--- libcpp/include/cpplib.h.jj	2024-10-12 10:50:41.065854381 +0200
+++ libcpp/include/cpplib.h	2024-10-14 17:05:37.018748463 +0200
@@ -546,6 +546,12 @@ struct cpp_options
   /* Nonzero for C++23 delimited escape sequences.  */
   unsigned char delimited_escape_seqs;
 
+  /* Nonzero for C++23 named universal character escape sequences.  */
+  unsigned char named_uc_escape_seqs;
+
+  /* Nonzero for C2Y 0o prefixed octal integer constants.  */
+  unsigned char octal_constants;
+
   /* Nonzero for 'true' and 'false' in #if expressions.  */
   unsigned char true_false;
 
@@ -577,6 +583,9 @@ struct cpp_options
   /* True if warn about differences between C11 and C23.  */
   signed char cpp_warn_c11_c23_compat;
 
+  /* True if warn about differences between C23 and C2Y.  */
+  signed char cpp_warn_c23_c2y_compat;
+
   /* True if warn about differences between C++98 and C++11.  */
   bool cpp_warn_cxx11_compat;
 
@@ -711,6 +720,7 @@ enum cpp_warning_reason {
   CPP_W_PEDANTIC,
   CPP_W_C90_C99_COMPAT,
   CPP_W_C11_C23_COMPAT,
+  CPP_W_C23_C2Y_COMPAT,
   CPP_W_CXX11_COMPAT,
   CPP_W_CXX20_COMPAT,
   CPP_W_CXX14_EXTENSIONS,
--- libcpp/init.cc.jj	2024-10-12 10:50:41.065854381 +0200
+++ libcpp/init.cc	2024-10-14 17:37:19.958977766 +0200
@@ -108,46 +108,48 @@ struct lang_flags
   unsigned int elifdef : 1;
   unsigned int warning_directive : 1;
   unsigned int delimited_escape_seqs : 1;
+  unsigned int named_uc_escape_seqs : 1;
+  unsigned int octal_constants : 1;
   unsigned int true_false : 1;
   unsigned int embed : 1;
 };
 
 static const struct lang_flags lang_defaults[] = {
-  /*					       u         e w
-					 b d   8         l a   t
-			     x         u i i   c v s   s i r d r e
-		       x     i   d u r d n g t h a c   z f n e u m
-		   c c n x c d s i l l l c s r l o o d l d d l f b
-		   9 + u i 1 i t g i i i s e i i p p f i e i i a e
-		   9 + m d 1 d d r t t t t p g t t e p t f r m l d  */
-  /* GNUC89   */ { 0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0 },
-  /* GNUC99   */ { 1,0,1,1,0,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0 },
-  /* GNUC11   */ { 1,0,1,1,1,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0 },
-  /* GNUC17   */ { 1,0,1,1,1,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0 },
-  /* GNUC23   */ { 1,0,1,1,1,1,0,1,1,1,0,1,1,0,1,1,1,1,0,1,1,0,1,1 },
-  /* GNUC2Y   */ { 1,0,1,1,1,1,0,1,1,1,0,1,1,0,1,1,1,1,0,1,1,0,1,1 },
-  /* STDC89   */ { 0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0 },
-  /* STDC94   */ { 0,0,0,0,0,0,1,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0 },
-  /* STDC99   */ { 1,0,1,1,0,0,1,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0 },
-  /* STDC11   */ { 1,0,1,1,1,0,1,1,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0 },
-  /* STDC17   */ { 1,0,1,1,1,0,1,1,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0 },
-  /* STDC23   */ { 1,0,1,1,1,1,1,1,1,0,0,1,1,0,1,1,1,1,0,1,1,0,1,1 },
-  /* STDC2Y   */ { 1,0,1,1,1,1,1,1,1,0,0,1,1,0,1,1,1,1,0,1,1,0,1,1 },
-  /* GNUCXX   */ { 0,1,1,1,0,1,0,1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,1,0 },
-  /* CXX98    */ { 0,1,0,1,0,1,1,1,0,0,0,0,0,1,0,0,1,0,0,0,0,0,1,0 },
-  /* GNUCXX11 */ { 1,1,1,1,1,1,0,1,1,1,1,0,0,0,0,1,1,0,0,0,0,0,1,0 },
-  /* CXX11    */ { 1,1,0,1,1,1,1,1,1,1,1,0,0,1,0,0,1,0,0,0,0,0,1,0 },
-  /* GNUCXX14 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,0,1,1,0,0,0,0,0,1,0 },
-  /* CXX14    */ { 1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,0,1,0,0,0,0,0,1,0 },
-  /* GNUCXX17 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,0,0,0,0,1,0 },
-  /* CXX17    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,0,1,0,0,0,0,0,1,0 },
-  /* GNUCXX20 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,0,0,0,0,1,0 },
-  /* CXX20    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,0,0,0,0,1,0 },
-  /* GNUCXX23 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0 },
-  /* CXX23    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0 },
-  /* GNUCXX26 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0 },
-  /* CXX26    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0 },
-  /* ASM      */ { 0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }
+  /*					       u         e w   n
+					 b d   8         l a   a   t
+			     x         u i i   c v s   s i r d m o r e
+		       x     i   d u r d n g t h a c   z f n e e c u m
+		   c c n x c d s i l l l c s r l o o d l d d l d t f b
+		   9 + u i 1 i t g i i i s e i i p p f i e i i u a a e
+		   9 + m d 1 d d r t t t t p g t t e p t f r m c l l d  */
+  /* GNUC89   */ { 0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0 },
+  /* GNUC99   */ { 1,0,1,1,0,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0 },
+  /* GNUC11   */ { 1,0,1,1,1,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0 },
+  /* GNUC17   */ { 1,0,1,1,1,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0 },
+  /* GNUC23   */ { 1,0,1,1,1,1,0,1,1,1,0,1,1,0,1,1,1,1,0,1,1,0,0,0,1,1 },
+  /* GNUC2Y   */ { 1,0,1,1,1,1,0,1,1,1,0,1,1,0,1,1,1,1,0,1,1,1,0,1,1,1 },
+  /* STDC89   */ { 0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0 },
+  /* STDC94   */ { 0,0,0,0,0,0,1,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0 },
+  /* STDC99   */ { 1,0,1,1,0,0,1,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0 },
+  /* STDC11   */ { 1,0,1,1,1,0,1,1,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0 },
+  /* STDC17   */ { 1,0,1,1,1,0,1,1,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0 },
+  /* STDC23   */ { 1,0,1,1,1,1,1,1,1,0,0,1,1,0,1,1,1,1,0,1,1,0,0,0,1,1 },
+  /* STDC2Y   */ { 1,0,1,1,1,1,1,1,1,0,0,1,1,0,1,1,1,1,0,1,1,1,0,1,1,1 },
+  /* GNUCXX   */ { 0,1,1,1,0,1,0,1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,1,0 },
+  /* CXX98    */ { 0,1,0,1,0,1,1,1,0,0,0,0,0,1,0,0,1,0,0,0,0,0,0,0,1,0 },
+  /* GNUCXX11 */ { 1,1,1,1,1,1,0,1,1,1,1,0,0,0,0,1,1,0,0,0,0,0,0,0,1,0 },
+  /* CXX11    */ { 1,1,0,1,1,1,1,1,1,1,1,0,0,1,0,0,1,0,0,0,0,0,0,0,1,0 },
+  /* GNUCXX14 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,0,1,1,0,0,0,0,0,0,0,1,0 },
+  /* CXX14    */ { 1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,0,1,0,0,0,0,0,0,0,1,0 },
+  /* GNUCXX17 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,0,0,0,0,0,0,1,0 },
+  /* CXX17    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,0,1,0,0,0,0,0,0,0,1,0 },
+  /* GNUCXX20 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,0,0,0,0,0,0,1,0 },
+  /* CXX20    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,0,0,0,0,0,0,1,0 },
+  /* GNUCXX23 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,0 },
+  /* CXX23    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,0 },
+  /* GNUCXX26 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,0 },
+  /* CXX26    */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,0 },
+  /* ASM      */ { 0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }
 };
 
