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v8.1
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v8.1
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'\" et
.nh \" Disable hyphenation
.ad l \" Flush-left
.
.\" Adaptive monospace fonts
.ie t \{
. ds ` \\f(CR
. ds ' \\fP
. ds C? \\f(CR
. ds C! \\f(CR
. ds CW \\f(CR
. ds CI \\f(CI
. ds CB \\f(CB
. ie \\n(.g .ds CE \\f[CBI]
. el .ds CE \\f(CB \}
.el \{
. ds ` \\(lq\\fI
. ds ' \\fP\\(rq
. ds C? \\fI
. ds C! \\fB
. ds CW \\f1
. ds CI \\fI
. ds CB \\fB
. ds CE \\f(BI \}
.\" End of font setup
.
.\" Whether HTML is the targeted output medium
.if '\*(.T'html' .nr H 1
.if '\*(.T'xhtml' .nr H 1
.
.\" Use monochrome hyperlinks
.defcolor pdf:href.colour rgb 0.0 0.0 0.0
.
.\" More obvious tilde: \*~ instead of \(ap
.ds ~ \(ap
.
.\" Nicer-looking C++ (taken from Pod headers)
.ie t .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.el .ds C+ C++
.
.
.\" Monospace text
.de ``
. ds a \\f(CW
. ds z \\f1
. if n \{\
. ds a `
. ds z `
. \}
. ie \\n(.$>2 \\$1\\*a\\$2\\*z\\$3
. el \\*(f2 \\*a\\$1\\*z\\$2
..
.
.\" Variable reference
.de VAR
. ds a \\$1
. ds z \\$2
' if \\n(.$>2 'if 'R'\\$1' \{\
' ds a \\$2
' ds z \\$3 \}
.
. \" HTML output: generate a real variable tag
. ie \\nH=1 \{\
. HTML <var>
. ie \\n(.u=0 \\*a
. el \h'-1n'\\*a\h'-1n'
. HTML </var>
. ie \\n(.u=0 \\*z
. el \h'-1n'\\*z
. \}
.
. \" Everything else: italicise name
. el \\*(CI\\*a\\fP\\*z
. rm a
. rm z
..
.
.\" Bare URL, underlined or hyperlinked
.de LK
' ie '\*(.T'pdf' \l'\w,\\$1,u\(ul'\h'-\w,\\$1,u'\\$1\\$2
' el 'ie t \{\
' UR \\$1
' UE \\$2 \}
' el \\fI\\$1\\fP\\$2
..
.
.\" JavaScript object
.de JS
' ds s https://mdn.io/\\$1
' ie \\nH=1 <a href="\\*s"><code>\\$1</code></a>\\$2
' el 'ie '\*(.T'pdf' \{\
' pdfhref W -D "\\*s" -A \&\\$2 -- \\*(C?\\$1\\fP\}
' el 'ie t \{\
' UR \\*s
\\*(C?\\$1\\fP\\$2
' UE \}
' el \\*(CR\\$1\fP\\$2
. rm s
. rm n
..
.
.\" Describe a V8 flag option
.de V8
. rr pA
. rm N
. if '\\$2'(INTERNAL)' .ds N Internal use only.
. if '\\$2'(TEST)' .ds N Testing only.
. if '\\$2'(WIP)' .ds N In progress.
. if '\\$2'|' .nr pA 1
. if !'\\*N'' .nr pA 1
. if \\n(pA=1 \{\
. ds T \\$3
. ds D \\$4
. \}
. dX \\$1
. TP
\\*(CB \-\-\\$1 \\fR
. ie !'\\*T'' \{\
. B "Type:\t"
\\*T
. br
. B "Default:\t"
. if t .ft CW
\\*D
. if t .ft
. if !'\\*N'' \\fB\\*N\\fR
. sp 1l
. \}
. el .if !'\\*N'' \{\
. B \\*N
. sp 1l
. \}
. rm T
..
