Many (all?) of the expression parsers implement yyerror to handle
parser errors, and all of these functions are basically identical.
This commit adds a new parser_state::parse_error() function, which
implements the common error handling code, this function can then be
called from all the different yyerror functions.
The benefit of this is that (in a future commit) I can improve the
error output, and all the expression parsers will benefit.
This commit is pure refactoring though, and so, there should be no
user visible changes after this commit.
Approved-By: John Baldwin <jhb@FreeBSD.org>
While working on a later commit in this series I realised that the
error() function doesn't support output styling. Due to the way that
output from error() calls is passed around within the exception
object and often combined with other output, it's not immediately
obvious to me if we should be trying to support styling in this
context or not.
On inspection, I found one place in GDB where we apparently try to
apply styling within the error() output (in procfs.c). I suspect this
error() call might not be tested.
Rather than try to implement styling in the error() output, right now
I'm proposing to just remove the attempt to style error() output.
This doesn't mean that someone shouldn't add error() styling in the
future, but right now, I'm not planning to do that, I just wanted to
fix this in passing.
Approved-By: John Baldwin <jhb@FreeBSD.org>
Currently GDB when executing in reverse over multiple statements in a single
line of source code, GDB stops in the middle of the line. Thus requiring
multiple commands to reach the previous line. GDB should stop at the first
instruction of the line, not in the middle of the line.
The following description of the incorrect behavior was taken from an
earlier message by Pedro Alves <pedro@palves.net>:
https://sourceware.org/pipermail/gdb-patches/2023-January/196110.html
---------------------------------
The source line looks like:
func1 (); func2 ();
in the test case:
(gdb) list 1
1 void func1 ()
2 {
3 }
4
5 void func2 ()
6 {
7 }
8
9 int main ()
10 {
11 func1 (); func2 ();
12 }
compiled with:
$ gcc reverse.c -o reverse -g3 -O0
$ gcc -v
...
gcc version 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04)
Now let's debug it with target record, using current gdb git master
(f3d8ae90b2),
$ gdb ~/reverse
GNU gdb (GDB) 14.0.50.20230124-git
...
Reading symbols from /home/pedro/reverse...
(gdb) start
Temporary breakpoint 1 at 0x1147: file reverse.c, line 11.
Starting program: /home/pedro/reverse
[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 reverse.c:11
11 func1 (); func2 ();
(gdb) record
(gdb) disassemble /s
Dump of assembler code for function main:
reverse.c:
10 {
0x000055555555513f <+0>: endbr64
0x0000555555555143 <+4>: push %rbp
0x0000555555555144 <+5>: mov %rsp,%rbp
11 func1 (); func2 ();
=> 0x0000555555555147 <+8>: mov $0x0,%eax
0x000055555555514c <+13>: call 0x555555555129 <func1>
0x0000555555555151 <+18>: mov $0x0,%eax
0x0000555555555156 <+23>: call 0x555555555134 <func2>
0x000055555555515b <+28>: mov $0x0,%eax
12 }
0x0000555555555160 <+33>: pop %rbp
0x0000555555555161 <+34>: ret
End of assembler dump.
(gdb) n
12 }
So far so good, a "next" stepped over the whole of line 11 and stopped at
line 12.
Let's confirm where we are now:
(gdb) disassemble /s
Dump of assembler code for function main:
reverse.c:
10 {
0x000055555555513f <+0>: endbr64
0x0000555555555143 <+4>: push %rbp
0x0000555555555144 <+5>: mov %rsp,%rbp
11 func1 (); func2 ();
0x0000555555555147 <+8>: mov $0x0,%eax
0x000055555555514c <+13>: call 0x555555555129 <func1>
0x0000555555555151 <+18>: mov $0x0,%eax
0x0000555555555156 <+23>: call 0x555555555134 <func2>
0x000055555555515b <+28>: mov $0x0,%eax
12 }
=> 0x0000555555555160 <+33>: pop %rbp
0x0000555555555161 <+34>: ret
End of assembler dump.
Good, we're at the first instruction of line 12.
Now let's undo the "next", with "reverse-next":
(gdb) reverse-next
11 func1 (); func2 ();
Seemingly stopped at line 11. Let's see exactly where:
(gdb) disassemble /s
Dump of assembler code for function main:
reverse.c:
10 {
0x000055555555513f <+0>: endbr64
0x0000555555555143 <+4>: push %rbp
0x0000555555555144 <+5>: mov %rsp,%rbp
11 func1 (); func2 ();
0x0000555555555147 <+8>: mov $0x0,%eax
0x000055555555514c <+13>: call 0x555555555129 <func1>
=> 0x0000555555555151 <+18>: mov $0x0,%eax
0x0000555555555156 <+23>: call 0x555555555134 <func2>
0x000055555555515b <+28>: mov $0x0,%eax
12 }
0x0000555555555160 <+33>: pop %rbp
0x0000555555555161 <+34>: ret
End of assembler dump.
(gdb)
And lo, we stopped in the middle of line 11! That is a bug, we should have
stepped back all the way to the beginning of the line. The "reverse-next"
should have fully undone the prior "next" command.
--------------------
This patch fixes the incorrect GDB behavior by ensuring that GDB stops at
the first instruction in the line.
The test case gdb.reverse/func-map-to-same-line.exp is added to testsuite
to verify this fix when the line table information is and is not available.
