CMake/Modules/AddExternalProject.cmake

704 lines
23 KiB
CMake

# Requires CVS CMake for 'function' and '-E touch' and '--build'
find_package(CVS)
find_package(Subversion)
function(get_external_project_directories base_dir_var build_dir_var downloads_dir_var install_dir_var sentinels_dir_var source_dir_var tmp_dir_var)
set(base "${CMAKE_BINARY_DIR}/CMakeExternals")
set(${base_dir_var} "${base}" PARENT_SCOPE)
set(${build_dir_var} "${base}/Build" PARENT_SCOPE)
set(${downloads_dir_var} "${base}/Downloads" PARENT_SCOPE)
set(${install_dir_var} "${base}/Install" PARENT_SCOPE)
set(${sentinels_dir_var} "${base}/Sentinels" PARENT_SCOPE)
set(${source_dir_var} "${base}/Source" PARENT_SCOPE)
set(${tmp_dir_var} "${base}/tmp" PARENT_SCOPE)
endfunction(get_external_project_directories)
function(get_configure_build_working_dir name working_dir_var)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
get_target_property(dir ${name} AEP_CONFIGURE_DIR)
if(dir)
if (IS_ABSOLUTE "${dir}")
set(working_dir "${dir}")
else()
set(working_dir "${source_dir}/${name}/${dir}")
endif()
else()
set(working_dir "${build_dir}/${name}")
endif()
set(${working_dir_var} "${working_dir}" PARENT_SCOPE)
endfunction(get_configure_build_working_dir)
function(get_configure_command_id name cfg_cmd_id_var)
get_target_property(cmd ${name} AEP_CONFIGURE_COMMAND)
if(cmd STREQUAL "")
# Explicit empty string means no configure step for this project
set(${cfg_cmd_id_var} "none" PARENT_SCOPE)
else()
if(NOT cmd)
# Default is "use cmake":
set(${cfg_cmd_id_var} "cmake" PARENT_SCOPE)
else()
# Otherwise we have to analyze the value:
if(cmd MATCHES "/configure$")
set(${cfg_cmd_id_var} "configure" PARENT_SCOPE)
else()
if(cmd MATCHES "cmake")
set(${cfg_cmd_id_var} "cmake" PARENT_SCOPE)
else()
if(cmd MATCHES "config")
set(${cfg_cmd_id_var} "configure" PARENT_SCOPE)
else()
set(${cfg_cmd_id_var} "unknown:${cmd}" PARENT_SCOPE)
endif()
endif()
endif()
endif()
endif()
endfunction(get_configure_command_id)
function(mkdir d)
file(MAKE_DIRECTORY "${d}")
#message(STATUS "mkdir d='${d}'")
if(NOT EXISTS "${d}")
message(FATAL_ERROR "error: dir '${d}' does not exist after file(MAKE_DIRECTORY call...")
endif()
endfunction(mkdir)
function(add_external_project_download_command name)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
get_target_property(cmd ${name} AEP_DOWNLOAD_COMMAND)
if(cmd STREQUAL "")
# Explicit empty string means no download step for this project
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${sentinels_dir}
COMMENT "No download step for '${name}'"
DEPENDS ${sentinels_dir}/CMakeExternals-directories
)
return()
else()
if(cmd)
set(args "")
get_target_property(download_args ${name} AEP_DOWNLOAD_ARGS)
if(download_args)
set(args "${download_args}")
separate_arguments(args)
endif()
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${cmd} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${downloads_dir}
COMMENT "Performing download step for '${name}'"
DEPENDS ${sentinels_dir}/CMakeExternals-directories
)
return()
else()
