1Quick Start Guide 2----------------- 3 41. Install Microsoft Visual Studio 2017 with Python workload and 5 Python native development component. 61a. Optionally install Python 3.6 or later. If not installed, 7 get_externals.bat (via build.bat) will download and use Python via 8 NuGet. 92. Run "build.bat" to build Python in 32-bit Release configuration. 103. (Optional, but recommended) Run the test suite with "rt.bat -q". 11 12 13Building Python using Microsoft Visual C++ 14------------------------------------------ 15 16This directory is used to build CPython for Microsoft Windows NT version 176.0 or higher (Windows Vista, Windows Server 2008, or later) on 32 and 64 18bit platforms. Using this directory requires an installation of 19Microsoft Visual Studio 2017 (MSVC 14.1) with the *Python workload* and 20its optional *Python native development* component selected. (For 21command-line builds, Visual Studio 2015 may also be used.) 22 23Building from the command line is recommended in order to obtain any 24external dependencies. To build, simply run the "build.bat" script without 25any arguments. After this succeeds, you can open the "pcbuild.sln" 26solution in Visual Studio to continue development. 27 28To build an installer package, refer to the README in the Tools/msi folder. 29 30The solution currently supports two platforms. The Win32 platform is 31used to build standard x86-compatible 32-bit binaries, output into the 32win32 sub-directory. The x64 platform is used for building 64-bit AMD64 33(aka x86_64 or EM64T) binaries, output into the amd64 sub-directory. 34The Itanium (IA-64) platform is no longer supported. 35 36Four configuration options are supported by the solution: 37Debug 38 Used to build Python with extra debugging capabilities, equivalent 39 to using ./configure --with-pydebug on UNIX. All binaries built 40 using this configuration have "_d" added to their name: 41 python37_d.dll, python_d.exe, parser_d.pyd, and so on. Both the 42 build and rt (run test) batch files in this directory accept a -d 43 option for debug builds. If you are building Python to help with 44 development of CPython, you will most likely use this configuration. 45PGInstrument, PGUpdate 46 Used to build Python in Release configuration using PGO, which 47 requires Premium Edition of Visual Studio. See the "Profile 48 Guided Optimization" section below for more information. Build 49 output from each of these configurations lands in its own 50 sub-directory of this directory. The official Python releases may 51 be built using these configurations. 52Release 53 Used to build Python as it is meant to be used in production 54 settings, though without PGO. 55 56 57Building Python using the build.bat script 58---------------------------------------------- 59 60In this directory you can find build.bat, a script designed to make 61building Python on Windows simpler. This script will use the env.bat 62script to detect either Visual Studio 2017 or 2015, either of 63which may be used to build Python. Currently Visual Studio 2017 is 64officially supported. 65 66By default, build.bat will build Python in Release configuration for 67the 32-bit Win32 platform. It accepts several arguments to change 68this behavior, try `build.bat -h` to learn more. 69 70 71C Runtime 72--------- 73 74Visual Studio 2017 uses version 14.0 of the C runtime (vcruntime140). 75The executables no longer use the "Side by Side" assemblies used in 76previous versions of the compiler. This simplifies distribution of 77applications. 78 79The run time libraries are available under the redist folder of your 80Visual Studio distribution. For more info, see the Readme in the 81redist folder. 82 83 84Sub-Projects 85------------ 86 87The CPython project is split up into several smaller sub-projects which 88are managed by the pcbuild.sln solution file. Each sub-project is 89represented by a .vcxproj and a .vcxproj.filters file starting with the 90name of the sub-project. These sub-projects fall into a few general 91categories: 92 93The following sub-projects represent the bare minimum required to build 94a functioning CPython interpreter. If nothing else builds but these, 95you'll have a very limited but usable python.exe: 96pythoncore 97 .dll and .lib 98python 99 .exe 100 101These sub-projects provide extra executables that are useful for running 102CPython in different ways: 103pythonw 104 pythonw.exe, a variant of python.exe that doesn't open a Command 105 Prompt window 106pylauncher 107 py.exe, the Python Launcher for Windows, see 108 http://docs.python.org/3/using/windows.html#launcher 109pywlauncher 110 pyw.exe, a variant of py.exe that doesn't open a Command Prompt 111 window 112_testembed 113 _testembed.exe, a small program that embeds Python for testing 114 purposes, used by test_capi.py 115 116These are miscellaneous sub-projects that don't really fit the other 117categories: 118_freeze_importlib 119 _freeze_importlib.exe, used to regenerate Python\importlib.h after 120 changes have been made to Lib\importlib\_bootstrap.py 121pyshellext 122 pyshellext.dll, the shell extension deployed with the launcher 123python3dll 124 python3.dll, the PEP 384 Stable ABI dll 125xxlimited 126 builds an example module that makes use of the PEP 384 Stable ABI, 127 see Modules\xxlimited.c 128 129The following sub-projects are for individual modules of the standard 130library which are implemented in C; each one builds a DLL (renamed to 131.pyd) of the same name as the project: 132_asyncio 133_ctypes 134_ctypes_test 135_decimal 136_elementtree 137_hashlib 138_msi 139_multiprocessing 140_overlapped 141_socket 142_testbuffer 143_testcapi 144_testconsole 145_testimportmultiple 146_testmultiphase 147_tkinter 148pyexpat 149select 150unicodedata 151winsound 152 153The following Python-controlled sub-projects wrap external projects. 