# Share targets between src and tests subdirectory
**URL:** https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564
**Category:** Code
**Created:** [April 4, 2024, 9:11am UTC](https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564 "2024-04-04T09:11:52Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@mredenti](https://discourse.cmake.org/u/mredenti)
#### Post date: [April 4, 2024, 9:11am UTC](https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564/1 "2024-04-04T09:11:53Z")
How can I make use of already compiled targets in another subdirectory? Do I necessarily need to build a library?
Suppose I have a (mini) finite element code and have structured the project as follows
│── CMakeLists.txt
│── unit-tests
│ └── CMakeLists.txt
│ └── test\_mesh.cpp
│ └── test\_element.cpp
│ └── test\_solver.cpp
│── src
└── CMakeLists.txt
└── mesh.cpp/.hpp
└── element.cpp/.hpp
└── solver.cpp/.hpp
└── main.cpp
The src/CMakeLists.txt files will have a main target composed of mesh.cpp, node.cpp, solver.cpp, element.cpp. I also have a unit-test/CMakeLists.txt that unit tests the mesh, element and solver components. How to avoid having to recompile the same mesh.cpp, node.cpp, solver.cpp, element.cpp also in the unit-test subdirectory? I do not want to define them as targets again but rather be able to use the targets already defined in src/CMakeLists.txt
---
### Author:  [@buildSystemPerson](https://discourse.cmake.org/u/buildSystemPerson)
#### Post date: [April 4, 2024, 3:42pm UTC](https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564/2 "2024-04-04T15:42:29Z")
The simplest solution is to make a STATIC library that your executable links.
```auto
# src/CMakeLists.txt
add_library(foo STATIC)
target_sources(foo PRIVATE
mesh.cpp
element.cpp
solver.cpp
)
target_include_directories(foo PUBLIC .)
add_executable(bar)
target_sources(bar PRIVATE main.cpp)
target_link_libraries(bar PRIVATE foo)
```
```auto
# unit-tests/CMakeLists.txt
add_executable(tests)
target_sources(tests PRIVATE
test_mesh.cpp
test_element.cpp
test_solver.cpp
)
target_link_libraries(tests PRIVATE foo)
```
---
### Author:  [@mredenti](https://discourse.cmake.org/u/mredenti)
#### Post date: [April 4, 2024, 3:45pm UTC](https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564/3 "2024-04-04T15:45:50Z")
Ok, thank you. I have two follow up questions:
- Should I make them imported targets or imported targets should left only for dependencies?
- What would be a non-simplest solution?
---
### Author:  [@buildSystemPerson](https://discourse.cmake.org/u/buildSystemPerson)
#### Post date: [April 4, 2024, 4:05pm UTC](https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564/4 "2024-04-04T16:05:18Z")
> Should I make them imported targets or imported targets should left only for dependencies?
None of what you are showing requires imported targets at all.
> What would be a non-simplest solution?
I’d just encourage looking into using ctest for running your unit tests.
This blog gives a good introduction to ctest: [Using CMake’s CTest and add\_test To Run All Your Tests](https://matgomes.com/cmake-ctest-to-add-cpp-tests/)
---
### Author:  [@mredenti](https://discourse.cmake.org/u/mredenti)
#### Post date: [April 5, 2024, 1:49pm UTC](https://discourse.cmake.org/t/share-targets-between-src-and-tests-subdirectory/10564/5 "2024-04-05T13:49:40Z")
> [@buildSystemPerson](#):
>
> I’d just encourage looking into using ctest for running your unit tests.
>
> This blog gives a good introduction to ctest: [Using CMake’s CTest and add\_test To Run All Your Tests](https://matgomes.com/cmake-ctest-to-add-cpp-tests/)
The blog follows the same approach you mentioned of defining a library. It does not really use an alternative approach. It only adds the use of CTest and GTest to the mix but that I am already doing.
Thus, in essence it seems the approach is to define a library