IDebugBreakpointChecksumRequest2::GetChecksum

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Retrieves the document checksum for a breakpoint request given the unique identifier of the checksum algorithm to use.

Syntax

public int GetChecksum(
    ref Guid               guidAlgorithm,
    out enum_CHECKSUM_DATA pChecksumData
);

Parameters

guidAlgorithm
[in] Unique identifier of the checksum algorithm.

pChecksumData
[out] Document checksum for the breakpoint request.

Return Value

If successful, returns S_OK; otherwise, returns an error code.

Example

The following example shows a function that checks whether the checksum of a document, which is about to be bound, matches one from the UI.

bool CDebugProgram::DoChecksumsMatch(CDebugPendingBreakpoint *pPending, CDebugCodeContext *pContext)
{
    bool fRet = false;
    HRESULT hRes;

    // Get the checksum for the document we are about to bind to from the pdb side
    GUID guidAlgorithmId;
    BYTE *pChecksum = NULL;
    ULONG cNumBytes = 0;

    hRes = pContext->GetDocumentChecksumAndAlgorithmId(&guidAlgorithmId, &pChecksum, &cNumBytes);

    if ( S_OK == hRes )
    {
        // Get checksum data for the document from the UI (request) side
        CComPtr<IDebugBreakpointChecksumRequest2> pChecksumRequest;

        hRes = pPending->GetChecksumRequest(&pChecksumRequest);

        if ( S_OK == hRes )
        {
            CHECKSUM_DATA data;

            hRes = pChecksumRequest->GetChecksum(guidAlgorithmId, &data);

            if ( S_OK == hRes )
            {
                if ( data.ByteCount == cNumBytes && memcmp(data.pBytes, pChecksum, cNumBytes) == 0 )
                    fRet = true;
                else
                    fRet = false;

                // Free up data allocated for checksum data
                CoTaskMemFree(data.pBytes);
            }
            else
                fRet = true; // checksums not available - user disabed checksums
        }
        else
            fRet = true; // we couldn't get checksum from UI - default to past behavior

        // free up space allocated for checksum from pdb
        CoTaskMemFree(pChecksum);
    }
    else
        fRet = true; // we don't have a checksum to compare with.

    return ( fRet );
}

See also