OptionsList.h

/*
 * Copyright (C) 2019-2026 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <JavaScriptCore/GCLogging.h>
#include <JavaScriptCore/JSCWebPreferenceOptions.h>
#include <JavaScriptCore/JSExportMacros.h>

#if OS(DARWIN)
#include <mach/vm_param.h>
#endif

using WTF::PrintStream;

namespace JSC {

#define MAXIMUM_NUMBER_OF_FTL_COMPILER_THREADS 8

JS_EXPORT_PRIVATE bool canUseJITCage();
bool canUseWasm();
bool hasCapacityToUseLargeGigacage();

// How do JSC VM options work?
// ===========================
// The FOR_EACH_JSC_OPTION() macro below defines a list of all JSC options in use,
// along with their types and default values. The options values are actually
// realized as fields in OptionsStorage embedded in JSC::Config.
//
//     Options::initialize() will initialize the option values with the defaults
// specified in FOR_EACH_JSC_OPTION() below. After that, the values can be
// programmatically read and written to using an accessor method with the same
// name as the option. For example, the option "useJIT" can be read and set like
// so:
//
//     bool jitIsOn = Options::useJIT();  // Get the option value.
//     Options::useJIT() = false;         // Sets the option value.
//
//     If you want to tweak any of these values programmatically for testing
// purposes, you can do so in Options::initialize() after the default values
// are set.
//
//     Alternatively, you can override the default values by specifying
// environment variables of the form: JSC_<name of JSC option>.
//
// Note: Options::initialize() tries to ensure some sanity on the option values
// which are set by doing some range checks, and value corrections. These
// checks are done after the option values are set. If you alter the option
// values after the sanity checks (for your own testing), then you're liable to
// ensure that the new values set are sane and reasonable for your own run.
//
// Any modifications to options must be done before the first VM is instantiated.
// On instantiation of the first VM instance, the Options will be write protected
// and cannot be modified thereafter.

