[Mlir-commits] [mlir] [mlir][python] declare `_PyClassMethod_New` undefined at link time (PR #121597)

[Marius Brehler]

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@@ -686,6 +686,12 @@ function(add_mlir_python_extension libname extname)
   endif()
 
   target_compile_options(${libname} PRIVATE ${eh_rtti_enable})
+  if(APPLE)
+    # NanobindAdaptors.h uses PyClassMethod_New to build `pure_subclass`es but nanobind
+    # doesn't declare this API as undefined in its linker flags. So we need to declare it as such
+    # for downstream users that do not do something like -undefined dynamic_lookup
+    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-U -Wl,_PyClassMethod_New")
+  endif()
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marbre wrote:

Should this be moved into the `elseif(ARG_PYTHON_BINDINGS_LIBRARY STREQUAL "nanobind")` block above?

https://github.com/llvm/llvm-project/pull/121597