libcpp: adjust pedwarn handling

Using cpp_pedwarning (CPP_W_PEDANTIC instead of if (CPP_PEDANTIC cpp_error
lets users suppress these diagnostics with
 #pragma GCC diagnostic ignored "-Wpedantic".

This patch changes all instances of the cpp_error (CPP_DL_PEDWARN to
cpp_pedwarning.  In cases where the extension appears in a later C++
revision, we now condition the warning on the relevant -Wc++??-extensions
flag instead of -Wpedantic; in such cases often the if (CPP_PEDANTIC) check
is retained to preserve the default non-warning behavior.

I didn't attempt to adjust the warning flags for the C compiler, since it
seems to follow a different system than C++.

The CPP_PEDANTIC check is also kept in _cpp_lex_direct to avoid an ICE in
the self-tests from cb.diagnostics not being initialized.

While working on testcases for these changes I noticed that the c-c++-common
tests are not run with -pedantic-errors by default like the gcc.dg and
g++.dg directories are.  And if I specify -pedantic-errors with dg-options,
the default -std= changes from c++?? to gnu++??, which interferes with some
other pedwarns.  So two of the tests are C++-only.

libcpp/ChangeLog:

	* include/cpplib.h (enum cpp_warning_reason): Add
	CPP_W_CXX{14,17,20,23}_EXTENSIONS.
	* charset.cc (_cpp_valid_ucn, convert_hex, convert_oct)
	(convert_escape, narrow_str_to_charconst): Use cpp_pedwarning
	instead of cpp_error for pedwarns.
	* directives.cc (directive_diagnostics, _cpp_handle_directive)
	(do_line, do_elif): Likewise.
	* expr.cc (cpp_classify_number, eval_token): Likewise.
	* lex.cc (skip_whitespace, maybe_va_opt_error)
	(_cpp_lex_direct): Likewise.
	* macro.cc (_cpp_arguments_ok): Likewise.
	(replace_args): Use -Wvariadic-macros for pedwarn about
	empty macro arguments.

gcc/c-family/ChangeLog:

	* c.opt: Add CppReason for Wc++{14,17,20,23}-extensions.
	* c-pragma.cc (handle_pragma_diagnostic_impl): Don't check
	OPT_Wc__23_extensions.

gcc/testsuite/ChangeLog:

	* c-c++-common/pragma-diag-17.c: New test.
	* g++.dg/cpp0x/va-opt1.C: New test.
	* g++.dg/cpp23/named-universal-char-escape3.C: New test.

6 files changed, 147 insertions, 115 deletions

diff --git a/libcpp/charset.cc b/libcpp/charset.cc
index fd57f61..32b6fd5 100644
--- a/libcpp/charset.cc
+++ b/libcpp/charset.cc
@@ -1633,9 +1633,11 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **pstr,
 	      else if ((!identifier_pos || strict)
 		       && !CPP_OPTION (pfile, delimited_escape_seqs)
 		       && CPP_OPTION (pfile, cpp_pedantic))
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "named universal character escapes are only valid "
-			   "in C++23");
+		cpp_pedwarning (pfile,
+				CPP_OPTION (pfile, cplusplus)
+				? CPP_W_CXX23_EXTENSIONS : CPP_W_PEDANTIC,
+				"named universal character escapes are only "
+				"valid in C++23");
 	      if (name == str)
 		result = 0x40;
 	      else
@@ -1757,8 +1759,9 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **pstr,
 		   "empty delimited escape sequence");
       else if (!CPP_OPTION (pfile, delimited_escape_seqs)
 	       && CPP_OPTION (pfile, cpp_pedantic))
-	cpp_error (pfile, CPP_DL_PEDWARN,
-		   "delimited escape sequences are only valid in C++23");
+	cpp_pedwarning (pfile, (CPP_OPTION (pfile, cplusplus)
+				? CPP_W_CXX23_EXTENSIONS : CPP_W_PEDANTIC),
+			"delimited escape sequences are only valid in C++23");
       str++;
       length = 0;
       delimited = false;
@@ -2129,10 +2132,11 @@ convert_hex (cpp_reader *pfile, const uchar *from, const uchar *limit,
 		     "empty delimited escape sequence");
 	  return from;
 	}
-     else if (!CPP_OPTION (pfile, delimited_escape_seqs)
-	      && CPP_OPTION (pfile, cpp_pedantic))
-	cpp_error (pfile, CPP_DL_PEDWARN,
-		   "delimited escape sequences are only valid in C++23");
+      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");
       delimited = false;
       extend_char_range (&char_range, loc_reader);
     }
@@ -2234,8 +2238,10 @@ convert_oct (cpp_reader *pfile, const uchar *from, const uchar *limit,
 	    }
 	  else if (!CPP_OPTION (pfile, delimited_escape_seqs)
 		   && CPP_OPTION (pfile, cpp_pedantic))
-	    cpp_error (pfile, CPP_DL_PEDWARN,
-		       "delimited escape sequences are only valid in C++23");
+	    cpp_pedwarning (pfile, (CPP_OPTION (pfile, cplusplus)
+				    ? CPP_W_CXX23_EXTENSIONS : CPP_W_PEDANTIC),
+			    "delimited escape sequences are only valid "
+			    "in C++23");
 	  extend_char_range (&char_range, loc_reader);
 	}
       else
@@ -2300,20 +2306,20 @@ convert_escape (cpp_reader *pfile, const uchar *from, const uchar *limit,
 			  char_range, loc_reader, ranges);
 
