Bug 1606568 - Add public BigInt API. r=jwalden
authorPhilip Chimento <philip.chimento@gmail.com>
Wed, 22 Jul 2020 02:53:06 +0000
changeset 541546 5bbe7e5166e7ff7eb9f7594d942d8d6b6eb691c9
parent 541545 18a0675bd755d8bad9a5825e43f94294f4375da9
child 541547 d2787ae2b2105c9f4c6a228e7409c8c854264e5b
push id37627
push userncsoregi@mozilla.com
push dateWed, 22 Jul 2020 15:50:17 +0000
treeherdermozilla-central@5e83cc94405f [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewersjwalden
bugs1606568
milestone80.0a1
first release with
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
last release without
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
Bug 1606568 - Add public BigInt API. r=jwalden Differential Revision: https://phabricator.services.mozilla.com/D82480
js/public/BigInt.h
js/src/jsapi-tests/moz.build
js/src/jsapi-tests/testBigInt.cpp
js/src/moz.build
js/src/vm/BigIntType.cpp
new file mode 100644
--- /dev/null
+++ b/js/public/BigInt.h
@@ -0,0 +1,139 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/* BigInt. */
+
+#ifndef js_BigInt_h
+#define js_BigInt_h
+
+#include "mozilla/Range.h"  // mozilla::Range
+
+#include <limits>       // std::numeric_limits
+#include <stdint.h>     // int64_t, uint64_t
+#include <type_traits>  // std::enable_if_t, std::{true,false}_type, std::is_{integral,signed,unsigned}_v
+#include <utility>      // std::declval
+
+#include "jstypes.h"        // JS_PUBLIC_API
+#include "js/RootingAPI.h"  // JS::Handle
+#include "js/Value.h"       // JS::Value
+
+struct JS_PUBLIC_API JSContext;
+
+namespace JS {
+
+class JS_PUBLIC_API BigInt;
+
+namespace detail {
+
+extern JS_PUBLIC_API BigInt* BigIntFromInt64(JSContext* cx, int64_t num);
+extern JS_PUBLIC_API BigInt* BigIntFromUint64(JSContext* cx, uint64_t num);
+extern JS_PUBLIC_API BigInt* BigIntFromBool(JSContext* cx, bool b);
+
+template <typename T, typename = void>
+struct NumberToBigIntConverter;
+
+template <typename SignedIntT>
+struct NumberToBigIntConverter<
+    SignedIntT,
+    std::enable_if_t<std::is_integral_v<SignedIntT> &&
+                     std::is_signed_v<SignedIntT> &&
+                     std::numeric_limits<SignedIntT>::digits <= 64>> {
+  static BigInt* convert(JSContext* cx, SignedIntT num) {
+    return BigIntFromInt64(cx, num);
+  }
+};
+
+template <typename UnsignedIntT>
+struct NumberToBigIntConverter<
+    UnsignedIntT,
+    std::enable_if_t<std::is_integral_v<UnsignedIntT> &&
+                     std::is_unsigned_v<UnsignedIntT> &&
+                     std::numeric_limits<UnsignedIntT>::digits <= 64>> {
+  static BigInt* convert(JSContext* cx, UnsignedIntT num) {
+    return BigIntFromUint64(cx, num);
+  }
+};
+
+template <>
+struct NumberToBigIntConverter<bool> {
+  static BigInt* convert(JSContext* cx, bool b) {
+    return BigIntFromBool(cx, b);
+  }
+};
+
+}  // namespace detail
+
+/**
+ * Create a BigInt from an integer value. All integral types not larger than 64
+ * bits in size are supported.
+ */
+template <typename NumericT>
+extern JS_PUBLIC_API BigInt* NumberToBigInt(JSContext* cx, NumericT val) {
+  return detail::NumberToBigIntConverter<NumericT>::convert(cx, val);
+}
+
+/**
+ * Create a BigInt from a floating-point value. If the number isn't integral
+ * (that is, if it's NaN, an infinity, or contains a fractional component),
+ * this function returns null and throws an exception.
+ *
+ * Passing -0.0 will produce the bigint 0n.
