--- a/js/src/builtin/JSON.cpp
+++ b/js/src/builtin/JSON.cpp
@@ -906,25 +906,23 @@ js::ParseJSONWithReviver(JSContext* cx, 
 template bool
 js::ParseJSONWithReviver(JSContext* cx, const mozilla::Range<const Latin1Char> chars,
                          HandleValue reviver, MutableHandleValue vp);
 
 template bool
 js::ParseJSONWithReviver(JSContext* cx, const mozilla::Range<const char16_t> chars, HandleValue reviver,
                          MutableHandleValue vp);
 
-#if JS_HAS_TOSOURCE
 static bool
 json_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().JSON);
     return true;
 }
-#endif
 
 /* ES5 15.12.2. */
 static bool
 json_parse(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
 
     /* Step 1. */
@@ -975,19 +973,17 @@ json_stringify(JSContext* cx, unsigned a
     } else {
         args.rval().setUndefined();
     }
 
     return true;
 }
 
 static const JSFunctionSpec json_static_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,  json_toSource,      0, 0),
-#endif
     JS_FN("parse",          json_parse,         2, 0),
     JS_FN("stringify",      json_stringify,     3, 0),
     JS_FS_END
 };
 
 JSObject*
 js::InitJSONClass(JSContext* cx, HandleObject obj)
 {

--- a/js/src/builtin/Object.cpp
+++ b/js/src/builtin/Object.cpp
@@ -107,17 +107,16 @@ js::obj_propertyIsEnumerable(JSContext* 
     if (!GetOwnPropertyDescriptor(cx, obj, idRoot, &desc))
         return false;
 
     /* Steps 4-5. */
     args.rval().setBoolean(desc.object() && desc.enumerable());
     return true;
 }
 
-#if JS_HAS_TOSOURCE
 static bool
 obj_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
 
     if (!CheckRecursionLimit(cx))
         return false;
 
@@ -426,17 +425,16 @@ js::ObjectToSource(JSContext* cx, Handle
 
     if (!buf.append('}'))
         return nullptr;
     if (outermost && !buf.append(')'))
         return nullptr;
 
     return buf.finishString();
 }
-#endif /* JS_HAS_TOSOURCE */
 
 static bool
 GetBuiltinTagSlow(JSContext* cx, HandleObject obj, MutableHandleString builtinTag)
 {
     // Step 4.
     bool isArray;
     if (!IsArray(cx, obj, &isArray))
         return false;
@@ -1946,38 +1944,32 @@ ProtoSetter(JSContext* cx, unsigned argc
     if (!SetPrototype(cx, obj, newProto))
         return false;
 
     args.rval().setUndefined();
     return true;
 }
 
 static const JSFunctionSpec object_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,             obj_toSource,                0,0),
-#endif
     JS_INLINABLE_FN(js_toString_str,   obj_toString,                0,0, ObjectToString),
     JS_SELF_HOSTED_FN(js_toLocaleString_str, "Object_toLocaleString", 0, 0),
     JS_SELF_HOSTED_FN(js_valueOf_str,  "Object_valueOf",            0,0),
     JS_SELF_HOSTED_FN(js_hasOwnProperty_str, "Object_hasOwnProperty", 1,0),
     JS_FN(js_isPrototypeOf_str,        obj_isPrototypeOf,           1,0),
     JS_FN(js_propertyIsEnumerable_str, obj_propertyIsEnumerable,    1,0),
-#if JS_OLD_GETTER_SETTER_METHODS
     JS_SELF_HOSTED_FN(js_defineGetter_str, "ObjectDefineGetter",    2,0),
     JS_SELF_HOSTED_FN(js_defineSetter_str, "ObjectDefineSetter",    2,0),
     JS_SELF_HOSTED_FN(js_lookupGetter_str, "ObjectLookupGetter",    1,0),
     JS_SELF_HOSTED_FN(js_lookupSetter_str, "ObjectLookupSetter",    1,0),
-#endif
     JS_FS_END
 };
 
 static const JSPropertySpec object_properties[] = {
-#if JS_HAS_OBJ_PROTO_PROP
     JS_PSGS("__proto__", ProtoGetter, ProtoSetter, 0),
-#endif
     JS_PS_END
 };
 
 static const JSFunctionSpec object_static_methods[] = {
     JS_FN("assign",                    obj_assign,                  2, 0),
     JS_SELF_HOSTED_FN("getPrototypeOf", "ObjectGetPrototypeOf",     1, 0),
     JS_FN("setPrototypeOf",            obj_setPrototypeOf,          2, 0),
     JS_SELF_HOSTED_FN("getOwnPropertyDescriptor", "ObjectGetOwnPropertyDescriptor", 2, 0),

