Target deprecation, round three

[Zack Weinberg <zack at codesourcery dot com>]

Let's try to get a final list for deprecations in the 3.3 release by
the end of the week.  I once again have to apologize for dropping the
ball.

The majority of the targets on my "round two" list
(http://gcc.gnu.org/ml/gcc/2002-12/msg00702.html) went over without
comment.  With a couple of exceptions I've dropped the targets which
someone spoke up in favor of; let's discuss the exceptions a bit more
carefully.  (If your favorite target is still on the list, speak up!
If you did already, it means I lost your mail; my apologies, and
please remind me.)

I'm pushing back on the following:

	i370-*-*

  All respect to the people who continue working on this back end, but
  they are doing so outside the official repository and have shown no
  interest in merging their work back.  Also, this is the same
  architecture as the s390-*-* back end, which is actively maintained.
  It would be better for the health of the compiler as a whole if that
  back end were augmented to support the things that it currently
  doesn't but the i370 back end does.

  Note that this is the only back end which defines HOST_EBCDIC and
  TARGET_EBCDIC.  There is no difficulty in continuing to support
  TARGET_EBCDIC - the s390 back end might plausibly want to use it in
  the future - but supporting HOST_EBCDIC in conjunction with certain
  features of C99 (which effectively require internal use of the ISO
  10646 aka Unicode charset) would force us to make substantial
  changes to the C front end that would leave it much harder to
  maintain.  (The short version is that character constants could not
  be used anywhere.)  Thus I would like to drop HOST_EBCDIC
  permanently at the same time this target is removed.  This does
  *not* mean the compiler will be unable to accept input files encoded
  in EBCDIC; it only means that it will itself need to be built in an
  environment where the execution character set is a superset of ASCII.

	alpha*-*-linux*libc1*
	i?86-*-linux*libc1*
	m68k-*-linux*libc1*
	powerpc*-*-linux*libc1*
	sparc-*-linux*libc1*

  I received a couple of messages expressing continued interest in
  some of these targets.  I have no problem keeping those that are
  actually used; however, I am not clear on which those are.  Is it
  just ix86, or are others in use too, and if so which ones?

	arm*-*-aof*

  This target is responsible for masses of #ifdefs all over the ARM
  back end.  Is it *really* necessary to continue using this rather
  quirky assembler?  Could you perhaps move to GAS and arm-elf
  instead?

        m68k-sun-sunos*
        sparc-sun-sunos*

  These targets are hosted systems with C libraries that predate C89,
  which means they impose disproportionate maintenance burdens.  They
  have long since been EOLed by Sun.  Please advise whether you really
  need a 3.x GCC for these targets.

In addition to target deprecation, I would also like to propose the
removal of support for DWARF version 1.  There are only two target
patterns that request DWARF 1 but not DWARF 2: mips-sni-sysv4, which
is already on the deprecation list, and arc-*-*, which I see no
intrinsic reason why it couldn't migrate to DWARF 2; it is already an
ELF target.  Tangentially, my impression is that the ARC target itself
is still actively maintained, but I am not sure.  Please speak up if
you have a current need for this target.

zw

Current list of targets to deprecate:

        i370-*-*
        i960-*-*
        m88k-*-*
        romp-*-*

	alpha*-*-interix*
	alpha*-*-linux*libc1*

	arm*-*-aout*
	arm*-*-aof*
	arm*-*-conix*
	arm*-*-oabi
	strongarm-*-coff*

	hppa1.0-*-osf*
	hppa1.0-*-bsd*
	hppa1.[01]-*-hpux[789]*
	hppa*-*-hiux*
	hppa*-*-lites*
	hppa*-*-mpeix*

	i?86-ncr-*
	i?86-sequent-*
	i?86-moss-*
	i?86-*-netware
	i?86-*-freebsd2*
	i?86-*-netbsd*aout*
	i?86-*-coff*
	i?86-*-linux*aout*
	i?86-*-linux*libc1
	i?86-*-moss*
	i?86-*-sysv3*
	i?86-*-vsta
	i?86-*-interix # not interix3

	m68000-hp-bsd*
	m68000-hp-hpux*
	m68000-sun-sunos*
	m68000-att-sysv*
	m68k-atari-sysv*
	m68k-motorola-sysv*
	m68k-ncr-sysv*
	m68k-plexus-sysv*
	m68k-tti-*
	m68k-crds-unos*
	m68k-cbm-sysv*
	m68k-ccur-rtu*
	m68k-hp-bsd*
	m68k-hp-hpux*
	m68k-sun-mach*
	m68k-sun-sunos*
	m68k-*-linux*aout*
	m68k-*-linux*libc1
	m68k-*-psos*

	mips*-*-ecoff*
        mips-sni-sysv4

	powerpc*-*-sysv*  # the generic one only
	powerpc*-*-linux*libc1
	rs6000-ibm-aix[123]*
	rs6000-bull-bosx
	rs6000-*-mach*

	sparc-*-aout*
	sparc-*-netbsd*aout*
	sparc-*-bsd*
	sparc-*-chorusos*
	sparc-*-linux*aout*
	sparc-*-linux*libc1*
	sparc-*-lynxos*
	sparc-hal-solaris2*
	sparc-*-sunos[34]*
	sparclet-*-aout*
	sparclite-*-coff*
	sparclite-*-aout*
	sparc86x-*-aout*

	vax-*-bsd*
	vax-*-sysv*
	vax-*-netbsd*aout*
        vax-*-vms*