5.8. Tailoring error signaling, error handling,
and program exit
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. See
also Chapter 6 Floating-point Support.
See the rt_misc.h include file for more
information on error-related functions.
The trap and error-handling functions are shown in Table 5.11. See also Tailoring the C library to a new execution
environment for additional
information about application initialization and shutdown.
Table 5.11. Trap and error handling
| Function | Description |
|---|
_sys_exit() | Called, eventually, by all exits from the library.
See _sys_exit(). |
errno | Is a static variable used with error handling.
See errno. |
__rt_errno_addr() | This function is called to obtain the address
of the variable errno. See __rt_errno_addr(). |
__raise() | Raises a signal to indicate a runtime anomaly.
See __raise(). |
__rt_raise() | Raises a signal to indicate a runtime anomaly.
See __rt_raise(). |
__default_signal_handler() | Displays an error indication to the user. See __default_signal_handler(). |
_ttywrch() | The default implementation of _ttywrch() is semihosted
and, therefore, uses the semihosting SVC. See _ttywrch(). |
__rt_fp_status_addr() | This function is called to obtain the address
of the fp status word. See __rt_fp_status_addr(). |
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