diagnostics: use unique_ptr for m_format_postprocessor

No functional change intended.

gcc/cp/ChangeLog:
	* error.cc (cxx_format_postprocessor::clone): Update to use
	unique_ptr.
	(cxx_dump_pretty_printer::cxx_dump_pretty_printer): Likewise.
	(cxx_initialize_diagnostics): Likewise.

gcc/ChangeLog:
	* pretty-print.cc (pretty_printer::pretty_printer): Use "nullptr"
	rather than "NULL".  Remove explicit delete of
	m_format_postprocessor.
	* pretty-print.h (format_postprocessor::clone): Use unique_ptr.
	(pretty_printer::set_format_postprocessor): New.
	(pretty_printer::m_format_postprocessor): Use unique_ptr.
	(pp_format_postprocessor): Update for use of unique_ptr, removing
	reference from return type.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

gcc/cp/error.cc

@@ -182,9 +182,10 @@ class cxx_format_postprocessor : public format_postprocessor
   : m_type_a (), m_type_b ()
   {}
 
-  format_postprocessor *clone() const final override
+  std::unique_ptr<format_postprocessor>
+  clone() const final override
   {
-    return new cxx_format_postprocessor ();
+    return std::make_unique<cxx_format_postprocessor> ();
   }
 
   void handle (pretty_printer *pp) final override;
@@ -204,8 +205,7 @@ cxx_dump_pretty_printer (int phase)
   if (outf)
     {
       pp_format_decoder (this) = cp_printer;
-      /* This gets deleted in ~pretty_printer.  */
-      pp_format_postprocessor (this) = new cxx_format_postprocessor ();
+      set_format_postprocessor (std::make_unique<cxx_format_postprocessor> ());
       set_output_stream (outf);
     }
 }
@@ -301,7 +301,7 @@ void
 cxx_initialize_diagnostics (diagnostic_context *context)
 {
   cxx_pretty_printer *pp = new cxx_pretty_printer ();
-  pp_format_postprocessor (pp) = new cxx_format_postprocessor ();
+  pp->set_format_postprocessor (std::make_unique<cxx_format_postprocessor> ());
   context->set_pretty_printer (std::unique_ptr<pretty_printer> (pp));
 
   c_common_diagnostics_set_defaults (context);

gcc/pretty-print.cc

@@ -2461,7 +2461,7 @@ pretty_printer::pretty_printer (int maximum_length)
     m_indent_skip (0),
     m_wrapping (),
     m_format_decoder (nullptr),
-    m_format_postprocessor (NULL),
+    m_format_postprocessor (nullptr),
     m_token_printer (nullptr),
     m_emitted_prefix (false),
     m_need_newline (false),
@@ -2487,7 +2487,7 @@ pretty_printer::pretty_printer (const pretty_printer &other)
   m_indent_skip (other.m_indent_skip),
   m_wrapping (other.m_wrapping),
   m_format_decoder (other.m_format_decoder),
-  m_format_postprocessor (NULL),
+  m_format_postprocessor (nullptr),
   m_token_printer (other.m_token_printer),
   m_emitted_prefix (other.m_emitted_prefix),
   m_need_newline (other.m_need_newline),
@@ -2508,8 +2508,6 @@ pretty_printer::pretty_printer (const pretty_printer &other)
 
 pretty_printer::~pretty_printer ()
 {
-  if (m_format_postprocessor)
-    delete m_format_postprocessor;
   m_buffer->~output_buffer ();
   XDELETE (m_buffer);
   free (m_prefix);

gcc/pretty-print.h

@@ -196,7 +196,7 @@ class format_postprocessor
 {
  public:
   virtual ~format_postprocessor () {}
-  virtual format_postprocessor *clone() const = 0;
+  virtual std::unique_ptr<format_postprocessor> clone() const = 0;
   virtual void handle (pretty_printer *) = 0;
 };
 
@@ -229,7 +229,7 @@ inline int & pp_indentation (pretty_printer *pp);
 inline bool & pp_translate_identifiers (pretty_printer *pp);
 inline bool & pp_show_color (pretty_printer *pp);
 inline printer_fn &pp_format_decoder (pretty_printer *pp);
-inline format_postprocessor *& pp_format_postprocessor (pretty_printer *pp);
+inline format_postprocessor *pp_format_postprocessor (pretty_printer *pp);
 inline bool & pp_show_highlight_colors (pretty_printer *pp);
 
 class urlifier;
@@ -256,7 +256,7 @@ public:
   friend bool & pp_translate_identifiers (pretty_printer *pp);
   friend bool & pp_show_color (pretty_printer *pp);
   friend printer_fn &pp_format_decoder (pretty_printer *pp);
-  friend format_postprocessor *& pp_format_postprocessor (pretty_printer *pp);
+  friend format_postprocessor * pp_format_postprocessor (pretty_printer *pp);
   friend bool & pp_show_highlight_colors (pretty_printer *pp);
 
   friend void pp_output_formatted_text (pretty_printer *,
@@ -316,6 +316,11 @@ public:
   void set_real_maximum_length ();
   int remaining_character_count_for_line ();
 
+  void set_format_postprocessor (std::unique_ptr<format_postprocessor> p)
+  {
+    m_format_postprocessor = std::move (p);
+  }
+
   void dump (FILE *out, int indent) const;
   void DEBUG_FUNCTION dump () const { dump (stderr, 0); }
 
@@ -356,7 +361,7 @@ private:
      have been processed, to allow for client-specific postprocessing.
      This is used by the C++ frontend for handling the %H and %I
      format codes (which interract with each other).  */
-  format_postprocessor *m_format_postprocessor;
+  std::unique_ptr<format_postprocessor> m_format_postprocessor;
 
   /* This is used by pp_output_formatted_text after it has converted all
      formatted chunks into a single list of tokens.
@@ -443,10 +448,10 @@ pp_format_decoder (pretty_printer *pp)
   return pp->m_format_decoder;
 }
 
-inline format_postprocessor *&
+inline format_postprocessor *
 pp_format_postprocessor (pretty_printer *pp)
 {
-  return pp->m_format_postprocessor;
+  return pp->m_format_postprocessor.get ();
 }
 
 inline bool &