Merge pull request #207 from dean0x7d/cmake

Simplify CMake build using add_subdirectory

Author: wjakob

.travis.yml

@@ -9,6 +9,7 @@ addons:
     sources:
       - ubuntu-toolchain-r-test
       - deadsnakes
+      - kubuntu-backports # cmake 2.8.12
     packages:
       - g++-4.8
       - g++-4.8-multilib
@@ -17,6 +18,7 @@ addons:
       - python3.5-dev
       - python3.5-venv
       - python3.5-dev:i386
+      - cmake
 matrix:
   include:
     - os: linux

CMakeLists.txt

@@ -5,187 +5,62 @@
 # All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 2.8.12)
 
 project(pybind11)
 
-option(PYBIND11_INSTALL "Install pybind11 header files?" ON)
+# Check if pybind11 is being used directly or via add_subdirectory
+set(PYBIND11_MASTER_PROJECT OFF)
+if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
+  set(PYBIND11_MASTER_PROJECT ON)
+endif ()
+
+option(PYBIND11_INSTALL "Install pybind11 header files?" ${PYBIND11_MASTER_PROJECT})
+option(PYBIND11_TEST "Build tests?" ${PYBIND11_MASTER_PROJECT})
 
 # Add a CMake parameter for choosing a desired Python version
 set(PYBIND11_PYTHON_VERSION "" CACHE STRING "Python version to use for compiling the example application")
 
-include(CheckCXXCompilerFlag)
-
-# Set a default build configuration if none is specified. 'MinSizeRel' produces the smallest binaries
-if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
-  message(STATUS "Setting build type to 'MinSizeRel' as none was specified.")
-  set(CMAKE_BUILD_TYPE MinSizeRel CACHE STRING "Choose the type of build." FORCE)
-  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
-    "MinSizeRel" "RelWithDebInfo")
-endif()
-string(TOUPPER "${CMAKE_BUILD_TYPE}" U_CMAKE_BUILD_TYPE)
-
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/tools")
 set(Python_ADDITIONAL_VERSIONS 3.4 3.5 3.6 3.7)
-if (NOT ${PYBIND11_PYTHON_VERSION} STREQUAL "")
-  find_package(PythonLibs ${PYBIND11_PYTHON_VERSION} EXACT)
-  if (NOT PYTHONLIBS_FOUND)
-    find_package(PythonLibs ${PYBIND11_PYTHON_VERSION} REQUIRED)
-  endif()
-else()
-  find_package(PythonLibs REQUIRED)
-endif()
-# The above sometimes returns version numbers like "3.4.3+"; the "+" must be removed for the next line to work
-string(REPLACE "+" "" PYTHONLIBS_VERSION_STRING "+${PYTHONLIBS_VERSION_STRING}")
-find_package(PythonInterp ${PYTHONLIBS_VERSION_STRING} EXACT REQUIRED)
+find_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} REQUIRED)
+
+include(CheckCXXCompilerFlag)
 
-if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-  CHECK_CXX_COMPILER_FLAG("-std=c++14" HAS_CPP14_FLAG)
-  CHECK_CXX_COMPILER_FLAG("-std=c++11" HAS_CPP11_FLAG)
+if(NOT MSVC AND NOT PYBIND11_CPP_STANDARD)
+  check_cxx_compiler_flag("-std=c++14" HAS_CPP14_FLAG)
+  check_cxx_compiler_flag("-std=c++11" HAS_CPP11_FLAG)
 
   if (HAS_CPP14_FLAG)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
+    set(PYBIND11_CPP_STANDARD -std=c++14)
   elseif (HAS_CPP11_FLAG)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+    set(PYBIND11_CPP_STANDARD -std=c++11)
   else()
     message(FATAL_ERROR "Unsupported compiler -- pybind11 requires C++11 support!")
   endif()
 
