newlib/libc/stdio/asnprintf.c

   1 /* Copyright (C) 2007, 2008 Eric Blake
   2  * Permission to use, copy, modify, and distribute this software
   3  * is freely granted, provided that this notice is preserved.
   4  */
   5 /* This code was derived from asprintf.c */
   6 /* doc in sprintf.c */
   7
   8 #include <_ansi.h>
   9 #include <reent.h>
  10 #include <stdio.h>
  11 #include <stdarg.h>
  12 #include <limits.h>
  13 #include <errno.h>
  14 #include "local.h"
  15
  16 char *
  17 _asnprintf_r (struct _reent *__restrict ptr,
  18        char *buf,
  19        size_t *lenp,
  20        const char *__restrict fmt, ...)
  21 {
  22   int ret;
  23   va_list ap;
  24   FILE f;
  25   size_t len = *lenp;
  26
  27   if (buf && len)
  28     {
  29       /* mark an existing buffer, but allow allocation of larger string */
  30       f._flags = __SWR | __SSTR | __SOPT;
  31     }
  32   else
  33     {
  34       /* mark a zero-length reallocatable buffer */
  35       f._flags = __SWR | __SSTR | __SMBF;
  36       len = 0;
  37       buf = NULL;
  38     }
  39   f._flags2 = 0;
  40   f._bf._base = f._p = (unsigned char *) buf;
  41   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
  42      FIXME - it would be nice to rewrite sys/reent.h to support size_t
  43      for _size.  */
  44   if (len > INT_MAX)
  45     {
  46       _REENT_ERRNO(ptr) = EOVERFLOW;
  47       return NULL;
  48     }
  49   f._bf._size = f._w = len;
  50   f._file = -1;  /* No file. */
  51   va_start (ap, fmt);
  52   ret = _svfprintf_r (ptr, &f, fmt, ap);
  53   va_end (ap);
  54   if (ret < 0)
  55     return NULL;
  56   *lenp = ret;
  57   *f._p = '\0';
  58   return (char *) f._bf._base;
  59 }
  60
  61 #ifdef _NANO_FORMATTED_IO
  62 char *
  63 _asniprintf_r (struct _reent *, char *, size_t *, const char *, ...)
  64        _ATTRIBUTE ((__alias__("_asnprintf_r")));
  65 #endif
  66
  67 #ifndef _REENT_ONLY
  68
  69 char *
  70 asnprintf (char *__restrict buf,
  71        size_t *__restrict lenp,
  72        const char *__restrict fmt, ...)
  73 {
  74   int ret;
  75   va_list ap;
  76   FILE f;
  77   size_t len = *lenp;
  78   struct _reent *ptr = _REENT;
  79
  80   if (buf && len)
  81     {
  82       /* mark an existing buffer, but allow allocation of larger string */
  83       f._flags = __SWR | __SSTR | __SOPT;
  84     }
  85   else
  86     {
  87       /* mark a zero-length reallocatable buffer */
  88       f._flags = __SWR | __SSTR | __SMBF;
  89       len = 0;
  90       buf = NULL;
  91     }
  92   f._flags2 = 0;
  93   f._bf._base = f._p = (unsigned char *) buf;
  94   /* For now, inherit the 32-bit signed limit of FILE._bf._size.
  95      FIXME - it would be nice to rewrite sys/reent.h to support size_t
  96      for _size.  */
  97   if (len > INT_MAX)
  98     {
  99       _REENT_ERRNO(ptr) = EOVERFLOW;
 100       return NULL;
 101     }
 102   f._bf._size = f._w = len;
 103   f._file = -1;  /* No file. */
 104   va_start (ap, fmt);
 105   ret = _svfprintf_r (ptr, &f, fmt, ap);
 106   va_end (ap);
 107   if (ret < 0)
 108     return NULL;
 109   *lenp = ret;
 110   *f._p = '\0';
 111   return (char *) f._bf._base;
 112 }
 113
 114 #ifdef _NANO_FORMATTED_IO
 115 char *
 116 asniprintf (char *, size_t *, const char *, ...)
 117        _ATTRIBUTE ((__alias__("asnprintf")));
 118 #endif
 119 #endif /* ! _REENT_ONLY */