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_strings, false, "enable harmony string")
177 DEFINE_bool(harmony_arrays, false, "enable harmony arrays")
178 DEFINE_bool(harmony, false, "enable all harmony features (except typeof)")
179 DEFINE_implication(harmony, harmony_scoping)
180 DEFINE_implication(harmony, harmony_modules)
181 DEFINE_implication(harmony, harmony_symbols)
182 DEFINE_implication(harmony, harmony_proxies)
183 DEFINE_implication(harmony, harmony_collections)
184 DEFINE_implication(harmony, harmony_observation)
185 DEFINE_implication(harmony, harmony_generators)
186 DEFINE_implication(harmony, harmony_iteration)
187 DEFINE_implication(harmony, harmony_numeric_literals)
188 DEFINE_implication(harmony, harmony_strings)
189 DEFINE_implication(harmony, harmony_arrays)
190 DEFINE_implication(harmony_modules, harmony_scoping)
191 DEFINE_implication(harmony_observation, harmony_collections)
192 // TODO[dslomov] add harmony => harmony_typed_arrays
194 // Flags for experimental implementation features.
195 DEFINE_bool(packed_arrays, true, "optimizes arrays that have no holes")
196 DEFINE_bool(smi_only_arrays, true, "tracks arrays with only smi values")
197 DEFINE_bool(compiled_keyed_stores, true, "use optimizing compiler to "
198 "generate keyed store stubs")
199 DEFINE_bool(clever_optimizations,
201 "Optimize object size, Array shift, DOM strings and string +")
202 DEFINE_bool(pretenuring, true, "allocate objects in old space")
203 // TODO(hpayer): We will remove this flag as soon as we have pretenuring
204 // support for specific allocation sites.
205 DEFINE_bool(pretenuring_call_new, false, "pretenure call new")
206 DEFINE_bool(track_fields, true, "track fields with only smi values")
207 DEFINE_bool(track_double_fields, true, "track fields with double values")
208 DEFINE_bool(track_heap_object_fields, true, "track fields with heap values")
209 DEFINE_bool(track_computed_fields, true, "track computed boilerplate fields")
210 DEFINE_implication(track_double_fields, track_fields)
211 DEFINE_implication(track_heap_object_fields, track_fields)
212 DEFINE_implication(track_computed_fields, track_fields)
213 DEFINE_bool(smi_binop, true, "support smi representation in binary operations")
215 // Flags for data representation optimizations
216 DEFINE_bool(unbox_double_arrays, true, "automatically unbox arrays of doubles")
217 DEFINE_bool(string_slices, true, "use string slices")
219 // Flags for Crankshaft.
220 DEFINE_bool(crankshaft, true, "use crankshaft")
221 DEFINE_string(hydrogen_filter, "*", "optimization filter")
222 DEFINE_bool(use_range, true, "use hydrogen range analysis")
223 DEFINE_bool(use_gvn, true, "use hydrogen global value numbering")
224 DEFINE_bool(use_canonicalizing, true, "use hydrogen instruction canonicalizing")
225 DEFINE_bool(use_inlining, true, "use function inlining")
226 DEFINE_bool(use_escape_analysis, false, "use hydrogen escape analysis")
227 DEFINE_bool(use_allocation_folding, true, "use allocation folding")
228 DEFINE_int(max_inlining_levels, 5, "maximum number of inlining levels")
229 DEFINE_int(max_inlined_source_size, 600,
230 "maximum source size in bytes considered for a single inlining")
231 DEFINE_int(max_inlined_nodes, 196,
232 "maximum number of AST nodes considered for a single inlining")
233 DEFINE_int(max_inlined_nodes_cumulative, 400,
234 "maximum cumulative number of AST nodes considered for inlining")
235 DEFINE_bool(loop_invariant_code_motion, true, "loop invariant code motion")
236 DEFINE_bool(fast_math, true, "faster (but maybe less accurate) math functions")
237 DEFINE_bool(collect_megamorphic_maps_from_stub_cache,
239 "crankshaft harvests type feedback from stub cache")
240 DEFINE_bool(hydrogen_stats, false, "print statistics for hydrogen")
241 DEFINE_bool(trace_hydrogen, false, "trace generated hydrogen to file")
242 DEFINE_bool(trace_hydrogen_stubs, false, "trace generated hydrogen for stubs")
243 DEFINE_string(trace_hydrogen_file, NULL, "trace hydrogen to given file name")
244 DEFINE_string(trace_phase, "HLZ", "trace generated IR for specified phases")
