Commit Graph

82997 Commits

Author SHA1 Message Date
Nick Clifton
73f43896e3 Fixes a bug building the ARM Linux kernel with a toolchain compiled with CPU_DEFAULT set.
PR gas/17852
	* config/tc-arm.c (md_begin): Ensure that selected_cpu is
	initialised when CPU_DEFAULT is defined.
2015-03-10 10:01:45 +00:00
Mike Frysinger
6defcd57e9 sim: bfin: fix up linux-fixed-code.h generation more [PR sim/13160]
Add a trailing semi-colon to the sed print command as the BSD sed
implementation wants it.  It's a nop otherwise and works fine on
GNU/etc... implementations too.
2015-03-10 01:43:31 -04:00
GDB Administrator
a24582147f Automatic date update in version.in 2015-03-10 00:00:08 +00:00
Pedro Alves
b2df3cefb1 Delete gdb/testsuite/dg-extract-results.py
Unfortunately, the Python version of the dg-extract-results.sh script
doesn't produce stable-enough results for GDB.  The test messages
appear to end up alpha sorted (losing the original sequence) and also
sorting changes between runs for some reason.  That may be tolerable
for GCC, but for GDB, it often renders test results diffing between
different revisions unworkable.

Until that is fixed upstream, delete the script from the GDB tree.

testsuite/ChangeLog:
2015-03-09  Pedro Alves  <palves@redhat.com>

	* dg-extract-results.py: Delete.
2015-03-09 17:47:18 +00:00
Pedro Alves
ef878e5310 Make dg-extract-results.sh explicitly treat .{sum,log} files as text
This merges Sergio's fix from GCC:
  https://gcc.gnu.org/ml/gcc-patches/2014-12/msg01293.html

gdb/testsuite/ChangeLog:
2015-03-09  Pedro Alves  <palves@redhat.com>

	Merge dg-extract-results.sh from GCC upstream (r218843).

	2014-12-17  Sergio Durigan Junior  <sergiodj@redhat.com>
		* dg-extract-results.sh: Use --text with grep to avoid issues with
		binary files.  Fall back to cat -v, if that doesn't work.
2015-03-09 17:47:17 +00:00
Mike Frysinger
411b642274 sim: bfin: fix bug reference 2015-03-09 13:26:51 -04:00
Cary Coutant
e16631979e Fix failure in exception_static_test.
Because the __EH_FRAME_BEGIN__ symbol is provided in an empty .eh_frame
section in crtbeginT.o, if crt1.o has a non-empty .eh_frame section,
we place all optimized .eh_frame sections into the output section ahead
of the __EH_FRAME_BEGIN__ symbol, which breaks EH for statically-linked
binaries.

This patch fixes the problem by delaying the attachment of the optimized
.eh_frame sections to the output section until we see the end marker
section (or to the end of pass 1 if we never see an end marker).

gold/
	PR gold/14675
	* ehframe.cc (Eh_frame::add_ehframe_input_section): Change return type;
	return enum indicating whether .eh_frame section is empty, optimizable,
	unrecognized, or an end marker. Adjust explicit instantiations.
	* ehframe.h (Eh_frame::Eh_frame_section_disposition): New enum type.
	(Eh_frame::add_ehframe_input_section): Change return type.
	* gold.cc (queue_middle_tasks): Call Layout::finalize_eh_frame_section.
	* layout.cc (Layout::layout_eh_frame): Don't add optimized sections
	to the .eh_frame output section until we see the end marker.
	(Layout::finalize_eh_frame_section): New.
	* layout.h: (Layout::finalize_eh_frame_section): New.
2015-03-09 10:12:06 -07:00
Pedro Alves
9a9df97001 gdbserver/tracepoint: Add 'struct sockaddr_un *' -> 'struct sockaddr *' cast
Fixes this in C++ mode:

  gdb/gdbserver/tracepoint.c: In function ‘void* gdb_agent_helper_thread(void*)’:
  gdb/gdbserver/tracepoint.c:7190:47: error: cannot convert ‘sockaddr_un*’ to ‘sockaddr*’ for argument ‘2’ to ‘int accept(int, sockaddr*, socklen_t*)’
	  fd = accept (listen_fd, &sockaddr, &tmp);

gdb/gdbserver/ChangeLog:
2015-03-09  Pedro Alves  <palves@redhat.com>

	* tracepoint.c (gdb_agent_helper_thread): Cast '&sockaddr' to
	'struct sockaddr' pointer in 'accept' call.
2015-03-09 11:29:57 +00:00
Pedro Alves
9eb1356e38 Revert union gdb_sockaddr_u
This reverts 366c75fc.

We don't actually need to access the object through
"struct sockaddr *", so we don't need the union:
   https://sourceware.org/ml/gdb-patches/2015-03/msg00213.html

gdb/ChangeLog:
2015-03-09  Pedro Alves  <palves@redhat.com>

	Revert:
	2015-03-07  Pedro Alves  <palves@redhat.com>
	* common/gdb_socket.h: New file.
	* ser-tcp.c: Include gdb_socket.h.  Don't include netinet/in.h nor
	sys/socket.h.
	(net_open): Use union gdb_sockaddr_u.

gdb/gdbserver/ChangeLog:
2015-03-09  Pedro Alves  <palves@redhat.com>

	Revert:
	2015-03-07  Pedro Alves  <palves@redhat.com>
	* gdbreplay.c: No longer include <netinet/in.h>, <sys/socket.h>,
	or <winsock2.h> here.  Instead include "gdb_socket.h".
	(remote_open): Use union gdb_sockaddr_u.
	* remote-utils.c: No longer include <netinet/in.h>, <sys/socket.h>
	or <winsock2.h> here.  Instead include "gdb_socket.h".
	(handle_accept_event, remote_prepare): Use union gdb_sockaddr_u.
	* tracepoint.c: Include "gdb_socket.h" instead of <sys/socket.h>
	or <sys/un.h>.
	(init_named_socket, gdb_agent_helper_thread): Use union
	gdb_sockaddr_u.
2015-03-09 11:27:05 +00:00
Mike Frysinger
43fa85d9a8 sim: bfin: fix up linux-fixed-code.h generation [PR sim/10143]
The use of $< ends up picking the wrong object out of the depend
list.  Specify the input name directly to avoid fragility.

On BSD systems, we need to make sure all options come before the
non-options (i.e. the files).

