This recent commit:
commit b1c0ab2080
Date: Wed Jul 12 21:56:50 2023 +0100
gdb: avoid double stop after failed breakpoint condition check
Addressed a problem where two MI stopped events would be reported if a
breakpoint condition failed due to a signal, this commit was a
replacement for this commit:
commit 2e411b8c68
Date: Fri Oct 14 14:53:15 2022 +0100
gdb: don't always print breakpoint location after failed condition check
which solved the two stop problem, but only for the CLI. Before both
of these commits, if a b/p condition failed due to a signal then the
user would see two stops reported, the first at the location where the
signal occurred, and the second at the location of the breakpoint.
By default GDB remains at the location where the signal occurred, so
the second reported stop can be confusing, this is the problem that
commit 2e411b8c68 tried to solve (for the CLI) and b1c0ab2080
extended also address the issue for MI too.
However, while working on another patch I realised that there was a
problem with GDB after the above commits. Neither of the above
commits considered 'set unwindonsignal on'. With this setting on,
when an inferior function call fails with a signal GDB will unwind the
stack back to the location where the inferior function call started.
In the b/p case we're looking at, the stop should be reported at the
location of the breakpoint, not at the location where the signal
occurred, and this isn't what happens.
This commit fixes this by ensuring that when unwindonsignal is 'on',
GDB reports a single stop event at the location of the breakpoint,
this fixes things for both CLI and MI.
The function call_thread_fsm::should_notify_stop is called when the
inferior function call completes and GDB is figuring out if the user
should be notified about this stop event by calling normal_stop from
fetch_inferior_event in infrun.c. If normal_stop is called, then this
notification will be for the location where the inferior call stopped,
which will be the location at which the signal occurred.
Prior to this commit, the only time that normal_stop was not called,
was if the inferior function call completed successfully, this was
controlled by ::should_notify_stop, which only turns false when the
inferior function call has completed successfully.
In this commit I have extended the logic in ::should_notify_stop. Now
there are three cases in which ::should_notify_stop will return false,
and we will not announce the first stop (by calling normal_stop).
These three reasons are:
1. If the inferior function call completes successfully, this is
unchanged behaviour,
2. If the inferior function call stopped due to a signal and 'set
unwindonsignal on' is in effect, and
3. If the inferior function call stopped due to an uncaught C++
exception, and 'set unwind-on-terminating-exception on' is in
effect.
However, if we don't call normal_stop then we need to call
async_enable_stdin in call_thread_fsm::should_stop. Prior to this
commit this was only done for the case where the inferior function
call completed successfully.
In this commit I now call ::should_notify_stop and use this to
determine if we need to call async_enable_stdin. With this done we
now call async_enable_stdin for each of the three cases listed above,
which means that GDB will exit wait_sync_command_done correctly (see
run_inferior_call in infcall.c).
With these two changes the problem is mostly resolved. However, the
solution isn't ideal, we've still lost some information.
Here is how GDB 13.1 behaves, this is before commits b1c0ab2080 and
2e411b8c68:
$ gdb -q /tmp/mi-condbreak-fail \
-ex 'set unwindonsignal on' \
-ex 'break 30 if (cond_fail())' \
-ex 'run'
Reading symbols from /tmp/mi-condbreak-fail...
Breakpoint 1 at 0x40111e: file /tmp/mi-condbreak-fail.c, line 30.
Starting program: /tmp/mi-condbreak-fail
Program received signal SIGSEGV, Segmentation fault.
0x0000000000401116 in cond_fail () at /tmp/mi-condbreak-fail.c:24
24 return *p; /* Crash here. */
Error in testing breakpoint condition:
The program being debugged was signaled while in a function called from GDB.
GDB has restored the context to what it was before the call.
To change this behavior use "set unwindonsignal off".
Evaluation of the expression containing the function
(cond_fail) will be abandoned.
Breakpoint 1, foo () at /tmp/mi-condbreak-fail.c:30
30 global_counter += 1; /* Set breakpoint here. */
(gdb)
In this state we see two stop notifications, the first is where the
signal occurred, while the second is where the breakpoint is located.
As GDB has unwound the stack (thanks to unwindonsignal) the second
stop notification reflects where the inferior is actually located.
Then after commits b1c0ab2080 and 2e411b8c68 the behaviour changed
to this:
$ gdb -q /tmp/mi-condbreak-fail \
-ex 'set unwindonsignal on' \
-ex 'break 30 if (cond_fail())' \
-ex 'run'
Reading symbols from /tmp/mi-condbreak-fail...
Breakpoint 1 at 0x40111e: file /tmp/mi-condbreak-fail.c, line 30.
Starting program: /tmp/mi-condbreak-fail
Program received signal SIGSEGV, Segmentation fault.
0x0000000000401116 in cond_fail () at /tmp/mi-condbreak-fail.c:24
24 return *p; /* Crash here. */
Error in testing condition for breakpoint 1:
The program being debugged was signaled while in a function called from GDB.
GDB has restored the context to what it was before the call.
To change this behavior use "set unwindonsignal off".
Evaluation of the expression containing the function
(cond_fail) will be abandoned.
(gdb) bt 1
#0 foo () at /tmp/mi-condbreak-fail.c:30
(More stack frames follow...)
(gdb)
This is the broken state. GDB is reports the SIGSEGV location, but
not the unwound breakpoint location. The final 'bt 1' shows that the
inferior is not located in cond_fail, which is the only location GDB
reported, so this is clearly wrong.
After implementing the fixes described above we now get this
behaviour:
$ gdb -q /tmp/mi-condbreak-fail \
-ex 'set unwindonsignal on' \
-ex 'break 30 if (cond_fail())' \
-ex 'run'
Reading symbols from /tmp/mi-condbreak-fail...
Breakpoint 1 at 0x40111e: file /tmp/mi-condbreak-fail.c, line 30.
Starting program: /tmp/mi-condbreak-fail
Error in testing breakpoint condition for breakpoint 1:
The program being debugged was signaled while in a function called from GDB.
GDB has restored the context to what it was before the call.
To change this behavior use "set unwindonsignal off".
Evaluation of the expression containing the function
(cond_fail) will be abandoned.
Breakpoint 1, foo () at /tmp/mi-condbreak-fail.c:30
30 global_counter += 1; /* Set breakpoint here. */
(gdb)
This is better. GDB now reports a single stop at the location of the
breakpoint, which is where the inferior is actually located. However,
by removing the first stop notification we have lost some potentially
useful information about which signal caused the inferior to stop.
To address this I've reworked the message that is printed to include
the signal information. GDB now reports this:
$ gdb -q /tmp/mi-condbreak-fail \
-ex 'set unwindonsignal on' \
-ex 'break 30 if (cond_fail())' \
-ex 'run'
Reading symbols from /tmp/mi-condbreak-fail...
Breakpoint 1 at 0x40111e: file /tmp/mi-condbreak-fail.c, line 30.
Starting program: /tmp/mi-condbreak-fail
Error in testing condition for breakpoint 1:
The program being debugged received signal SIGSEGV, Segmentation fault
while in a function called from GDB. GDB has restored the context
to what it was before the call. To change this behavior use
"set unwindonsignal off". Evaluation of the expression containing
the function (cond_fail) will be abandoned.
Breakpoint 1, foo () at /tmp/mi-condbreak-fail.c:30
30 global_counter += 1; /* Set breakpoint here. */
(gdb)
This is better, the user now sees a single stop notification at the
correct location, and the error message describes which signal caused
the inferior function call to stop.