+ */
+extern JS_PUBLIC_API BigInt* NumberToBigInt(JSContext* cx, double num);
+
+/**
+ * Create a BigInt by parsing a string using the ECMAScript StringToBigInt
+ * algorithm (https://tc39.es/ecma262/#sec-stringtobigint). Latin1 and two-byte
+ * character ranges are supported. It may be convenient to use
+ * JS::ConstLatin1Chars or JS::ConstTwoByteChars.
+ *
+ * (StringToBigInt performs parsing similar to that performed by the |Number|
+ * global function when passed a string, but it doesn't allow infinities,
+ * decimal points, or exponential notation, and neither algorithm allows numeric
+ * separators or an 'n' suffix character. This fast-and-loose description is
+ * offered purely as a convenience to the reader: see the specification
+ * algorithm for exact behavior.)
+ *
+ * If parsing fails, this function returns null and throws an exception.
+ */
+extern JS_PUBLIC_API BigInt* StringToBigInt(
+    JSContext* cx, mozilla::Range<const Latin1Char> chars);
+
+extern JS_PUBLIC_API BigInt* StringToBigInt(
+    JSContext* cx, mozilla::Range<const char16_t> chars);
+
+/**
+ * Create a BigInt by parsing a string consisting of an optional sign character
+ * followed by one or more alphanumeric ASCII digits in the provided radix.
+ *
+ * If the radix is not in the range [2, 36], or the string fails to parse, this
+ * function returns null and throws an exception.
+ */
+extern JS_PUBLIC_API BigInt* SimpleStringToBigInt(
+    JSContext* cx, mozilla::Span<const char> chars, unsigned radix);
+
+/**
+ * Convert a JS::Value to a BigInt using the ECMAScript ToBigInt algorithm
+ * (https://tc39.es/ecma262/#sec-tobigint).
+ *
+ * (Note in particular that this will throw if passed a value whose type is
+ * 'number'. To convert a number to a BigInt, use one of the overloads of
+ * JS::NumberToBigInt().)
+ */
+extern JS_PUBLIC_API BigInt* ToBigInt(JSContext* cx, Handle<Value> val);
+
+/**
+ * Convert the given BigInt, modulo 2**64, to a signed 64-bit integer.
+ */
+extern JS_PUBLIC_API int64_t ToBigInt64(BigInt* bi);
+
+/**
+ * Convert the given BigInt, modulo 2**64, to an unsigned 64-bit integer.
+ */
+extern JS_PUBLIC_API uint64_t ToBigUint64(BigInt* bi);
+
+}  // namespace JS
+
+#endif /* js_BigInt_h */
--- a/js/src/jsapi-tests/moz.build
+++ b/js/src/jsapi-tests/moz.build
@@ -13,16 +13,17 @@ UNIFIED_SOURCES += [
     'selfTest.cpp',
     'testAddPropertyPropcache.cpp',
     'testArgumentsObject.cpp',
     'testArrayBuffer.cpp',
     'testArrayBufferView.cpp',
     'testArrayBufferWithUserOwnedContents.cpp',
     'testAtomicOperations.cpp',
     'testAtomizeUtf8NonAsciiLatin1CodePoint.cpp',
+    'testBigInt.cpp',
     'testBoundFunction.cpp',
     'testBug604087.cpp',
     'testCallArgs.cpp',
     'testCallNonGenericMethodOnProxy.cpp',
     'testChromeBuffer.cpp',
     'testCompileNonSyntactic.cpp',
     'testCompileUtf8.cpp',
     'testDateToLocaleString.cpp',
new file mode 100644
--- /dev/null
+++ b/js/src/jsapi-tests/testBigInt.cpp
@@ -0,0 +1,442 @@
+/* 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/. */
+
+#include "mozilla/Range.h"  // mozilla::Range
+#include "mozilla/Span.h"   // mozilla::MakeStringSpan
+
+#include <stdint.h>
+
