drt: functions changed to have more explicit output

src/drt/src/pa/FlexPA.h

@@ -122,7 +122,7 @@ class FlexPA
     unique_insts_.setDesign(in);
   }
   void applyPatternsFile(const char* file_path);
-  void getViaRawPriority(frViaDef* via_def, ViaRawPriorityTuple& priority);
+  ViaRawPriorityTuple getViaRawPriority(frViaDef* via_def);
   bool isSkipInstTermLocal(frInstTerm* in);
   bool isSkipInstTerm(frInstTerm* in);
   bool isDistributed() const { return !remote_host_.empty(); }
@@ -143,11 +143,8 @@ class FlexPA
   template <typename T>
   int prepPoint_pin(T* pin, frInstTerm* inst_term = nullptr);
   template <typename T>
-  void prepPoint_pin_mergePinShapes(
-      std::vector<gtl::polygon_90_set_data<frCoord>>& pin_shapes,
-      T* pin,
-      frInstTerm* inst_term,
-      bool is_shrink = false);
+  std::vector<gtl::polygon_90_set_data<frCoord>>
+  mergePinShapes(T* pin, frInstTerm* inst_term, bool is_shrink = false);
   // type 0 -- on-grid; 1 -- half-grid; 2 -- center; 3 -- via-enc-opt
   template <typename T>
   void prepPoint_pin_genPoints(

src/drt/src/pa/FlexPA_init.cpp

@@ -48,14 +48,13 @@ void FlexPA::initViaRawPriority()
     for (auto& via_def :
          design_->getTech()->getLayer(layer_num)->getViaDefs()) {
       const int cutNum = int(via_def->getCutFigs().size());
-      ViaRawPriorityTuple priority;
-      getViaRawPriority(via_def, priority);
+      const ViaRawPriorityTuple priority = getViaRawPriority(via_def);
       layer_num_to_via_defs_[layer_num][cutNum][priority] = via_def;
     }
   }
 }
 
-void FlexPA::getViaRawPriority(frViaDef* via_def, ViaRawPriorityTuple& priority)
+ViaRawPriorityTuple FlexPA::getViaRawPriority(frViaDef* via_def)
 {
   const bool is_not_default_via = !(via_def->getDefault());
   gtl::polygon_90_set_data<frCoord> via_layer_PS1;
@@ -108,13 +107,13 @@ void FlexPA::getViaRawPriority(frViaDef* via_def, ViaRawPriorityTuple& priority)
   const frCoord layer1_area = gtl::area(via_layer_PS1);
   const frCoord layer2_area = gtl::area(via_layer_PS2);
 
-  priority = std::make_tuple(is_not_default_via,
-                             layer1_width,
-                             layer2_width,
-                             is_not_upper_align,
-                             layer2_area,
-                             layer1_area,
-                             is_not_lower_align);
+  return std::make_tuple(is_not_default_via,
+                         layer1_width,
+                         layer2_width,
+                         is_not_upper_align,
+                         layer2_area,
+                         layer1_area,
+                         is_not_lower_align);
 }
 
 void FlexPA::initTrackCoords()

src/drt/src/pa/FlexPA_prep.cpp

@@ -50,12 +50,10 @@ namespace drt {
 using utl::ThreadException;
 
 template <typename T>
-void FlexPA::prepPoint_pin_mergePinShapes(
-    std::vector<gtl::polygon_90_set_data<frCoord>>& pin_shapes,
-    T* pin,
-    frInstTerm* inst_term,
-    const bool is_shrink)
+std::vector<gtl::polygon_90_set_data<frCoord>>
+FlexPA::mergePinShapes(T* pin, frInstTerm* inst_term, const bool is_shrink)
 {
+  std::vector<gtl::polygon_90_set_data<frCoord>> pin_shapes;
   frInst* inst = nullptr;
   if (inst_term) {
     inst = inst_term->getInst();
@@ -113,11 +111,10 @@ void FlexPA::prepPoint_pin_mergePinShapes(
       using boost::polygon::operators::operator+=;
       pin_shapes[layer_num] += poly;
     } else {
-      logger_->error(
-          DRT, 67, "FlexPA prepPoint_pin_mergePinShapes unsupported shape.");
-      exit(1);
+      logger_->error(DRT, 67, "FlexPA mergePinShapes unsupported shape.");
     }
   }
+  return pin_shapes;
 }
 
 void FlexPA::prepPoint_pin_genPoints_rect_genGrid(
@@ -1488,8 +1485,8 @@ int FlexPA::prepPoint_pin(T* pin, frInstTerm* inst_term)
     graphics_->startPin(pin, inst_term, inst_class);
   }
 
