Turn python_callouts.cmake into GodotCPPModule.cmake

Move the find_package for python into it.
Recommend adding godot-cpp/cmake to CMAKE_MODULE_PATH and using include( GodotCPPModule ) to use functions.
Add target_doc_sources function to simplify the addition of documentation to a binary.

CMakeLists.txt

@@ -41,9 +41,6 @@ include( cmake/godotcpp.cmake )
 
 godotcpp_options()
 
-#[[ Python is required for code generation ]]
-find_package(Python3 3.4 REQUIRED) # pathlib should be present
-
 # Define our project.
 project( godot-cpp
         VERSION 4.4

cmake/GodotCPPModule.cmake

@@ -1,14 +1,24 @@
 #[=======================================================================[.rst:
-python_callouts.cmake
+GodotCPPModule.cmake
 ---------------------
 
-This file contains functions which which rely on calling Python
+This file contains functions and tests which may be needed by consumers.
 
 * Generate Trimmed API
 * Generate File List
 * Generate Bindings
-]=======================================================================]
 
+If you want to use these functions in your project extend the CMAKE_MODULE_PATH
+by adding these two lines into your CMakeLists.txt after the inclusion
+godot-cpp
+
+.. highlight:: cmake
+
+    list(APPEND CMAKE_MODULE_PATH "${godot-cpp_SOURCE_DIR}/cmake")
+    include( GodotCPPModule )
+
+]=======================================================================]
+find_package(Python3 3.4 REQUIRED) # pathlib should be present
 
 #[[ Generate Trimmed API
 
@@ -106,22 +116,51 @@ endfunction(  )
 The documentation displayed in the Godot editor is compiled into the extension.
 It takes a list of XML source files, and transforms them into a cpp file that
 is added to the sources list.]]
-function( generate_doc_source OUTPUT_PATH XML_SOURCES )
-    # Transform the CMake list into the content of a python list
-    # quote and join to form the interior of a python array
-    list( TRANSFORM XML_SOURCES REPLACE "(.*\.xml)" "'\\1'" )
-    list( JOIN XML_SOURCES "," XML_SOURCES )
+function( generate_doc_source OUTPUT_PATH SOURCES )
+    # Transform SOURCES CMake LIST
+    # quote each path with ''
+    # join with , to transform into a python list minus the surrounding []
+    set( PYTHON_LIST "${SOURCES}")
+    list( TRANSFORM PYTHON_LIST REPLACE "(.*\.xml)" "'\\1'" )
+    list( JOIN PYTHON_LIST "," PYTHON_LIST )
 
     # Python one-liner to run our command
     # lists in CMake are just strings delimited by ';', so this works.
     set( PYTHON_SCRIPT "from doc_source_generator import generate_doc_source"
-            "generate_doc_source( '${OUTPUT_PATH}', [${XML_SOURCES}] )" )
+            "generate_doc_source( '${OUTPUT_PATH}', [${PYTHON_LIST}] )" )
 
     add_custom_command( OUTPUT "${OUTPUT_PATH}"
             COMMAND "${Python3_EXECUTABLE}" "-c" "${PYTHON_SCRIPT}"
             VERBATIM
             WORKING_DIRECTORY "${godot-cpp_SOURCE_DIR}"
-            DEPENDS "${godot-cpp_SOURCE_DIR}/doc_source_generator.py"
-            COMMENT "Generating Doc Data"
+            DEPENDS
+            "${godot-cpp_SOURCE_DIR}/doc_source_generator.py"
+            "${SOURCES}"
+            COMMENT "Generating: ${OUTPUT_PATH}"
     )
 endfunction()
+
+#[[ target_doc_sources
+A simpler interface to add xml files as doc source to a output target.
+TARGET: The gdexension library target
+SOURCES: a list of xml files to use for source generation and inclusion.
+This function also adds a doc_gen target to test source generation.]]
+function( target_doc_sources TARGET SOURCES )
+    # set the generated file name
+    set( DOC_SOURCE_FILE "${CMAKE_CURRENT_BINARY_DIR}/gen/doc_source.cpp" )
+
+    # Create the file generation target, this won't be triggered unless a target
+    # that depends on DOC_SOURCE_FILE is built
+    generate_doc_source( "${DOC_SOURCE_FILE}" ${SOURCES} )
+
+    # Add DOC_SOURCE_FILE as a dependency to TARGET
+    target_sources( ${TARGET} PRIVATE "${DOC_SOURCE_FILE}" )
+
+    # Create a dummy target that depends on the source so that users can
+    # test the file generation task.
+    if( TARGET doc_gen )
+    else()
+        add_custom_target( doc_gen )
+    endif()
+    target_sources( doc_gen PRIVATE "${DOC_SOURCE_FILE}"  )
+endfunction()

cmake/godotcpp.cmake

@@ -23,6 +23,7 @@ project directive, it means that
   directive was
 
 ]=======================================================================]
+include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/GodotCPPModule.cmake)
 include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/common_compiler_flags.cmake)
 include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/android.cmake)
 include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/ios.cmake)
@@ -30,7 +31,7 @@ include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/linux.cmake)
 include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/macos.cmake)
 include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/web.cmake)
 include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/windows.cmake)
-include( ${CMAKE_CURRENT_SOURCE_DIR}/cmake/python_callouts.cmake)
+
 
 # Detect number of processors
 include(ProcessorCount)

test/CMakeLists.txt

@@ -13,9 +13,6 @@ file( GLOB_RECURSE DOC_XML
     CONFIGURE_DEPENDS
     "${CMAKE_CURRENT_SOURCE_DIR}/doc_classes/*.xml" )
 
-set( DOC_DATA_SOURCE "${CMAKE_CURRENT_BINARY_DIR}/src/gen/doc_data.gen.cpp" )
-generate_doc_source( "${DOC_DATA_SOURCE}" "${DOC_XML}" )
-
 foreach( TARGET_ALIAS template_debug template_release editor )
     set( TARGET_NAME "godot-cpp.test.${TARGET_ALIAS}" )
 
@@ -30,13 +27,13 @@ foreach( TARGET_ALIAS template_debug template_release editor )
             src/tests.h
     )
 
-    set( OUTPUT_DIR "${CMAKE_CURRENT_SOURCE_DIR}/project/bin/" )
-
     # conditionally add doc data to compile output
     if( TARGET_ALIAS MATCHES "editor|template_debug" )
-        target_sources( ${TARGET_NAME} PRIVATE "${DOC_DATA_SOURCE}" )
+        target_doc_sources( ${TARGET_NAME} ${DOC_XML} )
     endif()
 
+    set( OUTPUT_DIR "${CMAKE_CURRENT_SOURCE_DIR}/project/bin/" )
+
     # Link to godot-cpp target
     set( LINK_TARGET "godot-cpp::${TARGET_ALIAS}" )
     target_link_libraries( ${TARGET_NAME} PRIVATE ${LINK_TARGET} )