Invoke add_custom_command everytime make is called [duplicate] - cmake

Question

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How to always run command when building regardless of any dependency?
(4 answers)
Closed 1 year ago.
I wanna run a bash script using cmake. And I am partially successful. I am not understanding the workflow properly.
main.cxx
# include <iostream>
int main()
{
std::cout << "hello\n";
}
script.sh
#!/bin/bash
touch file;
CMakeLists.txt
cmake_minimum_required(VERSION 3.21.1)
project(testdir)
add_executable(mainbin "main.cxx")
add_custom_command(TARGET mainbin
POST_BUILD
COMMAND /bin/sh /path/to/testdir/script.sh
)
So, this is my directory tree.
testdir
|
|---CMakeLists.txt
|
|---main.cxx
|
|---script.sh
When I do "cmake . ; make ;", cmake runs the bash script and except the cmake build related files, the directory tree looks like this:
testdir
|
|---file
|
|---CMakeLists.txt
|
|---main.cxx
|
|---script.sh
So it worked.
But now I would want to rename "file" to "renamed_file". So I would edit script.sh. New script.sh looks like this:
#!/bin/bash
mv file renamed_file;
Now when I do "cmake . ; make ;" again, it doesn't work. I mean file "file" doesn't change to "renamed_file". I wanna run script.sh everytime I call "cmake . ; make ;".
Maybe I am missing a very simple thing/basic understanding. What should I do to achieve that?

Answer 1

As you want to keep track of the content of the script, adding it as a source of a custom target will keep track of its mtime and copy it to the build directory if changed. Something like this will help you to achieve that.
add_custom_target(myscript
COMMAND /bin/sh /path/to/testdir/script.sh
SOURCES /path/to/testdir/script.sh
)
Disclaimer, I have not tried it, you night need to iterate on this.
More info: https://cmake.org/cmake/help/latest/command/add_custom_target.html