 /* Sets internal flags correctly for a given language.  */
@@ -180,6 +182,8 @@ cpp_set_lang (cpp_reader *pfile, enum c_
   CPP_OPTION (pfile, elifdef)			 = l->elifdef;
   CPP_OPTION (pfile, warning_directive)		 = l->warning_directive;
   CPP_OPTION (pfile, delimited_escape_seqs)	 = l->delimited_escape_seqs;
+  CPP_OPTION (pfile, named_uc_escape_seqs)	 = l->named_uc_escape_seqs;
+  CPP_OPTION (pfile, octal_constants)		 = l->octal_constants;
   CPP_OPTION (pfile, true_false)		 = l->true_false;
   CPP_OPTION (pfile, embed)			 = l->embed;
 }
@@ -230,6 +234,7 @@ cpp_create_reader (enum c_lang lang, cpp
   CPP_OPTION (pfile, warn_endif_labels) = 1;
   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
   CPP_OPTION (pfile, cpp_warn_c11_c23_compat) = -1;
+  CPP_OPTION (pfile, cpp_warn_c23_c2y_compat) = -1;
   CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0;
   CPP_OPTION (pfile, cpp_warn_cxx20_compat) = 0;
   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
--- libcpp/charset.cc.jj	2024-10-12 10:50:41.063854408 +0200
+++ libcpp/charset.cc	2024-10-14 17:06:21.715119420 +0200
@@ -1579,7 +1579,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const
     {
       length = 4;
       if (identifier_pos
-	  && !CPP_OPTION (pfile, delimited_escape_seqs)
+	  && !CPP_OPTION (pfile, named_uc_escape_seqs)
 	  && CPP_OPTION (pfile, std))
 	{
 	  *cp = 0;
@@ -1631,7 +1631,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const
 		cpp_error (pfile, CPP_DL_ERROR,
 			   "empty named universal character escape sequence");
 	      else if ((!identifier_pos || strict)
-		       && !CPP_OPTION (pfile, delimited_escape_seqs)
+		       && !CPP_OPTION (pfile, named_uc_escape_seqs)
 		       && CPP_OPTION (pfile, cpp_pedantic))
 		cpp_pedwarning (pfile,
 				CPP_OPTION (pfile, cplusplus)
@@ -1653,7 +1653,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const
 		    {
 		      bool ret = true;
 		      if (identifier_pos
-			  && (!CPP_OPTION (pfile, delimited_escape_seqs)
+			  && (!CPP_OPTION (pfile, named_uc_escape_seqs)
 			      || !strict))
 			ret = cpp_warning (pfile, CPP_W_UNICODE,
 					   "%<\\N{%.*s}%> is not a valid "
@@ -1676,7 +1676,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const
 		      else
 			result = 0xC0;
 		      if (identifier_pos
-			  && (!CPP_OPTION (pfile, delimited_escape_seqs)
+			  && (!CPP_OPTION (pfile, named_uc_escape_seqs)
 			      || !strict))
 			{
 			  *cp = 0;
@@ -1746,6 +1746,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const
 
   if (delimited && str < limit && *str == '}')
     {
+      bool warned = false;
       if (length == 32 && identifier_pos)
 	{
 	  cpp_warning (pfile, CPP_W_UNICODE,
@@ -1755,13 +1756,28 @@ _cpp_valid_ucn (cpp_reader *pfile, const
 	  return false;
 	}
       else if (length == 32)
-	cpp_error (pfile, CPP_DL_ERROR,
-		   "empty delimited escape sequence");
+	{
+	  cpp_error (pfile, CPP_DL_ERROR, "empty delimited escape sequence");
+	  warned = true;
+	}
       else if (!CPP_OPTION (pfile, delimited_escape_seqs)
 	       && CPP_OPTION (pfile, cpp_pedantic))
-	cpp_pedwarning (pfile, (CPP_OPTION (pfile, cplusplus)
-				? CPP_W_CXX23_EXTENSIONS : CPP_W_PEDANTIC),
-			"delimited escape sequences are only valid in C++23");
+	{
+	  if (CPP_OPTION (pfile, cplusplus))
+	    warned
+	      = cpp_pedwarning (pfile, CPP_W_CXX23_EXTENSIONS,
+				"delimited escape sequences are only valid "
+				"in C++23");
+	  else
+	    warned
+	      = cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				"delimited escape sequences are only valid "
+				"in C2Y");
+	}
+      if (!warned && CPP_OPTION (pfile, cpp_warn_c23_c2y_compat) > 0)
+	cpp_warning (pfile, CPP_W_C11_C23_COMPAT,
+		     "delimited escape sequences are only valid in C2Y");
+
       str++;
       length = 0;
       delimited = false;
@@ -2125,6 +2141,7 @@ convert_hex (cpp_reader *pfile, const uc
 
   if (delimited && from < limit && *from == '}')
     {
+      bool warned = false;
       from++;
       if (!digits_found)
 	{
@@ -2134,9 +2151,21 @@ convert_hex (cpp_reader *pfile, const uc
 	}
       else if (!CPP_OPTION (pfile, delimited_escape_seqs)
 	       && CPP_OPTION (pfile, cpp_pedantic))
-	cpp_pedwarning (pfile, (CPP_OPTION (pfile, cplusplus)
-				? CPP_W_CXX23_EXTENSIONS : CPP_W_PEDANTIC),
-			"delimited escape sequences are only valid in C++23");
+	{
+	  if (CPP_OPTION (pfile, cplusplus))
+	    warned
+	      = cpp_pedwarning (pfile, CPP_W_CXX23_EXTENSIONS,
+				"delimited escape sequences are only valid "
+				"in C++23");
+	  else
+	    warned
+	      = cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				"delimited escape sequences are only valid "
+				"in C2Y");
+	}
+      if (!warned && CPP_OPTION (pfile, cpp_warn_c23_c2y_compat) > 0)
+	cpp_warning (pfile, CPP_W_C11_C23_COMPAT,
+		     "delimited escape sequences are only valid in C2Y");
       delimited = false;
       extend_char_range (&char_range, loc_reader);
     }
@@ -2229,6 +2258,7 @@ convert_oct (cpp_reader *pfile, const uc
     {
       if (from < limit && *from == '}')
 	{
+	  bool warned = false;
 	  from++;
 	  if (count == 1)
 	    {
@@ -2238,10 +2268,21 @@ convert_oct (cpp_reader *pfile, const uc
 	    }
 	  else if (!CPP_OPTION (pfile, delimited_escape_seqs)
 		   && CPP_OPTION (pfile, cpp_pedantic))
-	    cpp_pedwarning (pfile, (CPP_OPTION (pfile, cplusplus)
-				    ? CPP_W_CXX23_EXTENSIONS : CPP_W_PEDANTIC),
-			    "delimited escape sequences are only valid "
-			    "in C++23");
+	    {
+	      if (CPP_OPTION (pfile, cplusplus))
+		warned
+		  = cpp_pedwarning (pfile, CPP_W_CXX23_EXTENSIONS,
+				    "delimited escape sequences are only "
+				    "valid in C++23");
+	      else
+		warned
+		  = cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				    "delimited escape sequences are only "
+				    "valid in C2Y");
+	    }
+	  if (!warned && CPP_OPTION (pfile, cpp_warn_c23_c2y_compat) > 0)
+	    cpp_warning (pfile, CPP_W_C11_C23_COMPAT,
+			 "delimited escape sequences are only valid in C2Y");
 	  extend_char_range (&char_range, loc_reader);
 	}
       else
--- libcpp/expr.cc.jj	2024-10-12 10:50:41.064854395 +0200
+++ libcpp/expr.cc	2024-10-14 17:06:05.826343034 +0200
@@ -556,6 +556,7 @@ cpp_classify_number (cpp_reader *pfile,
   enum {NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON} float_flag;
   bool seen_digit;
   bool seen_digit_sep;
+  bool zero_o_prefix;
 
   if (ud_suffix)
     *ud_suffix = NULL;
@@ -571,6 +572,7 @@ cpp_classify_number (cpp_reader *pfile,
   radix = 10;
   seen_digit = false;
   seen_digit_sep = false;
+  zero_o_prefix = false;
 
   /* First, interpret the radix.  */
   if (*str == '0')
@@ -601,6 +603,17 @@ cpp_classify_number (cpp_reader *pfile,
 	    SYNTAX_ERROR_AT (virtual_location,
 			     "digit separator after base indicator");
 	}
+      else if ((*str == 'o' || *str == 'O') && !CPP_OPTION (pfile, cplusplus))
+	{
+	  if (ISDIGIT (str[1]))
+	    {
+	      zero_o_prefix = true;
+	      str++;
+	    }
+	  else if (DIGIT_SEP (str[1]))
+	    SYNTAX_ERROR_AT (virtual_location,
+			     "digit separator after base indicator");
+	}
     }
 
