This updates the documentation of the gdb-remote protocol, as well as the help messages, to include the new --per-core-tracing option.
Differential Revision: https://reviews.llvm.org/D124640
The race is between these two pieces of code that are executed in two separate
lldb-vscode threads (the first is in the main thread and another is in the
event-handling thread):
```
// lldb-vscode.cpp
g_vsc.debugger.SetAsync(false);
g_vsc.target.Launch(launch_info, error);
g_vsc.debugger.SetAsync(true);
```
```
// Target.cpp
bool old_async = debugger.GetAsyncExecution();
debugger.SetAsyncExecution(true);
debugger.GetCommandInterpreter().HandleCommands(GetCommands(), exc_ctx,
options, result);
debugger.SetAsyncExecution(old_async);
```
The sequence that leads to the bug is this one:
1. Main thread enables synchronous mode and launches the process.
2. When the process is launched, it generates the first stop event.
3. This stop event is catched by the event-handling thread and DoOnRemoval
is invoked.
4. Inside DoOnRemoval, this thread runs stop hooks. And before running stop
hooks, the current synchronization mode is stored into old_async (and
right now it is equal to "false").
5. The main thread finishes the launch and returns to lldb-vscode, the
synchronization mode is restored to asynchronous by lldb-vscode.
6. Event-handling thread finishes stop hooks processing and restores the
synchronization mode according to old_async (i.e. makes the mode synchronous)
7. And now the mode is synchronous while lldb-vscode expects it to be
asynchronous. Synchronous mode forbids the process to broadcast public stop
events, so, VS Code just hangs because lldb-vscode doesn't notify it about
stops.
So, this diff makes the target intercept the first stop event if the process is
launched in the synchronous mode, thus preventing stop hooks execution.
The bug is only present on Windows because other platforms already
intercept this event using their own hijacking listeners.
So, this diff also fixes some problems with lldb-vscode tests on Windows to make
it possible to run the related test. Other tests still can't be enabled because
the debugged program prints something into stdout and LLDB can't intercept this
output and redirect it to lldb-vscode properly.
Reviewed By: jingham
Differential Revision: https://reviews.llvm.org/D119548
We discovered that when using "launchCommands" or "attachCommands" that there was an issue where these commands were not being run synchronously. There were further problems in this case where we would get thread events for the process that was just launched or attached before the IDE was ready, which is after "configurationDone" was sent to lldb-vscode.
This fix introduces the ability to wait for the process to stop after the run or attach to ensure that we have a stopped process at the entry point that is ready for the debug session to proceed. This also allows us to run the normal launch or attach without needing to play with the async flag the debugger. We spin up the thread that listens for process events before we start the launch or attach, but we stop the first eStateStopped (with stop ID of zero) event from being delivered through the DAP protocol because the "configurationDone" request handler will deliver it manually as the IDE expects a stop after configuration done. The request_configurationDone will also only deliver the stop packet if the "stopOnEntry" is False in the launch configuration.
Also added a new "timeout" to the launch and attach launch configuration arguments that can be set and defaults to 30 seconds. Since we now poll to detect when the process is stopped, we need a timeout that can be changed in case certain workflows take longer that 30 seconds to attach. If the process is not stopped by the timeout, an error will be retured for the launch or attach.
Added a flag to the vscode.py protocol classes that detects and ensures that no "stopped" events are sent prior to "configurationDone" has been sent and will raise an error if it does happen.
This should make our launching and attaching more reliable and avoid some deadlocks that were being seen (https://reviews.llvm.org/D119548).
Differential Revision: https://reviews.llvm.org/D119797
Instead of using sleeps, have the inferior notify us (via a trap opcode) that
the requested number of threads have been created.
This allows us to get rid of some fairly dodgy test utility code --
wait_for_thread_count seemed like it was waiting for the threads to
appear, but it never actually let the inferior run, so it only succeeded
if the threads were already started when the function was called. Since
the function was called after a fairly small delay (1s, usually), this
is probably the reason why the tests were failing on some bots.
Differential Revision: https://reviews.llvm.org/D119167
This fixes TestGdbRemoteSingleStep.py and TestGdbRemote_vCont.py. This
patch updates the test to account for the possibility that the constants
are already materialized. This appears to behave differently between
embedded arm64 devices and Apple Silicon.
Implement the qXfer:siginfo:read that is used to read the siginfo_t
(extended signal information) for the current thread. This is currently
implemented on FreeBSD and Linux.
Differential Revision: https://reviews.llvm.org/D117113
GDB and LLDB use different signal models. GDB uses a predefined set
of signal codes, and maps platform's signos to them. On the other hand,
LLDB has historically simply passed native signos.
