1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 // This file defines all of the flags. It is separated into different section,
29 // for Debug, Release, Logging and Profiling, etc. To add a new flag, find the
30 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
32 // This include does not have a guard, because it is a template-style include,
33 // which can be included multiple times in different modes. It expects to have
34 // a mode defined before it's included. The modes are FLAG_MODE_... below:
36 // We want to declare the names of the variables for the header file. Normally
37 // this will just be an extern declaration, but for a readonly flag we let the
38 // compiler make better optimizations by giving it the value.
39 #if defined(FLAG_MODE_DECLARE)
40 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
41 extern ctype FLAG_##nam;
42 #define FLAG_READONLY(ftype, ctype, nam, def, cmt) \
43 static ctype const FLAG_##nam = def;
44 #define DEFINE_implication(whenflag, thenflag)
46 // We want to supply the actual storage and value for the flag variable in the
47 // .cc file. We only do this for writable flags.
48 #elif defined(FLAG_MODE_DEFINE)
49 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
50 ctype FLAG_##nam = def;
51 #define FLAG_READONLY(ftype, ctype, nam, def, cmt)
52 #define DEFINE_implication(whenflag, thenflag)
54 // We need to define all of our default values so that the Flag structure can
55 // access them by pointer. These are just used internally inside of one .cc,
56 // for MODE_META, so there is no impact on the flags interface.
57 #elif defined(FLAG_MODE_DEFINE_DEFAULTS)
58 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
59 static ctype const FLAGDEFAULT_##nam = def;
60 #define FLAG_READONLY(ftype, ctype, nam, def, cmt)
61 #define DEFINE_implication(whenflag, thenflag)
63 // We want to write entries into our meta data table, for internal parsing and
64 // printing / etc in the flag parser code. We only do this for writable flags.
65 #elif defined(FLAG_MODE_META)
66 #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
67 { Flag::TYPE_##ftype, #nam, &FLAG_##nam, &FLAGDEFAULT_##nam, cmt, false },
68 #define FLAG_READONLY(ftype, ctype, nam, def, cmt)
69 #define DEFINE_implication(whenflag, thenflag)
71 // We produce the code to set flags when it is implied by another flag.
72 #elif defined(FLAG_MODE_DEFINE_IMPLICATIONS)
73 #define FLAG_FULL(ftype, ctype, nam, def, cmt)
74 #define FLAG_READONLY(ftype, ctype, nam, def, cmt)
75 #define DEFINE_implication(whenflag, thenflag) \
76 if (FLAG_##whenflag) FLAG_##thenflag = true;
79 #error No mode supplied when including flags.defs
82 #ifdef FLAG_MODE_DECLARE
83 // Structure used to hold a collection of arguments to the JavaScript code.
84 #define JSARGUMENTS_INIT {{}}
87 inline int argc() const {
88 return static_cast<int>(storage_[0]);
90 inline const char** argv() const {
91 return reinterpret_cast<const char**>(storage_[1]);
93 inline const char*& operator[] (int idx) const {
96 inline JSArguments& operator=(JSArguments args) {
97 set_argc(args.argc());
98 set_argv(args.argv());
101 static JSArguments Create(int argc, const char** argv) {
108 void set_argc(int argc) {
111 void set_argv(const char** argv) {
112 storage_[1] = reinterpret_cast<AtomicWord>(argv);
115 // Contains argc and argv. Unfortunately we have to store these two fields
116 // into a single one to avoid making the initialization macro (which would be
117 // "{ 0, NULL }") contain a coma.
118 AtomicWord storage_[2];
122 #if (defined CAN_USE_VFP3_INSTRUCTIONS) || !(defined ARM_TEST)
123 # define ENABLE_VFP3_DEFAULT true
125 # define ENABLE_VFP3_DEFAULT false
127 #if (defined CAN_USE_ARMV7_INSTRUCTIONS) || !(defined ARM_TEST)
128 # define ENABLE_ARMV7_DEFAULT true
130 # define ENABLE_ARMV7_DEFAULT false
132 #if (defined CAN_USE_VFP32DREGS) || !(defined ARM_TEST)
133 # define ENABLE_32DREGS_DEFAULT true
135 # define ENABLE_32DREGS_DEFAULT false
138 #define DEFINE_bool(nam, def, cmt) FLAG(BOOL, bool, nam, def, cmt)
139 #define DEFINE_int(nam, def, cmt) FLAG(INT, int, nam, def, cmt)
140 #define DEFINE_float(nam, def, cmt) FLAG(FLOAT, double, nam, def, cmt)
141 #define DEFINE_string(nam, def, cmt) FLAG(STRING, const char*, nam, def, cmt)
142 #define DEFINE_args(nam, def, cmt) FLAG(ARGS, JSArguments, nam, def, cmt)
145 // Flags in all modes.
