Merge branch 'feat/320' into 'master'

feat: CMake 3.20

See merge request CLIUtils/modern-cmake!50

.bumpversion.cfg

@@ -1,16 +1,16 @@
 [bumpversion]
-current_version = 3.19.4
+current_version = 3.20.0
 
 [bumpversion:file:.gitlab-ci.yml]
-search = cmake-{current_version}-Linux
-replace = cmake-{new_version}-Linux
+search = cmake-{current_version}-linux
+replace = cmake-{new_version}-linux
 
 [bumpversion:file (2):.gitlab-ci.yml]
 serialize = {major}.{minor}
 
 [bumpversion:file:chapters/intro/installing.md]
-search = cmake-{current_version}-Linux
-replace = cmake-{new_version}-Linux
+search = cmake-{current_version}-linux
+replace = cmake-{new_version}-linux
 
 [bumpversion:file (2):chapters/intro/installing.md]
 serialize = {major}.{minor}

.gitlab-ci.yml

@@ -5,7 +5,7 @@ test_code:
     - apt-get update && apt-get install -y make cmake libboost-dev git
     # We will install latest CMake, even though Ubuntu has a recent one
     - mkdir -p $HOME/.local
-    - curl -s "https://cmake.org/files/v3.19/cmake-3.19.4-Linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C $HOME/.local
+    - curl -s "https://cmake.org/files/v3.20/cmake-3.20.0-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C $HOME/.local
     - export PATH=$HOME/.local/bin:$PATH
   script:
     - cmake -S examples -B build

README.md

@@ -7,7 +7,7 @@ Certainly there are no shortage of problems when building.
 But I think that, in 2020, we have a very good solution to quite a few of those problems.
 It's CMake. Not CMake 2.8 though; that was released before C++11 even existed!
 Nor the horrible examples out there for CMake (even those posted on KitWare's own tutorials list).
-I'm talking about Modern CMake. CMake 3.1+, maybe even CMake 3.19+!
+I'm talking about Modern CMake. CMake 3.1+, maybe even CMake 3.20+!
 It's clean, powerful, and elegant, so you can spend most of your time coding, not adding lines to an unreadable, unmaintainable Make (Or CMake 2) file.
 And CMake 3.11+ is supposed to be significantly faster, as well!
 

chapters/basics.md

@@ -36,7 +36,7 @@ Windows users, who also usually have a very recent version of CMake.
 This is what new projects should do:
 
 ```cmake
-cmake_minimum_required(VERSION 3.7...3.19)
+cmake_minimum_required(VERSION 3.7...3.20)
 
 if(${CMAKE_VERSION} VERSION_LESS 3.12)
     cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
@@ -56,10 +56,10 @@ you will want to do this instead:
 ```cmake
 cmake_minimum_required(VERSION 3.7)
 