#define FOR_EACH_JSC_OPTION(v)                                          \
    v(Bool, useKernTCSM, defaultTCSMValue(), Normal, "Note: this needs to go before other options since they depend on this value."_s) \
    v(Bool, validateOptions, false, Normal, "crashes if mis-typed JSC options were passed to the VM"_s) \
    v(Unsigned, dumpOptions, 0, Normal, "dumps JSC options (0 = None, 1 = Overridden only, 2 = All, 3 = Verbose)"_s) \
    v(OptionString, configFile, nullptr, Normal, "file to configure JSC options and logging location"_s) \
    \
    v(Bool, useLLInt,  true, Normal, "allows the LLINT to be used if true"_s) \
    v(Bool, useJIT, jitEnabledByDefault(), Normal, "allows the executable pages to be allocated for JIT and thunks if true"_s) \
    v(Bool, useBaselineJIT, true, Normal, "allows the baseline JIT to be used if true"_s) \
    v(Bool, useDFGJIT, jitEnabledByDefault(), Normal, "allows the DFG JIT to be used if true"_s) \
    v(Bool, useRegExpJIT, jitEnabledByDefault(), Normal, "allows the RegExp JIT to be used if true"_s) \
    v(Bool, useDOMJIT, jitEnabledByDefault(), Normal, "allows the DOMJIT to be used if true"_s) \
    \
    v(Bool, reportMustSucceedExecutableAllocations, false, Normal, nullptr) \
    \
    v(Unsigned, maxPerThreadStackUsage, 5 * MB, Normal, "Max allowed stack usage by the VM"_s) \
    v(Unsigned, softReservedZoneSize, 128 * KB, Normal, "A buffer greater than reservedZoneSize that reserves space for stringifying exceptions."_s) \
    v(Unsigned, reservedZoneSize, 64 * KB, Normal, "The amount of stack space we guarantee to our clients (and to interal VM code that does not call out to clients)."_s) \
    \
    v(Bool, crashOnDisallowedVMEntry, ASSERT_ENABLED, Normal, "Forces a crash if we attempt to enter the VM when disallowed"_s) \
    v(Bool, crashIfCantAllocateJITMemory, false, Normal, nullptr) \
    v(Unsigned, structureHeapSizeInKB, 0, Normal, "Override for Structure Heap size (in KBs) if non-zero"_s) \
    v(Unsigned, jitMemoryReservationSize, 0, Normal, "Set this number to change the executable allocation size in ExecutableAllocatorFixedVMPool. (In bytes.)"_s) \
    v(Size, jitMemoryReservationAddress, 0, Restricted, "If non-zero, we will attempt to allocate JIT memory at the address provided and crash if we cannot.") \
    v(Size, maximumCachedAssemblerDataCapacity, 4 * MB, Normal, "When useCachedAssemblerDataCapacityLimit is true, a thread does not keep an AssemblerData buffer larger than this cached for reuse. (In bytes.)"_s) \
    \
    v(Bool, forceCodeBlockLiveness, false, Normal, nullptr) \
    v(Bool, forceICFailure, false, Normal, nullptr) \
    v(Bool, forceUnlinkedDFG, false, Normal, nullptr) \
    \
    v(Unsigned, repatchCountForCoolDown, 8, Normal, nullptr) \
    v(Unsigned, initialCoolDownCount, 20, Normal, nullptr) \
    v(Unsigned, repatchBufferingCountdown, 6, Normal, nullptr) \
    v(Unsigned, initialRepatchBufferingCountdown, 6, Normal, nullptr) \
    \
    v(Bool, dumpGeneratedBytecodes, false, Normal, nullptr) \
    v(Bool, dumpBytecodeLivenessResults, false, Normal, nullptr) \
    v(Bool, validateBytecode, false, Normal, nullptr) \
    v(Bool, forceDebuggerBytecodeGeneration, false, Normal, nullptr) \
    v(Bool, debuggerTriggersBreakpointException, false, Normal, "Using the debugger statement will trigger an breakpoint exception (Useful when lldbing)"_s) \
    v(Bool, verboseWasmDebugger, false, Normal, nullptr) \
    v(Bool, enableWasmDebugger, false, Normal, nullptr) \
    v(Bool, verboseWasmTypeCleanup, false, Normal, "Log per-invocation counts from Wasm::TypeInformation::tryCleanup (scanned / live / reclaimed)."_s) \
    v(Bool, dumpBytecodesBeforeGeneratorification, false, Normal, nullptr) \
    v(Unsigned, switchJumpTableAmountThreshold, 15, Normal, nullptr) \
    \
    v(Bool, useFunctionDotArguments, true, Normal, nullptr) \
    v(Bool, useTailCalls, true, Normal, nullptr) \
    v(Bool, optimizeRecursiveTailCalls, true, Normal, nullptr) \
    v(Bool, alwaysUseShadowChicken, false, Normal, nullptr) \
    v(Unsigned, shadowChickenLogSize, 1000, Normal, nullptr) \
    v(Unsigned, shadowChickenMaxTailDeletedFramesSize, 128, Normal, nullptr) \
    \
    v(OSLogType, useOSLog, OSLogType::None, Normal, "Log dataLog()s to os_log instead of stderr"_s) \
    /* dumpDisassembly implies dumpDFGDisassembly. */ \
    v(Bool, needDisassemblySupport, false, Normal, nullptr) \
    v(Bool, dumpDisassembly, false, Normal, "dumps disassembly of all JIT compiled code upon compilation"_s) \
    v(Bool, logJIT, false, Normal, nullptr) \
    v(Bool, dumpBaselineDisassembly, false, Normal, "dumps disassembly of Baseline function upon compilation"_s) \
    v(Bool, dumpDFGDisassembly, false, Normal, "dumps disassembly of DFG function upon compilation"_s) \
    v(Bool, dumpFTLDisassembly, false, Normal, "dumps disassembly of FTL function upon compilation"_s) \
    v(Bool, dumpCSSJITDisassembly, false, Normal, "dumps disassembly of CSS Selector JIT upon compilation"_s) \
    v(Bool, dumpRegExpDisassembly, false, Normal, "dumps disassembly of RegExp upon compilation"_s) \
    v(Bool, traceRegExpJITExecution, false, Normal, "traces RegExp JIT execution at reentry points"_s) \
    v(Bool, dumpWasmDisassembly, false, Normal, "dumps disassembly of all wasm code upon compilation"_s) \
    v(OptionString, dumpWasmSourceFileName, nullptr, Normal, "log every wasm module validation, and dump source bytes to <filename>.0.wasm, <filename>.1.wasm, etc..."_s) \
    v(OptionString, wasmOMGFunctionsToDump, nullptr, Normal, "file with newline separated list of function indices to dump IR/disassembly for, if no such file exists, the function index itself"_s) \
    v(Bool, dumpBBQDisassembly, false, Normal, "dumps disassembly of BBQ wasm code upon compilation"_s) \
    v(Bool, dumpOMGDisassembly, false, Normal, "dumps disassembly of OMG wasm code upon compilation"_s) \
    v(Bool, useJITDump, false, Normal, "generates JITDump side-data") \
    v(Bool, useGdbJITInfo, false, Normal, "generates GDB JIT API side-data; to use with lldb on macos, add `settings set plugin.jit-loader.gdb.enable on` to .lldbinit") \
    v(Bool, useTextMarkers, false, Normal, "generates text markers side-data") \
    v(OptionString, jitDumpDirectory, nullptr, Normal, "Directory to place JITDump"_s) \
    v(Bool, useIRDump, false, Normal, "generates IR dump files and JIT_CODE_DEBUG_INFO in JITDump"_s) \
    v(OptionString, irDumpDirectory, nullptr, Normal, "Directory to place IR dump files"_s) \
    v(Bool, useSourceCodeDump, false, Normal, "generates source code debug info in JITDump"_s) \
    v(OptionString, sourceCodeDumpDirectory, nullptr, Normal, "Directory to place dumped source files"_s) \
    v(OptionString, textMarkersDirectory, nullptr, Normal, "Directory to place MarkerTxt") \
    v(OptionRange, bytecodeRangeToJITCompile, nullptr, Normal, "bytecode size range to allow compilation on, e.g. 1:100"_s) \
    v(OptionRange, bytecodeRangeToDFGCompile, nullptr, Normal, "bytecode size range to allow DFG compilation on, e.g. 1:100"_s) \
    v(OptionRange, bytecodeRangeToFTLCompile, nullptr, Normal, "bytecode size range to allow FTL compilation on, e.g. 1:100"_s) \
    v(OptionString, jitAllowlist, nullptr, Normal, "file with newline separated list of function signatures to allow compilation on or, if no such file exists, the function signature to allow"_s) \
    v(OptionString, dfgAllowlist, nullptr, Normal, "file with newline separated list of function signatures to allow DFG compilation on or, if no such file exists, the function signature to allow"_s) \
    v(OptionString, ftlAllowlist, nullptr, Normal, "file with newline separated list of function signatures to allow FTL compilation on or, if no such file exists, the function signature to allow"_s) \
    v(OptionString, bbqAllowlist, nullptr, Normal, "file with newline separated list of function indices to allow BBQ compilation on or, if no such file exists, the function index to allow"_s) \
    v(OptionString, omgAllowlist, nullptr, Normal, "file with newline separated list of function indices to allow OMG compilation on or, if no such file exists, the function index to allow"_s) \
    v(OptionString, loopUnrollingAllowlist, nullptr, Normal, "file with newline separated list of function signatures to allow loop unrolling on or, if no such file exists, the function signature to allow"_s) \
    v(OptionString, dumpGraphAllowlist, nullptr, Normal, "file with newline separated list of function signatures to filter graph dumps without restricting JIT compilation, or if no such file exists, the function signature to allow (affects dumpGraphAtEachPhase, dumpDFGGraphAtEachPhase, and dumpDFGFTLGraphAtEachPhase)"_s) \
    v(Bool, dumpSourceAtDFGTime, false, Normal, "dumps source code of JS function being DFG compiled"_s) \
    v(Bool, dumpBytecodeAtDFGTime, false, Normal, "dumps bytecode of JS function being DFG compiled"_s) \
    v(Bool, dumpGraphAfterParsing, false, Normal, nullptr) \
    v(Bool, dumpGraphAtEachPhase, false, Normal, nullptr) \
    v(Bool, dumpDFGGraphAtEachPhase, false, Normal, "dumps the DFG graph at each phase of DFG compilation (note this excludes DFG graphs during FTL compilation)"_s) \
    v(Bool, dumpDFGFTLGraphAtEachPhase, false, Normal, "dumps the DFG graph at each phase of DFG compilation when compiling FTL code"_s) \
    v(Bool, dumpB3GraphAtEachPhase, false, Normal, "dumps the B3 graph at each phase of compilation"_s) \
    v(Bool, dumpAirGraphAtEachPhase, false, Normal, "dumps the Air graph at each phase of compilation"_s) \
    v(Bool, verboseDFGBytecodeParsing, false, Normal, nullptr) \
    v(Bool, safepointBeforeEachPhase, true, Normal, nullptr) \
    v(Bool, verboseCompilation, false, Normal, nullptr) \
    v(Bool, verboseFTLCompilation, false, Normal, nullptr) \
    v(Bool, logCompilationChanges, false, Normal, nullptr) \
    v(Bool, printEachOSRExit, false, Normal, nullptr) \
    v(Bool, printEachDFGFTLInlineCall, false, Normal, nullptr) \
    v(Bool, useJITAsserts, ASSERT_ENABLED, Normal, nullptr) \
    v(Bool, validateDoesGC, ASSERT_ENABLED, Normal, nullptr) \
    v(Bool, validateGraph, false, Normal, nullptr) \
    v(Bool, validateGraphAtEachPhase, false, Normal, nullptr) \
    v(Bool, verboseValidationFailure, false, Normal, nullptr) \
    v(Bool, verboseOSR, false, Normal, nullptr) \
    v(Bool, verboseDFGOSRExit, false, Normal, nullptr) \
    v(Bool, verboseFTLOSRExit, false, Normal, nullptr) \
    v(Bool, verboseCallLink, false, Normal, nullptr) \
    v(Bool, verboseCompilationQueue, false, Normal, nullptr) \