147 #define FLAG FLAG_FULL
149 // Flags for language modes and experimental language features.
150 DEFINE_bool(use_strict, false, "enforce strict mode")
151 DEFINE_bool(es5_readonly, true,
152 "activate correct semantics for inheriting readonliness")
153 DEFINE_bool(es52_globals, true,
154 "activate new semantics for global var declarations")
156 DEFINE_bool(harmony_typeof, false, "enable harmony semantics for typeof")
157 DEFINE_bool(harmony_scoping, false, "enable harmony block scoping")
158 DEFINE_bool(harmony_modules, false,
159 "enable harmony modules (implies block scoping)")
160 DEFINE_bool(harmony_symbols, false,
161 "enable harmony symbols (a.k.a. private names)")
162 DEFINE_bool(harmony_proxies, false, "enable harmony proxies")
163 DEFINE_bool(harmony_collections, false,
164 "enable harmony collections (sets, maps, and weak maps)")
165 DEFINE_bool(harmony_observation, false,
166 "enable harmony object observation (implies harmony collections")
167 DEFINE_bool(harmony_typed_arrays, false,
168 "enable harmony typed arrays")
169 DEFINE_bool(harmony_array_buffer, false,
170 "enable harmony array buffer")
171 DEFINE_implication(harmony_typed_arrays, harmony_array_buffer)
172 DEFINE_bool(harmony_generators, false, "enable harmony generators")
173 DEFINE_bool(harmony_iteration, false, "enable harmony iteration (for-of)")
174 DEFINE_bool(harmony_numeric_literals, false,
175 "enable harmony numeric literals (0o77, 0b11)")
176 DEFINE_bool(harmony, false, "enable all harmony features (except typeof)")
177 DEFINE_implication(harmony, harmony_scoping)
178 DEFINE_implication(harmony, harmony_modules)
179 DEFINE_implication(harmony, harmony_symbols)
180 DEFINE_implication(harmony, harmony_proxies)
181 DEFINE_implication(harmony, harmony_collections)
182 DEFINE_implication(harmony, harmony_observation)
183 DEFINE_implication(harmony, harmony_generators)
184 DEFINE_implication(harmony, harmony_iteration)
185 DEFINE_implication(harmony, harmony_numeric_literals)
186 DEFINE_implication(harmony_modules, harmony_scoping)
187 DEFINE_implication(harmony_observation, harmony_collections)
188 // TODO[dslomov] add harmony => harmony_typed_arrays
190 // Flags for experimental implementation features.
191 DEFINE_bool(packed_arrays, true, "optimizes arrays that have no holes")
192 DEFINE_bool(smi_only_arrays, true, "tracks arrays with only smi values")
193 DEFINE_bool(compiled_transitions, true, "use optimizing compiler to "
194 "generate array elements transition stubs")
195 DEFINE_bool(compiled_keyed_stores, true, "use optimizing compiler to "
196 "generate keyed store stubs")
197 DEFINE_bool(clever_optimizations,
199 "Optimize object size, Array shift, DOM strings and string +")
200 DEFINE_bool(pretenuring, true, "allocate objects in old space")
201 // TODO(hpayer): We will remove this flag as soon as we have pretenuring
202 // support for specific allocation sites.
203 DEFINE_bool(pretenuring_call_new, false, "pretenure call new")
204 DEFINE_bool(track_fields, true, "track fields with only smi values")
205 DEFINE_bool(track_double_fields, true, "track fields with double values")
206 DEFINE_bool(track_heap_object_fields, true, "track fields with heap values")
207 DEFINE_bool(track_computed_fields, true, "track computed boilerplate fields")
208 DEFINE_implication(track_double_fields, track_fields)
209 DEFINE_implication(track_heap_object_fields, track_fields)
210 DEFINE_implication(track_computed_fields, track_fields)
212 // Flags for data representation optimizations
213 DEFINE_bool(unbox_double_arrays, true, "automatically unbox arrays of doubles")
214 DEFINE_bool(string_slices, true, "use string slices")
216 // Flags for Crankshaft.
