llvm dev - Dec 2020 - Unable to get started with LLI and LLC

Hello Tim,

Thank you so much for replying, I tried building llvm from a separate build
directory inside llvm-project as described in the documentation,
now i see all the tools in the build directory at least, just couldn't
figure out how do i build the specific tools lli and llc in the build
directory.

I tried this out inside* llvm-project/build *
*cmake -G Ninja  tools/lli*
*cmake -G Ninja  tools/llc*

but none of it worked, although the subdirectories do exist under the
llvm-project/build/tools/llc or lli

While building the whole llvm i had tried

*cmake -G Ninja -DLLVM_ENABLE_PROJECTS="clang;lli;llc" ../llvm*  this
command which resulted in the build directory getting loaded with many
subdirectories including *tools *directory containing lli and llc. But
still it didn't enable lli and llc even after mentioning it in the
ENABLE_PROJECTS flag


Thankyou in advance!
Jagrat Patkar

On Mon, Nov 30, 2020 at 3:33 PM Tim Northover <t.p.northover at gmail.com>
wrote:
> Hi Jagrat,
>
> On Sun, 29 Nov 2020 at 14:15, Jagrat Patkar via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > I was just getting started with LLVM to create a small compiler of my
> own, while skimming through the docs came across the use of lli and llc in
> the development process, have successfully installed clang but somehow the
> lli and llc command are not working, I have a macOS  it is showing the
> error "command not found" , if I try to build lli and llc with
CMake it
> throws this error
> >
> > CMake Error at CMakeLists.txt:23 (add_llvm_tool):
> >   Unknown CMake command "add_llvm_tool".
>
> It sounds like you might be trying to point CMake at the llc or lli
> tool's own directory (/path/to/llvm-project/llvm/tools/llc). Instead
> CMake has to be told to start from /path/to/llvm-project/llvm, and
> then both llc and lli are targets you can ask it to build.
>
> There's some documentation on how to build LLVM (what options you
> might want and so on). https://llvm.org/docs/GettingStarted.html, and
> https://llvm.org/docs/CMake.html.
>
> Cheers.
>
> Tim.
>
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On Wed, 2 Dec 2020 at 02:09, Jagrat Patkar <jagratpatkar at gmail.com>
wrote:
> I tried this out inside llvm-project/build
> cmake -G Ninja  tools/lli
> cmake -G Ninja  tools/llc
>
> but none of it worked, although the subdirectories do exist under the 
llvm-project/build/tools/llc or lli
Yep, those two are never going to work. The CMakeLists.txt in those
directories aren't self-contained.
> cmake -G Ninja -DLLVM_ENABLE_PROJECTS="clang;lli;llc" ../llvm 
this command which resulted in the build directory getting loaded with many
subdirectories including tools directory containing lli and llc. But still it
didn't enable lli and llc even after mentioning it in the ENABLE_PROJECTS
flag
You don't need lli or llc in LLVM_ENABLE_PROJECTS because they're part
of baseline LLVM. But other than that it should have worked. What
error message did you get when you tried running "ninja llc" after
that CMake command?

Cheers.

Tim.