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Table of Contents generated with DocToc

use_strict false {Boolean}

enforce strict mode

  • default: false
  • type: Boolean
  • readonly: false

es5_readonly true {Boolean}

activate correct semantics for inheriting readonliness

  • default: true
  • type: Boolean
  • readonly: false

es52_globals true {Boolean}

activate new semantics for global var declarations

  • default: true
  • type: Boolean
  • readonly: false

harmony_typeof false {Boolean}

enable harmony semantics for typeof

  • default: false
  • type: Boolean
  • readonly: false

Note: this feature seems to work in v8 even without turning on this flag.

Resources

harmony_scoping false {Boolean}

enable harmony block scoping

  • default: false
  • type: Boolean
  • readonly: false

harmony_modules false {Boolean}

enable harmony modules (implies block scoping)

  • default: false
  • type: Boolean
  • readonly: false

Implications

  • harmony_scoping

References

harmony_proxies false {Boolean}

enable harmony proxies

NOTE: This flag cannot be configured after the process started up!

  • default: false
  • type: Boolean
  • readonly: false

Resources

harmony_collections false {Boolean}

enable harmony collections (sets, maps, and weak maps)

NOTE: This flag cannot be configured after the process started up!

  • default: false
  • type: Boolean
  • readonly: false

References

harmony false {Boolean}

enable all harmony features (except typeof)

  • default: false
  • type: Boolean
  • readonly: false

Implications

  • harmony_scoping
  • harmony_modules
  • harmony_proxies
  • harmony_collections

