/usr/bin/js91

Usage: /usr/bin/js91 [options] [[script] scriptArgs*]

  The SpiderMonkey shell provides a command line interface to the
  JavaScript engine. Code and file options provided via the command
  line are run left to right. If provided, the optional script argument
  is run after all options have been processed. Just-In-Time
  compilation modes may be enabled via command line options.

Version: JavaScript-C91.13.0

Arguments:
  script      A script to execute (after all options)
  scriptArgs  String arguments to bind as |scriptArgs| in the shell's global

Options:
  -f --file=PATH                           File path to run, parsing file
                                           contents as UTF-8
  -u --utf16-file=PATH                     File path to run, inflating the
                                           file's UTF-8 contents to UTF-16 and
                                           then parsing that
  -m --module=PATH                         Module path to run
  -e --execute=CODE                        Inline code to run
  --selfhosted-xdr-path=[filename]         Read/Write selfhosted script data
                                           from/to the given XDR file
  --selfhosted-xdr-mode=(encode,decode,off) Whether to encode/decode data of the
                                           file providedwith
                                           --selfhosted-xdr-path.
  -i --shell                               Enter prompt after running code
  -c --compileonly                         Only compile, don't run (syntax
                                           checking mode)
  -w --warnings                            Emit warnings
  -W --nowarnings                          Don't emit warnings
  -D --dump-bytecode                       Dump bytecode with exec count for
                                           all scripts
  -b --print-timing                        Print sub-ms runtime for each file
                                           that's run
  --code-coverage                          Enable code coverage
                                           instrumentation.
  --disable-parser-deferred-alloc          Disable deferred allocation of GC
                                           objects until after parser
  --cpu-count=COUNT                        Set the number of CPUs (hardware
                                           threads) to COUNT, the default is
                                           the actual number of CPUs. The total
                                           number of background helper threads
                                           is the CPU count plus some constant.
  --thread-count=COUNT                     Alias for --cpu-count.
  --ion                                    Enable IonMonkey (default)
  --no-ion                                 Disable IonMonkey
  --no-ion-for-main-context                Disable IonMonkey for the main
                                           context only
  --inlining-entry-threshold=COUNT         The minimum stub entry count before
                                           trial-inlining a call
  --small-function-length=COUNT            The maximum bytecode length of a
                                           'small function' for the purpose of
                                           inlining.
  --no-asmjs                               Disable asm.js compilation
  --wasm-compiler=[option]                 Choose to enable a subset of the
                                           wasm compilers, valid options are
                                           'none', 'baseline', 'ion',
                                           'cranelift', 'optimizing',
                                           'baseline+ion',
                                           'baseline+cranelift',
                                           'baseline+optimizing'. Choosing
                                           'ion' when Ion is not available or
                                           'cranelift' when Cranelift is not
                                           available will fail; use
                                           'optimizing' for cross-compiler
                                           compatibility.
  --wasm-verbose                           Enable WebAssembly verbose logging
  --disable-wasm-huge-memory               Disable WebAssembly huge memory
  --test-wasm-await-tier2                  Forcibly activate tiering and block
                                           instantiation on completion of tier2
  --no-wasm-simd                           Disable wasm simdfeature.
  --wasm-extended-const                    Enable experimental wasm
                                           extended-constfeature.
  --wasm-exceptions                        Enable experimental wasm
                                           exceptionsfeature.
  --wasm-function-references               Enable experimental wasm
                                           function-referencesfeature.
  --wasm-gc                                Enable experimental wasm gcfeature.
  --wasm-relaxed-simd                      Enable experimental wasm
                                           relaxed-simdfeature.
  --wasm-simd-wormhole                     Enable wasm SIMD wormhole (UTSL)
  --no-native-regexp                       Disable native regexp compilation
  --regexp-warmup-threshold=COUNT          Wait for COUNT invocations before
                                           compiling regexps to native code
                                           (default 10)
  --trace-regexp-parser                    Trace regexp parsing
  --trace-regexp-assembler                 Trace regexp assembler
  --trace-regexp-interpreter               Trace regexp interpreter
  --trace-regexp-peephole                  Trace regexp peephole optimization
  --enable-streams                         Enable WHATWG Streams (default)
  --no-streams                             Disable WHATWG Streams
  --enable-readable-byte-streams           Enable support for WHATWG
                                           ReadableStreams of type 'bytes'
  --enable-byob-stream-readers             Enable support for getting BYOB
                                           readers for WHATWG ReadableStreams
                                           of type "bytes"
  --enable-writable-streams                Enable support for WHATWG
                                           WritableStreams
  --enable-readablestream-pipeto           Enable support for WHATWG
                                           ReadableStream.prototype.pipeTo
  --disable-weak-refs                      Disable weak references
  --disable-tosource                       Disable toSource/uneval
  --disable-property-error-message-fix     Disable fix for the error message
                                           when accessing property of null or
                                           undefined
  --enable-iterator-helpers                Enable iterator helpers
  --disable-private-fields                 Disable private class fields
  --disable-private-methods                Disable private class methods
  --enable-ergonomic-brand-checks          Enable ergonomic brand checks for
                                           private class fields (no-op)
  --disable-ergonomic-brand-checks         Disable ergonomic brand checks for
                                           private class fields
  --enable-top-level-await                 Enable top-level await
  --enable-class-static-blocks             Enable class static blocks
  --off-thread-parse-global                Use parseGlobal in all off-thread
                                           compilation
  --no-large-arraybuffers                  Disallow creating ArrayBuffers
                                           larger than 2 GB on 64-bit platforms
  --shared-memory=on/off                   SharedArrayBuffer and Atomics
                                           (default: on, off to disable)
  --spectre-mitigations=on/off             Whether Spectre mitigations are
                                           enabled (default: off, on to enable)
  --cache-ir-stubs=on/off/call             Use CacheIR stubs (default: on, off
                                           to disable, call to enable
                                           work-in-progress call ICs)
  --ion-shared-stubs=on/off                Use shared stubs (default: on, off
                                           to disable)
  --ion-scalar-replacement=on/off          Scalar Replacement (default: on, off
                                           to disable)
  --ion-gvn=[mode]                         Specify Ion global value numbering:
                                             off: disable GVN
                                             on: enable GVN (default)