    v(Bool, reportCompileTimes, false, Normal, "dumps JS function signature and the time it took to compile in all tiers"_s) \
    v(Bool, reportBaselineCompileTimes, false, Normal, "dumps JS function signature and the time it took to BaselineJIT compile"_s) \
    v(Bool, reportDFGCompileTimes, false, Normal, "dumps JS function signature and the time it took to DFG and FTL compile"_s) \
    v(Bool, reportFTLCompileTimes, false, Normal, "dumps JS function signature and the time it took to FTL compile"_s) \
    v(Bool, reportTotalCompileTimes, false, Normal, nullptr) \
    v(Bool, reportTotalPhaseTimes, false, Normal, "This prints phase times at the end of running script inside jsc.cpp"_s) \
    v(Bool, reportParseTimes, false, Normal, "dumps JS function signature and the time it took to parse"_s) \
    v(Bool, reportBytecodeCompileTimes, false, Normal, "dumps JS function signature and the time it took to bytecode compile"_s) \
    v(Bool, reportBytecodeCacheDecodeTimes, false, Normal, "dumps the time it took to decode bytecode from the disk cache"_s) \
    v(Bool, countParseTimes, false, Normal, "counts parse times"_s) \
    v(Bool, verboseExitProfile, false, Normal, nullptr) \
    v(Bool, verboseCFA, false, Normal, nullptr) \
    v(Bool, verboseDFGFailure, false, Normal, nullptr) \
    v(Bool, verboseFTLToJSThunk, false, Normal, nullptr) \
    v(Bool, verboseFTLFailure, false, Normal, nullptr) \
    v(Bool, testTheFTL, false, Normal, nullptr) \
    v(Bool, verboseSanitizeStack, false, Normal, nullptr) \
    v(Bool, useGenerationalGC, true, Normal, nullptr) \
    v(Bool, useConcurrentGC, true, Normal, nullptr) \
    v(Bool, collectContinuously, false, Normal, nullptr) \
    v(Double, collectContinuouslyPeriodMS, 1, Normal, nullptr) \
    v(Unsigned, initialHeapVersion, 0, Restricted, "If nonzero, the version each heap's marking, newly allocated and Eden versions start at. A value near the maximum makes them wrap within a few collections."_s) \
    v(Bool, forceFencedBarrier, false, Normal, nullptr) \
    v(Bool, verboseVisitRace, false, Normal, nullptr) \
    v(Bool, verboseHeapSnapshotLogging, true, Normal, nullptr) \
    v(Unsigned, largeHeapSize, 32 * 1024 * 1024, Normal, nullptr) \
    v(Unsigned, mediumHeapSize, 4 * 1024 * 1024, Normal, nullptr) \
    v(Unsigned, smallHeapSize, 1 * 1024 * 1024, Normal, nullptr) \
    v(Double, smallHeapRAMFraction, 0.25, Normal, nullptr) \
    v(Double, smallHeapGrowthFactor, 2, Normal, nullptr) \
    v(Double, mediumHeapRAMFraction, 0.5, Normal, nullptr) \
    v(Double, mediumHeapGrowthFactor, 1.5, Normal, nullptr) \
    v(Double, largeHeapGrowthFactor, 1.24, Normal, nullptr) \
    v(Double, miniVMHeapGrowthFactor, 1.20, Normal, nullptr) \
    v(Double, heapGrowthSteepnessFactor, 2.00, Normal, nullptr) \
    v(Double, heapGrowthMaxIncrease, 3.00, Normal, nullptr) \
    v(Unsigned, aggressiveHeapThresholdInMB, 16 * 1024, Normal, nullptr) \
    v(Double, maxEdenSizeForRateLimitingMultiplier, 8.0, Normal, nullptr) \
    v(Double, gcRateLimitingHalfLifeInMS, 1000.00, Normal, nullptr) \
    v(Double, criticalGCMemoryThreshold, 0.80, Normal, "percent memory in use the GC considers critical.  The collector is much more aggressive above this threshold"_s) \
    v(Double, minimumMutatorUtilization, 0, Normal, nullptr) \
    v(Double, maximumMutatorUtilization, 0.7, Normal, nullptr) \
    v(Double, epsilonMutatorUtilization, 0.01, Normal, nullptr) \
    v(Double, concurrentGCMaxHeadroom, 1.5, Normal, nullptr) \
    v(Double, concurrentGCPeriodMS, 2, Normal, nullptr) \
    v(Bool, useStochasticMutatorScheduler, true, Normal, nullptr) \
    v(Double, minimumGCPauseMS, 0.3, Normal, nullptr) \
    v(Double, gcPauseScale, 0.3, Normal, nullptr) \
    v(Double, gcIncrementBytes, 10000, Normal, nullptr) \
    v(Double, gcIncrementMaxBytes, 100000, Normal, nullptr) \
    v(Double, gcIncrementScale, 0, Normal, nullptr) \
    v(Bool, useWarmUpMarkedBlocks, true, Normal, "hand MarkedBlock allocation pages that a helper thread already made resident"_s) \
    v(Unsigned, warmUpMarkedBlockCount, 32, Normal, "how many MarkedBlocks the helper thread keeps ready with their pages already resident; 0 turns it off"_s) \
    v(Double, warmUpMarkedBlockIdleTimeout, 10, Normal, "seconds without a MarkedBlock request before the helper thread releases what it is holding and shuts down"_s) \
    v(Bool, scribbleFreeCells, false, Normal, nullptr) \
    v(Double, sizeClassProgression, 1.4, Normal, nullptr) \
    v(Unsigned, preciseAllocationCutoff, 100000, Normal, nullptr) \
    v(Bool, dumpSizeClasses, false, Normal, nullptr) \
    v(Bool, stealEmptyBlocksFromOtherAllocators, true, Normal, nullptr) \
    v(Unsigned, weakBlockPoolDivisor, 16, Normal, "MarkedBlocks per empty WeakBlock the Heap keeps pooled for reuse. 0 pools nothing.") \
    v(Bool, eagerlyUpdateTopCallFrame, false, Normal, nullptr) \
    v(Bool, dumpZappedCellCrashData, false, Normal, nullptr) \
    \
    v(Bool, useOSREntryToDFG, true, Normal, nullptr) \
    v(Bool, useOSREntryToFTL, true, Normal, nullptr) \
    \
    v(Bool, useFTLJIT, true, Normal, "allows the FTL JIT to be used if true"_s) \
    v(Bool, validateFTLOSRExitLiveness, false, Normal, nullptr) \
    v(Bool, poisonDeadOSRExitVariables, ASSERT_ENABLED, Normal, "Put an unmapped cell-like pointer (poisonedDeadOSRExitValue) into dead OSR exit values rather than jsUndefined, so accidental reads of dead variables crash at the access site"_s) \
    v(Unsigned, defaultB3OptLevel, 2, Normal, nullptr) \
    v(Bool, b3AlwaysFailsBeforeCompile, false, Normal, nullptr) \
    v(Bool, b3AlwaysFailsBeforeLink, false, Normal, nullptr) \
    v(Bool, validateSerializedValue, false, Normal, nullptr) /* tests CloneSerializer/Deserializer */ \
    v(Bool, ftlCrashes, false, Normal, nullptr) /* fool-proof way of checking that you ended up in the FTL. ;-) */\
    v(Bool, clobberAllRegsInFTLICSlowPath, ASSERT_ENABLED, Normal, nullptr) \
    v(Bool, useJITDebugAssertions, ASSERT_ENABLED, Normal, nullptr) \
    v(Bool, useAccessInlining, true, Normal, nullptr) \
    v(Unsigned, maxAccessVariantListSize, 8, Normal, nullptr) \
    v(Double, thresholdForUndesiredMegamorphicAccessVariantListSize, 0.5, Normal, nullptr) \
    v(Bool, usePolyvariantDevirtualization, true, Normal, nullptr) \
    v(Bool, usePolymorphicAccessInlining, true, Normal, nullptr) \
    v(Unsigned, maxPolymorphicAccessInliningListSize, 8, Normal, nullptr) \
    v(Bool, usePolymorphicCallInlining, true, Normal, nullptr) \
    v(Bool, usePolymorphicCallInliningForNonStubStatus, false, Normal, nullptr) \
    v(Unsigned, maxPolymorphicCallVariantListSize, 8, Normal, nullptr) \
    v(Unsigned, maxPolymorphicCallVariantListSizeForTopTier, 5, Normal, nullptr) \
    v(Unsigned, maxPolymorphicCallVariantListSizeForWasmToJS, 5, Normal, nullptr) \
    v(Unsigned, maxPolymorphicCallVariantsForInlining, 5, Normal, nullptr) \
    v(Unsigned, frequentCallThreshold, 2, Normal, nullptr) \
    v(Double, minimumCallToKnownRate, 0.51, Normal, nullptr) \
    v(Bool, createPreHeaders, true, Normal, nullptr) \
    v(Bool, useMovHintRemoval, true, Normal, nullptr) \
    v(Bool, usePutStackSinking, true, Normal, nullptr) \
    v(Bool, useObjectAllocationSinking, true, Normal, nullptr) \
    v(Bool, verboseObjectAllocationSinking, false, Normal, nullptr) \
    v(Bool, useValueRepElimination, true, Normal, nullptr) \
    v(Bool, useArityFixupInlining, true, Normal, nullptr) \
    v(Bool, logExecutableAllocation, false, Normal, nullptr) \
    v(Unsigned, maxDFGNodesInBasicBlockForPreciseAnalysis, 20000, Normal, "Disable precise but costly analysis and give conservative results if the number of DFG nodes in a block exceeds this threshold"_s) \
    \
    v(Bool, useConcurrentJIT, true, Normal, "allows the DFG / FTL compilation in threads other than the executing JS thread"_s) \
    v(Unsigned, minNumberOfWorklistThreads, computeNumberOfWorkerThreads(3, 2), Normal, nullptr) \
    v(Unsigned, maxNumberOfWorklistThreads, computeNumberOfWorkerThreads(3, 2), Normal, nullptr) \
    v(Unsigned, numberOfBaselineCompilerThreads, computeNumberOfWorkerThreads(3, 2), Normal, nullptr) \
    v(Unsigned, numberOfDFGCompilerThreads, computeNumberOfWorkerThreads(3, 2) - 1, Normal, nullptr) \
    v(Unsigned, numberOfFTLCompilerThreads, computeNumberOfWorkerThreads(MAXIMUM_NUMBER_OF_FTL_COMPILER_THREADS, 2) - 1, Normal, nullptr) \
    v(Unsigned, numberOfWasmCompilerThreads, computeNumberOfWorkerThreads(INT32_MAX, 2) - 1, Normal, nullptr) \
    v(Unsigned, worklistLoadFactor, 1, Normal, nullptr) \
    v(Unsigned, worklistBaselineLoadWeight, 1, Normal, nullptr) \
    v(Unsigned, worklistDFGLoadWeight, 1, Normal, nullptr) \
    v(Unsigned, worklistFTLLoadWeight, 1, Normal, nullptr) \
    v(Int32, priorityDeltaOfDFGCompilerThreads, computePriorityDeltaOfWorkerThreads(-1, 0), Normal, nullptr) \
    v(Int32, priorityDeltaOfFTLCompilerThreads, computePriorityDeltaOfWorkerThreads(-2, 0), Normal, nullptr) \
    v(Int32, priorityDeltaOfWasmCompilerThreads, computePriorityDeltaOfWorkerThreads(-1, 0), Normal, nullptr) \
    \
    v(Bool, useProfiler, false, Normal, nullptr) \
    v(Bool, dumpProfilerDataAtExit, false, Normal, nullptr) \
    v(Bool, disassembleBaselineForProfiler, true, Normal, nullptr) \
    v(Unsigned, abbreviateSourceCodeForProfiler, 0, Normal, nullptr) \
    \
    v(Bool, useArchitectureSpecificOptimizations, true, Normal, nullptr) \
    \
    v(Bool, breakOnThrow, false, Normal, nullptr) \
    \
    v(Unsigned, maximumOptimizationCandidateBytecodeCost, 100000, Normal, nullptr) \
    \
    v(Unsigned, maximumFunctionForCallInlineCandidateBytecodeCostForDFG, 80, Normal, nullptr) \
    v(Unsigned, maximumFunctionForClosureCallInlineCandidateBytecodeCostForDFG, 80, Normal, nullptr) \
    v(Unsigned, maximumFunctionForConstructInlineCandidateBytecodeCostForDFG, 80, Normal, nullptr) \
    v(Unsigned, maximumFunctionForCallInlineCandidateBytecodeCostForFTL, 170, Normal, nullptr) \
    v(Unsigned, maximumFunctionForClosureCallInlineCandidateBytecodeCostForFTL, 100, Normal, nullptr) \
    v(Unsigned, maximumFunctionForConstructInlineCandidateBytecodeCostForFTL, 100, Normal, nullptr) \
    \
    v(Unsigned, maximumFTLCandidateBytecodeCost, 60000, Normal, nullptr) \
    \
    v(Double, ratioFTLNodesToBytecodeCost, 1.9, Normal, "Ratio converting FTL # of DFG nodes to approx bytecode cost") \
    \
    /* Depth of inline stack, so 1 = no inlining, 2 = one level, etc. */ \
    v(Unsigned, maximumInliningDepth, 5, Normal, "maximum allowed inlining depth.  Depth of 1 means no inlining"_s) \
