Question

I’ve coded an script that generates a header file with constants like version, svn tag, build number. Then, I have a class that creates a string with this information.

My problem is the following: As the file is created in every compilation, the compiler detects that the header has changed, and forces the recompilation of a large number of files. I guess that the problem is in the situation of the header file. My project is a library and header has to be in the “interface to the world” header file (it must to be public).

I need some advice to minimize this compilation time or to reduce the files forced to recompile.

Answer 1

In the header write something like:

extern const char *VERSION;
extern const char *TAG;
extern const char *BUILD_DATE;

and create a .c (or .cpp) file that will contain

const char *VERSION = "0.13";
const char *TAG = "v_0_13";
const char *BUILD_DATE = "2011-02-02 11:19 UTC+0100";

If your script updates the .c file, only that file will have to be recompiled, but the files that include your header won’t.