+ raiseExceptionHelper
+
+ This function is called by the raise# primitve, just so that we can
+ move some of the tricky bits of raising an exception from C-- into
+ C. Who knows, it might be a useful re-useable thing here too.
+ -------------------------------------------------------------------------- */
+
+StgWord
+raiseExceptionHelper (StgTSO *tso, StgClosure *exception)
+{
+ StgClosure *raise_closure = NULL;
+ StgPtr p, next;
+ StgRetInfoTable *info;
+ //
+ // This closure represents the expression 'raise# E' where E
+ // is the exception raise. It is used to overwrite all the
+ // thunks which are currently under evaluataion.
+ //
+
+ //
+ // LDV profiling: stg_raise_info has THUNK as its closure
+ // type. Since a THUNK takes at least MIN_UPD_SIZE words in its
+ // payload, MIN_UPD_SIZE is more approprate than 1. It seems that
+ // 1 does not cause any problem unless profiling is performed.
+ // However, when LDV profiling goes on, we need to linearly scan
+ // small object pool, where raise_closure is stored, so we should
+ // use MIN_UPD_SIZE.
+ //
+ // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate,
+ // sizeofW(StgClosure)+1);
+ //
+
+ //
+ // Walk up the stack, looking for the catch frame. On the way,
+ // we update any closures pointed to from update frames with the
+ // raise closure that we just built.
+ //
+ p = tso->sp;
+ while(1) {
+ info = get_ret_itbl((StgClosure *)p);
+ next = p + stack_frame_sizeW((StgClosure *)p);
+ switch (info->i.type) {
+
+ case UPDATE_FRAME:
+ // Only create raise_closure if we need to.
+ if (raise_closure == NULL) {
+ raise_closure =
+ (StgClosure *)allocate(sizeofW(StgClosure)+MIN_UPD_SIZE);
+ SET_HDR(raise_closure, &stg_raise_info, CCCS);
+ raise_closure->payload[0] = exception;
+ }
+ UPD_IND(((StgUpdateFrame *)p)->updatee,raise_closure);
+ p = next;
+ continue;
+
+ case CATCH_FRAME:
+ tso->sp = p;
+ return CATCH_FRAME;
+
+ case STOP_FRAME:
+ tso->sp = p;
+ return STOP_FRAME;
+
+ default:
+ p = next;
+ continue;
+ }
+ }
+}
+
+/* -----------------------------------------------------------------------------
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