154Note that these external libraries are not necessary for a working 155interpreter, but they do implement several major features. See the 156"Getting External Sources" section below for additional information 157about getting the source for building these libraries. The sub-projects 158are: 159_bz2 160 Python wrapper for version 1.0.6 of the libbzip2 compression library 161 Homepage: 162 http://www.bzip.org/ 163_lzma 164 Python wrapper for version 5.2.2 of the liblzma compression library 165 Homepage: 166 http://tukaani.org/xz/ 167_ssl 168 Python wrapper for version 1.1.0h of the OpenSSL secure sockets 169 library, which is downloaded from our binaries repository at 170 https://github.com/python/cpython-bin-deps. 171 172 Homepage: 173 http://www.openssl.org/ 174 175 Building OpenSSL requires Perl on your path, and can be performed by 176 running PCbuild\prepare_ssl.bat. This will retrieve the version of 177 the sources matched to the current commit from the OpenSSL branch 178 in our source repository at 179 https://github.com/python/cpython-source-deps. 180 181 To use an alternative build of OpenSSL completely, you should replace 182 the files in the externals/openssl-bin-<version> folder with your own. 183 As long as this folder exists, its contents will not be downloaded 184 again when building. 185 186_sqlite3 187 Wraps SQLite 3.21.0.0, which is itself built by sqlite3.vcxproj 188 Homepage: 189 http://www.sqlite.org/ 190_tkinter 191 Wraps version 8.6.6 of the Tk windowing system, which is downloaded 192 from our binaries repository at 193 https://github.com/python/cpython-bin-deps. 194 195 Homepage: 196 http://www.tcl.tk/ 197 198 Building Tcl and Tk can be performed by running 199 PCbuild\prepare_tcltk.bat. This will retrieve the version of the 200 sources matched to the current commit from the Tcl and Tk branches 201 in our source repository at 202 https://github.com/python/cpython-source-deps. 203 204 The two projects install their respective components in a 205 directory alongside the source directories called "tcltk" on 206 Win32 and "tcltk64" on x64. They also copy the Tcl and Tk DLLs 207 into the current output directory, which should ensure that Tkinter 208 is able to load Tcl/Tk without having to change your PATH. 209 210 211Getting External Sources 212------------------------ 213 214The last category of sub-projects listed above wrap external projects 215Python doesn't control, and as such a little more work is required in 216order to download the relevant source files for each project before they 217can be built. However, a simple script is provided to make this as 218painless as possible, called "get_externals.bat" and located in this 219directory. This script extracts all the external sub-projects from 220 https://github.com/python/cpython-source-deps 221and 222 https://github.com/python/cpython-bin-deps 223via a Python script called "get_external.py", located in this directory. 224If Python 3.6 or later is not available via the "py.exe" launcher, the 225path or command to use for Python can be provided in the PYTHON_FOR_BUILD 226environment variable, or get_externals.bat will download the latest 227version of NuGet and use it to download the latest "pythonx86" package 228for use with get_external.py. Everything downloaded by these scripts is 229stored in ..\externals (relative to this directory). 230 231It is also possible to download sources from each project's homepage, 232though you may have to change folder names or pass the names to MSBuild 233as the values of certain properties in order for the build solution to 234find them. This is an advanced topic and not necessarily fully 235supported. 236 237The get_externals.bat script is called automatically by build.bat 238unless you pass the '-E' option. 239 240 241Profile Guided Optimization 242--------------------------- 243 244The solution has two configurations for PGO. The PGInstrument 245configuration must be built first. The PGInstrument binaries are linked 246against a profiling library and contain extra debug information. The 247PGUpdate configuration takes the profiling data and generates optimized 248binaries. 249 250The build_pgo.bat script automates the creation of optimized binaries. 251It creates the PGI files, runs the unit test suite or PyBench with the 252PGI python, and finally creates the optimized files. 253 254See 255 http://msdn.microsoft.com/en-us/library/e7k32f4k(VS.140).aspx 256for more on this topic. 257 258 259Static library 260-------------- 261 262The solution has no configuration for static libraries. However it is 263easy to build a static library instead of a DLL. You simply have to set 264the "Configuration Type" to "Static Library (.lib)" and alter the 265preprocessor macro "Py_ENABLE_SHARED" to "Py_NO_ENABLE_SHARED". You may 266also have to change the "Runtime Library" from "Multi-threaded DLL 267(/MD)" to "Multi-threaded (/MT)". 268 269 270Visual Studio properties 271------------------------ 272 273The PCbuild solution makes use of Visual Studio property files (*.props) 274to simplify each project. The properties can be viewed in the Property 275Manager (View -> Other Windows -> Property Manager) but should be 276carefully modified by hand. 277 278The property files used are: 279 * python (versions, directories and build names) 280 * pyproject (base settings for all projects) 281 * openssl (used by projects dependent upon OpenSSL) 282 * tcltk (used by _tkinter, tcl, tk and tix projects) 283 284The pyproject property file defines all of the build settings for each 285project, with some projects overriding certain specific values. The GUI 286doesn't always reflect the correct settings and may confuse the user 287with false information, especially for settings that automatically adapt 288for diffirent configurations. 289