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Author SHA1 Message Date
Tom Tromey
c80e29dba9 Change get_ada_task_ptid parameter type 
get_ada_task_ptid currently takes a 'long' as its 'thread' parameter
type.  However, on some platforms this is actually a pointer, and
using 'long' can sometimes end up with the value being sign-extended.
This sign extension can cause problems later, if the tid is then later
used as an address again.

This patch changes the parameter type to ULONGEST and updates all the
uses.  This approach preserves sign extension on the targets where it
is apparently intended, while avoiding it on others.

Co-Authored-By: John Baldwin <jhb@FreeBSD.org>
 2021-09-23 09:30:54 -06:00
Andrew Burgess
611841bb1a gdb: make thread_info::executing private 
Rename thread_info::executing to thread_info::m_executing, and make it
private.  Add a new get/set member functions, and convert GDB to make
use of these.

The only real change of interest in this patch is in thread.c where I
have deleted the helper function set_executing_thread, and now just
use the new set function thread_info::set_executing.  However, the old
helper function set_executing_thread included some code to reset the
thread's stop_pc, so I moved this code into the new function
thread_info::set_executing.  However, I don't believe there is
anywhere that this results in a change of behaviour, previously the
executing flag was always set true through a call to
set_executing_thread anyway.
 2021-09-07 12:44:08 +01:00
Simon Marchi
82d1f134cc gdb: follow-fork: push target and add thread in target_follow_fork 
In the context of ROCm-gdb [1], the ROCm target sits on top of the
linux-nat target.  when a process forks, it needs to carry over some
data from the forking inferior to the fork child inferior.  Ideally, the
ROCm target would implement the follow_fork target_ops method, but there
are some small problems.  This patch fixes these, which helps the ROCm
target, but also makes things more consistent and a bit nicer in
general, I believe.

The main problem is: when follow-fork-mode is "parent",
target_follow_fork is called with the parent as the current inferior.
When it's "child", target_follow_fork is called with the child as the
current inferior.  This means that target_follow_fork is sometimes
called on the parent's target stack and sometimes on the child's target
stack.

The parent's target stack may contain targets above the process target,
such as the ROCm target.  So if follow-fork-child is "parent", the ROCm
target would get notified of the fork and do whatever is needed.  But
the child's target stack, at that moment, only contains the exec and
process target copied over from the parent.  The child's target stack is
set up by follow_fork_inferior, before calling target_follow_fork.  In
that case, the ROCm target wouldn't get notified of the fork.

For consistency, I think it would be good to always call
target_follow_fork on the parent inferior's target stack.  I think it
makes sense as a way to indicate "this inferior has called fork, do
whatever is needed".  The desired outcome of the fork (whether an
inferior is created for the child, do we need to detach from the child)
can be indicated by passed parameter.

I therefore propose these changes:

 - make follow_fork_inferior always call target_follow_fork with the
   parent as the current inferior.  That lets all targets present on the
   parent's target stack do some fork-related handling and push
   themselves on the fork child's target stack if needed.

   For this purpose, pass the child inferior down to target_follow_fork
   and follow_fork implementations.  This is nullptr if no inferior is
   created for the child, because we want to detach from it.

 - as a result, in follow_fork_inferior, detach from the parent inferior
   (if needed) only after the target_follow_fork call.  This is needed
   because we want to call target_follow_fork before the parent's
   target stack is torn down.

 - hand over to the targets in the parent's target stack (including the
   process target) the responsibility to push themselves, if needed, to
   the child's target stack.  Also hand over the responsibility to the
   process target, at the same time, to create the child's initial
   thread (just like we do for follow_exec).

 - pass the child inferior to exec_on_vfork, so we don't need to swap
   the current inferior between parent and child.  Nothing in
   exec_on_vfork depends on the current inferior, after this change.

   Although this could perhaps be replaced with just having the exec
   target implement follow_fork and push itself in the child's target
   stack, like the process target does... We would just need to make
   sure the process target calls beneath()->follow_fork(...).  I'm not
   sure about this one.

gdb/ChangeLog:

	* target.h (struct target_ops) <follow_fork>: Add inferior*
	parameter.
	(target_follow_fork): Likewise.
	* target.c (default_follow_fork): Likewise.
	(target_follow_fork): Likewise.
	* fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise.
	(fbsd_nat_target::follow_fork): Likewise, and call
	inf_ptrace_target::follow_fork.
	* linux-nat.h (class linux_nat_target) <follow_fork>: Likewise.
	* linux-nat.c (linux_nat_target::follow_fork): Likewise, and
	call inf_ptrace_target::follow_fork.
	* obsd-nat.h (obsd_nat_target) <follow_fork>: Likewise.
	* obsd-nat.c (obsd_nat_target::follow_fork): Likewise, and call
	inf_ptrace_target::follow_fork.
	* remote.c (class remote_target) <follow_fork>: Likewise.
	(remote_target::follow_fork): Likewise, and call
	process_stratum_target::follow_fork.
	* process-stratum-target.h (class process_stratum_target)
	<follow_fork>: New.
	* process-stratum-target.c
	(process_stratum_target::follow_fork): New.
	* target-delegates.c: Re-generate.

[1] https://github.com/ROCm-Developer-Tools/ROCgdb

Change-Id: I460bd0af850f0485e8aed4b24c6d8262a4c69929
 2021-08-03 20:26:49 -04:00
Simon Marchi
5538b03c98 gdb: remove cmd_list_element::function::sfunc 
I don't understand what the sfunc function type in
cmd_list_element::function is for.  Compared to cmd_simple_func_ftype,
it has an extra cmd_list_element parameter, giving the callback access
to the cmd_list_element for the command being invoked.  This allows
registering the same callback with many commands, and alter the behavior
using the cmd_list_element's context.

From the comment in cmd_list_element, it sounds like at some point it
was the callback function type for set and show functions, hence the
"s".  But nowadays, it's used for many more commands that need to access
the cmd_list_element object (see add_catch_command for example).

I don't really see the point of having sfunc at all, since do_sfunc is
just a trivial shim that changes the order of the arguments.  All
commands using sfunc could just as well set cmd_list_element::func to
their callback directly.

Therefore, remove the sfunc field in cmd_list_element and everything
that goes with it.  Rename cmd_const_sfunc_ftype to cmd_func_ftype and
use it for cmd_list_element::func, as well as for the add_setshow
commands.

Change-Id: I1eb96326c9b511c293c76996cea0ebc51c70fac0
 2021-07-23 15:38:54 -04:00
Simon Marchi
3a849a3454 gdb: pass child_ptid and fork kind to target_ops::follow_fork 
This is a small cleanup I think would be nice, that I spotted while
doing the following patch.

gdb/ChangeLog:

	* target.h (struct target_ops) <follow_fork>: Add ptid and
	target_waitkind parameters.
	(target_follow_fork): Likewise.
	* target.c (default_follow_fork): Likewise.
	(target_follow_fork): Likewise.
	* fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise.
	* fbsd-nat.c (fbsd_nat_target::follow_fork): Likewise.
	* linux-nat.h (class linux_nat_target) <follow_fork>: Likewise.
	* linux-nat.c (linux_nat_target::follow_fork): Likewise.
	* obsd-nat.h (class obsd_nat_target) <follow_fork>: Likewise.
	* obsd-nat.c (obsd_nat_target::follow_fork): Likewise.
	* remote.c (class remote_target) <follow_fork>: Likewise.
	* target-debug.h (target_debug_print_target_waitkind): New.
	* target-delegates.c: Re-generate.

Change-Id: I5421a542f2e19100a22b74cc333d2b235d0de3c8
 2021-07-14 23:21:30 -04:00
Pedro Alves
d7cb0ef35b Fix detach with target remote (PR gdb/28080) 
Commit 408f66864a1a823591b26420410c982174c239a2 ("detach in all-stop
with threads running") regressed "detach" with "target remote":

 (gdb) detach
 Detaching from program: target:/any/program, process 3671843
 Detaching from process 3671843
 Ending remote debugging.
 [Inferior 1 (process 3671843) detached]
 In main
 terminate called after throwing an instance of 'gdb_exception_error'
 Aborted (core dumped)

Here's the exception above being thrown:

 (top-gdb) bt
 #0  throw_error (error=TARGET_CLOSE_ERROR, fmt=0x555556035588 "Remote connection closed") at src/gdbsupport/common-exceptions.cc:222
 #1  0x0000555555bbaa46 in remote_target::readchar (this=0x555556a11040, timeout=10000) at src/gdb/remote.c:9440
 #2  0x0000555555bbb9e5 in remote_target::getpkt_or_notif_sane_1 (this=0x555556a11040, buf=0x555556a11058, forever=0, expecting_notif=0, is_notif=0x0) at src/gdb/remote.c:9928
 #3  0x0000555555bbbda9 in remote_target::getpkt_sane (this=0x555556a11040, buf=0x555556a11058, forever=0) at src/gdb/remote.c:10030
 #4  0x0000555555bc0e75 in remote_target::remote_hostio_send_command (this=0x555556a11040, command_bytes=13, which_packet=14, remote_errno=0x7fffffffcfd0, attachment=0x0, attachment_len=0x0) at src/gdb/remote.c:12137
 #5  0x0000555555bc1b6c in remote_target::remote_hostio_close (this=0x555556a11040, fd=8, remote_errno=0x7fffffffcfd0) at src/gdb/remote.c:12455
 #6  0x0000555555bc1bb4 in remote_target::fileio_close (During symbol reading: .debug_line address at offset 0x64f417 is 0 [in module build/gdb/gdb]
 this=0x555556a11040, fd=8, remote_errno=0x7fffffffcfd0) at src/gdb/remote.c:12462
 #7  0x0000555555c9274c in target_fileio_close (fd=3, target_errno=0x7fffffffcfd0) at src/gdb/target.c:3365
 #8  0x000055555595a19d in gdb_bfd_iovec_fileio_close (abfd=0x555556b9f8a0, stream=0x555556b11530) at src/gdb/gdb_bfd.c:439
 #9  0x0000555555e09e3f in opncls_bclose (abfd=0x555556b9f8a0) at src/bfd/opncls.c:599
 #10 0x0000555555e0a2c7 in bfd_close_all_done (abfd=0x555556b9f8a0) at src/bfd/opncls.c:847
 #11 0x0000555555e0a27a in bfd_close (abfd=0x555556b9f8a0) at src/bfd/opncls.c:814
 #12 0x000055555595a9d3 in gdb_bfd_close_or_warn (abfd=0x555556b9f8a0) at src/gdb/gdb_bfd.c:626
 #13 0x000055555595ad29 in gdb_bfd_unref (abfd=0x555556b9f8a0) at src/gdb/gdb_bfd.c:715
 #14 0x0000555555ae4730 in objfile::~objfile (this=0x555556515540, __in_chrg=<optimized out>) at src/gdb/objfiles.c:573
 #15 0x0000555555ae955a in std::_Sp_counted_ptr<objfile*, (__gnu_cxx::_Lock_policy)2>::_M_dispose (this=0x555556c20db0) at /usr/include/c++/9/bits/shared_ptr_base.h:377
 #16 0x000055555572b7c8 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release (this=0x555556c20db0) at /usr/include/c++/9/bits/shared_ptr_base.h:155
 #17 0x00005555557263c3 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count (this=0x555556bf0588, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr_base.h:730
 #18 0x0000555555ae745e in std::__shared_ptr<objfile, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr (this=0x555556bf0580, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr_base.h:1169
 #19 0x0000555555ae747e in std::shared_ptr<objfile>::~shared_ptr (this=0x555556bf0580, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr.h:103
 #20 0x0000555555b1c1dc in __gnu_cxx::new_allocator<std::_List_node<std::shared_ptr<objfile> > >::destroy<std::shared_ptr<objfile> > (this=0x5555564cdd60, __p=0x555556bf0580) at /usr/include/c++/9/ext/new_allocator.h:153
 #21 0x0000555555b1bb1d in std::allocator_traits<std::allocator<std::_List_node<std::shared_ptr<objfile> > > >::destroy<std::shared_ptr<objfile> > (__a=..., __p=0x555556bf0580) at /usr/include/c++/9/bits/alloc_traits.h:497
 #22 0x0000555555b1b73e in std::__cxx11::list<std::shared_ptr<objfile>, std::allocator<std::shared_ptr<objfile> > >::_M_erase (this=0x5555564cdd60, __position=std::shared_ptr<objfile> (expired, weak count 1) = {get() = 0x555556515540}) at /usr/include/c++/9/bits/stl_list.h:1921
 #23 0x0000555555b1afeb in std::__cxx11::list<std::shared_ptr<objfile>, std::allocator<std::shared_ptr<objfile> > >::erase (this=0x5555564cdd60, __position=std::shared_ptr<objfile> (expired, weak count 1) = {get() = 0x555556515540}) at /usr/include/c++/9/bits/list.tcc:158
 #24 0x0000555555b19576 in program_space::remove_objfile (this=0x5555564cdd20, objfile=0x555556515540) at src/gdb/progspace.c:210
 #25 0x0000555555ae4502 in objfile::unlink (this=0x555556515540) at src/gdb/objfiles.c:487
 #26 0x0000555555ae5a12 in objfile_purge_solibs () at src/gdb/objfiles.c:875
 #27 0x0000555555c09686 in no_shared_libraries (ignored=0x0, from_tty=1) at src/gdb/solib.c:1236
 #28 0x00005555559e3f5f in detach_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:2769

So frame #28 already detached the remote process, and then we're
purging the shared libraries.  GDB had opened remote shared libraries
via the target: sysroot, so it tries closing them.  GDBserver is
tearing down already, so remote communication breaks down and we close
the remote target and throw TARGET_CLOSE_ERROR.

Note frame #14:

 #14 0x0000555555ae4730 in objfile::~objfile (this=0x555556515540, __in_chrg=<optimized out>) at src/gdb/objfiles.c:573

That's a dtor, thus noexcept.  That's the reason for the
std::terminate.

Stepping back a bit, why do we still have open remote files if we've
managed to detach already, and, we're debugging with "target remote"?
The reason is that commit 408f66864a1a823591b26420410c982174c239a2
makes detach_command hold a reference to the target, so the remote
target won't be finally closed until frame #28 returns.  It's closing
the target that invalidates target file I/O handles.

This commit fixes the issue by not relying on target_close to
invalidate the target file I/O handles, instead invalidate them
immediately in remote_unpush_target.  So when GDB purges the solibs,
and we end up in target_fileio_close (frame #7 above), there's nothing
to do, and we don't try to talk with the remote target anymore.

The regression isn't seen when testing with
--target_board=native-gdbserver, because that does "set sysroot" to
disable the "target:" sysroot, for test run speed reasons.  So this
commit adds a testcase that explicitly tests detach with "set sysroot
target:".

gdb/ChangeLog:
yyyy-mm-dd  Pedro Alves  <pedro@palves.net>

	PR gdb/28080
	* remote.c (remote_unpush_target): Invalidate file I/O target
	handles.
	* target.c (fileio_handles_invalidate_target): Make extern.
	* target.h (fileio_handles_invalidate_target): Declare.

