# How to ignore 3rd-party sources from static analysis
**URL:** https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596
**Category:** Usage
**Created:** [July 25, 2023, 3:50pm UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596 "2023-07-25T15:50:46Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@decomplect](https://discourse.cmake.org/u/decomplect)
#### Post date: [July 25, 2023, 3:50pm UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596/1 "2023-07-25T15:50:46Z")
I’ve been using [project options](https://github.com/aminya/project_options) as a way to get some solid defaults for my projects without too much trouble.
One problem I’ve been running into though is the `CMAKE_$LANG_CPPCHECK` defaults and how they apply to 3rd party dependencies.
It seems like when this option is set, 3rd party libraries (in my case, Catch2) are also subject to these globals. Static analysis (e.g. cppcheck) is performed on them and fails, when it is not my intention to run it on these 3rd-party libs. If it matters, I’m using CPM to download Catch2.
**Is there a preferred way to globally ignore 3rd party libraries globally** from static analysis like cppcheck?
My current approach is to do `set_target_properties(my_target PROPERTIES CXX_CPPCHECK ${some_good_options})`, where `some_good_options` are the ones set by project\_options. I clear these `CMAKE_$LANG_CPPCHECK` properties right after calling into project\_options for it to set them up.
---
### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [July 26, 2023, 4:37pm UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596/2 "2023-07-26T16:37:53Z")
These `CMAKE_` variables just initialize target properties when the target is defined. You can do something like:
```auto
block (SCOPE_FOR VARIABLES)
unset(CMAKE_CXX_CPPCHECK)
add_subdirectory(Catch2)
endblock ()
```
to clear these initializations for your 3p projects.
---
### Author:  [@rlalik](https://discourse.cmake.org/u/rlalik)
#### Post date: [October 3, 2023, 7:51am UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596/3 "2023-10-03T07:51:14Z")
How would that work with `FetchContent`? I tried this:
```cmake
block (SCOPE_FOR VARIABLES)
unset(CMAKE_CXX_CPPCHECK)
FetchContent_Declare(3rdPartyProject
GIT_REPOSITORY repo_url
GIT_TAG master
)
FetchContent_MakeAvailable(3rdPartyProject)
endblock ()
```
but the project is still included in the checks. The third party project provides static library and cpp check runs when the lib is build.
---
### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [October 3, 2023, 10:40am UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596/4 "2023-10-03T10:40:12Z")
I would make sure that the project isn’t setting up `CMAKE_CXX_CPPCHECK` itself. Or you may need to also unset `CMAKE_C_CPPCHECK`. Configuring with `cmake --trace-expand` may help surface any such code.
---
### Author:  [@rlalik](https://discourse.cmake.org/u/rlalik)
#### Post date: [October 3, 2023, 11:55am UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596/5 "2023-10-03T11:55:43Z")
No, the subproject is also my CMakeLists.txt and I do not use CPPCHECK there, also unsetting` CMAKE_C_CPPCHECK` is not helping.
I assume `--trace-expand` is something like a verbose cmake mode? I never used it before, but when I add this option then cmake finishes with errors, whereas it finishes fine without it.
---
### Author:  [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [October 3, 2023, 12:08pm UTC](https://discourse.cmake.org/t/how-to-ignore-3rd-party-sources-from-static-analysis/8596/6 "2023-10-03T12:08:01Z")
It does enable some developer mode bits as well, but there’s not enough context here to know. Basically, something is setting the `_CPPCHECK` property on the relevant targets; that needs found.
I suppose one thing that could be confusing it is a cache variable. If a cache variable exists, `unset(CMAKE__CPPCHECK` will only unset the scoped variable of that name.