217 DEFINE_bool(crankshaft, true, "use crankshaft")
218 DEFINE_string(hydrogen_filter, "*", "optimization filter")
219 DEFINE_bool(use_range, true, "use hydrogen range analysis")
220 DEFINE_bool(use_gvn, true, "use hydrogen global value numbering")
221 DEFINE_bool(use_canonicalizing, true, "use hydrogen instruction canonicalizing")
222 DEFINE_bool(use_inlining, true, "use function inlining")
223 DEFINE_bool(use_escape_analysis, false, "use hydrogen escape analysis")
224 DEFINE_bool(use_allocation_folding, true, "use allocation folding")
225 DEFINE_int(max_inlining_levels, 5, "maximum number of inlining levels")
226 DEFINE_int(max_inlined_source_size, 600,
227 "maximum source size in bytes considered for a single inlining")
228 DEFINE_int(max_inlined_nodes, 196,
229 "maximum number of AST nodes considered for a single inlining")
230 DEFINE_int(max_inlined_nodes_cumulative, 400,
231 "maximum cumulative number of AST nodes considered for inlining")
232 DEFINE_bool(loop_invariant_code_motion, true, "loop invariant code motion")
233 DEFINE_bool(fast_math, true, "faster (but maybe less accurate) math functions")
234 DEFINE_bool(collect_megamorphic_maps_from_stub_cache,
236 "crankshaft harvests type feedback from stub cache")
237 DEFINE_bool(hydrogen_stats, false, "print statistics for hydrogen")
238 DEFINE_bool(trace_hydrogen, false, "trace generated hydrogen to file")
239 DEFINE_string(trace_phase, "Z", "trace generated IR for specified phases")
240 DEFINE_bool(trace_inlining, false, "trace inlining decisions")
241 DEFINE_bool(trace_alloc, false, "trace register allocator")
242 DEFINE_bool(trace_all_uses, false, "trace all use positions")
243 DEFINE_bool(trace_range, false, "trace range analysis")
244 DEFINE_bool(trace_gvn, false, "trace global value numbering")
245 DEFINE_bool(trace_representation, false, "trace representation types")
246 DEFINE_bool(trace_escape_analysis, false, "trace hydrogen escape analysis")
247 DEFINE_bool(trace_allocation_folding, false, "trace allocation folding")
248 DEFINE_bool(trace_track_allocation_sites, false,
249 "trace the tracking of allocation sites")
250 DEFINE_bool(trace_migration, false, "trace object migration")
251 DEFINE_bool(trace_generalization, false, "trace map generalization")
252 DEFINE_bool(stress_pointer_maps, false, "pointer map for every instruction")
253 DEFINE_bool(stress_environments, false, "environment for every instruction")
254 DEFINE_int(deopt_every_n_times,
256 "deoptimize every n times a deopt point is passed")
257 DEFINE_int(deopt_every_n_garbage_collections,
259 "deoptimize every n garbage collections")
260 DEFINE_bool(print_deopt_stress, false, "print number of possible deopt points")
261 DEFINE_bool(trap_on_deopt, false, "put a break point before deoptimizing")
262 DEFINE_bool(deoptimize_uncommon_cases, true, "deoptimize uncommon cases")
263 DEFINE_bool(polymorphic_inlining, true, "polymorphic inlining")
264 DEFINE_bool(use_osr, true, "use on-stack replacement")
265 DEFINE_bool(idefs, false, "use informative definitions")
266 DEFINE_bool(array_bounds_checks_elimination, true,
267 "perform array bounds checks elimination")
268 DEFINE_bool(array_index_dehoisting, true,
269 "perform array index dehoisting")
270 DEFINE_bool(analyze_environment_liveness, true,
271 "analyze liveness of environment slots and zap dead values")
272 DEFINE_bool(dead_code_elimination, true, "use dead code elimination")
273 DEFINE_bool(fold_constants, true, "use constant folding")
274 DEFINE_bool(trace_dead_code_elimination, false, "trace dead code elimination")
275 DEFINE_bool(unreachable_code_elimination, false,
276 "eliminate unreachable code (hidden behind soft deopts)")
277 DEFINE_bool(track_allocation_sites, true,
278 "Use allocation site info to reduce transitions")
279 DEFINE_bool(trace_osr, false, "trace on-stack replacement")
280 DEFINE_int(stress_runs, 0, "number of stress runs")
281 DEFINE_bool(optimize_closures, true, "optimize closures")
282 DEFINE_bool(lookup_sample_by_shared, true,
283 "when picking a function to optimize, watch for shared function "
284 "info, not JSFunction itself")
285 DEFINE_bool(cache_optimized_code, true,
286 "cache optimized code for closures")
287 DEFINE_bool(flush_optimized_code_cache, true,
288 "flushes the cache of optimized code for closures on every GC")
289 DEFINE_bool(inline_construct, true, "inline constructor calls")
290 DEFINE_bool(inline_arguments, true, "inline functions with arguments object")
291 DEFINE_bool(inline_accessors, true, "inline JavaScript accessors")
292 DEFINE_int(loop_weight, 1, "loop weight for representation inference")
294 DEFINE_bool(optimize_for_in, true,
295 "optimize functions containing for-in loops")
296 DEFINE_bool(opt_safe_uint32_operations, true,
297 "allow uint32 values on optimize frames if they are used only in "
300 DEFINE_bool(parallel_recompilation, true,
301 "optimizing hot functions asynchronously on a separate thread")
302 DEFINE_bool(trace_parallel_recompilation, false, "track parallel recompilation")
303 DEFINE_int(parallel_recompilation_queue_length, 8,
304 "the length of the parallel compilation queue")
305 DEFINE_int(parallel_recompilation_delay, 0,
306 "artificial compilation delay in ms")
307 DEFINE_bool(omit_prototype_checks_for_leaf_maps, true,
308 "do not emit prototype checks if all prototypes have leaf maps, "
309 "deoptimize the optimized code if the layout of the maps changes.")