--- a/js/src/builtin/Object.h
+++ b/js/src/builtin/Object.h
@@ -66,21 +66,19 @@ GetOwnPropertyDescriptorToArray(JSContex
 /*
  * Like IdToValue, but convert int jsids to strings. This is used when
  * exposing a jsid to script for Object.getOwnProperty{Names,Symbols}
  * or scriptable proxy traps.
  */
 MOZ_MUST_USE bool
 IdToStringOrSymbol(JSContext* cx, JS::HandleId id, JS::MutableHandleValue result);
 
-#if JS_HAS_TOSOURCE
 // Object.prototype.toSource. Function.prototype.toSource and uneval use this.
 JSString*
 ObjectToSource(JSContext* cx, JS::HandleObject obj);
-#endif // JS_HAS_TOSOURCE
 
 extern MOZ_MUST_USE bool
 WatchHandler(JSContext* cx, JSObject* obj, jsid id, const JS::Value& old,
              JS::Value* nvp, void* closure);
 
 } /* namespace js */
 
 #endif /* builtin_Object_h */

--- a/js/src/builtin/RegExp.cpp
+++ b/js/src/builtin/RegExp.cpp
@@ -759,19 +759,17 @@ const JSPropertySpec js::regexp_properti
     JS_PSG("multiline", regexp_multiline, 0),
     JS_PSG("source", regexp_source, 0),
     JS_PSG("sticky", regexp_sticky, 0),
     JS_PSG("unicode", regexp_unicode, 0),
     JS_PS_END
 };
 
 const JSFunctionSpec js::regexp_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_SELF_HOSTED_FN(js_toSource_str, "RegExpToString", 0, 0),
-#endif
     JS_SELF_HOSTED_FN(js_toString_str, "RegExpToString", 0, 0),
     JS_FN("compile",        regexp_compile,     2,0),
     JS_SELF_HOSTED_FN("exec", "RegExp_prototype_Exec", 1,0),
     JS_SELF_HOSTED_FN("test", "RegExpTest" ,    1,0),
     JS_SELF_HOSTED_SYM_FN(match, "RegExpMatch", 1,0),
     JS_SELF_HOSTED_SYM_FN(replace, "RegExpReplace", 2,0),
     JS_SELF_HOSTED_SYM_FN(search, "RegExpSearch", 1,0),
     JS_SELF_HOSTED_SYM_FN(split, "RegExpSplit", 2,0),

--- a/js/src/builtin/intl/Collator.cpp
+++ b/js/src/builtin/intl/Collator.cpp
@@ -45,36 +45,32 @@ const ClassOps CollatorObject::classOps_
 
 const Class CollatorObject::class_ = {
     js_Object_str,
     JSCLASS_HAS_RESERVED_SLOTS(CollatorObject::SLOT_COUNT) |
     JSCLASS_FOREGROUND_FINALIZE,
     &CollatorObject::classOps_
 };
 
-#if JS_HAS_TOSOURCE
 static bool
 collator_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().Collator);
     return true;
 }
-#endif
 
 static const JSFunctionSpec collator_static_methods[] = {
     JS_SELF_HOSTED_FN("supportedLocalesOf", "Intl_Collator_supportedLocalesOf", 1, 0),
     JS_FS_END
 };
 
 static const JSFunctionSpec collator_methods[] = {
     JS_SELF_HOSTED_FN("resolvedOptions", "Intl_Collator_resolvedOptions", 0, 0),
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, collator_toSource, 0, 0),
-#endif
     JS_FS_END
 };
 
 static const JSPropertySpec collator_properties[] = {
     JS_SELF_HOSTED_GET("compare", "Intl_Collator_compare_get", 0),
     JS_STRING_SYM_PS(toStringTag, "Object", JSPROP_READONLY),
     JS_PS_END
 };

--- a/js/src/builtin/intl/DateTimeFormat.cpp
+++ b/js/src/builtin/intl/DateTimeFormat.cpp
@@ -51,37 +51,33 @@ const ClassOps DateTimeFormatObject::cla
 
 const Class DateTimeFormatObject::class_ = {
     js_Object_str,
     JSCLASS_HAS_RESERVED_SLOTS(DateTimeFormatObject::SLOT_COUNT) |
     JSCLASS_FOREGROUND_FINALIZE,
     &DateTimeFormatObject::classOps_
 };
 
