Is there a command on CMake to started executable resulted from build? - cmake

I'm trying to write generic way to run executable resulted after build using CMake's way.
git clone git#github.com:gargamel/ihatesmurfs.git
cmake -E make_directory build
cmake -Sihatesmurfs -Bbuild
cmake --build build
cmake -E chdir build
Now I want to start executable but on *nix, it's like:
./output
and on Windows:
output.exe
Is there a way to escape this with any possible CMake command?

Expanding on my comment a bit, you can modify the CMakeLists.txt file of the project to include add_custom_command. If your CMake creates an executable named HateSmurfs, you can add the custom command to run the executable after compilation completes:
add_executable(HateSmurfs smurfs.cpp)
# Add this piece of code to run the executable after it is built.
add_custom_command(
TARGET HateSmurfs
POST_BUILD
COMMAND HateSmurfs
)

According to add_custom_command documentation:
COMMAND
If COMMAND specifies an executable target name (created by the add_executable() command) it will automatically be replaced by the location of the executable created at build time.

Related

CMake: dependecies of add_custom_command

Let's say I have a Python script which does something with just built executable. And I want CMake to rebuild that executable if the script was modified (actually it is enough to just re-run the script, but rebuild an executable is fine too).
add_executable(App src/main.cpp)
add_custom_command(
TARGET App
POST_BUILD
COMMAND "${Python3_EXECUTABLE}" ARGS "scripts/do_stuff.py" "$<TARGET_FILE:App>"
WORKING_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}"
)
How can I achieve that? add_custom_command with TARGET argument doesn't support DEPENDS argument. add_dependency(App "scripts/do_stuff.py") produces an error, because "scripts/do_stuff.py" is not a target, but just a file.
Running the script is very important for correct working of the executable so I don't want define completely separate target via add_custom_command allowing bypass script execution by building just App target.
actually it is enough to just re-run the script
So the executable does not depend on the script. So re-run the script, not the executable.
add_executable(app src/main.cpp)
add_custom_command(
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/did_do_stuff
COMMAND "${Python3_EXECUTABLE}" "scripts/do_stuff.py" "$<TARGET_FILE:app>"
COMMAND ${CMAKE_COMMAND} -E touch ${CMAKE_CURRENT_BINARY_DIR}/did_do_stuff
DEPENDS "$<TARGET_FILE:app>"
"${CMAKE_CURRENT_LIST_DIR}/scripts/do_stuff.py"
WORKING_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}"
)
add_custom_target(do_stuff
DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/did_do_stuff
)
And build target do_stuff (or all) to run it.

Cmake add_custom_command is never running

My question is very similar to cmake: add_custom_command / add_custom_target ignoring dependency
But the answer specified does not solve my issue, and also it is for a newer version of cmake (3.20)
I want some files (shader files) to be copied to the executable directory every time the shader source changes
So I have the following code in cmake:
add_custom_command(
OUTPUT ${CMAKE_BINARY_DIR}/Shaders.txt
COMMAND ${CMAKE_COMMAND} -E echo "Actually Copying shaders"
COMMAND ${CMAKE_COMMAND} -E copy_directory ${CMAKE_CURRENT_SOURCE_DIR}/assets/ $<TARGET_FILE_DIR:Editor>/assets
COMMAND ${CMAKE_COMMAND} -E touch ${CMAKE_BINARY_DIR}/Shaders.txt
DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/assets
)
add_custom_target(CopyShaders ALL DEPENDS ${CMAKE_BINARY_DIR}/Shaders.txt)
Now, as I understand, CopyShaders will always be built (since it is always out of date), but Shaders.txt should only be built once (after the shader source is changed), after which it is up to date
I'm trying to build the target CopyShaders using cmake --build build --target CopyShaders
If I'm using MinGW, then "Actually copying shaders" never gets printed if Shaders.txt is present, even if the assets folder containing the shaders has been modified
If I'm using MSVC, I get the following warning on the terminal:
warning MSB8064: Custom build for item "D:\Acads\Programming\opengl\SummerOfCode\build\CMakeFiles\05fb3856b7a5e1f6ce1ea66ca9091779\Shaders.txt.rule" succeeded, but specified dependency "d:\acads\programming\opengl\summerofcode\editor\assets" does not exist. This may cause incremental build to work incorrectly. [D:\Acads\Programming\opengl\SummerOfCode\build\Editor\CopyShaders.vcxproj]
Again, I do have the folder existing
I figured it out
DEPENDS should only take as input files, not folders
Replacing it with all the files inside /assets works

