diff --git a/Project-Setup.md b/Project-Setup.md
index 9d10459..f28186f 100644
--- a/Project-Setup.md
+++ b/Project-Setup.md
@@ -232,6 +232,35 @@ ccls -index ~/Dev/Linux -init='{"clang":{"excludeArgs":[
 ], "extraArgs":["--gcc-toolchain=/usr"]}}'
 ```
 
+### LLVM multirepo
+
+```zsh
+git clone https://git.llvm.org/git/llvm.git
+cd llvm
+git clone https://git.llvm.org/git/clang.git tools/clang
+git clone https://git.llvm.org/git/lldb.git tools/lldb
+git clone https://git.llvm.org/git/lld.git projects/lld
+git clone https://git.llvm.org/git/compiler-rt.git projects/compiler-rt
+git clone https://git.llvm.org/git/libcxx.git projects/libcxx
+git clone https://git.llvm.org/git/libcxxabi.git projects/libcxxabi
+
+# cmake -H. -BDebug -GNinja -DCMAKE_BUILD_TYPE=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS=On <other options>
+ln -s Debug/compile_commands.json
+
+# Let clients know llvm/ is the project root, llvm/tools/clang etc are not.
+# emacs-ccls knows this file but other clients may require manual configuration.
+touch .ccls-root
+```
+
+### LLVM monorepo
+
+```zsh
+git clone git@github.com:llvm/llvm-project.git
+
+# cmake -Hllvm -BDebug -GNinja -DCMAKE_BUILD_TYPE=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_PROJECTS='llvm;clang' <other options>
+ln -s llvm/compile_commands.json
+```
+
 ### musl
 
 ```zsh