    v(Unsigned, maximumInliningRecursion, 2, Normal, nullptr) \
    \
    /* Maximum size of a caller for enabling inlining. This is purely to protect us */\
    /* from super long compiles that take a lot of memory. */\
    v(Unsigned, maximumInliningCallerBytecodeCost, 10000, Normal, nullptr) \
    \
    v(Bool, useGlobalInliningPlanner, true, Normal, "Survey and rank every inlining candidate before parsing and spend one compilation-wide budget on the best of them, instead of deciding each call site in bytecode order"_s) \
    v(Unsigned, globalInliningPlanBudgetForDFG, 2500, Normal, "Total callee bytecode cost the DFG may plan to inline in one compilation"_s) \
    v(Unsigned, globalInliningPlanBudgetForFTL, 12000, Normal, "Total callee bytecode cost the FTL may plan to inline in one compilation"_s) \
    v(Unsigned, maximumGlobalInliningPlanSites, 20000, Normal, "Cap on how many call sites one inlining plan will survey"_s) \
    v(Double, inliningPlanTierBonusBase, 2.0, Normal, "Multiplicative benefit per tier the callee has reached (LLInt, Baseline, DFG, FTL) when ranking inlining candidates"_s) \
    v(Double, inliningPlanTierBonusPowerForFTL, 3.0, Normal, "Base for the bonus multiplier for FTL callees"_s) \
    v(Double, inliningPlanTierBonusPowerForDFG, 2.0, Normal, "Base for the bonus multiplier for DFG callees"_s) \
    v(Double, inliningPlanTierBonusPowerForBaseline, 1.0, Normal, "Base for the bonus multiplier for Baseline callees"_s) \
    v(Double, inliningPlanDepthPenalty, 1.5, Normal, "Divisive benefit penalty per level of inline-stack nesting when ranking inlining candidates"_s) \
    \
    v(Unsigned, maximumVarargsForInlining, 100, Normal, nullptr) \
    \
    v(Unsigned, maximumBinaryStringSwitchCaseLength, 50, Normal, nullptr) \
    v(Unsigned, maximumBinaryStringSwitchTotalLength, 2000, Normal, nullptr) \
    v(Unsigned, maximumInlineStringSwitchCaseCount, 64, Normal, "Maximum number of cases for which the baseline JIT dispatches op_switch_string inline instead of calling out."_s) \
    v(Unsigned, maximumRegExpTestInlineCodesize, 500, Normal, "Maximum code size in bytes for inlined RegExp.test JIT code."_s) \
    v(Unsigned, maximumRegExpJITCodeSize, 16 * MB, Normal, "Maximum generated code size in bytes for RegExp JIT compilation before falling back to the interpreter."_s) \
    \
    v(Unsigned, wasmInliningMaximumDepth, 7, Normal, "Maximum inlining depth to consider inlining a wasm function."_s) \
    v(Unsigned, wasmInliningMaximumWasmCalleeSize, 500, Normal, "Maximum wasm size in bytes to consider inlining a wasm function."_s) \
    v(Unsigned, wasmInliningMaximumCount, 60, Normal, "Maximum inlining count to consider inlining a wasm function."_s) \
    v(Unsigned, wasmInliningMinimumBudget, 50, Normal, "Minimum budget for which the wasmInliningFactor does not apply"_s) \
    v(Unsigned, wasmInliningFactor, 5, Normal, "Maximum multiple budget in comparison to initial wasm size"_s) \
    v(Unsigned, wasmInliningBudget, 6000, Normal, "Maximum budget that allows inlining more"_s) \
    v(Double, wasmInliningLargeFunctionGrowthFactor, 1.4, Normal, "Minimum growth factor (multiplied by initial wasm size) that bounds the large-function inlining budget."_s) \
    v(Unsigned, wasmInliningTinyFunctionThreshold, 12, Normal, "Wasm size threshold for tiny wasm functions"_s) \
    v(Unsigned, wasmInliningSmallFunctionThreshold, 50, Normal, "Wasm size threshold for small wasm functions"_s) \
    \
    v(Double, jitPolicyScale, 1.0, Normal, "scale JIT thresholds to this specified ratio between 0.0 (compile ASAP) and 1.0 (compile like normal)."_s) \
    v(Int32, numberOfSuperAndPerformanceCoresOverride, 0, Normal, "If non-zero, overrides the number of Super and Performance (i.e. non-Efficiency) cores reported by the hardware; 0 means use the value reported by the hardware."_s) \
    v(Double, dfgThresholdScaleForFewPerformanceCores, 2.0, Normal, "On Apple silicon Macs with few Super and Performance cores, scale the DFG tier-up thresholds (thresholdForOptimize*) by this factor."_s) \
    v(Double, ftlThresholdScaleForFewPerformanceCores, 1.5, Normal, "On Apple silicon Macs with few Super and Performance cores, scale the FTL tier-up thresholds (thresholdForFTLOptimize*) by this factor."_s) \
    v(Double, ftlThresholdScaleForFewCores, 4.0, Normal, "On Linux ARM64 devices (not Android) with four or fewer cores, scale the FTL tier-up thresholds (thresholdForFTLOptimize*) by this factor."_s) \
    v(Bool, forceEagerCompilation, false, Normal, nullptr) \
    v(Int32, thresholdForJITAfterWarmUp, 500, Normal, nullptr) \
    v(Int32, thresholdForJITSoon, 100, Normal, nullptr) \
    \
    v(Int32, thresholdForOptimizeAfterWarmUp, 1000, Normal, nullptr) \
    v(Int32, thresholdForOptimizeAfterLongWarmUp, 1000, Normal, nullptr) \
    v(Int32, thresholdForOptimizeSoon, 1000, Normal, nullptr) \
    v(Int32, executionCounterIncrementForLoop, 1, Normal, nullptr) \
    v(Int32, executionCounterIncrementForEntry, 15, Normal, nullptr) \
    \
    v(Int32, thresholdForFTLOptimizeAfterWarmUp, 64000, Normal, nullptr) \
    v(Int32, thresholdForFTLOptimizeSoon, 1000, Normal, nullptr) \
    v(Int32, ftlTierUpCounterIncrementForLoop, 1, Normal, nullptr) \
    v(Int32, ftlTierUpCounterIncrementForReturn, 15, Normal, nullptr) \
    v(Unsigned, ftlOSREntryFailureCountForReoptimization, 15, Normal, nullptr) \
    v(Unsigned, ftlOSREntryRetryThreshold, 100, Normal, nullptr) \
    \
    v(Int32, evalThresholdMultiplier, 10, Normal, nullptr) \
    v(Unsigned, maximumEvalCacheableSourceLength, 256, Normal, nullptr) \
    \
    v(Int32, maximumExecutionCountsBetweenCheckpointsForBaseline, 1000, Normal, nullptr) \
    v(Int32, maximumExecutionCountsBetweenCheckpointsForUpperTiers, 30000, Normal, nullptr) \
    v(Int32, highCostBaselineProfilingFunctionBytecodeCost, 10000, Normal, nullptr) \
    v(Int32, valueProfileFillingRateMonitoringBytecodeCost, 5000, Normal, nullptr) \
    \
    v(Unsigned, likelyToTakeSlowCaseMinimumCount, 20, Normal, nullptr) \
    v(Unsigned, couldTakeSlowCaseMinimumCount, 10, Normal, nullptr) \
    \
    v(Unsigned, osrExitCountForReoptimization, 100, Normal, nullptr) \
    v(Unsigned, osrExitCountForReoptimizationFromLoop, 5, Normal, nullptr) \
    \
    v(Unsigned, reoptimizationRetryCounterMax, 0, Normal, nullptr)  \
    \
    v(Unsigned, minimumOptimizationDelay, 1, Normal, nullptr) \
    v(Unsigned, maximumOptimizationDelay, 5, Normal, nullptr) \
    v(Double, desiredProfileLivenessRate, 0.75, Normal, nullptr) \
    v(Double, desiredProfileFullnessRate, 0.35, Normal, nullptr) \
    \
    v(Double, quickDFGTierUpThresholdFactor, defaultQuickDFGTierUpThresholdFactor(), Normal, "Threshold factor for quick DFG tier-up"_s) \
    v(Double, relaxedProfileCoverageFactorForQuickDFGTierUp, defaultRelaxedProfileCoverageFactorForQuickDFGTierUp(), Normal, "Profile coverage scaling factor for quick DFG tier-up"_s) \
    v(Double, quickFTLTierUpThresholdFactor, defaultQuickFTLTierUpThresholdFactor(), Normal, "Threshold factor for quick FTL tier-up"_s) \
    \
    v(Double, doubleVoteRatioForDoubleFormat, 2, Normal, nullptr) \
    v(Double, structureCheckVoteRatioForHoisting, 1, Normal, nullptr) \
    v(Double, checkArrayVoteRatioForHoisting, 1, Normal, nullptr) \
    \
    v(Unsigned, maximumDirectCallStackSize, 200, Normal, nullptr) \
    \
    v(Unsigned, minimumNumberOfScansBetweenRebalance, 100, Normal, nullptr) \
    v(Unsigned, numberOfGCMarkers, computeNumberOfGCMarkers(8), Normal, nullptr) \
    v(Bool, useParallelMarkingConstraintSolver, true, Normal, nullptr) \
    v(Unsigned, opaqueRootMergeThreshold, 1000, Normal, nullptr) \
    v(Unsigned, maxHeapSizeAsRAMSizeMultiple, 0, Normal, nullptr) \
    v(Double, minHeapUtilization, 0.8, Normal, nullptr) \
    v(Double, minMarkedBlockUtilization, 0.9, Normal, nullptr) \
    v(Unsigned, slowPathAllocsBetweenGCs, 0, Normal, "force a GC on every Nth slow path alloc, where N is specified by this option"_s) \
    /* WARNING: this option is important for compatibility be *VERY* careful when lowering it. See: rdar://145585141 and https://bugs.webkit.org/show_bug.cgi?id=289330 */ \
    v(Unsigned, maxRegExpStackSize, 128 * MB, Normal, nullptr) \
    \
    v(Double, percentCPUPerMBForFullTimer, 0.0003125, Normal, nullptr) \
    v(Double, percentCPUPerMBForEdenTimer, 0.0025, Normal, nullptr) \
    v(Double, collectionTimerMaxPercentCPU, 0.10, Normal, nullptr) \
    \
    v(Bool, forceWeakRandomSeed, false, Normal, nullptr) \
    v(Unsigned, forcedWeakRandomSeed, 0, Normal, nullptr) \
    \
    v(Bool, alwaysHaveABadTime, false, Normal, "debugging option to test HaveABadTime mode"_s) \
    v(Bool, allowDoubleShape, true, Normal, "debugging option to test disabling use of DoubleShape"_s) \
    v(Bool, useZombieMode, false, Normal, "debugging option to scribble over dead objects with 0xbadbeef0"_s) \
    v(Bool, useImmortalObjects, false, Normal, "debugging option to keep all objects alive forever"_s) \
    v(Bool, sweepSynchronously, false, Normal, "debugging option to sweep all dead objects synchronously at GC end before resuming mutator"_s) \
    v(Unsigned, maxSingleAllocationSize, 0, Configurable, "debugging option to limit individual allocations to a max size (0 = limit not set, N = limit size in bytes)"_s) \
    \
    v(GCLogLevel, logGC, GCLogging::None, Normal, "debugging option to log GC activity (0 = None, 1 = Basic, 2 = Verbose)"_s) \
    v(Bool, useGC, true, Normal, nullptr) \
    v(Bool, useGlobalGC, false, Normal, nullptr) \
    v(Bool, gcAtEnd, false, Normal, "If true, the jsc CLI will do a GC before exiting"_s) \
    v(Bool, forceGCSlowPaths, false, Normal, "If true, we will force all JIT fast allocations down their slow paths."_s) \
    v(Bool, forceDidDeferGCWork, false, Normal, "If true, we will force all DeferGC destructions to perform a GC."_s) \
    v(Unsigned, gcMaxHeapSize, 0, Normal, nullptr) \
    v(Size, forceRAMSize, 0, Normal, nullptr) \
    v(Bool, recordGCPauseTimes, false, Normal, nullptr) \
    v(Bool, dumpHeapStatisticsAtVMDestruction, false, Normal, nullptr) \
    v(Bool, enableStrongRefTracker, false, Normal, "Enable logging of live Strong<*> values. Use alongside $vm.triggerMemoryPressure() and dumpHeapOnLowMemory."_s) \
    v(Bool, dumpHeapOnLowMemory, false, Normal, "Dump a heap dump when the memory handler is triggered. Use alongside $vm.triggerMemoryPressure() and enableStrongRefTracker."_s) \
