text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // This file defines all of the flags.  It is separated into different section,
  // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
  // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
  //
  // This include does not have a guard, because it is a template-style include,
  // which can be included multiple times in different modes.  It expects to have
  // a mode defined before it's included.  The modes are FLAG_MODE_... below:
  
  #define DEFINE_IMPLICATION(whenflag, thenflag)              \
    DEFINE_VALUE_IMPLICATION(whenflag, thenflag, true)
  
  #define DEFINE_NEG_IMPLICATION(whenflag, thenflag)          \
    DEFINE_VALUE_IMPLICATION(whenflag, thenflag, false)
  
  #define DEFINE_NEG_NEG_IMPLICATION(whenflag, thenflag) \
    DEFINE_NEG_VALUE_IMPLICATION(whenflag, thenflag, false)
  
  // We want to declare the names of the variables for the header file.  Normally
  // this will just be an extern declaration, but for a readonly flag we let the
  // compiler make better optimizations by giving it the value.
  #if defined(FLAG_MODE_DECLARE)
  #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
    V8_EXPORT_PRIVATE extern ctype FLAG_##nam;
  #define FLAG_READONLY(ftype, ctype, nam, def, cmt) \
    static ctype const FLAG_##nam = def;
  
  // We want to supply the actual storage and value for the flag variable in the
  // .cc file.  We only do this for writable flags.
  #elif defined(FLAG_MODE_DEFINE)
  #ifdef USING_V8_SHARED
  #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
    V8_EXPORT_PRIVATE extern ctype FLAG_##nam;
  #else
  #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
    V8_EXPORT_PRIVATE ctype FLAG_##nam = def;
  #endif
  
  // We need to define all of our default values so that the Flag structure can
  // access them by pointer.  These are just used internally inside of one .cc,
  // for MODE_META, so there is no impact on the flags interface.
  #elif defined(FLAG_MODE_DEFINE_DEFAULTS)
  #define FLAG_FULL(ftype, ctype, nam, def, cmt) \
    static ctype const FLAGDEFAULT_##nam = def;
  
  // We want to write entries into our meta data table, for internal parsing and
  // printing / etc in the flag parser code.  We only do this for writable flags.
  #elif defined(FLAG_MODE_META)
  #define FLAG_FULL(ftype, ctype, nam, def, cmt)                              \
    { Flag::TYPE_##ftype, #nam, &FLAG_##nam, &FLAGDEFAULT_##nam, cmt, false } \
    ,
  #define FLAG_ALIAS(ftype, ctype, alias, nam)                     \
    {                                                              \
      Flag::TYPE_##ftype, #alias, &FLAG_##nam, &FLAGDEFAULT_##nam, \
          "alias for --" #nam, false                               \
    }                                                              \
    ,
  
  // We produce the code to set flags when it is implied by another flag.
  #elif defined(FLAG_MODE_DEFINE_IMPLICATIONS)
  #define DEFINE_VALUE_IMPLICATION(whenflag, thenflag, value) \
    if (FLAG_##whenflag) FLAG_##thenflag = value;
  
  #define DEFINE_NEG_VALUE_IMPLICATION(whenflag, thenflag, value) \
    if (!FLAG_##whenflag) FLAG_##thenflag = value;
  
  #else
  #error No mode supplied when including flags.defs
  #endif
  
  // Dummy defines for modes where it is not relevant.
  #ifndef FLAG_FULL
  #define FLAG_FULL(ftype, ctype, nam, def, cmt)
  #endif
  
  #ifndef FLAG_READONLY
  #define FLAG_READONLY(ftype, ctype, nam, def, cmt)
  #endif
  
  #ifndef FLAG_ALIAS
  #define FLAG_ALIAS(ftype, ctype, alias, nam)
  #endif
  
  #ifndef DEFINE_VALUE_IMPLICATION
  #define DEFINE_VALUE_IMPLICATION(whenflag, thenflag, value)
  #endif
  
  #ifndef DEFINE_NEG_VALUE_IMPLICATION
  #define DEFINE_NEG_VALUE_IMPLICATION(whenflag, thenflag, value)
  #endif
  
  #define COMMA ,
  
  #ifdef FLAG_MODE_DECLARE
  // Structure used to hold a collection of arguments to the JavaScript code.
  struct JSArguments {
   public:
    inline const char*& operator[](int idx) const { return argv[idx]; }
    static JSArguments Create(int argc, const char** argv) {
      JSArguments args;
      args.argc = argc;
      args.argv = argv;
      return args;
    }
    int argc;
    const char** argv;
  };
  
  struct MaybeBoolFlag {
    static MaybeBoolFlag Create(bool has_value, bool value) {
      MaybeBoolFlag flag;
      flag.has_value = has_value;
      flag.value = value;
      return flag;
    }
    bool has_value;
    bool value;
  };
  #endif
  
  #ifdef DEBUG
  #define DEBUG_BOOL true
  #else
  #define DEBUG_BOOL false
  #endif
  
  // Supported ARM configurations are:
  //  "armv6":       ARMv6 + VFPv2
  //  "armv7":       ARMv7 + VFPv3-D32 + NEON
  //  "armv7+sudiv": ARMv7 + VFPv4-D32 + NEON + SUDIV
  //  "armv8":       ARMv8 (including all of the above)
  #if !defined(ARM_TEST_NO_FEATURE_PROBE) ||                            \
      (defined(CAN_USE_ARMV8_INSTRUCTIONS) &&                           \
       defined(CAN_USE_ARMV7_INSTRUCTIONS) && defined(CAN_USE_SUDIV) && \
       defined(CAN_USE_NEON) && defined(CAN_USE_VFP3_INSTRUCTIONS))
  #define ARM_ARCH_DEFAULT "armv8"
  #elif defined(CAN_USE_ARMV7_INSTRUCTIONS) && defined(CAN_USE_SUDIV) && \
      defined(CAN_USE_NEON) && defined(CAN_USE_VFP3_INSTRUCTIONS)
  #define ARM_ARCH_DEFAULT "armv7+sudiv"
  #elif defined(CAN_USE_ARMV7_INSTRUCTIONS) && defined(CAN_USE_NEON) && \
      defined(CAN_USE_VFP3_INSTRUCTIONS)
  #define ARM_ARCH_DEFAULT "armv7"
  #else
  #define ARM_ARCH_DEFAULT "armv6"
  #endif
  
  #ifdef V8_OS_WIN
  # define ENABLE_LOG_COLOUR false
  #else
  # define ENABLE_LOG_COLOUR true
  #endif
  
  #define DEFINE_BOOL(nam, def, cmt) FLAG(BOOL, bool, nam, def, cmt)
  #define DEFINE_BOOL_READONLY(nam, def, cmt) \
    FLAG_READONLY(BOOL, bool, nam, def, cmt)
  #define DEFINE_MAYBE_BOOL(nam, cmt) \
    FLAG(MAYBE_BOOL, MaybeBoolFlag, nam, {false COMMA false}, cmt)
  #define DEFINE_INT(nam, def, cmt) FLAG(INT, int, nam, def, cmt)
  #define DEFINE_UINT(nam, def, cmt) FLAG(UINT, unsigned int, nam, def, cmt)
  #define DEFINE_FLOAT(nam, def, cmt) FLAG(FLOAT, double, nam, def, cmt)
  #define DEFINE_STRING(nam, def, cmt) FLAG(STRING, const char*, nam, def, cmt)
  #define DEFINE_ARGS(nam, cmt) \
    FLAG(ARGS, JSArguments, nam, {0 COMMA nullptr}, cmt)
  
  #define DEFINE_ALIAS_BOOL(alias, nam) FLAG_ALIAS(BOOL, bool, alias, nam)
  #define DEFINE_ALIAS_INT(alias, nam) FLAG_ALIAS(INT, int, alias, nam)
  #define DEFINE_ALIAS_FLOAT(alias, nam) FLAG_ALIAS(FLOAT, double, alias, nam)
  #define DEFINE_ALIAS_STRING(alias, nam) \
    FLAG_ALIAS(STRING, const char*, alias, nam)
  #define DEFINE_ALIAS_ARGS(alias, nam) FLAG_ALIAS(ARGS, JSArguments, alias, nam)
  
  //
  // Flags in all modes.
  //
  #define FLAG FLAG_FULL
  
  DEFINE_BOOL(experimental_extras, false,
              "enable code compiled in via v8_experimental_extra_library_files")
  
  // Flags for language modes and experimental language features.
  DEFINE_BOOL(use_strict, false, "enforce strict mode")
  
