cmake: add option to disable linking of python extension modules to python-libraries

CMakeLists.txt

@@ -106,11 +106,17 @@ if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_COMPILER_IS_CLANGXX)
     INCLUDE_DIRECTORIES(${CMAKE_CURRENT_BINARY_DIR})
 
     # get linker errors as soon as possible and not at runtime e.g. for modules
-    if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-        set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-undefined,error")
-    elseif(UNIX)
-        set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined")
-    endif()
+    if(BUILD_DYNAMIC_LINK_PYTHON)
+        if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+            set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-undefined,error")
+        elseif(UNIX)
+            set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined")
+        endif()
+    else(BUILD_DYNAMIC_LINK_PYTHON)
+        if(CMAKE_COMPILER_IS_CLANGXX)
+            set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-undefined,dynamic_lookup")
+        endif()
+    endif(BUILD_DYNAMIC_LINK_PYTHON)
 endif(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_COMPILER_IS_CLANGXX)
 
 if(CMAKE_COMPILER_IS_CLANGXX)
@@ -209,6 +215,7 @@ OPTION(FREECAD_USE_EXTERNAL_KDL "Use system installed orocos-kdl instead of the
 OPTION(FREECAD_USE_FREETYPE "Builds the features using FreeType libs" ON)
 OPTION(FREECAD_BUILD_DEBIAN "Prepare for a build of a Debian package" OFF)
 OPTION(BUILD_WITH_CONDA "Set ON if you build freecad with conda" OFF)
+OPTION(BUILD_DYNAMIC_LINK_PYTHON "If OFF extension-modules do not link against python-libraries" ON)
 OPTION(OCCT_CMAKE_FALLBACK "disable usage of occt-config files" OFF)
 if (WIN32 OR APPLE)
     OPTION(FREECAD_USE_QT_FILEDIALOG "Use Qt's file dialog instead of the native one." OFF)

src/Base/CMakeLists.txt

@@ -17,10 +17,14 @@ include_directories(
     ${PYCXX_INCLUDE_DIR}
 )
 
+if (BUILD_DYNAMIC_LINK_PYTHON)
+    set(LINK_PYTHON_LIBRARIES ${PYTHON_LIBRARIES})
+endif (BUILD_DYNAMIC_LINK_PYTHON)
+
 if(MSVC)
     set(FreeCADBase_LIBS
         ${Boost_LIBRARIES}
-        ${PYTHON_LIBRARIES}
+        ${LINK_PYTHON_LIBRARIES}
         debug ${XercesC_DEBUG_LIBRARIES}
         optimized ${XercesC_LIBRARIES}
         ${ZLIB_LIBRARIES}
@@ -45,7 +49,7 @@ if(MSVC)
     endif()
 elseif(MINGW)
     set(FreeCADBase_LIBS
-        ${PYTHON_LIBRARIES}
+        ${LINK_PYTHON_LIBRARIES}
         ${XercesC_LIBRARIES}
         ${Boost_LIBRARIES}
         ${ZLIB_LIBRARIES}
@@ -53,7 +57,7 @@ elseif(MINGW)
     )
 else(MSVC)
     set(FreeCADBase_LIBS
-        ${PYTHON_LIBRARIES}
+        ${LINK_PYTHON_LIBRARIES}
         ${XercesC_LIBRARIES}
         ${Boost_LIBRARIES}
         ${ZLIB_LIBRARIES}

src/Main/CMakeLists.txt

@@ -42,6 +42,12 @@ if(BUILD_GUI)
     add_executable(FreeCADMain WIN32 ${FreeCAD_SRCS})
     target_link_libraries(FreeCADMain ${FreeCAD_LIBS})
 
