From 25a67b39acb2f7a715ea6021ddaf179e77ddf070 Mon Sep 17 00:00:00 2001
From: David Malcolm <dmalcolm@redhat.com>
Date: Wed, 16 Oct 2019 16:35:59 -0400
Subject: [PATCH 11/97] Add diagnostic_metadata and CWE support

This patch adds support for associating a diagnostic with an optional
diagnostic_metadata object, so that plugins can add extra data to their
diagnostics (e.g. mapping a diagnostic to a taxonomy or coding standard
such as from CERT or MISRA).

Currently this only supports associating a CWE identifier with a
diagnostic (which is what I'm using for the analyzer warnings later in
the patch kit), but adding a diagnostic_metadata class allows for future
growth in this area without an explosion of further "warning_at" overloads
for all of the different kinds of custom data that a plugin might want to
add.

gcc/ChangeLog:
	* common.opt (fdiagnostics-show-metadata): New option.
	* diagnostic-core.h (class diagnostic_metadata): New forward decl.
	(warning_at): Add overload taking a const diagnostic_metadata &.
	(emit_diagnostic_valist): Add overload taking a
	const diagnostic_metadata *.
	* diagnostic-format-json.cc: Include "diagnostic-metadata.h".
	(json_from_metadata): New function.
	(json_end_diagnostic): Call it to add "metadata" child for
	diagnostics with metadata.
	(diagnostic_output_format_init): Clear context->show_metadata.
	* diagnostic-metadata.h: New file.
	* diagnostic.c: Include "diagnostic-metadata.h".
	(diagnostic_impl): Add const diagnostic_metadata * param.
	(diagnostic_n_impl): Likewise.
	(diagnostic_initialize): Initialize context->show_metadata.
	(diagnostic_set_info_translated): Initialize diagnostic->metadata.
	(get_cwe_url): New function.
	(print_any_metadata): New function.
	(diagnostic_report_diagnostic): Call print_any_metadata if the
	diagnostic has non-NULL metadata.
	(emit_diagnostic): Pass NULL as the metadata in the call to
	diagnostic_impl.
	(emit_diagnostic_valist): Likewise.
	(emit_diagnostic_valist): New overload taking a
	const diagnostic_metadata *.
	(inform): Pass NULL as the metadata in the call to
	diagnostic_impl.
	(inform_n): Likewise for diagnostic_n_impl.
	(warning): Likewise.
	(warning_at): Likewise.  Add overload that takes a
	const diagnostic_metadata &.
	(warning_n): Pass NULL as the metadata in the call to
	diagnostic_n_impl.
	(pedwarn): Likewise for diagnostic_impl.
	(permerror): Likewise.
	(error): Likewise.
	(error_n): Likewise.
	(error_at): Likewise.
	(sorry): Likewise.
	(sorry_at): Likewise.
	(fatal_error): Likewise.
	(internal_error): Likewise.
	(internal_error_no_backtrace): Likewise.
	* diagnostic.h (diagnostic_info::metadata): New field.
	(diagnostic_context::show_metadata): New field.
	* doc/invoke.texi (-fno-diagnostics-show-metadata): New option.
	* opts.c (common_handle_option): Handle
	OPT_fdiagnostics_show_metadata.
	* toplev.c (general_init): Initialize global_dc->show_metadata.
---
 gcc/common.opt                |   4 ++
 gcc/diagnostic-core.h         |  10 +++
 gcc/diagnostic-format-json.cc |  23 +++++++
 gcc/diagnostic-metadata.h     |  42 +++++++++++++
 gcc/diagnostic.c              | 142 +++++++++++++++++++++++++++++++++---------
 gcc/diagnostic.h              |   7 +++
 gcc/doc/invoke.texi           |   8 +++
 gcc/opts.c                    |   4 ++
 gcc/toplev.c                  |   2 +
 9 files changed, 211 insertions(+), 31 deletions(-)
 create mode 100644 gcc/diagnostic-metadata.h

diff --git a/gcc/common.opt b/gcc/common.opt
index 3c024b3..228df32 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1334,6 +1334,10 @@ fdiagnostics-show-option
 Common Var(flag_diagnostics_show_option) Init(1)
 Amend appropriate diagnostic messages with the command line option that controls them.
 