packed_arrays true {Boolean}

optimizes arrays that have no holes

  • default: true
  • type: Boolean
  • readonly: false

smi_only_arrays true {Boolean}

tracks arrays with only smi values

  • default: true
  • type: Boolean
  • readonly: false

clever_optimizations true {Boolean}

Optimize object size, Array shift, DOM strings and string +

  • default: true
  • type: Boolean
  • readonly: false

unbox_double_arrays true {Boolean}

automatically unbox arrays of doubles

  • default: true
  • type: Boolean
  • readonly: false

string_slices true {Boolean}

use string slices

  • default: true
  • type: Boolean
  • readonly: false

crankshaft true {Boolean}

use crankshaft

  • default: true
  • type: Boolean
  • readonly: false

Resources

hydrogen_filter `` {String}

optimization filter

  • default: ``
  • type: String
  • readonly: false

use_range true {Boolean}

use hydrogen range analysis

  • default: true
  • type: Boolean
  • readonly: false

eliminate_dead_phis true {Boolean}

eliminate dead phis

  • default: true
  • type: Boolean
  • readonly: false

use_gvn true {Boolean}

use hydrogen global value numbering

  • default: true
  • type: Boolean
  • readonly: false

use_canonicalizing true {Boolean}

use hydrogen instruction canonicalizing

  • default: true
  • type: Boolean
  • readonly: false

use_inlining true {Boolean}

use function inlining

  • default: true
  • type: Boolean
  • readonly: false

max_inlined_source_size 600 {Integer}

maximum source size in bytes considered for a single inlining

  • default: 600
  • type: Integer
  • readonly: false

max_inlined_nodes 196 {Integer}

maximum number of AST nodes considered for a single inlining

  • default: 196
  • type: Integer
  • readonly: false

max_inlined_nodes_cumulative 196 {Integer}

maximum cumulative number of AST nodes considered for inlining

  • default: 196
  • type: Integer
  • readonly: false

loop_invariant_code_motion true {Boolean}

loop invariant code motion

  • default: true
  • type: Boolean
  • readonly: false

collect_megamorphic_maps_from_stub_cache true {Boolean}

crankshaft harvests type feedback from stub cache

  • default: true
  • type: Boolean
  • readonly: false

hydrogen_stats false {Boolean}

print statistics for hydrogen

  • default: false
  • type: Boolean
  • readonly: false

trace_hydrogen false {Boolean}

trace generated hydrogen to file

  • default: false
  • type: Boolean
  • readonly: false

trace_phase Z {String}

trace generated IR for specified phases

  • default: Z
  • type: String
  • readonly: false

trace_inlining false {Boolean}

trace inlining decisions

  • default: false
  • type: Boolean
  • readonly: false

trace_alloc false {Boolean}

trace register allocator

  • default: false
  • type: Boolean
  • readonly: false

trace_all_uses false {Boolean}

trace all use positions

  • default: false
  • type: Boolean
  • readonly: false

trace_range false {Boolean}

trace range analysis

  • default: false
  • type: Boolean
  • readonly: false

trace_gvn false {Boolean}

trace global value numbering

  • default: false
  • type: Boolean
  • readonly: false

trace_representation false {Boolean}

trace representation types

  • default: false
  • type: Boolean
  • readonly: false

stress_pointer_maps false {Boolean}

pointer map for every instruction

  • default: false
  • type: Boolean
  • readonly: false

stress_environments false {Boolean}

environment for every instruction

  • default: false
  • type: Boolean
  • readonly: false

deopt_every_n_times 0 {Integer}

deoptimize every n times a deopt point is passed

  • default: 0
  • type: Integer
  • readonly: false

trap_on_deopt false {Boolean}

put a break point before deoptimizing

  • default: false
  • type: Boolean
  • readonly: false

deoptimize_uncommon_cases true {Boolean}

deoptimize uncommon cases

  • default: true
  • type: Boolean
  • readonly: false

polymorphic_inlining true {Boolean}

polymorphic inlining

  • default: true
  • type: Boolean
  • readonly: false

use_osr true {Boolean}

use on-stack replacement

  • default: true
  • type: Boolean
  • readonly: false

array_bounds_checks_elimination true {Boolean}

perform array bounds checks elimination

  • default: true
  • type: Boolean
  • readonly: false

array_index_dehoisting true {Boolean}

perform array index dehoisting

  • default: true
  • type: Boolean
  • readonly: false

dead_code_elimination true {Boolean}

use dead code elimination

  • default: true
  • type: Boolean
  • readonly: false

Resources

v8 hydrogen.cc v8 hydrogin-dce.cc

Note: not available below node: 0.10 - v8: 3.14

trace_dead_code_elimination false {Boolean}

trace dead code elimination

  • default: false
  • type: Boolean
  • readonly: false

trace_osr false {Boolean}

trace on-stack replacement

  • default: false
  • type: Boolean
  • readonly: false

stress_runs 0 {Integer}

number of stress runs

  • default: 0
  • type: Integer
  • readonly: false

optimize_closures true {Boolean}

optimize closures

  • default: true
  • type: Boolean
  • readonly: false

lookup_sample_by_shared true {Boolean}

when picking a function to optimize, watch for shared function info, not JSFunction itself