   /* Now scan for a well-formed integer or float.  */
@@ -694,6 +707,12 @@ cpp_classify_number (cpp_reader *pfile,
 			       "invalid prefix %<0b%> for floating constant");
 	  return CPP_N_INVALID;
 	}
+      if (zero_o_prefix)
+	{
+	  cpp_error_with_line (pfile, CPP_DL_ERROR, virtual_location, 0,
+			       "invalid prefix %<0o%> for floating constant");
+	  return CPP_N_INVALID;
+	}
 
       if (radix == 16 && !seen_digit)
 	SYNTAX_ERROR_AT (virtual_location,
@@ -897,8 +916,7 @@ cpp_classify_number (cpp_reader *pfile,
   if (radix == 2)
     {
       bool warned = false;
-      if (!CPP_OPTION (pfile, binary_constants)
-	  && CPP_PEDANTIC (pfile))
+      if (!CPP_OPTION (pfile, binary_constants) && CPP_PEDANTIC (pfile))
 	{
 	  if (CPP_OPTION (pfile, cplusplus))
 	    warned
@@ -916,6 +934,19 @@ cpp_classify_number (cpp_reader *pfile,
 			       virtual_location, 0,
 			       "binary constants are a C23 feature");
     }
+  if (zero_o_prefix)
+    {
+      bool warned = false;
+      if (!CPP_OPTION (pfile, octal_constants) && CPP_PEDANTIC (pfile))
+	warned
+	  = cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC, virtual_location,
+				      0, "%<0o%> prefixed constants are a C2Y "
+					 "feature or GCC extension");
+      if (!warned && CPP_OPTION (pfile, cpp_warn_c23_c2y_compat) > 0)
+	cpp_warning_with_line (pfile, CPP_W_C23_C2Y_COMPAT,
+			       virtual_location, 0,
+			       "%<0o%> prefixed constants are a C2Y feature");
+    }
 
   if (radix == 10)
     result |= CPP_N_DECIMAL;
@@ -967,6 +998,8 @@ cpp_interpret_integer (cpp_reader *pfile
 	{
 	  base = 8;
 	  p++;
+	  if (*p == 'o' || *p == 'O')
+	    p++;
 	}
       else if ((type & CPP_N_RADIX) == CPP_N_HEX)
 	{
--- gcc/c-family/c.opt.jj	2024-10-11 11:30:38.497394831 +0200
+++ gcc/c-family/c.opt	2024-10-14 15:59:25.964318381 +0200
@@ -452,7 +452,7 @@ C ObjC Alias(Wc11-c23-compat)
 Deprecated in favor of -Wc11-c23-compat.
 
 Wc23-c2y-compat
-C ObjC Var(warn_c23_c2y_compat) Init(-1) Warning
+C ObjC CPP(cpp_warn_c23_c2y_compat) CppReason(CPP_W_C23_C2Y_COMPAT) Var(warn_c23_c2y_compat) Init(-1) Warning
 Warn about features not present in ISO C23, but present in ISO C2Y.
 
