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. |