  • default: true
  • type: Boolean
  • readonly: false

cache_optimized_code true {Boolean}

cache optimized code for closures

  • default: true
  • type: Boolean
  • readonly: false

inline_construct true {Boolean}

inline constructor calls

  • default: true
  • type: Boolean
  • readonly: false

inline_arguments true {Boolean}

inline functions with arguments object

  • default: true
  • type: Boolean
  • readonly: false

inline_accessors true {Boolean}

inline JavaScript accessors

  • default: true
  • type: Boolean
  • readonly: false

loop_weight 1 {Integer}

loop weight for representation inference

  • default: 1
  • type: Integer
  • readonly: false

optimize_for_in true {Boolean}

optimize functions containing for-in loops

  • default: true
  • type: Boolean
  • readonly: false

opt_safe_uint32_operations true {Boolean}

allow uint32 values on optimize frames if they are used only insafe operations

  • default: true
  • type: Boolean
  • readonly: false

parallel_recompilation false {Boolean}

optimizing hot functions asynchronously on a separate thread

  • default: false
  • type: Boolean
  • readonly: false

trace_parallel_recompilation false {Boolean}

track parallel recompilation

  • default: false
  • type: Boolean
  • readonly: false

parallel_recompilation_queue_length 2 {Integer}

the length of the parallel compilation queue

  • default: 2
  • type: Integer
  • readonly: false

experimental_profiler true {Boolean}

enable all profiler experiments

  • default: true
  • type: Boolean
  • readonly: false

Implications

  • watch_ic_patching
  • self_optimization
  • retry_self_opt
  • count_based_interrupts
  • interrupt_at_exit
  • weighted_back_edges

watch_ic_patching false {Boolean}

profiler considers IC stability

  • default: false
  • type: Boolean
  • readonly: false

frame_count 1 {Integer}

number of stack frames inspected by the profiler

  • default: 1
  • type: Integer
  • readonly: false

self_optimization false {Boolean}

primitive functions trigger their own optimization

  • default: false
  • type: Boolean
  • readonly: false

direct_self_opt false {Boolean}

call recompile stub directly when self-optimizing

  • default: false
  • type: Boolean
  • readonly: false

retry_self_opt false {Boolean}

re-try self-optimization if it failed

  • default: false
  • type: Boolean
  • readonly: false

count_based_interrupts false {Boolean}

trigger profiler ticks based on counting instead of timing

  • default: false
  • type: Boolean
  • readonly: false

interrupt_at_exit false {Boolean}

insert an interrupt check at function exit

  • default: false
  • type: Boolean
  • readonly: false

weighted_back_edges false {Boolean}

weight back edges by jump distance for interrupt triggering

  • default: false
  • type: Boolean
  • readonly: false

interrupt_budget 5888 {Integer}

execution budget before interrupt is triggered

  • default: 5888
  • type: Integer
  • readonly: false

type_info_threshold 15 {Integer}

percentage of ICs that must have type info to allow optimization

  • default: 15
  • type: Integer
  • readonly: false

self_opt_count 130 {Integer}

call count before self-optimization

  • default: 130
  • type: Integer
  • readonly: false

trace_opt_verbose false {Boolean}

extra verbose compilation tracing

  • default: false
  • type: Boolean
  • readonly: false

Implications

  • trace_opt

debug_code false {Boolean}

generate extra code (assertions) for debugging

  • default: false
  • type: Boolean
  • readonly: false

code_comments false {Boolean}

emit comments in code disassembly

  • default: false
  • type: Boolean
  • readonly: false

Resources

Note: not available below node: 0.11 - v8: 3.25

enable_sse2 true {Boolean}

enable use of SSE2 instructions if available

  • default: true
  • type: Boolean
  • readonly: false

enable_sse3 true {Boolean}

enable use of SSE3 instructions if available

  • default: true
  • type: Boolean
  • readonly: false

enable_sse4_1 true {Boolean}

enable use of SSE4.1 instructions if available

  • default: true
  • type: Boolean
  • readonly: false

enable_cmov true {Boolean}

enable use of CMOV instruction if available

  • default: true
  • type: Boolean
  • readonly: false

enable_rdtsc true {Boolean}

enable use of RDTSC instruction if available

  • default: true
  • type: Boolean
  • readonly: false

enable_sahf true {Boolean}

enable use of SAHF instruction if available (X64 only)

  • default: true
  • type: Boolean
  • readonly: false

enable_vfp3 true {Boolean}

enable use of VFP3 instructions if available - this implies enabling ARMv7 and VFP2 instructions (ARM only)

  • default: true
  • type: Boolean
  • readonly: false

enable_vfp2 true {Boolean}

enable use of VFP2 instructions if available

  • default: true
  • type: Boolean
  • readonly: false

enable_armv7 true {Boolean}

enable use of ARMv7 instructions if available (ARM only)