# No explicit DOWNLOAD_COMMAND property. Look for other properties
# indicating which download method to use in the logic below...
endif()
endif()
get_target_property(cvs_repository ${name} AEP_CVS_REPOSITORY)
if(cvs_repository)
if(NOT CVS_EXECUTABLE)
message(FATAL_ERROR "error: could not find cvs for checkout of ${name}")
endif()
get_target_property(cvs_module ${name} AEP_CVS_MODULE)
if(NOT cvs_module)
message(FATAL_ERROR "error: no CVS_MODULE")
endif()
get_target_property(tag ${name} AEP_CVS_TAG)
set(cvs_tag)
if(tag)
set(cvs_tag ${tag})
endif()
set(args -d ${cvs_repository} -q co ${cvs_tag} -d ${name} ${cvs_module})
set(repository ${cvs_repository})
set(module ${cvs_module})
set(tag ${cvs_tag})
configure_file(
"${CMAKE_ROOT}/Modules/RepositoryInfo.txt.in"
"${sentinels_dir}/${name}-cvsinfo.txt"
@ONLY
)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CVS_EXECUTABLE} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (CVS checkout) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-cvsinfo.txt
)
return()
endif()
get_target_property(svn_repository ${name} AEP_SVN_REPOSITORY)
if(svn_repository)
if(NOT Subversion_SVN_EXECUTABLE)
message(FATAL_ERROR "error: could not find svn for checkout of ${name}")
endif()
get_target_property(tag ${name} AEP_SVN_TAG)
set(svn_tag)
if(tag)
set(svn_tag ${tag})
endif()
set(args co ${svn_repository} ${svn_tag} ${name})
set(repository ${svn_repository})
set(module)
set(tag ${svn_tag})
configure_file(
"${CMAKE_ROOT}/Modules/RepositoryInfo.txt.in"
"${sentinels_dir}/${name}-svninfo.txt"
@ONLY
)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${Subversion_SVN_EXECUTABLE} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (SVN checkout) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-svninfo.txt
)
return()
endif()
get_target_property(dir ${name} AEP_DIR)
if(dir)
get_filename_component(abs_dir "${dir}" ABSOLUTE)
set(repository "add_external_project DIR")
set(module "${abs_dir}")
set(tag "")
configure_file(
"${CMAKE_ROOT}/Modules/RepositoryInfo.txt.in"
"${sentinels_dir}/${name}-dirinfo.txt"
@ONLY
)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CMAKE_COMMAND} -E remove_directory ${source_dir}/${name}
COMMAND ${CMAKE_COMMAND} -E copy_directory ${abs_dir} ${source_dir}/${name}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (DIR copy) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-dirinfo.txt
)
return()
endif()
get_target_property(tar ${name} AEP_TAR)
if(tar)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CMAKE_COMMAND} -Dfilename=${tar} -Dtmp=${tmp_dir}/${name} -Ddirectory=${source_dir}/${name} -P ${CMAKE_ROOT}/Modules/UntarFile.cmake
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (TAR untar) for '${name}'"
DEPENDS ${tar}
)
return()
endif()
get_target_property(tgz ${name} AEP_TGZ)
if(tgz)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CMAKE_COMMAND} -Dfilename=${tgz} -Dtmp=${tmp_dir}/${name} -Ddirectory=${source_dir}/${name} -P ${CMAKE_ROOT}/Modules/UntarFile.cmake
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (TGZ untar) for '${name}'"
DEPENDS ${tgz}
)
return()
endif()
get_target_property(tgz_url ${name} AEP_TGZ_URL)
if(tgz_url)
set(repository "add_external_project TGZ_URL")
set(module "${tgz_url}")
set(tag "")
configure_file(
"${CMAKE_ROOT}/Modules/RepositoryInfo.txt.in"
"${sentinels_dir}/${name}-urlinfo.txt"
@ONLY
)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CMAKE_COMMAND} -Dremote=${tgz_url} -Dlocal=${downloads_dir}/${name}.tgz -P ${CMAKE_ROOT}/Modules/DownloadFile.cmake
COMMAND ${CMAKE_COMMAND} -Dfilename=${downloads_dir}/${name} -Dtmp=${tmp_dir}/${name} -Ddirectory=${source_dir}/${name} -P ${CMAKE_ROOT}/Modules/UntarFile.cmake
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (TGZ_URL download and untar) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-urlinfo.txt
)
return()
endif()
get_target_property(tar_url ${name} AEP_TAR_URL)
if(tar_url)
set(repository "add_external_project TAR_URL")
set(module "${tar_url}")
set(tag "")
configure_file(
"${CMAKE_ROOT}/Modules/RepositoryInfo.txt.in"
