--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/diagnostic-format-json.cc	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,361 @@
+/* JSON output for diagnostics
+   Copyright (C) 2018-2020 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "diagnostic.h"
+#include "diagnostic-metadata.h"
+#include "json.h"
+#include "selftest.h"
+
+/* The top-level JSON array of pending diagnostics.  */
+
+static json::array *toplevel_array;
+
+/* The JSON object for the current diagnostic group.  */
+
+static json::object *cur_group;
+
+/* The JSON array for the "children" array within the current diagnostic
+   group.  */
+
+static json::array *cur_children_array;
+
+/* Generate a JSON object for LOC.  */
+
+json::value *
+json_from_expanded_location (location_t loc)
+{
+  expanded_location exploc = expand_location (loc);
+  json::object *result = new json::object ();
+  if (exploc.file)
+    result->set ("file", new json::string (exploc.file));
+  result->set ("line", new json::integer_number (exploc.line));
+  result->set ("column", new json::integer_number (exploc.column));
+  return result;
+}
+
+/* Generate a JSON object for LOC_RANGE.  */
+
+static json::object *
+json_from_location_range (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;
+
+  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 ();
+  result->set ("caret", json_from_expanded_location (caret_loc));
+  if (start_loc != caret_loc
+      && start_loc != UNKNOWN_LOCATION)
+    result->set ("start", json_from_expanded_location (start_loc));
+  if (finish_loc != caret_loc
+      && finish_loc != UNKNOWN_LOCATION)
+    result->set ("finish", json_from_expanded_location (finish_loc));
+
+  if (loc_range->m_label)
+    {
+      label_text text;
+      text = loc_range->m_label->get_text (range_idx);
+      if (text.m_buffer)
+	result->set ("label", new json::string (text.m_buffer));
+      text.maybe_free ();
+    }
+
+  return result;
+}
+
+/* Generate a JSON object for HINT.  */
+
+static json::object *
+json_from_fixit_hint (const fixit_hint *hint)
+{
+  json::object *fixit_obj = new json::object ();
+
+  location_t start_loc = hint->get_start_loc ();
+  fixit_obj->set ("start", json_from_expanded_location (start_loc));
+  location_t next_loc = hint->get_next_loc ();
+  fixit_obj->set ("next", json_from_expanded_location (next_loc));
+  fixit_obj->set ("string", new json::string (hint->get_string ()));
+
+  return fixit_obj;
+}
+
+/* Generate a JSON object for METADATA.  */
+
+static json::object *
+json_from_metadata (const diagnostic_metadata *metadata)
+{
+  json::object *metadata_obj = new json::object ();
+
+  if (metadata->get_cwe ())
+    metadata_obj->set ("cwe",
+		       new json::integer_number (metadata->get_cwe ()));
+
+  return metadata_obj;
+}
+
+/* No-op implementation of "begin_diagnostic" for JSON output.  */
+
+static void
+json_begin_diagnostic (diagnostic_context *, diagnostic_info *)
+{
+}
+
+/* Implementation of "end_diagnostic" for JSON output.
+   Generate a JSON object for DIAGNOSTIC, and store for output
+   within current diagnostic group.  */
+
+static void
+json_end_diagnostic (diagnostic_context *context, diagnostic_info *diagnostic,
+		     diagnostic_t orig_diag_kind)
+{
+  json::object *diag_obj = new json::object ();
+
+  /* Get "kind" of diagnostic.  */
+  {
+    static const char *const diagnostic_kind_text[] = {
+#define DEFINE_DIAGNOSTIC_KIND(K, T, C) (T),
+#include "diagnostic.def"
+#undef DEFINE_DIAGNOSTIC_KIND
+      "must-not-happen"
+    };
+    /* Lose the trailing ": ".  */
+    const char *kind_text = diagnostic_kind_text[diagnostic->kind];
+    size_t len = strlen (kind_text);
+    gcc_assert (len > 2);
+    gcc_assert (kind_text[len - 2] == ':');
+    gcc_assert (kind_text[len - 1] == ' ');
+    char *rstrip = xstrdup (kind_text);
+    rstrip[len - 2] = '\0';
+    diag_obj->set ("kind", new json::string (rstrip));
+    free (rstrip);
+  }
+
+  // FIXME: encoding of the message (json::string requires UTF-8)
+  diag_obj->set ("message",
+		 new json::string (pp_formatted_text (context->printer)));
+  pp_clear_output_area (context->printer);
+
+  char *option_text;
+  option_text = context->option_name (context, diagnostic->option_index,
+				      orig_diag_kind, diagnostic->kind);
+  if (option_text)
+    {
+      diag_obj->set ("option", new json::string (option_text));
+      free (option_text);
+    }
+
+  if (context->get_option_url)
+    {
+      char *option_url = context->get_option_url (context,
+						  diagnostic->option_index);
