RE: nano printf + powerpc gcc

["Jon Beniston" <jon at beniston dot com>]

Added comment as requested, but otherwise the same as earlier patch.

Cheers,
Jon

From: Jon Beniston <jon@beniston.com>
Date: Thu, 1 Feb 2018 09:01:42 +0000
Subject: [PATCH] Fix vprintf and vfscanf for GCC PR 14577

---
 newlib/libc/stdio/nano-vfprintf.c | 29 +++++++++++------------------
 newlib/libc/stdio/nano-vfscanf.c  | 28 +++++++++++++---------------
 2 files changed, 24 insertions(+), 33 deletions(-)

diff --git a/newlib/libc/stdio/nano-vfprintf.c b/newlib/libc/stdio/nano-vfprintf.c
index ed7316a77..bc7ed0743 100644
--- a/newlib/libc/stdio/nano-vfprintf.c
+++ b/newlib/libc/stdio/nano-vfprintf.c
@@ -168,16 +168,6 @@ static char *rcsid = "$Id$";
 #include "vfieeefp.h"
 #include "nano-vfprintf_local.h"
 
-
-/* GCC PR 14577 at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14557 */
-#if __STDC_VERSION__ >= 201112L
-#define va_ptr(ap) _Generic(&(ap), va_list *: &(ap), default: (va_list *)(ap))
-#elif __GNUC__ >= 4
-#define va_ptr(ap) __builtin_choose_expr(__builtin_types_compatible_p(__typeof__(&(ap)), va_list *), &(ap), (va_list *)(ap))
-#else
-#define va_ptr(ap) (sizeof(ap) == sizeof(va_list) ? (va_list *)&(ap) : (va_list *)(ap))
-#endif
-
 /* The __ssputs_r function is shared between all versions of vfprintf
    and vfwprintf.  */
 #ifdef STRING_ONLY
@@ -485,6 +475,7 @@ _VFPRINTF_R (struct _reent *data,
   register char *cp;	/* Handy char pointer (short term usage).  */
   const char *flag_chars;
   struct _prt_data_t prt_data;	/* All data for decoding format string.  */
+  va_list ap_copy;
 
   /* Output function pointer.  */
   int (*pfunc)(struct _reent *, FILE *, const char *, size_t len);
@@ -522,6 +513,9 @@ _VFPRINTF_R (struct _reent *data,
   prt_data.blank = ' ';
   prt_data.zero = '0';
 
+  /* GCC PR 14577 at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14557 */
+  va_copy (ap_copy, ap);
+
   /* Scan the format for conversions (`%' character).  */
   for (;;)
     {
@@ -577,7 +571,7 @@ _VFPRINTF_R (struct _reent *data,
 	   *	-- ANSI X3J11
 	   * They don't exclude field widths read from args.
 	   */
-	  prt_data.width = GET_ARG (n, ap, int);
+	  prt_data.width = GET_ARG (n, ap_copy, int);
 	  if (prt_data.width < 0)
 	    {
 	      prt_data.width = -prt_data.width;
@@ -598,7 +592,7 @@ _VFPRINTF_R (struct _reent *data,
 	  if (*fmt == '*')
 	    {
 	      fmt++;
-	      prt_data.prec = GET_ARG (n, ap, int);
+	      prt_data.prec = GET_ARG (n, ap_copy, int);
 	      if (prt_data.prec < 0)
 		prt_data.prec = -1;
 	    }
@@ -630,18 +624,16 @@ _VFPRINTF_R (struct _reent *data,
 	  if (_printf_float == NULL)
 	    {
 	      if (prt_data.flags & LONGDBL)
-		GET_ARG (N, ap, _LONG_DOUBLE);
+		GET_ARG (N, ap_copy, _LONG_DOUBLE);
 	      else
-		GET_ARG (N, ap, double);
+		GET_ARG (N, ap_copy, double);
 	    }
 	  else
-	    {
-	      n = _printf_float (data, &prt_data, fp, pfunc, va_ptr(ap));
-	    }
+            n = _printf_float (data, &prt_data, fp, pfunc, &ap_copy);
 	}
       else
 #endif
-	n = _printf_i (data, &prt_data, fp, pfunc, va_ptr(ap));
+	n = _printf_i (data, &prt_data, fp, pfunc, &ap_copy);
 
       if (n == -1)
 	goto error;
@@ -654,6 +646,7 @@ error:
 #ifndef STRING_ONLY
   _newlib_flockfile_end (fp);
 #endif
+  va_end (ap_copy);
   return (__sferror (fp) ? EOF : prt_data.ret);
 }
 
diff --git a/newlib/libc/stdio/nano-vfscanf.c b/newlib/libc/stdio/nano-vfscanf.c
index 5579cb0f1..97810b739 100644
--- a/newlib/libc/stdio/nano-vfscanf.c
+++ b/newlib/libc/stdio/nano-vfscanf.c
@@ -119,15 +119,6 @@ Supporting OS subroutines required:
 #include "../stdlib/local.h"
 #include "nano-vfscanf_local.h"
 
