1<!-- 2Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3 4SPDX-License-Identifier: curl 5--> 6 7# Building curl with Visual C++ 8 9 This document describes how to compile, build and install curl and libcurl 10 from sources using the Visual C++ build tool. To build with VC++, you will of 11 course have to first install VC++. The minimum required version of VC is 6 12 (part of Visual Studio 6). However using a more recent version is strongly 13 recommended. 14 15 VC++ is also part of the Windows Platform SDK. You do not have to install the 16 full Visual Studio or Visual C++ if all you want is to build curl. 17 18 The latest Platform SDK can be downloaded freely from [Windows SDK and 19 emulator 20 archive](https://developer.microsoft.com/en-us/windows/downloads/sdk-archive) 21 22## Prerequisites 23 24 If you wish to support zlib, OpenSSL, c-ares, ssh2, you will have to download 25 them separately and copy them to the `deps` directory as shown below: 26 27 somedirectory\ 28 |_curl-src 29 | |_winbuild 30 | 31 |_deps 32 |_ lib 33 |_ include 34 |_ bin 35 36 It is also possible to create the `deps` directory in some other random places 37 and tell the `Makefile` its location using the `WITH_DEVEL` option. 38 39## Building straight from git 40 41 When you check out code git and build it, as opposed from a released source 42 code archive, you need to first run the `buildconf.bat` batch file (present 43 in the source code root directory) to set things up. 44 45## Open a command prompt 46 47Open a Visual Studio Command prompt: 48 49 Using the **'VS [version] [platform] [type] Command Prompt'** menu entry: 50 where [version] is the Visual Studio version, [platform] is e.g. x64 and 51 [type] Native or Cross platform build. This type of command prompt may not 52 exist in all Visual Studio versions. For example, to build a 64-bit curl open 53 the x64 Native Tools prompt. 54 55 See also: 56 57 [How to: Enable a 64-Bit, x64 hosted MSVC toolset on the command line](https://docs.microsoft.com/en-us/cpp/build/how-to-enable-a-64-bit-visual-cpp-toolset-on-the-command-line) 58 59 [Set the Path and Environment Variables for Command-Line Builds](https://docs.microsoft.com/en-us/cpp/build/building-on-the-command-line) 60 61 [Developer Command Prompt for Visual Studio](https://docs.microsoft.com/en-us/dotnet/framework/tools/developer-command-prompt-for-vs) 62 63## Build in the console 64 65 Once you are in the console, go to the winbuild directory in the Curl 66 sources: 67 68 cd curl-src\winbuild 69 70 Then you can call `nmake /f Makefile.vc` with the desired options (see 71 below). The builds will be in the top src directory, `builds\` directory, in 72 a directory named using the options given to the nmake call. 73 74 nmake /f Makefile.vc mode=<static or dll> <options> 75 76where `<options>` is one or many of: 77 78 - `VC=<num>` - VC version. 6 or later. 79 - `WITH_DEVEL=<path>` - Paths for the development files (SSL, zlib, etc.) 80 Defaults to sibling directory: `../deps` 81 - `WITH_SSL=<dll/static>` - Enable OpenSSL support, DLL or static 82 - `WITH_NGHTTP2=<dll/static>` - Enable HTTP/2 support, DLL or static 83 - `WITH_MSH3=<dll/static>` - Enable (experimental) HTTP/3 support, DLL or static 84 - `WITH_MBEDTLS=<dll/static>` - Enable mbedTLS support, DLL or static 85 - `WITH_WOLFSSL=<dll/static>` - Enable wolfSSL support, DLL or static 86 - `WITH_CARES=<dll/static>` - Enable c-ares support, DLL or static 87 - `WITH_ZLIB=<dll/static>` - Enable zlib support, DLL or static 88 - `WITH_SSH=<dll/static>` - Enable libssh support, DLL or static 89 - `WITH_SSH2=<dll/static>` - Enable libssh2 support, DLL or static 90 - `WITH_PREFIX=<dir>` - Where to install the build 91 - `ENABLE_SSPI=<yes/no>` - Enable SSPI support, defaults to yes 92 - `ENABLE_IPV6=<yes/no>` - Enable IPv6, defaults to yes 93 - `ENABLE_IDN=<yes or no>` - Enable use of Windows IDN APIs, defaults to yes 94 Requires Windows Vista or later 95 - `ENABLE_SCHANNEL=<yes/no>` - Enable native Windows SSL support, defaults 96 to yes if SSPI and no other SSL library 97 - `ENABLE_OPENSSL_AUTO_LOAD_CONFIG=<yes/no>` 98 - Enable loading OpenSSL configuration 99 automatically, defaults to yes 100 - `ENABLE_UNICODE=<yes/no>` - Enable Unicode support, defaults to no 101 - `GEN_PDB=<yes/no>` - Generate External Program Database 102 (debug symbols for release build) 103 - `DEBUG=<yes/no>` - Debug builds 104 - `MACHINE=<x86/x64/arm64>` - Target architecture (default is x86) 105 - `CARES_PATH=<path>` - Custom path for c-ares 106 - `MBEDTLS_PATH=<path>` - Custom path for mbedTLS 107 - `WOLFSSL_PATH=<path>` - Custom path for wolfSSL 108 - `NGHTTP2_PATH=<path>` - Custom path for nghttp2 109 - `MSH3_PATH=<path>` - Custom path for msh3 110 - `SSH2_PATH=<path>` - Custom path for libssh2 111 - `SSL_PATH=<path>` - Custom path for OpenSSL 112 - `ZLIB_PATH=<path>` - Custom path for zlib 113 114## Cleaning a build 115 116 For most build configurations you can remove a bad build by using the same 117 options with the added keyword "clean". For example: 118 119 nmake /f Makefile.vc mode=static clean 120 121 Build errors due to switching Visual Studio platform tools or mistakenly 122 specifying the wrong machine platform for the tools can usually be solved by 123 first cleaning the bad build. 