+#include "jsapi.h"        // JS_IsExceptionPending, JS_StringEqualsLiteral
+#include "jsfriendapi.h"  // JSMSG_BIGINT_INVALID_SYNTAX
+
+#include "js/BigInt.h"  // JS::{,Number,String,SimpleString}ToBigInt, JS::ToBig{I,Ui}nt64
+#include "js/CharacterEncoding.h"  // JS::Const{Latin1,TwoByte}Chars
+#include "js/Conversions.h"        // JS::ToString
+#include "js/ErrorReport.h"        // JS::ErrorReportBuilder, JSEXN_SYNTAXERR
+#include "js/Exception.h"          // JS::StealPendingExceptionStack
+#include "js/RootingAPI.h"         // JS::Rooted
+#include "js/Value.h"              // JS::FalseValue, JS::Value
+
+#include "jsapi-tests/tests.h"
+#include "util/Text.h"  // js::InflateString
+
+struct JS_PUBLIC_API JSContext;
+class JS_PUBLIC_API JSString;
+
+namespace JS {
+
+class JS_PUBLIC_API BigInt;
+
+}  // namespace JS
+
+BEGIN_TEST(testToBigInt64) {
+  JS::Rooted<JS::Value> v(cx);
+
+  EVAL("0n", &v);
+  CHECK(v.isBigInt());
+  CHECK(JS::ToBigInt64(v.toBigInt()) == 0);
+
+  EVAL("9223372036854775807n", &v);
+  CHECK(v.isBigInt());
+  CHECK(JS::ToBigInt64(v.toBigInt()) == 9223372036854775807L);
+
+  EVAL("-9223372036854775808n", &v);
+  CHECK(v.isBigInt());
+  CHECK(JS::ToBigInt64(v.toBigInt()) == -9223372036854775807L - 1L);
+
+  return true;
+}
+END_TEST(testToBigInt64)
+
+BEGIN_TEST(testToBigUint64) {
+  JS::Rooted<JS::Value> v(cx);
+
+  EVAL("0n", &v);
+  CHECK(v.isBigInt());
+  CHECK(JS::ToBigUint64(v.toBigInt()) == 0);
+
+  EVAL("18446744073709551615n", &v);
+  CHECK(v.isBigInt());
+  CHECK(JS::ToBigUint64(v.toBigInt()) == 18446744073709551615UL);
+
+  return true;
+}
+END_TEST(testToBigUint64)
+
+#define GENERATE_INTTYPE_TEST(bits)             \
+  BEGIN_TEST(testNumberToBigInt_Int##bits) {    \
+    int##bits##_t i = INT##bits##_MIN;          \
+    JS::BigInt* bi = JS::NumberToBigInt(cx, i); \
+    CHECK(bi);                                  \
+    CHECK(JS::ToBigInt64(bi) == i);             \
+                                                \
+    i = INT##bits##_MAX;                        \
+    bi = JS::NumberToBigInt(cx, i);             \
+    CHECK(bi);                                  \
+    CHECK(JS::ToBigInt64(bi) == i);             \
+                                                \
+    uint##bits##_t u = 0;                       \
+    bi = JS::NumberToBigInt(cx, u);             \
+    CHECK(bi);                                  \
+    CHECK(JS::ToBigUint64(bi) == 0);            \
+                                                \
+    u = UINT##bits##_MAX;                       \
+    bi = JS::NumberToBigInt(cx, u);             \
+    CHECK(bi);                                  \
+    CHECK(JS::ToBigUint64(bi) == u);            \
+                                                \
+    return true;                                \
+  }                                             \
+  END_TEST(testNumberToBigInt_Int##bits)
+
+GENERATE_INTTYPE_TEST(8);
+GENERATE_INTTYPE_TEST(16);
+GENERATE_INTTYPE_TEST(32);
+GENERATE_INTTYPE_TEST(64);
+
+#undef GENERATE_INTTYPE_TEST
+
+#define GENERATE_SIGNED_VALUE_TEST(type, tag, val) \
+  BEGIN_TEST(testNumberToBigInt_##type##_##tag) {  \
+    type v = val;                                  \