"${sentinels_dir}/${name}-urlinfo.txt"
@ONLY
)
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-download
COMMAND ${CMAKE_COMMAND} -Dremote=${tar_url} -Dlocal=${downloads_dir}/${name}.tar -P ${CMAKE_ROOT}/Modules/DownloadFile.cmake
COMMAND ${CMAKE_COMMAND} -Dfilename=${downloads_dir}/${name} -Dtmp=${tmp_dir}/${name} -Ddirectory=${source_dir}/${name} -P ${CMAKE_ROOT}/Modules/UntarFile.cmake
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-download
WORKING_DIRECTORY ${source_dir}
COMMENT "Performing download step (TAR_URL download and untar) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-urlinfo.txt
)
return()
endif()
message(SEND_ERROR "error: no download info for '${name}'")
endfunction(add_external_project_download_command)
function(add_external_project_update_command name)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
get_target_property(cmd ${name} AEP_UPDATE_COMMAND)
if(cmd STREQUAL "")
# Explicit empty string means no update step for this project
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-update
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-update
WORKING_DIRECTORY ${sentinels_dir}
COMMENT "No update step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-download
)
return()
else()
if(cmd)
set(args "")
get_target_property(update_args ${name} AEP_UPDATE_ARGS)
if(update_args)
set(args "${update_args}")
separate_arguments(args)
endif()
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-update
COMMAND ${cmd} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-update
WORKING_DIRECTORY ${source_dir}/${name}
COMMENT "Performing update step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-download
)
return()
else()
# No explicit UPDATE_COMMAND property. Look for other properties
# indicating which update method to use in the logic below...
endif()
endif()
get_target_property(cvs_repository ${name} AEP_CVS_REPOSITORY)
if(cvs_repository)
if(NOT CVS_EXECUTABLE)
message(FATAL_ERROR "error: could not find cvs for update of ${name}")
endif()
get_target_property(tag ${name} AEP_CVS_TAG)
set(cvs_tag)
if(tag)
set(cvs_tag ${tag})
endif()
set(args -d ${cvs_repository} -q up -dP ${cvs_tag})
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-update
COMMAND ${CVS_EXECUTABLE} ${args}
WORKING_DIRECTORY ${source_dir}/${name}
COMMENT "Performing update step (CVS update) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-download
)
# Since the update sentinel is not actually written:
set_property(SOURCE ${sentinels_dir}/${name}-update
PROPERTY SYMBOLIC 1)
return()
endif()
get_target_property(svn_repository ${name} AEP_SVN_REPOSITORY)
if(svn_repository)
if(NOT Subversion_SVN_EXECUTABLE)
message(FATAL_ERROR "error: could not find svn for update of ${name}")
endif()
get_target_property(tag ${name} AEP_SVN_TAG)
set(svn_tag)
if(tag)
set(svn_tag ${tag})
endif()
set(args up ${svn_tag})
mkdir("${source_dir}/${name}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-update
COMMAND ${Subversion_SVN_EXECUTABLE} ${args}
WORKING_DIRECTORY ${source_dir}/${name}
COMMENT "Performing update step (SVN update) for '${name}'"
DEPENDS ${sentinels_dir}/${name}-download
)
# Since the update sentinel is not actually written:
set_property(SOURCE ${sentinels_dir}/${name}-update
PROPERTY SYMBOLIC 1)
return()
endif()
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-update
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-update
WORKING_DIRECTORY ${sentinels_dir}
COMMENT "No update step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-download
)
endfunction(add_external_project_update_command)
function(add_external_project_configure_command name)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
get_configure_build_working_dir(${name} working_dir)
get_target_property(file_deps ${name} AEP_FILE_DEPENDS)
if(NOT file_deps)
set(file_deps)
endif()
#message(STATUS "info: name='${name}' file_deps='${file_deps}'")
# Create the working_dir for configure, build and install steps:
#
mkdir("${working_dir}")
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-working_dir
