tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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Boolean.cpp (4923B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * vim: set ts=8 sts=2 et sw=2 tw=80:
      3 * This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 /*
      8 * JS boolean implementation.
      9 */
     10 
     11 #include "builtin/Boolean-inl.h"
     12 
     13 #include "jstypes.h"
     14 
     15 #include "jit/InlinableNatives.h"
     16 #include "js/PropertySpec.h"
     17 #include "util/StringBuilder.h"
     18 #include "vm/BigIntType.h"
     19 #include "vm/GlobalObject.h"
     20 #include "vm/JSContext.h"
     21 #include "vm/JSObject.h"
     22 
     23 #include "vm/BooleanObject-inl.h"
     24 
     25 using namespace js;
     26 
     27 const JSClass BooleanObject::class_ = {
     28    "Boolean",
     29    JSCLASS_HAS_RESERVED_SLOTS(1) | JSCLASS_HAS_CACHED_PROTO(JSProto_Boolean),
     30    JS_NULL_CLASS_OPS,
     31    &BooleanObject::classSpec_,
     32 };
     33 
     34 MOZ_ALWAYS_INLINE bool IsBoolean(HandleValue v) {
     35  return v.isBoolean() || (v.isObject() && v.toObject().is<BooleanObject>());
     36 }
     37 
     38 // ES2020 draft rev ecb4178012d6b4d9abc13fcbd45f5c6394b832ce
     39 // 19.4.3 Properties of the Boolean Prototype Object,  thisBooleanValue.
     40 static MOZ_ALWAYS_INLINE bool ThisBooleanValue(HandleValue val) {
     41  // Step 3, the error case, is handled by CallNonGenericMethod.
     42  MOZ_ASSERT(IsBoolean(val));
     43 
     44  // Step 1.
     45  if (val.isBoolean()) {
     46    return val.toBoolean();
     47  }
     48 
     49  // Step 2.
     50  return val.toObject().as<BooleanObject>().unbox();
     51 }
     52 
     53 MOZ_ALWAYS_INLINE bool bool_toSource_impl(JSContext* cx, const CallArgs& args) {
     54  bool b = ThisBooleanValue(args.thisv());
     55 
     56  JSStringBuilder sb(cx);
     57  if (!sb.append("(new Boolean(") || !BooleanToStringBuilder(b, sb) ||
     58      !sb.append("))")) {
     59    return false;
     60  }
     61 
     62  JSString* str = sb.finishString();
     63  if (!str) {
     64    return false;
     65  }
     66  args.rval().setString(str);
     67  return true;
     68 }
     69 
     70 static bool bool_toSource(JSContext* cx, unsigned argc, Value* vp) {
     71  CallArgs args = CallArgsFromVp(argc, vp);
     72  return CallNonGenericMethod<IsBoolean, bool_toSource_impl>(cx, args);
     73 }
     74 
     75 // ES2020 draft rev ecb4178012d6b4d9abc13fcbd45f5c6394b832ce
     76 // 19.3.3.2 Boolean.prototype.toString ( )
     77 MOZ_ALWAYS_INLINE bool bool_toString_impl(JSContext* cx, const CallArgs& args) {
     78  // Step 1.
     79  bool b = ThisBooleanValue(args.thisv());
     80 
     81  // Step 2.
     82  args.rval().setString(BooleanToString(cx, b));
     83  return true;
     84 }
     85 
     86 static bool bool_toString(JSContext* cx, unsigned argc, Value* vp) {
     87  CallArgs args = CallArgsFromVp(argc, vp);
     88  return CallNonGenericMethod<IsBoolean, bool_toString_impl>(cx, args);
     89 }
     90 
     91 // ES2020 draft rev ecb4178012d6b4d9abc13fcbd45f5c6394b832ce
     92 // 19.3.3.3 Boolean.prototype.valueOf ( )
     93 MOZ_ALWAYS_INLINE bool bool_valueOf_impl(JSContext* cx, const CallArgs& args) {
     94  // Step 1.
     95  args.rval().setBoolean(ThisBooleanValue(args.thisv()));
     96  return true;
     97 }
     98 
     99 static bool bool_valueOf(JSContext* cx, unsigned argc, Value* vp) {
    100  CallArgs args = CallArgsFromVp(argc, vp);
    101  return CallNonGenericMethod<IsBoolean, bool_valueOf_impl>(cx, args);
    102 }
    103 
    104 static const JSFunctionSpec boolean_methods[] = {
    105    JS_FN("toSource", bool_toSource, 0, 0),
    106    JS_FN("toString", bool_toString, 0, 0),
    107    JS_FN("valueOf", bool_valueOf, 0, 0),
    108    JS_FS_END,
    109 };
    110 
    111 // ES2020 draft rev ecb4178012d6b4d9abc13fcbd45f5c6394b832ce
    112 // 19.3.1.1 Boolean ( value )
    113 static bool Boolean(JSContext* cx, unsigned argc, Value* vp) {
    114  CallArgs args = CallArgsFromVp(argc, vp);
    115 
    116  // Step 1.
    117  bool b = args.length() != 0 ? JS::ToBoolean(args[0]) : false;
    118 
    119  if (args.isConstructing()) {
    120    // Steps 3-4.
    121    RootedObject proto(cx);
    122    if (!GetPrototypeFromBuiltinConstructor(cx, args, JSProto_Boolean,
    123                                            &proto)) {
    124      return false;
    125    }
    126 
    127    JSObject* obj = BooleanObject::create(cx, b, proto);
    128    if (!obj) {
    129      return false;
    130    }
    131 
    132    // Step 5.
    133    args.rval().setObject(*obj);
    134  } else {
    135    // Step 2.
    136    args.rval().setBoolean(b);
    137  }
    138  return true;
    139 }
    140 
    141 JSObject* BooleanObject::createPrototype(JSContext* cx, JSProtoKey key) {
    142  BooleanObject* booleanProto =
    143      GlobalObject::createBlankPrototype<BooleanObject>(cx, cx->global());
    144  if (!booleanProto) {
    145    return nullptr;
    146  }
    147  booleanProto->setFixedSlot(BooleanObject::PRIMITIVE_VALUE_SLOT,
    148                             BooleanValue(false));
    149  return booleanProto;
    150 }
    151 
    152 const ClassSpec BooleanObject::classSpec_ = {
    153    GenericCreateConstructor<Boolean, 1, gc::AllocKind::FUNCTION,
    154                             &jit::JitInfo_Boolean>,
    155    BooleanObject::createPrototype,
    156    nullptr,
    157    nullptr,
    158    boolean_methods,
    159    nullptr,
    160 };
    161 
    162 PropertyName* js::BooleanToString(JSContext* cx, bool b) {
    163  return b ? cx->names().true_ : cx->names().false_;
    164 }
    165 
    166 JS_PUBLIC_API bool js::ToBooleanSlow(HandleValue v) {
    167  if (v.isString()) {
    168    return v.toString()->length() != 0;
    169  }
    170  if (v.isBigInt()) {
    171    return !v.toBigInt()->isZero();
    172  }
    173 
    174  MOZ_ASSERT(v.isObject());
    175  return !EmulatesUndefined(&v.toObject());
    176 }