Cmake : post-package step - cmake

I'm looking for a way to execute a code after the packaging is done.
I tried to add a custom target that was depending on the PACKAGE target generated.
That looks like it does not work, here's cmake error:
CMake Error: The inter-target dependency graph contains the following strongly connected component (cycle):
"ALL_BUILD" of type UTILITY
depends on "UPLOAD" (strong)
"PACKAGE" of type GLOBAL_TARGET
depends on "ALL_BUILD" (strong)
"UPLOAD" of type UTILITY
depends on "PACKAGE" (strong)
At least one of these targets is not a STATIC_LIBRARY. Cyclic dependencies are allowed only among static libraries.
To do this I used to following code:
add_custom_target(UPLOAD ALL
COMMAND cmake -E echo "Should be post packging!"
)
add_dependencies(UPLOAD PACKAGE)
Is there some way to have the target to UPLOAD the PACKAGEd file?

Create your own package target.
add_custom_target(mypackage
COMMAND ${CMAKE_CPACK_COMMAND}
COMMAND ${CMAKE_COMMAND} -E echo "after packaging"
)

Upd: Since CMake 3.19 there is CPACK_POST_BUILD_SCRIPTS to do any tasks after CPack produced packages.

Related

CMake - how to block executing installation scripts during packaging?

My CMakeLists.txt file contains commands, which should be executed by make install, and all this works fine. The sample CMakeLists.txt below is a short excerpt from my actual CMake file (the tm0001.cpp content is not important here - it might be any C++ program):
cmake_minimum_required(VERSION 3.12)
project(tm0001)
set(CMAKE_CXX_STANDARD 11)
add_executable(${PROJECT_NAME} tm0001.cpp)
install(
TARGETS ${PROJECT_NAME}
DESTINATION /usr/local/bin
PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
)
install(CODE "message(\"-- This must be called during installation only\")")
set(CPACK_PACKAGE_CONTACT "HEKTO")
set(CPACK_GENERATOR "DEB")
include(CPack)
I see the message command is executed by make package as well, which is not I want.
How to tell CMake not to execute installation scripts by the make package command? I couldn't find any way to do that with the CMake if command.
As it already said in the comment, it's an extremely bad idea to "work w/ systemd" (and doing anything not related to build or packaging of your project) from install commands. The install command (even SCRIPT and CODE signatures) are intended to be used for install actions and not for any other side effects.
The correct way to act here is to produce a native package (DEB/RPM) w/ post-install script, where using the system-provided macros (like described here), you can install your package properly. Take a look to CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA for the way to provide package install actions.
The other bad thing is to use the hardcoded path (/usr/bin/). And BTW, a better place for the (pure) daemon app I suggest /usr/sbin/. Take a look to GNUInstallDirs module shipped w/ CMake for further references.
What I did was to specify install commands with CODE/SCRIPT as separate component e.g. install(CODE ... COMPONENT post-install).
Then also added other non-code install commands as a different component e.g. install(FILES ... COMPONENT files-install)
The CPack then needs to be configured to package only files-install component (solution to this can be found easily - hint: use CPACK_COMPONENTS_ALL_IN_ONE_PACKAGE, CPACK_COMPONENTS_ALL and CPACK_(RPM/DEB/...)_COMPONENT_INSTALL variables).
Of course then the resulting package won't run these CODE components during installing the package - they need to be added separately as a post install script.
I'm answering my own question, because the existing answer doesn't address my main problem. I couldn't find any way (on the CMake level) to block install commands from running during make package - even the postinst script is called by this command.
Fortunately, I could modify the postinst script itself to do nothing in case it's called not by the dpkg:
if [ -z ${DPKG_ADMINDIR} ]; then
echo "postinst: missing 'dpkg' environment (not an error during packaging)"
exit 0
fi
It's a trick of course, but it worked for me.