.\" GNU Troff: Debug method to trace option definitions
.if \n(.g .if !\n(.C=1 \{\
. ds V8-OPTS "DEFINED OPTIONS:"
. de dX
. if \\nD=1 .tm Defining: \\$1
. ie d V8_\\$1 .tm Already defined: \\$1
. el \{\
. as V8-OPTS \\$1
. ds V8_\\$1 1
. \}
. .
.\}
.
.\"======================================================
.\" BEGIN DOCUMENT
.TH V8 1 "March 16, 2023" "V8 11.3.180" V8
.
.SH NAME
.BR v8 " \(em Google\(cqs JavaScript engine
.
.SH SYNOPSIS
.
.\" Modify man(7) macros to respect monospace setting (controlled by `\n(CW` register)
.nr CW 0
.de B
. ie (\\n(CW=1) \\*(CB\\$*\fR
. el \fB\\$*\fR
..
.de I
. ie (\\n(CW=1) \\*(CI\\$*\fR
. el \fI\\$*\fR
..
.de BI
. ie (\\n(CW=1) \\*(CB\\$1\\*(CI\\$2\\*(CB\\$3\\*(CI\\$4\\*(CB\\$5\\*(CI\\$6\\*(CB\\$7\\*(CI\\$8\\*(CB\\$9\fR
. el \fB\\$1\fI\\$2\fB\\$3\fI\\$4\fB\\$5\fI\\$6\fB\\$7\fI\\$8\fB\\$9\fR
..
.de BR
. ie (\\n(CW=1) \\*(CB\\$1\\*(CW\\$2\\*(CB\\$3\\*(CW\\$4\\*(CB\\$5\\*(CW\\$6\\*(CB\\$7\\*(CW\\$8\\*(CB\\$9\fR
. el \fB\\$1\fR\\$2\fB\\$3\fR\\$4\fB\\$5\fR\\$6\fB\\$7\fR\\$8\fB\\$9\fR
..
.de IB
. ie (\\n(CW=1) \\*(CI\\$1\\*(CB\\$2\\*(CI\\$3\\*(CB\\$4\\*(CI\\$5\\*(CB\\$6\\*(CI\\$7\\*(CB\\$8\\*(CI\\$9\fR
. el \fI\\$1\fB\\$2\fI\\$3\fB\\$4\fI\\$5\fB\\$6\fI\\$7\fB\\$8\fI\\$9\fR
..
.de IR
. ie (\\n(CW=1) \\*(CI\\$1\\*(CW\\$2\\*(CI\\$3\\*(CW\\$4\\*(CI\\$5\\*(CW\\$6\\*(CI\\$7\\*(CW\\$8\\*(CI\\$9\fR
. el \fI\\$1\fR\\$2\fI\\$3\fR\\$4\fI\\$5\fR\\$6\fI\\$7\fR\\$8\fI\\$9\fR
..
.de RB
. ie (\\n(CW=1) \\*(CW\\$1\\*(CB\\$2\\*(CW\\$3\\*(CB\\$4\\*(CW\\$5\\*(CB\\$6\\*(CW\\$7\\*(CB\\$8\\*(CW\\$9\fR
. el \fR\\$1\fB\\$2\fR\\$3\fB\\$4\fR\\$5\fB\\$6\fR\\$7\fB\\$8\fR\\$9\fR
..
.de RI
. ie (\\n(CW=1) \\*(CW\\$1\\*(CI\\$2\\*(CW\\$3\\*(CI\\$4\\*(CW\\$5\\*(CI\\$6\\*(CW\\$7\\*(CI\\$8\\*(CW\\$9\fR
. el \fR\\$1\fI\\$2\fR\\$3\fI\\$4\fR\\$5\fI\\$6\fR\\$7\fI\\$8\fR\\$9\fR
..
.
