[Buildroot] [PATCH 1/1] libcxx: new package
Norbert Lange
nolange79 at gmail.com
Mon Oct 22 09:02:16 UTC 2018
Am So., 21. Okt. 2018 um 13:20 Uhr schrieb Romain Naour
<romain.naour at gmail.com>:
>
> Hi Norbert,
>
> Le 13/06/2018 à 16:14, Norbert Lange a écrit :
> > provides llvm's libc++ as package,
> > probably needs some more work to
> > better fit into buildroots toolchain construction.
> >
> > It should be build after the host-g++ and C-Library,
> > but before any other packages and it does install a
> > small script host/bin/<xa-y-z>-g++-libc++
> > to allow easy use.
>
> You should take into account the external toolchain case.
>
> >
> > For lowlevel language support ABI, it can be built with
> > libstdc++ support library or its own libc++-abi.
> >
> > the parent LLVM software needs to be available,
> > apparently for a few tools. Its downloaded currently,
> > as depending on host-llvm means this package has to be
> > built - which takes forever.
>
> By now, llvm package is merged and updated to llvm 7.0.
> Can you try building libcxx as a standalone package (LIBCXX_STANDALONE_BUILD=ON)
> using the llvm package provided by Buildroot ?
It is a standalone package, but its needing a few scripts from LLVMs
buildsystem, I dont otherwise need to build/install anything from LLVM.
so I dont fully get the request. As noted, I could get those
scripts from host-llvm but then I need that built (completely),
even if libcxx would be independent (or rather sitting below the llvm package).
or do you mean I should add options for building libcxx to the
buildroots llvm package?
>
> Also libcxx and libcxxabi should be packaged separately.
>
> >
> > In the future, a option could potentially compile
> > all C++ Packages with this library.
> >
> > - depend on threading library if available?
> > (supposedly builds without)
> > - proper integration in toolchain step
> > - use libc++ for remaining packages
>
> Also you can take a look at the report from the FOSDEM meeting and the final
> report from Valentin:
> https://elinux.org/Buildroot:DeveloperDaysFOSDEM2018#LLVM.2FClang
> http://www.linuxembedded.fr/2018/07/llvmclang-integration-into-buildroot
This does not really help, as that document deals with several libraries
depending on llvm. The issues I have are with offering a second c++ std library,
and as its noted, toolchain support for llvm/clang which aint avaliable in
Buildroot for now.
>
> >
> > Signed-off-by: Norbert Lange <nolange79 at gmail.com>
> > ---
> > package/Config.in | 1 +
> > package/libcxx/Config.in | 29 +++++
> > package/libcxx/g++-libc++.in | 16 +++
> > package/libcxx/libcxx.hash | 7 ++
> > package/libcxx/libcxx.mk | 108 ++++++++++++++++++
> > ...i_fix_find_fpath_when_crosscompiling.patch | 27 +++++
> > 6 files changed, 188 insertions(+)
> > create mode 100644 package/libcxx/Config.in
> > create mode 100644 package/libcxx/g++-libc++.in
> > create mode 100644 package/libcxx/libcxx.hash
> > create mode 100644 package/libcxx/libcxx.mk
> > create mode 100644 package/libcxx/libcxxabi_fix_find_fpath_when_crosscompiling.patch
> >
> > diff --git a/package/Config.in b/package/Config.in
> > index fcabed4fde..cda825612a 100644
> > --- a/package/Config.in
> > +++ b/package/Config.in
> > @@ -1565,6 +1565,7 @@ menu "Other"
> > source "package/lightning/Config.in"
> > source "package/linux-pam/Config.in"
> > source "package/llvm/Config.in"
> > + source "package/libcxx/Config.in"
> > if BR2_PACKAGE_LINUX_PAM
> > comment "linux-pam plugins"
> > source "package/libpam-radius-auth/Config.in"
> > diff --git a/package/libcxx/Config.in b/package/libcxx/Config.in
> > new file mode 100644
> > index 0000000000..f5ff911b6d
> > --- /dev/null
> > +++ b/package/libcxx/Config.in
> > @@ -0,0 +1,29 @@
> > +config BR2_PACKAGE_LIBCXX
> > + bool "libc++"
> > + depends on BR2_INSTALL_LIBSTDCPP
>
> C++ dependency is not enough for C++11 dependency, you should add a dependency
> on gcc >= 4.8 (at least).