+fdiagnostics-show-metadata
+Common Var(flag_diagnostics_show_metadata) Init(1)
+Print additional metadata for diagnostic messages, where available.
+
 fdiagnostics-minimum-margin-width=
 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
 Set minimum width of left margin of source code when showing source.
diff --git a/gcc/diagnostic-core.h b/gcc/diagnostic-core.h
index efafde4..2e7f120 100644
--- a/gcc/diagnostic-core.h
+++ b/gcc/diagnostic-core.h
@@ -45,6 +45,9 @@ class auto_diagnostic_group
   ~auto_diagnostic_group ();
 };
 
+/* Forward decl.  */
+class diagnostic_metadata; /* See diagnostic-metadata.h.  */
+
 extern const char *progname;
 
 extern const char *trim_filename (const char *);
@@ -78,6 +81,9 @@ extern bool warning_at (location_t, int, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
 extern bool warning_at (rich_location *, int, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
+extern bool warning_at (rich_location *, const diagnostic_metadata &, int,
+			const char *, ...)
+    ATTRIBUTE_GCC_DIAG(4,5);
 extern void error (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2);
 extern void error_n (location_t, unsigned HOST_WIDE_INT, const char *,
 		     const char *, ...)
@@ -109,6 +115,10 @@ extern bool emit_diagnostic (diagnostic_t, rich_location *, int,
 			     const char *, ...) ATTRIBUTE_GCC_DIAG(4,5);
 extern bool emit_diagnostic_valist (diagnostic_t, location_t, int, const char *,
 				    va_list *) ATTRIBUTE_GCC_DIAG (4,0);
+extern bool emit_diagnostic_valist (diagnostic_t, rich_location *,
+				    const diagnostic_metadata *metadata,
+				    int, const char *, va_list *)
+  ATTRIBUTE_GCC_DIAG (5,0);
 extern bool seen_error (void);
 
 #ifdef BUFSIZ
diff --git a/gcc/diagnostic-format-json.cc b/gcc/diagnostic-format-json.cc
index eb99952..200e844 100644
--- a/gcc/diagnostic-format-json.cc
+++ b/gcc/diagnostic-format-json.cc
@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "system.h"
 #include "coretypes.h"
 #include "diagnostic.h"
+#include "diagnostic-metadata.h"
 #include "json.h"
 #include "selftest.h"
 
@@ -103,6 +104,19 @@ json_from_fixit_hint (const fixit_hint *hint)
   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::number (metadata->get_cwe ()));
+
+  return metadata_obj;
+}
+
 /* No-op implementation of "begin_diagnostic" for JSON output.  */
 
 static void
@@ -211,6 +225,12 @@ json_end_diagnostic (diagnostic_context *context, diagnostic_info *diagnostic,
      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);
+    }
 }
 
 /* No-op implementation of "begin_group_cb" for JSON output.  */
@@ -268,6 +288,9 @@ diagnostic_output_format_init (diagnostic_context *context,
 	context->end_group_cb =  json_end_group;
 	context->final_cb =  json_final_cb;
 
+	/* The metadata is handled in JSON format, rather than as text.  */
+	context->show_metadata = false;
+
 	/* The option is handled in JSON format, rather than as text.  */
 	context->show_option_requested = false;
 
diff --git a/gcc/diagnostic-metadata.h b/gcc/diagnostic-metadata.h
new file mode 100644
index 0000000..a759d44
--- /dev/null
+++ b/gcc/diagnostic-metadata.h
@@ -0,0 +1,42 @@
+/* Additional metadata for a diagnostic.
+   Copyright (C) 2019 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/>.  */
+
+#ifndef GCC_DIAGNOSTIC_METADATA_H
+#define GCC_DIAGNOSTIC_METADATA_H
+
+/* A bundle of additional metadata that can be associated with a
+   diagnostic.
+
+   Currently this only supports associating a CWE identifier with a
+   diagnostic.  */
+
+class diagnostic_metadata
+{
+ public:
+  diagnostic_metadata () : m_cwe (0) {}
+
+  void add_cwe (int cwe) { m_cwe = cwe; }
+  int get_cwe () const { return m_cwe; }
+
+ private:
+  int m_cwe;
+};
+
+#endif /* ! GCC_DIAGNOSTIC_METADATA_H */
diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c
index 81e0a10..e8d0613 100644
--- a/gcc/diagnostic.c
+++ b/gcc/diagnostic.c
@@ -32,6 +32,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "diagnostic.h"
 #include "diagnostic-color.h"
 #include "diagnostic-url.h"
+#include "diagnostic-metadata.h"
 #include "edit-context.h"
 #include "selftest.h"
 #include "selftest-diagnostic.h"
@@ -58,11 +59,13 @@ along with GCC; see the file COPYING3.  If not see
 #define permissive_error_option(DC) ((DC)->opt_permissive)
 