.nr CW 1
.ie t .B shell\t
.el .B shell
.RI [ options ]
.RB [ \-\-shell ]
.RI [ file... ]
.br
.ie t .B d8\t
.el .B d8\ \ \ \&
.RI [ options ]
.RB [ \-e\~ "\*(CIstring\fP]"
.RB [ \-\-lcov =\*(CIpath\fP]
.RB [ \-\-shell ]
.RI [[ "\*(CB\-\-module\fP" ] " file..." ]
.nr CW 0
.
.SH OPTIONS
.nr CW 1
.TP 6
.B \-\-
Capture all remaining arguments in JavaScript.
.TP 6
.BI \-e " string"
Execute \fIstring\fR in V8.
.TP 6
.BI \-\-lcov\*(CW=\fP path
Write
.BR lcov (1)
compatible coverage info to \fIpath\fP.
.IP
Note: the
.`` =
separator is mandatory; something like \(lq\*(CB--lcov\*(CW\~\*(CIpath\fR\(rq will
.ie t .I not
.el .B not
work.
.TP
.BI \-\-shell
Run an interactive JavaScript shell.
.TP
.B \-\-help
Print flags and usage message to stdout, then exit.
.TP
.B \-\-module
Execute \f(CIfile\fP as a JavaScript module.
.IP
Note: the \f(CB\-\-module\fP option is implicitly enabled for \*(CW*.mjs\fP files.
.nr CW 0
.
.SH V8 FLAGS
Option names beginning with
.RB \(lq no- \(rq
pertain to a boolean V8 flag enabled by default.
.\" BEGIN SCRAPE
.V8 abort-on-bad-builtin-profile-data
Flag for \*(C!mksnapshot\fP, abort if builtins profile can\(cqt be applied.
.V8 no-abort-on-contradictory-flags
Allow program to run even when called with contradictory flags.
.V8 abort-on-far-code-range
Abort if code range is allocated further away than 4GB from the
.`` .text
section.
.V8 abort-on-uncaught-exception
Abort program (dump core) when an uncaught exception is thrown.
.V8 no-adjust-os-scheduling-parameters
Don\(cqt adjust OS-specific scheduling parameters for the isolate.
.V8 no-allocation-buffer-parking
Disable buffer parking.
.V8 no-allocation-site-pretenuring
Don\(cqt pretenure with allocation sites.
.V8 no-allocation-site-tracking
Disable allocation site tracking.
.V8 allow-natives-for-differential-fuzzing
Only allow natives that\(cqre explicitly allowlisted for differential fuzzers.
.V8 allow-natives-syntax
Allow natives syntax.
.V8 allow-overwriting-for-next-flag
Temporarily disable flag contradiction so the next flag gets overwritten.
.V8 allow-unsafe-function-constructor
Allow invoking the function constructor without security checks.
.V8 always-osr
Always try to OSR functions.
.V8 always-sparkplug
Directly tier-up to Sparkplug code.
.V8 always-turbofan
Always try to optimise functions.
.V8 always-use-string-forwarding-table
Use string forwarding table instead of thin strings for all strings.
.V8 no-analyze-environment-liveness
Don\(cqt analyse liveness of environment slots and zap dead values.
.V8 arm-arch | String \(lqarmv8\(rq
Generate instructions for the selected ARM architecture if available: armv6, armv7, armv7+sudiv or armv8.
.V8 asm-wasm-lazy-compilation
Enable lazy compilation for asm-wasm modules.
.V8 assert-types
Generate runtime type assertions to test the typer.
.V8 no-async-stack-traces
Exclude async stack traces in
.JS Error.stack .
.V8 no-baseline-batch-compilation
Don\(cqt batch compile Sparkplug code.
.V8 baseline-batch-compilation-threshold | Int 4096
The estimated instruction size of a batch to trigger compilation.
.V8 no-better-code-range-allocation
Try harder to allocate code range near
.`` .text
section.
Works only for configurations with external code space and shared pointer compression cage.
.V8 no-builtin-subclassing
Disable subclassing support in built-in methods.
