Add CMake build flag for generating Python bindings

.github/CHANGELOG.md

@@ -1,4 +1,24 @@
-## Release 0.1.0
+## Release 0.2.0 (development release)
+
+### New features since last release
+
+* Running CMake with `-DBUILD_PYTHON=ON` now generates Python bindings within a `jet` package. [(#1)](https://github.com/XanaduAI/jet/pull/1)
+
+### Improvements
+
+### Breaking Changes
+
+### Bug Fixes
+
+### Documentation
+
+### Contributors
+
+This release contains contributions from (in alphabetical order):
+
+[Mikhail Andrenkov](https://github.com/Mandrenkov).
+
+## Release 0.1.0 (current release)
 
 ### New features since last release
 

.github/workflows/format.yml

@@ -6,6 +6,7 @@ on:
       - main
     paths:
       - "include/**"
+      - "python/**"
       - "test/**"
 
 jobs:
@@ -26,4 +27,4 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Run formatter
-        run: ./bin/format --check include test
+        run: ./bin/format --check include python test

.github/workflows/python.yml

@@ -0,0 +1,85 @@
+name: Python
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - ".github/**"
+      - "docs/**"
+      - "README.rst"
+
+jobs:
+  test-ubuntu:
+    name: Build (Ubuntu)
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Cancel previous runs
+        uses: styfle/[email protected]
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Install dependencies
+        run: sudo apt install -y libopenblas-dev python3.8-dev
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Initialize build directory
+        run: |
+          mkdir build
+          cd build
+          cmake -DBUILD_PYTHON=ON ../
+
+      - name: Generate Python bindings
+        run: |
+          cd build
+          make -j`nproc`
+
+      - name: Create virtual environment
+        run: |
+          cd python
+          make setup
+
+      - name: Run tests
+        run: |
+          cd python
+          make test
+
+  test-macos:
+    name: Build (MacOS)
+    runs-on: macos-10.15
+
+    steps:
+      - name: Cancel previous runs
+        uses: styfle/[email protected]
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Install dependencies
+        run: brew install libomp
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Initialize build directory
+        run: |
+          mkdir build
+          cd build
+          cmake -DBUILD_PYTHON=ON ../
+
+      - name: Generate Python bindings
+        run: |
+          cd build
+          make -j`sysctl -n hw.physicalcpu`
+
+      - name: Create virtual environment
+        run: |
+          cd python
+          make setup
+
+      - name: Run tests
+        run: |
+          cd python
+          make test

.gitignore

@@ -41,8 +41,9 @@ build
 # CMake build artifacts
 include/jet/CmakeMacros.hpp
 
-# Python virtualenv
+# Python
 .venv
+__pycache__
 
 # Sphinx documentation
 docs/__pycache__/*

CMakeLists.txt

@@ -1,7 +1,7 @@
 ##########################
 ## Set Project version
 ##########################
-cmake_minimum_required(VERSION 3.13)
+cmake_minimum_required(VERSION 3.14)
 set(JET_LOGO "
       ▄▄     ▄▄▄▄▄▄▄▄    ▄▄▄▄▄▄▄▄ 
       ██     ██▀▀▀▀▀▀    ▀▀▀██▀▀▀ 
@@ -30,11 +30,12 @@ option(ENABLE_NATIVE "Enable native build tuning" OFF)
 option(ENABLE_IPO "Enable interprocedural/link-time optimisation" OFF)
 
 # Build options
+option(BUILD_PYTHON "Generate Python bindings" OFF)
+option(BUILD_TESTS "Build tests" OFF)
 if(NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE "Release" CACHE STRING
             "Default build type: Release" FORCE)
 endif()
-option(BUILD_TESTS "Build tests" OFF)
 
 ##########################
 ## Enfore Compiler Support
@@ -88,7 +89,7 @@ endif()
 
 
 ##########################
-## Fetch Taskflow
+## Fetch dependencies
 ##########################
 Include(FetchContent)
 