COMMAND ${CMAKE_COMMAND} -E make_directory ${working_dir}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-working_dir
DEPENDS ${sentinels_dir}/${name}-update
${file_deps}
)
get_target_property(cmd ${name} AEP_CONFIGURE_COMMAND)
if(cmd STREQUAL "")
# Explicit empty string means no configure step for this project
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-configure
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-configure
WORKING_DIRECTORY ${working_dir}
COMMENT "No configure step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-working_dir
)
else()
if(NOT cmd)
set(cmd ${CMAKE_COMMAND})
endif()
set(args "")
get_target_property(configure_args ${name} AEP_CONFIGURE_ARGS)
if(configure_args)
set(args "${configure_args}")
separate_arguments(args)
endif()
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-configure
COMMAND ${cmd} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-configure
WORKING_DIRECTORY ${working_dir}
COMMENT "Performing configure step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-working_dir
)
endif()
endfunction(add_external_project_configure_command)
function(add_external_project_build_command name)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
get_configure_build_working_dir(${name} working_dir)
get_target_property(cmd ${name} AEP_BUILD_COMMAND)
if(cmd STREQUAL "")
# Explicit empty string means no build step for this project
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-build
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-build
WORKING_DIRECTORY ${working_dir}
COMMENT "No build step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-configure
)
else()
get_configure_command_id(${name} cfg_cmd_id)
if(NOT cmd)
set(cmd make)
if(cfg_cmd_id STREQUAL "cmake")
get_target_property(cfg_cmd ${name} AEP_CONFIGURE_COMMAND)
if(cfg_cmd)
set(cmd ${cfg_cmd})
else()
set(cmd ${CMAKE_COMMAND})
endif()
endif()
endif()
get_target_property(args ${name} AEP_BUILD_ARGS)
if(NOT args)
set(args)
if(cfg_cmd_id STREQUAL "cmake")
set(args --build ${working_dir} --config ${CMAKE_CFG_INTDIR})
endif()
endif()
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-build
COMMAND ${cmd} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-build
WORKING_DIRECTORY ${working_dir}
COMMENT "Performing build step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-configure
)
endif()
endfunction(add_external_project_build_command)
function(add_external_project_install_command name)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
get_configure_build_working_dir(${name} working_dir)
get_target_property(cmd ${name} AEP_INSTALL_COMMAND)
if(cmd STREQUAL "")
# Explicit empty string means no install step for this project
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-install
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-install
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-complete
WORKING_DIRECTORY ${working_dir}
COMMENT "No install step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-build
)
else()
get_configure_command_id(${name} cfg_cmd_id)
if(NOT cmd)
set(cmd make)
if(cfg_cmd_id STREQUAL "cmake")
get_target_property(cfg_cmd ${name} AEP_CONFIGURE_COMMAND)
if(cfg_cmd)
set(cmd ${cfg_cmd})
else()
set(cmd ${CMAKE_COMMAND})
endif()
endif()
endif()
get_target_property(args ${name} AEP_INSTALL_ARGS)
if(NOT args)
set(args)
if(cfg_cmd_id STREQUAL "cmake")
set(args --build ${working_dir} --config ${CMAKE_CFG_INTDIR} --target install)
endif()
if(cfg_cmd_id STREQUAL "configure")
set(args "install")
endif()
endif()
add_custom_command(
OUTPUT ${sentinels_dir}/${name}-install
COMMAND ${cmd} ${args}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-install
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/${name}-complete
WORKING_DIRECTORY ${working_dir}
COMMENT "Performing install step for '${name}'"
DEPENDS ${sentinels_dir}/${name}-build
)
endif()
endfunction(add_external_project_install_command)
function(add_CMakeExternals_target)
if(NOT TARGET CMakeExternals)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
