Re: Dependency tracking of pre processed Assembler files

[Ralf Wildenhues]

Hello Ralf,

I'll address PR 492 in its thread, lest the mixup of threads and topics
be un-disentangle-able.  ;-)

* Ralf Corsepius wrote on Thu, Oct 12, 2006 at 06:49:30AM CEST:
> > > 
> > > Yes, but ... with a simple testcase, I get this warning:
> > [...]
> > > With my real world test case, I don't get this warning. Probably
> > > because I am AC_SUBST'ing CCAS and CCASCOMPILE.
> > 
> > Thanks for reporting this.  Actually, two bugs here:
> > - there is no test for *.S,
> I don't understand.

Well the Automake test suite does not test that Automake's handling of
source files named *.S actually works as expected.  So far it only
tested *.s.  This is a bug from the perspective that the testsuite
should be as comprehensible as possible, ideally covering each code
path.

So I created asm2.test, which is very similar to asm.test, but deals
with *.S instead of *.s, and adjusted the details.  The new test exposes
the issue that, if you AC_SUBST the variables CCAS and CCASCOMPILE, then
you get a cryptic warning:

> > > > > /opt/gnu/share/automake-1.9c/am/depend2.am: am__fastdepCCAS does not
> > > > > appear in AM_CONDITIONAL

> > - above warning is suboptimal because there is too little help
> >   (the other warnings you posted had help, but were only present
> >   in the test case).

So the change to automake.in fixes the warning to (hopefully) be more
informative.

> > Further note a small buglet in m4/as.m4:
> > - without no-dependencies, we should not compute depmode.
> Could you elaborate what this issue is you are trying to fix?
> I must be missing something.

Certainly.  This issue only showed up for me during testing of the
patch.  If the Automake option no-dependencies was used, the the
dependency style should not be computed.  Here's a proto testsuite
addition to expose this (note the `exit 1' before you copy and paste
this in your running shell) that exposes the bug:

cat >configure.ac <<\EOF
AC_INIT([asm-nodep], 1, [devnull])
AM_INIT_AUTOMAKE([foreign no-dependencies])
AC_CONFIG_FILES([Makefile])
AM_PROG_AS
AC_OUTPUT
EOF
cat >Makefile.am <<\EOF
bin_PROGRAMS = foo
foo_SOURCES = foo.S
EOF
: >foo.S
aclocal
automake -a
autoconf
./configure | tee stdout
grep 'dependency style' stdout && exit 1
:

Cheers,
Ralf