Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add an elf note on ARM to store the MACHINE_ARCH an executable was built
for. This is useful for software needing to know which architecture a
binary is built for as arm and armv6 have slight differences meaning only
some binaries build for one will work as expected on the other. It is
expected pkgng will be able to make use of this to simplify the logic to
determine which package ABI to use.

Approved by: re (kib)

Only assign the environ in the startup code when environ is NULL.
Preloaded library could have changed the environment, and
unconditional assingment to the environ undoes the customization.
The binaries needs to be recompiled to get the fix.

Move the common code to set up environ and __progname into the helper.
Note that ia64 possibly not fixed, due to it still using old csu.

Reported and tested by: John Hein <jhein@symmetricom.com>
Reviewed by: kan, scf
Approved by: secteam (simon)
MFC after: 2 weeks

Stop calling _init/_fini methods from crt1 for dynamic binaries. Do
call preinit, init and fini arrays methods from crt1 for static binaries.

Mark new crt1 with FreeBSD-specific ELF note.

Move some common crt1 code into new MI file ignore_init.c, to reduce
duplication. Also, conservatively adjust nearby sources for style.

Reviewed by: kan
Tested by: andrew (arm), flo (sparc64)
MFC after: 3 weeks

Add a header with definitions useful for constructing ELF notes.

Reviewed by: kan
MFC after: 3 weeks

Apply a workaround for a binutils issue with the .note.ABI-tag section
generated from lib/csu/common/crtbrand.c (which ultimately ends up in
executables and shared libraries, via crt1.o, gcrt1.o or Scrt1.o).

For all arches except sparc, gcc emits the section directive for the
abitag struct in crtbrand.c with a PROGBITS type. However, newer
versions of binutils (after 2.16.90) require the section to be of NOTE
type, to guarantee that the .note.ABI-tag section correctly ends up in
the first page of the final executable.

Unfortunately, there is no clean way to tell gcc to use another section
type, so crtbrand.c (or the C files that include it) must be compiled in
multiple steps:

- Compile the .c file to a .s file.
- Edit the .s file to change the 'progbits' type to 'note', for the section
directive that defines the .note.ABI-tag section.
- Compile the .s file to an object file.

These steps are done in the invididual Makefiles for each applicable arch.

Reviewed by: kib

The __used (== __attribute__((__used)) ) silences the warning produced
by unreferenced symbol. Apply __used instead of rev. 1.5.

Requested by: kan

Restore the branding of the ELF executables. The structure was optimized out.

MFC after: 3 days

GC these crt{begin,end}.c, which are unused since the last FreeBSD platform
switched to those created from GCC's crtstuff.c 4 years ago.

Explicitly specify an alignment for abitag. Without it, gcc specifies a
section alignnment of 16 bytes for amd64 and this breaks file(1).
Before:
./cp: ELF 64-bit LSB executable, AMD x86-64, version 1 (FreeBSD), for \
FreeBSD 127.7.9, statically linked, stripped
after: ^^^^^^^
./ls: ELF 64-bit LSB executable, AMD x86-64, version 1 (FreeBSD), for \
FreeBSD 5.0.1, dynamically linked (uses shared libs), stripped

The reason for this is that the NOTE sections are not contiguous
internally. If the note section has an alignment of 16, then anything
that looks for the data is supposed to round up the payload start to
the next multiple of the alignment. But FreeBSD/amd64 broke because the
structure is declared as a single structure, not a (header,payload) group,
where the payload had an explicit alignment roundup.

The alternative is to change things like file(1) to ignore the ELF payload
alignment rules for the PT_NOTE section only for FreeBSD.

Set abitag __unused.

Fix the copyright dates.

GC code that moved to crtbrand.c.

Feh, it helps to include a file other than yourself... wonder how
GCC cpp liked that.

Properly include the branding info.

* Bring back the guts of crt{i,n}.S. This allows C++ exceptions to work
when using the egcs and gcc-devel ports, along with GCC built from stock
public FSF sources. With out this change, FreeBSD will be removed from
the list of systems GCC 3.0 must be evaluated on before release. With
the effort some of us put into getting FreeBSD on this list, we should
not turn this effort into a waste, else we might not be worth fighting
for in the future. (note that Alpha and IA-64 versions of crt{i,n}.S
are needed)

* Switch from our own crt{begin,in} to those created from GCC's crtstuff.c.
This will allow us to switch to DWARF2 exceptions in the future, along with
staying in sync with any future GCC requirements.

* Break out our ELF branding bits into a seperate file. Currently this
is now included by our crt1.c files (since this functionality was part of
our native crtbegin.c). Later crtbrand.o will be merged in the creation
of crti.o.

This is step 1 in an effort to unify the start-up files for the
various architectures. Now all the work is done in crtbegin.c.
It doesn't contain any assembly language code, so it should work
fine on all architectures. (I have tested it on the i386 and the
alpha.) The old assembly language files crt[in].S are now empty
shells that generate no code or data. They should not be removed
any time soon, because the various versions of gcc in src and ports
expect them to exist.

Next I will move crtbegin.c into a new common machine-independent
directory, and adjust the i386-elf Makefile to use that version.
After that I will adjust the alpha Makefile to use the common
version too.

Requested by: obrien

$Id$ -> $FreeBSD$

Reverse the order of processing object files within an executable or
shared library when invoking global constructors and destructors.
For constructors, the object files used to be processed from first
to last; now they're done from last to first. (Destructors are done
in the opposite order, as required by the C++ standard.) This makes
us consistent with standard gcc and egcs compilers. It also
eliminates ordering differences between dynamic and static
executables.

Bump the value of __FreeBSD_version to 400002 to reflect this
change.

Move the code for the ".init" and ".fini" sections outside of a
C function so the compiler won't try to emit line numbers for it
with "-g", breaking the build. This has the nice side-effect of
making crtbegin.o and crtbeginS.o a little bit smaller.

Remove "-Wno-unused" from the Makefile. Replace it with "__unused"
on particular function and variable declarations.

Import C startup files for ELF support.

Submitted by: John Polstra <jdp@polstra.com>