  DEFINE_BOOL(es_staging, false,
              "enable test-worthy harmony features (for internal use only)")
  DEFINE_BOOL(harmony, false, "enable all completed harmony features")
  DEFINE_BOOL(harmony_shipping, true, "enable all shipped harmony features")
  DEFINE_IMPLICATION(es_staging, harmony)
  // Enabling import.meta requires to also enable import()
  DEFINE_IMPLICATION(harmony_import_meta, harmony_dynamic_import)
  DEFINE_IMPLICATION(harmony_class_fields, harmony_public_fields)
  
  // Features that are still work in progress (behind individual flags).
  #define HARMONY_INPROGRESS(V)                                         \
    V(harmony_import_meta, "harmony import.meta property")              \
    V(harmony_array_prototype_values, "harmony Array.prototype.values") \
    V(harmony_function_sent, "harmony function.sent")                   \
    V(harmony_do_expressions, "harmony do-expressions")                 \
    V(harmony_class_fields, "harmony fields in class literals")         \
    V(harmony_public_fields, "harmony public fields in class literals") \
    V(harmony_bigint, "harmony arbitrary precision integers")
  
  // Features that are complete (but still behind --harmony/es-staging flag).
  #define HARMONY_STAGED(V)                                               \
    V(harmony_function_tostring, "harmony Function.prototype.toString")   \
    V(harmony_restrict_constructor_return,                                \
      "harmony disallow non undefined primitive return value from class " \
      "constructor")                                                      \
    V(harmony_dynamic_import, "harmony dynamic import")
  
  // Features that are shipping (turned on by default, but internal flag remains).
  #define HARMONY_SHIPPING_BASE(V)                                        \
    V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")             \
    V(harmony_regexp_named_captures, "harmony regexp named captures")     \
    V(harmony_regexp_property, "harmony Unicode regexp property classes") \
    V(harmony_async_iteration, "harmony async iteration")                 \
    V(harmony_promise_finally, "harmony Promise.prototype.finally")
  
  #ifdef V8_INTL_SUPPORT
  #define HARMONY_SHIPPING(V)                      \
    HARMONY_SHIPPING_BASE(V)                       \
    V(harmony_number_format_to_parts,              \
      "Intl.NumberFormat.prototype.formatToParts") \
    V(harmony_plural_rules, "Intl.PluralRules")
  #else
  #define HARMONY_SHIPPING(V) HARMONY_SHIPPING_BASE(V)
  #endif
  
  // Once a shipping feature has proved stable in the wild, it will be dropped
  // from HARMONY_SHIPPING, all occurrences of the FLAG_ variable are removed,
  // and associated tests are moved from the harmony directory to the appropriate
  // esN directory.
  
  
  #define FLAG_INPROGRESS_FEATURES(id, description) \
    DEFINE_BOOL(id, false, "enable " #description " (in progress)")
  HARMONY_INPROGRESS(FLAG_INPROGRESS_FEATURES)
  #undef FLAG_INPROGRESS_FEATURES
  
  #define FLAG_STAGED_FEATURES(id, description) \
    DEFINE_BOOL(id, false, "enable " #description) \
    DEFINE_IMPLICATION(harmony, id)
  HARMONY_STAGED(FLAG_STAGED_FEATURES)
  #undef FLAG_STAGED_FEATURES
  
  #define FLAG_SHIPPING_FEATURES(id, description) \
    DEFINE_BOOL(id, true, "enable " #description) \
    DEFINE_NEG_NEG_IMPLICATION(harmony_shipping, id)
  HARMONY_SHIPPING(FLAG_SHIPPING_FEATURES)
  #undef FLAG_SHIPPING_FEATURES
  
  #ifdef V8_INTL_SUPPORT
  DEFINE_BOOL(icu_timezone_data, false,
              "get information about timezones from ICU")
  #endif
  
  #ifdef V8_ENABLE_FUTURE
  #define FUTURE_BOOL true
  #else
  #define FUTURE_BOOL false
  #endif
  DEFINE_BOOL(future, FUTURE_BOOL,
              "Implies all staged features that we want to ship in the "
              "not-too-far future")
  
  DEFINE_IMPLICATION(future, preparser_scope_analysis)
  DEFINE_IMPLICATION(future, write_protect_code_memory)
  
  // Flags for experimental implementation features.
  DEFINE_BOOL(allocation_site_pretenuring, true,
              "pretenure with allocation sites")
  DEFINE_BOOL(page_promotion, true, "promote pages based on utilization")
  DEFINE_INT(page_promotion_threshold, 70,
             "min percentage of live bytes on a page to enable fast evacuation")
  DEFINE_BOOL(trace_pretenuring, false,
              "trace pretenuring decisions of HAllocate instructions")
  DEFINE_BOOL(trace_pretenuring_statistics, false,
              "trace allocation site pretenuring statistics")
  DEFINE_BOOL(track_fields, true, "track fields with only smi values")
  DEFINE_BOOL(track_double_fields, true, "track fields with double values")
  DEFINE_BOOL(track_heap_object_fields, true, "track fields with heap values")
  DEFINE_BOOL(track_computed_fields, true, "track computed boilerplate fields")
  DEFINE_IMPLICATION(track_double_fields, track_fields)
  DEFINE_IMPLICATION(track_heap_object_fields, track_fields)
  DEFINE_IMPLICATION(track_computed_fields, track_fields)
  DEFINE_BOOL(track_field_types, true, "track field types")
  DEFINE_IMPLICATION(track_field_types, track_fields)
  DEFINE_IMPLICATION(track_field_types, track_heap_object_fields)
  DEFINE_BOOL(trace_block_coverage, false,
              "trace collected block coverage information")
  DEFINE_BOOL(feedback_normalization, false,
              "feed back normalization to constructors")
  // TODO(jkummerow): This currently adds too much load on the stub cache.
  DEFINE_BOOL_READONLY(internalize_on_the_fly, true,
                       "internalize string keys for generic keyed ICs on the fly")
  
  // Flags for optimization types.
  DEFINE_BOOL(optimize_for_size, false,
              "Enables optimizations which favor memory size over execution "
              "speed")
  
  DEFINE_VALUE_IMPLICATION(optimize_for_size, max_semi_space_size, 1)
  
  // Flags for data representation optimizations
  DEFINE_BOOL(unbox_double_arrays, true, "automatically unbox arrays of doubles")
  DEFINE_BOOL_READONLY(string_slices, true, "use string slices")
  
  // Flags for Ignition.
  DEFINE_BOOL(ignition_elide_noneffectful_bytecodes, true,
              "elide bytecodes which won't have any external effect")
  DEFINE_BOOL(ignition_reo, true, "use ignition register equivalence optimizer")
  DEFINE_BOOL(ignition_filter_expression_positions, true,
              "filter expression positions before the bytecode pipeline")
  DEFINE_BOOL(print_bytecode, false,
              "print bytecode generated by ignition interpreter")
  DEFINE_STRING(print_bytecode_filter, "*",
                "filter for selecting which functions to print bytecode")
  #ifdef V8_TRACE_IGNITION
  DEFINE_BOOL(trace_ignition, false,
              "trace the bytecodes executed by the ignition interpreter")
  #endif
  #ifdef V8_TRACE_FEEDBACK_UPDATES
  DEFINE_BOOL(
      trace_feedback_updates, false,
      "trace updates to feedback vectors during ignition interpreter execution.")
  #endif
  DEFINE_BOOL(trace_ignition_codegen, false,
              "trace the codegen of ignition interpreter bytecode handlers")
  DEFINE_BOOL(trace_ignition_dispatches, false,
              "traces the dispatches to bytecode handlers by the ignition "
              "interpreter")
  DEFINE_STRING(trace_ignition_dispatches_output_file, nullptr,
                "the file to which the bytecode handler dispatch table is "
                "written (by default, the table is not written to a file)")
  
  DEFINE_BOOL(fast_math, true, "faster (but maybe less accurate) math functions")
  DEFINE_BOOL(trace_track_allocation_sites, false,
              "trace the tracking of allocation sites")
  DEFINE_BOOL(trace_migration, false, "trace object migration")
  DEFINE_BOOL(trace_generalization, false, "trace map generalization")
  
  // Flags for concurrent recompilation.
  DEFINE_BOOL(concurrent_recompilation, true,
              "optimizing hot functions asynchronously on a separate thread")
  DEFINE_BOOL(trace_concurrent_recompilation, false,
              "track concurrent recompilation")
  DEFINE_INT(concurrent_recompilation_queue_length, 8,
             "the length of the concurrent compilation queue")
  DEFINE_INT(concurrent_recompilation_delay, 0,
             "artificial compilation delay in ms")
  DEFINE_BOOL(block_concurrent_recompilation, false,
              "block queued jobs until released")
  
