6.31.25 RL78 Function Attributes

These function attributes are supported by the RL78 back end:

interrupt

brk_interrupt

These attributes 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.

Use brk_interrupt instead of interrupt for handlers intended to be used with the BRK opcode (i.e. those that must end with RETB instead of RETI).

naked

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 basic asm and C code may appear to work, they cannot be depended upon to work reliably and are not supported.