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Re: misdefined macro _T in winnt.h


Eric Paire wrote:
> 
> Earnie Boyd wrote:
> >
> > Eric PAIRE wrote:
> > >
> > > Hi cygwin people,
> > >
> > > I have found a problem with the _T macro definition as it is defined in
> > > w32api/include/winnt.h: "#define _T TEXT" does not compile correctly the
> > > following small program:
> > >
> > > ------  Cut Here  ------  Cut Here  ------  Cut Here  ------  Cut Here  ------
> > >  #include <windows.h>
> > >  #define __DIR "dir"
> > >
> > >  main() {
> > >         size_t len = wcslen(_T(__DIR)) + wcslen(_T("dir"));
> > >         exit(len);
> > >  }
> > > ------  Cut Here  ------  Cut Here  ------  Cut Here  ------  Cut Here  ------
> > >
> >
> > What problems do you see compiling this with the current headers?  I'm
> > not having problems compiling this example.
> >
> Sorry folks, I have forgotten to tell you to compile it with the _UNICODE
> and UNICODE defined. Here is a corrected  version that has some problems
> when compiled:
> 
> ------  Cut Here  ------  Cut Here  ------  Cut Here  ------  Cut Here  ------
>  #define __DIR "dir"
> 
>  #include <stddef.h>
>  #include <tchar.h>
>  main() {
>         size_t len = wcslen(_T(__DIR)) + wcslen(_T("dir"));
>         size_t len = wcslen(_TEXT(__DIR)) + wcslen(_TEXT("dir"));
>         exit(len);
>  }
> ------  Cut Here  ------  Cut Here  ------  Cut Here  ------  Cut Here  ------
> 
> You will see that the problem is around the evaluation of the __DIR macro
> (there is no problem with "dir"), both for _TEXT and _T. In addition, this
> should be fixed also for the _T and _TEXT definitions in <winnt.h>, which
> should be coherent with those in <tchar.h> (They are not for now, as _T is
> defined either as an object-like macro (in <winnt.h>) or as a function-like
> macro (in <tchar.h>)).
> 
> If you want me to provide you with a patch (and a ChangeLog), let me know...
> 

No, I don't need a patch.  I do need to know if
  L"dir" == L("dir")
?  The problem with this macro is the use of the macro concatenation ##
and the order in which the macros are resolved.  Currently we have
  #define _T(x) L ## x
and if you pass a macro FOO as an argument to this macro you get LFOO
returned and not the value of FOO appended to L.  If I change this to
  #define _T(x) L(x)
then I get returned L("bar") where "bar" is the value of FOO.  This
allows the program to compile but does L"bar" == L("bar")?

Earnie.

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