[pushed:,r15-3556] diagnostics: introduce struct diagnostic_option_id

diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
index e7e371fd26f6..ec6a5da892dd 100644
--- a/gcc/c-family/c-common.cc
+++ b/gcc/c-family/c-common.cc
@@ -6787,7 +6787,7 @@  c_parse_error (const char *gmsgid, enum cpp_ttype token_type,
 /* Return the gcc option code associated with the reason for a cpp
    message, or 0 if none.  */
 
-static int
+static diagnostic_option_id
 c_option_controlling_cpp_diagnostic (enum cpp_warning_reason reason)
 {
   const struct cpp_reason_option_codes_t *entry;
@@ -6870,9 +6870,8 @@  c_cpp_diagnostic (cpp_reader *pfile ATTRIBUTE_UNUSED,
     richloc->set_range (0, input_location, SHOW_RANGE_WITH_CARET);
   diagnostic_set_info_translated (&diagnostic, msg, ap,
 				  richloc, dlevel);
-  diagnostic_override_option_index
-    (&diagnostic,
-     c_option_controlling_cpp_diagnostic (reason));
+  diagnostic_set_option_id (&diagnostic,
+			    c_option_controlling_cpp_diagnostic (reason));
   ret = diagnostic_report_diagnostic (global_dc, &diagnostic);
   if (level == CPP_DL_WARNING_SYSHDR)
     global_dc->m_warn_system_headers = save_warn_system_headers;
diff --git a/gcc/c/c-errors.cc b/gcc/c/c-errors.cc
index f36e7f9780a3..c6b7c108354b 100644
--- a/gcc/c/c-errors.cc
+++ b/gcc/c/c-errors.cc
@@ -32,7 +32,9 @@  along with GCC; see the file COPYING3.  If not see
    when C2Y is specified.  */
 
 bool
-pedwarn_c23 (location_t location, int opt, const char *gmsgid, ...)
+pedwarn_c23 (location_t location,
+	     diagnostic_option_id option_id,
+	     const char *gmsgid, ...)
 {
   diagnostic_info diagnostic;
   va_list ap;
@@ -47,7 +49,7 @@  pedwarn_c23 (location_t location, int opt, const char *gmsgid, ...)
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 			   (pedantic && !flag_isoc2y)
 			   ? DK_PEDWARN : DK_WARNING);
-      diagnostic.option_index = OPT_Wc23_c2y_compat;
+      diagnostic.option_id = OPT_Wc23_c2y_compat;
       warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   /* -Wno-c23-c2y-compat suppresses even the pedwarns.  */
@@ -57,7 +59,7 @@  pedwarn_c23 (location_t location, int opt, const char *gmsgid, ...)
   else if (pedantic && !flag_isoc2y)
     {
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc, DK_PEDWARN);
-      diagnostic.option_index = opt;
+      diagnostic.option_id = option_id;
       warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   va_end (ap);
@@ -71,7 +73,9 @@  pedwarn_c23 (location_t location, int opt, const char *gmsgid, ...)
    when C23 is specified.  */
 
 bool
-pedwarn_c11 (location_t location, int opt, const char *gmsgid, ...)
+pedwarn_c11 (location_t location,
+	     diagnostic_option_id option_id,
+	     const char *gmsgid, ...)
 {
   diagnostic_info diagnostic;
   va_list ap;
@@ -86,7 +90,7 @@  pedwarn_c11 (location_t location, int opt, const char *gmsgid, ...)
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 			   (pedantic && !flag_isoc23)
 			   ? DK_PEDWARN : DK_WARNING);
-      diagnostic.option_index = OPT_Wc11_c23_compat;
+      diagnostic.option_id = OPT_Wc11_c23_compat;
       warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   /* -Wno-c11-c23-compat suppresses even the pedwarns.  */
@@ -96,7 +100,7 @@  pedwarn_c11 (location_t location, int opt, const char *gmsgid, ...)
   else if (pedantic && !flag_isoc23)
     {
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc, DK_PEDWARN);
-      diagnostic.option_index = opt;
+      diagnostic.option_id = option_id;
       warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   va_end (ap);
@@ -110,7 +114,9 @@  pedwarn_c11 (location_t location, int opt, const char *gmsgid, ...)
    when C11 is specified.  */
 
 bool
-pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
+pedwarn_c99 (location_t location,
+	     diagnostic_option_id option_id,
+	     const char *gmsgid, ...)
 {
   diagnostic_info diagnostic;
   va_list ap;
@@ -125,7 +131,7 @@  pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 			   (pedantic && !flag_isoc11)
 			   ? DK_PEDWARN : DK_WARNING);
-      diagnostic.option_index = OPT_Wc99_c11_compat;
+      diagnostic.option_id = OPT_Wc99_c11_compat;
       warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   /* -Wno-c99-c11-compat suppresses even the pedwarns.  */
@@ -135,7 +141,7 @@  pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
   else if (pedantic && !flag_isoc11)
     {
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc, DK_PEDWARN);
-      diagnostic.option_index = opt;
+      diagnostic.option_id = option_id;
       warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   va_end (ap);
@@ -150,7 +156,9 @@  pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
    when C99 is specified.  (There is no flag_c90.)  */
 
 bool
-pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
+pedwarn_c90 (location_t location,
+	     diagnostic_option_id option_id,
+	     const char *gmsgid, ...)
 {
   diagnostic_info diagnostic;
   va_list ap;
@@ -159,9 +167,9 @@  pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
 
   va_start (ap, gmsgid);
   /* Warnings such as -Wvla are the most specific ones.  */
-  if (opt != OPT_Wpedantic)
+  if (option_id.m_idx != OPT_Wpedantic)
     {
-      int opt_var = *(int *) option_flag_var (opt, &global_options);
+      int opt_var = *(int *) option_flag_var (option_id.m_idx, &global_options);
       if (opt_var == 0)
         goto out;
       else if (opt_var > 0)
@@ -169,7 +177,7 @@  pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
 	  diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 			       (pedantic && !flag_isoc99)
 			       ? DK_PEDWARN : DK_WARNING);
-	  diagnostic.option_index = opt;
+	  diagnostic.option_id = option_id;
 	  diagnostic_report_diagnostic (global_dc, &diagnostic);
 	  warned = true;
 	  goto out;
@@ -182,7 +190,7 @@  pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 			   (pedantic && !flag_isoc99)
 			   ? DK_PEDWARN : DK_WARNING);
-      diagnostic.option_index = OPT_Wc90_c99_compat;
+      diagnostic.option_id = OPT_Wc90_c99_compat;
       diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   /* -Wno-c90-c99-compat suppresses the pedwarns.  */
@@ -192,7 +200,7 @@  pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
   else if (pedantic && !flag_isoc99)
     {
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc, DK_PEDWARN);
-      diagnostic.option_index = opt;
+      diagnostic.option_id = option_id;
       diagnostic_report_diagnostic (global_dc, &diagnostic);
       warned = true;
     }
diff --git a/gcc/c/c-tree.h b/gcc/c/c-tree.h
index 57befb94c083..b3e7bb013b6a 100644
--- a/gcc/c/c-tree.h
+++ b/gcc/c/c-tree.h
@@ -899,13 +899,13 @@  extern void c_bind (location_t, tree, bool);
 extern bool tag_exists_p (enum tree_code, tree);
 