-#if JS_HAS_TOSOURCE
 static bool
 dateTimeFormat_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().DateTimeFormat);
     return true;
 }
-#endif
 
 static const JSFunctionSpec dateTimeFormat_static_methods[] = {
     JS_SELF_HOSTED_FN("supportedLocalesOf", "Intl_DateTimeFormat_supportedLocalesOf", 1, 0),
     JS_FS_END
 };
 
 static const JSFunctionSpec dateTimeFormat_methods[] = {
     JS_SELF_HOSTED_FN("resolvedOptions", "Intl_DateTimeFormat_resolvedOptions", 0, 0),
     JS_SELF_HOSTED_FN("formatToParts", "Intl_DateTimeFormat_formatToParts", 1, 0),
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, dateTimeFormat_toSource, 0, 0),
-#endif
     JS_FS_END
 };
 
 static const JSPropertySpec dateTimeFormat_properties[] = {
     JS_SELF_HOSTED_GET("format", "Intl_DateTimeFormat_format_get", 0),
     JS_STRING_SYM_PS(toStringTag, "Object", JSPROP_READONLY),
     JS_PS_END
 };

--- a/js/src/builtin/intl/IntlObject.cpp
+++ b/js/src/builtin/intl/IntlObject.cpp
@@ -479,30 +479,26 @@ js::intl_GetLocaleInfo(JSContext* cx, un
     return true;
 }
 
 const Class js::IntlClass = {
     js_Object_str,
     JSCLASS_HAS_CACHED_PROTO(JSProto_Intl)
 };
 
-#if JS_HAS_TOSOURCE
 static bool
 intl_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().Intl);
     return true;
 }
-#endif
 
 static const JSFunctionSpec intl_static_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,  intl_toSource,        0, 0),
-#endif
     JS_SELF_HOSTED_FN("getCanonicalLocales", "Intl_getCanonicalLocales", 1, 0),
     JS_FS_END
 };
 
 /**
  * Initializes the Intl Object and its standard built-in properties.
  * Spec: ECMAScript Internationalization API Specification, 8.0, 8.1
  */

--- a/js/src/builtin/intl/NumberFormat.cpp
+++ b/js/src/builtin/intl/NumberFormat.cpp
@@ -52,37 +52,33 @@ const ClassOps NumberFormatObject::class
 
 const Class NumberFormatObject::class_ = {
     js_Object_str,
     JSCLASS_HAS_RESERVED_SLOTS(NumberFormatObject::SLOT_COUNT) |
     JSCLASS_FOREGROUND_FINALIZE,
     &NumberFormatObject::classOps_
 };
 
-#if JS_HAS_TOSOURCE
 static bool
 numberFormat_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().NumberFormat);
     return true;
 }
-#endif
 
 static const JSFunctionSpec numberFormat_static_methods[] = {
     JS_SELF_HOSTED_FN("supportedLocalesOf", "Intl_NumberFormat_supportedLocalesOf", 1, 0),
     JS_FS_END
 };
 
 static const JSFunctionSpec numberFormat_methods[] = {
     JS_SELF_HOSTED_FN("resolvedOptions", "Intl_NumberFormat_resolvedOptions", 0, 0),
     JS_SELF_HOSTED_FN("formatToParts", "Intl_NumberFormat_formatToParts", 1, 0),
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, numberFormat_toSource, 0, 0),
-#endif
     JS_FS_END
 };
 
 static const JSPropertySpec numberFormat_properties[] = {
     JS_SELF_HOSTED_GET("format", "Intl_NumberFormat_format_get", 0),
     JS_STRING_SYM_PS(toStringTag, "Object", JSPROP_READONLY),
     JS_PS_END
 };

--- a/js/src/builtin/intl/PluralRules.cpp
+++ b/js/src/builtin/intl/PluralRules.cpp
@@ -42,37 +42,33 @@ const ClassOps PluralRulesObject::classO
 
 const Class PluralRulesObject::class_ = {
     js_Object_str,
     JSCLASS_HAS_RESERVED_SLOTS(PluralRulesObject::SLOT_COUNT) |
     JSCLASS_FOREGROUND_FINALIZE,
     &PluralRulesObject::classOps_
 };
 
-#if JS_HAS_TOSOURCE
 static bool
 pluralRules_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().PluralRules);
     return true;
 }
-#endif
 
 static const JSFunctionSpec pluralRules_static_methods[] = {
     JS_SELF_HOSTED_FN("supportedLocalesOf", "Intl_PluralRules_supportedLocalesOf", 1, 0),
     JS_FS_END
 };
 
 static const JSFunctionSpec pluralRules_methods[] = {
     JS_SELF_HOSTED_FN("resolvedOptions", "Intl_PluralRules_resolvedOptions", 0, 0),
     JS_SELF_HOSTED_FN("select", "Intl_PluralRules_select", 1, 0),
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, pluralRules_toSource, 0, 0),
-#endif
     JS_FS_END
 };
 
 /**
  * PluralRules constructor.
  * Spec: ECMAScript 402 API, PluralRules, 13.2.1
  */
 static bool

