https://github.com/Kitware/CMake
Tip revision: 91ccfa330240ccd9766f59d9efcac595c4a1b033 authored by Brad King on 01 November 2022, 13:36:33 UTC
CMake 3.23.5
CMake 3.23.5
Tip revision: 91ccfa3
CMakeLists.txt
cmake_minimum_required (VERSION 2.6)
project (ExternalOBJ)
if(APPLE)
# set _CMAKE_OSX_MACHINE to umame -m
exec_program(uname ARGS -m OUTPUT_VARIABLE _CMAKE_OSX_MACHINE)
# check for Power PC and change to ppc
if("${_CMAKE_OSX_MACHINE}" MATCHES "Power")
set(_CMAKE_OSX_MACHINE ppc)
endif()
set(CMAKE_OSX_ARCHITECTURES ${_CMAKE_OSX_MACHINE})
endif()
# Build the external object file.
try_compile(EXTERNAL_OBJECT_BUILT
${ExternalOBJ_BINARY_DIR}/Object
${ExternalOBJ_SOURCE_DIR}/Object
Object
external
OUTPUT_VARIABLE OUTPUT
)
if(EXTERNAL_OBJECT_BUILT)
message(
"Building external_object.cxx succeeded with the following output:\n"
"[${OUTPUT}]"
)
else()
message(FATAL_ERROR
"Building external_object.cxx failed with the following output:\n"
"[${OUTPUT}]"
)
endif()
# Find the external object file.
set(DIR ${ExternalOBJ_BINARY_DIR}/Object)
file(GLOB_RECURSE EXTERNAL_OBJECT
"${DIR}/external_object*${CMAKE_CXX_OUTPUT_EXTENSION}")
if(EXTERNAL_OBJECT)
list (GET EXTERNAL_OBJECT 0 EXTERNAL_OBJECT)
message("Found \"${EXTERNAL_OBJECT}\".")
else()
message(FATAL_ERROR "Could not find external object.")
endif()
# Test creation of external objects by custom commands.
set(CUSTOM_OBJECT
${CMAKE_CURRENT_BINARY_DIR}/custom_object${CMAKE_C_OUTPUT_EXTENSION})
add_custom_command(
OUTPUT ${CUSTOM_OBJECT}
COMMAND ${CMAKE_COMMAND} -E copy ${EXTERNAL_OBJECT} ${CUSTOM_OBJECT}
DEPENDS ${EXTERNAL_OBJECT}
)
message("${EXTERNAL_OBJECT}")
# Build an executable using the external object file.
add_executable(ExternalOBJ executable.cxx ${CUSTOM_OBJECT})
# A bug showed up in VS2010 where an object file that was
# part of a custom command output worked, but ones that were
# not didn't work. So, repeat the executable using the object
# directly and not from the output of the copy.
add_executable(ExternalOBJ2 executable.cxx ${EXTERNAL_OBJECT})
add_subdirectory(Sub)