  • default: true
  • type: Boolean
  • readonly: false

enable_sudiv true {Boolean}

enable use of SDIV and UDIV instructions if available (ARM only)

  • default: true
  • type: Boolean
  • readonly: false

enable_movw_movt false {Boolean}

enable loading 32-bit constant by means of movw/movt instruction pairs (ARM only)

  • default: false
  • type: Boolean
  • readonly: false

enable_unaligned_accesses true {Boolean}

enable unaligned accesses for ARMv7 (ARM only)

  • default: true
  • type: Boolean
  • readonly: false

enable_fpu true {Boolean}

enable use of MIPS FPU instructions if available (MIPS only)

  • default: true
  • type: Boolean
  • readonly: false

expose_natives_as undefined {String}

expose natives in global object

NOTE: This flag cannot be configured after the process started up!

  • default: undefined
  • type: String
  • readonly: false

expose_debug_as undefined {String}

expose debug in global object

NOTE: This flag cannot be configured after the process started up!

  • default: undefined
  • type: String
  • readonly: false

expose_gc false {Boolean}

expose gc extension

NOTE: This flag cannot be configured after the process started up!

  • default: false
  • type: Boolean
  • readonly: false

expose_externalize_string false {Boolean}

expose externalize string extension

  • default: false
  • type: Boolean
  • readonly: false

stack_trace_limit 10 {Integer}

number of stack frames to capture

  • default: 10
  • type: Integer
  • readonly: false

builtins_in_stack_traces false {Boolean}

show built-in functions in stack traces

  • default: false
  • type: Boolean
  • readonly: false

disable_native_files false {Boolean}

disable builtin natives files

  • default: false
  • type: Boolean
  • readonly: false

inline_new true {Boolean}

use fast inline allocation

  • default: true
  • type: Boolean
  • readonly: false

stack_trace_on_abort true {Boolean}

print a stack trace if an assertion failure occurs

  • default: true
  • type: Boolean
  • readonly: false

trace false {Boolean}

trace function calls

  • default: false
  • type: Boolean
  • readonly: false

mask_constants_with_cookie true {Boolean}

use random jit cookie to mask large constants

  • default: true
  • type: Boolean
  • readonly: false

lazy true {Boolean}

use lazy compilation

  • default: true
  • type: Boolean
  • readonly: false

trace_opt false {Boolean}

trace lazy optimization

  • default: false
  • type: Boolean
  • readonly: false

trace_opt_stats false {Boolean}

trace lazy optimization statistics

  • default: false
  • type: Boolean
  • readonly: false

opt true {Boolean}

use adaptive optimizations

  • default: true
  • type: Boolean
  • readonly: false

always_opt false {Boolean}

always try to optimize functions

  • default: false
  • type: Boolean
  • readonly: false

Note: not properly working below node: 0.10 - v8: 3.14

prepare_always_opt false {Boolean}

prepare for turning on always opt

  • default: false
  • type: Boolean
  • readonly: false

trace_deopt false {Boolean}

trace deoptimization

  • default: false
  • type: Boolean
  • readonly: false

min_preparse_length 1024 {Integer}

minimum length for automatic enable preparsing

  • default: 1024
  • type: Integer
  • readonly: false

always_full_compiler false {Boolean}

try to use the dedicated run-once backend for all code

  • default: false
  • type: Boolean
  • readonly: false

max_opt_count 10 {Integer}

maximum number of optimization attempts before giving up.

  • default: 10
  • type: Integer
  • readonly: false

compilation_cache true {Boolean}

enable compilation cache

  • default: true
  • type: Boolean
  • readonly: false

The compilation cache keeps shared function infos for compiled scripts and evals. The shared function infos are looked up using the source string as the key. For regular expressions the compilation data is cached.

Enable/Disable is used by debugger to disable compilation cache during debugging to make sure new scripts are always compiled, however both this flag and the enabled_ property need to be true in order for the compilation cache to get used.

