# How to use CMAKE\_SYSTEM\_PROCESSOR policy?

**URL:** https://discourse.cmake.org/t/how-to-use-cmake-system-processor-policy/4906
**Category:** Usage
**Created:** [January 25, 2022, 4:00pm UTC](https://discourse.cmake.org/t/how-to-use-cmake-system-processor-policy/4906 "2022-01-25T16:00:06Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![DavidA](https://discourse.cmake.org/user_avatar/discourse.cmake.org/davida/32/128_2.png) [@DavidA](https://discourse.cmake.org/u/DavidA)
#### Post date: [January 25, 2022, 4:00pm UTC](https://discourse.cmake.org/t/how-to-use-cmake-system-processor-policy/4906/1 "2022-01-25T16:00:06Z")

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There is a discussion in the following link about how CMAKE\_SYSTEM\_PROCESSOR is restrictive for armclang (it adds --cpu flag which may not be wanted).

[https://gitlab.kitware.com/cmake/cmake/-/issues/21173](https://gitlab.kitware.com/cmake/cmake/-/issues/21173)

Apparently the behaviour can now be overridden by a ‘policy’. I’m not familiar with CMake ‘policies’. How would I invoke the relevant policy please?

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<div class="post-metadata">

### Author: ![DavidA](https://discourse.cmake.org/user_avatar/discourse.cmake.org/davida/32/128_2.png) [@DavidA](https://discourse.cmake.org/u/DavidA)
#### Post date: [January 25, 2022, 4:22pm UTC](https://discourse.cmake.org/t/how-to-use-cmake-system-processor-policy/4906/2 "2022-01-25T16:22:19Z")

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Sorry, explained here:

[CMP0123 — CMake 3.22.2 Documentation](https://cmake.org/cmake/help/latest/policy/CMP0123.html)

and here:

[cmake\_policy — CMake 3.20.6 Documentation](https://cmake.org/cmake/help/v3.20/command/cmake_policy.html#setting-policies-explicitly)