+
+ case CATCH_FRAME:
+ // If we find a CATCH_FRAME, and we've got an exception to raise,
+ // then build the THUNK raise(exception), and leave it on
+ // top of the CATCH_FRAME ready to enter.
+ //
+ {
+#ifdef PROFILING
+ StgCatchFrame *cf = (StgCatchFrame *)frame;
+#endif
+ StgThunk *raise;
+
+ if (exception == NULL) break;
+
+ // we've got an exception to raise, so let's pass it to the
+ // handler in this frame.
+ //
+ raise = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+MIN_UPD_SIZE);
+ TICK_ALLOC_SE_THK(1,0);
+ SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
+ raise->payload[0] = exception;
+
+ // throw away the stack from Sp up to the CATCH_FRAME.
+ //
+ sp = frame - 1;
+
+ /* Ensure that async excpetions are blocked now, so we don't get
+ * a surprise exception before we get around to executing the
+ * handler.
+ */
+ if (tso->blocked_exceptions == NULL) {
+ tso->blocked_exceptions = END_TSO_QUEUE;
+ }
+
+ /* Put the newly-built THUNK on top of the stack, ready to execute
+ * when the thread restarts.
+ */
+ sp[0] = (W_)raise;
+ sp[-1] = (W_)&stg_enter_info;
+ tso->sp = sp-1;
+ tso->what_next = ThreadRunGHC;
+ IF_DEBUG(sanity, checkTSO(tso));
+ return;
+ }
+
+ case ATOMICALLY_FRAME:
+ if (stop_at_atomically) {
+ ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
+ stmCondemnTransaction(cap, tso -> trec);
+#ifdef REG_R1
+ tso->sp = frame;
+#else
+ // R1 is not a register: the return convention for IO in
+ // this case puts the return value on the stack, so we
+ // need to set up the stack to return to the atomically
+ // frame properly...
+ tso->sp = frame - 2;
+ tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
+ tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
+#endif
+ tso->what_next = ThreadRunGHC;
+ return;
+ }
+ // Not stop_at_atomically... fall through and abort the
+ // transaction.
+
+ case CATCH_RETRY_FRAME:
+ // IF we find an ATOMICALLY_FRAME then we abort the
+ // current transaction and propagate the exception. In
+ // this case (unlike ordinary exceptions) we do not care
+ // whether the transaction is valid or not because its
+ // possible validity cannot have caused the exception
+ // and will not be visible after the abort.
+ IF_DEBUG(stm,
+ debugBelch("Found atomically block delivering async exception\n"));
+ StgTRecHeader *trec = tso -> trec;
+ StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+ stmAbortTransaction(cap, trec);
+ tso -> trec = outer;
+ break;