    v(Bool, forceCodeBlockToJettisonDueToOldAge, false, Normal, "If true, this means that anytime we can jettison a CodeBlock due to old age, we do."_s) \
    v(Bool, useEagerCodeBlockJettisonTiming, false, Normal, "If true, the time slices for jettisoning a CodeBlock due to old age are shrunk significantly."_s) \
    \
    v(Bool, useTypeProfiler, false, Normal, nullptr) \
    v(Bool, useControlFlowProfiler, false, Normal, nullptr) \
    \
    v(Bool, useSamplingProfiler, false, Normal, nullptr) \
    v(Unsigned, sampleInterval, 1000, Normal, "Time between stack traces in microseconds."_s) \
    v(Bool, collectExtraSamplingProfilerData, false, Normal, "This corresponds to the JSC shell's --sample option, or if we're wanting to use the sampling profiler via the Debug menu in the browser."_s) \
    v(Unsigned, samplingProfilerTopFunctionsCount, 12, Normal, "Number of top functions to report when using the command line interface."_s) \
    v(Unsigned, samplingProfilerTopBytecodesCount, 40, Normal, "Number of top bytecodes to report when using the command line interface."_s) \
    v(Bool, samplingProfilerIgnoreExternalSourceID, false, Normal, "Ignore external source ID when aggregating results from sampling profiler"_s) \
    v(OptionString, samplingProfilerPath, nullptr, Normal, "The path to the directory to write sampiling profiler output to. This probably will not work with WK2 unless the path is in the sandbox."_s) \
    v(Bool, sampleCCode, false, Normal, "Causes the sampling profiler to record profiling data for C frames."_s) \
    \
    v(Bool, alwaysGeneratePCToCodeOriginMap, false, Normal, "This will make sure we always generate a PCToCodeOriginMap for JITed code."_s) \
    \
    v(Double, randomIntegrityAuditRate, 0.05, Normal, "Probability of random integrity audits [0.0 - 1.0]"_s) \
    v(Bool, verifyGC, false, Normal, nullptr) \
    v(Bool, verboseVerifyGC, false, Normal, nullptr) \
    v(Bool, verifyHeap, false, Normal, nullptr) \
    v(Unsigned, numberOfGCCyclesToRecordForVerification, 3, Normal, nullptr) \
    \
    v(Unsigned, exceptionStackTraceLimit, 100, Normal, "Stack trace limit for internal Exception object"_s) \
    v(Unsigned, defaultErrorStackTraceLimit, 100, Normal, "The default value for Error.stackTraceLimit"_s) \
    v(Bool, exitOnResourceExhaustion, false, Normal, nullptr) \
    v(Bool, useExceptionFuzz, false, Normal, nullptr) \
    v(Unsigned, fireExceptionFuzzAt, 0, Normal, nullptr) \
    v(Bool, fuzzAtomicJITMemcpy, false, Normal, nullptr) \
    v(Bool, validateDFGExceptionHandling, ASSERT_ENABLED, Normal, "Causes the DFG to emit code validating exception handling for each node that can exit"_s) \
    v(Bool, dumpSimulatedThrows, false, Normal, "Dumps the call stack of the last simulated throw if exception scope verification fails"_s) \
    v(Bool, validateExceptionChecks, false, Normal, "Verifies that needed exception checks are performed."_s) \
    v(Unsigned, unexpectedExceptionStackTraceLimit, 100, Normal, "Stack trace limit for debugging unexpected exceptions observed in the VM"_s) \
    \
    v(Bool, validateDFGClobberize, false, Normal, "Emits code in the DFG/FTL to validate the Clobberize phase"_s) \
    v(Bool, validateBoundsCheckElimination, false, Normal, "Emits code in the DFG/FTL to validate bounds check elimination"_s) \
    v(Bool, validateDFGMayExit, ASSERT_ENABLED, Normal, "Emits code in the DFG/FTL to validate the MayExit phase"_s) \
    \
    v(Bool, validateVMEntryCalleeSaves, false, Configurable, "Causes vmEntryToJavaScript to validate VMEntry callee saves are properly restored"_s) \
    \
    v(Bool, useExecutableAllocationFuzz, false, Normal, nullptr) \
    v(Unsigned, fireExecutableAllocationFuzzAt, 0, Normal, nullptr) \
    v(Unsigned, fireExecutableAllocationFuzzAtOrAfter, 0, Normal, nullptr) \
    v(Bool, fireExecutableAllocationFuzzRandomly, false, Normal, nullptr) \
    v(Double, fireExecutableAllocationFuzzRandomlyProbability, 0.1, Normal, nullptr) \
    v(Bool, verboseExecutableAllocationFuzz, false, Normal, nullptr) \
    v(Bool, zeroExecutableMemoryOnFree, false, Normal, "0 out instructions when freeing JIT memory."_s) \
    \
    v(Bool, useOSRExitFuzz, false, Normal, nullptr) \
    v(Unsigned, fireOSRExitFuzzAtStatic, 0, Normal, nullptr) \
    v(Unsigned, fireOSRExitFuzzAt, 0, Normal, nullptr) \
    v(Unsigned, fireOSRExitFuzzAtOrAfter, 0, Normal, nullptr) \
    v(Bool, verboseOSRExitFuzz, true, Normal, nullptr) \
    \
    /* LOL options */ \
    v(Bool, useLOLJIT, false, Normal, "Use LOL instead of Baseline"_s) \
    v(Bool, verboseLOLAllocation, false, Normal, "Log info about LOL's register allocation state"_s) \
    \
    v(Unsigned, seedOfVMRandomForFuzzer, 0, Normal, "0 means not fuzzing this; use a cryptographically random seed"_s) \
    v(Bool, useRandomizingFuzzerAgent, false, Normal, nullptr) \
    v(Unsigned, seedOfRandomizingFuzzerAgent, 1, Normal, nullptr) \
    v(Bool, dumpFuzzerAgentPredictions, false, Normal, nullptr) \
    v(Bool, useDoublePredictionFuzzerAgent, false, Normal, nullptr) \
    v(Bool, useFileBasedFuzzerAgent, false, Normal, nullptr) \
    v(Bool, usePredictionFileCreatingFuzzerAgent, false, Normal, nullptr) \
    v(Bool, requirePredictionForFileBasedFuzzerAgent, false, Normal, nullptr) \
    v(OptionString, fuzzerPredictionsFile, nullptr, Normal, "file with list of predictions for FileBasedFuzzerAgent"_s) \
    v(Bool, useNarrowingNumberPredictionFuzzerAgent, false, Normal, nullptr) \
    v(Bool, useWideningNumberPredictionFuzzerAgent, false, Normal, nullptr) \
    \
    v(Bool, logPhaseTimes, false, Normal, nullptr) \
    v(Double, rareBlockPenalty, 0.001, Normal, nullptr) \
    v(Bool, airGreedyRegAllocVerbose, false, Normal, nullptr) \
    v(OptionString, airGreedyRegAllocDumpFunction, nullptr, Normal, "dump greedy register allocator state and IR for functions matching this substring"_s) \
    v(Double, airGreedyRegAllocSplitMultiplier, 2.0, Normal, nullptr) \
    v(Bool, airGreedyRegAllocSplitAroundLoops, false, Normal, nullptr) \
    v(Double, airGreedyRegAllocLoopSplitMaxLoopFraction, 0.75, Normal, nullptr) \
    v(Bool, airGreedyRegAllocSpillsEverything, false, Normal, nullptr) \
    v(Bool, airDumpPhaseStats, false, Normal, nullptr) \
    v(Bool, airValidateGreedRegAlloc, ASSERT_ENABLED, Normal, nullptr) \
    v(Bool, airRandomizeRegs, false, Normal, nullptr) \
    v(Unsigned, airRandomizeRegsSeed, 0, Normal, nullptr) \
    v(Bool, coalesceSpillSlots, true, Normal, nullptr) \
    v(Bool, logAirRegisterPressure, false, Normal, nullptr) \
    v(Bool, useB3TailDup, true, Normal, nullptr) \
    v(Unsigned, maxB3TailDupBlockSize, 3, Normal, nullptr) \
    v(Unsigned, maxB3TailDupBlockSuccessors, 3, Normal, nullptr) \
    v(Bool, useB3HoistLoopInvariantValues, true, Normal, nullptr) \
    v(Bool, useB3CanonicalizePrePostIncrements, false, Normal, nullptr) \
    v(Bool, useB3EliminateWasmGCAllocations, true, Normal, "eliminate non-escaping wasm-GC struct allocations in B3"_s) \
    v(Unsigned, maxB3WasmGCEpochSnapshotEntries, 1024 * 1024, Normal, "blocks times version counters above which B3 reduceStrength gives all wasm-GC struct fields one shared counter rather than one each"_s) \
    v(Bool, useB3SpecializeSelect, true, Normal, "turn Selects consumed by a nearby Check into control flow in B3"_s) \
    v(Bool, useAirOptimizePairedLoadStore, true, Normal, nullptr) \
    \
    v(Bool, useDollarVM, false, Restricted, "installs the $vm debugging tool in global objects"_s) \
    v(OptionString, functionOverrides, nullptr, Restricted, "file with debugging overrides for function bodies"_s) \
    \
    v(Unsigned, watchdog, 0, Normal, "watchdog timeout (0 = Disabled, N = a timeout period of N milliseconds)"_s) \
    v(Bool, usePollingTraps, false, Normal, "use polling (instead of signalling) VM traps"_s) \
    v(Bool, forceTrapAwareStackChecks, false, Normal, "force trap aware stack checks to be taken for testing"_s) \
    \
    v(Bool, useMachForExceptions, true, Normal, "Use mach exceptions rather than signals to handle faults and pass thread messages. (This does nothing on platforms without mach)"_s) \
    v(Bool, allowNonSPTagging, true, Normal, "allow use of the pacib instruction instead of just pacibsp (This can break lldb/posix signals as it puts live data below SP)"_s) \
    \
    v(Bool, useICStats, false, Normal, nullptr) \
    \
    v(Bool, useFuzzerMode, false, Normal, nullptr) \
    \
    v(Unsigned, prototypeHitCountForLLIntCaching, 2, Normal, "Number of prototype property hits before caching a prototype in the LLInt. A count of 0 means never cache."_s) \
    \
    v(Bool, dumpCompiledRegExpPatterns, false, Normal, nullptr) \
    v(Bool, verboseRegExpCompilation, false, Normal, nullptr) \
    \
    v(Bool, dumpModuleRecord, false, Normal, nullptr) \
    v(Bool, dumpModuleLoadingState, false, Normal, nullptr) \
    v(Bool, exposeInternalModuleLoader, false, Normal, "expose the internal module loader object to the global space for debugging"_s) \
    \
    v(Bool, exposePrivateIdentifiers, false, Normal, "Allow non-builtin scripts to use private identifiers. Mostly useful to expose @superSamplerBegin/End intrinsics for profiling"_s) \
    \
    v(Bool, useSuperSampler, false, Normal, nullptr) \
    \
    v(Bool, useSourceProviderCache, true, Normal, "If false, the parser will not use the source provider cache. It's good to verify everything works when this is false. Because the cache is so successful, it can mask bugs."_s) \
    v(Bool, useCodeCache, true, Normal, "If false, the unlinked byte code cache will not be used."_s) \
    \
    v(Bool, useWasm, canUseWasm(), Normal, "Expose the Wasm global object."_s) \
    \
    v(Bool, failToCompileWasmCode, false, Normal, "If true, no Wasm::Plan will sucessfully compile a function."_s) \
    v(Size, wasmSmallPartialCompileLimit, 5000, Normal, "Limit on the number of bytes a Wasm::Plan::compile should attempt for small wasm binary before checking for other work."_s) \
    v(Size, wasmLargePartialCompileLimit, 20000, Normal, "Limit on the number of bytes a Wasm::Plan::compile should attempt for large wasm binary before checking for other work."_s) \
    v(Unsigned, wasmOMGOptimizationLevel, Options::defaultB3OptLevel(), Normal, "B3 Optimization level for OMG Web Assembly module compilations."_s) \
    v(Bool, useWasmByteLoopReplacement, true, Normal, "If true, OMG replaces a loop that copies or fills linear memory one byte per iteration with the equivalent bulk memory operation."_s) \
    \
    v(Bool, useBBQTierUpChecks, true, Normal, "Enables tier up checks for our BBQ code."_s) \
