modern-cmake/chapters/intro/newcmake.md

What's new in in CMake

This is an abbreviated version of the CMake changlog with just the highlights for authors. Names for each release are arbitrarily picked by the author.

CMake 3.0 : Interface libraries

There were a ton of additions to this version of CMake, primarily to fill out the target interface. Some bits of needed functionality were missed and implemented in CMake 3.1 instead.

• New documentation
• INTERFACE libraries
• Project VERSION support
• Exporting build trees easily
• Bracket arguments and comments available (not widely used)
• Lots of improvements

CMake 3.1 : C++11 and compile features

This is the first release of CMake to support C++11. Combined with fixes to the new features of CMake 3.0, this is currently a common minimum version of CMake for libraries that want to support old CMake builds.

• C++11 Support
• Compile features support
• Sources can be added later with target_sources
• Better support for generator expressions and INTERFACE targets

CMake 3.2 : UTF8

This is a smaller release, with mostly small features and fixes. Internal changes, like better Windows and UTF8 support, were the focus.

• continue() inside loops
• File and directory locks added

CMake 3.3 : if IN_LIST

This is notable for the useful IN_LIST option for if, but it also added better library search using $PATH (See CMake 3.6), dependencies for INTERFACE libraries, and several other useful improvements. The addition of a COMPILE_LANGUAGE generator expression would prove very useful in the future as more languages are added. Makefiles now produce better output in parallel.

• IN_LIST added to if
• *_INCLUDE_WHAT_YOU_USE property added
• COMPILE_LANGUAGE generator expression (limited support in some generators)

CMake 3.4 : Swift & CCache

This release adds lots of useful tools, support for the Swift language, and the usual improvements. It also started supporting compiler launchers, like CCache.

• Added Swift language
• Added BASE_DIR to get_filename_component
• if(TEST ...) added
• string(APPEND ...) added
• CMAKE_*_COMPILER_LAUNCHER added for make and ninja
• TARGET_MESSAGES allow makefiles to print messages after target is completed
• Imported targets are beginning to show up in the official Find*.cmake files

CMake 3.5 : ARM

This release expanded CMake to more platforms, and make warnings easier to control from the command line.

• Multiple input files supported for several of the cmake -E commands.
• cmake_parse_arguments now builtin
• Boost, GTest, and more now support imported targets
• ARMCC now supported, better support for iOS
• XCode backslash fix

CMake 3.6 : Clang-Tidy

This release added Clang-Tidy support, along with more utilities and improvements. It also removed the search of $PATH on Unix systems due to problems, instead users should use $CMAKE_PREFIX_PATH.

• EXCLUDE_FROM_ALL for install
• list(FILTER added
• CMAKE_*_STANDARD_INCLUDE_DIRECTORIES and CMAKE_*_STANDARD_LIBRARIES added for toolchains
• Try-compile improvements
• *_CLANG_TIDY property added
• External projects can now be shallow clones, and other improvements

CMake 3.7 : Android & CMake Server

You can now cross-compile to Android. Useful new if statement options really help clarify code. And the new server mode should (eventually?) improve integration with IDEs. Support for the VIM editor was also improved.

• PARSE_ARGV mode for cmake_parse_arguments
• Better 32-bit support on 64-bit machines
• Lots of useful new if comparisons, like VERSION_GREATER_EQUAL (really, why did it take this long?)
• LINK_WHAT_YOU_USE added
• Lots of custom properties related to files and directories
• CMake Server added
• Added --trace-source="filename" to monitor certain files only

CMake 3.8 : C# & CUDA

This adds CUDA as a language, as well as cxx_std_11 as a compiler meta-feature. The new generator expression could be really useful if you can require CMake 3.8+!

• Native support for C# as a language
• Native support for CUDA as a language
• Meta features cxx_std_11 (and 14, 17) added
• try_compile has better language support
• BUILD_RPATH property added
• COMPILE_FLAGS now supports generator expression
• *_CPPLINT added
• $<IF:cond,true-value,false-value> added (wow!)

CMake 3.9 : IPO

Lots of fixes to CUDA support went into this release, including PTX support and MSVC generators. Interprocedural Optimizations are now supported properly. Even more modules provide imported targets, including MPI.

• CUDA supported for Windows
• Better object library support in several situations
• DESCRIPTION added to project
• separate_arguments gets NATIVE_COMMAND
• INTERPROCEDURAL_OPTIMIZATION enforced (and CMAKE_* initializer added, CheckIPOSupported added, Clang and GCC support)
• New GoogleTest module
• FindDoxygen drastically improved

CMake 3.10 : CppCheck

CMake now is built with C++11 compilers. Lots of useful improvements help write cleaner code.

• Support for flang Fortran compiler
• Compiler launcher added to CUDA
• Indented #cmakedefines now supported for configure_file
• include_guard() added to ensure a file gets included only once
• string(PREPEND added
• *_CPPCHECK property added
• LABELS added to directories
• FindMPI vastly expanded
• FindOpenMP improved
• Dynamic test discovery for GoogleTest

CMake 3.11 : Faster & IMPORTED INTERFACE

This release is supposed to be much faster. You can also finally directly add INTERFACE targets to IMPORTED libraries (the internal Find*.cmake scripts should become much cleaner eventually).

• Fortran supports compiler launchers
• Xcode and Visual Studio support COMPILE_LANGUAGE generator expressions finally
• You can now add INTERFACE targets directly to IMPORTED INTERFACE libraries (Wow!)
• Source file properties have been expanded
• FetchContent module now allows downloads to happen at configure time (Wow)

CMake 3.12 : Version ranges and CONFIGURE_DEPENDS

Very powerful release, containing lots of smaller long-requested features. One of the smaller but immediately noticeable changes is the addition of version ranges; you can now set both the minimum and maximum known CMake version easily. You can also set CONFIGURE_DEPENDS on a GLOBed set of files, and the build system will check those files and rerun if needed! You can use the general PackageName_ROOT for all find_package searches. Lots of additions to strings and lists, module updates, shiny new Python find module (2 and 3 versions too), and many more.

• Support for cmake_minimum_required ranges (backward compatible)
• Support for -j,--parallel in --build mode (passed on to build tool)
• Support for $<SHELL: shell strings (not deduplicated)
• New FindPython module
• string(JOIN and list(JOIN, and list(TRANSFORM
• file(TOUCH and file(GLOB CONFIGURE_DEPENDS
• C++20 support
• CUDA as a language improvements: CUDA < 7.5 supported
• Support for OpenMP on macOS (command line only)
• Several new properties and property initializers
• CPack finally reads CMAKE_PROJECT_VERSION variables

CMake 3.13 : Linking control

You can now make symbolic links on Windows! Lots of new functions that fill out the popular requests for CMake, such as add_link_options, target_link_directories, and target_link_options. You can now do quite a bit more modification to targets outside of the source directory, for better file separation. And, target_sources finally handles relative paths properly (policy 76).

• New ctest --progress option for live output
• target_link_options and add_link_options added
• target_link_directories added
• Symbolic link creation, -E create_symlink, supported on Windows
• IPO supported on Windows
• You can use -S and -B for source and build directories
• target_link_libraries and install work outside the current target directory
• STATIC_LIBRARY_OPTIONS property added
• target_sources is now relative to the current source directory (CMP0076)
• If you use Xcode, you now can experimentally set schema fields