binutils_os216

Fork

Fix -var-update for registers in frames 1 and up

XXX palves:

Watchpoints on locals are quite similar in principle with varobjs on
locals. Likewise wathpoints/varobjs on registers.

So this actually makes "watch $pc" in non-current frames be a local
watchpoint.

So

up
watch $pc
down
continue

now does the "right" thing. I'm not sure this is really right,
though.

Haven't done anything on the varobjs side.

gdb/testsuite/ChangeLog:
2016-06-13 Don Breazeal <dbreazea@my.domain.org>

* gdb.ada/mi_interface.exp: Add thread-id field to expected
output of -var-create and -var-list-children.
* gdb.ada/mi_var_array.exp: Add thread-id field to expected
output of -var-list-children.
* gdb.mi/mi-break.exp (test_error): Add thread-id field to
expected output of -var-create.
* gdb.mi/mi-frame-regs.exp: New test script.
* gdb.mi/mi-var-cmd.exp: Add thread-id field to expected
output of -var-create.
* gdb.mi/mi-var-create-rtti.exp: Likewise.

gdb/ChangeLog:
2016-06-13 Don Breazeal <donb@codesourcery.com>
Andrew Burgess <andrew.burgess@embecosm.com>

* varobj.c (varobj_create): Initialize innermost_block to
the global block instead of NULL.
(new_root_variable): Initialize the thread_id and next
fields.
(value_of_root_1): Set within_scope if the variable's
valid_block field is the global block.

Fix ERROR: target-cc does not exist

PR ld/20436
* testsuite/lib/ld-lib.exp (at_least_gcc_version): Don't ignore
remote_exec status.
(check_gcc_plugin_enabled): Likewise.

Export the single step function from the AArch64 simulator.

* interp.c (sim_create_inferior): Allow for being called with a
NULL abfd parameter. If a bfd is provided, initialise the sim
with that start address.
* simulator.c (HALT_NYI): Just print out the numeric value of the
instruction when not tracing.
(aarch64_step): Change from static to global.
* simulator.h: Add a prototype for aarch64_step().

Fix fallout from gdb/20413's fix (x32: linux_ptrace_test_ret_to_nx: Cannot PTRACE_PEEKUSER)

Fixes, on NIOS GNU/Linux:

In file included from
/scratch/mbilal/nois-lite/src/gdb-trunk/gdb/gdbserver/../nat/linux-ptrace.c:26:0:
/scratch/mbilal/nois-lite/src/gdb-trunk/gdb/gdbserver/../gregset.h:27:23:
error: unknown type name 'gregset_t'
#define GDB_GREGSET_T gregset_t
^

Fix this by including sys/procfs.h directly. We shouldn't really be
including a gdb-only header in a gdb/nat/ file, anyway. Whoops.

gdb/ChangeLog:
2016-08-11 Pedro Alves <palves@redhat.com>

PR gdb/20413
* nat/linux-ptrace.c: Include <sys/procfs.h> instead of
"gregset.h".

Avoid testsuite errors about missing compilers.

PR ld/20436
* testsuite/lib/ld-lib.exp (check_gcc_plugin_enabled): When not
testing remotely, check to see if target compiler is installed
before trying to run it.

[AArch64] Reject -0.0 as an 8-bit FP immediate

parse_aarch64_imm_float was accepting -0.0 even though that's not
a valid immediate for any instruction. The FPIMM0 caller rejected
it, but the FPIMM one would silently treat it as -2.0.

This patch rejects -0.0 and adds testcases to illegal.[sd].

Before the patch, the final error emitted for illegal.s was:

Error: cannot do 16-byte relocation

which was matched by:

[^:]*:569: Error: .*

The error was reported against the last line of the file rather than
the instruction that required the reloc. Adding more instructions
meant that the line number also changed.

Reporting against the wrong line isn't good from a QoI perspective
but isn't what I'm trying to fix here. Until it's fixed, I thought
it would be better to adjust the match to be against an end-of-file
comment rather than against whatever the last instruction happens to be.

gas/
* config/tc-aarch64.c (parse_aarch64_imm_float): Reject -0.0.
* testsuite/gas/aarch64/illegal.s, testsuite/gas/aarch64/illegal.l:
Add tests for -0.0. Add an end-of-file comment.