 Wc90-c99-compat
--- gcc/c-family/c-opts.cc.jj	2024-10-04 12:28:08.544902990 +0200
+++ gcc/c-family/c-opts.cc	2024-10-14 17:48:29.550582149 +0200
@@ -1892,7 +1892,7 @@ set_std_c23 (int iso)
 static void
 set_std_c2y (int iso)
 {
-  cpp_set_lang (parse_in, iso ? CLK_STDC23: CLK_GNUC23);
+  cpp_set_lang (parse_in, iso ? CLK_STDC2Y : CLK_GNUC2Y);
   flag_no_asm = iso;
   flag_no_nonansi_builtin = iso;
   flag_iso = iso;
--- gcc/c-family/c-lex.cc.jj	2024-10-12 10:50:41.054854533 +0200
+++ gcc/c-family/c-lex.cc	2024-10-14 16:52:00.322193835 +0200
@@ -899,6 +899,10 @@ interpret_integer (const cpp_token *toke
 	{
 	  max_bits_per_digit = 3;
 	  prefix_len = 1;
+	  if (token->val.str.len > 2
+	      && (token->val.str.text[1] == 'o'
+		  || token->val.str.text[1] == 'O'))
+	    prefix_len = 2;
 	}
       else if ((flags & CPP_N_RADIX) == CPP_N_HEX)
 	{
--- gcc/testsuite/gcc.dg/bitint-112.c.jj	2024-10-14 19:01:19.743225831 +0200
+++ gcc/testsuite/gcc.dg/bitint-112.c	2024-10-14 19:02:30.459231810 +0200
@@ -0,0 +1,5 @@
+/* { dg-do compile { target bitint575 } } */
+/* { dg-options "-std=c2y" } */
+
+static_assert (0o177777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777wb / 2wb * 2wb + 1wb == 0x3fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffwb, "");
+static_assert (0O3211423263360473024126605062402061031423012516423720422320324010721642021266620206352436541213777372642147046071532121506001467430513304743521547653653136162305775772330633147605317353126354wb == 0x1a2626b3784ec2856c28ca04310cc4c154e89f4224d06a023a3a208adb20867547ac28bffbeb4467130e6b451a30066f18a5b13c751b3eaf565e39317fbfa6c66ccf8567bacacecwb, "");
--- gcc/testsuite/gcc.dg/c23-octal-constants-1.c.jj	2024-10-14 18:51:29.007529522 +0200
+++ gcc/testsuite/gcc.dg/c23-octal-constants-1.c	2024-10-14 18:52:36.996573833 +0200
@@ -0,0 +1,11 @@
+/* Test that octal constants are diagnosed in C23 mode: -pedantic.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c23 -pedantic" } */
+
+int a = 0o7; /* { dg-warning "'0o' prefixed constants" } */
+#if 0o107 /* { dg-warning "'0o' prefixed constants" } */
+#endif
+
+int b = 0O7; /* { dg-warning "'0o' prefixed constants" } */
+#if 0O107 /* { dg-warning "'0o' prefixed constants" } */
+#endif
--- gcc/testsuite/gcc.dg/c23-octal-constants-2.c.jj	2024-10-14 18:51:31.924488521 +0200
+++ gcc/testsuite/gcc.dg/c23-octal-constants-2.c	2024-10-14 18:53:12.635072879 +0200
@@ -0,0 +1,11 @@
+/* Test that octal constants are diagnosed in C23 mode: -pedantic-errors.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c23 -pedantic-errors" } */
+
+int a = 0o7; /* { dg-error "'0o' prefixed constants" } */
+#if 0o107 /* { dg-error "'0o' prefixed constants" } */
+#endif
+
+int b = 0O7; /* { dg-error "'0o' prefixed constants" } */
+#if 0O107 /* { dg-error "'0o' prefixed constants" } */
+#endif
--- gcc/testsuite/gcc.dg/c2y-octal-constants-1.c.jj	2024-10-14 18:48:16.043241934 +0200
+++ gcc/testsuite/gcc.dg/c2y-octal-constants-1.c	2024-10-14 18:48:37.884934914 +0200
@@ -0,0 +1,5 @@
+/* Test C2Y octal constants.  Valid syntax and types.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors" } */
+
+#include "octal-constants-1.c"
--- gcc/testsuite/gcc.dg/c2y-octal-constants-2.c.jj	2024-10-14 18:48:21.969158637 +0200
+++ gcc/testsuite/gcc.dg/c2y-octal-constants-2.c	2024-10-14 18:49:45.002991468 +0200
@@ -0,0 +1,11 @@
+/* Test that octal constants are accepted in C2Y mode: compat warnings.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -Wc23-c2y-compat" } */
+
+int a = 0o7; /* { dg-warning "C2Y feature" } */
+#if 0o107 /* { dg-warning "C2Y feature" } */
+#endif
+
+int b = 0O7; /* { dg-warning "C2Y feature" } */
+#if 0O107 /* { dg-warning "C2Y feature" } */
+#endif
--- gcc/testsuite/gcc.dg/c2y-octal-constants-3.c.jj	2024-10-14 18:48:24.854118083 +0200
+++ gcc/testsuite/gcc.dg/c2y-octal-constants-3.c	2024-10-14 18:50:44.167159824 +0200
@@ -0,0 +1,9 @@
+/* Test C2Y octal constants.  Invalid constants.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors" } */
+
+int a = 0o; /* { dg-error "invalid suffix" } */
+int b = 0Oa; /* { dg-error "invalid suffix" } */
+int c = 0O08; /* { dg-error "invalid digit" } */
+int d = 0o1.1; /* { dg-error "invalid prefix" } */
+int e = 0O0p0; /* { dg-error "invalid suffix" } */
--- gcc/testsuite/gcc.dg/cpp/c23-delimited-escape-seq-1.c.jj	2024-10-14 17:58:54.436815339 +0200
+++ gcc/testsuite/gcc.dg/cpp/c23-delimited-escape-seq-1.c	2024-10-14 17:59:05.032666716 +0200
@@ -0,0 +1,87 @@
+/* P2290R3 - Delimited escape sequences */
+/* { dg-do compile } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=c23 -pedantic -Wno-c++-compat" } */
+
+#include <wchar.h>
+typedef __CHAR16_TYPE__ char16_t;
+typedef __CHAR32_TYPE__ char32_t;
+
+const char32_t *a = U"\u{1234}\u{10fffd}\u{000000000000000000000000000000000000000000000000000000000001234}\u{10FFFD}";		/* { dg-warning "delimited escape sequences are only valid in" } */
+const char32_t *b = U"\x{1234}\x{10fffd}\x{000000000000000000000000000000000000000000000000000000000001234}";			/* { dg-warning "delimited escape sequences are only valid in" } */
+const char32_t *c = U"\o{1234}\o{4177775}\o{000000000000000000000000000000000000000000000000000000000000000000000000004177775}";/* { dg-warning "delimited escape sequences are only valid in" } */
+const char16_t *d = u"\u{1234}\u{bFFd}\u{00000000000000000000000000000001234}";							/* { dg-warning "delimited escape sequences are only valid in" } */
+const char16_t *e = u"\x{1234}\x{BffD}\x{000001234}";										/* { dg-warning "delimited escape sequences are only valid in" } */
+const char16_t *f = u"\o{1234}\o{137775}\o{000000000000000137775}";								/* { dg-warning "delimited escape sequences are only valid in" } */
+const wchar_t *g = L"\u{1234}\u{bFFd}\u{00000000000000000000000000000001234}";							/* { dg-warning "delimited escape sequences are only valid in" } */
+const wchar_t *h = L"\x{1234}\x{bFFd}\x{000001234}";										/* { dg-warning "delimited escape sequences are only valid in" } */
+const wchar_t *i = L"\o{1234}\o{137775}\o{000000000000000137775}";								/* { dg-warning "delimited escape sequences are only valid in" } */
+const char *k = "\x{34}\x{000000000000000003D}";										/* { dg-warning "delimited escape sequences are only valid in" } */
+const char *l = "\o{34}\o{000000000000000176}";											/* { dg-warning "delimited escape sequences are only valid in" } */
+
+#if U'\u{1234}' != U'\u1234' || U'\u{10fffd}' != U'\U0010FFFD' \
+    || U'\x{00000001234}' != U'\x1234' || U'\x{010fffd}' != U'\x10FFFD' \
+    || U'\o{1234}' != U'\x29c' || U'\o{004177775}' != U'\x10FFFD' \
+    || u'\u{1234}' != u'\u1234' || u'\u{0bffd}' != u'\uBFFD' \
+    || u'\x{00000001234}' != u'\x1234' || u'\x{0Bffd}' != u'\x0bFFD' \
+    || u'\o{1234}' != u'\x29c' || u'\o{00137775}' != u'\xBFFD' \
+    || L'\u{1234}' != L'\u1234' || L'\u{0bffd}' != L'\uBFFD' \
+    || L'\x{00000001234}' != L'\x1234' || L'\x{0bffd}' != L'\x0bFFD' \
+    || L'\o{1234}' != L'\x29c' || L'\o{00137775}' != L'\xBFFD' \
+    || '\x{34}' != '\x034' || '\x{0003d}' != '\x003D' \
+    || '\o{34}' != '\x1C' || '\o{176}' != '\x007E'
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+#error Bad
+#endif
+
+int
+main ()
+{
+  if (a[0] != U'\u1234' || a[0] != U'\u{1234}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || a[1] != U'\U0010FFFD' || a[1] != U'\u{000010fFfD}'			/* { dg-warning "delimited escape sequences are only valid in" } */
+      || a[2] != a[0]
+      || a[3] != a[1]
+      || b[0] != U'\x1234' || b[0] != U'\x{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || b[1] != U'\x10FFFD' || b[1] != U'\x{0010fFfD}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || b[2] != b[0]