However, we have lost the information about where the signal
occurred. I did consider trying to include this information in the
error message, but, in the end, I opted not too. I wasn't sure it was
worth the effort. If the user has selected to unwind on signal, then
surely this implies they maybe aren't interested in debugging failed
inferior calls, so, hopefully, just knowing the signal name will be
enough. I figure we can always add this information in later if
there's a demand for it.
While looking at a bug, I noticed what I think is an off-by-one
mistake in a call to vector::reserve. This code:
new_args.reserve (args.size ());
new_args.push_back
(value_from_pointer (lookup_pointer_type (values_type), struct_addr));
new_args.insert (new_args.end (), args.begin (), args.end ());
... reserves 'size()' entries, but then proceeds to push one extra
one.
This shouldn't have any really bad effects, as insert will grow the
vector. Still, it seems better to use the correct size if we're going
to bother calling reserve.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30780
Reviewed-by: John Baldwin <jhb@FreeBSD.org>
This commit replaces this earlier commit:
commit 2e411b8c68
Date: Fri Oct 14 14:53:15 2022 +0100
gdb: don't always print breakpoint location after failed condition check
and is a result of feedback received here[1].
The original commit addressed a problem where, if a breakpoint
condition included an inferior function call, and if the inferior
function call failed, then GDB would announce the stop twice. Here's
an example of GDB's output before the above commit that shows the
problem being addressed:
(gdb) break foo if (some_func ())
Breakpoint 1 at 0x40111e: file bpcond.c, line 11.
(gdb) r
Starting program: /tmp/bpcond
Program received signal SIGSEGV, Segmentation fault.
0x0000000000401116 in some_func () at bpcond.c:5
5 return *p;
Error in testing condition for breakpoint 1:
The program being debugged stopped while in a function called from GDB.
Evaluation of the expression containing the function
(some_func) will be abandoned.
When the function is done executing, GDB will silently stop.
Breakpoint 1, 0x0000000000401116 in some_func () at bpcond.c:5
5 return *p;
(gdb)
The original commit addressed this issue in breakpoint.c, by spotting
that the $pc had changed while evaluating the breakpoint condition,
and inferring from this that GDB must have stopped elsewhere.
However, the way in which the original commit suppressed the second
stop announcement was to set bpstat::print to true -- this tells GDB
not to print the frame during the stop announcement, and for the CLI
this is fine, however, it was pointed out that for the MI this still
isn't really enough. Below is an example from an MI session after the
above commit was applied, this shows the problem with the above
commit:
-break-insert -c "cond_fail()" foo
^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000040111e",func="foo",file="/tmp/mi-condbreak-fail.c",line="30",thread-groups=["i1"],cond="cond_fail()",times="0",original-location="foo"}
(gdb)
-exec-run
=thread-group-started,id="i1",pid="2636270"
=thread-created,id="1",group-id="i1"
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1",ranges=[{from="0x00007ffff7fd3110",to="0x00007ffff7ff2bb4"}]
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/libm.so.6",target-name="/lib64/libm.so.6",host-name="/lib64/libm.so.6",symbols-loaded="0",thread-group="i1",ranges=[{from="0x00007ffff7e59390",to="0x00007ffff7ef4f98"}]
=library-loaded,id="/lib64/libc.so.6",target-name="/lib64/libc.so.6",host-name="/lib64/libc.so.6",symbols-loaded="0",thread-group="i1",ranges=[{from="0x00007ffff7ca66b0",to="0x00007ffff7df3c5f"}]
~"\nProgram"
~" received signal SIGSEGV, Segmentation fault.\n"
~"0x0000000000401116 in cond_fail () at /tmp/mi-condbreak-fail.c:24\n"
~"24\t return *p;\t\t\t/* Crash here. */\n"
*stopped,reason="signal-received",signal-name="SIGSEGV",signal-meaning="Segmentation fault",frame={addr="0x0000000000401116",func="cond_fail",args=[],file="/tmp/mi-condbreak-fail.c",fullname="/tmp/mi-condbreak-fail.c",line="24",arch="i386:x86-64"},thread-id="1",stopped-threads="all",core="9"
&"Error in testing condition for breakpoint 1:\n"
&"The program being debugged was signaled while in a function called from GDB.\n"
&"GDB remains in the frame where the signal was received.\n"
&"To change this behavior use \"set unwindonsignal on\".\n"
&"Evaluation of the expression containing the function\n"
&"(cond_fail) will be abandoned.\n"
&"When the function is done executing, GDB will silently stop.\n"
=breakpoint-modified,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x000000000040111e",func="foo",file="/tmp/mi-condbreak-fail.c",fullname="/tmp/mi-condbreak-fail.c",line="30",thread-groups=["i1"],cond="cond_fail()",times="1",original-location="foo"}
*stopped
(gdb)
Notice that we still see two '*stopped' lines, the first includes the
full frame information, while the second has no frame information,
this is a result of bpstat::print having been set. Ideally, the
second '*stopped' line should not be present.
By setting bpstat::print I was addressing the problem too late, this
flag really only changes how interp::on_normal_stop prints the stop
event, and interp::on_normal_stop is called (indirectly) from the
normal_stop function in infrun.c. A better solution is to avoid
calling normal_stop at all for the stops which should not be reported
to the user, and this is what I do in this commit.
This commit has 3 parts:
1. In breakpoint.c, revert the above commit,
2. In fetch_inferior_event (infrun.c), capture the stop-id before
calling handle_inferior_event. If, after calling
handle_inferior_event, the stop-id has changed, then this indicates
that somewhere within handle_inferior_event, a stop was announced to
the user. If this is the case then GDB should not call normal_stop,
and we should rely on whoever announced the stop to ensure that we
are in a PROMPT_NEEDED state, which means the prompt will be
displayed once fetch_inferior_event returns. And,
3. In infcall.c, do two things:
(a) In run_inferior_call, after making the inferior call, ensure
that either async_disable_stdin or async_enable_stdin is called
to put the prompt state, and stdin handling into the correct
state based on whether the inferior call completed successfully
or not, and
(b) In call_thread_fsm::should_stop, call async_enable_stdin
rather than changing the prompt state directly. This isn't
strictly necessary, but helped me understand this code more.
This async_enable_stdin call is only reached if normal_stop is
not going to be called, and replaces the async_enable_stdin call
that exists in normal_stop. Though we could just adjust the
prompt state if felt (to me) much easier to understand when I
could see this call and the corresponding call in normal_stop.
With these changes in place now, when the inferior call (from the
breakpoint condition) fails, infcall.c leaves the prompt state as
PROMPT_NEEDED, and leaves stdin registered with the event loop.
Back in fetch_inferior_event GDB notices that the stop-id has changed
and so avoids calling normal_stop.
And on return from fetch_inferior_event GDB will display the prompt
and handle input from stdin.
As normal_stop is not called the MI problem is solved, and the test
added in the earlier mentioned commit still passes just fine, so the
CLI has not regressed.
[1] https://inbox.sourceware.org/gdb-patches/6fd4aa13-6003-2563-5841-e80d5a55d59e@palves.net/
I'd like to move some things so they become methods on struct ui. But
first, I think that struct ui and the related things are big enough to
deserve their own file, instead of being scattered through top.{c,h} and
event-top.c.
Change-Id: I15594269ace61fd76ef80a7b58f51ff3ab6979bc
Consider the following case:
(gdb) list some_func
1 int
2 some_func ()
3 {
4 int *p = 0;
5 return *p;
6 }
7
8 void
9 foo ()
10 {
(gdb) break foo if (some_func ())
Breakpoint 1 at 0x40111e: file bpcond.c, line 11.