In order to improve compatibility between LLDB and gdbserver, the GDB
signal model should be used. However, GDB does not provide a mapping
for all existing signals on Linux and unsupported signals are passed
as 'unknown'. Limiting LLDB to this behavior could be considered
a regression.
To get the best of both worlds, use the LLDB signal model when talking
to lldb-server, and the GDB signal model otherwise. For this purpose,
new versions of lldb-server indicate "native-signals+" via qSupported.
At the same time, we also detect older versions of lldb-server
via QThreadSuffixSupported for backwards compatibility. If neither test
succeeds, we assume gdbserver or another implementation using GDB model.
Differential Revision: https://reviews.llvm.org/D108078
SetSourceMapFromArguments is called after the core is loaded. This means
that the source file for the crashing code won't have the source map applied.
Move the call to SetSourceMapFromArguments in request_attach to just after
the call to RunInitCommands, matching request_launch behavior.
Reviewed By: clayborg, wallace
Differential Revision: https://reviews.llvm.org/D112834
We had two sets of build<flavour> methods, whose bodies were largely
identical. This makes any kind of modification in their vicinity
repetitive and error-prone.
Replace each set with a single method taking an optional debug_info
parameter.
Differential Revision: https://reviews.llvm.org/D111989
Regex is matching a binary so it needs `re.DOTALL`.
vFile:fstat packet data ATTACHMENT is not hex-encoded but it is only
escaped.
It is difficult to reproduce, it came from buildbot:
https://lab.llvm.org/staging/#/builders/16/builds/10597
******************** TEST 'lldb-api :: tools/lldb-server/TestGdbRemotePlatformFile.py' FAILED ********************
FAIL: test_platform_file_fstat_llgs (TestGdbRemotePlatformFile.TestGdbRemotePlatformFile)
----------------------------------------------------------------------
Traceback (most recent call last):
File "lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py", line 52, in test_method
return attrvalue(self)
File "lldb/test/API/tools/lldb-server/TestGdbRemotePlatformFile.py", line 259, in test_platform_file_fstat
context = self.expect_gdbremote_sequence()
File "lldb/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py", line 621, in expect_gdbremote_sequence
return expect_lldb_gdbserver_replay(
File "lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py", line 198, in expect_lldb_gdbserver_replay
context = sequence_entry.assert_match(
File "lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py", line 479, in assert_match
return self._assert_regex_match(asserter, actual_packet, context)
File "lldb/packages/Python/lldbsuite/test/tools/lldb-server/lldbgdbserverutils.py", line 446, in _assert_regex_match
asserter.fail(
AssertionError: regex '^\$F([0-9a-fA-F]+);(.*)#[0-9a-fA-F]{2}$' failed to match against content '$F40;^@^@^@ ^@
^C<8d>^@^@<81><80>^@^@^@^A^@^@^CX^@^@^CX^@^@^@^@^@^@^@^@^@^@^@^W^@^@^@^@^@^@^P^@^@^@^@^@^@^@^@
a=XXa=XXa=XX#6b'
Add a new SaveCore() process method that can be used to request a core
dump. This is currently implemented on NetBSD via the PT_DUMPCORE
ptrace(2) request, and enabled via 'savecore' extension.
Protocol-wise, a new qSaveCore packet is introduced. It accepts zero
or more semicolon-separated key:value options, invokes the core dump
and returns a key:value response. Currently the only option supported
is "path-hint", and the return value contains the "path" actually used.
The support for the feature is exposed via qSaveCore qSupported feature.
Differential Revision: https://reviews.llvm.org/D101285
This feature "memory-tagging+" indicates that lldb-server
supports memory tagging packets. (added in a later patch)
We check HWCAP2_MTE to decide whether to enable this
feature for Linux.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D97282
A few times tests have been flaky, presumably by crashed of lldb-vscode
itself. They can be caught by looking at the DAP logs, so I'm dumping
them when the session ends.
Add a new feature to process save-core on Darwin systems -- for
lldb to create a user process corefile with only the dirty (modified
memory) pages included. All of the binaries that were used in the
corefile are assumed to still exist on the system for the duration
of the use of the corefile. A new --style option to process save-core
is added, so a full corefile can be requested if portability across
systems, or across time, is needed for this corefile.
debugserver can now identify the dirty pages in a memory region
when queried with qMemoryRegionInfo, and the size of vm pages is
given in qHostInfo.