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <pedro@palves.net>

	PR gdb/28080
	* gdb.base/detach-sysroot-target.exp: New.
	* gdb.base/detach-sysroot-target.c: New.

Reported-By: Jonah Graham <jonah@kichwacoders.com>

Change-Id: I851234910172f42a1b30e731161376c344d2727d
 2021-07-13 15:30:04 +01:00
Simon Marchi
0f8e203412 gdb: add context getter/setter to cmd_list_element 
Straightforward replacement of get_cmd_context / set_cmd_context with
cmd_list_element methods.

gdb/ChangeLog:

	* cli/cli-decode.h (struct cmd_list_element) <set_context,
	context>: New.
	<context>: Rename to...
	<m_context>: ... this.
	* cli/cli-decode.c (set_cmd_context, get_cmd_context): Remove.
	* command.h (set_cmd_context, get_cmd_context): Remove, use
	cmd_list_element::set_context and cmd_list_element::context
	everywhere instead.

Change-Id: I5016b0079014e3f17d1aa449ada7954473bf2b5d
 2021-06-25 21:35:40 -04:00
Simon Marchi
294c36eb6a gdb: on exec, delegate pushing / unpushing target and adding thread to target_ops::follow_exec 
On "exec", some targets need to unpush themselves from the inferior,
and do some bookkeeping, like forgetting the data associated to the
exec'ing inferior.

One such example is the thread-db target.  It does so in
a special case in thread_db_target::wait, just before returning the
TARGET_WAITKIND_EXECD event to its caller.

We have another such case in the context of rocm-gdb [1], where the
"rocm" target is pushed on top of the linux-nat target.  When an exec
happens, we want to unpush the rocm target from the exec'ing inferior to
close some file descriptors that refer to the pre-exec address space and
forget about that inferior.  We then want to push the target on the
inferior in which execution continues, to open the file descriptors for
the post-exec address space.

I think that a good way to address this cleanly is to do all this in the
target_ops::follow_exec implementations.  Make the
process_stratum_target::follow_exec implementation have the default
behavior of pushing itself to the new inferior's target stack (if
execution continues in a new inferior) and add the initial thread.

remote_target::follow_exec is an example of process target that wants to
do a bit more than the default behavior.  So it calls
process_stratum_target::follow_exec first and does the extra work
second.

linux-thread-db (a non-process target) implements follow_exec to do some
bookeeping (forget about that process' data), before handing down the
event down to the process target (which hits
process_stratum_target::follow_exec).

gdb/ChangeLog:

	* target.h (struct target_ops) <follow_exec>: Add ptid_t
	parameter.
	(target_follow_exec): Likewise.
	* target.c (target_follow_exec): Add ptid_t parameter.
	* infrun.c (follow_exec): Adjust call to target_follow_exec,
	don't push target nor create thread.
	* linux-thread-db.c (class thread_db_target) <follow_exec>: New.
	(thread_db_target::wait): Just return on TARGET_WAITKIND_EXECD.
	(thread_db_target::follow_exec): New.
	* remote.c (class remote_target) <follow_exec>: Add ptid_t parameter.
	(remote_target::follow_exec): Call
	process_stratum_target::follow_exec.
	* target-delegates.c: Re-generate.

Change-Id: I3f96d0ba3ea0dde6540b7e1b4d5cdb01635088c8
 2021-05-13 15:29:00 -04:00
Marco Barisione
2f822da535 gdb: generate the prefix name for prefix commands on demand 
Previously, the prefixname field of struct cmd_list_element was manually
set for prefix commands.  This seems verbose and error prone as it
required every single call to functions adding prefix commands to
specify the prefix name while the same information can be easily
generated.

Historically, this was not possible as the prefix field was null for
many commands, but this was fixed in commit
3f4d92ebdf7f848b5ccc9e8d8e8514c64fde1183 by Philippe Waroquiers, so
we can rely on the prefix field being set when generating the prefix
name.

This commit also fixes a use after free in this scenario:
* A command gets created via Python (using the gdb.Command class).
  The prefix name member is dynamically allocated.
* An alias to the new command is created. The alias's prefixname is set
  to point to the prefixname for the original command with a direct
  assignment.
* A new command with the same name as the Python command is created.
* The object for the original Python command gets freed and its
  prefixname gets freed as well.
* The alias is updated to point to the new command, but its prefixname
  is not updated so it keeps pointing to the freed one.

gdb/ChangeLog:

	* command.h (add_prefix_cmd): Remove the prefixname argument as
	it can now be generated automatically.  Update all callers.
	(add_basic_prefix_cmd): Ditto.
	(add_show_prefix_cmd): Ditto.
	(add_prefix_cmd_suppress_notification): Ditto.
	(add_abbrev_prefix_cmd): Ditto.
	* cli/cli-decode.c (add_prefix_cmd): Ditto.
	(add_basic_prefix_cmd): Ditto.
	(add_show_prefix_cmd): Ditto.
	(add_prefix_cmd_suppress_notification): Ditto.
	(add_prefix_cmd_suppress_notification): Ditto.
	(add_abbrev_prefix_cmd): Ditto.
	* cli/cli-decode.h (struct cmd_list_element): Replace the
	prefixname member variable with a method which generates the
	prefix name at runtime.  Update all code reading the prefix
	name to use the method, and remove all code setting it.
	* python/py-cmd.c (cmdpy_destroyer): Remove code to free the
	prefixname member as it's now a method.
	(cmdpy_function): Determine if the command is a prefix by
	looking at prefixlist, not prefixname.
 2021-05-12 11:19:22 +01:00
Simon Marchi
bedc473418 gdb: remove reference to current inferior in target_stack::unpush 
target_stack::unpush needs to get the target beneath the target being
unpushed to update the m_top field (which keeps the stratum of the
top-most target).  It currently does so using target_ops::beneath, which
uses the target stack of the current inferior.  The target stack of the
current inferior is the same as the `this` in the unpush method.

Avoid this detour and remove this reference to the current inferior by
calling target_ops::find_beneath and passing `this` to find the target
beneath `t` in the target stack that is `this`.

gdb/ChangeLog:

	* target.c (target_stack::unpush): Call target_ops::find_beneath
	to get the target beneath `t`.

Change-Id: If9d9661567c5c16f655d270bd2ec9f1b3aa6dadc
 2021-05-07 11:52:51 -04:00
Simon Marchi
27f0a4314a gdb: make target_close check that the target isn't pushed in all inferiors 
The target_close function currently checks that the target to be closed
isn't pushed in the current inferior:

    gdb_assert (!current_inferior ()->target_is_pushed (targ));

Normally, a target is closed when its refcount has dropped to 0, due to
not being used in any inferior anymore.  I think it would make sense to
change that assert to not only check in the current inferior, but to
check in all inferiors.  It would be quite bad (and a bug) to close a
target while it's still pushed in one of the non-current inferiors.

gdb/ChangeLog:

	* target.c (target_close): Check in all inferiors that the
	target is not pushed.

Change-Id: I6e37fc3f3476a0593da1e476604642b2de90f1d5
 2021-05-07 11:51:39 -04:00
Simon Marchi
e97007b64a gdb: make target_ops::follow_fork return void 
I noticed that all implementations return false, so
target_ops::follow_fork doesn't really need to return a value.  Change
it to return void.

gdb/ChangeLog:

	* target.h (struct target_ops) <follow_fork>: Return void.
	(target_follow_fork): Likewise.
	* target.c (default_follow_fork): Likewise.
	(target_follow_fork): Likewise.
	* infrun.c (follow_fork_inferior): Adjust.
	* fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Return void.
	* fbsd-nat.c (fbsd_nat_target:::follow_fork): Likewise.
	* linux-nat.h (class linux_nat_target) <follow_fork>: Likewise.
	* linux-nat.c (linux_nat_target::follow_fork): Return void.
	* obsd-nat.h (class obsd_nat_target) <follow_fork>: Return void.
	* obsd-nat.c (obsd_nat_target::follow_fork): Likewise.
	* remote.c (class remote_target) <follow_fork>: Likewise.
	(remote_target::follow_fork): Likewise.
	* target-delegates.c: Re-generate.

Change-Id: If908c2f68b29fa275be2b0b9deb41e4c6a1b7879
 2021-04-07 16:57:29 -04:00
Simon Marchi
b4b1a226df gdb: defer commit resume until all available events are consumed 
Rationale
---------

Let's say you have multiple threads hitting a conditional breakpoint
at the same time, and all of these are going to evaluate to false.
All these threads will need to be resumed.

Currently, GDB fetches one target event (one SIGTRAP representing the
breakpoint hit) and decides that the thread should be resumed.  It
calls resume and commit_resume immediately.  It then fetches the
second target event, and does the same, until it went through all
threads.

The result is therefore something like:

  - consume event for thread A
  - resume thread A
  - commit resume (affects thread A)
  - consume event for thread B
  - resume thread B
  - commit resume (affects thread B)
  - consume event for thread C
  - resume thread C
  - commit resume (affects thread C)

For targets where it's beneficial to group resumptions requests (most
likely those that implement target_ops::commit_resume), it would be
much better to have:

  - consume event for thread A
  - resume thread A
  - consume event for thread B
  - resume thread B
  - consume event for thread C
  - resume thread C
  - commit resume (affects threads A, B and C)

Implementation details
----------------------

To achieve this, this patch adds another check in
maybe_set_commit_resumed_all_targets to avoid setting the
commit-resumed flag of targets that readily have events to provide to
infrun.

To determine if a target has events readily available to report, this
patch adds an `has_pending_events` target_ops method.  The method
returns a simple bool to say whether or not it has pending events to
report.

Testing
=======

To test this, I start GDBserver with a program that spawns multiple
threads:

 $ ../gdbserver/gdbserver --once :1234 ~/src/many-threads-stepping-over-breakpoints/many-threads-stepping-over-breakpoints

I then connect with GDB and install a conditional breakpoint that always
evaluates to false (and force the evaluation to be done by GDB):

 $ ./gdb -nx --data-directory=data-directory \
     /home/simark/src/many-threads-stepping-over-breakpoints/many-threads-stepping-over-breakpoints \
     -ex "set breakpoint condition-evaluation host" \
     -ex "set pag off" \
     -ex "set confirm off" \
     -ex "maint set target-non-stop on" \
     -ex "tar rem :1234" \
     -ex "tb main" \
     -ex "b 13 if 0" \
     -ex c \
     -ex "set debug infrun" \
     -ex "set debug remote 1" \
     -ex "set debug displaced"

I then do "continue" and look at the log.

The remote target receives a bunch of stop notifications for all
threads that have hit the breakpoint.  infrun consumes and processes
one event, decides it should not cause a stop, prepares a displaced
step, after which we should see:

 [infrun] maybe_set_commit_resumed_all_process_targets: not requesting commit-resumed for target remote, target has pending events

Same for a second thread (since we have 2 displaced step buffers).
For the following threads, their displaced step is deferred since
there are no more buffers available.

After consuming the last event the remote target has to offer, we get:

 [infrun] maybe_set_commit_resumed_all_process_targets: enabling commit-resumed for target remote
 [infrun] maybe_call_commit_resumed_all_process_targets: calling commit_resumed for target remote
 [remote] Sending packet: $vCont;s:p14d16b.14d1b1;s:p14d16b.14d1b2#55
 [remote] Packet received: OK

Without the patch, there would have been one vCont;s just after each
prepared displaced step.

gdb/ChangeLog:
yyyy-mm-dd  Simon Marchi  <simon.marchi@efficios.com>
	    Pedro Alves  <pedro@palves.net>

	* async-event.c (async_event_handler_marked): New.
	* async-event.h (async_event_handler_marked): Declare.
	* infrun.c (maybe_set_commit_resumed_all_targets): Switch to
	inferior before calling target method.  Don't commit-resumed if
	target_has_pending_events is true.
	* remote.c (remote_target::has_pending_events): New.
	* target-delegates.c: Regenerate.
	* target.c (target_has_pending_events): New.
	* target.h (target_ops::has_pending_events): New target method.
	(target_has_pending_events): New.

Change-Id: I18112ba19a1ff4986530c660f530d847bb4a1f1d
 2021-03-26 16:02:11 +00:00
Simon Marchi
1192f124a3 gdb: generalize commit_resume, avoid commit-resuming when threads have pending statuses 
The rationale for this patch comes from the ROCm port [1], the goal
being to reduce the number of back and forths between GDB and the
target when doing successive operations.  I'll start with explaining
the rationale and then go over the implementation.  In the ROCm / GPU
world, the term "wave" is somewhat equivalent to a "thread" in GDB.
So if you read if from a GPU stand point, just s/thread/wave/.

ROCdbgapi, the library used by GDB [2] to communicate with the GPU
target, gives the illusion that it's possible for the debugger to
control (start and stop) individual threads.  But in reality, this is
not how it works.  Under the hood, all threads of a queue are
controlled as a group.  To stop one thread in a group of running ones,
the state of all threads is retrieved from the GPU, all threads are
destroyed, and all threads but the one we want to stop are re-created
from the saved state.  The net result, from the point of view of GDB,
is that the library stopped one thread.  The same thing goes if we
want to resume one thread while others are running: the state of all
running threads is retrieved from the GPU, they are all destroyed, and
they are all re-created, including the thread we want to resume.

This leads to some inefficiencies when combined with how GDB works,
here are two examples:

 - Stopping all threads: because the target operates in non-stop mode,
   when the user interface mode is all-stop, GDB must stop all threads
   individually when presenting a stop.  Let's suppose we have 1000
   threads and the user does ^C.  GDB asks the target to stop one
   thread.  Behind the scenes, the library retrieves 1000 thread
   states and restores the 999 others still running ones.  GDB asks
   the target to stop another one.  The target retrieves 999 thread
   states and restores the 998 remaining ones.  That means that to
   stop 1000 threads, we did 1000 back and forths with the GPU.  It
   would have been much better to just retrieve the states once and
   stop there.

 - Resuming with pending events: suppose the 1000 threads hit a
   breakpoint at the same time.  The breakpoint is conditional and
   evaluates to true for the first thread, to false for all others.
   GDB pulls one event (for the first thread) from the target, decides
   that it should present a stop, so stops all threads using
   stop_all_threads.  All these other threads have a breakpoint event
   to report, which is saved in `thread_info::suspend::waitstatus` for
   later.  When the user does "continue", GDB resumes that one thread
   that did hit the breakpoint.  It then processes the pending events
   one by one as if they just arrived.  It picks one, evaluates the
   condition to false, and resumes the thread.  It picks another one,
   evaluates the condition to false, and resumes the thread.  And so
   on.  In between each resumption, there is a full state retrieval
   and re-creation.  It would be much nicer if we could wait a little
   bit before sending those threads on the GPU, until it processed all
   those pending events.

To address this kind of performance issue, ROCdbgapi has a concept
called "forward progress required", which is a boolean state that
allows its user (i.e. GDB) to say "I'm doing a bunch of operations,
you can hold off putting the threads on the GPU until I'm done" (the
"forward progress not required" state).  Turning forward progress back
on indicates to the library that all threads that are supposed to be
running should now be really running on the GPU.