245 DEFINE_bool(trace_inlining, false, "trace inlining decisions")
246 DEFINE_bool(trace_alloc, false, "trace register allocator")
247 DEFINE_bool(trace_all_uses, false, "trace all use positions")
248 DEFINE_bool(trace_range, false, "trace range analysis")
249 DEFINE_bool(trace_gvn, false, "trace global value numbering")
250 DEFINE_bool(trace_representation, false, "trace representation types")
251 DEFINE_bool(trace_escape_analysis, false, "trace hydrogen escape analysis")
252 DEFINE_bool(trace_allocation_folding, false, "trace allocation folding")
253 DEFINE_bool(trace_track_allocation_sites, false,
254 "trace the tracking of allocation sites")
255 DEFINE_bool(trace_migration, false, "trace object migration")
256 DEFINE_bool(trace_generalization, false, "trace map generalization")
257 DEFINE_bool(stress_pointer_maps, false, "pointer map for every instruction")
258 DEFINE_bool(stress_environments, false, "environment for every instruction")
259 DEFINE_int(deopt_every_n_times,
261 "deoptimize every n times a deopt point is passed")
262 DEFINE_int(deopt_every_n_garbage_collections,
264 "deoptimize every n garbage collections")
265 DEFINE_bool(print_deopt_stress, false, "print number of possible deopt points")
266 DEFINE_bool(trap_on_deopt, false, "put a break point before deoptimizing")
267 DEFINE_bool(trap_on_stub_deopt, false,
268 "put a break point before deoptimizing a stub")
269 DEFINE_bool(deoptimize_uncommon_cases, true, "deoptimize uncommon cases")
270 DEFINE_bool(polymorphic_inlining, true, "polymorphic inlining")
271 DEFINE_bool(use_osr, true, "use on-stack replacement")
272 DEFINE_bool(array_bounds_checks_elimination, true,
273 "perform array bounds checks elimination")
274 DEFINE_bool(array_bounds_checks_hoisting, false,
275 "perform array bounds checks hoisting")
276 DEFINE_bool(array_index_dehoisting, true,
277 "perform array index dehoisting")
278 DEFINE_bool(analyze_environment_liveness, true,
279 "analyze liveness of environment slots and zap dead values")
280 DEFINE_bool(dead_code_elimination, true, "use dead code elimination")
281 DEFINE_bool(fold_constants, true, "use constant folding")
282 DEFINE_bool(trace_dead_code_elimination, false, "trace dead code elimination")
283 DEFINE_bool(unreachable_code_elimination, false,
284 "eliminate unreachable code (hidden behind soft deopts)")
285 DEFINE_bool(track_allocation_sites, true,
286 "Use allocation site info to reduce transitions")
287 DEFINE_bool(trace_osr, false, "trace on-stack replacement")
288 DEFINE_int(stress_runs, 0, "number of stress runs")
289 DEFINE_bool(optimize_closures, true, "optimize closures")
290 DEFINE_bool(lookup_sample_by_shared, true,
291 "when picking a function to optimize, watch for shared function "
292 "info, not JSFunction itself")
293 DEFINE_bool(cache_optimized_code, true,
294 "cache optimized code for closures")
295 DEFINE_bool(flush_optimized_code_cache, true,
296 "flushes the cache of optimized code for closures on every GC")
297 DEFINE_bool(inline_construct, true, "inline constructor calls")
298 DEFINE_bool(inline_arguments, true, "inline functions with arguments object")
299 DEFINE_bool(inline_accessors, true, "inline JavaScript accessors")
300 DEFINE_int(loop_weight, 1, "loop weight for representation inference")
302 DEFINE_bool(optimize_for_in, true,
303 "optimize functions containing for-in loops")
304 DEFINE_bool(opt_safe_uint32_operations, true,
305 "allow uint32 values on optimize frames if they are used only in "
308 DEFINE_bool(parallel_recompilation, true,
309 "optimizing hot functions asynchronously on a separate thread")
310 DEFINE_bool(trace_parallel_recompilation, false, "track parallel recompilation")
311 DEFINE_int(parallel_recompilation_queue_length, 8,
312 "the length of the parallel compilation queue")
313 DEFINE_int(parallel_recompilation_delay, 0,
314 "artificial compilation delay in ms")
315 DEFINE_bool(omit_map_checks_for_leaf_maps, true,
316 "do not emit check maps for constant values that have a leaf map, "
317 "deoptimize the optimized code if the layout of the maps changes.")
