Re: [boost] Using Clang compiler in place of GCC

Subject: Re: [boost] Using Clang compiler in place of GCC
From: Edward Diener (eldiener_at_[hidden])
Date: 2015-06-24 08:46:02

On 6/24/2015 8:02 AM, Paul A. Bristow wrote:
>
>
>> -----Original Message-----
>> From: Boost [mailto:boost-bounces_at_[hidden]] On Behalf Of Edward Diener
>> Sent: 23 June 2015 21:00
>> To: boost_at_[hidden]
>> Subject: Re: [boost] Using Clang compiler in place of GCC
>>
>> On 6/23/2015 7:41 AM, Paul A. Bristow wrote:
>>> I have installed Clang 3.6.1 (along with previously used versions of
>>> GCC)
>>>
>>> downloaded from LLVM and using the clang for LLVM Windows installer on
>>> Windows 8.1
>>>
>>> I:\modular-boost\libs\fixed_point\example>clang++ --version clang
>>> version 3.6.1 (tags/RELEASE_361/final)
>>> Target: i686-pc-windows-gnu
>>> Thread model: posix
>>>
>>> suggests that I have the compiler in place OK and it should be in my
>>> PATH (becos I asked for it to be).
>>>
>>> --debug-configuration
>>>
>>> notice: will use 'C:/LLVM/bin/clang++.exe' for clang-linux, condition
>>> <toolset>clang-linux-3.6.1
>>>
>>> For a project, I have a jamfile starting
>>>
>>> project
>>>      : requirements
>>>        <include>../include # quickdox/include
>>>        <include>../../.. # modular-boost root
>>>        #toolset requirements.
>>>        # GCC requirements.
>>>       #<toolset>gcc:<cxxflags>-std=gnu++11 # If requires C++11 library.
>>>       <toolset>gcc:<cxxflags>-Wno-unused-local-typedefs
>>>       <toolset>gcc:<cxxflags>-Wno-missing-braces
>>>       # Clang requirements.
>>>       #<toolset>clang:<cxxflags>-std=c++11 # If requires C++11 library.
>>>
>>> (I also have environment BOOST_ROOT = I:\modular-boost)
>>>
>>> when I run b2 toolset=gcc
>>>
>>> all compiles and run as expected.
>>>
>>> when I run b2 toolset=clang
>>>
>>> I get messages like
>>>
>>> common.mkdir
>>> ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-
>>> linux-3.6.1 common.mkdir
>>> ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\clang-
>>> linux-3.6.1\debug
>>>
>>> clang-linux.compile.c++.without-pth
>>> ..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test\
>>> clang-linux-3.6.1\debug\quick_auto_dox_index.obj
>>> quick_auto_dox_index.cpp:53:10: fatal error: 'iostream' file not found
>>> (or other files like cstddef, iomanip on other projects) #include
>>> <iostream>
>>>            ^
>>> 1 error generated.
>>>
>>>     "C:/LLVM/bin/clang++.exe" -c -x c++ -O0 -g -fno-inline -Wall -g
>>> -march=i686 -m32  -DBOOST_ALL_NO_L
>>> IB=1 -I"..\..\.." -I"..\include" -o
>>> "..\..\..\bin.v2\libs\quickdox\example\quick_auto_dox_index.test
>>> \clang-linux-3.6.1\debug\quick_auto_dox_index.obj" "quick_auto_dox_index.cpp"
>>>
>>> (Full log attached).
>>>
>>> This suggests that it is not finding the system file <iostream> ...
>>>
>>> but I'm puzzled at what is missing (and why).
>>>
>>> Suggestions most welcome.
>>
>> Reiterating what Peter says you need a mingw distribution at c:\mingw or you need c:\mingw to be a
>> symbolic directory link to your Mingw distribution. Not only that but the distribution needs to be
> mingw
>> and not mingw-64. I have mentioned this dependence on only mingw (as oposed to the better mingw-64
> )
>> on the clang developers mailing list and someone has replied telling me that they intend to work
> on
>> compatibility with mingw-64, but you know how that goes...
>
> Sigh :-(
>
>> I have found that the latest mingw distribution works with clang.
>
> :-)
>
> OK - I've installed c:/mingw  and C:\MinGW\bin>mingw-get.exe install mingw32-gcc-g++
>
> and I've got lots of .exe and .dll files at C:\MinGW\bin including a g++.exe and libstd++-6.dll
>
> c:/program files/mingw-builds/x64-4.8.1-win32-seh-rev5/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/4.8
> .1/../../../../x86_64-w64-mingw32/bin/ld.exe: skipping incompatible c:/program files/mingw-builds/x6
> 4-4.8.1-win32-seh-rev5/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/4.8.1/libstdc++.dll.a when searchin
> g for -lstdc++
>
> And I've run Peter's suggested clang++ -v test.cpp with
>
> I:\modular-boost\libs\quickdox\example>clang++ -v test.cpp
>
> #include <iostream>
>
> std::cout <<"hello world" << std:;endl;
>
> and got the output clang_v_test.log
>
> Obviously I am still missing something, but I'm still puzzled at what.

The 'x64' suggests you installed mingw-64 rather than mingw or else you 
have a mingw-64 installation in your PATH before the mingw installation. 
Make sure that c:\mingw\bin is at the beginning of your PATH when you 
compile/link with clang.