[j.0] CMake minor cleanup ()

Merging branch 'j.0'  into 'main'.

See merge request !2482

CMakeLists.txt

@@ -77,6 +77,10 @@ endif()
 
 # check compatibility of options
 
+if(BA_APPLE_BUNDLE AND NOT APPLE)
+    message(FATAL_ERROR "BA_APPLE_BUNDLE=ON although hardware is not APPLE")
+endif()
+
 if(BA_WHEEL AND NOT BORNAGAIN_PYTHON)
     message(FATAL_ERROR "BA_WHEEL is ON although BORNAGAIN_PYTHON is OFF")
 endif()
@@ -136,7 +140,7 @@ if(BA_TESTS)
 
 ### Operating system
 
-# introduce `LINUX` flag (along with `APPLE` and `WIN32`)
+# introduce `LINUX` flag (whereas `APPLE` and `WIN32` are set by CMake)
 if(UNIX AND CMAKE_SYSTEM_NAME MATCHES Linux)
     set(LINUX ON)
 endif()

cmake/BornAgain/Directories.cmake

@@ -76,8 +76,6 @@ if(WIN32)
     # under Windows, .pyd files are needed as the Python extension; see
     # <https://docs.python.org/3/faq/windows.html#is-a-pyd-file-the-same-as-a-dll>
     set(libsuffix .pyd)
-elseif(APPLE)
-    set(libsuffix .so)
 else()
     set(libsuffix .so)
 endif()
@@ -89,7 +87,7 @@ set(destination_suffix ${CMAKE_PROJECT_NAME}_${PROJECT_VERSION})
 
 set(dstIds "")
 
-if(APPLE AND BA_APPLE_BUNDLE)
+if(BA_APPLE_BUNDLE)
     set(destination_bundle BornAgain.app)
     set(destination_root ${destination_bundle}/Contents/)
     list(APPEND dstIds "bundle")