jpayne@68: # This CMake script adds imported targets for each shared library and executable distributed by
jpayne@68: # Cap'n Proto's autotools build.
jpayne@68: #
jpayne@68: # This file IS NOT USED by the CMake build! The CMake build generates its own version of this script
jpayne@68: # from its set of exported targets. I used such a generated script as a reference when writing this
jpayne@68: # one.
jpayne@68: #
jpayne@68: # The set of library targets provided by this script is automatically generated from the list of .pc
jpayne@68: # files maintained in configure.ac. The set of executable targets is hard-coded in this file.
jpayne@68: #
jpayne@68: # You can request that this script print debugging information by invoking cmake with:
jpayne@68: #
jpayne@68: #   -DCapnProto_DEBUG=ON
jpayne@68: #
jpayne@68: # TODO(someday): Distinguish between debug and release builds. I.e., set IMPORTED_LOCATION_RELEASE
jpayne@68: #   rather than IMPORTED_LOCATION, etc., if this installation was configured as a release build. But
jpayne@68: #   how do we tell? grep for -g in CXXFLAGS?
jpayne@68: 
jpayne@68: if(CMAKE_VERSION VERSION_LESS 3.1)
jpayne@68:   message(FATAL_ERROR "CMake >= 3.1 required")
jpayne@68: endif()
jpayne@68: 
jpayne@68: set(forwarded_config_flags)
jpayne@68: if(CapnProto_FIND_QUIETLY)
jpayne@68:   list(APPEND forwarded_config_flags QUIET)
jpayne@68: endif()
jpayne@68: if(CapnProto_FIND_REQUIRED)
jpayne@68:   list(APPEND forwarded_config_flags REQUIRED)
jpayne@68: endif()
jpayne@68: # If the consuming project called find_package(CapnProto) with the QUIET or REQUIRED flags, forward
jpayne@68: # them to calls to find_package(PkgConfig) and pkg_check_modules(). Note that find_dependency()
jpayne@68: # would do this for us in the former case, but there is no such forwarding wrapper for
jpayne@68: # pkg_check_modules().
jpayne@68: 
jpayne@68: find_package(PkgConfig ${forwarded_config_flags})
jpayne@68: if(NOT ${PkgConfig_FOUND})
jpayne@68:   # If we're here, the REQUIRED flag must not have been passed, else we would have had a fatal
jpayne@68:   # error. Nevertheless, a diagnostic for this case is probably nice.
jpayne@68:   if(NOT CapnProto_FIND_QUIETLY)
jpayne@68:     message(WARNING "pkg-config cannot be found")
jpayne@68:   endif()
jpayne@68:   set(CapnProto_FOUND OFF)
jpayne@68:   return()
jpayne@68: endif()
jpayne@68: 
jpayne@68: function(_capnp_import_pkg_config_target target)
jpayne@68:   # Add an imported library target named CapnProto::${target}, using the output of various
jpayne@68:   # invocations of `pkg-config ${target}`. The generated imported library target tries to mimic the
jpayne@68:   # behavior of a real CMake-generated imported target as closely as possible.
jpayne@68:   #
jpayne@68:   # Usage: _capnp_import_pkg_config_target(target <all Cap'n Proto targets>)
jpayne@68: 
jpayne@68:   set(all_targets ${ARGN})
jpayne@68: 
jpayne@68:   pkg_check_modules(${target} ${forwarded_config_flags} ${target})
jpayne@68: 
jpayne@68:   if(NOT ${${target}_FOUND})
jpayne@68:     if(NOT CapnProto_FIND_QUIETLY)
jpayne@68:       message(WARNING "CapnProtoConfig.cmake was configured to search for ${target}.pc, but pkg-config cannot find it. Ignoring this target.")
jpayne@68:     endif()
jpayne@68:     return()
jpayne@68:   endif()
jpayne@68: 
jpayne@68:   if(CapnProto_DEBUG)
jpayne@68:     # Dump the information pkg-config discovered.
jpayne@68:     foreach(var VERSION LIBRARY_DIRS LIBRARIES LDFLAGS_OTHER INCLUDE_DIRS CFLAGS_OTHER)
jpayne@68:       message(STATUS "${target}_${var} = ${${target}_${var}}")
jpayne@68:     endforeach()
jpayne@68:   endif()
jpayne@68: 
jpayne@68:   if(NOT ${${target}_VERSION} VERSION_EQUAL ${CapnProto_VERSION})
jpayne@68:     if(NOT CapnProto_FIND_QUIETLY)
jpayne@68:       message(WARNING "CapnProtoConfig.cmake was configured to search for version ${CapnProto_VERSION}, but ${target} version ${${target}_VERSION} was found. Ignoring this target.")