124 125## Static linking of Microsoft's C runtime (CRT): 126 127 If you are using mode=static nmake will create and link to the static build 128 of libcurl but *not* the static CRT. If you must you can force nmake to link 129 in the static CRT by passing `RTLIBCFG=static`. Typically you shouldn't use 130 that option, and nmake will default to the DLL CRT. `RTLIBCFG` is rarely used 131 and therefore rarely tested. When passing `RTLIBCFG` for a configuration that 132 was already built but not with that option, or if the option was specified 133 differently, you must destroy the build directory containing the 134 configuration so that nmake can build it from scratch. 135 136 This option is not recommended unless you have enough development experience 137 to know how to match the runtime library for linking (that is, the CRT). If 138 `RTLIBCFG=static` then release builds use `/MT` and debug builds use `/MTd`. 139 140## Building your own application with libcurl (Visual Studio example) 141 142 When you build curl and libcurl, nmake will show the relative path where the 143 output directory is. The output directory is named from the options nmake used 144 when building. You may also see temp directories of the same name but with 145 suffixes -obj-curl and -obj-lib. 146 147 For example let's say you've built curl.exe and libcurl.dll from the Visual 148 Studio 2010 x64 Win64 Command Prompt: 149 150 nmake /f Makefile.vc mode=dll VC=10 151 152 The output directory will have a name similar to 153 `..\builds\libcurl-vc10-x64-release-dll-ipv6-sspi-schannel`. 154 155 The output directory contains subdirectories bin, lib and include. Those are 156 the directories to set in your Visual Studio project. You can either copy the 157 output directory to your project or leave it in place. Following the example, 158 let's assume you leave it in place and your curl top source directory is 159 `C:\curl-7.82.0`. You would set these options for configurations using the 160 x64 platform: 161 162~~~ 163 - Configuration Properties > Debugging > Environment 164 PATH=C:\curl-7.82.0\builds\libcurl-vc10-x64-release-dll-ipv6-sspi-schannel\bin;%PATH% 165 166 - C/C++ > General > Additional Include Directories 167 C:\curl-7.82.0\builds\libcurl-vc10-x64-release-dll-ipv6-sspi-schannel\include; 168 169 - Linker > General > Additional Library Directories 170 C:\curl-7.82.0\builds\libcurl-vc10-x64-release-dll-ipv6-sspi-schannel\lib; 171 172 - Linker > Input > Additional Dependencies 173 libcurl.lib; 174~~~ 175 176 For configurations using the x86 platform (aka Win32 platform) you would 177 need to make a separate x86 build of libcurl. 178 179 If you build libcurl static (`mode=static`) or debug (`DEBUG=yes`) then the 180 library name will vary and separate builds may be necessary for separate 181 configurations of your project within the same platform. This is discussed in 182 the next section. 183 184## Building your own application with a static libcurl 185 186 When building an application that uses the static libcurl library on Windows, 187 you must define `CURL_STATICLIB`. Otherwise the linker will look for dynamic 188 import symbols. 189 190 The static library name has an `_a` suffix in the basename and the debug 191 library name has a `_debug` suffix in the basename. For example, 192 `libcurl_a_debug.lib` is a static debug build of libcurl. 193 194 You may need a separate build of libcurl for each VC configuration combination 195 (for example: Debug|Win32, Debug|x64, Release|Win32, Release|x64). 196 197 You must specify any additional dependencies needed by your build of static 198 libcurl (for example: 199 `advapi32.lib;crypt32.lib;normaliz.lib;ws2_32.lib;wldap32.lib`). 200 201## Legacy Windows and SSL 202 203 When you build curl using the build files in this directory the default SSL 204 backend will be Schannel (Windows SSPI), the native SSL library that comes 205 with the Windows OS. Schannel in Windows 8 and earlier is not able to connect 206 to servers that no longer support the legacy handshakes and algorithms used by 207 those versions. If you will be using curl in one of those earlier versions of 208 Windows you should choose another SSL backend like OpenSSL. 209