     case 'x':
-      if (uneval && CPP_PEDANTIC (pfile))
-	cpp_error (pfile, CPP_DL_PEDWARN,
-		   "numeric escape sequence in unevaluated string: "
-		   "'\\%c'", (int) c);
+      if (uneval)
+	cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+			"numeric escape sequence in unevaluated string: "
+			"'\\%c'", (int) c);
       return convert_hex (pfile, from, limit, tbuf, cvt,
 			  char_range, loc_reader, ranges);
 
     case '0':  case '1':  case '2':  case '3':
     case '4':  case '5':  case '6':  case '7':
     case 'o':
-      if (uneval && CPP_PEDANTIC (pfile))
-	cpp_error (pfile, CPP_DL_PEDWARN,
-		   "numeric escape sequence in unevaluated string: "
-		   "'\\%c'", (int) c);
+      if (uneval)
+	cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+			"numeric escape sequence in unevaluated string: "
+			"'\\%c'", (int) c);
       return convert_oct (pfile, from, limit, tbuf, cvt,
 			  char_range, loc_reader, ranges);
 
@@ -2345,9 +2351,8 @@ convert_escape (cpp_reader *pfile, const uchar *from, const uchar *limit,
       break;
 
     case 'e': case 'E':
-      if (CPP_PEDANTIC (pfile))
-	cpp_error (pfile, CPP_DL_PEDWARN,
-		   "non-ISO-standard escape sequence, '\\%c'", (int) c);
+      cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+		      "non-ISO-standard escape sequence, '\\%c'", (int) c);
       c = charconsts[2];
       break;
 
@@ -2757,7 +2762,7 @@ narrow_str_to_charconst (cpp_reader *pfile, cpp_string str,
 
