diagnostics: JSON output: use std::unique_ptr throughout

No functional change intended.

gcc/ChangeLog:
	* diagnostic-format-json.cc: Include "make-unique.h".
	(json_output_format::m_toplevel_array): Convert to
	std::unique_ptr.
	(json_output_format::json_output_format): Update accordingly.
	(json_output_format::~json_output_format): Remove manual
	"delete" of field.
	(json_from_expanded_location): Convert return type to
	std::unique_ptr.
	(json_from_location_range): Likewise.  Use nullptr rather than
	NULL.
	(json_from_fixit_hint): Convert return type to std::unique_ptr.
	(json_from_metadata): Likewise.
	(make_json_for_path): Likewise.
	(json_output_format::on_end_diagnostic): Use std::unique_ptr
	throughout.
	(json_file_output_format::~json_file_output_format): Use nullptr.
	(selftest::test_unknown_location): Update to use std::unique_ptr.
	(selftest::test_bad_endpoints): Likewise.  Replace NULL with
	nullptr.

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

gcc/diagnostic-format-json.cc

@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "json.h"
 #include "selftest.h"
 #include "logical-location.h"
+#include "make-unique.h"
 
 /* Subclass of diagnostic_output_format for JSON output.  */
 
@@ -62,7 +63,7 @@ protected:
   json_output_format (diagnostic_context &context,
 		      bool formatted)
   : diagnostic_output_format (context),
-    m_toplevel_array (new json::array ()),
+    m_toplevel_array (::make_unique<json::array> ()),
     m_cur_group (nullptr),
     m_cur_children_array (nullptr),
     m_formatted (formatted)
@@ -75,31 +76,30 @@ protected:
   {
     m_toplevel_array->dump (outf, m_formatted);
     fprintf (outf, "\n");
-    delete m_toplevel_array;
     m_toplevel_array = nullptr;
   }
 
 private:
   /* The top-level JSON array of pending diagnostics.  */
-  json::array *m_toplevel_array;
+  std::unique_ptr<json::array> m_toplevel_array;
 
   /* The JSON object for the current diagnostic group.  */
-  json::object *m_cur_group;
+  json::object *m_cur_group; // borrowed
 
   /* The JSON array for the "children" array within the current diagnostic
      group.  */
-  json::array *m_cur_children_array;
+  json::array *m_cur_children_array; // borrowed
 
   bool m_formatted;
 };
 
 /* Generate a JSON object for LOC.  */
 
-static json::value *
+static std::unique_ptr<json::object>
 json_from_expanded_location (diagnostic_context &context, location_t loc)
 {
   expanded_location exploc = expand_location (loc);
-  json::object *result = new json::object ();
+  std::unique_ptr<json::object> result = ::make_unique <json::object> ();
   if (exploc.file)
     result->set_string ("file", exploc.file);
   result->set_integer ("line", exploc.line);
@@ -130,26 +130,29 @@ json_from_expanded_location (diagnostic_context &context, location_t loc)
 
 /* Generate a JSON object for LOC_RANGE.  */
 
-static json::object *
+static std::unique_ptr<json::object>
 json_from_location_range (diagnostic_context &context,
 			  const location_range *loc_range, unsigned range_idx)
 {
   location_t caret_loc = get_pure_location (loc_range->m_loc);
 
   if (caret_loc == UNKNOWN_LOCATION)
-    return NULL;
+    return nullptr;
 
   location_t start_loc = get_start (loc_range->m_loc);
   location_t finish_loc = get_finish (loc_range->m_loc);
 
-  json::object *result = new json::object ();
+  std::unique_ptr<json::object> result = ::make_unique <json::object> ();
-  result->set ("caret", json_from_expanded_location (context, caret_loc));
+  result->set ("caret",
+	       json_from_expanded_location (context, caret_loc));
   if (start_loc != caret_loc
       && start_loc != UNKNOWN_LOCATION)
-    result->set ("start", json_from_expanded_location (context, start_loc));
+    result->set ("start",
+		 json_from_expanded_location (context, start_loc));
   if (finish_loc != caret_loc
       && finish_loc != UNKNOWN_LOCATION)
-    result->set ("finish", json_from_expanded_location (context, finish_loc));
+    result->set ("finish",
+		 json_from_expanded_location (context, finish_loc));
 
   if (loc_range->m_label)
     {
@@ -163,15 +166,17 @@ json_from_location_range (diagnostic_context &context,
 
