diff --git a/doc/build-windows.md b/doc/build-windows.md index 822aa664c..2f9eee1f7 100644 --- a/doc/build-windows.md +++ b/doc/build-windows.md @@ -3,81 +3,112 @@ WINDOWS BUILD NOTES Below are some notes on how to build Litecoin Core for Windows. -Most developers use cross-compilation from Ubuntu to build executables for -Windows. Cross-compilation is also used to build the release binaries. +The options known to work for building Litecoin Core on Windows are: -Currently only building on Ubuntu Trusty 14.04 or Ubuntu Zesty 17.04 or later is supported. -Building on Ubuntu Xenial 16.04 is known to be broken, see extensive discussion in issue [8732](https://github.com/bitcoin/bitcoin/issues/8732). -While it may be possible to do so with work arounds, it's potentially dangerous and not recommended. +* On Linux using the [Mingw-w64](https://mingw-w64.org/doku.php) cross compiler tool chain. Ubuntu Trusty 14.04 is recommended +and is the platform used to build the Litecoin Core Windows release binaries. +* On Windows using [Windows +Subsystem for Linux (WSL)](https://msdn.microsoft.com/commandline/wsl/about) and the Mingw-w64 cross compiler tool chain. -While there are potentially a number of ways to build on Windows (for example using msys / mingw-w64), -using the Windows Subsystem For Linux is the most straightforward. If you are building with -another method, please contribute the instructions here for others who are running versions -of Windows that are not compatible with the Windows Subsystem for Linux. +Other options which may work but which have not been extensively tested are (please contribute instructions): -Compiling with Windows Subsystem For Linux -------------------------------------------- +* On Windows using a POSIX compatibility layer application such as [cygwin](http://www.cygwin.com/) or [msys2](http://www.msys2.org/). +* On Windows using a native compiler tool chain such as [Visual Studio](https://www.visualstudio.com). + +Installing Windows Subsystem for Linux +--------------------------------------- With Windows 10, Microsoft has released a new feature named the [Windows -Subsystem for Linux](https://msdn.microsoft.com/commandline/wsl/about). This +Subsystem for Linux (WSL)](https://msdn.microsoft.com/commandline/wsl/about). This feature allows you to run a bash shell directly on Windows in an Ubuntu-based environment. Within this environment you can cross compile for Windows without -the need for a separate Linux VM or server. +the need for a separate Linux VM or server. Note that while WSL can be installed with +other Linux variants, such as OpenSUSE, the following instructions have only been +tested with Ubuntu. This feature is not supported in versions of Windows prior to Windows 10 or on Windows Server SKUs. In addition, it is available [only for 64-bit versions of Windows](https://msdn.microsoft.com/en-us/commandline/wsl/install_guide). -To get the bash shell, you must first activate the feature in Windows. +Full instructions to install WSL are available on the above link. +To install WSL on Windows 10 with Fall Creators Update installed (version >= 16215.0) do the following: -1. Turn on Developer Mode - * Open Settings -> Update and Security -> For developers - * Select the Developer Mode radio button - * Restart if necessary -2. Enable the Windows Subsystem for Linux feature +1. Enable the Windows Subsystem for Linux feature * From Start, search for "Turn Windows features on or off" (type 'turn') - * Select Windows Subsystem for Linux (beta) + * Select Windows Subsystem for Linux * Click OK * Restart if necessary +2. Install Ubuntu + * Open Microsoft Store and search for Ubuntu or use [this link](https://www.microsoft.com/store/productId/9NBLGGH4MSV6) + * Click Install 3. Complete Installation - * Open a cmd prompt and type "bash" - * Accept the license + * Open a cmd prompt and type "Ubuntu" * Create a new UNIX user account (this is a separate account from your Windows account) After the bash shell is active, you can follow the instructions below, starting with the "Cross-compilation" section. Compiling the 64-bit version is recommended but it is possible to compile the 32-bit version. -Cross-compilation -------------------- +Cross-compilation for Ubuntu and Windows Subsystem for Linux +------------------------------------------------------------ + +At the time of writing the Windows Subsystem for Linux installs Ubuntu Xenial 16.04. The Mingw-w64 package +for Ubuntu Xenial does not produce working executables for some of the Litecoin Core applications. +It is possible to build on Ubuntu Xenial by installing the cross compiler packages from Ubuntu Zesty, see the steps below. +Building on Ubuntu Zesty 17.04 up to 17.10 has been verified to work. -These steps can be performed on, for example, an Ubuntu VM. The depends system +The steps below can be performed on Ubuntu (including in a VM) or WSL. The depends system will also work on other Linux distributions, however the commands for installing the toolchain will be different. First, install the