Reported-by: Chris Johns <chrisj@rtems.org>
URL: https://sourceware.org/bugzilla/show_bug.cgi?id=13160
2015-03-09 00:00:05 -04:00
GDB Administrator
ccf946cb5c Automatic date update in version.in 2015-03-09 00:00:08 +00:00
Mike Frysinger
3e95021c77 sim: microblaze: fix printf string
Since sizeof returns a size_t, use %zu to display it.
2015-03-08 03:24:09 -04:00
GDB Administrator
d1771b7685 Automatic date update in version.in 2015-03-08 00:00:08 +00:00
Pedro Alves
aac331e484 Remove C-specific warnings from common warning set
Whoops, these are C specific, but I somehow missed the warnings before:

  cc1plus: warning: command line option ‘-Wmissing-prototypes’ is valid for C/ObjC but not for C++ [enabled by default]
  cc1plus: warning: command line option ‘-Wdeclaration-after-statement’ is valid for C/ObjC but not for C++ [enabled by default]
  cc1plus: warning: command line option ‘-Wmissing-parameter-type’ is valid for C/ObjC but not for C++ [enabled by default]
  cc1plus: warning: command line option ‘-Wold-style-declaration’ is valid for C/ObjC but not for C++ [enabled by default]
  cc1plus: warning: command line option ‘-Wold-style-definition’ is valid for C/ObjC but not for C++ [enabled by default]

gdb/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* configure.ac (build_warnings): Move -Wmissing-prototypes
	-Wdeclaration-after-statement -Wmissing-parameter-type
	-Wold-style-declaration -Wold-style-definition to the C-specific
	set.
	* configure: Regenerate.

gdb/gdbserver/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* configure.ac (build_warnings): Move
	-Wdeclaration-after-statement to the C-specific set.
	* configure: Regenerate.
2015-03-07 18:00:15 +00:00
Pedro Alves
366c75fc91 Fix struct sockaddr/sockaddr_in/sockaddr_un strict aliasing violations
Building gdbserver in C++ mode shows:

  gdb/gdbserver/tracepoint.c: In function ‘void* gdb_agent_helper_thread(void*)’:
  gdb/gdbserver/tracepoint.c:7190:47: error: cannot convert ‘sockaddr_un*’ to ‘sockaddr*’ for argument ‘2’ to ‘int accept(int, sockaddr*, socklen_t*)’
	  fd = accept (listen_fd, &sockaddr, &tmp);

A few places in the tree already have an explicit cast to struct
sockaddr *, but that's a strict aliasing violation.  Instead of
propagating invalid code, fix this by using a union instead.

gdb/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* common/gdb_socket.h: New file.
	* ser-tcp.c: Include gdb_socket.h.  Don't include netinet/in.h nor
	sys/socket.h.
	(net_open): Use union gdb_sockaddr_u.

gdb/gdbserver/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* gdbreplay.c: No longer include <netinet/in.h>, <sys/socket.h>,
	or <winsock2.h> here.  Instead include "gdb_socket.h".
	(remote_open): Use union gdb_sockaddr_u.
	* remote-utils.c: No longer include <netinet/in.h>, <sys/socket.h>
	or <winsock2.h> here.  Instead include "gdb_socket.h".
	(handle_accept_event, remote_prepare): Use union gdb_sockaddr_u.
	* tracepoint.c: Include "gdb_socket.h" instead of <sys/socket.h>
	or <sys/un.h>.
	(init_named_socket, gdb_agent_helper_thread): Use union
	gdb_sockaddr_u.
2015-03-07 17:30:46 +00:00
Pedro Alves
72df25b28d Make TRY/CATCH use real C++ try/catch in C++ mode
Although the current TRY/CATCH implementation works in C++ mode too,
it relies on setjmp/longjmp, and longjmp bypasses calling the
destructors of objects on the stack, which is obviously bad for C++.

This patch fixes this by makes TRY/CATCH use real try/catch in C++
mode behind the scenes.  The way this is done allows RAII and cleanups
to coexist while we phase out cleanups, instead of requiring a flag
day.

This patch is not strictly necessary until we require a C++ compiler
and start actually using RAII, though I'm all for baby steps, and it
shows my proposed way forward.  Putting it in now, allows for easier
experimentation and exposure of potential problems with real C++
exceptions.

gdb/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* common/common-exceptions.c [!__cplusplus] (enum catcher_state)
	(exceptions_state_mc_action_iter)
	(exceptions_state_mc_action_iter_1, exceptions_state_mc_catch):
	Don't define.
	[__cplusplus] (try_scope_depth): New global.
	[__cplusplus] (exception_try_scope_entry)
	(exception_try_scope_exit, gdb_exception_sliced_copy)
	(exception_rethrow): New functions.
	(throw_exception): In C++ mode, throw
	gdb_exception_RETURN_MASK_QUIT for RETURN_QUIT and
	gdb_exception_RETURN_MASK_ERROR for RETURN_ERROR.
	(throw_it): In C++ mode, use try_scope_depth.
	* common/common-exceptions.h [!__cplusplus]
	(exceptions_state_mc_action_iter)
	(exceptions_state_mc_action_iter_1, exceptions_state_mc_catch):
	Don't declare.
	[__cplusplus] (exception_try_scope_entry)
	(exception_try_scope_exit, exception_rethrow): Declare.
	[__cplusplus] (struct exception_try_scope): New struct.
	[__cplusplus] (TRY, CATCH, END_CATCH): Reimplement on top of real
	C++ exceptions.
	(struct gdb_exception_RETURN_MASK_ALL)
	(struct gdb_exception_RETURN_MASK_ERROR)
	(struct gdb_exception_RETURN_MASK_QUIT): New types.
2015-03-07 15:26:27 +00:00
Pedro Alves
284e6217cf kill volatile struct gdb_exception
After the previous patch, this is the last remaining use of a volatile
struct gdb_exception.  Kill it, as it's troublesome for C++: we can't
assign volatile <-> non-volatile without copy constructors /
assignment operators that do that, which I'd rather avoid.

gdb/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* main.c (handle_command_errors): Remove volatile qualifier from
	parameter.
2015-03-07 15:25:09 +00:00
Pedro Alves
6c63c96a22 more making TRY/CATCH callers look more like real C++ try/catch blocks
All these were caught by actually making TRY/CATCH use try/catch
behind the scenes, which then resulted in the build failing (on x86_64
Fedora 20) because there was code between the try and catch blocks.