PowerPC64 ELFv1 undefined weak functions

Undefined weak functions, like __gmon_start__, were not being made
dynamic or emitting plt call code. While the behaviour of undefined
weak symbols is not defined in the ELF standard, the intention on
powerpc64 was to make it possible to link without a definition of such
symbols and at run time behave the same as if a definition was found
at link time in a shared library.

* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Don't exit with
non_got_ref true in any case where we could have generated dynbss
copies but decide not to do so.

Automatic date update in version.in

PR ld/15428: MIPS/LD/testsuite: Un-KFAIL `__ehdr_start' test 2

Complement commit b75d42bce560 ("Fix mips segfault on GOT access of
absolute symbol") and unmark the `__ehdr_start' test 2 as known to fail
for the n32 and n64 ABIs, as with the change referred in place the
causing issue has been properly addressed and consequently the tests do
not fail anymore and neither are supposed to.

ld/
PR ld/15428
* testsuite/ld-mips-elf/mips-elf.exp: Un-KFAIL `__ehdr_start'
test 2.

Fix PR gdb/19187 (process record over a fork causes internal error)

Right after a fork is detected, we detach breakpoints from the child
(detach_breakpoints), which calls into target_remove_breakpoint with
inferior_ptid pointing at the child process, but leaves the breakpoint
marked inserted (in the parent).

The problem is that record-full.c always deletes all knowledge of the
breakpoint. Then when we later really delete the breakpoint from the
parent, we fail the assertion, since the breakpoint is unexpectedly
not found in the record-full.c breakpoint table.

The fix is simply to not forget about the breakpoint if we're
detaching it from a fork child.

gdb/ChangeLog:
2016-08-10 Pedro Alves <palves@redhat.com>

PR gdb/19187
* record-full.c (record_full_remove_breakpoint): Don't remove the
breakpoint from the record_full_breakpoints VEC if we're detaching
the breakpoint from a fork child.

gdb/testsuite/ChangeLog:
2016-08-10 Pedro Alves <palves@redhat.com>

PR gdb/19187
* gdb.reverse/waitpid-reverse.exp: Add comment and remove
setup_kfails.

Plumb enum remove_bp_reason all the way to target_remove_breakpoint

So the target knows whether we're detaching breakpoints.
Nothing uses the parameter in this patch yet.

gdb/ChangeLog:
2016-08-10 Pedro Alves <palves@redhat.com>

PR gdb/19187
* break-catch-sig.c (signal_catchpoint_remove_location): Adjust
interface.
* break-catch-syscall.c (remove_catch_syscall):
* breakpoint.c (enum remove_bp_reason): Moved to breakpoint.h.
(remove_breakpoint_1): Pass 'reason' down.
(remove_catch_fork, remove_catch_vfork, remove_catch_solib)
(remove_catch_exec, remove_watchpoint, remove_masked_watchpoint)
(base_breakpoint_remove_location, bkpt_remove_location)
(bkpt_probe_remove_location, bkpt_probe_remove_location): Adjust
interface.
* breakpoint.h (enum remove_bp_reason): Moved here from
breakpoint.c.
(struct breakpoint_ops) <remove_location>: Add 'reason' parameter.
* corelow.c (core_remove_breakpoint): New function.
(init_core_ops): Install it as to_remove_breakpoint method.
* exec.c (exec_remove_breakpoint): New function.
(init_exec_ops): Install it as to_remove_breakpoint method.
* mem-break.c (memory_remove_breakpoint): Adjust interface.
* record-btrace.c (record_btrace_remove_breakpoint): Adjust
interface.
* record-full.c (record_full_remove_breakpoint)
(record_full_core_remove_breakpoint): Adjust interface.
* remote.c (remote_remove_breakpoint): Adjust interface.
* target-debug.h (target_debug_print_enum_remove_bp_reason): New
macro.
* target-delegates.c: Regenerate.
* target.c (target_remove_breakpoint): Add 'reason' parameter.
* target.h (struct target_ops) <to_remove_breakpoint>: Add
'reason' parameter.
(target_remove_breakpoint, memory_remove_breakpoint): Add 'reason'
parameter.

Introduce 'enum remove_bp_reason'

Makes the code more obvious.

gdb/ChangeLog:
2016-08-10 Pedro Alves <palves@redhat.com>

PR gdb/19187
* breakpoint.c (insertion_state_t): Delete.
(enum remove_bp_reason): New.
(detach_breakpoints, remove_breakpoint_1, remove_breakpoint):
Adjust to use enum remove_bp_reason instead of insertion_state_t.

