[Bug libstdc++/49953] New: _toupper() and _tolower() macros in ctype.h are broken

[Bug libstdc++/49953] New: _toupper() and _tolower() macros in ctype.h are broken

[jmichae3 at yahoo dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49953

           Summary: _toupper() and _tolower() macros in ctype.h are broken
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jmichae3@yahoo.com


not sure if I categorized this correctly.
in ctype.h I found
#define _tolower(_Char) ((_Char)-'A'+'a')
#define _toupper(_Char) ((_Char)-'a'+'A')

this code is broken when it is used in the situations where the character is
already in the desired case.  then you get garbage characters.
try it yourself.
example: _tolower('a') produces garbage.


#include <ctype.h>
#include <stdio.h>
int main(void) {
    printf("%c%c", _toupper('A'),_tolower('a')); 
    //result is !ü which is not proper
    return 0;
}

a proper bug fix would be

#define _tolower(_Char) ((_Char>='A'&&_Char<='Z')?_Char+('a'-'A'):_Char)
#define _toupper(_Char) ((_Char>='a'&&_Char<='z')?_Char-('a'-'A'):_Char)


//#include <ctype.h>
#include <stdio.h>
#define _tolower(_Char) ((_Char>='A'&&_Char<='Z')?_Char+('a'-'A'):_Char)
#define _toupper(_Char) ((_Char>='a'&&_Char<='z')?_Char-('a'-'A'):_Char)
int main(void) {
    printf("%c%c%c%c", _toupper('A'),_toupper('a'),
_tolower('A'),_tolower('a'));
    //result is AAaa
    return 0;
}

[Bug libstdc++/49953] _toupper() and _tolower() macros in ctype.h are broken

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49953

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-08-03 05:42:28 UTC ---
_tolower and _toupper are internal macros to ctype.h and should not be used
directly.  Also GCC does not include a ctype.h rather it comes from the libc
you are using (most likely glibc or newlib).