When running GDB's testsuite on aarch64-linux/Ubuntu 20.04 (also spotted on
the ppc backend), there are failures in gdb.reverse/solib-precsave.exp and
gdb.reverse/solib-reverse.exp.
The failure happens around the following code:
38 b[1] = shr2(17); /* middle part two */
40 b[0] = 6; b[1] = 9; /* generic statement, end part two */
42 shr1 ("message 1\n"); /* shr1 one */
Normal execution:
- step from line 38 will land on line 40.
- step from line 40 will land on line 42.
Reverse execution:
- step from line 42 will land on line 40.
- step from line 40 will land on line 40.
- step from line 40 will land on line 38.
The problem here is that line 40 contains two contiguous but distinct
PC ranges in the line table, like so:
Line 40 - [0x7ec ~ 0x7f4]
Line 40 - [0x7f4 ~ 0x7fc]
The two distinct ranges are generated because GCC started outputting source
column information, which GDB doesn't take into account at the moment.
When stepping forward from line 40, we skip both of these ranges and land on
line 42. When stepping backward from line 42, we stop at the start PC of the
second (or first, going backwards) range of line 40.
Since we've reached ecs->event_thread->control.step_range_start, we stop
stepping backwards.
The above issues were fixed by introducing a new function that looks for
adjacent PC ranges for the same line, until we notice a line change. Then
we take that as the start PC of the range. The new start PC for the range
is used for the control.step_range_start when setting up a step range.
The test case gdb.reverse/map-to-same-line.exp is added to test the fix
for the above reverse step issues.
Patch has been tested on PowerPC, X86 and AArch64 with no regressions.
This patch adds two new options to gdb_compile to specify if the compile
should or should not generate the line table information. The
options are supported on clang and gcc version 7 and newer.
Patch has been tested on PowerPC with both gcc and clang.
This commit adds a mechanism for GDB to detect the linetable opcode
DW_LNS_set_epilogue_begin. This opcode is set by compilers to indicate
that a certain instruction marks the point where the frame is destroyed.
While the standard allows for multiple points marked with epilogue_begin
in the same function, for performance reasons, the function that
searches for the epilogue address will only find the last address that
sets this flag for a given block.
This commit also changes amd64_stack_frame_destroyed_p_1 to attempt to
use the epilogue begin directly, and only if an epilogue can't be found
will it attempt heuristics based on the current instruction.
Finally, this commit also changes the dwarf assembler to be able to emit
epilogue-begin instructions, to make it easier to test this patch
Approved-By: Tom Tromey <tom@tromey.com>
Mark pointed out that a recent patch of mine caused the buildbot to
complain about the formatting of some Python test code. This patch
re-runs 'black' to fix the problem.
On aarch64-linux with a gdb build without libexpat, I run into:
...
(gdb) PASS: gdb.base/catch-syscall.exp: determine pipe syscall: \
catch syscall 59
continue
Continuing.
Catchpoint 5 (call to syscall 59), 0x0000fffff7e04578 in pipe () from \
/lib64/libc.so.6
(gdb) FAIL: gdb.base/catch-syscall.exp: determine pipe syscall: continue
...
In the test-case, this pattern handles either the syscall name or number for
the pipe syscall:
...
-re -wrap "Catchpoint $decimal \\(call to syscall (pipe|$SYS_pipe)\\).*" {
...
but the pattern for the pipe2 syscall mistakenly uses SYS_pipe instead of
SYS_pipe2:
...
-re -wrap "Catchpoint $decimal \\(call to syscall (pipe2|$SYS_pipe)\\).*" {
...
and consequently doesn't handle the pipe2 syscall number.
Fix the typo by using SYS_pipe2 instead.
Tested on aarch64-linux.
The gdb docs promise that methods with more than two or more arguments
will accept keywords. However, I found that TuiWindow.write didn't
allow them. This patch adds the missing support.
When running test-case gdb.base/gdb-index-err.exp in a container as root user,
I run into:
...
FAIL: gdb.base/gdb-index-err.exp: flag=: \
try to write index to a non-writable directory
FAIL: gdb.base/gdb-index-err.exp: flag=-dwarf-5: \
try to write index to a non-writable directory
...
The test-case creates a directory without write permissions:
...
$ ls -ald private
dr-xr-xr-x 2 root root 4096 Dec 29 06:26 private/
...
but apparently the root user is still able to write in it.
Fix this by making the test unsupported for the root user.
Tested on x86_64-linux.
Reviewed-By: Lancelot SIX <lancelot.six@amd.com>
PR testsuite/31197
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31197
Fortran provides additional entry points for subroutines and functions.
These entry points may use only a subset (or a different set) of the
parameters of the original subroutine. The entry points may be described
via the DWARF tag DW_TAG_entry_point.
This commit adds support for parsing the DW_TAG_entry_point DWARF tag.
Currently, between ifx/ifort/gfortran, only ifort is actually emitting
this tag. Both, ifx and gfortran use the DW_TAG_subprogram tag as
workaround/alternative. Thus, this patch really only adds more ifort
support. Even so, some of the attached tests still fail for ifort, due
to some wrong line info generated for the entry points in ifort.
After this patch it is possible to set a breakpoint in gdb with the
ifort compiled example at the entry points 'foo' and 'foobar', which was not
possible before.