311 // Experimental profiler changes.
312 DEFINE_bool(experimental_profiler, true, "enable all profiler experiments")
313 DEFINE_bool(watch_ic_patching, false, "profiler considers IC stability")
314 DEFINE_int(frame_count, 1, "number of stack frames inspected by the profiler")
315 DEFINE_bool(self_optimization, false,
316 "primitive functions trigger their own optimization")
317 DEFINE_bool(direct_self_opt, false,
318 "call recompile stub directly when self-optimizing")
319 DEFINE_bool(retry_self_opt, false, "re-try self-optimization if it failed")
320 DEFINE_bool(interrupt_at_exit, false,
321 "insert an interrupt check at function exit")
322 DEFINE_bool(weighted_back_edges, false,
323 "weight back edges by jump distance for interrupt triggering")
324 // 0x1700 fits in the immediate field of an ARM instruction.
325 DEFINE_int(interrupt_budget, 0x1700,
326 "execution budget before interrupt is triggered")
327 DEFINE_int(type_info_threshold, 25,
328 "percentage of ICs that must have type info to allow optimization")
329 DEFINE_int(self_opt_count, 130, "call count before self-optimization")
331 DEFINE_implication(experimental_profiler, watch_ic_patching)
332 DEFINE_implication(experimental_profiler, self_optimization)
333 // Not implying direct_self_opt here because it seems to be a bad idea.
334 DEFINE_implication(experimental_profiler, retry_self_opt)
335 DEFINE_implication(experimental_profiler, interrupt_at_exit)
336 DEFINE_implication(experimental_profiler, weighted_back_edges)
338 DEFINE_bool(trace_opt_verbose, false, "extra verbose compilation tracing")
339 DEFINE_implication(trace_opt_verbose, trace_opt)
341 // assembler-ia32.cc / assembler-arm.cc / assembler-x64.cc
342 DEFINE_bool(debug_code, false,
343 "generate extra code (assertions) for debugging")
344 DEFINE_bool(code_comments, false, "emit comments in code disassembly")
345 DEFINE_bool(enable_sse2, true,
346 "enable use of SSE2 instructions if available")
347 DEFINE_bool(enable_sse3, true,
348 "enable use of SSE3 instructions if available")
349 DEFINE_bool(enable_sse4_1, true,
350 "enable use of SSE4.1 instructions if available")
351 DEFINE_bool(enable_cmov, true,
352 "enable use of CMOV instruction if available")
353 DEFINE_bool(enable_rdtsc, true,
354 "enable use of RDTSC instruction if available")
355 DEFINE_bool(enable_sahf, true,
356 "enable use of SAHF instruction if available (X64 only)")
357 DEFINE_bool(enable_vfp3, ENABLE_VFP3_DEFAULT,
358 "enable use of VFP3 instructions if available")
359 DEFINE_bool(enable_armv7, ENABLE_ARMV7_DEFAULT,
360 "enable use of ARMv7 instructions if available (ARM only)")
361 DEFINE_bool(enable_neon, true,
362 "enable use of NEON instructions if available (ARM only)")
363 DEFINE_bool(enable_sudiv, true,
364 "enable use of SDIV and UDIV instructions if available (ARM only)")
365 DEFINE_bool(enable_movw_movt, false,
366 "enable loading 32-bit constant by means of movw/movt "
367 "instruction pairs (ARM only)")
368 DEFINE_bool(enable_unaligned_accesses, true,
369 "enable unaligned accesses for ARMv7 (ARM only)")
370 DEFINE_bool(enable_32dregs, ENABLE_32DREGS_DEFAULT,
371 "enable use of d16-d31 registers on ARM - this requires VFP3")
372 DEFINE_bool(enable_vldr_imm, false,
373 "enable use of constant pools for double immediate (ARM only)")
376 DEFINE_bool(enable_i18n, true, "enable i18n extension")
