I want a add_custom_target to run a loop over some files to create several symbolic links (and maybe doing more stuff).
My approach (maybe not the best?) has been:
add_custom_target(myTargetNAme-link echo "HERE" # This is printed
COMMAND
for file in /mylocation/*
do
### Create links using $file
done
DEPENDS dependency
WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
COMMENT "Create a link to use files in dev env" VERBATIM
)
And I get the following error:
/bin/sh: -c: line 1: syntax error: unexpected end of file
Is this a smart way to do operations over files?
What's the right syntax for a foor loop like this in CMAKE?
EDIT
Following the comment in the question, I'd like to be more precise:
I have a project that produces a .so file containing a python module AND it should come with a couple .py files.
What I really want to do is to create a symbolic link from the .so and .py files to the python installation.
I was reusing some code, these targets were called in a script using:
nice -n 11 ninja myTargetNAme-link
Maybe I could avoid doing this as well?
ALSO
I deleted the VERBATIM keyword and it made it possible to use *.py for ln so now the symbolic link are actually generated.
Related
Let's assume I have a Cmake C project, and I have something like this in the project:
project(my_project C CXX ASM)
set(my_executable_sources
main.c
file_one.c
)
set(my_executable_sources ${my_executable_sources} file_two.c)
add_executable(my_executable
${my_executable_sources}
file_three.c
)
Let's assume I'm in the ./build subfolder, and cmake ../ -G "Unix Makefiles" has passed successfully.
Can I somehow query build information from the command line using cmake?
For instance, I'm interested here in the final list of source files for my_executable; is there a command that would easily retrieve them? Say, like the following pseudocode:
$ cmake --pseudo-query-build --project="my_project" --target="my_executable" --query="source_files"
my_executable source files:
main.c
file_one.c
file_two.c
file_three.c
I don't see any cmake-generator-independent way of achieving this and even if you know the generator in use the project files generated.
You could modify your project to include a custom target that prints the sources though:
add_custom_target(print_my_executable_sources COMMAND ${CMAKE_COMMAND} -E echo "$<TARGET_PROPERTY:my_executable,SOURCES>" COMMAND_EXPAND_LISTS)
this allows you to use
cmake --build <binary_dir> [--config <configuration>] --target print_my_executable_sources
to print the sources, even if generator expressions are used in the sources.
Note: This does print all files in a single line; to get all the file names on separate lines, you could instead run cmake with the -P option passing the soures via -D and add logic to print one file name per line in the cmake script file.
Alternatively setting the CMAKE_EXPORT_COMPILE_COMMANDS variable to True during configuration could result in the generation of json files that would allow for the extraction of the information, but you'd need a json parser to extract the info. Furthermore this approach only works for the Makefile and Ninja CMake generators. Also I'm not sure you can tell which target a source file belongs to in all cases.
Start by obtaining the target's sources via this line (after add_executable):
get_target_property(MY_TARGET_SOURCES my_executable SOURCES)
And then proceed with a simple line at the end of the file (after add_executable)
message(STATUS ${MY_TARGET_SOURCES})
EDIT: For a full list of available target properties refer to this link.
EDIT2: As I've noticed now that you probably intend to just use it within the CLI, then for my solution you would also have to encapsulate it with a if/endif that checks for a definition e.g. if(SOURCES_DEBUG_INFO) and then run it with -DSOURCES_DEBUG_INFO=TRUE
Edit: my question targets the early configure stage where CMake input files are still being parsed and thus have to be present before include() is being called. So the answer found here: Force CMake to generate configure_file target every build does not solve my problem since it generates files after include() statements have been interpreted.
I have a CMakeLists.txt that includes a file which is generated in the configure stage:
execute_process(COMMAND "my-generator -o generated.cmake")
include(generated.cmake)
Apart from the fact that this approach doesn't feel right (not to say elegant) I now need to re-generate that file before every build (my-generator produces output that incorporates the current time).
My assumption is that I can't use add_custom_command() or add_custom_target() because the file would be generated at compile time but needed in the configure-step.
This very old post suggests to touch the input file so I did this:
execute_process(
COMMAND "my-generator -o generated.cmake"
COMMAND cmake -E touch "${CMAKE_CURRENT_LIST_FILE}")
.. which does not produce errors but calling make multiple times won't run the configure step more than once.
What do I do wrong? Is there a better approach?
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
This is what typically happens. I get source code that has cmake build scripts. I create a build subdirectory, change to it, run cmake <options> ... Depending upon the project and its dependencies I have to repeat the last step until it finds all necessary dependencies and generates makefiles. I successfully build and use the project. Few days pass, I forget about this installation. Then one day I'm trying to setup the same project on another machine and now I can't recall what exact CMake command line I used in the past to get things working.
I still have the old build directory on the old machine. Can I find the cmake command line I used in the past, by looking into some of the autogenerated files in the build directory? I was expecting CMake would just put the exact command line I used in one of these files in commented form. But if it does so, I haven't found it yet.
How can I find the original CMake command line I used?
You can't.
Original CMake command can be guessed from analysis of CMakeCache.txt
As a workaround, you could always create a simple wrapper to store the original command line used. Something along these lines:
#!/bin/bash
echo "$#" > cmake_command.log
$#
I have created a simple application that works ok. However, now I need to link with some libraries in the following directory.
/opt/norton/lib
In my make file I have the following with works, but I need to use cmake
LIBS_PATH = -L/opt/norton/lib
INC_PATH = -I/opt/norton/inc
LIBS = -lntctrl
In my CMakeList.txt I have this but doesn't work I keep gettng the following error:
undefined reference to `nt_init'
This is my CMakeList.txt
# Includes files
INCLUDE_DIRECTORIES(/opt/norton/inc)
# Link libraries
LINK_DIRECTORIES(/opt/norton/lib)
# Add the library that is used by nt_init
TARGET_LINK_LIBRARIES(-lntctrl)
ADD_LIBRARY(application initialize_nw)
Many thanks for any advice,
Try out TARGET_LINK_LIBRARIES(ntctrl), the -l flag should not be used there (guess from what I have in mind)
This is how I would write the cmake file:
include_directories(/opt/norton/inc)
link_directories(/opt/norton/lib)
add_executable(application initialize_nw)
target_link_libraries(application ntctrl)
To show what are the actual command lines run during a make, use:
make VERBOSE=1
Maybe this shows you the difference between what you ran manually and the cmake generated commands.