Bug 1606568 - Add public BigInt API. r=jwalden

Differential Revision: https://phabricator.services.mozilla.com/D82480

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 */

js/src/jsapi-tests/moz.build

@@ -18,6 +18,7 @@ UNIFIED_SOURCES += [
     'testArrayBufferWithUserOwnedContents.cpp',
     'testAtomicOperations.cpp',
     'testAtomizeUtf8NonAsciiLatin1CodePoint.cpp',
+    'testBigInt.cpp',
     'testBoundFunction.cpp',
     'testBug604087.cpp',
     'testCallArgs.cpp',

js/src/jsapi-tests/testBigInt.cpp

@@ -0,0 +1,441 @@
+/* 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 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)

js/src/moz.build

@@ -126,6 +126,7 @@ EXPORTS.js += [
     '../public/Array.h',
     '../public/ArrayBuffer.h',
     '../public/ArrayBufferMaybeShared.h',
+    '../public/BigInt.h',
     '../public/BuildId.h',
     '../public/CallArgs.h',
     '../public/CallNonGenericMethod.h',

js/src/vm/BigIntType.cpp

@@ -86,6 +86,7 @@
 #include "mozilla/MemoryChecking.h"
 #include "mozilla/Range.h"
 #include "mozilla/RangedPtr.h"
+#include "mozilla/Span.h"  // mozilla::Span
 #include "mozilla/WrappingOperations.h"
 
 #include <functional>
@@ -99,6 +100,7 @@
 
 #include "builtin/BigInt.h"
 #include "gc/Allocator.h"
+#include "js/BigInt.h"
 #include "js/Conversions.h"
 #include "js/Initialization.h"
 #include "js/StableStringChars.h"
@@ -2963,7 +2965,7 @@ BigInt* js::ToBigInt(JSContext* cx, HandleValue val) {
 }
 
 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();
   }
@@ -2971,7 +2973,7 @@ JS::Result<int64_t> js::ToBigInt64(JSContext* cx, HandleValue v) {
 }
 
 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();
   }
@@ -3725,3 +3727,95 @@ template XDRResult js::XDRBigInt(XDRState<XDR_ENCODE>* xdr,
 
 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;
+  BigInt* bi = ParseStringBigIntLiteral(cx, chars, &parseError);
+  if (parseError) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                              JSMSG_BIGINT_INVALID_SYNTAX);
+  }
+  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 (haveParseError) {
+    JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
+                              JSMSG_BIGINT_INVALID_SYNTAX);
+  }
+
+  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);
+}