Resources

cache_prototype_transitions true {Boolean}

cache prototype transitions

  • default: true
  • type: Boolean
  • readonly: false

Resources:

trace_debug_json false {Boolean}

trace debugging JSON request/response

  • default: false
  • type: Boolean
  • readonly: false

debugger_auto_break true {Boolean}

automatically set the debug break flag when debugger commands are in the queue

  • default: true
  • type: Boolean
  • readonly: false

enable_liveedit true {Boolean}

enable liveedit experimental feature

  • default: true
  • type: Boolean
  • readonly: false

break_on_abort true {Boolean}

always cause a debug break before aborting

  • default: true
  • type: Boolean
  • readonly: false

stack_size 984 {Integer}

default size of stack region v8 is allowed to use (in kBytes)

  • default: 984
  • type: Integer
  • readonly: false

max_stack_trace_source_length 300 {Integer}

maximum length of function source code printed in a stack trace.

  • default: 300
  • type: Integer
  • readonly: false

always_inline_smi_code false {Boolean}

always inline smi code in non-opt code

  • default: false
  • type: Boolean
  • readonly: false

max_new_space_size 0 {Integer}

max size of the new generation (in kBytes)

  • default: 0
  • type: Integer
  • readonly: false

max_old_space_size 0 {Integer}

max size of the old generation (in Mbytes)

  • default: 0
  • type: Integer
  • readonly: false

max_executable_size 0 {Integer}

max size of executable memory (in Mbytes)

  • default: 0
  • type: Integer
  • readonly: false

gc_global false {Boolean}

always perform global GCs

  • default: false
  • type: Boolean
  • readonly: false

gc_interval -1 {Integer}

garbage collect after allocations

  • default: -1
  • type: Integer
  • readonly: false

trace_gc false {Boolean}

print one trace line following each garbage collection

  • default: false
  • type: Boolean
  • readonly: false

trace_gc_nvp false {Boolean}

print one detailed trace line in name=value format after each garbage collection

  • default: false
  • type: Boolean
  • readonly: false

trace_gc_ignore_scavenger false {Boolean}

do not print trace line after scavenger collection

  • default: false
  • type: Boolean
  • readonly: false

print_cumulative_gc_stat false {Boolean}

print cumulative GC statistics in name=value format on exit

  • default: false
  • type: Boolean
  • readonly: false

trace_gc_verbose false {Boolean}

print more details following each garbage collection

  • default: false
  • type: Boolean
  • readonly: false

trace_fragmentation false {Boolean}

report fragmentation for old pointer and data pages

  • default: false
  • type: Boolean
  • readonly: false

trace_external_memory false {Boolean}

print amount of external allocated memory after each time it is adjusted.

  • default: false
  • type: Boolean
  • readonly: false

collect_maps true {Boolean}

garbage collect maps from which no objects can be reached

  • default: true
  • type: Boolean
  • readonly: false

flush_code true {Boolean}

flush code that we expect not to use again before full gc

  • default: true
  • type: Boolean
  • readonly: false

incremental_marking true {Boolean}

use incremental marking

  • default: true
  • type: Boolean
  • readonly: false

incremental_marking_steps true {Boolean}

do incremental marking steps

  • default: true
  • type: Boolean
  • readonly: false

trace_incremental_marking false {Boolean}

trace progress of the incremental marking

  • default: false
  • type: Boolean
  • readonly: false

track_gc_object_stats false {Boolean}

track object counts and memory usage

  • default: false
  • type: Boolean
  • readonly: false

use_idle_notification true {Boolean}

Use idle notification to reduce memory footprint.

