type: bool default: false

--strong_mode (experimental strong language mode)

type: bool default: false

--strong_this (don't allow 'this' to escape from constructors)

type: bool default: true

--es_staging (enable all completed harmony features)

type: bool default: false

--harmony (enable all completed harmony features)

type: bool default: false

--harmony_shipping (enable all shipped harmony fetaures)

type: bool default: true

--legacy_const (legacy semantics for const in sloppy mode)

type: bool default: true

--harmony_modules (enable "harmony modules" (in progress))

type: bool default: false

--harmony_regexps (enable "harmony regular expression extensions" (in progress))

type: bool default: false

--harmony_proxies (enable "harmony proxies" (in progress))

type: bool default: false

--harmony_sloppy_function (enable "harmony sloppy function block scoping" (in progress))

type: bool default: false

--harmony_sloppy_let (enable "harmony let in sloppy mode" (in progress))

type: bool default: false

--harmony_unicode_regexps (enable "harmony unicode regexps" (in progress))

type: bool default: false

--harmony_reflect (enable "harmony Reflect API" (in progress))

type: bool default: false

--harmony_destructuring (enable "harmony destructuring" (in progress))

type: bool default: false

--harmony_default_parameters (enable "harmony default parameters" (in progress))

type: bool default: false

--harmony_sharedarraybuffer (enable "harmony sharedarraybuffer" (in progress))

type: bool default: false

--harmony_atomics (enable "harmony atomics" (in progress))

type: bool default: false

--harmony_simd (enable "harmony simd" (in progress))

type: bool default: false

--harmony_array_includes (enable "harmony Array.prototype.includes")

type: bool default: false

--harmony_tostring (enable "harmony toString")

type: bool default: false

--harmony_concat_spreadable (enable "harmony isConcatSpreadable")

type: bool default: false

--harmony_rest_parameters (enable "harmony rest parameters")

type: bool default: false

--harmony_sloppy (enable "harmony features in sloppy mode")

type: bool default: false

--harmony_arrow_functions (enable "harmony arrow functions")

type: bool default: true

--harmony_new_target (enable "harmony new.target")

type: bool default: true

--harmony_object_observe (enable "harmony Object.observe")

type: bool default: true

--harmony_spreadcalls (enable "harmony spread-calls")

type: bool default: true

--harmony_spread_arrays (enable "harmony spread in array literals")

type: bool default: true

--harmony_object (enable "harmony Object methods")

type: bool default: true

--compiled_keyed_generic_loads (use optimizing compiler to generate keyed generic load stubs)

type: bool default: false

type: bool default: true

--smi_binop (support smi representation in binary operations)

type: bool default: true

--optimize_for_size (Enables optimizations which favor memory size over execution speed)

type: bool default: false

--unbox_double_arrays (automatically unbox arrays of doubles)

type: bool default: true

--string_slices (use string slices)

type: bool default: true

--ignition (use ignition interpreter)

type: bool default: false

--ignition_filter (filter for ignition interpreter)

type: string default: ~~

--print_bytecode (print bytecode generated by ignition interpreter)

type: bool default: false

--trace_ignition_codegen (trace the codegen of ignition interpreter bytecode handlers)

type: bool default: false

--crankshaft (use crankshaft)

type: bool default: true

--hydrogen_filter (optimization filter)

type: bool default: true

--concurrent_recompilation (optimizing hot functions asynchronously on a separate thread)

type: bool default: true

--trace_concurrent_recompilation (track concurrent recompilation)

type: bool default: false

--concurrent_recompilation_queue_length (the length of the concurrent compilation queue)

type: bool default: true

--omit_map_checks_for_leaf_maps (do not emit check maps for constant values that have a leaf map, deoptimize the optimized code if the layout of the maps changes.)