+    JS::BigInt* bi = JS::NumberToBigInt(cx, v);    \
+    CHECK(bi);                                     \
+    CHECK(JS::ToBigInt64(bi) == (val));            \
+    return true;                                   \
+  }                                                \
+  END_TEST(testNumberToBigInt_##type##_##tag)
+
+#define GENERATE_UNSIGNED_VALUE_TEST(type, tag, val) \
+  BEGIN_TEST(testNumberToBigInt_##type##_##tag) {    \
+    type v = val;                                    \
+    JS::BigInt* bi = JS::NumberToBigInt(cx, v);      \
+    CHECK(bi);                                       \
+    CHECK(JS::ToBigUint64(bi) == (val));             \
+    return true;                                     \
+  }                                                  \
+  END_TEST(testNumberToBigInt_##type##_##tag)
+
+GENERATE_SIGNED_VALUE_TEST(int, zero, 0);
+GENERATE_SIGNED_VALUE_TEST(int, aValue, -42);
+GENERATE_UNSIGNED_VALUE_TEST(unsigned, zero, 0);
+GENERATE_UNSIGNED_VALUE_TEST(unsigned, aValue, 42);
+GENERATE_SIGNED_VALUE_TEST(long, zero, 0);
+GENERATE_SIGNED_VALUE_TEST(long, aValue, -42);
+GENERATE_UNSIGNED_VALUE_TEST(uintptr_t, zero, 0);
+GENERATE_UNSIGNED_VALUE_TEST(uintptr_t, aValue, 42);
+GENERATE_UNSIGNED_VALUE_TEST(size_t, zero, 0);
+GENERATE_UNSIGNED_VALUE_TEST(size_t, aValue, 42);
+GENERATE_SIGNED_VALUE_TEST(double, zero, 0);
+GENERATE_SIGNED_VALUE_TEST(double, aValue, -42);
+
+#undef GENERATE_SIGNED_VALUE_TEST
+#undef GENERATE_UNSIGNED_VALUE_TEST
+
+BEGIN_TEST(testNumberToBigInt_bool) {
+  JS::BigInt* bi = JS::NumberToBigInt(cx, true);
+  CHECK(bi);
+  CHECK(JS::ToBigUint64(bi) == 1);
+
+  bi = JS::NumberToBigInt(cx, false);
+  CHECK(bi);
+  CHECK(JS::ToBigUint64(bi) == 0);
+
+  return true;
+}
+END_TEST(testNumberToBigInt_bool)
+
+BEGIN_TEST(testNumberToBigInt_NonIntegerValueFails) {
+  JS::BigInt* bi = JS::NumberToBigInt(cx, 3.1416);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+  JS_ClearPendingException(cx);
+  return true;
+}
+END_TEST(testNumberToBigInt_NonIntegerValueFails)
+
+BEGIN_TEST(testStringToBigInt_FromTwoByteStringSpan) {
+  mozilla::Range<const char16_t> input{
+      mozilla::MakeStringSpan(u"18446744073709551616")};
+  JS::BigInt* bi = JS::StringToBigInt(cx, input);
+  CHECK(bi);
+  JS::Rooted<JS::Value> val(cx, JS::BigIntValue(bi));
+  JS::Rooted<JSString*> str(cx, JS::ToString(cx, val));
+  CHECK(str);
+  bool match;
+  CHECK(JS_StringEqualsLiteral(cx, str, "18446744073709551616", &match));
+  CHECK(match);
+  return true;
+}
+END_TEST(testStringToBigInt_FromTwoByteStringSpan)
+
+BEGIN_TEST(testStringToBigInt_FromLatin1Range) {
+  const JS::Latin1Char string[] = "12345 and some junk at the end";
+  JS::ConstLatin1Chars range(string, 5);
+  JS::BigInt* bi = JS::StringToBigInt(cx, range);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == 12345);
+  return true;
+}
+END_TEST(testStringToBigInt_FromLatin1Range)
+
+BEGIN_TEST(testStringToBigInt_FromTwoByteRange) {
+  const char16_t string[] = u"12345 and some junk at the end";
+  JS::ConstTwoByteChars range(string, 5);
+  JS::BigInt* bi = JS::StringToBigInt(cx, range);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == 12345);
+  return true;
+}
+END_TEST(testStringToBigInt_FromTwoByteRange)
