Align behavior of xmethod commands with that of pretty-printer commands.

Currently, the xmethod commands lookup xmethod matchers in the current
progspace even if the locus regular expression matches the progspace's
filename.  Pretty printer commands do not match the current progspace's
filename.

gdb/

	* python/lib/gdb/command/xmethods.py
	(get_method_matchers_in_loci):  Lookup xmethod matchers in the
	current progspace only if the string "progspace" matches LOCUS_RE.

gdb/testsuite

	* gdb.python/py-xmethods.exp: Use "progspace" instead of the
	progspace's filename in 'info', 'enable' and 'disable' command
	tests.
x86 Linux watchpoints: Couldn't write debug register: Invalid argument.

This patch fixes this on x86 Linux:

 (gdb) watch *buf@2
 Hardware watchpoint 8: *buf@2
 (gdb) si
 0x00000000004005a7      34        for (i = 0; i < 100000; i++); /* stepi line */
 (gdb) del
 Delete all breakpoints? (y or n) y
 (gdb) watch *(buf+1)@1
 Hardware watchpoint 9: *(buf+1)@1
 (gdb) si
 0x00000000004005a7 in main () at ../../../src/gdb/testsuite/gdb.base/watchpoint-reuse-slot.c:34
 34        for (i = 0; i < 100000; i++); /* stepi line */
 Couldn't write debug register: Invalid argument.
 (gdb)

In the example above the debug registers are being switched from this
state:

        CONTROL (DR7): 0000000000050101          STATUS (DR6): 0000000000000000
        DR0: addr=0x0000000000601040, ref.count=1  DR1: addr=0x0000000000000000, ref.count=0
        DR2: addr=0x0000000000000000, ref.count=0  DR3: addr=0x0000000000000000, ref.count=0

to this:

        CONTROL (DR7): 0000000000010101          STATUS (DR6): 0000000000000000
        DR0: addr=0x0000000000601041, ref.count=1  DR1: addr=0x0000000000000000, ref.count=0
        DR2: addr=0x0000000000000000, ref.count=0  DR3: addr=0x0000000000000000, ref.count=0

That is, before, DR7 was setup for watching a 2 byte region starting
at what's in DR0 (0x601040).

And after, DR7 is setup for watching a 1 byte region starting at
what's in DR0 (0x601041).

We always write DR0..DR3 before DR7, because if we enable a slot's
bits in DR7, you need to have already written the corresponding
DR0..DR3 registers -- the kernel rejects the DR7 write with EINVAL
otherwise.

The error shown above is the opposite scenario.  When we try to write
0x601041 to DR0, DR7's bits still indicate intent of watching a 2-byte
region.  That DR0/DR7 combination is invalid, because 0x601041 is
unaligned.  To watch two bytes, we'd have to use two slots.  So the
kernel errors out with EINVAL.

Fix this by always first clearing DR7, then writing DR0..DR3, and then
setting DR7's bits.

A little optimization -- if we're disabling the last watchpoint, then
we can clear DR7 just once.  The changes to nat/i386-dregs.c make that
easier to detect, and as bonus, they make it a little easier to make
sense of DR7 in the debug logs, as we no longer need to remember we're
seeing stale bits.

Tested on x86_64 Fedora 20, native and GDBserver.

This adds an exhaustive test that switches between many different
combinations of watchpoint types and addresses and widths.

gdb/
2014-06-23  Pedro Alves  <palves@redhat.com>

	* amd64-linux-nat.c (amd64_linux_prepare_to_resume): Clear
	DR_CONTROL before setting DR0..DR3.
	* i386-linux-nat.c (i386_linux_prepare_to_resume): Likewise.
	* nat/i386-dregs.c (i386_remove_aligned_watchpoint): Clear all
	bits of DR_CONTROL related to the debug register slot being
	disabled.  If all slots are vacant, clear local slowdown as well,
	and assert DR_CONTROL is 0.

gdb/gdbserver/
2014-06-23  Pedro Alves  <palves@redhat.com>

	* linux-x86-low.c (x86_linux_prepare_to_resume): Clear DR_CONTROL
	before setting DR0..DR3.