-  # Enable link time optimization and set the default symbol
-  # visibility to hidden (very important to obtain small binaries)
-  if (NOT ${U_CMAKE_BUILD_TYPE} MATCHES DEBUG)
-    # Default symbol visibility
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
-
-    # Check for Link Time Optimization support
-    # (GCC/Clang)
-    CHECK_CXX_COMPILER_FLAG("-flto" HAS_LTO_FLAG)
-    if (HAS_LTO_FLAG)
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -flto")
-    endif()
-
-    # Intel equivalent to LTO is called IPO
-    if (CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-      CHECK_CXX_COMPILER_FLAG("-ipo" HAS_IPO_FLAG)
-      if (HAS_IPO_FLAG)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ipo")
-      endif()
-    endif()
-  endif()
-endif()
-
-# Compile with compiler warnings turned on
-if(MSVC)
-  if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
-    string(REGEX REPLACE "/W[0-4]" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-  else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
-  endif()
-elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra")
+  set(PYBIND11_CPP_STANDARD ${PYBIND11_CPP_STANDARD} CACHE STRING
+      "C++ standard flag, e.g. -std=c++11 or -std=c++14. Defaults to latest available.")
 endif()
 
+# Cache variables so pybind11_add_module can be used in parent projects
+set(PYBIND11_INCLUDE_DIR "${CMAKE_CURRENT_LIST_DIR}/include" CACHE INTERNAL "")
+set(PYTHON_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS} CACHE INTERNAL "")
+set(PYTHON_LIBRARIES ${PYTHON_LIBRARIES} CACHE INTERNAL "")
+set(PYTHON_MODULE_PREFIX ${PYTHON_MODULE_PREFIX} CACHE INTERNAL "")
+set(PYTHON_MODULE_EXTENSION ${PYTHON_MODULE_EXTENSION} CACHE INTERNAL "")
 
-# Check if Eigen is available
-set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/tools")
-find_package(Eigen3 QUIET)
-
-# Include path for pybind11 header files
-include_directories(include)
-
-# Include path for Python header files
-include_directories(${PYTHON_INCLUDE_DIR})
-
-set(PYBIND11_HEADERS
-  include/pybind11/attr.h
-  include/pybind11/cast.h
-  include/pybind11/common.h
-  include/pybind11/complex.h
-  include/pybind11/descr.h
-  include/pybind11/eigen.h
-  include/pybind11/functional.h
-  include/pybind11/numpy.h
-  include/pybind11/operators.h
-  include/pybind11/pybind11.h
-  include/pybind11/pytypes.h
-  include/pybind11/stl.h
-  include/pybind11/stl_bind.h
-  include/pybind11/typeid.h
-)
-
-set(PYBIND11_EXAMPLES
-  example/example1.cpp
-  example/example2.cpp
-  example/example3.cpp
-  example/example4.cpp
-  example/example5.cpp
-  example/example6.cpp
-  example/example7.cpp
-  example/example8.cpp
-  example/example9.cpp
-  example/example10.cpp
-  example/example11.cpp
-  example/example12.cpp
-  example/example13.cpp
-  example/example14.cpp
-  example/example15.cpp
-  example/example16.cpp
-  example/example17.cpp
-  example/issues.cpp
-)
-
-if (EIGEN3_FOUND)
-  include_directories(${EIGEN3_INCLUDE_DIR})
-  list(APPEND PYBIND11_EXAMPLES example/eigen.cpp)
-  add_definitions(-DPYBIND11_TEST_EIGEN)
-  message(STATUS "Building Eigen testcase")
-else()
-  message(STATUS "NOT Building Eigen testcase")
-endif()
-
-# Create the binding library
-add_library(example SHARED
-  ${PYBIND11_HEADERS}
-  example/example.cpp
-  ${PYBIND11_EXAMPLES}
-)
-
-# Don't add a 'lib' prefix to the shared library
-set_target_properties(example PROPERTIES PREFIX "")
-
-# Always write the output file directly into the 'example' directory (even on MSVC)
-set(CompilerFlags
-  LIBRARY_OUTPUT_DIRECTORY LIBRARY_OUTPUT_DIRECTORY_RELEASE LIBRARY_OUTPUT_DIRECTORY_DEBUG
-  LIBRARY_OUTPUT_DIRECTORY_MINSIZEREL LIBRARY_OUTPUT_DIRECTORY_RELWITHDEBINFO
-  RUNTIME_OUTPUT_DIRECTORY RUNTIME_OUTPUT_DIRECTORY_RELEASE RUNTIME_OUTPUT_DIRECTORY_DEBUG
-  RUNTIME_OUTPUT_DIRECTORY_MINSIZEREL RUNTIME_OUTPUT_DIRECTORY_RELWITHDEBINFO)
-
-foreach(CompilerFlag ${CompilerFlags})
-  set_target_properties(example PROPERTIES ${CompilerFlag} ${PROJECT_SOURCE_DIR}/example)
-endforeach()
-
-if (WIN32)
-  if (MSVC)
-    # /MP enables multithreaded builds (relevant when there are many files), /bigobj is
-    # needed for bigger binding projects due to the limit to 64k addressable sections
-    set_property(TARGET example APPEND PROPERTY COMPILE_OPTIONS /MP /bigobj)
-    # Enforce size-based optimization and link time code generation on MSVC
-    # (~30% smaller binaries in experiments); do nothing in debug mode.
-    set_property(TARGET example APPEND PROPERTY COMPILE_OPTIONS
-      "$<$<CONFIG:Release>:/Os>" "$<$<CONFIG:Release>:/GL>"
-      "$<$<CONFIG:MinSizeRel>:/Os>" "$<$<CONFIG:MinSizeRel>:/GL>"
-      "$<$<CONFIG:RelWithDebInfo>:/Os>" "$<$<CONFIG:RelWithDebInfo>:/GL>"
-    )
-    set_property(TARGET example APPEND_STRING PROPERTY LINK_FLAGS_RELEASE "/LTCG ")
-    set_property(TARGET example APPEND_STRING PROPERTY LINK_FLAGS_MINSIZEREL "/LTCG ")
-    set_property(TARGET example APPEND_STRING PROPERTY LINK_FLAGS_RELWITHDEBINFO "/LTCG ")
-  endif()
+# Build a Python extension module:
+# pybind11_add_module(<name> source1 [source2 ...])
+#
+function(pybind11_add_module target_name)
+  add_library(${target_name} MODULE ${ARGN})
+  target_include_directories(${target_name} PUBLIC ${PYBIND11_INCLUDE_DIR} ${PYTHON_INCLUDE_DIRS})
 
