What could happen when you call function returning int with void (*)() pointer?

When you call a function returning int using a void (*)() pointer (a pointer to a function that takes no arguments and returns void), you're essentially attempting to call a function with a mismatched function signature. This can lead to undefined behavior and unpredictable results.

Here's what could happen:

1. Compilation Errors: Depending on the compiler and settings, you might get a compilation error indicating that you are trying to call a function with an incompatible signature.

2. Undefined Behavior: If the function signatures do not match, the behavior of your program is undefined. This means that your program might crash, produce incorrect results, or exhibit any other unexpected behavior. The outcome is not predictable.

3. Stack Corruption: Incorrect function calling conventions and parameter passing might result in stack corruption, which could lead to crashes or incorrect data.

4. Data Corruption: If the function being called with the wrong signature interacts with data or memory, it could potentially lead to data corruption or memory issues.

5. Execution of Invalid Code: The code generated by the compiler for the function call might not be what you expect. It might try to execute instructions that are invalid for the function signature you provided.

In summary, it's essential to call functions using the correct function pointers that match the function's signature. Mismatched function signatures can lead to unexpected behavior, crashes, and data corruption. Always ensure that the types of function pointers you are using match the types of the functions you intend to call.