gdb/testsuite/
2014-06-23  Pedro Alves  <palves@redhat.com>

	* gdb.base/watchpoint-reuse-slot.c: New file.
	* gdb.base/watchpoint-reuse-slot.exp: New file.
Add myself as write-after-approval maintainer.
gold/
	* mips.cc: New file.
	* Makefile.am (TARGETSOURCES): Add mips.cc
	(ALL_TARGETOBJS): Add mips.$(OBJEXT)
	* configure.tgt: Add entries for mips*.
	* configure.ac: Likewise.
	* Makefile.in: Regenerate.
	* configure: Likewise.
daily update
Skip 'bx reg' trampoline on arm-none-eabi

After this patch
<https://gcc.gnu.org/ml/gcc-patches/2005-01/msg00813.html> applied to
GCC, a new trampoline is generated but GDB doesn't recognize it.  This
patch is to teach GDB to understand this trampoline.  See details
about this trampoline and the heuristics in the comments.

gdb:

2014-06-24  Yao Qi  <yao@codesourcery.com>

	* arm-tdep.c (arm_skip_bx_reg): New function.
	(arm_skip_stub): Call arm_skip_bx_reg.
Apply stub unwinder to 'bx reg' trampoline

In target arm-none-eabi, prologue unwinder is used for trampoline
'bx reg'.  However, in target arm-linux, exidx unwinder is selected for
trampoline at first, which is not expected.  The main function and the
trampoline is,

   0x00009dfc <main+0>: push    {r4, r5, r6, r7, lr}
   ......
   0x0000ac30 <main+3636>:      ldrdeq  r3, [r1], -r8
   0x0000ac34:  bx      r2
   0x0000ac36:  bx      r4

and .ARM.exidx is:

0x9dfc <main>: @0xb404
  Compact model index: 1
  0x97      vsp = r7
  0x20      vsp = vsp + 132
  0x3f      vsp = vsp + 256
  0x80 0xf0 pop {r8, r9, r10, r11}
  0xab      pop {r4, r5, r6, r7, r14}

0xac38 <__aeabi_drsub>: 0x1 [cantunwind]

Trampolines 'bx r2' and 'bx r4' doesn't belong to main, but the exidx
for main is still selected form them because there is no end address
of each exidx entry.

Instead of teaching exidx unwinder ignore this trampoline (which looks
complicated and error prone), I decide to let stub unwinder to handle
trampoline, because stub undwinder is installed before exidx unwinder,
and this trampoline can be regarded as a stub too.

This patch is to add the code to match 'bx reg' trampoline in the
sniffer of stub unwinder.

gdb:

2014-06-24  Yao Qi  <yao@codesourcery.com>

	* arm-tdep.c (arm_stub_unwind_sniffer): Return 1 if
	arm_skip_bx_reg returns	non-zero.
Skip 'bx reg' on arm-linux

In arm-tdep.c, arm_skip_stub is installed to gdbarch
skip_trampoline_code, but in arm-linux-tdep.c,
find_solib_trampoline_target is installed to skip_trampoline_code.
That means gdb configured for arm-linux target doesn't recognize some
arm specific trampolines or stubs.  Beside handling generic solib
trampoline, gdb for arm-linux target should be able to handle arm
specific trampolines.  This patch is to skip arm specific stubs, if
any, and as a fallback, skip the generic solib trampoline.

gdb:

2014-06-24  Yao Qi  <yao@codesourcery.com>

	* arm-linux-tdep.c (arm_linux_skip_trampoline_code): New.
	(arm_linux_init_abi): Set skip_trampoline_code with
	gdbarch_skip_trampoline_code instead of
	find_solib_trampoline_target.
Don't strip section defining _SDA_BASE_

Prior to 93d1b056 _SDA_BASE_ used to be defined in a linker script
output section.  Now _SDA_BASE_ is defined in an input section that is
subject to being stripped.  If the section is stripped we don't output
the symbol, which results in --emit-relocs trying to emit relocs with
dangling references to _SDA_BASE_.

	* elf32-ppc.c (ppc_elf_size_dynamic_sections): Arrange to keep
	.sdata/.sdata2 when _SDA_BASE_/_SDA2_BASE_ should be output
	for --emit-relocs.
Merge #include directives

Built and regtested on i686 and x86_64 RHEL 6.5

The FIXME... gdbserver doesn't do this, at least
not obviously, so I don't think this is affecting
anybody.