2007-05-23 Simon Martin <simartin@users.sourceforge.net>

	PR preprocessor/20077
	* macro.c (create_iso_definition): Fixed the method to determine whether
	the token-pasting operator appears at the beginning or the end of a macro.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@125000 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 19 insertions, 8 deletions

diff --git a/libcpp/macro.c b/libcpp/macro.c
index 748635f408e..12681c34338 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -1434,6 +1434,9 @@ create_iso_definition (cpp_reader *pfile, cpp_macro *macro)
 {
   cpp_token *token;
   const cpp_token *ctoken;
+  bool following_paste_op = false;
+  const char *paste_op_error_msg =
+    N_("'##' cannot appear at either end of a macro expansion");
 
   /* Get the first token of the expansion (or the '(' of a
      function-like macro).  */
@@ -1527,26 +1530,34 @@ create_iso_definition (cpp_reader *pfile, cpp_macro *macro)
 	}
 
       if (token->type == CPP_EOF)
-	break;
+	{
+	  /* Paste operator constraint 6.10.3.3.1:
+	     Token-paste ##, can appear in both object-like and
+	     function-like macros, but not at the end.  */
+	  if (following_paste_op)
+	    {
+	      cpp_error (pfile, CPP_DL_ERROR, paste_op_error_msg);
+	      return false;
+	    }
+	  break;
+	}
 
       /* Paste operator constraint 6.10.3.3.1.  */
       if (token->type == CPP_PASTE)
 	{
 	  /* Token-paste ##, can appear in both object-like and
-	     function-like macros, but not at the ends.  */
-	  if (--macro->count > 0)
-	    token = lex_expansion_token (pfile, macro);
-
-	  if (macro->count == 0 || token->type == CPP_EOF)
+	     function-like macros, but not at the beginning.  */
+	  if (macro->count == 1)
 	    {
-	      cpp_error (pfile, CPP_DL_ERROR,
-		 "'##' cannot appear at either end of a macro expansion");
+	      cpp_error (pfile, CPP_DL_ERROR, paste_op_error_msg);
 	      return false;
 	    }
 
+	  --macro->count;
 	  token[-1].flags |= PASTE_LEFT;
 	}
 
+      following_paste_op = (token->type == CPP_PASTE);
       token = lex_expansion_token (pfile, macro);
     }