   if (type == CPP_UTF8CHAR)
     max_chars = 1;
-  else if (i > 1 && CPP_OPTION (pfile, cplusplus) && CPP_PEDANTIC (pfile))
+  else if (i > 1 && CPP_OPTION (pfile, cplusplus))
     {
       /* C++ as a DR since
 	 P1854R4 - Making non-encodable string literals ill-formed
@@ -2773,15 +2778,15 @@ narrow_str_to_charconst (cpp_reader *pfile, cpp_string str,
 	    {
 	      if (src_chars <= 2)
 		diagnosed
-		  = cpp_error (pfile, CPP_DL_PEDWARN,
-			       "character not encodable in a single execution "
-			       "character code unit");
+		  = cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				    "character not encodable in a single "
+				    "execution character code unit");
 	      else
 		diagnosed
-		  = cpp_error (pfile, CPP_DL_PEDWARN,
-			       "at least one character in a multi-character "
-			       "literal not encodable in a single execution "
-			       "character code unit");
+		  = cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				    "at least one character in a multi-"
+				    "character literal not encodable in a "
+				    "single execution character code unit");
 	      if (diagnosed && i > max_chars)
 		i = max_chars;
 	    }
diff --git a/libcpp/directives.cc b/libcpp/directives.cc
index f8d9898..859cd04 100644
--- a/libcpp/directives.cc
+++ b/libcpp/directives.cc
@@ -383,28 +383,37 @@ directive_diagnostics (cpp_reader *pfile, const directive *dir, int indented)
      -pedantic take precedence if both are applicable.  */
   if (! pfile->state.skipping)
     {
+      bool warned = false;
       if (dir->origin == EXTENSION
-	  && !(dir == &dtable[T_IMPORT] && CPP_OPTION (pfile, objc))
-	  && CPP_PEDANTIC (pfile))
-	cpp_error (pfile, CPP_DL_PEDWARN, "#%s is a GCC extension", dir->name);
-      else if (dir == &dtable[T_WARNING])
+	  && !(dir == &dtable[T_IMPORT] && CPP_OPTION (pfile, objc)))
+	warned
+	  = cpp_pedwarning (pfile, CPP_W_PEDANTIC, "#%s is a GCC extension",
+			    dir->name);
+      if (!warned && dir == &dtable[T_WARNING])
 	{
 	  if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, warning_directive))
 	    {
 	      if (CPP_OPTION (pfile, cplusplus))
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "#%s before C++23 is a GCC extension", dir->name);
+		warned
+		  = cpp_pedwarning (pfile, CPP_W_CXX23_EXTENSIONS,
+				    "#%s before C++23 is a GCC extension",
+				    dir->name);
 	      else
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "#%s before C23 is a GCC extension", dir->name);
+		warned
+		  = cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				    "#%s before C23 is a GCC extension",
+				    dir->name);
 	    }
-	  else if (CPP_OPTION (pfile, cpp_warn_c11_c23_compat) > 0)
-	    cpp_warning (pfile, CPP_W_C11_C23_COMPAT,
-			 "#%s before C23 is a GCC extension", dir->name);
+
+	  if (!warned && CPP_OPTION (pfile, cpp_warn_c11_c23_compat) > 0)
+	    warned = cpp_warning (pfile, CPP_W_C11_C23_COMPAT,
+				  "#%s before C23 is a GCC extension",
+				  dir->name);
 	}
-      else if (((dir->flags & DEPRECATED) != 0
-		|| (dir == &dtable[T_IMPORT] && !CPP_OPTION (pfile, objc)))
-	       && CPP_OPTION (pfile, cpp_warn_deprecated))
+
+      if (((dir->flags & DEPRECATED) != 0
+	   || (dir == &dtable[T_IMPORT] && !CPP_OPTION (pfile, objc)))
+	  && !warned)
 	cpp_warning (pfile, CPP_W_DEPRECATED,
                      "#%s is a deprecated GCC extension", dir->name);
     }
@@ -450,9 +459,9 @@ _cpp_handle_directive (cpp_reader *pfile, bool indented)
 
   if (was_parsing_args)
     {
-      if (CPP_OPTION (pfile, cpp_pedantic))
-	cpp_error (pfile, CPP_DL_PEDWARN,
-	     "embedding a directive within macro arguments is not portable");
+      cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+		      "embedding a directive within macro arguments is not "
+		      "portable");
       pfile->state.parsing_args = 0;
       pfile->state.prevent_expansion = 0;
     }
@@ -477,10 +486,10 @@ _cpp_handle_directive (cpp_reader *pfile, bool indented)
   else if (dname->type == CPP_NUMBER && CPP_OPTION (pfile, lang) != CLK_ASM)
     {
       dir = &linemarker_dir;
-      if (CPP_PEDANTIC (pfile) && ! CPP_OPTION (pfile, preprocessed)
+      if (! CPP_OPTION (pfile, preprocessed)
 	  && ! pfile->state.skipping)
-	cpp_error (pfile, CPP_DL_PEDWARN,
-		   "style of line directive is a GCC extension");
+	cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+			"style of line directive is a GCC extension");
     }
 
   if (dir)
@@ -1388,8 +1397,9 @@ do_line (cpp_reader *pfile)
       return;
     }
 
-  if (CPP_PEDANTIC (pfile) && (new_lineno == 0 || new_lineno > cap || wrapped))
-    cpp_error (pfile, CPP_DL_PEDWARN, "line number out of range");
+  if ((new_lineno == 0 || new_lineno > cap || wrapped)
+      && cpp_pedwarning (pfile, CPP_W_PEDANTIC, "line number out of range"))
+    ;
   else if (wrapped)
     cpp_error (pfile, CPP_DL_WARNING, "line number out of range");
 