  --ion-licm=on/off                        Loop invariant code motion (default:
                                           on, off to disable)
  --ion-edgecase-analysis=on/off           Find edge cases where Ion can avoid
                                           bailouts (default: on, off to
                                           disable)
  --ion-pruning=on/off                     Branch pruning (default: on, off to
                                           disable)
  --ion-range-analysis=on/off              Range analysis (default: on, off to
                                           disable)
  --ion-sink=on/off                        Sink code motion (default: off, on
                                           to enable)
  --ion-optimization-levels=on/off         No-op for fuzzing
  --ion-loop-unrolling=on/off              (NOP for fuzzers)
  --ion-instruction-reordering=on/off      Instruction reordering (default:
                                           off, on to enable)
  --ion-check-range-analysis               Range analysis checking
  --ion-extra-checks                       Perform extra dynamic validation
                                           checks
  --ion-inlining=on/off                    Inline methods where possible
                                           (default: on, off to disable)
  --ion-osr=on/off                         On-Stack Replacement (default: on,
                                           off to disable)
  --disable-bailout-loop-check             Turn off bailout loop check
  --scalar-replace-arguments               Use scalar replacement to optimize
                                           ArgumentsObject
  --ion-limit-script-size=on/off           Don't compile very large scripts
                                           (default: on, off to disable)
  --ion-warmup-threshold=COUNT             Wait for COUNT calls or iterations
                                           before compiling at the normal
                                           optimization level (default: 1000)
  --ion-full-warmup-threshold=COUNT        No-op for fuzzing
  --ion-regalloc=[mode]                    Specify Ion register allocation:
                                             backtracking: Priority based
                                             backtracking register allocation
                                             (default)
                                             testbed: Backtracking allocator
                                             with experimental features
                                             stupid: Simple block local
                                             register allocation
  --ion-eager                              Always ion-compile methods (implies
                                           --baseline-eager)
  --fast-warmup                            Reduce warmup thresholds for each
                                           tier.
  --ion-offthread-compile=on/off           Compile scripts off thread (default:
                                           on)
  --ion-parallel-compile=on/off            --ion-parallel compile is
                                           deprecated. Use
                                           --ion-offthread-compile.
  --baseline                               Enable baseline compiler (default)
  --no-baseline                            Disable baseline compiler
  --no-warp-async                          Don't Warp compile Async Functions
  --no-warp-generator                      Warp compile Generator Functions
  --warp-async                             Warp compile Async Functions
  --warp-generator                         Don't Warp compile Generator
                                           Functions
  --baseline-eager                         Always baseline-compile methods
  --baseline-warmup-threshold=COUNT        Wait for COUNT calls or iterations
                                           before baseline-compiling (default:
                                           10)
  --blinterp                               Enable Baseline Interpreter
                                           (default)
  --no-blinterp                            Disable Baseline Interpreter
  --blinterp-eager                         Always Baseline-interpret scripts
  --blinterp-warmup-threshold=COUNT        Wait for COUNT calls or iterations
                                           before Baseline-interpreting
                                           (default: 10)
  --trial-inlining-warmup-threshold=COUNT  Wait for COUNT calls or iterations
                                           before trial-inlining (default: 500)
  --non-writable-jitcode                   (NOP for fuzzers) Allocate JIT code
                                           as non-writable memory.