gdb/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (save_breakpoints): Adjust to avoid code between
	TRY and CATCH.
	* gdbtypes.c (safe_parse_type): Remove empty line.
	(types_deeply_equal):
	* guile/scm-frame.c (gdbscm_frame_name):
	* linux-thread-db.c (find_new_threads_once):
	* python/py-breakpoint.c (bppy_get_commands):
	* record-btrace.c (record_btrace_insert_breakpoint)
	(record_btrace_remove_breakpoint, record_btrace_start_replaying)
	(record_btrace_start_replaying): Adjust to avoid code between TRY
	and CATCH.
2015-03-07 15:19:57 +00:00
Pedro Alves
492d29ea1c Split TRY_CATCH into TRY + CATCH
This patch splits the TRY_CATCH macro into three, so that we go from
this:

~~~
  volatile gdb_exception ex;

  TRY_CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  if (ex.reason < 0)
    {
    }
~~~

to this:

~~~
  TRY
    {
    }
  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH
~~~

Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.

This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.

TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:

  TRY
    {
    }

  // some code here.

  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH

Just like it isn't valid to do that with C++'s native try/catch.

By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.

The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved.  After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch].  The result was folded into this patch so that GDB
still builds at each incremental step.

END_CATCH is necessary for two reasons:

First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:

  #define CATCH(EXCEPTION, mask) \
    for (struct gdb_exception EXCEPTION; \
         exceptions_state_mc_catch (&EXCEPTION, MASK); \
	 EXCEPTION = exception_none)

would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.

Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow.  That will
be done in END_CATCH.

After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.

IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.

gdb/ChangeLog.
2015-03-07  Pedro Alves  <palves@redhat.com>

	* common/common-exceptions.c (struct catcher) <exception>: No
	longer a pointer to volatile exception.  Now an exception value.
	<mask>: Delete field.
	(exceptions_state_mc_init): Remove all parameters.  Adjust.
	(exceptions_state_mc): No longer pop the catcher here.
	(exceptions_state_mc_catch): New function.
	(throw_exception): Adjust.
	* common/common-exceptions.h (exceptions_state_mc_init): Remove
	all parameters.
	(exceptions_state_mc_catch): Declare.
	(TRY_CATCH): Rename to ...
	(TRY): ... this.  Remove EXCEPTION and MASK parameters.
	(CATCH, END_CATCH): New.
	All callers adjusted.

gdb/gdbserver/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
	instead.
2015-03-07 15:14:14 +00:00
Tom Tromey
ece957c859 quit_force: Replace TRY_CATCH wrapper macros
More preparation for running the TRY_CATCH->TRY/CATCH conversion
script.

gdb/ChangeLog:
2015-03-07  Tom Tromey  <tromey@redhat.com>

	* top.c (quit_force): Inline and delete DO_TRY, DO_PRINT_EX.
2015-03-07 14:56:47 +00:00
Pedro Alves
7556d4a4f6 Normalize TRY_CATCH exception handling block
This normalizes some exception catch blocks that check for ex.reason
to look like this:

~~~
  volatile gdb_exception ex;

  TRY_CATCH (ex, RETURN_MASK_ALL)
    {
      ...
    }
  if (ex.reason < 0)
    {
      ...
    }
~~~

This is a preparation step for running a script that converts all
TRY_CATCH uses to look like this instead:

~~~
  TRY
    {
      ...
    }
  CATCH (ex, RETURN_MASK_ALL)
    {
      ...
    }
  END_CATCH
~~~

The motivation for that change is being able to reimplent TRY/CATCH in
terms of C++ try/catch.

This commit makes it so that:

 - no condition other than ex.reason < 0 is checked in the if
   predicate

 - there's no "else" block to check whether no exception was caught

 - there's no code between the TRY_CATCH (TRY) block and the
   'if (ex.reason < 0)' block (CATCH).

 - the exception object is no longer referred to outside the if/catch
   block.  Note the local volatile exception objects that are
   currently defined inside functions that use TRY_CATCH will
   disappear.  In cases it's more convenient to still refer to the
   exception outside the catch block, a new non-volatile local is
   added and copy to that object is made within the catch block.

The following patches should make this all clearer.

gdb/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	* amd64-tdep.c (amd64_frame_cache, amd64_sigtramp_frame_cache)
	(amd64_epilogue_frame_cache): Normal exception handling code.
	* break-catch-throw.c (check_status_exception_catchpoint)
	(re_set_exception_catchpoint): Ditto.
	* cli/cli-interp.c (safe_execute_command):
	* cli/cli-script.c (script_from_file): Ditto.
	* compile/compile-c-symbols.c (generate_c_for_for_one_variable):
	Ditto.
	* compile/compile-object-run.c (compile_object_run): Ditto.
	* cp-abi.c (baseclass_offset): Ditto.
	* cp-valprint.c (cp_print_value): Ditto.
	* exceptions.c (catch_exceptions_with_msg):
	* frame-unwind.c (frame_unwind_try_unwinder): Ditto.
	* frame.c (get_frame_address_in_block_if_available): Ditto.
	* i386-tdep.c (i386_frame_cache, i386_epilogue_frame_cache)
	(i386_sigtramp_frame_cache): Ditto.
	* infcmd.c (post_create_inferior): Ditto.
	* linespec.c (parse_linespec, find_linespec_symbols):
	* p-valprint.c (pascal_object_print_value): Ditto.
	* parse.c (parse_expression_for_completion): Ditto.
	* python/py-finishbreakpoint.c (bpfinishpy_init): Ditto.
	* remote.c (remote_get_noisy_reply): Ditto.
	* s390-linux-tdep.c (s390_frame_unwind_cache): Ditto.
	* solib-svr4.c (solib_svr4_r_map): Ditto.
2015-03-07 14:56:43 +00:00
Pedro Alves
f873665f44 Fix mail address format of a couple recent ChangeLog entries 2015-03-07 14:52:22 +00:00
GDB Administrator
f6162ff58e Automatic date update in version.in 2015-03-07 00:00:08 +00:00
Yao Qi
60a191edda Use show_debug_regs as a boolean
I happen to see that show_debug_regs is used as an arithmetic type,
but it should be a boolean,

  if (show_debug_regs > 1)

On the other hand, GDB RSP only allows setting it to either 0 or 1,
so it makes no sense to check whether it is greater than 1.  This
patch fixes it.