> Also add a dependency on llvm supported architectures.
Ok will look at that.
>
> > + help
> > + libc++ is a new implementation of the C++ standard library,
> > + targeting C++11 (and newer). Part of the LLVM Project.
> > +
> > + The LLVM Project is a collection of modular and reusable
> > + compiler and toolchain technologies.
> > +
> > +if BR2_PACKAGE_LIBCXX
> > +choice
> > + prompt "libc++ abi support"
> > + default BR2_PACKAGE_LIBCXX_ABI_SUPCXX
> > + help
> > + Select the c++ abi support: libsupc++ (from gcc toolchain)
> > + or libc++-abi (from llvm).
> > +
> > +config BR2_PACKAGE_LIBCXX_ABI_SUPCXX
> > + bool "libsupc++"
> > +
> > +config BR2_PACKAGE_LIBCXX_ABI_CXXABI
> > + bool "libc++-abi"
> > +
> > +endchoice
> > +endif
> > +
> > +comment "libc++ needs a toolchain w/ C++"
> > + depends on !BR2_INSTALL_LIBSTDCPP
> > diff --git a/package/libcxx/g++-libc++.in b/package/libcxx/g++-libc++.in
>
> What's the purpose of this script ?
You will end up with 2 C++ standard libraries,
one from the GCC Toolchain (libstdc++) and
one from this package (libc++).
The script will add the necessary flags to GCC to
use correct include paths and linkerflags.
in other words, if eg. use this line, then the package will use
libc++:
./configure CXX=g++-libc++ CC=gchost-llvmc
>
> > new file mode 100644
> > index 0000000000..db6d050a7c
> > --- /dev/null
> > +++ b/package/libcxx/g++-libc++.in
> > @@ -0,0 +1,16 @@
> > +#!/bin/sh
> > +SCRIPTPATH=$(readlink -f "$(dirname "$0")")
> > +cxx_libs="-lc++ @link_abi@"
> > +c_libs="-lc @link_comrt@"
> > +pthread_libs="-lpthread $c_libs"
> > +
> > +libs="$cxx_libs $c_libs"
> > +
> > +for i; do
> > + if test x"$i" = x"-pthread"; then
> > + libs="$libs $pthread_libs"
> > + break
> > + fi
> > +done
> > +
> > +exec "$SCRIPTPATH"/@TARGET_CROSS at g++ -nodefaultlibs -nostdinc++ $libs -isystem"$SCRIPTPATH"/../../staging/usr/include/c++/v1 "$@"
> > diff --git a/package/libcxx/libcxx.hash b/package/libcxx/libcxx.hash
> > new file mode 100644
> > index 0000000000..7d384365b6
> > --- /dev/null
> > +++ b/package/libcxx/libcxx.hash
> > @@ -0,0 +1,7 @@
> > +# locally calculated
> > +sha256 1ff53c915b4e761ef400b803f07261ade637b0c269d99569f18040f3dcee4408 llvm-6.0.0.src.tar.xz
> > +sha256 70931a87bde9d358af6cb7869e7535ec6b015f7e6df64def6d2ecdd954040dd9 libcxx-6.0.0.src.tar.xz
> > +sha256 91c6d9c5426306ce28d0627d6a4448e7d164d6a3f64b01cb1d196003b16d641b libcxxabi-6.0.0.src.tar.xz
> > +
> > +
> > +sha256 c1938c0e9e90639d1e8f5a7f6bebaab83a3642e0ee44295a4c69934686d0bda8 LICENSE.TXT
> > diff --git a/package/libcxx/libcxx.mk b/package/libcxx/libcxx.mk
> > new file mode 100644
> > index 0000000000..9d9efc90b0
> > --- /dev/null
> > +++ b/package/libcxx/libcxx.mk
> > @@ -0,0 +1,108 @@
> > +################################################################################
> > +#
> > +# libc++
> > +#
> > +################################################################################
> > +
> > +LIBCXX_VERSION = 6.0.0
>
> Can you try with 7.0.0 version ?
Yeah will do when I got some time.
