[mlir] Refactor finding python

This drops the use of deprecated CMake modules to find python.

Differential Revision: https://reviews.llvm.org/D91197

Author: marbre

mlir/CMakeLists.txt

@@ -78,10 +78,9 @@ set(MLIR_PYTHON_BINDINGS_VERSION_LOCKED 1 CACHE BOOL
        "Links to specific python libraries, resolving all symbols.")
 
 if(MLIR_BINDINGS_PYTHON_ENABLED)
-  find_package(PythonInterp REQUIRED)
-  find_package(PythonLibs REQUIRED)
-  message(STATUS "Found python include dirs: ${PYTHON_INCLUDE_DIRS}")
-  message(STATUS "Found python libraries: ${PYTHON_LIBRARIES}")
+  find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
+  message(STATUS "Found python include dirs: ${Python3_INCLUDE_DIRS}")
+  message(STATUS "Found python libraries: ${Python3_LIBRARIES}")
   find_package(pybind11 CONFIG REQUIRED)
   # TODO: pybind11 v2.6 switched from pybind11_INCLUDE_DIRS (plural) to
   # pybind11_INCLUDE_DIR (singular). A lot has changed in this area since this

mlir/cmake/modules/AddMLIRPythonExtension.cmake

@@ -24,12 +24,12 @@ function(add_mlir_python_extension libname extname)
   # symbols, which is better for development. Note that not all python
   # configurations provide build-time libraries to link against, in which
   # case, we fall back to MODULE linking.
-  if(PYTHON_LIBRARIES STREQUAL "" OR NOT MLIR_PYTHON_BINDINGS_VERSION_LOCKED)
+  if(Python3_LIBRARIES STREQUAL "" OR NOT MLIR_PYTHON_BINDINGS_VERSION_LOCKED)
     set(PYEXT_LINK_MODE MODULE)
     set(PYEXT_LIBADD)
   else()
     set(PYEXT_LINK_MODE SHARED)
-    set(PYEXT_LIBADD ${PYTHON_LIBRARIES})
+    set(PYEXT_LIBADD ${Python3_LIBRARIES})
   endif()
 
   # The actual extension library produces a shared-object or DLL and has
@@ -40,7 +40,7 @@ function(add_mlir_python_extension libname extname)
   )
 
   target_include_directories(${libname} PRIVATE
-    "${PYTHON_INCLUDE_DIRS}"
+    "${Python3_INCLUDE_DIRS}"
     "${pybind11_INCLUDE_DIR}"
   )