Simplify remove_breakpoint interface

All callers pass mark_uninserted, so there's no need for the 'is'
parameter.

gdb/ChangeLog:
2016-08-10 Pedro Alves <palves@redhat.com>

PR gdb/19187
* breakpoint.c (remove_breakpoint): Remove 'is' parameter and
always pass mark_uninserted to remove_breakpoint_1.
(insert_breakpoint_locations, remove_breakpoints)
(remove_breakpoints_pid, update_global_location_list): Update
callers.

MIPS/LD/testsuite: Verify microMIPS LA25 stub generation

Repeat `PIC and non-PIC test 1' checks for microMIPS LA25 stubs,
covering code generation and stub symbol annotation.

ld/
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips-rel.dd: New
test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips-rel.nd: New
test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips.dd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips.nd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1a-micromips.s: New test
source.
* testsuite/ld-mips-elf/pic-and-nonpic-1b-micromips.s: New test
source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.

MIPS/BFD: Actually produce short microMIPS LA25 stubs

For the case where a function which requires an LA25 stub is at the
beginning of a section we use a short sequence comprised of a LUI/ADDIU
instruction pair only and prepended to the associated function rather
than using a trailing jump to reach the function. This works by
checking for the offset into section of the function symbol being 0.

This is however never the case for microMIPS function symbols, which
have the ISA bit set. Consequently the short LA25 sequence is never
produced for microMIPS functions, like with the following example:

$ cat la25a.s
.abicalls

.global f1
.ent f1
f1:
.set noreorder
.cpload $25
.set reorder
.option pic0
jal f2
.option pic2
jr $31
.end f1

.global f2
.ent f2
f2:
jr $31
.end f2
$ cat la25b.s
.abicalls
.option pic0

.global __start
.ent __start
__start:
jal f1
jal f2
.end __start
$ as -mmicromips -32 -EB -o la25a.o la25a.s
$ as -mmicromips -32 -EB -o la25b.o la25b.s
$ ld -melf32btsmip -o la25 la25a.o la25b.o
$ objdump -d la25

la25: file format elf32-tradbigmips

Disassembly of section .text:

004000d0 <.pic.f2>:
4000d0: 41b9 0040 lui t9,0x40
4000d4: d420 0083 j 400106 <f2>
4000d8: 3339 0107 addiu t9,t9,263
4000dc: 0000 0000 nop

004000e0 <.pic.f1>:
4000e0: 41b9 0040 lui t9,0x40
4000e4: d420 0078 j 4000f0 <f1>
4000e8: 3339 00f1 addiu t9,t9,241
4000ec: 0000 0000 nop

004000f0 <f1>:
4000f0: 41bc 0002 lui gp,0x2
4000f4: 339c 801f addiu gp,gp,-32737
4000f8: 033c e150 addu gp,gp,t9
4000fc: f420 0083 jal 400106 <f2>
400100: 0000 0000 nop
400104: 45bf jrc ra

00400106 <f2>:
400106: 45bf jrc ra
...

00400110 <__start>:
400110: f420 0070 jal 4000e0 <.pic.f1>
400114: 0000 0000 nop
400118: f420 0068 jal 4000d0 <.pic.f2>
40011c: 0000 0000 nop
$

where `.pic.f1' could omit the trailing jump and the filler NOP and just
fall through to `f1'.

Correct the problem by masking out the ISA bit from microMIPS functions,
which fixes the earlier example:

$ objdump -d la25

la25: file format elf32-tradbigmips

Disassembly of section .text:

004000d0 <.pic.f2>:
4000d0: 41b9 0040 lui t9,0x40
4000d4: d420 0083 j 400106 <f2>
4000d8: 3339 0107 addiu t9,t9,263
...

004000e8 <.pic.f1>:
4000e8: 41b9 0040 lui t9,0x40
4000ec: 3339 00f1 addiu t9,t9,241

004000f0 <f1>:
4000f0: 41bc 0002 lui gp,0x2
4000f4: 339c 801f addiu gp,gp,-32737
4000f8: 033c e150 addu gp,gp,t9
4000fc: f420 0083 jal 400106 <f2>
400100: 0000 0000 nop
400104: 45bf jrc ra

00400106 <f2>:
400106: 45bf jrc ra
...