>
> > +LIBCXX_SITE = http://llvm.org/releases/$(LIBCXX_VERSION)
> > +LIBCXX_SOURCE = llvm-$(LIBCXX_VERSION).src.tar.xz
> > +LIBCXX_LICENSE = MIT
> > +#LIBCXX_LICENSE_FILES = COPYRIGHT
> > +LIBCXX_SUPPORTS_IN_SOURCE_BUILD = NO
> > +LIBCXX_INSTALL_STAGING = YES
> > +
> > +LIBCXX_EXTRA_DOWNLOADS = $(patsubst %,$(LIBCXX_SITE)/%-$(LIBCXX_VERSION).src.tar.xz,libcxx libcxxabi)
>
> Can you try to package libcxx and libcxxabi separately ?
I considered that and had some problems with it,
the commands that need to be passed to gcc will depend on
whether libcxx uses libcxxabi or the gcc equivalent,
so those packages are closely related.
LLVM is generally pretty monolithic to build aswell,
its easiest to tell its build system what you want so
the dependent libraries will be configured correctly.
>
> > +
> > +define LIBCXX_EXTRA_EXTRACT
> > + $(foreach arch,$(LIBCXX_EXTRA_DOWNLOADS), \
> > + TDIR=projects/$(patsubst $(LIBCXX_SITE)/%-$(LIBCXX_VERSION).src.tar.xz,%,$(arch)); \
> > + mkdir -p $(@D)/$$TDIR && \
> > + $(call suitable-extractor,$(notdir $(arch))) $(LIBCXX_DL_DIR)/$(notdir $(arch)) | \
> > + $(TAR) --strip-components=1 -C $(@D)/$$TDIR $(TAR_OPTIONS) -
> > + )
> > +endef> +
> > +LIBCXX_POST_EXTRACT_HOOKS += LIBCXX_EXTRA_EXTRACT
> > +
> > +# Before libcxx is configured, we must have the first stage
> > +# cross-compiler and the clibrary
> > +LIBCXX_DEPENDENCIES = host-gcc-initial
> > +
> > +ifeq ($(BR2_PACKAGE_LIBCXX_ABI_CXXABI),y)
> > +_LIBCXX_ABI_TARGET = cxxabi
> > +endif
> > +
> > +_LIBCXX_ABI-$(BR2_PACKAGE_LIBCXX_ABI_CXXABI) = libcxxabi
> > +_LIBCXX_ABI-$(BR2_PACKAGE_LIBCXX_ABI_SUPCXX) = libsupc++
> > +
> > +_LIBCXX_ABI_LINK-$(BR2_PACKAGE_LIBCXX_ABI_CXXABI) = c++abi
> > +_LIBCXX_ABI_LINK-$(BR2_PACKAGE_LIBCXX_ABI_SUPCXX) = supc++
> > +
> > +LIBCXX_MAKE_OPTS = $(_LIBCXX_ABI_TARGET) cxx
> > +
> > +LIBCXX_INSTALL_STAGING_OPTS = DESTDIR=$(STAGING_DIR) $(addprefix install-,$(_LIBCXX_ABI_TARGET) cxx)
> > +
> > +LIBCXX_INSTALL_TARGET_OPTS = DESTDIR=$(TARGET_DIR) $(addprefix install-,$(_LIBCXX_ABI_TARGET) cxx)
> > +
> > +
> > +#LIBCXXABI_SYSROOT LIBCXX_SYSROOT
> > +# TODO: potentially depend on threading library?
> > +# allow using gccs libsupc++
> > +# consider whether its better to statically link libc++-abi
> > +# USe this library to build the remaining C++ packages?
