Introduce common-regcache.h

This introduces common-regcache.h.  This contains two functions that
allow nat/linux-btrace.c to be simplified.  A better long term
solution would be unify the regcache code, but this is sufficient for
now.

gdb/ChangeLog:

	* common/common-regcache.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add common/common-regcache.h.
	* regcache.h: Include common-regcache.h.
	(regcache_read_pc): Don't declare.
	* regcache.c (get_thread_regcache_for_ptid): New function.
	* nat/linux-btrace.c: Don't include regcache.h.
	Include common-regcache.h.
	(perf_event_read_bts): Use get_thread_regcache_for_ptid.

gdb/gdbserver/ChangeLog:

	* regcache.h: Include common-regcache.h.
	(regcache_read_pc): Don't declare.
	* regcache.c (get_thread_regcache_for_ptid): New function.
Include common-defs.h instead of defs.h/server.h in shared code

This commit makes 19 of the 22 shared .c files in common, nat and
target include common-defs.h instead of defs.h/server.h.  The
remaining three files need slight extra work and are dealt with
in separate commits.

gdb/ChangeLog:

	* common/agent.c: Include common-defs.h.
	Don't include defs.h or server.h.
	* common/buffer.c: Likewise.
	* common/common-debug.c: Likewise.
	* common/common-utils.c: Likewise.
	* common/errors.c: Likewise.
	* common/filestuff.c: Likewise.
	* common/format.c: Likewise.
	* common/gdb_vecs.c: Likewise.
	* common/print-utils.c: Likewise.
	* common/ptid.c: Likewise.
	* common/rsp-low.c: Likewise.
	* common/signals.c: Likewise.
	* common/vec.c: Likewise.
	* common/xml-utils.c: Likewise.
	* nat/linux-osdata.c: Likewise.
	* nat/linux-procfs.c: Likewise.
	* nat/linux-ptrace.c: Likewise.
	* nat/mips-linux-watch.c: Likewise.
	* target/waitstatus.c: Likewise.
Remove GDBSERVER uses from linux-btrace.c

This commit makes nat/linux-btrace.c include common-defs.h rather
than defs.h or server.h.  A couple of minor changes were required
to support this change.

gdb/ChangeLog:

	* nat/linux-btrace.c: Include common-defs.h.
	Don't include defs.h, server.h or gdbthread.h.
	* nat/linux-btrace.h (struct target_ops): New forward declaration.
Remove GDBSERVER uses from x86-dregs.c

This commit makes nat/x86-dregs.c include common-defs.h rather than
defs.h or server.h.  An extra header required including in order to
support this change.

gdb/ChangeLog:

	* nat/x86-dregs.c: Include common-defs.h and break-common.h.
	Don't include defs.h or server.h.
Clarify GDBSERVER use in linux-waitpid.c

This commit makes linux-waitpid.c include common-defs.h.  GDB's
inclusion of defs.h is removed, but gdbserver's inclusion of
server.h remains to support some gdbserver-specific debug code
that cannot presently be merged.  A new FIXME documents this.

gdb/ChangeLog:

	* nat/linux-waitpid.c: Include common-defs.h.
	[GDBSERVER]: Add FIXME comment.
	[!GDBSERVER]: Don't include defs.h or signal.h.
	(linux_debug) [!GDBSERVER]: Remove empty block.
testsuite: Fix runaway attach processes

I have started seeing occasional runaway 'attach' processes these days.
I cannot be certain it is really caused by this patch, for example
grep 'FAIL.*cmdline attach run' does not show anything in my logs.

But as I remember this 'attach' runaway process always happened in GDB (but
I do not remember it in the past months) I think it would be most safe to just
solve it forever by [attached].

gdb/testsuite/ChangeLog
2014-09-12  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.base/attach.c: Include unistd.h.
	(main): Call alarm.  Add label postloop.
	* gdb.base/attach.exp (do_attach_tests): Use gdb_get_line_number,
	gdb_breakpoint, gdb_continue_to_breakpoint.
	(test_command_line_attach_run): Kill ${testpid} in one exit path.
PR tdep/17379: Fix internal-error when stack pointer is invalid.

The problem is that rs6000_frame_cache attempts to read the stack backchain via
read_memory_unsigned_integer, which throws an exception if the stack pointer is
invalid.  With this patch, it calls safe_read_memory_integer instead, which
doesn't throw an exception and allows for safe handling of that situation.

gdb/ChangeLog
2014-09-12  Edjunior Barbosa Machado  <emachado@linux.vnet.ibm.com>
	    Ulrich Weigand  <uweigand@de.ibm.com>

	PR tdep/17379
	* rs6000-tdep.c (rs6000_frame_cache): Use safe_read_memory_integer
	instead of read_memory_unsigned_integer.

gdb/testcase/ChangeLog
2014-09-12  Edjunior Barbosa Machado  <emachado@linux.vnet.ibm.com>

	PR tdep/17379
	* gdb.arch/powerpc-stackless.S: New file.
	* gdb.arch/powerpc-stackless.exp: New file.
Add mips*-img-elf* target triple.