Create a new "all image infos" LC_NOTE for Mach-O which allows us
to describe all of the binaries that were loaded in the process --
load address, UUID, file path, segment load addresses, and optionally
whether code from the binary was executing on any thread. The old
"read dyld_all_image_infos and then the in-memory Mach-O load
commands to get segment load addresses" no longer works when we
only have dirty memory.
rdar://69670807
Differential Revision: https://reviews.llvm.org/D88387
This adds a basic SB API for creating and stopping traces.
Note: This doesn't add any APIs for inspecting individual instructions. That'd be a more complicated change and it might be better to enhande the dump functionality to output the data in binary format. I'll leave that for a later diff.
This also enhances the existing tests so that they test the same flow using both the command interface and the SB API.
I also did some cleanup of legacy code.
Differential Revision: https://reviews.llvm.org/D103500
Introduce a NativeProcessProtocol API for indicating support for
protocol extensions and enabling them. LLGS calls
GetSupportedExtensions() method on the process factory to determine
which extensions are supported by the plugin. If the future is both
supported by the plugin and reported as supported by the client, LLGS
enables it and reports to the client as supported by the server.
The extension is enabled on the process instance by calling
SetEnabledExtensions() method. This is done after qSupported exchange
(if the debugger is attached to any process), as well as after launching
or attaching to a new inferior.
The patch adds 'fork' extension corresponding to 'fork-events+'
qSupported feature and 'vfork' extension for 'vfork-events+'. Both
features rely on 'multiprocess+' being supported as well.
Differential Revision: https://reviews.llvm.org/D100153
VSCode doesn't render multiple variables with the same name in the variables view. It only renders one of them. This is a situation that happens often when there are shadowed variables.
The nodejs debugger solves this by adding a number suffix to the variable, e.g. "x", "x2", "x3" are the different x variables in nested blocks.
In this patch I'm doing something similar, but the suffix is " @ <file_name:line>), e.g. "x @ main.cpp:17", "x @ main.cpp:21". The fallback would be an address if the source and line information is not present, which should be rare.
This fix is only needed for globals and locals. Children of variables don't suffer of this problem.
When there are shadowed variables
{F16182150}
Without shadowed variables
{F16182152}
Modifying these variables through the UI works
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D99989
In certain occasions times, like when LLDB is initializing and
evaluating the .lldbinit files, it tries to print to stderr and stdout
directly. This confuses the IDE with malformed data, as it talks to
lldb-vscode using stdin and stdout following the JSON RPC protocol. This
ends up terminating the debug session with the user unaware of what's
going on. There might be other situations in which this can happen, and
they will be harder to debug than the .lldbinit case.
After several discussions with @clayborg, @yinghuitan and @aadsm, we
realized that the best course of action is to simply redirect stdout and
stderr to the console, without modifying LLDB itself. This will prove to
be resilient to future bugs or features.
I made the simplest possible redirection logic I could come up with. It
only works for POSIX, and to make it work with Windows should be merely
changing pipe and dup2 for the windows equivalents like _pipe and _dup2.
Sadly I don't have a Windows machine, so I'll do it later once my office
reopens, or maybe someone else can do it.
I'm intentionally not adding a stop-redirecting logic, as I don't see it
useful for the lldb-vscode case (why would we want to do that, really?).
I added a test.
Note: this is a simpler version of D80659. I first tried to implement a
RIIA version of it, but it was problematic to manage the state of the
thread and reverting the redirection came with some non trivial
complexities, like what to do with unflushed data after the debug
session has finished on the IDE's side.
This diff ass postRunCommands, which are the counterpart of the preRunCommands. TThey will be executed right after the target is launched or attached correctly, which means that the targets can assume that the target is running.
Differential Revision: https://reviews.llvm.org/D100340
This functionality is used exactly once, and it is trivial to implement
it differently (capture into two distinct variables, and compare for
equality afterwards).
These two functions are doing the same thing, only one of them is
sending the packets immediately and the other "queues" them to be sent
later. The first one is better as in case of errors, the backtrace will
point straight to the place that caused them.
Modify the first method to avoid duplication, and ten standardize on it.
Add a minimal support for the multiprocess extension in lldb-server.
The server indicates support for it via qSupported, and accepts
thread-ids containing a PID. However, it still does not support
debugging more than one inferior, so any other PID value results
in an error.
Differential Revision: https://reviews.llvm.org/D98482
TestVSCode_disconnect.test_launch fails with clean up error because
disconnect gets called twice once from the test case and once from
the tear down hook.
This patch disables disconnect after its been called from test_launch
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D99491
LLDB can often appear deadlocked to users that use IDEs when it is indexing DWARF, or parsing symbol tables. These long running operations can make a debug session appear to be doing nothing even though a lot of work is going on inside LLDB. This patch adds a public API to allow clients to listen to debugger events that report progress and will allow UI to create an activity window or display that can show users what is going on and keep them informed of expensive operations that are going on inside LLDB.
