Re: xlcpp: use of undeclared identifier 'decltype' used in boost/thread/lockable_traits.hpp

From: Edward Diener (eldiener_at_[hidden])
Date: 2019-09-10 20:36:23

On 9/10/2019 2:43 PM, Roy Musselman via Boost-users wrote:
> It would be convenient if the compiler flag cxxflags=-std=c++1 worked. 
> It's specified in the spec used on the spack install command but it 
> seems that, for boost, the spack compiler wrappers are being bypassed. 
> Even the CXXFLAGS environment variable is being ignored. However the 
> option *"cxxstd=11"*made it all the way from the spack install command 
> down to the invocation of b2. But the underlying xlcpp.jam file was not 
> respecting that option, unlike jam files for other compilers.
> 
> './bootstrap.sh' 
> '--prefix=${path_to_boost}/boost-1.70.0-urzwfgarnvpznbxfbwzgh4b7u5xfs5dz' '--with-toolset=xlcpp' 
> '--with-libraries=locale,random,wave,atomic,serialization,mpi,iostreams,regex,date_time,exception,log,thread,chrono,graph,system,timer,python,program_options,filesystem,test,math,graph_parallel' 
> '--with-python=/usr/tce/packages/python/python-3.7.2/bin/python3.7'
> Building Boost.Build engine with toolset xlcpp... 
> tools/build/src/engine/bin.linuxppc/b2
> . . .
> './b2' 'install' 'threading=multi' '-j' '32' 
> '--user-config=${path_to_boost}/boost-1.70.0-urzwfgarnvpznbxfbwzgh4b7u5xfs5dz/spack-src/user-config.jam' 
> 'variant=release' '-s' 'BZIP2_INCLUDE=/usr/bin/include' '-s' 
> 'BZIP2_LIBPATH=/usr/bin/lib' '-s' 'ZLIB_INCLUDE=/usr/lib64/include' '-s' 
> 'ZLIB_LIBPATH=/usr/lib64/lib' 'link=static,shared' '--layout=system' 
> 'toolset=xlcpp' '*cxxstd=11*' 'visibility=hidden'
> 
> Here are the various options for the -std= flag supported by the XL 
> compilers.
> 
> -std syntax (C only)
> -std=
> gnu9x
> gnu99
> c89
> c90
> c99
> c9x
> c11
> c1x
> iso9899:1990
> iso9899:199409
> iso9899:1999
> iso9899:199x
> iso9899:2011
> gnu89
> gnu90
> gnu11
> 
> -std syntax (C++ only)
> -std=
> gnu++98
> gnu++03
> c++98
> c++03
> gnu++11
> c++0x
> gnu++0x
> c++11
> c++1y

I assume "c++1y" implements the c++14 standard.

I created a pull request for Boost Build on the 'develop' branch. Thanks 
for bringing this up.