PR c/15444

	* c-format.c (avoid_dollar_number): New function.
	(check_format_info_main): Call avoid_dollar_number when operand
	numbers might occur but has_operand_number == 0.

testsuite:
	* gcc.dg/format/xopen-1.c: Adjust expected message.
	* gcc.dg/format/xopen-3.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@81871 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 36 insertions, 0 deletions

diff --git a/gcc/c-format.c b/gcc/c-format.c
index 17ef68a608a..c4a6ecedb9b 100644
--- a/gcc/c-format.c
+++ b/gcc/c-format.c
@@ -1023,6 +1023,7 @@ static void status_warning (int *, const char *, ...)
 static void init_dollar_format_checking (int, tree);
 static int maybe_read_dollar_number (int *, const char **, int,
 				     tree, tree *, const format_kind_info *);
+static bool avoid_dollar_number (int *, const char *);
 static void finish_dollar_format_checking (int *, format_check_results *, int);
 
 static const format_flag_spec *get_flag_spec (const format_flag_spec *,
@@ -1304,6 +1305,26 @@ maybe_read_dollar_number (int *status, const char **format,
   return argnum;
 }
 
+/* Ensure that FORMAT does not start with a decimal number followed by
+   a $; give a diagnostic and return true if it does, false otherwise.  */
+
+static bool
+avoid_dollar_number (int *status, const char *format)
+{
+  if (!ISDIGIT (*format))
+    return false;
+  while (ISDIGIT (*format))
+    format++;
+  if (*format == '$')
+    {
+      status_warning (status,
+		      "$ operand number used after format"
+		      " without operand number");
+      return true;
+    }
+  return false;
+}
+
 
 /* Finish the checking for a format string that used $ operand number formats
    instead of non-$ formats.  We check for unused operands before used ones
@@ -1721,6 +1742,11 @@ check_format_info_main (int *status, format_check_results *res,
 	      main_arg_num = opnum + info->first_arg_num - 1;
 	    }
 	}
+      else if (fki->flags & FMT_FLAG_USE_DOLLAR)
+	{
+	  if (avoid_dollar_number (status, format_chars))
+	    return;
+	}
 
       /* Read any format flags, but do not yet validate them beyond removing
 	 duplicates, since in general validation depends on the rest of
@@ -1780,6 +1806,11 @@ check_format_info_main (int *status, format_check_results *res,
 		  else
 		    has_operand_number = 0;
 		}
+	      else
+		{
+		  if (avoid_dollar_number (status, format_chars))
+		    return;
+		}
 	      if (info->first_arg_num != 0)
 		{
 		  if (params == 0)
@@ -1879,6 +1910,11 @@ check_format_info_main (int *status, format_check_results *res,
 		  else
 		    has_operand_number = 0;
 		}
+	      else
+		{
+		  if (avoid_dollar_number (status, format_chars))
+		    return;
+		}
 	      if (info->first_arg_num != 0)
 		{
 		  if (params == 0)