Differential Revision: https://reviews.llvm.org/D97739
Summary:
The request "evaluate" supports a "context" attribute, which is sent by VSCode. The attribute is defined here https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Evaluate
The "clipboard" context is not yet supported by lldb-vscode, so we can forget about it for now. The 'repl' (i.e. Debug Console) and 'watch' (i.e. Watch Expression) contexts must use the expression parser in case the frame's variable path is not enough, as the user expects these expressions to never fail. On the other hand, the 'hover' expression is invoked whenever the user hovers on any keyword on the UI and the user is fine with the expression not being fully resolved, as they know that the 'repl' case is the fallback they can rely on.
Given that the 'hover' expression is invoked many many times without the user noticing it due to it being triggered by the mouse, I'm making it use only the frame's variable path functionality and not the expression parser. This should speed up tremendously the responsiveness of a debug session when the user only sets source breakpoints and inspect local variables, as the entire debug info is not needed to be parsed.
Regarding tests, I've tried to be as comprehensive as possible considering a multi-file project. Fortunately, the results from the "hover" case are enough most of the times.
Differential Revision: https://reviews.llvm.org/D98656
This reapplies 7df4eaaa93/D96202, which was reverted due to issues on
windows. These were caused by problems in the computation of the liblldb
directory, which was fixed by D96779.
The original commit message was:
Our test configuration logic assumes that the tests can be run either
with debugserver or with lldb-server. This is not entirely correct,
since lldb server has two "personalities" (platform server and debug
server) and debugserver is only a replacement for the latter.
A consequence of this is that it's not possible to test the platform
behavior of lldb-server on macos, as it is not possible to get a hold of
the lldb-server binary.
One solution to that would be to duplicate the server configuration
logic to be able to specify both executables. However, that seems
excessively redundant.
A well-behaved lldb should be able to find the debug server on its own,
and testing lldb with a different (lldb-|debug)server does not seem very
useful (even in the out-of-tree debugserver setup, we copy the server
into the build tree to make it appear "real").
Therefore, this patch deletes the configuration altogether and changes
the low-level server retrieval functions to be able to both lldb-server
and debugserver paths. They do this by consulting the "support
executable" directory of the lldb under test.
Differential Revision: https://reviews.llvm.org/D96202
Our test configuration logic assumes that the tests can be run either
with debugserver or with lldb-server. This is not entirely correct,
since lldb server has two "personalities" (platform server and debug
server) and debugserver is only a replacement for the latter.
A consequence of this is that it's not possible to test the platform
behavior of lldb-server on macos, as it is not possible to get a hold of
the lldb-server binary.
One solution to that would be to duplicate the server configuration
logic to be able to specify both executables. However, that seems
excessively redundant.
A well-behaved lldb should be able to find the debug server on its own,
and testing lldb with a different (lldb-|debug)server does not seem very
useful (even in the out-of-tree debugserver setup, we copy the server
into the build tree to make it appear "real").
Therefore, this patch deletes the configuration altogether and changes
the low-level server retrieval functions to be able to both lldb-server
and debugserver paths. They do this by consulting the "support
executable" directory of the lldb under test.
Differential Revision: https://reviews.llvm.org/D96202
Depends on D93874.
runInTerminal was using --wait-for, but it was some problems because it uses process polling looking for a single instance of the debuggee:
- it gets to know of the target late, which renders breakpoints in the main function almost impossible
- polling might fail if there are already other processes with the same name
- polling might also fail on some linux machine, as it's implemented with the ps command, and the ps command's args and output are not standard everywhere
As a better way to implement this so that it works well on Darwin and Linux, I'm using now the following process:
- lldb-vscode notices the runInTerminal, so it spawns lldb-vscode with a special flag --launch-target <target>. This flags tells lldb-vscode to wait to be attached and then it execs the target program. I'm using lldb-vscode itself to do this, because it makes finding the launcher program easier. Also no CMAKE INSTALL scripts are needed.
- Besides this, the debugger creates a temporary FIFO file where the launcher program will write its pid to. That way the debugger will be sure of which program to attach.
- Once attach happend, the debugger creates a second temporary file to notify the launcher program that it has been attached, so that it can then exec. I'm using this instead of using a signal or a similar mechanism because I don't want the launcher program to wait indefinitely to be attached in case the debugger crashed. That would pollute the process list with a lot of hanging processes. Instead, I'm setting a 20 seconds timeout (that's an overkill) and the launcher program seeks in intervals the second tepmorary file.
