Re: Makefile to Makefile.am

[Thien-Thi Nguyen]

() "samson.pierre" <address@hidden>
() Sun, 15 Aug 2010 03:09:50 +0200 (CEST)

   > > %.bmp: %.xcf
   > > $(GIMP) -i -b '(xcf-bmp "$<" "$@")' -b '(gimp-quit 0)'

   Is there an equivalent or anything else which can help me to write this
   rule avoiding this warning message?

I think here you can use something like:

.xcf.bmp:
        $(GIMP) -i -b '(xcf-bmp "$<" "$@")' -b '(gimp-quit 0)'

Note the order is PREREQ-EXT before TARGET-EXT, which is opposite
of the pattern rule order.  Probably Automake manual (and its readers)
could benefit from changing the mysterious:

  We do not discuss pattern rules here because they are not
  portable, but they can be convenient in packages that assume GNU
  `make'.

to something like:

  Although pattern rules are not portable, they can be convenient
  in packages that assume GNU `make'.  In the common case where
  the pattern rule is used to match the stem of a filename, you
  can use the old fashioned suffix rule (pxref here) instead.
  For example:

  # pattern rule, not portable
  %.bmp : %.xcf
          $(GIMP) -i -b '(xcf-bmp "$<" "$@")' -b '(gimp-quit 0)'

  # old fashioned suffix rule, portable
  .xcf.bmp:
          $(GIMP) -i -b '(xcf-bmp "$<" "$@")' -b '(gimp-quit 0)'

Hey, maybe Automake hackers can riff off this thread in time for
the next release... (or, "Would you like me to submit a patch?").