 /* Prototypes.  */
-static bool diagnostic_impl (rich_location *, int, const char *,
-			     va_list *, diagnostic_t) ATTRIBUTE_GCC_DIAG(3,0);
-static bool diagnostic_n_impl (rich_location *, int, unsigned HOST_WIDE_INT,
+static bool diagnostic_impl (rich_location *, const diagnostic_metadata *,
+			     int, const char *,
+			     va_list *, diagnostic_t) ATTRIBUTE_GCC_DIAG(4,0);
+static bool diagnostic_n_impl (rich_location *, const diagnostic_metadata *,
+			       int, unsigned HOST_WIDE_INT,
 			       const char *, const char *, va_list *,
-			       diagnostic_t) ATTRIBUTE_GCC_DIAG(5,0);
+			       diagnostic_t) ATTRIBUTE_GCC_DIAG(6,0);
 
 static void error_recursion (diagnostic_context *) ATTRIBUTE_NORETURN;
 static void real_abort (void) ATTRIBUTE_NORETURN;
@@ -183,6 +186,7 @@ diagnostic_initialize (diagnostic_context *context, int n_opts)
   diagnostic_set_caret_max_width (context, pp_line_cutoff (context->printer));
   for (i = 0; i < rich_location::STATICALLY_ALLOCATED_RANGES; i++)
     context->caret_chars[i] = '^';
+  context->show_metadata = false;
   context->show_option_requested = false;
   context->abort_on_error = false;
   context->show_column = false;
@@ -300,6 +304,7 @@ diagnostic_set_info_translated (diagnostic_info *diagnostic, const char *msg,
   diagnostic->message.format_spec = msg;
   diagnostic->message.m_richloc = richloc;
   diagnostic->richloc = richloc;
+  diagnostic->metadata = NULL;
   diagnostic->kind = kind;
   diagnostic->option_index = 0;
 }
@@ -899,6 +904,47 @@ update_effective_level_from_pragmas (diagnostic_context *context,
   return diag_class;
 }
 
+/* Generate a URL string describing CWE.  The caller is responsible for
+   freeing the string.  */
+
+static char *
+get_cwe_url (int cwe)
+{
+  return xasprintf ("https://cwe.mitre.org/data/definitions/%i.html", cwe);
+}
+
+/* If DIAGNOSTIC has metadata, print it.
+
+   For example, if the diagnostic metadata associates it with CWE-119,
+   " [CWE-119]" will be printed, suitably colorized, and with a URL of a
+   description of the security issue.  */
+
+static void
+print_any_metadata (diagnostic_context *context,
+		    const diagnostic_info *diagnostic)
+{
+  if (diagnostic->metadata == NULL)
+    return;
+
+  int cwe = diagnostic->metadata->get_cwe ();
+  if (cwe)
+    {
+      pretty_printer *pp = context->printer;
+      char *saved_prefix = pp_take_prefix (context->printer);
+      pp_string (pp, " [");
+      pp_string (pp, colorize_start (pp_show_color (pp),
+				     diagnostic_kind_color[diagnostic->kind]));
+      char *cwe_url = get_cwe_url (cwe);
+      pp_begin_url (pp, cwe_url);
+      free (cwe_url);
+      pp_printf (pp, "CWE-%i", cwe);
+      pp_set_prefix (context->printer, saved_prefix);
+      pp_end_url (pp);
+      pp_string (pp, colorize_stop (pp_show_color (pp)));
+      pp_character (pp, ']');
+    }
+}
+
 /* Print any metadata about the option used to control DIAGNOSTIC to CONTEXT's
    printer, e.g. " [-Werror=uninitialized]".
    Subroutine of diagnostic_report_diagnostic.  */
@@ -1059,6 +1105,8 @@ diagnostic_report_diagnostic (diagnostic_context *context,
   pp_format (context->printer, &diagnostic->message);
   (*diagnostic_starter (context)) (context, diagnostic);
   pp_output_formatted_text (context->printer);
+  if (context->show_metadata)
+    print_any_metadata (context, diagnostic);
   if (context->show_option_requested)
     print_option_information (context, diagnostic, orig_diag_kind);
   (*diagnostic_finalizer (context)) (context, diagnostic, orig_diag_kind);
@@ -1190,8 +1238,8 @@ diagnostic_append_note (diagnostic_context *context,
    permerror, error, error_at, error_at, sorry, fatal_error, internal_error,
    and internal_error_no_backtrace, as documented and defined below.  */
 static bool
-diagnostic_impl (rich_location *richloc, int opt,
-		 const char *gmsgid,
+diagnostic_impl (rich_location *richloc, const diagnostic_metadata *metadata,
+		 int opt, const char *gmsgid,
 		 va_list *ap, diagnostic_t kind)
 {
   diagnostic_info diagnostic;
@@ -1207,13 +1255,15 @@ diagnostic_impl (rich_location *richloc, int opt,
       if (kind == DK_WARNING || kind == DK_PEDWARN)
 	diagnostic.option_index = opt;
     }
+  diagnostic.metadata = metadata;
   return diagnostic_report_diagnostic (global_dc, &diagnostic);
 }
 
