Analysis of information sources in references of the Wikipedia article "Unreachable code" in English language version.
Because compilers are not obligated to generate code for undefined behavior, these behaviors are candidates for optimization.
The combination of requirements traceability with coverage analysis can also turn up areas of "dead code," or code that's never executed. This code can mostly be an inconvenience, but it can also be a security threat if a hacker can gain access and from there gain control. It's code that can't be traced and should therefore be eliminated.
Rule 2.2 there shall be no dead code. Any operation that is executed but whose removal would not affect program behavior constitutes dead code.
Dead code – Executable Object Code (or data) which exists as a result of a software development error but cannot be executed (code) or used (data) in any operational configuration of the target computer environment. It is not traceable to a system or software requirement. The following exceptions are often mistakenly categorized as dead code but are necessary for implementation of the requirements/design: embedded identifiers, defensive programming structures to improve robustness, and deactivated code such as unused library functions. [Since requirements-based review should identified such code as untraceable to functional requirements, static code analysis should identify such code as unreachable, and structural coverage analysis of requirements-based testing results should identify such code as unreachable, presence of unjustified dead code in a project should raise consideration of the effectiveness of the organization's development and verification processes.]