377 DEFINE_string(expose_natives_as, NULL, "expose natives in global object")
378 DEFINE_string(expose_debug_as, NULL, "expose debug in global object")
379 DEFINE_bool(expose_gc, false, "expose gc extension")
380 DEFINE_string(expose_gc_as,
382 "expose gc extension under the specified name")
383 DEFINE_implication(expose_gc_as, expose_gc)
384 DEFINE_bool(expose_externalize_string, false,
385 "expose externalize string extension")
386 DEFINE_int(stack_trace_limit, 10, "number of stack frames to capture")
387 DEFINE_bool(builtins_in_stack_traces, false,
388 "show built-in functions in stack traces")
389 DEFINE_bool(disable_native_files, false, "disable builtin natives files")
392 DEFINE_bool(inline_new, true, "use fast inline allocation")
395 DEFINE_bool(stack_trace_on_abort, true,
396 "print a stack trace if an assertion failure occurs")
398 // codegen-ia32.cc / codegen-arm.cc
399 DEFINE_bool(trace_codegen, false,
400 "print name of functions for which code is generated")
401 DEFINE_bool(trace, false, "trace function calls")
402 DEFINE_bool(mask_constants_with_cookie,
404 "use random jit cookie to mask large constants")
407 DEFINE_bool(lazy, true, "use lazy compilation")
408 DEFINE_bool(trace_opt, false, "trace lazy optimization")
409 DEFINE_bool(trace_opt_stats, false, "trace lazy optimization statistics")
410 DEFINE_bool(opt, true, "use adaptive optimizations")
411 DEFINE_bool(always_opt, false, "always try to optimize functions")
412 DEFINE_bool(always_osr, false, "always try to OSR functions")
413 DEFINE_bool(prepare_always_opt, false, "prepare for turning on always opt")
414 DEFINE_bool(trace_deopt, false, "trace optimize function deoptimization")
415 DEFINE_bool(trace_stub_failures, false,
416 "trace deoptimization of generated code stubs")
419 DEFINE_int(min_preparse_length, 1024,
420 "minimum length for automatic enable preparsing")
421 DEFINE_bool(always_full_compiler, false,
422 "try to use the dedicated run-once backend for all code")
423 DEFINE_int(max_opt_count, 10,
424 "maximum number of optimization attempts before giving up.")
426 // compilation-cache.cc
427 DEFINE_bool(compilation_cache, true, "enable compilation cache")
429 DEFINE_bool(cache_prototype_transitions, true, "cache prototype transitions")
432 DEFINE_bool(trace_debug_json, false, "trace debugging JSON request/response")
433 DEFINE_bool(trace_js_array_abuse, false,
434 "trace out-of-bounds accesses to JS arrays")
435 DEFINE_bool(trace_external_array_abuse, false,
436 "trace out-of-bounds-accesses to external arrays")
437 DEFINE_bool(trace_array_abuse, false,
438 "trace out-of-bounds accesses to all arrays")
439 DEFINE_implication(trace_array_abuse, trace_js_array_abuse)
440 DEFINE_implication(trace_array_abuse, trace_external_array_abuse)
441 DEFINE_bool(debugger_auto_break, true,
442 "automatically set the debug break flag when debugger commands are "
444 DEFINE_bool(enable_liveedit, true, "enable liveedit experimental feature")
445 DEFINE_bool(break_on_abort, true, "always cause a debug break before aborting")
448 // Slightly less than 1MB on 64-bit, since Windows' default stack size for
449 // the main execution thread is 1MB for both 32 and 64-bit.
450 DEFINE_int(stack_size, kPointerSize * 123,
451 "default size of stack region v8 is allowed to use (in kBytes)")
454 DEFINE_int(max_stack_trace_source_length, 300,
455 "maximum length of function source code printed in a stack trace.")