 /* Implement inform_n, warning_n, and error_n, as documented and
    defined below.  */
 static bool
-diagnostic_n_impl (rich_location *richloc, int opt, unsigned HOST_WIDE_INT n,
+diagnostic_n_impl (rich_location *richloc, const diagnostic_metadata *metadata,
+		   int opt, unsigned HOST_WIDE_INT n,
 		   const char *singular_gmsgid,
 		   const char *plural_gmsgid,
 		   va_list *ap, diagnostic_t kind)
@@ -1233,6 +1283,7 @@ diagnostic_n_impl (rich_location *richloc, int opt, unsigned HOST_WIDE_INT n,
   diagnostic_set_info_translated (&diagnostic, text, ap, richloc, kind);
   if (kind == DK_WARNING)
     diagnostic.option_index = opt;
+  diagnostic.metadata = metadata;
   return diagnostic_report_diagnostic (global_dc, &diagnostic);
 }
 
@@ -1246,7 +1297,7 @@ emit_diagnostic (diagnostic_t kind, location_t location, int opt,
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = diagnostic_impl (&richloc, opt, gmsgid, &ap, kind);
+  bool ret = diagnostic_impl (&richloc, NULL, opt, gmsgid, &ap, kind);
   va_end (ap);
   return ret;
 }
@@ -1260,7 +1311,7 @@ emit_diagnostic (diagnostic_t kind, rich_location *richloc, int opt,
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = diagnostic_impl (richloc, opt, gmsgid, &ap, kind);
+  bool ret = diagnostic_impl (richloc, NULL, opt, gmsgid, &ap, kind);
   va_end (ap);
   return ret;
 }
@@ -1272,7 +1323,18 @@ emit_diagnostic_valist (diagnostic_t kind, location_t location, int opt,
 			const char *gmsgid, va_list *ap)
 {
   rich_location richloc (line_table, location);
-  return diagnostic_impl (&richloc, opt, gmsgid, ap, kind);
+  return diagnostic_impl (&richloc, NULL, opt, gmsgid, ap, kind);
+}
+
+/* Wrapper around diagnostic_impl taking a va_list parameter.  */
+
+bool
+emit_diagnostic_valist (diagnostic_t kind, rich_location *richloc,
+			const diagnostic_metadata *metadata,
+			int opt,
+			const char *gmsgid, va_list *ap)
+{
+  return diagnostic_impl (richloc, metadata, opt, gmsgid, ap, kind);
 }
 
 /* An informative note at LOCATION.  Use this for additional details on an error
@@ -1284,7 +1346,7 @@ inform (location_t location, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_NOTE);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_NOTE);
   va_end (ap);
 }
 
@@ -1297,7 +1359,7 @@ inform (rich_location *richloc, const char *gmsgid, ...)
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  diagnostic_impl (richloc, -1, gmsgid, &ap, DK_NOTE);
+  diagnostic_impl (richloc, NULL, -1, gmsgid, &ap, DK_NOTE);
   va_end (ap);
 }
 