    v(Bool, useWasmOSR, true, Normal, nullptr) \
    v(Int32, thresholdForBBQOptimizeAfterWarmUp, 150, Normal, "The count before we tier up a function to BBQ."_s) \
    v(Int32, thresholdForBBQOptimizeSoon, 50, Normal, nullptr) \
    v(Int32, thresholdForOMGOptimizeAfterWarmUp, 50000, Normal, "The count before we tier up a function to OMG."_s) \
    v(Int32, thresholdForOMGOptimizeSoon, 500, Normal, nullptr) \
    v(Unsigned, maximumOMGCandidateCost, 100000, Normal, nullptr) \
    v(Int32, omgTierUpCounterIncrementForLoop, 1, Normal, "The amount the tier up counter is incremented on each loop backedge."_s) \
    v(Int32, omgTierUpCounterIncrementForEntry, 15, Normal, "The amount the tier up counter is incremented on each function entry."_s) \
    v(Int32, wasmOMGEntryIncrementSizeReference, 128, Normal, "If non-zero, the BBQ->OMG function-entry tier-up increment is scaled down for functions whose bytecode size is below this reference (work-proportional tier-up): increment = clamp(entryIncrement * size / reference, 1, entryIncrement). 0 disables (flat increment)."_s) \
    v(Bool, useWasmFastMemory, true, Normal, "If true, we will try to use a 32-bit address space with a signal handler to bounds check wasm memory."_s) \
    v(Bool, logWasmMemory, false, Normal, nullptr) \
    v(Unsigned, wasmFastMemoryRedzonePages, 128, Normal, "Wasm fast memories use 4GiB virtual allocations, plus a redzone (counted as multiple of 64KiB Wasm pages) at the end to catch reg+imm accesses which exceed 32-bit, anything beyond the redzone is explicitly bounds-checked"_s) \
    v(Bool, crashIfWasmCantFastMemory, false, Normal, "If true, we will crash if we can't obtain fast memory for wasm."_s) \
    v(Bool, crashOnFailedWasmValidate, false, Normal, "If true, we will crash if we can't validate a wasm module instead of throwing an exception."_s) \
    v(Unsigned, maxNumWasmFastMemories, hasCapacityToUseLargeGigacage() ? 8 : 3, Normal, nullptr) \
    v(Bool, verboseBBQJITAllocation, false, Normal, "Logs extra information about register allocation during BBQ JIT"_s) \
    v(Bool, verboseBBQJITInstructions, false, Normal, "Logs instruction information during BBQ JIT"_s) \
    v(Bool, disableBBQConsts, false, Normal, "Wasm <type>.const instructions in BBQ JIT won't lower to a const BBQ::Value"_s) \
    v(Bool, useBBQJIT, true, Normal, "allows the BBQ JIT to be used if true"_s) \
    v(Bool, useOMGJIT, true, Normal, "allows the OMG JIT to be used if true"_s) \
    v(OptionRange, wasmFunctionIndexRangeToCompile, nullptr, Normal, "wasm function index range to allow compilation on, e.g. 1:100"_s) \
    v(Bool, useEagerWasmModuleHashing, false, Normal, "Unnamed Wasm modules are identified in backtraces through their hash, if available."_s) \
    v(Bool, useArrayAllocationProfiling, true, Normal, "If true, we will use our normal array allocation profiling. If false, the allocation profile will always claim to be undecided."_s) \
    v(Bool, forcePolyProto, false, Normal, "If true, create_this will always create an object with a poly proto structure."_s) \
    v(Bool, forceMiniVMMode, false, Normal, "If true, it will force mini VM mode on."_s) \
    v(Bool, useTracePoints, false, Normal, nullptr) \
    v(Bool, useCompilerSignpost, false, Normal, nullptr) \
    v(Bool, useGCSignpost, false, Normal, nullptr) \
    v(Bool, traceLLIntExecution, false, Configurable, nullptr) \
    v(Bool, traceLLIntSlowPath, false, Configurable, nullptr) \
    v(Bool, traceBaselineJITExecution, false, Normal, nullptr) \
    v(Unsigned, thresholdForGlobalLexicalBindingEpoch, UINT_MAX, Normal, "Threshold for global lexical binding epoch. If the epoch reaches to this value, CodeBlock metadata for scope operations will be revised globally. It needs to be greater than 1."_s) \
    v(OptionString, diskCachePath, nullptr, Restricted, nullptr) \
    v(Bool, forceDiskCache, false, Restricted, nullptr) \
    v(Bool, validateAbstractInterpreterState, false, Restricted, nullptr) \
    v(Double, validateAbstractInterpreterStateProbability, 0.5, Normal, nullptr) \
    v(OptionString, dumpJITMemoryPath, nullptr, Restricted, nullptr) \
    v(Double, dumpJITMemoryFlushInterval, 10, Restricted, "Maximum time in between flushes of the JIT memory dump in seconds."_s) \
    v(Bool, useUnlinkedCodeBlockJettisoning, false, Normal, "If true, UnlinkedCodeBlock can be jettisoned."_s) \
    v(Bool, forceOSRExitToLLInt, false, Normal, "If true, we always exit to the LLInt. If false, we exit to whatever is most convenient."_s) \
    v(Unsigned, getByValICMaxNumberOfIdentifiers, 4, Normal, "Number of identifiers we see in the LLInt that could cause us to bail on generating an IC for get_by_val."_s) \
    v(Bool, useRandomizingExecutableIslandAllocation, false, Normal, "For the arm64 ExecutableAllocator, if true, select which region to use randomly. This is useful for testing that jump islands work."_s) \
    v(Bool, exposeProfilersOnGlobalObject, false, Normal, "If true, we will expose functions to enable/disable both the sampling profiler and the super sampler"_s) \
    v(Bool, allowUnsupportedTiers, false, Normal, "If true, we will not disable DFG or FTL when an experimental feature is enabled."_s) \
    v(Bool, returnEarlyFromInfiniteLoopsForFuzzing, false, Normal, nullptr) \
    v(Size, earlyReturnFromInfiniteLoopsLimit, 1300000000, Normal, "When returnEarlyFromInfiniteLoopsForFuzzing is true, this determines the number of executions a loop can run for before just returning. This is helpful for the fuzzer so it doesn't get stuck in infinite loops."_s) \
    v(Bool, useLICMFuzzing, false, Normal, nullptr) \
    v(Unsigned, seedForLICMFuzzer, 424242, Normal, nullptr) \
    v(Double, allowHoistingLICMProbability, 0.5, Normal, nullptr) \
    v(Bool, exposeCustomSettersOnGlobalObjectForTesting, false, Normal, nullptr) \
    v(Bool, useJITCage, canUseJITCage(), Normal, nullptr) \
    v(Bool, useAllocationProfiling, false, Normal, "Allows toggling of bmalloc/libPAS allocation profiling features at JSC launch."_s) \
    v(Unsigned, allocationProfilingMode, 0, Normal, "Allows custom arguments to be passed to bmalloc/libPAS allocation profiling features at JSC launch."_s) \
    v(Bool, dumpBaselineJITSizeStatistics, false, Normal, nullptr) \
    v(Bool, dumpDFGJITSizeStatistics, false, Normal, nullptr) \
    v(Bool, useLoopUnrolling, true, Normal, nullptr) \
    v(Bool, usePartialLoopUnrolling, true, Normal, nullptr) \
    v(Bool, verboseLoopUnrolling, false, Normal, nullptr) \
    v(Bool, disallowLoopUnrollingForNonInnermost, true, Normal, nullptr) \
    v(Unsigned, maxLoopUnrollingCount, 5, Normal, nullptr) \
    v(Unsigned, maxLoopUnrollingBodyNodeSize, 200, Normal, nullptr) \
    v(Unsigned, maxLoopUnrollingIterationCount, 4, Normal, nullptr) \
    v(Unsigned, maxPartialLoopUnrollingBodyNodeSize, 70, Normal, nullptr) \
    v(Unsigned, maxPartialLoopUnrollingIterationCount, 4, Normal, nullptr) \
    v(Unsigned, maxNumericHotLoopSize, 225, Normal, nullptr) \
    v(Unsigned, maxIntegerRangeOptimizationRelationshipsPerNode, 24, Normal, "How many relationships IRO keeps about any one node, 0 for no cap."_s) \
    v(Unsigned, maxIntegerRangeOptimizationWork, 50000000, Normal, "Give up threshold for IRO"_s) \
    v(Bool, printEachUnrolledLoop, false, Normal, nullptr) \
    v(Bool, verboseExecutablePoolAllocation, false, Normal, nullptr) \
    v(Bool, useHandlerICInFTL, false, Normal, nullptr) \
    v(Bool, useLLIntICs, true, Normal, "Use property and call ICs in LLInt code."_s) \
    v(Bool, useBaselineJITCodeSharing, jitEnabledByDefault(), Normal, nullptr) \
    v(Bool, libpasScavengeContinuously, false, Normal, nullptr) \
    v(Unsigned, libpasForcePGMWithRate, 0, Normal, "Forces on probablistic guard malloc and guards allocations with a rate 1/N (0 is disabled)"_s) \
    v(Bool, useWasmFaultSignalHandler, true, Normal, nullptr) \
    v(Bool, dumpUnlinkedDFGValidation, false, Normal, nullptr) \
    v(Bool, dumpWasmOpcodeStatistics, false, Normal, nullptr) \
    v(Bool, dumpWasmWarnings, false, Normal, nullptr) \
    v(Bool, useRecursiveJSONParse, true, Normal, nullptr) \
    v(Unsigned, thresholdForStringReplaceCache, 0x1000, Normal, nullptr) \
    v(Bool, useWasmIPInt, ipintEnabledByDefault(), Normal, "Use the in-place interpereter for WASM instead of LLInt."_s) \
    v(Bool, useWasmIPIntPrologueOSR, true, Normal, "Allow IPInt to tier up during function prologues"_s) \
    v(Bool, useWasmIPIntLoopOSR, true, Normal, "Allow IPInt to tier up during loop iterations"_s) \
    v(Bool, useWasmIPIntEpilogueOSR, true, Normal, "Allow IPInt to tier up during function epilogues"_s) \
    v(Bool, useWasmIPIntSIMD, true, Normal, "Allow IPInt to interpret SIMD code"_s) \
    v(Bool, traceWasmIPIntExecution, false, Normal, nullptr) \
    v(Bool, forceAllFunctionsToUseSIMD, false, Normal, "Force all functions to act conservatively w.r.t fp/vector registers for testing."_s) \
    v(Bool, useOMGInlining, true, Normal, "Use OMG inlining"_s) \
    v(Bool, freeRetiredWasmCode, true, Normal, "free BBQ/OMG-OSR wasm code once it's no longer reachable."_s) \
    v(Bool, useArrayAllocationSinking, true, Normal, nullptr) \
    v(Bool, dumpFTLCodeSize, false, Normal, nullptr) \
    v(Bool, dumpOptimizationTracing, false, Normal, nullptr) \
    v(Bool, dumpIonGraph, false, Normal, nullptr) \
    v(OptionString, ionGraphDirectory, nullptr, Normal, "Directory to place IonGraph"_s) \
    v(Unsigned, markedBlockDumpInfoCount, 0, Normal, nullptr) /* FIXME: rdar://139998916 */ \
    \
    /* Feature Flags */\
    \
    /* Feature-flag options whose source of truth is UnifiedWebPreferences.yaml. */ \
    FOR_EACH_JSC_WEB_PREFERENCE_OPTION(v) \
    /* Restricted so some app doesn't set this environment variable and start using it. */ \
    v(Bool, disallowMixedWasmExceptions, true, Restricted, "Disallow using both legacy and modern (try_table) wasm exception specs in the same module."_s) \
    /* Not sourced from UnifiedWebPreferences.yaml: exposes SharedArrayBuffer to every global object. */ \
    v(Bool, useSharedArrayBuffer, false, Normal, nullptr) \
    /* Not sourced from UnifiedWebPreferences.yaml: lets an embedder expose SharedArrayBuffer to some global objects, see JSGlobalObject::exposeSharedArrayBuffer(). */ \
    v(Bool, allowSharedArrayBuffer, true, Normal, nullptr) \
    /* Not sourced from UnifiedWebPreferences.yaml: shares its semantics with the WebCore-bound TrustedTypes feature. */ \
    v(Bool, useTrustedTypes, true, Normal, "Enable trusted types eval protection feature."_s) \



