According to [1], the template parameter must be cv-unqualified and one
of unsigned short, unsigned int, unsigned long, or unsigned long long.
Should fix the following MSVC error:
error: static assertion failed due to requirement
'_Is_any_of_v<unsigned char, unsigned short, unsigned int, unsigned
long, unsigned long long>': invalid template argument for
independent_bits_engine: N4659
[1] https://en.cppreference.com/w/cpp/numeric/random/independent_bits_engine
Hoist UUID generation into the UUID class and add a trivial unit test.
This also changes the telemetry code to drop the double underscore if we
failed to generate a UUID and subsequently logs to the Host instead of
Object log channel.
The tests for the
[intel-pt](3483740289/lldb/docs/use/intel_pt.rst)
trace plugin were failing for multiple reasons.
On machines where tracing is supported many of the tests were crashing
because of a nullptr dereference. It looks like the `core_file`
parameter in `ProcessTrace::CreateInstance` was once ignored, but was
changed to always being dereferenced. This caused the tests to fail even
when tracing was supported.
On machines where tracing is not supported we would still run tests that
attempt to take a trace. These would obviously fail because the required
hardware is not present. Note that some of the tests simply read
serialized json as trace files which does not require any special
hardware.
This PR fixes these two issues by guarding the pointer dereference and
then skipping unsupported tests on machines. With these changes the
trace tests pass on both types of machines.
We also add a new unit test to validate that a process can be created
with a nullptr core_file through the generic process trace plugin path.
So the dSYM can be told what target it has been loaded into.
When lldb is loading modules, while creating a target, it will run
"command script import" on any Python modules in Resources/Python in the
dSYM. However, this happens WHILE the target is being created, so it is
not yet in the target list. That means that these scripts can't act on
the target that they a part of when they get loaded.
This patch adds a new python API that lldb will call:
__lldb_module_added_to_target
if it is defined in the module, passing in the Target the module was
being added to, so that code in these dSYM's don't have to guess.
This patch adds --platform-available-ports option to the dotest.py
script to avoid hardcoded gdb ports in lldb testsuite.
Currently, this option could be helpful in GdbRemoteTestCases (e.g.
TestLldbGdbServer, TestNonStop, TestGdbRemoteThreadsInStopReply,
TestGdbRemotePlatformFile, TestGdbRemote_vCont)
Since lldb 20, these have had no effect:
https://releases.llvm.org/20.1.0/docs/ReleaseNotes.html#changes-to-lldb
> lldb-server now listens to a single port for gdbserver connections and
> provides that port to the connection handler processes. This means
that
> only 2 ports need to be opened in the firewall (one for the
lldb-server
> platform, one for gdbserver connections). In addition, due to this
work,
lldb-server now works on Windows in the server mode.
Remove them.
Simplify and fix the logic to clear the old statusline when the terminal
window dimensions have changed. I accidentally broke the terminal
resizing behavior when addressing code review feedback.
I'd really like to figure out a way to test this. PExpect isn't a good
fit for this, because I really need to check the result, rather than the
control characters, as the latter doesn't tell me whether any part of
the old statusline is still visible.
These tests are currently filtered on macOS if your on an M1 (or newer)
device. These tests do work on macOS, for me at least on M1 Max with
macOS 15.3.2 and Xcode 16.2.
Enabling them again, but if we have CI problems with them we can keep
them disabled.
The `locked` variable can be accessed from the asynchronous thread until
the call to f.wait() completes. However, the variable is scoped in a
lexical block that ends before that, leading to a use-after-free.
Convert Breakpoint & Watchpoints structs to classes to provide proper
access control. This is in preparation for adopting SBMutex to protect
the underlying SBBreakpoint and SBWatchpoint.
This patch improves LLDB launch time on Linux machines for **preload
scenarios**, particularly for executables with a lot of shared library
dependencies (or modules). Specifically:
* Launching a binary with `target.preload-symbols = true`
* Attaching to a process with `target.preload-symbols = true`.
It's completely controlled by a new flag added in the first commit
`plugin.dynamic-loader.posix-dyld.parallel-module-load`, which *defaults
to false*. This was inspired by similar work on Darwin #110646.
Some rough numbers to showcase perf improvement, run on a very beefy
machine:
* Executable with ~5600 modules: baseline 45s, improvement 15s
* Executable with ~3800 modules: baseline 25s, improvement 10s
* Executable with ~6650 modules: baseline 67s, improvement 20s
* Executable with ~12500 modules: baseline 185s, improvement 85s
* Executable with ~14700 modules: baseline 235s, improvement 120s
A lot of targets we deal with have a *ton* of modules, and unfortunately
we're unable to convince other folks to reduce the number of modules, so
performance improvements like this can be very impactful for user
experience.
This patch achieves the performance improvement by parallelizing
`DynamicLoaderPOSIXDYLD::RefreshModules` for the launch scenario, and
`DynamicLoaderPOSIXDYLD::LoadAllCurrentModules` for the attach scenario.