It turns out that GDB has a similar concept, though not as general,
commit_resume.  One difference is that commit_resume is not stateful:
the target can't look up "does the core need me to schedule resumed
threads for execution right now".  It is also specifically linked to
the resume method, it is not used in other contexts.  The target
accumulates resumption requests through target_ops::resume calls, and
then commits those resumptions when target_ops::commit_resume is
called.  The target has no way to check if it's ok to leave resumed
threads stopped in other target methods.

To bridge the gap, this patch generalizes the commit_resume concept in
GDB to match the forward progress concept of ROCdbgapi.  The current
name (commit_resume) can be interpreted as "commit the previous resume
calls".  I renamed the concept to "commit_resumed", as in "commit the
threads that are resumed".

In the new version, we have two things:

 - the commit_resumed_state field in process_stratum_target: indicates
   whether GDB requires target stacks using this target to have
   resumed threads committed to the execution target/device.  If
   false, an execution target is allowed to leave resumed threads
   un-committed at the end of whatever method it is executing.

 - the commit_resumed target method: called when commit_resumed_state
   transitions from false to true.  While commit_resumed_state was
   false, the target may have left some resumed threads un-committed.
   This method being called tells it that it should commit them back
   to the execution device.

Let's take the "Stopping all threads" scenario from above and see how
it would work with the ROCm target with this change.  Before stopping
all threads, GDB would set the target's commit_resumed_state field to
false.  It would then ask the target to stop the first thread.  The
target would retrieve all threads' state from the GPU and mark that
one as stopped.  Since commit_resumed_state is false, it leaves all
the other threads (still resumed) stopped.  GDB would then proceed to
call target_stop for all the other threads.  Since resumed threads are
not committed, this doesn't do any back and forth with the GPU.

To simplify the implementation of targets, this patch makes it so that
when calling certain target methods, the contract between the core and
the targets guarantees that commit_resumed_state is false.  This way,
the target doesn't need two paths, one for commit_resumed_state ==
true and one for commit_resumed_state == false.  It can just assert
that commit_resumed_state is false and work with that assumption.
This also helps catch places where we forgot to disable
commit_resumed_state before calling the method, which represents a
probable optimization opportunity.  The commit adds assertions in the
target method wrappers (target_resume and friends) to have some
confidence that this contract between the core and the targets is
respected.

The scoped_disable_commit_resumed type is used to disable the commit
resumed state of all process targets on construction, and selectively
re-enable it on destruction (see below for criteria).  Note that it
only sets the process_stratum_target::commit_resumed_state flag.  A
subsequent call to maybe_call_commit_resumed_all_targets is necessary
to call the commit_resumed method on all target stacks with process
targets that got their commit_resumed_state flag turned back on.  This
separation is because we don't want to call the commit_resumed methods
in scoped_disable_commit_resumed's destructor, as they may throw.

On destruction, commit-resumed is not re-enabled for a given target
if:

 1. this target has no threads resumed, or

 2. this target has at least one resumed thread with a pending status
    known to the core (saved in thread_info::suspend::waitstatus).

The first point is not technically necessary, because a proper
commit_resumed implementation would be a no-op if the target has no
resumed threads.  But since we have a flag do to a quick check, it
shouldn't hurt.

The second point is more important: together with the
scoped_disable_commit_resumed instance added in fetch_inferior_event,
it makes it so the "Resuming with pending events" described above is
handled efficiently.  Here's what happens in that case:

 1. The user types "continue".

 2. Upon destruction, the scoped_disable_commit_resumed in the
    `proceed` function does not enable commit-resumed, as it sees some
    threads have pending statuses.

 3. fetch_inferior_event is called to handle another event, the
    breakpoint hit evaluates to false, and that thread is resumed.
    Because there are still more threads with pending statuses, the
    destructor of scoped_disable_commit_resumed in
    fetch_inferior_event still doesn't enable commit-resumed.

 4. Rinse and repeat step 3, until the last pending status is handled
    by fetch_inferior_event.  In that case,
    scoped_disable_commit_resumed's destructor sees there are no more
    threads with pending statues, so it asks the target to commit
    resumed threads.

This allows us to avoid all unnecessary back and forths, there is a
single commit_resumed call once all pending statuses are processed.

This change required remote_target::remote_stop_ns to learn how to
handle stopping threads that were resumed but pending vCont.  The
simplest example where that happens is when using the remote target in
all-stop, but with "maint set target-non-stop on", to force it to
operate in non-stop mode under the hood.  If two threads hit a
breakpoint at the same time, GDB will receive two stop replies.  It
will present the stop for one thread and save the other one in
thread_info::suspend::waitstatus.

Before this patch, when doing "continue", GDB first resumes the thread
without a pending status:

    Sending packet: $vCont;c:p172651.172676#f3

It then consumes the pending status in the next fetch_inferior_event
call:

    [infrun] do_target_wait_1: Using pending wait status status->kind = stopped, signal = GDB_SIGNAL_TRAP for Thread 1517137.1517137.
    [infrun] target_wait (-1.0.0, status) =
    [infrun]   1517137.1517137.0 [Thread 1517137.1517137],
    [infrun]   status->kind = stopped, signal = GDB_SIGNAL_TRAP

It then realizes it needs to stop all threads to present the stop, so
stops the thread it just resumed:

    [infrun] stop_all_threads:   Thread 1517137.1517137 not executing
    [infrun] stop_all_threads:   Thread 1517137.1517174 executing, need stop
    remote_stop called
    Sending packet: $vCont;t:p172651.172676#04

This is an unnecessary resume/stop.  With this patch, we don't commit
resumed threads after proceeding, because of the pending status:

    [infrun] maybe_commit_resumed_all_process_targets: not requesting commit-resumed for target extended-remote, a thread has a pending waitstatus

When GDB handles the pending status and stop_all_threads runs, we stop a
resumed but pending vCont thread:

    remote_stop_ns: Enqueueing phony stop reply for thread pending vCont-resume (1520940, 1520976, 0)

That thread was never actually resumed on the remote stub / gdbserver,
so we shouldn't send a packet to the remote side asking to stop the
thread.

Note that there are paths that resume the target and then do a
synchronous blocking wait, in sort of nested event loop, via
wait_sync_command_done.  For example, inferior function calls, or any
run control command issued from a breakpoint command list.  We handle
that making wait_sync_command_one a "sync" point -- force forward
progress, or IOW, force-enable commit-resumed state.

gdb/ChangeLog:
yyyy-mm-dd  Simon Marchi  <simon.marchi@efficios.com>
	    Pedro Alves  <pedro@palves.net>

	* infcmd.c (run_command_1, attach_command, detach_command)
	(interrupt_target_1): Use scoped_disable_commit_resumed.
	* infrun.c (do_target_resume): Remove
	target_commit_resume call.
	(commit_resume_all_targets): Remove.
	(maybe_set_commit_resumed_all_targets): New.
	(maybe_call_commit_resumed_all_targets): New.
	(enable_commit_resumed): New.
	(scoped_disable_commit_resumed::scoped_disable_commit_resumed)
	(scoped_disable_commit_resumed::~scoped_disable_commit_resumed)
	(scoped_disable_commit_resumed::reset)
	(scoped_disable_commit_resumed::reset_and_commit)
	(scoped_enable_commit_resumed::scoped_enable_commit_resumed)
	(scoped_enable_commit_resumed::~scoped_enable_commit_resumed):
	New.
	(proceed): Use scoped_disable_commit_resumed and
	maybe_call_commit_resumed_all_targets.
	(fetch_inferior_event): Use scoped_disable_commit_resumed.
	* infrun.h (struct scoped_disable_commit_resumed): New.
	(maybe_call_commit_resumed_all_process_targets): New.
	(struct scoped_enable_commit_resumed): New.
	* mi/mi-main.c (exec_continue): Use scoped_disable_commit_resumed.
	* process-stratum-target.h (class process_stratum_target):
	<commit_resumed_state>: New.
	* record-full.c (record_full_wait_1): Change commit_resumed_state
	around calling commit_resumed.
	* remote.c (class remote_target) <commit_resume>: Rename to...
	<commit_resumed>: ... this.
	(struct stop_reply): Move up.
	(remote_target::commit_resume): Rename to...
	(remote_target::commit_resumed): ... this.  Check if there is any
	thread pending vCont resume.
	(remote_target::remote_stop_ns): Generate stop replies for resumed
	but pending vCont threads.
	(remote_target::wait_ns): Add gdb_assert.
	* target-delegates.c: Regenerate.
	* target.c (target_wait, target_resume): Assert that the current
	process_stratum target isn't in commit-resumed state.
	(defer_target_commit_resume): Remove.
	(target_commit_resume): Remove.
	(target_commit_resumed): New.
	(make_scoped_defer_target_commit_resume): Remove.
	(target_stop): Assert that the current process_stratum target
	isn't in commit-resumed state.
	* target.h (struct target_ops) <commit_resume>: Rename to ...
	 <commit_resumed>: ... this.
	(target_commit_resume): Remove.
	(target_commit_resumed): New.
	(make_scoped_defer_target_commit_resume): Remove.
	* top.c (wait_sync_command_done): Use
	scoped_enable_commit_resumed.

[1] https://github.com/ROCm-Developer-Tools/ROCgdb/
[2] https://github.com/ROCm-Developer-Tools/ROCdbgapi

Change-Id: I836135531a29214b21695736deb0a81acf8cf566
 2021-03-26 15:58:47 +00:00
Pedro Alves
e5b9b39f88 target_is_non_stop_p and sync targets 
gdb.base/maint-target-async-off.exp fails if you test against
gdbserver with "maint set target-non-stop on" forced.

  (gdb) run
  Starting program: build/gdb/testsuite/outputs/gdb.base/maint-target-async-off/maint-target-async-off

  Breakpoint 1, main () at src/gdb/testsuite/gdb.base/maint-target-async-off.c:21
  21        return 0;
  (gdb) FAIL: gdb.base/maint-target-async-off.exp: continue until exit (timeout)

Above, GDB just stopped listening to stdin.

Basically, GDB assumes that a target working in non-stop mode
operation also supports async mode; it's a requirement.  GDB
misbehaves badly otherwise, and even hits failed assertions.

Fix this by making target_is_non_stop_p return false if async is off.

gdb/ChangeLog:

	* target.c (target_always_non_stop_p): Also check whether the
	target can async.

Change-Id: I7e52e1061396a5b9b02ada462f68a14b76d68974
 2021-03-26 15:57:25 +00:00
Simon Marchi
328d42d87e gdb: remove current_top_target function 
The current_top_target function is a hidden dependency on the current
inferior.  Since I'd like to slowly move towards reducing our dependency
on the global current state, remove this function and make callers use

  current_inferior ()->top_target ()

There is no expected change in behavior, but this one step towards
making those callers use the inferior from their context, rather than
refer to the global current inferior.

gdb/ChangeLog:

	* target.h (current_top_target): Remove, make callers use the
	current inferior instead.
	* target.c (current_top_target): Remove.

Change-Id: Iccd457036f84466cdaa3865aa3f9339a24ea001d
 2021-03-24 18:08:24 -04:00
Simon Marchi
d777bf0df2 gdb: move all "current target" wrapper implementations to target.c 
The following patch removes the current_top_target function, replacing
uses with `current_inferior ()->top_target ()`.  This is a problem for
uses in target.h, because they don't have access to the current_inferior
function and the inferior structure: target.h can't include inferior.h,
otherwise that would make a cyclic inclusion.

Avoid this by moving all implementations of the wrappers that call
target methods with the current target to target.c.  Many of them are
changed from a macro to a function, which is an improvement for
readability and debuggability, IMO.

target_shortname and target_longname were not function-like macros, so a
few adjustments are needed.

gdb/ChangeLog:

