Require at least CMake 3.4.

CMakeLists.txt

@@ -23,21 +23,14 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.4)
-
-# Configuration fails on < 3.4 if only C++ is enabled (CheckFunctionExists
-# macro called from FindX11). Also, Android needs C for compiling some glue
-# code.
-if(NOT CMAKE_VERSION VERSION_LESS 3.4.0 AND NOT CMAKE_SYSTEM_NAME STREQUAL "Android")
-    set(LANG CXX)
-endif()
 
 option(HUNTER_ENABLED "Get dependencies (Corrade, GLFW, SDL2, ...) via Hunter" OFF)
 if(HUNTER_ENABLED)
     include(${CMAKE_CURRENT_LIST_DIR}/package/hunter/HunterInit.cmake)
 endif()
 
-project(Magnum ${LANG})
+project(Magnum CXX)
 
 if(HUNTER_ENABLED)
     include(${CMAKE_CURRENT_LIST_DIR}/package/hunter/HunterAddPackages.cmake)

doc/building.dox

@@ -40,7 +40,7 @@ Minimal set of tools and libraries required for building is:
 -   C++ compiler with good C++11 support. Compilers which are tested to have
     everything needed are **GCC** >= 4.8.1, **Clang** >= 3.3 and **MSVC**
     >= 2015. On Windows you can also use **MinGW-w64**.
--   **CMake** >= 3.1
+-   **CMake** >= 3.4
 -   **Corrade** --- Plugin management and utility library. See
     @ref building-corrade "Corrade download and installation guide" for more
     information.

doc/changelog.dox

@@ -38,6 +38,15 @@ See also:
 
 @section changelog-latest Changes since 2019.01
 
+@subsection changelog-latest-dependencies Dependency changes
+
+-   Minimal supported CMake version is now 3.4. Older versions are not
+    supported anymore and all workarounds for them were removed. Download a
+    prebuilt release of a newer version if you need to use Corrade on older
+    systems (such as Ubuntu 14.04 or Debian 8). This is a conservative change
+    that shouldn't affect any additional distribution compared to the CMake 3.1
+    requirement in 2019.01.
+
 @subsection changelog-latest-new New features
 
 -   MSVC 2019 compatibility, with slightly less workarounds needed compared to

doc/generated/CMakeLists.txt

@@ -23,9 +23,9 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.4)
 
-project(MagnumDocumentationImageGenerator)
+project(MagnumDocumentationImageGenerator CXX)
 
 set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/../../modules/" ${CMAKE_MODULE_PATH})
 

package/ci/travis.yml

@@ -212,12 +212,12 @@ install:
 - if [ "$TRAVIS_OS_NAME" == "linux" ] && ( [ "$TARGET" == "desktop" ] || [ "$TARGET" == "desktop-sanitizers" ] ); then export PLATFORM_GL_API=GLX; fi
 - if [ "$TRAVIS_OS_NAME" == "linux" ] && [ "$TARGET" == "desktop-gles" ]; then export PLATFORM_GL_API=EGL; fi
 - if [ "$TRAVIS_OS_NAME" == "linux" ] && [ "$TARGET" == "android" ]; then wget -nc https://dl.google.com/android/repository/android-ndk-r16b-linux-x86_64.zip && unzip -q android-*.zip; fi
-# Download CMake 3.1.3 to ensure we're still compatible with it (Travis has
+# Download CMake 3.4.3 to ensure we're still compatible with it (Travis has
 # 3.9 since December 2017). Also, the PATH setting can't be cached, so it's
 # separate (bit me two times already). Android needs CMake 3.7, but
 # https://gitlab.kitware.com/cmake/cmake/issues/17253 is fixed in 3.9.2, so
 # grab that. FindVulkan is since 3.7, in that case just use the system package.
-- if [ "$TRAVIS_OS_NAME" == "linux" ] && [ ! "$TARGET" == "desktop-vulkan" ] && [ ! "$TARGET" == "android" ] && [ ! -e "$HOME/cmake/bin" ]; then cd $HOME ; wget -nc --no-check-certificate https://cmake.org/files/v3.1/cmake-3.1.3-Linux-x86_64.tar.gz && mkdir -p cmake && cd cmake && tar --strip-components=1 -xzf ../cmake-3.1.3-Linux-x86_64.tar.gz && cd $TRAVIS_BUILD_DIR ; fi
+- if [ "$TRAVIS_OS_NAME" == "linux" ] && [ ! "$TARGET" == "desktop-vulkan" ] && [ ! "$TARGET" == "android" ] && [ ! -e "$HOME/cmake/bin" ]; then cd $HOME ; wget -nc --no-check-certificate https://cmake.org/files/v3.4/cmake-3.4.3-Linux-x86_64.tar.gz && mkdir -p cmake && cd cmake && tar --strip-components=1 -xzf ../cmake-3.4.3-Linux-x86_64.tar.gz && cd $TRAVIS_BUILD_DIR ; fi
 - if [ "$TRAVIS_OS_NAME" == "linux" ] && [ "$TARGET" == "android" ] && [ ! -e "$HOME/cmake/bin" ]; then cd $HOME ; wget -nc --no-check-certificate https://cmake.org/files/v3.9/cmake-3.9.2-Linux-x86_64.tar.gz && mkdir -p cmake && cd cmake && tar --strip-components=1 -xzf ../cmake-3.9.2-Linux-x86_64.tar.gz && cd $TRAVIS_BUILD_DIR ; fi
 - if [ "$TRAVIS_OS_NAME" == "linux" ] && [ ! "$TARGET" == "desktop-vulkan" ]; then export PATH=$HOME/cmake/bin:$PATH && cmake --version; fi
 - if [ "$TRAVIS_OS_NAME" == "osx" ]; then HOMEBREW_NO_AUTO_UPDATE=1 brew install ninja; fi

src/Magnum/Platform/CMakeLists.txt

@@ -144,6 +144,7 @@ if(WITH_ANDROIDAPPLICATION)
     set(MagnumAndroidApplication_PRIVATE_HEADERS
         Implementation/Egl.h)
 
+    enable_language(C)
     add_library(MagnumAndroidApplicationGlue OBJECT
         "${CMAKE_ANDROID_NDK}/sources/android/native_app_glue/android_native_app_glue.c")
     set_target_properties(MagnumAndroidApplicationGlue PROPERTIES