Building Extempore from Source
When we talk about installing extempore, we mean:
- building the
extemporeexecutable and putting it somewhere your system can find it (e.g. on your
- getting a bunch of helpful libraries which provide extended functionality (e.g. for audiofile I/O, FFTs, graphics)
- ahead-of-time (AOT) compiling the Extempore standard library, so that things load up much quicker when you start Extempore
In general, it’s nice to have all of these things, although technically you really only need step 1 to start writing xtlang code. Most of these instructions will do all three steps by default, with comments about there are ways to tailor your install if you want something different.
Option 1: download a pre-built binary
Download a binary
release, unzip it and run
extempore.exe from inside the
If you want the latest version, you can try a nightly build—these are usually fairly stable1, but you can get the older “stable” release if the nightly doesn’t work for you.
If you’re not planning to make changes to Extempore itself, then downloading a binary is probably the best option. You can still write your own xtlang code, run the examples, etc.
Option 2: build from source
The build-from-source workflow will download and build all the dependencies you need (including LLVM).
If you’ve got the requirements:
- a C++ compiler (
- ALSA (Linux only)
then here are some one-liner build commands:
# linux/macOS git clone https://github.com/digego/extempore && mkdir extempore/cmake-build && cd extempore/cmake-build && cmake .. && make install # Windows git clone https://github.com/digego/extempore && mkdir extempore/cmake-build && cd extempore/cmake-build && cmake -G"Visual Studio 15 2017 Win64" .. && cmake --build . --target ALL_BUILD --config Release
If you have problems, check out the platform-specific build notes below.
If you’re using the CMake GUI, then these will appear as checkboxes/drop-down
menus. If you’re using CMake from the CLI, then remember that you specify
options using the
Here are a few of the more interesting CMake options:
ON) controls whether or not the build process will also download and build the extended libraries (e.g. glfw, libsndfile). If you want to get those things through another package manager (or not use them at all) then set this to
ONfor both) are useful if you want to build the supporting libs for graphics/audio but not both (so you should set the one you don’t want to
OFF) prepares everything (including all extended deps and AOT-compilation) to create a zipfile for binary distribution. The main effect of this flag is to disable processor-specific optimisations for all the build commands, which gives you the best chance of producing a portable binary. This option also adds a
packagetarget to the makefile/solution, which can be used to actually generate the zipfile/dmg/deb.
The default target will build Extempore, all the dependencies, and AOT-compile the standard library. However, in other situations the following targets might come in handy:
on macOS and Linux, the
installtarget will move the extempore executable to
/usr/local/bin(or similar) and the rest of the Extempore share directory to
/usr/local/share/extempore(does nothing on Windows)
aottarget will ahead-of-time compile just the core standard library, i.e. the pure-xtlang libraries with no external C library dependencies
clean_aottarget will remove all AOT-compiled files
assetstarget won’t build anything per. se., but it will download the assets e.g. sound files, 3D model files which are referenced in the examples (it’s pretty big, so make sure you’re on an internet connection where you don’t mind downloading a bunch of data)
Extempore should build with clang or gcc, the easiest way to get these is through Xcode or the command line tools.
On macOS 10.14 (Mojave) Apple removed some of the system OpenGL headers, which means that some of Extempore’s dependencies (e.g. nanovg) won’t build. This blog post has more details, but if you just want a one-liner to fix it, it’s
sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target /
There are lots of distros, with lots of quirks! If you come across any tips, then either let us know on the mailing list or submit a pull request.
Extempore is most-often used on Ubuntu, but is also known to work with Debian, Fedora, Arch, and also inside a docker container.