  --no-sse3                                Pretend CPU does not support SSE3
                                           instructions and above to test JIT
                                           codegen (no-op on platforms other
                                           than x86 and x64).
  --no-ssse3                               Pretend CPU does not support SSSE3
                                           [sic] instructions and above to test
                                           JIT codegen (no-op on platforms
                                           other than x86 and x64).
  --no-sse41                               Pretend CPU does not support SSE4.1
                                           instructions to test JIT codegen
                                           (no-op on platforms other than x86
                                           and x64).
  --no-sse4                                Alias for --no-sse41
  --no-sse42                               Pretend CPU does not support SSE4.2
                                           instructions to test JIT codegen
                                           (no-op on platforms other than x86
                                           and x64).
  --enable-avx                             AVX is disabled by default. Enable
                                           AVX. (no-op on platforms other than
                                           x86 and x64).
  --no-avx                                 No-op. AVX is currently disabled by
                                           default.
  --more-compartments                      Make newGlobal default to creating a
                                           new compartment.
  --fuzzing-safe                           Don't expose functions that aren't
                                           safe for fuzzers to call
  --disable-oom-functions                  Disable functions that cause
                                           artificial OOMs
  --no-threads                             Disable helper threads
  --no-ggc                                 Disable Generational GC
  --no-cgc                                 Disable Compacting GC
  --no-incremental-gc                      Disable Incremental GC
  --nursery-strings=on/off                 Allocate strings in the nursery
  --nursery-bigints=on/off                 Allocate BigInts in the nursery
  --available-memory=SIZE                  Select GC settings based on
                                           available memory (MB)
  --arm-hwcap=[features]                   Specify ARM code generation
                                           features, or 'help' to list all
                                           features.
  --arm-asm-nop-fill=SIZE                  Insert the given number of NOP
                                           instructions at all possible pool
                                           locations.
  --asm-pool-max-offset=OFFSET             The maximum pc relative OFFSET
                                           permitted in pool reference
                                           instructions.
  --arm-sim-icache-checks                  Enable icache flush checks in the
                                           ARM simulator.
  --arm-sim-stop-at=NUMBER                 Stop the ARM simulator after the
                                           given NUMBER of instructions.
  --mips-sim-icache-checks                 Enable icache flush checks in the
                                           MIPS simulator.
  --mips-sim-stop-at=NUMBER                Stop the MIPS simulator after the
                                           given NUMBER of instructions.
  --nursery-size=SIZE-MB                   Set the maximum nursery size in MB
  -z --gc-zeal=LEVEL(;LEVEL)*[,N]          option ignored in non-gc-zeal builds
  --module-load-path=DIR                   Set directory to load modules from
  --no-source-pragmas                      Disable source(Mapping)URL pragma
                                           parsing
  --no-async-stacks                        Disable async stacks
  --async-stacks-capture-debuggee-only     Limit async stack capture to only
                                           debuggees
  --dll=LIBRARY                            Dynamically load LIBRARY
  --suppress-minidump                      Suppress crash minidumps
  --smoosh                                 No-op
  --wasm-compile-and-serialize             Compile the wasm bytecode from stdin
                                           and serialize the results to stdout
  --telemetry-dir=[directory]              Output telemetry results in a
                                           directory
  --use-fdlibm-for-sin-cos-tan             Use fdlibm for Math.sin, Math.cos,
                                           and Math.tan