 /* In c-errors.cc */
-extern bool pedwarn_c90 (location_t, int opt, const char *, ...)
+extern bool pedwarn_c90 (location_t, diagnostic_option_id, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
-extern bool pedwarn_c99 (location_t, int opt, const char *, ...)
+extern bool pedwarn_c99 (location_t, diagnostic_option_id, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
-extern bool pedwarn_c11 (location_t, int opt, const char *, ...)
+extern bool pedwarn_c11 (location_t, diagnostic_option_id, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
-extern bool pedwarn_c23 (location_t, int opt, const char *, ...)
+extern bool pedwarn_c23 (location_t, diagnostic_option_id, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
 
 extern void
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index b0adbb9036d9..db2a9c1543e1 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -168,7 +168,7 @@  constexpr_error (location_t location, bool constexpr_fundef_p,
     {
       diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 			   cxx_dialect < cxx23 ? DK_PEDWARN : DK_WARNING);
-      diagnostic.option_index = OPT_Winvalid_constexpr;
+      diagnostic.option_id = OPT_Winvalid_constexpr;
       ret = diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
   else
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 2eeb5e3e8b16..307e802a9c47 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7185,7 +7185,9 @@  extern const char *class_key_or_enum_as_string	(tree);
 extern void maybe_warn_variadic_templates       (void);
 extern void maybe_warn_cpp0x			(cpp0x_warn_str str,
 						 location_t = input_location);
-extern bool pedwarn_cxx98                       (location_t, int, const char *, ...) ATTRIBUTE_GCC_DIAG(3,4);
+extern bool pedwarn_cxx98                       (location_t,
+						 diagnostic_option_id option_id,
+						 const char *, ...) ATTRIBUTE_GCC_DIAG(3,4);
 extern location_t location_of                   (tree);
 extern void qualified_name_lookup_error		(tree, tree, tree,
 						 location_t);
diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc
index fbabf66376e1..f868325fac77 100644
--- a/gcc/cp/error.cc
+++ b/gcc/cp/error.cc
@@ -231,7 +231,7 @@  cp_adjust_diagnostic_info (diagnostic_context *context,
   if (diagnostic->kind == DK_ERROR)
     if (tree tmpl = get_current_template ())
       {
-	diagnostic->option_index = OPT_Wtemplate_body;
+	diagnostic->option_id = OPT_Wtemplate_body;
 
 	if (context->m_permissive)
 	  diagnostic->kind = DK_WARNING;
@@ -4768,11 +4768,13 @@  maybe_warn_variadic_templates (void)
 
 
 /* Issue an ISO C++98 pedantic warning at LOCATION, conditional on
-   option OPT with text GMSGID.  Use this function to report
+   option OPTION_ID with text GMSGID.  Use this function to report
    diagnostics for constructs that are invalid C++98, but valid
    C++0x.  */
 bool
-pedwarn_cxx98 (location_t location, int opt, const char *gmsgid, ...)
+pedwarn_cxx98 (location_t location,
+	       diagnostic_option_id option_id,
+	       const char *gmsgid, ...)
 {
   diagnostic_info diagnostic;
   va_list ap;
@@ -4782,7 +4784,7 @@  pedwarn_cxx98 (location_t location, int opt, const char *gmsgid, ...)
   va_start (ap, gmsgid);
   diagnostic_set_info (&diagnostic, gmsgid, &ap, &richloc,
 		       (cxx_dialect == cxx98) ? DK_PEDWARN : DK_WARNING);
-  diagnostic.option_index = opt;
+  diagnostic.option_id = option_id;
   ret = diagnostic_report_diagnostic (global_dc, &diagnostic);
   va_end (ap);
   return ret;
diff --git a/gcc/d/d-diagnostic.cc b/gcc/d/d-diagnostic.cc
index 5cf74ef964d4..373075ca54de 100644
--- a/gcc/d/d-diagnostic.cc
+++ b/gcc/d/d-diagnostic.cc
@@ -198,7 +198,7 @@  d_diagnostic_report_diagnostic (const Loc &loc, int opt, const char *format,
       diagnostic_set_info_translated (&diagnostic, xformat, &argp,
 				      &rich_loc, kind);
       if (opt != 0)
-	diagnostic.option_index = opt;
+	diagnostic.option_id = opt;
 
       diagnostic_report_diagnostic (global_dc, &diagnostic);
     }
diff --git a/gcc/diagnostic-core.h b/gcc/diagnostic-core.h
index 8071cc1f69b5..0fddf25403ce 100644
--- a/gcc/diagnostic-core.h
+++ b/gcc/diagnostic-core.h
@@ -51,6 +51,27 @@  class auto_diagnostic_group
 /* Forward decl.  */
 class diagnostic_metadata; /* See diagnostic-metadata.h.  */
 
+/* A class to use for the ID of an option that controls
+   a particular diagnostic.
+   This is just a wrapper around "int", but better documents
+   the intent of the code.  */
+
+struct diagnostic_option_id
+{
+  diagnostic_option_id () : m_idx (0) {}
+
+  diagnostic_option_id (int idx) : m_idx (idx) {}
+  /* Ideally we'd take an enum opt_code here, but we don't
+     want to depend on its decl.  */
+
+  bool operator== (diagnostic_option_id other) const
+  {
+    return m_idx == other.m_idx;
+  }
+
+  int m_idx;
+};
+
 extern const char *progname;
 
