Merge pull request #49251 from smuzaffar/llvm21-fix-bzero-non-trivially-copyable

MkFitCore/Track: Fix for llvm21 warning calling bzero on pointer to non-trivially copyable type

Author: cmsbuild

RecoTracker/MkFitCore/interface/Track.h

@@ -432,8 +432,6 @@ namespace mkfit {
     // Used by TrackCand::ExportTrack
     void setHitIdxAtPos(int pos, const HitOnTrack& hot) { hitsOnTrk_[pos] = hot; }
 
-    void resizeHitsForInput();
-
     void addHitIdx(int hitIdx, int hitLyr, float chi2) {
       hitsOnTrk_.push_back({hitIdx, hitLyr});
       ++lastHitIdx_;
@@ -490,6 +488,8 @@ namespace mkfit {
       return mcHitID;
     }
 
+    const std::vector<HitOnTrack>& refHitsOnTrackVector() const { return hitsOnTrk_; }
+
     const HitOnTrack* getHitsOnTrackArray() const { return hitsOnTrk_.data(); }
     const HitOnTrack* beginHitsOnTrack() const { return hitsOnTrk_.data(); }
     const HitOnTrack* endHitsOnTrack() const { return hitsOnTrk_.data() + (lastHitIdx_ + 1); }

RecoTracker/MkFitCore/src/Track.cc

@@ -386,11 +386,6 @@ namespace mkfit {
   // Track
   //==============================================================================
 
-  void Track::resizeHitsForInput() {
-    bzero(&hitsOnTrk_, sizeof(hitsOnTrk_));
-    hitsOnTrk_.resize(lastHitIdx_ + 1);
-  }
-
   void Track::sortHitsByLayer() {
     std::stable_sort(&hitsOnTrk_[0], &hitsOnTrk_[lastHitIdx_ + 1], [](const auto& h1, const auto& h2) {
       return h1.layer < h2.layer;

RecoTracker/MkFitCore/standalone/Event.cc

@@ -6,6 +6,7 @@
 #include "RecoTracker/MkFitCore/src/Debug.h"
 
 #include <memory>
+#include <cstring>
 
 namespace {
   std::unique_ptr<mkfit::Validation> dummyValidation(mkfit::Validation::make_validation("dummy", nullptr));
@@ -451,8 +452,10 @@ namespace mkfit {
       fread(tracks.data(), sizeof(Track), n_tracks, fp);
 
       for (int i = 0; i < n_tracks; ++i) {
-        tracks[i].resizeHitsForInput();
-        fread(tracks[i].beginHitsOnTrack_nc(), sizeof(HitOnTrack), tracks[i].nTotalHits(), fp);
+        auto &hot_vec = const_cast<std::vector<HitOnTrack> &>(tracks[i].refHitsOnTrackVector());
+        memset((void *)&hot_vec, 0, sizeof(hot_vec));
+        hot_vec.resize(tracks[i].nTotalHits());
+        fread(hot_vec.data(), sizeof(HitOnTrack), tracks[i].nTotalHits(), fp);
       }
     }