build: Use cmake_host_system_information to make registry queries in cmake (#1943)

Author: bobtista

Generals/CMakeLists.txt

@@ -15,28 +15,31 @@ add_subdirectory(Code)
 
 # If we are building on windows for windows, try and get the game install path from the registry.
 if("${CMAKE_HOST_SYSTEM}" MATCHES "Windows" AND "${CMAKE_SYSTEM}" MATCHES "Windows")
-    # Check the CD registry path
-    if(NOT RTS_INSTALL_PREFIX_GENERALS)
-        get_filename_component(RTS_INSTALL_PREFIX_GENERALS  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Electronic Arts\\EA Games\\Generals;InstallPath]" ABSOLUTE CACHE)
-    endif()
+    include(${CMAKE_SOURCE_DIR}/cmake/registry.cmake)
 
-    # Check the WOW6432Node registry path (for EA App on 64-bit Windows)
-    if(NOT RTS_INSTALL_PREFIX_GENERALS OR "${RTS_INSTALL_PREFIX_GENERALS}" STREQUAL "/registry")
-        get_filename_component(RTS_INSTALL_PREFIX_GENERALS  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\WOW6432Node\\Electronic Arts\\EA Games\\Generals;InstallPath]" ABSOLUTE CACHE)
-    endif()
+    # Check the EA App/CD registry path
+    fetch_registry_value(
+        "HKEY_LOCAL_MACHINE/SOFTWARE/Electronic Arts/EA Games/Generals"
+        "InstallPath"
+        RTS_INSTALL_PREFIX_GENERALS
+        "Generals install path from registry")
 
     # Check the "First Decade" registry path
-    if(NOT RTS_INSTALL_PREFIX_GENERALS OR "${RTS_INSTALL_PREFIX_GENERALS}" STREQUAL "/registry")
-        get_filename_component(RTS_INSTALL_PREFIX_GENERALS  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Electronic Arts\\EA Games\\Command and Conquer The First Decade;gr_folder]" ABSOLUTE CACHE)
-    endif()
+    fetch_registry_value(
+        "HKEY_LOCAL_MACHINE/SOFTWARE/Electronic Arts/EA Games/Command and Conquer The First Decade"
+        "gr_folder"
+        RTS_INSTALL_PREFIX_GENERALS
+        "Generals install path from registry")
 
     # Check the Steam registry path
-    if(NOT RTS_INSTALL_PREFIX_GENERALS OR "${RTS_INSTALL_PREFIX_GENERALS}" STREQUAL "/registry")
-        get_filename_component(RTS_INSTALL_PREFIX_GENERALS  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Electronic Arts\\EA Games\\Generals;installPath]" ABSOLUTE CACHE)
-    endif()
+    fetch_registry_value(
+        "HKEY_LOCAL_MACHINE/SOFTWARE/Electronic Arts/EA Games/Generals"
+        "installPath"
+        RTS_INSTALL_PREFIX_GENERALS
+        "Generals install path from registry")
 endif()
 
-if(RTS_INSTALL_PREFIX_GENERALS AND NOT "${RTS_INSTALL_PREFIX_GENERALS}" STREQUAL "/registry")
+if(RTS_INSTALL_PREFIX_GENERALS)
     install(TARGETS g_generals RUNTIME DESTINATION "${RTS_INSTALL_PREFIX_GENERALS}")
     install(FILES $<TARGET_PDB_FILE:g_generals> DESTINATION "${RTS_INSTALL_PREFIX_GENERALS}" OPTIONAL)
 

GeneralsMD/CMakeLists.txt

@@ -15,27 +15,31 @@ add_subdirectory(Code)
 
