Add option to skip C++ metrics calculations for lambdas and nested classes

Author: Barnabás Domozi

plugins/cpp/model/include/model/cpprecord.h

@@ -49,8 +49,21 @@ typedef std::shared_ptr<CppMemberType> CppMemberTypePtr;
 #pragma db object
 struct CppRecord : CppEntity
 {
+  enum Context {
+    TOP_LEVEL,
+    NAMESPACE,
+    RECORD,
+    FUNCTION,
+    OTHER
+  };
+
   bool isAbstract = false;
   bool isPOD = false;
+  bool isLambda = false;
+
+  // Context defines where the CppRecord is located in (e.g. in a namespace).
+  // Context = RECORD means it is nested within another record.
+  Context context = Context::OTHER;
 
   std::string toString() const
   {
@@ -72,6 +85,18 @@ struct CppRecord : CppEntity
 
     return ret;
   }
+
+  std::string getContextString()
+  {
+    switch (context)
+    {
+      case Context::TOP_LEVEL: return "Top Level";
+      case Context::NAMESPACE: return "Namespace";
+      case Context::RECORD: return "Record";
+      case Context::FUNCTION: return "Function";
+      case Context::OTHER: return "Other";
+    }
+  }
 };
 
 typedef std::shared_ptr<CppRecord> CppRecordPtr;

plugins/cpp/parser/src/clangastvisitor.h

@@ -614,6 +614,20 @@ class ClangASTVisitor : public clang::RecursiveASTVisitor<ClangASTVisitor>
     cppRecord->entityHash = astNode->entityHash;
     cppRecord->name = rd_->getNameAsString();
     cppRecord->qualifiedName = rd_->getQualifiedNameAsString();
+    cppRecord->isLambda = rd_->isLambda();
+
+    const clang::DeclContext* parentDecl = rd_->getParent();
+    if (parentDecl) {
+      if (parentDecl->isTranslationUnit()) {
+        cppRecord->context = model::CppRecord::Context::TOP_LEVEL;
+      } else if (parentDecl->isNamespace()) {
+        cppRecord->context = model::CppRecord::Context::NAMESPACE;
+      } else if (parentDecl->isRecord()) {
+        cppRecord->context = model::CppRecord::Context::RECORD;
+      } else if (parentDecl->isFunctionOrMethod()) {
+        cppRecord->context = model::CppRecord::Context::FUNCTION;
+      }
+    }
 
     if (const clang::CXXRecordDecl* crd
       = llvm::dyn_cast<clang::CXXRecordDecl>(rd_))

plugins/cpp/service/src/cppservice.cpp

@@ -333,9 +333,12 @@ void CppServiceHandler::getProperties(
             return_["Abstract type"] = "true";
           if (type.isPOD)
             return_["POD type"] = "true";
+          if(type.isLambda)
+            return_["Lambda"] = "true";
 
           return_["Name"] = type.name;
           return_["Qualified name"] = type.qualifiedName;
+          return_["Context"] = type.getContextString();
         }
         else
           LOG(warning)

plugins/cpp_metrics/parser/include/cppmetricsparser/cppmetricsparser.h

@@ -7,6 +7,9 @@
 #include <model/cppastnodemetrics.h>
 #include <model/cppastnodemetrics-odb.hxx>
 
+#include <model/cppcohesionmetrics.h>
+#include <model/cppcohesionmetrics-odb.hxx>
+
 #include <model/cppfunction.h>
 #include <model/cppfunction-odb.hxx>
 
@@ -88,6 +91,8 @@ class CppMetricsParser : public AbstractParser
   void relationalCohesionModuleLevel();
   // Returns module path query based on parser configuration.
   odb::query<model::File> getModulePathsQuery();
+  // Returns cohesion record query based on parser configuration.
+  odb::query<model::CohesionCppRecordView> getCohesionRecordQuery();
 
   /// @brief Constructs an ODB query that you can use to filter only
   /// the database records of the given parameter type whose path

plugins/cpp_metrics/parser/src/cppmetricsparser.cpp

@@ -264,13 +264,28 @@ void CppMetricsParser::typeMcCabe()
   });
 }
 
+odb::query<model::CohesionCppRecordView> CppMetricsParser::getCohesionRecordQuery()
+{
+  odb::query<model::CohesionCppRecordView> query = getFilterPathsQuery<model::CohesionCppRecordView>();
+
+  if (_ctx.options.count("cppmetrics-ignore-lambdas")) {
+    query = query && odb::query<model::CohesionCppRecordView>::CppRecord::isLambda == false;
+  }
+
+  if (_ctx.options.count("cppmetrics-ignore-nested-classes")) {
+    query = query && odb::query<model::CohesionCppRecordView>::CppRecord::context != model::CppRecord::Context::RECORD;
+  }
+
+  return query;
+}
+
 void CppMetricsParser::lackOfCohesion()
 {
   // Calculate the cohesion metric for all types on parallel threads.
   parallelCalcMetric<model::CohesionCppRecordView>(
     "Lack of cohesion",
     _threadCount * lackOfCohesionPartitionMultiplier, // number of jobs; adjust for granularity
-    getFilterPathsQuery<model::CohesionCppRecordView>(),
+    getCohesionRecordQuery(),
     [&, this](const MetricsTasks<model::CohesionCppRecordView>& tasks)
   {
     util::OdbTransaction {_ctx.db} ([&, this]
@@ -376,7 +391,7 @@ void CppMetricsParser::efferentTypeLevel()
   parallelCalcMetric<model::CohesionCppRecordView>(
     "Efferent coupling of types",
     _threadCount * efferentCouplingTypesPartitionMultiplier,// number of jobs; adjust for granularity
-    getFilterPathsQuery<model::CohesionCppRecordView>(),
+    getCohesionRecordQuery(),
     [&, this](const MetricsTasks<model::CohesionCppRecordView>& tasks)
     {
       util::OdbTransaction{_ctx.db}([&, this]
@@ -456,7 +471,7 @@ void CppMetricsParser::afferentTypeLevel()
   parallelCalcMetric<model::CohesionCppRecordView>(
     "Afferent coupling of types",
     _threadCount * afferentCouplingTypesPartitionMultiplier,// number of jobs; adjust for granularity
-    getFilterPathsQuery<model::CohesionCppRecordView>(),
+    getCohesionRecordQuery(),
     [&, this](const MetricsTasks<model::CohesionCppRecordView>& tasks)
     {
       util::OdbTransaction{_ctx.db}([&, this]
@@ -697,6 +712,12 @@ extern "C"
   {
     boost::program_options::options_description description("C++ Metrics Plugin");
 
+    description.add_options()
+    ("cppmetrics-ignore-lambdas",
+      "Skip Efferent/Afferent Coupling, Lack of Cohesion C++ metrics calculations for lambdas.")
+    ("cppmetrics-ignore-nested-classes",
+      "Skip Efferent/Afferent Coupling, Lack of Cohesion C++ metrics calculations for nested classes.");
+
     return description;
   }