 /* Generate a JSON object for HINT.  */
 
-static json::object *
+static std::unique_ptr<json::object>
 json_from_fixit_hint (diagnostic_context &context, const fixit_hint *hint)
 {
-  json::object *fixit_obj = new json::object ();
+  std::unique_ptr<json::object> fixit_obj = ::make_unique <json::object> ();
 
   location_t start_loc = hint->get_start_loc ();
-  fixit_obj->set ("start", json_from_expanded_location (context, start_loc));
+  fixit_obj->set ("start",
+		  json_from_expanded_location (context, start_loc));
   location_t next_loc = hint->get_next_loc ();
-  fixit_obj->set ("next", json_from_expanded_location (context, next_loc));
+  fixit_obj->set ("next",
+		  json_from_expanded_location (context, next_loc). release ());
   fixit_obj->set_string ("string", hint->get_string ());
 
   return fixit_obj;
@@ -179,10 +184,10 @@ json_from_fixit_hint (diagnostic_context &context, const fixit_hint *hint)
 
 /* Generate a JSON object for METADATA.  */
 
-static json::object *
+static std::unique_ptr<json::object>
 json_from_metadata (const diagnostic_metadata *metadata)
 {
-  json::object *metadata_obj = new json::object ();
+  std::unique_ptr<json::object> metadata_obj = ::make_unique <json::object> ();
 
   if (metadata->get_cwe ())
     metadata_obj->set_integer ("cwe", metadata->get_cwe ());
@@ -192,16 +197,16 @@ json_from_metadata (const diagnostic_metadata *metadata)
 
 /* Make a JSON value for PATH.  */
 
-static json::value *
+static std::unique_ptr<json::array>
 make_json_for_path (diagnostic_context &context,
 		    const diagnostic_path *path)
 {
-  json::array *path_array = new json::array ();
+  std::unique_ptr<json::array> path_array = ::make_unique<json::array> ();
   for (unsigned i = 0; i < path->num_events (); i++)
     {
       const diagnostic_event &event = path->get_event (i);
 
-      json::object *event_obj = new json::object ();
+      std::unique_ptr<json::object> event_obj = ::make_unique <json::object> ();
       if (event.get_location ())
 	event_obj->set ("location",
 			json_from_expanded_location (context,
@@ -214,7 +219,7 @@ make_json_for_path (diagnostic_context &context,
 	  event_obj->set_string ("function", name.get ());
 	}
       event_obj->set_integer ("depth", event.get_stack_depth ());
-      path_array->append (event_obj);
+      path_array->append (std::move (event_obj));
     }
   return path_array;
 }
@@ -273,37 +278,41 @@ json_output_format::on_end_diagnostic (const diagnostic_info &diagnostic,
     {
       /* Otherwise, make diag_obj be the top-level object within the group;
 	 add a "children" array and record the column origin.  */
-      m_toplevel_array->append (diag_obj);
       m_cur_group = diag_obj;
-      m_cur_children_array = new json::array ();
+      std::unique_ptr<json::array> children_array
-      diag_obj->set ("children", m_cur_children_array);
+	= ::make_unique<json::array> ();
+      m_cur_children_array = children_array.get (); // borrowed
+      diag_obj->set ("children", std::move (children_array));
       diag_obj->set_integer ("column-origin", m_context.m_column_origin);
+      m_toplevel_array->append (diag_obj);
     }
 
+  /* diag_obj is now owned by either m_cur_children_array or
+     m_toplevel_array; further uses of diag_obj are borrowing it.  */
+
   const rich_location *richloc = diagnostic.richloc;
 