+
+BEGIN_TEST(testStringToBigInt_AcceptedInput) {
+  CHECK(Allowed(u"", 0));
+  CHECK(Allowed(u"\n", 0));
+  CHECK(Allowed(u" ", 0));
+  CHECK(Allowed(u"0\n", 0));
+  CHECK(Allowed(u"0 ", 0));
+  CHECK(Allowed(u"\n1", 1));
+  CHECK(Allowed(u" 1", 1));
+  CHECK(Allowed(u"\n2 ", 2));
+  CHECK(Allowed(u" 2\n", 2));
+  CHECK(Allowed(u"0b11", 3));
+  CHECK(Allowed(u"0x17", 23));
+  CHECK(Allowed(u"-5", -5));
+  CHECK(Allowed(u"+5", 5));
+  CHECK(Allowed(u"-0", 0));
+
+  CHECK(Fails(u"!!!!!!111one1111one1!1!1!!"));
+  CHECK(Fails(u"3.1416"));
+  CHECK(Fails(u"6.022e23"));
+  CHECK(Fails(u"1e3"));
+  CHECK(Fails(u".25"));
+  CHECK(Fails(u".25e2"));
+  CHECK(Fails(u"1_000_000"));
+  CHECK(Fails(u"3n"));
+  CHECK(Fails(u"-0x3"));
+  CHECK(Fails(u"Infinity"));
+
+  return true;
+}
+
+template <size_t N>
+inline bool Allowed(const char16_t (&str)[N], int64_t expected) {
+  JS::BigInt* bi = JS::StringToBigInt(cx, mozilla::MakeStringSpan(str));
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == expected);
+  return true;
+}
+
+template <size_t N>
+inline bool Fails(const char16_t (&str)[N]) {
+  JS::BigInt* bi = JS::StringToBigInt(cx, mozilla::MakeStringSpan(str));
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+
+  JS::ExceptionStack exnStack(cx);
+  CHECK(JS::StealPendingExceptionStack(cx, &exnStack));
+
+  JS::ErrorReportBuilder report(cx);
+  CHECK(report.init(cx, exnStack, JS::ErrorReportBuilder::NoSideEffects));
+  CHECK(report.report()->exnType == JSEXN_SYNTAXERR);
+  CHECK(report.report()->errorNumber == JSMSG_BIGINT_INVALID_SYNTAX);
+
+  CHECK(!JS_IsExceptionPending(cx));
+
+  return true;
+}
+END_TEST(testStringToBigInt_AcceptedInput)
+
+BEGIN_TEST(testSimpleStringToBigInt_AcceptedInput) {
+  CHECK(Allowed("12345", 10, 12345));
+  CHECK(Allowed("+12345", 10, 12345));
+  CHECK(Allowed("-12345", 10, -12345));
+  CHECK(Allowed("775", 8, 0775));
+  CHECK(Allowed("+775", 8, 0775));
+  CHECK(Allowed("-775", 8, -0775));
+  CHECK(Allowed("cAfE", 16, 0xCAFE));
+  CHECK(Allowed("+cAfE", 16, +0xCAFE));
+  CHECK(Allowed("-cAfE", 16, -0xCAFE));
+  CHECK(Allowed("-0", 10, 0));
+
+  CHECK(Fails("", 10));
+  CHECK(Fails("\n", 10));
+  CHECK(Fails(" ", 10));
+  CHECK(Fails("0\n", 10));
+  CHECK(Fails("0 ", 10));
+  CHECK(Fails("\n1", 10));
+  CHECK(Fails(" 1", 10));
+  CHECK(Fails("\n2 ", 10));
+  CHECK(Fails(" 2\n", 10));
+  CHECK(Fails("0b11", 2));
+  CHECK(Fails("0x17", 16));
+  CHECK(Fails("!!!!!!111one1111one1!1!1!!", 10));
+  CHECK(Fails("3.1416", 10));
+  CHECK(Fails("6.022e23", 10));
+  CHECK(Fails("1e3", 10));
+  CHECK(Fails(".25", 10));
+  CHECK(Fails(".25e2", 10));
+  CHECK(Fails("1_000_000", 10));
+  CHECK(Fails("3n", 10));
+  CHECK(Fails("-0x3", 10));
+  CHECK(Fails("Infinity", 10));
+  CHECK(Fails("555", 4));
+  CHECK(Fails("fff", 15));
+
+  return true;
+}
+
+template <size_t N>
+inline bool Allowed(const char (&str)[N], unsigned radix, int64_t expected) {
+  JS::BigInt* bi = JS::SimpleStringToBigInt(cx, {str, N - 1}, radix);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == expected);
+  return true;
+}
+
+template <size_t N>
+inline bool Fails(const char (&str)[N], unsigned radix) {
