llvm dev - Dec 2016 - libcompiler_rt.so and libcompiler_rt.a are not being built

I want to build LLVM-based toolchain with Musl, I have LLVM sources with clang
and lld (under `tools` directory) and libunwind, compiler-rt, libcxx and
libcxxabi (under `projects` directory). All are the latest versions cloned from
GitHub mirror, branch `master`.

I'm trying to configure with the following options:
    CLANG_DEFAULT_CXX_STDLIB = libc++
    CLANG_DEFAULT_RTLIB = compiler-rt
    CLANG_DEFAULT_LINKER = lld
    LLVM_DEFAULT_TARGET_TRIPLE=x86_64-pc-linux-musl 

I use cmake to configure and ninja to build.

It configures fine and builds, but I need libcompiler_rt.so and it is not among
build targets, so it is not built and installed.

I think it is a bug and libcompiler_rt.so should be built. I don't have a
bugzilla account, so I would appreciate if someone reports it for me.

Regards,
Dmitry

> On Dec 16, 2016, at 7:06 AM, Dmitry Golovin via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> I want to build LLVM-based toolchain with Musl, I have LLVM sources with
clang and lld (under `tools` directory) and libunwind, compiler-rt, libcxx and
libcxxabi (under `projects` directory). All are the latest versions cloned from
GitHub mirror, branch `master`.
> 
> I'm trying to configure with the following options:
>    CLANG_DEFAULT_CXX_STDLIB = libc++
>    CLANG_DEFAULT_RTLIB = compiler-rt
>    CLANG_DEFAULT_LINKER = lld
>    LLVM_DEFAULT_TARGET_TRIPLE=x86_64-pc-linux-musl 
> 
> I use cmake to configure and ninja to build.
> 
> It configures fine and builds, but I need libcompiler_rt.so and it is not
among build targets, so it is not built and installed.
> 
> I think it is a bug and libcompiler_rt.so should be built. I don't have
a bugzilla account, so I would appreciate if someone reports it for me.
I don't think a single library that encompasses all of compiler-rt exists,
or
even *can* exist. E.g, the runtimes for ASan and TSan both export interceptors
for common library routines which would be mutually incompatible. So, I
don't
think this is a bug.

If you want to build all of compiler-rt, try building the phony
'compiler-rt'
target. All of the libraries you need will show up in:

  <build-dir>/lib/clang/<version>/lib


best,
vedant
> 
> Regards,
> Dmitry
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

16.12.2016, 18:23, "Vedant Kumar" <vsk at
apple.com>:
>>  On Dec 16, 2016, at 7:06 AM, Dmitry Golovin via llvm-dev <llvm-dev
at lists.llvm.org> wrote:
>>
>>  I want to build LLVM-based toolchain with Musl, I have LLVM sources
with clang and lld (under `tools` directory) and libunwind, compiler-rt, libcxx
and libcxxabi (under `projects` directory). All are the latest versions cloned
from GitHub mirror, branch `master`.
>>
>>  I'm trying to configure with the following options:
>>     CLANG_DEFAULT_CXX_STDLIB = libc++
>>     CLANG_DEFAULT_RTLIB = compiler-rt
>>     CLANG_DEFAULT_LINKER = lld
>>     LLVM_DEFAULT_TARGET_TRIPLE=x86_64-pc-linux-musl
>>
>>  I use cmake to configure and ninja to build.
>>
>>  It configures fine and builds, but I need libcompiler_rt.so and it is
not among build targets, so it is not built and installed.
>>
>>  I think it is a bug and libcompiler_rt.so should be built. I don't
have a bugzilla account, so I would appreciate if someone reports it for me.
>
> I don't think a single library that encompasses all of compiler-rt
exists, or
> even *can* exist. E.g, the runtimes for ASan and TSan both export
interceptors
> for common library routines which would be mutually incompatible. So, I
don't
> think this is a bug.
>
> If you want to build all of compiler-rt, try building the phony
'compiler-rt'
> target. All of the libraries you need will show up in:
>
>   <build-dir>/lib/clang/<version>/lib
>
> best,
> vedant
>
>>  Regards,
>>  Dmitry
I'm sure that this library can and should exist. You can search it by
it's name and it is mentioned a lot on the Internet. Now I've got a
linking problem when building musl:

    (function cpow): undefined symbol '__muldc3'
    (function cpowf): undefined symbol '__mulsc3'
    (function cpowl): undefined symbol '__mulxc3'
    (function csqrt): undefined symbol '__muldc3'

I'm pretty sure this problem is solved by just adding -lcompiler_rt to
LDFLAGS.

Regards,
Dmitry