-  json::array *loc_array = new json::array ();
+  {
-  diag_obj->set ("locations", loc_array);
+    std::unique_ptr<json::array> loc_array = ::make_unique<json::array> ();
-
+    for (unsigned int i = 0; i < richloc->get_num_locations (); i++)
-  for (unsigned int i = 0; i < richloc->get_num_locations (); i++)
+      {
-    {
+	const location_range *loc_range = richloc->get_range (i);
-      const location_range *loc_range = richloc->get_range (i);
+	if (std::unique_ptr<json::object> loc_obj
-      json::object *loc_obj
+	      = json_from_location_range (m_context, loc_range, i))
-	= json_from_location_range (m_context, loc_range, i);
+	  loc_array->append (std::move (loc_obj));
-      if (loc_obj)
+      }
-	loc_array->append (loc_obj);
+    diag_obj->set ("locations", std::move (loc_array));
-    }
+  }
 
   if (richloc->get_num_fixit_hints ())
     {
-      json::array *fixit_array = new json::array ();
+      std::unique_ptr<json::array> fixit_array = ::make_unique<json::array> ();
-      diag_obj->set ("fixits", fixit_array);
       for (unsigned int i = 0; i < richloc->get_num_fixit_hints (); i++)
 	{
 	  const fixit_hint *hint = richloc->get_fixit_hint (i);
-	  json::object *fixit_obj = json_from_fixit_hint (m_context, hint);
+	  fixit_array->append (json_from_fixit_hint (m_context, hint));
-	  fixit_array->append (fixit_obj);
 	}
+      diag_obj->set ("fixits", std::move (fixit_array));
     }
 
   /* TODO: tree-ish things:
@@ -312,20 +321,13 @@ json_output_format::on_end_diagnostic (const diagnostic_info &diagnostic,
      TODO: macro expansion information.  */
 
   if (diagnostic.metadata)
-    {
+    diag_obj->set ("metadata", json_from_metadata (diagnostic.metadata));
-      json::object *metadata_obj = json_from_metadata (diagnostic.metadata);
-      diag_obj->set ("metadata", metadata_obj);
-    }
 
   const diagnostic_path *path = richloc->get_path ();
   if (path)
-    {
+    diag_obj->set ("path", make_json_for_path (m_context, path));
-      json::value *path_value = make_json_for_path (m_context, path);
-      diag_obj->set ("path", path_value);
-    }
 
-  diag_obj->set ("escape-source",
+  diag_obj->set_bool ("escape-source", richloc->escape_on_output_p ());
-		 new json::literal (richloc->escape_on_output_p ()));
 }
 
 class json_stderr_output_format : public json_output_format
@@ -359,7 +361,7 @@ public:
 
   ~json_file_output_format ()
   {
-    char *filename = concat (m_base_file_name, ".gcc.json", NULL);
+    char *filename = concat (m_base_file_name, ".gcc.json", nullptr);
     free (m_base_file_name);
     m_base_file_name = nullptr;
     FILE *outf = fopen (filename, "w");
@@ -441,7 +443,7 @@ static void
 test_unknown_location ()
 {
   test_diagnostic_context dc;
-  delete json_from_expanded_location (dc, UNKNOWN_LOCATION);
+  json_from_expanded_location (dc, UNKNOWN_LOCATION);
 }
 
 /* Verify that we gracefully handle attempts to serialize bad
@@ -457,16 +459,16 @@ test_bad_endpoints ()
   location_range loc_range;
   loc_range.m_loc = bad_endpoints;
   loc_range.m_range_display_kind = SHOW_RANGE_WITH_CARET;
-  loc_range.m_label = NULL;
+  loc_range.m_label = nullptr;
 
   test_diagnostic_context dc;
-  json::object *obj = json_from_location_range (dc, &loc_range, 0);
+  std::unique_ptr<json::object> obj
+    = json_from_location_range (dc, &loc_range, 0);
   /* We should have a "caret" value, but no "start" or "finish" values.  */
-  ASSERT_TRUE (obj != NULL);
+  ASSERT_TRUE (obj != nullptr);
-  ASSERT_TRUE (obj->get ("caret") != NULL);
+  ASSERT_TRUE (obj->get ("caret") != nullptr);
-  ASSERT_TRUE (obj->get ("start") == NULL);
+  ASSERT_TRUE (obj->get ("start") == nullptr);
-  ASSERT_TRUE (obj->get ("finish") == NULL);
+  ASSERT_TRUE (obj->get ("finish") == nullptr);
-  delete obj;
 }
 
 /* Run all of the selftests within this file.  */