-if(${CMAKE_VERSION} VERSION_LESS 3.19)
+if(${CMAKE_VERSION} VERSION_LESS 3.20)
     cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
 else()
-    cmake_policy(VERSION 3.19)
+    cmake_policy(VERSION 3.20)
 endif()
 ```
 

chapters/features/cpp11.md

@@ -24,8 +24,6 @@ You can ask for specific compiler features to be available. This was more granul
 
 If you have optional features, you can use the list `CMAKE_CXX_COMPILE_FEATURES` and use `if(... IN_LIST ...)` from CMake 3.3+ to see if that feature is supported, and add it conditionally. See [the docs here](https://cmake.org/cmake/help/latest/manual/cmake-compile-features.7.html) for other use cases.
 
-A related feature, [`WriteCompilerDetectionHeader`](https://cmake.org/cmake/help/latest/module/WriteCompilerDetectionHeader.html), is worth checking out. It is a module that lets you make a file with macros allowing you to check and support optional features for specific compilers. Like any header generator, this will require that you build with CMake so that your header can be generated as part of the build process (only important if you care about supporting multiple build systems, or if you are making a no-build header-only library).
-
 
 ## CMake 3.1+: Global and property settings
 

chapters/features/modules.md

@@ -50,30 +50,6 @@ Note that `OUTPUT_VARIABLE` will also appear in the configuration printout, so c
 This is just one of many similar modules, such as `CheckIncludeFileCXX`, `CheckStructHasMember`, `TestBigEndian`, and `CheckTypeSize` that allow you
 to check for information about the system (and you can communicate that to your source code).
 
-## «module:WriteCompilerDetectionHeader»
-
-This is an amazing module similar to the ones listed above, but special enough to deserve its own section. It allows you
-to look for a list of features that some compilers support, and write out a C++ header file that lets you know whether that
-feature is available. It even can provide compatibility macros for features that have changed names!
-
-To use:
-
-```cmake
-write_compiler_detection_header(
-  FILE myoutput.h
-  PREFIX My
-  COMPILERS GNU Clang MSVC Intel
-  FEATURES cxx_variadic_templates
-)
-```
-
-This supports compiler features (defined to 0 or 1), symbols (defined to empty or the symbol), and macros that
-support different names. They will be prefixed with the PREFIX you provide. You can separate compilers into different
-files using `OUTPUT_FILES_DIR`.
-
-The downside is that you do have to list the compilers you expect to support. If you use the `ALLOW_UNKNOWN_COMPILERS` flag(s),
-you can keep this from erroring on unknown compilers, but it will still leave all features empty.
-
 ## «command:`try_compile`»/«command:`try_run`»
 
 This is not exactly a module, but is crucial to many of the modules listed above. You can attempt to compile (and possibly run) a bit of code at configure time. This can allow you to get information about the capabilities of your system. The basic syntax is:

chapters/intro/installing.md

@@ -4,7 +4,7 @@
 Your CMake version should be newer than your compiler. It should be newer than the libraries you are using (especially Boost). New versions work better for everyone.
 {% endhint %}
 
-If you have a built in copy of CMake, it isn't special or customized for your system. You can easily install a new one instead, either on the system level or the user level. Feel free to instruct your users here if they complain about a CMake requirement being set too high. Especially if they want 3.1+ support. Maybe even if they want 3.19+ support...
+If you have a built in copy of CMake, it isn't special or customized for your system. You can easily install a new one instead, either on the system level or the user level. Feel free to instruct your users here if they complain about a CMake requirement being set too high. Especially if they want 3.1+ support. Maybe even if they want 3.20+ support...
 
 #### Quick list (more info on each method below)
 
@@ -34,14 +34,14 @@ You can [download CMake from KitWare][download]. This is how you will probably g
 On Linux, there are several options. Kitware provides a [Debian/Ubunutu apt repository][apt], as well as [snap packages][snap]. There are universal Linux binaries provided, but you'll need to pick an install location. If you already use `~/.local` for user-space packages, the following single line command[^1] will get CMake for you [^2]:
 
 {% term %}
-~ $ wget -qO- "https://cmake.org/files/v3.19/cmake-3.19.4-Linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C ~/.local
+~ $ wget -qO- "https://cmake.org/files/v3.20/cmake-3.20.0-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C ~/.local
 {% endterm %}
 
-If you just want a local folder with CMake only:
