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Build Instructions

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Wyatt Childers edited this page Jul 10, 2020 · 17 revisions

Scripts (Recommended: Windows)

We currently have scripts for the following platforms with their own instructions to get you up and running faster:

  • Windows

    Note: Unlike the manual instructions for Windows below, this only supports the feature/metaprogramming branch in release mode. It is however, still recommended as this is the easiest way to experiment with the complete reflection and metaprogramming compiler.

Manual Instructions (Recommended: Unix)

If you prefer manual instructions, or we do not have a script for your platform, please use one of the following guides.

Linux

Initial build instructions:

  1. Get the required tools.
    • See Getting Started with the LLVM System - Requirements.
    • Standard build process uses CMake. Get it at: http://www.cmake.org/download
    • Note also that Python is needed for running the test suite. Get it at: http://www.python.org/download
    • We highly recommend using the gold linker (or lld) for memory efficiency reasons. We recommend gold over lld as we've experienced problems debugging binaries using gdb when clang is compiled using lld. If you've overcome these problems and are happy building and developing with lld feel free to reach out and let us know!
    • We only support Ninja for the build system, make is not supported by llvm's LLVM_PARALLEL_LINK_JOBS or LLVM_PARALLEL_COMPILE_JOBS build flags. Without these flags it is much harder to control the jobs in a way which prevents your system from running out of memory.
    • If you do run into problems with system instability caused by too much RAM being used oomd is an excellent tool for user space out of memory management which can intervene to maintain system stability.
  2. Clone the project
    • Change directory to where you want the llvm directory placed.
    • git clone https://github.com/lock3/meta.git llvm-project
    • If interested in a branch other than feature/reflect:
      • cd llvm-project
      • git checkout <branch name>
      • cd ..
  3. Build llvm and clang
    • mkdir build (in-tree build is not supported)
    • cd build
    • Figure out how many linkers you can run concurrently, we recommend min { CPU Threads, GB RAM / 4 }, we'll call this LINK_NUM
    • Figure out how many compilers + linkers you can run concurrently, we recommend min { CPU Threads, GB RAM / 1.5 }, we'll call this JOB_NUM
    • If you want a release build (gold):
      • cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" -G Ninja -DLLVM_USE_LINKER=gold -DLLVM_USE_SPLIT_DWARF=ON -DCMAKE_SHARED_LINKER_FLAGS="-fuse-ld=gold" -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=gold" -DCMAKE_BUILD_TYPE=Release -DLLVM_PARALLEL_LINK_JOBS=<LINK_NUM> -DLLVM_PARALLEL_COMPILE_JOBS=<JOB_NUM> ../llvm-project/llvm
    • If you want a debug build (gold):
      • cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" -G Ninja -DLLVM_USE_LINKER=gold -DLLVM_USE_SPLIT_DWARF=ON -DCMAKE_SHARED_LINKER_FLAGS="-fuse-ld=gold -Wl,--gdb-index" -DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=gold -Wl,--gdb-index" -DLLVM_PARALLEL_LINK_JOBS=<LINK_NUM> -DLLVM_PARALLEL_COMPILE_JOBS=<JOB_NUM> ../llvm-project/llvm/
    • If you want a release build without gold (ld - not recommend, see step 1: Get the required tools):
      • cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" -G Ninja -DCMAKE_BUILD_TYPE=Release -DLLVM_PARALLEL_LINK_JOBS=<LINK_NUM / 2> -DLLVM_PARALLEL_COMPILE_JOBS=<JOB_NUM> ../llvm-project/llvm
    • ninja
    • Note: For subsequent Clang builds/development, you can just run make clang.

Update instructions:

  1. Update the project
    • cd llvm-project
    • git pull
    • cd ..
  2. Build llvm and clang
    • cd build
    • ninja

Mac OS

Initial build instructions:

  1. Get the required tools.
  2. Clone the project
    • Change directory to where you want the llvm directory placed.
    • git clone https://github.com/lock3/meta.git llvm-project
    • If interested in a branch other than feature/reflect:
      • cd llvm-project
      • git checkout <branch name>
      • cd ..
  3. Build llvm and clang
    • mkdir build (in-tree build is not supported)
    • cd build
    • If you want a release build:
      • cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release ../llvm-project/llvm
    • If you want a debug build:
      • cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" -G "Unix Makefiles" ../llvm-project/llvm
    • make -j
    • Note: For subsequent Clang development, you can just run make clang.

Update instructions:

  1. Update the project
    • cd llvm-project
    • git pull
    • cd ..
  2. Build llvm and clang
    • cd build
    • make -j

Windows

Initial build instructions:

  1. Make sure you have installed
    • Visual Studio 2015 or higher
    • Git. Get it at: https://git-scm.com/downloads
    • CMake 3.12 or higher. Get it at: https://cmake.org/download/
    • Note also that Python is needed for running the test suite. Get it at: http://www.python.org/download
    • GnuWin32 tools The Clang and LLVM test suite use various GNU core utilities, such as grep, sed, and find. The gnuwin32 packages are the oldest and most well-tested way to get these tools. However, the MSys utilities provided by git for Windows have been known to work. Cygwin has worked in the past, but is not well tested. If you don't already have the core utilies from some other source, get gnuwin32 at http://getgnuwin32.sourceforge.net/.
  2. Clone the project
    • git clone https://github.com/lock3/meta.git llvm-project
    • If interested in a branch other than feature/reflect:
      • cd llvm-project
      • git checkout <branch name>
      • cd ..
  3. Build llvm and clang
    • md build (in-tree build is not supported)
    • cd build
    • cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi" -G "Visual Studio 15 2017" -A x64 -Thost=x64 -DLLVM_TARGETS_TO_BUILD="X86" ..\llvm
    • If you want to build a debug build
      • cmake --build . --target ALL_BUILD --config Debug
    • If you want to build a release build
      • cmake --build . --target ALL_BUILD --config Release

Update instructions:

  1. Update clang
    • cd llvm-project
    • git pull
    • cd ..
  2. Build llvm and clang
    • cd build
    • cmake --build . --target ALL_BUILD --config Debug

Troubleshooting

C Headers not found - Mac OS

Due to a recent update, even with everything correctly installed, finding the system's C headers can be problematic. To resolve this we recommend adding the following to your .bash_profile or .zprofile depending on your shell:

export CFLAGS="-I/usr/local/include -I$(xcrun --show-sdk-path)/usr/include"

This will allow the C header path to be found "dynamically" based off information provided by xcrun, and it is the most stable solution we've found.

Additionally, if using the built compiler you may benefit from a wrapper script in your build directory to run the compiler (run_clang.sh):

#!/bin/sh
./bin/clang++ -I/usr/local/include -I$(xcrun --show-sdk-path)/usr/include $@

You can then use ./run_clang.sh scratch.cpp in place of the usual ./bin/clang++ scratch.cpp. This allows the built compiler to find the C headers in the same way the CFLAGS environment variable works.

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