 extern const char *trim_filename (const char *);
@@ -73,19 +94,29 @@  extern void internal_error (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2)
 extern void internal_error_no_backtrace (const char *, ...)
      ATTRIBUTE_GCC_DIAG(1,2) ATTRIBUTE_NORETURN;
 /* Pass one of the OPT_W* from options.h as the first parameter.  */
-extern bool warning (int, const char *, ...) ATTRIBUTE_GCC_DIAG(2,3);
-extern bool warning_n (location_t, int, unsigned HOST_WIDE_INT,
+extern bool warning (diagnostic_option_id,
+		     const char *, ...) ATTRIBUTE_GCC_DIAG(2,3);
+extern bool warning_n (location_t,
+		       diagnostic_option_id,
+		       unsigned HOST_WIDE_INT,
 		       const char *, const char *, ...)
     ATTRIBUTE_GCC_DIAG(4,6) ATTRIBUTE_GCC_DIAG(5,6);
-extern bool warning_n (rich_location *, int, unsigned HOST_WIDE_INT,
+extern bool warning_n (rich_location *,
+		       diagnostic_option_id,
+		       unsigned HOST_WIDE_INT,
 		       const char *, const char *, ...)
     ATTRIBUTE_GCC_DIAG(4, 6) ATTRIBUTE_GCC_DIAG(5, 6);
-extern bool warning_at (location_t, int, const char *, ...)
+extern bool warning_at (location_t,
+			diagnostic_option_id,
+			const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
-extern bool warning_at (rich_location *, int, const char *, ...)
+extern bool warning_at (rich_location *,
+			diagnostic_option_id,
+			const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
 extern bool warning_meta (rich_location *,
-			  const diagnostic_metadata &, int,
+			  const diagnostic_metadata &,
+			  diagnostic_option_id,
 			  const char *, ...)
     ATTRIBUTE_GCC_DIAG(4,5);
 extern void error (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2);
@@ -101,17 +132,25 @@  extern void error_meta (rich_location *, const diagnostic_metadata &,
 extern void fatal_error (location_t, const char *, ...) ATTRIBUTE_GCC_DIAG(2,3)
      ATTRIBUTE_NORETURN;
 /* Pass one of the OPT_W* from options.h as the second parameter.  */
-extern bool pedwarn (location_t, int, const char *, ...)
+extern bool pedwarn (location_t,
+		     diagnostic_option_id,
+		     const char *, ...)
      ATTRIBUTE_GCC_DIAG(3,4);
-extern bool pedwarn (rich_location *, int, const char *, ...)
+extern bool pedwarn (rich_location *,
+		     diagnostic_option_id,
+		     const char *, ...)
      ATTRIBUTE_GCC_DIAG(3,4);
 extern bool permerror (location_t, const char *, ...) ATTRIBUTE_GCC_DIAG(2,3);
 extern bool permerror (rich_location *, const char *,
 				   ...) ATTRIBUTE_GCC_DIAG(2,3);
-extern bool permerror_opt (location_t, int, const char *, ...)
+extern bool permerror_opt (location_t,
+			   diagnostic_option_id,
+			   const char *, ...)
+  ATTRIBUTE_GCC_DIAG(3,4);
+extern bool permerror_opt (rich_location *,
+			   diagnostic_option_id,
+			   const char *, ...)
   ATTRIBUTE_GCC_DIAG(3,4);
-extern bool permerror_opt (rich_location *, int, const char *,
-			   ...) ATTRIBUTE_GCC_DIAG(3,4);
 extern void sorry (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2);
 extern void sorry_at (location_t, const char *, ...) ATTRIBUTE_GCC_DIAG(2,3);
 extern void inform (location_t, const char *, ...) ATTRIBUTE_GCC_DIAG(2,3);
@@ -120,16 +159,23 @@  extern void inform_n (location_t, unsigned HOST_WIDE_INT, const char *,
 		      const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,5) ATTRIBUTE_GCC_DIAG(4,5);
 extern void verbatim (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2);
-extern bool emit_diagnostic (diagnostic_t, location_t, int,
+extern bool emit_diagnostic (diagnostic_t,
+			     location_t,
+			     diagnostic_option_id,
 			     const char *, ...) ATTRIBUTE_GCC_DIAG(4,5);
-extern bool emit_diagnostic (diagnostic_t, rich_location *, int,
+extern bool emit_diagnostic (diagnostic_t,
+			     rich_location *,
+			     diagnostic_option_id,
 			     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,
+				    location_t,
+				    diagnostic_option_id,
+				    const char *, va_list *)
+  ATTRIBUTE_GCC_DIAG (4,0);
 extern bool emit_diagnostic_valist_meta (diagnostic_t,
 					 rich_location *,
 					 const diagnostic_metadata *,
-					 int,
+					 diagnostic_option_id,
 					 const char *,
 					 va_list *) ATTRIBUTE_GCC_DIAG (5,0);
 extern bool seen_error (void);
diff --git a/gcc/diagnostic-format-json.cc b/gcc/diagnostic-format-json.cc
index 3a7b07d1cb0c..a98269d5d48b 100644
--- a/gcc/diagnostic-format-json.cc
+++ b/gcc/diagnostic-format-json.cc
@@ -252,7 +252,7 @@  json_output_format::on_report_diagnostic (const diagnostic_info &diagnostic,
   diag_obj->set_string ("message", pp_formatted_text (pp));
   pp_clear_output_area (pp);
 
-  if (char *option_text = m_context.make_option_name (diagnostic.option_index,
+  if (char *option_text = m_context.make_option_name (diagnostic.option_id,
 						      orig_diag_kind,
 						      diagnostic.kind))
     {
@@ -260,7 +260,7 @@  json_output_format::on_report_diagnostic (const diagnostic_info &diagnostic,
       free (option_text);
     }
 
-  if (char *option_url = m_context.make_option_url (diagnostic.option_index))
+  if (char *option_url = m_context.make_option_url (diagnostic.option_id))
     {
       diag_obj->set_string ("option_url", option_url);
       free (option_url);
diff --git a/gcc/diagnostic-format-sarif.cc b/gcc/diagnostic-format-sarif.cc
index 1fa19ed08735..33d60a680beb 100644
--- a/gcc/diagnostic-format-sarif.cc
+++ b/gcc/diagnostic-format-sarif.cc
@@ -1642,7 +1642,7 @@  sarif_builder::make_result_object (diagnostic_context &context,
   /* "ruleId" property (SARIF v2.1.0 section 3.27.5).  */
   /* Ideally we'd have an option_name for these.  */
   if (char *option_text
-	= context.make_option_name (diagnostic.option_index,
+	= context.make_option_name (diagnostic.option_id,
 				    orig_diag_kind, diagnostic.kind))
     {
       /* Lazily create reportingDescriptor objects for and add to m_rules_arr.
@@ -1754,7 +1754,7 @@  make_reporting_descriptor_object_for_warning (diagnostic_context &context,
      it seems redundant compared to "id".  */
 
   /* "helpUri" property (SARIF v2.1.0 section 3.49.12).  */
-  if (char *option_url = context.make_option_url (diagnostic.option_index))
+  if (char *option_url = context.make_option_url (diagnostic.option_id))
     {
       reporting_desc->set_string ("helpUri", option_url);
       free (option_url);
diff --git a/gcc/diagnostic-format-text.cc b/gcc/diagnostic-format-text.cc
index fcca72a3b2b4..f87addc44b24 100644
--- a/gcc/diagnostic-format-text.cc
+++ b/gcc/diagnostic-format-text.cc
@@ -190,13 +190,13 @@  print_option_information (const diagnostic_info &diagnostic,
 			  diagnostic_t orig_diag_kind)
 {
   if (char *option_text
-      = m_context.make_option_name (diagnostic.option_index,
+      = m_context.make_option_name (diagnostic.option_id,
 				    orig_diag_kind, diagnostic.kind))
     {
       char *option_url = nullptr;
       pretty_printer * const pp = get_printer ();
       if (pp->supports_urls_p ())
-	option_url = m_context.make_option_url (diagnostic.option_index);
+	option_url = m_context.make_option_url (diagnostic.option_id);
       pp_string (pp, " [");
       const char *kind_color = diagnostic_get_color_for_kind (diagnostic.kind);
       pp_string (pp, colorize_start (pp_show_color (pp), kind_color));
diff --git a/gcc/diagnostic-global-context.cc b/gcc/diagnostic-global-context.cc
index a329b2a045ba..9e151905a6bb 100644
--- a/gcc/diagnostic-global-context.cc
+++ b/gcc/diagnostic-global-context.cc
@@ -53,15 +53,17 @@  verbatim (const char *gmsgid, ...)
    implying global_dc and taking a variable argument list.  */
 
 bool
-emit_diagnostic (diagnostic_t kind, location_t location, int opt,
+emit_diagnostic (diagnostic_t kind,
+		 location_t location,
+		 diagnostic_option_id option_id,
 		 const char *gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, opt, gmsgid, &ap,
-					 kind);
+  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, option_id,
+					 gmsgid, &ap, kind);
   va_end (ap);
   return ret;
 }
@@ -69,14 +71,16 @@  emit_diagnostic (diagnostic_t kind, location_t location, int opt,
 /* As above, but for rich_location *.  */
 
 bool
-emit_diagnostic (diagnostic_t kind, rich_location *richloc, int opt,
+emit_diagnostic (diagnostic_t kind,
+		 rich_location *richloc,
+		 diagnostic_option_id option_id,
 		 const char *gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = global_dc->diagnostic_impl (richloc, nullptr, opt, gmsgid, &ap,
-					 kind);
+  bool ret = global_dc->diagnostic_impl (richloc, nullptr, option_id,
+					 gmsgid, &ap, kind);
   va_end (ap);
   return ret;
 }
@@ -84,11 +88,14 @@  emit_diagnostic (diagnostic_t kind, rich_location *richloc, int opt,
 /* As above, but taking a variable argument list.  */
 
 bool
-emit_diagnostic_valist (diagnostic_t kind, location_t location, int opt,
+emit_diagnostic_valist (diagnostic_t kind,
+			location_t location,
+			diagnostic_option_id option_id,
 			const char *gmsgid, va_list *ap)
 {
   rich_location richloc (line_table, location);
-  return global_dc->diagnostic_impl (&richloc, nullptr, opt, gmsgid, ap, kind);
+  return global_dc->diagnostic_impl (&richloc, nullptr, option_id,
+				     gmsgid, ap, kind);
 }
 
