Make use of upstream CMake infrastructure to detect the compiler toolchainv5.45.0-rc1v5.45.0

Summary:
Instead of having ad-hoc code for gcc, let CMake do its thing. It has a lot of
logic that we may be interested in, for example it will make the clang switch
much smoother.

Note it raises the minimum cmake to 3.7 for Android, which was released almost
2 years ago.

Test Plan: Built kalgebra on it using kdeorg/android-sdk

Reviewers: #frameworks, #build_system, vkrause

Reviewed By: vkrause

Subscribers: vkrause

Tags: #frameworks, #build_system

Differential Revision: https://phabricator.kde.org/D11776

3 files changed, 24 insertions, 59 deletions

diff --git a/toolchain/Android.cmake b/toolchain/Android.cmake
index df9d9b0e..14d5b901 100644
--- a/toolchain/Android.cmake
+++ b/toolchain/Android.cmake
@@ -133,7 +133,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-cmake_minimum_required(VERSION "3.1")
+cmake_minimum_required(VERSION "3.7")
 
 #input
 set(ANDROID_NDK "$ENV{ANDROID_NDK}" CACHE path "Android NDK path")
@@ -146,21 +146,18 @@ set(ANDROID_GCC_VERSION "4.9" CACHE string "Used GCC version" )
 set(ANDROID_API_LEVEL "14" CACHE string "Android API Level")
 set(ANDROID_SDK_BUILD_TOOLS_REVISION "21.1.1" CACHE string "Android API Level")
 
-set(_HOST "${CMAKE_HOST_SYSTEM_NAME}-${CMAKE_HOST_SYSTEM_PROCESSOR}")
-string(TOLOWER "${_HOST}" _HOST)
 
-get_filename_component(_CMAKE_ANDROID_DIR "${CMAKE_TOOLCHAIN_FILE}" PATH)
-
-set(CMAKE_SYSROOT
-    "${ANDROID_NDK}/platforms/android-${ANDROID_API_LEVEL}/arch-${ANDROID_ARCHITECTURE}")
-if(NOT EXISTS ${CMAKE_SYSROOT})
-    message(FATAL_ERROR "Couldn't find the Android NDK Root in ${CMAKE_SYSROOT}")
+set(CMAKE_ANDROID_NDK ${ANDROID_NDK})
+set(CMAKE_SYSTEM_VERSION ${ANDROID_API_LEVEL})
+set(CMAKE_ANDROID_ARCH ${ANDROID_ARCHITECTURE})
+set(CMAKE_ANDROID_ARCH_ABI ${ANDROID_ABI})
+set(CMAKE_SYSTEM_NAME Android)
+if (NOT CMAKE_ANDROID_STL_TYPE)
+    set(CMAKE_ANDROID_STL_TYPE gnustl_shared)
 endif()
 
-#actual code
-SET(CMAKE_SYSTEM_NAME Android)
-SET(CMAKE_SYSTEM_VERSION 1)
-SET(ANDROID TRUE)
+include(${CMAKE_ROOT}/Modules/Platform/Android-GNU.cmake REQUIRED)
+include(${CMAKE_ROOT}/Modules/Platform/Android-Initialize.cmake REQUIRED)
 
 if (NOT DEFINED ECM_ADDITIONAL_FIND_ROOT_PATH)
     SET(ECM_ADDITIONAL_FIND_ROOT_PATH ${CMAKE_PREFIX_PATH})
@@ -171,55 +168,11 @@ set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
 
