# Change in behavior wrt LANGUAGE source property?
**URL:** https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600
**Category:** Usage
**Created:** [December 6, 2021, 8:27am UTC](https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600 "2021-12-06T08:27:10Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ingolf](https://discourse.cmake.org/u/ingolf)
#### Post date: [December 6, 2021, 8:27am UTC](https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600/1 "2021-12-06T08:27:10Z")
Hi,
in our project, we have a few `.S` assembly files which up to now were treated like regular C files (i.e. they were compiled with the same compiler + flags/options as C files). This was achieved by `set_source_files_properties(file1.S file2.S PROPERTIES LANGUAGE C)` before `add_library(foo some.c other.c file1.S file2.S etc.c)`.
As long as project stated `cmake_minimum_required(VERSION 3.17)`, everything was fine with CMake in version 3.21.3. However, the very same CMake adds `-x c` to the compile flags when the project uses `cmake_minimum_required(VERSION 3.20)`; in consequence, `gcc` reports problems with the assembly file.
What is the correct way to tell CMake that the `.S` files are to be compiled in the same way as C language files (i.e. without adding `-x c`)?
Kind regards
Ingolf
---
### Author:  [@marc.chevrier](https://discourse.cmake.org/u/marc.chevrier)
#### Post date: [December 6, 2021, 11:21am UTC](https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600/2 "2021-12-06T11:21:39Z")
From your description, I suppose that your files are not C source but assembly with pre-processing.
So, it is, anyway, an error to specify `C` as language when the files do not contained `C` source…
Maybe this [discussion](https://discourse.cmake.org/t/processing-assembly-files-with-c-preprocessor-statements/3599) can be of some help.
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### Author:  [@ingolf](https://discourse.cmake.org/u/ingolf)
#### Post date: [December 6, 2021, 11:30am UTC](https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600/3 "2021-12-06T11:30:37Z")
@marc.chevrier, I admit that declaring the assembler files C language is kind of wrong. However, up to somwhere between `cmake_minimum_required(VERSION 3.17)` and `... 3.20)`, this was a successful workaround without having cumbersome constructs like `add_custom_command()`.
Isn’t there some official way to tell CMake “please treat this `.S` source file in exactly the same way as you would usually do with `.c` files even if it is no C language file”?
Cheers
Ingolf
---
### Author:  [@marc.chevrier](https://discourse.cmake.org/u/marc.chevrier)
#### Post date: [December 6, 2021, 11:36am UTC](https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600/4 "2021-12-06T11:36:24Z")
Possibly, specify your `C` compiler as `ASM` compiler:
```auto
env ASM=gcc cmake ...
```
And do not specify any `LANGUAGE` for your assembly files.
---
### Author:  [@ingolf](https://discourse.cmake.org/u/ingolf)
#### Post date: [December 6, 2021, 12:00pm UTC](https://discourse.cmake.org/t/change-in-behavior-wrt-language-source-property/4600/5 "2021-12-06T12:00:28Z")
For the record, I just found the [comments on the `LANGUAGE` property in the context of `CMP0119`](https://cmake.org/cmake/help/latest/policy/CMP0119.html).
Removing `set_source_files_properties(file1.S file2.c PROPERTIES LANGUAGE C)` and instead declaring `enable_language(ASM)` solved my problem. Thanks for your support.
Cheers
Ingolf