@@ -97,31 +98,30 @@ FetchContent_Declare(
   GIT_REPOSITORY https://github.com/taskflow/taskflow.git
   GIT_TAG        v3.1.0
 )
+FetchContent_Declare(
+  Pybind11
+  GIT_REPOSITORY https://github.com/pybind/pybind11.git
+  GIT_TAG        v2.6.2
+)
 
-# FetchContent_MakeAvailable() requires CMake 3.14 or newer.
-FetchContent_GetProperties(Taskflow)
-if(NOT Taskflow_POPULATED)
-  FetchContent_Populate(Taskflow)
-  # Don't build the Taskflow tests or examples.
-  set(TF_BUILD_EXAMPLES OFF CACHE INTERNAL "Build Taskflow examples")
-  set(TF_BUILD_TESTS OFF CACHE INTERNAL "Build Taskflow tests")
-  add_subdirectory(${taskflow_SOURCE_DIR} ${taskflow_BINARY_DIR})
+# Don't build the Taskflow tests or examples.
+set(TF_BUILD_EXAMPLES OFF CACHE INTERNAL "Build Taskflow examples")
+set(TF_BUILD_TESTS OFF CACHE INTERNAL "Build Taskflow tests")
+
+if(BUILD_PYTHON)
+  FetchContent_MakeAvailable(Taskflow Pybind11)
+else()
+  FetchContent_MakeAvailable(Taskflow)
 endif()
 
 find_package(OpenMP QUIET)
 
-message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
-message(STATUS "BLAS_LIBRARIES: ${BLAS_LIBRARIES}")
-message(STATUS "BLAS_INCLUDE_DIRS: ${BLAS_INCLUDE_DIRS}")
-message(STATUS "ENABLE_NATIVE: ${ENABLE_NATIVE}")
-message(STATUS "ENABLE_IPO: ${ENABLE_IPO}")
-
 ##########################
 ## Create Jet target
 ##########################
 
 add_library(Jet INTERFACE)
-target_include_directories(Jet INTERFACE    
+target_include_directories(Jet INTERFACE
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include> 
     ${BLAS_INCLUDE_DIRS}
 )
@@ -137,24 +137,47 @@ if (ENABLE_OPENMP AND OPENMP_FOUND)
 elseif (ENABLE_OPENMP AND NOT OPENMP_FOUND)
     message(FATAL_ERROR "\nOpenMP is enabled but could not be found")
 endif()
+
 if(ENABLE_SANITIZERS)
     target_compile_options(Jet INTERFACE -g -fsanitize=address,undefined)
     target_link_options(Jet INTERFACE -fsanitize=address,undefined)
 endif()
+
 if(ENABLE_WARNINGS)
     target_compile_options(Jet INTERFACE -Wall -Wextra -Werror)
 endif()
+
 if(ENABLE_NATIVE)
     target_compile_options(Jet INTERFACE -march=native)
 endif()
+
 if(ENABLE_IPO)
     target_compile_options(Jet INTERFACE -flto)
 endif()
 
 ##########################
-## Build tests
+## Report
 ##########################
 
+message(STATUS "BLAS_INCLUDE_DIRS: ${BLAS_INCLUDE_DIRS}")
+message(STATUS "BLAS_LIBRARIES: ${BLAS_LIBRARIES}")
+message(STATUS "BUILD_PYTHON: ${BUILD_PYTHON}")
+message(STATUS "BUILD_TESTS: ${BUILD_TESTS}")
+message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
+message(STATUS "ENABLE_IPO: ${ENABLE_IPO}")
+message(STATUS "ENABLE_NATIVE: ${ENABLE_NATIVE}")
+message(STATUS "ENABLE_SANITIZERS: ${ENABLE_SANITIZERS}")
+message(STATUS "ENABLE_WARNINGS: ${ENABLE_WARNINGS}")
+
+##########################
+## Build targets
+##########################
+
+if(BUILD_PYTHON)
+  pybind11_add_module(jet python/src/Python.cpp)
+  target_link_libraries(jet PRIVATE Jet)
+endif()
+
 if(BUILD_TESTS)
     enable_testing()
     add_subdirectory(test)