(gdb) r
Starting program: /tmp/bpcond
Program received signal SIGSEGV, Segmentation fault.
0x0000000000401116 in some_func () at bpcond.c:5
5 return *p;
Error in testing breakpoint condition:
The program being debugged was signaled while in a function called from GDB.
GDB remains in the frame where the signal was received.
To change this behavior use "set unwindonsignal on".
Evaluation of the expression containing the function
(some_func) will be abandoned.
When the function is done executing, GDB will silently stop.
Program received signal SIGSEGV, Segmentation fault.
Breakpoint 1, 0x0000000000401116 in some_func () at bpcond.c:5
5 return *p;
(gdb)
Notice that this line:
Program received signal SIGSEGV, Segmentation fault.
Appears twice in the output. The first time is followed by the
current location. The second time is a little odd, why do we print
that?
Printing that line is controlled, in part, by a global variable,
stopped_by_random_signal. This variable is reset to zero in
handle_signal_stop, and is set if/when GDB figures out that the
inferior stopped due to some random signal.
The problem is, in our case, GDB first stops at the breakpoint for
foo, and enters handle_signal_stop and the stopped_by_random_signal
global is reset to 0.
Later within handle_signal_stop GDB calls bpstat_stop_status, it is
within this function (via bpstat_check_breakpoint_conditions) that the
breakpoint condition is checked, and, we end up calling the inferior
function (some_func in our example above).
In our case above the thread performing the inferior function call
segfaults in some_func. GDB catches the SIGSEGV and handles the stop,
this causes us to reenter handle_signal_stop. The global variable
stopped_by_random_signal is updated, this time it is set to true
because the thread stopped due to SIGSEGV. As a result of this we
print the first instance of the line (as seen above in the example).
Finally we unwind GDB's call stack, the inferior function call is
complete, and we return to the original handle_signal_stop. However,
the stopped_by_random_signal global is still carrying the value as
computed for the inferior function call's stop, which is why we now
print a second instance of the line, as seen in the example.
To prevent this, I propose adding a scoped_restore before we start an
inferior function call. This will save and restore the global
stopped_by_random_signal value.
With this done, the output from our example is now this:
(gdb) list some_func
1 int
2 some_func ()
3 {
4 int *p = 0;
5 return *p;
6 }
7
8 void
9 foo ()
10 {
(gdb) break foo if (some_func ())
Breakpoint 1 at 0x40111e: file bpcond.c, line 11.
(gdb) r
Starting program: /tmp/bpcond
Program received signal SIGSEGV, Segmentation fault.
0x0000000000401116 in some_func () at bpcond.c:5
5 return *p;
Error in testing condition for breakpoint 1:
The program being debugged stopped while in a function called from GDB.
Evaluation of the expression containing the function
(some_func) will be abandoned.
When the function is done executing, GDB will silently stop.
Breakpoint 1, 0x0000000000401116 in some_func () at bpcond.c:5
5 return *p;
(gdb)
We now only see the 'Program received signal SIGSEGV, ...' line once,
which I think makes more sense.
Finally, I'm aware that the last few lines, that report the stop as
being at 'Breakpoint 1', when this is not where the thread is actually
located anymore, is not great. I'll address that in the next commit.
This removes deprecated_lval_hack and the VALUE_LVAL macro, replacing
all uses with a call to value::lval.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
This turns the remaining value_contents functions -- value_contents,
value_contents_all, value_contents_for_printing, and
value_contents_for_printing_const -- into methods of value. It also
converts the static functions require_not_optimized_out and
require_available to be private methods.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
This is the second step of making frame_info_ptr automatic, reinflate on
demand whenever trying to obtain the wrapper frame_info pointer, either
through the get method or operator->. Make the reinflate method
private, it is used as a convenience method in those two.
Add an "is_null" method, because it is often needed to know whether the
frame_info_ptr wraps an frame_info or is empty.
Make m_ptr mutable, so that it's possible to reinflate const
frame_info_ptr objects. Whether m_ptr is nullptr or not does not change
the logical state of the object, because we re-create it on demand. I
believe this is the right use case for mutable.
Change-Id: Icb0552d0035e227f81eb3c121d8a9bb2f9d25794
Reviewed-By: Bruno Larsen <blarsen@redhat.com>
This is the first step of making frame_info_ptr automatic. Remove the
frame_info_ptr::prepare_reinflate method, move that code to the
constructor.
Change-Id: I85cdae3ab1c043c70e2702e7fb38e9a4a8a675d8
Reviewed-By: Bruno Larsen <blarsen@redhat.com>
PR record/29927 - reverse-finish requires two reverse next instructions to
reach previous source line
Currently on X86, when executing the finish command in reverse, gdb does a
single step from the first instruction in the callee to get back to the
caller. GDB stops on the last instruction in the source code line where
the call was made. When stopped at the last instruction of the source code
line, a reverse next or step command will stop at the first instruction
of the same source code line thus requiring two step/next commands to
reach the previous source code line. It should only require one step/next
command to reach the previous source code line.
By contrast, a reverse next or step command from the first line in a
function stops at the first instruction in the source code line where the
call was made.
This patch fixes the reverse finish command so it will stop at the first
instruction of the source line where the function call was made. The
behavior on X86 for the reverse-finish command now matches doing a
reverse-next from the beginning of the function.
The proceed_to_finish flag in struct thread_control_state is no longer
used. This patch removes the declaration, initialization and setting of
the flag.
This patch requires a number of regression tests to be updated. Test
gdb.mi/mi-reverse.exp no longer needs to execute two steps to get to the
previous line. The gdb output for tests gdb.reverse/until-precsave.exp
and gdb.reverse/until-reverse.exp changed slightly. The expected result in
tests gdb.reverse/amd64-failcall-reverse.exp and
gdb.reverse/singlejmp-reverse.exp are updated to the correct expected
result.
This patch adds a new test gdb.reverse/finish-reverse-next.exp to test the
reverse-finish command when returning from the entry point and from the
body of the function.
The step_until proceedure in test gdb.reverse/step-indirect-call-thunk.exp
was moved to lib/gdb.exp and renamed cmd_until.
The patch has been tested on X86 and PowerPC to verify no additional
regression failures occured.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29927
get_call_return_value can handle RETURN_VALUE_STRUCT_CONVENTION,
because the call is completely managed by gdb. However, it does not
handle variably-sized types correctly. The simplest way to fix this
is to use value_at_non_lval, which does type resolution.
The gdbarch "return_value" can't correctly handle variably-sized
types. The problem here is that the TYPE_LENGTH of such a type is 0,
until the type is resolved, which requires reading memory. However,
gdbarch_return_value only accepts a buffer as an out parameter.
Fixing this requires letting the implementation of the gdbarch method
resolve the type and return a value -- that is, both the contents and
the new type.
After an attempt at this, I realized I wouldn't be able to correctly
update all implementations (there are ~80) of this method. So,
instead, this patch adds a new method that falls back to the current
method, and it updates gdb to only call the new method. This way it's
possible to incrementally convert the architectures that I am able to
test.
With a simple test-case:
...
$ cat test.c
char *p = "a";
int main (void) {
return strlen (p);
}
$ gcc -g test.c
...
we run into this segfault:
...
