Improve Lightning package for external use

.github/CHANGELOG.md

@@ -6,6 +6,9 @@
 
 ### Improvements
 
+* Improve Lightning package structure for external use as a C++ library.
+[(#369)](https://github.com/PennyLaneAI/pennylane-lightning/pull/369)
+
 ### Documentation
 
 ### Bug fixes
@@ -14,6 +17,8 @@
 
 This release contains contributions from (in alphabetical order):
 
+Lee J. O'Riordan
+
 ---
 
 # Release 0.27.0
@@ -99,8 +104,6 @@ def circuit():
     return qml.expval(obs)
 ```
 
-### Documentation
-
 ### Bug fixes
 
 * Test updates to reflect new measurement error messages.
@@ -116,7 +119,7 @@ def circuit():
 
 This release contains contributions from (in alphabetical order):
 
-Amintor Dusko, Christina Lee, Chae-Yeun Park
+Amintor Dusko, Christina Lee, Lee J. O'Riordan, Chae-Yeun Park
 
 ---
 

.github/workflows/tests_linux.yml

@@ -42,11 +42,11 @@ jobs:
 
       - name: Build and run unit tests
         run: |
-            cmake pennylane_lightning/src -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DBUILD_TESTS=ON -DENABLE_KOKKOS=OFF -DENABLE_PYTHON=OFF -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./Build
             cd ./Build
             mkdir -p ./tests/results
-            ./tests/runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
+            ./runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
 
       - name: Upload test results
         uses: actions/upload-artifact@v3
@@ -57,10 +57,10 @@ jobs:
 
       - name: Build and run unit tests for code coverage
         run: |
-            cmake pennylane_lightning/src -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_KOKKOS=OFF -DENABLE_PYTHON=OFF -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./BuildCov
             cd ./BuildCov
-            ./tests/runner
+            ./runner
             lcov --directory . -b ../pennylane_lightning/src --capture --output-file coverage.info
             lcov --remove coverage.info '/usr/*' --output-file coverage.info
             mv coverage.info coverage-${{ github.job }}.info
@@ -109,7 +109,7 @@ jobs:
       - name: Install lightning.qubit device
         run: |
           cd main
-          python setup.py build_ext -i --define="ENABLE_KOKKOS=OFF;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
+          python setup.py build_ext -i --define="ENABLE_KOKKOS=OFF;ENABLE_PYTHON=ON;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
           pip install -e .
 
       - name: Run PennyLane-Lightning unit tests
@@ -155,11 +155,11 @@ jobs:
 
       - name: Build and run unit tests
         run: |
-            cmake pennylane_lightning/src -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_BLAS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_KOKKOS=OFF -DENABLE_PYTHON=OFF -DENABLE_BLAS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./Build
             cd ./Build
             mkdir -p ./tests/results
-            ./tests/runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
+            ./runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
 
       - name: Upload test results
         uses: actions/upload-artifact@v3
@@ -170,10 +170,10 @@ jobs:
 
       - name: Build and run unit tests for code coverage
         run: |
-            cmake pennylane_lightning/src -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_BLAS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_KOKKOS=OFF -DENABLE_PYTHON=OFF -DENABLE_BLAS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./BuildCov
             cd ./BuildCov
-            ./tests/runner
+            ./runner
             lcov --directory . -b ../pennylane_lightning/src --capture --output-file coverage.info
             lcov --remove coverage.info '/usr/*' --output-file coverage.info
             mv coverage.info coverage-${{ github.job }}.info
@@ -227,7 +227,7 @@ jobs:
       - name: Install lightning.qubit device
         run: |
           cd main
-          python setup.py build_ext -i --define="ENABLE_BLAS=ON;ENABLE_KOKKOS=OFF;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
+          python setup.py build_ext -i --define="ENABLE_BLAS=ON;ENABLE_KOKKOS=OFF;ENABLE_PYTHON=ON;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
           pip install -e .
 
       - name: Run PennyLane-Lightning unit tests
@@ -294,11 +294,11 @@ jobs:
 
       - name: Build and run unit tests
         run: |
-            cmake pennylane_lightning/src -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_KOKKOS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_KOKKOS=ON -DENABLE_PYTHON=OFF -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./Build
             cd ./Build
             mkdir -p ./tests/results
-            ./tests/runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
+            ./runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
 
       - name: Upload test results
         uses: actions/upload-artifact@v3
@@ -309,10 +309,10 @@ jobs:
 
       - name: Build and run unit tests for code coverage
         run: |
-            cmake pennylane_lightning/src -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_KOKKOS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_KOKKOS=ON -DENABLE_PYTHON=OFF -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./BuildCov
             cd ./BuildCov
-            ./tests/runner
+            ./runner
             lcov --directory . -b ../pennylane_lightning/src --capture --output-file coverage.info
             lcov --remove coverage.info '/usr/*' --output-file coverage.info
             mv coverage.info coverage-${{ github.job }}.info
@@ -382,7 +382,7 @@ jobs:
       - name: Install lightning.qubit device
         run: |
           cd main
-          python setup.py build_ext -i --define="CMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
+          python setup.py build_ext -i --define="CMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos;ENABLE_KOKKOS=ON;ENABLE_PYTHON=ON;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
