CMAKE auto header file dependency - linux

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Handling header files dependencies with cmake
I have sample program dir having main.c main.h and CMakeLists.txt
main.h contents are
#ifndef MAIN_H
#define MAIN_H
int t=3;
int y=2;
#endif
main.c contents are
#include <main.h>
#include<stdio.h>
int main(){
printf("%d apple",t);
}
and CMakeLists.txt
PROJECT( test )
AUX_SOURCE_DIRECTORY(. test_SRCS)
include_directories(.)
ADD_EXECUTABLE (main ${test_SRCS})
but cmake is not rebuilding main.c on modification of header file.
I want it to auto-generate header file dependency.
Is it possible using cmake ?
if not is there any other tool which can do that ?

Answer 1

As mentioned in my comment, I have tried out your example and things were working fine: if main.h was modified then main.c would be recompiled.
My installation of CMake (version 2.8.0) told me to add
cmake_minimum_required(VERSION 2.8)
to the CMakeLists.txt file, but that is all of the adjustments I needed.

Answer 2

Answering this for others that google search...
I ran into this problem with one of my projects. As it turns out I added the header to the cpp file after running cmake. Re-running cmake fixed the problem. If you run into this, try that and see if it fixes the issue.

Answer 3

From the cmake 2.8.0 documentation of AUX_SOURCE_DIRECTORY:
It is tempting to use this command to avoid writing the list of source
files for a library or executable target. While this seems to work,
there is no way for CMake to generate a build system that knows when a
new source file has been added. Normally the generated build system
knows when it needs to rerun CMake because the CMakeLists.txt file is
modified to add a new source. When the source is just added to the
directory without modifying this file, one would have to manually
rerun CMake to generate a build system incorporating the new file.
Why do you want to avoid creating a list of files? Such lists generally do not change frequently.