Re: Post-Processing Step

[Ralf Wildenhues]

Hello Mike,

* Mike Melanson wrote on Fri, Sep 29, 2006 at 02:55:55AM CEST:
> 
> Is there an easy, official way to add a post-processing step to a 
> Makefile.am? Specifically, after the primary build target is linked via 
> autotool magic, how can I specify an extra 'objcopy' command to be 
> executed on the linked binary? My best guess on this would be hijacking 
> the 'all' target. Better solution?

You can use the all-local target to extend it.  In order to be safe for
parallel make, it should depend on the files it needs, though.
Something similar to this:

all-local: mybinary
        objcopy mybinary mynewbinary

Some ideas to improve this:
- you can make a separate rule for mynewbinary.  This isn't only nicer
  for clarity, it also helps `make' to remove the output file in case
  you interrupt it during rule execution.
- objcopy is not portable (many GNU/Linux systems do not have it
  installed), so maybe it would be better to have a configure test that
  checks this and sets OBJCOPY to objcopy or to `:', or some other
  replacement method to create the new from the old (dunny if `cp' as a
  replacement would be good enough).  Using AC_CHECK_TOOL, as in
    AC_CHECK_TOOL([OBJCOPY], [objcopy], [:])
  would even help to find a cross-compile objcopy
  (I realize these notes may be marginal for you; but this list is for
  others to read as well).
- In case this should be portable to cross-compilation from a unixy host
  to a w32 system, the manual rules should use $(EXEEXT)

So we'd end up at something like

all-local: mynewbinary$(EXEEXT)
mynewbinary$(EXEEXT): mybinary$(EXEEXT)
        $(OBJCOPY) mybinary $@

Cheers,
Ralf