@@ -2531,13 +2541,13 @@ do_elif (cpp_reader *pfile)
 	      && !pfile->state.skipping)
 	    {
 	      if (CPP_OPTION (pfile, cplusplus))
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "#%s before C++23 is a GCC extension",
-			   pfile->directive->name);
+		cpp_pedwarning (pfile, CPP_W_CXX23_EXTENSIONS,
+				"#%s before C++23 is a GCC extension",
+				pfile->directive->name);
 	      else
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "#%s before C23 is a GCC extension",
-			   pfile->directive->name);
+		cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				"#%s before C23 is a GCC extension",
+				pfile->directive->name);
 	    }
 	  pfile->state.skipping = 1;
 	}
@@ -2570,13 +2580,13 @@ do_elif (cpp_reader *pfile)
 		      && pfile->state.skipping != skip)
 		    {
 		      if (CPP_OPTION (pfile, cplusplus))
-			cpp_error (pfile, CPP_DL_PEDWARN,
-				   "#%s before C++23 is a GCC extension",
-				   pfile->directive->name);
+			cpp_pedwarning (pfile, CPP_W_CXX23_EXTENSIONS,
+					"#%s before C++23 is a GCC extension",
+					pfile->directive->name);
 		      else
-			cpp_error (pfile, CPP_DL_PEDWARN,
-				   "#%s before C23 is a GCC extension",
-				   pfile->directive->name);
+			cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+					"#%s before C23 is a GCC extension",
+					pfile->directive->name);
 		    }
 		  pfile->state.skipping = skip;
 		}
diff --git a/libcpp/expr.cc b/libcpp/expr.cc
index 3202d8e..089bf3e 100644
--- a/libcpp/expr.cc
+++ b/libcpp/expr.cc
@@ -662,9 +662,9 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
 	  if (radix == 8)
 	    radix = 10;
 
-	  if (CPP_PEDANTIC (pfile))
-	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-				 "fixed-point constants are a GCC extension");
+	  cpp_pedwarning_with_line
+	    (pfile, CPP_W_PEDANTIC, virtual_location, 0,
+	     "fixed-point constants are a GCC extension");
 	  goto syntax_ok;
 	}
       else
@@ -701,11 +701,13 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
 	  && !CPP_OPTION (pfile, extended_numbers))
 	{
 	  if (CPP_OPTION (pfile, cplusplus))
-	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-				 "use of C++17 hexadecimal floating constant");
+	    cpp_pedwarning_with_line (pfile, CPP_W_CXX17_EXTENSIONS,
+				      virtual_location, 0, "use of C++17 "
+				      "hexadecimal floating constant");
 	  else
-	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-				 "use of C99 hexadecimal floating constant");
+	    cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC,
+				      virtual_location, 0, "use of C99 "
+				      "hexadecimal floating constant");
 	}
 
       if (float_flag == AFTER_EXPON)
@@ -766,9 +768,10 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
       /* A suffix for double is a GCC extension via decimal float support.
 	 If the suffix also specifies an imaginary value we'll catch that
 	 later.  */
-      if ((result == CPP_N_MEDIUM) && CPP_PEDANTIC (pfile))
-	cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-			     "suffix for double constant is a GCC extension");
+      if (result == CPP_N_MEDIUM)
+	cpp_pedwarning_with_line
+	  (pfile, CPP_W_PEDANTIC, virtual_location, 0,
+	   "suffix for double constant is a GCC extension");
 
       /* Radix must be 10 for decimal floats.  */
       if ((result & CPP_N_DFLOAT) && radix != 10)
@@ -779,15 +782,16 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
           return CPP_N_INVALID;
         }
 