/
	* configure.ac: Add mips*-img-elf* target triple.
	* configure: Regenerate.

bfd/
	* config.bfd: Add mips*-img-elf* target triple.

gas/
	* configure.tgt: Add mips*-img-elf* target triple.

gas/testsuite/
	* gas/mips/mips.exp: Add mips*-img-elf* target triple.

binutils/testsuite/
	* binutils-all/objcopy.exp: Add mips*-img-elf* target triple.
	* binutils-all/readelf.exp: Likewise.

ld/
	* configure.tgt: Add mips*-img-elf* target triple.

ld/testsuite/
	* ld-mips-elf/mips-elf.exp: Add support for mips*-img-elf* target
	triple.
gas: fix bumping to architectures >v9 in sparc64-* targets.

This patch fixes two related problems:

- By default gas is supposed to bump the current architecture
  (starting with v6) as it finds "higher" instructions as the
  assembling progresses.  There are four possible cases depending on
  the usage of the -A and -bump options:

  (a) No -A and -bump are specified.  In this case max_architecture
      must be the highest architecture not conflicting with the
      default architecture.  The default opcode architecture is
      indirectly set in configure.tgt and is "v9" in sparc64 systems
      (from "v9-64").  Thus the maximum architecture in sparc64
      systems must be "v9b".  No warnings are echoed when the assembly
      of an instruction bumps the current architecture.

  (b) Only -bump is specified.  This is like (a) but warnings are
      always issued when the assembly of an instruction bumps the
      current architecture.

  (c) Only -A is specified.  In this case bumping to a new
      architecture is an error.

  (d) Both -A and -bump are specified.  In this case max_architecture
      must be the highest architecture not conflicting with the
      default architecture, but warnings are only to be issued when
      bumping to an architecture higher than the architecture selected
      in the -A option.

  `max_architecture' is a global variable defined in tc-sparc.c which
  is initialized to the opcode architecture corresponding to the
  default architecture ("sparclite" for sparc-* targets and "v9" for
  sparc64-* targets).  Then in `md_begin' it is set to the highest
  non-conflicting architecture, but only when both -A and -bump are
  specified.

  Thus (a) does not work:

    $ echo "fzero %f0" | as
    {standard input}: Assembler messages:
    {standard input}:1: Error: Architecture mismatch on "fzero".
    {standard input}:1:  (Requires v9a|v9b; requested architecture is v9.)

  Neither (b):

    $ echo "fzero %f0" | as -bump
    {standard input}: Assembler messages:
    {standard input}:1: Error: Architecture mismatch on "fzero".
    {standard input}:1:  (Requires v9a|v9b; requested architecture is v9.)

  Only (d) does:

    $ echo "fzero %f0" | as -Av9 -bump
    {standard input}: Assembler messages:
    {standard input}:1: Warning: architecture bumped from "v6" to "v9a" on "fzero"

  This patch fixes that function to "upgrade" `max_architecture' also
  in the (a) and (b) cases.

  Note that this problem becomes apparent only in sparc64-* targets
  because in sparc-* targets the default architecture is the "higher"
  among the 32bit architectures ("sparclite").

- Gas maintains a set of hardware capabilities associated with each
  gas architecture, in `sparc_arch_table'.  On the other hand
  libopcodes maintains a set of hardware capabilities needed by each
  individual sparc instruction.

  When an instruction is assembled in `sparc_ip' gas checks for the
  presence of the hardware capabilities required by the instruction,
  emitting an error if some capability is missing.

  However, this mechanism does not work properly if the current
  architecture is bumped due to an instruction requiring new hw
  capabilities not present on either the default architecture or an
  architecture specified with -A:

  $ echo "fzero %f0" | as -bump
  {standard input}: Assembler messages:
  {standard input}:1: Warning: architecture bumped from "v6" to "v9a" on "fzero"
  {standard input}:1: Error: Hardware capability "vis" not enabled for "fzero".

  This patch fixes this by adding the set of required hw caps of an
  instruction if it triggers an architecture bump.

The patch has been tested in sparc64-unknown-linux-gnu.

gas/ChangeLog:

2014-09-12  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* config/tc-sparc.c (sparc_ip): Update the set of allowed hwcaps
	when bumping the current architecture.
	(md_begin): Adjust the highetst architecture level also when a
	specific architecture is not requested.