  • default: true
  • type: Boolean
  • readonly: false

use_ic true {Boolean}

use inline caching

  • default: true
  • type: Boolean
  • readonly: false

native_code_counters false {Boolean}

generate extra code for manipulating stats counters

  • default: false
  • type: Boolean
  • readonly: false

always_compact false {Boolean}

Perform compaction on every full GC

  • default: false
  • type: Boolean
  • readonly: false

lazy_sweeping true {Boolean}

Use lazy sweeping for old pointer and data spaces

  • default: true
  • type: Boolean
  • readonly: false

never_compact false {Boolean}

Never perform compaction on full GC - testing only

  • default: false
  • type: Boolean
  • readonly: false

compact_code_space true {Boolean}

Compact code space on full non-incremental collections

  • default: true
  • type: Boolean
  • readonly: false

incremental_code_compaction true {Boolean}

Compact code space on full incremental collections

  • default: true
  • type: Boolean
  • readonly: false

cleanup_code_caches_at_gc true {Boolean}

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

  • default: true
  • type: Boolean
  • readonly: false

random_seed 0 {Integer}

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

  • default: 0
  • type: Integer
  • readonly: false

use_verbose_printer true {Boolean}

allows verbose printing

  • default: true
  • type: Boolean
  • readonly: false

allow_natives_syntax false {Boolean}

allow natives syntax

  • default: false
  • type: Boolean
  • readonly: false

trace_parse false {Boolean}

trace parsing and preparsing

  • default: false
  • type: Boolean
  • readonly: false

trace_sim false {Boolean}

Trace simulator execution

  • default: false
  • type: Boolean
  • readonly: false

check_icache false {Boolean}

Check icache flushes in ARM and MIPS simulator

  • default: false
  • type: Boolean
  • readonly: false

stop_sim_at 0 {Integer}

Simulator stop after x number of instructions

  • default: 0
  • type: Integer
  • readonly: false

sim_stack_alignment 8 {Integer}

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

  • default: 8
  • type: Integer
  • readonly: false

abort_on_uncaught_exception false {Boolean}

abort program (dump core) when an uncaught exception is thrown

  • default: false
  • type: Boolean
  • readonly: false

trace_exception false {Boolean}

print stack trace when throwing exceptions

  • default: false
  • type: Boolean
  • readonly: false

preallocate_message_memory false {Boolean}

preallocate some memory to build stack traces.

  • default: false
  • type: Boolean
  • readonly: false

randomize_hashes true {Boolean}

randomize hashes to avoid predictable hash collisions (with snapshots this option cannot override the baked-in seed)

  • default: true
  • type: Boolean
  • readonly: false

hash_seed 0 {Integer}

Fixed seed to use to hash property keys (0 means random)(with snapshots this option cannot override the baked-in seed)

  • default: 0
  • type: Integer
  • readonly: false

preemption false {Boolean}

activate a 100ms timer that switches between V8 threads

  • default: false
  • type: Boolean
  • readonly: false

regexp_optimization true {Boolean}

generate optimized regexp code

  • default: true
  • type: Boolean
  • readonly: false

testing_string_flag Hello, world! {String}

string-flag

  • default: Hello, world!
  • type: String
  • readonly: false

testing_serialization_file /tmp/serdes {String}

file in which to serialize heap

  • default: /tmp/serdes
  • type: String
  • readonly: false

extra_code undefined {String}

A filename with extra code to be included in the snapshot (mksnapshot only)

  • default: undefined
  • type: String
  • readonly: false

help false {Boolean}

Print usage message, including flags, on console

  • default: false
  • type: Boolean
  • readonly: false

dump_counters false {Boolean}

Dump counters on exit

  • default: false
  • type: Boolean
  • readonly: false

map_counters `` {String}

Map counters to a file

  • default: ``
  • type: String
  • readonly: false

debug_compile_events true {Boolean}

Enable debugger compile events

  • default: true
  • type: Boolean
  • readonly: false

Resources

v8 debug.h

Note: disabled by default on WebOS

debug_script_collected_events true {Boolean}

Enable debugger script collected events

  • default: true
  • type: Boolean
  • readonly: false

gdbjit false {Boolean}

enable GDBJIT interface (disables compacting GC)