# Make the directories at CMake configure time *and* add a custom command
# to make them at build time. They need to exist at makefile generation
# time for Borland make and wmake so that CMake may generate makefiles
# with "cd C:\short\paths\with\no\spaces" commands in them.
#
# Additionally, the add_custom_command is still used in case somebody
# removes one of the necessary directories and tries to rebuild without
# re-running cmake.
#
mkdir("${build_dir}")
mkdir("${downloads_dir}")
mkdir("${install_dir}")
mkdir("${sentinels_dir}")
mkdir("${source_dir}")
mkdir("${tmp_dir}")
add_custom_command(
OUTPUT ${sentinels_dir}/CMakeExternals-directories
COMMAND ${CMAKE_COMMAND} -E make_directory ${build_dir}
COMMAND ${CMAKE_COMMAND} -E make_directory ${downloads_dir}
COMMAND ${CMAKE_COMMAND} -E make_directory ${install_dir}
COMMAND ${CMAKE_COMMAND} -E make_directory ${sentinels_dir}
COMMAND ${CMAKE_COMMAND} -E make_directory ${source_dir}
COMMAND ${CMAKE_COMMAND} -E make_directory ${tmp_dir}
COMMAND ${CMAKE_COMMAND} -E touch ${sentinels_dir}/CMakeExternals-directories
COMMENT "Creating CMakeExternals directories"
)
add_custom_target(CMakeExternals ALL
DEPENDS ${sentinels_dir}/CMakeExternals-directories
)
endif()
endfunction(add_CMakeExternals_target)
function(is_known_aep_property_key key result_var)
set(${result_var} 0 PARENT_SCOPE)
if(key MATCHES "^BUILD_ARGS|BUILD_COMMAND|CONFIGURE_ARGS|CONFIGURE_COMMAND|CONFIGURE_DIR|CVS_REPOSITORY|CVS_MODULE|CVS_TAG|DEPENDS|DOWNLOAD_ARGS|DOWNLOAD_COMMAND|DIR|INSTALL_ARGS|INSTALL_COMMAND|SVN_REPOSITORY|SVN_TAG|TAR|TAR_URL|TGZ|TGZ_URL|UPDATE_ARGS|UPDATE_COMMAND$"
)
#message(STATUS "info: recognized via MATCHES - key='${key}'")
set(${result_var} 1 PARENT_SCOPE)
else()
message(STATUS "warning: is_known_aep_property_key unknown key='${key}'")
endif()
endfunction(is_known_aep_property_key)
function(add_external_project name)
get_external_project_directories(base_dir build_dir downloads_dir install_dir
sentinels_dir source_dir tmp_dir)
# Ensure root CMakeExternals target and directories are created.
# All external projects will depend on this root CMakeExternals target.
#
add_CMakeExternals_target()
# Add a custom target for the external project and make its DEPENDS
# the output of the final build step:
#
add_custom_target(${name} ALL
DEPENDS ${sentinels_dir}/${name}-install
)
set_target_properties(${name} PROPERTIES AEP_IS_EXTERNAL_PROJECT 1)
add_dependencies(${name} CMakeExternals)
# Transfer the arguments to this function into target properties for the
# new custom target we just added so that we can set up all the build steps
# correctly based on target properties.
#
# Loop over ARGN by 2's extracting key/value pairs from the non-explicit
# arguments to this function:
#
list(LENGTH ARGN n)
set(i 0)
while(i LESS n)
math(EXPR j ${i}+1)
list(GET ARGN ${i} key)
list(GET ARGN ${j} value)
is_known_aep_property_key("${key}" is_known_key)
if(is_known_key)
if(key STREQUAL "DEPENDS")
if(NOT value STREQUAL "")
add_dependencies(${name} ${value})
set_property(TARGET ${name} APPEND PROPERTY AEP_FILE_DEPENDS "${sentinels_dir}/${value}-complete")
else()
message(STATUS "warning: empty DEPENDS value in add_external_project")
endif()
else()
set_property(TARGET ${name} PROPERTY AEP_${key} "${value}")
endif()
else()
message(SEND_ERROR "error: unknown add_external_project key with name='${name}' key='${key}' value='${value}'")
endif()
math(EXPR i ${i}+2)
endwhile()
# Set up custom build steps based on the target properties.
# Each step depends on the previous one.
#
# The target depends on the output of the final step.
# (Already set up above in the DEPENDS of the add_custom_target command.)
#
add_external_project_download_command(${name})
add_external_project_update_command(${name})
add_external_project_configure_command(${name})
add_external_project_build_command(${name})
add_external_project_install_command(${name})
endfunction(add_external_project)