Boost C++ Libraries: Ticket #4763: boost/units/detail/utility.hpp uses gcc demangle API which is not available on clang

anonymous — Sat, 29 Jan 2011 21:03:31 GMT

I just tried to compile boost/units/detail/utility.hpp with clang (trunk from monday) and no errors. I think the issue is not clang itself, but the C++ standard library used with it: I am using libstdc++ that came with gcc 4.2.

But using another standard library does not mean that abi::__cxa_demangle (the function used by utility.hpp) does not exist, as that function is not gcc-specific, but part of the C++ ABI: http://www.codesourcery.com/public/cxx-abi/abi.html#demangler

__cxa_demangle is defined in the header file cxxabi.h. Perhaps at build-time, bjam should check for the existence of this header file.

attachment set

Thu, 28 Jul 2011 07:57:56 GMT

attachment → units_detail_utility.patch

A patch for boost/units/detail/utility.hpp (against trunk r73307).

owner changed

Thu, 28 Jul 2011 08:00:47 GMT

owner changed from Matthias Schabel to Steven Watanabe

Attached a patch that enables to use abi::__cxa_demangle in libc++ (though I don't fully understand the OP's problem).

Sun, 07 Aug 2011 06:17:16 GMT

Attached a patch that enables to use abi::__cxa_demangle in libc++

This is a wrong patch. libc++ does not provide __cxa_demangle (and cxxabi.h); it's libc++abi that provides them. I withdraw the patch.

In Mac OS X, to build libc++, libc++abi is needed (libc++abi is dynamically linked to libc++ and its symbols are re-exported). So using libc++ in Mac OS X implies that the functionality of libc++abi is also available.

#if defined(__GLIBCXX__) || defined(__GLIBCPP__) || (defined(_LIBCPP_VERSION) && defined(__APPLE__))

can detect this environment (and I locally use this code).

Sorry for the noise.

attachment set

Sat, 13 Aug 2011 15:05:18 GMT

attachment → units_detail_utility.2.patch

A new patch for boost/units/detail/utility.hpp. This patch enables to detect <cxxabi.h> header file when compiling with clang.

Sat, 13 Aug 2011 15:11:32 GMT

comment:1

__cxa_demangle is defined in the header file cxxabi.h. Perhaps at build-time, bjam should check for the existence of this header file.

I made a new patch along this line (but the check is done at the compile-time, not at the build-time). Clang has __has_include macro that can detect a specified header file. So this check can be done at the compile-time when compiling with clang.

I tested the patch on gcc 4.3-4.6 and clang TOT (with libstdc++ and libc++) in both C++03 and C++0x modes. boost::units::detail::demangle works fine on them.

Michel Morin — Sat, 07 Apr 2012 00:59:05 GMT

I created a new ticket #6773 (with a cleaned up patch), since my patch does not try to resolve OP's request.

Andrey Semashev — Wed, 11 Jun 2014 18:52:33 GMT

I believe the ticket can be closed as soon as #10116 is closed.

owner, status changed

Jürgen Hunold — Wed, 05 Nov 2014 09:27:08 GMT

owner changed from Steven Watanabe to Jürgen Hunold
status new → assigned

status, milestone changed; resolution set

Jürgen Hunold — Wed, 05 Nov 2014 09:27:20 GMT

status assigned → closed
resolution → fixed
milestone To Be Determined → Boost 1.57.0