The commits have some context on their specific changes as well --
hopefully this helps the review.
# More context on implementation
We discovered the bottlenecks by via `perf record -g -p <lldb's pid>` on
a Linux machine. With an executable known to have 1000s of shared
library dependencies, I ran
```
(lldb) b main
(lldb) r
# taking a while
```
and showed the resulting perf trace (snippet shown)
```
Samples: 85K of event 'cycles:P', Event count (approx.): 54615855812
Children Self Command Shared Object Symbol
- 93.54% 0.00% intern-state libc.so.6 [.] clone3
clone3
start_thread
lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*) r
std::_Function_handler<void* (), lldb_private::Process::StartPrivateStateThread(bool)::$_0>::_M_invoke(std::_Any_data const&)
lldb_private::Process::RunPrivateStateThread(bool) n
- lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
- 93.54% lldb_private::Process::ShouldBroadcastEvent(lldb_private::Event*)
- 93.54% lldb_private::ThreadList::ShouldStop(lldb_private::Event*)
- lldb_private::Thread::ShouldStop(lldb_private::Event*) *
- 93.53% lldb_private::StopInfoBreakpoint::ShouldStopSynchronous(lldb_private::Event*) t
- 93.52% lldb_private::BreakpointSite::ShouldStop(lldb_private::StoppointCallbackContext*) i
lldb_private::BreakpointLocationCollection::ShouldStop(lldb_private::StoppointCallbackContext*) k
lldb_private::BreakpointLocation::ShouldStop(lldb_private::StoppointCallbackContext*) b
lldb_private::BreakpointOptions::InvokeCallback(lldb_private::StoppointCallbackContext*, unsigned long, unsigned long) i
DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit(void*, lldb_private::StoppointCallbackContext*, unsigned long, unsigned lo
- DynamicLoaderPOSIXDYLD::RefreshModules() O
- 93.42% DynamicLoaderPOSIXDYLD::RefreshModules()::$_0::operator()(DYLDRendezvous::SOEntry const&) const u
- 93.40% DynamicLoaderPOSIXDYLD::LoadModuleAtAddress(lldb_private::FileSpec const&, unsigned long, unsigned long, bools
- lldb_private::DynamicLoader::LoadModuleAtAddress(lldb_private::FileSpec const&, unsigned long, unsigned long, boos
- 83.90% lldb_private::DynamicLoader::FindModuleViaTarget(lldb_private::FileSpec const&) o
- 83.01% lldb_private::Target::GetOrCreateModule(lldb_private::ModuleSpec const&, bool, lldb_private::Status*
- 77.89% lldb_private::Module::PreloadSymbols()
- 44.06% lldb_private::Symtab::PreloadSymbols()
- 43.66% lldb_private::Symtab::InitNameIndexes()
...
```
We saw that majority of time was spent in `RefreshModules`, with the
main culprit within it `LoadModuleAtAddress` which eventually calls
`PreloadSymbols`.
At first, `DynamicLoaderPOSIXDYLD::LoadModuleAtAddress` appears fairly
independent -- most of it deals with different files and then getting or
creating Modules from these files. The portions that aren't independent
seem to deal with ModuleLists, which appear concurrency safe. There were
members of `DynamicLoaderPOSIXDYLD` I had to synchronize though: namely
`m_loaded_modules` which `DynamicLoaderPOSIXDYLD` maintains to map its
loaded modules to their link addresses. Without synchronizing this, I
ran into SEGFAULTS and other issues when running `check-lldb`. I also
locked the assignment and comparison of `m_interpreter_module`, which
may be unnecessary.
# Alternate implementations
When creating this patch, another implementation I considered was
directly background-ing the call to `Module::PreloadSymbol` in
`Target::GetOrCreateModule`. It would have the added benefit of working
across platforms generically, and appeared to be concurrency safe. It
was done via `Debugger::GetThreadPool().async` directly. However, there
were a ton of concurrency issues, so I abandoned that approach for now.
# Testing
With the feature active, I tested via `ninja check-lldb` on both Debug
and Release builds several times (~5 or 6 altogether?), and didn't spot
additional failing or flaky tests.
I also tested manually on several different binaries, some with around
14000 modules, but just basic operations: launching, reaching main,
setting breakpoint, stepping, showing some backtraces.
I've also tested with the flag off just to make sure things behave
properly synchronously.
Remove raw access to PluginInstances vector
This commit modifies the PluginInstances class to remove direct access
to the m_instances vector. Instead, we expose a new `GetSnapshot` method
that returns a copy of the current state of the instances vector. All
external iteration over the instances is updated to use the new method.
The motivation for the change is to allow modifying the way we store
instances without having to change all the clients. This is a
preliminary change to allow enabling/disabling of plugins in which case
we want to iterate over only enabled plugins.
We also considered using a custom iterator that wraps the vector
iterator and can skip over disabled instances. That works, but the
iterator code is a bit messy with all template and typedefs to make a
compliant iterator.