319 // Experimental profiler changes.
320 DEFINE_bool(experimental_profiler, true, "enable all profiler experiments")
321 DEFINE_bool(watch_ic_patching, false, "profiler considers IC stability")
322 DEFINE_int(frame_count, 1, "number of stack frames inspected by the profiler")
323 DEFINE_bool(self_optimization, false,
324 "primitive functions trigger their own optimization")
325 DEFINE_bool(direct_self_opt, false,
326 "call recompile stub directly when self-optimizing")
327 DEFINE_bool(retry_self_opt, false, "re-try self-optimization if it failed")
328 DEFINE_bool(interrupt_at_exit, false,
329 "insert an interrupt check at function exit")
330 DEFINE_bool(weighted_back_edges, false,
331 "weight back edges by jump distance for interrupt triggering")
332 // 0x1700 fits in the immediate field of an ARM instruction.
333 DEFINE_int(interrupt_budget, 0x1700,
334 "execution budget before interrupt is triggered")
335 DEFINE_int(type_info_threshold, 25,
336 "percentage of ICs that must have type info to allow optimization")
337 DEFINE_int(self_opt_count, 130, "call count before self-optimization")
339 DEFINE_implication(experimental_profiler, watch_ic_patching)
340 DEFINE_implication(experimental_profiler, self_optimization)
341 // Not implying direct_self_opt here because it seems to be a bad idea.
342 DEFINE_implication(experimental_profiler, retry_self_opt)
343 DEFINE_implication(experimental_profiler, interrupt_at_exit)
344 DEFINE_implication(experimental_profiler, weighted_back_edges)
346 DEFINE_bool(trace_opt_verbose, false, "extra verbose compilation tracing")
347 DEFINE_implication(trace_opt_verbose, trace_opt)
349 // assembler-ia32.cc / assembler-arm.cc / assembler-x64.cc
350 DEFINE_bool(debug_code, false,
351 "generate extra code (assertions) for debugging")
352 DEFINE_bool(code_comments, false, "emit comments in code disassembly")
353 DEFINE_bool(enable_sse2, true,
354 "enable use of SSE2 instructions if available")
355 DEFINE_bool(enable_sse3, true,
356 "enable use of SSE3 instructions if available")
357 DEFINE_bool(enable_sse4_1, true,
358 "enable use of SSE4.1 instructions if available")
359 DEFINE_bool(enable_cmov, true,
360 "enable use of CMOV instruction if available")
361 DEFINE_bool(enable_rdtsc, true,
362 "enable use of RDTSC instruction if available")
363 DEFINE_bool(enable_sahf, true,
364 "enable use of SAHF instruction if available (X64 only)")
365 DEFINE_bool(enable_vfp3, ENABLE_VFP3_DEFAULT,
366 "enable use of VFP3 instructions if available")
367 DEFINE_bool(enable_armv7, ENABLE_ARMV7_DEFAULT,
368 "enable use of ARMv7 instructions if available (ARM only)")
369 DEFINE_bool(enable_neon, true,
370 "enable use of NEON instructions if available (ARM only)")
371 DEFINE_bool(enable_sudiv, true,
372 "enable use of SDIV and UDIV instructions if available (ARM only)")
373 DEFINE_bool(enable_movw_movt, false,
374 "enable loading 32-bit constant by means of movw/movt "
375 "instruction pairs (ARM only)")
376 DEFINE_bool(enable_unaligned_accesses, true,
377 "enable unaligned accesses for ARMv7 (ARM only)")
378 DEFINE_bool(enable_32dregs, ENABLE_32DREGS_DEFAULT,
379 "enable use of d16-d31 registers on ARM - this requires VFP3")
380 DEFINE_bool(enable_vldr_imm, false,
381 "enable use of constant pools for double immediate (ARM only)")
