Re: [PATCH/committed] sim: touch modules target

[Tom Tromey <tom@tromey.com>]

>>>>> "Mike" == Mike Frysinger via Gdb-patches <gdb-patches@sourceware.org> writes:

Mike> If there are no updates to the file, touch the result so we don't
Mike> keep trying to regenerate it.

Normally you don't want to do it this way.  I think it will result in
recompilations if the inputs change but the output does not.  Since it
depends on Makefile and all the source files, this may be pretty often.

Now, if that's ok with you, it's simpler to just replace the
move-if-change with a $(MV).

The more common approach is to use a stamp file.  So you write:

modules.c: modules-c-stamp ; @true
modules-c-stamp: ... the existing code, but also touch modules-c-stamp

There are a few examples of this idiom already in the tree.  hw-config.h
uses this, in the same file.  You'd also want to add the stamp file to
the clean rule.

Tom