+      || c[0] != U'\x29c' || c[0] != U'\o{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || c[1] != U'\x10FFFD' || c[1] != U'\o{4177775}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || c[2] != c[1])
+    __builtin_abort ();
+  if (d[0] != u'\u1234' || d[0] != u'\u{1234}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || d[1] != u'\U0000BFFD' || d[1] != u'\u{00000bFfD}'			/* { dg-warning "delimited escape sequences are only valid in" } */
+      || d[2] != d[0]
+      || e[0] != u'\x1234' || e[0] != u'\x{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || e[1] != u'\xBFFD' || e[1] != u'\x{00bFfD}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || e[2] != e[0]
+      || f[0] != u'\x29c' || f[0] != u'\o{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || f[1] != u'\xbFFD' || f[1] != u'\o{137775}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || f[2] != f[1])
+    __builtin_abort ();
+  if (g[0] != L'\u1234' || g[0] != L'\u{1234}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || g[1] != L'\U0000BFFD' || g[1] != L'\u{00000bFfD}'			/* { dg-warning "delimited escape sequences are only valid in" } */
+      || g[2] != g[0]
+      || h[0] != L'\x1234' || h[0] != L'\x{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || h[1] != L'\xBFFD' || h[1] != L'\x{00bFfD}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || h[2] != h[0]
+      || i[0] != L'\x29c' || i[0] != L'\o{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || i[1] != L'\xbFFD' || i[1] != L'\o{137775}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || i[2] != i[1])
+    __builtin_abort ();
+  if (k[0] != '\x034' || k[0] != '\x{0034}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || k[1] != '\x3D' || k[1] != '\x{3d}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || l[0] != '\x1c' || l[0] != '\o{0034}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || l[1] != '\x07e' || l[1] != '\o{176}' || l[1] != '\176')		/* { dg-warning "delimited escape sequences are only valid in" } */
+    __builtin_abort ();
+  return 0;
+}
--- gcc/testsuite/gcc.dg/cpp/c23-delimited-escape-seq-2.c.jj	2024-10-14 17:59:16.808501539 +0200
+++ gcc/testsuite/gcc.dg/cpp/c23-delimited-escape-seq-2.c	2024-10-14 17:59:28.721334439 +0200
@@ -0,0 +1,87 @@
+/* P2290R3 - Delimited escape sequences */
+/* { dg-do compile } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=c23 -pedantic-errors -Wno-c++-compat" } */
+
+#include <wchar.h>
+typedef __CHAR16_TYPE__ char16_t;
+typedef __CHAR32_TYPE__ char32_t;
+
+const char32_t *a = U"\u{1234}\u{10fffd}\u{000000000000000000000000000000000000000000000000000000000001234}\u{10FFFD}";		/* { dg-error "delimited escape sequences are only valid in" } */
+const char32_t *b = U"\x{1234}\x{10fffd}\x{000000000000000000000000000000000000000000000000000000000001234}";			/* { dg-error "delimited escape sequences are only valid in" } */
+const char32_t *c = U"\o{1234}\o{4177775}\o{000000000000000000000000000000000000000000000000000000000000000000000000004177775}";/* { dg-error "delimited escape sequences are only valid in" } */
+const char16_t *d = u"\u{1234}\u{bFFd}\u{00000000000000000000000000000001234}";							/* { dg-error "delimited escape sequences are only valid in" } */
+const char16_t *e = u"\x{1234}\x{BffD}\x{000001234}";										/* { dg-error "delimited escape sequences are only valid in" } */
+const char16_t *f = u"\o{1234}\o{137775}\o{000000000000000137775}";								/* { dg-error "delimited escape sequences are only valid in" } */
+const wchar_t *g = L"\u{1234}\u{bFFd}\u{00000000000000000000000000000001234}";							/* { dg-error "delimited escape sequences are only valid in" } */
+const wchar_t *h = L"\x{1234}\x{bFFd}\x{000001234}";										/* { dg-error "delimited escape sequences are only valid in" } */
+const wchar_t *i = L"\o{1234}\o{137775}\o{000000000000000137775}";								/* { dg-error "delimited escape sequences are only valid in" } */
+const char *k = "\x{34}\x{000000000000000003D}";										/* { dg-error "delimited escape sequences are only valid in" } */
+const char *l = "\o{34}\o{000000000000000176}";											/* { dg-error "delimited escape sequences are only valid in" } */
+
+#if U'\u{1234}' != U'\u1234' || U'\u{10fffd}' != U'\U0010FFFD' \
+    || U'\x{00000001234}' != U'\x1234' || U'\x{010fffd}' != U'\x10FFFD' \
+    || U'\o{1234}' != U'\x29c' || U'\o{004177775}' != U'\x10FFFD' \
+    || u'\u{1234}' != u'\u1234' || u'\u{0bffd}' != u'\uBFFD' \
+    || u'\x{00000001234}' != u'\x1234' || u'\x{0Bffd}' != u'\x0bFFD' \
+    || u'\o{1234}' != u'\x29c' || u'\o{00137775}' != u'\xBFFD' \
+    || L'\u{1234}' != L'\u1234' || L'\u{0bffd}' != L'\uBFFD' \
+    || L'\x{00000001234}' != L'\x1234' || L'\x{0bffd}' != L'\x0bFFD' \
+    || L'\o{1234}' != L'\x29c' || L'\o{00137775}' != L'\xBFFD' \
+    || '\x{34}' != '\x034' || '\x{0003d}' != '\x003D' \
+    || '\o{34}' != '\x1C' || '\o{176}' != '\x007E'
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-error "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+#error Bad
+#endif
+
+int
+main ()
+{
+  if (a[0] != U'\u1234' || a[0] != U'\u{1234}'					/* { dg-error "delimited escape sequences are only valid in" } */
+      || a[1] != U'\U0010FFFD' || a[1] != U'\u{000010fFfD}'			/* { dg-error "delimited escape sequences are only valid in" } */
+      || a[2] != a[0]
+      || a[3] != a[1]
+      || b[0] != U'\x1234' || b[0] != U'\x{001234}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || b[1] != U'\x10FFFD' || b[1] != U'\x{0010fFfD}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || b[2] != b[0]
+      || c[0] != U'\x29c' || c[0] != U'\o{001234}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || c[1] != U'\x10FFFD' || c[1] != U'\o{4177775}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || c[2] != c[1])
+    __builtin_abort ();
+  if (d[0] != u'\u1234' || d[0] != u'\u{1234}'					/* { dg-error "delimited escape sequences are only valid in" } */
+      || d[1] != u'\U0000BFFD' || d[1] != u'\u{00000bFfD}'			/* { dg-error "delimited escape sequences are only valid in" } */
+      || d[2] != d[0]
+      || e[0] != u'\x1234' || e[0] != u'\x{001234}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || e[1] != u'\xBFFD' || e[1] != u'\x{00bFfD}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || e[2] != e[0]
+      || f[0] != u'\x29c' || f[0] != u'\o{001234}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || f[1] != u'\xbFFD' || f[1] != u'\o{137775}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || f[2] != f[1])
+    __builtin_abort ();
+  if (g[0] != L'\u1234' || g[0] != L'\u{1234}'					/* { dg-error "delimited escape sequences are only valid in" } */
+      || g[1] != L'\U0000BFFD' || g[1] != L'\u{00000bFfD}'			/* { dg-error "delimited escape sequences are only valid in" } */
+      || g[2] != g[0]
+      || h[0] != L'\x1234' || h[0] != L'\x{001234}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || h[1] != L'\xBFFD' || h[1] != L'\x{00bFfD}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || h[2] != h[0]
+      || i[0] != L'\x29c' || i[0] != L'\o{001234}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || i[1] != L'\xbFFD' || i[1] != L'\o{137775}'				/* { dg-error "delimited escape sequences are only valid in" } */
+      || i[2] != i[1])
+    __builtin_abort ();
+  if (k[0] != '\x034' || k[0] != '\x{0034}'					/* { dg-error "delimited escape sequences are only valid in" } */
+      || k[1] != '\x3D' || k[1] != '\x{3d}'					/* { dg-error "delimited escape sequences are only valid in" } */
+      || l[0] != '\x1c' || l[0] != '\o{0034}'					/* { dg-error "delimited escape sequences are only valid in" } */
+      || l[1] != '\x07e' || l[1] != '\o{176}' || l[1] != '\176')		/* { dg-error "delimited escape sequences are only valid in" } */