There are a few extra dependencies which you may need to get through your package manager. For example, on Ubuntu 19.10 I needed:
sudo apt-get install libasound2-dev xorg-dev libglu1-mesa-dev
You’ll also need to specify an ALSA backend for
portaudio. To use the asound portaudio backend (the default) you’ll need the
libasound package. This might have a slightly different name on different
distros, e.g. on Mint 18 it’s called
libasound2-dev. To use the
Jack portaudio backend, you’ll need to have Jack
installed, and then to set the
JACK CMake option with
Extempore has been tested on Windows 7 & Windows 10 with Visual Studio Community 2017
If you don’t want to use the the command-line described
above, note that CMake generates a Visual Studio solution
.sln), so just open that and build the
On Windows, Extempore requires a few components of the Boost 1.59 libs for
TCP/UDP handling. These will be automatically downloaded for you if you’ve got
the nuget command line tool installed, or
if you want to build boost yourself (remember to keep the labyrinthine boost
directory structure intact) just tell the build process where it is using the
BOOST_DIR CMake variable.
If you want to use the ASIO audio backend on Windows (which might give you
lower-latency audio, but is not essential) you need to download the ASIO
from Steinberg. You have to create a third party developer
then you can log in and download the ASIO SDK (make sure you get the right SDK).
You also need to download and install ASIO4ALL with
the ‘offline setup panel’ option enabled. After that, copy the ASIO files into
src/portaudio/src/hostapi/asio, and use the
-DASIO=ON CMake option.
The (musical) sampler also requires the
Currently, we host pre-built binaries on
the CMake build process will download for you and move into
libs/platform-shlibs. If anyone can figure out how to build a 64-bit
libsndfile on Windows (preferrably with CMake) in a sane way then let me know.
Shared library dependencies
The full list of external libraries required for the Extempore standard library are:
- assimp 3.2
- glfw3 3.1.2
- kiss_fft 1.3.0
- portmidi 217
- sndfile 1.0.26
For those who are interested, there are a few reasons that Extempore builds and maintains its own “world” of shared lib dependencies:
- there’s no lib path on Windows, so it’s up to each program to make sure it ships with the dlls it needs (and knows where to find them)
- library versioning is a bit of a mess at the best of times, so by building specific versions of e.g. GLFW or assimp, Extempore can guarantee that the bindings will work - otherwise you’ll get weird errors.
- for packaging (as described above in the note on the
PACKAGEvariable) it’s important to turn off all cpu-specific optimisations, and set various compiler flags. Packages installed through a package manager don’t do this, and so when building e.g. a dmg for distribution on OSX it’s necessary to make sure any compiled objects (including dependencies and Extempore itself) have been compiled with the right flags.
If you’re keen to get these libraries some other way (e.g. through your
system-provided package manager) then that’s fine - just use
If you don’t have an
EXT_LLVM_DIR environment variable set on your
system, then Extempore will download, patch and build LLVM 3.8.0 for you
as part of the
make extempore step. However, if you do want to build
it yourself, then here’s how.
Grab the 3.8.0 source tarball,
cd /path/to/llvm-3.8.0.src patch -p0 < /path/to/extempore/extras/extempore-llvm-3.8.0.patch
On Windows, the
< redirection will work with
cmd.exe, but not
Then build LLVM, moving the libraries into
/path/to/extempore/llvm as part of
mkdir cmake-build && cd cmake-build cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DCMAKE_INSTALL_PREFIX=c:/path/to/extempore/llvm .. && make && make install
On Windows, you’ll also need to specify a 64-bit generator e.g.
Studio 15 2017 Win64"
To build, open the
Extempore.sln file and build the
ALL_BUILD target, then
INSTALL target. If the install step doesn’t work, you can try directly
cmake -P cmake_install.cmake which should be in the same directory. On
Windows, the LLVM build output must be installed into an
llvm subdirectory in
the top-level Extempore directory (since the AOT compilation process will look
in there to find
If LLVM complains about not being able to find python, you can specify a path to
your python executable with the
PYTHON_EXECUTABLE CMake variable:
cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DCMAKE_INSTALL_PREFIX=c:/path/to/extempore/llvm -DPYTHON_EXECUTABLE=c:/path/to/python .. && make && make install
If you do build your own patched version of LLVM for Extempore, then make
sure you set the
EXT_LLVM_DIR environment variable to point to that directory
(where you installed LLVM) so that the Extempore build process knows where to
except when they’re not ↩