These function attributes are supported by the RX back end:
Use this attribute on the RX port to indicate that the specified
function is a fast interrupt handler. This is just like the
interrupt attribute, except that
freit is used to return
Use this attribute to indicate that the specified function is an interrupt handler. The compiler generates function entry and exit sequences suitable for use in an interrupt handler when this attribute is present.
On RX and RL78 targets, you may specify one or more vector numbers as arguments
to the attribute, as well as naming an alternate table name.
Parameters are handled sequentially, so one handler can be assigned to
multiple entries in multiple tables. One may also pass the magic
"$default" which causes the function to be used for any
unfilled slots in the current table.
This example shows a simple assignment of a function to one vector in the default table (note that preprocessor macros may be used for chip-specific symbolic vector names):
void __attribute__ ((interrupt (5))) txd1_handler ();
This example assigns a function to two slots in the default table
(using preprocessor macros defined elsewhere) and makes it the default
void __attribute__ ((interrupt (RXD1_VECT,RXD2_VECT,"dct","$default"))) txd1_handler ();
This attribute allows the compiler to construct the
requisite function declaration, while allowing the body of the
function to be assembly code. The specified function will not have
prologue/epilogue sequences generated by the compiler. Only basic
asm statements can safely be included in naked functions
(see Basic Asm). While using extended
asm or a mixture of
asm and C code may appear to work, they cannot be
depended upon to work reliably and are not supported.
This RX attribute is similar to the
interrupt attribute, including its
parameters, but does not make the function an interrupt-handler type
function (i.e. it retains the normal C function calling ABI). See the
interrupt attribute for a description of its arguments.