	* target.h (target_shortname): Change to function declaration.
	(target_longname): Likewise.
	(target_attach_no_wait): Likewise.
	(target_post_attach): Likewise.
	(target_prepare_to_store): Likewise.
	(target_supports_enable_disable_tracepoint): Likewise.
	(target_supports_string_tracing): Likewise.
	(target_supports_evaluation_of_breakpoint_conditions): Likewise.
	(target_supports_dumpcore): Likewise.
	(target_dumpcore): Likewise.
	(target_can_run_breakpoint_commands): Likewise.
	(target_files_info): Likewise.
	(target_post_startup_inferior): Likewise.
	(target_insert_fork_catchpoint): Likewise.
	(target_remove_fork_catchpoint): Likewise.
	(target_insert_vfork_catchpoint): Likewise.
	(target_remove_vfork_catchpoint): Likewise.
	(target_insert_exec_catchpoint): Likewise.
	(target_remove_exec_catchpoint): Likewise.
	(target_set_syscall_catchpoint): Likewise.
	(target_rcmd): Likewise.
	(target_can_lock_scheduler): Likewise.
	(target_can_async_p): Likewise.
	(target_is_async_p): Likewise.
	(target_execution_direction): Likewise.
	(target_extra_thread_info): Likewise.
	(target_pid_to_exec_file): Likewise.
	(target_thread_architecture): Likewise.
	(target_find_memory_regions): Likewise.
	(target_make_corefile_notes): Likewise.
	(target_get_bookmark): Likewise.
	(target_goto_bookmark): Likewise.
	(target_stopped_by_watchpoint): Likewise.
	(target_stopped_by_sw_breakpoint): Likewise.
	(target_supports_stopped_by_sw_breakpoint): Likewise.
	(target_stopped_by_hw_breakpoint): Likewise.
	(target_supports_stopped_by_hw_breakpoint): Likewise.
	(target_have_steppable_watchpoint): Likewise.
	(target_can_use_hardware_watchpoint): Likewise.
	(target_region_ok_for_hw_watchpoint): Likewise.
	(target_can_do_single_step): Likewise.
	(target_insert_watchpoint): Likewise.
	(target_remove_watchpoint): Likewise.
	(target_insert_hw_breakpoint): Likewise.
	(target_remove_hw_breakpoint): Likewise.
	(target_can_accel_watchpoint_condition): Likewise.
	(target_can_execute_reverse): Likewise.
	(target_get_ada_task_ptid): Likewise.
	(target_filesystem_is_local): Likewise.
	(target_trace_init): Likewise.
	(target_download_tracepoint): Likewise.
	(target_can_download_tracepoint): Likewise.
	(target_download_trace_state_variable): Likewise.
	(target_enable_tracepoint): Likewise.
	(target_disable_tracepoint): Likewise.
	(target_trace_start): Likewise.
	(target_trace_set_readonly_regions): Likewise.
	(target_get_trace_status): Likewise.
	(target_get_tracepoint_status): Likewise.
	(target_trace_stop): Likewise.
	(target_trace_find): Likewise.
	(target_get_trace_state_variable_value): Likewise.
	(target_save_trace_data): Likewise.
	(target_upload_tracepoints): Likewise.
	(target_upload_trace_state_variables): Likewise.
	(target_get_raw_trace_data): Likewise.
	(target_get_min_fast_tracepoint_insn_len): Likewise.
	(target_set_disconnected_tracing): Likewise.
	(target_set_circular_trace_buffer): Likewise.
	(target_set_trace_buffer_size): Likewise.
	(target_set_trace_notes): Likewise.
	(target_get_tib_address): Likewise.
	(target_set_permissions): Likewise.
	(target_static_tracepoint_marker_at): Likewise.
	(target_static_tracepoint_markers_by_strid): Likewise.
	(target_traceframe_info): Likewise.
	(target_use_agent): Likewise.
	(target_can_use_agent): Likewise.
	(target_augmented_libraries_svr4_read): Likewise.
	(target_log_command): Likewise.
	* target.c (target_shortname): New.
	(target_longname): New.
	(target_attach_no_wait): New.
	(target_post_attach): New.
	(target_prepare_to_store): New.
	(target_supports_enable_disable_tracepoint): New.
	(target_supports_string_tracing): New.
	(target_supports_evaluation_of_breakpoint_conditions): New.
	(target_supports_dumpcore): New.
	(target_dumpcore): New.
	(target_can_run_breakpoint_commands): New.
	(target_files_info): New.
	(target_post_startup_inferior): New.
	(target_insert_fork_catchpoint): New.
	(target_remove_fork_catchpoint): New.
	(target_insert_vfork_catchpoint): New.
	(target_remove_vfork_catchpoint): New.
	(target_insert_exec_catchpoint): New.
	(target_remove_exec_catchpoint): New.
	(target_set_syscall_catchpoint): New.
	(target_rcmd): New.
	(target_can_lock_scheduler): New.
	(target_can_async_p): New.
	(target_is_async_p): New.
	(target_execution_direction): New.
	(target_extra_thread_info): New.
	(target_pid_to_exec_file): New.
	(target_thread_architecture): New.
	(target_find_memory_regions): New.
	(target_make_corefile_notes): New.
	(target_get_bookmark): New.
	(target_goto_bookmark): New.
	(target_stopped_by_watchpoint): New.
	(target_stopped_by_sw_breakpoint): New.
	(target_supports_stopped_by_sw_breakpoint): New.
	(target_stopped_by_hw_breakpoint): New.
	(target_supports_stopped_by_hw_breakpoint): New.
	(target_have_steppable_watchpoint): New.
	(target_can_use_hardware_watchpoint): New.
	(target_region_ok_for_hw_watchpoint): New.
	(target_can_do_single_step): New.
	(target_insert_watchpoint): New.
	(target_remove_watchpoint): New.
	(target_insert_hw_breakpoint): New.
	(target_remove_hw_breakpoint): New.
	(target_can_accel_watchpoint_condition): New.
	(target_can_execute_reverse): New.
	(target_get_ada_task_ptid): New.
	(target_filesystem_is_local): New.
	(target_trace_init): New.
	(target_download_tracepoint): New.
	(target_can_download_tracepoint): New.
	(target_download_trace_state_variable): New.
	(target_enable_tracepoint): New.
	(target_disable_tracepoint): New.
	(target_trace_start): New.
	(target_trace_set_readonly_regions): New.
	(target_get_trace_status): New.
	(target_get_tracepoint_status): New.
	(target_trace_stop): New.
	(target_trace_find): New.
	(target_get_trace_state_variable_value): New.
	(target_save_trace_data): New.
	(target_upload_tracepoints): New.
	(target_upload_trace_state_variables): New.
	(target_get_raw_trace_data): New.
	(target_get_min_fast_tracepoint_insn_len): New.
	(target_set_disconnected_tracing): New.
	(target_set_circular_trace_buffer): New.
	(target_set_trace_buffer_size): New.
	(target_set_trace_notes): New.
	(target_get_tib_address): New.
	(target_set_permissions): New.
	(target_static_tracepoint_marker_at): New.
	(target_static_tracepoint_markers_by_strid): New.
	(target_traceframe_info): New.
	(target_use_agent): New.
	(target_can_use_agent): New.
	(target_augmented_libraries_svr4_read): New.
	(target_log_command): New.
	* bfin-tdep.c (bfin_sw_breakpoint_from_kind): Adjust.
	* infrun.c (set_schedlock_func): Adjust.
	* mi/mi-main.c (exec_reverse_continue): Adjust.
	* reverse.c (exec_reverse_once): Adjust.
	* sh-tdep.c (sh_sw_breakpoint_from_kind): Adjust.
	* tui/tui-stack.c (tui_locator_window::make_status_line): Adjust.
	* remote-sim.c (gdbsim_target::detach): Adjust.
	(gdbsim_target::files_info): Adjust.

Change-Id: I72ef56e9a25adeb0b91f1ad05e34c89f77ebeaa8
 2021-03-24 18:07:30 -04:00
Simon Marchi
c8fbd44a01 gdb: remove target_is_pushed free function 
Same principle as the previous patches.

gdb/ChangeLog:

	* target.h (target_is_pushed): Remove, update callers to use
	inferior::target_is_pushed instead.
	* target.c (target_is_pushed): Remove.

Change-Id: I9862e6205acc65672da807cbe4b46cde009e7b9d
 2021-03-23 09:50:36 -04:00
Simon Marchi
02980c5645 gdb: remove push_target free functions 
Same as the previous patch, but for the push_target functions.

The implementation of the move variant is moved to a new overload of
inferior::push_target.

gdb/ChangeLog:

	* target.h (push_target): Remove, update callers to use
	inferior::push_target.
	* target.c (push_target): Remove.
	* inferior.h (class inferior) <push_target>: New overload.

Change-Id: I5a95496666278b8f3965e5e8aecb76f54a97c185
 2021-03-23 09:50:35 -04:00
Simon Marchi
fadf6add30 gdb: remove unpush_target free function 
unpush_target unpushes the passed-in target from the current inferior's
target stack.  Calling it is therefore an implicit dependency on the
current global inferior.  Remove that function and make the callers use
the inferior::unpush_target method directly.  This sometimes allows
using the inferior from the context rather than the global current
inferior.

target_unpusher::operator() now needs to be implemented in target.c,
otherwise target.h and inferior.h both need to include each other, and
that wouldn't work.

gdb/ChangeLog:

	* target.h (unpush_target): Remove, update all callers
	to use `inferior::unpush_target` instead.
	(struct target_unpusher) <operator()>: Just declare.
	* target.c (unpush_target): Remove.
	(target_unpusher::operator()): New.

Change-Id: Ia5172dfb3f373e0a75b991885b50322ca2142a8c
 2021-03-23 09:50:32 -04:00
Simon Marchi
dffdd8b51f gdb: relax assertion in target_mourn_inferior 
As reported in PR 26861, when killing an inferior on macOS, we hit the
assert:

    ../../gdb-10.1/gdb/target.c:2149: internal-error: void target_mourn_inferior(ptid_t): Assertion `ptid == inferior_ptid' failed.

This is because darwin_nat_target::kill passes a pid-only ptid to
target_mourn_inferior, with the pid of the current inferior:

    target_mourn_inferior (ptid_t (inf->pid));

... which doesn't satisfy the assert in target_mourn_inferior:

    gdb_assert (ptid == inferior_ptid);

The reason for this assertion is that target_mourn_inferior is a
prototype shared between GDB and GDBserver, so that shared code in
gdb/nat (used in both GDB and GDBserver) can call target_mourn_inferior.
In GDB's implementation, it is likely that some targets still rely on
inferior_ptid being set to "the current thread we are working on".  So
until targets are completely decoupled from inferior_ptid (at least
their mourn_inferior implementations), we need to ensure the passed in
ptid matches inferior_ptid, to ensure the calling code called
target_mourn_inferior with the right global context.

However, I think the assert is a bit too restrictive.  The
mourn_inferior operation works on an inferior, not a specific thread.
And by the time we call mourn_inferior, the threads of the inferior
don't exist anymore, the process is gone, so it doesn't really make
sense to require inferior_ptid to point a specific thread.

I looked at all the target_ops::mourn_inferior implementations, those
that read inferior_ptid only care about the pid field, which supports
the idea that only the inferior matters.  Other implementations look at
the current inferior (call `current_inferior ()`).

I think it would make sense to change target_mourn_inferior to accept
only a pid rather than a ptid.  It would then assert that the pid is the
same as the current inferior's pid.  However, this would be a quite
involved change, so I'll keep it for later.

To fix the macOS issue immediately, I propose to relax the assert to
only compare the pids, as is done in this patch.

Another solution would obviously be to make darwin_nat_target::kill pass
inferior_ptid to target_mourn_inferior.  However, the solution I propose
is more in line with where I think we want to go (passing a pid to
target_mourn_inferior).

gdb/ChangeLog:

	PR gdb/26861
	* target.c (target_mourn_inferior): Only compare pids in
	target_mourn_inferior.

Change-Id: If2439ccc5aa67272ea16148a43c5362ef23fb2b8
 2021-02-25 15:52:29 -05:00
Andrew Burgess
336aa7b740 gdb: move get_section_table from exec_target to dummy_target 
The only target that implements target_ops::get_section_table in a
meaningful way is exec_target.  This target calls back into the
program space to return the current global section_table.

The global section table is populated whenever the user provides GDB
with an executable, or when a symbol file is loaded, e.g. when a
dynamic library is loaded, or when the user does add-symbol-file.

I recently ran into a situation where a user, debugging a remote
target, was not supplying GDB with a main executable at all.  Instead
the user attached to the target then did add-symbol-file, and then
proceeded to debug the target.

This works fine, but it was noticed that even when
trust-readonly-sections was on GDB was still accessing the target to
get the contents of readonly sections.

The problem is that by not providing an executable there was no
exec_target in the target stack, and so when GDB calls the
target_ops::get_section_table function GDB ends up in
dummy_target::get_section_table, which just returns NULL.

What I want is that even when GDB doesn't have an exec_target in the
target stack, a call to target_ops::get_section_table will still
return the section_table from the current program space.

When considering how to achieve this my first though was, why is the
request for the section table going via the target stack at all?  The
set of sections loaded is a property of the program space, not the
target.  This is, after all, why the data is being stored in the
program space.

So I initially tried changing target_get_section_table so that,
instead of calling into the target it just returns
current_program_space->target_sections ().

This would be fine except for one issue, target_bfd (from
bfd-target.c).  This code is used from solib-svr4.c to create a
temporary target_ops structure that implements two functions
target_bfd::xfer_partial and target_bfd::get_section_table.

The purpose behind the code is to enable two targets, ppc64 and frv to
decode function descriptors from the dynamic linker, based on the
non-relocated addresses from within the dynamic linker bfd object.

Both of the implemented functions in target_bfd rely on the target_bfd
object holding a section table, and the ppc64 target requires that the
target_bfd implement ::get_section_table.

The frv target doesn't require ::get_section_table, instead it
requires the ::xfer_partial.  We could in theory change the ppc64
target to use the same approach as frv, however, this would be a bad
idea.  I believe that the frv target approach is broken.  I'll
explain:

The frv target calls get_target_memory_unsigned to read the function
descriptor.  The address being read is the non-relocated address read
from the dynamic linker in solib-srv4.c:enable_break.  Calling
get_target_memory_unsigned eventually ends up in target_xfer_partial
with an object type of TARGET_OBJECT_RAW_MEMORY.  This will then call
memory_xfer_check_region.  I believe that it is quite possible that a
the non-relocated addresses pulled from the dynamic linker could be in
a memory region that is not readable, while the relocated addresses
are in a readable memory region.  If this was ever the case for the
frv target then GDB would reject the attempt to read the non-relocated
function pointer.

In contrast the ppc64 target calls target_section_by_addr, which calls
target_get_section_table, which then calls the ::get_section_table
function on the target.

Thus, when reflecting on target_bfd we see two functions,
::xfer_partial and ::get_section_table.  The former is required by the
frv target, but that target is (I think) potentially broken.  While
the latter is required by the ppc64 target, but this forces
::get_section_table to exist as a target_ops member function.

So my original plan, have target_get_section_table NOT call a
target_ops member function appears to be flawed.

My next idea was to remove exec_target::get_section_table, and instead
move the implementation into dummy_target::get_section_table.
Currently the dummy_target implementation always returns NULL
indicating no section table, but plenty of other dummy_target member
functions do more than just return null values.

So now, dummy_target::get_section_table returns the section table from
the current program space.  This allows target_bfd to remain
unchanged, so ppc64 and frv should not be affected.

Making this change removes the requirement for the user to provide an
executable, GDB can now always access the section_table, as the
dummy_target always exists in the target stack.

Finally, there's a test that the target_section table is not empty in
the case where the user does add-symbol-file without providing an
executable.

gdb/ChangeLog:

	* exec.c (exec_target::get_section_table): Delete member function.
	(section_table_read_available_memory): Use current_top_target, not
	just the exec_ops target.
	* target-delegates.c: Regenerate.
	* target.c (default_get_section_table): New function.
	* target.h (target_ops::get_section_table): Change default
	behaviour to call default_get_section_table.
	(default_get_section_table): Declare.
 2021-02-24 16:58:04 +00:00
Andrew Burgess
19cf757a87 gdb: spread a little 'const' through the target_section_table code 
The code to access the target section table can be made more const, so
lets do that.  There should be no user visible changes after this
commit.

gdb/ChangeLog:

	* gdb/bfd-target.c (class target_bfd) <get_section_table>: Make
	return type const.
	* gdb/exec.c (struct exec_target) <get_section_table>: Likewise.
	(section_table_read_available_memory): Make local const.
	(exec_target::xfer_partial): Make local const.
	(print_section_info): Make parameter const.
	* gdb/exec.h (print_section_info): Likewise.
	* gdb/ppc64-tdep.c (ppc64_convert_from_func_ptr_addr): Make local
	const.
	* gdb/record-btrace.c (record_btrace_target::xfer_partial):
	Likewise.
	* gdb/remote.c (remote_target::remote_xfer_live_readonly_partial):
	Likewise.
	* gdb/s390-tdep.c (s390_load): Likewise.
	* gdb/solib-dsbt.c (scan_dyntag): Likewise.
	* gdb/solib-svr4.c (scan_dyntag): Likewise.
	* gdb/target-debug.h (target_debug_print_target_section_table_p):
	Rename to...
	(target_debug_print_const_target_section_table_p): ...this.
	* gdb/target-delegates.c: Regenerate.
	* gdb/target.c (target_get_section_table): Make return type const.
	(target_section_by_addr): Likewise.  Also make some locals const.
	(memory_xfer_partial_1): Make some locals const.
	* gdb/target.h (struct target_ops) <get_section_table>: Make
	return type const.
	(target_section_by_addr): Likewise.
	(target_get_section_table): Likewise.
 2021-02-24 16:58:02 +00:00
Simon Marchi
6ff267e186 gdb: make target_is_non_stop_p return bool 
gdb/ChangeLog:

	* target.c (target_is_non_stop_p): Return bool.
	* target.h (target_is_non_stop_p): Return bool.

Change-Id: Icdb37ffe917798e59b822976794d4b1b7aafd709
 2021-02-04 15:47:28 -05:00
Pedro Alves
e87f0fe823 detach and breakpoint removal 
A following patch will add a testcase that has a number of threads
constantly stepping over a breakpoint, and then has GDB detach the
process.  That testcase sometimes fails with the inferior crashing
with SIGTRAP after the detach because of the bug fixed by this patch,
when tested with the native target.