type: bool default: true

--turbo (enable TurboFan compiler)

type: bool default: false

--turbo_shipping (enable TurboFan compiler on subset)

type: bool default: true

--turbo_greedy_regalloc (use the greedy register allocator)

type: bool default: false

--turbo_preprocess_ranges (run pre-register allocation heuristics)

type: bool default: false

--turbo_filter (optimization filter for TurboFan compiler)

type: string default: ~~

--trace_turbo (trace generated TurboFan IR)

type: bool default: false

--trace_turbo_graph (trace generated TurboFan graphs)

type: bool default: false

--trace_turbo_jt (trace TurboFan's jump threading)

type: bool default: false

--trace_turbo_ceq (trace TurboFan's control equivalence)

type: bool default: false

--turbo_asm (enable TurboFan for asm.js code)

type: bool default: true

--turbo_asm_deoptimization (enable deoptimization in TurboFan for asm.js code)

type: bool default: false

--turbo_verify (verify TurboFan graphs at each phase)

type: bool default: false

--turbo_stats (print TurboFan statistics)

type: bool default: true

--turbo_type_feedback (use type feedback in TurboFan)

type: bool default: false

--turbo_allocate (enable inline allocations in TurboFan)

type: bool default: false

--turbo_source_positions (track source code positions when building TurboFan IR)

type: bool default: false

--context_specialization (enable context specialization in TurboFan)

type: bool default: false

--turbo_inlining (enable inlining in TurboFan)

type: bool default: false

--trace_turbo_inlining (trace TurboFan inlining)

type: bool default: false

--loop_assignment_analysis (perform loop assignment analysis)

type: bool default: true

--turbo_profiling (enable profiling in TurboFan)

type: bool default: false

--turbo_verify_allocation (verify register allocation in TurboFan)

type: bool default: false

--turbo_move_optimization (optimize gap moves in TurboFan)

type: bool default: true

--turbo_osr (enable OSR in TurboFan)

type: bool default: true

--turbo_try_catch (enable try-catch support in TurboFan)

type: bool default: true

--turbo_try_finally (enable try-finally support in TurboFan)

type: bool default: false

--turbo_stress_loop_peeling (stress loop peeling optimization)

type: bool default: false

--turbo_cf_optimization (optimize control flow in TurboFan)

type: bool default: true

--turbo_frame_elision (elide frames in TurboFan)

type: bool default: true

--turbo_cache_shared_code (cache context-independent code)

type: bool default: true

--turbo_preserve_shared_code (keep context-independent code)

type: bool default: false

--typed_array_max_size_in_heap (threshold for in-heap typed array)

type: int default: 64

--frame_count (number of stack frames inspected by the profiler)

type: bool default: true

--enable_fma3 (enable use of FMA3 instructions if available)

type: bool default: true

--enable_bmi1 (enable use of BMI1 instructions if available)

type: bool default: true

--enable_bmi2 (enable use of BMI2 instructions if available)

type: bool default: true

--enable_lzcnt (enable use of LZCNT instruction if available)

type: bool default: true

--enable_popcnt (enable use of POPCNT instruction if available)

type: bool default: true

--enable_vfp3 (enable use of VFP3 instructions if available)

type: bool default: true

--enable_armv7 (enable use of ARMv7 instructions if available (ARM only))

type: bool default: false

--trace_gc_verbose (print more details following each garbage collection)

type: bool default: false

--trace_allocation_stack_interval (print stack trace after <n> free-list allocations)

type: int default: -1

--trace_fragmentation (report fragmentation for old space)

type: bool default: false

--trace_fragmentation_verbose (report fragmentation for old space (detailed))

type: bool default: false

--trace_mutator_utilization (print mutator utilization, allocation speed, gc speed)

type: bool default: false

--weak_embedded_maps_in_optimized_code (make maps embedded in optimized code weak)

type: bool default: true

--weak_embedded_objects_in_optimized_code (make objects embedded in optimized code weak)

type: bool default: true

--flush_code (flush code that we expect not to use again)

type: bool default: true

--trace_code_flushing (trace code flushing progress)

type: bool default: false

--age_code (track un-executed functions to age code and flush only old code (required for code flushing))

type: bool default: true

--incremental_marking (use incremental marking)

