reactos/lib/sdk/crt/string/wcstombs_s.c

   1 /*
   2  * COPYRIGHT:         See COPYING in the top level directory
   3  * PROJECT:           ReactOS CRT
   4  * PURPOSE:           Implementation of mbstowcs_s
   5  * FILE:              lib/sdk/crt/stdlib/mbstowcs_s.c
   6  * PROGRAMMER:        Timo Kreuzer
   7  */
   8
   9 #include <precomp.h>
  10
  11 _Success_(return!=EINVAL)
  12 _Check_return_wat_
  13 _CRTIMP
  14 errno_t
  15 __cdecl
  16 wcstombs_s(
  17     _Out_opt_ size_t * pcchConverted,
  18     _Out_writes_bytes_to_opt_(cjDstSize, *pcchConverted)
  19         char * pmbstrDst,
  20     _In_ size_t cjDstSize,
  21     _In_z_ const wchar_t * pwszSrc,
  22     _In_ size_t cjMaxCount)
  23 {
  24     size_t cchMax, cchConverted;
  25     errno_t retval = 0;
  26
  27     /* Make sure, either we have a target buffer > 0 bytes, or no buffer */
  28     if (!MSVCRT_CHECK_PMT( ((cjDstSize != 0) && (pmbstrDst != 0)) ||
  29                            ((cjDstSize == 0) && (pmbstrDst == 0)) ))
  30     {
  31         _set_errno(EINVAL);
  32         return EINVAL;
  33     }
  34
  35     /* Check if we have a return value pointer */
  36     if (pcchConverted)
  37     {
  38         /* Default to 0 bytes written */
  39         *pcchConverted = 0;
  40     }
  41
  42     if (!MSVCRT_CHECK_PMT((cjMaxCount == 0) || (pwszSrc != 0)))
  43     {
  44         _set_errno(EINVAL);
  45         return EINVAL;
  46     }
  47
  48     /* Check if there is anything to do */
  49     if ((pmbstrDst == 0) && (pwszSrc == 0))
  50     {
  51         _set_errno(EINVAL);
  52         return EINVAL;
  53     }
  54
  55     /* Check if we have a wchar string */
  56     if (pwszSrc)
  57     {
  58         /* Check if we also have a multibyte buffer */
  59         if (pmbstrDst)
  60         {
  61             /* Calculate the maximum that we can write */
  62             cchMax = (cjMaxCount < cjDstSize) ? cjMaxCount + 1 : cjDstSize;
  63
  64             /* Now do the conversion */
  65             cchConverted = wcstombs(pmbstrDst, pwszSrc, cchMax);
  66
  67             /* Check if the buffer was not zero terminated */
  68             if (cchConverted == cchMax)
  69             {
  70                 /* Check if we reached the max size of the dest buffer */
  71                 if (cchConverted == cjDstSize)
  72                 {
  73                     /* Does the caller allow this? */
  74                     if (cjMaxCount != _TRUNCATE)
  75                     {
  76                         /* Not allowed, truncate to 0 length */
  77                         pmbstrDst[0] = L'\0';
  78
  79                         /* Return error */
  80                         _set_errno(ERANGE);
  81                         return ERANGE;
  82                     }
  83
  84                     /* Inform the caller about truncation */
  85                     retval = STRUNCATE;
  86                 }
  87
  88                 /* zero teminate the buffer */
  89                 pmbstrDst[cchConverted - 1] = L'\0';
  90             }
  91             else
  92             {
  93                 /* The buffer is zero terminated, count the terminating char */
  94                 cchConverted++;
  95             }
  96         }
  97         else
  98         {
  99             /* Get the length of the string, plus 0 terminator */
 100             cchConverted = wcsnlen(pwszSrc, cjMaxCount) + 1;
 101         }
 102     }
 103     else
 104     {
 105         cchConverted = cjMaxCount + 1;
 106     }
 107
 108     /* Check if we have a return value pointer */
 109     if (pcchConverted)
 110     {
 111         /* Default to 0 bytes written */
 112         *pcchConverted = cchConverted;
 113     }
 114
 115     return retval;
 116 }