--- a/js/src/builtin/intl/RelativeTimeFormat.cpp
+++ b/js/src/builtin/intl/RelativeTimeFormat.cpp
@@ -42,37 +42,33 @@ const ClassOps RelativeTimeFormatObject:
 
 const Class RelativeTimeFormatObject::class_ = {
     js_Object_str,
     JSCLASS_HAS_RESERVED_SLOTS(RelativeTimeFormatObject::SLOT_COUNT) |
     JSCLASS_FOREGROUND_FINALIZE,
     &RelativeTimeFormatObject::classOps_
 };
 
-#if JS_HAS_TOSOURCE
 static bool
 relativeTimeFormat_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().RelativeTimeFormat);
     return true;
 }
-#endif
 
 static const JSFunctionSpec relativeTimeFormat_static_methods[] = {
     JS_SELF_HOSTED_FN("supportedLocalesOf", "Intl_RelativeTimeFormat_supportedLocalesOf", 1, 0),
     JS_FS_END
 };
 
 static const JSFunctionSpec relativeTimeFormat_methods[] = {
     JS_SELF_HOSTED_FN("resolvedOptions", "Intl_RelativeTimeFormat_resolvedOptions", 0, 0),
     JS_SELF_HOSTED_FN("format", "Intl_RelativeTimeFormat_format", 2, 0),
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, relativeTimeFormat_toSource, 0, 0),
-#endif
     JS_FS_END
 };
 
 /**
  * RelativeTimeFormat constructor.
  * Spec: ECMAScript 402 API, RelativeTimeFormat, 1.1
  */
 static bool

--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -1052,19 +1052,17 @@ static const JSStdName builtin_property_
 
     /* String global functions. */
     { EAGER_ATOM(escape), JSProto_String },
     { EAGER_ATOM(unescape), JSProto_String },
     { EAGER_ATOM(decodeURI), JSProto_String },
     { EAGER_ATOM(encodeURI), JSProto_String },
     { EAGER_ATOM(decodeURIComponent), JSProto_String },
     { EAGER_ATOM(encodeURIComponent), JSProto_String },
-#if JS_HAS_UNEVAL
     { EAGER_ATOM(uneval), JSProto_String },
-#endif
 
     { 0, JSProto_LIMIT }
 };
 
 #undef EAGER_ATOM
 
 JS_PUBLIC_API(bool)
 JS_ResolveStandardClass(JSContext* cx, HandleObject obj, HandleId id, bool* resolved)

--- a/js/src/jsarray.cpp
+++ b/js/src/jsarray.cpp
@@ -1120,18 +1120,16 @@ ArraySpeciesCreate(JSContext* cx, Handle
         return false;
     }
 
     MOZ_ASSERT(rval.isObject());
     arr.set(&rval.toObject());
     return true;
 }
 
-#if JS_HAS_TOSOURCE
-
 static bool
 array_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     if (!CheckRecursionLimit(cx))
         return false;
 
     CallArgs args = CallArgsFromVp(argc, vp);
 
@@ -1199,18 +1197,16 @@ array_toSource(JSContext* cx, unsigned a
     JSString* str = sb.finishString();
     if (!str)
         return false;
 
     args.rval().setString(str);
     return true;
 }
 
-#endif
-
 struct EmptySeparatorOp
 {
     bool operator()(JSContext*, StringBuffer& sb) { return true; }
 };
 
 template <typename CharT>
 struct CharSeparatorOp
 {
@@ -3495,19 +3491,17 @@ const JSJitInfo js::array_splice_info = 
   { 0 }, /* unused */
   { 0 }, /* unused */
   JSJitInfo::IgnoresReturnValueNative,
   JSJitInfo::AliasEverything,
   JSVAL_TYPE_UNDEFINED,
 };
 
 static const JSFunctionSpec array_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,      array_toSource,     0,0),
-#endif
     JS_SELF_HOSTED_FN(js_toString_str, "ArrayToString",      0,0),
     JS_FN(js_toLocaleString_str,       array_toLocaleString, 0,0),
 
     /* Perl-ish methods. */
     JS_INLINABLE_FN("join",     array_join,         1,0, ArrayJoin),
     JS_FN("reverse",            array_reverse,      0,0),
     JS_SELF_HOSTED_FN("sort",   "ArraySort",        1,0),
     JS_INLINABLE_FN("push",     array_push,         1,0, ArrayPush),

--- a/js/src/jsbool.cpp
+++ b/js/src/jsbool.cpp
@@ -31,17 +31,16 @@ const Class BooleanObject::class_ = {
 };
 
