Finds functions registered as signal handlers that call non asynchronous-safe functions. Any function that cannot be determined to be an asynchronous-safe function call is assumed to be non-asynchronous-safe by the checker, including user functions for which only the declaration is visible. User function calls with visible definition are checked recursively. The check handles only C code.

The minimal list of asynchronous-safe system functions is: abort(), _Exit(), quick_exit() and signal() (for signal there are additional conditions that are not checked). The check accepts only these calls as asynchronous-safe.

This check corresponds to the CERT C Coding Standard rule SIG30-C. Call only asynchronous-safe functions within signal handlers.