Hi Ralf,
In the end, this is where I wound up:
1. In configure.ac, ensure that there is some compilation language
a la AC_PROG_CC that enables the ``if AMDEP'' machinery
(i.e. AM_SET_DEPDIR gets invoked).
2. in Makefile.ac you have something like this:
> if AMDEP
> DEP_ARG = -MF$(DEPDIR)/opts-dep
> TOUCH_SENTINEL = touch -r $(DEPDIR)/opts-dep $@
> include $(DEPDIR)/opts-dep
> else
> DEP_FILE =
> DEP_ARG =
> TOUCH_SENTINEL = touch $@
> endif
> stamp-opts : opts.def $(CLexe) $(AGexe)
> $(AG_ENV) ; $(AGEXE_LIB) $(DEP_ARG) $(srcdir)/opts.def
> $(TOUCH_SENTINEL)
3. This depends upon AC_PROG_CC defining AMDEP as an automake
conditional *AND* jiggering some per-directory configury
scripting (aka "config.status" scripting) to grep out
file names from ``include $(DEPDIR)/whatever'' lines to
insert "# dummy" text into them.
It means that I cannot (directly) use the dependency file as
the sentinel because the time stamp after the ``echo "# dummy">xxx''
command is too recent. I guess that's not the end of the world
since everybody has "touch -r" :)
Still and all, it would be Really Nice to change the doc for
AM_SET_DEPDIR so I could use it legally:
> 6.4.3 Private Macros
> --------------------
>
> The following macros are private macros you should not call directly.
> They are called by the other public macros when appropriate. Do not
> rely on them, as they might be changed in a future version. Consider
> them as implementation details; or better, do not consider them at all:
> skip this section!
>
> `_AM_DEPENDENCIES'
> `AM_SET_DEPDIR'
> `AM_DEP_TRACK'
> `AM_OUTPUT_DEPENDENCY_COMMANDS'
> These macros are used to implement Automake's automatic dependency
> tracking scheme. They are called automatically by Automake when
> required, and there should be no need to invoke them manually.
or some other alternative and document the infrastructure used. :)
Thanks - Bruce
