Bump minimal CMake version to 3.5 to silence a CMake 3.27 warning.

CMakeLists.txt

@@ -23,7 +23,8 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
-cmake_minimum_required(VERSION 3.4)
+# Matches Corrade requirement, see its root CMakeLists for more information.
+cmake_minimum_required(VERSION 3.5)
 
 project(MagnumBindings CXX)
 
@@ -121,15 +122,7 @@ if(_MAGNUMBINDINGS_ACCEPT_DEPRECATED_UNPREFIXED_OPTIONS AND MAGNUM_BUILD_DEPRECA
     endforeach()
 
     if(_MAGNUMBINDINGS_WARN_DEPRECATED_UNPREFIXED_OPTION)
-        # CMake 3.5+ has deprecation warnings enabled by default (which makes
-        # sense), 3.4 not. Use a warning there instead.
-        # TODO: drop when 3.4 is not supported anymore
-        if(CMAKE_VERSION VERSION_LESS 3.5)
-            set(DEPRECATION_OR_WARNING WARNING)
-        else()
-            set(DEPRECATION_OR_WARNING DEPRECATION)
-        endif()
-        message(${DEPRECATION_OR_WARNING} "Unprefixed options such as ${_MAGNUMBINDINGS_WARN_DEPRECATED_UNPREFIXED_OPTION} are deprecated, use MAGNUM_${_MAGNUMBINDINGS_WARN_DEPRECATED_UNPREFIXED_OPTION} instead. Delete the unprefixed variable from CMake cache or set both to the same value to silence this warning.")
+        message(DEPRECATION "Unprefixed options such as ${_MAGNUMBINDINGS_WARN_DEPRECATED_UNPREFIXED_OPTION} are deprecated, use MAGNUM_${_MAGNUMBINDINGS_WARN_DEPRECATED_UNPREFIXED_OPTION} instead. Delete the unprefixed variable from CMake cache or set both to the same value to silence this warning.")
     endif()
 endif()
 

doc/python/pages/building.rst

@@ -204,7 +204,7 @@ following commands, the resulting HTML overview is located in
 =========================
 
 In ``package/ci/`` there is a ``circleci.yml`` file that compiles and tests the
-bindings on Linux GCC 4.8 + CMake 3.4 and on macOS, online at
+bindings on Linux GCC 4.8 + CMake 3.5 and on macOS, online at
 https://circleci.com/gh/mosra/magnum-bindings. For Windows there is an
 ``appveyor.yml`` testing on Windows with MSVC, online at
 https://ci.appveyor.com/project/mosra/magnum-bindings. Code coverage for both

doc/python/pages/changelog.rst

@@ -35,6 +35,11 @@ Changelog
 `Changes since 2020.06`_
 ========================
 
+-   Minimal supported CMake version is now 3.5, changed from 3.4, since CMake
+    3.27+ warns if a compatibility with CMake below 3.5 is requested. Older
+    versions are not supported anymore and all workarounds for them were
+    removed. This is a conservative change, as there are no known supported
+    distributions which would have anything older than 3.5.
 -   Exposed the :ref:`corrade.BUILD_DEPRECATED` and
     :ref:`magnum.BUILD_DEPRECATED` constants, as some features may work
     differently depending on these being enabled or not and it's useful to be

package/ci/circleci.yml

@@ -33,7 +33,8 @@ commands:
         command: |
           apt update
           if [[ "$CMAKE_CXX_FLAGS" == *"--coverage"* ]]; then export LCOV_PACKAGES="lcov curl"; fi
-          apt install -y git ninja-build $LCOV_PACKAGES << parameters.extra >>
+          # libidn11 needed by CMake
+          apt install -y git ninja-build libidn11 $LCOV_PACKAGES << parameters.extra >>
 
   install-base-macos:
     parameters:
@@ -60,17 +61,27 @@ commands:
           echo 'export CC=gcc-4.8' >> $BASH_ENV
           echo 'export CXX=g++-4.8' >> $BASH_ENV
 
-  install-cmake-3_4:
+  install-cmake:
+    parameters:
+      version:
+        type: string
+      sudo:
+        type: string
+        default: ""
     steps:
     - run:
-        name: Install CMake 3.4
+        name: Install CMake << parameters.version >>
         command: |
-          apt install -y wget libidn11
+          version_short=<< parameters.version >>
+          version_short="${version_short%.*}"
+          << parameters.sudo >> apt install -y wget
           mkdir -p $HOME/cmake && cd $HOME/cmake
-          wget -nc --no-check-certificate https://cmake.org/files/v3.4/cmake-3.4.3-Linux-x86_64.tar.gz
-          tar --strip-components=1 -xzf cmake-3.4.3-Linux-x86_64.tar.gz
+          wget -nc --no-check-certificate https://cmake.org/files/v$version_short/cmake-<< parameters.version >>-Linux-x86_64.tar.gz
+          tar --strip-components=1 -xzf cmake-<< parameters.version >>-Linux-x86_64.tar.gz
           echo 'export PATH=$HOME/cmake/bin:$PATH' >> $BASH_ENV
-          source $BASH_ENV && cmake --version | grep 3.4
+          source $BASH_ENV
+          cmake --version | grep << parameters.version >>
+          ctest --version | grep << parameters.version >>
 
   install-python-3_6:
     # Can't use the python3.6 docker image because there I can't install GCC
@@ -221,7 +232,8 @@ jobs:
     - install-base-linux:
         extra: libgl1-mesa-dev libsdl2-dev libglfw3-dev
     - install-gcc-4_8
-    - install-cmake-3_4
+    - install-cmake:
+        version: "3.5.2"
     - install-python-3_6
     - install-pybind11
     - install-meshoptimizer
@@ -243,7 +255,8 @@ jobs:
     - install-base-linux:
         extra: libsdl2-dev libglfw3-dev wget unzip
     - install-gcc-4_8
-    - install-cmake-3_4
+    - install-cmake:
+        version: "3.5.2"
     - install-python-3_6
     - install-pybind11
     - install-meshoptimizer
@@ -267,7 +280,8 @@ jobs:
     - install-base-linux:
         extra: libsdl2-dev libglfw3-dev wget unzip
     - install-gcc-4_8
-    - install-cmake-3_4
+    - install-cmake:
+        version: "3.5.2"
     - install-python-3_6
     - install-pybind11
     - install-meshoptimizer
@@ -292,7 +306,8 @@ jobs:
     - install-base-linux:
         extra: libsdl2-dev libglfw3-dev
     - install-gcc-4_8
-    - install-cmake-3_4
+    - install-cmake:
+        version: "3.5.2"
     - install-python-3_6
     - install-pybind11
     - install-meshoptimizer