As gcc and ifx do not emit the tag I also added a test to gdb.dwarf2
which uses some underlying c compiled code and adds some Fortran style DWARF
to it emitting the DW_TAG_entry_point. Before this patch it was not
possible to actually define breakpoint at the entry point tags.
For gfortran there actually exists a bug on bugzilla, asking for the use
of DW_TAG_entry_point over DW_TAG_subprogram:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37134
This patch was originally posted here
https://sourceware.org/legacy-ml/gdb-patches/2017-07/msg00317.html
but its review/pinging got lost after a while. I reworked it to fit the
current GDB.
Co-authored-by: Bernhard Heckel <bernhard.heckel@intel.com>
Co-authored-by: Tim Wiederhake <tim.wiederhake@intel.com>
Approved-by: Tom Tromey <tom@tromey.com>
In dwarf2_get_pc_bounds we were writing unchecked to *lowpc. This
commit adds a gdb_assert to first check that lowpc != nullptr.
Approved-by: Tom Tromey <tom@tromey.com>
This commit is in preparation of the next commit. There, we will add
a second variation to retrieve the pc bounds for DIEs tagged with
DW_TAG_entry_point. Instead of dwarf_get_pc_bounds_ranges_or_highlow_pc
we will call a separate method for entry points. As the validity checks
at the endo f dwarf2_get_pc_bounds are the same for both variants,
we introduced the new dwarf_get_pc_bounds_ranges_or_highlow_pc method,
outsourcing part of dwarf2_get_pc_bounds.
This commit should have no functional impact on GDB.
Approved-by: Tom Tromey <tom@tromey.com>
Some spots loop on the frame chain to find the first next non-inline
frame, and pass that as the "next frame" to
value::allocate_register_lazy / value::allocate_register. This is
necessary if the value is used in the process of computing the id of
"this frame". If the frame next to "this frame" is inlined into "this
frame", then you that next frame won't have a computed id yet. You have
to go past that to find the next non-inline frame, which will have a
computed id.
In other cases, it's fine to store the id of an inline frame as the
"next frame id" in a register struct value. When trying to unwind a
register from it, it will just call inline_frame_prev_register, which
will forward the request to the next next frame, until we hit the next
physical frame.
I think it would make things simpler to just never store the id of an
inline frame as the next frame id of register struct values, and go with
the first next non-inline frame directly. This way, we don't have to
wonder which code paths have to skip inline frames when creating
register values and which don't.
So, change value::allocate_register_lazy to do that work, and remove the
loops for the callers that did it.
Change-Id: Ic88115dac49dc14e3053c95f92050062b24b7310
Remove VALUE_REGNUM, replace it with a method on struct value. Set
`m_location.reg.regnum` directly from value::allocate_register_lazy,
which is fine because allocate_register_lazy is a static creation
function for struct value.
Change-Id: Id632502357da971617d9dce1e2eab9b56dbcf52d
Remove VALUE_NEXT_FRAME_ID, replace it with a method on struct value. Set
`m_location.reg.next_frame_id` directly from value::allocate_register_lazy,
which is fine because allocate_register_lazy is a static creation
function for struct value.
Change-Id: Ic9f0f239c166a88dccfee836f9f51871e67548e6
As explained in the comment removed by the previous commit "gdb: pass
non-nullptr frame to gdbarch_value_from_register in
address_from_register", address_from_register copies some implementation
bits from value_from_register:
/* This routine may be called during early unwinding, at a time
where the ID of FRAME is not yet known. Calling value_from_register
would therefore abort in get_frame_id. However, since we only need
a temporary value that is never used as lvalue, we actually do not
really need to set its VALUE_NEXT_FRAME_ID. Therefore, we re-implement
the core of value_from_register, but use the null_frame_id. */
This is no longer relevant, since we now create a value with a valid next
frame id, so change address_from_register to use value_from_register.
Change-Id: I189bd96f28735ed9f47750ffd73764c459ec6f43
By now, all register struct values should have a valid next frame id
(assuming they are created using value::allocate_register or
value::allocate_register_lazy), so there should be no need to pass a
frame alongside the value to read_frame_register_value. Remove the
frame parameter and adjust read_frame_register_value accordingly.
While at it, make read_frame_register_value static, it's only used in
findvar.c.
Change-Id: I118959ef8c628499297c67810916e8ba9934bfac
Some places that create register struct values don't use register_type
to obtain the value type. This prevents them from using the current
version of value::allocate_register. One spot (value_of_register_lazy)
also creates a lazy register value.
Add a value::allocate_register_lazy method. Add some type parameters
to value::allocate_register and value::allocate_register_lazy, to let
the caller specify the type to use for the value. The parameters
default to nullptr, in which case we use register_type to obtain the
type.
Change-Id: I640ec0a5a0f4a55eba12d515dbfd25933229f8ec
address_from_register used to pass null_frame_id to
gdbarch_value_from_register as "this frame"'s id, because it's possible
for it to be called during unwind, when "this frame"'s id is not yet
known. This create an oddity where those register struct values are
created without a valid next frame id. I would much prefer for things
to be consistent and have all register struct values to have a valid
next frame id.
Since gdbarch_value_from_register takes a frame_info_ptr now, rather
than a frame_id, we can pass down "this frame", even if it doesn't have
a valid id. gdbarch_value_from_register implementations can obtain the
next frame from it.