gdb/gdbserver:

2015-03-06  Yao Qi  <yao.qi@linaro.org>

	* linux-aarch64-low.c (aarch64_insert_point): Use
	show_debug_regs as a boolean.
	(aarch64_remove_point): Likewise.
2015-03-06 14:14:27 +00:00
Nick Clifton
65164438aa Fix an undefined 32-bit right shift by replacing it with two 16-bit right shifts.
PR binutils/17765
	* elflink.c (put_value): Like previous delta, but for the 32-bit
	case.
2015-03-06 09:46:15 +00:00
Gary Benson
61012eef84 New common function "startswith"
This commit introduces a new inline common function "startswith"
which takes two string arguments and returns nonzero if the first
string starts with the second.  It also updates the 295 places
where this logic was written out longhand to use the new function.

gdb/ChangeLog:

	* common/common-utils.h (startswith): New inline function.
	All places where this logic was used updated to use the above.
2015-03-06 09:42:06 +00:00
GDB Administrator
e80417caef Automatic date update in version.in 2015-03-06 00:00:08 +00:00
Pedro Alves
9494d2199f gdb.base/bp-permanent.exp: Tighten regex
Trying to fix a permanent breakpoints bug, I broke "next" over a
regular breakpoint.  "next" would immediately hit the breakpoint the
program was already stopped at.  But, the "next over setup" test
failed to notice this and still issued a pass.  That's because the
regex matches "testsuite" in:

  Breakpoint 2 at 0x400687: file src/gdb/testsuite/gdb.base/bp-permanent.c, line 46.

gdb/testsuite/ChangeLog:
2015-03-05  Pedro Alves  <palves@redhat.com>

	* gdb.base/bp-permanent.exp: Tighten "next over setup" regex.
2015-03-05 23:40:39 +00:00
Pedro Alves
68901c4d43 PR gdb/18002: Fix reinsert of a permanent breakpoints
When we find out that a breakpoint is set on top of a program
breakpoint, we mark it as "permanent".  E.g.,:

...
  if (bp_loc_is_permanent (loc))
    {
      loc->inserted = 1;
      loc->permanent = 1;
    }
...

Note we didn't fill in the breakpoint's shadow (shadow_len remains 0).

In case the target claims support for evaluating breakpoint
conditions, GDB sometimes reinserts breakpoints that are already
inserted (to update the conditions on the target side).  Since GDB
doesn't know whether the target supports evaluating conditions _of_
software breakpoints (vs hardware breakpoints, etc.) until it actually
tries it, if the target doesn't actually support z0 breakpoints, GDB
ends up reinserting a GDB-managed software/memory breakpoint
(mem-break.c).

And that is the case that is buggy: breakpoints that are marked
inserted contribute their shadows (if any) to the memory returned by
target_read_memory, to mask out breakpoints.  Permanent breakpoints
are always marked as inserted.  So if the permanent breakpoint doesn't
have a shadow yet in its shadow buffer, but we set shadow_len before
calling target_read_memory, then the still clear shadow_contents
buffer will be used by the breakpoint masking code...  And then from
there on, the permanent breakpoint has a broken shadow buffer, and
thus any memory read out of that address will read bogus code, and
many random bad things fall out from that.

The fix is just to set shadow_len at the same time shadow_contents is
set, not one before and another after...

Fixes all gdb.base/bp-permanent.exp FAILs on PPC64 GNU/Linux gdbserver
and probably any other gdbserver port that doesn't do z0 breakpoints.

gdb/ChangeLog:
2015-03-05  Pedro Alves  <palves@redhat.com>

	PR gdb/18002
	* mem-break.c (default_memory_insert_breakpoint): Set shadow_len
	after reading the breakpoint's shadow memory.
2015-03-05 23:39:45 +00:00
Nick Clifton
41cd1ad1b9 Fix a potentially undefined right shift by replacing it with two smaller right shifts.
PR binutils/17765
	* elflink.c (put_value): Avoid using an undefined shift
	operation.
2015-03-05 17:26:10 +00:00
Nick Clifton
4fd77a3d12 Extend description of --add-gnu-debuglink option to explain why the file must exist.
PR binutils/18064
	* doc/binutils.texi (objcopy): Extend description of
	--add-gnu-debuglink option to explain that the separate debug info
	file must exist.  Add a description of what to do if the debug
	info file is built in one place but then installed into a separate
	location.
2015-03-05 16:45:15 +00:00
Mark Kettenis
2dcb2b1a45 Enable rthreads support on OpenBSD/hppa
gdb/
2015-03-05  Mark Kettenis  <kettenis@gnu.org>

        * hppabsd-nat.c: Remove file.
        * hppaobsd-nat.c: New file.
        * Makefile.in (ALLDEPFILES): Remove hppabsd-nat.c.  Add
        hppaobsd-nat.c.
        * config/pa/obsd.mh (NATDEPFILES): Replace hppabsd-nat.o with
        hppaobsd-nat.o.
2015-03-05 17:21:03 +01:00
H.J. Lu
beb8418f47 Remove typename on elfcpp::Elf_types<size>::Elf_Addr
GCC 4.2 complains:

binutils/gold/object.cc:3261: error: using ‘typename’ outside of template

This patch removes typename.  It works with both GCC 4.2 and 4.8.

	* output.cc (Relobj::initialize_input_to_output_map<size>):
	Remove typename on elfcpp::Elf_types<size>::Elf_Addr.
2015-03-05 07:52:41 -08:00
Nick Clifton
81fb971a3d Fixes PR 17994 - which reported that dlltool was not deleting temporary files if it encounters a fatal error.
PR binutils/17994
	* dlltool.c (temp_file_to_remove): New local array.
	(unlink_temp_files): New functions - unlinks any file in the
	temp_file_to_remove array, unless dotdeltemps is set.
	(gen_exp_file): Add temp files to array.
	(make_head): Likewise.
	(make_delay_head): Likewise.
	(make_tail): Likewise.
	(gen_lib_file): Call unlink_temp_files.
2015-03-05 15:13:08 +00:00
H.J. Lu
ca3fe95e46 Add extern_protected_data and set it for x86
With copy relocation, address of protected data defined in the shared
library may be external.  This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.

