Clean up some virtual interfaces.

- nvbench::benchmark doesn't add state, no need to override the destructor.
- nvbench::printer_base's virtual API should support decoration, not just
  overriding. Making the virtual API protected instead of private allows
  derived classes to extend base class behavior.
- nvbench::printer_base needs a virtual destructor.
- Fix a bug in nvbench::printer_multiplex that caused the new
  `get_[total|completed]_state_count()` methods to always return 0.

nvbench/benchmark.cuh

@@ -64,11 +64,6 @@ struct benchmark final : public benchmark_base
       : benchmark_base(type_axes{})
   {}
 
-  // Note that this inline virtual dtor may cause vtable issues if linking
-  // benchmark TUs together. That's not a likely scenario, so we'll deal with
-  // that if it comes up.
-  ~benchmark() override = default;
-
 private:
   std::unique_ptr<benchmark_base> do_clone() const final
   {

nvbench/csv_printer.cuh

@@ -30,7 +30,7 @@ struct csv_printer : nvbench::printer_base
 {
   using printer_base::printer_base;
 
-private:
+protected:
   // Virtual API from printer_base:
   void do_print_benchmark_results(const benchmark_vector &benches) override;
 };

nvbench/json_printer.cuh

@@ -30,7 +30,7 @@ struct json_printer : nvbench::printer_base
 {
   using printer_base::printer_base;
 
-private:
+protected:
   // Virtual API from printer_base:
   void do_print_benchmark_results(const benchmark_vector &benches) override;
 };

nvbench/markdown_printer.cuh

@@ -50,7 +50,7 @@ struct markdown_printer : nvbench::printer_base
   [[nodiscard]] bool get_color() const { return m_color; }
   /*!@}*/
 
-private:
+protected:
   // Virtual API from printer_base:
   void do_print_device_info() override;
   void do_print_log_preamble() override;

nvbench/printer_base.cuh

@@ -56,7 +56,7 @@ struct printer_base
    * Construct a new printer_base that will write to ostream.
    */
   explicit printer_base(std::ostream &ostream);
-  ~printer_base();
+  virtual ~printer_base();
 
   // move-only
   printer_base(const printer_base &) = delete;
@@ -141,12 +141,6 @@ struct printer_base
   /*!@}*/
 
 protected:
-  std::ostream &m_ostream;
-
-  std::size_t m_completed_state_count{};
-  std::size_t m_total_state_count{};
-
-private:
   // Implementation hooks for subclasses:
   virtual void do_print_device_info() {}
   virtual void do_print_log_preamble() {}
@@ -156,24 +150,17 @@ private:
   virtual void do_print_benchmark_list(const benchmark_vector &) {}
   virtual void do_print_benchmark_results(const benchmark_vector &) {}
 
-  virtual void do_set_completed_state_count(std::size_t states)
-  {
-    m_completed_state_count = states;
-  }
-  virtual void do_add_completed_state() { ++m_completed_state_count; }
-  [[nodiscard]] virtual std::size_t do_get_completed_state_count() const
-  {
-    return m_completed_state_count;
-  }
+  virtual void do_set_completed_state_count(std::size_t states);
+  virtual void do_add_completed_state();
+  [[nodiscard]] virtual std::size_t do_get_completed_state_count() const;
 
-  virtual void do_set_total_state_count(std::size_t states)
-  {
-    m_total_state_count = states;
-  }
-  [[nodiscard]] virtual std::size_t do_get_total_state_count() const
-  {
-    return m_total_state_count;
-  }
+  virtual void do_set_total_state_count(std::size_t states);
+  [[nodiscard]] virtual std::size_t do_get_total_state_count() const;
+
+  std::ostream &m_ostream;
+
+  std::size_t m_completed_state_count{};
+  std::size_t m_total_state_count{};
 };
 
 } // namespace nvbench

nvbench/printer_base.cxx

@@ -30,4 +30,26 @@ printer_base::printer_base(std::ostream &ostream)
 // Defined here to keep <ostream> out of the header
 printer_base::~printer_base() = default;
 
+void printer_base::do_set_completed_state_count(std::size_t states)
+{
+  m_completed_state_count = states;
+}
+
+void printer_base::do_add_completed_state() { ++m_completed_state_count; }
+
+std::size_t printer_base::do_get_completed_state_count() const
+{
+  return m_completed_state_count;
+}
+
+void printer_base::do_set_total_state_count(std::size_t states)
+{
+  m_total_state_count = states;
+}
+
+std::size_t printer_base::do_get_total_state_count() const
+{
+  return m_total_state_count;
+}
+
 } // namespace nvbench

nvbench/printer_multiplex.cuh

@@ -31,7 +31,6 @@ namespace nvbench
  */
 struct printer_multiplex : nvbench::printer_base
 {
-
   printer_multiplex();
 
   template <typename Format, typename... Ts>
@@ -46,7 +45,7 @@ struct printer_multiplex : nvbench::printer_base
     return m_printers.size();
   }
 
-private:
+protected:
   void do_print_device_info() override;
   void do_print_log_preamble() override;
   void do_print_log_epilogue() override;
@@ -54,7 +53,6 @@ private:
   void do_log_run_state(const nvbench::state &) override;
   void do_print_benchmark_list(const benchmark_vector &benches) override;
   void do_print_benchmark_results(const benchmark_vector &benches) override;
-
   void do_set_completed_state_count(std::size_t states) override;
   void do_add_completed_state() override;
   void do_set_total_state_count(std::size_t states) override;

nvbench/printer_multiplex.cxx

@@ -85,6 +85,7 @@ void printer_multiplex::do_print_benchmark_results(
 }
 void printer_multiplex::do_set_completed_state_count(std::size_t states)
 {
+  printer_base::do_set_completed_state_count(states);
   for (auto &format_ptr : m_printers)
   {
     format_ptr->set_completed_state_count(states);
@@ -93,6 +94,7 @@ void printer_multiplex::do_set_completed_state_count(std::size_t states)
 
 void printer_multiplex::do_add_completed_state()
 {
+  printer_base::do_add_completed_state();
   for (auto &format_ptr : m_printers)
   {
     format_ptr->add_completed_state();
@@ -101,6 +103,7 @@ void printer_multiplex::do_add_completed_state()
 
 void printer_multiplex::do_set_total_state_count(std::size_t states)
 {
+  printer_base::do_set_total_state_count(states);
   for (auto &format_ptr : m_printers)
   {
     format_ptr->set_total_state_count(states);