  // Flags for stress-testing the compiler.
  DEFINE_INT(stress_runs, 0, "number of stress runs")
  DEFINE_INT(deopt_every_n_times, 0,
             "deoptimize every n times a deopt point is passed")
  DEFINE_BOOL(print_deopt_stress, false, "print number of possible deopt points")
  
  // Flags for TurboFan.
  DEFINE_BOOL(turbo_sp_frame_access, false,
              "use stack pointer-relative access to frame wherever possible")
  DEFINE_BOOL(turbo_preprocess_ranges, true,
              "run pre-register allocation heuristics")
  DEFINE_STRING(turbo_filter, "*", "optimization filter for TurboFan compiler")
  DEFINE_BOOL(trace_turbo, false, "trace generated TurboFan IR")
  DEFINE_BOOL(trace_turbo_graph, false, "trace generated TurboFan graphs")
  DEFINE_BOOL(trace_turbo_scheduled, false, "trace TurboFan IR with schedule")
  DEFINE_IMPLICATION(trace_turbo_scheduled, trace_turbo_graph)
  DEFINE_STRING(trace_turbo_cfg_file, nullptr,
                "trace turbo cfg graph (for C1 visualizer) to a given file name")
  DEFINE_BOOL(trace_turbo_types, true, "trace TurboFan's types")
  DEFINE_BOOL(trace_turbo_scheduler, false, "trace TurboFan's scheduler")
  DEFINE_BOOL(trace_turbo_reduction, false, "trace TurboFan's various reducers")
  DEFINE_BOOL(trace_turbo_trimming, false, "trace TurboFan's graph trimmer")
  DEFINE_BOOL(trace_turbo_jt, false, "trace TurboFan's jump threading")
  DEFINE_BOOL(trace_turbo_ceq, false, "trace TurboFan's control equivalence")
  DEFINE_BOOL(trace_turbo_loop, false, "trace TurboFan's loop optimizations")
  DEFINE_BOOL(trace_alloc, false, "trace register allocator")
  DEFINE_BOOL(trace_all_uses, false, "trace all use positions")
  DEFINE_BOOL(trace_representation, false, "trace representation types")
  DEFINE_BOOL(turbo_verify, DEBUG_BOOL, "verify TurboFan graphs at each phase")
  DEFINE_STRING(turbo_verify_machine_graph, nullptr,
                "verify TurboFan machine graph before instruction selection")
  #ifdef ENABLE_VERIFY_CSA
  DEFINE_BOOL(verify_csa, DEBUG_BOOL,
              "verify TurboFan machine graph of code stubs")
  #else
  // Define the flag as read-only-false so that code still compiles even in the
  // non-ENABLE_VERIFY_CSA configuration.
  DEFINE_BOOL_READONLY(verify_csa, false,
                       "verify TurboFan machine graph of code stubs")
  #endif
  DEFINE_BOOL(trace_verify_csa, false, "trace code stubs verification")
  DEFINE_STRING(csa_trap_on_node, nullptr,
                "trigger break point when a node with given id is created in "
                "given stub. The format is: StubName,NodeId")
  DEFINE_BOOL(turbo_stats, false, "print TurboFan statistics")
  DEFINE_BOOL(turbo_stats_nvp, false,
              "print TurboFan statistics in machine-readable format")
  DEFINE_BOOL(turbo_splitting, true, "split nodes during scheduling in TurboFan")
  DEFINE_BOOL(function_context_specialization, false,
              "enable function context specialization in TurboFan")
  DEFINE_BOOL(turbo_inlining, true, "enable inlining in TurboFan")
  DEFINE_INT(max_inlined_bytecode_size, 500,
             "maximum size of bytecode for a single inlining")
  DEFINE_INT(max_inlined_bytecode_size_cumulative, 1000,
             "maximum cumulative size of bytecode considered for inlining")
  DEFINE_INT(max_inlined_bytecode_size_absolute, 5000,
             "maximum cumulative size of bytecode considered for inlining")
  DEFINE_FLOAT(reserve_inline_budget_scale_factor, 1.2,
               "maximum cumulative size of bytecode considered for inlining")
  DEFINE_INT(max_inlined_bytecode_size_small, 30,
             "maximum size of bytecode considered for small function inlining")
  DEFINE_FLOAT(min_inlining_frequency, 0.15, "minimum frequency for inlining")
  DEFINE_BOOL(polymorphic_inlining, true, "polymorphic inlining")
  DEFINE_BOOL(stress_inline, false,
              "set high thresholds for inlining to inline as much as possible")
  DEFINE_VALUE_IMPLICATION(stress_inline, max_inlined_bytecode_size, 999999)
  DEFINE_VALUE_IMPLICATION(stress_inline, max_inlined_bytecode_size_cumulative,
                           999999)
  DEFINE_VALUE_IMPLICATION(stress_inline, max_inlined_bytecode_size_absolute,
                           999999)
  DEFINE_VALUE_IMPLICATION(stress_inline, min_inlining_frequency, 0)
  DEFINE_VALUE_IMPLICATION(stress_inline, polymorphic_inlining, true)
  DEFINE_BOOL(trace_turbo_inlining, false, "trace TurboFan inlining")
  DEFINE_BOOL(inline_accessors, true, "inline JavaScript accessors")
  DEFINE_BOOL(inline_into_try, true, "inline into try blocks")
  DEFINE_BOOL(turbo_inline_array_builtins, true,
              "inline array builtins in TurboFan code")
  DEFINE_BOOL(use_osr, true, "use on-stack replacement")
  DEFINE_BOOL(trace_osr, false, "trace on-stack replacement")
  DEFINE_BOOL(analyze_environment_liveness, true,
              "analyze liveness of environment slots and zap dead values")
  DEFINE_BOOL(trace_environment_liveness, false,
              "trace liveness of local variable slots")
  DEFINE_BOOL(turbo_load_elimination, true, "enable load elimination in TurboFan")
  DEFINE_BOOL(trace_turbo_load_elimination, false,
              "trace TurboFan load elimination")
  DEFINE_BOOL(turbo_profiling, false, "enable profiling in TurboFan")
  DEFINE_BOOL(turbo_verify_allocation, DEBUG_BOOL,
              "verify register allocation in TurboFan")
  DEFINE_BOOL(turbo_move_optimization, true, "optimize gap moves in TurboFan")
  DEFINE_BOOL(turbo_jt, true, "enable jump threading in TurboFan")
  DEFINE_BOOL(turbo_loop_peeling, true, "Turbofan loop peeling")
  DEFINE_BOOL(turbo_loop_variable, true, "Turbofan loop variable optimization")
  DEFINE_BOOL(turbo_cf_optimization, true, "optimize control flow in TurboFan")
  DEFINE_BOOL(turbo_escape, true, "enable escape analysis")
  DEFINE_BOOL(turbo_instruction_scheduling, false,
              "enable instruction scheduling in TurboFan")
  DEFINE_BOOL(turbo_stress_instruction_scheduling, false,
              "randomly schedule instructions to stress dependency tracking")
  DEFINE_BOOL(turbo_store_elimination, true,
              "enable store-store elimination in TurboFan")
  DEFINE_BOOL(trace_store_elimination, false, "trace store elimination")
  DEFINE_BOOL(turbo_rewrite_far_jumps, true,
              "rewrite far to near jumps (ia32,x64)")
  
  // Flags to help platform porters
  DEFINE_BOOL(minimal, false,
              "simplifies execution model to make porting "
              "easier (e.g. always use Ignition, never optimize)")
  DEFINE_NEG_IMPLICATION(minimal, opt)
  DEFINE_NEG_IMPLICATION(minimal, use_ic)
  