+    __builtin_abort ();
+  return 0;
+}
--- gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-1.c.jj	2024-10-14 17:21:25.805396557 +0200
+++ gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-1.c	2024-10-14 17:21:21.009464008 +0200
@@ -0,0 +1,6 @@
+/* N3353 - Delimited escape sequences */
+/* { dg-do run } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=c2y -pedantic-errors -Wno-c++-compat" } */
+
+#include "../../c-c++-common/cpp/delimited-escape-seq-1.c"
--- gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-2.c.jj	2024-10-14 17:21:54.203997156 +0200
+++ gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-2.c	2024-10-14 17:53:22.709468583 +0200
@@ -0,0 +1,5 @@
+/* N3353 - Delimited escape sequences */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors -Wno-c++-compat" } */
+
+#include "../../c-c++-common/cpp/delimited-escape-seq-2.c"
--- gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-3.c.jj	2024-10-14 17:22:50.102210967 +0200
+++ gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-3.c	2024-10-14 17:54:10.714795032 +0200
@@ -0,0 +1,30 @@
+/* P2290R3 - Delimited escape sequences */
+/* { dg-do compile } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=c2y -pedantic-errors -Wno-c++-compat" } */
+
+typedef __CHAR32_TYPE__ char32_t;
+
+const char32_t *a = U"\u{}";				/* { dg-error "empty delimited escape sequence" } */
+							/* { dg-error "is not a valid universal character" "" { target c } .-1 } */
+const char32_t *b = U"\u{12" "34}";			/* { dg-error "'\\\\u\\{' not terminated with '\\}' after" } */
+const char32_t *c = U"\u{0000ffffffff}";		/* { dg-error "is not a valid universal character" } */
+const char32_t *d = U"\u{010000edcb}";			/* { dg-error "is not a valid universal character" } */
+const char32_t *e = U"\u{02000000000000000000edcb}";	/* { dg-error "is not a valid universal character" } */
+const char32_t *f = U"\u{123ghij}";			/* { dg-error "'\\\\u\\{' not terminated with '\\}' after" } */
+const char32_t *g = U"\u{123.}";			/* { dg-error "'\\\\u\\{' not terminated with '\\}' after" } */
+const char32_t *h = U"\u{.}";				/* { dg-error "'\\\\u\\{' not terminated with '\\}' after" } */
+const char32_t *i = U"\x{}";				/* { dg-error "empty delimited escape sequence" } */
+const char32_t *j = U"\x{12" "34}";			/* { dg-error "'\\\\x\\{' not terminated with '\\}' after" } */
+const char32_t *k = U"\x{0000ffffffff}";
+const char32_t *l = U"\x{010000edcb}";			/* { dg-error "hex escape sequence out of range" } */
+const char32_t *m = U"\x{02000000000000000000edcb}";	/* { dg-error "hex escape sequence out of range" } */
+const char32_t *n = U"\x{123ghij}";			/* { dg-error "'\\\\x\\{' not terminated with '\\}' after" } */
+const char32_t *o = U"\x{123.}";			/* { dg-error "'\\\\x\\{' not terminated with '\\}' after" } */
+const char32_t *p = U"\o{}";				/* { dg-error "empty delimited escape sequence" } */
+const char32_t *q = U"\o{12" "34}";			/* { dg-error "'\\\\o\\{' not terminated with '\\}' after" } */
+const char32_t *r = U"\o{0000037777777777}";
+const char32_t *s = U"\o{040000166713}";		/* { dg-error "octal escape sequence out of range" } */
+const char32_t *t = U"\o{02000000000000000000000166713}";/* { dg-error "octal escape sequence out of range" } */
+const char32_t *u = U"\o{1238}";			/* { dg-error "'\\\\o\\{' not terminated with '\\}' after" } */
+const char32_t *v = U"\o{.}";				/* { dg-error "'\\\\o\\{' not terminated with '\\}' after" } */
--- gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-4.c.jj	2024-10-14 17:33:21.867325501 +0200
+++ gcc/testsuite/gcc.dg/cpp/c2y-delimited-escape-seq-4.c	2024-10-14 17:58:19.985298584 +0200
@@ -0,0 +1,87 @@
+/* P2290R3 - Delimited escape sequences */
+/* { dg-do compile } */
+/* { dg-require-effective-target wchar } */
+/* { dg-options "-std=c2y -Wc23-c2y-compat -Wno-c++-compat" } */
+
+#include <wchar.h>
+typedef __CHAR16_TYPE__ char16_t;
+typedef __CHAR32_TYPE__ char32_t;
+
+const char32_t *a = U"\u{1234}\u{10fffd}\u{000000000000000000000000000000000000000000000000000000000001234}\u{10FFFD}";		/* { dg-warning "delimited escape sequences are only valid in" } */
+const char32_t *b = U"\x{1234}\x{10fffd}\x{000000000000000000000000000000000000000000000000000000000001234}";			/* { dg-warning "delimited escape sequences are only valid in" } */
+const char32_t *c = U"\o{1234}\o{4177775}\o{000000000000000000000000000000000000000000000000000000000000000000000000004177775}";/* { dg-warning "delimited escape sequences are only valid in" } */
+const char16_t *d = u"\u{1234}\u{bFFd}\u{00000000000000000000000000000001234}";							/* { dg-warning "delimited escape sequences are only valid in" } */
+const char16_t *e = u"\x{1234}\x{BffD}\x{000001234}";										/* { dg-warning "delimited escape sequences are only valid in" } */
+const char16_t *f = u"\o{1234}\o{137775}\o{000000000000000137775}";								/* { dg-warning "delimited escape sequences are only valid in" } */
+const wchar_t *g = L"\u{1234}\u{bFFd}\u{00000000000000000000000000000001234}";							/* { dg-warning "delimited escape sequences are only valid in" } */
+const wchar_t *h = L"\x{1234}\x{bFFd}\x{000001234}";										/* { dg-warning "delimited escape sequences are only valid in" } */
+const wchar_t *i = L"\o{1234}\o{137775}\o{000000000000000137775}";								/* { dg-warning "delimited escape sequences are only valid in" } */
+const char *k = "\x{34}\x{000000000000000003D}";										/* { dg-warning "delimited escape sequences are only valid in" } */
+const char *l = "\o{34}\o{000000000000000176}";											/* { dg-warning "delimited escape sequences are only valid in" } */
+
+#if U'\u{1234}' != U'\u1234' || U'\u{10fffd}' != U'\U0010FFFD' \
+    || U'\x{00000001234}' != U'\x1234' || U'\x{010fffd}' != U'\x10FFFD' \
+    || U'\o{1234}' != U'\x29c' || U'\o{004177775}' != U'\x10FFFD' \
+    || u'\u{1234}' != u'\u1234' || u'\u{0bffd}' != u'\uBFFD' \
+    || u'\x{00000001234}' != u'\x1234' || u'\x{0Bffd}' != u'\x0bFFD' \
+    || u'\o{1234}' != u'\x29c' || u'\o{00137775}' != u'\xBFFD' \
+    || L'\u{1234}' != L'\u1234' || L'\u{0bffd}' != L'\uBFFD' \
+    || L'\x{00000001234}' != L'\x1234' || L'\x{0bffd}' != L'\x0bFFD' \
+    || L'\o{1234}' != L'\x29c' || L'\o{00137775}' != L'\xBFFD' \
+    || '\x{34}' != '\x034' || '\x{0003d}' != '\x003D' \
+    || '\o{34}' != '\x1C' || '\o{176}' != '\x007E'
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+/* { dg-warning "delimited escape sequences are only valid in" "" { target *-*-* } .-11 } */
+#error Bad
+#endif
+
+int
+main ()
+{
+  if (a[0] != U'\u1234' || a[0] != U'\u{1234}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || a[1] != U'\U0010FFFD' || a[1] != U'\u{000010fFfD}'			/* { dg-warning "delimited escape sequences are only valid in" } */
+      || a[2] != a[0]
+      || a[3] != a[1]
+      || b[0] != U'\x1234' || b[0] != U'\x{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || b[1] != U'\x10FFFD' || b[1] != U'\x{0010fFfD}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || b[2] != b[0]
+      || c[0] != U'\x29c' || c[0] != U'\o{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || c[1] != U'\x10FFFD' || c[1] != U'\o{4177775}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || c[2] != c[1])
+    __builtin_abort ();
+  if (d[0] != u'\u1234' || d[0] != u'\u{1234}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || d[1] != u'\U0000BFFD' || d[1] != u'\u{00000bFfD}'			/* { dg-warning "delimited escape sequences are only valid in" } */
+      || d[2] != d[0]
+      || e[0] != u'\x1234' || e[0] != u'\x{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || e[1] != u'\xBFFD' || e[1] != u'\x{00bFfD}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || e[2] != e[0]
