[RFA] Introdue warning_n; fix singulars in the final keyword wanrings

Index: diagnostic.c
===================================================================
--- diagnostic.c	(revision 213526)
+++ diagnostic.c	(working copy)
@@ -986,6 +986,28 @@  warning_at (location_t location, int opt
   return ret;
 }
 
+/* A warning at LOCATION.  Use this for code which is correct according 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_n (location_t location, int opt, int n, const char *singular_gmsgid,
+	   const char *plural_gmsgid, ...)
+{
+  diagnostic_info diagnostic;
+  va_list ap;
+  bool ret;
+
+  va_start (ap, plural_gmsgid);
+  diagnostic_set_info_translated (&diagnostic,
+                                  ngettext (singular_gmsgid, plural_gmsgid, n),
+                                  &ap, location, DK_WARNING);
+  diagnostic.option_index = opt;
+  ret = report_diagnostic (&diagnostic);
+  va_end (ap);
+  return ret;
+}
+
 /* A "pedantic" warning at LOCATION: issues a warning unless
    -pedantic-errors was given on the command line, in which case it
    issues an error.  Use this for diagnostics required by the relevant
Index: diagnostic-core.h
===================================================================
--- diagnostic-core.h	(revision 213526)
+++ diagnostic-core.h	(working copy)
@@ -58,6 +58,8 @@  extern void internal_error (const char *
      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, int, const char *, const char *, ...)
+    ATTRIBUTE_GCC_DIAG(4,6) ATTRIBUTE_GCC_DIAG(5,6);
 extern bool warning_at (location_t, int, const char *, ...)
     ATTRIBUTE_GCC_DIAG(3,4);
 extern void error (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2);
Index: ipa-devirt.c
===================================================================
--- ipa-devirt.c	(revision 213526)
+++ ipa-devirt.c	(working copy)
@@ -3279,12 +3279,31 @@  ipa_devirt (void)
 	    if (final_warning_records->type_warnings[i].count)
 	      {
 	        tree type = final_warning_records->type_warnings[i].type;
-		warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (type)),
-			    OPT_Wsuggest_final_types,
-			    "Declaring type %qD final "
-			    "would enable devirtualization of %i calls",
-			    type,
-			    final_warning_records->type_warnings[i].count);
+	        int count = final_warning_records->type_warnings[i].count;
+	        long long dyn_count
+		  = final_warning_records->type_warnings[i].dyn_count;
+
+		if (!dyn_count)
+		  warning_n (DECL_SOURCE_LOCATION (TYPE_NAME (type)),
+			     OPT_Wsuggest_final_types, count,
+			     "Declaring type %qD final "
+			     "would enable devirtualization of %i call",
+			     "Declaring type %qD final "
+			     "would enable devirtualization of %i calls",
+			     type,
+			     count);
+		else
+		  warning_n (DECL_SOURCE_LOCATION (TYPE_NAME (type)),
+			     OPT_Wsuggest_final_types, count,
+			     "Declaring type %qD final "
+			     "would enable devirtualization of %i call "
+			     "executed %lli times",
+			     "Declaring type %qD final "
+			     "would enable devirtualization of %i calls "
+			     "executed %lli times",
+			     type,
+			     count,
+			     dyn_count);
 	      }
 	}
 
@@ -3299,19 +3318,45 @@  ipa_devirt (void)
 	    {
 	      tree decl = decl_warnings_vec[i]->decl;
 	      int count = decl_warnings_vec[i]->count;
+	      long long dyn_count = decl_warnings_vec[i]->dyn_count;
 
-	      if (DECL_CXX_DESTRUCTOR_P (decl))
-		warning_at (DECL_SOURCE_LOCATION (decl),
-			    OPT_Wsuggest_final_methods,
-			    "Declaring virtual destructor of %qD final "
-			    "would enable devirtualization of %i calls",
-			    DECL_CONTEXT (decl), count);
-	      else
-		warning_at (DECL_SOURCE_LOCATION (decl),
-			    OPT_Wsuggest_final_methods,
-			    "Declaring method %qD final "
-			    "would enable devirtualization of %i calls",
-			    decl, count);
+	      if (!dyn_count)
+		if (DECL_CXX_DESTRUCTOR_P (decl))
+		  warning_n (DECL_SOURCE_LOCATION (decl),
+			      OPT_Wsuggest_final_methods, count,
+			      "Declaring virtual destructor of %qD final "
+			      "would enable devirtualization of %i call",
+			      "Declaring virtual destructor of %qD final "
+			      "would enable devirtualization of %i calls",
+			      DECL_CONTEXT (decl), count);
+		else
+		  warning_n (DECL_SOURCE_LOCATION (decl),
+			      OPT_Wsuggest_final_methods, count,
+			      "Declaring method %qD final "
+			      "would enable devirtualization of %i call",
+			      "Declaring method %qD final "
+			      "would enable devirtualization of %i calls",
+			      decl, count);
+	       else if (DECL_CXX_DESTRUCTOR_P (decl))
+		  warning_n (DECL_SOURCE_LOCATION (decl),
+			      OPT_Wsuggest_final_methods, count,
+			      "Declaring virtual destructor of %qD final "
+			      "would enable devirtualization of %i call "
+			      "executed %lli times",
+			      "Declaring virtual destructor of %qD final "
+			      "would enable devirtualization of %i calls "
+			      "executed %lli times",
+			      DECL_CONTEXT (decl), count, dyn_count);
+		else
+		  warning_n (DECL_SOURCE_LOCATION (decl),
+			      OPT_Wsuggest_final_methods, count,
+			      "Declaring method %qD final "
+			      "would enable devirtualization of %i call "
+			      "executed %lli times",
+			      "Declaring method %qD final "
+			      "would enable devirtualization of %i calls "
+			      "executed %lli times",
+			      decl, count, dyn_count);
 	    }
 	}