bfd/

	PR ld/pr15228
	PR ld/pr17709
	* elf-bfd.h (elf_backend_data): Add extern_protected_data.
	* elf32-i386.c (elf_backend_extern_protected_data): New.
	Defined to 1.
	* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
	* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
	copy relocs against protected symbols if extern_protected_data
	is true.
	(_bfd_elf_symbol_refs_local_p): Don't return true on protected
	non-function symbols if extern_protected_data is true.
	* elfxx-target.h (elf_backend_extern_protected_data): New.
	Default to 0.
	(elfNN_bed): Initialize extern_protected_data with
	elf_backend_extern_protected_data.

ld/testsuite/

	PR ld/pr15228
	PR ld/pr17709
	* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
	* ld-i386/pr17709-nacl.rd: New file.
	* ld-i386/pr17709.rd: Likewise.
	* ld-i386/pr17709a.s: Likewise.
	* ld-i386/pr17709b.s: Likewise.
	* ld-i386/protected3.d: Updated.
	* ld-i386/protected3.s: Likewise.
	* ld-x86-64/pr17709-nacl.rd: New file.
	* ld-x86-64/pr17709.rd: Likewise.
	* ld-x86-64/pr17709a.s: Likewise.
	* ld-x86-64/pr17709b.s: Likewise.
	* ld-x86-64/protected3.d: Updated.
	* ld-x86-64/protected3.s: Likewise.
	* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
2015-03-05 06:34:53 -08:00
Nick Clifton
a26de52c63 Fixes a thinko in the implementation of the V850 -m8byte-align and -m4byte-align command line options.
* config/tc-v850.c (md_parse_option): Fix code to set or clear
	EF_RH850_DATA_ALIGN8 bit in ELF header, based upon the use of the
	-m8byte-align and -m4byte-align command line options.
2015-03-05 13:04:33 +00:00
Nick Clifton
425bd9e1bb Allows the binutils to cope with PE binaries where the section addresses have been changed, but the DWARF debug info has not been altered.
PR binutils/18025
	* coffgen.c (coff_find_nearest_line_with_names): If the dwarf2
	lookup fails, check for an address bias in the dwarf info, and if
	one exists, retry the lookup with the biased value.
	* dwarf2.c (_bfd_dwarf2_find_symbol_bias): New function.
	Determines if a bias exists bewteen the addresses of functions
	based on DWARF information vs symbol table information.
	* libbfd-in.h (_bfd_dwarf2_find_symbol_bias): Prototype.
	* libbfd.h: Regenerate.
2015-03-05 12:14:26 +00:00
Pedro Alves
f5771b1d96 Fix Windows/SPU/NTO/Lynx gdbserver builds
I forgot to update these target_ops instances when I added these new
hooks.

I confirmed mingw32-w64 builds again at least.

gdb/gdbserver/ChangeLog:
2015-03-05  Pedro Alves  <palves@redhat.com>

	* lynx-low.c (lynx_target_ops): Install NULL hooks for
	stopped_by_sw_breakpoint, supports_stopped_by_sw_breakpoint,
	stopped_by_hw_breakpoint, supports_stopped_by_hw_breakpoint.
	* nto-low.c (nto_target_ops): Likewise.
	* spu-low.c (spu_target_ops): Likewise.
	* win32-low.c (win32_target_ops): Likewise.
2015-03-05 10:24:58 +00:00
GDB Administrator
7e848b1a60 Automatic date update in version.in 2015-03-05 00:00:08 +00:00
Cary Coutant
48c734280a Fix a race condition when setting default target for ARM targets.
gold/
	* parameters.cc (Parameters::set_target_once): Call
	Target::select_as_default_target just once from here...
	(set_parameters_target): ...instead of from here.
2015-03-04 15:17:23 -08:00
Rafael Ávila de Espíndola
dbe40a8891 Remove empty class Merge_map.
2015-03-02  Rafael Ávila de Espíndola <rafael.espindola@gmail.com>

	* ehframe.cc (Cie::set_output_offset): Pass in and use a
	Output_section_data instead of a Merge_map.
	(Eh_frame::Eh_frame): Don't initialize merge_map_.
	(Eh_frame::read_cie): Use add_merge_mapping instead of
	Merge_map::add_mapping.
	(Eh_frame::read_fde): Ditto.
	(Eh_frame::set_final_data_size): Use this instead of this->merge_map_.
	(Eh_frame::do_output_offset): Use merge_output_offset istead of
	merge_map_->get_output_offset.
	(Eh_frame::do_is_merge_section_for): Delete.
	* ehframe.h (Fde::add_mapping): Pass in and use a Output_section_data
	instead of a Merge_map.
	(Cie::set_output_offset): Pass in a Output_section_data instead of a
	Merge_map.
	(Eh_frame::do_is_merge_section_for): Delete.
	(Eh_frame::merge_map_): Delete.
	* merge.cc (Object_merge_map::get_or_make_input_merge_map): Pass in
	and use a Output_section_data instead of a Merge_map.
	(Object_merge_map::add_mapping): Ditto.
	(Object_merge_map::get_output_offset): Remove the merge_map argument.
	(Object_merge_map::is_merge_section_for): Pass in and use a
	Output_section_data instead of a Merge_map.
	(Merge_map): Delete.
	(Output_merge_base::do_output_offset): Use merge_output_offset instead
	of merge_map_.get_output_offset.
	(Output_merge_base::do_is_merge_section_for): Delete.
	(Output_merge_data::do_add_input_section): Use
	object->add_merge_mapping instead of add_mapping.
	(Output_merge_string<Char_type>::finalize_merged_data): Ditto.
	* merge.h (Merge_map): Delete forward declaration.
	(Object_merge_map::add_mapping): Pass in and use a Output_section_data
	instead of a Merge_map.
	(Object_merge_map::get_output_offset): Remove the merge_map argument.
	(Object_merge_map::is_merge_section_for): Pass in and use a
	Output_section_data instead of a Merge_map.
	(Input_merge_map::Object_merge_map::merge_map): Replace with
	output_data.
	(Object_merge_map::get_or_make_input_merge_map): Pass in and use a
	Output_section_data instead of a Merge_map.
	(Merge_map): Delete.
	(Output_merge_base::Output_merge_base): Don't initialize merge_map_.
	(Output_merge_base::do_is_merge_section_for): Delete.
	(Output_merge_base::add_mapping): Delete.
	(Output_merge_base::merge_map_): Delete.
	* object.cc (Relobj::initialize_input_to_output_map): New.
	(Relobj::initialize_input_to_output_map): New.
	(Relobj::merge_output_offset): New.
	(Relobj::is_merge_section_for): New.
	(Relobj::initialize_input_to_output_map): Instantiate for 32 and 64
	bits.
	* object.h (Relobj::merge_map): Delete.
	(initialize_input_to_output_map): New.
	(set_merge_map): Delete.
	(add_merge_mapping): New.
	(merge_output_offset): New.
	(is_merge_section_for): New.
	* output.cc (Output_section::Input_section::is_merge_section_for):
	Use object->is_merge_section_for.
	* output.h (Output_section_data::is_merge_section_for): Delete.
	(Output_section_data::do_is_merge_section_for): Delete.
	* reloc.cc (Merged_symbol_value<size>::initialize_input_to_output_map):
	Use object->initialize_input_to_output_map.
	(Merged_symbol_value<size>::value_from_output_section): Use
	object->merge_output_offset.
2015-03-04 15:10:18 -08:00
Simon Marchi
a8d9763abd Accept all-stop alternative in mi_expect_interrupt
When interrupting a thread in non-stop vs all-stop, the signal given in
the MI *stopped event is not the same. Currently, mi_expect_interrupt only
accepts the case for non-stop, so this adds the alternative for all-stop.

