--- libcpp/charset.cc.jj	2022-08-21 19:03:48.747215419 +0200
+++ libcpp/charset.cc	2022-08-21 19:39:04.717421624 +0200
@@ -944,6 +944,7 @@ struct uname2c_data
 {
   char *canon_name;
   char prev_char;
+  char *spellcheck;
 };
 
 /* Map NAME, a Unicode character name or correction/control/alternate
@@ -1006,6 +1007,11 @@ _cpp_uname2c (const char *name, size_t l
 	  ret = memcmp (name, key, len > key_len ? key_len : len);
 	  len_adj = key_len;
 	}
+      else if (data->spellcheck)
+	{
+	  ret = 0;
+	  len_adj = 0;
+	}
       else
 	{
 	  const char *p = name, *q = key;
@@ -1076,7 +1082,54 @@ _cpp_uname2c (const char *name, size_t l
 	    {
 	      name += len_adj;
 	      len -= len_adj;
-	      if (codepoint == 0xd800)
+	      if (__builtin_expect (data != NULL, 0) && data->spellcheck)
+		{
+		  memcpy (data->canon_name, key, key_len);
+		  if (codepoint == 0xd800)
+		    {
+		      /* NR1 - Hangul syllables.  */
+		      size_t i, j, k, s1 = hangul_count[0] + hangul_count[1];
+		      size_t s2 = s1 + hangul_count[2];
+
+		      for (i = 0; i < (size_t) hangul_count[0]; ++i)
+			{
+			  strcpy (data->canon_name + key_len,
+				  hangul_syllables[i]);
+			  char *p1 = strchr (data->canon_name + key_len, '\0');
+			  for (j = hangul_count[0]; j < s1; ++j)
+			    {
+			      strcpy (p1, hangul_syllables[j]);
+			      char *p2 = strchr (p1, '\0');
+			      for (k = s1; k < s2; ++k)
+				{
+				  strcpy (p2, hangul_syllables[k]);
+				  /* In place of get_edit_distance etc.  */
+				  fprintf (stderr, "%s\n", data->spellcheck);
+				}
+			    }
+			}
+		    }
+		  else
+		    {
+		      /* NR2 - prefix followed by hexadecimal codepoint.  */
+		      const cppchar_t *p
+			= (uname2c_pairs
+			   + uname2c_generated[codepoint - 0xd800]);
+		      for (; *p; p += 2)
+			{
+			  cppchar_t c;
+
+			  for (c = p[0]; c <= p[1]; ++c)
+			    {
+			      sprintf (data->canon_name + key_len, "%lX",
+				       (long) c);
+			      /* In place of get_edit_distance etc.  */
+			      fprintf (stderr, "%s\n", data->spellcheck);
+			    }
+			}
+		    }
+		}
+	      else if (codepoint == 0xd800)
 		{
 		  /* NR1 - Hangul syllables.  */
 		  size_t start = 0, end, i, j;
@@ -1158,7 +1211,17 @@ _cpp_uname2c (const char *name, size_t l
 	    }
 	  else if (__builtin_expect (data != NULL, 0))
 	    {
-	      if (len == len_adj)
+	      if (data->spellcheck)
+		{
+		  if (codepoint != (cppchar_t) -1)
+		    {
+		      memcpy (data->canon_name, key, key_len);
+		      data->canon_name[key_len] = '\0';
+		      /* In place of get_edit_distance etc.  */
+		      fprintf (stderr, "%s\n", data->spellcheck);
+		    }
+		}
+	      else if (len == len_adj)
 		{
 		  memcpy (data->canon_name, key, key_len);
 		  data->canon_name[key_len] = '\0';
@@ -1490,6 +1553,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const
 			  struct uname2c_data data;
 			  data.canon_name = canon_name;
 			  data.prev_char = ' ';
+			  data.spellcheck = NULL;
 			  /* Hangul Jungseong O- E
 			     after UAX44-LM2 should be HANGULJUNGSEONGO-E
 			     and so should match U+1180.  */