As the documentation states, using this is not safe in multithreaded
programs, and I have traced it to a rare deadlock in some of the tests.
The reason this was introduced was to be able to attach to a program
from the very first instruction, where our usual mechanism of
synchronization -- waiting for a file to appear -- does not work.
However, this is only needed for a single test
(TestGdbRemoteAttachWait) so instead of doing this everywhere, I create
a bespoke solution for that single test. The solution basically
consists of outsourcing the preexec_fn code to a separate (and
single-threaded) shim process, which enables attaching and then executes
the real program.
This pattern could be generalized in case we needed to use it for other
tests, but I suspect that we will not be having many tests like this.
This effectively reverts commit
a997a1d7fbe229433fb458bb0035b32424ecf3bd.
TestVSCode_breakpointEvents.py is failing on macOS Ventura because we
receive 3 breakpoint events instead of one. This is likely the result of
dyld moving into the shared cache.
Replace the use of "trap" with a new "stop" command in fork tests,
that maps to `raise(SIGSTOP)`. Since traps do not increment PC on some
architectures (notably ARM), using traps would require special logic
to increment it while testing. Using SIGSTOP avoids the problem
and is probably more logical, given that the purpose of the "trap"s
was to simply stop the inferior at a synchronization point. This fixes
tests on AArch64 (and possibly ARM, I'll update XFAILs when it is
confirmed by the buildbot).
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128780
Split the test that's gotten very long in two, in hope that it will
resolve the arm/aarch64 buildbot failures. Even if it does not, it
could help pinpointing where the problem lies.
Sponsored by: The FreeBSD Foundation
Fix lldb-server in the non-stop + multiprocess mode to exit on vStopped
only if all processes have exited, rather than when the first one exits.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128639
Extend the most of baseline fork tests to run in nonstop mode as well.
For more cases, we're just testing one example scenario to save time.
This patch does not cover tests that rely on correct exit handling,
as fixing that is addressed in a followup patch.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128638
Implement support for the "t" action that is used to stop a thread.
Normally this action is used only in non-stop mode. However, there's
no technical reason why it couldn't be also used in all-stop mode,
e.g. to express "resume all threads except ..." (`t:...;c`).
While at it, add a more complete test for vCont correctly resuming
a subset of program's threads.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D126983
Now preserving the non-standard behavior of returning "OK" response
when there is no debugged process.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128152
This reverts part of commit 75757c86c695a6b4695458343637b3c4fe86def6.
It broke the following test:
commands/target/auto-install-main-executable/TestAutoInstallMainExecutable.py
I need more time to figure it out, so I'm reverting the code changes
and marking the tests depending on them xfail.
Implement the 'T' packet that is used to verify whether the specified
thread belongs to the debugged processes.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128170
Update the `qfThreadInfo` handler to report threads of all debugged
processes and include PIDs when in multiprocess mode.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128152
Extend vCont function to support resuming a process with an arbitrary
PID, that could be different than the one selected via Hc (or no process
at all may be selected). Resuming more than one process simultaneously
is not supported yet.
Remove the ReadTid() method that was only used by Handle_vCont(),
and furthermore it was wrongly using m_current_process rather than
m_continue_process.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127862
Add a test verifying that it is possible to resume a single process
via the `c` packet when multiple processes are being debugged. This
includes a tiny change to the test program — when `fork()` is called,
the child process is no longer terminated immediately but continues
performing the same tasks as queued for the parent.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127755
Implement the support for the vKill packet. This is the modern packet
used by the GDB Remote Serial Protocol to kill one of the debugged
processes. Unlike the `k` packet, it has well-defined semantics.
The `vKill` packet takes the PID of the process to kill, and always
replies with an `OK` reply (rather than the exit status, as LLGS does
for `k` packets at the moment). Additionally, unlike the `k` packet
it does not cause the connection to be terminated once the last process
is killed — the client needs to close it explicitly.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127667
Modify the behavior of the `k` packet to kill all inferiors rather than
just the current one. The specification leaves the exact behavior
of this packet up to the implementation but since vKill is specifically
meant to be used to kill a single process, it seems logical to use `k`
to provide the alternate function of killing all of them.
Move starting stdio forwarding from the "running" response
to the packet handlers that trigger the process to start. This avoids
attempting to start it multiple times when multiple processes are killed
on Linux which implicitly causes LLGS to receive "started" events
for all of them. This is probably also more correct as the ability
to send "O" packets is implied by the continue-like command being issued
(and therefore the client waiting for responses) rather than the start
notification.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127500
Add a test verifying that plain 'D' packet correctly detaches all
processes.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127291
Refactor the fork and vfork tests to reuse the code better, avoid
unnecessary regexps and avoid unnecessary conversions between
hex-strings and integers.
Verify the server state after detaching. In particular, verify that
the detached process' PID/TID pair is no longer valid,
and that the correct process remains running.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127290
Fix ThreadStopInfo struct to include the signal number for all events.