458 DEFINE_bool(always_inline_smi_code, false,
459 "always inline smi code in non-opt code")
462 DEFINE_int(max_new_space_size, 0, "max size of the new generation (in kBytes)")
463 DEFINE_int(max_old_space_size, 0, "max size of the old generation (in Mbytes)")
464 DEFINE_int(max_executable_size, 0, "max size of executable memory (in Mbytes)")
465 DEFINE_bool(gc_global, false, "always perform global GCs")
466 DEFINE_int(gc_interval, -1, "garbage collect after <n> allocations")
467 DEFINE_bool(trace_gc, false,
468 "print one trace line following each garbage collection")
469 DEFINE_bool(trace_gc_nvp, false,
470 "print one detailed trace line in name=value format "
471 "after each garbage collection")
472 DEFINE_bool(trace_gc_ignore_scavenger, false,
473 "do not print trace line after scavenger collection")
474 DEFINE_bool(print_cumulative_gc_stat, false,
475 "print cumulative GC statistics in name=value format on exit")
476 DEFINE_bool(trace_gc_verbose, false,
477 "print more details following each garbage collection")
478 DEFINE_bool(trace_fragmentation, false,
479 "report fragmentation for old pointer and data pages")
480 DEFINE_bool(trace_external_memory, false,
481 "print amount of external allocated memory after each time "
483 DEFINE_bool(collect_maps, true,
484 "garbage collect maps from which no objects can be reached")
485 DEFINE_bool(weak_embedded_maps_in_optimized_code, true,
486 "make maps embedded in optimized code weak")
487 DEFINE_bool(flush_code, true,
488 "flush code that we expect not to use again (during full gc)")
489 DEFINE_bool(flush_code_incrementally, true,
490 "flush code that we expect not to use again (incrementally)")
491 DEFINE_bool(trace_code_flushing, false, "trace code flushing progress")
492 DEFINE_bool(age_code, true,
493 "track un-executed functions to age code and flush only "
494 "old code (required for code flushing)")
495 DEFINE_bool(incremental_marking, true, "use incremental marking")
496 DEFINE_bool(incremental_marking_steps, true, "do incremental marking steps")
497 DEFINE_bool(trace_incremental_marking, false,
498 "trace progress of the incremental marking")
499 DEFINE_bool(track_gc_object_stats, false,
500 "track object counts and memory usage")
501 DEFINE_bool(parallel_sweeping, true, "enable parallel sweeping")
502 DEFINE_bool(concurrent_sweeping, false, "enable concurrent sweeping")
503 DEFINE_int(sweeper_threads, 0,
504 "number of parallel and concurrent sweeping threads")
505 DEFINE_bool(parallel_marking, false, "enable parallel marking")
506 DEFINE_int(marking_threads, 0, "number of parallel marking threads")
508 DEFINE_bool(verify_heap, false, "verify heap pointers before and after GC")
512 DEFINE_bool(use_idle_notification, true,
513 "Use idle notification to reduce memory footprint.")
515 DEFINE_bool(use_ic, true, "use inline caching")
517 // macro-assembler-ia32.cc
518 DEFINE_bool(native_code_counters, false,
519 "generate extra code for manipulating stats counters")
522 DEFINE_bool(always_compact, false, "Perform compaction on every full GC")
523 DEFINE_bool(lazy_sweeping, true,
524 "Use lazy sweeping for old pointer and data spaces")
525 DEFINE_bool(never_compact, false,
526 "Never perform compaction on full GC - testing only")
527 DEFINE_bool(compact_code_space, true,
528 "Compact code space on full non-incremental collections")
529 DEFINE_bool(incremental_code_compaction, true,
530 "Compact code space on full incremental collections")
531 DEFINE_bool(cleanup_code_caches_at_gc, true,
532 "Flush inline caches prior to mark compact collection and "
533 "flush code caches in maps during mark compact cycle.")
534 DEFINE_bool(use_marking_progress_bar, true,
535 "Use a progress bar to scan large objects in increments when "
536 "incremental marking is active.")
537 DEFINE_int(random_seed, 0,
538 "Default seed for initializing random generator "
539 "(0, the default, means to use system random).")
542 DEFINE_bool(use_verbose_printer, true, "allows verbose printing")
545 DEFINE_bool(allow_natives_syntax, false, "allow natives syntax")
546 DEFINE_bool(trace_parse, false, "trace parsing and preparsing")
548 // simulator-arm.cc and simulator-mips.cc
549 DEFINE_bool(trace_sim, false, "Trace simulator execution")
550 DEFINE_bool(check_icache, false,
551 "Check icache flushes in ARM and MIPS simulator")
552 DEFINE_int(stop_sim_at, 0, "Simulator stop after x number of instructions")
553 DEFINE_int(sim_stack_alignment, 8,
554 "Stack alingment in bytes in simulator (4 or 8, 8 is default)")
557 DEFINE_bool(abort_on_uncaught_exception, false,
558 "abort program (dump core) when an uncaught exception is thrown")
559 DEFINE_bool(trace_exception, false,
560 "print stack trace when throwing exceptions")
561 DEFINE_bool(preallocate_message_memory, false,
562 "preallocate some memory to build stack traces.")
