[mlir][Python] Check numpy in Python bindings configuration.

[zhanghb97]

Summary

The test process of the ir_array_attributes.py depends on numpy. This patch checks numpy in Python bindings configuration.

• Add NumPy in find_package as a required component to check numpy.
• If numpy is found, print the version and include directory.

[mehdi_amini]

mlir/CMakeLists.txt

82

Numpy can just be one of the COMPONENTS here I believe?

[zhanghb97]

Check numpy in find_package by adding OPTIONAL_COMPONENTS NumPy.

mlir/CMakeLists.txt

82

I use OPTIONAL_COMPONENTS here, because I think the lack of numpy does not affect the building process of Python bindings, it only fails the test so I also report a WARNING.

[mehdi_amini]

mlir/CMakeLists.txt

82

If we can't run the test for the python bindings, I rather error out here and make it required.

88

Is pip the universal and only solution to get numpy? What if the user has configured Conda or something like that?

[stellaraccident]

mlir/CMakeLists.txt

88

Of course it's not :)

I would just add an "or equiv" to the end.

But I think this whole condition goes away if making it required.

[zhanghb97]

Add NumPy as a required component.

mlir/CMakeLists.txt

82

Done - Add the NumPy as a required component.

88

The NumPy is added to the required component, so we don't need the condition now.

[zhanghb97]

I can't figure out why checking the numpy can fail the LLVM codegen test?

[mehdi_amini]

It can't.

mlir/CMakeLists.txt

 
 set(MLIR_BINDINGS_PYTHON_ENABLED 0 CACHE BOOL
        "Enables building of Python bindings.")
 set(MLIR_PYTHON_BINDINGS_VERSION_LOCKED 1 CACHE BOOL
        "Links to specific python libraries, resolving all symbols.")
 
 if(MLIR_BINDINGS_PYTHON_ENABLED)
   include(MLIRDetectPythonEnv)
-  find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
+  find_package(Python3 COMPONENTS Interpreter Development REQUIRED OPTIONAL_COMPONENTS NumPy)
   message(STATUS "Found python include dirs: ${Python3_INCLUDE_DIRS}")
   message(STATUS "Found python libraries: ${Python3_LIBRARIES}")
+  if(Python3_NumPy_FOUND)
+    message(STATUS "Found numpy v${Python3_NumPy_VERSION}: ${Python3_NumPy_INCLUDE_DIRS}")
+  else()
+    message(WARNING "Not found numpy (install via 'pip install numpy')")
+  endif()
   mlir_detect_pybind11_install()
   find_package(pybind11 2.6 CONFIG REQUIRED)
   message(STATUS "Found pybind11 v${pybind11_VERSION}: ${pybind11_INCLUDE_DIR}")
   message(STATUS "Python prefix = '${PYTHON_MODULE_PREFIX}', "
                  "suffix = '${PYTHON_MODULE_SUFFIX}', "
                  "extension = '${PYTHON_MODULE_EXTENSION}")
 endif()