However, it's possible for the "this frame"'s next frame to be an
inline frame, inlined in "this frame", in which case that next frame's
id is also not known. So, loop until we get to the next non-inline
frame (which is actually the frame where registers for "this frame" are
unwound from). This is the same thing that we do in
value_of_register_lazy, for the same reason. A later patch will factor
out this "while next frame is inline" loop to apply it to all register
struct values, so this is somewhat temporary.
Change-Id: If487c82620cc5a4a4ea5807f0a0bad80ab984078
Pass a frame_info_ptr rather than a frame_id. This avoids having to do
a frame lookup on the callee side, when we can just pass the frame down
directly.
I think this fixes a bug in rs6000-tdep.c where the id of the wrong
frame was set to `VALUE_NEXT_FRAME_ID (v)`.
Change-Id: I77039bc87ea8fc5262f16d0e1446515efa21c565
I don't think that setting the next frame id is needed there, all code
paths in cooked_read_value do set it properly, AFAIK.
Change-Id: Idb9d9e6f89c2c95c5ebfeec2a63fde89ed84cf3d
This changes the test suite to look for rogue DAP exceptions in the
log file, and issue a "fail" if one is found.
Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
I noticed that the DAP attach test case (and similarly
remoted-dap.exp) had a rogue exception stack trace in the log. It
turns out that an attach will generate a stop that does not have a
reason.
This patch fixes the problem in the _on_stop event listener by making
it a bit more careful when examining the event reason. It also adds
some machinery so that attach stops can be suppressed, which I think
is the right thing to do.
Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
This adds a new parameter to control the DAP logging level. By
default, "expected" exceptions are not logged, but the parameter lets
the user change this when more logging is desired.
This also changes a couple of spots to avoid logging the stack trace
for a DAPException.
This patch also documents the existing DAP logging parameter. I
forgot to document this before.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
This introduces a new DAPException class, and then changes various
spots in the DAP implementation to wrap "expected" exceptions in this.
This class will help detect rogue exceptions caused by bugs in the
implementation.
Reviewed-By: Kévin Le Gouguec <legouguec@adacore.com>
In 2023-12-14 "gdb: make get_frame_register_bytes take the next frame"
(9fc79b4236), *_register_to_value functions were made to (a) call
get_next_frame_sentinel_okay (frame) (b) pass that next frame to
get_frame_register_bytes.
Step (b) was omitted for rs6000-tdep.c; this manifests as a regression on
PPC platforms for e.g. O2_float_param: instead of seeing…
Temporary breakpoint 1, callee.increment (val=val@entry=99.0, msg=...) at callee.adb:19
… we get "optimized_out" for val. Passing next_frame to
get_frame_register_bytes fixes the issue.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
In many cases, it's not possible for gdb to discover the executable
when a DAP 'attach' request is used. This patch lets the IDE supply
this information.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
The project has been using Tested-By (tb), Reviewed-By (rb) and
Approved-By (ab) for some time, but there has been no information to be
found in the actual repository. This commit changes that by adding
information about all git trailers to the MAINTAINERS file, so that it
can be easily double-checked. Simply put, the trailers in use work as
follows:
* Tested-by: The person tested the patch and it fixes the problem, or
introduces no regressions (or both).
* Acked-by: The general outline looks good, but the maintainer hasn't
looked at the code
* Reviewed-by: The code looks good, but the reviewer has not approved
the patch to go upstream
* Approved-by: The patch is ready to be pushed to master
These last 3 trailers can also be restricted to one or more areas of GDB
by adding the areas in a comma separated list in parenthesis after the
trailers.
Finally, for completeness sake, the trailers Co-Authored-By and Bug
were added, even though they have been in use for a long time already
Reviewed-By: Kevin Buettner <kevinb@redhat.com>
Reviewed-By: Luis Machado <luis.machado@arm.com>
Approved-By: John Baldwin <jhb@FreeBSD.org>
The TUI status window is called the "locator" in the source, but
"status" in the documentation. Whenever I've needed to find the code,
I've had to search to "locate" it (ha, ha). This patch renames the
window to match the public name of the window.
The TUI status line is called the "status" window in the
documentation, but not in the source. There, the relevant files are
named "tui-stack", which to me makes it sound like they have something
to do with backtraces. This patch renames them to "tui-status".
Commit d5cebea18e ("Make cached_reg_t own its data") added a
destructor to cached_reg_t.
That caused a build problem with Clang, which errors out like so:
> CXX python/py-unwind.o
> gdb/python/py-unwind.c:126:16: error: flexible array member 'reg' of type 'cached_reg_t[]' with non-trivial destruction
> 126 | cached_reg_t reg[];
> | ^
This is is not really a problem for our code, which allocates the
whole structure with xmalloc, and then initializes the array elements
with in-place new, and then takes care to call the destructor
manually. Like, commit d5cebea18e did:
@@ -928,7 +927,7 @@ pyuw_dealloc_cache (frame_info *this_frame, void *cache)
cached_frame_info *cached_frame = (cached_frame_info *) cache;
for (int i = 0; i < cached_frame->reg_count; i++)
- xfree (cached_frame->reg[i].data);
+ cached_frame->reg[i].~cached_reg_t ();
Maybe we should get rid of the flexible array member and use a bog
standard std::vector. I doubt this would cause any visible
performance issue.