384 DEFINE_bool(enable_i18n, true, "enable i18n extension")
385 DEFINE_string(expose_natives_as, NULL, "expose natives in global object")
386 DEFINE_string(expose_debug_as, NULL, "expose debug in global object")
387 DEFINE_bool(expose_gc, false, "expose gc extension")
388 DEFINE_string(expose_gc_as,
390 "expose gc extension under the specified name")
391 DEFINE_implication(expose_gc_as, expose_gc)
392 DEFINE_bool(expose_externalize_string, false,
393 "expose externalize string extension")
394 DEFINE_int(stack_trace_limit, 10, "number of stack frames to capture")
395 DEFINE_bool(builtins_in_stack_traces, false,
396 "show built-in functions in stack traces")
397 DEFINE_bool(disable_native_files, false, "disable builtin natives files")
400 DEFINE_bool(inline_new, true, "use fast inline allocation")
403 DEFINE_bool(stack_trace_on_abort, true,
404 "print a stack trace if an assertion failure occurs")
406 // codegen-ia32.cc / codegen-arm.cc
407 DEFINE_bool(trace_codegen, false,
408 "print name of functions for which code is generated")
409 DEFINE_bool(trace, false, "trace function calls")
410 DEFINE_bool(mask_constants_with_cookie,
412 "use random jit cookie to mask large constants")
415 DEFINE_bool(lazy, true, "use lazy compilation")
416 DEFINE_bool(trace_opt, false, "trace lazy optimization")
417 DEFINE_bool(trace_opt_stats, false, "trace lazy optimization statistics")
418 DEFINE_bool(opt, true, "use adaptive optimizations")
419 DEFINE_bool(always_opt, false, "always try to optimize functions")
420 DEFINE_bool(always_osr, false, "always try to OSR functions")
421 DEFINE_bool(prepare_always_opt, false, "prepare for turning on always opt")
422 DEFINE_bool(trace_deopt, false, "trace optimize function deoptimization")
423 DEFINE_bool(trace_stub_failures, false,
424 "trace deoptimization of generated code stubs")
427 DEFINE_int(min_preparse_length, 1024,
428 "minimum length for automatic enable preparsing")
429 DEFINE_bool(always_full_compiler, false,
430 "try to use the dedicated run-once backend for all code")
431 DEFINE_int(max_opt_count, 10,
432 "maximum number of optimization attempts before giving up.")
434 // compilation-cache.cc
435 DEFINE_bool(compilation_cache, true, "enable compilation cache")
437 DEFINE_bool(cache_prototype_transitions, true, "cache prototype transitions")
440 DEFINE_bool(trace_debug_json, false, "trace debugging JSON request/response")
441 DEFINE_bool(trace_js_array_abuse, false,
442 "trace out-of-bounds accesses to JS arrays")
443 DEFINE_bool(trace_external_array_abuse, false,
444 "trace out-of-bounds-accesses to external arrays")
445 DEFINE_bool(trace_array_abuse, false,
446 "trace out-of-bounds accesses to all arrays")
447 DEFINE_implication(trace_array_abuse, trace_js_array_abuse)
448 DEFINE_implication(trace_array_abuse, trace_external_array_abuse)
449 DEFINE_bool(debugger_auto_break, true,
450 "automatically set the debug break flag when debugger commands are "
452 DEFINE_bool(enable_liveedit, true, "enable liveedit experimental feature")
453 DEFINE_bool(break_on_abort, true, "always cause a debug break before aborting")
456 // Slightly less than 1MB on 64-bit, since Windows' default stack size for
457 // the main execution thread is 1MB for both 32 and 64-bit.
