All trap or error signals raised by the C library go through
the __raise() function. You can re-implement
this function or the lower-level functions that it uses.
Caution
The IEEE 754 standard for floating-point processing states
that the default response to an exception is to proceed without
a trap. You can modify floating-point error handling by tailoring the
functions and definitions in fenv.h.
The rt_misc.h header file contains more
information on error-related functions.
The trap and error-handling functions are shown in Table 8.
Table 8. Trap and error handling
| Function | Description |
|---|---|
_sys_exit() | Called, eventually, by all exits from the library. |
errno | Is a static variable used with error handling. |
__rt_errno_addr() | Is called to obtain the address of the variable errno. |
__raise() | Raises a signal to indicate a runtime anomaly. |
__rt_raise() | Raises a signal to indicate a runtime anomaly. |
__default_signal_handler() | Displays an error indication to the user. |
_ttywrch() | Writes a character to the console. The default implementation
of _ttywrch() is semihosted and, therefore,
uses semihosting calls. |
__rt_fp_status_addr() | This function is called to obtain the address of the floating-point status word. |
See also- Reference
ARM® C and C++ Libraries and Floating-Point Support Reference:
PDF version