**When Should You Use the `[[noreturn]]` Attribute in C ?**

Clarifying the Purpose of the [[noreturn]] Attribute

The [[noreturn]] attribute, specified in [dcl.attr.noreturn], indicates that a function does not return to the calling function. This declaration signifies that the function either performs an action that terminates the program (such as exiting or throwing an exception) or indefinitely loops, preventing the flow of control from returning to the caller.

Difference from Void Return Types

While void functions do not return values, they do return to the caller. In contrast, functions with the [[noreturn]] attribute explicitly indicate that they do not return control after their execution. This declaration is particularly useful for functions that perform irreversible actions or enter infinite loops.

Usage and Benefits

The [[noreturn]] attribute allows compilers to perform specific optimizations and provide helpful warnings. For instance, if a function f has the [[noreturn]] attribute, the compiler can:

• Warn if a subsequent call to g() is dead code after executing f() since f will not return.
• Avoid unnecessary return statements in code following a call to f() as the function does not return.

By using the [[noreturn]] attribute, you provide additional information to the compiler, enabling it to enhance code efficiency and catch potential errors.

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