Hi,
I have problems generating a file that contains a target_file-generator expression.
I reduced the issue to a small example:
CMakeLists.txt
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
int main(int argc, char *argv[]){
return 0;
}
test.h.in
const char* test = "$<TARGET_FILE:generateTest>";
If I try to generate the project using the MSVC generator it fails:
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 $<CONFIG> to get the a unique output filename (cf. https://gitlab.kitware.com/cmake/cmake/-/issues/26898#note_1652172 & https://cmake.org/cmake/help/latest/command/file.html#generate)
If I do this, i.e.
file(GENERATE OUTPUT test$<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