Re: undefined reference to `strlwr' on 64bit Cygwin

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Mar 17 08:53, Ken Brown wrote:
> On 3/17/2013 5:51 AM, Corinna Vinschen wrote:
> >On Mar 16 22:08, Ken Brown wrote:
> >>$ uname -a
> >>CYGWIN_NT-6.1 fiona 1.7.18(0.263/5/3) 2013-03-15 16:35 x86_64 Cygwin
> >>
> >>$ gcc --version
> >>gcc (GCC) 4.8.0 20130307 (experimental)
> >>
> >>$ cat strlwr_test.c
> >>#include <string.h>
> >>#include <stdio.h>
> >>
> >>int
> >>main ()
> >>{
> >>   char str[] = "FRED";
> >>   printf ("%s\n", strlwr (str));
> >>}
> >>
> >>$ gcc strlwr_test.c
> >>/tmp/ccW2SOn8.o:strlwr_test.c:(.text+0x20): undefined reference to `strlwr'
> >>/tmp/ccW2SOn8.o:strlwr_test.c:(.text+0x20): relocation truncated to
> >>fit: R_X86_64_PC32 against undefined symbol `strlwr'
> >>/usr/lib/gcc/x86_64-pc-cygwin/4.8.0/../../../../x86_64-pc-cygwin/bin/ld:
> >>/tmp/ccW2SOn8.o: bad reloc address 0x0 in section `.pdata'
> >>/usr/lib/gcc/x86_64-pc-cygwin/4.8.0/../../../../x86_64-pc-cygwin/bin/ld:
> >>final link failed: Invalid operation
> >>collect2: error: ld returned 1 exit status
> >
> >Thanks for the hint, I added it back to cygwin64.din.
> >
> >However, do you really use this function?  It's broken by design.  In
> >theory it's one of those functions which should never have been exported
> >since it only works on single-byte charsets and glibc rightfully doesn't
> >provide it at all.  If you use it with UTF-8 non-ASCII chars, the result
> >is random nonsense.
> 
> It's used in the cygw32 build of emacs, in w32font.c.  The native
> Windows build uses _strlwr, and Daniel added `#define _strlwr
> strlwr' for Cygwin.  Maybe he can comment on this.

Btw., a safe method to uppercase/lowercase a multibyte string is this:

  #include <stdlib.h>
  #include <wchar.h>
  #include <wctype.h>

  /* Return converted string in newly malloc'd buffer */
  char *
  safe_strupr (const char *str)
  {
    size_t len;
    wchar_t *wstr = NULL;
    char *res = NULL;

    len = mbstowcs (NULL, str, 0) + 1;
    if (len != (size_t) -1)
      wstr = (wchar_t *) malloc (len * sizeof (wchar_t));
    if (!wstr)
      return NULL;
    mbstowcs (wstr, str, len);
    while (len-- > 0)     /* Ignore WEOF here */
      wstr[len] = (wchar_t) towupper ((wint_t) wstr[len]);
    len = wcstombs (NULL, wstr, 0) + 1;
    if (len != (size_t) -1)
      {
	res = (char *) malloc (len);
	if (res)
	  wcstombs (res, wstr, len);
      }
    free (wstr);
    return res;
  }


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
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