+The names changed in 3.20; older releases had names like `cmake-3.19.7-Linux-x86_64.tar.gz`. If you just want a local folder with CMake only:
 
 {% term %}
-~ $ mkdir -p cmake-3.19 && wget -qO- "https://cmake.org/files/v3.19/cmake-3.19.4-Linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C cmake-3.19
-~ $ export PATH=`pwd`/cmake-3.19/bin:$PATH
+~ $ mkdir -p cmake-3.20 && wget -qO- "https://cmake.org/files/v3.20/cmake-3.20.0-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C cmake-3.20
+~ $ export PATH=`pwd`/cmake-3.20/bin:$PATH
 {% endterm %}
 
 You'll obviously want to append to the PATH every time you start a new terminal, or add it to your `.bashrc` or to an [LMod][] system.
@@ -49,7 +49,7 @@ You'll obviously want to append to the PATH every time you start a new terminal,
 And, if you want a system install, install to `/usr/local`; this is an excellent choice in a Docker container, for example on GitLab CI. Do not try it on a non-containerized system.
 
 {% term %}
-docker $ wget -qO- "https://cmake.org/files/v3.19/cmake-3.19.4-Linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C /usr/local
+docker $ wget -qO- "https://cmake.org/files/v3.20/cmake-3.20.0-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C /usr/local
 {% endterm %}
 
 

chapters/intro/newcmake.md

@@ -305,6 +305,21 @@ for permissions. Further support for generator expressions in more places.
 * FindPython: `Python*_LINK_OPTIONS` added
 * `compute-sanitizer` for ctest now supports CUDA for memcheck
 
+## [CMake 3.20][] : ...
+
+The CMake docs received a major boost in productivity by adding "new in" tags
+to quickly see what was added without having to toggle documentation versions!
+C++ 23 support added. Source files must have the extension listed now, and
+LANGUAGE is always respected. Quite a bit of cleanup was done; make sure your
+code is tested with `...3.20` before deploying that as your maximum.
+
+* Support added for C++23
+* CUDAARCHS environment variable for setting CUDA architectures.
+* The new `IntelLLVM` compilers are now supported (OneAPI 2021.1), and `NVHPC` NVIDIA HPC SDK, as well.
+* Some expanded generator expression support in custom commands/targets, install renaming.
+* New `cmake_path` command for working with paths.
+* Several removals, like `cmake-server`, `WriteCompilerDetectionHeader` (if policy set to 3.20+), and a few things that have newer methods now.
+
 
 [Releases]: https://cmake.org/cmake/help/latest/release/index.html
 [CMake 3.0]: https://cmake.org/cmake/help/latest/release/3.0.html
@@ -327,6 +342,7 @@ for permissions. Further support for generator expressions in more places.
 [CMake 3.17]: https://cmake.org/cmake/help/latest/release/3.17.html
 [CMake 3.18]: https://cmake.org/cmake/help/latest/release/3.18.html
 [CMake 3.19]: https://cmake.org/cmake/help/latest/release/3.19.html
+[CMake 3.20]: https://cmake.org/cmake/help/latest/release/3.20.html
 [CMake master]: https://cmake.org/cmake/help/git-master/release/index.html
 [fastercmake]: https://blog.kitware.com/improving-cmakes-runtime-performance/
 

examples/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.11...3.19)
+cmake_minimum_required(VERSION 3.11...3.20)
 
 project(ModernCMakeExamples)
 set(MODERN_CMAKE_BUILD_TESTING ON)

examples/extended-project/CMakeLists.txt

@@ -1,5 +1,5 @@
-# Works with 3.11 and tested through 3.19
-cmake_minimum_required(VERSION 3.11...3.19)
+# Works with 3.11 and tested through 3.20
+cmake_minimum_required(VERSION 3.11...3.20)
 
 # Project name and a few useful settings. Other commands can pick up the results
 project(

examples/fetch/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.14...3.19)
+cmake_minimum_required(VERSION 3.14...3.20)
 
 project(FetchExample LANGUAGES CXX)
 

examples/root-dict/CMakeLists.txt

@@ -2,7 +2,7 @@
 
 ## [main]
 
-cmake_minimum_required(VERSION 3.4...3.19)
+cmake_minimum_required(VERSION 3.4...3.20)
 
 project(RootDictExample LANGUAGES CXX)
 

examples/root-simple/CMakeLists.txt

@@ -1,7 +1,7 @@
 # CMake ROOT simple example
 
 ## [main]
-cmake_minimum_required(VERSION 3.1...3.19)
+cmake_minimum_required(VERSION 3.1...3.20)
 
 project(RootSimpleExample LANGUAGES CXX)
 

examples/root-usefile/CMakeLists.txt

@@ -1,7 +1,7 @@
 # CMake ROOT usefile example
 
 ## [main]
-cmake_minimum_required(VERSION 3.1...3.19)
+cmake_minimum_required(VERSION 3.1...3.20)
 
 project(RootUseFileExample LANGUAGES CXX)
 

examples/simple-project/CMakeLists.txt

@@ -6,7 +6,7 @@
 # You should always specify a range with the newest
 # and oldest tested versions of CMake. This will ensure
 # you pick up the best policies.
-cmake_minimum_required(VERSION 3.1...3.19)
+cmake_minimum_required(VERSION 3.1...3.20)
 
 # This is your project statement. You should always list languages;
 # Listing the version is nice here since it sets lots of useful variables