llvm dev - Dec 2017 - Bootstrapping LLVM+LLD with GCC toolchain failure

Hello,
I have a working GCC toolchain and wanted to use LLVM tooling instead.
Following the instructions on the website I set up my build directory
and have lld as an internal project under tools/. I'd like to make use
of lld in stage 2 of the build and thought -DLLVM_ENABLE_LLD was the
correct option to pass. However, adding this options makes the
configure step fail, complaining that the compiler (GCC) does not
support -fuse-ld=lld.
Is it possible, and if yes - how, to set up a 2-stages build to compile
LLVM, Clang and LLD so that in stage 2, only LLVM tools are part of the
build process?

Kind regards

On 26 Dec 2017, at 12:00, S. Jacobi via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> Hello,
> I have a working GCC toolchain and wanted to use LLVM tooling instead.
> Following the instructions on the website I set up my build directory
> and have lld as an internal project under tools/. I'd like to make use
> of lld in stage 2 of the build and thought -DLLVM_ENABLE_LLD was the
> correct option to pass. However, adding this options makes the
> configure step fail, complaining that the compiler (GCC) does not
> support -fuse-ld=lld.
> Is it possible, and if yes - how, to set up a 2-stages build to compile
> LLVM, Clang and LLD so that in stage 2, only LLVM tools are part of the
> build process?
For your second stage, use -D CMAKE_C_COMPILER=/path/to/your/first/stage/clang
-D CMAKE_CXX_COMPILER=/path/to/your/first/stage/clang++, and add -D
LINK_FLAGS=-fuse-ld=lld.

-Dimitry

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On Tue, 26 Dec 2017 16:14:02 +0100
Dimitry Andric <dimitry at andric.com> wrote:
> On 26 Dec 2017, at 12:00, S. Jacobi via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > 
> > Hello,
> > I have a working GCC toolchain and wanted to use LLVM tooling
> > instead. Following the instructions on the website I set up my
> > build directory and have lld as an internal project under tools/.
> > I'd like to make use of lld in stage 2 of the build and thought
> > -DLLVM_ENABLE_LLD was the correct option to pass. However, adding
> > this options makes the configure step fail, complaining that the
> > compiler (GCC) does not support -fuse-ld=lld.
> > Is it possible, and if yes - how, to set up a 2-stages build to
> > compile LLVM, Clang and LLD so that in stage 2, only LLVM tools are
> > part of the build process?  
> 
> For your second stage, use -D
> CMAKE_C_COMPILER=/path/to/your/first/stage/clang -D
> CMAKE_CXX_COMPILER=/path/to/your/first/stage/clang++, and add -D
> LINK_FLAGS=-fuse-ld=lld.
> 
> -Dimitry
> 
So to achieve what I want I have to use 2 cmake invocations? Because,
and I should have been clear about that in the first mail, what I was
hoping for is a simple setup where I pass the -DCLANG_ENABLE_BOOTSTRAP
option next to all other cmake options I want to set and after that
invoke the generator once, hoping that cmake set up targets for stage 1
and 2, with the proper dependencies.