-set(ANDROID_TOOLCHAIN_ROOT "${ANDROID_NDK}/toolchains/${ANDROID_TOOLCHAIN}-${ANDROID_GCC_VERSION}/prebuilt/${_HOST}/bin")
-set(ANDROID_LIBS_ROOT "${ANDROID_NDK}/sources/cxx-stl/gnu-libstdc++/${ANDROID_GCC_VERSION}")
-
-# includes
-include_directories(SYSTEM
-    "${CMAKE_SYSROOT}/usr/include"
-    "${ANDROID_LIBS_ROOT}/include/"
-    "${ANDROID_LIBS_ROOT}/libs/${ANDROID_ABI}/include"
-    "${ANDROID_NDK}/sysroot/usr/include"
-    "${ANDROID_NDK}/sysroot/usr/include/${ANDROID_COMPILER_PREFIX}"
-)
-
-# libraries
-set(ANDROID_LIBRARIES_PATH
-    "${CMAKE_SYSROOT}/usr/lib")
-set(CMAKE_SYSTEM_LIBRARY_PATH
-    ${ANDROID_LIBRARIES_PATH}
-    "${ANDROID_LIBS_ROOT}/libs/${ANDROID_ABI}/"
-)
-set(CMAKE_FIND_LIBRARY_SUFFIXES ".so")
-set(CMAKE_FIND_LIBRARY_PREFIXES "lib")
-
-# Settling hard on gnustl_shared as C++ helper runtime for now,
-# given this is most similar to what is on GNU/Linux, which is what
-# the average software targetted by this toolchain is built against otherwise.
-# If requested by devs, the used helper runtime could be made an option later.
-# Related info: https://developer.android.com/ndk/guides/cpp-support.html
-find_library(GNUSTL_SHARED gnustl_shared)
-if(NOT GNUSTL_SHARED)
-    message(FATAL_ERROR "Selected Android platform does not provide gnustl_shared: ${CMAKE_SYSTEM_LIBRARY_PATH}")
-endif()
-
-link_directories(${CMAKE_SYSTEM_LIBRARY_PATH})
-
-set(CMAKE_C_COMPILER "${ANDROID_TOOLCHAIN_ROOT}/${ANDROID_COMPILER_PREFIX}-gcc")
-set(CMAKE_CXX_COMPILER "${ANDROID_TOOLCHAIN_ROOT}/${ANDROID_COMPILER_PREFIX}-g++")
-
-set(CMAKE_EXE_LINKER_FLAGS "${GNUSTL_SHARED} -Wl,-rpath-link,${ANDROID_LIBRARIES_PATH} -llog -lz -lm -ldl -lc -lgcc" CACHE STRING "")
-set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}" CACHE STRING "")
-set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}" CACHE STRING "")
-
 #we want executables to be shared libraries, hooks will invoke the exported cmake function
 set(CMAKE_CXX_LINK_EXECUTABLE
     "<CMAKE_CXX_COMPILER> <CMAKE_SHARED_LIBRARY_CXX_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS> <SONAME_FLAG><TARGET_SONAME> -o <TARGET> <OBJECTS> <LINK_LIBRARIES>"
 )
 
-# ANDROID is needed for Qt to define Q_OS_ANDROID, __ANDROID_API__ is expected by the Android NDK
-add_definitions(-DANDROID -D__ANDROID_API__=${ANDROID_API_LEVEL})
-
 set(ECM_DIR "${CMAKE_CURRENT_LIST_DIR}/../cmake" CACHE STRING "")
 
 ######### generation
@@ -229,6 +182,7 @@ set(CREATEAPK_TARGET_NAME "create-apk-${QTANDROID_EXPORTED_TARGET}")
 # from CMakeDetermineSystem.cmake and from CMakeSystem.cmake generated within the
 # build directory.
 if(DEFINED QTANDROID_EXPORTED_TARGET AND NOT TARGET ${CREATEAPK_TARGET_NAME})
+    get_filename_component(_CMAKE_ANDROID_DIR "${CMAKE_TOOLCHAIN_FILE}" PATH)
     if(NOT DEFINED ANDROID_APK_DIR)
         message(FATAL_ERROR "Define an apk dir to initialize from using -DANDROID_APK_DIR=<path>. The specified directory must contain the AndroidManifest.xml file.")
     elseif(NOT EXISTS "${ANDROID_APK_DIR}/AndroidManifest.xml")
@@ -259,12 +213,20 @@ if(DEFINED QTANDROID_EXPORTED_TARGET AND NOT TARGET ${CREATEAPK_TARGET_NAME})
             set(EXTRA_PREFIX_DIRS "\"${prefix}\"")
         endif()
     endforeach()
+    string(TOLOWER "${CMAKE_HOST_SYSTEM_NAME}" _LOWER_CMAKE_HOST_SYSTEM_NAME)
     configure_file("${_CMAKE_ANDROID_DIR}/deployment-file.json.in" "${QTANDROID_EXPORTED_TARGET}-deployment.json.in")
 