Run PowerShell or Shell script from CMake

I have a (power)shell script that generates a version file used in other source files in the project.
How can I "register" this script to be used with CMake in build time? Here is what I have tried:
function(version)
set(SRC version.h)
set(VERSION_CMD ${CMAKE_SOURCE_DIR}/fw_lib/version/version.ps1)
ADD_CUSTOM_TARGET(version DEPENDS ${SRC})
ADD_CUSTOM_COMMAND(
OUTPUT ${SRC} COMMAND ${VERSION_CMD}
${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR}
)
endfunction(version)
Note that ${CMAKE_SOURCE_DIR} and ${CMAKE_BINARY_DIR} are input arguments to the script.
I get the following error:
process_begin: CreateProcess(....) failed.
make (e=193): Error 193
How can I make this work?
Maybe it is too late, but for future:
# find Powershell executable
find_program(POWERSHELL_PATH NAMES powershell)
add_custom_command(
TARGET "program"
POST_BUILD
COMMAND ${POWERSHELL_PATH} "Some Powershell command")

Generate script during build with cmake

I have a cmake project with a single source file called main.c. I want to additionally provide a wrapper script which calls main with specific parameters.
My CMakeLists.txt looks as follows:
cmake_minimum_required(VERSION 3.1...3.16)
file(WRITE ${CMAKE_BINARY_DIR}/wrapper "#!/usr/bin/env bash\n")
file(APPEND ${CMAKE_BINARY_DIR}/wrapper "./main options\n")
add_executable(main main.c)
add_custom_target(wrapper_target
ALL DEPENDS wrapper)
add_custom_target(main_target
ALL DEPENDS main wrapper_target)
add_dependencies(main wrapper_target)
install(
TARGETS main
RUNTIME DESTINATION bin/)
install(
PROGRAMS wrapper
DESTINATION bin/)
If I run cmake --install ., the script wrapper is installed together with the binary main. Running cmake --build . produces the script wrapper, but it is not marked as executable (on Linux).
How can I tell cmake to also generate wrapper during build and mark it as executable?
Note: I need this for an automated build system which runs build and not install, and expects a specific file to be available on build.
Try:
file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/wrapper.tmp
"#!/usr/bin/env bash
# Note that './main' is relative from whatever directory you are in
# Use just main assuming the install prefix is in your bath
# Or use $<TARGET_FILE:main>
# Or maybe ${CMAKE_INSTALL_PREFIX}/bin/main
./main options
")
# add execute permissions
file(
COPY ${CMAKE_CURRENT_BINARY_DIR}/wrapper.tmp
DESTINATION ${CMAKE_CURRENT_BINARY_DIR}
FILE_PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE
)
# Rename the file
file(RENAME
${CMAKE_CURRENT_BINARY_DIR}/wrapper.tmp
${CMAKE_CURRENT_BINARY_DIR}/wrapper
)
How can I tell cmake to also generate wrapper during build and mark it as executable?
file( is a in a cmake script - it is executed during configuration phase, when cmake is executed. To generate the file during build use add_custom_command, the most "portable" way in cmake sense would be to run a cmake script inside add_custom_command:
add_custom_command
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/wrapper
COMMAND $(CMAKE_COMMAND)
-D CMAKE_CURRENT_BINARY_DIR=${CMAKE_CURRENT_BINARY_DIR}
-P ${CMAKE_CURRENT_SOURCE_DIR}/the_cmake_script.cmake
DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/the_cmake_script.cmake
COMMAND Generating wrapper script...
VERBATIM
)
then inside the_cmake_script.cmake you could do the script above - add_custom_command will execute the command cmake -P <the script> during build of you project. That way you can DEPEND properly on the wrapper script.
CMake 3.20 added support for FILE_PERMISSIONS attribute to the FILE command. So one could simply:
FILE(GENERATE OUTPUT ${CMAKE_BINARY_DIR}/wrapper
CONTENT
"#!/usr/bin/env bash
./main options
"
FILE_PERMISSIONS OWNER_EXECUTE OWNER_WRITE OWNER_READ)

cmake, how to specify the output directory

I'm using cmake to generate a VS2017 solution (and projects...), I try to generate everything in a different folder.
I used both the command line and different variables, but no way, it generate in the "source" folder !
Here are some examples of what I tried:
cd source
cmake -B../build ...
cd build
cmake ../source
cmake --build "../build"
cmake -Dxxx=../build
Any idea ? all theses solutions are expected to generate in the build folder !
Once you have performed in-source build (in source directory), it is impossible to build the project out-of-source: every such attempt will modify in-source build.
You need to clear build files (CMakeCache.txt, probably some other ones) in source directory before using out-of-source builds.
I fixed with:
cd VSBuild
cmake ../
instead of
cd VSBuild
cmake ..
Have you tried this? This will put all the build files under "out"
$ cmake -H. -Bout
To execute:
$ cmake --build out