1# Macros and functions related to detecting details of the Python environment.
2
3# Finds and configures python packages needed to build MLIR Python bindings.
4macro(mlir_configure_python_dev_packages)
5  if(CMAKE_VERSION VERSION_LESS "3.15.0")
6  message(SEND_ERROR
7      "Building MLIR Python bindings is known to rely on CMake features "
8      "that require at least version 3.15. Recommend upgrading to 3.18+ "
9      "for full support. Detected current version: ${CMAKE_VERSION}")
10  endif()
11
12  # After CMake 3.18, we are able to limit the scope of the search to just
13  # Development.Module. Searching for Development will fail in situations where
14  # the Python libraries are not available. When possible, limit to just
15  # Development.Module.
16  # See https://pybind11.readthedocs.io/en/stable/compiling.html#findpython-mode
17  if(CMAKE_VERSION VERSION_LESS "3.18.0")
18    message(WARNING
19        "This version of CMake is not compatible with statically built Python "
20        "installations. If Python fails to detect below this may apply to you. "
21        "Recommend upgrading to at least CMake 3.18. "
22        "Detected current version: ${CMAKE_VERSION}"
23    )
24    set(_python_development_component Development)
25  else()
26    if(MLIR_DETECT_PYTHON_ENV_PRIME_SEARCH)
27      # Prime the search for python to see if there is a full development
28      # package. This seems to work around cmake bugs searching only for
29      # Development.Module in some environments. However, in other environments
30      # it may interfere with the subsequent search for Development.Module.
31      find_package(Python3 ${LLVM_MINIMUM_PYTHON_VERSION}
32        COMPONENTS Interpreter Development)
33    endif()
34    set(_python_development_component Development.Module)
35  endif()
36  find_package(Python3 ${LLVM_MINIMUM_PYTHON_VERSION}
37    COMPONENTS Interpreter ${_python_development_component} NumPy REQUIRED)
38  unset(_python_development_component)
39  message(STATUS "Found python include dirs: ${Python3_INCLUDE_DIRS}")
40  message(STATUS "Found python libraries: ${Python3_LIBRARIES}")
41  message(STATUS "Found numpy v${Python3_NumPy_VERSION}: ${Python3_NumPy_INCLUDE_DIRS}")
42  mlir_detect_pybind11_install()
43  find_package(pybind11 2.8 CONFIG REQUIRED)
44  message(STATUS "Found pybind11 v${pybind11_VERSION}: ${pybind11_INCLUDE_DIR}")
45  message(STATUS "Python prefix = '${PYTHON_MODULE_PREFIX}', "
46                 "suffix = '${PYTHON_MODULE_SUFFIX}', "
47                 "extension = '${PYTHON_MODULE_EXTENSION}")
48endmacro()
49
50# Detects a pybind11 package installed in the current python environment
51# and sets variables to allow it to be found. This allows pybind11 to be
52# installed via pip, which typically yields a much more recent version than
53# the OS install, which will be available otherwise.
54function(mlir_detect_pybind11_install)
55  if(pybind11_DIR)
56    message(STATUS "Using explicit pybind11 cmake directory: ${pybind11_DIR} (-Dpybind11_DIR to change)")
57  else()
58    message(STATUS "Checking for pybind11 in python path...")
59    execute_process(
60      COMMAND "${Python3_EXECUTABLE}"
61      -c "import pybind11;print(pybind11.get_cmake_dir(), end='')"
62      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
63      RESULT_VARIABLE STATUS
64      OUTPUT_VARIABLE PACKAGE_DIR
65      ERROR_QUIET)
66    if(NOT STATUS EQUAL "0")
67      message(STATUS "not found (install via 'pip install pybind11' or set pybind11_DIR)")
68      return()
69    endif()
70    message(STATUS "found (${PACKAGE_DIR})")
71    set(pybind11_DIR "${PACKAGE_DIR}" PARENT_SCOPE)
72  endif()
73endfunction()
74