+      || f[0] != u'\x29c' || f[0] != u'\o{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || f[1] != u'\xbFFD' || f[1] != u'\o{137775}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || f[2] != f[1])
+    __builtin_abort ();
+  if (g[0] != L'\u1234' || g[0] != L'\u{1234}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || g[1] != L'\U0000BFFD' || g[1] != L'\u{00000bFfD}'			/* { dg-warning "delimited escape sequences are only valid in" } */
+      || g[2] != g[0]
+      || h[0] != L'\x1234' || h[0] != L'\x{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || h[1] != L'\xBFFD' || h[1] != L'\x{00bFfD}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || h[2] != h[0]
+      || i[0] != L'\x29c' || i[0] != L'\o{001234}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || i[1] != L'\xbFFD' || i[1] != L'\o{137775}'				/* { dg-warning "delimited escape sequences are only valid in" } */
+      || i[2] != i[1])
+    __builtin_abort ();
+  if (k[0] != '\x034' || k[0] != '\x{0034}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || k[1] != '\x3D' || k[1] != '\x{3d}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || l[0] != '\x1c' || l[0] != '\o{0034}'					/* { dg-warning "delimited escape sequences are only valid in" } */
+      || l[1] != '\x07e' || l[1] != '\o{176}' || l[1] != '\176')		/* { dg-warning "delimited escape sequences are only valid in" } */
+    __builtin_abort ();
+  return 0;
+}
--- gcc/testsuite/gcc.dg/octal-constants-1.c.jj	2024-10-14 18:12:07.413692711 +0200
+++ gcc/testsuite/gcc.dg/octal-constants-1.c	2024-10-14 18:42:45.683885903 +0200
@@ -0,0 +1,311 @@
+/* Test for octal integer constants.  */
+
+/* Derived from: binary-constants-1.c, by Jakub Jelinek <jakub@redhat.com>.  */
+/* Origin: Joerg Wunsch <j.gnu@uriah.heep.sax.de>.  */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99" } */
+
+#include <limits.h>
+
+/* Assertion that constant C is of type T.  */
+#define ASSERT_CONST_TYPE(C, T)			\
+	do {					\
+	  typedef T type;			\
+	  typedef type **typepp;		\
+	  typedef __typeof__((C)) ctype;	\
+	  typedef ctype **ctypepp;		\
+	  typepp x = 0;				\
+	  ctypepp y = 0;			\
+	  x = y;				\
+	  y = x;				\
+	} while (0)
+
+/* (T *) if E is zero, (void *) otherwise.  */
+#define type_if_not(T, E) __typeof__(0 ? (T *)0 : (void *)(E))
+
+/* (T *) if E is nonzero, (void *) otherwise.  */
+#define type_if(T, E) type_if_not(T, !(E))
+
+/* Combine pointer types, all but one (void *).  */
+#define type_comb2(T1, T2) __typeof__(0 ? (T1)0 : (T2)0)
+#define type_comb3(T1, T2, T3) type_comb2(T1, type_comb2(T2, T3))
+#define type_comb4(T1, T2, T3, T4)				\
+	type_comb2(T1, type_comb2(T2, type_comb2(T3, T4)))
+#define type_comb6(T1, T2, T3, T4, T5, T6)				   \
+	type_comb2(T1,							   \
+		   type_comb2(T2,					   \
+			      type_comb2(T3,				   \
+					 type_comb2(T4,			   \
+						    type_comb2(T5, T6)))))
+
+/* (T1 *) if E1, otherwise (T2 *) if E2.  */
+#define first_of2p(T1, E1, T2, E2) type_comb2(type_if(T1, (E1)),	   \
+					     type_if(T2, (!(E1) && (E2))))
+/* (T1 *) if E1, otherwise (T2 *) if E2, otherwise (T3 *) if E3.  */
+#define first_of3p(T1, E1, T2, E2, T3, E3)			\
+	type_comb3(type_if(T1, (E1)),				\
+		   type_if(T2, (!(E1) && (E2))),		\
+		   type_if(T3, (!(E1) && !(E2) && (E3))))
+/* (T1 *) if E1, otherwise (T2 *) if E2, otherwise (T3 *) if E3, otherwise
+   (T4 *) if E4.  */
+#define first_of4p(T1, E1, T2, E2, T3, E3, T4, E4)			\
+	type_comb4(type_if(T1, (E1)),					\
+		   type_if(T2, (!(E1) && (E2))),			\
+		   type_if(T3, (!(E1) && !(E2) && (E3))),		\
+		   type_if(T4, (!(E1) && !(E2) && !(E3) && (E4))))
+/* (T1 *) if E1, otherwise (T2 *) if E2, otherwise (T3 *) if E3, otherwise
+   (T4 *) if E4, otherwise (T5 *) if E5, otherwise (T6 *) if E6.  */
+#define first_of6p(T1, E1, T2, E2, T3, E3, T4, E4, T5, E5, T6, E6)	    \
+	type_comb6(type_if(T1, (E1)),					    \
+		   type_if(T2, (!(E1) && (E2))),			    \
+		   type_if(T3, (!(E1) && !(E2) && (E3))),		    \
+		   type_if(T4, (!(E1) && !(E2) && !(E3) && (E4))),	    \
+		   type_if(T5, (!(E1) && !(E2) && !(E3) && !(E4) && (E5))), \
+		   type_if(T6, (!(E1) && !(E2) && !(E3)			    \
+				&& !(E4) && !(E5) && (E6))))
+
+/* Likewise, but return the original type rather than a pointer type.  */
+#define first_of2(T1, E1, T2, E2)			\
+	__typeof__(*((first_of2p(T1, (E1), T2, (E2)))0))
+#define first_of3(T1, E1, T2, E2, T3, E3)				\
+	__typeof__(*((first_of3p(T1, (E1), T2, (E2), T3, (E3)))0))
+#define first_of4(T1, E1, T2, E2, T3, E3, T4, E4)			    \
+	__typeof__(*((first_of4p(T1, (E1), T2, (E2), T3, (E3), T4, (E4)))0))
+#define first_of6(T1, E1, T2, E2, T3, E3, T4, E4, T5, E5, T6, E6)	\
+	__typeof__(*((first_of6p(T1, (E1), T2, (E2), T3, (E3),		\
+				 T4, (E4), T5, (E5), T6, (E6)))0))
+
+/* Types of constants according to the C99 rules.  */
+#define C99_UNSUF_TYPE(C)					\
+	first_of6(int, (C) <= INT_MAX,				\
+		  unsigned int, (C) <= UINT_MAX,		\
+		  long int, (C) <= LONG_MAX,			\
+		  unsigned long int, (C) <= ULONG_MAX,		\
+		  long long int, (C) <= LLONG_MAX,		\
+		  unsigned long long int, (C) <= ULLONG_MAX)
+#define C99_SUFu_TYPE(C)					\
+	first_of3(unsigned int, (C) <= UINT_MAX,		\
+		  unsigned long int, (C) <= ULONG_MAX,		\
+		  unsigned long long int, (C) <= ULLONG_MAX)
+#define C99_SUFl_TYPE(C)					\
+	first_of4(long int, (C) <= LONG_MAX,			\
+		  unsigned long int, (C) <= ULONG_MAX,		\
+		  long long int, (C) <= LLONG_MAX,		\
+		  unsigned long long int, (C) <= ULLONG_MAX)
+#define C99_SUFul_TYPE(C)					\
+	first_of2(unsigned long int, (C) <= ULONG_MAX,		\
+		  unsigned long long int, (C) <= ULLONG_MAX)
+#define C99_SUFll_TYPE(C)					\
+	first_of2(long long int, (C) <= LLONG_MAX,		\
+		  unsigned long long int, (C) <= ULLONG_MAX)
+
+/* Checks that constants have correct type.  */
+#define CHECK_UNSUF_TYPE(C)				\
+	ASSERT_CONST_TYPE((C), C99_UNSUF_TYPE((C)))
+#define CHECK_SUFu_TYPE(C) ASSERT_CONST_TYPE((C), C99_SUFu_TYPE((C)))
+#define CHECK_SUFl_TYPE(C)				\
+	ASSERT_CONST_TYPE((C), C99_SUFl_TYPE((C)))
+#define CHECK_SUFul_TYPE(C) ASSERT_CONST_TYPE((C), C99_SUFul_TYPE((C)))
+#define CHECK_SUFll_TYPE(C)				\
+	ASSERT_CONST_TYPE((C), C99_SUFll_TYPE((C)))
+#define CHECK_SUFull_TYPE(C) ASSERT_CONST_TYPE((C), unsigned long long int)
+
+/* Check an octal or hexadecimal value, with all suffixes.  */
+#define CHECK_CONST(C)                  	\
+	CHECK_UNSUF_TYPE(C);                    \
+	CHECK_SUFu_TYPE(C##u);			\
+	CHECK_SUFu_TYPE(C##U);			\
+	CHECK_SUFl_TYPE(C##l);                  \
+	CHECK_SUFl_TYPE(C##L);                  \
+	CHECK_SUFul_TYPE(C##ul);		\
+	CHECK_SUFul_TYPE(C##uL);		\
+	CHECK_SUFul_TYPE(C##Ul);		\
+	CHECK_SUFul_TYPE(C##UL);		\
+	CHECK_SUFll_TYPE(C##ll);		\
+	CHECK_SUFll_TYPE(C##LL);		\
+	CHECK_SUFull_TYPE(C##ull);		\
+	CHECK_SUFull_TYPE(C##uLL);		\
+	CHECK_SUFull_TYPE(C##Ull);		\
+	CHECK_SUFull_TYPE(C##ULL);
+
+#define CHECK_OCT_CONST(C)			\
+	CHECK_CONST(0o##C);                     \
+	CHECK_CONST(0O##C);
+
+/* True iff "long long" is at least B bits.  This presumes that (B-2)/3 is at
+   most 63.  */
+#define LLONG_AT_LEAST(B)			\
+	(LLONG_MAX >> ((B)-2)/3 >> ((B)-2)/3	\
+	 >> ((B)-2 - ((B)-2)/3 - ((B)-2)/3))
+
+#define LLONG_HAS_BITS(B) (LLONG_AT_LEAST((B)) && !LLONG_AT_LEAST((B) + 1))
+
+#define FOO 0o1307
+#if !FOO
+# error "preprocessor does not accept octal constants"
+#endif
+
+void
+foo (void)
+{
+  /* Check all 2^n and 2^n - 1 up to 2^72 - 1.  */
+  CHECK_OCT_CONST(1);
+  CHECK_OCT_CONST(2);
+  CHECK_OCT_CONST(3);
+  CHECK_OCT_CONST(4);
+  CHECK_OCT_CONST(7);
+  CHECK_OCT_CONST(10);
+  CHECK_OCT_CONST(17);
+  CHECK_OCT_CONST(20);
+  CHECK_OCT_CONST(37);
+  CHECK_OCT_CONST(40);
+  CHECK_OCT_CONST(77);
+  CHECK_OCT_CONST(100);
+  CHECK_OCT_CONST(177);
+  CHECK_OCT_CONST(200);
+  CHECK_OCT_CONST(377);
+  CHECK_OCT_CONST(400);
