Add "include" directories from multiple folders - cmake

On Windows, I install dependencies to c:\sdk\my_dependency\, where each dependency folder contains include, lib, bin etc...
Within a CMakeLists.txt for a project, how can I add every sub-include folder within c:\sdk to my list of include directories? (And similarly for lib to my list of link library directories)
i.e. is it possible to specify c:\sdk\**\include in my CMakeLists.txt?
And is this advisable practice?

Although the typical CMake idiom is to use find_package() for finding and populating CMake variables (*_INCLUDE_DIRS, *_LIBRARIES) for third-party packages, what you're suggesting can also be achieved using the GLOB subcommand of file(). You can use * in the globbing expression to grab all of the include or lib directories in C:/sdk:
# Make a list of all the include directories.
file(GLOB MY_INCLUDE_DIRS
C:/sdk/*/include
)
# Make a list of all the lib directories.
file(GLOB MY_LIB_DIRS
C:/sdk/*/lib
)
The GLOB option is powerful, and has a recursive capability for more complex situations, so I encourage you to check out the documentation.

Related

Building cmake project with dozens of package dependencies in different subdirectories

I am trying to build an example project that requires dozens of packages contained in different subdirectories, for example
/home/Olumide/src/project/Release/modules/module1/CMakeFiles/Export/lib/cmake/module1
/home/Olumide/src/project/Release/modules/module2/CMakeFiles/Export/lib/cmake/module2
/home/Olumide/src/project/Release/modules/module3/CMakeFiles/Export/lib/cmake/module3
...
Given that the application that I'm trying to build is in the location /home/Olumide/src/project/applications/tutorial, is it possible to build the application without explicitly specifying the paths to all each package that the project requires, or modifying the CMakeLists.txt file, for example by specify a common root path to be searched for all the packages, for example:
cmake -DCMAKE_MODULE_PATH=/home/Olumide/src/project/Release/modules .
Unfortunately this does not work and cmake complains that it cannot find package configuration files with the names Modul1eConfig.cmake or module1-config.cmake etc.
If all of the modules adhere tho this exact pattern you should be able to provide the "root path" via cache variable and pass a the info where to look for the libs to find_package via PATHS parameter:
# maybe a more reasonable default here?
set(MYPROJECT_MODULE_PATH "/home/Olumide/src/project/Release/modules" CACHE PATH "the path to the modules we're looking for")
set(MYPROJECT_MODULE_NAMES
module1
module2
...
)
foreach(_MODULE IN LISTS MYPROJECT_MODULE_NAMES)
find_package(${_MODULE} REQUIRED CONFIG
PATHS "${MYPROJECT_MODULE_PATH}/${_MODULE}/CMakeFiles/Export"
)
endforeach()
In general if these packages logically belong to the same software package, you should provide a way of finding those modules by passing them as components for find_package but since this seems to be code not under your own control you may not have that luxury. (E.g. boost provides this functionality: find_package(boost COMPONENTS test mpl ...).) However it may be worth some investigation if there is a configuration script somewhere that's supposed to automatically include the modules, if listed as components, e.g. somewhere in Release or Release/modules.

Install a target defined in an included directory [duplicate]

Consider the following CMakeLists.txt file:
add_subdirectory(execA)
add_subdirectory(libB)
install(TARGETS execA libB
RUNTIME DESTINATION bin
LIBRARY DESTINATION lib
ARCHIVE DESTINATION lib)
I get the following error:
install TARGETS given target "execA" which does not exist in this
directory
execA and libB have their own CMakeList.txt files and are located under project directory, as well as the build directory I'm running cmake (cmake ..):
project
|------ CMakeList.txt (the one with the code)
|----execA
| \- .cpp, .hpp and CMakelist.txt
|----libB
| \- .cpp, .hpp and CMakelist.txt
|---- lib
|---- bin
\---- build (where I´m commanding: $ cmake ..
How do I fix this error?
According to this bugreport, install(TARGETS) command flow accepts only targets created within the same directory.
So you need either move the add_library() call into the top-level directory, or split install(TARGETS) call into per-target ones, and move each of them into the corresponding subdirectory.
Since CMake 3.13 install(TARGETS) can work even with targets created in other directories.
install(TARGETS) can install targets that were created in other directories. When using such cross-directory install rules, running make install (or similar) from a subdirectory will not guarantee that targets from other directories are up-to-date.
Even though it would help seeing the CMakeLists.txt files contained in the subdirectories, I guess they contain add_executable and/or add_library statements to create your stuff.
Also, because of your example, I guess you are using the same name of your directories for your targets.
That said, you should know that symbols defined in a CMakeLists.txt file in a subdirectory are not visible by default within the context of the CMakeLists.txt file in the parent directory. Because of that, you should rather move your install statements within the CMakeLists.txt files within your subdirectories.
This should solve the problem, if my thoughts were right. Otherwise, I strongly suggest you to post in your question also the content of the other files above mentioned.
Anyway, the error is quite clear.
The file that contains the install statement for the target named X does not contain a target creation statement (add_executable and the others) that gives birth to that target, so it goes on saying that that target does not exist in that directory.
This still seems to be a pain point in CMake 3.11.
In our codebase, we have many targets defined in subdirectories and need to create an assortment of installers with different configurations and (potentially overlapping) combinations of targets.
Here's my solution:
Before calling add_subdirectory in your root CMakeLists.txt file, create a GLOBAL property with the names of the target(s) you want to include in your installer.
Wrap target creation functions (add_executable, etc.) in your own custom functions. Within those functions check if the target is present in the global property, and invoke install accordingly.
That approach allows you to centralize installer configuration.
Also: To support creation of multiple installers, we populate our global list along with other installer properties in separate .cmake files. When we invoke cmake, we pass the name of the installer configuration CMake file as a command-line argument. Our root CMakeLists.txt file simply calls include with that file.