jpayne@68:     endif()
jpayne@68:     return()
jpayne@68:   endif()
jpayne@68: 
jpayne@68:   # Make an educated guess as to what the target's .so and .a filenames must be.
jpayne@68:   set(target_name_shared
jpayne@68:       ${CMAKE_SHARED_LIBRARY_PREFIX}${target}-${CapnProto_VERSION}${CMAKE_SHARED_LIBRARY_SUFFIX})
jpayne@68:   set(target_name_static
jpayne@68:       ${CMAKE_STATIC_LIBRARY_PREFIX}${target}${CMAKE_STATIC_LIBRARY_SUFFIX})
jpayne@68: 
jpayne@68:   # Find the actual target's file. find_library() sets a cache variable, so I made the variable name
jpayne@68:   # unique-ish.
jpayne@68:   find_library(CapnProto_${target}_IMPORTED_LOCATION
jpayne@68:     NAMES ${target_name_shared} ${target_name_static}  # prefer libfoo-version.so over libfoo.a
jpayne@68:     PATHS ${${target}_LIBRARY_DIRS}
jpayne@68:     NO_DEFAULT_PATH
jpayne@68:   )
jpayne@68:   # If the installed version of Cap'n Proto is in a system location, pkg-config will not have filled
jpayne@68:   # in ${target}_LIBRARY_DIRS. To account for this, fall back to a regular search.
jpayne@68:   find_library(CapnProto_${target}_IMPORTED_LOCATION
jpayne@68:     NAMES ${target_name_shared} ${target_name_static}  # prefer libfoo-version.so over libfoo.a
jpayne@68:   )
jpayne@68: 
jpayne@68:   if(NOT CapnProto_${target}_IMPORTED_LOCATION)
jpayne@68:     # Not an error if the library doesn't exist -- we may have found a lite mode installation.
jpayne@68:     if(CapnProto_DEBUG)
jpayne@68:       message(STATUS "${target} library does not exist")
jpayne@68:     endif()
jpayne@68:     return()
jpayne@68:   endif()
jpayne@68: 
jpayne@68:   # Record some information about this target -- shared versus static, location and soname -- which
jpayne@68:   # we'll use to build our imported target later.
jpayne@68: 
jpayne@68:   set(target_location ${CapnProto_${target}_IMPORTED_LOCATION})
jpayne@68:   get_filename_component(target_name "${target_location}" NAME)
jpayne@68: 
jpayne@68:   set(target_type STATIC)
jpayne@68:   set(imported_soname_property)
jpayne@68:   if(target_name STREQUAL ${target_name_shared})
jpayne@68:     set(target_type SHARED)
jpayne@68:     set(imported_soname_property IMPORTED_SONAME ${target_name})
jpayne@68:   endif()
jpayne@68: 
jpayne@68:   # Each library dependency of the target is either the target itself, a sibling Cap'n Proto
jpayne@68:   # library, or a system library. We ignore the first case by removing this target from the
jpayne@68:   # dependencies. The remaining dependencies are either passed through or, if they are a sibling
jpayne@68:   # Cap'n Proto library, prefixed with `CapnProto::`.
jpayne@68:   set(dependencies ${${target}_LIBRARIES})
jpayne@68:   list(REMOVE_ITEM dependencies ${target})
jpayne@68:   set(target_interface_libs)
jpayne@68:   foreach(dependency ${dependencies})
jpayne@68:     list(FIND all_targets ${dependency} target_index)
jpayne@68:     # TODO(cleanup): CMake >= 3.3 lets us write: `if(NOT ${dependency} IN_LIST all_targets)`
jpayne@68:     if(target_index EQUAL -1)
jpayne@68:       list(APPEND target_interface_libs ${dependency})
jpayne@68:     else()
jpayne@68:       list(APPEND target_interface_libs CapnProto::${dependency})
jpayne@68:     endif()
jpayne@68:   endforeach()
jpayne@68: 
jpayne@68:   add_library(CapnProto::${target} ${target_type} IMPORTED)
jpayne@68:   set_target_properties(CapnProto::${target} PROPERTIES
jpayne@68:     ${imported_soname_property}
jpayne@68:     IMPORTED_LOCATION "${target_location}"
jpayne@68:     # TODO(cleanup): Use cxx_std_14 once it's safe to require cmake 3.8.
jpayne@68:     INTERFACE_COMPILE_FEATURES "cxx_generic_lambdas"
jpayne@68:     INTERFACE_COMPILE_OPTIONS "${${target}_CFLAGS_OTHER}"
jpayne@68:     INTERFACE_INCLUDE_DIRECTORIES "${${target}_INCLUDE_DIRS}"
jpayne@68: 
jpayne@68:     # I'm dumping LDFLAGS_OTHER in with the libraries because there exists no
jpayne@68:     # INTERFACE_LINK_OPTIONS. See https://gitlab.kitware.com/cmake/cmake/issues/16543.