+  JS::BigInt* bi = JS::SimpleStringToBigInt(cx, {str, N - 1}, radix);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+
+  JS::ExceptionStack exnStack(cx);
+  CHECK(JS::StealPendingExceptionStack(cx, &exnStack));
+
+  JS::ErrorReportBuilder report(cx);
+  CHECK(report.init(cx, exnStack, JS::ErrorReportBuilder::NoSideEffects));
+  CHECK(report.report()->exnType == JSEXN_SYNTAXERR);
+  CHECK(report.report()->errorNumber == JSMSG_BIGINT_INVALID_SYNTAX);
+
+  CHECK(!JS_IsExceptionPending(cx));
+
+  return true;
+}
+END_TEST(testSimpleStringToBigInt_AcceptedInput)
+
+BEGIN_TEST(testSimpleStringToBigInt_AllPossibleDigits) {
+  const char allPossible[] =
+      "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
+  JS::BigInt* bi =
+      JS::SimpleStringToBigInt(cx, mozilla::MakeStringSpan(allPossible), 36);
+  CHECK(bi);
+  JS::Rooted<JS::Value> val(cx, JS::BigIntValue(bi));
+  JS::Rooted<JSString*> str(cx, JS::ToString(cx, val));
+  CHECK(str);
+
+  // Answer calculated using Python:
+  // int('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890', 36)
+  // Do not trust online base-36 calculators for values > UINT32_MAX!
+  bool match;
+  CHECK(
+      JS_StringEqualsLiteral(cx, str,
+                             "8870050151210747660007771095260505028056221996735"
+                             "67534007158336222790086855213834764150805438340",
+                             &match));
+  CHECK(match);
+  return true;
+}
+END_TEST(testSimpleStringToBigInt_AllPossibleDigits)
+
+BEGIN_TEST(testSimpleStringToBigInt_RadixOutOfRange) {
+  CHECK(RadixOutOfRange(1));
+  CHECK(RadixOutOfRange(37));
+  return true;
+}
+
+inline bool RadixOutOfRange(unsigned radix) {
+  JS::BigInt* bi =
+      JS::SimpleStringToBigInt(cx, mozilla::MakeStringSpan("1"), radix);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+
+  JS::ExceptionStack exnStack(cx);
+  CHECK(JS::StealPendingExceptionStack(cx, &exnStack));
+
+  JS::ErrorReportBuilder report(cx);
+  CHECK(report.init(cx, exnStack, JS::ErrorReportBuilder::NoSideEffects));
+  CHECK(report.report()->exnType == JSEXN_RANGEERR);
+  CHECK(report.report()->errorNumber == JSMSG_BAD_RADIX);
+
+  CHECK(!JS_IsExceptionPending(cx));
+
+  return true;
+}
+END_TEST(testSimpleStringToBigInt_RadixOutOfRange)
+
+BEGIN_TEST(testToBigInt_Undefined) {
+  JS::Rooted<JS::Value> v(cx, JS::UndefinedValue());
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+  JS_ClearPendingException(cx);
+  return true;
+}
+END_TEST(testToBigInt_Undefined)
+
+BEGIN_TEST(testToBigInt_Null) {
+  JS::Rooted<JS::Value> v(cx, JS::NullValue());
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+  JS_ClearPendingException(cx);
+  return true;
+}
+END_TEST(testToBigInt_Null)
+
+BEGIN_TEST(testToBigInt_Boolean) {
+  JS::Rooted<JS::Value> v(cx, JS::TrueValue());
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == 1);
+
+  v = JS::FalseValue();
+  bi = JS::ToBigInt(cx, v);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == 0);
+
+  return true;
+}
+END_TEST(testToBigInt_Boolean)
+
+BEGIN_TEST(testToBigInt_BigInt) {
+  JS::Rooted<JS::Value> v(cx);
+  EVAL("42n", &v);
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == 42);
+  return true;
+}
+END_TEST(testToBigInt_BigInt)
