TCling: Register, give access to and print list of autoparsed class.

Use `gInterpreter->Print("autoparsed");` to print a list
of the class names that directly lead to auto-parsing.

Use `gCling->GetAutoParseClasses()` to programatically get a set
of the class names that directly lead to auto-parsing.

Author: pcanal

core/metacling/src/TCling.cxx

@@ -2662,6 +2662,29 @@ void TCling::PrintIntro()
 {
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Print information about the interpreter.
+///\param[in] option Selects the type of information to print.
+///
+/// List of currently support options:
+///   - autoparsed: Print the list of classes that triggered autoparsing.
+void TCling::Print(Option_t *option) const
+{
+   if (option && *option) {
+      if (!strcmp(option, "autoparsed")) {
+         std::cout << "Auto parsed classes:" << std::endl;
+         for(auto & cls : fAutoParseClasses) {
+            std::cout << "  " << cls << std::endl;
+         }
+      } else {
+         ::Error("TCling::Print", "Unknown option '%s'", option);
+      }
+   } else {
+      ::Info("TCling::Print", "No options specified");
+   }
+}
+
+
 ////////////////////////////////////////////////////////////////////////////////
 /// \brief Add a directory to the list of directories in which the
 ///        interpreter looks for include files.
@@ -6533,6 +6556,12 @@ UInt_t TCling::AutoParseImplRecurse(const char *cls, bool topLevel)
       }
    }
 
+   if (nHheadersParsed) {
+      // Register that we did autoparsing for this class.
+      fAutoParseClasses.insert(cls);
+      if (gDebug)
+         Info("AutoParse", "Parsed %d headers for %s", nHheadersParsed, cls);
+   }
    return nHheadersParsed;
 
 }

core/metacling/src/TCling.h

@@ -121,6 +121,7 @@ class TCling final : public TInterpreter {
    std::set<size_t> fLookedUpClasses; // Set of classes for which headers were looked up already
    std::set<size_t> fPayloads; // Set of payloads
    std::set<const char*> fParsedPayloadsAddresses; // Set of payloads which were parsed
+   std::set<std::string> fAutoParseClasses; // Set of classes for which we autoparsed a header
    std::hash<std::string> fStringHashFunction; // A simple hashing function
    std::unordered_set<const clang::NamespaceDecl*> fNSFromRootmaps;   // Collection of namespaces fwd declared in the rootmaps
    TObjArray*      fRootmapFiles;     // Loaded rootmap files.
@@ -200,6 +201,7 @@ class TCling final : public TInterpreter {
    Int_t   AutoLoad(const char *classname, Bool_t knowDictNotLoaded = kFALSE) final;
    Int_t   AutoLoad(const std::type_info& typeinfo, Bool_t knowDictNotLoaded = kFALSE) final;
    Int_t   AutoParse(const char* cls) final;
+   const std::set<std::string>& GetAutoParseClasses() const { return fAutoParseClasses; }
    void*   LazyFunctionCreatorAutoload(const std::string& mangled_name);
    bool    LibraryLoadingFailed(const std::string&, const std::string&, bool, bool);
    Bool_t  IsAutoLoadNamespaceCandidate(const clang::NamespaceDecl* nsDecl);
@@ -240,6 +242,7 @@ class TCling final : public TInterpreter {
    Longptr_t ProcessLineAsynch(const char* line, EErrorCode* error = nullptr);
    Longptr_t ProcessLineSynch(const char* line, EErrorCode* error = nullptr) final;
    void    PrintIntro() final;
+   void    Print(Option_t *option="") const final;
    bool    RegisterPrebuiltModulePath(const std::string& FullPath,
                                       const std::string& ModuleMapName = "module.modulemap") const final;
    void    RegisterModule(const char* modulename,