$ gdb -q -batch a.out -ex start -ex "p strlen (p)"
Temporary breakpoint 1 at 0x1151: file test.c, line 4.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Temporary breakpoint 1, main () at test.c:4
4 return strlen (p);
Fatal signal: Segmentation fault
...
The strlen is an ifunc, and consequently during the call to
call_function_by_hand_dummy for "p strlen (p)" another call
to call_function_by_hand_dummy is used to resolve the ifunc.
This invalidates the get_current_frame () result in the outer call.
Fix this by using prepare_reinflate and reinflate.
Note that this series (
https://inbox.sourceware.org/gdb-patches/20221214033441.499512-1-simon.marchi@polymtl.ca/ )
should address this problem, but this patch is a simpler fix which is easy to
backport.
Tested on x86_64-linux.
Co-Authored-By: Tom de Vries <tdevries@suse.de>
PR gdb/29941
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29941
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
Currently, every internal_error call must be passed __FILE__/__LINE__
explicitly, like:
internal_error (__FILE__, __LINE__, "foo %d", var);
The need to pass in explicit __FILE__/__LINE__ is there probably
because the function predates widespread and portable variadic macros
availability. We can use variadic macros nowadays, and in fact, we
already use them in several places, including the related
gdb_assert_not_reached.
So this patch renames the internal_error function to something else,
and then reimplements internal_error as a variadic macro that expands
__FILE__/__LINE__ itself.
The result is that we now should call internal_error like so:
internal_error ("foo %d", var);
Likewise for internal_warning.
The patch adjusts all calls sites. 99% of the adjustments were done
with a perl/sed script.
The non-mechanical changes are in gdbsupport/errors.h,
gdbsupport/gdb_assert.h, and gdb/gdbarch.py.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: Ia6f372c11550ca876829e8fd85048f4502bdcf06
Add two new commands:
set debug infcall on|off
show debug infcall
These enable some new debugging related to when GDB makes inferior
function calls. I've added some basic debugging for what I think are
the major steps in the inferior function call process, but I'm sure we
might want to add more later.
This changes GDB to use frame_info_ptr instead of frame_info *
The substitution was done with multiple sequential `sed` commands:
sed 's/^struct frame_info;/class frame_info_ptr;/'
sed 's/struct frame_info \*/frame_info_ptr /g' - which left some
issues in a few files, that were manually fixed.
sed 's/\<frame_info \*/frame_info_ptr /g'
sed 's/frame_info_ptr $/frame_info_ptr/g' - used to remove whitespace
problems.
The changed files were then manually checked and some 'sed' changes
undone, some constructors and some gets were added, according to what
made sense, and what Tromey originally did
Co-Authored-By: Bruno Larsen <blarsen@redhat.com>
Approved-by: Tom Tomey <tom@tromey.com>
Currently, the test-case contained in this patch fails:
...
(gdb) p (int) foo ()^M
Invalid cast.^M
(gdb) FAIL: gdb.dwarf2/dw2-unspecified-type.exp: p (int) foo ()
...
because DW_TAG_unspecified_type is translated as void.
There's some code in read_unspecified_type that marks the type as stub, but
that's only active for ada:
...
if (cu->lang () == language_ada)
type->set_is_stub (true);
...
Fix this by:
- marking the type as a stub for all languages, and
- handling the stub return type case in call_function_by_hand_dummy.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29558
This patch removes ui_register_input_event_handler and
ui_unregister_input_event_handler, replacing them with methods on
'ui'. It also changes gdb to use these methods everywhere, rather
than sometimes reaching in to the ui to manage the file descriptor
directly.
In passing I noticed that there are three local variables in
run_inferior_call that are used to save, and then restore some state,
I think these could all be replaced with a RAII style scoped_restore
instead.
Of the three locals that I've changed, the only one that I believe is
now restored in a different location is ui::async, before this commit
the async field was restored after a call to either delete_file_handle
or ui_register_input_event_handler, and after this commit, the field
is restored before these calls. However, I don't believe that either
of these functions depend on the value of the async field, so I
believe the commit is fine.
Tested on x86-64/Linux passes with no regressions.
Now that filtered and unfiltered output can be treated identically, we
can unify the printf family of functions. This is done under the name
"gdb_printf". Most of this patch was written by script.
It is possible for a compiler to optimize a function in a such ways that
the function does not follow the calling convention of the target. In
such situation, the compiler can use the DW_AT_calling_convention
attribute with the value DW_CC_nocall to tell the debugger that it is
unsafe to call the function. The DWARF5 standard states, in 3.3.1.1:
> If the value of the calling convention attribute is the constant
> DW_CC_nocall, the subroutine does not obey standard calling
> conventions, and it may not be safe for the debugger to call this
> subroutine.
Non standard calling convention can affect GDB's assumptions in multiple
ways, including how arguments are passed to the function, how values are
returned, and so on. For this reason, it is unsafe for GDB to try to do
the following operations on a function with marked with DW_CC_nocall:
- call / print an expression requiring the function to be evaluated,
- inspect the value a function returns using the 'finish' command,
- force the value returned by a function using the 'return' command.
This patch ensures that if a command which relies on GDB's knowledge of
the target's calling convention is used on a function marked nocall, GDB
prints an appropriate message to the user and does not proceed with the
operation which is unreliable.
Note that it is still possible for someone to use a vendor specific
value for the DW_AT_calling_convention attribute for example to indicate
the use of an alternative calling convention. This commit does not
prevent this, and target dependent code can be adjusted if one wanted to
support multiple calling conventions.
Tested on x86_64-Linux, with no regression observed.
Change-Id: I72970dae68234cb83edbc0cf71aa3d6002a4a540
While working on function calls, I realized that the thread_fsm member
of struct thread_info is a raw pointer to a resource it owns. This
commit changes the type of the thread_fsm member to a std::unique_ptr in
order to signify this ownership relationship and slightly ease resource
management (no need to manually call delete).
To ensure consistent use, the field is made a private member
(m_thread_fsm). The setter method (set_thread_fsm) can then check
that it is incorrect to associate a FSM to a thread_info object if
another one is already in place. This is ensured by an assertion.
The function run_inferior_call takes an argument as a pointer to a
call_thread_fsm and installs it in it in a thread_info instance. Also
change this function's signature to accept a unique_ptr in order to
signify that the ownership of the call_thread_fsm is transferred during
the call.
No user visible change expected after this commit.
Tested on x86_64-linux with no regression observed.
Change-Id: Ia1224f72a4afa247801ce6650ce82f90224a9ae8
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
The bug fixed by this [1] patch was caused by an out-of-bounds access to
a value's content. The code gets the value's content (just a pointer)
and then indexes it with a non-sensical index.
This made me think of changing functions that return value contents to
return array_views instead of a plain pointer. This has the advantage
that when GDB is built with _GLIBCXX_DEBUG, accesses to the array_view
are checked, making bugs more apparent / easier to find.
This patch changes the return types of these functions, and updates
callers to call .data() on the result, meaning it's not changing
anything in practice. Additional work will be needed (which can be done
little by little) to make callers propagate the use of array_view and
reap the benefits.
[1] https://sourceware.org/pipermail/gdb-patches/2021-September/182306.html
Change-Id: I5151f888f169e1c36abe2cbc57620110673816f3
In this commit:
commit 7022349d5c
Date: Mon Sep 4 20:21:13 2017 +0100
Stop assuming no-debug-info functions return int
A new if case was added to call_function_by_hand_dummy to decide if a
function should be considered prototyped or not. Previously the code
was structured like this:
if (COND_1)
ACTION_1
else if (COND_2)
ACTION_2
else
ACTION_3
With the new block the code now looks like this:
if (COND_1)
ACTION_1
if (NEW_COND)
NEW_ACTION
else if (COND_2)
ACTION_2
else
ACTION_3
Notice the new block was added as and 'if' not 'else if'. I'm running
into a case where GDB executes ACTION_1 and then ACTION_2. Prior to
the above commit GDB would only have executed ACTION_1.