 /* As above, but with rich_location and metadata.  */
@@ -97,10 +104,11 @@  bool
 emit_diagnostic_valist_meta (diagnostic_t kind,
 			     rich_location *richloc,
 			     const diagnostic_metadata *metadata,
-			     int opt,
+			     diagnostic_option_id option_id,
 			     const char *gmsgid, va_list *ap)
 {
-  return global_dc->diagnostic_impl (richloc, metadata, opt, gmsgid, ap, kind);
+  return global_dc->diagnostic_impl (richloc, metadata, option_id,
+				     gmsgid, ap, kind);
 }
 
 /* An informative note at LOCATION.  Use this for additional details on an error
@@ -149,14 +157,14 @@  inform_n (location_t location, unsigned HOST_WIDE_INT n,
    to the relevant language specification but is likely to be buggy anyway.
    Returns true if the warning was printed, false if it was inhibited.  */
 bool
-warning (int opt, const char *gmsgid, ...)
+warning (diagnostic_option_id option_id, const char *gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, input_location);
-  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, opt, gmsgid, &ap,
-					 DK_WARNING);
+  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -166,14 +174,16 @@  warning (int opt, const char *gmsgid, ...)
    Returns true if the warning was printed, false if it was inhibited.  */
 
 bool
-warning_at (location_t location, int opt, const char *gmsgid, ...)
+warning_at (location_t location,
+	    diagnostic_option_id option_id,
+	    const char *gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, opt, gmsgid, &ap,
-					 DK_WARNING);
+  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -181,15 +191,17 @@  warning_at (location_t location, int opt, const char *gmsgid, ...)
 /* Same as "warning at" above, but using RICHLOC.  */
 
 bool
-warning_at (rich_location *richloc, int opt, const char *gmsgid, ...)
+warning_at (rich_location *richloc,
+	    diagnostic_option_id option_id,
+	    const char *gmsgid, ...)
 {
   gcc_assert (richloc);
 
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = global_dc->diagnostic_impl (richloc, nullptr, opt, gmsgid, &ap,
-					 DK_WARNING);
+  bool ret = global_dc->diagnostic_impl (richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -199,15 +211,16 @@  warning_at (rich_location *richloc, int opt, const char *gmsgid, ...)
 bool
 warning_meta (rich_location *richloc,
 	      const diagnostic_metadata &metadata,
-	      int opt, const char *gmsgid, ...)
+	      diagnostic_option_id option_id,
+	      const char *gmsgid, ...)
 {
   gcc_assert (richloc);
 
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = global_dc->diagnostic_impl (richloc, &metadata, opt, gmsgid, &ap,
-					 DK_WARNING);
+  bool ret = global_dc->diagnostic_impl (richloc, &metadata, option_id,
+					 gmsgid, &ap, DK_WARNING);
   va_end (ap);
   return ret;
 }
@@ -215,7 +228,9 @@  warning_meta (rich_location *richloc,
 /* Same as warning_n plural variant below, but using RICHLOC.  */
 
 bool
-warning_n (rich_location *richloc, int opt, unsigned HOST_WIDE_INT n,
+warning_n (rich_location *richloc,
+	   diagnostic_option_id option_id,
+	   unsigned HOST_WIDE_INT n,
 	   const char *singular_gmsgid, const char *plural_gmsgid, ...)
 {
   gcc_assert (richloc);
@@ -223,7 +238,7 @@  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 = global_dc->diagnostic_n_impl (richloc, nullptr, opt, n,
+  bool ret = global_dc->diagnostic_n_impl (richloc, nullptr, option_id, n,
 					   singular_gmsgid, plural_gmsgid,
 					   &ap, DK_WARNING);
   va_end (ap);
@@ -235,14 +250,16 @@  warning_n (rich_location *richloc, int opt, unsigned HOST_WIDE_INT n,
    Returns true if the warning was printed, false if it was inhibited.  */
 
 bool
-warning_n (location_t location, int opt, unsigned HOST_WIDE_INT n,
+warning_n (location_t location,
+	   diagnostic_option_id option_id,
+	   unsigned HOST_WIDE_INT n,
 	   const char *singular_gmsgid, const char *plural_gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, plural_gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = global_dc->diagnostic_n_impl (&richloc, nullptr, opt, n,
+  bool ret = global_dc->diagnostic_n_impl (&richloc, nullptr, option_id, n,
 					   singular_gmsgid, plural_gmsgid,
 					   &ap, DK_WARNING);
   va_end (ap);
@@ -263,14 +280,16 @@  warning_n (location_t location, int opt, unsigned HOST_WIDE_INT n,
    Returns true if the warning was printed, false if it was inhibited.  */
 
 bool
-pedwarn (location_t location, int opt, const char *gmsgid, ...)
+pedwarn (location_t location,
+	 diagnostic_option_id option_id,
+	 const char *gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, opt, gmsgid, &ap,
-					 DK_PEDWARN);
+  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_PEDWARN);
   va_end (ap);
   return ret;
 }
@@ -278,15 +297,17 @@  pedwarn (location_t location, int opt, const char *gmsgid, ...)
 /* Same as pedwarn above, but using RICHLOC.  */
 
 bool
-pedwarn (rich_location *richloc, int opt, const char *gmsgid, ...)
+pedwarn (rich_location *richloc,
+	 diagnostic_option_id option_id,
+	 const char *gmsgid, ...)
 {
   gcc_assert (richloc);
 
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = global_dc->diagnostic_impl (richloc, nullptr, opt, gmsgid, &ap,
-					 DK_PEDWARN);
+  bool ret = global_dc->diagnostic_impl (richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_PEDWARN);
   va_end (ap);
   return ret;
 }
@@ -332,14 +353,16 @@  permerror (rich_location *richloc, const char *gmsgid, ...)
    diagnostic can also be downgraded by -Wno-error=opt.  */
 
 bool
-permerror_opt (location_t location, int opt, const char *gmsgid, ...)
+permerror_opt (location_t location,
+	       diagnostic_option_id option_id,
+	       const char *gmsgid, ...)
 {
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
   rich_location richloc (line_table, location);
-  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, opt, gmsgid, &ap,
-					 DK_PERMERROR);
+  bool ret = global_dc->diagnostic_impl (&richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_PERMERROR);
   va_end (ap);
   return ret;
 }
@@ -347,15 +370,17 @@  permerror_opt (location_t location, int opt, const char *gmsgid, ...)
 /* Same as "permerror" above, but at RICHLOC.  */
 
 bool
-permerror_opt (rich_location *richloc, int opt, const char *gmsgid, ...)
+permerror_opt (rich_location *richloc,
+	       diagnostic_option_id option_id,
+	       const char *gmsgid, ...)
 {
   gcc_assert (richloc);
 
   auto_diagnostic_group d;
   va_list ap;
   va_start (ap, gmsgid);
-  bool ret = global_dc->diagnostic_impl (richloc, nullptr, opt, gmsgid, &ap,
-					 DK_PERMERROR);
+  bool ret = global_dc->diagnostic_impl (richloc, nullptr, option_id,
+					 gmsgid, &ap, DK_PERMERROR);
   va_end (ap);
   return ret;
 }
diff --git a/gcc/diagnostic.cc b/gcc/diagnostic.cc
index 0e0ab7aeb838..03fc346501e4 100644
--- a/gcc/diagnostic.cc
+++ b/gcc/diagnostic.cc
@@ -482,7 +482,7 @@  diagnostic_set_info_translated (diagnostic_info *diagnostic, const char *msg,
   diagnostic->richloc = richloc;
   diagnostic->metadata = NULL;
   diagnostic->kind = kind;
-  diagnostic->option_index = 0;
+  diagnostic->option_id = 0;
 }
 