The problem is that target_detach removes breakpoints from the target
immediately, and that does not work with the native GNU/Linux target
(and probably no other native target) currently.  The test wouldn't
fail with this issue when testing against gdbserver, because gdbserver
does allow accessing memory while the current thread is running, by
transparently pausing all threads temporarily, without GDB noticing.
Implementing that in gdbserver was a lot of work, so I'm not looking
forward right now to do the same in the native target.  Instead, I
came up with a simpler solution -- push the breakpoints removal down
to the targets.  The Linux target conveniently already pauses all
threads before detaching them, since PTRACE_DETACH only works with
stopped threads, so we move removing breakpoints to after that.  Only
the remote and GNU/Linux targets support support async execution, so
no other target should really need this.

gdb/ChangeLog:

	* linux-nat.c (linux_nat_target::detach): Remove breakpoints
	here...
	* remote.c (remote_target::remote_detach_1): ... and here ...
	* target.c (target_detach): ... instead of here.
	* target.h (target_ops::detach): Add comment.
 2021-02-03 01:15:12 +00:00
Joel Brobecker
3666a04883 Update copyright year range in all GDB files 
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...

gdb/ChangeLog

        Update copyright year range in copyright header of all GDB files.
 2021-01-01 12:12:21 +04:00
Simon Marchi
dda83cd783 gdb, gdbserver, gdbsupport: fix leading space vs tabs issues 
Many spots incorrectly use only spaces for indentation (for example,
there are a lot of spots in ada-lang.c).  I've always found it awkward
when I needed to edit one of these spots: do I keep the original wrong
indentation, or do I fix it?  What if the lines around it are also
wrong, do I fix them too?  I probably don't want to fix them in the same
patch, to avoid adding noise to my patch.

So I propose to fix as much as possible once and for all (hopefully).

One typical counter argument for this is that it makes code archeology
more difficult, because git-blame will show this commit as the last
change for these lines.  My counter counter argument is: when
git-blaming, you often need to do "blame the file at the parent commit"
anyway, to go past some other refactor that touched the line you are
interested in, but is not the change you are looking for.  So you
already need a somewhat efficient way to do this.

Using some interactive tool, rather than plain git-blame, makes this
trivial.  For example, I use "tig blame <file>", where going back past
the commit that changed the currently selected line is one keystroke.
It looks like Magit in Emacs does it too (though I've never used it).
Web viewers of Github and Gitlab do it too.  My point is that it won't
really make archeology more difficult.

The other typical counter argument is that it will cause conflicts with
existing patches.  That's true... but it's a one time cost, and those
are not conflicts that are difficult to resolve.  I have also tried "git
rebase --ignore-whitespace", it seems to work well.  Although that will
re-introduce the faulty indentation, so one needs to take care of fixing
the indentation in the patch after that (which is easy).

gdb/ChangeLog:

	* aarch64-linux-tdep.c: Fix indentation.
	* aarch64-ravenscar-thread.c: Fix indentation.
	* aarch64-tdep.c: Fix indentation.
	* aarch64-tdep.h: Fix indentation.
	* ada-lang.c: Fix indentation.
	* ada-lang.h: Fix indentation.
	* ada-tasks.c: Fix indentation.
	* ada-typeprint.c: Fix indentation.
	* ada-valprint.c: Fix indentation.
	* ada-varobj.c: Fix indentation.
	* addrmap.c: Fix indentation.
	* addrmap.h: Fix indentation.
	* agent.c: Fix indentation.
	* aix-thread.c: Fix indentation.
	* alpha-bsd-nat.c: Fix indentation.
	* alpha-linux-tdep.c: Fix indentation.
	* alpha-mdebug-tdep.c: Fix indentation.
	* alpha-nbsd-tdep.c: Fix indentation.
	* alpha-obsd-tdep.c: Fix indentation.
	* alpha-tdep.c: Fix indentation.
	* amd64-bsd-nat.c: Fix indentation.
	* amd64-darwin-tdep.c: Fix indentation.
	* amd64-linux-nat.c: Fix indentation.
	* amd64-linux-tdep.c: Fix indentation.
	* amd64-nat.c: Fix indentation.
	* amd64-obsd-tdep.c: Fix indentation.
	* amd64-tdep.c: Fix indentation.
	* amd64-windows-tdep.c: Fix indentation.
	* annotate.c: Fix indentation.
	* arc-tdep.c: Fix indentation.
	* arch-utils.c: Fix indentation.
	* arch/arm-get-next-pcs.c: Fix indentation.
	* arch/arm.c: Fix indentation.
	* arm-linux-nat.c: Fix indentation.
	* arm-linux-tdep.c: Fix indentation.
	* arm-nbsd-tdep.c: Fix indentation.
	* arm-pikeos-tdep.c: Fix indentation.
	* arm-tdep.c: Fix indentation.
	* arm-tdep.h: Fix indentation.
	* arm-wince-tdep.c: Fix indentation.
	* auto-load.c: Fix indentation.
	* auxv.c: Fix indentation.
	* avr-tdep.c: Fix indentation.
	* ax-gdb.c: Fix indentation.
	* ax-general.c: Fix indentation.
	* bfin-linux-tdep.c: Fix indentation.
	* block.c: Fix indentation.
	* block.h: Fix indentation.
	* blockframe.c: Fix indentation.
	* bpf-tdep.c: Fix indentation.
	* break-catch-sig.c: Fix indentation.
	* break-catch-syscall.c: Fix indentation.
	* break-catch-throw.c: Fix indentation.
	* breakpoint.c: Fix indentation.
	* breakpoint.h: Fix indentation.
	* bsd-uthread.c: Fix indentation.
	* btrace.c: Fix indentation.
	* build-id.c: Fix indentation.
	* buildsym-legacy.h: Fix indentation.
	* buildsym.c: Fix indentation.
	* c-typeprint.c: Fix indentation.
	* c-valprint.c: Fix indentation.
	* c-varobj.c: Fix indentation.
	* charset.c: Fix indentation.
	* cli/cli-cmds.c: Fix indentation.
	* cli/cli-decode.c: Fix indentation.
	* cli/cli-decode.h: Fix indentation.
	* cli/cli-script.c: Fix indentation.
	* cli/cli-setshow.c: Fix indentation.
	* coff-pe-read.c: Fix indentation.
	* coffread.c: Fix indentation.
	* compile/compile-cplus-types.c: Fix indentation.
	* compile/compile-object-load.c: Fix indentation.
	* compile/compile-object-run.c: Fix indentation.
	* completer.c: Fix indentation.
	* corefile.c: Fix indentation.
	* corelow.c: Fix indentation.
	* cp-abi.h: Fix indentation.
	* cp-namespace.c: Fix indentation.
	* cp-support.c: Fix indentation.
	* cp-valprint.c: Fix indentation.
	* cris-linux-tdep.c: Fix indentation.
	* cris-tdep.c: Fix indentation.
	* darwin-nat-info.c: Fix indentation.
	* darwin-nat.c: Fix indentation.
	* darwin-nat.h: Fix indentation.
	* dbxread.c: Fix indentation.
	* dcache.c: Fix indentation.
	* disasm.c: Fix indentation.
	* dtrace-probe.c: Fix indentation.
	* dwarf2/abbrev.c: Fix indentation.
	* dwarf2/attribute.c: Fix indentation.
	* dwarf2/expr.c: Fix indentation.
	* dwarf2/frame.c: Fix indentation.
	* dwarf2/index-cache.c: Fix indentation.
	* dwarf2/index-write.c: Fix indentation.
	* dwarf2/line-header.c: Fix indentation.
	* dwarf2/loc.c: Fix indentation.
	* dwarf2/macro.c: Fix indentation.
	* dwarf2/read.c: Fix indentation.
	* dwarf2/read.h: Fix indentation.
	* elfread.c: Fix indentation.
	* eval.c: Fix indentation.
	* event-top.c: Fix indentation.
	* exec.c: Fix indentation.
	* exec.h: Fix indentation.
	* expprint.c: Fix indentation.
	* f-lang.c: Fix indentation.
	* f-typeprint.c: Fix indentation.
	* f-valprint.c: Fix indentation.
	* fbsd-nat.c: Fix indentation.
	* fbsd-tdep.c: Fix indentation.
	* findvar.c: Fix indentation.
	* fork-child.c: Fix indentation.
	* frame-unwind.c: Fix indentation.
	* frame-unwind.h: Fix indentation.
	* frame.c: Fix indentation.
	* frv-linux-tdep.c: Fix indentation.
	* frv-tdep.c: Fix indentation.
	* frv-tdep.h: Fix indentation.
	* ft32-tdep.c: Fix indentation.
	* gcore.c: Fix indentation.
	* gdb_bfd.c: Fix indentation.
	* gdbarch.sh: Fix indentation.
	* gdbarch.c: Re-generate
	* gdbarch.h: Re-generate.
	* gdbcore.h: Fix indentation.
	* gdbthread.h: Fix indentation.
	* gdbtypes.c: Fix indentation.
	* gdbtypes.h: Fix indentation.
	* glibc-tdep.c: Fix indentation.
	* gnu-nat.c: Fix indentation.
	* gnu-nat.h: Fix indentation.
	* gnu-v2-abi.c: Fix indentation.
	* gnu-v3-abi.c: Fix indentation.
	* go32-nat.c: Fix indentation.
	* guile/guile-internal.h: Fix indentation.
	* guile/scm-cmd.c: Fix indentation.
	* guile/scm-frame.c: Fix indentation.
	* guile/scm-iterator.c: Fix indentation.
	* guile/scm-math.c: Fix indentation.
	* guile/scm-ports.c: Fix indentation.
	* guile/scm-pretty-print.c: Fix indentation.
	* guile/scm-value.c: Fix indentation.
	* h8300-tdep.c: Fix indentation.
	* hppa-linux-nat.c: Fix indentation.
	* hppa-linux-tdep.c: Fix indentation.
	* hppa-nbsd-nat.c: Fix indentation.
	* hppa-nbsd-tdep.c: Fix indentation.
	* hppa-obsd-nat.c: Fix indentation.
	* hppa-tdep.c: Fix indentation.
	* hppa-tdep.h: Fix indentation.
	* i386-bsd-nat.c: Fix indentation.
	* i386-darwin-nat.c: Fix indentation.
	* i386-darwin-tdep.c: Fix indentation.
	* i386-dicos-tdep.c: Fix indentation.
	* i386-gnu-nat.c: Fix indentation.
	* i386-linux-nat.c: Fix indentation.
	* i386-linux-tdep.c: Fix indentation.
	* i386-nto-tdep.c: Fix indentation.
	* i386-obsd-tdep.c: Fix indentation.
	* i386-sol2-nat.c: Fix indentation.
	* i386-tdep.c: Fix indentation.
	* i386-tdep.h: Fix indentation.
	* i386-windows-tdep.c: Fix indentation.
	* i387-tdep.c: Fix indentation.
	* i387-tdep.h: Fix indentation.
	* ia64-libunwind-tdep.c: Fix indentation.
	* ia64-libunwind-tdep.h: Fix indentation.
	* ia64-linux-nat.c: Fix indentation.
	* ia64-linux-tdep.c: Fix indentation.
	* ia64-tdep.c: Fix indentation.
	* ia64-tdep.h: Fix indentation.
	* ia64-vms-tdep.c: Fix indentation.
	* infcall.c: Fix indentation.
	* infcmd.c: Fix indentation.
	* inferior.c: Fix indentation.
	* infrun.c: Fix indentation.
	* iq2000-tdep.c: Fix indentation.
	* language.c: Fix indentation.
	* linespec.c: Fix indentation.
	* linux-fork.c: Fix indentation.
	* linux-nat.c: Fix indentation.
	* linux-tdep.c: Fix indentation.
	* linux-thread-db.c: Fix indentation.
	* lm32-tdep.c: Fix indentation.
	* m2-lang.c: Fix indentation.
	* m2-typeprint.c: Fix indentation.
	* m2-valprint.c: Fix indentation.
	* m32c-tdep.c: Fix indentation.
	* m32r-linux-tdep.c: Fix indentation.
	* m32r-tdep.c: Fix indentation.
	* m68hc11-tdep.c: Fix indentation.
	* m68k-bsd-nat.c: Fix indentation.
	* m68k-linux-nat.c: Fix indentation.
	* m68k-linux-tdep.c: Fix indentation.
	* m68k-tdep.c: Fix indentation.
	* machoread.c: Fix indentation.
	* macrocmd.c: Fix indentation.
	* macroexp.c: Fix indentation.
	* macroscope.c: Fix indentation.
	* macrotab.c: Fix indentation.
	* macrotab.h: Fix indentation.
	* main.c: Fix indentation.
	* mdebugread.c: Fix indentation.
	* mep-tdep.c: Fix indentation.
	* mi/mi-cmd-catch.c: Fix indentation.
	* mi/mi-cmd-disas.c: Fix indentation.
	* mi/mi-cmd-env.c: Fix indentation.
	* mi/mi-cmd-stack.c: Fix indentation.
	* mi/mi-cmd-var.c: Fix indentation.
	* mi/mi-cmds.c: Fix indentation.
	* mi/mi-main.c: Fix indentation.
	* mi/mi-parse.c: Fix indentation.
	* microblaze-tdep.c: Fix indentation.
	* minidebug.c: Fix indentation.
	* minsyms.c: Fix indentation.
	* mips-linux-nat.c: Fix indentation.
	* mips-linux-tdep.c: Fix indentation.
	* mips-nbsd-tdep.c: Fix indentation.
	* mips-tdep.c: Fix indentation.
	* mn10300-linux-tdep.c: Fix indentation.
	* mn10300-tdep.c: Fix indentation.
	* moxie-tdep.c: Fix indentation.
	* msp430-tdep.c: Fix indentation.
	* namespace.h: Fix indentation.
	* nat/fork-inferior.c: Fix indentation.
	* nat/gdb_ptrace.h: Fix indentation.
	* nat/linux-namespaces.c: Fix indentation.
	* nat/linux-osdata.c: Fix indentation.
	* nat/netbsd-nat.c: Fix indentation.
	* nat/x86-dregs.c: Fix indentation.
	* nbsd-nat.c: Fix indentation.
	* nbsd-tdep.c: Fix indentation.
	* nios2-linux-tdep.c: Fix indentation.
	* nios2-tdep.c: Fix indentation.
	* nto-procfs.c: Fix indentation.
	* nto-tdep.c: Fix indentation.
	* objfiles.c: Fix indentation.
	* objfiles.h: Fix indentation.
	* opencl-lang.c: Fix indentation.
	* or1k-tdep.c: Fix indentation.
	* osabi.c: Fix indentation.
	* osabi.h: Fix indentation.
	* osdata.c: Fix indentation.
	* p-lang.c: Fix indentation.
	* p-typeprint.c: Fix indentation.
	* p-valprint.c: Fix indentation.
	* parse.c: Fix indentation.
	* ppc-linux-nat.c: Fix indentation.
	* ppc-linux-tdep.c: Fix indentation.
	* ppc-nbsd-nat.c: Fix indentation.
	* ppc-nbsd-tdep.c: Fix indentation.
	* ppc-obsd-nat.c: Fix indentation.
	* ppc-ravenscar-thread.c: Fix indentation.
	* ppc-sysv-tdep.c: Fix indentation.
	* ppc64-tdep.c: Fix indentation.
	* printcmd.c: Fix indentation.
	* proc-api.c: Fix indentation.
	* producer.c: Fix indentation.
	* producer.h: Fix indentation.
	* prologue-value.c: Fix indentation.
	* prologue-value.h: Fix indentation.
	* psymtab.c: Fix indentation.
	* python/py-arch.c: Fix indentation.
	* python/py-bpevent.c: Fix indentation.
	* python/py-event.c: Fix indentation.
	* python/py-event.h: Fix indentation.
	* python/py-finishbreakpoint.c: Fix indentation.
	* python/py-frame.c: Fix indentation.
	* python/py-framefilter.c: Fix indentation.
	* python/py-inferior.c: Fix indentation.
	* python/py-infthread.c: Fix indentation.
	* python/py-objfile.c: Fix indentation.
	* python/py-prettyprint.c: Fix indentation.
	* python/py-registers.c: Fix indentation.
	* python/py-signalevent.c: Fix indentation.
	* python/py-stopevent.c: Fix indentation.
	* python/py-stopevent.h: Fix indentation.
	* python/py-threadevent.c: Fix indentation.
	* python/py-tui.c: Fix indentation.
	* python/py-unwind.c: Fix indentation.
	* python/py-value.c: Fix indentation.
	* python/py-xmethods.c: Fix indentation.
	* python/python-internal.h: Fix indentation.
	* python/python.c: Fix indentation.
	* ravenscar-thread.c: Fix indentation.
	* record-btrace.c: Fix indentation.
	* record-full.c: Fix indentation.
	* record.c: Fix indentation.
	* reggroups.c: Fix indentation.
	* regset.h: Fix indentation.
	* remote-fileio.c: Fix indentation.
	* remote.c: Fix indentation.
	* reverse.c: Fix indentation.
	* riscv-linux-tdep.c: Fix indentation.
	* riscv-ravenscar-thread.c: Fix indentation.
	* riscv-tdep.c: Fix indentation.
	* rl78-tdep.c: Fix indentation.
	* rs6000-aix-tdep.c: Fix indentation.
	* rs6000-lynx178-tdep.c: Fix indentation.
	* rs6000-nat.c: Fix indentation.
	* rs6000-tdep.c: Fix indentation.
	* rust-lang.c: Fix indentation.
	* rx-tdep.c: Fix indentation.
	* s12z-tdep.c: Fix indentation.
	* s390-linux-tdep.c: Fix indentation.
	* score-tdep.c: Fix indentation.
	* ser-base.c: Fix indentation.
	* ser-mingw.c: Fix indentation.
	* ser-uds.c: Fix indentation.
	* ser-unix.c: Fix indentation.
	* serial.c: Fix indentation.
	* sh-linux-tdep.c: Fix indentation.
	* sh-nbsd-tdep.c: Fix indentation.
	* sh-tdep.c: Fix indentation.
	* skip.c: Fix indentation.
	* sol-thread.c: Fix indentation.
	* solib-aix.c: Fix indentation.
	* solib-darwin.c: Fix indentation.
	* solib-frv.c: Fix indentation.
	* solib-svr4.c: Fix indentation.
	* solib.c: Fix indentation.
	* source.c: Fix indentation.
	* sparc-linux-tdep.c: Fix indentation.
	* sparc-nbsd-tdep.c: Fix indentation.
	* sparc-obsd-tdep.c: Fix indentation.
	* sparc-ravenscar-thread.c: Fix indentation.
	* sparc-tdep.c: Fix indentation.
	* sparc64-linux-tdep.c: Fix indentation.
	* sparc64-nbsd-tdep.c: Fix indentation.
	* sparc64-obsd-tdep.c: Fix indentation.
	* sparc64-tdep.c: Fix indentation.
	* stabsread.c: Fix indentation.
	* stack.c: Fix indentation.
	* stap-probe.c: Fix indentation.
	* stubs/ia64vms-stub.c: Fix indentation.
	* stubs/m32r-stub.c: Fix indentation.
	* stubs/m68k-stub.c: Fix indentation.
	* stubs/sh-stub.c: Fix indentation.
	* stubs/sparc-stub.c: Fix indentation.
	* symfile-mem.c: Fix indentation.
	* symfile.c: Fix indentation.
	* symfile.h: Fix indentation.
	* symmisc.c: Fix indentation.
	* symtab.c: Fix indentation.
	* symtab.h: Fix indentation.
	* target-float.c: Fix indentation.
	* target.c: Fix indentation.
	* target.h: Fix indentation.
	* tic6x-tdep.c: Fix indentation.
	* tilegx-linux-tdep.c: Fix indentation.
	* tilegx-tdep.c: Fix indentation.
	* top.c: Fix indentation.
	* tracefile-tfile.c: Fix indentation.
	* tracepoint.c: Fix indentation.
	* tui/tui-disasm.c: Fix indentation.
	* tui/tui-io.c: Fix indentation.
	* tui/tui-regs.c: Fix indentation.
	* tui/tui-stack.c: Fix indentation.
	* tui/tui-win.c: Fix indentation.
	* tui/tui-winsource.c: Fix indentation.
	* tui/tui.c: Fix indentation.
	* typeprint.c: Fix indentation.
	* ui-out.h: Fix indentation.
	* unittests/copy_bitwise-selftests.c: Fix indentation.
	* unittests/memory-map-selftests.c: Fix indentation.
	* utils.c: Fix indentation.
	* v850-tdep.c: Fix indentation.
	* valarith.c: Fix indentation.
	* valops.c: Fix indentation.
	* valprint.c: Fix indentation.
	* valprint.h: Fix indentation.
	* value.c: Fix indentation.
	* value.h: Fix indentation.
	* varobj.c: Fix indentation.
	* vax-tdep.c: Fix indentation.
	* windows-nat.c: Fix indentation.
	* windows-tdep.c: Fix indentation.
	* xcoffread.c: Fix indentation.
	* xml-syscall.c: Fix indentation.
	* xml-tdesc.c: Fix indentation.
	* xstormy16-tdep.c: Fix indentation.
	* xtensa-config.c: Fix indentation.
	* xtensa-linux-nat.c: Fix indentation.
	* xtensa-linux-tdep.c: Fix indentation.
	* xtensa-tdep.c: Fix indentation.