-      if ((result & (CPP_N_FRACT | CPP_N_ACCUM)) && CPP_PEDANTIC (pfile))
-	cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-			     "fixed-point constants are a GCC extension");
+      if (result & (CPP_N_FRACT | CPP_N_ACCUM))
+	cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC, virtual_location, 0,
+				  "fixed-point constants are a GCC extension");
 
       if (result & CPP_N_DFLOAT)
 	{
-	  if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, dfp_constants))
-	    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-				 "decimal float constants are a C23 feature");
+	  if (!CPP_OPTION (pfile, dfp_constants))
+	    cpp_pedwarning_with_line
+	      (pfile, CPP_W_PEDANTIC, virtual_location, 0,
+	       "decimal float constants are a C23 feature");
 	  else if (CPP_OPTION (pfile, cpp_warn_c11_c23_compat) > 0)
 	    cpp_warning_with_line (pfile, CPP_W_C11_C23_COMPAT,
 				   virtual_location, 0,
@@ -870,12 +874,12 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
 		cpp_warning_with_line (pfile, CPP_W_C11_C23_COMPAT,
 				       virtual_location, 0, message);
 	    }
-	  else if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, true_false))
+	  else if (!CPP_OPTION (pfile, true_false))
 	    {
 	      const char *message = N_("ISO C does not support literal "
 				       "%<wb%> suffixes before C23");
-	      cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-				   message);
+	      cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC,
+					virtual_location, 0, message);
 	    }
 	}
 
@@ -883,20 +887,27 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token,
     }
 
  syntax_ok:
-  if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile))
-    cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-			 "imaginary constants are a GCC extension");
+  if (result & CPP_N_IMAGINARY)
+    cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC, virtual_location, 0,
+			      "imaginary constants are a GCC extension");
   if (radix == 2)
     {
+      bool warned = false;
       if (!CPP_OPTION (pfile, binary_constants)
 	  && CPP_PEDANTIC (pfile))
-	cpp_error_with_line (pfile, CPP_DL_PEDWARN, virtual_location, 0,
-			     CPP_OPTION (pfile, cplusplus)
-			     ? N_("binary constants are a C++14 feature "
-				  "or GCC extension")
-			     : N_("binary constants are a C23 feature "
-				  "or GCC extension"));
-      else if (CPP_OPTION (pfile, cpp_warn_c11_c23_compat) > 0)
+	{
+	  if (CPP_OPTION (pfile, cplusplus))
+	    warned
+	      = (cpp_pedwarning_with_line
+		 (pfile, CPP_W_CXX14_EXTENSIONS, virtual_location, 0,
+		  "binary constants are a C++14 feature or GCC extension"));
+	  else
+	    warned
+	      = (cpp_pedwarning_with_line
+		 (pfile, CPP_W_PEDANTIC, virtual_location, 0,
+		  "binary constants are a C23 feature or GCC extension"));
+	}
+      if (!warned && CPP_OPTION (pfile, cpp_warn_c11_c23_compat) > 0)
 	cpp_warning_with_line (pfile, CPP_W_C11_C23_COMPAT,
 			       virtual_location, 0,
 			       "binary constants are a C23 feature");
@@ -1267,10 +1278,10 @@ eval_token (cpp_reader *pfile, const cpp_token *token,
 	{
 	  /* A pedantic warning takes precedence over a deprecated
 	     warning here.  */
-	  if (CPP_PEDANTIC (pfile))
-	    cpp_error_with_line (pfile, CPP_DL_PEDWARN,
-				 virtual_location, 0,
-				 "assertions are a GCC extension");
+	  if (cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC,
+					virtual_location, 0,
+					"assertions are a GCC extension"))
+	    ;
 	  else if (CPP_OPTION (pfile, cpp_warn_deprecated))
 	    cpp_warning_with_line (pfile, CPP_W_DEPRECATED, virtual_location, 0,
 				   "assertions are a deprecated extension");
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 317e5430..76e2437 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -702,6 +702,10 @@ enum cpp_warning_reason {
   CPP_W_C11_C23_COMPAT,
   CPP_W_CXX11_COMPAT,
   CPP_W_CXX20_COMPAT,
+  CPP_W_CXX14_EXTENSIONS,
+  CPP_W_CXX17_EXTENSIONS,
+  CPP_W_CXX20_EXTENSIONS,
+  CPP_W_CXX23_EXTENSIONS,
   CPP_W_EXPANSION_TO_DEFINED,
   CPP_W_BIDIRECTIONAL,
   CPP_W_INVALID_UTF8,
diff --git a/libcpp/lex.cc b/libcpp/lex.cc
index dffe49f..4025e5c 100644
--- a/libcpp/lex.cc
+++ b/libcpp/lex.cc
@@ -1856,11 +1856,12 @@ skip_whitespace (cpp_reader *pfile, cppchar_t c)
       /* Just \f \v or \0 left.  */
       else if (c == '\0')
 	saw_NUL = true;
-      else if (pfile->state.in_directive && CPP_PEDANTIC (pfile))
-	cpp_error_with_line (pfile, CPP_DL_PEDWARN, pfile->line_table->highest_line,
-			     CPP_BUF_COL (buffer),
-			     "%s in preprocessing directive",
-			     c == '\f' ? "form feed" : "vertical tab");
+      else if (pfile->state.in_directive)
+	cpp_pedwarning_with_line (pfile, CPP_W_PEDANTIC,
+				  pfile->line_table->highest_line,
+				  CPP_BUF_COL (buffer),
+				  "%s in preprocessing directive",
+				  c == '\f' ? "form feed" : "vertical tab");
 
