WIP: generates stubs on usual CMake builds, having issues when buildi…

…ng through pip

CMakeLists.txt

@@ -51,6 +51,7 @@ option(MATERIALX_BUILD_SHARED_LIBS "Build MaterialX libraries as shared rather t
 option(MATERIALX_BUILD_MONOLITHIC "Build a single monolithic MaterialX library." OFF)
 option(MATERIALX_BUILD_USE_CCACHE "Enable the use of ccache to speed up build time, if present." ON)
 option(MATERIALX_PYTHON_LTO "Enable link-time optimizations for MaterialX Python." ON)
+option(MATERIALX_PYTHON_STUBS "Enable the automated generation of MaterialX Python '.pyi' stub files through mypy's stubgen." ON)
 option(MATERIALX_INSTALL_PYTHON "Install the MaterialX Python package as a third-party library when the install target is built." ON)
 option(MATERIALX_INSTALL_RESOURCES "Install the resources folder when building render modules." ON)
 option(MATERIALX_TEST_RENDER "Run rendering tests for MaterialX Render module. GPU required for graphics validation." ON)
@@ -142,6 +143,7 @@ mark_as_advanced(MATERIALX_BUILD_USE_CCACHE)
 mark_as_advanced(MATERIALX_NAMESPACE_SUFFIX)
 mark_as_advanced(MATERIALX_LIBNAME_SUFFIX)
 mark_as_advanced(MATERIALX_PYTHON_LTO)
+mark_as_advanced(MATERIALX_PYTHON_STUBS)
 mark_as_advanced(MATERIALX_INSTALL_PYTHON)
 mark_as_advanced(MATERIALX_INSTALL_RESOURCES)
 mark_as_advanced(MATERIALX_TEST_RENDER)

pyproject.toml

@@ -2,7 +2,11 @@
 # Use a fixed version because we use an experimental feature
 # (a custom plugin) and for now that functionality has
 # no compatibility promises.
-requires = ["scikit-build-core==0.4.4"]
+requires = [
+  "scikit-build-core==0.4.4",
+  # For generating .pyi stub files:
+  "mypy==1.11.2"
+  ]
 build-backend = "scikit_build_core.build"
 
 [project]
@@ -71,6 +75,7 @@ sdist.exclude = [
 [tool.scikit-build.cmake.define]
 MATERIALX_BUILD_SHARED_LIBS = 'OFF' # Be explicit
 MATERIALX_BUILD_PYTHON = 'ON'
+MATERIALX_PYTHON_STUBS = 'ON'
 MATERIALX_TEST_RENDER = 'OFF'
 MATERIALX_WARNINGS_AS_ERRORS = 'ON'
 MATERIALX_BUILD_TESTS = 'OFF'

python/CMakeLists.txt

@@ -18,6 +18,38 @@ if(MATERIALX_PYTHON_OCIO_DIR)
   install(DIRECTORY "${MATERIALX_PYTHON_OCIO_DIR}/" DESTINATION "${MATERIALX_PYTHON_FOLDER_NAME}/config/" MESSAGE_NEVER)
 endif()
 
+if (MATERIALX_PYTHON_STUBS)
+  # attempts to find mypy stubgen executable
+  find_program(_MYPY_STUBGEN_EXECUTABLE "stubgen")
+  message("Found stubgen executable: _MYPY_STUBGEN_EXECUTABLE=${MATERIALX_PYTHON_STUBS}")
+
+  # check if stubgen can be accessed
+  execute_process(
+    COMMAND ${_MYPY_STUBGEN_EXECUTABLE} --help
+    OUTPUT_VARIABLE _MYPY_STUBGEN_HELP_OUTPUT
+    ERROR_VARIABLE _MYPY_STUBGEN_HELP_OUTPUT
+    RESULT_VARIABLE _MYPY_STUBGEN_HELP_EXITCODE
+  )
+
+  # build stubs if stubgen could be found properly
+  if (_MYPY_STUBGEN_HELP_EXITCODE EQUAL "0")
+    install(CODE "
+      execute_process(
+        COMMAND ${_MYPY_STUBGEN_EXECUTABLE} -p MaterialX --inspect-mode -o \"${CMAKE_INSTALL_PREFIX}/python\" -v --ignore-errors
+        WORKING_DIRECTORY \"${CMAKE_INSTALL_PREFIX}/python\")
+    ")
+  else ()
+    # prints errors if mypy couldn't be found
+    # TODO: should this be a fatal error or?
+    message(
+        FATAL_ERROR
+        "MATERIALX_PYTHON_STUBS=${MATERIALX_PYTHON_STUBS} but"
+        " mypy stubgen not found: status=${_MYPY_STUBGEN_HELP_EXITCODE}:"
+        " ${_MYPY_STUBGEN_HELP_OUTPUT}"
+    )
+  endif ()
+endif()
+
 if(MATERIALX_INSTALL_PYTHON AND PYTHON_EXECUTABLE AND NOT SKBUILD)
   set(SETUP_PY "${CMAKE_INSTALL_PREFIX}/python/setup.py")
   configure_file("${CMAKE_CURRENT_SOURCE_DIR}/setup.py.in" "${SETUP_PY}")