foundationdb/SWIFT_IDE_SETUP.md

FoundationDB/Swift IDE Setup Guide

Swift provides a language server implementation (https://github.com/apple/sourcekit-lsp) that should work with any LSP compatible editor.

In this guide we'll cover how to set up VSCode for local development on a Mac, however other setups should work in the same way.

Swift Versions

Note that Swift 5.9 (or higher) is required for the build at the time of writing this guide. You can download Swift toolchains from https://www.swift.org/download/, or by using the experimental https://github.com/swift-server/swiftly which simplifies this process.

VSCode + Cross Compilation (MacOS to Linux)

Host toolchain setup

Download and install latest Swift toolchain: https://www.swift.org/download/

Use the following version:

• Snapshots / Trunk Development (5.9)

Note the path of the installed toolchain suffixed with /usr as FOUNDATIONDB_SWIFT_TOOLCHAIN_ROOT, e.g.:

export FOUNDATIONDB_SWIFT_TOOLCHAIN_ROOT=/Library/Developer/Toolchains/swift-5.9-DEVELOPMENT-SNAPSHOT-2023-05-01-a.xctoolchain/usr

For linker and object file tools:

• Download LLVM toolchain:
  • arm64: https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.7/clang+llvm-15.0.7-arm64-apple-darwin22.0.tar.xz
    • from: https://github.com/llvm/llvm-project/releases/tag/llvmorg-15.0.7

Note the path of the installed LLVM toolchain + /usr as FOUNDATIONDB_LLVM_TOOLCHAIN_ROOT, e.g.

cd ~/Downloads
wget https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.7/clang+llvm-15.0.7-arm64-apple-darwin22.0.tar.xz
tar xzf clang+llvm-15.0.7-arm64-apple-darwin22.0.tar.xz

export FOUNDATIONDB_LLVM_TOOLCHAIN_ROOT=~/Downloads/clang+llvm-15.0.7-arm64-apple-darwin22.0

For actor compiler: Download and install mono: https://www.mono-project.com, e.g.

brew install mono

Host container setup

The Foundation DB will be used on the host as the system SDK/root against which to build. This is done by using docker and extracting the image

You may need to make sure that you have the latest foundationdb docker image pulled:

docker pull foundationdb/build:centos7-latest

cd
mkdir fdb-build && cd fdb-build

docker run -ti foundationdb/build:centos7-latest

# and in another terminal session (without terminating centos container):
# $ docker ps
#    CONTAINER ID   IMAGE          COMMAND       CREATED         STATUS         PORTS     NAMES
#    5fe40defb063   07d50e07570b   "/bin/bash"   9 seconds ago   Up 8 seconds             vigilant_gauss
# $ docker export 07d50e07570b -o container-root.tar

mkdir container-root && cd container-root
tar -xzf ../container-root.tar

This

Note that FOUNDATIONDB_LINUX_CONTAINER_ROOT becomes ~/fdb-build/container-root.

export FOUNDATIONDB_LINUX_CONTAINER_ROOT=~/fdb-build/container-root

CMake

Now that you have setup your host, and obtained FOUNDATIONDB_SWIFT_TOOLCHAIN_ROOT , FOUNDATIONDB_LLVM_TOOLCHAIN_ROOT, FOUNDATIONDB_LINUX_CONTAINER_ROOT you can run cmake.

You need to ensure you pass in these three flags, and -C<foundation-db-source>/cmake/toolchain/macos-to-linux.cmake after the flags.

For example:

cd ~/fdb-build
mkdir build && cd build

xcrun cmake -G Ninja -DCMAKE_MAKE_PROGRAM=$(xcrun --find ninja)             \
   -DFOUNDATIONDB_SWIFT_TOOLCHAIN_ROOT=$FOUNDATIONDB_SWIFT_TOOLCHAIN_ROOT  \
   -DFOUNDATIONDB_LLVM_TOOLCHAIN_ROOT=$FOUNDATIONDB_LLVM_TOOLCHAIN_ROOT    \
   -DFOUNDATIONDB_LINUX_CONTAINER_ROOT=$FOUNDATIONDB_LINUX_CONTAINER_ROOT  \
   -C$HOME/src/foundationdb/cmake/toolchain/macos-to-linux.cmake           \
   $HOME/src/foundationdb 

# Which would be this with all the parameters substituted:
#
# xcrun cmake -G Ninja -DCMAKE_MAKE_PROGRAM=/opt/homebrew/bin/ninja \
#   -DFOUNDATIONDB_SWIFT_TOOLCHAIN_ROOT=/Library/Developer/Toolchains/swift-5.9-DEVELOPMENT-SNAPSHOT-2023-05-01-a.xctoolchain/usr \
#   -DFOUNDATIONDB_LLVM_TOOLCHAIN_ROOT=$HOME/Downloads/clang1507 \
#   -DFOUNDATIONDB_LINUX_CONTAINER_ROOT=$HOME/fdb-build/container-root \
#   -C$HOME/src/foundationdb/cmake/toolchain/macos-to-linux.cmake \
#   $HOME/src/foundationdb 

If you get a warning about not being able to execute lld or other binaries from the toolchain because they're not trusted, open Privacy & Security and find a button "Allow Anyway" and click it once. [Image: Screenshot 2023-04-17 at 12.47.01.png]

Prebuild project for IDE

After configuration, make sure things get pre build to be usable in IDE:

xcrun cmake --build . -- prebuild_for_ide

Now you should see that your source directory has a compile_commands.json file.

VSCode setup

Now you can open your source directory in VSCode.

Setup:

• Install the official Swift plugin
  • it's the one maintained by Swift Server Work Group
• For extension settings
  • Update Swift: Path to point to the Swift toolchain installed in the first step (e.g. /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2023-05-01-a.xctoolchain/usr/bin)
  • Do not omit the /usr/bin in the path (!)

[Image: Screenshot 2023-03-16 at 7.25.21 PM.png]

• Disable the default "C++" plugin
  • To make sure sourcekit-lsp is used for C++ files.

Known issues

• jump-to-definition fails to open actor header files.
• jump-to-definition from C++ to Swift does not work.
• Code completion for semantic responses in Swift can be slow sometimes especially in files that import both FDBServer and FDBClient