  • default: false
  • type: Boolean
  • readonly: false

gdbjit_full false {Boolean}

enable GDBJIT interface for all code objects

  • default: false
  • type: Boolean
  • readonly: false

gdbjit_dump false {Boolean}

dump elf objects with debug info to disk

  • default: false
  • type: Boolean
  • readonly: false

gdbjit_dump_filter `` {String}

dump only objects containing this substring

  • default: ``
  • type: String
  • readonly: false

force_marking_deque_overflows false {Boolean}

force overflows of marking deque by reducing it's size to 64 words

  • default: false
  • type: Boolean
  • readonly: false

stress_compaction false {Boolean}

stress the GC compactor to flush out bugs (implies --force_marking_deque_overflows)

  • default: false
  • type: Boolean
  • readonly: false

enable_slow_asserts false {Boolean}

enable asserts that are slow to execute

  • default: false
  • type: Boolean
  • readonly: true

trace_codegen false {Boolean}

print name of functions for which code is generated

  • default: false
  • type: Boolean
  • readonly: true

print_source false {Boolean}

pretty print source code

  • default: false
  • type: Boolean
  • readonly: true

print_builtin_source false {Boolean}

pretty print source code for builtins

  • default: false
  • type: Boolean
  • readonly: true

print_ast false {Boolean}

print source AST

  • default: false
  • type: Boolean
  • readonly: true

print_builtin_ast false {Boolean}

print source AST for builtins

  • default: false
  • type: Boolean
  • readonly: true

stop_at `` {String}

function name where to insert a breakpoint

  • default: ``
  • type: String
  • readonly: true

print_builtin_scopes false {Boolean}

print scopes for builtins

  • default: false
  • type: Boolean
  • readonly: true

print_scopes false {Boolean}

print scopes

  • default: false
  • type: Boolean
  • readonly: true

trace_contexts false {Boolean}

trace contexts operations

  • default: false
  • type: Boolean
  • readonly: true

gc_greedy false {Boolean}

perform GC prior to some allocations

  • default: false
  • type: Boolean
  • readonly: true

gc_verbose false {Boolean}

print stuff during garbage collection

  • default: false
  • type: Boolean
  • readonly: true

heap_stats false {Boolean}

report heap statistics before and after GC

  • default: false
  • type: Boolean
  • readonly: true

code_stats false {Boolean}

report code statistics after GC

  • default: false
  • type: Boolean
  • readonly: true

Resources

verify_native_context_separation false {Boolean}

verify that code holds on to at most one native context after GC

  • default: false
  • type: Boolean
  • readonly: true

print_handles false {Boolean}

report handles after GC

  • default: false
  • type: Boolean
  • readonly: true

print_global_handles false {Boolean}

report global handles after GC

  • default: false
  • type: Boolean
  • readonly: true

trace_ic false {Boolean}

trace inline cache state transitions

  • default: false
  • type: Boolean
  • readonly: true

print_interfaces false {Boolean}

print interfaces

  • default: false
  • type: Boolean
  • readonly: true

print_interface_details false {Boolean}

print interface inference details

  • default: false
  • type: Boolean
  • readonly: true

print_interface_depth 5 {Integer}

depth for printing interfaces

  • default: 5
  • type: Integer
  • readonly: true

trace_normalization false {Boolean}

prints when objects are turned into dictionaries.

  • default: false
  • type: Boolean
  • readonly: true

trace_lazy false {Boolean}

trace lazy compilation

  • default: false
  • type: Boolean
  • readonly: true

collect_heap_spill_statistics false {Boolean}

report heap spill statistics along with heap_stats (requires heap_stats)

  • default: false
  • type: Boolean
  • readonly: true

trace_isolates false {Boolean}

trace isolate state changes

  • default: false
  • type: Boolean
  • readonly: true

log_state_changes false {Boolean}

Log state changes.

