remove almost all the ability to build netbsd with an a.out target.
we're ELF now, and there are many missing checks against OBJECT_FMT.
if we ever consider switching, the we can figure out what new ones
we need but for now it's just clutter.

this doesn't remove any of the support for exec_aout or any actually
required-for-boot a.out support, only the ability to build a netbsd
release in a.out format. ie, most of this code has been dead for
over a decade.

i've tested builds on vax, amd64, i386, mac68k, macppc, sparc, atari,
amiga, shark, cats, dreamcast, landisk, mmeye and x68k. this covers
the 5 MACHINE_ARCH's affected, and all the other arch code touched.
it also includes some actual run-time testing of sparc, i386 and
shark, and i performed binary comparison upon amiga and x68k as well.


some minor details relevant:
- move shlib.[ch] from ld.aout_so into ldconfig proper, and cut them
down to only the parts ldconfig needs
- remove various unused source files
- switch amiga bootblocks to using elf2bb.h instead of aout2bb.h

Use ${NETBSDSRCDIR}/some/path instead of ${.CURDIR}/../../some/path (etc).
(Reduces make output by ~ 20%)

branches: 1.1.6;
Move dl* function definitions to libc on ELF.
Based on the patch supplied by Takuya Shiozaki <tshiozak@astec.co.jp>.
See http://mail-index.netbsd.org/tech-userlevel/2000/02/23/0000.html.

libc: Fix missing membar_consumer in dl_iterate_phdr.

Pairs with the existing membar_producer.

XXX pullup-8
XXX pullup-9
XXX pullup-10

branches: 1.16.2; 1.16.10;
Compute relocbase correctly for static PIE. AT_BASE is not usable in
this case.

branches: 1.15.2; 1.15.4;
Register dl_iterate_phdr in the libc's namespace.h

The NetBSD Standard C Library uses internally some of its functions with
a mangled symbol name, usually "_symbol". The internal functions shall not
use the global (public) symbols.

Stop using the public global name of dl_iterate_phdr in tls/tls.c:
__libc_static_tls_setup().

Follow the approach with other dlopen(3)-like functions with the
namespace.h in the dl_iterate_phdr() case. Use internally a weak symbol:
__dl_iterate_phdr instead of dl_iterate_phdr.

Sponsored by <The NetBSD Foundation>

Implement __cxa_thread_atexit and __cxa_thread_atexit_impl. This
functions are used for destructors of thread_local objects.

If a pending destructor exists, prevent unloading of shared objects.
Introduce __dl_cxa_refcount interface for this purpose. When the last
reference is gone and the object has been dlclose'd before, the
unloading is finalized.

Ideally, __cxa_thread_atexit_impl wouldn't exist, but libstdc++ insists
on providing __cxa_thread_atexit as direct wrapper without further
patching.

branches: 1.13.24;
fix old style definitions; XXX: gcc should have picked them up but it did not.

PR/45989: Martin Husemann: lint invocation does include -w only on i386

- turn lint -w for all the platforms after fixing the lint warnings.
- add _DIAGASSERTS() for casts that would assign values to types that
would not fit.
- change types, add casts
- change into ansii prototypes
- turn on _DIAGNOSTIC for libc (during current, to be eliminated for release
builds)

approved by core@

Add _dlauxinfo helper function to provide access to the ELF auxilary
vector. This can normally be found via __ps_strings, but libc is
initialised too early when linked dynamically and doesn't have access to
it yet, so provide an alternative mechanism via ld.elf_so.
Bump libc minor.

branches: 1.10.2;
PR/45015: ld.elf_so: support ELF symbol versioning
Applied latest patch.

Avoid a dependency issue between pthread TLS by using simple atomic
initialisation, possibly running the initialisation loop more than once.

Pass down ELF Auxillary Vectors for static NetBSD binaries too.
Rename __libc_init to _libc_init and call it explicitly from CSU code.
This enforces the constructor run order for newly linked programs.
Keep it as constructor with run-once semantic for binary compatibility.
Implement dl_iterate_phdr for statically linked programs.

This material is based upon work partially supported by
The NetBSD Foundation under a contract with Joerg Sonnenberger.

Implement dl_iterate_phdr.

Somewhat taken from FreeBSD. Manual page from OpenBSD.

Add Solarisa-like dlinfo() interface to the ELF dynamic linker.
Implement RTLD_DI_LINKMAP which returns a pointer to the linkmap
chain at the given object. Other Solaris queries are currently
unimplemented.

branches: 1.5.32; 1.5.40;
- Change the strong dlfcn names in libc to ___name, and make the __name
versions used by others in libc weak, so that we have:
name: weak
__name: weak
___name: strong
- Add __name strong aliases of the dlfcn names in ld.elf_so, so that we have:
name: strong
__name: strong

This allows ld.elf_so to self-resolve both the name and __name variants
of the dlfcn functions, the former being required for dlfcn support in
applications, the latter being required for dlfcn support in libc.

Fixes the problem described in:

http://mail-index.netbsd.org/tech-toolchain/2004/07/17/0000.html

Reviewed by Nick.

branches: 1.4.2;
Resolve dlsym(3) and friends directly so that dlsym(RTLD_NEXT,...) works.

Previously dlsym resolved to the version in crt0.o or libc which would
mean that the caller's shared object couldn't be determined correctly
using __builtin_return_address(0).

Mainly from FreeBSD, but adapted by me. Benefits of this solutions are:

- backward comptibility maintained
- existing broken binaries are fixed with a new ld.elf_so
- __mainprog_obj can be removed from crt0.o
- we do the same thing as FreeBSD

Fixes PR 22067.

OKed by Jason and Christos.

don't test PIC here.

branches: 1.2.2; 1.2.4;
remove extra semi's

Move dl* function definitions to libc on ELF.
Based on the patch supplied by Takuya Shiozaki <tshiozak@astec.co.jp>.
See http://mail-index.netbsd.org/tech-userlevel/2000/02/23/0000.html.

Resolve dlsym(3) and friends directly so that dlsym(RTLD_NEXT,...) works.

Previously dlsym resolved to the version in crt0.o or libc which would
mean that the caller's shared object couldn't be determined correctly
using __builtin_return_address(0).

Mainly from FreeBSD, but adapted by me. Benefits of this solutions are:

- backward comptibility maintained
- existing broken binaries are fixed with a new ld.elf_so
- __mainprog_obj can be removed from crt0.o
- we do the same thing as FreeBSD

Fixes PR 22067.

OKed by Jason and Christos.

netbsd.org->NetBSD.org

branches: 1.3.6;
sweep of my licenses (userland files w/o only my copyright) for
consistency. (no functional changes)

fix up NetBSD RCS Ids to match the standard, and the leading comment as
to match as well. No functional changes.

branches: 1.1.2;
Move dl* function definitions to libc on ELF.
Based on the patch supplied by Takuya Shiozaki <tshiozak@astec.co.jp>.
See http://mail-index.netbsd.org/tech-userlevel/2000/02/23/0000.html.