The actions in the code in question are trying to figure out if a
function should be considered prototyped or not. When a function is
not prototyped some arguments will be coerced, e.g. floats to doubles.
The COND_1 / ACTION_1 are a very broad, any member function should be
considered prototyped, however, after the above patch GDB is now
executing the later ACTION_2 which checks to see if the function's
type has the 'prototyped' flag set - this is not the case for the
member functions I'm testing, and so GDB treats the function as
unprototyped and casts the float argument to a double.
I believe that adding the new check as 'if' rather than 'else if' was
a mistake, and so in this commit I add in the missing 'else'.
gdb/ChangeLog:
* infcall.c (call_function_by_hand_dummy): Add missing 'else' when
setting prototyped flag.
gdb/testsuite/ChangeLog:
* gdb.cp/method-call-in-c.cc (struct foo_type): Add static member
function static_method.
(global_var): New global.
(main): Use new static_method to ensure it is compiled in.
* gdb.cp/method-call-in-c.exp: Test calls to static member
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
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.
Remove the `TYPE_FIELD_TYPE` macro, changing all the call sites to use
`type::field` and `field::type` directly.
gdb/ChangeLog:
* gdbtypes.h (TYPE_FIELD_TYPE): Remove. Change all call sites
to use type::field and field::type instead.
Change-Id: Ifda6226a25c811cfd334a756a9fbc5c0afdddff3
Remove `TYPE_NFIELDS`, changing all the call sites to use
`type::num_fields` directly. This is quite a big diff, but this was
mostly done using sed and coccinelle. A few call sites were done by
hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_NFIELDS): Remove. Change all cal sites to use
type::num_fields instead.
Change-Id: Ib73be4c36f9e770e0f729bac3b5257d7cb2f9591
Remove `TYPE_NAME`, changing all the call sites to use `type::name`
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_NAME): Remove. Change all cal sites to use
type::name instead.
Remove TYPE_CODE, changing all the call sites to use type::code
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_CODE): Remove. Change all call sites to use
type::code instead.
This commit adds multi-target support to GDB. What this means is that
with this commit, GDB can now be connected to different targets at the
same time. E.g., you can debug a live native process and a core dump
at the same time, connect to multiple gdbservers, etc.
Actually, the word "target" is overloaded in gdb. We already have a
target stack, with pushes several target_ops instances on top of one
another. We also have "info target" already, which means something
completely different to what this patch does.
So from here on, I'll be using the "target connections" term, to mean
an open process_stratum target, pushed on a target stack. This patch
makes gdb have multiple target stacks, and multiple process_stratum
targets open simultaneously. The user-visible changes / commands will
also use this terminology, but of course it's all open to debate.
User-interface-wise, not that much changes. The main difference is
that each inferior may have its own target connection.
A target connection (e.g., a target extended-remote connection) may
support debugging multiple processes, just as before.
Say you're debugging against gdbserver in extended-remote mode, and
you do "add-inferior" to prepare to spawn a new process, like:
(gdb) target extended-remote :9999
...
(gdb) start
...
(gdb) add-inferior
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) file a.out
...
(gdb) start
...
At this point, you have two inferiors connected to the same gdbserver.
With this commit, GDB will maintain a target stack per inferior,
instead of a global target stack.
To preserve the behavior above, by default, "add-inferior" makes the
new inferior inherit a copy of the target stack of the current
inferior. Same across a fork - the child inherits a copy of the
target stack of the parent. While the target stacks are copied, the
targets themselves are not. Instead, target_ops is made a
refcounted_object, which means that target_ops instances are
refcounted, which each inferior counting for a reference.
What if you want to create an inferior and connect it to some _other_
target? For that, this commit introduces a new "add-inferior
-no-connection" option that makes the new inferior not share the
current inferior's target. So you could do:
(gdb) target extended-remote :9999
Remote debugging using :9999
...
(gdb) add-inferior -no-connection
[New inferior 2]
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 <null>
(gdb) tar extended-remote :10000
Remote debugging using :10000
...
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 process 18450 target:/home/pedro/tmp/main
(gdb)
A following patch will extended "info inferiors" to include a column
indicating which connection an inferior is bound to, along with a
couple other UI tweaks.
Other than that, debugging is the same as before. Users interact with
inferiors and threads as before. The only difference is that
inferiors may be bound to processes running in different machines.
That's pretty much all there is to it in terms of noticeable UI
changes.
On to implementation.
Since we can be connected to different systems at the same time, a
ptid_t is no longer a unique identifier. Instead a thread can be
identified by a pair of ptid_t and 'process_stratum_target *', the
later being the instance of the process_stratum target that owns the
process/thread. Note that process_stratum_target inherits from
target_ops, and all process_stratum targets inherit from
process_stratum_target. In earlier patches, many places in gdb were
converted to refer to threads by thread_info pointer instead of
ptid_t, but there are still places in gdb where we start with a
pid/tid and need to find the corresponding inferior or thread_info
objects. So you'll see in the patch many places adding a
process_stratum_target parameter to functions that used to take only a
ptid_t.
Since each inferior has its own target stack now, we can always find
the process_stratum target for an inferior. That is done via a
inf->process_target() convenience method.
Since each inferior has its own target stack, we need to handle the
"beneath" calls when servicing target calls. The solution I settled
with is just to make sure to switch the current inferior to the
inferior you want before making a target call. Not relying on global
context is just not feasible in current GDB. Fortunately, there
aren't that many places that need to do that, because generally most
code that calls target methods already has the current context
pointing to the right inferior/thread. Note, to emphasize -- there's
no method to "switch to this target stack". Instead, you switch the
current inferior, and that implicitly switches the target stack.
In some spots, we need to iterate over all inferiors so that we reach
all target stacks.
Native targets are still singletons. There's always only a single
instance of such targets.
Remote targets however, we'll have one instance per remote connection.
The exec target is still a singleton. There's only one instance. I
did not see the point of instanciating more than one exec_target
object.
After vfork, we need to make sure to push the exec target on the new
inferior. See exec_on_vfork.
For type safety, functions that need a {target, ptid} pair to identify
a thread, take a process_stratum_target pointer for target parameter
instead of target_ops *. Some shared code in gdb/nat/ also need to
gain a target pointer parameter. This poses an issue, since gdbserver
doesn't have process_stratum_target, only target_ops. To fix this,
this commit renames gdbserver's target_ops to process_stratum_target.
I think this makes sense. There's no concept of target stack in
gdbserver, and gdbserver's target_ops really implements a
process_stratum-like target.
The thread and inferior iterator functions also gain
process_stratum_target parameters. These are used to be able to
iterate over threads and inferiors of a given target. Following usual
conventions, if the target pointer is null, then we iterate over
threads and inferiors of all targets.
I tried converting "add-inferior" to the gdb::option framework, as a
preparatory patch, but that stumbled on the fact that gdb::option does
not support file options yet, for "add-inferior -exec". I have a WIP
patchset that adds that, but it's not a trivial patch, mainly due to
need to integrate readline's filename completion, so I deferred that
to some other time.
