You can use a external tool like http://oclint.org/
OCLint is a static code analysis tool for improving quality and reducing defects by inspecting C, C++ and Objective-C code and looking for potential problems like:
- Possible bugs - empty if/else/try/catch/finally statements
- Unused code - unused local variables and parameters
- Complicated code - high cyclomatic complexity, NPath complexity and high NCSS
- Redundant code - redundant if statement and useless parentheses
- Code smells - long method and long parameter list
- Bad practices - inverted logic and parameter reassignment
Two non free options: Xclarify (99$ or 400$) and SonarQube (5,000€).