-  # .PYD file extension on Windows
-  set_target_properties(example PROPERTIES SUFFIX ".pyd")
+  # The prefix and extension are provided by FindPythonLibsNew.cmake
+  set_target_properties(${target_name} PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX}")
+  set_target_properties(${target_name} PROPERTIES SUFFIX "${PYTHON_MODULE_EXTENSION}")
 
-  # Link against the Python shared library
-  target_link_libraries(example ${PYTHON_LIBRARY})
-elseif (UNIX)
   # It's quite common to have multiple copies of the same Python version
   # installed on one's system. E.g.: one copy from the OS and another copy
   # that's statically linked into an application like Blender or Maya.
@@ -199,41 +74,94 @@ elseif (UNIX)
   # link against the Python library. The resulting shared library will have
   # missing symbols, but that's perfectly fine -- they will be resolved at
   # import time.
-
-  # .SO file extension on Linux/Mac OS
-  set_target_properties(example PROPERTIES SUFFIX ".so")
-
-  # Optimize for a small binary size
-  if (NOT ${U_CMAKE_BUILD_TYPE} MATCHES DEBUG)
-    set_target_properties(example PROPERTIES COMPILE_FLAGS "-Os")
+  if(MSVC)
+    target_link_libraries(${target_name} PRIVATE ${PYTHON_LIBRARIES})
+  elseif(APPLE)
+    # Make sure OS X does not have any issues with missing symbols
+    target_link_libraries(${target_name} PRIVATE "-undefined dynamic_lookup")
   endif()
 