In infrun.c/infcmd.c, the main change is that we need to poll events
out of all targets. See do_target_wait. Right after collecting an
event, we switch the current inferior to an inferior bound to the
target that reported the event, so that target methods can be used
while handling the event. This makes most of the code transparent to
multi-targets. See fetch_inferior_event.
infrun.c:stop_all_threads is interesting -- in this function we need
to stop all threads of all targets. What the function does is send an
asynchronous stop request to all threads, and then synchronously waits
for events, with target_wait, rinse repeat, until all it finds are
stopped threads. Now that we have multiple targets, it's not
efficient to synchronously block in target_wait waiting for events out
of one target. Instead, we implement a mini event loop, with
interruptible_select, select'ing on one file descriptor per target.
For this to work, we need to be able to ask the target for a waitable
file descriptor. Such file descriptors already exist, they are the
descriptors registered in the main event loop with add_file_handler,
inside the target_async implementations. This commit adds a new
target_async_wait_fd target method that just returns the file
descriptor in question. See wait_one / stop_all_threads in infrun.c.
The 'threads_executing' global is made a per-target variable. Since
it is only relevant to process_stratum_target targets, this is where
it is put, instead of in target_ops.
You'll notice that remote.c includes some FIXME notes. These refer to
the fact that the global arrays that hold data for the remote packets
supported are still globals. For example, if we connect to two
different servers/stubs, then each might support different remote
protocol features. They might even be different architectures, like
e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a
host/controller scenario as a single program. That isn't going to
work correctly today, because of said globals. I'm leaving fixing
that for another pass, since it does not appear to be trivial, and I'd
rather land the base work first. It's already useful to be able to
debug multiple instances of the same server (e.g., a distributed
cluster, where you have full control over the servers installed), so I
think as is it's already reasonable incremental progress.
Current limitations:
- You can only resume more that one target at the same time if all
targets support asynchronous debugging, and support non-stop mode.
It should be possible to support mixed all-stop + non-stop
backends, but that is left for another time. This means that
currently in order to do multi-target with gdbserver you need to
issue "maint set target-non-stop on". I would like to make that
mode be the default, but we're not there yet. Note that I'm
talking about how the target backend works, only. User-visible
all-stop mode works just fine.
- As explained above, connecting to different remote servers at the
same time is likely to produce bad results if they don't support the
exact set of RSP features.
FreeBSD updates courtesy of John Baldwin.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
John Baldwin <jhb@FreeBSD.org>
* aarch64-linux-nat.c
(aarch64_linux_nat_target::thread_architecture): Adjust.
* ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call.
(task_command_1): Likewise.
* aix-thread.c (sync_threadlists, aix_thread_target::resume)
(aix_thread_target::wait, aix_thread_target::fetch_registers)
(aix_thread_target::store_registers)
(aix_thread_target::thread_alive): Adjust.
* amd64-fbsd-tdep.c: Include "inferior.h".
(amd64fbsd_get_thread_local_address): Pass down target.
* amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle
thread's gdbarch instead of target_gdbarch.
* break-catch-sig.c (signal_catchpoint_print_it): Adjust call to
get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Likewise.
* breakpoint.c (breakpoints_should_be_inserted_now): Consider all
inferiors.
(update_inserted_breakpoint_locations): Skip if inferiors with no
execution.
(update_global_location_list): When handling moribund locations,
find representative inferior for location's pspace, and use thread
count of its process_stratum target.
* bsd-kvm.c (bsd_kvm_target_open): Pass target down.
* bsd-uthread.c (bsd_uthread_target::wait): Use
as_process_stratum_target and adjust thread_change_ptid and
add_thread calls.
(bsd_uthread_target::update_thread_list): Use
as_process_stratum_target and adjust find_thread_ptid,
thread_change_ptid and add_thread calls.
* btrace.c (maint_btrace_packet_history_cmd): Adjust
find_thread_ptid call.
* corelow.c (add_to_thread_list): Adjust add_thread call.
(core_target_open): Adjust add_thread_silent and thread_count
calls.
(core_target::pid_to_str): Adjust find_inferior_ptid call.
* ctf.c (ctf_target_open): Adjust add_thread_silent call.
* event-top.c (async_disconnect): Pop targets from all inferiors.
* exec.c (add_target_sections): Push exec target on all inferiors
sharing the program space.
(remove_target_sections): Remove the exec target from all
inferiors sharing the program space.
(exec_on_vfork): New.
* exec.h (exec_on_vfork): Declare.
* fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter.
Pass it down.
(fbsd_nat_target::update_thread_list): Adjust.
(fbsd_nat_target::resume): Adjust.
(fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it
down.
(fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust.
* fbsd-tdep.c (fbsd_corefile_thread): Adjust
get_thread_arch_regcache call.
* fork-child.c (gdb_startup_inferior): Pass target down to
startup_inferior and set_executing.
* gdbthread.h (struct process_stratum_target): Forward declare.
(add_thread, add_thread_silent, add_thread_with_info)
(in_thread_list): Add process_stratum_target parameter.
(find_thread_ptid(inferior*, ptid_t)): New overload.
(find_thread_ptid, thread_change_ptid): Add process_stratum_target
parameter.
(all_threads()): Delete overload.
(all_threads, all_non_exited_threads): Add process_stratum_target
parameter.
(all_threads_safe): Use brace initialization.
(thread_count): Add process_stratum_target parameter.
(set_resumed, set_running, set_stop_requested, set_executing)
(threads_are_executing, finish_thread_state): Add
process_stratum_target parameter.
(switch_to_thread): Use is_current_thread.
* i386-fbsd-tdep.c: Include "inferior.h".
(i386fbsd_get_thread_local_address): Pass down target.
* i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust.
* inf-child.c (inf_child_target::maybe_unpush_target): Remove
have_inferiors check.
* inf-ptrace.c (inf_ptrace_target::create_inferior)
(inf_ptrace_target::attach): Adjust.
* infcall.c (run_inferior_call): Adjust.
* infcmd.c (run_command_1): Pass target to
scoped_finish_thread_state.
(proceed_thread_callback): Skip inferiors with no execution.
(continue_command): Rename 'all_threads' local to avoid hiding
'all_threads' function. Adjust get_last_target_status call.
(prepare_one_step): Adjust set_running call.
(signal_command): Use user_visible_resume_target. Compare thread
pointers instead of inferior_ptid.
(info_program_command): Adjust to pass down target.
(attach_command): Mark target's 'thread_executing' flag.
(stop_current_target_threads_ns): New, factored out from ...
(interrupt_target_1): ... this. Switch inferior before making
target calls.
* inferior-iter.h
(struct all_inferiors_iterator, struct all_inferiors_range)
(struct all_inferiors_safe_range)
(struct all_non_exited_inferiors_range): Filter on
process_stratum_target too. Remove explicit.
* inferior.c (inferior::inferior): Push dummy target on target
stack.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors):
Add process_stratum_target parameter, and pass it down.
(have_live_inferiors): Adjust.
(switch_to_inferior_and_push_target): New.
(add_inferior_command, clone_inferior_command): Handle
"-no-connection" parameter. Use
switch_to_inferior_and_push_target.
(_initialize_inferior): Mention "-no-connection" option in
the help of "add-inferior" and "clone-inferior" commands.
* inferior.h: Include "process-stratum-target.h".
(interrupt_target_1): Use bool.
(struct inferior) <push_target, unpush_target, target_is_pushed,
find_target_beneath, top_target, process_target, target_at,
m_stack>: New.
