[MkFit] Fix UBSAN error - skip processing of layers with no hits.

RecoTracker/MkFit/plugins/MkFitProducer.cc

@@ -141,6 +141,10 @@ void MkFitProducer::produce(edm::StreamID iID, edm::Event& iEvent, const edm::Ev
   const auto& stripHits = iEvent.get(stripHitsToken_);
   const auto& eventOfHits = iEvent.get(eventOfHitsToken_);
   const auto& seeds = iEvent.get(seedToken_);
+  if (seeds.seeds().empty()) {
+    iEvent.emplace(putToken_, mkfit::TrackVec(), not backwardFitInCMSSW_);
+    return;
+  }
   // This producer does not strictly speaking need the MkFitGeometry,
   // but the ESProducer sets global variables (yes, that "feature"
   // should be removed), so getting the MkFitGeometry makes it

RecoTracker/MkFitCMS/standalone/Makefile

@@ -8,13 +8,19 @@ LIB_CMS := ../libMicCMS.so
 MAIN    := ../mkFit
 WRMEMF  := ../writeMemoryFile
 
-TGTS := ${LIB_CMS} ${MAIN} ${WRMEMF}
+TGTS := ${LIB_CMS} ${MAIN}
+ifdef WITH_ROOT
+TGTS += ${WRMEMF}
+endif
 
 .PHONY: all clean distclean
 
 all: ${TGTS}
 
-SRCS := $(wildcard ${CMS_DIR}/src/*.cc) $(wildcard ${SACMS}/*.cc) ${SACMS}/tkNtuple/WriteMemoryFile.cc
+SRCS := $(wildcard ${CMS_DIR}/src/*.cc) $(wildcard ${SACMS}/*.cc)
+ifdef WITH_ROOT
+SRCS += ${SACMS}/tkNtuple/WriteMemoryFile.cc
+endif
 SRCB := $(notdir ${SRCS})
 DEPS := $(SRCB:.cc=.d)
 OBJS := $(SRCB:.cc=.o)

RecoTracker/MkFitCore/src/MatriplexPackers.h

@@ -21,7 +21,7 @@ namespace mkfit {
     int m_pos;
 
   public:
-    MatriplexPackerSlurpIn(const D& base) : m_base(&base), m_pos(0) {}
+    MatriplexPackerSlurpIn(const D* base) : m_base(base), m_pos(0) {}
 
     void reset() { m_pos = 0; }
 
@@ -69,8 +69,8 @@ namespace mkfit {
     int m_off_param;
 
   public:
-    MatriplexErrParPackerSlurpIn(const T& t)
-        : MatriplexPackerSlurpIn<D>(*t.errArray()), m_off_param(t.posArray() - this->m_base) {}
+    MatriplexErrParPackerSlurpIn(const T* t)
+        : MatriplexPackerSlurpIn<D>(t ? t->errArray() : nullptr), m_off_param(t ? (t->posArray() - this->m_base) : 0) {}
 
     void addInput(const T& item) {
       // Could issue L1 prefetch requests here.

RecoTracker/MkFitCore/src/MkBuilder.cc

@@ -430,7 +430,7 @@ namespace mkfit {
 
   void MkBuilder::find_tracks_load_seeds_BH(const TrackVec &in_seeds) {
     // bool debug = true;
-
+    assert(!in_seeds.empty());
     m_tracks.reserve(in_seeds.size());
     m_tracks.clear();
 
@@ -512,10 +512,10 @@ namespace mkfit {
                           m_job->m_iter_config.m_layer_configs[curr_layer],
                           m_job->get_mask_for_layer(curr_layer));
 
-            dprint("at layer " << curr_layer);
             const LayerOfHits &layer_of_hits = m_job->m_event_of_hits[curr_layer];
             const LayerInfo &layer_info = trk_info.layer(curr_layer);
             const FindingFoos &fnd_foos = FindingFoos::get_finding_foos(layer_info.is_barrel());
+            dprint("at layer " << curr_layer << ", nHits in layer " << layer_of_hits.nHits());
 
             // Pick up seeds that become active on current layer -- unless already fully loaded.
             if (curr_tridx < rng.n_proc()) {
@@ -595,9 +595,8 @@ namespace mkfit {
 
   void MkBuilder::find_tracks_load_seeds(const TrackVec &in_seeds) {
     // This will sort seeds according to iteration configuration.
-
-    // m_tracks can be used for BkFit.
-    m_tracks.clear();
+    assert(!in_seeds.empty());
+    m_tracks.clear();  // m_tracks can be used for BkFit.
 
     m_event_of_comb_cands.reset((int)in_seeds.size(), m_job->max_max_cands());
 
