable use of embedded constant pools (PPC only)")
1754 
1755 DEFINE_BOOL(unbox_double_fields, V8_DOUBLE_FIELDS_UNBOXING,
1756             "enable in-object double fields unboxing (64-bit only)")
1757 DEFINE_IMPLICATION(unbox_double_fields, track_double_fields)
1758 
1759 // Cleanup...
1760 #undef FLAG_FULL
1761 #undef FLAG_READONLY
1762 #undef FLAG
1763 #undef FLAG_ALIAS
1764 
1765 #undef DEFINE_BOOL
1766 #undef DEFINE_MAYBE_BOOL
1767 #undef DEFINE_DEBUG_BOOL
1768 #undef DEFINE_INT
1769 #undef DEFINE_STRING
1770 #undef DEFINE_FLOAT
1771 #undef DEFINE_IMPLICATION
1772 #undef DEFINE_NEG_IMPLICATION
1773 #undef DEFINE_NEG_VALUE_IMPLICATION
1774 #undef DEFINE_VALUE_IMPLICATION
1775 #undef DEFINE_GENERIC_IMPLICATION
1776 #undef DEFINE_ALIAS_BOOL
1777 #undef DEFINE_ALIAS_INT
1778 #undef DEFINE_ALIAS_STRING
1779 #undef DEFINE_ALIAS_FLOAT
1780 
1781 #undef FLAG_MODE_DECLARE
1782 #undef FLAG_MODE_DEFINE
1783 #undef FLAG_MODE_DEFINE_DEFAULTS
1784 #undef FLAG_MODE_META
1785 #undef FLAG_MODE_DEFINE_IMPLICATIONS
1786 #undef FLAG_MODE_APPLY
1787 
1788 #undef COMMA
1789