Meanwhile, to unbreak the build, this commit switches from C99-style
flexible array member to 0-length array. It behaves the same, and
Clang doesn't complain. I got the idea from here:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70932#c11
GCC 9, our oldest support version, already supported this:
https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Zero-Length.html
but the extension is actually much older than that. Note that
C99-style flexible array members are not standard C++ either.
Change-Id: I37dda18f367e238a41d610619935b2a0f2acacce
Downstream, AMD is carrying a testcase
(gdb.rocm/continue-over-kernel-exit.exp) that exposes a couple issues
with the amd-dbgapi target's handling of exited threads. The test
can't be added upstream yet, unfortunately, due to dependency on DWARF
extensions that can't be upstreamed yet. However, it can be found on
the mailing list on the same series as this patch.
The test spawns a kernel with a number of waves. The waves do nothing
but exit. There is a breakpoint on the s_endpgm instruction. Once
that breakpoint is hit, the test issues a "continue" command. We
should see one breakpoint hit per wave, and then the whole program
exiting. We do see that, however we also see this:
[New AMDGPU Wave ?:?:?:1 (?,?,?)/?]
[AMDGPU Wave ?:?:?:1 (?,?,?)/? exited]
*repeat for other waves*
...
[Thread 0x7ffff626f640 (LWP 3048491) exited]
[Thread 0x7fffeb7ff640 (LWP 3048488) exited]
[Inferior 1 (process 3048475) exited normally]
That "New AMDGPU Wave" output comes from infrun.c itself adding the
thread to the GDB thread list, because it got an event for a thread
not on the thread list yet. The output shows "?"s instead of proper
coordinates, because the event was a TARGET_WAITKIND_THREAD_EXITED,
i.e., the wave was already gone when infrun.c added the thread to the
thread list.
That shouldn't ever happen for the amd-dbgapi target, threads should
only ever be added by the backend.
Note "New AMDGPU Wave ?:?:?:1" is for wave 1. What happened was that
wave 1 terminated previously, and a previous call to
amd_dbgapi_target::update_thread_list() noticed the wave had vanished
and removed it from the GDB thread list. However, because the wave
was stepping when it terminated (due to the displaced step over the
s_endpgm) instruction, it is guaranteed that the amd-dbgapi library
queues a WAVE_COMMAND_TERMINATED event for the exit.
When we process that WAVE_COMMAND_TERMINATED event, in
amd-dbgapi-target.c:process_one_event, we return it to the core as a
TARGET_WAITKIND_THREAD_EXITED event:
static void
process_one_event (amd_dbgapi_event_id_t event_id,
amd_dbgapi_event_kind_t event_kind)
{
...
if (status == AMD_DBGAPI_STATUS_ERROR_INVALID_WAVE_ID
&& event_kind == AMD_DBGAPI_EVENT_KIND_WAVE_COMMAND_TERMINATED)
ws.set_thread_exited (0);
...
}
Recall the wave is already gone from the GDB thread list. So when GDB
sees that TARGET_WAITKIND_THREAD_EXITED event for a thread it doesn't
know about, it adds the thread to the thread list, resulting in that:
[New AMDGPU Wave ?:?:?:1 (?,?,?)/?]
and then, because it was a TARGET_WAITKIND_THREAD_EXITED event, GDB
marks the thread exited right afterwards:
[AMDGPU Wave ?:?:?:1 (?,?,?)/? exited]
The fix is to make amd_dbgapi_target::update_thread_list() _not_
delete vanishing waves iff they were stepping or in progress of being
stopped. These two cases are the ones dbgapi guarantees will result
in a WAVE_COMMAND_TERMINATED event if the wave terminates:
/**
* A command for a wave was not able to complete because the wave has
* terminated.
*
* Commands that can result in this event are ::amd_dbgapi_wave_stop and
* ::amd_dbgapi_wave_resume in single step mode. Since the wave terminated
* before stopping, this event will be reported instead of
* ::AMD_DBGAPI_EVENT_KIND_WAVE_STOP.
*
* The wave that terminated is available by the ::AMD_DBGAPI_EVENT_INFO_WAVE
* query. However, the wave will be invalid since it has already terminated.
* It is the client's responsibility to know what command was being performed
* and was unable to complete due to the wave terminating.
*/
AMD_DBGAPI_EVENT_KIND_WAVE_COMMAND_TERMINATED = 2,
As the comment says, it's GDB's responsability to know whether the
wave was stepping or being stopped. Since we now have a wave_info map
with one entry for each wave, that seems like the place to store that
information. However, I still decided to put all the coordinate
information in its own structure. I.e., basically renamed the
existing wave_info to wave_coordinates, and then added a new wave_info
structure that holds the new state, plus a wave_coordinates object.
This seemed cleaner as there are places where we only need to
instantiate a wave_coordinates object.
There's an extra twist. The testcase also exercises stopping at a new
kernel right after the first kernel fully exits. In that scenario, we
were hitting this assertion after the first kernel fully exits and the
hit of the breakpoint at the second kernel is handled:
[amd-dbgapi] process_event_queue: Pulled event from dbgapi: event_id.handle = 26, event_kind = WAVE_STOP
[amd-dbgapi-lib] suspending queue_3, queue_2, queue_1 (refresh wave list)
../../src/gdb/amd-dbgapi-target.c:1625: internal-error: amd_dbgapi_thread_deleted: Assertion `it != info->wave_info_map.end ()' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
This is the exact same problem as above, just a different
manifestation. In this scenario, we end up in update_thread_list
successfully deleting the exited thread (because it was no longer the
current thread) that was incorrectly added by infrun.c. Because it
was added by infrun.c and not by amd-dbgapi-target.c:add_gpu_thread,
it doesn't have an entry in the wave_info map, so
amd_dbgapi_thread_deleted trips on this assertion:
gdb_assert (it != info->wave_info_map.end ());
here:
...