  // Flags for native WebAssembly.
  DEFINE_BOOL(expose_wasm, true, "expose wasm interface to JavaScript")
  DEFINE_BOOL(assume_asmjs_origin, false,
              "force wasm decoder to assume input is internal asm-wasm format")
  DEFINE_BOOL(wasm_disable_structured_cloning, false,
              "disable wasm structured cloning")
  DEFINE_INT(wasm_num_compilation_tasks, 10,
             "number of parallel compilation tasks for wasm")
  DEFINE_BOOL(wasm_trace_native_heap, false, "trace wasm native heap events")
  DEFINE_BOOL(wasm_jit_to_native, false,
              "JIT wasm code to native (not JS GC) memory")
  DEFINE_BOOL(wasm_trace_serialization, false,
              "trace serialization/deserialization")
  DEFINE_BOOL(wasm_async_compilation, true,
              "enable actual asynchronous compilation for WebAssembly.compile")
  DEFINE_BOOL(wasm_stream_compilation, false,
              "enable streaming compilation for WebAssembly")
  DEFINE_IMPLICATION(wasm_stream_compilation, wasm_async_compilation)
  DEFINE_BOOL(wasm_test_streaming, false,
              "use streaming compilation instead of async compilation for tests")
  DEFINE_IMPLICATION(wasm_test_streaming, wasm_stream_compilation)
  // Parallel compilation confuses turbo_stats, force single threaded.
  DEFINE_VALUE_IMPLICATION(turbo_stats, wasm_num_compilation_tasks, 0)
  DEFINE_UINT(wasm_max_mem_pages, v8::internal::wasm::kV8MaxWasmMemoryPages,
              "maximum memory size of a wasm instance")
  DEFINE_UINT(wasm_max_table_size, v8::internal::wasm::kV8MaxWasmTableSize,
              "maximum table size of a wasm instance")
  DEFINE_BOOL(trace_wasm_decoder, false, "trace decoding of wasm code")
  DEFINE_BOOL(trace_wasm_decode_time, false, "trace decoding time of wasm code")
  DEFINE_BOOL(trace_wasm_compiler, false, "trace compiling of wasm code")
  DEFINE_BOOL(trace_wasm_interpreter, false, "trace interpretation of wasm code")
  DEFINE_BOOL(trace_wasm_streaming, false,
              "trace streaming compilation of wasm code")
  DEFINE_INT(trace_wasm_ast_start, 0,
             "start function for wasm AST trace (inclusive)")
  DEFINE_INT(trace_wasm_ast_end, 0, "end function for wasm AST trace (exclusive)")
  DEFINE_BOOL(liftoff, false,
              "enable liftoff, the experimental wasm baseline compiler")
  DEFINE_BOOL(trace_liftoff, false, "trace liftoff, the wasm baseline compiler")
  DEFINE_UINT(skip_compiling_wasm_funcs, 0, "start compiling at function N")
  DEFINE_BOOL(wasm_break_on_decoder_error, false,
              "debug break when wasm decoder encounters an error")
  DEFINE_BOOL(wasm_trace_memory, false,
              "print all memory updates performed in wasm code")
  
  DEFINE_BOOL(validate_asm, true, "validate asm.js modules before compiling")
  DEFINE_BOOL(suppress_asm_messages, false,
              "don't emit asm.js related messages (for golden file testing)")
  DEFINE_BOOL(trace_asm_time, false, "log asm.js timing info to the console")
  DEFINE_BOOL(trace_asm_scanner, false,
              "log tokens encountered by asm.js scanner")
  DEFINE_BOOL(trace_asm_parser, false, "verbose logging of asm.js parse failures")
  DEFINE_BOOL(stress_validate_asm, false, "try to validate everything as asm.js")
  
  DEFINE_BOOL(dump_wasm_module, false, "dump wasm module bytes")
  DEFINE_STRING(dump_wasm_module_path, nullptr,
                "directory to dump wasm modules to")
  
  DEFINE_BOOL(experimental_wasm_simd, false,
              "enable prototype simd opcodes for wasm")
  DEFINE_BOOL(experimental_wasm_eh, false,
              "enable prototype exception handling opcodes for wasm")
  DEFINE_BOOL(experimental_wasm_mv, false,
              "enable prototype multi-value support for wasm")
  DEFINE_BOOL(experimental_wasm_threads, false,
              "enable prototype threads for wasm")
  
  DEFINE_BOOL(wasm_opt, false, "enable wasm optimization")
  DEFINE_BOOL(wasm_no_bounds_checks, false,
              "disable bounds checks (performance testing only)")
  DEFINE_BOOL(wasm_no_stack_checks, false,
              "disable stack checks (performance testing only)")
  
  DEFINE_BOOL(wasm_trap_handler, false,
              "use signal handlers to catch out of bounds memory access in wasm"
              " (experimental, currently Linux x86_64 only)")
  DEFINE_BOOL(wasm_code_fuzzer_gen_test, false,
              "Generate a test case when running the wasm-code fuzzer")
  DEFINE_BOOL(print_wasm_code, false, "Print WebAssembly code")
  DEFINE_BOOL(wasm_interpret_all, false,
              "Execute all wasm code in the wasm interpreter")
  DEFINE_BOOL(asm_wasm_lazy_compilation, false,
              "enable lazy compilation for asm-wasm modules")
  DEFINE_IMPLICATION(validate_asm, asm_wasm_lazy_compilation)
  DEFINE_BOOL(wasm_lazy_compilation, false,
              "enable lazy compilation for all wasm modules")
  DEFINE_BOOL(trace_wasm_lazy_compilation, false,
              "trace lazy compilation of wasm functions")
  // wasm-interpret-all resets {asm-,}wasm-lazy-compilation.
  DEFINE_NEG_IMPLICATION(wasm_interpret_all, asm_wasm_lazy_compilation)
  DEFINE_NEG_IMPLICATION(wasm_interpret_all, wasm_lazy_compilation)
  
  // Profiler flags.
  DEFINE_INT(frame_count, 1, "number of stack frames inspected by the profiler")
  DEFINE_INT(type_info_threshold, 25,
             "percentage of ICs that must have type info to allow optimization")
  
