Re: [boost] [clang] How to use CLang for Windows?

29 Sep 2013


      On 9/28/2013 10:31 PM, Edward Diener wrote:
...
On 9/28/2013 1:26 PM, Beman Dawes wrote:
...
On Tue, Sep 24, 2013 at 10:36 AM, Sergey Cheban 
wrote:
...
On 24.09.2013 16:41, Jonathan Wakely wrote:
Beman said they want bug reports, so http://llvm.org/bugs/ seem the
...
obvious choice.
I think that it is too early to fill any external bug reports for the
compiler that is unable to compile the first "hello world" example
from the
Stroustrup's book.
I've confirmed in face-to-face discussion with several key Clang folks
that
they do indeed to want bug reports against the Windows port. In other
words, just what Jonathan said.
Unfortunately there is still no workable Boost Build implementation of
clang for Windows, so it is impossible to test clang with Boost Build. I
built the latest clang from llvm/clang and then ran the tests of the
central Boost library for all template metaprogramming, Boost.MPL, with
clang on Windows. The results were many errors almost certainly because
of some setup problem with clang and Boost Build:
------------------------------------------------------------
clang-linux.compile.c++.without-pth
..\..\..\bin.v2\libs\mpl\test\largest_int.test\clang-linux-3.4\debug\largest_int.obj
"C:/Programming/VersionControl/bclang/bin/Release/clang.exe" -c -x
c++ -O0 -g -fno-inline -Wall -g  -DBOOST_ALL_NO_LIB=1 -I"..\..\.." -o
"..\..\..\bin.v2\libs\mpl\test\largest_int.test\clang-linux-3.4\debug\largest_int.obj"
"aux_\largest_int.cpp"
In file included from aux_\largest_int.cpp:14:
In file included from ..\..\..\boost/mpl/aux_/largest_int.hpp:17:
..\..\..\boost/mpl/if.hpp:131:1: error: pasting formed
'BOOST_PP_TUPLE_ELEM_E_2(', an invalid preprocessing token
[-Winvalid-token-paste]
BOOST_MPL_AUX_NA_SPEC(3, if_)
^
..\..\..\boost/mpl/aux_/na_spec.hpp:149:40: note: expanded from macro
'BOOST_MPL_AUX_NA_SPEC'
#define BOOST_MPL_AUX_NA_SPEC(i, name) \
                                        ^
..\..\..\boost/mpl/aux_/na_spec.hpp:142:47: note: expanded from macro '\
BOOST_MPL_AUX_NA_SPEC_NO_ETI'
#define BOOST_MPL_AUX_NA_SPEC_NO_ETI(i, name) \
                                               ^
..\..\..\boost/mpl/aux_/na_spec.hpp:63:9: note: expanded from macro '\
BOOST_MPL_AUX_NA_SPEC_MAIN'
         BOOST_MPL_PP_NESTED_DEF_PARAMS_TAIL(i, typename T, na) \
         ^
note: (skipping 5 expansions in backtrace; use -fmacro-backtrace-limit=0
to see all)
..\..\..\boost/preprocessor/tuple/elem.hpp:36:114: note: expanded from
macro 'BOOST_PP_TUPLE_ELEM'
#        define BOOST_PP_TUPLE_ELEM(size, n, tuple)
BOOST_PP_TUPLE_ELEM_I(BOOST_PP_CAT(BOOST_PP_TUPLE_ELEM_, n),
BOOST_PP_CAT(BOOST_PP_CAT(BOOST_PP_TUPLE_ELEM_E_, size), tuple))
^
..\..\..\boost/preprocessor/cat.hpp:22:32: note: expanded from macro
'BOOST_PP_CAT'
#    define BOOST_PP_CAT(a, b) BOOST_PP_CAT_I(a, b)
                                ^
..\..\..\boost/preprocessor/cat.hpp:31:55: note: expanded from macro
'BOOST_PP_CAT_I'
#    define BOOST_PP_CAT_I(a, b) BOOST_PP_CAT_II(~, a ## b)
I believe part of the error is in the preprocessor config.hpp file where 
clang is treated as VC++ because _MSC_VER is defined for the Windows 
version of clang. I am looking to correct this now as soon as I can find 
what macro define clang uses to identify itself.

It does also look as if clang complaining that '##' is an invalid 
preprocessing token is an error in the Windows implementation of clang 
and I will report this to clang as a bug as soon as I can create a 
simple test case for it.
...
------------------------------------------------------------
I doubt this is a clang problem per se since clang on Linux handles
Boost.MPL quite easily. No doubt the default setup for clang in Windows
under Boost Build does not work and I don't really know how to make it
work.
If we ever have a build of clang for Windows that works with Boost Build
in Windows it will be a boon for testing Boost under Windows. But it is
not yet a reality.