       c = *buffer->cur++;
     }
@@ -2026,11 +2027,11 @@ maybe_va_opt_error (cpp_reader *pfile)
       if (!_cpp_in_system_header (pfile))
 	{
 	  if (CPP_OPTION (pfile, cplusplus))
-	    cpp_error (pfile, CPP_DL_PEDWARN,
-		       "__VA_OPT__ is not available until C++20");
+	    cpp_pedwarning (pfile, CPP_W_CXX20_EXTENSIONS,
+			    "__VA_OPT__ is not available until C++20");
 	  else
-	    cpp_error (pfile, CPP_DL_PEDWARN,
-		       "__VA_OPT__ is not available until C23");
+	    cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+			    "__VA_OPT__ is not available until C23");
 	}
     }
   else if (!pfile->state.va_args_ok)
@@ -3903,8 +3904,9 @@ _cpp_lex_direct (cpp_reader *pfile)
 		   && CPP_PEDANTIC (pfile)
 		   && ! buffer->warned_cplusplus_comments)
 	    {
-	      if (cpp_error (pfile, CPP_DL_PEDWARN,
-			     "C++ style comments are not allowed in ISO C90"))
+	      if (cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				  "C++ style comments are not allowed "
+				  "in ISO C90"))
 		cpp_error (pfile, CPP_DL_NOTE,
 			   "(this will be reported only once per input file)");
 	      buffer->warned_cplusplus_comments = 1;
diff --git a/libcpp/macro.cc b/libcpp/macro.cc
index dbb9925..f679b6a 100644
--- a/libcpp/macro.cc
+++ b/libcpp/macro.cc
@@ -1196,13 +1196,13 @@ _cpp_arguments_ok (cpp_reader *pfile, cpp_macro *macro, const cpp_hashnode *node
 	      && ! CPP_OPTION (pfile, va_opt))
 	    {
 	      if (CPP_OPTION (pfile, cplusplus))
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "ISO C++11 requires at least one argument "
-			   "for the \"...\" in a variadic macro");
+		cpp_pedwarning (pfile, CPP_W_CXX20_EXTENSIONS,
+				"ISO C++11 requires at least one argument "
+				"for the \"...\" in a variadic macro");
 	      else
-		cpp_error (pfile, CPP_DL_PEDWARN,
-			   "ISO C99 requires at least one argument "
-			   "for the \"...\" in a variadic macro");
+		cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+				"ISO C99 requires at least one argument "
+				"for the \"...\" in a variadic macro");
 	    }
 	  return true;
 	}
@@ -2391,7 +2391,7 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
 	       && ! macro->syshdr && ! _cpp_in_system_header (pfile))
 	{
 	  if (CPP_OPTION (pfile, cplusplus))
-	    cpp_pedwarning (pfile, CPP_W_PEDANTIC,
+	    cpp_pedwarning (pfile, CPP_W_VARIADIC_MACROS,
 			    "invoking macro %s argument %d: "
 			    "empty macro arguments are undefined"
 			    " in ISO C++98",