  // Garbage collections flags.
  DEFINE_INT(min_semi_space_size, 0,
             "min size of a semi-space (in MBytes), the new space consists of two"
             "semi-spaces")
  DEFINE_INT(max_semi_space_size, 0,
             "max size of a semi-space (in MBytes), the new space consists of two"
             "semi-spaces")
  DEFINE_INT(semi_space_growth_factor, 2, "factor by which to grow the new space")
  DEFINE_BOOL(experimental_new_space_growth_heuristic, false,
              "Grow the new space based on the percentage of survivors instead "
              "of their absolute value.")
  DEFINE_INT(max_old_space_size, 0, "max size of the old space (in Mbytes)")
  DEFINE_INT(initial_old_space_size, 0, "initial old space size (in Mbytes)")
  DEFINE_BOOL(gc_global, false, "always perform global GCs")
  DEFINE_INT(gc_interval, -1, "garbage collect after <n> allocations")
  DEFINE_INT(retain_maps_for_n_gc, 2,
             "keeps maps alive for <n> old space garbage collections")
  DEFINE_BOOL(trace_gc, false,
              "print one trace line following each garbage collection")
  DEFINE_BOOL(trace_gc_nvp, false,
              "print one detailed trace line in name=value format "
              "after each garbage collection")
  DEFINE_BOOL(trace_gc_ignore_scavenger, false,
              "do not print trace line after scavenger collection")
  DEFINE_BOOL(trace_idle_notification, false,
              "print one trace line following each idle notification")
  DEFINE_BOOL(trace_idle_notification_verbose, false,
              "prints the heap state used by the idle notification")
  DEFINE_BOOL(trace_gc_verbose, false,
              "print more details following each garbage collection")
  DEFINE_INT(trace_allocation_stack_interval, -1,
             "print stack trace after <n> free-list allocations")
  DEFINE_BOOL(trace_fragmentation, false, "report fragmentation for old space")
  DEFINE_BOOL(trace_fragmentation_verbose, false,
              "report fragmentation for old space (detailed)")
  DEFINE_BOOL(trace_evacuation, false, "report evacuation statistics")
  DEFINE_BOOL(trace_mutator_utilization, false,
              "print mutator utilization, allocation speed, gc speed")
  DEFINE_BOOL(incremental_marking, true, "use incremental marking")
  DEFINE_BOOL(incremental_marking_wrappers, true,
              "use incremental marking for marking wrappers")
  DEFINE_BOOL(parallel_scavenge, true, "parallel scavenge")
  DEFINE_BOOL(trace_parallel_scavenge, false, "trace parallel scavenge")
  DEFINE_BOOL(write_protect_code_memory, false, "write protect code memory")
  #ifdef V8_CONCURRENT_MARKING
  #define V8_CONCURRENT_MARKING_BOOL true
  #else
  #define V8_CONCURRENT_MARKING_BOOL false
  #endif
  DEFINE_BOOL(concurrent_marking, V8_CONCURRENT_MARKING_BOOL,
              "use concurrent marking")
  DEFINE_BOOL(parallel_marking, true, "use parallel marking in atomic pause")
  DEFINE_IMPLICATION(parallel_marking, concurrent_marking)
  DEFINE_BOOL(trace_concurrent_marking, false, "trace concurrent marking")
  DEFINE_BOOL(minor_mc_parallel_marking, true,
              "use parallel marking for the young generation")
  DEFINE_BOOL(trace_minor_mc_parallel_marking, false,
              "trace parallel marking for the young generation")
  DEFINE_BOOL(minor_mc, false, "perform young generation mark compact GCs")
  DEFINE_BOOL(black_allocation, true, "use black allocation")
  DEFINE_BOOL(concurrent_store_buffer, true,
              "use concurrent store buffer processing")
  DEFINE_BOOL(concurrent_sweeping, true, "use concurrent sweeping")
  DEFINE_BOOL(parallel_compaction, true, "use parallel compaction")
  DEFINE_BOOL(parallel_pointer_update, true,
              "use parallel pointer update during compaction")
  DEFINE_BOOL(trace_incremental_marking, false,
              "trace progress of the incremental marking")
  DEFINE_BOOL(track_gc_object_stats, false,
              "track object counts and memory usage")
  DEFINE_BOOL(trace_gc_object_stats, false,
              "trace object counts and memory usage")
  DEFINE_BOOL(track_retaining_path, false,
              "enable support for tracking retaining path")
  DEFINE_BOOL(concurrent_array_buffer_freeing, true,
              "free array buffer allocations on a background thread")
  DEFINE_INT(gc_stats, 0, "Used by tracing internally to enable gc statistics")
  DEFINE_IMPLICATION(trace_gc_object_stats, track_gc_object_stats)
  DEFINE_VALUE_IMPLICATION(track_gc_object_stats, gc_stats, 1)
  DEFINE_VALUE_IMPLICATION(trace_gc_object_stats, gc_stats, 1)
  DEFINE_NEG_IMPLICATION(trace_gc_object_stats, incremental_marking)
  DEFINE_NEG_IMPLICATION(track_retaining_path, incremental_marking)
  DEFINE_NEG_IMPLICATION(track_retaining_path, parallel_marking)
  DEFINE_NEG_IMPLICATION(track_retaining_path, concurrent_marking)
  DEFINE_BOOL(track_detached_contexts, true,
              "track native contexts that are expected to be garbage collected")
  DEFINE_BOOL(trace_detached_contexts, false,
              "trace native contexts that are expected to be garbage collected")
  DEFINE_IMPLICATION(trace_detached_contexts, track_detached_contexts)
  #ifdef VERIFY_HEAP
  DEFINE_BOOL(verify_heap, false, "verify heap pointers before and after GC")
  DEFINE_BOOL(verify_heap_skip_remembered_set, false,
              "disable remembered set verification")
  #endif
  DEFINE_BOOL(move_object_start, true, "enable moving of object starts")
  DEFINE_BOOL(memory_reducer, true, "use memory reducer")
  DEFINE_INT(heap_growing_percent, 0,
             "specifies heap growing factor as (1 + heap_growing_percent/100)")
  DEFINE_INT(v8_os_page_size, 0, "override OS page size (in KBytes)")
  DEFINE_BOOL(always_compact, false, "Perform compaction on every full GC")
  DEFINE_BOOL(never_compact, false,
              "Never perform compaction on full GC - testing only")
  DEFINE_BOOL(compact_code_space, true, "Compact code space on full collections")
  DEFINE_BOOL(use_marking_progress_bar, true,
              "Use a progress bar to scan large objects in increments when "
              "incremental marking is active.")
  DEFINE_BOOL(force_marking_deque_overflows, false,
              "force overflows of marking deque by reducing it's size "
              "to 64 words")
  DEFINE_BOOL(stress_compaction, false,
              "stress the GC compactor to flush out bugs (implies "
              "--force_marking_deque_overflows)")
  DEFINE_BOOL(stress_compaction_random, false,
              "Stress GC compaction by selecting random percent of pages as "
              "evacuation candidates. It overrides stress_compaction.")
  DEFINE_BOOL(stress_incremental_marking, false,
              "force incremental marking for small heaps and run it more often")
  DEFINE_INT(stress_marking, 0,
             "force marking at random points between 0 and X (inclusive) percent "
             "of the regular marking start limit")
  DEFINE_BOOL(manual_evacuation_candidates_selection, false,
              "Test mode only flag. It allows an unit test to select evacuation "
              "candidates pages (requires --stress_compaction).")
  DEFINE_BOOL(fast_promotion_new_space, false,
              "fast promote new space on high survival rates")
  
  // assembler-ia32.cc / assembler-arm.cc / assembler-x64.cc
  DEFINE_BOOL(debug_code, DEBUG_BOOL,
              "generate extra code (assertions) for debugging")
  DEFINE_BOOL(code_comments, false,
              "emit comments in code disassembly; for more readable source "
              "positions you should add --no-concurrent_recompilation")
  DEFINE_BOOL(enable_sse3, true, "enable use of SSE3 instructions if available")
  DEFINE_BOOL(enable_ssse3, true, "enable use of SSSE3 instructions if available")
  DEFINE_BOOL(enable_sse4_1, true,
              "enable use of SSE4.1 instructions if available")
  DEFINE_BOOL(enable_sahf, true,
              "enable use of SAHF instruction if available (X64 only)")
  DEFINE_BOOL(enable_avx, true, "enable use of AVX instructions if available")
  DEFINE_BOOL(enable_fma3, true, "enable use of FMA3 instructions if available")
  DEFINE_BOOL(enable_bmi1, true, "enable use of BMI1 instructions if available")
  DEFINE_BOOL(enable_bmi2, true, "enable use of BMI2 instructions if available")
  DEFINE_BOOL(enable_lzcnt, true, "enable use of LZCNT instruction if available")
  DEFINE_BOOL(enable_popcnt, true,
              "enable use of POPCNT instruction if available")
  DEFINE_STRING(arm_arch, ARM_ARCH_DEFAULT,
                "generate instructions for the selected ARM architecture if "
                "available: armv6, armv7, armv7+sudiv or armv8")
  DEFINE_BOOL(enable_vldr_imm, false,
              "enable use of constant pools for double immediate (ARM only)")
  DEFINE_BOOL(force_long_branches, false,
              "force all emitted branches to be in long mode (MIPS/PPC only)")
  DEFINE_STRING(mcpu, "auto", "enable optimization for specific cpu")
  
  // Deprecated ARM flags (replaced by arm_arch).
  DEFINE_MAYBE_BOOL(enable_armv7, "deprecated (use --arm_arch instead)")
  DEFINE_MAYBE_BOOL(enable_vfp3, "deprecated (use --arm_arch instead)")
  DEFINE_MAYBE_BOOL(enable_32dregs, "deprecated (use --arm_arch instead)")
  DEFINE_MAYBE_BOOL(enable_neon, "deprecated (use --arm_arch instead)")
  DEFINE_MAYBE_BOOL(enable_sudiv, "deprecated (use --arm_arch instead)")
  DEFINE_MAYBE_BOOL(enable_armv8, "deprecated (use --arm_arch instead)")
  
  // regexp-macro-assembler-*.cc
  DEFINE_BOOL(enable_regexp_unaligned_accesses, true,
              "enable unaligned accesses for the regexp engine")
  
  // api.cc
  DEFINE_BOOL(script_streaming, true, "enable parsing on background")
  DEFINE_BOOL(disable_old_api_accessors, false,
              "Disable old-style API accessors whose setters trigger through the "
              "prototype chain")
  
  // bootstrapper.cc
  DEFINE_STRING(expose_natives_as, nullptr, "expose natives in global object")
  DEFINE_BOOL(expose_free_buffer, false, "expose freeBuffer extension")
  DEFINE_BOOL(expose_gc, false, "expose gc extension")
  DEFINE_STRING(expose_gc_as, nullptr,
                "expose gc extension under the specified name")
  DEFINE_IMPLICATION(expose_gc_as, expose_gc)
  DEFINE_BOOL(expose_externalize_string, false,
              "expose externalize string extension")
  DEFINE_BOOL(expose_trigger_failure, false, "expose trigger-failure extension")
  DEFINE_INT(stack_trace_limit, 10, "number of stack frames to capture")
  DEFINE_BOOL(builtins_in_stack_traces, false,
              "show built-in functions in stack traces")
  DEFINE_BOOL(enable_experimental_builtins, true,
              "enable new csa-based experimental builtins")
  
  // builtins.cc
  DEFINE_BOOL(allow_unsafe_function_constructor, false,
              "allow invoking the function constructor without security checks")
  DEFINE_BOOL(force_slow_path, false, "always take the slow path for builtins")
  
  // builtins-ia32.cc
  DEFINE_BOOL(inline_new, true, "use fast inline allocation")
  
  // codegen-ia32.cc / codegen-arm.cc
  DEFINE_BOOL(trace, false, "trace function calls")
  