 MOZ_ALWAYS_INLINE bool
 IsBoolean(HandleValue v)
 {
     return v.isBoolean() || (v.isObject() && v.toObject().is<BooleanObject>());
 }
 
-#if JS_HAS_TOSOURCE
 MOZ_ALWAYS_INLINE bool
 bool_toSource_impl(JSContext* cx, const CallArgs& args)
 {
     HandleValue thisv = args.thisv();
     MOZ_ASSERT(IsBoolean(thisv));
 
     bool b = thisv.isBoolean() ? thisv.toBoolean() : thisv.toObject().as<BooleanObject>().unbox();
 
@@ -57,17 +56,16 @@ bool_toSource_impl(JSContext* cx, const 
 }
 
 static bool
 bool_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsBoolean, bool_toSource_impl>(cx, args);
 }
-#endif
 
 MOZ_ALWAYS_INLINE bool
 bool_toString_impl(JSContext* cx, const CallArgs& args)
 {
     HandleValue thisv = args.thisv();
     MOZ_ASSERT(IsBoolean(thisv));
 
     bool b = thisv.isBoolean() ? thisv.toBoolean() : thisv.toObject().as<BooleanObject>().unbox();
@@ -96,19 +94,17 @@ bool_valueOf_impl(JSContext* cx, const C
 static bool
 bool_valueOf(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsBoolean, bool_valueOf_impl>(cx, args);
 }
 
 static const JSFunctionSpec boolean_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,  bool_toSource,  0, 0),
-#endif
     JS_FN(js_toString_str,  bool_toString,  0, 0),
     JS_FN(js_valueOf_str,   bool_valueOf,   0, 0),
     JS_FS_END
 };
 
 static bool
 Boolean(JSContext* cx, unsigned argc, Value* vp)
 {

--- a/js/src/jsdate.cpp
+++ b/js/src/jsdate.cpp
@@ -2901,17 +2901,16 @@ date_toDateString_impl(JSContext* cx, co
 
 static bool
 date_toDateString(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsDate, date_toDateString_impl>(cx, args);
 }
 
-#if JS_HAS_TOSOURCE
 MOZ_ALWAYS_INLINE bool
 date_toSource_impl(JSContext* cx, const CallArgs& args)
 {
     StringBuffer sb(cx);
     if (!sb.append("(new Date(") ||
         !NumberValueToStringBuffer(cx, args.thisv().toObject().as<DateObject>().UTCTime(), sb) ||
         !sb.append("))"))
     {
@@ -2926,17 +2925,16 @@ date_toSource_impl(JSContext* cx, const 
 }
 
 static bool
 date_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsDate, date_toSource_impl>(cx, args);
 }
-#endif
 
 // ES6 20.3.4.41.
 MOZ_ALWAYS_INLINE bool
 date_toString_impl(JSContext* cx, const CallArgs& args)
 {
     // Steps 1-2.
     return FormatDate(cx, args.thisv().toObject().as<DateObject>().UTCTime().toNumber(),
                       FormatSpec::DateTime, args.rval());
@@ -3040,19 +3038,17 @@ static const JSFunctionSpec date_methods
     JS_FN(js_toLocaleString_str, date_toLocaleString,     0,0),
     JS_FN("toLocaleDateString",  date_toLocaleDateString, 0,0),
     JS_FN("toLocaleTimeString",  date_toLocaleTimeString, 0,0),
 #endif
     JS_FN("toDateString",        date_toDateString,       0,0),
     JS_FN("toTimeString",        date_toTimeString,       0,0),
     JS_FN("toISOString",         date_toISOString,        0,0),
     JS_FN(js_toJSON_str,         date_toJSON,             1,0),
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,       date_toSource,           0,0),
-#endif
     JS_FN(js_toString_str,       date_toString,           0,0),
     JS_FN(js_valueOf_str,        date_valueOf,            0,0),
     JS_SYM_FN(toPrimitive,       date_toPrimitive,        1,JSPROP_READONLY),
     JS_FS_END
 };
 
 static bool
 NewDateObject(JSContext* cx, const CallArgs& args, ClippedTime t)

--- a/js/src/jsexn.cpp
+++ b/js/src/jsexn.cpp
@@ -69,19 +69,17 @@ ErrorObject::protoClasses[JSEXN_ERROR_LI
 
