V565. An empty exception handler. Silent suppression of exceptions can hide the presence of bugs in source code during testing.


An exception handler was found that does not do anything. Consider this code:

try {
  ...
}
catch (MyExcept &)
{
}

Of course, this code is not necessarily incorrect. But it is very odd to suppress an exception by doing nothing. Such exception handling might conceal defects in the program and complicate the testing process.

You must react to exceptions somehow. For instance, you may add "assert(false)" at least:

try {
  ...
}
catch (MyExcept &)
{
  assert(false);
}

Programmers sometimes use such constructs to return control from a number of nested loops or recursive functions. But it is bad practice because exceptions are very resource-intensive operations. They must be used according to their intended purpose, i.e. for possible contingencies that must be handled on a higher level.

The only thing where you may simply suppress exceptions is destructors. A destructor must not throw exceptions. But it is often not quite clear what to do with exceptions in destructors and the exception handler might well remain empty. The analyzer does not warn you about empty handlers inside destructors:

CClass::~ CClass()
{
  try {
    DangerousFreeResource();
  }
  catch (...) {
  }
}

According to Common Weakness Enumeration, potential errors found by using this diagnostic are classified as CWE-544.

You can look at examples of errors detected by the V565 diagnostic.


Bugs Found

Checked Projects
334
Collected Errors
12 668