How to reload cmake targets - cmake

Question

Following is the my scenario. I have one top level CMakeList.txt and another 2 internal CMakeList.txt. In top level cmake I have 3 custom targets that are copy, build, copyandbuild. As name specifies make copy copies the source directories (i.e dir1, dir2) to ${CMAKE_SOURCE_DIR}. make build creates libs and executables. make copyandbuild (copy+build).
Running cmake .. from build directory completes successfully.
If I run make copyandbuild it is copying to ${CMAKE_SOURCE_DIR} but at the time of build it is showing error that
No rule to make target `dir1/libmylib.so', needed by `CMaketargetdbuild'. Stop
MyProject
dir1
CMakeLists.txt
dir2
CMakeLists.txt
CMakeLists.txt
It is working if i execute commands in below order.
cmake ..
make copyandbuild
cmake ..
make build
My requirement is it should work with out running cmake and make build again as copyandbuild doing the same work.
Top level CMakeLists.txt:
cmake_minimum_required(VERSION 2.6)
cmake_minimum_required(VERSION 2.6)
set(RE_BUILD make rebuild_cache)
set(OUTPUT_DIR ${CMAKE_SOURCE_DIR}/../)
if(EXISTS ${CMAKE_SOURCE_DIR}/dir1)
message(WARNING "Found dir1 dir")
add_subdirectory(dir1 EXCLUDE_FROM_ALL)
else()
message(WARNING "Couldn't find dir1 directory ")
endif()
if(EXISTS ${CMAKE_SOURCE_DIR}/dir2)
add_subdirectory(dir2 EXCLUDE_FROM_ALL)
else()
message(WARNING "Couldn't find dir2 directory")
endif()
set(MOVE_LIB_COMMAND mv src/myapp . && mv dir1/mylib .)
set(COPY_COMMAND cp -r ../sourceCode1 ../dir1 && cp -r ../sourceCode2 ../dir2)
set(CLEAN_DIR1_COMMAND cmake -E remove_directory ${CMAKE_SOURCE_DIR}/dir1)
set(CLEAN_DIR2_COMMAND cmake -E remove_directory ${CMAKE_SOURCE_DIR}/dir2)
set(SET_SLEEP sync)
#Copy command
add_custom_target(
copy ${COPY_COMMAND}
COMMAND ${RE_BUILD}
WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
)
#Compilation
add_custom_target(
build
COMMAND ${MOVE_LIB_COMMAND}
WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
DEPENDS mylib myapp
)
#copy and compile
add_custom_target(
copyandbuild
COMMAND ${MOVE_LIB_COMMAND}
WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
DEPENDS copy mylib myapp
)
add_custom_command(TARGET copy POST_BUILD
COMMAND ${SET_SLEEP}
)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11")
dir1 CMake is :
cmake_minimum_required(VERSION 2.6)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11")
include_directories(
${MY_APP_INCLUDE_DIRS}
)
link_directories(
${MY_APP_LIBDIR}
)
add_library(mylib
SHARED
com/*.cpp
)
target_link_libraries(mylib myapp_lib)
dir2 CMake is :
cmake_minimum_required(VERSION 2.6)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11")
include_directories(
${MY_APP_INCLUDE_DIRS}
)
link_directories(
${MY_APP_LIBDIR}
)

Answer 1

You are using CMake in a way that prevents its proper function. By explicitly invoking shell commands in many places, when you could use CMake built in features, you are robbing CMake of any context that it could use to build your programs. Also, using wildcards like *.cpp in CMake is considered bad practice. And you have a number of duplicate statements--you do not need cmake_minimum_required() or setting compiler flags other than at the top level.
In short, your CMakeLists.txt at the top level should look more like this:
cmake_minimum_required(VERSION 2.6)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11")
add_subdirectory(dir1 EXCLUDE_FROM_ALL)
You should not need to copy source files around--just build them from where they are, for example your dir1/CMakeLists.txt might be:
add_library(mylib
SHARED
sourceCode1/mylib.cpp
)
Keep it simple. Get it working. Then ask questions if you need to add missing features.