458 DEFINE_int(stack_size, kPointerSize * 123,
459 "default size of stack region v8 is allowed to use (in kBytes)")
462 DEFINE_int(max_stack_trace_source_length, 300,
463 "maximum length of function source code printed in a stack trace.")
466 DEFINE_bool(always_inline_smi_code, false,
467 "always inline smi code in non-opt code")
470 DEFINE_int(max_new_space_size, 0, "max size of the new generation (in kBytes)")
471 DEFINE_int(max_old_space_size, 0, "max size of the old generation (in Mbytes)")
472 DEFINE_int(max_executable_size, 0, "max size of executable memory (in Mbytes)")
473 DEFINE_bool(gc_global, false, "always perform global GCs")
474 DEFINE_int(gc_interval, -1, "garbage collect after <n> allocations")
475 DEFINE_bool(trace_gc, false,
476 "print one trace line following each garbage collection")
477 DEFINE_bool(trace_gc_nvp, false,
478 "print one detailed trace line in name=value format "
479 "after each garbage collection")
480 DEFINE_bool(trace_gc_ignore_scavenger, false,
481 "do not print trace line after scavenger collection")
482 DEFINE_bool(print_cumulative_gc_stat, false,
483 "print cumulative GC statistics in name=value format on exit")
484 DEFINE_bool(trace_gc_verbose, false,
485 "print more details following each garbage collection")
486 DEFINE_bool(trace_fragmentation, false,
487 "report fragmentation for old pointer and data pages")
488 DEFINE_bool(trace_external_memory, false,
489 "print amount of external allocated memory after each time "
491 DEFINE_bool(collect_maps, true,
492 "garbage collect maps from which no objects can be reached")
493 DEFINE_bool(weak_embedded_maps_in_optimized_code, true,
494 "make maps embedded in optimized code weak")
495 DEFINE_bool(flush_code, true,
496 "flush code that we expect not to use again (during full gc)")
497 DEFINE_bool(flush_code_incrementally, true,
498 "flush code that we expect not to use again (incrementally)")
499 DEFINE_bool(trace_code_flushing, false, "trace code flushing progress")
500 DEFINE_bool(age_code, true,
501 "track un-executed functions to age code and flush only "
502 "old code (required for code flushing)")
503 DEFINE_bool(incremental_marking, true, "use incremental marking")
504 DEFINE_bool(incremental_marking_steps, true, "do incremental marking steps")
505 DEFINE_bool(trace_incremental_marking, false,
506 "trace progress of the incremental marking")
507 DEFINE_bool(track_gc_object_stats, false,
508 "track object counts and memory usage")
509 DEFINE_bool(parallel_sweeping, true, "enable parallel sweeping")
510 DEFINE_bool(concurrent_sweeping, false, "enable concurrent sweeping")
511 DEFINE_int(sweeper_threads, 0,
512 "number of parallel and concurrent sweeping threads")
513 DEFINE_bool(parallel_marking, false, "enable parallel marking")
514 DEFINE_int(marking_threads, 0, "number of parallel marking threads")
516 DEFINE_bool(verify_heap, false, "verify heap pointers before and after GC")
520 DEFINE_bool(use_idle_notification, true,
521 "Use idle notification to reduce memory footprint.")
