[cmake] Refactored (and fixed) processes setup logic.

Before:

One could use the CMake variables `OGS_BUILD_PROCESSES` or
`OGS_BUILD_PROCESS_XYZ` but behavior was not consistent when switching
back and forth and using both methods. Also building multiple
processes via `OGS_BUILD_PROCESSES` was broken.

Changed:

- Removed `OGS_BUILD_PROCESS_XYZ` options.
- Use `OGS_BUILD_PROCESSES` with the following values:
  - ON  -> All processes are built.
  - OFF -> Disable all processes.
  - Select a single process by name, e.g. `TH2M`.
  - Give a ;-separated list of processes, e.g. '"THM;TH2M"'
- `OGS_BUILD_PROCESSES` can be set via ccmake or cmake-gui with a
  convenient dropdown, although setting multiple processes can only be
  done via the cli!

.gitlab-ci.yml

@@ -8,10 +8,10 @@ stages:
 variables:
   # Build config
   BUILD_TYPE: Release
-  BUILD_PROCESSES: "" # Empty string: builds all processes
+  BUILD_PROCESSES: "ON" # or OFF or ;-separated list of processes
   BUILD_TESTS: "true"
   BUILD_CTEST: "true"
-  CPU_TARGET: ivybridge # envinf2 has oldest cpu
+  CPU_TARGET: ivybridge # envinf1 has oldest cpu
 
 workflow:
   rules:

Applications/ApplicationsLib/CMakeLists.txt

@@ -8,19 +8,14 @@ ogs_add_library(ApplicationsLib ${LIB_SOURCES})
 target_link_libraries(
     ApplicationsLib
     PUBLIC BaseLib GeoLib NumLib
-    PRIVATE CMakeInfoLib
-            MathLib
-            MeshLib
-            MeshGeoToolsLib
+    PRIVATE CMakeInfoLib MathLib MeshLib MeshGeoToolsLib
             $<$<BOOL:${OGS_USE_PYTHON}>:pybind11::pybind11>
             $<$<BOOL:${OGS_USE_PETSC}>:petsc>
 )
 
 if(OGS_BUILD_CLI OR OGS_BUILD_UTILS OR OGS_BUILD_TESTING)
     target_link_libraries(
-        ApplicationsLib
-        PUBLIC Processes
-        PRIVATE ParameterLib ProcessLib
+        ApplicationsLib PUBLIC Processes PRIVATE ParameterLib ProcessLib
     )
 elseif(OGS_BUILD_GUI)
     target_link_libraries(ApplicationsLib PRIVATE nlohmann_json::nlohmann_json)
@@ -36,12 +31,10 @@ target_compile_definitions(
 )
 
 # Set cpp definitions if the cmake option is enabled for the given process.
-foreach(process ${_processes_list})
-    if(OGS_BUILD_PROCESS_${process})
-        string(TOUPPER "OGS_BUILD_PROCESS_${process}" EnableProcess)
-        set_property(
-            TARGET ApplicationsLib APPEND PROPERTY COMPILE_DEFINITIONS
-                                                   ${EnableProcess}
-        )
-    endif()
+foreach(process ${_enabled_processes})
+    string(TOUPPER "OGS_BUILD_PROCESS_${process}" EnableProcess)
+    set_property(
+        TARGET ApplicationsLib APPEND PROPERTY COMPILE_DEFINITIONS
+                                               ${EnableProcess}
+    )
 endforeach()

ProcessLib/CMakeLists.txt

 # Collect the process libraries in interface library
 add_library(Processes INTERFACE)
 
-foreach(process ${_processes_list})
-    if(OGS_BUILD_PROCESS_${process})
-        add_subdirectory(${process})
-        target_link_libraries(Processes INTERFACE ${process})
-        set_target_properties(
-            ${process} PROPERTIES JOB_POOL_COMPILE heavy_tasks
-        )
-    endif()
+foreach(process ${_enabled_processes})
+    add_subdirectory(${process})
+    target_link_libraries(Processes INTERFACE ${process})
+    set_target_properties(${process} PROPERTIES JOB_POOL_COMPILE heavy_tasks)
 endforeach()
 
 get_source_files(SOURCES)

scripts/cmake/ProcessesSetup.cmake

@@ -28,44 +28,47 @@ set(_processes_list
     TwoPhaseFlowWithPrho
 )
 
-# Add a cmake option for each process.
-foreach(process ${_processes_list})
-    option(OGS_BUILD_PROCESS_${process} "Build the ${process} process." ON)
-endforeach()
-
-set(OGS_BUILD_PROCESSES ""
+set(OGS_BUILD_PROCESSES ON
     CACHE STRING "Semicolon-separated list of processes to build"
 )
+
+# Drop-down (cmake-gui), cycle-through list (ccmake) for easiere interactive
+# selection. For enabling multiple selected processes cmake usage via cli is
+# required!
+set_property(
+    CACHE OGS_BUILD_PROCESSES PROPERTY STRINGS ON OFF ${_processes_list}
+)
+
 if(NOT OGS_BUILD_CLI)
     set(OGS_BUILD_PROCESSES OFF "" CACHE STRING "" FORCE)
     message(
         STATUS
             "ATTENTION: OGS_BUILD_CLI=OFF -> OGS_BUILD_PROCESSES is set to OFF too.\n"
             "   If cli is switched on again, remember to switch processes back to on \n"
-            "   too with -DOGS_BUILD_PROCESSES=\"\"!"
+            "   too with -DOGS_BUILD_PROCESSES=ON!"
     )
 endif()
-if(NOT "${OGS_BUILD_PROCESSES}" STREQUAL "")
-    if(${OGS_BUILD_PROCESSES})
-        foreach(process ${OGS_BUILD_PROCESSES})
-            if(NOT "${process}" IN_LIST _processes_list)
-                message(
-                    FATAL_ERROR
-                        "${process} given in OGS_BUILD_PROCESSES is "
-                        "not a valid process name! Valid names are ${_processes_list}"
-                )
-            endif()
-        endforeach()
-        message(STATUS "Enabled processes:")
+
+if("${OGS_BUILD_PROCESSES}" STREQUAL "ON" OR "${OGS_BUILD_PROCESSES}" STREQUAL
+                                             "OFF"
+)
+    if(OGS_BUILD_PROCESSES)
+        message(STATUS "All processes enabled.")
+        set(_enabled_processes ${_processes_list})
     else()
         message(STATUS "All processes disabled.")
+        unset(_enabled_processes)
     endif()
-    foreach(process ${_processes_list})
-        if("${process}" IN_LIST OGS_BUILD_PROCESSES)
-            set(OGS_BUILD_PROCESS_${process} ON CACHE BOOL "" FORCE)
-            message(STATUS "  ${process}")
-        else()
-            set(OGS_BUILD_PROCESS_${process} OFF CACHE BOOL "" FORCE)
+else()
+    foreach(process ${OGS_BUILD_PROCESSES})
+        if(NOT "${process}" IN_LIST _processes_list)
+            message(
+                FATAL_ERROR
+                    "${process} given in OGS_BUILD_PROCESSES is "
+                    "not a valid process name! Valid names are ${_processes_list}"
+            )
         endif()
     endforeach()
+    set(_enabled_processes ${OGS_BUILD_PROCESSES})
+    message(STATUS "Enabled processes: ${OGS_BUILD_PROCESSES}")
 endif()