re PR preprocessor/31869 (stringifying empty macros)

libcpp:
	PR preprocessor/31869
	* macro.c (stringify_arg): Handle NULL source token in padding
	token where previous padding token did not have source token with
	preceding whitespace.

gcc/testsuite:
	* gcc.dg/cpp/strify5.c: New test.

From-SVN: r145989

gcc/testsuite/ChangeLog

+2009-04-12  Joseph Myers  <joseph@codesourcery.com>
+
+	PR preprocessor/31869
+	* gcc.dg/cpp/strify5.c: New test.
+
 2009-04-12  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/enum1.adb: New test.

libcpp/ChangeLog

+2009-04-12  Joseph Myers  <joseph@codesourcery.com>
+
+	PR preprocessor/31869
+	* macro.c (stringify_arg): Handle NULL source token in padding
+	token where previous padding token did not have source token with
+	preceding whitespace.
+
 2009-04-09  Jakub Jelinek  <jakub@redhat.com>
 
 	* Makefile.in: Change copyright header to refer to version

libcpp/macro.c

@@ -369,7 +369,9 @@ stringify_arg (cpp_reader *pfile, macro_arg *arg)
 
       if (token->type == CPP_PADDING)
 	{
-	  if (source == NULL)
+	  if (source == NULL
+	      || (!(source->flags & PREV_WHITE)
+		  && token->val.source == NULL))
 	    source = token->val.source;
 	  continue;
 	}