-/* GCC PR 14577 at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14557 */
-#if __STDC_VERSION__ >= 201112L
-#define va_ptr(ap) _Generic(&(ap), va_list *: &(ap), default: (va_list *)(ap))
-#elif __GNUC__ >= 4
-#define va_ptr(ap) __builtin_choose_expr(__builtin_types_compatible_p(__typeof__(&(ap)), va_list *), &(ap), (va_list *)(ap))
-#else
-#define va_ptr(ap) (sizeof(ap) == sizeof(va_list) ? (va_list *)&(ap) : (va_list *)(ap))
-#endif
-
 #define VFSCANF vfscanf
 #define _VFSCANF_R _vfscanf_r
 #define __SVFSCANF __svfscanf
@@ -272,6 +263,7 @@ __SVFSCANF_R (struct _reent *rptr,
   register int c;		/* Character from format, or conversion.  */
   register char *p;		/* Points into all kinds of strings.  */
   char ccltab[256];		/* Character class table for %[...].  */
+  va_list ap_copy;
 
   int ret;
   char *cp;
@@ -287,6 +279,9 @@ __SVFSCANF_R (struct _reent *rptr,
   scan_data.pfn_ungetc = _ungetc_r;
   scan_data.pfn_refill = __srefill_r;
 
+  /* GCC PR 14577 at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14557 */
+  va_copy (ap_copy, ap);
+
   for (;;)
     {
       if (*fmt == 0)
@@ -379,17 +374,18 @@ __SVFSCANF_R (struct _reent *rptr,
 	    continue;
 
 	  if (scan_data.flags & SHORT)
-	    *GET_ARG (N, ap, short *) = scan_data.nread;
+	    *GET_ARG (N, ap_copy, short *) = scan_data.nread;
 	  else if (scan_data.flags & LONG)
-	    *GET_ARG (N, ap, long *) = scan_data.nread;
+	    *GET_ARG (N, ap_copy, long *) = scan_data.nread;
 	  else
-	    *GET_ARG (N, ap, int *) = scan_data.nread;
+	    *GET_ARG (N, ap_copy, int *) = scan_data.nread;
 
 	  continue;
 
 	/* Disgusting backwards compatibility hacks.	XXX.  */
 	case '\0':		/* compat.  */
 	  _newlib_flockfile_exit (fp);
+	  va_end (ap_copy);
 	  return EOF;
 
 #ifdef FLOATING_POINT
@@ -427,12 +423,12 @@ __SVFSCANF_R (struct _reent *rptr,
 	}
       ret = 0;
       if (scan_data.code < CT_INT)
-	ret = _scanf_chars (rptr, &scan_data, fp, va_ptr(ap));
+	ret = _scanf_chars (rptr, &scan_data, fp, &ap_copy);
       else if (scan_data.code < CT_FLOAT)
-	ret = _scanf_i (rptr, &scan_data, fp, va_ptr(ap));
+	ret = _scanf_i (rptr, &scan_data, fp, &ap_copy);
 #ifdef FLOATING_POINT
       else if (_scanf_float)
-	ret = _scanf_float (rptr, &scan_data, fp, va_ptr(ap));
+	ret = _scanf_float (rptr, &scan_data, fp, &ap_copy);
 #endif
 
       if (ret == MATCH_FAILURE)
@@ -446,12 +442,14 @@ input_failure:
      invalid format string), return EOF if no matches yet, else number
      of matches made prior to failure.  */
   _newlib_flockfile_exit (fp);
+  va_end (ap_copy);
   return scan_data.nassigned && !(fp->_flags & __SERR) ? scan_data.nassigned
 						       : EOF;
 match_failure:
 all_done:
   /* Return number of matches, which can be 0 on match failure.  */
   _newlib_flockfile_end (fp);
+  va_end (ap_copy);
   return scan_data.nassigned;
 }
 
-- 
2.15.1