gdb/testsuite/ChangeLog:

	* lib/mi-support.exp (mi_expect_interrupt): Accept
	alternative event for when in all-stop mode.
2015-03-04 17:56:58 -05:00
Pedro Alves
527a273ac1 garbage collect target_decr_pc_after_break
record-btrace was the only target making use of this, and it no longer
uses it.

gdb/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* target.h (struct target_ops) <to_decr_pc_after_break>: Delete.
	(target_decr_pc_after_break): Delete declaration.
	* target.c (default_target_decr_pc_after_break)
	(target_decr_pc_after_break): Delete.
	* linux-nat.c (check_stopped_by_breakpoint, linux_nat_wait_1): Use
	gdbarch_decr_pc_after_break instead of target_decr_pc_after_break.
	* linux-thread-db.c (check_event): Likewise.
	* infrun.c (adjust_pc_after_break): Likewise.
	* darwin-nat.c (cancel_breakpoint): Likewise.
	* aix-thread.c (aix_thread_wait): Likewise.
	* target-delegates.c: Regenerate.
2015-03-04 20:41:17 +00:00
Pedro Alves
3e572f7104 gdbserver/Linux: Use TRAP_BRKPT/TRAP_HWBPT
This patch adjusts gdbserver's Linux backend to tell gdbserver core
(and ultimately GDB) whether a trap was caused by a breakpoint.

It teaches the backend to get that information out of the si_code of
the SIGTRAP siginfo.

gdb/gdbserver/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

        * linux-low.c (check_stopped_by_breakpoint) [USE_SIGTRAP_SIGINFO]:
	Decide whether a breakpoint triggered based on the SIGTRAP's
	siginfo.si_code.
        (thread_still_has_status_pending_p) [USE_SIGTRAP_SIGINFO]: Don't check whether a
        breakpoint is inserted if relying on SIGTRAP's siginfo.si_code.
	(linux_low_filter_event): Check for breakpoints before checking
	watchpoints.
	(linux_wait_1): Don't re-increment the PC if relying on SIGTRAP's
	siginfo.si_code.
        (linux_stopped_by_sw_breakpoint)
        (linux_supports_stopped_by_sw_breakpoint)
        (linux_stopped_by_hw_breakpoint)
        (linux_supports_stopped_by_hw_breakpoint): New functions.
        (linux_target_ops): Install new target methods.
2015-03-04 20:41:17 +00:00
Pedro Alves
1ec68e26c9 gdbserver: Support the "swbreak"/"hwbreak" stop reasons
This patch teaches the core of gdbserver about the new "swbreak" and
"hwbreak" stop reasons, and adds the necessary hooks a backend needs
to implement to support the feature.

gdb/gdbserver/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* remote-utils.c (prepare_resume_reply): Report swbreak/hbreak.
	* server.c (swbreak_feature, hwbreak_feature): New globals.
	(handle_query) <qSupported>: Handle "swbreak+" and "hwbreak+".
	(captured_main): Clear swbreak_feature and hwbreak_feature.
	* server.h (swbreak_feature, hwbreak_feature): Declare.
	* target.h (struct target_ops) <stopped_by_sw_breakpoint,
	supports_stopped_by_sw_breakpoint, stopped_by_hw_breakpoint,
	supports_stopped_by_hw_breakpoint>: New fields.
	(target_supports_stopped_by_sw_breakpoint)
	(target_stopped_by_sw_breakpoint)
	(target_supports_stopped_by_hw_breakpoint)
	(target_stopped_by_hw_breakpoint): Declare.
2015-03-04 20:41:16 +00:00
Pedro Alves
faf09f0119 Linux native: Use TRAP_BRKPT/TRAP_HWBPT
This patch adjusts the native Linux target backend to tell the core
whether a trap was caused by a breakpoint.

It teaches the target to get that information out of the si_code of
the SIGTRAP siginfo.

Tested on x86-64 Fedora 20, s390 RHEL 7, and PPC64 Fedora 18.  An
earlier version was tested on ARM Fedora 21.

gdb/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* linux-nat.c (save_sigtrap): Check for breakpoints before
	checking watchpoints.
	(status_callback) [USE_SIGTRAP_SIGINFO]: Don't check whether a
	breakpoint is inserted if relying on SIGTRAP's siginfo.si_code.
	(check_stopped_by_breakpoint) [USE_SIGTRAP_SIGINFO]: Decide whether
	a breakpoint triggered based on the SIGTRAP's siginfo.si_code.
	(linux_nat_stopped_by_sw_breakpoint)
	(linux_nat_supports_stopped_by_sw_breakpoint)
	(linux_nat_stopped_by_hw_breakpoint)
	(linux_nat_supports_stopped_by_hw_breakpoint): New functions.
	(linux_nat_wait_1): Don't re-increment the PC if relying on
	SIGTRAP's siginfo->si_code.
	(linux_nat_add_target): Install new target methods.
	* linux-thread-db.c (check_event): Don't account for breakpoint PC
	offset if the target already adjusted the PC.
	* nat/linux-ptrace.h (USE_SIGTRAP_SIGINFO): New.
	(GDB_ARCH_TRAP_BRKPT): New.
	(TRAP_HWBKPT): Define if not already defined.
2015-03-04 20:41:16 +00:00
Pedro Alves
f7e6eed528 remote+docs: software/hardware breakpoint traps
This adjusts target remote to tell the core whether a trap was caused
by a breakpoint.

