Hi Albert,
On Sun, Jun 23, 2013 at 12:29 AM, Albert ARIBAUD albert.u.boot@aribaud.netwrote:
Hi Simon,
On Mon, 17 Jun 2013 07:44:52 -0700, Simon Glass sjg@chromium.org wrote:
Note that a config_drop.h file is added - this defines all the CONFIGs which are not used in any board config file. Without this, autoconf
cannot
define the macros for this CONFIGs.
Compile time for main.c does not seem to be any different in my tests.
The
time to perform the 'dep' step (which now creates autoconf.h) increases, from about 2.8s to about 4.6s. This additional time is used to grep, sed and sort the contents of all the header file in U-Boot. The time for an incremental build is not affected.
It would be much more efficient to maintain a list of all available
CONFIG
defines, but no such list exists at present.
Stop me if I am wrong, but do you not have this list already, since at one point you grep, sed and sort the whole list of config options, then at another point generate the list of unused ones?
Well yes I create the list. But I don't 'have' it in the sense that it is a pre-existing file in the tree. My point was that if the file existed I would not need to create it in the build system. I asked about this at one point, and the comment was made that putting it in the source tree 'staticly' is risky, since someone might add a new option and it would not work.
Perhaps when Kconfig is in there things will be different.
Granted, that's the list of config options defined, not necessarily the list of options used, but a second variation of the grep/sed/sort might give you a hint on that.
Plus, I would love having scripts in tools/ that look for either defined or used config options.
With this series you kind-of get this feature - you can look at the files it creates along the way.
Regards, Simon