enum OptionEquivalence {
    SameOption,
    InvertedOption,
};

#define FOR_EACH_JSC_ALIASED_OPTION(v) \
    v(enableFunctionDotArguments, useFunctionDotArguments, SameOption) \
    v(enableTailCalls, useTailCalls, SameOption) \
    v(showDisassembly, dumpDisassembly, SameOption) \
    v(showDFGDisassembly, dumpDFGDisassembly, SameOption) \
    v(showFTLDisassembly, dumpFTLDisassembly, SameOption) \
    v(dumpGraphAtEachDFGFTLPhase, dumpDFGFTLGraphAtEachPhase, SameOption) \
    v(dumpGraphAtEachDFGPhase, dumpDFGGraphAtEachPhase, SameOption) \
    v(dumpGraphAtEachB3Phase, dumpB3GraphAtEachPhase, SameOption) \
    v(dumpGraphAtEachAirPhase, dumpAirGraphAtEachPhase, SameOption) \
    v(alwaysDoFullCollection, useGenerationalGC, InvertedOption) \
    v(enableOSREntryToDFG, useOSREntryToDFG, SameOption) \
    v(enableOSREntryToFTL, useOSREntryToFTL, SameOption) \
    v(enableAccessInlining, useAccessInlining, SameOption) \
    v(enablePolyvariantDevirtualization, usePolyvariantDevirtualization, SameOption) \
    v(enablePolymorphicAccessInlining, usePolymorphicAccessInlining, SameOption) \
    v(enablePolymorphicCallInlining, usePolymorphicCallInlining, SameOption) \
    v(enableObjectAllocationSinking, useObjectAllocationSinking, SameOption) \
    v(enableConcurrentJIT, useConcurrentJIT, SameOption) \
    v(enableProfiler, useProfiler, SameOption) \
    v(enableArchitectureSpecificOptimizations, useArchitectureSpecificOptimizations, SameOption) \
    v(objectsAreImmortal, useImmortalObjects, SameOption) \
    v(disableGC, useGC, InvertedOption) \
    v(enableTypeProfiler, useTypeProfiler, SameOption) \
    v(enableControlFlowProfiler, useControlFlowProfiler, SameOption) \
    v(enableExceptionFuzz, useExceptionFuzz, SameOption) \
    v(enableExecutableAllocationFuzz, useExecutableAllocationFuzz, SameOption) \
    v(enableOSRExitFuzz, useOSRExitFuzz, SameOption) \
    v(enableDollarVM, useDollarVM, SameOption) \
    v(maximumOptimizationCandidateInstructionCount, maximumOptimizationCandidateBytecodeCost, SameOption) \
    v(maximumFTLCandidateInstructionCount, maximumFTLCandidateBytecodeCost, SameOption) \
    v(maximumInliningCallerSize, maximumInliningCallerBytecodeCost, SameOption) \
    v(validateBCE, validateBoundsCheckElimination, SameOption) \