  // codegen.cc
  DEFINE_BOOL(lazy, true, "use lazy compilation")
  DEFINE_BOOL(trace_opt, false, "trace lazy optimization")
  DEFINE_BOOL(trace_opt_verbose, false, "extra verbose compilation tracing")
  DEFINE_IMPLICATION(trace_opt_verbose, trace_opt)
  DEFINE_BOOL(trace_opt_stats, false, "trace lazy optimization statistics")
  DEFINE_BOOL(trace_deopt, false, "trace optimize function deoptimization")
  DEFINE_BOOL(trace_file_names, false,
              "include file names in trace-opt/trace-deopt output")
  DEFINE_BOOL(trace_interrupts, false, "trace interrupts when they are handled")
  DEFINE_BOOL(opt, true, "use adaptive optimizations")
  DEFINE_BOOL(always_opt, false, "always try to optimize functions")
  DEFINE_BOOL(always_osr, false, "always try to OSR functions")
  DEFINE_BOOL(prepare_always_opt, false, "prepare for turning on always opt")
  
  DEFINE_BOOL(trace_serializer, false, "print code serializer trace")
  #ifdef DEBUG
  DEFINE_BOOL(external_reference_stats, false,
              "print statistics on external references used during serialization")
  #endif  // DEBUG
  
  // compilation-cache.cc
  DEFINE_BOOL(compilation_cache, true, "enable compilation cache")
  
  DEFINE_BOOL(cache_prototype_transitions, true, "cache prototype transitions")
  
  // compiler-dispatcher.cc
  DEFINE_BOOL(compiler_dispatcher, false, "enable compiler dispatcher")
  DEFINE_BOOL(trace_compiler_dispatcher, false,
              "trace compiler dispatcher activity")
  
  // compiler-dispatcher-job.cc
  DEFINE_BOOL(
      trace_compiler_dispatcher_jobs, false,
      "trace progress of individual jobs managed by the compiler dispatcher")
  
  // cpu-profiler.cc
  DEFINE_INT(cpu_profiler_sampling_interval, 1000,
             "CPU profiler sampling interval in microseconds")
  
  // Array abuse tracing
  DEFINE_BOOL(trace_js_array_abuse, false,
              "trace out-of-bounds accesses to JS arrays")
  DEFINE_BOOL(trace_external_array_abuse, false,
              "trace out-of-bounds-accesses to external arrays")
  DEFINE_BOOL(trace_array_abuse, false,
              "trace out-of-bounds accesses to all arrays")
  DEFINE_IMPLICATION(trace_array_abuse, trace_js_array_abuse)
  DEFINE_IMPLICATION(trace_array_abuse, trace_external_array_abuse)
  
  // debugger
  DEFINE_BOOL(enable_liveedit, true, "enable liveedit experimental feature")
  DEFINE_BOOL(
      trace_side_effect_free_debug_evaluate, false,
      "print debug messages for side-effect-free debug-evaluate for testing")
  DEFINE_BOOL(hard_abort, true, "abort by crashing")
  
  // inspector
  DEFINE_BOOL(expose_inspector_scripts, false,
              "expose injected-script-source.js for debugging")
  
  // execution.cc
  DEFINE_INT(stack_size, V8_DEFAULT_STACK_SIZE_KB,
             "default size of stack region v8 is allowed to use (in kBytes)")
  
  // frames.cc
  DEFINE_INT(max_stack_trace_source_length, 300,
             "maximum length of function source code printed in a stack trace.")
  
  // execution.cc, messages.cc
  DEFINE_BOOL(clear_exceptions_on_js_entry, false,
              "clear pending exceptions when entering JavaScript")
  
  // counters.cc
  DEFINE_INT(histogram_interval, 600000,
             "time interval in ms for aggregating memory histograms")
  
  // heap-snapshot-generator.cc
  DEFINE_BOOL(heap_profiler_trace_objects, false,
              "Dump heap object allocations/movements/size_updates")
  
  
  // sampling-heap-profiler.cc
  DEFINE_BOOL(sampling_heap_profiler_suppress_randomness, false,
              "Use constant sample intervals to eliminate test flakiness")
  
  
  // v8.cc
  DEFINE_BOOL(use_idle_notification, true,
              "Use idle notification to reduce memory footprint.")
  // ic.cc
  DEFINE_BOOL(use_ic, true, "use inline caching")
  DEFINE_BOOL(trace_ic, false,
              "trace inline cache state transitions for tools/ic-processor")
  DEFINE_IMPLICATION(trace_ic, log_code)
  DEFINE_INT(ic_stats, 0, "inline cache state transitions statistics")
  DEFINE_VALUE_IMPLICATION(trace_ic, ic_stats, 1)
  DEFINE_BOOL_READONLY(track_constant_fields, false,
                       "enable constant field tracking")
  DEFINE_BOOL_READONLY(modify_map_inplace, false, "enable in-place map updates")
  
  // macro-assembler-ia32.cc
  DEFINE_BOOL(native_code_counters, false,
              "generate extra code for manipulating stats counters")
  
  // objects.cc
  DEFINE_BOOL(thin_strings, true, "Enable ThinString support")
  DEFINE_BOOL(trace_weak_arrays, false, "Trace WeakFixedArray usage")
  DEFINE_BOOL(trace_prototype_users, false,
              "Trace updates to prototype user tracking")
  DEFINE_BOOL(use_verbose_printer, true, "allows verbose printing")
  DEFINE_BOOL(trace_for_in_enumerate, false, "Trace for-in enumerate slow-paths")
  DEFINE_BOOL(trace_maps, false, "trace map creation")
  DEFINE_IMPLICATION(trace_maps, log_code)
  
  // parser.cc
  DEFINE_BOOL(allow_natives_syntax, false, "allow natives syntax")
  DEFINE_BOOL(lazy_inner_functions, true, "enable lazy parsing inner functions")
  DEFINE_BOOL(aggressive_lazy_inner_functions, false,
              "even lazier inner function parsing")
  DEFINE_IMPLICATION(aggressive_lazy_inner_functions, lazy_inner_functions)
  DEFINE_BOOL(preparser_scope_analysis, true,
              "perform scope analysis for preparsed inner functions")
  DEFINE_IMPLICATION(preparser_scope_analysis, aggressive_lazy_inner_functions)
  
  // compiler.cc
  DEFINE_BOOL(background_compile, false, "enable background compilation")
  
  // simulator-arm.cc, simulator-arm64.cc and simulator-mips.cc
  DEFINE_BOOL(trace_sim, false, "Trace simulator execution")
  DEFINE_BOOL(debug_sim, false, "Enable debugging the simulator")
  DEFINE_BOOL(check_icache, false,
              "Check icache flushes in ARM and MIPS simulator")
  DEFINE_INT(stop_sim_at, 0, "Simulator stop after x number of instructions")
  #if defined(V8_TARGET_ARCH_ARM64) || defined(V8_TARGET_ARCH_MIPS64) || \
      defined(V8_TARGET_ARCH_PPC64)
  DEFINE_INT(sim_stack_alignment, 16,
             "Stack alignment in bytes in simulator. This must be a power of two "
             "and it must be at least 16. 16 is default.")
  #else
  DEFINE_INT(sim_stack_alignment, 8,
             "Stack alingment in bytes in simulator (4 or 8, 8 is default)")
  #endif
  DEFINE_INT(sim_stack_size, 2 * MB / KB,
             "Stack size of the ARM64, MIPS64 and PPC64 simulator "
             "in kBytes (default is 2 MB)")
  DEFINE_BOOL(log_colour, ENABLE_LOG_COLOUR,
              "When logging, try to use coloured output.")
  DEFINE_BOOL(ignore_asm_unimplemented_break, false,
              "Don't break for ASM_UNIMPLEMENTED_BREAK macros.")
  DEFINE_BOOL(trace_sim_messages, false,
              "Trace simulator debug messages. Implied by --trace-sim.")
  