general dependencies: - sudo apt-get install build-essential libtool autotools-dev automake pkg-config bsdmainutils curl + sudo apt install build-essential libtool autotools-dev automake pkg-config bsdmainutils curl git A host toolchain (`build-essential`) is necessary because some dependency packages (such as `protobuf`) need to build host utilities that are used in the build process. - -If you're building on Ubuntu 17.04 or later, run these two commands, selecting the 'posix' variant for both, -to work around issues with mingw-w64. See issue [8732](https://github.com/bitcoin/bitcoin/issues/8732) for more information. -``` -sudo update-alternatives --config x86_64-w64-mingw32-g++ -sudo update-alternatives --config x86_64-w64-mingw32-gcc -``` +See also: [dependencies.md](dependencies.md). ## Building for 64-bit Windows -To build executables for Windows 64-bit, install the following dependencies: +The first step is to install the mingw-w64 cross-compilation tool chain. Due to different Ubuntu +packages for each distribution and problems with the Xenial packages the steps for each are different. - sudo apt-get install g++-mingw-w64-x86-64 mingw-w64-x86-64-dev +Common steps to install mingw32 cross compiler tool chain: -Then build using: + sudo apt install g++-mingw-w64-x86-64 + +Ubuntu Trusty 14.04: + + No further steps required + +Ubuntu Xenial 16.04 and Windows Subsystem for Linux [1](#footnote1),[2](#footnote2): + + sudo apt install software-properties-common + sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu zesty universe" + sudo apt update + sudo apt upgrade + sudo update-alternatives --config x86_64-w64-mingw32-g++ # Set the default mingw32 g++ compiler option to posix. + +Ubuntu Zesty 17.04 [2](#footnote2): + + sudo update-alternatives --config x86_64-w64-mingw32-g++ # Set the default mingw32 g++ compiler option to posix. + +Once the tool chain is installed the build steps are common: + +Note that for WSL the Litecoin Core source path MUST be somewhere in the default mount file system, for +example /usr/src/litecoin, AND not under /mnt/d/. If this is not the case the dependency autoconf scripts will fail. +This means you cannot use a directory that located directly on the host Windows file system to perform the build. + +The next three steps are an example of how to acquire the source in an appropriate way. + + cd /usr/src + sudo git clone https://github.com/litecoin-project/litecoin.git + sudo chmod -R a+rw litecoin + +Once the source code is ready the build steps are below. PATH=$(echo "$PATH" | sed -e 's/:\/mnt.*//g') # strip out problematic Windows %PATH% imported var cd depends @@ -91,7 +122,21 @@ Then build using: To build executables for Windows 32-bit, install the following dependencies: - sudo apt-get install g++-mingw-w64-i686 mingw-w64-i686-dev + sudo apt install g++-mingw-w64-i686 mingw-w64-i686-dev + +For Ubuntu Xenial 16.04, Ubuntu Zesty 17.04 and Windows Subsystem for Linux [2](#footnote2): + + sudo update-alternatives --config i686-w64-mingw32-g++ # Set the default mingw32 g++ compiler option to posix. + +Note that for WSL the Litecoin Core source path MUST be somewhere in the default mount file system, for +example /usr/src/litecoin, AND not under /mnt/d/. If this is not the case the dependency autoconf scripts will fail. +This means you cannot use a directory that located directly on the host Windows file system to perform the build. + +The next three steps are an example of how to acquire the source in an appropriate way. + + cd /usr/src + sudo git clone https://github.com/litecoin-project/litecoin.git + sudo chmod -R a+rw litecoin Then build using: @@ -116,3 +161,20 @@ as they appear in the release `.zip` archive. This can be done in the following way. This will install to `c:\workspace\litecoin`, for example: make install DESTDIR=/mnt/c/workspace/litecoin + +Footnotes +--------- + +1: There is currently a bug in the 64 bit Mingw-w64 cross compiler packaged for WSL/Ubuntu Xenial 16.04 that +causes two of the litecoin executables to crash shortly after start up. The bug is related to the +-fstack-protector-all g++ compiler flag which is used to mitigate buffer overflows. +Installing the Mingw-w64 packages from the Ubuntu 17 distribution solves the issue, however, this is not +an officially supported approach and it's only recommended if you are prepared to reinstall WSL/Ubuntu should +something break. + +2: Starting from Ubuntu Xenial 16.04 both the 32 and 64 bit Mingw-w64 packages install two different +compiler options to allow a choice between either posix or win32 threads. The default option is win32 threads which is the more +efficient since it will result in binary code that links directly with the Windows kernel32.lib. Unfortunately, the headers +required to support win32 threads conflict with some of the classes in the C++11 standard library in particular std::mutex. +It's not possible to build the litecoin code using the win32 version of the Mingw-w64 cross compilers (at least not without +modifying headers in the litecoin source code).