     IMPLEMENT_ERROR_PROTO_CLASS(DebuggeeWouldRun),
     IMPLEMENT_ERROR_PROTO_CLASS(CompileError),
     IMPLEMENT_ERROR_PROTO_CLASS(LinkError),
     IMPLEMENT_ERROR_PROTO_CLASS(RuntimeError)
 };
 
 static const JSFunctionSpec error_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, exn_toSource, 0, 0),
-#endif
     JS_SELF_HOSTED_FN(js_toString_str, "ErrorToString", 0,0),
     JS_FS_END
 };
 
 static const JSPropertySpec error_properties[] = {
     JS_STRING_PS("message", "", 0),
     JS_STRING_PS("name", "Error", 0),
     // Only Error.prototype has .stack!
@@ -492,17 +490,16 @@ Error(JSContext* cx, unsigned argc, Valu
                                              lineNumber, columnNumber, nullptr, message, proto));
     if (!obj)
         return false;
 
     args.rval().setObject(*obj);
     return true;
 }
 
-#if JS_HAS_TOSOURCE
 /*
  * Return a string that may eval to something similar to the original object.
  */
 static bool
 exn_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     if (!CheckRecursionLimit(cx))
         return false;
@@ -571,17 +568,16 @@ exn_toSource(JSContext* cx, unsigned arg
         return false;
 
     JSString* str = sb.finishString();
     if (!str)
         return false;
     args.rval().setString(str);
     return true;
 }
-#endif
 
 /* static */ JSObject*
 ErrorObject::createProto(JSContext* cx, JSProtoKey key)
 {
     JSExnType type = ExnTypeFromProtoKey(key);
 
     if (type == JSEXN_ERR) {
         return GlobalObject::createBlankPrototype(cx, cx->global(),

--- a/js/src/jsmath.cpp
+++ b/js/src/jsmath.cpp
@@ -1429,30 +1429,26 @@ js::math_cbrt_uncached(double x)
 }
 
 bool
 js::math_cbrt(JSContext* cx, unsigned argc, Value* vp)
 {
     return math_function<math_cbrt_impl>(cx, argc, vp);
 }
 
-#if JS_HAS_TOSOURCE
 static bool
 math_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().Math);
     return true;
 }
-#endif
 
 static const JSFunctionSpec math_static_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,  math_toSource,        0, 0),
-#endif
     JS_INLINABLE_FN("abs",    math_abs,             1, 0, MathAbs),
     JS_INLINABLE_FN("acos",   math_acos,            1, 0, MathACos),
     JS_INLINABLE_FN("asin",   math_asin,            1, 0, MathASin),
     JS_INLINABLE_FN("atan",   math_atan,            1, 0, MathATan),
     JS_INLINABLE_FN("atan2",  math_atan2,           2, 0, MathATan2),
     JS_INLINABLE_FN("ceil",   math_ceil,            1, 0, MathCeil),
     JS_INLINABLE_FN("clz32",  math_clz32,           1, 0, MathClz32),
     JS_INLINABLE_FN("cos",    math_cos,             1, 0, MathCos),

--- a/js/src/jsnum.cpp
+++ b/js/src/jsnum.cpp
@@ -522,17 +522,16 @@ IsNumber(HandleValue v)
 static inline double
 Extract(const Value& v)
 {
     if (v.isNumber())
         return v.toNumber();
     return v.toObject().as<NumberObject>().unbox();
 }
 
-#if JS_HAS_TOSOURCE
 MOZ_ALWAYS_INLINE bool
 num_toSource_impl(JSContext* cx, const CallArgs& args)
 {
     double d = Extract(args.thisv());
 
     StringBuffer sb(cx);
     if (!sb.append("(new Number(") ||
         !NumberValueToStringBuffer(cx, NumberValue(d), sb) ||
@@ -549,17 +548,16 @@ num_toSource_impl(JSContext* cx, const C
 }
 
 static bool
 num_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsNumber, num_toSource_impl>(cx, args);
 }
-#endif
 
 ToCStringBuf::ToCStringBuf() : dbuf(nullptr)
 {
     static_assert(sbufSize >= DTOSTR_STANDARD_BUFFER_SIZE,
                   "builtin space must be large enough to store even the "
                   "longest string produced by a conversion");
 }
 
@@ -1089,19 +1087,17 @@ num_toPrecision_impl(JSContext* cx, cons
 static bool
 num_toPrecision(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsNumber, num_toPrecision_impl>(cx, args);
 }
 
 static const JSFunctionSpec number_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,       num_toSource,          0, 0),
-#endif
     JS_FN(js_toString_str,       num_toString,          1, 0),
 #if EXPOSE_INTL_API
     JS_SELF_HOSTED_FN(js_toLocaleString_str, "Number_toLocaleString", 0,0),
 #else
     JS_FN(js_toLocaleString_str, num_toLocaleString,     0,0),
 #endif
     JS_FN(js_valueOf_str,        num_valueOf,           0, 0),
     JS_FN("toFixed",             num_toFixed,           1, 0),