 /* Initialize DIAGNOSTIC, where the message GMSGID has not yet been
@@ -1004,23 +1004,23 @@  default_diagnostic_finalizer (diagnostic_context *context,
 
 /* Interface to specify diagnostic kind overrides.  Returns the
    previous setting, or DK_UNSPECIFIED if the parameters are out of
-   range.  If OPTION_INDEX is zero, the new setting is for all the
+   range.  If OPTION_ID is zero, the new setting is for all the
    diagnostics.  */
 diagnostic_t
 diagnostic_option_classifier::
 classify_diagnostic (const diagnostic_context *context,
-		     int option_index,
+		     diagnostic_option_id option_id,
 		     diagnostic_t new_kind,
 		     location_t where)
 {
   diagnostic_t old_kind;
 
-  if (option_index < 0
-      || option_index >= m_n_opts
+  if (option_id.m_idx < 0
+      || option_id.m_idx >= m_n_opts
       || new_kind >= DK_LAST_DIAGNOSTIC_KIND)
     return DK_UNSPECIFIED;
 
-  old_kind = m_classify_diagnostic[option_index];
+  old_kind = m_classify_diagnostic[option_id.m_idx];
 
   /* Handle pragmas separately, since we need to keep track of *where*
      the pragmas were.  */
@@ -1031,13 +1031,13 @@  classify_diagnostic (const diagnostic_context *context,
       /* Record the command-line status, so we can reset it back on DK_POP. */
       if (old_kind == DK_UNSPECIFIED)
 	{
-	  old_kind = !context->option_enabled_p (option_index)
+	  old_kind = !context->option_enabled_p (option_id)
 	    ? DK_IGNORED : DK_ANY;
-	  m_classify_diagnostic[option_index] = old_kind;
+	  m_classify_diagnostic[option_id.m_idx] = old_kind;
 	}
 
       for (i = m_n_classification_history - 1; i >= 0; i --)
-	if (m_classification_history[i].option == option_index)
+	if (m_classification_history[i].option == option_id.m_idx)
 	  {
 	    old_kind = m_classification_history[i].kind;
 	    break;
@@ -1048,12 +1048,12 @@  classify_diagnostic (const diagnostic_context *context,
 	(diagnostic_classification_change_t *) xrealloc (m_classification_history, (i + 1)
 							 * sizeof (diagnostic_classification_change_t));
       m_classification_history[i].location = where;
-      m_classification_history[i].option = option_index;
+      m_classification_history[i].option = option_id.m_idx;
       m_classification_history[i].kind = new_kind;
       m_n_classification_history ++;
     }
   else
-    m_classify_diagnostic[option_index] = new_kind;
+    m_classify_diagnostic[option_id.m_idx] = new_kind;
 
   return old_kind;
 }
@@ -1205,9 +1205,9 @@  update_effective_level_from_pragmas (diagnostic_info *diagnostic) const
 	      continue;
 	    }
 
-	  int option = hist.option;
+	  diagnostic_option_id option = hist.option;
 	  /* The option 0 is for all the diagnostics.  */
-	  if (option == 0 || option == diagnostic->option_index)
+	  if (option == 0 || option == diagnostic->option_id)
 	    {
 	      diagnostic_t kind = hist.kind;
 	      if (kind != DK_UNSPECIFIED)
@@ -1239,13 +1239,13 @@  diagnostic_context::diagnostic_enabled (diagnostic_info *diagnostic)
   get_any_inlining_info (diagnostic);
 
   /* Diagnostics with no option or -fpermissive are always enabled.  */
-  if (!diagnostic->option_index
-      || diagnostic->option_index == m_opt_permissive)
+  if (!diagnostic->option_id.m_idx
+      || diagnostic->option_id == m_opt_permissive)
     return true;
 
   /* This tests if the user provided the appropriate -Wfoo or
      -Wno-foo option.  */
-  if (!option_enabled_p (diagnostic->option_index))
+  if (!option_enabled_p (diagnostic->option_id))
     return false;
 
   /* This tests for #pragma diagnostic changes.  */
@@ -1255,10 +1255,10 @@  diagnostic_context::diagnostic_enabled (diagnostic_info *diagnostic)
   /* This tests if the user provided the appropriate -Werror=foo
      option.  */
   if (diag_class == DK_UNSPECIFIED
-      && !option_unspecified_p (diagnostic->option_index))
+      && !option_unspecified_p (diagnostic->option_id))
     {
       const diagnostic_t new_kind
-	= m_option_classifier.get_current_override (diagnostic->option_index);
+	= m_option_classifier.get_current_override (diagnostic->option_id);
       if (new_kind != DK_ANY)
 	/* DK_ANY means the diagnostic is not to be ignored, but we don't want
 	   to change it specifically to DK_ERROR or DK_WARNING; we want to
@@ -1274,17 +1274,18 @@  diagnostic_context::diagnostic_enabled (diagnostic_info *diagnostic)
   return true;
 }
 
-/* Returns whether warning OPT is enabled at LOC.  */
+/* Returns whether warning OPTION_ID is enabled at LOC.  */
 
 bool
-diagnostic_context::warning_enabled_at (location_t loc, int opt)
+diagnostic_context::warning_enabled_at (location_t loc,
+					diagnostic_option_id option_id)
 {
   if (!diagnostic_report_warnings_p (this, loc))
     return false;
 
   rich_location richloc (line_table, loc);
   diagnostic_info diagnostic = {};
-  diagnostic.option_index = opt;
+  diagnostic.option_id = option_id;
   diagnostic.richloc = &richloc;
   diagnostic.message.m_richloc = &richloc;
   diagnostic.kind = DK_WARNING;
@@ -1527,7 +1528,8 @@  diagnostic_append_note (diagnostic_context *context,
 bool
 diagnostic_context::diagnostic_impl (rich_location *richloc,
 				     const diagnostic_metadata *metadata,
-				     int opt, const char *gmsgid,
+				     diagnostic_option_id option_id,
+				     const char *gmsgid,
 				     va_list *ap, diagnostic_t kind)
 {
   diagnostic_info diagnostic;
@@ -1535,13 +1537,13 @@  diagnostic_context::diagnostic_impl (rich_location *richloc,
     {
       diagnostic_set_info (&diagnostic, gmsgid, ap, richloc,
 			   m_permissive ? DK_WARNING : DK_ERROR);
-      diagnostic.option_index = (opt != -1 ? opt : m_opt_permissive);
+      diagnostic.option_id = (option_id.m_idx != -1 ? option_id : m_opt_permissive);
     }
   else
     {
       diagnostic_set_info (&diagnostic, gmsgid, ap, richloc, kind);
       if (kind == DK_WARNING || kind == DK_PEDWARN)
-	diagnostic.option_index = opt;
+	diagnostic.option_id = option_id;
     }
   diagnostic.metadata = metadata;
   return report_diagnostic (&diagnostic);
@@ -1552,7 +1554,8 @@  diagnostic_context::diagnostic_impl (rich_location *richloc,
 bool
 diagnostic_context::diagnostic_n_impl (rich_location *richloc,
 				       const diagnostic_metadata *metadata,
-				       int opt, unsigned HOST_WIDE_INT n,
+				       diagnostic_option_id option_id,
+				       unsigned HOST_WIDE_INT n,
 				       const char *singular_gmsgid,
 				       const char *plural_gmsgid,
 				       va_list *ap, diagnostic_t kind)
@@ -1571,7 +1574,7 @@  diagnostic_context::diagnostic_n_impl (rich_location *richloc,
   const char *text = ngettext (singular_gmsgid, plural_gmsgid, gtn);
   diagnostic_set_info_translated (&diagnostic, text, ap, richloc, kind);
   if (kind == DK_WARNING)
-    diagnostic.option_index = opt;
+    diagnostic.option_id = option_id;
   diagnostic.metadata = metadata;
   return report_diagnostic (&diagnostic);
 }
diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
index 7244f425936c..b7c38267bd08 100644
--- a/gcc/diagnostic.h
+++ b/gcc/diagnostic.h
@@ -136,7 +136,7 @@  enum diagnostic_text_art_charset
 struct diagnostic_info
 {
   diagnostic_info ()
-    : message (), richloc (), metadata (), x_data (), kind (), option_index (),
+    : message (), richloc (), metadata (), x_data (), kind (), option_id (),
       m_iinfo ()
   { }
 
