Bug in Dead Code Detection?

Hello David,

The code sample

using(var connection = new SqlConnection(connectionString))
{
 connection.Open();
 using(var transaction = connection.BeginTransaction())
 {
 SqlHelper.ExecuteNonQuery(transaction, procedureName, parameters);
 transaction.Commit;
 return true;
 }
}

return false;

is actually transformed by the compiler into

SqlConnection connection;
try
{
 connection = new SqlConnection(connectionString))
 connection.Open();
 using(var transaction = connection.BeginTransaction())
 {
 SqlHelper.ExecuteNonQuery(transaction, procedureName, parameters);
 transaction.Commit;
 return true;
 }
}
finally
{
 if(connection != null)
 connection.Dispose();
}

return false;

According to C# Language Specification the try/finally block re-throws the
exception after executing the 'finally' block, so the execution will never
reach the last return statement. Thank you!


Andrey Serebryansky
Support Engineer
JetBrains, Inc
http://www.jetbrains.com
"Develop with pleasure!"

I have found a possible issue with the dead code detection.  Given the
following code:

<code>
using(var connection = new SqlConnection(connectionString))
{
connection.Open();
using(var transaction = connection.BeginTransaction())
{
SqlHelper.ExecuteNonQuery(transaction, procedureName,
parameters);
transaction.Commit;
return true;
}
}
return false;
</code>
the final line is marked as unreachable - which is false.  If any
exceptions happen inside of either <c>using</c> expression, then the
last line will be reached.  Only in the case where no exceptions
happen is it unreachable.

---
Original message URL:
http://devnet.jetbrains.net/message/5269228#5269228