@@ -1311,7 +1373,7 @@ inform_n (location_t location, unsigned HOST_WIDE_INT n,
   va_start (ap, plural_gmsgid);
   auto_diagnostic_group d;
   rich_location richloc (line_table, location);
-  diagnostic_n_impl (&richloc, -1, n, singular_gmsgid, plural_gmsgid,
+  diagnostic_n_impl (&richloc, NULL, -1, n, singular_gmsgid, plural_gmsgid,
 		     &ap, DK_NOTE);
   va_end (ap);
 }
@@ -1326,7 +1388,7 @@ warning (int opt, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, input_location);
-  bool ret = diagnostic_impl (&richloc, opt, gmsgid, &ap, DK_WARNING);
+  bool ret = diagnostic_impl (&richloc, NULL, opt, gmsgid, &ap, DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -1342,7 +1404,7 @@ warning_at (location_t location, int opt, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = diagnostic_impl (&richloc, opt, gmsgid, &ap, DK_WARNING);
+  bool ret = diagnostic_impl (&richloc, NULL, opt, gmsgid, &ap, DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -1357,7 +1419,25 @@ warning_at (rich_location *richloc, int opt, const char *gmsgid, ...)
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = diagnostic_impl (richloc, opt, gmsgid, &ap, DK_WARNING);
+  bool ret = diagnostic_impl (richloc, NULL, opt, gmsgid, &ap, DK_WARNING);
+  va_end (ap);
+  return ret;
+}
+
+/* Same as "warning at" above, but using METADATA.  */
+
+bool
+warning_at (rich_location *richloc, const diagnostic_metadata &metadata,
+	    int opt, const char *gmsgid, ...)
+{
+  gcc_assert (richloc);
+
+  auto_diagnostic_group d;
+  va_list ap;
+  va_start (ap, gmsgid);
+  bool ret
+    = diagnostic_impl (richloc, &metadata, opt, gmsgid, &ap,
+		       DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -1373,7 +1453,7 @@ warning_n (rich_location *richloc, int opt, unsigned HOST_WIDE_INT n,
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, plural_gmsgid);
-  bool ret = diagnostic_n_impl (richloc, opt, n,
+  bool ret = diagnostic_n_impl (richloc, NULL, opt, n,
 				singular_gmsgid, plural_gmsgid,
 				&ap, DK_WARNING);
   va_end (ap);
@@ -1392,7 +1472,7 @@ warning_n (location_t location, int opt, unsigned HOST_WIDE_INT n,
   va_list ap;
   va_start (ap, plural_gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = diagnostic_n_impl (&richloc, opt, n,
+  bool ret = diagnostic_n_impl (&richloc, NULL, opt, n,
 				singular_gmsgid, plural_gmsgid,
 				&ap, DK_WARNING);
   va_end (ap);
@@ -1419,7 +1499,7 @@ pedwarn (location_t location, int opt, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = diagnostic_impl (&richloc, opt, gmsgid, &ap, DK_PEDWARN);
+  bool ret = diagnostic_impl (&richloc, NULL, opt, gmsgid, &ap, DK_PEDWARN);
   va_end (ap);
   return ret;
 }
@@ -1434,7 +1514,7 @@ pedwarn (rich_location *richloc, int opt, const char *gmsgid, ...)
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = diagnostic_impl (richloc, opt, gmsgid, &ap, DK_PEDWARN);
+  bool ret = diagnostic_impl (richloc, NULL, opt, gmsgid, &ap, DK_PEDWARN);
   va_end (ap);
   return ret;
 }
@@ -1453,7 +1533,7 @@ permerror (location_t location, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_PERMERROR);
+  bool ret = diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_PERMERROR);
   va_end (ap);
   return ret;
 }
@@ -1468,7 +1548,7 @@ permerror (rich_location *richloc, const char *gmsgid, ...)
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = diagnostic_impl (richloc, -1, gmsgid, &ap, DK_PERMERROR);
+  bool ret = diagnostic_impl (richloc, NULL, -1, gmsgid, &ap, DK_PERMERROR);
   va_end (ap);
   return ret;
 }
@@ -1482,7 +1562,7 @@ error (const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, input_location);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_ERROR);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_ERROR);
   va_end (ap);
 }
 
@@ -1496,7 +1576,7 @@ error_n (location_t location, unsigned HOST_WIDE_INT n,
   va_list ap;
   va_start (ap, plural_gmsgid);
   rich_location richloc (line_table, location);
-  diagnostic_n_impl (&richloc, -1, n, singular_gmsgid, plural_gmsgid,
+  diagnostic_n_impl (&richloc, NULL, -1, n, singular_gmsgid, plural_gmsgid,
 		     &ap, DK_ERROR);
   va_end (ap);
 }
@@ -1509,7 +1589,7 @@ error_at (location_t loc, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, loc);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_ERROR);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_ERROR);
   va_end (ap);
 }
 
@@ -1523,7 +1603,7 @@ error_at (rich_location *richloc, const char *gmsgid, ...)
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  diagnostic_impl (richloc, -1, gmsgid, &ap, DK_ERROR);
+  diagnostic_impl (richloc, NULL, -1, gmsgid, &ap, DK_ERROR);
   va_end (ap);
 }
 
