Can I implement a software exception handler in C language to simulate a Throw/Catch in Java. This should be available on the Cortex-M4

There is setjmp()/longjmp() in C for simple exception handling.​

hi @Dfinn.1​ ,

to go further on setjmp()/longjmp() mentionned by @berendi​ , you can refer to http://www.di.unipi.it/~nids/docs/longjump_try_trow_catch.html.

This works like a charm on STM32WB.

Beware if you use the THROW command inside interrupts! Here is a sample implementation with an example on HardFault_Handler.

/* Credit to http://www.di.unipi.it/~nids/docs/longjump_try_trow_catch.html */
#define TRY do { switch( setjmp(s_jumpBuffer) ) { case 0: while(1) {
#define CATCH(x) break; case x:
#define FINALLY break; } default: {
#define ETRY break; } } }while(0)
#define THROW(x) longjmp(s_jumpBuffer, x)
 
void HardFault_Handler(void)
{
 /* Rewrite manually the stack frame to execute the longjump when exiting the HardFault_Handler. */
 /* Calling THROW(HARDFAULT_EXCEPTION) is not enough as after execution of longjmp we are still in interrupt context. */
 InterruptStackFrame_t *isf = (InterruptStackFrame_t*)__get_MSP(); /* Beware, here we assume the code execute on main stack */
 isf->R0 = (uint32_t)&s_jumpBuffer;
 isf->R1 = HARDFAULT_EXCEPTION;
 isf->ReturnAddress = (uint32_t)longjmp;
}

Hope it can helps.

Pierre.