-  # Strip unnecessary sections of the binary on Linux/Mac OS
-  if(APPLE)
-    set_target_properties(example PROPERTIES MACOSX_RPATH ".")
-    set_target_properties(example PROPERTIES LINK_FLAGS "-undefined dynamic_lookup ")
-    if (NOT ${U_CMAKE_BUILD_TYPE} MATCHES DEBUG)
-      add_custom_command(TARGET example POST_BUILD COMMAND strip -u -r ${PROJECT_SOURCE_DIR}/example/example.so)
-    endif()
-  else()
+  if(NOT MSVC)
+    # Make sure C++11/14 are enabled
+    target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})
+
+    # Enable link time optimization and set the default symbol
+    # visibility to hidden (very important to obtain small binaries)
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" U_CMAKE_BUILD_TYPE)
     if (NOT ${U_CMAKE_BUILD_TYPE} MATCHES DEBUG)
-      add_custom_command(TARGET example POST_BUILD COMMAND strip ${PROJECT_SOURCE_DIR}/example/example.so)
+      # Check for Link Time Optimization support (GCC/Clang)
+      check_cxx_compiler_flag("-flto" HAS_LTO_FLAG)
+      if(HAS_LTO_FLAG)
+        target_compile_options(${target_name} PRIVATE -flto)
+      endif()
+
+      # Intel equivalent to LTO is called IPO
+      if(CMAKE_CXX_COMPILER_ID MATCHES "Intel")
+        check_cxx_compiler_flag("-ipo" HAS_IPO_FLAG)
+        if(HAS_IPO_FLAG)
+          target_compile_options(${target_name} PRIVATE -ipo)
+        endif()
+      endif()
+
+      # Default symbol visibility
+      target_compile_options(${target_name} PRIVATE "-fvisibility=hidden")
+
+      # Strip unnecessary sections of the binary on Linux/Mac OS
+      if(CMAKE_STRIP)
+        if(APPLE)
+          add_custom_command(TARGET ${target_name} POST_BUILD
+                             COMMAND ${CMAKE_STRIP} -u -r $<TARGET_FILE:${target_name}>)
+        else()
+          add_custom_command(TARGET ${target_name} POST_BUILD
+                             COMMAND ${CMAKE_STRIP} $<TARGET_FILE:${target_name}>)
+        endif()
+      endif()
     endif()
+  elseif(MSVC)
+    # /MP enables multithreaded builds (relevant when there are many files), /bigobj is
+    # needed for bigger binding projects due to the limit to 64k addressable sections
+    target_compile_options(${target_name} PRIVATE /MP /bigobj)
+
+    # Enforce link time code generation on MSVC, except in debug mode
+    target_compile_options(${target_name} PRIVATE $<$<NOT:$<CONFIG:Debug>>:/GL>)
+    # Fancy generator expressions don't work with linker flags, for reasons unknown
+    set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS_RELEASE /LTCG)
+    set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS_MINSIZEREL /LTCG)
+    set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS_RELWITHDEBINFO /LTCG)
   endif()
-endif()
+endfunction()
 
-enable_testing()
+# Compile with compiler warnings turned on
+function(pybind11_turn_on_warnings target_name)
+  if(MSVC)
+    target_compile_options(${target_name} PRIVATE /W4)
+  else()
+    target_compile_options(${target_name} PRIVATE -Wall -Wextra)
+  endif()
+endfunction()
 
-set(RUN_TEST ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/example/run_test.py)
-if (MSVC OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-  set(RUN_TEST ${RUN_TEST} --relaxed)
+if (PYBIND11_TEST)
+  enable_testing()
+  add_subdirectory(example)
 endif()
 
-foreach(VALUE ${PYBIND11_EXAMPLES})
-  string(REGEX REPLACE "^example/(.+).cpp$" "\\1" EXAMPLE_NAME "${VALUE}")
-  add_test(NAME ${EXAMPLE_NAME} COMMAND ${RUN_TEST} ${EXAMPLE_NAME})
-endforeach()
-
 if (PYBIND11_INSTALL)
-    install(FILES ${PYBIND11_HEADERS} DESTINATION include/pybind11)
+  set(PYBIND11_HEADERS
+    include/pybind11/attr.h
+    include/pybind11/cast.h
+    include/pybind11/common.h
+    include/pybind11/complex.h
+    include/pybind11/descr.h
+    include/pybind11/eigen.h
+    include/pybind11/functional.h
+    include/pybind11/numpy.h
+    include/pybind11/operators.h
+    include/pybind11/pybind11.h
+    include/pybind11/pytypes.h
+    include/pybind11/stl.h
+    include/pybind11/stl_bind.h
+    include/pybind11/typeid.h
+  )
+
+  install(FILES ${PYBIND11_HEADERS} DESTINATION include/pybind11)
 endif()