+  CHECK_OCT_CONST(777);
+  CHECK_OCT_CONST(1000);
+  CHECK_OCT_CONST(1777);
+  CHECK_OCT_CONST(2000);
+  CHECK_OCT_CONST(3777);
+  CHECK_OCT_CONST(4000);
+  CHECK_OCT_CONST(7777);
+  CHECK_OCT_CONST(10000);
+  CHECK_OCT_CONST(17777);
+  CHECK_OCT_CONST(20000);
+  CHECK_OCT_CONST(37777);
+  CHECK_OCT_CONST(40000);
+  CHECK_OCT_CONST(77777);
+  CHECK_OCT_CONST(100000);
+  CHECK_OCT_CONST(177777);
+  CHECK_OCT_CONST(200000);
+  CHECK_OCT_CONST(377777);
+  CHECK_OCT_CONST(400000);
+  CHECK_OCT_CONST(777777);
+  CHECK_OCT_CONST(1000000);
+  CHECK_OCT_CONST(1777777);
+  CHECK_OCT_CONST(2000000);
+  CHECK_OCT_CONST(3777777);
+  CHECK_OCT_CONST(4000000);
+  CHECK_OCT_CONST(7777777);
+  CHECK_OCT_CONST(10000000);
+  CHECK_OCT_CONST(17777777);
+  CHECK_OCT_CONST(20000000);
+  CHECK_OCT_CONST(37777777);
+  CHECK_OCT_CONST(40000000);
+  CHECK_OCT_CONST(77777777);
+  CHECK_OCT_CONST(100000000);
+  CHECK_OCT_CONST(177777777);
+  CHECK_OCT_CONST(200000000);
+  CHECK_OCT_CONST(377777777);
+  CHECK_OCT_CONST(400000000);
+  CHECK_OCT_CONST(777777777);
+  CHECK_OCT_CONST(1000000000);
+  CHECK_OCT_CONST(1777777777);
+  CHECK_OCT_CONST(2000000000);
+  CHECK_OCT_CONST(3777777777);
+  CHECK_OCT_CONST(4000000000);
+  CHECK_OCT_CONST(7777777777);
+  CHECK_OCT_CONST(10000000000);
+  CHECK_OCT_CONST(17777777777);
+  CHECK_OCT_CONST(20000000000);
+  CHECK_OCT_CONST(37777777777);
+  CHECK_OCT_CONST(40000000000);
+  CHECK_OCT_CONST(77777777777);
+  CHECK_OCT_CONST(100000000000);
+  CHECK_OCT_CONST(177777777777);
+  CHECK_OCT_CONST(200000000000);
+  CHECK_OCT_CONST(377777777777);
+  CHECK_OCT_CONST(400000000000);
+  CHECK_OCT_CONST(777777777777);
+  CHECK_OCT_CONST(1000000000000);
+  CHECK_OCT_CONST(1777777777777);
+  CHECK_OCT_CONST(2000000000000);
+  CHECK_OCT_CONST(3777777777777);
+  CHECK_OCT_CONST(4000000000000);
+  CHECK_OCT_CONST(7777777777777);
+  CHECK_OCT_CONST(10000000000000);
+  CHECK_OCT_CONST(17777777777777);
+  CHECK_OCT_CONST(20000000000000);
+  CHECK_OCT_CONST(37777777777777);
+  CHECK_OCT_CONST(40000000000000);
+  CHECK_OCT_CONST(77777777777777);
+  CHECK_OCT_CONST(100000000000000);
+  CHECK_OCT_CONST(177777777777777);
+  CHECK_OCT_CONST(200000000000000);
+  CHECK_OCT_CONST(377777777777777);
+  CHECK_OCT_CONST(400000000000000);
+  CHECK_OCT_CONST(777777777777777);
+  CHECK_OCT_CONST(1000000000000000);
+  CHECK_OCT_CONST(1777777777777777);
+  CHECK_OCT_CONST(2000000000000000);
+  CHECK_OCT_CONST(3777777777777777);
+  CHECK_OCT_CONST(4000000000000000);
+  CHECK_OCT_CONST(7777777777777777);
+  CHECK_OCT_CONST(10000000000000000);
+  CHECK_OCT_CONST(17777777777777777);
+  CHECK_OCT_CONST(20000000000000000);
+  CHECK_OCT_CONST(37777777777777777);
+  CHECK_OCT_CONST(40000000000000000);
+  CHECK_OCT_CONST(77777777777777777);
+  CHECK_OCT_CONST(100000000000000000);
+  CHECK_OCT_CONST(177777777777777777);
+  CHECK_OCT_CONST(200000000000000000);
+  CHECK_OCT_CONST(377777777777777777);
+  CHECK_OCT_CONST(400000000000000000);
+  CHECK_OCT_CONST(777777777777777777);
+  CHECK_OCT_CONST(1000000000000000000);
+  CHECK_OCT_CONST(1777777777777777777);
+  CHECK_OCT_CONST(2000000000000000000);
+  CHECK_OCT_CONST(3777777777777777777);
+  CHECK_OCT_CONST(4000000000000000000);
+  CHECK_OCT_CONST(7777777777777777777);
+  CHECK_OCT_CONST(10000000000000000000);
+  CHECK_OCT_CONST(17777777777777777777);
+  CHECK_OCT_CONST(20000000000000000000);
+  CHECK_OCT_CONST(37777777777777777777);
+  CHECK_OCT_CONST(40000000000000000000);
+  CHECK_OCT_CONST(77777777777777777777);
+  CHECK_OCT_CONST(100000000000000000000);
+  CHECK_OCT_CONST(177777777777777777777);
+  CHECK_OCT_CONST(200000000000000000000);
+  CHECK_OCT_CONST(377777777777777777777);
+  CHECK_OCT_CONST(400000000000000000000);
+  CHECK_OCT_CONST(777777777777777777777);
+  CHECK_OCT_CONST(1000000000000000000000);
+  CHECK_OCT_CONST(1777777777777777777777);
+#if LLONG_AT_LEAST(65)
+  CHECK_OCT_CONST(2000000000000000000000);
+  CHECK_OCT_CONST(3777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(66)
+  CHECK_OCT_CONST(4000000000000000000000);
+  CHECK_OCT_CONST(7777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(67)
+  CHECK_OCT_CONST(10000000000000000000000);
+  CHECK_OCT_CONST(17777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(68)
+  CHECK_OCT_CONST(20000000000000000000000);
+  CHECK_OCT_CONST(37777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(69)
+  CHECK_OCT_CONST(40000000000000000000000);
+  CHECK_OCT_CONST(77777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(70)
+  CHECK_OCT_CONST(100000000000000000000000);
+  CHECK_OCT_CONST(177777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(71)
+  CHECK_OCT_CONST(200000000000000000000000);
+  CHECK_OCT_CONST(377777777777777777777777);
+#endif
+#if LLONG_AT_LEAST(72)
+  CHECK_OCT_CONST(400000000000000000000000);
+  CHECK_OCT_CONST(777777777777777777777777);
+#endif
+}
--- gcc/testsuite/gcc.dg/octal-constants-2.c.jj	2024-10-14 18:12:33.292329850 +0200
+++ gcc/testsuite/gcc.dg/octal-constants-2.c	2024-10-14 18:44:54.220078934 +0200
@@ -0,0 +1,16 @@
+/* Test for octal integer constants: -pedantic warnings.  */
+
+/* Origin: Joerg Wunsch <j.gnu@uriah.heep.sax.de>.  */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1999 -pedantic -ftrack-macro-expansion=0" } */
+
+#define FOO 0o1307
+
+int
+foo (void)
+{
+#if FOO /* { dg-warning "'0o' prefixed constants are a C2Y feature or GCC extension" } */
+  return 23;
+#endif
+  return 0o1307; /* { dg-warning "'0o' prefixed constants are a C2Y feature or GCC extension" } */
+}
--- gcc/testsuite/gcc.dg/octal-constants-3.c.jj	2024-10-14 18:12:39.450243502 +0200
+++ gcc/testsuite/gcc.dg/octal-constants-3.c	2024-10-14 18:44:44.115220989 +0200
@@ -0,0 +1,16 @@
+/* Test for octal integer constants: -pedantic-errors.  */
+
+/* Origin: Joerg Wunsch <j.gnu@uriah.heep.sax.de>.  */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors -ftrack-macro-expansion=0" } */
+
+#define FOO 0o1307
+
+int
+foo (void)
+{
+#if FOO /* { dg-error "'0o' prefixed constants are a C2Y feature or GCC extension" } */
+  return 23;
+#endif
+  return 0o1307; /* { dg-error "'0o' prefixed constants are a C2Y feature or GCC extension" } */
+}
--- gcc/testsuite/gcc.dg/octal-constants-4.c.jj	2024-10-14 18:12:42.258204132 +0200
+++ gcc/testsuite/gcc.dg/octal-constants-4.c	2024-10-14 18:47:07.455206044 +0200
@@ -0,0 +1,18 @@
+/* Test for octal integer constants: random errors.  */
+
+/* Origin: Joerg Wunsch <j.gnu@uriah.heep.sax.de>.  */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99" } */
+
+void
+foo(void)
+{
+  double d;
+  int i;
+
+  d = 0o1307;
+  d = 0o1307p1; /* { dg-error "invalid suffix 'p1' on integer constant" } */
+  d = 0x1307p1;
+  i = 0oa011;   /* { dg-error "invalid suffix 'oa011' on integer constant" } */
+  i = 0o118;    /* { dg-error "invalid digit '8' in octal constant" } */
+}
--- gcc/testsuite/gcc.dg/system-octal-constants-1.c.jj	2024-10-14 18:53:39.686692627 +0200
+++ gcc/testsuite/gcc.dg/system-octal-constants-1.c	2024-10-14 18:54:39.343854054 +0200
@@ -0,0 +1,18 @@
+/* 
+   Origin: Dodji Seketeli <dodji@redhat.com>
+   { dg-options "-std=iso9899:1999 -pedantic" } 
+   { dg-do compile } 
+ */
+
+#include "system-octal-constants-1.h"
+
+int
+foo (void)
+{
+#if OCTAL_INT_CONSTANT_IN_SYSTEM_HEADER /* A octal constant defined
+					   in system header.  No
+					   warning.  */
+  return 23;
+#endif
+  return 0o1307; /* { dg-warning "'0o' prefixed constants are a C2Y feature or GCC extension" } */
+}
--- gcc/testsuite/gcc.dg/system-octal-constants-1.h.jj	2024-10-14 18:53:42.600651667 +0200
+++ gcc/testsuite/gcc.dg/system-octal-constants-1.h	2024-10-14 18:55:41.613978752 +0200
@@ -0,0 +1,3 @@
+#pragma GCC system_header
+
+#define OCTAL_INT_CONSTANT_IN_SYSTEM_HEADER 0o1307
