V3052. The original exception object was swallowed. Stack of original exception could be lost.

The analyzer detected that the original object of a caught exception was not used properly when re-throwing from a catch block. This issue makes some errors hard to detect since the stack of the original exception is lost.

Further we will discuss a couple of examples of incorrect code. The first example:

public Asn1Object ToAsn1Object()
{
    try
    {
        return Foo(_constructed, _tagNumber);
    }
    catch (IOException e)
    {
        throw new ParsingException(e.Message);
    }
}

In this code, the programmer wanted to transform the caught I/O exception into a new exception of type ParsingException. However, only the message from the first exception is included, so some of the information is lost.

The fixed version of the code:

public Asn1Object ToAsn1Object()
{
    try
    {
        return Foo(_constructed, _tagNumber);
    }
    catch (IOException e)
    {
        throw new ParsingException(e.Message, e);
    }
}

In the fixed version, the original exception is re-thrown as an inner one, so all the information about the original error is saved.

Here's the second example:

private int ReadClearText(byte[] buffer, int offset, int count)
{
    int pos = offset;
    try
    {
        ....
    }
    catch (IOException ioe)
    {
        if (pos == offset) throw ioe;
    }
    return pos - offset;
}

In this case, the caught I/O exception is thrown again, completely erasing the stack of the original error. To avoid this defect, we just need to re-throw the original exception.

The fixed version of the code:

private int ReadClearText(byte[] buffer, int offset, int count)
{
    int pos = offset;
    try
    {
        ....
    }
    catch (IOException ioe)
    {
        if (pos == offset) throw;
    }
    return pos - offset;
}

This diagnostic is classified as:

You can look at examples of errors detected by the V3052 diagnostic.


Bugs Found

Checked Projects
412
Collected Errors
14 132
This website uses cookies and other technology to provide you a more personalized experience. By continuing the view of our web-pages you accept the terms of using these files. If you don't want your personal data to be processed, please, leave this site. Learn More →
Accept