523 DEFINE_bool(use_ic, true, "use inline caching")
525 // macro-assembler-ia32.cc
526 DEFINE_bool(native_code_counters, false,
527 "generate extra code for manipulating stats counters")
530 DEFINE_bool(always_compact, false, "Perform compaction on every full GC")
531 DEFINE_bool(lazy_sweeping, true,
532 "Use lazy sweeping for old pointer and data spaces")
533 DEFINE_bool(never_compact, false,
534 "Never perform compaction on full GC - testing only")
535 DEFINE_bool(compact_code_space, true,
536 "Compact code space on full non-incremental collections")
537 DEFINE_bool(incremental_code_compaction, true,
538 "Compact code space on full incremental collections")
539 DEFINE_bool(cleanup_code_caches_at_gc, true,
540 "Flush inline caches prior to mark compact collection and "
541 "flush code caches in maps during mark compact cycle.")
542 DEFINE_bool(use_marking_progress_bar, true,
543 "Use a progress bar to scan large objects in increments when "
544 "incremental marking is active.")
545 DEFINE_int(random_seed, 0,
546 "Default seed for initializing random generator "
547 "(0, the default, means to use system random).")
550 DEFINE_bool(use_verbose_printer, true, "allows verbose printing")
553 DEFINE_bool(allow_natives_syntax, false, "allow natives syntax")
554 DEFINE_bool(trace_parse, false, "trace parsing and preparsing")
556 // simulator-arm.cc and simulator-mips.cc
557 DEFINE_bool(trace_sim, false, "Trace simulator execution")
558 DEFINE_bool(check_icache, false,
559 "Check icache flushes in ARM and MIPS simulator")
560 DEFINE_int(stop_sim_at, 0, "Simulator stop after x number of instructions")
561 DEFINE_int(sim_stack_alignment, 8,
562 "Stack alingment in bytes in simulator (4 or 8, 8 is default)")
565 DEFINE_bool(abort_on_uncaught_exception, false,
566 "abort program (dump core) when an uncaught exception is thrown")
567 DEFINE_bool(trace_exception, false,
568 "print stack trace when throwing exceptions")
569 DEFINE_bool(preallocate_message_memory, false,
570 "preallocate some memory to build stack traces.")
571 DEFINE_bool(randomize_hashes,
573 "randomize hashes to avoid predictable hash collisions "
574 "(with snapshots this option cannot override the baked-in seed)")
575 DEFINE_int(hash_seed,
577 "Fixed seed to use to hash property keys (0 means random)"
578 "(with snapshots this option cannot override the baked-in seed)")
581 DEFINE_bool(preemption, false,
582 "activate a 100ms timer that switches between V8 threads")
585 DEFINE_bool(regexp_optimization, true, "generate optimized regexp code")
587 // Testing flags test/cctest/test-{flags,api,serialization}.cc
588 DEFINE_bool(testing_bool_flag, true, "testing_bool_flag")
589 DEFINE_int(testing_int_flag, 13, "testing_int_flag")
590 DEFINE_float(testing_float_flag, 2.5, "float-flag")
591 DEFINE_string(testing_string_flag, "Hello, world!", "string-flag")
592 DEFINE_int(testing_prng_seed, 42, "Seed used for threading test randomness")
594 DEFINE_string(testing_serialization_file, "C:\\Windows\\Temp\\serdes",
595 "file in which to testing_serialize heap")
597 DEFINE_string(testing_serialization_file, "/tmp/serdes",
598 "file in which to serialize heap")
602 DEFINE_string(extra_code, NULL, "A filename with extra code to be included in"
603 " the snapshot (mksnapshot only)")
609 DEFINE_bool(help, false, "Print usage message, including flags, on console")
610 DEFINE_bool(dump_counters, false, "Dump counters on exit")
612 #ifdef ENABLE_DEBUGGER_SUPPORT
613 DEFINE_bool(debugger, false, "Enable JavaScript debugger")
614 DEFINE_bool(remote_debugger, false, "Connect JavaScript debugger to the "
615 "debugger agent in another process")
616 DEFINE_bool(debugger_agent, false, "Enable debugger agent")
617 DEFINE_int(debugger_port, 5858, "Port to use for remote debugging")
618 #endif // ENABLE_DEBUGGER_SUPPORT
620 DEFINE_string(map_counters, "", "Map counters to a file")
621 DEFINE_args(js_arguments, JSARGUMENTS_INIT,
622 "Pass all remaining arguments to the script. Alias for \"--\".")