.V8 builtins-in-stack-traces
Show built-in functions in stack traces.
.V8 bytecode-old-age | Int 5
Number of GCs before we flush code.
.V8 bytecode-size-allowance-per-tick | Int 150
Increase the number of ticks required for optimisation by
.EQ
( bytecode"\."length / X ).
.EN
.V8 no-cache-prototype-transitions
Don\(cqt cache prototype transitions.
.V8 check-handle-count
Check there aren't too many handles at garbage collection.
.V8 clear-exceptions-on-js-entry
Clear pending exceptions when entering JavaScript.
.V8 clear-free-memory
Initialise free memory with 0.
.V8 code-comments
Emit comments in code disassembly; for more readable source positions you should add \*(C!--no-concurrent-recompilation\fP.
.V8 code-stats
Report code statistics after garbage collection.
.V8 no-compact
Don\(cqt perform compaction on full GCs based on V8\(cqs default heuristics.
.V8 no-compact-code-space
Don\(cqt perform code space compaction on full collections.
.V8 no-compact-code-space-with-stack
Don\(cqt perform code space compaction when finalising a full GC with stack.
.V8 compact-on-every-full-gc
Perform compaction on every full GC.
.V8 no-compact-with-stack
Don\(cqt perform compaction when finalising a full GC with stack.
.V8 no-compilation-cache
Disable compilation cache.
.V8 no-concurrent-array-buffer-sweeping
Don\(cqt sweep array buffers concurrently.
.V8 no-concurrent-cache-deserialization
Don't deserialise code caches in background threads.
.V8 no-concurrent-marking
Don\(cqt use concurrent marking.
.V8 concurrent-marking-max-worker-num | Int 7
Maximum worker number of concurrent marking, 0 for
.`` NumberOfWorkerThreads .
.V8 concurrent-minor-mc-marking
Perform young generation marking concurrently (experimental).
.V8 no-concurrent-osr
Disable concurrent on-stack replacement.
.V8 no-concurrent-recompilation
Force synchronous optimisation of hot functions.
.V8 concurrent-recompilation-delay | Int 0
Artificial compilation delay in ms.
.V8 concurrent-recompilation-queue-length | Int 8
The length of the concurrent compilation queue.
.V8 no-concurrent-sparkplug
Don\(cqt compile Sparkplug code in background threads.
.V8 concurrent-sparkplug-high-priority-threads
Use high-priority compiler threads for concurrent Sparkplug.
.V8 concurrent-sparkplug-max-threads | Uint 1
Maximum number of threads that concurrent Sparkplug can use (0 for unbounded).
.V8 no-concurrent-sweeping
Don\(cqt use concurrent sweeping.
.V8 conservative-stack-scanning
Use conservative stack scanning.
.V8 correctness-fuzzer-suppressions
Suppress certain unspecified behaviours to ease correctness fuzzing:
abort program when the stack overflows or a string exceeds maximum length (as opposed to throwing
.JS RangeError ),
and use a fixed suppression string for error messages.
.V8 cppgc-young-generation
Run young generation garbage collections in Oilpan (experimental).
.V8 cppheap-concurrent-marking
Use concurrent marking for CppHeap.
.V8 cppheap-incremental-marking
Use incremental marking for CppHeap.
.V8 cpu-profiler-sampling-interval | Int 1000
CPU profiler sampling interval in microseconds.
.V8 crash-on-aborted-evacuation
Crash when evacuation of page fails.
.V8 csa-trap-on-node | String \(lq\(rq
Trigger break point when a node with given id is created in given stub.
The format is: \(oq\c
.VAR StubName ,\c
.VAR NodeId \(cq.
.
.V8 no-debug-code
Don\(cqt generate extra code (assertions) for debugging.
.V8 default-to-experimental-regexp-engine
Execute regular expressions using the experimental engine where possible.
.V8 deopt-every-n-times | Int 0
Deoptimise every n times a deopt point is passed.
