--- a/gcc/substring-locations.c	Fri Oct 27 22:46:09 2017 +0900
+++ b/gcc/substring-locations.c	Thu Oct 25 07:37:49 2018 +0900
@@ -1,5 +1,5 @@
 /* Source locations within string literals.
-   Copyright (C) 2016-2017 Free Software Foundation, Inc.
+   Copyright (C) 2016-2018 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -20,16 +20,18 @@
 #include "config.h"
 #include "system.h"
 #include "coretypes.h"
+#include "intl.h"
 #include "diagnostic.h"
 #include "cpplib.h"
 #include "tree.h"
 #include "langhooks.h"
 #include "substring-locations.h"
+#include "gcc-rich-location.h"
 
-/* Emit a warning governed by option OPT, using GMSGID as the format
-   string and AP as its arguments.
+/* format_string_diagnostic_t's ctor, giving information for use by
+   the emit_warning* member functions, as follows:
 
-   Attempt to obtain precise location information within a string
+   They attempt to obtain precise location information within a string
    literal from FMT_LOC.
 
    Case 1: if substring location is available, and is within the range of
@@ -45,7 +47,7 @@
 
    Case 2: if the substring location is available, but is not within
    the range of the format string, the primary location is that of the
-   format string, and an note is emitted showing the substring location.
+   format string, and a note is emitted showing the substring location.
 
    For example:
      test.c:90:10: warning: problem with '%i' here [-Wformat=]
@@ -86,6 +88,27 @@
      printf(fmt, msg);
             ^~~  ~~~
 
+   If non-NULL, then FMT_LABEL will be used to label the location within the
+   string for cases 1 and 2; if non-NULL, then PARAM_LABEL will be used to label
+   the parameter.  For example with case 1:
+
+    test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
+     printf ("foo %s bar", long_i + long_j);
+                  ~^       ~~~~~~~~~~~~~~~
+                                  |
+                                  int
+
+   and with case 2:
+
+     test.c:90:10: warning: problem with '%i' here [-Wformat=]
+     printf("hello " INT_FMT " world", msg);
+            ^~~~~~~~~~~~~~~~~~~~~~~~~
+     test.c:19: note: format string is defined here
+     #define INT_FMT "%i"
+                      ~^
+                       |
+                       int
+
    If CORRECTED_SUBSTRING is non-NULL, use it for cases 1 and 2 to provide
    a fix-it hint, suggesting that it should replace the text within the
    substring range.  For example:
@@ -95,26 +118,47 @@
                     ~^
                     %s
 
+*/
+
+format_string_diagnostic_t::
+format_string_diagnostic_t (const substring_loc &fmt_loc,
+			    const range_label *fmt_label,
+			    location_t param_loc,
+			    const range_label *param_label,
+			    const char *corrected_substring)
+: m_fmt_loc (fmt_loc),
+  m_fmt_label (fmt_label),
+  m_param_loc (param_loc),
+  m_param_label (param_label),
+  m_corrected_substring (corrected_substring)
+{
+}
+
+/* Emit a warning governed by option OPT, 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.
+
    Return true if a warning was emitted, false otherwise.  */
 
-ATTRIBUTE_GCC_DIAG (5,0)
 bool
-format_warning_va (const substring_loc &fmt_loc,
-		   location_t param_loc,
-		   const char *corrected_substring,
-		   int opt, const char *gmsgid, va_list *ap)
+format_string_diagnostic_t::emit_warning_n_va (int opt,
+					       unsigned HOST_WIDE_INT n,
+					       const char *singular_gmsgid,
+					       const char *plural_gmsgid,
+					       va_list *ap) const
 {
   bool substring_within_range = false;
   location_t primary_loc;
   location_t fmt_substring_loc = UNKNOWN_LOCATION;
   source_range fmt_loc_range
-    = get_range_from_loc (line_table, fmt_loc.get_fmt_string_loc ());
-  const char *err = fmt_loc.get_location (&fmt_substring_loc);
+    = get_range_from_loc (line_table, m_fmt_loc.get_fmt_string_loc ());
+  const char *err = m_fmt_loc.get_location (&fmt_substring_loc);
   source_range fmt_substring_range
     = get_range_from_loc (line_table, fmt_substring_loc);
   if (err)
     /* Case 3: unable to get substring location.  */
-    primary_loc = fmt_loc.get_fmt_string_loc ();
+    primary_loc = m_fmt_loc.get_fmt_string_loc ();
   else
     {
       if (fmt_substring_range.m_start >= fmt_loc_range.m_start
@@ -130,20 +174,44 @@
 	/* Case 2.  */
 	{
 	  substring_within_range = false;
-	  primary_loc = fmt_loc.get_fmt_string_loc ();
+	  primary_loc = m_fmt_loc.get_fmt_string_loc ();
 	}
     }
 