625 DEFINE_bool(debug_compile_events, false, "Enable debugger compile events")
626 DEFINE_bool(debug_script_collected_events, false,
627 "Enable debugger script collected events")
629 DEFINE_bool(debug_compile_events, true, "Enable debugger compile events")
630 DEFINE_bool(debug_script_collected_events, true,
631 "Enable debugger script collected events")
636 // GDB JIT integration flags.
639 DEFINE_bool(gdbjit, false, "enable GDBJIT interface (disables compacting GC)")
640 DEFINE_bool(gdbjit_full, false, "enable GDBJIT interface for all code objects")
641 DEFINE_bool(gdbjit_dump, false, "dump elf objects with debug info to disk")
642 DEFINE_string(gdbjit_dump_filter, "",
643 "dump only objects containing this substring")
646 DEFINE_bool(force_marking_deque_overflows, false,
647 "force overflows of marking deque by reducing it's size "
650 DEFINE_bool(stress_compaction, false,
651 "stress the GC compactor to flush out bugs (implies "
652 "--force_marking_deque_overflows)")
659 #define FLAG FLAG_FULL
661 #define FLAG FLAG_READONLY
665 DEFINE_bool(enable_slow_asserts, false,
666 "enable asserts that are slow to execute")
668 // codegen-ia32.cc / codegen-arm.cc
669 DEFINE_bool(print_source, false, "pretty print source code")
670 DEFINE_bool(print_builtin_source, false,
671 "pretty print source code for builtins")
672 DEFINE_bool(print_ast, false, "print source AST")
673 DEFINE_bool(print_builtin_ast, false, "print source AST for builtins")
674 DEFINE_string(stop_at, "", "function name where to insert a breakpoint")
677 DEFINE_bool(print_builtin_scopes, false, "print scopes for builtins")
678 DEFINE_bool(print_scopes, false, "print scopes")
681 DEFINE_bool(trace_contexts, false, "trace contexts operations")
684 DEFINE_bool(gc_greedy, false, "perform GC prior to some allocations")
685 DEFINE_bool(gc_verbose, false, "print stuff during garbage collection")
686 DEFINE_bool(heap_stats, false, "report heap statistics before and after GC")
687 DEFINE_bool(code_stats, false, "report code statistics after GC")
688 DEFINE_bool(verify_native_context_separation, false,
689 "verify that code holds on to at most one native context after GC")
690 DEFINE_bool(print_handles, false, "report handles after GC")
691 DEFINE_bool(print_global_handles, false, "report global handles after GC")
694 DEFINE_bool(trace_ic, false, "trace inline cache state transitions")
697 DEFINE_bool(print_interfaces, false, "print interfaces")
698 DEFINE_bool(print_interface_details, false, "print interface inference details")
699 DEFINE_int(print_interface_depth, 5, "depth for printing interfaces")
702 DEFINE_bool(trace_normalization,
704 "prints when objects are turned into dictionaries.")
707 DEFINE_bool(trace_lazy, false, "trace lazy compilation")
710 DEFINE_bool(collect_heap_spill_statistics, false,
711 "report heap spill statistics along with heap_stats "
712 "(requires heap_stats)")
714 DEFINE_bool(trace_isolates, false, "trace isolate state changes")
717 DEFINE_bool(regexp_possessive_quantifier,
719 "enable possessive quantifier syntax for testing")
720 DEFINE_bool(trace_regexp_bytecodes, false, "trace regexp bytecode execution")
721 DEFINE_bool(trace_regexp_assembler,
723 "trace regexp macro assembler calls.")