-> stop_all_threads
-> update_thread_list
-> target_update_thread_list
-> amd_dbgapi_target::update_thread_list
-> thread_db_target::update_thread_list
-> linux_nat_target::update_thread_list
-> delete_exited_threads
-> delete_thread
-> delete_thread_1
-> gdb::observers::observable<thread_info*>::notify
-> amd_dbgapi_thread_deleted
-> internal_error_loc
The testcase thus tries both running to exit after the first kernel
exits, and running to a breakpoint in a second kernel after the first
kernel exits.
Approved-By: Lancelot Six <lancelot.six@amd.com> (amdgpu)
Change-Id: I43a66f060c35aad1fe0d9ff022ce2afd0537f028
Currently, if you step over kernel exit, you see:
stepi
[AMDGPU Wave ?:?:?:1 (?,?,?)/? exited]
Command aborted, thread exited.
(gdb)
Those '?' are because the thread/wave is already gone by the time GDB
prints the "exited" notification, we can't ask dbgapi for any info
about the wave anymore.
This commit fixes it by caching the wave's coordinates as soon as GDB
sees the wave for the first time, and making
amd_dbgapi_target::pid_to_str use the cached info.
At first I thought of clearing the wave_info object from a
thread_exited observer. However, that is too soon, resulting in this:
(gdb) si
[AMDGPU Wave 1:4:1:1 (0,0,0)/0 exited]
Command aborted, thread exited.
(gdb) thread
[Current thread is 6 (AMDGPU Wave ?:?:?:0 (?,?,?)/?) (exited)]
We need instead to clear the wave info when the thread is ultimately
deleted, so we get:
(gdb) si
[AMDGPU Wave 1:4:1:1 (0,0,0)/0 exited]
Command aborted, thread exited.
(gdb) thread
[Current thread is 6 (AMDGPU Wave 1:4:1:1 (0,0,0)/0) (exited)]
And for that, we need a new thread_deleted observable.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Approved-By: Lancelot Six <lancelot.six@amd.com> (amdgpu)
Change-Id: I6c3e22541f051e1205f75eb657b04dc15e547580
With AMD GPU debugging, I noticed that when stepping over a breakpoint
placed on top of the s_endpgm instruction inline (displaced=off), GDB
would behave differently -- it wouldn't print the wave exit. E.g:
With displaced stepping, or no breakpoint at all:
stepi
[AMDGPU Wave 1:4:1:1 (0,0,0)/0 exited]
Command aborted, thread exited.
(gdb)
With inline stepping:
stepi
Command aborted, thread exited.
(gdb)
In the cases we see the "exited" notification, handle_thread_exit is
what first called delete_thread on the exiting thread, which is
non-silent.
With inline stepping, however, handle_thread_exit ends up in
update_thread_list (via restart_threads) before any delete_thread
call. Thus, amd_dbgapi_target::update_thread_list notices that the
wave is gone and deletes it with delete_thread_silent.
This commit fixes it, by making handle_thread_exited call
set_thread_exited (with the default silent=false) early, which emits
the user-visible notification.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I22ab3145e18d07c99dace45576307b9f9d5d966f
displaced_step_finish can be called with event_status.kind ==
TARGET_WAITKIND_THREAD_EXITED, and in that case it is not possible to
get at the already-exited thread's registers.
This patch moves the get_thread_regcache calls to branches that
actually need it, where we know the thread is still alive.
It also adds an assertion to get_thread_regcache, to help catching
these broken cases sooner.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I63b5eacb3e02a538fc5087c270d8025adfda88c3
While making step over thread exit work properly on AMDGPU, I noticed
that if there's a breakpoint on top of the exit syscall, and,
displaced stepping is off, then when GDB reports "Command aborted,
thread exited.", GDB also switches focus to a random thread, instead
of leaving the exited thread as selected:
(gdb) thread
[Current thread is 6, lane 0 (AMDGPU Lane 1:4:1:1/0 (0,0,0)[0,0,0])]
(gdb) si
Command aborted, thread exited.
(gdb) thread
[Current thread is 5 (Thread 0x7ffff626f640 (LWP 3248392))]
(gdb)
The previous patch extended gdb.threads/step-over-thread-exit.exp to
exercise this on GNU/Linux (on the CPU side), and there, after that
"si", we always end up with the exiting thread as selected even
without this fix, but that's just a concidence, there's a code path
that happens to select the exiting thread for an unrelated reason.
This commit add the explict switch, fixing the latent problem for
GNU/Linux, and the actual problem on AMDGPU. I wrote a gdb.rocm/
testcase for this, but it can't be upstreamed yet, until more pieces
of the DWARF machinery are upstream as well.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I6ff57a79514ac0142bba35c749fe83d53d9e4e51
This commit makes the following improvements to
gdb.threads/step-over-thread-exit.exp:
- Add a third axis to stepping over the breakpoint with displaced vs
inline stepping -- also test with no breakpoint at all.