 # If we are building on windows for windows, try and get the game install path from the registry.
 if("${CMAKE_HOST_SYSTEM}" MATCHES "Windows" AND "${CMAKE_SYSTEM}" MATCHES "Windows")
-    if(NOT RTS_INSTALL_PREFIX_ZEROHOUR)
-        get_filename_component(RTS_INSTALL_PREFIX_ZEROHOUR  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Electronic Arts\\EA Games\\Command and Conquer Generals Zero Hour;InstallPath]" ABSOLUTE CACHE)
-    endif()
+    include(${CMAKE_SOURCE_DIR}/cmake/registry.cmake)
 
-    # Check the WOW6432Node registry path (for EA App on 64-bit Windows)
-    if(NOT RTS_INSTALL_PREFIX_ZEROHOUR OR "${RTS_INSTALL_PREFIX_ZEROHOUR}" STREQUAL "/registry")
-        get_filename_component(RTS_INSTALL_PREFIX_ZEROHOUR  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\WOW6432Node\\Electronic Arts\\EA Games\\Command and Conquer Generals Zero Hour;InstallPath]" ABSOLUTE CACHE)
-    endif()
+    # Check the EA App/CD registry path
+    fetch_registry_value(
+        "HKEY_LOCAL_MACHINE/SOFTWARE/Electronic Arts/EA Games/Command and Conquer Generals Zero Hour"
+        "InstallPath"
+        RTS_INSTALL_PREFIX_ZEROHOUR
+        "Zero Hour install path from registry")
 
     # Check the "First Decade" registry path
-    if(NOT RTS_INSTALL_PREFIX_ZEROHOUR OR "${RTS_INSTALL_PREFIX_ZEROHOUR}" STREQUAL "/registry")
-        get_filename_component(RTS_INSTALL_PREFIX_ZEROHOUR  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Electronic Arts\\EA Games\\Command and Conquer The First Decade;zh_folder]" ABSOLUTE CACHE)
-    endif()
+    fetch_registry_value(
+        "HKEY_LOCAL_MACHINE/SOFTWARE/Electronic Arts/EA Games/Command and Conquer The First Decade"
+        "zh_folder"
+        RTS_INSTALL_PREFIX_ZEROHOUR
+        "Zero Hour install path from registry")
 
     # Check the Steam registry path
-    if(NOT RTS_INSTALL_PREFIX_ZEROHOUR OR "${RTS_INSTALL_PREFIX_ZEROHOUR}" STREQUAL "/registry")
-        get_filename_component(RTS_INSTALL_PREFIX_ZEROHOUR  "[HKEY_LOCAL_MACHINE\\SOFTWARE\\Electronic Arts\\EA Games\\ZeroHour;installPath]" ABSOLUTE CACHE)
-    endif()
+    fetch_registry_value(
+        "HKEY_LOCAL_MACHINE/SOFTWARE/Electronic Arts/EA Games/ZeroHour"
+        "installPath"
+        RTS_INSTALL_PREFIX_ZEROHOUR
+        "Zero Hour install path from registry")
 endif()
 
-if(RTS_INSTALL_PREFIX_ZEROHOUR AND NOT "${RTS_INSTALL_PREFIX_ZEROHOUR}" STREQUAL "/registry")
+if(RTS_INSTALL_PREFIX_ZEROHOUR)
     install(TARGETS z_generals RUNTIME DESTINATION "${RTS_INSTALL_PREFIX_ZEROHOUR}")
     install(FILES $<TARGET_PDB_FILE:z_generals> DESTINATION "${RTS_INSTALL_PREFIX_ZEROHOUR}" OPTIONAL)
 

cmake/registry.cmake

@@ -0,0 +1,15 @@
+# Helper macro for querying Windows registry values
+# Queries both 32-bit and 64-bit registry views automatically
+macro(fetch_registry_value registry_key registry_value output_var description)
+    if(NOT ${output_var})
+        cmake_host_system_information(RESULT _variable
+            QUERY WINDOWS_REGISTRY
+            "${registry_key}"
+            VALUE "${registry_value}"
+            VIEW 32_64)
+        if(_variable)
+            set(${output_var} "${_variable}" CACHE PATH "${description}")
+        endif()
+    endif()
+endmacro()
+