> > +
> > +# llvm does not recommend using this
> > +LIBCXX_CONF_OPTS += -DBUILD_SHARED_LIBS:BOOL=OFF
> > +
> > +LIBCXX_CONF_OPTS += -DLIBCXXABI_INCLUDE_TESTS=OFF -DLIBCXXABI_ENABLE_ASSERTIONS=OFF -DLIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS=OFF -DLIBCXX_ENABLE_NEW_DELETE_DEFINITIONS=ON
> > +
> > +ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y)
> > +LIBCXX_CONF_OPTS += -DLIBCXX_HAS_MUSL_LIBC:BOOL=ON
> > +endif
> > +
> > +ifeq ($(BR2_SHARED_LIBS)$(BR2_SHARED_STATIC_LIBS),y)
> > +LIBCXX_CONF_OPTS += -DLIBCXXABI_ENABLE_SHARED:BOOL=ON -DLIBCXX_ENABLE_SHARED:BOOL=ON
> > +else
> > +LIBCXX_CONF_OPTS += -DLIBCXXABI_ENABLE_SHARED:BOOL=OFF -DLIBCXX_ENABLE_SHARED:BOOL=OFF
> > +endif
> > +
> > +ifeq ($(BR2_STATIC_LIBS)$(BR2_SHARED_STATIC_LIBS),y)
> > +LIBCXX_CONF_OPTS += -DLIBCXXABI_ENABLE_STATIC:BOOL=ON -DLIBCXX_ENABLE_STATIC:BOOL=ON
> > +else
> > +LIBCXX_CONF_OPTS += -DLIBCXXABI_ENABLE_STATIC:BOOL=OFF -DLIBCXX_ENABLE_STATIC:BOOL=OFF
> > +endif
> > +
> > +LIBCXX_CONF_OPTS += -DLIBCXX_ENABLE_ABI_LINKER_SCRIPT=ON
> > +
> > +#LIBCXX_CONF_OPTS += -DLLVM_PATH:PATH=$(@D)/llvm
> > +
> > +#LIBCXX_CONF_OPTS += -DLIBCXX_CXX_ABI:STRING=default
> > +
> > +# libc++ needs to be massaged to pick header and libs
> > +LIBCXX_CONF_OPTS += -DLIBCXX_CXX_ABI:STRING=$(_LIBCXX_ABI-y)
> > +
> > +ifneq ($(_LIBCXX_ABI_TARGET),)
> > +LIBCXX_CONF_OPTS += -DLIBCXX_CXX_ABI_INCLUDE_PATHS:PATH=$(@D)/projects/libcxxabi/include \
> > + -DLIBCXX_CXX_ABI_LIBRARY_PATH:PATH=../../../lib
> > +endif
> > +
> > +
> > +#LIBCXX_CONF_OPTS += -DLIBCXX_INCLUDE_BENCHMARKS:BOOL=OFF
> > +#LIBCXX_CONF_OPTS += -DLIBCXX_INCLUDE_DOCS:BOOL=OFF
> > +#LIBCXX_CONF_OPTS += -DLIBCXX_INCLUDE_TESTS:BOOL=OFF
> > +
> > +cxx_libs="-lc++ @link_abi@"
> > +c_libs="-lc @link_comrt@"
> > +
> > +# Create a g++ wrapper to add the necessary aguments for building with libc++
> > +define LIBCXX_CREATE_GXXWRAPPER_TARGET
> > + sed -e 's, at TARGET_CROSS@,$(notdir $(TARGET_CROSS)),g' \
> > + -e 's, at link_abi@,$(addprefix -l,$(_LIBCXX_ABI_LINK-y)),g' \
> > + -e 's, at link_comrt@,-lgcc_s,g' \
> > + $(LIBCXX_PKGDIR)g++-libc++.in > $(LIBCXX_BUILDDIR)gxxwrap.tmp
> > + install -D -m755 $(LIBCXX_BUILDDIR)gxxwrap.tmp $(TARGET_CROSS)g++-libc++
> > +endef
> > +LIBCXX_POST_INSTALL_TARGET_HOOKS = LIBCXX_CREATE_GXXWRAPPER_TARGET
> > +
> > +$(eval $(cmake-package))
> > diff --git a/package/libcxx/libcxxabi_fix_find_fpath_when_crosscompiling.patch b/package/libcxx/libcxxabi_fix_find_fpath_when_crosscompiling.patch
> > new file mode 100644
> > index 0000000000..2fd95178f7
> > --- /dev/null
> > +++ b/package/libcxx/libcxxabi_fix_find_fpath_when_crosscompiling.patch
>
> Please, provide a patch generated with git format-patch with a commit log,
> upstream status and you SoB line.
>
> I'll mark you patch "Change Requested" in the patchwork, please send an updated
> version.
Will do (hopefully I don't need patches with 7.0.0, this one was
nipped from upstream and should have ended in 7.0.0).
Norbert
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