563 DEFINE_bool(randomize_hashes,
565 "randomize hashes to avoid predictable hash collisions "
566 "(with snapshots this option cannot override the baked-in seed)")
567 DEFINE_int(hash_seed,
569 "Fixed seed to use to hash property keys (0 means random)"
570 "(with snapshots this option cannot override the baked-in seed)")
573 DEFINE_bool(preemption, false,
574 "activate a 100ms timer that switches between V8 threads")
577 DEFINE_bool(regexp_optimization, true, "generate optimized regexp code")
579 // Testing flags test/cctest/test-{flags,api,serialization}.cc
580 DEFINE_bool(testing_bool_flag, true, "testing_bool_flag")
581 DEFINE_int(testing_int_flag, 13, "testing_int_flag")
582 DEFINE_float(testing_float_flag, 2.5, "float-flag")
583 DEFINE_string(testing_string_flag, "Hello, world!", "string-flag")
584 DEFINE_int(testing_prng_seed, 42, "Seed used for threading test randomness")
586 DEFINE_string(testing_serialization_file, "C:\\Windows\\Temp\\serdes",
587 "file in which to testing_serialize heap")
589 DEFINE_string(testing_serialization_file, "/tmp/serdes",
590 "file in which to serialize heap")
594 DEFINE_string(extra_code, NULL, "A filename with extra code to be included in"
595 " the snapshot (mksnapshot only)")
601 DEFINE_bool(help, false, "Print usage message, including flags, on console")
602 DEFINE_bool(dump_counters, false, "Dump counters on exit")
604 #ifdef ENABLE_DEBUGGER_SUPPORT
605 DEFINE_bool(debugger, false, "Enable JavaScript debugger")
606 DEFINE_bool(remote_debugger, false, "Connect JavaScript debugger to the "
607 "debugger agent in another process")
608 DEFINE_bool(debugger_agent, false, "Enable debugger agent")
609 DEFINE_int(debugger_port, 5858, "Port to use for remote debugging")
610 #endif // ENABLE_DEBUGGER_SUPPORT
612 DEFINE_string(map_counters, "", "Map counters to a file")
613 DEFINE_args(js_arguments, JSARGUMENTS_INIT,
614 "Pass all remaining arguments to the script. Alias for \"--\".")
617 DEFINE_bool(debug_compile_events, false, "Enable debugger compile events")
618 DEFINE_bool(debug_script_collected_events, false,
619 "Enable debugger script collected events")
621 DEFINE_bool(debug_compile_events, true, "Enable debugger compile events")
622 DEFINE_bool(debug_script_collected_events, true,
623 "Enable debugger script collected events")
628 // GDB JIT integration flags.
631 DEFINE_bool(gdbjit, false, "enable GDBJIT interface (disables compacting GC)")
632 DEFINE_bool(gdbjit_full, false, "enable GDBJIT interface for all code objects")
633 DEFINE_bool(gdbjit_dump, false, "dump elf objects with debug info to disk")
634 DEFINE_string(gdbjit_dump_filter, "",
635 "dump only objects containing this substring")
638 DEFINE_bool(force_marking_deque_overflows, false,
639 "force overflows of marking deque by reducing it's size "
642 DEFINE_bool(stress_compaction, false,
643 "stress the GC compactor to flush out bugs (implies "
644 "--force_marking_deque_overflows)")
651 #define FLAG FLAG_FULL
653 #define FLAG FLAG_READONLY
657 DEFINE_bool(enable_slow_asserts, false,
658 "enable asserts that are slow to execute")
660 // codegen-ia32.cc / codegen-arm.cc
661 DEFINE_bool(print_source, false, "pretty print source code")
662 DEFINE_bool(print_builtin_source, false,
663 "pretty print source code for builtins")
664 DEFINE_bool(print_ast, false, "print source AST")
665 DEFINE_bool(print_builtin_ast, false, "print source AST for builtins")
666 DEFINE_string(stop_at, "", "function name where to insert a breakpoint")
669 DEFINE_bool(print_builtin_scopes, false, "print scopes for builtins")
670 DEFINE_bool(print_scopes, false, "print scopes")
673 DEFINE_bool(trace_contexts, false, "trace contexts operations")
676 DEFINE_bool(gc_greedy, false, "perform GC prior to some allocations")
677 DEFINE_bool(gc_verbose, false, "print stuff during garbage collection")
678 DEFINE_bool(heap_stats, false, "report heap statistics before and after GC")
679 DEFINE_bool(code_stats, false, "report code statistics after GC")
680 DEFINE_bool(verify_native_context_separation, false,
681 "verify that code holds on to at most one native context after GC")
682 DEFINE_bool(print_handles, false, "report handles after GC")
683 DEFINE_bool(print_global_handles, false, "report global handles after GC")
686 DEFINE_bool(trace_ic, false, "trace inline cache state transitions")
689 DEFINE_bool(print_interfaces, false, "print interfaces")
690 DEFINE_bool(print_interface_details, false, "print interface inference details")
691 DEFINE_int(print_interface_depth, 5, "depth for printing interfaces")
694 DEFINE_bool(trace_normalization,
696 "prints when objects are turned into dictionaries.")