.V8 deopt-to-baseline
Deoptimise to baseline code when available.
.V8 detailed-error-stack-trace
Include arguments for each function call in the error stack frames array.
.V8 detailed-line-info
Always generate detailed line information for CPU profiling.
.V8 no-detect-ineffective-gcs-near-heap-limit
Don\(cqt trigger out-of-memory failure to avoid GC storm near heap limit.
.V8 dict-property-const-tracking
Use const tracking on dictionary properties.
.V8 disable-abortjs
Disable AbortJS runtime function.
.V8 disable-old-api-accessors
Disable old-style API accessors whose setters trigger through the prototype chain.
.V8 disable-write-barriers
Disable write barriers when GC is non-incremental and heap contains single generation.
.V8 disallow-code-generation-from-strings
Disallow
.`` eval
and friends.
.V8 dump-wasm-module
Dump WASM module bytes.
.V8 dump-wasm-module-path | String \(lq\(rq
Directory to dump WASM modules to.
.V8 embedded-src | String \(lq\(rq
Path for the generated embedded data file.
(\*(C!mksnapshot\fP only).
.V8 embedded-variant | String \(lq\(rq
Label to disambiguate symbols in embedded data file.
(\*(C!mksnapshot\fP only).
.V8 embedder-instance-types
Enable type checking based on instance types provided by the embedder.
.V8 enable-32dregs | maybe_bool unset
Deprecated (use \*(C!--arm-arch\fP instead).
.V8 no-enable-allocation-folding
Don\(cqt use allocation folding globally.
.V8 enable-armv7 | maybe_bool unset
Deprecated (use \*(C!--arm-arch\fP instead).
.V8 enable-armv8 | maybe_bool unset
Deprecated (use \*(C!--arm-arch\fP instead).
.V8 no-enable-avx
Disable use of AVX instructions if available.
.V8 no-enable-avx2
Disable use of AVX2 instructions if available.
.V8 no-enable-bmi1
Disable use of BMI1 instructions if available.
.V8 no-enable-bmi2
Disable use of BMI2 instructions if available.
.V8 enable-etw-stack-walking
Enable ETW (Event Tracking for Windows) stack walking.
.V8 enable-experimental-regexp-engine
Enable experimental regular expression engine for regexes which use the \*(C!/l\fP (\(lqlinear\(rq) flag.
.V8 enable-experimental-regexp-engine-on-excessive-backtracks
Fall back to a breadth-first regexp engine on excessive backtracking.
.V8 no-enable-fma3
Disable use of FMA3 instructions if available.
.V8 no-enable-lazy-source-positions
Don\(cqt skip generating source positions during initial compile, but regenerate when actually required.
.V8 no-enable-lzcnt
Disable use of LZCNT instruction if available.
.V8 enable-neon | maybe_bool unset
Deprecated (use \*(C!--arm-arch\fP instead).
.V8 no-enable-popcnt
Disable use of POPCNT instruction if available.
.V8 no-enable-regexp-unaligned-accesses
Disable unaligned accesses for the regexp engine.
.V8 no-enable-sahf
Disable use of SAHF instruction if available (X64 only).
.V8 no-enable-sealed-frozen-elements-kind
Disable sealed, frozen elements kind.
.V8 enable-sharedarraybuffer-per-context
Enable the
.JS SharedArrayBuffer
constructor per context.
.V8 no-enable-slow-asserts
Disable asserts that are slow to execute.
.V8 enable-source-at-csa-bind
Include source information in the binary at CSA bind locations.
.V8 no-enable-sse3
Disable use of SSE3 instructions if available.
.V8 no-enable-sse4-1
Disable use of SSE4.1 instructions if available.
.V8 no-enable-sse4-2
Disable use of SSE4.2 instructions if available.
.V8 no-enable-ssse3
Disable use of SSSE3 instructions if available.
.V8 enable-sudiv | maybe_bool unset
Deprecated (use \*(C!--arm-arch\fP instead).
