[MERGE #5788 @duongnhn] BigInt: reallocate space, digit_t, increment, decrement

Merge pull request #5788 from duongnhn:user/duongn/bigint_size_t

In this PR, we implement
- reallocate space for BigInt if necessary -> make it arbitrarily-precision.
- make use of configuration with digit_t
- implement increment/decrement operators
- native tests for methods in Javascript BigInt class

I defer "assign along with inc/dec" `y=x++` and `y=++x` to a future PR

Author: duongnhn

bin/ChakraCore/TestHooks.cpp

@@ -19,6 +19,13 @@ int LogicalStringCompareImpl(const char16* p1, int p1size, const char16* p2, int
 }
 }
 
+namespace Js
+{
+    static digit_t AddDigit(digit_t a, digit_t b, digit_t * carry);
+    static digit_t SubtractDigit(digit_t a, digit_t b, digit_t * borrow);
+    static digit_t MulDigit(digit_t a, digit_t b, digit_t * high);
+}
+
 #ifdef ENABLE_TEST_HOOKS
 
 HRESULT __stdcall SetConfigFlags(__in int argc, __in_ecount(argc) LPWSTR argv[], ICustomConfigFlags* customConfigFlags)
@@ -168,6 +175,11 @@ HRESULT OnChakraCoreLoaded(OnChakraCoreLoadedPtr pfChakraCoreLoaded)
         SetEnableCheckMemoryLeakOutput,
         PlatformAgnostic::UnicodeText::Internal::LogicalStringCompareImpl,
 
+        //BigInt hooks
+        Js::JavascriptBigInt::AddDigit,
+        Js::JavascriptBigInt::SubDigit,
+        Js::JavascriptBigInt::MulDigit,
+
 #define FLAG(type, name, description, defaultValue, ...) FLAG_##type##(name)
 #define FLAGINCLUDE(name) \
     IsEnabled##name##Flag, \

bin/ChakraCore/TestHooks.h

@@ -31,6 +31,14 @@ struct TestHooks
     SetEnableCheckMemoryLeakOutputPtr pfSetEnableCheckMemoryLeakOutput;
     LogicalStringCompareImpl pfLogicalCompareStringImpl;
 
+    // Javasscript Bigint hooks
+    typedef digit_t(TESTHOOK_CALL *AddDigit)(digit_t a, digit_t b, digit_t* carry);
+    typedef digit_t(TESTHOOK_CALL *SubDigit)(digit_t a, digit_t b, digit_t* borrow);
+    typedef digit_t(TESTHOOK_CALL *MulDigit)(digit_t a, digit_t b, digit_t* high);
+    AddDigit pfAddDigit;
+    SubDigit pfSubDigit;
+    MulDigit pfMulDigit;
+
 #define FLAG(type, name, description, defaultValue, ...) FLAG_##type##(name)
 #define FLAG_String(name) \
     bool (TESTHOOK_CALL *pfIsEnabled##name##Flag)(); \

bin/NativeTests/JavascriptBigIntTests.cpp

@@ -0,0 +1,84 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+#include "stdafx.h"
+#pragma warning(disable:26434) // Function definition hides non-virtual function in base class
+#pragma warning(disable:26439) // Implicit noexcept
+#pragma warning(disable:26451) // Arithmetic overflow
+#pragma warning(disable:26495) // Uninitialized member variable
+#include "catch.hpp"
+
+#pragma warning(disable:4100) // unreferenced formal parameter
+#pragma warning(disable:6387) // suppressing preFAST which raises warning for passing null to the JsRT APIs
+#pragma warning(disable:6262) // CATCH is using stack variables to report errors, suppressing the preFAST warning.
+
+namespace JavascriptBigIntTests
+{
+    void Test_AddDigit(digit_t digit1, digit_t digit2, digit_t * carry, digit_t expectedResult, digit_t expectedCarry)
+    {
+        REQUIRE(g_testHooksLoaded);
+
+        digit_t res = g_testHooks.pfAddDigit(digit1, digit2, carry);
+
+        //test to check that the result from call to AddDigit is the expected value
+        REQUIRE(res == expectedResult);
+        REQUIRE(expectedCarry == *carry);
+    }
+
+    void Test_SubDigit(digit_t digit1, digit_t digit2, digit_t * borrow, digit_t expectedResult, digit_t expectedBorrow)
+    {
+        REQUIRE(g_testHooksLoaded);
+
+        digit_t res = g_testHooks.pfSubDigit(digit1, digit2, borrow);
+
+        //test to check that the result from call to SubtractDigit is the expected value
+        REQUIRE(res == expectedResult);
+        REQUIRE(*borrow == expectedBorrow);
+    }
+
+    void Test_MulDigit(digit_t digit1, digit_t digit2, digit_t * high, digit_t expectedResult, digit_t expectedHigh)
+    {
+        REQUIRE(g_testHooksLoaded);
+
+        digit_t res = g_testHooks.pfMulDigit(digit1, digit2, high);
+
+        //test to check that the result from call to SubtractDigit is the expected value
+        REQUIRE(res == expectedResult);
+        REQUIRE(*high == expectedHigh);
+    }
+
+    TEST_CASE("AddDigit", "[JavascriptBigIntTests]")
+    {
+        digit_t carry = 0;
+        Test_AddDigit(1, 2, &carry, 3, 0);
+
+        digit_t d1 = UINTPTR_MAX;
+        digit_t d2 = UINTPTR_MAX;
+        carry = 0;
+        Test_AddDigit(d1, d2, &carry, UINTPTR_MAX-1, 1);
+    }
+
+    TEST_CASE("SubDigit", "[JavascriptBigIntTests]")
+    {
+        digit_t borrow = 0;
+        Test_SubDigit(3, 2, &borrow, 1, 0);
+
+        digit_t d1 = 0;
+        digit_t d2 = 1;
+        borrow = 0;
+        Test_SubDigit(d1, d2, &borrow, UINTPTR_MAX, 1);
+    }
+
+    TEST_CASE("MulDigit", "[JavascriptBigIntTests]")
+    {
+        digit_t high = 0;
+        Test_MulDigit(3, 2, &high, 6, 0);
+
+        digit_t d1 = UINTPTR_MAX;
+        digit_t d2 = 2;
+        high = 0;
+        Test_MulDigit(d1, d2, &high, UINTPTR_MAX-1, 1);
+    }
+}

bin/NativeTests/NativeTests.vcxproj

@@ -48,6 +48,7 @@
     <ClInclude Include="stdafx.h" />
   </ItemGroup>
   <ItemGroup>
+    <ClCompile Include="JavascriptBigIntTests.cpp" />
     <ClCompile Include="BigUIntTest.cpp" />
     <ClCompile Include="CodexAssert.cpp" />
     <ClCompile Include="CodexTests.cpp" />

lib/Common/Core/CommonTypedefs.h

@@ -61,3 +61,6 @@ namespace Js
 {
     typedef uint32 LocalFunctionId;
 };
+
+// digit_t represents a digit in bigint underline
+typedef uintptr_t digit_t;