Hi,
Many thanks for this advice. I'm just now getting back to this. If I
solve the libgcc_s problem, I'll let you know.
Thanks again,
Chris.
On 2/19/20 4:02 PM, Richard Smith wrote:
On Thu, 23 Jan 2020 at 07:24, Christopher H Green via cfe-users
<cfe-users@lists.llvm.org <mailto:cfe-users@lists.llvm.org>> wrote:
Hi,
I've spent the last several days trying to build a fast,
full-featured relocatable distribution of LLVM/Clang 9.0.1 on
Linux RHEL7, which has an older native GCC (4.8.5)—I can't require
the RH toolset. I have access to a modern version of GCC in order
to make the stage-1 build, but I need the final product not only
to be relocatable, but also to be free of any dependence on that
GCC or its libraries. In other words, I want to be able to
distribute an LLVM/CLang which defaults to compiling using libc++,
libcxxabi, compiler-rt, libunwind, and ldd, and which itself
depends neither on libstdc++ or libgcc_s. I'd also like to be
able to to provide LTO, but whether the compiler is itself the
beneficiary of LTO is optional. As a final wish, I'd like the
distribution as installed to serve as an SDK against which to
build other components such as separately packaged lldb and f18.
Oh, and I want a pony.
Here's what I have so far (CMake cache files attached for stages 1
and 2). Invoked in a separate build directory with:
env CC=gcc-9 CXX=g++-9 \
'CXXFLAGS=-Wno-cast-function-type -Wno-deprecated-copy
-Wno-init-list-lifetime -Wno-pessimizing-move -Wno-redundant-move
-Wno-uninitialized -Wno-unused-function -Wno-unused-variable' \
cmake -GNinja -C FNAL.cmake -DCMAKE_INSTALL_PREFIX=<install-path> \
-DBOOTSTRAP_LLVM_CXX_STD=c++17 <src-path>
ninja
ninja install
(The CXXFLAGS are just to keep the noise down during the stage-1
build).
I appear (finally) to have a mostly functioning build /in situ/,
but the installed compiler depends upon libstdc++ to be able to
run, and I should have put --rtlib=compiler-rt in LINKER_FLAGS
rather than CXX_FLAGS. Additionally, I haven't been able to come
up with a good set of targets for LLVM_DISTRIBUTION_COMPONENTS,
but when I do I think I need to exclude static libraries if I'm
doing LTO, no?
I suspect I need a three stage build—well, two stage 2s, at
least—but any advice would be appreciated as I'm wandering around
in the dark at this point.
I have a two-stage setup that builds a GCC-free Clang except for
libgcc_s (I've not looked at what's pulling that in yet, but I expect
that's resolvable).
My stage1 cmake setup has: -DCLANG_DEFAULT_CXX_STDLIB=libc++
-DCLANG_DEFAULT_RTLIB=compiler-rt
My stage2 cmake setup additionally
has: -DLIBCXXABI_USE_LLVM_UNWINDER=ON -DLIBCXXABI_USE_COMPILER_RT=ON
-DLIBCXX_USE_COMPILER_RT=ON
(and points CMAKE_C_COMPILER and CMAKE_CXX_COMPILER at the stage1 clang).
There might be some other things you need, I'm not sure. But it should
be doable in two stages.
Many thanks for any help,
Chris.
_______________________________________________
cfe-users mailing list
cfe-users@lists.llvm.org <mailto:cfe-users@lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
<https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.llvm.org_cgi-2Dbin_mailman_listinfo_cfe-2Dusers&d=DwMFaQ&c=gRgGjJ3BkIsb5y6s49QqsA&r=kj1IkzpbbOO6DafO4zbQ7w&m=FIIJJm01Dy-T_1Fy2242m46OGICK9DChJUP91xh3UXg&s=2qYj-B0uBuvWEJmOP60fqRlTLu-3sXE_Va_7usXqMtQ&e=>
_______________________________________________
cfe-users mailing list
cfe-users@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