           pip install -e .
 
       - name: Run PennyLane-Lightning unit tests
@@ -443,11 +443,11 @@ jobs:
 
       - name: Build and run unit tests
         run: |
-            cmake pennylane_lightning/src -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_BLAS=ON -DENABLE_KOKKOS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuild -DCMAKE_BUILD_TYPE=RelWithDebInfo -DENABLE_BLAS=ON -DENABLE_KOKKOS=ON -DENABLE_PYTHON=OFF -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./Build
             cd ./Build
             mkdir -p ./tests/results
-            ./tests/runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
+            ./runner --order lex --reporter junit --out ./tests/results/report_${{ github.job }}.xml
 
       - name: Upload test results
         uses: actions/upload-artifact@v3
@@ -458,10 +458,10 @@ jobs:
 
       - name: Build and run unit tests for code coverage
         run: |
-            cmake pennylane_lightning/src -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_BLAS=ON -DENABLE_KOKKOS=ON -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
+            cmake . -BBuildCov -DCMAKE_BUILD_TYPE=Debug -DENABLE_BLAS=ON -DENABLE_KOKKOS=ON -DENABLE_PYTHON=OFF -DCMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos -DBUILD_TESTS=ON -DENABLE_COVERAGE=ON -DCMAKE_CXX_COMPILER="$(which g++-$GCC_VERSION)" -G Ninja
             cmake --build ./BuildCov
             cd ./BuildCov
-            ./tests/runner
+            ./runner
             lcov --directory . -b ../pennylane_lightning/src --capture --output-file coverage.info
             lcov --remove coverage.info '/usr/*' --output-file coverage.info
             mv coverage.info coverage-${{ github.job }}.info
@@ -531,7 +531,7 @@ jobs:
       - name: Install lightning.qubit device
         run: |
           cd main
-          python setup.py build_ext -i --define="ENABLE_BLAS=ON;ENABLE_KOKKOS=ON;CMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
+          python setup.py build_ext -i --define="ENABLE_BLAS=ON;ENABLE_KOKKOS=ON;DENABLE_PYTHON=ON;CMAKE_PREFIX_PATH=${{ github.workspace }}/Kokkos;CMAKE_CXX_COMPILER=$(which g++-$GCC_VERSION)"
           pip install -e .
 
       - name: Run PennyLane-Lightning unit tests

CMakeLists.txt

@@ -48,6 +48,8 @@ option(ENABLE_NATIVE "Enable native CPU build tuning" OFF)
 option(ENABLE_OPENMP "Enable OpenMP" ON)
 option(ENABLE_KOKKOS "Enable Kokkos" ON)
 option(ENABLE_BLAS "Enable BLAS" OFF)
+option(ENABLE_PYTHON "Enable compilation of the Python module" ON)
+option(ENABLE_GATE_DISPATCHER "Enable gate kernel dispatching on AVX/AVX2/AVX512" ON)
 
 # Other build options
 option(BUILD_TESTS "Build cpp tests" OFF)
@@ -59,12 +61,17 @@ include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/process_options.cmake")
 set(CMAKE_POLICY_DEFAULT_CMP0127 NEW) # To suppress pybind11 CMP0127 warning
 # Add pybind11
 include(FetchContent)
-FetchContent_Declare(pybind11
-                     GIT_REPOSITORY https://github.com/pybind/pybind11.git
-                     GIT_TAG        v2.10.1
-)
-FetchContent_MakeAvailable(pybind11)
 
+if(ENABLE_PYTHON)
+    find_package(Python COMPONENTS Interpreter Development)
+    FetchContent_Declare(pybind11
+                        GIT_REPOSITORY https://github.com/pybind/pybind11.git
+                        GIT_TAG        v2.10.1
+    )
+    FetchContent_MakeAvailable(pybind11)
+endif()
+
+set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 
 # All CMakeLists.txt in subdirectories use pennylane_lightning_compile_options and pennylane_lightning_external_libs
 add_subdirectory(pennylane_lightning/src)
@@ -76,22 +83,32 @@ add_library(pennylane_lightning INTERFACE)
 
 target_link_libraries(pennylane_lightning INTERFACE     lightning_utils
                                                         lightning_simulator
-                                                        lightning_algorithms)
+                                                        lightning_algorithms
+                                                        lightning_gates
+)
 target_include_directories(pennylane_lightning INTERFACE "pennylane_lightning/src")
 
 #####################################################
+if(ENABLE_PYTHON)
+    pybind11_add_module(lightning_qubit_ops "pennylane_lightning/src/bindings/Bindings.cpp")
+    target_link_libraries(lightning_qubit_ops PRIVATE lightning_algorithms
+                                                      lightning_gates
+                                                      lightning_simulator
+                                                      lightning_utils)
+
+    target_link_libraries(lightning_qubit_ops PRIVATE lightning_compile_options
+                                                      lightning_external_libs)
+    set_target_properties(lightning_qubit_ops PROPERTIES CXX_VISIBILITY_PRESET hidden)
+
+    target_compile_definitions(lightning_qubit_ops PRIVATE VERSION_INFO=${VERSION_STRING})
+endif()
 
-pybind11_add_module(lightning_qubit_ops "pennylane_lightning/src/bindings/Bindings.cpp")
-target_link_libraries(lightning_qubit_ops PRIVATE lightning_algorithms
-                                                  lightning_gates
-                                                  lightning_simulator
-                                                  lightning_utils)
-
-target_link_libraries(lightning_qubit_ops PRIVATE lightning_compile_options
-                                                  lightning_external_libs)
-set_target_properties(lightning_qubit_ops PROPERTIES CXX_VISIBILITY_PRESET hidden)
-
-target_compile_definitions(lightning_qubit_ops PRIVATE VERSION_INFO=${VERSION_STRING})
+install(TARGETS pennylane_lightning
+        RUNTIME DESTINATION bin
+        LIBRARY DESTINATION lib
+        ARCHIVE DESTINATION lib
+        INCLUDES DESTINATION include
+)
 
 if (BUILD_TESTS)
     enable_testing()