     if (CMAKE_GENERATOR STREQUAL "Unix Makefiles")
         set(arguments "\\$(ARGS)")
     endif()
 
+    function(havestl var access VALUE)
+        if (NOT VALUE STREQUAL "")
+            file(WRITE ${CMAKE_BINARY_DIR}/stl "${VALUE}")
+        endif()
+    endfunction()
+    variable_watch(CMAKE_CXX_STANDARD_LIBRARIES havestl)
+
     add_custom_target(${CREATEAPK_TARGET_NAME}
         COMMAND cmake -E echo "Generating $<TARGET_NAME:${QTANDROID_EXPORTED_TARGET}> with $<TARGET_FILE_DIR:Qt5::qmake>/androiddeployqt"
         COMMAND cmake -E remove_directory "${EXPORT_DIR}"
diff --git a/toolchain/deployment-file.json.in b/toolchain/deployment-file.json.in
index 92b1bba2..4eb579b5 100644
--- a/toolchain/deployment-file.json.in
+++ b/toolchain/deployment-file.json.in
@@ -5,7 +5,7 @@
    "toolchain-prefix": "@ANDROID_TOOLCHAIN@",
    "tool-prefix": "@ANDROID_COMPILER_PREFIX@",
    "toolchain-version": "@ANDROID_GCC_VERSION@",
-   "ndk-host": "@_HOST@",
+   "ndk-host": "@_LOWER_CMAKE_HOST_SYSTEM_NAME@-@CMAKE_HOST_SYSTEM_PROCESSOR@",
    "target-architecture": "@ANDROID_ABI@",
    "application-binary": "@EXECUTABLE_DESTINATION_PATH@",
    "qml-root-path": "@CMAKE_SOURCE_DIR@",
@@ -13,7 +13,7 @@
    ##EXTRALIBS##
    ##EXTRAPLUGINS##
    "android-package-source-directory": "@ANDROID_APK_DIR@",
-   "stdcpp-path": "@GNUSTL_SHARED@",
+   "stdcpp-path":##CMAKE_CXX_STANDARD_LIBRARIES##,
    "sdkBuildToolsRevision": "@ANDROID_SDK_BUILD_TOOLS_REVISION@",
    "extraPrefixDirs": [ @EXTRA_PREFIX_DIRS@ ]
 }
diff --git a/toolchain/specifydependencies.cmake b/toolchain/specifydependencies.cmake
index 8965d6da..a1bc4202 100644
--- a/toolchain/specifydependencies.cmake
+++ b/toolchain/specifydependencies.cmake
@@ -42,6 +42,9 @@ if(extraplugins)
 endif()
 
 file(READ "${INPUT_FILE}" CONTENTS)
+file(READ "stl" stl_contents)
+
 string(REPLACE "##EXTRALIBS##" "${extralibs}" NEWCONTENTS "${CONTENTS}")
 string(REPLACE "##EXTRAPLUGINS##" "${extraplugins}" NEWCONTENTS "${NEWCONTENTS}")
+string(REPLACE "##CMAKE_CXX_STANDARD_LIBRARIES##" "${stl_contents}" NEWCONTENTS "${NEWCONTENTS}")
 file(WRITE "${OUTPUT_FILE}" ${NEWCONTENTS})