+
+BEGIN_TEST(testToBigInt_Number) {
+  JS::Rooted<JS::Value> v(cx, JS::Int32Value(42));
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+  JS_ClearPendingException(cx);
+  return true;
+}
+END_TEST(testToBigInt_Number)
+
+BEGIN_TEST(testToBigInt_String) {
+  JS::Rooted<JS::Value> v(cx);
+  EVAL("'42'", &v);
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK(bi);
+  CHECK(JS::ToBigInt64(bi) == 42);
+  return true;
+}
+END_TEST(testToBigInt_String)
+
+BEGIN_TEST(testToBigInt_Symbol) {
+  JS::Rooted<JS::Value> v(cx);
+  EVAL("Symbol.toStringTag", &v);
+  JS::BigInt* bi = JS::ToBigInt(cx, v);
+  CHECK_NULL(bi);
+  CHECK(JS_IsExceptionPending(cx));
+  JS_ClearPendingException(cx);
+  return true;
+}
+END_TEST(testToBigInt_Symbol)
--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -121,16 +121,17 @@ EXPORTS += [
 ]
 
 EXPORTS.js += [
     '../public/AllocationRecording.h',
     '../public/AllocPolicy.h',
     '../public/Array.h',
     '../public/ArrayBuffer.h',
     '../public/ArrayBufferMaybeShared.h',
+    '../public/BigInt.h',
     '../public/BuildId.h',
     '../public/CallArgs.h',
     '../public/CallNonGenericMethod.h',
     '../public/CharacterEncoding.h',
     '../public/Class.h',
     '../public/ComparisonOperators.h',
     '../public/CompilationAndEvaluation.h',
     '../public/CompileOptions.h',
--- a/js/src/vm/BigIntType.cpp
+++ b/js/src/vm/BigIntType.cpp
@@ -81,29 +81,31 @@
 #include "mozilla/Casting.h"
 #include "mozilla/FloatingPoint.h"
 #include "mozilla/HashFunctions.h"
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/MemoryChecking.h"
 #include "mozilla/Range.h"
 #include "mozilla/RangedPtr.h"
+#include "mozilla/Span.h"  // mozilla::Span
 #include "mozilla/WrappingOperations.h"
 
 #include <functional>
 #include <limits>
 #include <math.h>
 #include <memory>
 #include <type_traits>  // std::is_same_v
 
 #include "jsapi.h"
 #include "jsnum.h"
 
 #include "builtin/BigInt.h"
 #include "gc/Allocator.h"
+#include "js/BigInt.h"
 #include "js/Conversions.h"
 #include "js/Initialization.h"
 #include "js/StableStringChars.h"
 #include "js/Utility.h"
 #include "util/CheckedArithmetic.h"
 #include "vm/JSContext.h"
 #include "vm/SelfHosting.h"
 
@@ -2958,25 +2960,25 @@ BigInt* js::ToBigInt(JSContext* cx, Hand
   }
 
   ReportValueError(cx, JSMSG_CANT_CONVERT_TO, JSDVG_IGNORE_STACK, v, nullptr,
                    "BigInt");
   return nullptr;
 }
 
 JS::Result<int64_t> js::ToBigInt64(JSContext* cx, HandleValue v) {
-  BigInt* bi = ToBigInt(cx, v);
+  BigInt* bi = js::ToBigInt(cx, v);
   if (!bi) {
     return cx->alreadyReportedError();
   }
   return BigInt::toInt64(bi);
 }
 
 JS::Result<uint64_t> js::ToBigUint64(JSContext* cx, HandleValue v) {
-  BigInt* bi = ToBigInt(cx, v);
+  BigInt* bi = js::ToBigInt(cx, v);
   if (!bi) {
     return cx->alreadyReportedError();
   }
   return BigInt::toUint64(bi);
 }
 
 double BigInt::numberValue(BigInt* x) {
   if (x->isZero()) {
@@ -3720,8 +3722,107 @@ XDRResult js::XDRBigInt(XDRState<mode>* 
   return Ok();
 }
 
 template XDRResult js::XDRBigInt(XDRState<XDR_ENCODE>* xdr,
                                  MutableHandleBigInt bi);
 
 template XDRResult js::XDRBigInt(XDRState<XDR_DECODE>* xdr,