Some notes:
- I preferred not to use sockets because it requires a lot of code and I only need a pid. It would also require a lot of code when windows support is implemented.
- I didn't add Windows support, as I don't have a windows machine, but adding support for it should be easy, as the FIFO file can be implemented with a named pipe, which is standard on Windows and works pretty much the same way.
The existing test which didn't pass on Linux, now passes.
Differential Revision: https://reviews.llvm.org/D93951
lldb-vsdode was communicating the list of modules to the IDE with events, which in practice ended up having some drawbacks
- when debugging large targets, the number of these events were easily 10k, which polluted the messages being transmitted, which caused the following: a harder time debugging the messages, a lag after terminated the process because of these messages being processes (this could easily take several seconds). The latter was specially bad, as users were complaining about it even when they didn't check the modules view.
- these events were rarely used, as users only check the modules view when something is wrong and they try to debug things.
After getting some feedback from users, we realized that it's better to not used events but make this simply a request and is triggered by users whenever they needed.
This diff achieves that and does some small clean up in the existing code.
Differential Revision: https://reviews.llvm.org/D94033
The test couldn't find lldb-server as it's path was being overridden by
LLDB_DEBUGSERVER_PATH environment variable (pointing to debugserver).
This test should always use lldb-server, as it tests its platform
capabilities.
There's no need for the environment override, as lldb-server tests
should test the executable they just built, so I just remote the
override capability.
The tests don't work with remote debugservers. This isn't a problem with
any particular test, but the test infrastructure itself, which is why
each of these tests has a @skipIfDarwinEmbedded decorator.
This patch replaces that with a central category-based solution. It also
moves the ad-hoc windows skipping mechanism there too.
This uses the same approach as the debug info tests to avoid needing to
explicitly spell out the two kinds of tests. I convert a handful of
tests to the new mechanism. The rest will be converted in follow-up
patches.
Nearly all of our lldb-server tests have two flavours (lldb-server and
debugserver). Each of them is tagged with an appropriate decorator, and
each of them starts with a call to a matching "init" method. The init
calls are mandatory, and it's not possible to meaningfully combine them
with a different decorator.
This patch leverages the existing decorators to also tag the tests with
the appropriate debug server tag, similar to how we do with debug info
flavours. This allows us to make the "init" calls from inside the common
setUp method.
lldb-server tests are a very special subclass of "api" tests. As they
communicate with lldb-server directly, they don't actually need most of
facilities provided by our TestBase class. In particular, they don't
need the ability to fork debug info flavours of tests (but they could
use debug server flavours).
This makes them inherit from "Base" instead. This avoids the need to
explicitly mark these tests as NO_DEBUG_INFO_TEST_CASE. Two additional
necessary tweaks were:
- move run_platform_command to the base (Base) class. This is used in
one test, and can be generally useful when running tests remotely.
- add a "build" method, forwarding to buildDefault. This is to avoid
updating each test case to use buildDefault (also, "build" sounds
better). It might be interesting to refactor the (Test)Base classes so
that all debug info flavour handling happens in TestBase, and the Base
class provides a simple build method automatically.
TestLldbGdbServer.py testcases are timing out on LLDB/AArch64 Linux
buildbot since recent changes. I am temporarily increasing
DEFAULT_TIMEOUT to 20 seconds to see impact.
Now that the class does not use a thread, the name is no longer
appropriate. Rename the class to "Server" and make it a long-lived
object (instead of recreating it for every expect_gdbremote_sequence
call). The idea is to make this class a wrapper for all communication
with debug/lldb-server. This will enable some additional cleanups as we
had some duplication between socket_pump non-pump code paths.
Also squeeze in some small improvements:
- use python-level timeouts on sockets instead of the manual select
calls
- use byte arrays instead of strings when working with raw packets
This patch carries forward our aim to remove offset field from qRegisterInfo
packets and XML register description. I have created a new function which
returns if offset fields are dynamic meaning client can calculate offset on
its own based on register number sequence and register size. For now this
function only returns true for NativeRegisterContextLinux_arm64 but we can
test this for other architectures and make it standard later.
As a consequence we do not send offset field from lldb-server (arm64 for now)
while other stubs dont have an offset field so it wont effect them for now.
On the client side we have replaced previous offset calculation algorithm
with a new scheme, where we sort all primary registers in increasing
order of remote regnum and then calculate offset incrementally.
This committ also includes a test to verify all of above functionality
on Arm64.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D91241
This patch ovverides GetExpeditedRegisterSet for
NativeRegisterContextLinux_arm64 to send vector granule register in
expedited register set if SVE mode is selected.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D82855
Walter Erquinigo