/* Unwinds after a handler. */
static void unwind_after_handler(MVMThreadContext *tc, void *sr_data) {
MVMFrame *frame;
MVMException *exception;
MVMuint32 goto_offset;
/* Get active handler; sanity check (though it's possible other cases
* should be supported). */
MVMActiveHandler *ah = (MVMActiveHandler *)sr_data;
if (tc->active_handlers != ah)
MVM_panic(1, "Trying to unwind from wrong handler");
/* Grab info we'll need to unwind. */
frame = ah->frame;
exception = (MVMException *)ah->ex_obj;
goto_offset = ah->handler->goto_offset;
/* Clean up. */
tc->active_handlers = ah->next_handler;
MVM_frame_dec_ref(tc, ah->frame);
free(ah);
/* Do the unwinding as needed. */
if (exception && exception->body.return_after_unwind) {
MVM_frame_unwind_to(tc, frame->caller, NULL, 0, tc->last_handler_result);
}
else {
MVM_frame_unwind_to(tc, frame, NULL, goto_offset, NULL);
}
}
static void run_handler(MVMThreadContext *tc, LocatedHandler lh, MVMObject *ex_obj, MVMuint32 category) {
switch (lh.handler->action) {
case MVM_EX_ACTION_GOTO:
if (lh.jit_handler) {
void **labels = lh.frame->spesh_cand->jitcode->labels;
MVMuint8 *pc = lh.frame->spesh_cand->jitcode->bytecode;
lh.frame->jit_entry_label = labels[lh.jit_handler->goto_label];
MVM_frame_unwind_to(tc, lh.frame, pc, 0, NULL);
} else {
MVM_frame_unwind_to(tc, lh.frame, NULL, lh.handler->goto_offset, NULL);
}
break;
case MVM_EX_ACTION_INVOKE: {
/* Create active handler record. */
MVMActiveHandler *ah = MVM_malloc(sizeof(MVMActiveHandler));
MVMFrame *cur_frame = tc->cur_frame;
MVMObject *handler_code;
/* Ensure we have an exception object. */
if (ex_obj == NULL) {
ex_obj = MVM_repr_alloc_init(tc, tc->instance->boot_types.BOOTException);
((MVMException *)ex_obj)->body.category = category;
}
/* Find frame to invoke. */
handler_code = MVM_frame_find_invokee(tc, lh.frame->work[lh.handler->block_reg].o, NULL);
/* Install active handler record. */
ah->frame = MVM_frame_inc_ref(tc, lh.frame);
ah->handler = lh.handler;
ah->jit_handler = lh.jit_handler;
ah->ex_obj = ex_obj;
ah->next_handler = tc->active_handlers;
tc->active_handlers = ah;
/* Set up special return to unwinding after running the
* handler. */
cur_frame->return_value = (MVMRegister *)&tc->last_handler_result;
cur_frame->return_type = MVM_RETURN_OBJ;
cur_frame->special_return = unwind_after_handler;
cur_frame->special_unwind = cleanup_active_handler;
cur_frame->special_return_data = ah;
/* Invoke the handler frame and return to runloop. */
STABLE(handler_code)->invoke(tc, handler_code, MVM_callsite_get_common(tc, MVM_CALLSITE_ID_NULL_ARGS),
cur_frame->args);
break;
}
default:
MVM_panic(1, "Unimplemented handler action");
}
}
static void continue_unwind(MVMThreadContext *tc, void *sr_data) {
MVMUnwindData *ud = (MVMUnwindData *)sr_data;
MVMFrame *frame = ud->frame;
MVMuint8 *abs_addr = ud->abs_addr;
MVMuint32 rel_addr = ud->rel_addr;
free(sr_data);
MVM_frame_unwind_to(tc, frame, abs_addr, rel_addr, NULL);
}
static void run_handler(MVMThreadContext *tc, LocatedHandler lh, MVMObject *ex_obj,
MVMuint32 category, MVMObject *payload) {
switch (lh.handler->action) {
case MVM_EX_ACTION_GOTO_WITH_PAYLOAD:
if (payload)
tc->last_payload = payload;
else if (ex_obj && ((MVMException *)ex_obj)->body.payload)
tc->last_payload = ((MVMException *)ex_obj)->body.payload;
else
tc->last_payload = tc->instance->VMNull;
/* Deliberate fallthrough to unwind below. */
case MVM_EX_ACTION_GOTO:
if (lh.jit_handler) {
void **labels = lh.frame->spesh_cand->jitcode->labels;
MVMuint8 *pc = lh.frame->spesh_cand->jitcode->bytecode;
lh.frame->jit_entry_label = labels[lh.jit_handler->goto_label];
MVM_frame_unwind_to(tc, lh.frame, pc, 0, NULL);
} else {
MVM_frame_unwind_to(tc, lh.frame, NULL, lh.handler->goto_offset, NULL);
}
break;
case MVM_EX_ACTION_INVOKE: {
/* Create active handler record. */
MVMActiveHandler *ah = MVM_malloc(sizeof(MVMActiveHandler));
MVMFrame *cur_frame = tc->cur_frame;
MVMObject *handler_code;
/* Ensure we have an exception object. */
if (ex_obj == NULL) {
MVMROOT(tc, cur_frame, {
MVMROOT(tc, lh.frame, {
MVMROOT(tc, payload, {
ex_obj = MVM_repr_alloc_init(tc, tc->instance->boot_types.BOOTException);
});
});
});
static void run_handler(MVMThreadContext *tc, LocatedHandler lh, MVMObject *ex_obj) {
switch (lh.handler->action) {
case MVM_EX_ACTION_GOTO:
MVM_frame_unwind_to(tc, lh.frame, NULL, lh.handler->goto_offset, NULL);
break;
case MVM_EX_ACTION_INVOKE: {
/* Create active handler record. */
MVMActiveHandler *ah = malloc(sizeof(MVMActiveHandler));
/* Find frame to invoke. */
MVMObject *handler_code = MVM_frame_find_invokee(tc,
lh.frame->work[lh.handler->block_reg].o, NULL);
/* Ensure we have an exception object. */
/* TODO: Can make one up. */
if (ex_obj == NULL)
MVM_panic(1, "Exception object creation NYI");
/* Install active handler record. */
ah->frame = MVM_frame_inc_ref(tc, lh.frame);
ah->handler = lh.handler;
ah->ex_obj = ex_obj;
ah->next_handler = tc->active_handlers;
tc->active_handlers = ah;
/* Set up special return to unwinding after running the
* handler. */
tc->cur_frame->return_value = (MVMRegister *)&tc->last_handler_result;
tc->cur_frame->return_type = MVM_RETURN_OBJ;
tc->cur_frame->special_return = unwind_after_handler;
tc->cur_frame->special_unwind = cleanup_active_handler;
tc->cur_frame->special_return_data = ah;
/* Invoke the handler frame and return to runloop. */
STABLE(handler_code)->invoke(tc, handler_code, &no_arg_callsite,
tc->cur_frame->args);
break;
}
default:
MVM_panic(1, "Unimplemented handler action");
}
}