Remove caching cmake vars (#1313)

* Remove Caching of global CMake variables.

* Add comment to non standard cmake variables which previously given in CACHE string.

* Need a commit to trigger workflows.

* Need a commit to trigger workflows.

* Replace set_property by set since no Cache value has to be changed.

Co-authored-by: Nils Schild <nils.schild@ipp.mpg.de>

Author: nischild

CMakeLists.txt

@@ -44,26 +44,21 @@ endif()
 #
 # temporary build directories
 if(NOT CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
-    set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-        CACHE PATH "Build directory for archives")
+    set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
 endif()
 if(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-    set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-        CACHE PATH "Build directory for libraries")
+    set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
 endif()
 if(NOT CMAKE_RUNTIME_OUTPUT_DIRECTORY)
-    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
-        CACHE PATH "Build directory for binaries")
+    set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
 endif()
 # install directories
 if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
     include(GNUInstallDirs)
-    set(CMAKE_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/openPMD"
-        CACHE PATH "CMake config package location for installed targets")
+    set(CMAKE_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/openPMD")
     if(WIN32)
-        set(CMAKE_INSTALL_LIBDIR Lib
-            CACHE PATH "Object code libraries")
-        set_property(CACHE CMAKE_INSTALL_CMAKEDIR PROPERTY VALUE "cmake")
+        set(CMAKE_INSTALL_LIBDIR Lib)
+        set(CMAKE_INSTALL_CMAKEDIR "cmake")
     endif()
 endif()
 
@@ -98,8 +93,7 @@ option(openPMD_USE_VERIFY "Enable internal VERIFY (assert) macro independent of
 
 set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
 if(NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE "Release" CACHE STRING
-        "Choose the build type, e.g. Release or Debug." FORCE)
+    set(CMAKE_BUILD_TYPE "Release")
 endif()
 
 include(CMakeDependentOption)
@@ -746,20 +740,16 @@ if(openPMD_HAVE_PYTHON)
 
     if(WIN32)
         set(CMAKE_INSTALL_PYTHONDIR_DEFAULT
-            "${CMAKE_INSTALL_LIBDIR}/site-packages"
-        )
+            "${CMAKE_INSTALL_LIBDIR}/site-packages")
     else()
         set(CMAKE_INSTALL_PYTHONDIR_DEFAULT
             "${CMAKE_INSTALL_LIBDIR}/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/site-packages"
         )
     endif()
-    set(CMAKE_INSTALL_PYTHONDIR "${CMAKE_INSTALL_PYTHONDIR_DEFAULT}"
-        CACHE STRING "Location for installed python package"
-    )
-    set(CMAKE_PYTHON_OUTPUT_DIRECTORY
-        "${openPMD_BINARY_DIR}/${CMAKE_INSTALL_PYTHONDIR}"
-        CACHE PATH "Build directory for python modules"
-    )
+    # Location for installed python package
+    set(CMAKE_INSTALL_PYTHONDIR "${CMAKE_INSTALL_PYTHONDIR_DEFAULT}")
+    # Build directory for python modules
+    set(CMAKE_PYTHON_OUTPUT_DIRECTORY "${openPMD_BINARY_DIR}/${CMAKE_INSTALL_PYTHONDIR}")
     set_target_properties(openPMD.py PROPERTIES
         ARCHIVE_OUTPUT_NAME openpmd_api_cxx
         LIBRARY_OUTPUT_NAME openpmd_api_cxx