Custom command / target run only for default build not install

I want to build my documentation (doxygen) alongside my project with CMake by default. I let CMake generate Makefiles. I know of these approaches so far:
1)
add_custom_target(doc ALL
COMMAND ${DOXYGEN_COMMAND})
2)
add_custom_command(
TARGET my-executable
POST_BUILD
COMMAND ${DOXYGEN_COMMAND})
The issue I have with the first approach is that the target is build both during build and install (i.e. when running make and when running make install). This is a no-go.
The issue with the second approach is that it is not actually correct: the documentation doesn't have to be built after the executable (in fact, it can be done in parallel even). Moreover I cannot build only the executable now.
Is there a way to create this custom command / target such that it is run only during make (building) and not during make install (installing) but independently from other targets such as executables?
Basically I'd need a "default target". Also I really want to avoid having to execute CMake recursively or make directly.
Just create a file, which existence means that documentation file have been built:
set(documentation_file ${CMAKE__BINARY_DIR}/docs_ready)
# Documentation target
add_custom_target(docs ALL DEPENDS ${documentation_file})
# Documentation command
add_custom_command(OUTPUT ${documentation_file}
COMMAND ${DOXYGEN_COMMAND}
# And mark that documentation is created
COMMAND ${CMAKE_COMMAND} -E touch ${documentation_file}
)
The solution given by #Tsyvarev works perfectly except for one issue:
Running make docs manually doesn't cause a re-build of the documentation because the "output file" ${documentation_file} is always considered up to date (there are no dependencies specified that could be newer).
Three workarounds I found:
Run make -B docs. The -B flags causes GNU Make to consider all targets out of date, and thus causes the documentation to be build.
Add a "manual docs" target which depends on first a docs-clean target which removes ${documentation_file} and then on docs itself (to build the documentation and the file), and run make docs-manual:
add_custom_target(docs-clean
COMMAND ${CMAKE_COMMAND} -E remove ${documentation_file})
add_custom_target(docs-manual)
add_dependencies(docs-manual docs-clean docs)
Note that I fear that this is just a dirty hack: AFAIK the order in which the dependencies (docs-clean and docs) are build isn't specified, and as they don't have a dependency between them, they could even be built in parallel.
Using add_custom_command with a TARGET docs-manual and PRE_BUILD (which runs the command before building dependencies) instead of the docs-clean target would've been perfect, but this only works for Visual Studio 7 or later.
Add a custom target that depends on docs but removes the generated ${documentation_file}:
add_custom_target(docs-manual
COMMAND ${CMAKE_COMMAND} -E remove ${documentation_file})
add_dependencies(docs-manual docs)
This works except for when running it the first time after a make docs, because then the generated file will still be there when docs is built.
edit: Use add_dependencies instead of DEPENDS of add_custom_target because the later is only intended for files, not for dependencies on targets.

Retrieve all link flags in CMake

In CMake, is it possible to programmatically retrieve the complete list of linker flags that will be used for a given target? The only way I can see to do this is to inspect the link.txt file in the target's CMakeFiles directory. Not ideal.
The use case that I'm interested in is to collect the data to include in something like a pkg-config file. I'm writing a library, and it includes a couple executable utilities that use the library. Building the executables (especially when the library is build statically) requires a non-trivial link line to link to my library and its dependencies. So I'd like to write out the link line necessary for building these executables to a data file included with the package such that other clients can know how to link.
As #Tsyvarev has commented there is no build-in command or property "to programmatically retrieve the complete list of linker flags" in CMake.
But inspired by your hint "so I'd like to write out the link line necessary for building these executables to a data file" I think I found a feasible solution (at least for makefile generators).
And if I understand your request correctly, we are not talking about simple verbose outputs like you get with e.g. CMAKE_VERBOSE_MAKEFILE, which would still need you to copy things manually.
So taking the following into account:
You need to run the generator first to get the real link line
CMake allows you to invent any linker language by name
You can define the link line with CMAKE_>LANG<_LINK_EXECUTABLE using variables and expansion rules
I came up with adding an LinkLine executable using my ECHO "linker" with the single purpose to create a link line file of my choosing:
set(CMAKE_ECHO_STANDARD_LIBRARIES ${CMAKE_CXX_STANDARD_LIBRARIES})
set(CMAKE_ECHO_FLAGS ${CMAKE_CXX_FLAGS})
set(CMAKE_ECHO_LINK_FLAGS ${CMAKE_CXX_LINK_FLAGS})
set(CMAKE_ECHO_IMPLICIT_LINK_DIRECTORIES ${CMAKE_CXX_IMPLICIT_LINK_DIRECTORIES})
set(
CMAKE_ECHO_LINK_EXECUTABLE
"<CMAKE_COMMAND> -E echo \"<FLAGS> <LINK_FLAGS> <LINK_LIBRARIES>\" > <TARGET>"
)
add_executable(LinkLine "")
target_link_libraries(LinkLine MyLibraryTarget)
set_target_properties(
LinkLine
PROPERTIES
LINKER_LANGUAGE ECHO
SUFFIX ".txt"
)
The nice thing about this approach is, that the output of my LinkLine target can be used as any other "officially generated" executable output (e.g. in install() commands or post-build steps with generator expressions):
add_custom_command(
TARGET LinkLine
POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:LinkLine> PackageCfg/$<TARGET_FILE_NAME:LinkLine>
)
References
Recursive list of LINK_LIBRARIES in CMake
add_custom_command is not generating a target

How to configure external cmake libraries?