- Check that when GDB reports "Command aborted, thread exited.", the
selected thread is the thread that exited. This is always true
currently on GNU/Linux by coincidence, but a similar testcase on AMD
GPU exposed a problem here. Better make the testcase catch any
potential regression.
- Fixes a race that Simon ran into with GDBserver testing.
(gdb) next
[New Thread 2143071.2143438]
Thread 3 "step-over-threa" hit Breakpoint 2, 0x000055555555524e in my_exit_syscall () at .../testsuite/lib/my-syscalls.S:74
74 SYSCALL (my_exit, __NR_exit)
(gdb) FAIL: gdb.threads/step-over-thread-exit.exp: displaced-stepping=auto: non-stop=on: target-non-stop=on: schedlock=off: cmd=next: ns_stop_all=0: command aborts when thread exits
I was not able to reproduce it, but I believe that what happens is
the following:
Once we continue, the thread 2 exits, and the main thread thus
unblocks from its pthread_join, and spawns a new thread. That new
thread may hit the breakpoint at my_exit_syscall very quickly. GDB
could then see/process that breakpoint event before the thread exit
event for the thread we care about, which would result in the
failure seen above.
The fix here is to not loop and start a new thread at all in the
scenario where the race can happen. We only need to loop and spawn
new threads when testing with "cmd=continue" and schedlock off, in
which case GDB doesn't abort the command when the thread exits.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I90c95c32f00630a3f682b1541c23aff52451f9b6
By inspection, I noticed that the previous patch went too far, here:
@@ -7705,7 +7713,8 @@ remote_target::discard_pending_stop_replies (struct inferior *inf)
if (rs->remote_desc == NULL)
return;
- reply = (struct stop_reply *) rns->pending_event[notif_client_stop.id];
+ stop_reply_up reply
+ = as_stop_reply_up (std::move (rns->pending_event[notif_client_stop.id]));
/* Discard the in-flight notification. */
if (reply != NULL && reply->ptid.pid () == inf->pid)
That is always moving the stop reply from pending_event, when we only
really want to peek into it. The code further below that even says:
/* Discard the in-flight notification. */
if (reply != NULL && reply->ptid.pid () == inf->pid)
{
/* Leave the notification pending, since the server expects that
we acknowledge it with vStopped. But clear its contents, so
that later on when we acknowledge it, we also discard it. */
This commit reverts that hunk back, adjusted to use unique_ptr::get().
Change-Id: Ifc809d1a8225150a4656889f056d51267100ee24
We already use unique_ptr with notif_event and stop_reply in some
places around the remote target, but not fully. There are several
code paths that still use raw pointers. This commit makes all of the
ownership of these objects tracked by unique pointers, making the
lifetime flow much more obvious, IMHO.
I notice that it fixes a leak -- in remote_notif_stop_ack, We weren't
destroying the stop_reply object if it was of TARGET_WAITKIND_IGNORE
kind.
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: Id81daf39653d8792c8795b2a145772176bfae77c
struct cached_reg_t owns its data buffer, but currently that is
managed manually. Convert it to use a unique_xmalloc_ptr.
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: I05a107098b717299e76de76aaba00d7fbaeac77b
tdesc_data is not part of a union, since commit 4f3681cc33 ("Fix thread's
gdbarch when SVE vector length changes"). Remove the stale comment and
constructor.
Change-Id: Ie895ce36614930e8bd9c4967174c8bf1b321c503
Here, we write single complete registers, we don't need the
functionality of put_frame_register_bytes, use put_frame_register
instead.
Change-Id: I987867a27249db4f792a694b47ecb21c44f64d08
Approved-By: Tom Tromey <tom@tromey.com>
This comment is no longer relevant, put_frame_register_bytes now accepts
the "next frame".
Change-Id: I077933a03f8bdb886f8ba10a98d1202a38bce0a9
Approved-By: Tom Tromey <tom@tromey.com>
gdbarches usually register functions to check when a frame is destroyed
which is used with software watchpoints, since the expression of the
watchpoint is no longer vlaid at this point. On amd64, this wasn't done
anymore because GCC started using CFA for variable locations instead.
However, clang doesn't use the CFA and instead relies on specifying when
an epilogue has started, meaning software watchpoints get a spurious hit
when a frame is destroyed. This patch re-adds the code to register the
function that detects when a frame is destroyed, but only uses this when
the producer is LLVM, so gcc code isn't affected. The logic that
identifies the epilogue has been factored out into the new function
amd64_stack_frame_destroyed_p_1, so the frame sniffer can call it
directly, and its behavior isn't changed.
This can also remove the XFAIL added to gdb.python/pq-watchpoint tests
that handled this exact flaw in clang.
Co-Authored-By: Andrew Burgess <aburgess@redhat.com>
Approved-By: Andrew Burgess <aburgess@redhat.com>
The gdb.threads/thread-specific-bp.exp test has been a little
problematic, see commits:
commit 89702edd93
Date: Thu Mar 9 12:31:26 2023 +0100
[gdb/testsuite] Fix gdb.threads/thread-specific-bp.exp on native-gdbserver
and
commit 2e5843d87c
Date: Fri Nov 19 14:33:39 2021 +0100
[gdb/testsuite] Fix gdb.threads/thread-specific-bp.exp
But I recently saw a test failure for that test, which looked like
this:
...