00400110 <__start>:
400110: f420 0074 jal 4000e8 <.pic.f1>
400114: 0000 0000 nop
400118: f420 0068 jal 4000d0 <.pic.f2>
40011c: 0000 0000 nop
$

There is no need to do anything for MIPS16 functions, because if any
LA25 stub has been generated for such a function, then it is only
required for an associated call thunk only, which is regular MIPS code
and the address of which, with the ISA bit clear, is returned by
`mips_elf_get_la25_target'.

This problem has been there since the beginning of microMIPS support:

commit df58fc944dbc6d5efd8d3826241b64b6af22f447
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Sun Jul 24 14:20:15 2011 +0000

<https://sourceware.org/ml/binutils/2011-07/msg00198.html>, ("MIPS:
microMIPS ASE support").

bfd/
* elfxx-mips.c (mips_elf_add_la25_stub): Clear the ISA bit of
the stub address retrieved if associated with a microMIPS
function.

MIPS/BFD: Add microMIPS annotation to LA25 stub symbols

Fix a problem with missing microMIPS symbol annotation with microMIPS
LA25 stub symbols. The consequence of the issue is these symbols appear
in the symbol table as regular MIPS symbols with the ISA bit set, as
shown with the example below:

$ cat la25a.s
.abicalls

.global f1
.ent f1
f1:
.set noreorder
.cpload $25
.set reorder
.option pic0
jal f2
.option pic2
jr $31
.end f1

.global f2
.ent f2
f2:
jr $31
.end f2
$ cat la25b.s
.abicalls
.option pic0

.global __start
.ent __start
__start:
jal f1
jal f2
.end __start
$ as -mmicromips -32 -EB -o la25a.o la25a.s
$ as -mmicromips -32 -EB -o la25b.o la25b.s
$ ld -melf32btsmip -o la25 la25a.o la25b.o
$ readelf -s la25

Symbol table '.symtab' contains 18 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00400098 0 SECTION LOCAL DEFAULT 1
2: 004000b0 0 SECTION LOCAL DEFAULT 2
3: 004000d0 0 SECTION LOCAL DEFAULT 3
4: 00000000 0 SECTION LOCAL DEFAULT 4
5: 00000000 0 SECTION LOCAL DEFAULT 5
6: 00418110 0 NOTYPE LOCAL DEFAULT 3 _gp
7: 004000e1 16 FUNC LOCAL DEFAULT 3 .pic.f1
8: 004000d1 16 FUNC LOCAL DEFAULT 3 .pic.f2
9: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _fdata
10: 00400110 16 FUNC GLOBAL DEFAULT [MICROMIPS] 3 __start
11: 00400106 2 FUNC GLOBAL DEFAULT [MICROMIPS] 3 f2
12: 004000d0 0 NOTYPE GLOBAL DEFAULT 3 _ftext
13: 00410120 0 NOTYPE GLOBAL DEFAULT 3 __bss_start
14: 004000f0 22 FUNC GLOBAL DEFAULT [MICROMIPS] 3 f1
15: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _edata
16: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _end
17: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _fbss
$

where microMIPS annotation is missing for `.pic.f1' and `.pic.f2' even
though these stubs are associated with microMIPS functions `f1' and `f2'
respectively.

Add the missing annotation then, by copying it from the function symbol
an LA25 stub is associated with, correcting the example above:

$ readelf -s la25

Symbol table '.symtab' contains 18 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00400098 0 SECTION LOCAL DEFAULT 1
2: 004000b0 0 SECTION LOCAL DEFAULT 2
3: 004000d0 0 SECTION LOCAL DEFAULT 3
4: 00000000 0 SECTION LOCAL DEFAULT 4
5: 00000000 0 SECTION LOCAL DEFAULT 5
6: 00418110 0 NOTYPE LOCAL DEFAULT 3 _gp
7: 004000e0 16 FUNC LOCAL DEFAULT [MICROMIPS] 3 .pic.f1
8: 004000d0 16 FUNC LOCAL DEFAULT [MICROMIPS] 3 .pic.f2
9: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _fdata
10: 00400110 16 FUNC GLOBAL DEFAULT [MICROMIPS] 3 __start
11: 00400106 2 FUNC GLOBAL DEFAULT [MICROMIPS] 3 f2
12: 004000d0 0 NOTYPE GLOBAL DEFAULT 3 _ftext
13: 00410120 0 NOTYPE GLOBAL DEFAULT 3 __bss_start
14: 004000f0 22 FUNC GLOBAL DEFAULT [MICROMIPS] 3 f1
15: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _edata
16: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _end
17: 00410120 0 NOTYPE GLOBAL DEFAULT 3 _fbss
$

This problem has been there since the beginning of microMIPS support:

commit df58fc944dbc6d5efd8d3826241b64b6af22f447
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Sun Jul 24 14:20:15 2011 +0000

<https://sourceware.org/ml/binutils/2011-07/msg00198.html>, ("MIPS:
microMIPS ASE support").

bfd/
* elfxx-mips.c (mips_elf_create_stub_symbol): For a microMIPS
stub also add STO_MICROMIPS annotation.

