[llvm] [mlir] [MLIR][Python] reland (narrower) type stub generation (PR #157930)

[Jacques Pienaar via llvm-commits]

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@@ -99,6 +99,84 @@ function(declare_mlir_python_sources name)
   endif()
 endfunction()
 
+# Function: generate_type_stubs
+# Turns on automatic type stub generation for extension modules.
+# Specifically, performs add_custom_command to run nanobind's stubgen on an extension module.
+#
+# Arguments:
+#   MODULE_NAME: The fully-qualified name of the extension module (used for importing in python).
+#   DEPENDS_TARGETS: List of targets these type stubs depend on being built; usually corresponding to the
+#     specific extension module (e.g., something like StandalonePythonModules.extension._standaloneDialectsNanobind.dso)
+#     and the core bindings extension module (e.g., something like StandalonePythonModules.extension._mlir.dso).
+#   OUTPUT_DIR: The root output directory to emit the type stubs into.
+#   OUTPUTS: List of expected outputs.
+#   DEPENDS_TARGET_SRC_DEPS: List of cpp sources for extension library (for generating a DEPFILE).
+#   IMPORT_PATHS: List of paths to add to PYTHONPATH for stubgen.
+# Outputs:
+#   NB_STUBGEN_CUSTOM_TARGET: The target corresponding to generation which other targets can depend on.
+function(generate_type_stubs)
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jpienaar wrote:

mlir_generate_type_stubs ? (I don't think cmake is nampespaced).

https://github.com/llvm/llvm-project/pull/157930