Halide pip package for python bindings

CMakeLists.txt

@@ -94,24 +94,6 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
         message(STATUS "Building tests disabled")
     endif ()
 
-    option(WITH_PYTHON_BINDINGS "Build Python bindings" ON)
-    if (WITH_PYTHON_BINDINGS)
-        if (Halide_ENABLE_RTTI AND Halide_ENABLE_EXCEPTIONS)
-            message(STATUS "Building Python bindings enabled")
-            add_subdirectory(python_bindings)
-        else ()
-            if (NOT Halide_ENABLE_RTTI)
-                message(WARNING "Building Python bindings disabled: must compile with RTTI")
-            endif ()
-            if (NOT Halide_ENABLE_EXCEPTIONS)
-                message(WARNING "Building Python bindings disabled: must compile with exceptions")
-            endif ()
-            set(WITH_PYTHON_BINDINGS OFF CACHE BOOL "Build Python bindings" FORCE)
-        endif ()
-    else ()
-        message(STATUS "Building Python bindings disabled")
-    endif ()
-
     option(WITH_TUTORIALS "Build tutorials" ON)
     if (WITH_TUTORIALS)
         message(STATUS "Building tutorials enabled")

cmake/FindHalide.cmake

@@ -0,0 +1,2 @@
+message(VERBOSE " Spoofing find_package(Halide) since in-tree builds already have Halide available.")
+set(Halide_FOUND 1)

packaging/CMakeLists.txt

@@ -45,17 +45,6 @@ foreach (dep IN ITEMS Halide_LLVM Halide_wabt)
     endif ()
 endforeach ()
 
-##
-# Python bindings
-##
-
-if (WITH_PYTHON_BINDINGS)
-    set(Halide_INSTALL_PYTHONDIR "${CMAKE_INSTALL_LIBDIR}/python3/site-packages"
-        CACHE STRING "Path to Halide Python bindings folder")
-    install(TARGETS Halide_Python
-            LIBRARY DESTINATION ${Halide_INSTALL_PYTHONDIR} COMPONENT Halide_Python
-            NAMELINK_COMPONENT Halide_Python)
-endif ()
 
 ##
 # Library-type-agnostic interface targets

python_bindings/CMakeLists.txt

@@ -1,11 +1,16 @@
-##
-# Load Python dependencies, including external pybind11
-##
+cmake_minimum_required(VERSION 3.16...3.23)
+project(Halide_Python)
 
-find_package(Python3 REQUIRED COMPONENTS Interpreter Development)
+set(CMAKE_CXX_STANDARD 17 CACHE STRING "The minimum C++ standard to use")
+option(CMAKE_CXX_STANDARD_REQUIRED "Prevent CMake C++ standard selection decay" ON)
+option(CMAKE_CXX_EXTENSIONS "Enable C++ vendor extensions (e.g. GNU)" OFF)
+
+set(PYBIND11_VER 2.6.2 CACHE STRING "The pybind11 version to use")
 
-set(PYBIND11_VER 2.6.2)
+find_package(Halide REQUIRED)
+find_package(Python3 REQUIRED COMPONENTS Interpreter Development)
 find_package(pybind11 ${PYBIND11_VER} QUIET)
+
 if (NOT pybind11_FOUND)
     include(FetchContent)
     FetchContent_Declare(pybind11
@@ -14,16 +19,4 @@ if (NOT pybind11_FOUND)
     FetchContent_MakeAvailable(pybind11)
 endif ()
 
-##
-# Add our sources to this sub-tree.
-##
-
 add_subdirectory(src)
-add_subdirectory(stub)
-
-option(WITH_TEST_PYTHON "Build Python tests" ON)
-if (WITH_TESTS AND WITH_TEST_PYTHON)
-    add_subdirectory(apps)
-    add_subdirectory(correctness)
-    add_subdirectory(tutorial)
-endif ()

python_bindings/pyproject.toml

@@ -0,0 +1,10 @@
+[build-system]
+requires = [
+  "setuptools>=42",
+  "wheel",
+  "scikit-build",
+  "pybind11==2.6.2",
+  "cmake>=3.22",
+  "ninja; platform_system!='Windows'"
+]
+build-backend = "setuptools.build_meta"

python_bindings/setup.py

@@ -0,0 +1,29 @@
+from skbuild import setup
+from setuptools import find_packages
+import pybind11
+
+with open("version.py", "r") as f:
+    version = f.read().strip().split(" ")[-1][1:-1]
+
+with open("readme.md", "r") as fp:
+    long_description = fp.read()
+
+setup(
+    name="halide",
+    version=version,
+    author="The Halide team",
+    author_email="",
+    description="",
+    long_description=long_description,
+    python_requires=">=3.6",
+    packages=find_packages(where="src"),
+    package_dir={"": "src"},
+    cmake_install_dir="src/halide",
+    cmake_args=[
+        f"-Dpybind11_ROOT={pybind11.get_cmake_dir()}",
+        "-DCMAKE_REQUIRE_FIND_PACKAGE_pybind11=YES",
+    ],
+    include_package_data=True,
+    extras_require={"test": ["pytest>=6.0"]},
+    zip_safe=False,
+)

python_bindings/src/CMakeLists.txt

@@ -28,22 +28,7 @@ set(SOURCES
     PyVar.cpp
     PyVarOrRVar.cpp
     )
-
-pybind11_add_module(Halide_Python MODULE ${SOURCES})
-add_library(Halide::Python ALIAS Halide_Python)
-set_target_properties(Halide_Python
-                      PROPERTIES
-                      LIBRARY_OUTPUT_NAME halide
-                      EXPORT_NAME Python)
-target_link_libraries(Halide_Python PRIVATE Halide::Halide)
-
-if (WIN32 AND BUILD_SHARED_LIBS)
-    # There's precious little information about why Python only sometimes prevents DLLs from loading from the PATH on Windows.
-    # This workaround places a copy of Halide.dll next to our Python module.
-    # Ref: https://stackoverflow.com/questions/59860465/pybind11-importerror-dll-not-found-when-trying-to-import-pyd-in-python-int
-    # Ref: https://bugs.python.org/issue36085
-    # Ref: https://docs.python.org/3/whatsnew/3.8.html#bpo-36085-whatsnew
-    add_custom_command(TARGET Halide_Python POST_BUILD
-                       COMMAND ${CMAKE_COMMAND} -E copy_if_different $<TARGET_FILE:Halide::Halide> $<TARGET_FILE_DIR:Halide::Python>
-                       VERBATIM)
-endif ()
+
+pybind11_add_module(halide_ MODULE ${SOURCES})
+target_link_libraries(halide_ PRIVATE Halide::Halide)
+install(TARGETS halide_ DESTINATION .)

python_bindings/src/PyHalide.cpp

@@ -31,7 +31,7 @@ static_assert(PY_VERSION_HEX >= 0x03000000,
               "We appear to be compiling against Python 2.x rather than 3.x, which is not supported.");
 
 #ifndef HALIDE_PYBIND_MODULE_NAME
-#define HALIDE_PYBIND_MODULE_NAME halide
+#define HALIDE_PYBIND_MODULE_NAME halide_
 #endif
 
 PYBIND11_MODULE(HALIDE_PYBIND_MODULE_NAME, m) {

python_bindings/src/halide/__init__.py

@@ -0,0 +1 @@
+from .halide_ import *

python_bindings/version.py

@@ -0,0 +1 @@
+__version__ = '1.0.0'