726 // Logging and profiling flags
729 #define FLAG FLAG_FULL
732 DEFINE_bool(log, false,
733 "Minimal logging (no API, code, GC, suspect, or handles samples).")
734 DEFINE_bool(log_all, false, "Log all events to the log file.")
735 DEFINE_bool(log_runtime, false, "Activate runtime system %Log call.")
736 DEFINE_bool(log_api, false, "Log API events to the log file.")
737 DEFINE_bool(log_code, false,
738 "Log code events to the log file without profiling.")
739 DEFINE_bool(log_gc, false,
740 "Log heap samples on garbage collection for the hp2ps tool.")
741 DEFINE_bool(log_handles, false, "Log global handle events.")
742 DEFINE_bool(log_snapshot_positions, false,
743 "log positions of (de)serialized objects in the snapshot.")
744 DEFINE_bool(log_suspect, false, "Log suspect operations.")
745 DEFINE_bool(prof, false,
746 "Log statistical profiling information (implies --log-code).")
747 DEFINE_bool(prof_lazy, false,
748 "Used with --prof, only does sampling and logging"
749 " when profiler is active.")
750 DEFINE_bool(prof_browser_mode, true,
751 "Used with --prof, turns on browser-compatible mode for profiling.")
752 DEFINE_bool(log_regexp, false, "Log regular expression execution.")
753 DEFINE_string(logfile, "v8.log", "Specify the name of the log file.")
754 DEFINE_bool(ll_prof, false, "Enable low-level linux profiler.")
755 DEFINE_string(gc_fake_mmap, "/tmp/__v8_gc__",
756 "Specify the name of the file for fake gc mmap used in ll_prof")
757 DEFINE_bool(log_internal_timer_events, false, "Time internal events.")
758 DEFINE_bool(log_timer_events, false,
759 "Time events including external callbacks.")
760 DEFINE_implication(log_timer_events, log_internal_timer_events)
761 DEFINE_implication(log_internal_timer_events, prof)
764 // Disassembler only flags
767 #ifdef ENABLE_DISASSEMBLER
768 #define FLAG FLAG_FULL
770 #define FLAG FLAG_READONLY
774 DEFINE_bool(trace_elements_transitions, false, "trace elements transitions")
777 DEFINE_bool(print_code_stubs, false, "print code stubs")
778 DEFINE_bool(test_secondary_stub_cache,
780 "test secondary stub cache by disabling the primary one")
782 DEFINE_bool(test_primary_stub_cache,
784 "test primary stub cache by disabling the secondary one")
786 // codegen-ia32.cc / codegen-arm.cc
787 DEFINE_bool(print_code, false, "print generated code")
788 DEFINE_bool(print_opt_code, false, "print optimized code")
789 DEFINE_bool(print_unopt_code, false, "print unoptimized code before "
790 "printing optimized code based on it")
791 DEFINE_bool(print_code_verbose, false, "print more information for code")
792 DEFINE_bool(print_builtin_code, false, "print generated code for builtins")
794 #ifdef ENABLE_DISASSEMBLER
795 DEFINE_bool(print_all_code, false, "enable all flags related to printing code")
796 DEFINE_implication(print_all_code, print_code)
797 DEFINE_implication(print_all_code, print_opt_code)
798 DEFINE_implication(print_all_code, print_unopt_code)
799 DEFINE_implication(print_all_code, print_code_verbose)
800 DEFINE_implication(print_all_code, print_builtin_code)
801 DEFINE_implication(print_all_code, print_code_stubs)
802 DEFINE_implication(print_all_code, code_comments)
804 DEFINE_implication(print_all_code, trace_codegen)
816 #undef DEFINE_implication
818 #undef FLAG_MODE_DECLARE
819 #undef FLAG_MODE_DEFINE
820 #undef FLAG_MODE_DEFINE_DEFAULTS
821 #undef FLAG_MODE_META
822 #undef FLAG_MODE_DEFINE_IMPLICATIONS