(discard_all_inferiors): Delete.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors)
(all_inferiors, all_non_exited_inferiors): Add
process_stratum_target parameter.
* infrun.c: Include "gdb_select.h" and <unordered_map>.
(target_last_proc_target): New global.
(follow_fork_inferior): Push target on new inferior. Pass target
to add_thread_silent. Call exec_on_vfork. Handle target's
reference count.
(follow_fork): Adjust get_last_target_status call. Also consider
target.
(follow_exec): Push target on new inferior.
(struct execution_control_state) <target>: New field.
(user_visible_resume_target): New.
(do_target_resume): Call target_async.
(resume_1): Set target's threads_executing flag. Consider resume
target.
(commit_resume_all_targets): New.
(proceed): Also consider resume target. Skip threads of inferiors
with no execution. Commit resumtion in all targets.
(start_remote): Pass current inferior to wait_for_inferior.
(infrun_thread_stop_requested): Consider target as well. Pass
thread_info pointer to clear_inline_frame_state instead of ptid.
(infrun_thread_thread_exit): Consider target as well.
(random_pending_event_thread): New inferior parameter. Use it.
(do_target_wait): Rename to ...
(do_target_wait_1): ... this. Add inferior parameter, and pass it
down.
(threads_are_resumed_pending_p, do_target_wait): New.
(prepare_for_detach): Adjust calls.
(wait_for_inferior): New inferior parameter. Handle it. Use
do_target_wait_1 instead of do_target_wait.
(fetch_inferior_event): Adjust. Switch to representative
inferior. Pass target down.
(set_last_target_status): Add process_stratum_target parameter.
Save target in global.
(get_last_target_status): Add process_stratum_target parameter and
handle it.
(nullify_last_target_wait_ptid): Clear 'target_last_proc_target'.
(context_switch): Check inferior_ptid == null_ptid before calling
inferior_thread().
(get_inferior_stop_soon): Pass down target.
(wait_one): Rename to ...
(poll_one_curr_target): ... this.
(struct wait_one_event): New.
(wait_one): New.
(stop_all_threads): Adjust.
(handle_no_resumed, handle_inferior_event): Adjust to consider the
event's target.
(switch_back_to_stepped_thread): Also consider target.
(print_stop_event): Update.
(normal_stop): Update. Also consider the resume target.
* infrun.h (wait_for_inferior): Remove declaration.
(user_visible_resume_target): New declaration.
(get_last_target_status, set_last_target_status): New
process_stratum_target parameter.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter, and use it.
(clear_inline_frame_state (thread_info*)): New.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter.
(clear_inline_frame_state (thread_info*)): Declare.
* linux-fork.c (delete_checkpoint_command): Pass target down to
find_thread_ptid.
(checkpoint_command): Adjust.
* linux-nat.c (linux_nat_target::follow_fork): Switch to thread
instead of just tweaking inferior_ptid.
(linux_nat_switch_fork): Pass target down to thread_change_ptid.
(exit_lwp): Pass target down to find_thread_ptid.
(attach_proc_task_lwp_callback): Pass target down to
add_thread/set_running/set_executing.
(linux_nat_target::attach): Pass target down to
thread_change_ptid.
(get_detach_signal): Pass target down to find_thread_ptid.
Consider last target status's target.
(linux_resume_one_lwp_throw, resume_lwp)
(linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp)
(stop_wait_callback, save_stop_reason, linux_nat_filter_event)
(linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down.
(linux_nat_target::async_wait_fd): New.
(linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass
target down.
* linux-nat.h (linux_nat_target::async_wait_fd): Declare.
* linux-tdep.c (get_thread_arch_regcache): Pass target down.
* linux-thread-db.c (struct thread_db_info::process_target): New
field.
(add_thread_db_info): Save target.
(get_thread_db_info): New process_stratum_target parameter. Also
match target.
(delete_thread_db_info): New process_stratum_target parameter.
Also match target.
(thread_from_lwp): Adjust to pass down target.
(thread_db_notice_clone): Pass down target.
(check_thread_db_callback): Pass down target.
(try_thread_db_load_1): Always push the thread_db target.
(try_thread_db_load, record_thread): Pass target down.
(thread_db_target::detach): Pass target down. Always unpush the
thread_db target.
(thread_db_target::wait, thread_db_target::mourn_inferior): Pass
target down. Always unpush the thread_db target.
(find_new_threads_callback, thread_db_find_new_threads_2)
(thread_db_target::update_thread_list): Pass target down.
(thread_db_target::pid_to_str): Pass current inferior down.
(thread_db_target::get_thread_local_address): Pass target down.
(thread_db_target::resume, maintenance_check_libthread_db): Pass
target down.
* nto-procfs.c (nto_procfs_target::update_thread_list): Adjust.
* procfs.c (procfs_target::procfs_init_inferior): Declare.
(proc_set_current_signal, do_attach, procfs_target::wait): Adjust.
(procfs_init_inferior): Rename to ...
(procfs_target::procfs_init_inferior): ... this and adjust.
(procfs_target::create_inferior, procfs_notice_thread)
(procfs_do_thread_registers): Adjust.
* ppc-fbsd-tdep.c: Include "inferior.h".
(ppcfbsd_get_thread_local_address): Pass down target.
* proc-service.c (ps_xfer_memory): Switch current inferior and
program space as well.
(get_ps_regcache): Pass target down.
* process-stratum-target.c
(process_stratum_target::thread_address_space)
(process_stratum_target::thread_architecture): Pass target down.
* process-stratum-target.h
(process_stratum_target::threads_executing): New field.
(as_process_stratum_target): New.
* ravenscar-thread.c
(ravenscar_thread_target::update_inferior_ptid): Pass target down.
(ravenscar_thread_target::wait, ravenscar_add_thread): Pass target
down.
* record-btrace.c (record_btrace_target::info_record): Adjust.
(record_btrace_target::record_method)
(record_btrace_target::record_is_replaying)
(record_btrace_target::fetch_registers)
(get_thread_current_frame_id, record_btrace_target::resume)
(record_btrace_target::wait, record_btrace_target::stop): Pass
target down.
* record-full.c (record_full_wait_1): Switch to event thread.
Pass target down.
* regcache.c (regcache::regcache)
(get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add
process_stratum_target parameter and handle it.
(current_thread_target): New global.
(get_thread_regcache): Add process_stratum_target parameter and
handle it. Switch inferior before calling target method.
(get_thread_regcache): Pass target down.
(get_thread_regcache_for_ptid): Pass target down.
(registers_changed_ptid): Add process_stratum_target parameter and
handle it.
(registers_changed_thread, registers_changed): Pass target down.
(test_get_thread_arch_aspace_regcache): New.
(current_regcache_test): Define a couple local test_target_ops
instances and use them for testing.
(readwrite_regcache): Pass process_stratum_target parameter.
(cooked_read_test, cooked_write_test): Pass mock_target down.
* regcache.h (get_thread_regcache, get_thread_arch_regcache)
(get_thread_arch_aspace_regcache): Add process_stratum_target
parameter.
(regcache::target): New method.
(regcache::regcache, regcache::get_thread_arch_aspace_regcache)
(regcache::registers_changed_ptid): Add process_stratum_target
parameter.
(regcache::m_target): New field.
(registers_changed_ptid): Add process_stratum_target parameter.
* remote.c (remote_state::supports_vCont_probed): New field.
(remote_target::async_wait_fd): New method.
