static void searchHeapBlocks()

in rts/CheckUnload.c [88:247]
128 lines of code
52 McCabe index (conditional complexity)

static void searchHeapBlocks (HashTable *addrs, bdescr *bd)
{
    StgPtr p;
    const StgInfoTable *info;
    uint32_t size;
    bool prim;

    for (; bd != NULL; bd = bd->link) {

        if (bd->flags & BF_PINNED) {
            // Assume that objects in PINNED blocks cannot refer to
            continue;
        }

        p = bd->start;
        while (p < bd->free) {
            info = get_itbl((StgClosure *)p);
            prim = false;

            switch (info->type) {

            case THUNK:
                size = thunk_sizeW_fromITBL(info);
                break;

            case THUNK_1_1:
            case THUNK_0_2:
            case THUNK_2_0:
                size = sizeofW(StgThunkHeader) + 2;
                break;

            case THUNK_1_0:
            case THUNK_0_1:
            case THUNK_SELECTOR:
                size = sizeofW(StgThunkHeader) + 1;
                break;

            case FUN:
            case FUN_1_0:
            case FUN_0_1:
            case FUN_1_1:
            case FUN_0_2:
            case FUN_2_0:
            case CONSTR:
            case CONSTR_NOCAF:
            case CONSTR_1_0:
            case CONSTR_0_1:
            case CONSTR_1_1:
            case CONSTR_0_2:
            case CONSTR_2_0:
                size = sizeW_fromITBL(info);
                break;

            case BLACKHOLE:
            case BLOCKING_QUEUE:
                prim = true;
                size = sizeW_fromITBL(info);
                break;

            case IND:
                // Special case/Delicate Hack: INDs don't normally
                // appear, since we're doing this heap census right
                // after GC.  However, GarbageCollect() also does
                // resurrectThreads(), which can update some
                // blackholes when it calls raiseAsync() on the
                // resurrected threads.  So we know that any IND will
                // be the size of a BLACKHOLE.
                prim = true;
                size = BLACKHOLE_sizeW();
                break;

            case BCO:
                prim = true;
                size = bco_sizeW((StgBCO *)p);
                break;

            case MVAR_CLEAN:
            case MVAR_DIRTY:
            case TVAR:
            case WEAK:
            case PRIM:
            case MUT_PRIM:
            case MUT_VAR_CLEAN:
            case MUT_VAR_DIRTY:
                prim = true;
                size = sizeW_fromITBL(info);
                break;

            case AP:
                prim = true;
                size = ap_sizeW((StgAP *)p);
                break;

            case PAP:
                prim = true;
                size = pap_sizeW((StgPAP *)p);
                break;

            case AP_STACK:
            {
                StgAP_STACK *ap = (StgAP_STACK *)p;
                prim = true;
                size = ap_stack_sizeW(ap);
                searchStackChunk(addrs, (StgPtr)ap->payload,
                                 (StgPtr)ap->payload + ap->size);
                break;
            }

            case ARR_WORDS:
                prim = true;
                size = arr_words_sizeW((StgArrBytes*)p);
                break;

            case MUT_ARR_PTRS_CLEAN:
            case MUT_ARR_PTRS_DIRTY:
            case MUT_ARR_PTRS_FROZEN_CLEAN:
            case MUT_ARR_PTRS_FROZEN_DIRTY:
                prim = true;
                size = mut_arr_ptrs_sizeW((StgMutArrPtrs *)p);
                break;

            case SMALL_MUT_ARR_PTRS_CLEAN:
            case SMALL_MUT_ARR_PTRS_DIRTY:
            case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
            case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
                prim = true;
                size = small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs *)p);
                break;

            case TSO:
                prim = true;
                size = sizeofW(StgTSO);
                break;

            case STACK: {
                StgStack *stack = (StgStack*)p;
                prim = true;
                searchStackChunk(addrs, stack->sp,
                                 stack->stack + stack->stack_size);
                size = stack_sizeW(stack);
                break;
            }

            case TREC_CHUNK:
                prim = true;
                size = sizeofW(StgTRecChunk);
                break;

            default:
                barf("heapCensus, unknown object: %d", info->type);
            }

            if (!prim) {
                checkAddress(addrs,info);
            }

            p += size;
        }
    }
}