# Generate header file containing the path to a build artifact for multi-config generators

**URL:** <https://discourse.cmake.org/t/generate-header-file-containing-the-path-to-a-build-artifact-for-multi-config-generators/13989>\
**Category:** Code\
**Created:** [April 25, 2025, 4:39pm UTC](https://discourse.cmake.org/t/generate-header-file-containing-the-path-to-a-build-artifact-for-multi-config-generators/13989 "2025-04-25T16:39:37Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![ottmar-zittlau](https://discourse.cmake.org/user_avatar/discourse.cmake.org/ottmar-zittlau/32/2713_2.png) [@ottmar-zittlau](https://discourse.cmake.org/u/ottmar-zittlau)\
**Post date:** [April 25, 2025, 4:39pm UTC](https://discourse.cmake.org/t/generate-header-file-containing-the-path-to-a-build-artifact-for-multi-config-generators/13989/1 "2025-04-25T16:39:37Z")

</div>

Hi,

I have problems generating a file that contains a target\_file-generator expression.

I reduced the issue to a small example:

CMakeLists.txt

```auto
cmake_minimum_required(VERSION 3.19)
project(GenerateTest LANGUAGES CXX)

add_executable(generateTest main.cpp)

file(GENERATE OUTPUT test.h INPUT test.h.in)

```

main.cpp

```auto
int main(int argc, char *argv[]){
    return 0;
}

```

test.h.in

```auto
const char* test = "$<TARGET_FILE:generateTest>";

```

If I try to generate the project using the MSVC generator it fails:

```auto
cmake ..
-- Building for: Visual Studio 17 2022
-- Selecting Windows SDK version 10.0.22621.0 to target Windows 10.0.26100.
-- The CXX compiler identification is MSVC 19.43.34810.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2022/BuildTools/VC/Tools/MSVC/14.43.34808/bin/Hostx64/x64/cl.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done (2.7s)
CMake Error in CMakeLists.txt:
  Evaluation file to be written multiple times with different content. This
  is generally caused by the content evaluating the configuration type,
  language, or location of object files:

   test.h
....

```

The same error also occurs for “Ninja Multi-Config” - however, using the single-config Ninja-generator works.

I asked this before and got the answer to use `$<CONFIG>` to get the a unique output filename (cf. [https://gitlab.kitware.com/cmake/cmake/-/issues/26898#note\_1652172](https://gitlab.kitware.com/cmake/cmake/-/issues/26898#note_1652172) & [https://cmake.org/cmake/help/latest/command/file.html#generate](https://cmake.org/cmake/help/latest/command/file.html#generate))

If I do this, i.e.

`file(GENERATE OUTPUT test$<CONFIG>.h INPUT test.h.in)`,

I end up with 4 header files `testDebug.h`, `testRelease.h` etc. - this would mean that wherever I use this file, I need to write `#include <test$<CONFIG>.h>` and apply `file(GENERATE)` to all files containing this. I think, that I don’t want to do this - how could I manage to get a header-file with a fixed name containing the path to the executable (which could change with build type)?

Thanks and best regards  
oz

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**Author:** ![LegalizeAdulthood](https://discourse.cmake.org/user_avatar/discourse.cmake.org/legalizeadulthood/32/5282_2.png) [@LegalizeAdulthood](https://discourse.cmake.org/u/LegalizeAdulthood)\
**Post date:** [April 25, 2025, 7:12pm UTC](https://discourse.cmake.org/t/generate-header-file-containing-the-path-to-a-build-artifact-for-multi-config-generators/13989/2 "2025-04-25T19:12:43Z")

</div>

Try using `$<CONFIG>` as a directory component and setting `target_include_directories` with a corresponding generator expression. Then your header file is the same name, but there’s a debug directory and a release directory, etc.