  // isolate.cc
  DEFINE_BOOL(stack_trace_on_illegal, false,
              "print stack trace when an illegal exception is thrown")
  DEFINE_BOOL(abort_on_uncaught_exception, false,
              "abort program (dump core) when an uncaught exception is thrown")
  DEFINE_BOOL(abort_on_stack_or_string_length_overflow, false,
              "Abort program when the stack overflows or a string exceeds "
              "maximum length (as opposed to throwing RangeError). This is "
              "useful for fuzzing where the spec behaviour would introduce "
              "nondeterminism.")
  DEFINE_BOOL(randomize_hashes, true,
              "randomize hashes to avoid predictable hash collisions "
              "(with snapshots this option cannot override the baked-in seed)")
  DEFINE_BOOL(rehash_snapshot, true,
              "rehash strings from the snapshot to override the baked-in seed")
  DEFINE_INT(hash_seed, 0,
             "Fixed seed to use to hash property keys (0 means random)"
             "(with snapshots this option cannot override the baked-in seed)")
  DEFINE_INT(random_seed, 0,
             "Default seed for initializing random generator "
             "(0, the default, means to use system random).")
  DEFINE_INT(fuzzer_random_seed, 0,
             "Default seed for initializing fuzzer random generator "
             "(0, the default, means to use system random).")
  DEFINE_BOOL(trace_rail, false, "trace RAIL mode")
  DEFINE_BOOL(print_all_exceptions, false,
              "print exception object and stack trace on each thrown exception")
  
  // runtime.cc
  DEFINE_BOOL(runtime_call_stats, false, "report runtime call counts and times")
  DEFINE_INT(runtime_stats, 0,
             "internal usage only for controlling runtime statistics")
  DEFINE_VALUE_IMPLICATION(runtime_call_stats, runtime_stats, 1)
  
  // snapshot-common.cc
  DEFINE_BOOL(lazy_deserialization, true,
              "Deserialize code lazily from the snapshot.")
  DEFINE_BOOL(lazy_handler_deserialization, true,
              "Deserialize bytecode handlers lazily from the snapshot.")
  DEFINE_IMPLICATION(lazy_handler_deserialization, lazy_deserialization)
  DEFINE_IMPLICATION(future, lazy_handler_deserialization)
  DEFINE_BOOL(trace_lazy_deserialization, false, "Trace lazy deserialization.")
  DEFINE_BOOL(profile_deserialization, false,
              "Print the time it takes to deserialize the snapshot.")
  DEFINE_BOOL(serialization_statistics, false,
              "Collect statistics on serialized objects.")
  
  // Regexp
  DEFINE_BOOL(regexp_optimization, true, "generate optimized regexp code")
  DEFINE_BOOL(regexp_mode_modifiers, false, "enable inline flags in regexp.")
  
  // Testing flags test/cctest/test-{flags,api,serialization}.cc
  DEFINE_BOOL(testing_bool_flag, true, "testing_bool_flag")
  DEFINE_MAYBE_BOOL(testing_maybe_bool_flag, "testing_maybe_bool_flag")
  DEFINE_INT(testing_int_flag, 13, "testing_int_flag")
  DEFINE_FLOAT(testing_float_flag, 2.5, "float-flag")
  DEFINE_STRING(testing_string_flag, "Hello, world!", "string-flag")
  DEFINE_INT(testing_prng_seed, 42, "Seed used for threading test randomness")
  
  // mksnapshot.cc
  DEFINE_STRING(startup_src, nullptr,
                "Write V8 startup as C++ src. (mksnapshot only)")
  DEFINE_STRING(startup_blob, nullptr,
                "Write V8 startup blob file. (mksnapshot only)")
  
  //
  // Dev shell flags
  //
  
  DEFINE_BOOL(help, false, "Print usage message, including flags, on console")
  DEFINE_BOOL(dump_counters, false, "Dump counters on exit")
  DEFINE_BOOL(dump_counters_nvp, false,
              "Dump counters as name-value pairs on exit")
  DEFINE_BOOL(use_external_strings, false, "Use external strings for source code")
  
  DEFINE_STRING(map_counters, "", "Map counters to a file")
  DEFINE_ARGS(js_arguments,
              "Pass all remaining arguments to the script. Alias for \"--\".")
  
  //
  // GDB JIT integration flags.
  //
  #undef FLAG
  #ifdef ENABLE_GDB_JIT_INTERFACE
  #define FLAG FLAG_FULL
  #else
  #define FLAG FLAG_READONLY
  #endif
  
  DEFINE_BOOL(gdbjit, false, "enable GDBJIT interface")
  DEFINE_BOOL(gdbjit_full, false, "enable GDBJIT interface for all code objects")
  DEFINE_BOOL(gdbjit_dump, false, "dump elf objects with debug info to disk")
  DEFINE_STRING(gdbjit_dump_filter, "",
                "dump only objects containing this substring")
  
  #ifdef ENABLE_GDB_JIT_INTERFACE
  DEFINE_IMPLICATION(gdbjit_full, gdbjit)
  DEFINE_IMPLICATION(gdbjit_dump, gdbjit)
  #endif
  DEFINE_NEG_IMPLICATION(gdbjit, compact_code_space)
  
  //
  // Debug only flags
  //
  #undef FLAG
  #ifdef DEBUG
  #define FLAG FLAG_FULL
  #else
  #define FLAG FLAG_READONLY
  #endif
  
  // checks.cc
  #ifdef ENABLE_SLOW_DCHECKS
  DEFINE_BOOL(enable_slow_asserts, false,
              "enable asserts that are slow to execute")
  #endif
  
  // codegen-ia32.cc / codegen-arm.cc / macro-assembler-*.cc
  DEFINE_BOOL(print_ast, false, "print source AST")
  DEFINE_BOOL(trap_on_abort, false, "replace aborts by breakpoints")
  
  // compiler.cc
  DEFINE_BOOL(print_builtin_scopes, false, "print scopes for builtins")
  DEFINE_BOOL(print_scopes, false, "print scopes")
  
  // contexts.cc
  DEFINE_BOOL(trace_contexts, false, "trace contexts operations")
  
  // heap.cc
  DEFINE_BOOL(gc_verbose, false, "print stuff during garbage collection")
  DEFINE_BOOL(heap_stats, false, "report heap statistics before and after GC")
  DEFINE_BOOL(code_stats, false, "report code statistics after GC")
  DEFINE_BOOL(print_handles, false, "report handles after GC")
  DEFINE_BOOL(check_handle_count, false,
              "Check that there are not too many handles at GC")
  DEFINE_BOOL(print_global_handles, false, "report global handles after GC")
  
  // TurboFan debug-only flags.
  DEFINE_BOOL(trace_turbo_escape, false, "enable tracing in escape analysis")
  
  // objects.cc
  DEFINE_BOOL(trace_module_status, false,
              "Trace status transitions of ECMAScript modules")
  DEFINE_BOOL(trace_normalization, false,
              "prints when objects are turned into dictionaries.")
  
  // runtime.cc
  DEFINE_BOOL(trace_lazy, false, "trace lazy compilation")
  
  // spaces.cc
  DEFINE_BOOL(collect_heap_spill_statistics, false,
              "report heap spill statistics along with heap_stats "
              "(requires heap_stats)")
  DEFINE_BOOL(trace_isolates, false, "trace isolate state changes")
  
  // Regexp
  DEFINE_BOOL(regexp_possessive_quantifier, false,
              "enable possessive quantifier syntax for testing")
  DEFINE_BOOL(trace_regexp_bytecodes, false, "trace regexp bytecode execution")
  DEFINE_BOOL(trace_regexp_assembler, false,
              "trace regexp macro assembler calls.")
  DEFINE_BOOL(trace_regexp_parser, false, "trace regexp parsing")
  
  // Debugger
  DEFINE_BOOL(print_break_location, false, "print source location on debug break")
  
  // wasm instance management
  DEFINE_BOOL(trace_wasm_instances, false,
              "trace creation and collection of wasm instances")
  
  //
  // Logging and profiling flags
  //
  #undef FLAG
  #define FLAG FLAG_FULL
  
  // log.cc
  DEFINE_BOOL(log, false,
              "Minimal logging (no API, code, GC, suspect, or handles samples).")
  DEFINE_BOOL(log_all, false, "Log all events to the log file.")
  DEFINE_BOOL(log_api, false, "Log API events to the log file.")
  DEFINE_BOOL(log_code, false,
              "Log code events to the log file without profiling.")
  DEFINE_BOOL(log_gc, false,
              "Log heap samples on garbage collection for the hp2ps tool.")
  DEFINE_BOOL(log_handles, false, "Log global handle events.")
  DEFINE_BOOL(log_suspect, false, "Log suspect operations.")
  DEFINE_BOOL(log_source_code, false, "Log source code.")
  DEFINE_BOOL(log_function_events, false,
              "Log function events "
              "(parse, compile, execute) separately.")
  DEFINE_BOOL(prof, false,
              "Log statistical profiling information (implies --log-code).")
  