What I wanted to do is call
add_subdirectory(ext/oglplus)
and be done with it. Unfortunately it is not that simple. There is a huge buildscript which detects various opengl settings. So I tried the following
ExternalProject_Add(liboglplus
SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/ext/oglplus
CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/ext/oglplus/configure.py --use-glew
BUILD_COMMAND ${MAKE})
The problem that I have is don't really want to build it like that. It also doesn't build correctly because for some reason it wants to install the library and because there is no install target it will abort the compilation.
But the build script is calling cmake under the hood.
So what I want to do is to tell cmake to use "cofigure.py" instead of "cmake .." and then use it like any other cmake library.
Is this possible?
I used to call Linux Kernel KBuild from CMake using
ADD_CUSTOM_COMMAND() and ADD_CUSTOM_TARGET()
This way you can run arbitrary commands (like your config.py) and use the output.
First setup the command with all command-line options as CMake-variables, in tou case this would be calling the config.py script ${CMAKE_CURRENT_SOURCE_DIR}/ext/oglplus/.
Instead of encoding the Path to your script in the command (adding ext/oglplus) I think it may be better adding WORKING_DIRECTORY to the custom command:
add_custom_command
SET(KBUILD_CMD ${CMAKE_MAKE_PROGRAM}
-C ${KERNEL_BUILD_DIR}
CROSS_COMPILE=${CROSS_COMPILE} ARCH=${ARCH}
EXTRA_CFLAGS=${KBUILD_EXTRA_CFLAGS}
INSTALL_MOD_PATH=${INSTALL_MOD_PATH}
M=${CMAKE_CURRENT_SOURCE_DIR}
KBUILD_EXTRA_SYMBOLS=${depends_module_ksyms}
)
Add a custom command that calls your build-script and creates a file in the CMAKE_CURRENT_BINARY_DIRECTORY (note the second COMMAND to touch a file)
ADD_CUSTOM_COMMAND(
OUTPUT ${module_name}.built
COMMAND ${KBUILD_CMD} modules
COMMAND cmake -E touch ${module_name}.built
COMMENT "Kernel make modules ${module_name}"
VERBATIM
)
Add a custom target, its always out of date, but if you want it to be called automatically add ALL otherwise you have to explicityly call make module_build, I guess this is what you want.
ADD_CUSTOM_TARGET("${module_name}_build" ALL
DEPENDS ${depends_module_ksyms}
${CMAKE_CURRENT_BINARY_DIR}/${module_name}.built
COMMENT "Building Kernel Module ${module_name}"
)

install(FILES "${CMAKE_CFG_INTDIR}/Abc_Win.dll" DESTINATION "Bin")

Because the 'Abc_Win.dll' is shared ('dll') and needs to be copied to the target-EXE I added a custom target - like this. I'm working with MS-VisualStudio 2005-2011 and using cmake 2.8.8.
add_custom_target( "Abc_Win.dll" )
add_custom_command( TARGET "Abc_Win.dll" POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_if_different
"MyDllSource/${CMAKE_CFG_INTDIR}/Abc_Win.dll"
"MyExeDest/${MWEB_CMAKE_CFG_INTDIR}/Abc_Win.dll" )
set_property(Abc_Win.dll" PROPERTY FOLDER ${MWEB_FOLDER_ADDON}/${MWEB_FOLDER_RTE})
All above working like I expect and the 'Abc_Win.dll' get on the right place when I build.
Now I add an the following install command - expecting 'Abc_Win.dll' in "Bin"-Directory beside my EXE.
install(FILES "MyDllSource/${CMAKE_CFG_INTDIR}/Abc_Win.dll" DESTINATION "Bin")
When I build now the CMakePredefinedTargets->INSTALL (doesn't matter which MS-StudioVersion I use) I get always a build error in the cmake generated file 'cmake_install.cmake':
file INSTALL cannot find
"MyDllSource/$(Configuration)/Abc_Win.dll"
I understand that cmake does not uses build-rules from MS-VS - like it does it for add_custom_command. It also seems to be that this cmake-file has no glue from the Content $(CONFIGRATION) which is set actual to 'Debug'.
Has anybody an idea how to solve this Problem? Help would be very appreciated. Thanks.
There's an undocumented variable you can use here: CMAKE_INSTALL_CONFIG_NAME.
Unless you happen to have defined this yourself in your CMakeLists.txt, it will be undefined when CMake runs.
However, when you use install commands in your CMakeLists.txt, CMake generates a file called "cmake_install.cmake" in the root of your build tree (same place as CMakeCache.txt). This is executed at install time, and it sets CMAKE_INSTALL_CONFIG_NAME to your current configuration in Visual Studio.
There's another slight twist; to avoid CMake expanding ${CMAKE_INSTALL_CONFIG_NAME} in the install command (it would expand to an empty string), you need to escape it with a \.
So, you just need to change your install command to:
install(FILES "MyDllSource/\${CMAKE_INSTALL_CONFIG_NAME}/Abc_Win.dll"
DESTINATION "Bin")