+      if (option_url)
+	{
+	  diag_obj->set ("option_url", new json::string (option_url));
+	  free (option_url);
+	}
+    }
+
+  /* If we've already emitted a diagnostic within this auto_diagnostic_group,
+     then add diag_obj to its "children" array.  */
+  if (cur_group)
+    {
+      gcc_assert (cur_children_array);
+      cur_children_array->append (diag_obj);
+    }
+  else
+    {
+      /* Otherwise, make diag_obj be the top-level object within the group;
+	 add a "children" array.  */
+      toplevel_array->append (diag_obj);
+      cur_group = diag_obj;
+      cur_children_array = new json::array ();
+      diag_obj->set ("children", cur_children_array);
+    }
+
+  const rich_location *richloc = diagnostic->richloc;
+
+  json::array *loc_array = new json::array ();
+  diag_obj->set ("locations", loc_array);
+
+  for (unsigned int i = 0; i < richloc->get_num_locations (); i++)
+    {
+      const location_range *loc_range = richloc->get_range (i);
+      json::object *loc_obj = json_from_location_range (loc_range, i);
+      if (loc_obj)
+	loc_array->append (loc_obj);
+    }
+
+  if (richloc->get_num_fixit_hints ())
+    {
+      json::array *fixit_array = new 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 (hint);
+	  fixit_array->append (fixit_obj);
+	}
+    }
+
+  /* TODO: tree-ish things:
+     TODO: functions
+     TODO: inlining information
+     TODO: macro expansion information.  */
+
+  if (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 && context->make_json_for_path)
+    {
+      json::value *path_value = context->make_json_for_path (context, path);
+      diag_obj->set ("path", path_value);
+    }
+}
+
+/* No-op implementation of "begin_group_cb" for JSON output.  */
+
+static void
+json_begin_group (diagnostic_context *)
+{
+}
+
+/* Implementation of "end_group_cb" for JSON output.  */
+
+static void
+json_end_group (diagnostic_context *)
+{
+  cur_group = NULL;
+  cur_children_array = NULL;
+}
+
+/* Callback for final cleanup for JSON output.  */
+
+static void
+json_final_cb (diagnostic_context *)
+{
+  /* Flush the top-level array.  */
+  toplevel_array->dump (stderr);
+  fprintf (stderr, "\n");
+  delete toplevel_array;
+  toplevel_array = NULL;
+}
+
+/* Set the output format for CONTEXT to FORMAT.  */
+
+void
+diagnostic_output_format_init (diagnostic_context *context,
+			       enum diagnostics_output_format format)
+{
+  switch (format)
+    {
+    default:
+      gcc_unreachable ();
+    case DIAGNOSTICS_OUTPUT_FORMAT_TEXT:
+      /* The default; do nothing.  */
+      break;
+
+    case DIAGNOSTICS_OUTPUT_FORMAT_JSON:
+      {
+	/* Set up top-level JSON array.  */
+	if (toplevel_array == NULL)
+	  toplevel_array = new json::array ();
+
+	/* Override callbacks.  */
+	context->begin_diagnostic = json_begin_diagnostic;
+	context->end_diagnostic = json_end_diagnostic;
+	context->begin_group_cb = json_begin_group;
+	context->end_group_cb =  json_end_group;
+	context->final_cb =  json_final_cb;
+	context->print_path = NULL; /* handled in json_end_diagnostic.  */
+
+	/* The metadata is handled in JSON format, rather than as text.  */
+	context->show_cwe = false;
+
+	/* The option is handled in JSON format, rather than as text.  */
+	context->show_option_requested = false;
+
+	/* Don't colorize the text.  */
+	pp_show_color (context->printer) = false;
+      }
+      break;
+    }
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* We shouldn't call json_from_expanded_location on UNKNOWN_LOCATION,
+   but verify that we handle this gracefully.  */
+
+static void
+test_unknown_location ()
+{
+  delete json_from_expanded_location (UNKNOWN_LOCATION);
+}
+
+/* Verify that we gracefully handle attempts to serialize bad
+   compound locations.  */
+
+static void
+test_bad_endpoints ()
+{
+  location_t bad_endpoints
+    = make_location (BUILTINS_LOCATION,
+		     UNKNOWN_LOCATION, UNKNOWN_LOCATION);
+
+  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;
+
+  json::object *obj = json_from_location_range (&loc_range, 0);
+  /* We should have a "caret" value, but no "start" or "finish" values.  */
+  ASSERT_TRUE (obj != NULL);
+  ASSERT_TRUE (obj->get ("caret") != NULL);
+  ASSERT_TRUE (obj->get ("start") == NULL);
+  ASSERT_TRUE (obj->get ("finish") == NULL);
+  delete obj;
+}
+
+/* Run all of the selftests within this file.  */
+
+void
+diagnostic_format_json_cc_tests ()
+{
+  test_unknown_location ();
+  test_bad_endpoints ();
+}
+
+} // namespace selftest
+
+#endif /* #if CHECKING_P */