-  rich_location richloc (line_table, primary_loc);
+  /* Only use fmt_label in the initial warning for case 1.  */
+  const range_label *primary_label = NULL;
+  if (substring_within_range)
+    primary_label = m_fmt_label;
 
-  if (param_loc != UNKNOWN_LOCATION)
-    richloc.add_range (param_loc, false);
+  auto_diagnostic_group d;
+  gcc_rich_location richloc (primary_loc, primary_label);
 
-  if (!err && corrected_substring && substring_within_range)
-    richloc.add_fixit_replace (fmt_substring_range, corrected_substring);
+  if (m_param_loc != UNKNOWN_LOCATION)
+    richloc.add_range (m_param_loc, SHOW_RANGE_WITHOUT_CARET, m_param_label);
+
+  if (!err && m_corrected_substring && substring_within_range)
+    richloc.add_fixit_replace (fmt_substring_range, m_corrected_substring);
 
   diagnostic_info diagnostic;
-  diagnostic_set_info (&diagnostic, gmsgid, ap, &richloc, DK_WARNING);
+  if (singular_gmsgid != plural_gmsgid)
+    {
+      unsigned long gtn;
+
+      if (sizeof n <= sizeof gtn)
+	gtn = n;
+      else
+	/* Use the largest number ngettext can handle, otherwise
+	   preserve the six least significant decimal digits for
+	   languages where the plural form depends on them.  */
+	gtn = n <= ULONG_MAX ? n : n % 1000000LU + 1000000LU;
+
+      const char *text = ngettext (singular_gmsgid, plural_gmsgid, gtn);
+      diagnostic_set_info_translated (&diagnostic, text, ap, &richloc,
+				      DK_WARNING);
+    }
+  else
+    diagnostic_set_info (&diagnostic, singular_gmsgid, ap, &richloc,
+			 DK_WARNING);
   diagnostic.option_index = opt;
   bool warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
 
@@ -151,29 +219,54 @@
     /* Case 2.  */
     if (warned)
       {
-	rich_location substring_richloc (line_table, fmt_substring_loc);
-	if (corrected_substring)
+	/* Use fmt_label in the note for case 2.  */
+	rich_location substring_richloc (line_table, fmt_substring_loc,
+					 m_fmt_label);
+	if (m_corrected_substring)
 	  substring_richloc.add_fixit_replace (fmt_substring_range,
-					       corrected_substring);
-	inform_at_rich_loc (&substring_richloc,
-			    "format string is defined here");
+					       m_corrected_substring);
+	inform (&substring_richloc,
+		"format string is defined here");
       }
 
   return warned;
 }
 
-/* Variadic call to format_warning_va.  */
+/* Singular-only version of the above.  */
 
 bool
-format_warning_at_substring (const substring_loc &fmt_loc,
-			     location_t param_loc,
-			     const char *corrected_substring,
-			     int opt, const char *gmsgid, ...)
+format_string_diagnostic_t::emit_warning_va (int opt, const char *gmsgid,
+					     va_list *ap) const
+{
+  return emit_warning_n_va (opt, 0, gmsgid, gmsgid, ap);
+}
+
+/* Variadic version of the above (singular only).  */
+
+bool
+format_string_diagnostic_t::emit_warning (int opt, const char *gmsgid,
+					  ...) const
 {
   va_list ap;
   va_start (ap, gmsgid);
-  bool warned = format_warning_va (fmt_loc, param_loc, corrected_substring,
-				   opt, gmsgid, &ap);
+  bool warned = emit_warning_va (opt, gmsgid, &ap);
+  va_end (ap);
+
+  return warned;
+}
+
+/* Variadic version of the above (singular vs plural).  */
+
+bool
+format_string_diagnostic_t::emit_warning_n (int opt, 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,
+				   &ap);
   va_end (ap);
 
   return warned;