Makefile

@@ -30,9 +30,9 @@ help:
 .PHONY: format
 format:
 ifdef check
-	./bin/format --check include test
+	./bin/format --check include python test
 else
-	./bin/format include test
+	./bin/format include python test
 endif
 
 

python/Makefile

@@ -0,0 +1,50 @@
+.VENV_DIR=.venv
+.VENV_BIN=$(.VENV_DIR)/bin
+
+python=python3
+
+define HELP_BODY
+Please use 'make [target]'.
+
+TARGETS
+
+  setup [python=<path>]       Set up virtualenv using the Python interpreter at <path>, defaults to $(python)
+
+  test [args=<pytest args>]   Run tests; use with 'args=<pytest args>' to pass test arguments
+
+  format [check=1]            Apply formatters; use with 'check=1' to check instead of modify
+
+  clean                       Remove all build artifacts
+
+endef
+
+.PHONY: help
+help:
+	@: $(info $(HELP_BODY))
+
+.PHONY: setup
+setup: $(.VENV_DIR)/requirements_test.txt.touch
+
+.PHONY: format
+format:
+ifdef check
+	$(.VENV_BIN)/black --check tests && $(.VENV_BIN)/isort --profile black --check-only tests
+else
+	$(.VENV_BIN)/black tests && $(.VENV_BIN)/isort --profile black tests
+endif
+
+.PHONY: test
+test: $(.VENV_DIR)/requirements_test.txt.touch
+	PYTHONPATH="../build" $(.VENV_BIN)/python -m pytest ./tests $(args)
+
+.PHONY: clean
+clean:
+	rm -rf $(.VENV_DIR)
+
+$(.VENV_DIR)/requirements_test.txt.touch: $(.VENV_DIR)/touch requirements_test.txt
+	$(.VENV_DIR)/bin/pip install -r requirements_test.txt
+	@touch $@
+
+$(.VENV_DIR)/touch:
+	$(python) -m venv ${.VENV_DIR}
+	@touch $@

python/requirements_test.txt

@@ -0,0 +1,3 @@
+black
+isort>5
+pytest>=5,<6

python/src/Python.cpp

@@ -0,0 +1,11 @@
+#include <pybind11/pybind11.h>
+
+#include "Version.hpp"
+
+PYBIND11_MODULE(jet, m)
+{
+    m.doc() = "Jet is a library for simulating quantum circuits using tensor "
+              "network contractions.";
+
+    AddBindingsForVersion(m);
+}

python/src/Version.hpp

@@ -0,0 +1,22 @@
+#include <pybind11/pybind11.h>
+
+#include <Jet.hpp>
+
+namespace py = pybind11;
+
+/**
+ * @brief Adds Python bindings for the include/jet/Version.hpp file.
+ *
+ * @param m Jet pybind11 module.
+ */
+void AddBindingsForVersion(py::module_ &m)
+{
+    m.attr("__version__") = Jet::Version();
+
+    m.def("version", Jet::Version, R"(
+        Returns the current Jet version.
+
+        Returns:
+            String representation of the current Jet version.
+    )");
+}

python/tests/test_version.py

@@ -0,0 +1,14 @@
+import re
+
+import jet
+
+
+class TestVersion:
+    def test_attribute(self):
+        """Tests that the version attribute has the correct form."""
+        semver_pattern = re.compile(r"^\d+\.\d+\.\d+$")
+        assert semver_pattern.match(jet.__version__)
+
+    def test_function(self):
+        """Tests that the version attribute matches the version function."""
+        assert jet.__version__ == jet.version()