Fix some compilation errors in some Android environments.

CMakeLists.txt

@@ -28,7 +28,9 @@ if(NOT CMAKE_CROSSCOMPILING)
 endif(NOT CMAKE_CROSSCOMPILING)
 find_package(Git REQUIRED)
 find_package(Threads REQUIRED)
-find_package(Boost QUIET)
+if(NOT ANDROID)
+    find_package(Boost QUIET)
+endif()
 
 include(simd)
 
@@ -147,7 +149,9 @@ if(WITH_GOLANG)
 endif(WITH_GOLANG)
 
 add_subdirectory(paddle)
-add_subdirectory(python)
+if(WITH_PYTHON)
+  add_subdirectory(python)
+endif()
 if(WITH_DOC)
     add_subdirectory(doc)
 endif()

cmake/generic.cmake

@@ -90,7 +90,7 @@
 # including binary directory for generated headers.
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 
-if(NOT APPLE)
+if(NOT APPLE AND NOT ANDROID)
     find_package(Threads REQUIRED)
     link_libraries(${CMAKE_THREAD_LIBS_INIT})
     set(CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_CXX_LINK_EXECUTABLE} -ldl")