Support disabling builds of the command-line tools and unit tests, and using an external compiler.

c++/CMakeLists.txt

 
+option(BUILD_TOOLS "Build command-line tools and compiler." ON)
+option(BUILD_TESTING "Build unit tests and enable CTest 'check' target." ON)
+option(EXTERNAL_CAPNP "Use the system capnp binary, or the one specified in $CAPNP, instead of using the compiled one." OFF)
+
+if (NOT BUILD_TOOLS AND BUILD_TESTING AND NOT EXTERNAL_CAPNP)
+  message(WARNING "Forcing BUILD_TOOLS to ON; required by BUILD_TESTING without EXTERNAL_CAPNP.")
+  set(BUILD_TOOLS TRUE)
+endif()
+
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter -std=c++11 -pthread")
 
 add_subdirectory(src)

c++/src/CMakeLists.txt

@@ -148,41 +148,57 @@ set(capnpc_headers
   capnp/rpc-twoparty.capnp
 )
 
-add_executable(capnp-tool
+if(BUILD_TOOLS)
+  add_executable(capnp-tool
     capnp/compiler/module-loader.c++
     capnp/compiler/capnp.c++
-)
-target_link_libraries(capnp-tool capnpc capnp kj)
-set_target_properties(capnp-tool PROPERTIES OUTPUT_NAME capnp)
+  )
+  target_link_libraries(capnp-tool capnpc capnp kj)
+  set_target_properties(capnp-tool PROPERTIES OUTPUT_NAME capnp)
 
-add_executable(capnpc_cpp
+  add_executable(capnpc_cpp
     capnp/compiler/capnpc-c++.c++
-)
-target_link_libraries(capnpc_cpp capnp kj)
-set_target_properties(capnpc_cpp PROPERTIES OUTPUT_NAME capnpc-c++)
+  )
+  target_link_libraries(capnpc_cpp capnp kj)
+  set_target_properties(capnpc_cpp PROPERTIES OUTPUT_NAME capnpc-c++)
 
-add_executable(capnpc_capnp
+  add_executable(capnpc_capnp
     capnp/compiler/capnpc-capnp.c++
-)
-target_link_libraries(capnpc_capnp capnp kj)
-set_target_properties(capnpc_capnp PROPERTIES OUTPUT_NAME capnpc-capnp)
+  )
+  target_link_libraries(capnpc_capnp capnp kj)
+  set_target_properties(capnpc_capnp PROPERTIES OUTPUT_NAME capnpc-capnp)
+endif()  # BUILD_TOOLS
 
 # Install ==============================================================
 
-export(TARGETS capnp capnp-tool capnp-rpc capnpc capnpc_cpp capnpc_capnp kj kj-async
+if(BUILD_TOOLS)
+  export(TARGETS capnp capnp-tool capnp-rpc capnpc capnpc_cpp capnpc_capnp kj kj-async
     FILE ${CMAKE_CURRENT_BINARY_DIR}/capnp-config.cmake
-)
+  )
+else()
+  export(TARGETS capnp capnp-rpc capnpc kj kj-async
+    FILE ${CMAKE_CURRENT_BINARY_DIR}/capnp-config.cmake
+  )
+endif()
 export(PACKAGE capnp)
 
-install(TARGETS capnp capnp-tool capnp-rpc capnpc capnpc_cpp capnpc_capnp kj kj-async
+if(BUILD_TOOLS)
+  install(TARGETS capnp capnp-tool capnp-rpc capnpc capnpc_cpp capnpc_capnp kj kj-async
     EXPORT capnp
     RUNTIME DESTINATION bin
     LIBRARY DESTINATION lib
     ARCHIVE DESTINATION lib
-)
+  )
 
-# Symlink capnpc -> capnp
-install(CODE "execute_process(COMMAND \"${CMAKE_COMMAND}\" -E create_symlink capnp ${CMAKE_INSTALL_PREFIX}/bin/capnpc)")
+  # Symlink capnpc -> capnp
+  install(CODE "execute_process(COMMAND \"${CMAKE_COMMAND}\" -E create_symlink capnp ${CMAKE_INSTALL_PREFIX}/bin/capnpc)")
+else()
+  install(TARGETS capnp capnp-rpc capnpc kj kj-async
+    EXPORT capnp
+    LIBRARY DESTINATION lib
+    ARCHIVE DESTINATION lib
+  )
+endif()
 
 install(FILES ${kj_headers} DESTINATION include/kj)
 install(FILES ${kj-async_headers} DESTINATION include/kj)
@@ -193,48 +209,73 @@ install(FILES ${capnpc_headers} DESTINATION include/capnp)
 
 # Tests ==============================================================
 
-# Setup googletest build and library targets (gtest and gtest_main)
-include(ExternalProject)
-ExternalProject_Add(gtest_build
+if(BUILD_TESTING)
+  # Setup googletest build and library targets (gtest and gtest_main)
+  include(ExternalProject)
+  ExternalProject_Add(gtest_build
     URL http://googletest.googlecode.com/files/gtest-1.7.0.zip
     URL_HASH SHA1=f85f6d2481e2c6c4a18539e391aa4ea8ab0394af
     CMAKE_ARGS -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
     INSTALL_COMMAND ""  # Disable install
-)
+  )
 
-ExternalProject_Get_Property(gtest_build binary_dir)
+  ExternalProject_Get_Property(gtest_build binary_dir)
 