+    if(NOT BUILD_DYNAMIC_LINK_PYTHON)
+        # executeables have to be linked against python libraries,
+        # because extension modules are not.
+        target_link_libraries(FreeCADMain ${PYTHON_LIBRARIES})
+    endif(NOT BUILD_DYNAMIC_LINK_PYTHON)
+
     SET_BIN_DIR(FreeCADMain FreeCAD)
 
     if(WIN32)
@@ -87,6 +93,12 @@ target_link_libraries(FreeCADMainCmd
     ${FreeCADMainCmd_LIBS}
 )
 
+if(NOT BUILD_DYNAMIC_LINK_PYTHON)
+    # executeables have to be linked against python libraries,
+    # because extension modules are not.
+    target_link_libraries(FreeCADMainCmd ${PYTHON_LIBRARIES})
+endif(NOT BUILD_DYNAMIC_LINK_PYTHON)
+
 SET_BIN_DIR(FreeCADMainCmd FreeCADCmd)
 
 if(WIN32)

src/Mod/MeshPart/App/CMakeLists.txt

@@ -128,7 +128,12 @@ if (BUILD_FLAT_MESH)
 
                 add_library(flatmesh SHARED ${FLATMESH_SRCS})
                 SET_PYTHON_PREFIX_SUFFIX(flatmesh)
-                target_link_libraries(flatmesh ${PYTHON_LIBRARIES} ${MeshPart_LIBS} ${Boost_LIBRARIES})
+
+                if (BUILD_DYNAMIC_LINK_PYTHON)
+                    target_link_libraries(flatmesh ${PYTHON_LIBRARIES})
+                endif(BUILD_DYNAMIC_LINK_PYTHON)
+
+                target_link_libraries(flatmesh ${MeshPart_LIBS} ${Boost_LIBRARIES})
 
                 SET_BIN_DIR(flatmesh flatmesh /Mod/MeshPart)
                 install(TARGETS flatmesh DESTINATION ${CMAKE_INSTALL_LIBDIR})

src/Mod/Path/libarea/CMakeLists.txt

@@ -1,8 +1,8 @@
 # Turn compiler warnings on for gcc 
-if (CMAKE_BUILD_TOOL MATCHES "make")
+if (CMAKE_BUILD_TOOL MATCHES "make" AND BUILD_DYNAMIC_LINK_PYTHON)
     MESSAGE(STATUS "setting gcc options: -Wall -Werror -Wno-deprecated -pedantic-errors")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")
-endif (CMAKE_BUILD_TOOL MATCHES "make")
+endif (CMAKE_BUILD_TOOL MATCHES "make" AND BUILD_DYNAMIC_LINK_PYTHON)
 
 if(MSVC)
     add_definitions(-D_CRT_SECURE_NO_WARNINGS /wd4244)
@@ -123,25 +123,31 @@ if(MSVC)
 
     set(area_LIBS
         ${Boost_LIBRARIES}
-        ${PYTHON_LIBRARIES}
         ${area_native_LIBS}
     )
+    if(BUILD_DYNAMIC_LINK_PYTHON)
+        list(APPEND area_LIBS ${PYTHON_LIBRARIES})
+    endif(BUILD_DYNAMIC_LINK_PYTHON)
 elseif(MINGW)
     set(area_native_LIBS
         Rpcrt4.lib
     )
     set(area_LIBS
         ${Boost_LIBRARIES}
-        ${PYTHON_LIBRARIES}
         ${area_native_LIBS}
     )
+    if(BUILD_DYNAMIC_LINK_PYTHON)
+        list(APPEND area_LIBS ${PYTHON_LIBRARIES})
+    endif(BUILD_DYNAMIC_LINK_PYTHON)
 else(MSVC)
     set(area_native_LIBS
         )
     set(area_LIBS
         ${Boost_LIBRARIES}
-        ${PYTHON_LIBRARIES}
     )
+    if(BUILD_DYNAMIC_LINK_PYTHON)
+        list(APPEND area_LIBS ${PYTHON_LIBRARIES})
+    endif(BUILD_DYNAMIC_LINK_PYTHON)
 endif(MSVC)
 
 target_link_libraries(area-native ${area_native_LIBS})