Do `goto` Statements Bypass Object Destructors in C ?

Can 'goto' Statements Jump Across Function Boundaries Without Calling Destructors?

It is commonly believed that goto jumps bypass the orderly execution of code, including the destruction of objects. However, this is a misconception that stems from a misunderstanding of C 's scoping rules.

Scope of Labels

Firstly, goto jumps are confined within the scope of their respective functions. Jumping across function boundaries, as in the example you provided, is not possible. The compiler will issue an error indicating that the label is not defined in the function where the jump originates.

Object Initialization and Scope

Secondly, goto jumps cannot cross the initialization of objects. If a jump is made past the point where an object is declared and initialized, the object's scope is entered, and its constructor is called. However, if the jump is made back into the scope of an already initialized object, its destructor is invoked before the jump executes.

Preservation of Object Scope

Finally, objects with automatic storage duration (i.e., variables declared within blocks) are not leaked by goto jumps. Leaving an object's scope via a goto triggers its destruction, ensuring that resource management is handled correctly.

Conclusion

Contrary to popular belief, goto statements in C do not allow for uncontrolled jumps that violate scoping rules or result in memory leaks. While the use of goto remains debatable for design reasons, it does not pose the inherent risks often attributed to it.

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