Re: Iconv / Solaris

[Tom Tromey <tromey@redhat.com>]

>>>>> "Daniel" == Daniel Jacobowitz <drow@false.org> writes:

Daniel> Just confirming what I said on IRC: __STDC_ISO_10646__ is not defined
Daniel> anywhere, but with __sun__ your patch from here:
Daniel> http://sourceware.org/ml/gdb-patches/2009-07/msg00434.html
Daniel> fixes an otherwise broken GDB on Solaris.  I think UCS-4 is right, but
Daniel> the Solaris documentation isn't clear; maybe it would be clear if I
Daniel> understood wide characters better.

Daniel> Actually, poking around the internet, it looks like wchar_t's contents
Daniel> may be locale-dependent...

Yeah :-(

I did a little digging on various sun.com sites, and all I could find is
that wchar_t will be UCS-4 if the current locale is using UTF-8.  That
is not a very strong guarantee -- it means that GDB might work for some
users but not others, if there are locales where wchar_t is not UCS-4.

The very safest thing to do is disable use of wchar_t on a platform like
this.  E.g., the appended hack can be used to try it.  This will provide
a user experience similar to GDB 6.8.

Alternatively, you could try using the __sun__ variant and running gdb
in a non-UTF-8 locale.  If it works we could go with (a variant of) this
approach.

Finally, I looked at libiconv-1.13.  It also supports converting to the
"wchar_t" encoding using mbrtowc, if that is available.  I guess it must
perform an intermediate conversion.  Maybe using libiconv on Solaris
would provide a better experience for your users.

Tom

*** gdb_wchar.h.~1.2.~	2009-04-15 15:59:05.000000000 -0600
--- gdb_wchar.h	2009-08-27 10:31:01.000000000 -0600
***************
*** 47,53 ****
  
  /* We use "btowc" as a sentinel to detect functioning wchar_t
     support.  */
! #if defined (HAVE_ICONV) && defined (HAVE_WCHAR_H) && defined (HAVE_BTOWC)
  
  #include <wchar.h>
  #include <wctype.h>
--- 47,53 ----
  
  /* We use "btowc" as a sentinel to detect functioning wchar_t
     support.  */
! #if defined (HAVE_ICONV) && defined (HAVE_WCHAR_H) && defined (HAVE_BTOWC) && !defined (__sun__)
  
  #include <wchar.h>
  #include <wctype.h>