.V8 enable-testing-opcode-in-wasm
Enable a testing opcode in WASM that is only implemented in TurboFan.
.V8 enable-third-party-heap
Use third-party heap.
.V8 enable-unconditional-write-barriers
Always use full write barriers.
.V8 enable-vfp3 | maybe_bool unset
Deprecated (use \*(C!--arm-arch\fP instead).
.V8 no-enable-wasm-arm64-generic-wrapper
Disallow use of the generic JS-to-WASM wrapper instead of per-signature wrappers on arm64.
.V8 ephemeron-fixpoint-iterations | Int 10
Number of fixpoint iterations it takes to switch to linear ephemeron algorithm.
.V8 exit-on-contradictory-flags
Exit with return code 0 on contradictory flags.
.V8 experimental
Indicate that V8 is running with experimental features enabled.
This flag is typically not set explicitly,
but instead enabled as an implication of other flags which enable experimental features.
.V8 no-experimental-flush-embedded-blob-icache
Disable an experiment used when evaluating icache flushing on certain CPUs.
.V8 experimental-stack-trace-frames
Enable experimental frames (API/Builtins) and stack trace layout.
.V8 experimental-value-unavailable
Enable experimental
.`` <value\~unavailable>
in scopes.
.V8 experimental-wasm-assume-ref-cast-succeeds
Assume
.`` ref.cast
always succeeds and skip the related type check (unsafe) for WASM.
.V8 experimental-wasm-branch-hinting
Enable prototype branch hinting for WASM.
.V8 experimental-wasm-compilation-hints
Enable prototype compilation hints section for WASM.
.V8 experimental-wasm-extended-const
Enable prototype extended constant expressions for WASM.
.V8 experimental-wasm-gc
Enable prototype garbage collection for WASM.
.V8 experimental-wasm-instruction-tracing
Enable prototype instruction tracing section for WASM.
.V8 experimental-wasm-js-inlining
Enable prototype inlining of small WebAssembly functions into JS for WASM.
.V8 experimental-wasm-memory64
Enable prototype
.`` memory64
for WASM.
.V8 experimental-wasm-pgo-from-file (WIP)
Read and use WASM PGO data from a local file.
Used for testing.
.V8 experimental-wasm-pgo-to-file (WIP)
Dump WASM PGO information to a local file.
Used for testing.
.V8 experimental-wasm-ref-cast-nop
Enable unsafe, experimental use of the
.`` ref.cast_nop
WebAssembly op-code.
.V8 experimental-wasm-relaxed-simd
Enable relaxed SIMD for WASM.
.V8 no-experimental-wasm-return-call
Disable prototype return call opcodes for WASM.
.V8 experimental-wasm-revectorize
Enable 128\(en to 256\(enbit revectorisation for Webassembly SIMD.
.V8 experimental-wasm-skip-bounds-checks
Enable prototype skipping of array bounds checks (unsafe) for WASM.
.V8 experimental-wasm-skip-null-checks
Enable prototype skipping of null checks for
.`` call.ref
and array and struct operations (unsafe) for WASM.
.V8 experimental-wasm-stack-switching
Enable prototype stack switching for WASM.
.V8 experimental-wasm-stringref
Enable prototype reference-typed strings for WASM.
.V8 experimental-wasm-type-reflection
Enable prototype WASM type reflection in JS for WASM.
.V8 experimental-wasm-typed-funcref
Enable prototype typed function references for WASM.
.V8 expose-async-hooks
Expose
.`` async_hooks
object.
.V8 expose-cputracemark-as | String \(lq\(rq
Expose
.`` cputracemark
extension under the specified name.
.V8 expose-externalize-string
Expose \*(CWexternalize\fP string extension.
.V8 expose-gc
Expose
.`` gc
extension.
.V8 expose-gc-as | String \(lq\(rq
Expose
.`` gc
extension under the specified name.