@@ -800,6 +799,8 @@ namespace mkfit {
                                                          layer_plan_it.is_pickup_only(),
                                                          iteration_dir);
 
+          dprintf("  Number of candidates to process: %d, nHits in layer: %d\n", theEndCand, layer_of_hits.nHits());
+
           if (layer_plan_it.is_pickup_only() || theEndCand == 0)
             continue;
 
@@ -1002,7 +1003,7 @@ namespace mkfit {
       const int theEndCand = find_tracks_unroll_candidates(
           seed_cand_idx, start_seed, end_seed, curr_layer, prev_layer, pickup_only, iteration_dir);
 
-      dprintf("  Number of candidates to process: %d\n", theEndCand);
+      dprintf("  Number of candidates to process: %d, nHits in layer: %d\n", theEndCand, layer_of_hits.nHits());
 
       // Don't bother messing with the clone engine if there are no candidates
       // (actually it crashes, so this protection is needed).

RecoTracker/MkFitCore/src/MkFinder.cc

@@ -714,7 +714,7 @@ namespace mkfit {
   void MkFinder::addBestHit(const LayerOfHits &layer_of_hits, const int N_proc, const FindingFoos &fnd_foos) {
     // debug = true;
 
-    MatriplexHitPacker mhp(*layer_of_hits.hitArray());
+    MatriplexHitPacker mhp(layer_of_hits.hitArray());
 
     float minChi2[NN];
     int bestHit[NN];
@@ -926,7 +926,7 @@ namespace mkfit {
                                 const FindingFoos &fnd_foos) {
     // bool debug = true;
 
-    MatriplexHitPacker mhp(*layer_of_hits.hitArray());
+    MatriplexHitPacker mhp(layer_of_hits.hitArray());
 
     int maxSize = 0;
 
@@ -1141,7 +1141,7 @@ namespace mkfit {
                                            const FindingFoos &fnd_foos) {
     // bool debug = true;
 
-    MatriplexHitPacker mhp(*layer_of_hits.hitArray());
+    MatriplexHitPacker mhp(layer_of_hits.hitArray());
 
     int maxSize = 0;
 
@@ -1358,7 +1358,7 @@ namespace mkfit {
   void MkFinder::bkFitInputTracks(TrackVec &cands, int beg, int end) {
     // Uses HitOnTrack vector from Track directly + a local cursor array to current hit.
 
-    MatriplexTrackPacker mtp(cands[beg]);
+    MatriplexTrackPacker mtp(&cands[beg]);
 
     int itrack = 0;
 
@@ -1385,7 +1385,7 @@ namespace mkfit {
     // XXXX - shall we assume only TrackCand-zero is needed and that we can freely
     // bork the HoTNode array?
 
-    MatriplexTrackPacker mtp(eocss[beg][0]);
+    MatriplexTrackPacker mtp(&eocss[beg][0]);
 
     int itrack = 0;
 

RecoTracker/MkFitCore/src/MkFitter.cc

@@ -129,7 +129,7 @@ namespace mkfit {
     // This might not be true for the last chunk!
     // assert(end - beg == NN);
 
-    MatriplexTrackPacker mtp(tracks[beg]);
+    MatriplexTrackPacker mtp(&tracks[beg]);
 
     for (int i = beg; i < end; ++i) {
       int itrack = i - beg;
@@ -147,7 +147,7 @@ namespace mkfit {
 
     // CopyIn seems fast enough, but indirections are quite slow.
     for (int hi = 0; hi < m_Nhits; ++hi) {
-      MatriplexHitPacker mhp(layerHits[hi][0]);
+      MatriplexHitPacker mhp(layerHits[hi].data());
 
       for (int i = beg; i < end; ++i) {
         const int hidx = tracks[i].getHitIdx(hi);
@@ -276,8 +276,8 @@ namespace mkfit {
     // XXXX MT Here the same idx array WAS used for slurping in of tracks and
     // hots. With this, two index arrays are built, one within each packer.
 
-    MatriplexTrackPacker mtp(tracks[beg]);
-    MatriplexHoTPacker mhotp(*tracks[beg].getHitsOnTrackArray());
+    MatriplexTrackPacker mtp(&tracks[beg]);
+    MatriplexHoTPacker mhotp(tracks[beg].getHitsOnTrackArray());
 
     int itrack = 0;
 
@@ -310,7 +310,7 @@ namespace mkfit {
 
     for (int ii = 0; ii < m_Nhits; ++ii) {
       // XXXX Assuming hit index corresponds to layer!
-      MatriplexHitPacker mhp(layersohits[ii][0]);
+      MatriplexHitPacker mhp(layersohits[ii].data());
 
       for (int i = 0; i < N_proc; ++i) {
         const int hidx = m_HoTArr[ii](i, 0, 0).index;