(remote_unpush_and_throw): Add remote_target parameter.
(get_current_remote_target): Adjust.
(remote_target::remote_add_inferior): Push target.
(remote_target::remote_add_thread)
(remote_target::remote_notice_new_inferior)
(get_remote_thread_info): Pass target down.
(remote_target::update_thread_list): Skip threads of inferiors
bound to other targets. (remote_target::close): Don't discard
inferiors. (remote_target::add_current_inferior_and_thread)
(remote_target::process_initial_stop_replies)
(remote_target::start_remote)
(remote_target::remote_serial_quit_handler): Pass down target.
(remote_target::remote_unpush_target): New remote_target
parameter. Unpush the target from all inferiors.
(remote_target::remote_unpush_and_throw): New remote_target
parameter. Pass it down.
(remote_target::open_1): Check whether the current inferior has
execution instead of checking whether any inferior is live. Pass
target down.
(remote_target::remote_detach_1): Pass down target. Use
remote_unpush_target.
(extended_remote_target::attach): Pass down target.
(remote_target::remote_vcont_probe): Set supports_vCont_probed.
(remote_target::append_resumption): Pass down target.
(remote_target::append_pending_thread_resumptions)
(remote_target::remote_resume_with_hc, remote_target::resume)
(remote_target::commit_resume): Pass down target.
(remote_target::remote_stop_ns): Check supports_vCont_probed.
(remote_target::interrupt_query)
(remote_target::remove_new_fork_children)
(remote_target::check_pending_events_prevent_wildcard_vcont)
(remote_target::remote_parse_stop_reply)
(remote_target::process_stop_reply): Pass down target.
(first_remote_resumed_thread): New remote_target parameter. Pass
it down.
(remote_target::wait_as): Pass down target.
(unpush_and_perror): New remote_target parameter. Pass it down.
(remote_target::readchar, remote_target::remote_serial_write)
(remote_target::getpkt_or_notif_sane_1)
(remote_target::kill_new_fork_children, remote_target::kill): Pass
down target.
(remote_target::mourn_inferior): Pass down target. Use
remote_unpush_target.
(remote_target::core_of_thread)
(remote_target::remote_btrace_maybe_reopen): Pass down target.
(remote_target::pid_to_exec_file)
(remote_target::thread_handle_to_thread_info): Pass down target.
(remote_target::async_wait_fd): New.
* riscv-fbsd-tdep.c: Include "inferior.h".
(riscv_fbsd_get_thread_local_address): Pass down target.
* sol2-tdep.c (sol2_core_pid_to_str): Pass down target.
* sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs)
(ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback):
Adjust.
* solib-spu.c (spu_skip_standalone_loader): Pass down target.
* solib-svr4.c (enable_break): Pass down target.
* spu-multiarch.c (parse_spufs_run): Pass down target.
* spu-tdep.c (spu2ppu_sniffer): Pass down target.
* target-delegates.c: Regenerate.
* target.c (g_target_stack): Delete.
(current_top_target): Return the current inferior's top target.
(target_has_execution_1): Refer to the passed-in inferior's top
target.
(target_supports_terminal_ours): Check whether the initial
inferior was already created.
(decref_target): New.
(target_stack::push): Incref/decref the target.
(push_target, push_target, unpush_target): Adjust.
(target_stack::unpush): Defref target.
(target_is_pushed): Return bool. Adjust to refer to the current
inferior's target stack.
(dispose_inferior): Delete, and inline parts ...
(target_preopen): ... here. Only dispose of the current inferior.
(target_detach): Hold strong target reference while detaching.
Pass target down.
(target_thread_name): Add assertion.
(target_resume): Pass down target.
(target_ops::beneath, find_target_at): Adjust to refer to the
current inferior's target stack.
(get_dummy_target): New.
(target_pass_ctrlc): Pass the Ctrl-C to the first inferior that
has a thread running.
(initialize_targets): Rename to ...
(_initialize_target): ... this.
* target.h: Include "gdbsupport/refcounted-object.h".
(struct target_ops): Inherit refcounted_object.
(target_ops::shortname, target_ops::longname): Make const.
(target_ops::async_wait_fd): New method.
(decref_target): Declare.
(struct target_ops_ref_policy): New.
(target_ops_ref): New typedef.
(get_dummy_target): Declare function.
(target_is_pushed): Return bool.
* thread-iter.c (all_matching_threads_iterator::m_inf_matches)
(all_matching_threads_iterator::all_matching_threads_iterator):
Handle filter target.
* thread-iter.h (struct all_matching_threads_iterator, struct
all_matching_threads_range, class all_non_exited_threads_range):
Filter by target too. Remove explicit.
* thread.c (threads_executing): Delete.
(inferior_thread): Pass down current inferior.
(clear_thread_inferior_resources): Pass down thread pointer
instead of ptid_t.
(add_thread_silent, add_thread_with_info, add_thread): Add
process_stratum_target parameter. Use it for thread and inferior
searches.
(is_current_thread): New.
(thread_info::deletable): Use it.
(find_thread_ptid, thread_count, in_thread_list)
(thread_change_ptid, set_resumed, set_running): New
process_stratum_target parameter. Pass it down.
(set_executing): New process_stratum_target parameter. Pass it
down. Adjust reference to 'threads_executing'.
(threads_are_executing): New process_stratum_target parameter.
Adjust reference to 'threads_executing'.
(set_stop_requested, finish_thread_state): New
process_stratum_target parameter. Pass it down.
(switch_to_thread): Also match inferior.
(switch_to_thread): New process_stratum_target parameter. Pass it
down.
(update_threads_executing): Reimplement.
* top.c (quit_force): Pop targets from all inferior.
(gdb_init): Don't call initialize_targets.
* windows-nat.c (windows_nat_target) <get_windows_debug_event>:
Declare.
(windows_add_thread, windows_delete_thread): Adjust.
(get_windows_debug_event): Rename to ...
(windows_nat_target::get_windows_debug_event): ... this. Adjust.
* tracefile-tfile.c (tfile_target_open): Pass down target.
* gdbsupport/common-gdbthread.h (struct process_stratum_target):
Forward declare.
(switch_to_thread): Add process_stratum_target parameter.
* mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target
parameter. Use it.
(mi_on_resume): Pass target down.
* nat/fork-inferior.c (startup_inferior): Add
process_stratum_target parameter. Pass it down.
* nat/fork-inferior.h (startup_inferior): Add
process_stratum_target parameter.
* python/py-threadevent.c (py_get_event_thread): Pass target down.
gdb/gdbserver/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* fork-child.c (post_fork_inferior): Pass target down to
startup_inferior.
* inferiors.c (switch_to_thread): Add process_stratum_target
parameter.
* lynx-low.c (lynx_target_ops): Now a process_stratum_target.
* nto-low.c (nto_target_ops): Now a process_stratum_target.
* linux-low.c (linux_target_ops): Now a process_stratum_target.
* remote-utils.c (prepare_resume_reply): Pass the target to
switch_to_thread.
* target.c (the_target): Now a process_stratum_target.
(done_accessing_memory): Pass the target to switch_to_thread.
(set_target_ops): Ajust to use process_stratum_target.
* target.h (struct target_ops): Rename to ...
(struct process_stratum_target): ... this.
(the_target, set_target_ops): Adjust.
(prepare_to_access_memory): Adjust comment.
* win32-low.c (child_xfer_memory): Adjust to use
process_stratum_target.
(win32_target_ops): Now a process_stratum_target.
Andrew Burgess