[LLVMdev] ISRs for PIC16 [was [llvm]r79631 ...]

[John Regehr]

> Function pointers are where things get fun. To do these, we need to
> determine at run time whether we need to call the ISR or the mainline
> version of a function

This sounds convenient but it may well be overkill.

On a PIC-class platform we can probably consider it to be a design flaw if 
the programmer doesn't know whether a function pointer will be 
dereferenced from interrupt context or not.  This suggests that for any 
function whose address is taken, there could be a required annotation such 
as ISR_ONLY or NONISR_ONLY.  The compiler could use this to do the right 
thing without any heroic static analysis or dynamic binding.

John