# V1116. Creating an exception object without an explanatory message may result in insufficient logging.

The analyzer has detected that an exception object is created without an explanatory message. It may lead to insufficient logging and hinder error detection.

The example:

    void DoSomething(const char *val)
    {
      if (!val) throw std::runtime_error { "" };

      // something happens here...
    }

    void foo()
    {
      const char *val = ....;
      try
      {
        DoSomething(val);
      }
      catch(std::runtime_error &err)
      {
        std::cerr << err.what() << std::endl;
      }
    }

The 'DoSomething' function throws an 'std::runtime_error' exception, which is handled in the 'foo' function. During handling, it is expected that 'std::cerr' contains data about the exception cause. Instead, 'std::cerr' outputs an empty string, thus complicating error detection.

The fixed code:

    void DoSomething(const char *val)
    {
      if (!val)
      {
        throw std::runtime_error{ "[DoSomething]: "
                                  "the poiner 'val' is nullptr." };
      }

      // something happens here...
    }

If the analyzer detects the standard exception without the explanatory message, it will issue the V1116 warning. To address such issues with user-defined exceptions, you can use the user annotation mechanism.

This diagnostic is classified as:

CWE-778

You can look at examples of errors detected by the V1116 diagnostic.