#ifndef _NTINTSAFE_H_INCLUDED_
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP | WINAPI_PARTITION_SYSTEM | WINAPI_PARTITION_GAMES)

//
// ULONGLONG addition
//
_Must_inspect_result_
__inline
NTSTATUS
RtlULongLongAdd(
    _In_ ULONGLONG ullAugend,
    _In_ ULONGLONG ullAddend,
    _Out_ _Deref_out_range_(==, ullAugend + ullAddend) ULONGLONG* pullResult)
{
    NTSTATUS status;

    if ((ullAugend + ullAddend) >= ullAugend)
    {
        *pullResult = (ullAugend + ullAddend);
        status = STATUS_SUCCESS;
    }
    else
    {
        *pullResult = ULONGLONG_ERROR;
        status = STATUS_INTEGER_OVERFLOW;
    }

    return status;
}

#endif
#endif
View code on GitHub

// ntintsafe.h

NTSTATUS RtlULongLongAdd(
  [in] ULONGLONG ullAugend,
  [in] ULONGLONG ullAddend,
       ULONGLONG *pullResult
);
View the official Windows Driver Kit DDI reference

NtDoc

No description available.

Edit description on GitHub

Windows Driver Kit DDI reference (nf-ntintsafe-rtlulonglongadd)

RtlULongLongAdd function

Description

Adds two values of type ULONGLONG.

Parameters

`ullAugend` [in]

The first value in the equation.

`ullAddend` [in]

The value to add to ullAugend.

`pullResult`

A pointer to the sum. If the operation results in a value that overflows or underflows the capacity of the type, the function returns STATUS_INTEGER_OVERFLOW and this parameter is not valid.

Return value

Returns STATUS_SUCCESS if the operation is successful.

See the implementation of this helper function in ntintsafe.h in the WDK for possible error return values.

Remarks

This is one of a set of inline functions designed to provide arithmetic operations and perform validity checks with minimal impact on performance.

View the official Windows Driver Kit DDI reference