699 DEFINE_bool(trace_lazy, false, "trace lazy compilation")
702 DEFINE_bool(collect_heap_spill_statistics, false,
703 "report heap spill statistics along with heap_stats "
704 "(requires heap_stats)")
706 DEFINE_bool(trace_isolates, false, "trace isolate state changes")
709 DEFINE_bool(regexp_possessive_quantifier,
711 "enable possessive quantifier syntax for testing")
712 DEFINE_bool(trace_regexp_bytecodes, false, "trace regexp bytecode execution")
713 DEFINE_bool(trace_regexp_assembler,
715 "trace regexp macro assembler calls.")
718 // Logging and profiling flags
721 #define FLAG FLAG_FULL
724 DEFINE_bool(log, false,
725 "Minimal logging (no API, code, GC, suspect, or handles samples).")
726 DEFINE_bool(log_all, false, "Log all events to the log file.")
727 DEFINE_bool(log_runtime, false, "Activate runtime system %Log call.")
728 DEFINE_bool(log_api, false, "Log API events to the log file.")
729 DEFINE_bool(log_code, false,
730 "Log code events to the log file without profiling.")
731 DEFINE_bool(log_gc, false,
732 "Log heap samples on garbage collection for the hp2ps tool.")
733 DEFINE_bool(log_handles, false, "Log global handle events.")
734 DEFINE_bool(log_snapshot_positions, false,
735 "log positions of (de)serialized objects in the snapshot.")
736 DEFINE_bool(log_suspect, false, "Log suspect operations.")
737 DEFINE_bool(prof, false,
738 "Log statistical profiling information (implies --log-code).")
739 DEFINE_bool(prof_auto, true,
740 "Used with --prof, starts profiling automatically")
741 DEFINE_bool(prof_lazy, false,
742 "Used with --prof, only does sampling and logging"
743 " when profiler is active (implies --noprof_auto).")
744 DEFINE_bool(prof_browser_mode, true,
745 "Used with --prof, turns on browser-compatible mode for profiling.")
746 DEFINE_bool(log_regexp, false, "Log regular expression execution.")
747 DEFINE_string(logfile, "v8.log", "Specify the name of the log file.")
748 DEFINE_bool(ll_prof, false, "Enable low-level linux profiler.")
749 DEFINE_string(gc_fake_mmap, "/tmp/__v8_gc__",
750 "Specify the name of the file for fake gc mmap used in ll_prof")
751 DEFINE_bool(log_internal_timer_events, false, "Time internal events.")
752 DEFINE_bool(log_timer_events, false,
753 "Time events including external callbacks.")
754 DEFINE_implication(log_timer_events, log_internal_timer_events)
755 DEFINE_implication(log_internal_timer_events, prof)
758 // Disassembler only flags
761 #ifdef ENABLE_DISASSEMBLER
762 #define FLAG FLAG_FULL
764 #define FLAG FLAG_READONLY
768 DEFINE_bool(trace_elements_transitions, false, "trace elements transitions")
771 DEFINE_bool(print_code_stubs, false, "print code stubs")
772 DEFINE_bool(test_secondary_stub_cache,
774 "test secondary stub cache by disabling the primary one")
776 DEFINE_bool(test_primary_stub_cache,
778 "test primary stub cache by disabling the secondary one")
780 // codegen-ia32.cc / codegen-arm.cc
781 DEFINE_bool(print_code, false, "print generated code")
782 DEFINE_bool(print_opt_code, false, "print optimized code")
783 DEFINE_bool(print_unopt_code, false, "print unoptimized code before "
784 "printing optimized code based on it")
785 DEFINE_bool(print_code_verbose, false, "print more information for code")
786 DEFINE_bool(print_builtin_code, false, "print generated code for builtins")
788 #ifdef ENABLE_DISASSEMBLER
789 DEFINE_bool(print_all_code, false, "enable all flags related to printing code")
790 DEFINE_implication(print_all_code, print_code)
791 DEFINE_implication(print_all_code, print_opt_code)
792 DEFINE_implication(print_all_code, print_unopt_code)
793 DEFINE_implication(print_all_code, print_code_verbose)
794 DEFINE_implication(print_all_code, print_builtin_code)
795 DEFINE_implication(print_all_code, print_code_stubs)
796 DEFINE_implication(print_all_code, code_comments)
798 DEFINE_implication(print_all_code, trace_codegen)
810 #undef DEFINE_implication
812 #undef FLAG_MODE_DECLARE
813 #undef FLAG_MODE_DEFINE
814 #undef FLAG_MODE_DEFINE_DEFAULTS
815 #undef FLAG_MODE_META
816 #undef FLAG_MODE_DEFINE_IMPLICATIONS