jpayne@68:     INTERFACE_LINK_LIBRARIES "${target_interface_libs};${${target}_LDFLAGS_OTHER}"
jpayne@68:   )
jpayne@68: 
jpayne@68:   if(CapnProto_DEBUG)
jpayne@68:     # Dump all the properties we generated for the imported target.
jpayne@68:     foreach(prop
jpayne@68:         IMPORTED_LOCATION
jpayne@68:         IMPORTED_SONAME
jpayne@68:         INTERFACE_COMPILE_FEATURES
jpayne@68:         INTERFACE_COMPILE_OPTIONS
jpayne@68:         INTERFACE_INCLUDE_DIRECTORIES
jpayne@68:         INTERFACE_LINK_LIBRARIES)
jpayne@68:       get_target_property(value CapnProto::${target} ${prop})
jpayne@68:       message(STATUS "CapnProto::${target} ${prop} = ${value}")
jpayne@68:     endforeach()
jpayne@68:   endif()
jpayne@68: endfunction()
jpayne@68: 
jpayne@68: # ========================================================================================
jpayne@68: # Imported library targets
jpayne@68: 
jpayne@68: # Build a list of targets to search for from the list of .pc files.
jpayne@68: # I.e. [somewhere/foo.pc, somewhere/bar.pc] -> [foo, bar]
jpayne@68: set(library_targets)
jpayne@68: foreach(filename ${CAPNP_PKG_CONFIG_FILES})
jpayne@68:   get_filename_component(target ${filename} NAME_WE)
jpayne@68:   list(APPEND library_targets ${target})
jpayne@68: endforeach()
jpayne@68: 
jpayne@68: # Try to add an imported library target CapnProto::foo for each foo.pc distributed with Cap'n Proto.
jpayne@68: foreach(target ${library_targets})
jpayne@68:   _capnp_import_pkg_config_target(${target} ${library_targets})
jpayne@68: endforeach()
jpayne@68: 
jpayne@68: # Handle lite-mode and no libraries found cases. It is tempting to set a CapnProto_LITE variable
jpayne@68: # here, but the real CMake-generated implementation does no such thing -- we'd need to set it in
jpayne@68: # CapnProtoConfig.cmake.in itself.
jpayne@68: if(TARGET CapnProto::capnp AND TARGET CapnProto::kj)
jpayne@68:   if(NOT TARGET CapnProto::capnp-rpc)
jpayne@68:     if(NOT CapnProto_FIND_QUIETLY)
jpayne@68:       message(STATUS "Found an installation of Cap'n Proto lite. Executable and library targets beyond libkj and libcapnp will be unavailable.")
jpayne@68:     endif()
jpayne@68:     # Lite mode doesn't include the executables, so return here.
jpayne@68:     return()
jpayne@68:   endif()
jpayne@68: else()
jpayne@68:   # If we didn't even find capnp or kj, then we didn't find anything usable.
jpayne@68:   set(CapnProto_FOUND OFF)
jpayne@68:   return()
jpayne@68: endif()
jpayne@68: 
jpayne@68: # ========================================================================================
jpayne@68: # Imported executable targets
jpayne@68: 
jpayne@68: get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
jpayne@68: get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
jpayne@68: get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
jpayne@68: get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
jpayne@68: 
jpayne@68: # Add executable targets for the capnp compiler and plugins. This list must be kept manually in sync
jpayne@68: # with the rest of the project.
jpayne@68: 
jpayne@68: add_executable(CapnProto::capnp_tool IMPORTED)
jpayne@68: set_target_properties(CapnProto::capnp_tool PROPERTIES
jpayne@68:   IMPORTED_LOCATION "${_IMPORT_PREFIX}/bin/capnp${CMAKE_EXECUTABLE_SUFFIX}"
jpayne@68: )
jpayne@68: 
jpayne@68: add_executable(CapnProto::capnpc_cpp IMPORTED)
jpayne@68: set_target_properties(CapnProto::capnpc_cpp PROPERTIES
jpayne@68:   IMPORTED_LOCATION "${_IMPORT_PREFIX}/bin/capnpc-c++${CMAKE_EXECUTABLE_SUFFIX}"
jpayne@68: )
jpayne@68: 
jpayne@68: add_executable(CapnProto::capnpc_capnp IMPORTED)
jpayne@68: set_target_properties(CapnProto::capnpc_capnp PROPERTIES
jpayne@68:   IMPORTED_LOCATION "${_IMPORT_PREFIX}/bin/capnpc-capnp${CMAKE_EXECUTABLE_SUFFIX}"
jpayne@68: )