MIPS/BFD: Set the ISA bit in microMIPS LA25 stub references

Fix a linker regression introduced with commit 9d862524f6ae ("MIPS:
Verify the ISA mode and alignment of branch and jump targets") causing a
build failure in microMIPS glibc where the `zdump' tool fails to link:

.../timezone/zdump.o: In function `yeartot':
.../timezone/zdump.c:758:(.text+0x62): Jump to a non-instruction-aligned address
.../timezone/zdump.c:758:(.text+0x76): Jump to a non-instruction-aligned address
.../timezone/zdump.c:768:(.text+0x112): Jump to a non-instruction-aligned address
.../timezone/zdump.c:774:(.text+0x1b8): Jump to a non-instruction-aligned address
.../timezone/zdump.c:774:(.text+0x1cc): Jump to a non-instruction-aligned address
collect2: error: ld returned 1 exit status
make[2]: *** [.../timezone/zdump] Error 1

The cause of the failure is the stricter check introduced with the said
change for jump and branch targets tripping on the address of microMIPS
LA25 stubs. Despite being microMIPS code these stubs do not have the
ISA bit set throughout the relocation calculation process, because they
have their address set to the memory offset into the stub section they
are placed in.

The `mips_elf_la25_stub' structure does not carry ISA mode information,
but there is no need to extend it, because the ISA mode can be inferred
from the original symbol, which will have STO_MICROMIPS annotation, so
use that instead to set the ISA bit appropriately. Also only LA25 stubs
associated with microMIPS symbols need to have the ISA bit set, because
other LA25 stubs are made with regular MIPS code, even if associated
with a MIPS16 symbol (in which case they are needed by a call thunk only
rather than the MIPS16 function proper).

bfd/
* elfxx-mips.c (mips_elf_calculate_relocation): Set the ISA bit
in microMIPS LA25 stub references.

Support setting thread names (MS-Windows)

This is done by catching an exception number 0x406d1388 (it has no
documented name, though MSDN dubs it "MS_VC_EXCEPTION" in one code
example), which is thrown by the program. The exception record
contains an ID of a thread and a name to give it.

This requires rolling back some changes in handle_exception(), which
now again returns more than two distinct values. The new
HANDLE_EXCEPTION_IGNORED value means that gdb should just continue,
without returning the thread ID up the stack (which would result in
further handling of the exception, which is not what we want).

gdb/ChangeLog:
2016-08-10 Руслан Ижбулатов <lrn1986@gmail.com>
Pedro Alves <palves@redhat.com>

* windows-nat.c (MS_VC_EXCEPTION): New define.
(handle_exception_result): New enum.
(windows_delete_thread): Free the thread's name.
(handle_exception): Handle MS_VC_EXCEPTION.
(get_windows_debug_event): Handle HANDLE_EXCEPTION_IGNORED.
(windows_thread_name): New function.
(windows_target): Install it as to_thread_name method.
* NEWS: Mention the thread naming support on MS-Windows.

Fix extraneous complaints about missing expected TLS relocation.

With some versions of gas, the call to tls_get_addr uses a GOTPCREL
relocation instead of a GOTPCRELX relocation. We should allow for that
when skip_call_tls_get_addr_ is true. We should also build the test
objects with the in-tree assembler.

This patch also fixes some cascading error messages caused by not
resetting the skip_call_tls_get_addr_ flag after printing the error.

gold/
PR gold/20216
* x86_64.cc (Target_x86_64::Relocate::relocate): Add check for
R_X86_64_GOTPCREL. Reset skip_call_tls_get_addr_ after printing
error message.
* testsuite/Makefile.am (pr20216_gd.o): Add -Bgcctestdir/.
(pr20216_ld.o): Likewise.
* testsuite/Makefile.in: Regenerate.

Fix potential crashes when Target::make_symbol() returns NULL.