--- a/js/src/jsstr.cpp
+++ b/js/src/jsstr.cpp
@@ -479,36 +479,32 @@ str_unescape(JSContext* cx, unsigned arg
     } else {
         result = str;
     }
 
     args.rval().setString(result);
     return true;
 }
 
-#if JS_HAS_UNEVAL
 static bool
 str_uneval(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     JSString* str = ValueToSource(cx, args.get(0));
     if (!str)
         return false;
 
     args.rval().setString(str);
     return true;
 }
-#endif
 
 static const JSFunctionSpec string_functions[] = {
     JS_FN(js_escape_str,             str_escape,                1, JSPROP_RESOLVING),
     JS_FN(js_unescape_str,           str_unescape,              1, JSPROP_RESOLVING),
-#if JS_HAS_UNEVAL
     JS_FN(js_uneval_str,             str_uneval,                1, JSPROP_RESOLVING),
-#endif
     JS_FN(js_decodeURI_str,          str_decodeURI,             1, JSPROP_RESOLVING),
     JS_FN(js_encodeURI_str,          str_encodeURI,             1, JSPROP_RESOLVING),
     JS_FN(js_decodeURIComponent_str, str_decodeURI_Component,   1, JSPROP_RESOLVING),
     JS_FN(js_encodeURIComponent_str, str_encodeURI_Component,   1, JSPROP_RESOLVING),
 
     JS_FS_END
 };
 
@@ -615,18 +611,16 @@ ToStringForStringFunction(JSContext* cx,
 }
 
 MOZ_ALWAYS_INLINE bool
 IsString(HandleValue v)
 {
     return v.isString() || (v.isObject() && v.toObject().is<StringObject>());
 }
 
-#if JS_HAS_TOSOURCE
-
 MOZ_ALWAYS_INLINE bool
 str_toSource_impl(JSContext* cx, const CallArgs& args)
 {
     MOZ_ASSERT(IsString(args.thisv()));
 
     Rooted<JSString*> str(cx, ToString<CanGC>(cx, args.thisv()));
     if (!str)
         return false;
@@ -648,18 +642,16 @@ str_toSource_impl(JSContext* cx, const C
 
 static bool
 str_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     return CallNonGenericMethod<IsString, str_toSource_impl>(cx, args);
 }
 
-#endif /* JS_HAS_TOSOURCE */
-
 MOZ_ALWAYS_INLINE bool
 str_toString_impl(JSContext* cx, const CallArgs& args)
 {
     MOZ_ASSERT(IsString(args.thisv()));
 
     args.rval().setString(args.thisv().isString()
                               ? args.thisv().toString()
                               : args.thisv().toObject().as<StringObject>().unbox());
@@ -3292,19 +3284,17 @@ js::str_concat(JSContext* cx, unsigned a
         }
     }
 
     args.rval().setString(str);
     return true;
 }
 
 static const JSFunctionSpec string_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,     str_toSource,          0,0),
-#endif
 
     /* Java-like methods. */
     JS_FN(js_toString_str,     str_toString,          0,0),
     JS_FN(js_valueOf_str,      str_toString,          0,0),
     JS_INLINABLE_FN("toLowerCase", str_toLowerCase,   0,0, StringToLowerCase),
     JS_INLINABLE_FN("toUpperCase", str_toUpperCase,   0,0, StringToUpperCase),
     JS_INLINABLE_FN("charAt",  str_charAt,            1,0, StringCharAt),
     JS_INLINABLE_FN("charCodeAt", str_charCodeAt,     1,0, StringCharCodeAt),

--- a/js/src/jstypes.h
+++ b/js/src/jstypes.h
@@ -21,23 +21,21 @@
 #ifndef jstypes_h
 #define jstypes_h
 
 #include "mozilla/Attributes.h"
 #include "mozilla/Casting.h"
 #include "mozilla/Types.h"
 
 // jstypes.h is (or should be!) included by every file in SpiderMonkey.
-// js-config.h and jsversion.h also should be included by every file.
-// So include them here.
-// XXX: including them in js/RequiredDefines.h should be a better option, since
+// js-config.h also should be included by every file. So include it here.
+// XXX: including it in js/RequiredDefines.h should be a better option, since
 // that is by definition the header file that should be included in all
 // SpiderMonkey code.  However, Gecko doesn't do this!  See bug 909576.
 #include "js-config.h"
-#include "jsversion.h"
 
 /***********************************************************************
 ** MACROS:      JS_EXTERN_API
 **              JS_EXPORT_API
 ** DESCRIPTION:
 **      These are only for externally visible routines and globals.  For
 **      internal routines, just use "extern" for type checking and that
 **      will not export internal cross-file or forward-declared symbols.