-add_library(gtest UNKNOWN IMPORTED)
-set_property(TARGET gtest
+  add_library(gtest UNKNOWN IMPORTED)
+  set_property(TARGET gtest
     PROPERTY IMPORTED_LOCATION ${binary_dir}/${CMAKE_FIND_LIBRARY_PREFIXES}gtest.a
-)
-add_dependencies(gtest gtest_build)
+  )
+  add_dependencies(gtest gtest_build)
 
-add_library(gtest_main UNKNOWN IMPORTED)
-set_property(TARGET gtest_main
+  add_library(gtest_main UNKNOWN IMPORTED)
+  set_property(TARGET gtest_main
     PROPERTY IMPORTED_LOCATION ${binary_dir}/${CMAKE_FIND_LIBRARY_PREFIXES}gtest_main.a
-)
-add_dependencies(gtest_main gtest)
+  )
+  add_dependencies(gtest_main gtest)
 
-ExternalProject_Get_Property(gtest_build source_dir)
-include_directories(${source_dir}/include)
+  ExternalProject_Get_Property(gtest_build source_dir)
+  include_directories(${source_dir}/include)
 
-set(test_capnp_files
+  set(test_capnp_files
     capnp/test.capnp
     capnp/test-import.capnp
     capnp/test-import2.capnp
-)
-
-set(CAPNP_EXECUTABLE $<TARGET_FILE:capnp-tool>)
-set(CAPNPC_CXX_EXECUTABLE $<TARGET_FILE:capnpc_cpp>)
-set(CAPNPC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/test_capnp)
-file(MAKE_DIRECTORY ${CAPNPC_OUTPUT_DIR})
-
-capnp_generate_cpp(test_capnp_cpp_files test_capnp_h_files ${test_capnp_files})
-
-include_directories(${CAPNPC_OUTPUT_DIR})
-
-add_executable(capnp-tests
+  )
+
+  # Setup paths to the schema compiler for generating ${test_capnp_files}
+  if(NOT EXTERNAL_CAPNP)
+    set(CAPNP_EXECUTABLE $<TARGET_FILE:capnp-tool>)
+    set(CAPNPC_CXX_EXECUTABLE $<TARGET_FILE:capnpc_cpp>)
+  else()
+    # Allow paths to tools to be set with one of: (1) the CMake variables from the
+    # the FindCapnProto module; (2) environment variables; or (3) find_program()
+    if (NOT CAPNP_EXECUTABLE)
+      if (DEFINED ENV{CAPNP})
+        set(CAPNP_EXECUTABLE $ENV{CAPNP})
+      else()
+        find_program(CAPNP_EXECUTABLE capnp)
+      endif()
+    endif()
+
+    if(NOT CAPNPC_CXX_EXECUTABLE)
+      if (DEFINED ENV{CAPNPC_CXX})
+        set(CAPNPC_CXX_EXECUTABLE $ENV{CAPNPC_CXX})
+      else()
+        # Also search in the same directory that `capnp` was found in
+        get_filename_component(capnp_dir ${CAPNP_EXECUTABLE} DIRECTORY)
+        find_program(CAPNPC_CXX_EXECUTABLE capnpc-c++ HINTS ${capnp_dir})
+      endif()
+    endif()
+  endif()
+
+  set(CAPNPC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/test_capnp)
+  file(MAKE_DIRECTORY ${CAPNPC_OUTPUT_DIR})
+
+  capnp_generate_cpp(test_capnp_cpp_files test_capnp_h_files ${test_capnp_files})
+
+  include_directories(${CAPNPC_OUTPUT_DIR})
+
+  add_executable(capnp-tests
     kj/common-test.c++
     kj/memory-test.c++
     kj/refcount-test.c++
@@ -283,8 +324,8 @@ add_executable(capnp-tests
     capnp/compiler/md5-test.c++
     ${test_capnp_cpp_files}
     ${test_capnp_h_files}
-)
-target_link_libraries(capnp-tests
+  )
+  target_link_libraries(capnp-tests
     capnpc
     capnp-rpc
     capnp
@@ -292,16 +333,17 @@ target_link_libraries(capnp-tests
     kj
     gtest
     gtest_main
-)
+  )
 
-add_executable(capnp-evolution-tests capnp/compiler/evolution-test.c++)
-target_link_libraries(capnp-evolution-tests capnpc capnp kj)
+  add_executable(capnp-evolution-tests capnp/compiler/evolution-test.c++)
+  target_link_libraries(capnp-evolution-tests capnpc capnp kj)
 
-include(CTest)
-add_test(NAME capnp-tests-run COMMAND capnp-tests)
-add_test(NAME capnp-evolution-tests-run COMMAND capnp-evolution-tests)
+  include(CTest)
+  add_test(NAME capnp-tests-run COMMAND capnp-tests)
+  add_test(NAME capnp-evolution-tests-run COMMAND capnp-evolution-tests)
 
-# Sadly, we can't use the 'test' target, as that's coopted by ctest
-add_custom_target(check ${CMAKE_CTEST_COMMAND} -V)
-add_dependencies(check capnp-tests)
-add_dependencies(check capnp-evolution-tests)
+  # Sadly, we can't use the 'test' target, as that's coopted by ctest
+  add_custom_target(check ${CMAKE_CTEST_COMMAND} -V)
+  add_dependencies(check capnp-tests)
+  add_dependencies(check capnp-evolution-tests)
+endif()  # BUILD_TESTING