gdbserver/ChangeLog:

	* ax.cc: Fix indentation.
	* dll.cc: Fix indentation.
	* inferiors.h: Fix indentation.
	* linux-low.cc: Fix indentation.
	* linux-nios2-low.cc: Fix indentation.
	* linux-ppc-ipa.cc: Fix indentation.
	* linux-ppc-low.cc: Fix indentation.
	* linux-x86-low.cc: Fix indentation.
	* linux-xtensa-low.cc: Fix indentation.
	* regcache.cc: Fix indentation.
	* server.cc: Fix indentation.
	* tracepoint.cc: Fix indentation.

gdbsupport/ChangeLog:

	* common-exceptions.h: Fix indentation.
	* event-loop.cc: Fix indentation.
	* fileio.cc: Fix indentation.
	* filestuff.cc: Fix indentation.
	* gdb-dlfcn.cc: Fix indentation.
	* gdb_string_view.h: Fix indentation.
	* job-control.cc: Fix indentation.
	* signals.cc: Fix indentation.

Change-Id: I4bad7ae6be0fbe14168b8ebafb98ffe14964a695
 2020-11-02 10:28:45 -05:00
Tom Tromey
a42d7dd873 Remove symfile_objfile macro 
This removes the symfile_objfile macro, in favor of just spelling out
the member access.

gdb/ChangeLog
2020-10-29  Tom Tromey  <tom@tromey.com>

	* windows-tdep.c (windows_solib_create_inferior_hook): Update.
	* target.c (info_target_command): Update.
	* symfile.c (syms_from_objfile_1, finish_new_objfile)
	(symbol_file_clear, reread_symbols): Update.
	* symfile-mem.c (add_symbol_file_from_memory_command): Update.
	* stabsread.c (scan_file_globals): Update.
	* solib.c (update_solib_list): Update.
	* solib-svr4.c (elf_locate_base, open_symbol_file_object)
	(svr4_fetch_objfile_link_map, enable_break)
	(svr4_relocate_main_executable)
	(svr4_iterate_over_objfiles_in_search_order): Update.
	* solib-frv.c (lm_base, enable_break)
	(frv_relocate_main_executable): Update.
	(main_got, frv_fdpic_find_canonical_descriptor): Update.
	(frv_fetch_objfile_link_map): Update.
	* solib-dsbt.c (lm_base, dsbt_relocate_main_executable): Update.
	* solib-darwin.c (darwin_solib_create_inferior_hook): Update.
	* solib-aix.c (solib_aix_solib_create_inferior_hook): Update.
	* remote.c (remote_target::get_offsets): Update.
	(remote_target::start_remote)
	(extended_remote_target::post_attach): Update.
	* objfiles.c (entry_point_address_query): Update.
	* nto-procfs.c (nto_procfs_target::create_inferior): Update.
	* minsyms.c (get_symbol_leading_char): Update.
	* frame.c (inside_main_func): Update.
	* progspace.h (symfile_objfile): Remove macro.
 2020-10-29 15:04:37 -06:00
Simon Marchi
24f5300a53 gdb: make target_ops::make_corefile_notes return a unique ptr 
Since we converted gdbarch_make_corefile_notes to returning a
gdb::unique_xmalloc_ptr, I figured it would make sense to converted
target_ops::make_corefile_notes as well.

The only implementation of that is in procfs.c, and it should ideally be
re-written as a gdbarch method (see comment in write_gcore_file_1), but
in the mean time I guess it doesn't hurt to throw some unique pointer at
it.

I tested that it builds on Solaris 11 (gcc compile farm machine gcc211),
but I am not able to test it, because I can't get GDB to start a
process (I'll look at that separately).

gdb/ChangeLog:

	* target.h (struct target_ops) <make_corefile_notes>:
	Change return type to unique pointer.
	* target.c (dummy_make_corefile_notes): Likewise.
	* exec.c (struct exec_target) <make_corefile_notes>:
	Likewise.
	(exec_target::make_corefile_notes): Likewise.
	* procfs.c (class procfs_target) <make_corefile_notes>:
	Likewise.
	(procfs_do_thread_registers): Adjust to unique pointer.
	(struct procfs_corefile_thread_data): Add constructor.
	<note_data>: Change type to unique pointer.
	(procfs_corefile_thread_callback): Adjust to unique pointer.
	(procfs_target::make_corefile_notes): Change return type to
	unique pointer.
	* target-delegates.c: Re-generate.
	* gcore.c (write_gcore_file_1): Adjust.
	* target-debug.h (target_debug_print_gdb_unique_xmalloc_ptr_char):
	New.

Change-Id: I768fb17ac0f7adc67d2fe95e952c784fe0ac37ab
 2020-10-22 12:58:21 -04:00
Simon Marchi
d3a071228e gdb: don't pass TARGET_WNOHANG to targets that can't async (PR 26642) 
Debugging with "maintenance set target-async off" on Linux has been
broken since 5b6d1e4fa4f ("Multi-target support").

The issue is easy to reproduce:

    $ ./gdb -q --data-directory=data-directory -nx ./test
    Reading symbols from ./test...
    (gdb) maintenance set target-async off
    (gdb) start
    Temporary breakpoint 1 at 0x1151: file test.c, line 5.
    Starting program: /home/simark/build/binutils-gdb/gdb/test

... and it hangs there.

The difference between pre-5b6d1e4fa4f and 5b6d1e4fa4f is that
fetch_inferior_event now calls target_wait with TARGET_WNOHANG for
non-async-capable targets, whereas it didn't before.

For non-async-capable targets, this is how it's expected to work when
resuming execution:

1. we call resume
2. the infrun async handler is marked in prepare_to_wait, to immediately
   wake up the event loop when we get back to it
3. fetch_inferior_event calls the target's wait method without
   TARGET_WNOHANG, effectively blocking until the target has something
   to report

However, since we call the target's wait method with TARGET_WNOHANG,
this happens:

1. we call resume
2. the infrun async handler is marked in prepare_to_wait, to immediately
   wake up the event loop when we get back to it
3. fetch_inferior_event calls the target's wait method with
   TARGET_WNOHANG, the target has nothing to report yet
4. we go back to blocking on the event loop
5. SIGCHLD finally arrives, but the event loop is not woken up, because
   we are not in async mode.  Normally, we should have been stuck in
   waitpid the SIGCHLD would have unblocked us.

We end up in this situation because these two necessary conditions are
met:

1. GDB uses the TARGET_WNOHANG option with a target that can't do async.
   I don't think this makes sense.  I mean, it's technically possible,
   the doc for TARGET_WNOHANG is:

  /* Return immediately if there's no event already queued.  If this
     options is not requested, target_wait blocks waiting for an
     event.  */
  TARGET_WNOHANG = 1,

   ... which isn't in itself necessarily incompatible with synchronous
   targets.  It could be possible for a target to support non-blocking
   polls, while not having a way to asynchronously wake up the event
   loop, which is also necessary to support async.  But as of today,
   we don't expect GDB and sync targets to work this way.

2. The linux-nat target, even in the mode where it emulates a
   synchronous target (with "maintenance set target-async off") respects
   TARGET_WNOHANG.  Other non-async targets, such as windows_nat_target,
   simply don't check / support TARGET_WNOHANG, so their wait method is
   always blocking.

Fix the first issue by avoiding using TARGET_WNOHANG on non-async
targets, in do_target_wait_1.  Add an assert in target_wait to verify it
doesn't happen.

The new test gdb.base/maint-target-async-off.exp is a simple test that
just tries running to main and then to the end of the program, with
"maintenance set target-async off".

gdb/ChangeLog:

	PR gdb/26642
	* infrun.c (do_target_wait_1): Clear TARGET_WNOHANG if the
	target can't do async.
	* target.c (target_wait): Assert that we don't pass
	TARGET_WNOHANG to a target that can't async.

gdb/testsuite/ChangeLog:

	PR gdb/26642
	* gdb.base/maint-target-async-off.c: New test.
	* gdb.base/maint-target-async-off.exp: New test.