-  std::vector<gtl::polygon_90_set_data<frCoord>> pin_shapes;
-  prepPoint_pin_mergePinShapes(pin_shapes, pin, inst_term);
+  std::vector<gtl::polygon_90_set_data<frCoord>> pin_shapes
+      = mergePinShapes(pin, inst_term);
 
   for (auto upper : {frAccessPointEnum::OnGrid,
                      frAccessPointEnum::HalfGrid,

src/drt/src/pa/FlexPA_unique.cpp

@@ -38,9 +38,9 @@ UniqueInsts::UniqueInsts(frDesign* design,
 {
 }
 
-void UniqueInsts::getPrefTrackPatterns(
-    std::vector<frTrackPattern*>& pref_track_patterns)
+std::vector<frTrackPattern*> UniqueInsts::getPrefTrackPatterns()
 {
+  std::vector<frTrackPattern*> pref_track_patterns;
   for (const auto& track_pattern : design_->getTopBlock()->getTrackPatterns()) {
     const bool is_vertical_track = track_pattern->isHorizontal();
     const frLayerNum layer_num = track_pattern->getLayerNum();
@@ -55,11 +55,12 @@ void UniqueInsts::getPrefTrackPatterns(
       }
     }
   }
+  return pref_track_patterns;
 }
 
-void UniqueInsts::initMaster2PinLayerRange(
-    MasterLayerRange& master_to_pin_layer_range)
+UniqueInsts::MasterLayerRange UniqueInsts::initMasterToPinLayerRange()
 {
+  MasterLayerRange master_to_pin_layer_range;
   std::set<frString> masters;
   for (odb::dbInst* inst : target_insts_) {
     masters.insert(inst->getMaster()->getName());
@@ -105,6 +106,7 @@ void UniqueInsts::initMaster2PinLayerRange(
     max_layer_num = std::min(max_layer_num + 2, num_layers);
     master_to_pin_layer_range[master] = {min_layer_num, max_layer_num};
   }
+  return master_to_pin_layer_range;
 }
 
 bool UniqueInsts::hasTrackPattern(frTrackPattern* tp, const Rect& box) const
@@ -209,11 +211,9 @@ void UniqueInsts::computeUnique(
 
 void UniqueInsts::initUniqueInstance()
 {
-  std::vector<frTrackPattern*> pref_track_patterns;
-  getPrefTrackPatterns(pref_track_patterns);
+  std::vector<frTrackPattern*> pref_track_patterns = getPrefTrackPatterns();
 
-  MasterLayerRange master_to_pin_layer_range;
-  initMaster2PinLayerRange(master_to_pin_layer_range);
+  MasterLayerRange master_to_pin_layer_range = initMasterToPinLayerRange();
 
   computeUnique(master_to_pin_layer_range, pref_track_patterns);
 }

src/drt/src/pa/FlexPA_unique.h

@@ -69,21 +69,31 @@ class UniqueInsts
   void setDesign(frDesign* design) { design_ = design; }
 
  private:
-  using LayerRange = std::tuple<frLayerNum, frLayerNum>;
+  using LayerRange = std::pair<frLayerNum, frLayerNum>;
   using MasterLayerRange = std::map<frMaster*, LayerRange, frBlockObjectComp>;
 
   frDesign* getDesign() const { return design_; }
   frTechObject* getTech() const { return design_->getTech(); }
   bool isNDRInst(frInst& inst);
   bool hasTrackPattern(frTrackPattern* tp, const Rect& box) const;
 
-  void getPrefTrackPatterns(std::vector<frTrackPattern*>& pref_track_patterns);
+  /**
+   * @brief Creates a vector of preferred track patterns.
+   *
+   * Not every track pattern is a preferred one,
+   * this function acts as filter of design_->getTopBlock()->getTrackPatterns()
+   * to only take the preferred ones, which are the ones in the routing
+   * direction of the layer.
+   *
+   * @return A vector of track patterns objects.
+   */
+  std::vector<frTrackPattern*> getPrefTrackPatterns();
   void applyPatternsFile(const char* file_path);
 
   void initUniqueInstance();
   void prepPoint_pin();
 
-  void initMaster2PinLayerRange(MasterLayerRange& master_to_pin_layer_range);
+  MasterLayerRange initMasterToPinLayerRange();
 
   void computeUnique(const MasterLayerRange& master_to_pin_layer_range,
                      const std::vector<frTrackPattern*>& pref_track_patterns);