enum ExperimentalOptionFlags {
    LLIntAndBaselineOnly = 0,
    SupportsDFG = 1 << 0,
    SupportsFTL = 1 << 1,
};

#define FOR_EACH_JSC_EXPERIMENTAL_OPTION(v) \

constexpr size_t countNumberOfJSCOptions()
{
#define COUNT_OPTION(type_, name_, defaultValue_, availability_, description_) count++;
    size_t count = 0;
    FOR_EACH_JSC_OPTION(COUNT_OPTION);
    return count;
#undef COUNT_OPTION
}

constexpr size_t NumberOfOptions = countNumberOfJSCOptions();

class OptionRange {
private:
    enum RangeState { Uninitialized, InitError, Normal, Inverted };
public:
    OptionRange() = default;
    OptionRange(std::nullptr_t) { }

    bool init(const char*);
    NODELETE bool isInRange(unsigned) const;
    const char* rangeString() const { return (m_state > InitError) ? m_rangeString : s_nullRangeStr; }

    void dump(PrintStream& out) const;

private:
    JS_EXPORT_PRIVATE static const char* const s_nullRangeStr;

    RangeState m_state { Uninitialized };
    const char* m_rangeString { nullptr };
    unsigned m_lowLimit { 0 };
    unsigned m_highLimit { 0 };
};

enum class OSLogType : uint8_t {
    None,
    // These corresponds to OS_LOG_TYPE_xxx.
    Default,
    Info,
    Debug,
    Error,
    Fault
};

struct OptionsStorage {
    using Bool = bool;
    using Unsigned = unsigned;
    using Double = double;
    using Int32 = int32_t;
    using Size = size_t;
    using OptionRange = JSC::OptionRange;
    using OptionString = const char8_t*;
    using GCLogLevel = GCLogging::Level;
    using OSLogType = JSC::OSLogType;

    bool allowUnfinalizedAccess;
    bool isFinalized;

#define DECLARE_OPTION(type_, name_, defaultValue_, availability_, description_) \
    type_ name_;
FOR_EACH_JSC_OPTION(DECLARE_OPTION)
#undef DECLARE_OPTION
};

// Options::Metadata's offsetOfOption and offsetOfOptionDefault relies on this.
static_assert(sizeof(OptionsStorage) <= 16 * KB);

} // namespace JSC