type: bool default: true

--overapproximate_weak_closure (overapproximate weak closer to reduce atomic pause time)

type: bool default: true

--min_progress_during_object_groups_marking (keep overapproximating the weak closure as long as we discover at least this many unmarked objects)

type: bool default: false

--track_gc_object_stats (track object counts and memory usage)

type: bool default: false

--trace_gc_object_stats (trace object counts and memory usage)

type: bool default: false

--track_detached_contexts (track native contexts that are expected to be garbage collected)

type: bool default: true

--trace_detached_contexts (trace native contexts that are expected to be garbage collected)

type: bool default: false

--histogram_interval (time interval in ms for aggregating memory histograms)

type: int default: 600000

--heap_profiler_trace_objects (Dump heap object allocations/movements/size_updates)

type: bool default: false

--use_idle_notification (Use idle notification to reduce memory footprint.)

type: bool default: true

--trace_ic (trace inline cache state transitions)

type: bool default: false

--vector_stores (use vectors for store ics)

type: bool default: false

--global_var_shortcuts (use ic-less global loads and stores)

type: bool default: false

--native_code_counters (generate extra code for manipulating stats counters)

type: bool default: false

--always_compact (Perform compaction on every full GC)

type: bool default: false

--never_compact (Never perform compaction on full GC - testing only)

type: bool default: false

--compact_code_space (Compact code space on full collections)

type: bool default: true

--cleanup_code_caches_at_gc (Flush inline caches prior to mark compact collection and flush code caches in maps during mark compact cycle.)

type: bool default: true

--use_marking_progress_bar (Use a progress bar to scan large objects in increments when incremental marking is active.)

type: bool default: true

--zap_code_space (Zap free memory in code space with 0xCC while sweeping.)

type: bool default: false

--random_seed (Default seed for initializing random generator (0, the default, means to use system random).)

type: int default: 0

--trace_weak_arrays (Trace WeakFixedArray usage)

type: bool default: false

--track_prototype_users (Keep track of which maps refer to a given prototype object)

type: bool default: false

--trace_prototype_users (Trace updates to prototype user tracking)

type: bool default: false

--eliminate_prototype_chain_checks (Collapse prototype chain checks into single-cell checks)

type: bool default: true

--use_verbose_printer (allows verbose printing)

type: bool default: true

--allow_natives_syntax (allow natives syntax)

type: int default: 0

--sim_stack_alignment (Stack alingment in bytes in simulator (4 or 8, 8 is default))

type: int default: 8

--sim_stack_size (Stack size of the ARM64, MIPS64 and PPC64 simulator in kBytes (default is 2 MB))

type: int default: 2048

--log_regs_modified (When logging register values, only print modified registers.)

type: bool default: true

type: int default: 0

--profile_deserialization (Print the time it takes to deserialize the snapshot.)

type: bool default: false

--serialization_statistics (Collect statistics on serialized objects.)

type: bool default: false

--regexp_optimization (generate optimized regexp code)

type: bool default: true

--testing_bool_flag (testing_bool_flag)

type: bool default: false

--manual_evacuation_candidates_selection (Test mode only flag. It allows an unit test to select evacuation candidates pages (requires --stress_compaction).)

type: bool default: false

--external_allocation_limit_incremental_time (Time spent in incremental marking steps (in ms) once the external allocation limit is reached)

type: int default: 1

--help (Print usage message, including flags, on console)

type: bool default: true

--dump_counters (Dump counters on exit)

type: bool default: false

--map_counters (Map counters to a file)

type: string default:

--js_arguments (Pass all remaining arguments to the script. Alias for "--".)

type: bool default: false

--perf_basic_prof (Enable perf linux profiler (basic support).)

type: bool default: false

--perf_basic_prof_only_functions (Only report function code ranges to perf (i.e. no stubs).)

type: bool default: false

--gc_fake_mmap (Specify the name of the file for fake gc mmap used in ll_prof)

type: string default: /tmp/__v8_gc__