<!-- Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. SPDX-License-Identifier: curl --> # Building with CMake This document describes how to configure, build and install curl and libcurl from source code using the CMake build tool. To build with CMake, you of course first have to install CMake. The minimum required version of CMake is specified in the file `CMakeLists.txt` found in the top of the curl source tree. Once the correct version of CMake is installed you can follow the instructions below for the platform you are building on. CMake builds can be configured either from the command line, or from one of CMake's GUIs. # Current flaws in the curl CMake build Missing features in the CMake build: - Builds libcurl without large file support - Does not support all SSL libraries (only OpenSSL, Schannel, Secure Transport, and mbedTLS, WolfSSL) - Does not allow different resolver backends (no c-ares build support) - No RTMP support built - Does not allow build curl and libcurl debug enabled - Does not allow a custom CA bundle path - Does not allow you to disable specific protocols from the build - Does not find or use krb4 or GSS - Rebuilds test files too eagerly, but still cannot run the tests - Does not detect the correct `strerror_r` flavor when cross-compiling (issue #1123) # Configuring A CMake configuration of curl is similar to the autotools build of curl. It consists of the following steps after you have unpacked the source. ## Using `cmake` You can configure for in source tree builds or for a build tree that is apart from the source tree. - Build in the source tree. $ cmake -B . - Build in a separate directory (parallel to the curl source tree in this example). The build directory is created for you. $ cmake -B ../curl-build ### Fallback for CMake before version 3.13 CMake before version 3.13 does not support the `-B` option. In that case, you must create the build directory yourself, `cd` to it and run `cmake` from there: $ mkdir ../curl-build $ cd ../curl-build $ cmake ../curl If you want to build in the source tree, it is enough to do this: $ cmake . ## Using `ccmake` CMake comes with a curses based interface called `ccmake`. To run `ccmake` on a curl use the instructions for the command line cmake, but substitute `ccmake` for `cmake`. This brings up a curses interface with instructions on the bottom of the screen. You can press the "c" key to configure the project, and the "g" key to generate the project. After the project is generated, you can run make. ## Using `cmake-gui` CMake also comes with a Qt based GUI called `cmake-gui`. To configure with `cmake-gui`, you run `cmake-gui` and follow these steps: 1. Fill in the "Where is the source code" combo box with the path to the curl source tree. 2. Fill in the "Where to build the binaries" combo box with the path to the directory for your build tree, ideally this should not be the same as the source tree, but a parallel directory called curl-build or something similar. 3. Once the source and binary directories are specified, press the "Configure" button. 4. Select the native build tool that you want to use. 5. At this point you can change any of the options presented in the GUI. Once you have selected all the options you want, click the "Generate" button. # Building Build (you have to specify the build directory). $ cmake --build ../curl-build ### Fallback for CMake before version 3.13 CMake before version 3.13 does not support the `--build` option. In that case, you have to `cd` to the build directory and use the building tool that corresponds to the build files that CMake generated for you. This example assumes that CMake generates `Makefile`: $ cd ../curl-build $ make # Testing (The test suite does not yet work with the cmake build) # Installing Install to default location (you have to specify the build directory). $ cmake --install ../curl-build ### Fallback for CMake before version 3.15 CMake before version 3.15 does not support the `--install` option. In that case, you have to `cd` to the build directory and use the building tool that corresponds to the build files that CMake generated for you. This example assumes that CMake generates `Makefile`: $ cd ../curl-build $ make install