To that end, the patch teaches GDB about new RSP stop reasons "T05
swbreak" and "T05 hwbreak", that remote targets report back to GDB,
similarly to how "T05 watch" indicates a stop caused by a watchpoint.

Because targets that can report these events are expected to
themselves adjust the PC after a software breakpoint, these new stop
reasons must only be reported if the stub is talking to a GDB that
understands them.  Because of that, the use of the new stop reasons
needs to be handshaked on initial connection, using the qSupported
mechanism.  GDB simply sends "swbreak+" in its qSupports query, and
the stub reports back "swbreak+" too.

Because these new stop reasons are required to fix a fundamental
non-stop mode problem, this commit extends the remote non-stop intro
section in the manual, documenting the events as required.

To be clear, GDB will still cope with remote targets that don't
support these new stop reasons; it will behave just like today.

Tested on x86-64 Fedora 20, native and gdbserver.

gdb/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* NEWS: Mention the new "swbreak" and "hwbreak" stop reasons.
	* remote.c (struct remote_state) <remote_stopped_by_watchpoint_p>:
	Delete field.
	<stop_reason>: New field.
	(PACKET_swbreak_feature, PACKET_hwbreak_feature): New enum values.
	(packet_set_cmd_state): New function.
	(remote_protocol_features): Register the "swbreak" and "hwbreak"
	features.
	(remote_query_supported): If not disabled with the corresponding
	"set remote foo-packet" command, report support for the swbreak
	and hwbreak features.
	(struct stop_reply) <remote_stopped_by_watchpoint_p>: Delete
	field.
	<stop_reason>: New field.
	(remote_parse_stop_reply): Handle "swbreak" and "hwbreak".
	(remote_wait_as): Adjust.
	(remote_stopped_by_sw_breakpoint)
	(remote_supports_stopped_by_sw_breakpoint)
	(remote_stopped_by_hw_breakpoint)
	(remote_supports_stopped_by_hw_breakpoint): New functions.
	(remote_stopped_by_watchpoint): New function.
	(init_remote_ops): Install them.
	(_initialize_remote): Register new "set/show remote
	swbreak-feature-packet" and "set/show remote
	swbreak-feature-packet" commands.

gdb/doc/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Remote Configuration): Document the "set/show
	remote swbreak-feature-packet" and "set/show remote
	hwbreak-feature-packet" commands.
	(Packets) <Z0>: Add cross link to the "swbreak" stop reason's
	decription.
	(Stop Reply Packets): Document the swbreak and hwbreak stop
	reasons.
	(General Query Packets): Document the swbreak and hwbreak
	qSupported features.
	(Remote Non-Stop): Explain that swbreak and hwbreak are required.
2015-03-04 20:41:16 +00:00
Pedro Alves
9e8915c6ce record-full/record-btrace: software/hardware breakpoint trap
This adjusts the record targets to tell the core whether a trap was
caused by a breakpoint.  Targets that can do this should report
breakpoint traps with the PC already adjusted, so this removes the
re-incrementing record-full was doing.

These targets need to be adjusted before process_stratum targets
beneath are, otherwise target_supports_stopped_by_sw_breakpoint,
etc. would fall through to the target beneath while
recording/replaying, and the core would get confused.

Tested on x86-64 Fedora 20, native and gdbserver.

gdb/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* btrace.h: Include target/waitstatus.h.
	(struct btrace_thread_info) <stop_reason>: New field.
	* record-btrace.c (record_btrace_step_thread): Use
	record_check_stopped_by_breakpoint instead of breakpoint_here_p.
	(record_btrace_decr_pc_after_break): Delete.
	(record_btrace_stopped_by_sw_breakpoint)
	(record_btrace_supports_stopped_by_sw_breakpoint)
	(record_btrace_stopped_by_hw_breakpoint)
	(record_btrace_supports_stopped_by_hw_breakpoint): New functions.
	(init_record_btrace_ops): Install them.
	* record-full.c (record_full_hw_watchpoint): Delete and replace
	with ...
	(record_full_stop_reason): ... this throughout.
	(record_full_exec_insn): Adjust.
	(record_full_wait_1): Adjust.  No longer re-increment the PC.
	(record_full_wait_1): Adjust.  Use
	record_check_stopped_by_breakpoint instead of breakpoint_here_p.
	(record_full_stopped_by_watchpoint): Adjust.
	(record_full_stopped_by_sw_breakpoint)
	(record_full_supports_stopped_by_sw_breakpoint)
	(record_full_supports_stopped_by_sw_breakpoint)
	(record_full_stopped_by_hw_breakpoint)
	(record_full_supports_stopped_by_hw_breakpoint): New functions.
	(init_record_full_ops, init_record_full_core_ops): Install them.
	* record.c (record_check_stopped_by_breakpoint): New function.
	* record.h: Include target/waitstatus.h.
	(record_check_stopped_by_breakpoint): New declaration.
2015-03-04 20:41:15 +00:00
Pedro Alves
15c66dd626 enum lwp_stop_reason -> enum target_stop_reason
We're going to need the same enum as enum lwp_stop_reason in more
targets, so this promotes it to common code.

gdb/gdbserver/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	enum lwp_stop_reason -> enum target_stop_reason
	* linux-low.c (check_stopped_by_breakpoint): Adjust.
	(thread_still_has_status_pending_p, check_stopped_by_watchpoint)
	(linux_wait_1, stuck_in_jump_pad_callback)
	(move_out_of_jump_pad_callback, linux_resume_one_lwp)
	(linux_stopped_by_watchpoint):
	* linux-low.h (enum lwp_stop_reason): Delete.
	(struct lwp_info) <stop_reason>: Now an enum target_stop_reason.
	* linux-x86-low.c (x86_linux_prepare_to_resume): Adjust.

gdb/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	enum lwp_stop_reason -> enum target_stop_reason
	* linux-nat.c (linux_resume_one_lwp, check_stopped_by_watchpoint)
	(linux_nat_stopped_by_watchpoint, status_callback)
	(linux_nat_wait_1): Adjust.
	* linux-nat.h (enum lwp_stop_reason): Delete.
	(struct lwp_info) <stop_reason>: Now an enum target_stop_reason.
	* x86-linux-nat.c (x86_linux_prepare_to_resume): Adjust.
	* target/waitstatus.h (enum target_stop_reason): New.
2015-03-04 20:41:15 +00:00
Pedro Alves
1cf4d9513a Teach GDB about targets that can tell whether a trap is a breakpoint event
The moribund locations heuristics are problematic.  This patch teaches
GDB about targets that can reliably tell whether a trap was caused by
a software or hardware breakpoint, and thus don't need moribund
locations, thus bypassing all the problems that mechanism has.