@@ -155,7 +155,7 @@  struct diagnostic_info
   /* The kind of diagnostic it is about.  */
   diagnostic_t kind;
   /* Which OPT_* directly controls this diagnostic.  */
-  int option_index;
+  diagnostic_option_id option_id;
 
   /* Inlining context containing locations for each call site along
      the inlining stack.  */
@@ -189,17 +189,17 @@  class diagnostic_option_manager
 public:
   virtual ~diagnostic_option_manager () {}
 
-  /* Return 1 if option OPT_IDX is enabled, 0 if it is disabled,
+  /* Return 1 if option OPTION_ID is enabled, 0 if it is disabled,
      or -1 if it isn't a simple on-off switch
      (or if the value is unknown, typically set later in target).  */
-  virtual int option_enabled_p (int opt_idx) const = 0;
+  virtual int option_enabled_p (diagnostic_option_id option_id) const = 0;
 
-  /* Return malloced memory for the name of the option OPT_IDX
+  /* Return malloced memory for the name of the option OPTION_ID
      which enabled a diagnostic, originally of type ORIG_DIAG_KIND but
      possibly converted to DIAG_KIND by options such as -Werror.
      May return NULL if no name is to be printed.
      May be passed 0 as well as the index of a particular option.  */
-  virtual char *make_option_name (int opt_idx,
+  virtual char *make_option_name (diagnostic_option_id option_id,
 				  diagnostic_t orig_diag_kind,
 				  diagnostic_t diag_kind) const = 0;
 
@@ -207,7 +207,7 @@  public:
      a diagnostic.
      May return NULL if no URL is available.
      May be passed 0 as well as the index of a particular option.  */
-  virtual char *make_option_url (int opt_idx) const = 0;
+  virtual char *make_option_url (diagnostic_option_id option_id) const = 0;
 };
 
 class edit_context;
@@ -236,20 +236,20 @@  public:
      is empty, revert to the state based on command line parameters.  */
   void pop (location_t where);
 
-  bool option_unspecified_p (int opt) const
+  bool option_unspecified_p (diagnostic_option_id option_id) const
   {
-    return get_current_override (opt) == DK_UNSPECIFIED;
+    return get_current_override (option_id) == DK_UNSPECIFIED;
   }
 
-  diagnostic_t get_current_override (int opt) const
+  diagnostic_t get_current_override (diagnostic_option_id option_id) const
   {
-    gcc_assert (opt < m_n_opts);
-    return m_classify_diagnostic[opt];
+    gcc_assert (option_id.m_idx < m_n_opts);
+    return m_classify_diagnostic[option_id.m_idx];
   }
 
   diagnostic_t
   classify_diagnostic (const diagnostic_context *context,
-		       int option_index,
+		       diagnostic_option_id option_id,
 		       diagnostic_t new_kind,
 		       location_t where);
 
@@ -263,7 +263,12 @@  private:
   struct diagnostic_classification_change_t
   {
     location_t location;
+
+    /* For DK_POP, this is the index of the corresponding push (as stored
+       in m_push_list).
+       Otherwise, this is an option index.  */
     int option;
+
     diagnostic_t kind;
   };
 
@@ -386,11 +391,11 @@  public:
   void begin_group ();
   void end_group ();
 
-  bool warning_enabled_at (location_t loc, int opt);
+  bool warning_enabled_at (location_t loc, diagnostic_option_id option_id);
 
-  bool option_unspecified_p (int opt) const
+  bool option_unspecified_p (diagnostic_option_id option_id) const
   {
-    return m_option_classifier.option_unspecified_p (opt);
+    return m_option_classifier.option_unspecified_p (option_id);
   }
 
   bool report_diagnostic (diagnostic_info *);
@@ -401,12 +406,12 @@  public:
   void action_after_output (diagnostic_t diag_kind);
 
   diagnostic_t
-  classify_diagnostic (int option_index,
+  classify_diagnostic (diagnostic_option_id option_id,
 		       diagnostic_t new_kind,
 		       location_t where)
   {
     return m_option_classifier.classify_diagnostic (this,
-						    option_index,
+						    option_id,
 						    new_kind,
 						    where);
   }
@@ -507,29 +512,29 @@  public:
   }
 
   /* Option-related member functions.  */
-  inline bool option_enabled_p (int option_index) const
+  inline bool option_enabled_p (diagnostic_option_id option_id) const
   {
     if (!m_option_mgr)
       return true;
-    return m_option_mgr->option_enabled_p (option_index);
+    return m_option_mgr->option_enabled_p (option_id);
   }
 
-  inline char *make_option_name (int option_index,
-				diagnostic_t orig_diag_kind,
-				diagnostic_t diag_kind) const
+  inline char *make_option_name (diagnostic_option_id option_id,
+				 diagnostic_t orig_diag_kind,
+				 diagnostic_t diag_kind) const
   {
     if (!m_option_mgr)
       return nullptr;
-    return m_option_mgr->make_option_name (option_index,
+    return m_option_mgr->make_option_name (option_id,
 					   orig_diag_kind,
 					   diag_kind);
   }
 
-  inline char *make_option_url (int option_index) const
+  inline char *make_option_url (diagnostic_option_id option_id) const
   {
     if (!m_option_mgr)
       return nullptr;
-    return m_option_mgr->make_option_url (option_index);
+    return m_option_mgr->make_option_url (option_id);
   }
 
   void
@@ -544,10 +549,10 @@  public:
   label_text get_location_text (const expanded_location &s) const;
 
   bool diagnostic_impl (rich_location *, const diagnostic_metadata *,
-			int, const char *,
+			diagnostic_option_id, const char *,
 			va_list *, diagnostic_t) ATTRIBUTE_GCC_DIAG(5,0);
   bool diagnostic_n_impl (rich_location *, const diagnostic_metadata *,
-			  int, unsigned HOST_WIDE_INT,
+			  diagnostic_option_id, unsigned HOST_WIDE_INT,
 			  const char *, const char *, va_list *,
 			  diagnostic_t) ATTRIBUTE_GCC_DIAG(7,0);
 
@@ -850,9 +855,10 @@  diagnostic_ready_p ()
    diagnostic.  */
 
 inline void
-diagnostic_override_option_index (diagnostic_info *info, int optidx)
+diagnostic_set_option_id (diagnostic_info *info,
+			  diagnostic_option_id option_id)
 {
-  info->option_index = optidx;
+  info->option_id = option_id;
 }
 