.V8 expose-ignition-statistics
Expose ignition-statistics extension (requires building with \*(C!--v8-enable-ignition-dispatch-counting\fP).
.V8 expose-inspector-scripts
Expose
.`` injected-script-source.js
for debugging.
.V8 expose-statistics
Expose statistics extension.
.V8 expose-trigger-failure
Expose trigger-failure extension.
.V8 no-expose-wasm
Don\(cqt expose WASM interface to JavaScript.
.V8 external-reference-stats
Print statistics on external references used during serialisation.
.V8 fast-forward-schedule
Fast-forward marking schedule.
.V8 fast-map-update
Enable fast map update by caching the migration target.
.V8 feedback-normalization
Feed back normalisation to constructors.
.V8 no-fixed-array-bounds-checks
Disable FixedArray bounds checks.
.V8 flush-baseline-code
Flush of baseline code when it has not been executed recently.
.V8 no-flush-bytecode
Don\(cqt flush bytecode that hasn\(cqt executed recently.
.V8 force-emit-interrupt-budget-checks
Force emit tier-up logic from all non-TurboFan code, even if it is the top enabled tier.
.V8 force-long-branches
Force all emitted branches to be in long mode (MIPS/PPC only).
.V8 force-marking-deque-overflows
Force overflows of marking deque by reducing its size to 64 words.
.V8 force-slow-path
Always take the slow path for builtins.
.V8 no-freeze-flags-after-init
Allow changes to flag values after initialising V8.
.V8 future
Implies all staged features that we want to ship in the not-too-far future.
.V8 fuzzer-gc-analysis
Print number of allocations and enable analysis mode for GC fuzz-testing, e.g. \*(C!--stress-marking\fP, \*(C!--stress-scavenge\fP.
.V8 fuzzer-random-seed | Int 0
Default seed for initialising fuzzer random generator (0, the default, means to use v8\(cqs random number generator seed).
.V8 fuzzing
Cause intrinsics to fail silently by returning
.`` undefined
for invalid usage.
.V8 gc-experiment-less-compaction
Use less compaction in non-memory reducing mode.
.V8 gc-fake-mmap | String \(lq/tmp/__v8_gc__\(rq
Specify the name of the file for fake gc mmap used in
.`` ll_prof .
.V8 gc-global
Always perform global GCs.
.V8 gc-interval | Int -1
Garbage collect after
.VAR N
allocations.
.V8 gc-memory-reducer-start-delay-ms | Int 8000
Delay before memory reducer start.
.V8 gc-stats | Int 0
Used by tracing internally to enable gc statistics.
.V8 gc-verbose
Print stuff during garbage collection.
.V8 gdbjit
Enable GDBJIT interface.
.V8 gdbjit-dump
Dump ELF objects with debug info to disk.
.V8 gdbjit-dump-filter | String \(lq\(rq
Dump only objects containing this substring.
.V8 gdbjit-full
Enable GDBJIT interface for all code objects.
.V8 no-global-ic-updated-flag
Cease tracking of inline cache changes, normally used in tier-up heuristics.
.V8 no-hard-abort
Don\(cqt abort by crashing.
.V8 harmony
Enable all completed Harmony features.
.V8 harmony-array-from-async (WIP)
Enable
.JS Array.fromAsync .
.V8 harmony-array-grouping
Enable array grouping.
.V8 no-harmony-atomics
Disable
.JS Atomics .
.V8 no-harmony-change-array-by-copy
Disable
.JS Array.prototype
methods that return a modified copy of the original.
.V8 no-harmony-import-assertions
Disable import assertions.
.V8 harmony-intl-best-fit-matcher (WIP)
Enable the
.JS Intl
.`` BestFitMatcher
algorithm.
.V8 harmony-intl-duration-format (WIP)
Enable Intl.DurationFormat API.
.V8 no-harmony-intl-number-format-v3
Disable version 3 of
.JS Intl.NumberFormat .
.V8 harmony-iterator-helpers (WIP)
Enable JavaScript iterator helpers.
