[llvm-dev] Building the CRT

Evandro Menezes via llvm-dev
Mon, 20 Mar 2017 21:21:48 -0000

On 03/20/2017 03:33 PM, Jonathan Roelofs wrote:
> On 3/20/17 1:47 PM, Evandro Menezes via llvm-dev wrote:
>> Folks,
>>
>> I'm at a loss trying to add Compiler-RT to an LLVM build, even
after
>> checking out the instructions at http://compiler-rt.llvm.org, so
I'd
>> appreciate your help.
>>
>> I've tried adding the CMake options LLVM_ENABLE_PROJECTS,
>> LLVM_BUILD_EXTERNAL_COMPILER_RT, LLVM_EXTERNAL_COMPILER_RT_SOURCE_DIR,
>> CLANG_DEFAULT_RTLIB.  All to no avail.
>
> You'll need to give a lot more details on what you tried, and how it
> failed. Without that information, nobody can really help you.

OK, what else can I say?

I checked out the projects side by side, as I usually do:

    ~/src/llvm.tip $ ls
    clang              compiler-rt  klee    libcxx     lld   llvm
    clang-tools-extra  dragonegg    libclc  libcxxabi  lldb  polly

So I expected that setting LLVM_ENABLE_PROJECTS="clang;compiler-rt"
would be enough to get Compiler-RT added to a functional build tree,
since setting it to just "clang" does result in Clang being built.  I
tired the other variables above for good measure, alas unsuccessfully.

In the end, everything gets built as before, except for Compiler-RT,
which I expect to be any built-in and sanitizer libraries.