(gdb) PASS: gdb.threads/thread-specific-bp.exp: non_stop=on: thread 1 selected
continue -a
Continuing.
Thread 1 "thread-specific" hit Breakpoint 4, end () at /tmp/binutils-gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.threads/thread-specific-bp.c:29
29 }
(gdb) [Thread 0x7ffff7c5c700 (LWP 1552086) exited]
Thread-specific breakpoint 3 deleted - thread 2 no longer in the thread list.
FAIL: gdb.threads/thread-specific-bp.exp: non_stop=on: continue to end (timeout)
...
This only crops up (for me) when running on a loaded machine, and
still only occurs sometimes. I've had to leave the test running in a
loop for 10+ minutes sometimes in order to see the failure.
The problem is that we use gdb_test_multiple to try and match two
patterns:
(1) The 'Thread-specific breakpoint 3 deleted ....' message, and
(2) The GDB prompt.
As written in the test, we understand that these patterns can occur in
any order, and we have a flag for each pattern. Once both patterns
have been seen then we PASS the test.
The problem is that once expect has matched a pattern, everything up
to, and including the matched text is discarded from the input
buffer. Thus, if the input buffer contains:
<PATTERN 2><PATTERN 1>
Then expect will first try to match <PATTERN 1>, which succeeds, and
then expect discards the entire input buffer up to the end of the
<PATTERN 1>. As a result, we will never spot <PATTERN 2>.
Obviously we can't just reorder the patterns within the
gdb_test_multiple, as the output can legitimately (and most often
does) occur in the other order, in which case the test would mostly
fail, and only occasionally pass!
I think the easiest solution here is just to have the
gdb_test_multiple contain two patterns, each pattern consists of the
two parts, but in the alternative orders, thus, for a particular
output configuration, only one regexp will match. With this change in
place, I no longer see the intermittent failure.
Approved-By: Tom Tromey <tom@tromey.com>
PR28987 notes that optimized code sometimes shows the wrong
value of variables at the entry point of a function, if some
code was optimized away and the variable has multiple values
stored in the debug info for this location.
In this example:
```
void foo()
{
int l_3 = 5, i = 0;
for (; i < 8; i++)
;
test(l_3, i);
}
```
When compiled with optimization, the entry point of foo is at
the test() function call, since everything else is optimized
away.
The debug info of i looks like this:
```
(gdb) info address i
Symbol "i" is multi-location:
Base address 0x140001600 Range 0x13fd41600-0x13fd41600: the constant 0
Range 0x13fd41600-0x13fd41600: the constant 1
Range 0x13fd41600-0x13fd41600: the constant 2
Range 0x13fd41600-0x13fd41600: the constant 3
Range 0x13fd41600-0x13fd41600: the constant 4
Range 0x13fd41600-0x13fd41600: the constant 5
Range 0x13fd41600-0x13fd41600: the constant 6
Range 0x13fd41600-0x13fd41600: the constant 7
Range 0x13fd41600-0x13fd4160f: the constant 8
(gdb) p i
$1 = 0
```
Currently, when at the entry point of a function, it will
always show the initial value (here 0), while the user would
expect the last value (here 8).
This logic was introduced for showing the entry-values of
function arguments if they are available, but for some
reason this was added for non-entry-values as well.
One of the tests of amd64-entry-value.exp shows the same
problem for function arguments, if you "break stacktest"
in the following example, you stop at this line:
```
124 static void __attribute__((noinline, noclone))
125 stacktest (int r1, int r2, int r3, int r4, int r5, int r6, int s1, int s2,
126 double d1, double d2, double d3, double d4, double d5, double d6,
127 double d7, double d8, double d9, double da)
128 {
129 s1 = 3;
130 s2 = 4;
131 d9 = 3.5;
132 da = 4.5;
133 -> e (v, v);
134 asm ("breakhere_stacktest:");
135 e (v, v);
136 }
```
But `bt` still shows the entry values:
```
s1=s1@entry=11, s2=s2@entry=12, ..., d9=d9@entry=11.5, da=da@entry=12.5
```
I've fixed this by only using the initial values when
explicitely looking for entry values.
Now the local variable of the first example is as expected:
```
(gdb) p i
$1 = 8
```
And the test of amd64-entry-value.exp shows the expected
current and entry values of the function arguments:
```
s1=3, s1@entry=11, s2=4, s2@entry=12, ..., d9=3.5, d9@entry=11.5, da=4.5, da@entry=12.5
```
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28987
Tested-By: Guinevere Larsen <blarsen@redhat.com>
Approved-By: Tom Tromey <tom@tromey.com>
Commit deb1ba4e38 ("[gdb/tui] Fix TUI resizing for TERM=ansi") introduced a
dependency on readline private variable _rl_term_autowrap.
There is precedent for this, but it's something we want to get rid of
(PR build/10723).
Remove the dependency on _rl_term_autowrap, and instead calculate
readline_hidden_cols by comparing the environment variable COLS with cols as
returned by rl_get_screen_size.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=10723
When starting gdb in CLI mode, running to main and switching into the TUI regs
layout:
...
$ gdb -q a.out -ex start -ex "layout regs"
...
we get:
...
+---------------------------------+
| |
| [ Register Values Unavailable ] |
| |
+---------------------------------+
...
Fix this by handling this case in tui_data_window::rerender.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
PR tui/28600
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28600
