This is an old rule from when structured programming was introduced. The prior state of affairs was that code would jump via gotos between functions to differen

This is an old rule from when structured programming was introduced. The prior state of affairs was that code would jump via gotos between functions to different labels within those functions (labels were global). The requirement that every function should have only a single entry point and a single exit point seemed like a good rule to establish sanity. MISRA C states the following rationale: “A single point of exit is required by IEC 61508 and ISO 26262 as part of the requirements for a modular approach. Early returns may lead to the unintentional omission of function termination code. If a function has exit points interspersed with statements that produce persistent side effects, it is not easy to determine which side effects will occur when the function is executed.” Note that the MISRA C rule is merely advisory, meaning it is a recommendation and not a hard requirement (i.e. it’s a “should” and not a “shall”).