The non-stop-fair-events.exp test is frequently failing currently.
E.g., see https://sourceware.org/ml/gdb-testers/2015-q1/msg03148.html.

The root cause is a fundamental problem with moribund locations.  For
example, the stepped_breakpoint logic added by af48d08f breaks in this
case (which is what happens with that test):

 - Step thread A, no breakpoint is set at PC.

 - The kernel doesn't schedule thread A yet.

 - Insert breakpoint at A's PC, for some reason (e.g., a step-resume
   breakpoint for thread B).

 - Kernel finally schedules thread A.

 - thread A's stepped_breakpoint flag is not set, even though it now
   stepped a breakpoint instruction.

 - adjust_pc_after_break gets the PC wrong, because PC == PREV_PC, but
   stepped_breakpoint is not set.

We needed the stepped_breakpoint logic to workaround moribund
locations, because otherwise adjust_pc_after_break could apply an
adjustment when it shouldn't just because there _used_ to be a
breakpoint at PC (a moribund breakpoint location).  For example, on
x86, that's wrong if the thread really hasn't executed an int3, but
instead executed some other 1-byte long instruction.  Getting the PC
adjustment wrong of course leads to the inferior executing the wrong
instruction.

Other problems with moribund locations are:

 - if a true SIGTRAP happens to be raised when the program is
   executing the PC that used to have a breakpoint, GDB will assume
   that is a trap for a breakpoint that has recently been removed, and
   thus we miss reporting the random signal to the user.

 - to minimize that, we get rid of moribund location after a while.
   That while is defined as just a certain number of events being
   processed.  That number of events sometimes passes by before a
   delayed breakpoint is processed, and GDB confuses the trap for a
   random signal, thus reporting the random trap.  Once the user
   resumes the thread, the program crashes because the PC was not
   adjusted...

The fix for all this is to bite the bullet and get rid of heuristics
and instead rely on the target knowing accurately what caused the
SIGTRAP.  The target/kernel/stub is in the best position to know what
that, because it can e.g. consult priviledged CPU flags GDB has no
access to, or by knowing which exception vector entry was called when
the instruction trapped, etc.  Most debug APIs I've seen to date
report breakpoint hits as a distinct event in some fashion.  For
example, on the Linux kernel, whether a breakpoint was executed is
exposed to userspace in the si_code field of the SIGTRAP's siginfo.
On Windows, the debug API reports a EXCEPTION_BREAKPOINT exception
code.

We needed to keep around deleted breakpoints in an on-the-side list
(the moribund locations) for two main reasons:

  - Know that a SIGTRAP actually is a delayed event for a hit of a
    breakpoint that was removed before the event was processed, and
    thus should not be reported as a random signal.

  - So we still do the decr_pc_after_break adjustment in that case, so
    that the thread is resumed at the correct address.

In the new model, if GDB processes an event the target tells is a
breakpoint trap, and GDB doesn't find the corresponding breakpoint in
its breakpoint tables, it means that event is a delayed event for a
breakpoint that has since been removed, and thus the event should be
ignored.

For the decr_pc_after_after issue, it ends up being much simpler that
on targets that can reliably tell whether a breakpoint trapped, for
the breakpoint trap to present the PC already adjusted.  Proper
multi-threading support already implies that targets needs to be doing
decr_pc_after_break adjustment themselves, otherwise for example, in
all-stop if two threads hit a breakpoint simultaneously, and the user
does "info threads", he'll see the non-event thread that hit the
breakpoint stopped at the wrong PC.

This way (target adjusts) also ends up eliminating the need for some
awkward re-incrementing of the PC in the record-full and Linux targets
that we do today, and the need for the target_decr_pc_after_break
hook.

If the target always adjusts, then there's a case where GDB needs to
re-increment the PC.  Say, on x86, an "int3" instruction that was
explicitly written in the program traps.  In this case, GDB should
report a random SIGTRAP signal to the user, with the PC pointing at
the instruction past the int3, just like if GDB was not debugging the
program.  The user may well decide to pass the SIGTRAP to the program
because the program being debugged has a SIGTRAP handler that handles
its own breakpoints, and expects the PC to be unadjusted.

Tested on x86-64 Fedora 20.

gdb/ChangeLog:
2015-03-04  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (need_moribund_for_location_type): New function.
	(bpstat_stop_status): Don't skipping checking moribund locations
	of breakpoint types which the target tell caused a stop.
	(program_breakpoint_here_p): New function, factored out from ...
	(bp_loc_is_permanent): ... this.
	(update_global_location_list): Don't create a moribund location if
	the target supports reporting stops of the type of the removed
	breakpoint.
	* breakpoint.h (program_breakpoint_here_p): New declaration.
	* infrun.c (adjust_pc_after_break): Return early if the target has
	already adjusted the PC.  Add comments.
	(handle_signal_stop): If nothing explains a signal, and the target
	tells us the stop was caused by a software breakpoint, check if
	there's a breakpoint instruction in the memory.  If so, adjust the
	PC before presenting the stop to the user.  Otherwise, ignore the
	trap.  If nothing explains a signal, and the target tells us the
	stop was caused by a hardware breakpoint, ignore the trap.
	* target.h (struct target_ops) <to_stopped_by_sw_breakpoint,
	to_supports_stopped_by_sw_breakpoint, to_stopped_by_hw_breakpoint,
	to_supports_stopped_by_hw_breakpoint>: New fields.
	(target_stopped_by_sw_breakpoint)
	(target_supports_stopped_by_sw_breakpoint)
	(target_stopped_by_hw_breakpoint)
	(target_supports_stopped_by_hw_breakpoint): Define.
	* target-delegates.c: Regenerate.
2015-03-04 20:41:15 +00:00