Patch for bug 15444

["Joseph S. Myers" <jsm at polyomino dot org dot uk>]

Here is a patch for PR c/15444, requesting a more specific diagnostic
when formats use $ operand numbers after a format without such a
number has been used in the format string.

Bootstrapped with no regressions on i686-pc-linux-gnu.  Applied to
mainline.

2004-05-15  Joseph S. Myers  <jsm@polyomino.org.uk>

	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.

2004-05-15  Joseph S. Myers  <jsm@polyomino.org.uk>

	PR c/15444
	* gcc.dg/format/xopen-1.c: Adjust expected message.
	* gcc.dg/format/xopen-3.c: New test.

diff -rupN gcc.orig/c-format.c gcc/c-format.c
--- gcc.orig/c-format.c	2004-05-13 08:47:12.000000000 +0000
+++ gcc/c-format.c	2004-05-14 20:32:58.000000000 +0000
@@ -1023,6 +1023,7 @@ static void status_warning (int *, const
 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, c
   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, for
 	      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, for
 		  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, for
 		  else
 		    has_operand_number = 0;
 		}
+	      else
+		{
+		  if (avoid_dollar_number (status, format_chars))
+		    return;
+		}
 	      if (info->first_arg_num != 0)
 		{
 		  if (params == 0)
diff -rupN gcc.orig/testsuite/gcc.dg/format/xopen-1.c gcc/testsuite/gcc.dg/format/xopen-1.c
--- gcc.orig/testsuite/gcc.dg/format/xopen-1.c	2001-11-25 18:50:24.000000000 +0000
+++ gcc/testsuite/gcc.dg/format/xopen-1.c	2004-05-14 20:35:24.000000000 +0000
@@ -95,7 +95,7 @@ foo (int i, unsigned int u, wint_t lc, w
   scanf ("%4$ld%7$ld%5$d%6$d%3$d%1$d%2$d", ip, ip, ip, lp, ip, ip, lp);
   printf ("%1$d%d", i, i); /* { dg-warning "missing" "mixing $ and non-$ formats" } */
   printf ("%%%1$d%%%2$d", i, i);
-  printf ("%d%2$d", i); /* { dg-warning "type character" "mixing $ and non-$ formats" } */
+  printf ("%d%2$d", i); /* { dg-warning "used after format" "mixing $ and non-$ formats" } */
   printf ("%1$*d", i, i); /* { dg-warning "missing" "mixing $ and non-$ formats" } */
   printf ("%*1$d", i); /* { dg-warning "missing" "mixing $ and non-$ formats" } */
   scanf ("%1$d%d", ip, ip); /* { dg-warning "missing" "mixing $ and non-$ formats" } */
diff -rupN gcc.orig/testsuite/gcc.dg/format/xopen-3.c gcc/testsuite/gcc.dg/format/xopen-3.c
--- gcc.orig/testsuite/gcc.dg/format/xopen-3.c	1970-01-01 00:00:00.000000000 +0000
+++ gcc/testsuite/gcc.dg/format/xopen-3.c	2004-05-14 20:39:01.000000000 +0000
@@ -0,0 +1,15 @@
+/* Test for warnings for $ operand numbers after ordinary formats.
+   Bug c/15444 from james-gcc-bugzilla-501qll3d at and dot org.  */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat" } */
+
+#include "format.h"
+
+void
+foo (int i)
+{
+  printf ("%d%2$d", i); /* { dg-warning "used after format" "mixing $ and non-$ formats" } */
+  printf ("%d%*1$d", i, i); /* { dg-warning "used after format" "mixing $ and non-$ formats" } */
+  printf ("%d%.*1$d", i, i); /* { dg-warning "used after format" "mixing $ and non-$ formats" } */
+}

-- 
Joseph S. Myers
jsm@polyomino.org.uk