2016-08-10 James Clarke <jrtc27@jrtc27.com>

gold/
PR gold/20443
* symtab.cc (Symbol_table::add_from_relobj): Handle NULL symbols,
which will be present for STT_SPARC_REGISTER.
(Symbol_table::add_from_pluginobj): Likewise.
(Symbol_table::add_from_dynobj): Likewise.
(Symbol_table::add_from_incrobj): Removed dead code.

Fix improper handling of R_SPARC_GOTDATA_OP_LOX10 relocation.

The fall-through in Target_sparc::Relocate::relocate for
R_SPARC_GOTDATA_OP_LOX10 is currently R_SPARC_GOT13, but should
clearly be R_SPARC_GOT10. GCC has been seen to emit a sethi/xor
rather than a sethi/or sequence to load a 32-bit immediate, but
if R_SPARC_GOT13 is used then bits 10-12 get zeroed out as both
the sethi and xor immediates contain them.

gold/
PR gold/20442
* sparc.cc (Target_sparc::Relocate::relocate): R_SPARC_GOTDATA_OP_LOX10
should fall back on R_SPARC_GOT10, not R_SPARC_GOT13.

Add support for R_SPARC_32 relocation.

gold/
PR gold/20441
* sparc.cc (Target_sparc::Scan::check_non_pic): Allow R_SPARC_32 on
sparc64.

Quiet ARI gettext checks

The ARI complains about this new file:

common/signals-state-save-restore.c:46: warning: gettext: All messages should be marked up with _.
common/signals-state-save-restore.c:59: warning: gettext: All messages should be marked up with _.
common/signals-state-save-restore.c:87: warning: gettext: All messages should be marked up with _.
common/signals-state-save-restore.c:92: warning: gettext: All messages should be marked up with _.

Since these are untranslatable strings, use () instead of _().

gdb/ChangeLog:
2016-08-10 Pedro Alves <palves@redhat.com>

* common/signals-state-save-restore.c
(save_original_signals_state, restore_original_signals_state):
Wrap perror_with_name arguments with '()'.

Automatic date update in version.in

Skip LTO tests for --disable-plugin

Don't run LTO tests if compiler is configured with --disable-plugin.

PR ld/20436
* testsuite/lib/ld-lib.exp (check_gcc_plugin_enabled): New
proc.
(check_lto_available): Return 0 if check_gcc_plugin_enabled
returns 0.
(check_lto_fat_available): Likewise.
(check_lto_shared_available): Likewise.

Fix PR gdb/20418 - Problems with synchronous commands and new-ui

When executing commands on a secondary UI running the MI interpreter,
some commands that should be synchronous are not. MI incorrectly
continues processing input right after the synchronous command is
sent, before the target stops.

The problem happens when we emit MI async events (=library-loaded,
etc.), and we go about restoring the previous terminal state, we end
up calling target_terminal_ours, which incorrectly always installs the
current UI's input_fd in the event loop... That is, code like this:

old_chain = make_cleanup_restore_target_terminal ();
target_terminal_ours_for_output ();

fprintf_unfiltered (mi->event_channel, "library-loaded");

...

do_cleanups (old_chain);

The fix is to move the add_file_handler/delete_file_handler calls out
of target_terminal_$foo, making these completely no-ops unless called
with the main UI as current UI.

gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>

PR gdb/20418
* event-top.c (ui_register_input_event_handler)
(ui_unregister_input_event_handler): New functions.
(async_enable_stdin): Register input in the event loop.
(async_disable_stdin): Unregister input from the event loop.
(gdb_setup_readline): Register input in the event loop.
* infrun.c (check_curr_ui_sync_execution_done): Register input in
the event loop.
* target.c (target_terminal_inferior): Don't unregister input from
the event loop.
(target_terminal_ours): Don't register input in the event loop.
* target.h (target_terminal_inferior)
(target_terminal_ours_for_output, target_terminal_ours): Update
comments.
* top.h (ui_register_input_event_handler)
(ui_unregister_input_event_handler): New declarations.
* utils.c (ui_unregister_input_event_handler_cleanup)
(prepare_to_handle_input): New functions.
(defaulted_query, prompt_for_continue): Use
prepare_to_handle_input.

gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
Simon Marchi <simon.marchi@ericsson.com>

PR gdb/20418
* gdb.mi/new-ui-mi-sync.c, gdb.mi/new-ui-mi-sync.exp: New files.
* lib/mi-support.exp (mi_expect_interrupt): Remove anchors.