Change-Id: I69ad3a14598863d21338a8c4e78700a58ce7ad86
 2020-10-13 12:01:19 -04:00
Tom Tromey
d7a78e5c41 Change target_section_table to std::vector alias 
Because target_section_table only holds a vector, and because it is
used in an "open" way, this patch makes it just be an alias for the
std::vector specialization.  This makes the code less wordy.  If we do
ever want to add more specialized behavior to this type, it's simple
enough to convert it back to a struct with the few needed methods
implied by this change.

gdb/ChangeLog
2020-10-12  Tom Tromey  <tom@tromey.com>

	* target.h (struct target_ops) <get_section_table>: Update.
	(target_get_section_table): Update.
	* target.c (target_get_section_table, target_section_by_addr)
	(memory_xfer_partial_1): Update.
	* target-section.h (target_section_table): Now an alias.
	* target-delegates.c: Rebuild.
	* target-debug.h (target_debug_print_target_section_table_p):
	Rename from target_debug_print_struct_target_section_table_p.
	* symfile.c (build_section_addr_info_from_section_table): Update.
	* solib.c (solib_map_sections, solib_contains_address_p): Update.
	* solib-svr4.c (scan_dyntag): Update.
	* solib-dsbt.c (scan_dyntag): Update.
	* remote.c (remote_target::remote_xfer_live_readonly_partial):
	Update.
	* record-full.c (record_full_core_target::xfer_partial): Update.
	* progspace.h (struct program_space) <target_sections>: Update.
	* exec.h (print_section_info): Update.
	* exec.c (exec_target::close, build_section_table)
	(add_target_sections, add_target_sections_of_objfile)
	(remove_target_sections, exec_on_vfork)
	(section_table_available_memory)
	(section_table_xfer_memory_partial)
	(exec_target::get_section_table, exec_target::xfer_partial)
	(print_section_info, set_section_command)
	(exec_set_section_address, exec_target::has_memory): Update.
	* corelow.c (core_target::build_file_mappings)
	(core_target::xfer_partial, core_target::info_proc_mappings)
	(core_target::info_proc_mappings): Update.
	* bfd-target.c (class target_bfd): Update
 2020-10-12 20:18:48 -06:00
Tom Tromey
bb2a67773c Use a std::vector in target_section_table 
This changes target_section_table to wrap a std::vector.  This
simplifies some code, and also enables the simplifications coming in
the subsequent patches.

Note that for solib, I chose to have it use a pointer to a
target_section_table.  This is more convoluted than would be ideal,
but I didn't want to convert solib to new/delete as a prerequisite for
this series.

gdb/ChangeLog
2020-10-12  Tom Tromey  <tom@tromey.com>

	* target.c (target_section_by_addr, memory_xfer_partial_1):
	Update.
	* target-section.h (struct target_section_table): Use
	std::vector.
	* symfile.h (build_section_addr_info_from_section_table): Take a
	target_section_table.
	* symfile.c (build_section_addr_info_from_section_table): Take a
	target_section_table.
	* solist.h (struct so_list) <sections>: Change type.
	<sections_end>: Remove.
	* solib.c (solib_map_sections, clear_so, solib_read_symbols)
	(solib_contains_address_p): Update.
	* solib-svr4.c (scan_dyntag): Update.
	* solib-dsbt.c (scan_dyntag): Update.
	* remote.c (remote_target::remote_xfer_live_readonly_partial):
	Update.
	* record-full.c (record_full_core_start, record_full_core_end):
	Remove.
	(record_full_core_sections): New global.
	(record_full_core_open_1, record_full_core_target::xfer_partial):
	Update.
	* exec.h (build_section_table, section_table_xfer_memory_partial)
	(add_target_sections): Take a target_section_table.
	* exec.c (exec_file_attach, clear_section_table): Update.
	(resize_section_table): Remove.
	(build_section_table, add_target_sections): Take a
	target_section_table.
	(add_target_sections_of_objfile, remove_target_sections)
	(exec_on_vfork): Update.
	(section_table_available_memory): Take a target_section_table.
	(section_table_read_available_memory): Update.
	(section_table_xfer_memory_partial): Take a target_section_table.
	(print_section_info, set_section_command)
	(exec_set_section_address, exec_target::has_memory): Update.
	* corelow.c (class core_target) <m_core_section_table,
	m_core_file_mappings>: Remove braces.
	<~core_target>: Remove.
	(core_target::core_target): Update.
	(core_target::~core_target): Remove.
	(core_target::build_file_mappings)
	(core_target::xfer_memory_via_mappings)
	(core_target::xfer_partial, core_target::info_proc_mappings):
	Update.
	* bfd-target.c (target_bfd::xfer_partial): Update.
	(target_bfd::target_bfd): Update.
	(target_bfd::~target_bfd): Remove.
 2020-10-12 20:18:47 -06:00
Tom Tromey
4a72de7366 Move simple_search_memory to gdbsupport/search.cc 
This moves the simple_search_memory function to a new file,
gdbsupport/search.cc.  The API is slightly changed to make it more
general.  This generality is useful for wiring it to gdbserver, and
also for unit testing.

gdb/ChangeLog
2020-10-07  Tom Tromey  <tromey@adacore.com>

	* target.h (simple_search_memory): Don't declare.
	* target.c (simple_search_memory): Move to gdbsupport.
	(default_search_memory): Update.
	* remote.c (remote_target::search_memory): Update.

gdbsupport/ChangeLog
2020-10-07  Tom Tromey  <tromey@adacore.com>

	* Makefile.in: Rebuild.
	* Makefile.am (libgdbsupport_a_SOURCES): Add search.cc.
	* search.h: New file.
	* search.cc: New file.
 2020-10-07 12:07:55 -06:00
Tom Tromey
55f6301ac0 Remove target_has_execution macro 
This removes the object-like macro target_has_execution, replacing it
with a function call.  target_has_execution_current is also now
handled by this function.

gdb/ChangeLog
2020-09-28  Tom Tromey  <tom@tromey.com>

	* inferior.h (class inferior) <has_execution>: Update.
	* windows-tdep.c (windows_solib_create_inferior_hook): Update.
	* valops.c (find_function_in_inferior)
	(value_allocate_space_in_inferior): Update.
	* top.c (kill_or_detach): Update.
	* target.c (target_preopen, set_target_permissions): Update.
	(target_has_execution_current): Remove.
	* sparc64-tdep.c (adi_examine_command, adi_assign_command):
	Update.
	* solib.c (update_solib_list, reload_shared_libraries): Update.
	* solib-svr4.c (svr4_solib_create_inferior_hook): Update.
	* solib-dsbt.c (enable_break): Update.
	* score-tdep.c (score7_fetch_inst): Update.
	* rs6000-nat.c (rs6000_nat_target::xfer_shared_libraries):
	Update.
	* remote.c (remote_target::start_remote)
	(remote_target::remote_check_symbols, remote_target::open_1)
	(remote_target::remote_detach_1, remote_target::verify_memory)
	(remote_target::xfer_partial, remote_target::read_description)
	(remote_target::get_min_fast_tracepoint_insn_len): Update.
	* record-full.c (record_full_open_1): Update.
	* record-btrace.c (record_btrace_target_open): Update.
	* objc-lang.c (lookup_objc_class, lookup_child_selector)
	(value_nsstring): Update.
	* linux-thread-db.c (add_thread_db_info)
	(thread_db_find_new_threads_silently, check_thread_db_callback)
	(try_thread_db_load_1, record_thread): Update.
	* linux-tdep.c (linux_info_proc, linux_vsyscall_range_raw):
	Update.
	* linux-fork.c (checkpoint_command): Update.
	* infrun.c (set_non_stop, set_observer_mode)
	(check_multi_target_resumption, for_each_just_stopped_thread)
	(maybe_remove_breakpoints, normal_stop)
	(class infcall_suspend_state): Update.
	* infcmd.c (ERROR_NO_INFERIOR, kill_if_already_running)
	(info_program_command, attach_command): Update.
	* infcall.c (call_function_by_hand_dummy): Update.
	* inf-loop.c (inferior_event_handler): Update.
	* gcore.c (gcore_command, derive_heap_segment): Update.
	* exec.c (exec_file_command): Update.
	* eval.c (evaluate_subexp): Update.
	* compile/compile.c (compile_to_object): Update.
	* cli/cli-dump.c (restore_command): Update.
	* breakpoint.c (update_watchpoint)
	(update_inserted_breakpoint_locations)
	(insert_breakpoint_locations, get_bpstat_thread): Update.
	* target.h (target_has_execution): Remove macro.
	(target_has_execution_current): Don't declare.
	(target_has_execution): Rename from target_has_execution_1.  Add
	argument default.
 2020-09-28 19:52:21 -06:00
Tom Tromey
05374cfd90 Turn target_can_execute_reverse into function 
This changes target_can_execute_reverse from an object-like macro to
an inline function.

gdb/ChangeLog
2020-09-28  Tom Tromey  <tom@tromey.com>

	* mi/mi-main.c (exec_reverse_continue)
	(mi_cmd_list_target_features): Update.
	* infrun.c (set_exec_direction_func): Update.
	* target.c (default_execution_direction): Update.
	* reverse.c (exec_reverse_once): Update.
	* target.h (target_can_execute_reverse): Now a function.
 2020-09-28 19:52:21 -06:00
Tom Tromey
9dccd06e8a Remove target_has_registers macro 
This removes the target_has_registers object-like macro, replacing it
with the underlying function.

gdb/ChangeLog
2020-09-28  Tom Tromey  <tom@tromey.com>

	* tui/tui-regs.c (tui_get_register)
	(tui_data_window::show_registers): Update.
	* thread.c (scoped_restore_current_thread::restore)
	(scoped_restore_current_thread::scoped_restore_current_thread):
	Update.
	* regcache-dump.c (regcache_print): Update.
	* python/py-finishbreakpoint.c (bpfinishpy_detect_out_scope_cb):
	Update.
	* mi/mi-main.c (mi_cmd_data_write_register_values): Update.
	* mep-tdep.c (current_me_module, current_options): Update.
	* linux-thread-db.c (thread_db_load): Update.
	* infcmd.c (registers_info, info_vector_command)
	(info_float_command): Update.
	* ia64-tdep.c (ia64_frame_prev_register)
	(ia64_sigtramp_frame_prev_register): Update.
	* ia64-libunwind-tdep.c (libunwind_frame_prev_register): Update.
	* gcore.c (derive_stack_segment): Update.
	* frame.c (get_current_frame, has_stack_frames): Update.
	* findvar.c (language_defn::read_var_value): Update.
	* arm-tdep.c (arm_pc_is_thumb): Update.
	* target.c (target_has_registers): Rename from
	target_has_registers_1.
	* target.h (target_has_registers): Remove macro.
	(target_has_registers): Rename from target_has_registers_1.
 2020-09-28 19:52:21 -06:00
Tom Tromey
841de12014 Remove target_has_stack macro 
This removes the target_has_stack object-like macro, replacing it with
the underlying function.

gdb/ChangeLog
2020-09-28  Tom Tromey  <tom@tromey.com>

	* windows-tdep.c (tlb_make_value): Update.
	* tui/tui-regs.c (tui_data_window::show_registers): Update.
	* thread.c (scoped_restore_current_thread::restore)
	(scoped_restore_current_thread::scoped_restore_current_thread)
	(thread_command): Update.
	* stack.c (backtrace_command_1, frame_apply_level_command)
	(frame_apply_all_command, frame_apply_command): Update.
	* infrun.c (siginfo_make_value, restore_infcall_control_state):
	Update.
	* gcore.c (derive_stack_segment): Update.
	* frame.c (get_current_frame, has_stack_frames): Update.
	* auxv.c (info_auxv_command): Update.
	* ada-tasks.c (ada_build_task_list): Update.
	* target.c (target_has_stack): Rename from target_has_stack_1.
	* target.h (target_has_stack): Remove macro.
	(target_has_stack): Rename from target_has_stack_1.
 2020-09-28 19:52:21 -06:00
Tom Tromey
a739972c7c Remove target_has_memory macro 
This removes the target_has_memory object-like macro, replacing it
with the underlying function.

gdb/ChangeLog
2020-09-28  Tom Tromey  <tom@tromey.com>

	* target.c (target_has_memory): Rename from target_has_memory_1.
	* tui/tui-regs.c (tui_data_window::show_registers): Update.
	* thread.c (scoped_restore_current_thread::restore)
	(scoped_restore_current_thread::scoped_restore_current_thread):
	Update.
	* frame.c (get_current_frame, has_stack_frames): Update.
	* target.h (target_has_memory): Remove macro.
	(target_has_memory): Rename from target_has_memory_1.
 2020-09-28 19:52:21 -06:00
Tom Tromey
5b8a477608 Remove target_has_all_memory 
target_has_all_memory isn't used anywhere, so this patch removes it.

gdb/ChangeLog
2020-09-28  Tom Tromey  <tom@tromey.com>

	* target.c (target_has_all_memory_1): Remove.
	* target.h (target_has_all_memory): Remove define.
	(target_has_all_memory_1): Don't declare.
 2020-09-28 19:52:21 -06:00
Tom Tromey
b60cea74de Make target_wait options use enum flags 
This changes TARGET_WNOHANG to be a member of an enum, rather than a
define, and also adds a DEF_ENUM_FLAGS_TYPE for this type.  Then, it
changes target_wait and the various target wait methods to use this
type rather than "int".

This didn't catch any bugs, but it seems like a decent cleanup
nevertheless.

I did not change deprecated_target_wait_hook, since that's only used
out-of-tree (by Insight), and there didn't seem to be a need.