Since signo was not included in the details for fork, vfork
and vforkdone stops, the code incidentally referenced the wrong union
member, resulting in wrong signo being sent.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127193
Implement the support for %Stop asynchronous notification packet format
in LLGS. This does not implement full support for non-stop mode for
threaded programs -- process plugins continue stopping all threads
on every event. However, it will be used to implement asynchronous
events in multiprocess debugging.
The non-stop protocol is enabled using QNonStop packet. When it is
enabled, the server uses notification protocol instead of regular stop
replies. Since all threads are always stopped, notifications are always
generated for all active threads and copied into stop notification
queue.
If the queue was empty, the initial asynchronous %Stop notification
is sent to the client immediately. The client needs to (eventually)
acknowledge the notification by sending the vStopped packet, in which
case it is popped from the queue and the stop reason for the next thread
is reported. This continues until notification queue is empty again,
in which case an OK reply is sent.
Asychronous notifications are also used for vAttach results and program
exits. The `?` packet uses a hybrid approach -- it returns the first
stop reason synchronously, and exposes the stop reasons for remaining
threads via vStopped queue.
The change includes a test case for a program generating a segfault
on 3 threads. The server is expected to generate a stop notification
for the segfaulting thread, along with the notifications for the other
running threads (with "no stop reason"). This verifies that the stop
reasons are correctly reported for all threads, and that notification
queue works.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D125575
This patch implements VSCode DAP logpoints feature (also called tracepoint
in other VS debugger).
This will provide a convenient way for user to do printf style logging
debugging without pausing debuggee.
Differential Revision: https://reviews.llvm.org/D127702
Fix test_platform_file_fstat to correctly truncate/max out the expected
value when GDB Remote Serial Protocol specifies a value as an unsigned
integer but the underlying platform type uses a signed integer.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D128042
Include the process identifier in the `T` stop responses when
multiprocess extension is enabled (i.e. prepend it to the thread
identifier). Use the exposed identifier to simplify the fork-and-follow
tests.
The LLDB client accounts for the possible PID since the multiprocess
extension support was added in b601c6719226fb83c43dae62a581e5ee08bfb169.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127192
Include the process identifier in W/X stop reasons when multiprocess
extensions are enabled.
The LLDB client does not support process identifiers there at the moment
but it parses packets in such a way that their presence does not cause
any problems.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127191
Eliminate boilerplate of having each test manually assign to `mydir` by calling
`compute_mydir` in lldbtest.py.
Differential Revision: https://reviews.llvm.org/D128077
I get to my work directory through a symlink, so the pathnames the
tests get for their build artifacts etc are via that symlink. There
are three tests which compare those symlink paths to a directory
received from dyld on macOS, which is the actual real pathname.
These tests have always failed for me on my dekstop but I finally
sat down to figure out why. Easy quick fix.
This was inspired by D109336 which got reverted because we didn't want
the test to fail silently. This patch prints a more informative error
message when we fail to parse the simctl output while still failing the
test.
Differential revision: https://reviews.llvm.org/D126217
This fixes an issue that optimized variable error message is not shown to end
users in lldb-vscode.
Differential Revision: https://reviews.llvm.org/D126014
To help user identify optimized code This diff adds a "[opt]" suffix to
optimized stack frames in lldb-vscode. This provides consistent experience
as command line lldb.
It also adds a new "optimized" attribute to DAP stack frame object so that
it is easy to identify from telemetry than parsing trailing "[opt]".
Differential Revision: https://reviews.llvm.org/D126013
Prior to this fix if we have a really large array or collection class, we would end up always creating all of the child variables for an array or collection class. If the number of children was very high this can cause delays when expanding variables. By adding the "indexedVariables" to variables with lots of children, we can keep good performance in the variables view at all times. This patch will add the "indexedVariables" key/value pair to any "Variable" JSON dictionairies when we have an array of synthetic child provider that will create more than 100 children.
We have to be careful to not call "uint32_t SBValue::GetNumChildren()" on any lldb::SBValue that we use because it can cause a class, struct or union to complete the type in order to be able to properly tell us how many children it has and this can be expensive if you have a lot of variables. By default LLDB won't need to complete a type if we have variables that are classes, structs or unions unless the user expands the variable in the variable view. So we try to only get the GetNumChildren() when we have an array, as this is a cheap operation, or a synthetic child provider, most of which are for showing collections that typically fall into this category. We add a variable reference, which indicates that something can be expanded, when the function "bool SBValue::MightHaveChildren()" is true as this call doesn't need to complete the type in order to return true. This way if no one ever expands class variables, we don't need to complete the type.
Differential Revision: https://reviews.llvm.org/D125347
This improves this test a lot because before when using the "attachCommands" to run the following commands:
(lldb) target create -d /path/to/a.out
(lldb) process launch
This was racy as it wasn't stopping the program at the entry point, and the process might run to completion before we can even debug it. With the recent changes to the "attachCommands" we were waiting for the process to stop, but the process might be exited already, and that _should_ have caused the attach to fail since there was no process to attach to. By adding "--stop-at-entry" to the process launch, we ensure this should be less racy and give us a valid process to attach to.