  • default: false
  • type: Boolean
  • readonly: true

regexp_possessive_quantifier false {Boolean}

enable possessive quantifier syntax for testing

  • default: false
  • type: Boolean
  • readonly: true

trace_regexp_bytecodes false {Boolean}

trace regexp bytecode execution

  • default: false
  • type: Boolean
  • readonly: true

trace_regexp_assembler false {Boolean}

trace regexp macro assembler calls.

  • default: false
  • type: Boolean
  • readonly: true

log false {Boolean}

Minimal logging (no API, code, GC, suspect, or handles samples).

  • default: false
  • type: Boolean
  • readonly: false

log_all false {Boolean}

Log all events to the log file.

  • default: false
  • type: Boolean
  • readonly: false

log_runtime false {Boolean}

Activate runtime system %Log call.

  • default: false
  • type: Boolean
  • readonly: false

log_api false {Boolean}

Log API events to the log file.

  • default: false
  • type: Boolean
  • readonly: false

log_code false {Boolean}

Log code events to the log file without profiling.

  • default: false
  • type: Boolean
  • readonly: false

log_gc false {Boolean}

Log heap samples on garbage collection for the hp2ps tool.

  • default: false
  • type: Boolean
  • readonly: false

log_handles false {Boolean}

Log global handle events.

  • default: false
  • type: Boolean
  • readonly: false

log_snapshot_positions false {Boolean}

log positions of (de)serialized objects in the snapshot.

  • default: false
  • type: Boolean
  • readonly: false

log_suspect false {Boolean}

Log suspect operations.

  • default: false
  • type: Boolean
  • readonly: false

prof false {Boolean}

Log statistical profiling information (implies --log-code).

  • default: false
  • type: Boolean
  • readonly: false

prof_auto true {Boolean}

Used with --prof, starts profiling automatically

  • default: true
  • type: Boolean
  • readonly: false

prof_lazy false {Boolean}

Used with --prof, only does sampling and logging when profiler is active (implies --noprof_auto).

  • default: false
  • type: Boolean
  • readonly: false

prof_browser_mode true {Boolean}

Used with --prof, turns on browser-compatible mode for profiling.

  • default: true
  • type: Boolean
  • readonly: false

log_regexp false {Boolean}

Log regular expression execution.

  • default: false
  • type: Boolean
  • readonly: false

sliding_state_window false {Boolean}

Update sliding state window counters.

  • default: false
  • type: Boolean
  • readonly: false

logfile v8.log {String}

Specify the name of the log file.

  • default: v8.log
  • type: String
  • readonly: false

ll_prof false {Boolean}

Enable low-level linux profiler.

  • default: false
  • type: Boolean
  • readonly: false

gc_fake_mmap /tmp/__v8_gc__ {String}

Specify the name of the file for fake gc mmap used in ll_prof

  • default: /tmp/__v8_gc__
  • type: String
  • readonly: false

trace_elements_transitions false {Boolean}

trace elements transitions

  • default: false
  • type: Boolean
  • readonly: true

print_code_stubs false {Boolean}

print code stubs

  • default: false
  • type: Boolean
  • readonly: true

test_secondary_stub_cache false {Boolean}

test secondary stub cache by disabling the primary one

  • default: false
  • type: Boolean
  • readonly: true

test_primary_stub_cache false {Boolean}

test primary stub cache by disabling the secondary one

  • default: false
  • type: Boolean
  • readonly: true

print_code false {Boolean}

print generated code

  • default: false
  • type: Boolean
  • readonly: true

print_opt_code false {Boolean}

print optimized code

  • default: false
  • type: Boolean
  • readonly: true

print_unopt_code false {Boolean}

print unoptimized code before printing optimized code based on it

  • default: false
  • type: Boolean
  • readonly: true

print_code_verbose false {Boolean}

print more information for code

  • default: false
  • type: Boolean
  • readonly: true

print_builtin_code false {Boolean}

print generated code for builtins

  • default: false
  • type: Boolean
  • readonly: true