deleted file mode 100644
--- a/js/src/jsversion.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
- * vim: set ts=8 sts=4 et sw=4 tw=99:
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#ifndef jsversion_h
-#define jsversion_h
-
-/*
- * JS Capability Macros.
- */
-#define JS_HAS_OBJ_PROTO_PROP   1       /* has o.__proto__ etc. */
-#define JS_HAS_TOSOURCE         1       /* has Object/Array toSource method */
-#define JS_HAS_UNEVAL           1       /* has uneval() top-level function */
-
-/*
- * Feature for Object.prototype.__{define,lookup}{G,S}etter__ legacy support;
- * support likely to be made opt-in at some future time.
- */
-#define JS_OLD_GETTER_SETTER_METHODS    1
-
-#endif /* jsversion_h */

--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -89,17 +89,16 @@ EXPORTS += [
     'jsalloc.h',
     'jsapi.h',
     'jsbytecode.h',
     'jsfriendapi.h',
     'jsprf.h',
     'jsprototypes.h',
     'jspubtd.h',
     'jstypes.h',
-    'jsversion.h',
     'jswrapper.h',
     'perf/jsperf.h',
 ]
 
 EXPORTS.js += [
     '../public/CallArgs.h',
     '../public/CallNonGenericMethod.h',
     '../public/CharacterEncoding.h',

--- a/js/src/vm/JSFunction.cpp
+++ b/js/src/vm/JSFunction.cpp
@@ -1116,17 +1116,16 @@ js::fun_toString(JSContext* cx, unsigned
     JSString* str = fun_toStringHelper(cx, obj, /* isToSource = */ false);
     if (!str)
         return false;
 
     args.rval().setString(str);
     return true;
 }
 
-#if JS_HAS_TOSOURCE
 static bool
 fun_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     MOZ_ASSERT(IsFunctionObject(args.calleev()));
 
     RootedObject obj(cx, ToObject(cx, args.thisv()));
     if (!obj)
@@ -1138,17 +1137,16 @@ fun_toSource(JSContext* cx, unsigned arg
     else
         str = ObjectToSource(cx, obj);
     if (!str)
         return false;
 
     args.rval().setString(str);
     return true;
 }
-#endif
 
 bool
 js::fun_call(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
 
     HandleValue func = args.thisv();
 
@@ -1645,19 +1643,17 @@ JSFunction::maybeRelazify(JSRuntime* rt)
         MOZ_ASSERT(isExtended());
         MOZ_ASSERT(getExtendedSlot(LAZY_FUNCTION_NAME_SLOT).toString()->isAtom());
     }
 
     comp->scheduleDelazificationForDebugger();
 }
 
 const JSFunctionSpec js::function_methods[] = {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str,   fun_toSource,   0,0),
-#endif
     JS_FN(js_toString_str,   fun_toString,   0,0),
     JS_FN(js_apply_str,      fun_apply,      2,0),
     JS_FN(js_call_str,       fun_call,       1,0),
     JS_SELF_HOSTED_FN("bind", "FunctionBind", 2, 0),
     JS_SYM_FN(hasInstance, fun_symbolHasInstance, 1, JSPROP_READONLY | JSPROP_PERMANENT),
     JS_FS_END
 };
 

--- a/js/src/wasm/WasmJS.cpp
+++ b/js/src/wasm/WasmJS.cpp
@@ -2116,25 +2116,23 @@ WasmGlobalObject::value() const
     return getReservedSlot(VALUE_SLOT);
 }
 
 #endif // ENABLE_WASM_GLOBAL
 
 // ============================================================================
 // WebAssembly class and static methods
 
-#if JS_HAS_TOSOURCE
 static bool
 WebAssembly_toSource(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setString(cx->names().WebAssembly);
     return true;
 }
-#endif
 
 static bool
 RejectWithPendingException(JSContext* cx, Handle<PromiseObject*> promise)
 {
     if (!cx->isExceptionPending())
         return false;
 
     RootedValue rejectionValue(cx);
@@ -2859,19 +2857,17 @@ WebAssembly_instantiateStreaming(JSConte
         return RejectWithPendingException(cx, promise, callArgs);
 
     callArgs.rval().setObject(*promise);
     return true;
 }
 
 static const JSFunctionSpec WebAssembly_static_methods[] =
 {
-#if JS_HAS_TOSOURCE
     JS_FN(js_toSource_str, WebAssembly_toSource, 0, 0),
-#endif
     JS_FN("compile", WebAssembly_compile, 1, 0),
     JS_FN("instantiate", WebAssembly_instantiate, 1, 0),
     JS_FN("validate", WebAssembly_validate, 1, 0),
     JS_FN("compileStreaming", WebAssembly_compileStreaming, 1, 0),
     JS_FN("instantiateStreaming", WebAssembly_instantiateStreaming, 1, 0),
     JS_FS_END
 };