 /* Diagnostic related functions.  */
@@ -925,11 +931,11 @@  diagnostic_initialize_input_context (diagnostic_context *context,
 /* Force diagnostics controlled by OPTIDX to be kind KIND.  */
 inline diagnostic_t
 diagnostic_classify_diagnostic (diagnostic_context *context,
-				int optidx,
+				diagnostic_option_id option_id,
 				diagnostic_t kind,
 				location_t where)
 {
-  return context->classify_diagnostic (optidx, kind, where);
+  return context->classify_diagnostic (option_id, kind, where);
 }
 
 inline void
@@ -1052,15 +1058,15 @@  extern char *build_message_string (const char *, ...) ATTRIBUTE_PRINTF_1;
 extern int num_digits (int);
 
 inline bool
-warning_enabled_at (location_t loc, int opt)
+warning_enabled_at (location_t loc, diagnostic_option_id option_id)
 {
-  return global_dc->warning_enabled_at (loc, opt);
+  return global_dc->warning_enabled_at (loc, option_id);
 }
 
 inline bool
-option_unspecified_p (int opt)
+option_unspecified_p (diagnostic_option_id option_id)
 {
-  return global_dc->option_unspecified_p (opt);
+  return global_dc->option_unspecified_p (option_id);
 }
 
 extern char *get_cwe_url (int cwe);
diff --git a/gcc/fortran/cpp.cc b/gcc/fortran/cpp.cc
index 3a6dbdc2003c..7c5f00cfd690 100644
--- a/gcc/fortran/cpp.cc
+++ b/gcc/fortran/cpp.cc
@@ -1057,7 +1057,7 @@  cb_used_define (cpp_reader *pfile, location_t line ATTRIBUTE_UNUSED,
 /* Return the gcc option code associated with the reason for a cpp
    message, or 0 if none.  */
 
-static int
+static diagnostic_option_id
 cb_cpp_diagnostic_cpp_option (enum cpp_warning_reason reason)
 {
   const struct cpp_reason_option_codes_t *entry;
@@ -1115,8 +1115,8 @@  cb_cpp_diagnostic (cpp_reader *pfile ATTRIBUTE_UNUSED,
     }
   diagnostic_set_info_translated (&diagnostic, msg, ap,
 				  richloc, dlevel);
-  diagnostic_override_option_index (&diagnostic,
-				    cb_cpp_diagnostic_cpp_option (reason));
+  diagnostic_set_option_id (&diagnostic,
+			    cb_cpp_diagnostic_cpp_option (reason));
   ret = diagnostic_report_diagnostic (global_dc, &diagnostic);
   if (level == CPP_DL_WARNING_SYSHDR)
     global_dc->m_warn_system_headers = save_warn_system_headers;
diff --git a/gcc/fortran/error.cc b/gcc/fortran/error.cc
index e328dbd13fc5..6a7f0b052bc5 100644
--- a/gcc/fortran/error.cc
+++ b/gcc/fortran/error.cc
@@ -978,7 +978,7 @@  gfc_warning (int opt, const char *gmsgid, va_list ap)
 
   diagnostic_set_info (&diagnostic, gmsgid, &argp, &rich_loc,
 		       DK_WARNING);
-  diagnostic.option_index = opt;
+  diagnostic.option_id = opt;
   bool ret = gfc_report_diagnostic (&diagnostic);
 
   if (buffered_p)
@@ -1367,7 +1367,7 @@  gfc_warning_now_at (location_t loc, int opt, const char *gmsgid, ...)
 
   va_start (argp, gmsgid);
   diagnostic_set_info (&diagnostic, gmsgid, &argp, &rich_loc, DK_WARNING);
-  diagnostic.option_index = opt;
+  diagnostic.option_id = opt;
   ret = gfc_report_diagnostic (&diagnostic);
   va_end (argp);
   return ret;
@@ -1386,7 +1386,7 @@  gfc_warning_now (int opt, const char *gmsgid, ...)
   va_start (argp, gmsgid);
   diagnostic_set_info (&diagnostic, gmsgid, &argp, &rich_loc,
 		       DK_WARNING);
-  diagnostic.option_index = opt;
+  diagnostic.option_id = opt;
   ret = gfc_report_diagnostic (&diagnostic);
   va_end (argp);
   return ret;
@@ -1405,7 +1405,7 @@  gfc_warning_internal (int opt, const char *gmsgid, ...)
   va_start (argp, gmsgid);
   diagnostic_set_info (&diagnostic, gmsgid, &argp, &rich_loc,
 		       DK_WARNING);
-  diagnostic.option_index = opt;
+  diagnostic.option_id = opt;
   ret = gfc_report_diagnostic (&diagnostic);
   va_end (argp);
   return ret;
diff --git a/gcc/ipa-pure-const.cc b/gcc/ipa-pure-const.cc
index d285462b6cf1..b5a1dcdc154f 100644
--- a/gcc/ipa-pure-const.cc
+++ b/gcc/ipa-pure-const.cc
@@ -199,11 +199,12 @@  function_always_visible_to_compiler_p (tree decl)
    by the function.  */
 
 static hash_set<tree> *
-suggest_attribute (int option, tree decl, bool known_finite,
+suggest_attribute (diagnostic_option_id option, tree decl, bool known_finite,
 		   hash_set<tree> *warned_about,
 		   const char * attrib_name)
 {
-  if (!option_enabled (option, lang_hooks.option_lang_mask (), &global_options))
+  if (!option_enabled (option.m_idx, lang_hooks.option_lang_mask (),
+		       &global_options))
     return warned_about;
   if (TREE_THIS_VOLATILE (decl)
       || (known_finite && function_always_visible_to_compiler_p (decl)))
diff --git a/gcc/lto-wrapper.cc b/gcc/lto-wrapper.cc
index 11eaa1f5f789..6d847e01a4ee 100644
--- a/gcc/lto-wrapper.cc
+++ b/gcc/lto-wrapper.cc
@@ -2148,11 +2148,13 @@  public:
   : gcc_diagnostic_option_manager (0 /* lang_mask */)
   {
   }
-  int option_enabled_p (int) const final override
+  int option_enabled_p (diagnostic_option_id) const final override
   {
     return true;
   }
-  char *make_option_name (int, diagnostic_t, diagnostic_t) const final override
+  char *make_option_name (diagnostic_option_id,
+			  diagnostic_t,
+			  diagnostic_t) const final override
   {
     return nullptr;
   }
diff --git a/gcc/opts-common.cc b/gcc/opts-common.cc
index 62d7bef552e0..70ac225e3968 100644
--- a/gcc/opts-common.cc
+++ b/gcc/opts-common.cc
@@ -1871,9 +1871,10 @@  option_enabled (int opt_idx, unsigned lang_mask, void *opts)
 }
 
 int
-compiler_diagnostic_option_manager::option_enabled_p (int opt_idx) const
+compiler_diagnostic_option_manager::
+option_enabled_p (diagnostic_option_id opt_id) const
 {
-  return option_enabled (opt_idx, m_lang_mask, m_opts);
+  return option_enabled (opt_id.m_idx, m_lang_mask, m_opts);
 }
 
 /* Fill STATE with the current state of option OPTION in OPTS.  Return
diff --git a/gcc/opts-diagnostic.h b/gcc/opts-diagnostic.h
index 2b78ce73b1b3..48cc21e31a48 100644
--- a/gcc/opts-diagnostic.h
+++ b/gcc/opts-diagnostic.h
@@ -25,7 +25,7 @@  along with GCC; see the file COPYING3.  If not see
 class gcc_diagnostic_option_manager : public diagnostic_option_manager
 {
 public:
-  char *make_option_url (int opt) const final override;
+  char *make_option_url (diagnostic_option_id option_id) const final override;
 
 protected:
   gcc_diagnostic_option_manager (unsigned lang_mask)
@@ -49,8 +49,8 @@  public:
   {
   }
 