@@ -1537,7 +1617,7 @@ sorry (const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, input_location);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_SORRY);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_SORRY);
   va_end (ap);
 }
 
@@ -1549,7 +1629,7 @@ sorry_at (location_t loc, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, loc);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_SORRY);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_SORRY);
   va_end (ap);
 }
 
@@ -1571,7 +1651,7 @@ fatal_error (location_t loc, const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, loc);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_FATAL);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_FATAL);
   va_end (ap);
 
   gcc_unreachable ();
@@ -1588,7 +1668,7 @@ internal_error (const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, input_location);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_ICE);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_ICE);
   va_end (ap);
 
   gcc_unreachable ();
@@ -1604,7 +1684,7 @@ internal_error_no_backtrace (const char *gmsgid, ...)
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, input_location);
-  diagnostic_impl (&richloc, -1, gmsgid, &ap, DK_ICE_NOBT);
+  diagnostic_impl (&richloc, NULL, -1, gmsgid, &ap, DK_ICE_NOBT);
   va_end (ap);
 
   gcc_unreachable ();
diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
index 2fb75e6..0e4b6ad 100644
--- a/gcc/diagnostic.h
+++ b/gcc/diagnostic.h
@@ -46,6 +46,10 @@ struct diagnostic_info
   /* The location at which the diagnostic is to be reported.  */
   rich_location *richloc;
 
+  /* An optional bundle of metadata associated with the diagnostic
+     (or NULL).  */
+  const diagnostic_metadata *metadata;
+
   /* Auxiliary data for client.  */
   void *x_data;
   /* The kind of diagnostic it is about.  */
@@ -126,6 +130,9 @@ struct diagnostic_context
   /* Character used for caret diagnostics.  */
   char caret_chars[rich_location::STATICALLY_ALLOCATED_RANGES];
 
+  /* True if we should print any metadata associated with diagnostics.  */
+  bool show_metadata;
+
   /* True if we should print the command line option which controls
      each diagnostic, if known.  */
   bool show_option_requested;
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index fc92913..209e2c6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -279,6 +279,7 @@ Objective-C and Objective-C++ Dialects}.
 -fno-diagnostics-show-option  -fno-diagnostics-show-caret @gol
 -fno-diagnostics-show-labels  -fno-diagnostics-show-line-numbers @gol
 -fdiagnostics-nn-line-numbers @gol
+-fno-diagnostics-show-metadata  @gol
 -fdiagnostics-minimum-margin-width=@var{width} @gol
 -fdiagnostics-parseable-fixits  -fdiagnostics-generate-patch @gol
 -fdiagnostics-show-template-tree  -fno-elide-type @gol
@@ -4012,6 +4013,13 @@ as the types of expressions:
 This option suppresses the printing of these labels (in the example above,
 the vertical bars and the ``char *'' and ``long int'' text).
 
+@item -fno-diagnostics-show-metadata
+@opindex fno-diagnostics-show-metadata
+@opindex fdiagnostics-show-metadata
+Diagnostics can optionally contain @url{https://cwe.mitre.org/index.html, CWE}
+metadata.  By default, if this information is present, it will be printed with
+the diagnostic.  This option suppresses the printing of this metadata.
+
 @item -fno-diagnostics-show-line-numbers
 @opindex fno-diagnostics-show-line-numbers
 @opindex fdiagnostics-show-line-numbers
diff --git a/gcc/opts.c b/gcc/opts.c
index 9928d01..0caaf04 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2491,6 +2491,10 @@ common_handle_option (struct gcc_options *opts,
       dc->parseable_fixits_p = value;
       break;
 
+    case OPT_fdiagnostics_show_metadata:
+      dc->show_metadata = value;
+      break;
+
     case OPT_fdiagnostics_show_option:
       dc->show_option_requested = value;
       break;
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 2d0a390..7136164 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1102,6 +1102,8 @@ general_init (const char *argv0, bool init_signals)
     = global_options_init.x_flag_diagnostics_show_line_numbers;
   global_dc->use_nn_for_line_numbers_p
     = global_options_init.x_flag_diagnostics_nn_line_numbers;
+  global_dc->show_metadata
+    = global_options_init.x_flag_diagnostics_show_metadata;
   global_dc->show_option_requested
     = global_options_init.x_flag_diagnostics_show_option;
   global_dc->min_margin_width
-- 
1.8.5.3

