[flang-dev] CMake standalone and compile flags

[Michael Kruse via flang-dev]

Am Mo., 4. Mai 2020 um 12:30 Uhr schrieb Mehdi AMINI via flang-dev
<flang-dev at lists.llvm.org>:
> On Mon, May 4, 2020 at 10:17 AM David Truby <David.Truby at arm.com> wrote:
>> That branch enables out of tree builds; I believe there are people that still rely on those which is why we added that branch in when rewriting the CMake infrastructure.
>
> I assume that folks were relying on this before the merge in the monorepo, but are there still reason to maintain this from now on? Can we put an end-date on it?
> I'm trying to figure out if this is just a transition thing or if this is really something useful on the long run (and why).

Other projects such as Clang
(https://github.com/llvm/llvm-project/blob/master/clang/CMakeLists.txt#L9),
Polly (https://github.com/llvm/llvm-project/blob/master/polly/CMakeLists.txt#L2),
lld (https://github.com/llvm/llvm-project/blob/master/lld/CMakeLists.txt#L2),
lldb (https://github.com/llvm/llvm-project/blob/master/lldb/CMakeLists.txt#L19),
libc++ (https://github.com/llvm/llvm-project/blob/master/libcxx/CMakeLists.txt#L31),
openmp (https://github.com/llvm/llvm-project/blob/master/openmp/CMakeLists.txt#L7)
support this build mode as well. This only subproject I could find
that does not support building to a pre-installed LLVM is MLIR.

Michael