Re: minor error and a question

[Peter Johansson]

On 11/30/11 11:11 AM, Joakim Tjernlund wrote:
> Question: "make install" always install all targets, even if some of then 
> haven't been rebuilt
> since last install. Is it possible to have some dependency sensitive install so 
> only rebuilt
> targets are reinstalled?
Hi Jocke,

In one of my projects I have the following snippet in top Makefile.am

# like the normal install target, but does not update header files
# (and their time stamps) if the content did not change.
install-modified:
    $(MAKE) install $(AM_MAKEFLAGS) INSTALL_HEADER="$(install_sh_DATA) -C"


It's useful when installing frequently and wanna avoid recompilations in 
downstream projects, but note that the install takes a bit longer time 
since it needs to compare all files to decide whether it should be 
copied instead.

It would be faster to use the time-stamp to make that decision but when 
I looked into it, it seemed dangerous. Unfortunately, I cannot remember 
the details from top of my head.

Cheers,
Peter