Re: [boost] Workaround for clang-linux + GNU stdlib + Boost.Iostreams

Subject: Re: [boost] Workaround for clang-linux + GNU stdlib + Boost.Iostreams
From: Doug Gregor (doug.gregor_at_[hidden])
Date: 2011-01-03 14:32:28

On Sat, Jan 1, 2011 at 1:35 PM, Bryce Lelbach
<admin_at_[hidden]> wrote:
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> There's a discrepancy in the definition of wint_t between GCC and some later
> versions of clang (clang defines it as an int, GCC an unsigned int). This
> ends breaking Boost.Iostreams with a GNU GCC compiled version of the GNU stdlib
> and clang (I'll restrain myself from giving the lengthy technical explaination -
> if you have link-time errors with clang + GCC compiled stdlib + Boost.Iostreams,
> this is probably the issue).
>
> Unfortunately, I cannot patch this issue with a workaround in Boost easily. The
> right combination of clang flags can work around this by not using the clang
> intrinsic/builtin headers, but this has a good chance of causing other problems.
>
> The simplest solution here is to rebuild clang (building the GNU stdlib with clang
> is tricky at best). I think newer version of the mainstream clang trunk may have
> fixed this, but if not, you need to change the assignment to WIntType in the
> clang::TargetInfo ctor ($CLANG_ROOT/lib/Basic/TargetInfo.cpp, line 40-50ish).
> It should be UnsignedInt.
>
> You also need to hack $CLANG_ROOT/lib/Headers/stdint.h, around 630 - the macro
> definition of WINT_MIN and WINT_MAX need to be changed to:
>
> #define WINT_MIN 0u
> #define WINT_MAX __UINTN_MAX(__WINT_WIDTH__)
>
> If you'd rather not recompile clang, you can try hacking your clang intrinsic
> headers (not advisable, might break more stuff). Find the resource/intrinsic
> header directory (usually something like /usr/local/clang/2.9/include/), and make
> the change specified above to the stdint.h header there. In the stddef.h header,
> around like 60, you can change the wint_t typedef.

Is there a corresponding Clang bug?

  - Doug