-  int option_enabled_p (int opt_idx) const final override;
-  char *make_option_name (int opt_idx,
+  int option_enabled_p (diagnostic_option_id option_id) const final override;
+  char *make_option_name (diagnostic_option_id option_id,
 			  diagnostic_t orig_diag_kind,
 			  diagnostic_t diag_kind) const final override;
 
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 3e50933a0a94..d48a1ac6602c 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -3705,22 +3705,22 @@  enable_warning_as_error (const char *arg, int value, unsigned int lang_mask,
 
 char *
 compiler_diagnostic_option_manager::
-make_option_name (int option_index,
+make_option_name (diagnostic_option_id option_id,
 		  diagnostic_t orig_diag_kind,
 		  diagnostic_t diag_kind) const
 {
-  if (option_index)
+  if (option_id.m_idx)
     {
       /* A warning classified as an error.  */
       if ((orig_diag_kind == DK_WARNING || orig_diag_kind == DK_PEDWARN)
 	  && diag_kind == DK_ERROR)
 	return concat (cl_options[OPT_Werror_].opt_text,
 		       /* Skip over "-W".  */
-		       cl_options[option_index].opt_text + 2,
+		       cl_options[option_id.m_idx].opt_text + 2,
 		       NULL);
       /* A warning with option.  */
       else
-	return xstrdup (cl_options[option_index].opt_text);
+	return xstrdup (cl_options[option_id.m_idx].opt_text);
     }
   /* A warning without option classified as an error.  */
   else if ((orig_diag_kind == DK_WARNING || orig_diag_kind == DK_PEDWARN
@@ -3781,11 +3781,13 @@  get_option_url_suffix (int option_index, unsigned lang_mask)
    which enabled a diagnostic.  */
 
 char *
-gcc_diagnostic_option_manager::make_option_url (int option_index) const
+gcc_diagnostic_option_manager::
+make_option_url (diagnostic_option_id option_id) const
 {
-  if (option_index)
+  if (option_id.m_idx)
     {
-      label_text url_suffix = get_option_url_suffix (option_index, m_lang_mask);
+      label_text url_suffix = get_option_url_suffix (option_id.m_idx,
+						     m_lang_mask);
       if (url_suffix.get ())
 	return concat (DOCUMENTATION_ROOT_URL, url_suffix.get (), nullptr);
     }
diff --git a/gcc/substring-locations.cc b/gcc/substring-locations.cc
index 00ad8edd5869..156c12134baf 100644
--- a/gcc/substring-locations.cc
+++ b/gcc/substring-locations.cc
@@ -143,7 +143,7 @@  format_string_diagnostic_t (const substring_loc &fmt_loc,
 {
 }
 
-/* Emit a warning governed by option OPT, using SINGULAR_GMSGID as the
+/* Emit a warning governed by option OPTION_ID, using SINGULAR_GMSGID as the
    format string (or if PLURAL_GMSGID is different from SINGULAR_GMSGID,
    using SINGULAR_GMSGID, PLURAL_GMSGID and N as arguments to ngettext)
    and AP as its arguments.
@@ -151,7 +151,7 @@  format_string_diagnostic_t (const substring_loc &fmt_loc,
    Return true if a warning was emitted, false otherwise.  */
 
 bool
-format_string_diagnostic_t::emit_warning_n_va (int opt,
+format_string_diagnostic_t::emit_warning_n_va (diagnostic_option_id option_id,
 					       unsigned HOST_WIDE_INT n,
 					       const char *singular_gmsgid,
 					       const char *plural_gmsgid,
@@ -223,7 +223,7 @@  format_string_diagnostic_t::emit_warning_n_va (int opt,
   else
     diagnostic_set_info (&diagnostic, singular_gmsgid, ap, &richloc,
 			 DK_WARNING);
-  diagnostic.option_index = opt;
+  diagnostic.option_id = option_id;
   bool warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
 
   if (!err && fmt_substring_loc && !substring_within_range)
@@ -248,21 +248,23 @@  format_string_diagnostic_t::emit_warning_n_va (int opt,
 /* Singular-only version of the above.  */
 
 bool
-format_string_diagnostic_t::emit_warning_va (int opt, const char *gmsgid,
+format_string_diagnostic_t::emit_warning_va (diagnostic_option_id option_id,
+					     const char *gmsgid,
 					     va_list *ap) const
 {
-  return emit_warning_n_va (opt, 0, gmsgid, gmsgid, ap);
+  return emit_warning_n_va (option_id, 0, gmsgid, gmsgid, ap);
 }
 
 /* Variadic version of the above (singular only).  */
 
 bool
-format_string_diagnostic_t::emit_warning (int opt, const char *gmsgid,
+format_string_diagnostic_t::emit_warning (diagnostic_option_id option_id,
+					  const char *gmsgid,
 					  ...) const
 {
   va_list ap;
   va_start (ap, gmsgid);
-  bool warned = emit_warning_va (opt, gmsgid, &ap);
+  bool warned = emit_warning_va (option_id, gmsgid, &ap);
   va_end (ap);
 
   return warned;
@@ -271,14 +273,15 @@  format_string_diagnostic_t::emit_warning (int opt, const char *gmsgid,
 /* Variadic version of the above (singular vs plural).  */
 
 bool
-format_string_diagnostic_t::emit_warning_n (int opt, unsigned HOST_WIDE_INT n,
+format_string_diagnostic_t::emit_warning_n (diagnostic_option_id option_id,
+					    unsigned HOST_WIDE_INT n,
 					    const char *singular_gmsgid,
 					    const char *plural_gmsgid,
 					    ...) const
 {
   va_list ap;
   va_start (ap, plural_gmsgid);
-  bool warned = emit_warning_n_va (opt, n, singular_gmsgid, plural_gmsgid,
+  bool warned = emit_warning_n_va (option_id, n, singular_gmsgid, plural_gmsgid,
 				   &ap);
   va_end (ap);
 
diff --git a/gcc/substring-locations.h b/gcc/substring-locations.h
index b286ae8e3b5f..ef67d981aa94 100644
--- a/gcc/substring-locations.h
+++ b/gcc/substring-locations.h
@@ -90,18 +90,24 @@  class format_string_diagnostic_t
 
   /* Functions for emitting a warning about a format string.  */
 
-  bool emit_warning_va (int opt, const char *gmsgid, va_list *ap) const
+  bool emit_warning_va (diagnostic_option_id option_id,
+			const char *gmsgid,
+			va_list *ap) const
     ATTRIBUTE_GCC_DIAG (3, 0);
 
-  bool emit_warning_n_va (int opt, unsigned HOST_WIDE_INT n,
+  bool emit_warning_n_va (diagnostic_option_id option_id,
+			  unsigned HOST_WIDE_INT n,
 			  const char *singular_gmsgid,
-			  const char *plural_gmsgid, va_list *ap) const
+			  const char *plural_gmsgid,
+			  va_list *ap) const
   ATTRIBUTE_GCC_DIAG (4, 0) ATTRIBUTE_GCC_DIAG (5, 0);
 
-  bool emit_warning (int opt, const char *gmsgid, ...) const
+  bool emit_warning (diagnostic_option_id option_id,
+		     const char *gmsgid, ...) const
     ATTRIBUTE_GCC_DIAG (3, 4);
 
-  bool emit_warning_n (int opt, unsigned HOST_WIDE_INT n,
+  bool emit_warning_n (diagnostic_option_id option_id,
+		       unsigned HOST_WIDE_INT n,
 		       const char *singular_gmsgid,
 		       const char *plural_gmsgid, ...) const
   ATTRIBUTE_GCC_DIAG (4, 6) ATTRIBUTE_GCC_DIAG (5, 6);