Fix PR mi/20431 - Missing MI prompts after sync execution MI command (-exec-continue, etc.) errors

gdb 7.11 introduced an MI regression: a failing MI sync execution
command misses printing the MI prompt, and then all subsequent command
miss it too:

$ gdb-7.11.1 -i=mi
[...]
p 1
&"p 1\n"
~"$1 = 1"
~"\n"
^done
(gdb) <<< prompted ok
-exec-continue
^error,msg="The program is not being run." <<< missing prompt after this
print 1
&"print 1\n"
~"$2 = 1"
~"\n"
^done <<< missing prompt after this


gdb 7.10.1 behaved correctly, even with "set mi-async on":

-exec-continue
^error,msg="The program is not being run."
(gdb) <<< prompted ok

etc.

Bisecting points at:

commit 0b333c5e7d6c
Author: Pedro Alves <palves@redhat.com>
Date: Wed Sep 9 18:23:23 2015 +0100

Merge async and sync code paths some more
[...]

The problem is that when an exception is thrown, we leave the prompt
state set to PROMPT_BLOCKED, and then mi_execute_command_input_handler
doesn't print the prompt. It used to work because before that patch,
we happened to skip disabling stdin if the current target didn't do
async (which it never does before execution).

I was surprised to find that this bug isn't caught by the testsuite,
so I made a thorough test that tests all combinations of pairs of:

- a failing synchronous execution command
- a failing non-execution command
- a non-failing command

gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>

PR mi/20431
* mi/mi-main.c (mi_execute_command): Enable input and set prompt
state to PROMPT_NEEDED.

gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>

PR mi/20431
* gdb.mi/mi-cmd-error.exp: New file.

Fix PR gdb/18653: gdb disturbs inferior's inherited signal dispositions

gdb's (or gdbserver's) own signal handling should not interfere with
the signal dispositions their spawned children inherit. However, it
currently does. For example, some paths in gdb cause SIGPIPE to be
set to SIG_IGN, and as consequence, the child starts with SIGPIPE to
set to SIG_IGN too, even though gdb was started with SIGPIPE set to
SIG_DFL.

This is because the exec family of functions does not reset the signal
disposition of signals that are set to SIG_IGN:

http://pubs.opengroup.org/onlinepubs/7908799/xsh/execve.html

Signals set to the default action (SIG_DFL) in the calling process
image are set to the default action in the new process
image. Signals set to be ignored (SIG_IGN) by the calling process
image are set to be ignored by the new process image. Signals set to
be caught by the calling process image are set to the default action
in the new process image (see <signal.h>).

And neither does it reset signal masks or flags.

In order to be transparent, when spawning new child processes to debug
(with "run", etc.), reset signal actions and mask back to what was
originally inherited from gdb/gdbserver's parent, just before execing
the target program to debug.

gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>

PR gdb/18653
* Makefile.in (SFILES): Add
common/signals-state-save-restore.c.
(HFILES_NO_SRCDIR): Add common/signals-state-save-restore.h.
(COMMON_OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* configure: Regenerate.
* fork-child.c: Include "signals-state-save-restore.h".
(fork_inferior): Call restore_original_signals_state.
* main.c: Include "signals-state-save-restore.h".
(captured_main): Call save_original_signals_state.
* common/common.m4: Add sigaction to AC_CHECK_FUNCS checks.
* common/signals-state-save-restore.c: New file.
* common/signals-state-save-restore.h: New file.

gdb/gdbserver/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>

PR gdb/18653
* Makefile.in (OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* config.in: Regenerate.
* configure: Regenerate.
* linux-low.c: Include "signals-state-save-restore.h".
(linux_create_inferior): Call
restore_original_signals_state.
* server.c: Include "dispositions-save-restore.h".
(captured_main): Call save_original_signals_state.

gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>

PR gdb/18653
* gdb.base/signals-state-child.c: New file.
* gdb.base/signals-state-child.exp: New file.
* gdb.gdb/selftest.exp (do_steps_and_nexts): Add new pattern.

Support -pie for arm*-eabi targets.

ld/
* emulparams/armelf.sh (GENERATE_PIE_SCRIPT): Set to yes.

Correct the calculation of the use_counts of merged .got entries.

* elf64-alpha.c (elf64_alpha_copy_indirect_symbol): Fix thinko
adjusting the use_count of merged .got entries.