  #if defined(ANDROID)
  // Phones and tablets have processors that are much slower than desktop
  // and laptop computers for which current heuristics are tuned.
  #define DEFAULT_PROF_SAMPLING_INTERVAL 5000
  #else
  #define DEFAULT_PROF_SAMPLING_INTERVAL 1000
  #endif
  DEFINE_INT(prof_sampling_interval, DEFAULT_PROF_SAMPLING_INTERVAL,
             "Interval for --prof samples (in microseconds).")
  #undef DEFAULT_PROF_SAMPLING_INTERVAL
  
  DEFINE_BOOL(prof_cpp, false, "Like --prof, but ignore generated code.")
  DEFINE_IMPLICATION(prof, prof_cpp)
  DEFINE_BOOL(prof_browser_mode, true,
              "Used with --prof, turns on browser-compatible mode for profiling.")
  DEFINE_STRING(logfile, "v8.log", "Specify the name of the log file.")
  DEFINE_BOOL(logfile_per_isolate, true, "Separate log files for each isolate.")
  DEFINE_BOOL(ll_prof, false, "Enable low-level linux profiler.")
  DEFINE_BOOL(perf_basic_prof, false,
              "Enable perf linux profiler (basic support).")
  DEFINE_NEG_IMPLICATION(perf_basic_prof, compact_code_space)
  DEFINE_BOOL(perf_basic_prof_only_functions, false,
              "Only report function code ranges to perf (i.e. no stubs).")
  DEFINE_IMPLICATION(perf_basic_prof_only_functions, perf_basic_prof)
  DEFINE_BOOL(perf_prof, false,
              "Enable perf linux profiler (experimental annotate support).")
  DEFINE_NEG_IMPLICATION(perf_prof, compact_code_space)
  DEFINE_BOOL(perf_prof_unwinding_info, false,
              "Enable unwinding info for perf linux profiler (experimental).")
  DEFINE_IMPLICATION(perf_prof, perf_prof_unwinding_info)
  DEFINE_STRING(gc_fake_mmap, "/tmp/__v8_gc__",
                "Specify the name of the file for fake gc mmap used in ll_prof")
  DEFINE_BOOL(log_internal_timer_events, false, "Time internal events.")
  DEFINE_BOOL(log_timer_events, false,
              "Time events including external callbacks.")
  DEFINE_IMPLICATION(log_timer_events, log_internal_timer_events)
  DEFINE_IMPLICATION(log_internal_timer_events, prof)
  DEFINE_BOOL(log_instruction_stats, false, "Log AArch64 instruction statistics.")
  DEFINE_STRING(log_instruction_file, "arm64_inst.csv",
                "AArch64 instruction statistics log file.")
  DEFINE_INT(log_instruction_period, 1 << 22,
             "AArch64 instruction statistics logging period.")
  
  DEFINE_BOOL(redirect_code_traces, false,
              "output deopt information and disassembly into file "
              "code-<pid>-<isolate id>.asm")
  DEFINE_STRING(redirect_code_traces_to, nullptr,
                "output deopt information and disassembly into the given file")
  
  DEFINE_BOOL(print_opt_source, false,
              "print source code of optimized and inlined functions")
  
  //
  // Disassembler only flags
  //
  #undef FLAG
  #ifdef ENABLE_DISASSEMBLER
  #define FLAG FLAG_FULL
  #else
  #define FLAG FLAG_READONLY
  #endif
  
  // elements.cc
  DEFINE_BOOL(trace_elements_transitions, false, "trace elements transitions")
  
  DEFINE_BOOL(trace_creation_allocation_sites, false,
              "trace the creation of allocation sites")
  
  // code-stubs.cc
  DEFINE_BOOL(print_code_stubs, false, "print code stubs")
  DEFINE_BOOL(test_secondary_stub_cache, false,
              "test secondary stub cache by disabling the primary one")
  
  DEFINE_BOOL(test_primary_stub_cache, false,
              "test primary stub cache by disabling the secondary one")
  
  DEFINE_BOOL(test_small_max_function_context_stub_size, false,
              "enable testing the function context size overflow path "
              "by making the maximum size smaller")
  
  // codegen-ia32.cc / codegen-arm.cc
  DEFINE_BOOL(print_code, false, "print generated code")
  DEFINE_BOOL(print_opt_code, false, "print optimized code")
  DEFINE_STRING(print_opt_code_filter, "*", "filter for printing optimized code")
  DEFINE_BOOL(print_code_verbose, false, "print more information for code")
  DEFINE_BOOL(print_builtin_code, false, "print generated code for builtins")
  DEFINE_BOOL(print_builtin_size, false, "print code size for builtins")
  
  #ifdef ENABLE_DISASSEMBLER
  DEFINE_BOOL(sodium, false,
              "print generated code output suitable for use with "
              "the Sodium code viewer")
  
  DEFINE_IMPLICATION(sodium, print_code_stubs)
  DEFINE_IMPLICATION(sodium, print_code)
  DEFINE_IMPLICATION(sodium, print_opt_code)
  DEFINE_IMPLICATION(sodium, code_comments)
  
  DEFINE_BOOL(print_all_code, false, "enable all flags related to printing code")
  DEFINE_IMPLICATION(print_all_code, print_code)
  DEFINE_IMPLICATION(print_all_code, print_opt_code)
  DEFINE_IMPLICATION(print_all_code, print_code_verbose)
  DEFINE_IMPLICATION(print_all_code, print_builtin_code)
  DEFINE_IMPLICATION(print_all_code, print_code_stubs)
  DEFINE_IMPLICATION(print_all_code, code_comments)
  #endif
  
  #undef FLAG
  #define FLAG FLAG_FULL
  
  //
  // Predictable mode related flags.
  //
  
  DEFINE_BOOL(predictable, false, "enable predictable mode")
  DEFINE_IMPLICATION(predictable, single_threaded)
  DEFINE_NEG_IMPLICATION(predictable, memory_reducer)
  DEFINE_VALUE_IMPLICATION(single_threaded, wasm_num_compilation_tasks, 0)
  
  //
  // Threading related flags.
  //
  
  DEFINE_BOOL(single_threaded, false, "disable the use of background tasks")
  DEFINE_IMPLICATION(single_threaded, single_threaded_gc)
  DEFINE_NEG_IMPLICATION(single_threaded, concurrent_recompilation)
  DEFINE_NEG_IMPLICATION(single_threaded, compiler_dispatcher)
  
  //
  // Parallel and concurrent GC (Orinoco) related flags.
  //
  DEFINE_BOOL(single_threaded_gc, false, "disable the use of background gc tasks")
  DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_marking)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_sweeping)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_compaction)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_marking)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_pointer_update)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, parallel_scavenge)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_store_buffer)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, minor_mc_parallel_marking)
  DEFINE_NEG_IMPLICATION(single_threaded_gc, concurrent_array_buffer_freeing)
  
  #undef FLAG
  
  #ifdef VERIFY_PREDICTABLE
  #define FLAG FLAG_FULL
  #else
  #define FLAG FLAG_READONLY
  #endif
  
  DEFINE_BOOL(verify_predictable, false,
              "this mode is used for checking that V8 behaves predictably")
  DEFINE_INT(dump_allocations_digest_at_alloc, -1,
             "dump allocations digest each n-th allocation")
  
  //
  // Read-only flags
  //
  #undef FLAG
  #define FLAG FLAG_READONLY
  
  // assembler.h
  DEFINE_BOOL(enable_embedded_constant_pool, V8_EMBEDDED_CONSTANT_POOL,
              "enable use of embedded constant pools (PPC only)")
  
  DEFINE_BOOL(unbox_double_fields, V8_DOUBLE_FIELDS_UNBOXING,
              "enable in-object double fields unboxing (64-bit only)")
  DEFINE_IMPLICATION(unbox_double_fields, track_double_fields)
  
  // Cleanup...
  #undef FLAG_FULL
  #undef FLAG_READONLY
  #undef FLAG
  #undef FLAG_ALIAS
  
  #undef DEFINE_BOOL
  #undef DEFINE_MAYBE_BOOL
  #undef DEFINE_INT
  #undef DEFINE_STRING
  #undef DEFINE_FLOAT
  #undef DEFINE_ARGS
  #undef DEFINE_IMPLICATION
  #undef DEFINE_NEG_IMPLICATION
  #undef DEFINE_NEG_VALUE_IMPLICATION
  #undef DEFINE_VALUE_IMPLICATION
  #undef DEFINE_ALIAS_BOOL
  #undef DEFINE_ALIAS_INT
  #undef DEFINE_ALIAS_STRING
  #undef DEFINE_ALIAS_FLOAT
  #undef DEFINE_ALIAS_ARGS
  
  #undef FLAG_MODE_DECLARE
  #undef FLAG_MODE_DEFINE
  #undef FLAG_MODE_DEFINE_DEFAULTS
  #undef FLAG_MODE_META
  #undef FLAG_MODE_DEFINE_IMPLICATIONS
  
  #undef COMMA
  