.V8 harmony-json-parse-with-source
Enable source-text access from
.JS JSON.parse
reviver functions.
.V8 no-harmony-rab-gsab
Disable
.JS ResizableArrayBuffer
and
.JS GrowableSharedArrayBuffer .
.V8 harmony-rab-gsab-transfer
Enable
.JS ArrayBuffer .
transfer.
.V8 no-harmony-regexp-unicode-sets
Disable RegExp Unicode Sets.
.V8 harmony-shadow-realm (WIP)
Enable
.JS ShadowRealm .
.V8 no-harmony-sharedarraybuffer
Disable
.JS SharedArrayBuffer .
.V8 no-harmony-shipping
Disable all shipped Harmony features.
.V8 no-harmony-string-is-well-formed
Disable
.JS String.isWellFormed
and
.JS String.toWellFormed
methods.
.V8 harmony-struct (WIP)
Enable structs, shared structs, and shared arrays.
.V8 no-harmony-symbol-as-weakmap-key
Forbid the use of
.JS Symbol
values as
.JS WeakMap
keys.
.V8 harmony-temporal (WIP)
Enable
.JS Temporal .
.V8 harmony-weak-refs-with-cleanup-some (WIP)
Enable weak references with
.JS FinalizationRegistry.prototype.cleanupSome .
.V8 hash-seed | Uint64 0
Fixed seed to use to hash property keys (0 means random).
With snapshots this option cannot override the baked-in seed.
.V8 heap-growing-percent | Int 0
Specifies heap growing factor as
.EQ
( 1 + heap_growing_percent / 100 ).
.EN
.V8 heap-profiler-show-hidden-objects
Use
.`` native
node-type in snapshots instead of the
.`` hidden
type.
.V8 heap-profiler-trace-objects
Dump heap object allocations/movements/size_updates.
.V8 no-heap-profiler-use-embedder-graph
Don\(cqt use the new EmbedderGraph API to get embedder nodes.
.V8 heap-snapshot-string-limit | Int 1024
Truncate strings to this length in the heap snapshot.
.V8 heap-snapshot-verify
Verify that heap snapshot matches marking visitor behaviour.
.V8 histogram-interval | Int 600000
Time interval in ms for aggregating memory histograms.
.V8 no-huge-max-old-generation-size
Don\(cqt increase maximum size of the old space to 4 GB for x64 systems with the physical memory bigger than 16 GB.
.V8 no-icu-timezone-data
Don\(cqt get information about timezones from ICU.
.V8 no-ignition-elide-noneffectful-bytecodes
Don\(cqt elide bytecodes which won\(cqt have any external effect.
.V8 no-ignition-filter-expression-positions
Don\(cqt filter expression positions before the bytecode pipeline.
.V8 no-ignition-reo
Don\(cqt use ignition register equivalence optimiser.
.V8 no-ignition-share-named-property-feedback
Don\(cqt share feedback slots when loading the same named property from the same object.
.V8 no-incremental-marking
Don\(cqt use incremental marking.
.V8 incremental-marking-hard-trigger | Int 0
Threshold for starting incremental marking immediately in percent of available space:
.EQ
( "limit\~" - "\~size" ).
.EN
.V8 incremental-marking-soft-trigger | Int 0
Threshold for starting incremental marking via a task in percent of available space:
.EQ
( "limit\~" - "\~size" ).
.EN
.V8 no-incremental-marking-task
Don\(cqt use tasks for incremental marking.
.V8 no-incremental-marking-wrappers
Don\(cqt use incremental marking for marking wrappers.
.V8 initial-heap-size | size_t 0
Initial size of the heap (in MBytes).
.V8 initial-old-space-size | size_t 0
Initial old space size (in MBytes).
.V8 initial-shared-heap-size | size_t 0
Initial size of the shared heap (in MBytes).
Other heap-size flags (e.g., \*(C!--initial-heap-size\fP) take precedence.