I would like to add libraries to my current project.
The idea was to do something like this :
if(build_libs)
add_subdirectory(libs1)
add_subdirectory(libs2)
add_subdirectory(libs3)
add_subdirectory(libs4)
endif()
But, libs2 need generated files/lib from libs1 after the build. There is a cmake verification/find from libs2 finding libs1.
How can I enforce libs1 to be build before adding subdir libs2 ?
Same for libs3->2, libs4->3
Related
I want anyone who cloned the repository can build it immediately, and don't need to install the dependencies.
Therefore, I found several ways:
Use git submodule and add_subdirectory.
Use find_package to find the built libraries and the headers.
The first one takes much time to build, so I think the second might be better. To make people be able to build the project instantly, I put the the files in the project, but it saied it doesn't know the linker language. What's this? And how to solve?
Direstories:
Project Root
lib
SDL2
(generated files when install)
include
(headers)
src
(sources)
CMakeLists.txt
CMakeLists.txt:
# ...
list(APPEND CMAKE_PREFIX_PATH lib)
find_package(SDL2)
# ...
I have a submodule with a CMakeLists.txt, which I would like to "amend" in a way to make it work for my specific purpose (I need to add compiler flags and a different output directory) The output is a static library. My current approach is as follows:
I have a CMakeLists.txt in the root directory, which adds the submodule CMakeLists.txt via add_subdirectory() like so:
set(CMAKE_CXX_FLAGS "-my_needed_flags "
add_subdirectory(SubmoduleLibrary)
set_target_properties(SubmoduleLibrary PROPERTIES ARCHIVE_OUTPUT_DIRECTORY output_folder)
add_custom_target(BuildLib)
add_dependencies(BuildLib SubmoduleLibrary)
Now this seems to work in some ways (the output directory is correctly chosen). But I get linker errors which I don't get when I compile the library adding the flags etc to the original CMakeLists.txt.
What is the correct way to build a library from an existing CMakeLists.txt with added parameters?
I am trying to get a basic cmake project to work with 2 subprojects (each a library) where one depends on the other.
As such I have a self-contained project for lib1 and a self-contained project for lib2 (but that depends on lib1). Some lib2 authors could while others will not have access to lib1 source. If no access is desired, it seems that building and installing one after the other is the way to go. Is there a way to build them in one go using cmake? Currently, I am trying using an overall project, libs.
However, as the libraries are related I want to call them in a boost / poco like fashion. That is for lib2 I would like to write:
find_package(libs COMPONENTS lib1 REQUIRED)
target_link_libraries(lib2 PUBLIC libs::lib1)
I have created config files for both lib1 and lib2 and libs. However, I keep getting the same error
CMake Error at libs/lib2/CMakeLists.txt:67 (find_package):
By not providing "Findlibs.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "libs", but
CMake did not find one.
Could not find a package configuration file provided by "libs" with any of
the following names:
libsConfig.cmake
libs-config.cmake
Add the installation prefix of "libs" to CMAKE_PREFIX_PATH or set
"libs_DIR" to a directory containing one of the above files. If "libs"
provides a separate development package or SDK, be sure it has been
installed.
I don't understand where to put these files. It searches for them under prefix/ etc but at the time of building none of these libraries is yet installed. What is the proper place to put the -config.cmake files? I have put them all in
${CMAKE_BINARY_DIR}/libs
which seems similar to Poco, but the error remains. How can the libraries find each other?
// update:
From the comments I understand that lib1 first needs to be build in order to use find_package. Is there a way (in cmake) to
build lib1, install it, build lib2
or is this better to do using a bash / python / etc script?
I have a project that needs to be built with an LLVM pass. Here is the project structure:
proj/
instrumentation/
CMakeLists.txt
Instrumentation.cpp
[My project files]
CMakeLists.txt
instrumentation/CMakeLists.txt has a target to build the LLVM pass called MyPass.
I've added the following the CMakeLists.txt:
add_subdirectory(instrumentation)
add_compile_options(
"SHELL:-Xclang -load"
"SHELL:-Xclang $<TARGET_FILE:MyPass>")
Now I just need to add MyPass as a dependency for all the targets in my project. I was wondering if there was a way to force MyPass to build first so that when compiling other files, the LLVM pass would be present. Maybe there a way to add a target compile_options dependencies?
Note: I'd rather not add the dependency manually to every target because there many targets in the project.
My solution to this is to create another project to wrap the compiler executable and automatically build with the LLVM pass. Then rebuild the original project with the wrapped compiler.
AFL does this exact thing when building with a clang compiler.
There are two libs libA and libB depending on libBase and including it into build process with
add_subdirectory(../libBase build/libBase)
Everything works when they are build separately. But when project prj wants to include everything into its build process:
add_subdirectory(../libA build/libA)
add_subdirectory(../libB build/libB)
Then cmake complaints about target redefinition:
add_library cannot create target "libBase" because another target with the same name already exists.
How to make such project (building all dependences in one step) correct? Is it achievable with add_subdirectory or sth else should be used to add dependencies?
Found it: include_guard() since cmake 3.10