I can't build some of these targets, so I modified them on a
best-effort basis.  I don't think this patch should go in before the
release branch is made.

gdb/ChangeLog
2020-09-18  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (struct windows_nat_target) <wait>: Update.
	(windows_nat_target::wait): Update.
	* target/wait.h (enum target_wait_flag): New.  Use
	DEF_ENUM_FLAGS_TYPE.
	* target/target.h (target_wait): Change type of options.
	* target.h (target_options_to_string, default_target_wait):
	Update.
	(struct target_ops) <wait>: Change type of options.
	* target.c (target_wait, default_target_wait, do_option): Change
	type of "options".
	(target_options_to_string): Likewise.
	* target-delegates.c: Rebuild.
	* target-debug.h (target_debug_print_target_wait_flags): Rename
	from target_debug_print_options.
	* sol-thread.c (class sol_thread_target) <wait>: Update.
	(sol_thread_target::wait): Update.
	* rs6000-nat.c (class rs6000_nat_target) <wait>: Update.
	(rs6000_nat_target::wait): Update.
	* remote.c (class remote_target) <wait, wait_ns, wait_as>:
	Update.
	(remote_target::wait_ns, remote_target::wait_as): Change type of
	"options".
	(remote_target::wait): Update.
	* remote-sim.c (struct gdbsim_target) <wait>: Update.
	(gdbsim_target::wait): Update.
	* record-full.c (class record_full_base_target) <wait>: Update.
	(record_full_wait_1): Change type of "options".
	(record_full_base_target::wait): Update.
	* record-btrace.c (class record_btrace_target) <wait>: Update.
	(record_btrace_target::wait): Update.
	* ravenscar-thread.c (struct ravenscar_thread_target) <wait>:
	Update.
	(ravenscar_thread_target::wait): Update.
	* procfs.c (class procfs_target) <wait>: Update.
	(procfs_target::wait): Update.
	* obsd-nat.h (class obsd_nat_target) <wait>: Update.
	* obsd-nat.c (obsd_nat_target::wait): Update.
	* nto-procfs.c (struct nto_procfs_target) <wait>: Update.
	(nto_procfs_target::wait): Update.
	* nbsd-nat.h (struct nbsd_nat_target) <wait>: Update.
	* nbsd-nat.c (nbsd_wait): Change type of "options".
	(nbsd_nat_target::wait): Update.
	* linux-thread-db.c (class thread_db_target) <wait>: Update.
	(thread_db_target::wait): Update.
	* linux-nat.h (class linux_nat_target) <wait>: Update.
	* linux-nat.c (linux_nat_target::wait): Update.
	(linux_nat_wait_1): Update.
	* infrun.c (do_target_wait_1, do_target_wait): Change type of
	"options".
	* inf-ptrace.h (struct inf_ptrace_target) <wait>: Update.
	* inf-ptrace.c (inf_ptrace_target::wait): Update.
	* go32-nat.c (struct go32_nat_target) <wait>: Update.
	(go32_nat_target::wait): Update.
	* gnu-nat.h (struct gnu_nat_target) <wait>: Update.
	* gnu-nat.c (gnu_nat_target::wait): Update.
	* fbsd-nat.h (class fbsd_nat_target) <wait>: Update.
	* fbsd-nat.c (fbsd_nat_target::wait): Update.
	* darwin-nat.h (class darwin_nat_target) <wait>: Update.
	* darwin-nat.c (darwin_nat_target::wait): Update.
	* bsd-uthread.c (struct bsd_uthread_target) <wait>: Update.
	(bsd_uthread_target::wait): Update.
	* aix-thread.c (class aix_thread_target) <wait>: Update.
	(aix_thread_target::wait): Update.

gdbserver/ChangeLog
2020-09-18  Tom Tromey  <tromey@adacore.com>

	* netbsd-low.h (class netbsd_process_target) <wait>: Update.
	* netbsd-low.cc (netbsd_waitpid, netbsd_wait)
	(netbsd_process_target::wait): Change type of target_options.
	* win32-low.h (class win32_process_target) <wait>: Update.
	* win32-low.cc (win32_process_target::wait): Update.
	* target.h (class process_stratum_target) <wait>: Update.
	(mywait): Update.
	* target.cc (mywait, target_wait): Change type of "options".
	* linux-low.h (class linux_process_target) <wait, wait_1>:
	Update.
	* linux-low.cc (linux_process_target::wait)
	(linux_process_target::wait_1): Update.
 2020-09-18 14:20:44 -06:00
Kevin Buettner
2735d4218e Provide access to non SEC_HAS_CONTENTS core file sections 
Consider the following program:

- - - mkmmapcore.c - - -

static char *buf;

int
main (int argc, char **argv)
{
  buf = mmap (NULL, 8192, PROT_READ | PROT_WRITE,
              MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
  abort ();
}
- - - end mkmmapcore.c - - -

Compile it like this:

gcc -g -o mkmmapcore mkmmapcore.c

Now let's run it from GDB.  I've already placed a breakpoint on the
line with the abort() call and have run to that breakpoint.

Breakpoint 1, main (argc=1, argv=0x7fffffffd678) at mkmmapcore.c:11
11	  abort ();
(gdb) x/x buf
0x7ffff7fcb000:	0x00000000

Note that we can examine the memory allocated via the call to mmap().

Now let's try debugging a core file created by running this program.
Depending on your system, in order to make a core file, you may have to
run the following as root (or using sudo):

    echo core > /proc/sys/kernel/core_pattern

It may also be necessary to do:

    ulimit -c unlimited

I'm using Fedora 31. YMMV if you're using one of the BSDs or some other
(non-Linux) system.

This is what things look like when we debug the core file:

    [kev@f31-1 tmp]$ gdb -q ./mkmmapcore core.304767
    Reading symbols from ./mkmmapcore...
    [New LWP 304767]
    Core was generated by `/tmp/mkmmapcore'.
    Program terminated with signal SIGABRT, Aborted.
    #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
    50	  return ret;
    (gdb) x/x buf
    0x7ffff7fcb000:	Cannot access memory at address 0x7ffff7fcb000

Note that we can no longer access the memory region allocated by mmap().

Back in 2007, a hack for GDB was added to _bfd_elf_make_section_from_phdr()
in bfd/elf.c:

	  /* Hack for gdb.  Segments that have not been modified do
	     not have their contents written to a core file, on the
	     assumption that a debugger can find the contents in the
	     executable.  We flag this case by setting the fake
	     section size to zero.  Note that "real" bss sections will
	     always have their contents dumped to the core file.  */
	  if (bfd_get_format (abfd) == bfd_core)
	    newsect->size = 0;

You can find the entire patch plus links to other discussion starting
here:

    https://sourceware.org/ml/binutils/2007-08/msg00047.html

This hack sets the size of certain BFD sections to 0, which
effectively causes GDB to ignore them.  I think it's likely that the
bug described above existed even before this hack was added, but I
have no easy way to test this now.

The output from objdump -h shows the result of this hack:

 25 load13        00000000  00007ffff7fcb000  0000000000000000  00013000  2**12
                  ALLOC

(The first field, after load13, shows the size of 0.)

Once the hack is removed, the output from objdump -h shows the correct
size:

 25 load13        00002000  00007ffff7fcb000  0000000000000000  00013000  2**12
                  ALLOC

(This is a digression, but I think it's good that objdump will now show
the correct size.)

If we remove the hack from bfd/elf.c, but do nothing to GDB, we'll
see the following regression:

FAIL: gdb.base/corefile.exp: print coremaker_ro

The reason for this is that all sections which have the BFD flag
SEC_ALLOC set, but for which SEC_HAS_CONTENTS is not set no longer
have zero size.  Some of these sections have data that can (and should)
be read from the executable.  (Sections for which SEC_HAS_CONTENTS
is set should be read from the core file; sections which do not have
this flag set need to either be read from the executable or, failing
that, from the core file using whatever BFD decides is the best value
to present to the user - it uses zeros.)

At present, due to the way that the target strata are traversed when
attempting to access memory, the non-SEC_HAS_CONTENTS sections will be
read as zeroes from the process_stratum (which in this case is the
core file stratum) without first checking the file stratum, which is
where the data might actually be found.

What we should be doing is this:

- Attempt to access core file data for SEC_HAS_CONTENTS sections.
- Attempt to access executable file data if the above fails.
- Attempt to access core file data for non SEC_HAS_CONTENTS sections, if
  both of the above fail.

This corresponds to the analysis of Daniel Jacobowitz back in 2007
when the hack was added to BFD:

    https://sourceware.org/legacy-ml/binutils/2007-08/msg00045.html

The difference, observed by Pedro in his review of my v1 patches, is
that I'm using "the section flags as proxy for the p_filesz/p_memsz
checks."

gdb/ChangeLog:

	PR corefiles/25631
	* corelow.c (core_target:xfer_partial):  Revise
	TARGET_OBJECT_MEMORY case to consider non-SEC_HAS_CONTENTS
	case after first checking the stratum beneath the core
	target.
	(has_all_memory): Return true.
	* target.c (raw_memory_xfer_partial): Revise comment
	regarding use of has_all_memory.
 2020-07-22 12:38:33 -07:00
Kevin Buettner
e56cb451c9 section_table_xfer_memory: Replace section name with callback predicate 
This patch is motivated by the need to be able to select sections
that section_table_xfer_memory_partial should consider for memory
transfers.  I'll use this facility in the next patch in this series.

section_table_xfer_memory_partial() can currently be passed a section
name which may be used to make name-based selections.  This is similar
to what I want to do, except that I want to be able to consider
section flags instead of the name.

I'm replacing the section name parameter with a predicate that,
when passed a pointer to a target_section struct, will return
true if that section should be further considered, or false which
indicates that it shouldn't.

I've converted the one existing use where a non-NULL section
name is passed to section_table_xfer_memory_partial().   Instead
of passing the section name, it now looks like this:

	  auto match_cb = [=] (const struct target_section *s)
	    {
	      return (strcmp (section_name, s->the_bfd_section->name) == 0);
	    };

	  return section_table_xfer_memory_partial (readbuf, writebuf,
						    memaddr, len, xfered_len,
						    table->sections,
						    table->sections_end,
						    match_cb);

The other callers all passed NULL; they've been simplified somewhat
in that they no longer need to pass NULL.

gdb/ChangeLog:

	* exec.h (section_table_xfer_memory): Revise declaration,
	replacing section name parameter with an optional callback
	predicate.
	* exec.c (section_table_xfer_memory): Likewise.
	* bfd-target.c, exec.c, target.c, corelow.c: Adjust all callers
	of section_table_xfer_memory.
 2020-07-22 12:36:42 -07:00
Pedro Alves
43667cc6f6 Fix latent bug in target_pass_ctrlc 
We were checking the thr->executing of an exited thread.

gdb/ChangeLog:

	PR gdb/26199
	* target.c (target_pass_ctrlc): Look at the inferior's non-exited
	threads, not all threads.
 2020-07-10 23:48:19 +01:00
Pedro Alves
a0776b131d Don't write to inferior_ptid in target.c 
gdb/ChangeLog:
2020-06-18  Pedro Alves  <palves@redhat.com>

	* target.c (generic_mourn_inferior): Use switch_to_no_thread
	instead of writing to inferior_ptid.
 2020-06-18 23:04:50 +01:00
Tom Tromey
6692031743 Change target_read_string API 
This simplifies the target_read_string API a bit.

Note that some code was using safe_strerror on the error codes
returned by target_read_string.  It seems to me that this is incorrect
(if it was ever correct, it must have been quite a long time ago).

gdb/ChangeLog
2020-06-15  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (windows_nat::handle_output_debug_string):
	Update.
	(windows_nat::handle_ms_vc_exception): Update.
	* target.h (target_read_string): Change API.
	* target.c (target_read_string): Change API.
	* solib-svr4.c (open_symbol_file_object, svr4_read_so_list):
	Update.
	* solib-frv.c (frv_current_sos): Update.
	* solib-dsbt.c (dsbt_current_sos): Update.
	* solib-darwin.c (darwin_current_sos): Update.
	* linux-thread-db.c (inferior_has_bug): Update.
	* expprint.c (print_subexp_standard): Update.
	* ada-lang.c (ada_main_name, ada_tag_name_from_tsd)
	(ada_exception_message_1): Update.
 2020-06-15 06:28:10 -06:00
Tom Tromey
670e35fad9 Rewrite target_read_string 
This rewrites target_read_string in terms of read_string.

gdb/ChangeLog
2020-06-15  Tom Tromey  <tromey@adacore.com>

	* valprint.c (read_string): Update comment.
	* target.c (MIN): Remove.
	(target_read_string): Rewrite.
 2020-06-15 06:28:09 -06:00
Pedro Alves
4111f652f9 Eliminate target_fileio_open_warn_if_slow 
This basically makes target_fileio_open_1 extern, renamed to
target_fileio_open, and eliminates the current
target_fileio_open_warn_if_slow and target_fileio_open.

A following parameter will want to change gdb_bfd_iovec_fileio_open,
the only caller of target_fileio_open_warn_if_slow, to pass down
"warn_if_slow" true/false from the caller, instead of hardcoding
"warn_if_slow" true.

gdb/ChangeLog:
2020-05-19  Pedro Alves  <palves@redhat.com>

	* gdb_bfd.c (gdb_bfd_iovec_fileio_open): Adjust.
	* target.c (target_fileio_open_1): Rename to target_fileio_open
	and make extern.  Use bool.
	(target_fileio_open, target_fileio_open_warn_if_slow): Delete.
	(target_fileio_read_alloc_1): Adjust.
	* target.h (target_fileio_open): Add 'warn_if_slow' parameter.
	(target_fileio_open_warn_if_slow): Delete declaration.
 2020-05-19 18:36:51 +01:00
Tom Tromey
3b6acaee89 Update more calls to add_prefix_cmd 
I looked at all the calls to add_prefix_cmd, and replaced them with
calls to add_basic_prefix_cmd or add_show_prefix_cmd when appropriate.
This makes gdb's command language a bit more regular.  I don't think
there's a significant downside.

Note that this patch removes a couple of tests.  The removed ones are
completely redundant.

gdb/ChangeLog
2020-05-03  Tom Tromey  <tom@tromey.com>

	* breakpoint.c (catch_command, tcatch_command): Remove.
	(_initialize_breakpoint): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	(set_breakpoint_cmd, show_breakpoint_cmd): Remove
	* utils.c (set_internal_problem_cmd, show_internal_problem_cmd):
	Remove.
	(add_internal_problem_command): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* mips-tdep.c (set_mipsfpu_command): Remove.
	(_initialize_mips_tdep): Use add_basic_prefix_cmd.
	* dwarf2/index-cache.c (set_index_cache_command): Remove.
	(_initialize_index_cache): Use add_basic_prefix_cmd.
	* memattr.c (dummy_cmd): Remove.
	(_initialize_mem): Use add_basic_prefix_cmd, add_show_prefix_cmd.
	* tui/tui-win.c (set_tui_cmd, show_tui_cmd): Remove.
	(_initialize_tui_win): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	* cli/cli-logging.c (set_logging_command): Remove.
	(_initialize_cli_logging): Use add_basic_prefix_cmd,
	add_show_prefix_cmd.
	(show_logging_command): Remove.
	* target.c (target_command): Remove.
	(add_target): Use add_basic_prefix_cmd.

gdb/testsuite/ChangeLog
2020-05-03  Tom Tromey  <tom@tromey.com>

	* gdb.base/sepdebug.exp: Remove "catch" test.
	* gdb.base/break.exp: Remove "catch" test.
	* gdb.base/default.exp: Update expected output.
 2020-05-03 11:31:20 -06:00
Tankut Baris Aktemur
a0714d305f gdb: define convenience function 'exists_non_stop_target' 
Define a predicate function that returns true if there exists an
inferior with a non-stop target.

gdb/ChangeLog:
2020-04-01  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* target.h (exists_non_stop_target): New function declaration.
	* target.c (exists_non_stop_target): New function.
 2020-04-01 21:33:05 +02:00
Simon Marchi
5ab2fbf185 gdb: bool-ify follow_fork 
Change parameters and return value of the various follow_fork
functions/methods from int to bool.

gdb/ChangeLog:

	* fbsd-nat.c (fbsd_nat_target::follow_fork): Change bool to int.
	* fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise.
	* inf-ptrace.c (inf_ptrace_target::follow_fork): Likewise.
	* inf-ptrace.h (struct inf_ptrace_target) <follow_fork>: Likewise.
	* infrun.c (follow_fork): Likewise.
	(follow_fork_inferior): Likewise.
	* linux-nat.c (linux_nat_target::follow_fork): Likewise.
	* linux-nat.h (class linux_nat_target): Likewise.
	* remote.c (class remote_target) <follow_fork>: Likewise.
	(remote_target::follow_fork): Likewise.
	* target-delegates.c: Re-generate.
	* target.c (default_follow_fork): Likewise.
	(target_follow_fork): Likewise.
	* target.h (struct target_ops) <follow_fork>: Likewise.
	(target_follow_fork): Likewise.
 2020-03-24 13:45:21 -04:00