Use NDK-supplied cmake binary

The CMake toolchain shipped with the NDK doesn't work with CMake-3.7.2
or 3.9.1. To ensure compatibility, use the shipped cmake binary. See
android/ndk#254 or
https://gitlab.kitware.com/cmake/cmake/issues/16708 as well as
android/ndk#504

Change-Id: I31366cd813edc44d0e62021872c63d9fc06ffb7c

CMakeLists.txt

@@ -7,7 +7,7 @@
 # material also contains confidential information which may not be
 # disclosed to others without the prior written consent of HERE.
 
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.6)
 project(hello_world)
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/../../cmake/modules/")

libhello/CMakeLists.txt

@@ -7,7 +7,7 @@
 # material also contains confidential information which may not be
 # disclosed to others without the prior written consent of HERE.
 
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.6)
 
 # Here we create a new library 'hello' for which to generate target platform bindings.
 # It aims to serve as a blueprint for real-world libraries such as libguidance or librouting.

platforms/CMakeLists.txt

@@ -7,6 +7,6 @@
 # material also contains confidential information which may not be
 # disclosed to others without the prior written consent of HERE.
 
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.6)
 
 add_subdirectory(cpp)

platforms/cpp/CMakeLists.txt

@@ -7,7 +7,7 @@
 # material also contains confidential information which may not be
 # disclosed to others without the prior written consent of HERE.
 
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.6)
 project(cpp_app)
 
 if(NOT HELLO_BUILD_CPP_APP)

scripts/build-android

@@ -32,6 +32,12 @@ CMAKE_CROSS_BUILD_PARAMETERS=$(cat <<EOF
 EOF
 )
 
+# The CMake toolchain shipped with the NDK doesn't work with CMake-3.72
+# or 3.9.1. To ensure compatibility, use the shipped cmake binary. See
+# https://github.com/android-ndk/ndk/issues/254 or
+# https://gitlab.kitware.com/cmake/cmake/issues/16708
+NDK_CMAKE_BINARY=$(find $ANDROID_HOME/cmake -executable -type f  -name cmake)
+
 # Do cross-compilation build for generating a proper Android Archive
 for arch in x86 armeabi-v7a ${HOST_ARCH} ; do
     build_dir=${PWD}/build-android-${arch}
@@ -43,21 +49,25 @@ for arch in x86 armeabi-v7a ${HOST_ARCH} ; do
     pushd ${build_dir}
 
     CMAKE_EXTRA_PARAMETERS=
-    # Do host-native build for testing on the JVM with Robolectric
+    # Do host-native build for testing on the JVM with Robolectric using the
+    # CMake binary supplied (and supported) by the NDK
     if [ "${arch}" != "host-$(uname -m)" ] ; then
         CMAKE_EXTRA_PARAMETERS="${CMAKE_CROSS_BUILD_PARAMETERS} \
         -DANDROID_ABI=${arch}"
+        CMAKE_BINARY=${NDK_CMAKE_BINARY}
+    else
+        CMAKE_BINARY=cmake
     fi
 
-    safe cmake \
+    safe ${CMAKE_BINARY} \
         ${CMAKE_DEFAULT_PARAMETERS} \
         ${CMAKE_EXTRA_PARAMETERS} \
         -DCMAKE_INSTALL_PREFIX=${install_dir} \
         ..
 
     popd
 
-    safe cmake \
+    safe ${CMAKE_BINARY} \
         --build ${build_dir} \
         --target install
 done