                                  MutableHandleBigInt bi);
+
+// Public API
+
+BigInt* JS::NumberToBigInt(JSContext* cx, double num) {
+  return js::NumberToBigInt(cx, num);
+}
+
+template <typename CharT>
+static inline BigInt* StringToBigIntHelper(JSContext* cx,
+                                           Range<const CharT>& chars) {
+  bool parseError = false;
+  BigInt* bi = ParseStringBigIntLiteral(cx, chars, &parseError);
+  if (!bi) {
+    if (parseError) {
+      JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                                JSMSG_BIGINT_INVALID_SYNTAX);
+    }
+    return nullptr;
+  }
+  MOZ_RELEASE_ASSERT(!parseError);
+  return bi;
+}
+
+BigInt* JS::StringToBigInt(JSContext* cx, Range<const Latin1Char> chars) {
+  return StringToBigIntHelper(cx, chars);
+}
+
+BigInt* JS::StringToBigInt(JSContext* cx, Range<const char16_t> chars) {
+  return StringToBigIntHelper(cx, chars);
+}
+
+static inline BigInt* SimpleStringToBigIntHelper(
+    JSContext* cx, mozilla::Span<const Latin1Char> chars, unsigned radix,
+    bool* haveParseError) {
+  if (chars.Length() > 1) {
+    if (chars[0] == '+') {
+      return BigInt::parseLiteralDigits(
+          cx, Range<const Latin1Char>{chars.From(1)}, radix,
+          /* isNegative = */ false, haveParseError);
+    }
+    if (chars[0] == '-') {
+      return BigInt::parseLiteralDigits(
+          cx, Range<const Latin1Char>{chars.From(1)}, radix,
+          /* isNegative = */ true, haveParseError);
+    }
+  }
+
+  return BigInt::parseLiteralDigits(cx, Range<const Latin1Char>{chars}, radix,
+                                    /* isNegative = */ false, haveParseError);
+}
+
+BigInt* JS::SimpleStringToBigInt(JSContext* cx, mozilla::Span<const char> chars,
+                                 unsigned radix) {
+  if (chars.empty()) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                              JSMSG_BIGINT_INVALID_SYNTAX);
+    return nullptr;
+  }
+  if (radix < 2 || radix > 36) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_RADIX);
+    return nullptr;
+  }
+
+  mozilla::Span<const Latin1Char> latin1{
+      reinterpret_cast<const Latin1Char*>(chars.data()), chars.size()};
+  bool haveParseError = false;
+  BigInt* bi = SimpleStringToBigIntHelper(cx, latin1, radix, &haveParseError);
+  if (!bi) {
+    if (haveParseError) {
+      JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                                JSMSG_BIGINT_INVALID_SYNTAX);
+    }
+    return nullptr;
+  }
+  MOZ_RELEASE_ASSERT(!haveParseError);
+  return bi;
+}
+
+BigInt* JS::ToBigInt(JSContext* cx, HandleValue val) {
+  return js::ToBigInt(cx, val);
+}
+
+int64_t JS::ToBigInt64(JS::BigInt* bi) { return BigInt::toInt64(bi); }
+
+uint64_t JS::ToBigUint64(JS::BigInt* bi) { return BigInt::toUint64(bi); }
+
+// Semi-public template details
+
+BigInt* JS::detail::BigIntFromInt64(JSContext* cx, int64_t num) {
+  return BigInt::createFromInt64(cx, num);
+}
+
+BigInt* JS::detail::BigIntFromUint64(JSContext* cx, uint64_t num) {
+  return BigInt::createFromUint64(cx, num);
+}
+
+BigInt* JS::detail::BigIntFromBool(JSContext* cx, bool b) {
+  return b ? BigInt::one(cx) : BigInt::zero(cx);
+}