libs/libc/stdio/lib_vsprintf.c and Kconfig:

- Numbered arguments now work by using two pass parsing and an argument list.
    The maximum number of numbered args is determined by CONFIG_LIBC_NL_ARGMAX
    which is then copied into NL_ARGMAX.
  - Size of pointer argument ('p') is determined before output.

include/limits.h:  Define NL_ARGMAX (as well as some of the other 'invariant
  values' per http://pubs.opengroup.org/onlinepubs/7908799/xsh/limits.h.html)

include/limits.h

@@ -1,7 +1,7 @@
 /********************************************************************************
  * include/limits.h
  *
- *   Copyright (C) 2007-2009, 2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2014, 2019 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -197,7 +197,7 @@
 #define _POSIX_SEM_NSEMS_MAX  INT_MAX
 #define _POSIX_SEM_VALUE_MAX  0x7fff
 
-/* Actual limits.  These values may be increased from the POSIX minimum
+/* Numerical limits.  These values may be increased from the POSIX minimum
  * values above or made indeterminate
  */
 
@@ -230,6 +230,71 @@
 #define TIMER_MAX      _POSIX_TIMER_MAX
 #define CLOCKRES_MIN   _POSIX_CLOCKRES_MIN
 
+/* Other invariant values */
+
+/* CHARCLASS_NAME_MAX
+ *   Maximum number of bytes in a character class name. Minimum Acceptable
+ *   Value: 14
+ */
+
+#define CHARCLASS_NAME_MAX 14
+
+/* Maximum value of digit in calls to the printf() and scanf() functions.
+ * Minimum Acceptable Value: 9
+ */
+
+#ifdef CONFIG_LIBC_NUMBERED_ARGS
+#  ifdef CONFIG_LIBC_NL_ARGMAX
+#    define NL_ARGMAX CONFIG_LIBC_NL_ARGMAX
+#  else
+#    define NL_ARGMAX 9
+#  endif
+#endif
+
+/* NL_LANGMAX
+ *    Maximum number of bytes in a LANG name. Minimum Acceptable Value: 14
+ */
+
+#define NL_LANGMAX 14
+
+/* NL_MSGMAX
+ *    Maximum message number. Minimum Acceptable Value: 32 67
+ */
+
+#define NL_MSGMAX 32767
+
+/* NL_NMAX
+ *   Maximum number of bytes in an N-to-1 collation mapping. Minimum
+ *   Acceptable Value: *
+ */
+
+/* NL_SETMAX
+ *   Maximum set number. Minimum Acceptable Value: 255
+ */
+
+#define NL_SETMAX 255
+
+/* NL_TEXTMAX
+ *   Maximum number of bytes in a message string. Minimum Acceptable Value:
+ *   _POSIX2_LINE_MAX
+ */
+
+#define NL_TEXTMAX _POSIX2_LINE_MAX
+
+/* NZERO
+ *   Default process priority. Minimum Acceptable Value: 20
+ */
+
+#define NZERO 20
+
+/* TMP_MAX
+ *   Minimum number of unique pathnames generated by tmpnam(). Maximum
+ *   number of times an application can call tmpnam() reliably. (LEGACY)
+ *   Minimum Acceptable Value: 10000
+ */
+
+#define TMP_MAX10000
+
 /* Required for asynchronous I/O */
 
 #define AIO_LISTIO_MAX _POSIX_AIO_LISTIO_MAX

libs/libc/stdio/Kconfig

@@ -97,16 +97,28 @@ config LIBC_PRINT_MINIMAL
 config LIBC_NUMBERED_ARGS
 	bool "Enable numbered arguments in printf"
 	default n
-	depends on (LIBC_FLOATINGPOINT || LIBC_LONG_LONG || !LIBC_PRINT_MINIMAL) && !LIBC_PRINT_LEGACY && EXPERIMENTAL
+	depends on (LIBC_FLOATINGPOINT || LIBC_LONG_LONG || !LIBC_PRINT_MINIMAL) && !LIBC_PRINT_LEGACY
 	---help---
 		Enables support for numbered arguments in printf.
 
 		  printf("%3$s %3$s %1$s %2$s\n", "1", "2", "3"); --> "3 3 1 2"
 		  printf("%3$*2$.*1$f\n", 4, 8, 1.234567); --> "  1.2346"
 
-		Attention mixing of numbered and traditional arguments in one
+		Attention: Mixing of numbered and sequential arguments in one
 		format string is not allowed according to POSIX.
 
+config LIBC_NL_ARGMAX
+	int "Maximum number of numbered arguments for printf"
+	default 16
+	depends on LIBC_NUMBERED_ARGS
+	---help---
+		Applies only if there are numbered arguments in your format string.
+		The number of sequential arguments isn't affected.
+		Will be copied into stdio POSIX macro NL_ARGMAX.
+
+		Attention: Increasing this value will increase stack usage
+		of printf.
+
 config LIBC_SCANSET
 	bool "Scanset support"
 	default n