CMake include path of installed libraries

Suppose your project has multiple authors and depends on some libraries that must be installed on your system - you don't ship them with the project.
Some people have installed that libraries in /usr, /usr/local/, /opt or /opt/local.
What is the best practice to add them to the include path, without messing up CMakeLists.txt with all possible paths?
I am aware of xxx_ROOT variables like BOOST_ROOT, but not all library detections based on such a variable.
Teach your users / co-authors to use custom CMAKE_PREFIX_PATH which they can pass to their CMake call:
cmake -DCMAKE_PREFIX_PATH=/opt/local;/home/brandstifter/boost-1.70/ ..
For each find command, CMake will also search within the paths from CMAKE_PREFIX_PATH. See its documentation.

is CMake ignoring CMAKE_LIBRARY_OUTPUT_DIRECTORY?

I just read this answer, suggesting the use of CMAKE_LIBRARY_OUTPUT_DIRECTORY for setting the directory in which library targets are created. Well, this doesn't seem to work for me:
# etc. etc.
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib/")
cuda_add_library(
mykernels
src/kernel_wrappers/kernel1.cu
src/kernel_wrappers/kernel2.cu)
When I make, the library libmyktkernels.a is created in the main project folder (where my CMakeFiles.txt is located), not in the lib/ subdirectory. Why is that?
Use CMAKE_ARCHIVE_OUTPUT_DIRECTORY for the static libraries.
CMAKE_LIBRARY_OUTPUT_DIRECTORY applies only to dynamic libraries.

cmake use one cmakelist.txt for a project with subdirectories

i like to structure my code in multiple subdirs but i dont want to create a new cmakelist.txt in each new subdir.
my folder structure is something like this:
project
>cmakelist.txt
>build
>src
>main.cpp
>multiple_subdirs_or_(c|h)pp_files_with_more_subdirs_or_(c|h)pp_files
my cmakelist.txt looks like this:
...
file(GLOB_RECURSE cpps RELATIVE ${CMAKE_CURRENT_LIST_DIR} "src/*.cpp")
file(GLOB_RECURSE hpps RELATIVE ${CMAKE_CURRENT_LIST_DIR} "src/*.hpp")
#remove files with main
list(REMOVE_ITEM cpps "src/test.cpp")
#bins
add_executable(test src/test.cpp src/test.cpp ${hpps} ${cpps})
#same problem if this is used instead of the other add_executable
add_library(foo OBJECT ${cpps} ${hpps})
add_executable(test src/test.cpp $<TARGET_OBJECTS:foo>)
the problem with my file:
source files created after the execution of cmake are not compiled and the build fails if they are used.
as predicted by http://www.cmake.org/cmake/help/v3.0/command/file.html in section GLOB:
We do not recommend using GLOB to collect a list of source files from
your source tree. If no CMakeLists.txt file changes when a source is
added or removed then the generated build system cannot know when to
ask CMake to regenerate.
the question: is it possible to use a single cmakelist.txt for a project with multiple sub directories? (without the problems of file(GLOB ...) )
You have two totally unrelated things here.
First, can you use only a single CMakeLists.txt file for your whole project? Yes, of course you can (although I'd personally not go this way after a project has reached a certain size), and you're already doing this.
Second, the problem with GLOB. You already quoted the part of the documentation where it states what problems the use of GLOB has. This cannot really be avoided at the moment if you want to continue using GLOB, as this is part of the cmake design where they distinguish between what is done during configure and build time. The alternative is to list all files manually. Whether you do this in a single CMakeLists.txt file in your projects main directory, or in multiple files across your subdirectories does not matter.
To answer your question: yes, it is possible to handle a project with multiple sub-directories and one CMakeLists.txt. I have two considerations for you to take into account:
I strongly recommend you not using file(GLOB ...) for sources.
You have to list the files manually. For example (src/ is the source-subdirectory):
set(cpps src/file1.cpp src/file2.cpp src/file3.cpp)