Include the LLDB version in the lldbassert error message, and prompt
users to include it in the bug report. The majority of users that bother
filing a bug report just copy past the stack trace and often forget to
include this important detail. By putting it after the backtrace and
before the prompt, I'm hoping it'll get copy-pasted in.
rdar://146793016
In #133211, Greg suggested making the rate limit configurable through a
setting. Although adding the setting is easy, the two places where we
currently use rate limiting aren't tied to a particular debugger.
Although it'd be possible to hook up, given how few progress events
currently implement rate limiting, I don't think it's worth threading
this through, if that's even possible.
I still think it's a good idea to be consistent and make it easy to pick
the same rate limiting value, so I've moved it into a constant in the
Progress class.
Hey,
This solves an issue where running lldb-server-20 with a non-absolute
path (for example, when it's installed into `/usr/bin` and the user runs
it as `lldb-server-20 ...` and not `/usr/bin/lldb-server-20 ...`) fails
with `error: spawn_process failed: execve failed: No such file or
directory`. The underlying issue is that when run that way, it attempts
to execute a binary named `lldb-server-20` from its current directory.
This is also a mild security hazard because lldb-server is often being
run as root in the directory /tmp, meaning that an unprivileged user can
create the file /tmp/lldb-server-20 and lldb-server will execute it as
root. (although, well, it's a debugging server we're talking about, so
that may not be a real concern)
I haven't previously contributed to this project; if you want me to
change anything in the code please don't hesitate to let me know.
Expose u target API mutex through the SB API. This is motivated by
lldb-dap, which is built on top of the SB API and needs a way to execute
a series of SB API calls in an atomic manner (see #131242).
We can solve this problem by either introducing an additional layer of
locking at the DAP level or by exposing the existing locking at the SB
API level. This patch implements the second approach.
This was discussed in an RFC on Discourse [0]. The original
implementation exposed a move-only lock rather than a mutex [1] which
doesn't work well with SWIG 4.0 [2]. This implement the alternative
solution of exposing the mutex rather than the lock. The SBMutex
conforms to the BasicLockable requirement [3] (which is why the methods
are called `lock` and `unlock` rather than Lock and Unlock) so it can be
used as `std::lock_guard<lldb::SBMutex>` and
`std::unique_lock<lldb::SBMutex>`.
[0]: https://discourse.llvm.org/t/rfc-exposing-the-target-api-lock-through-the-sb-api/85215/6
[1]: https://github.com/llvm/llvm-project/pull/131404
[2]: https://discourse.llvm.org/t/rfc-bumping-the-minimum-swig-version-to-4-1-0/85377/9
[3]: https://en.cppreference.com/w/cpp/named_req/BasicLockable
The function had special handling for -1, but that is incompatible with
functions whose entry point is not the first address. Use std::nullopt
instead.
We recently added an explicit finalize to SBProgress, #128966. I
realized while adding some additional implementations of SBProgress that
we should to add `with` support for ease of use. This patch addresses
adding and `__enter()__` method (which a no-op) and an `__exit()__` to
swig. I also refactor the emitter for the test to leverage `with`
instead of explicitly calling finalize, and I've updated the docstrings.
Running tests with ubsan enabled showed that the current
`protocol::AdapterFeature` and `protocol::ClientFeature` enums are
incorrectly defined if we want to use them in a `llvm::DenseSet`. The
enums are currently untyped and this results in the undefined behavior.
Adding `FLAGS_ENUM()` wrappers to all the enums in the
`lldb-dap::protocol` namespace to ensure they're typed so they can be
used with types like `llvm::DenseSet`.
This adds new types and helpers to support the 'initialize' request with
the new typed RequestHandler. While working on this I found there were a
few cases where we incorrectly treated initialize arguments as
capabilities. The new `lldb_dap::protocol::InitializeRequestArguments`
and `lldb_dap::protocol::Capabilities` uncovered the inconsistencies.
---------
Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>
Use the reverse video [1] font effect (`${ansi.negative}`) as the
default for the statusline. Inverting the foreground and background
color has a better change as looking reasonably good, compared to
picking an arbitrary color.
[1] https://en.wikipedia.org/wiki/Reverse_video
In the original SBProgress patch, #123837, I didn't ensure the debugger
was broadcasting these events to the CLI as SBProgress has far been
focused on DAP. We had an internal ask to have SBProgress events
broadcasted to the CLI so this patch addresses that.
<img width="387" alt="image"
src="https://github.com/user-attachments/assets/5eb93a46-1db6-4d46-a6b7-2b2f9bbe71db"
/>
Added a new setting called `lldb-dap.arguments` and a debug
configuration attribute called `debugAdapterArgs` that can be used to
set the arguments used to launch the debug adapter. Right now this is
mostly useful for debugging purposes to add the `--wait-for-debugger`
option to lldb-dap.
Additionally, the extension will now check for a changed lldb-dap
executable or arguments when launching a debug session in server mode. I
had to add a new `DebugConfigurationProvider` to do this because VSCode
will show an unhelpful error modal when the
`DebugAdapterDescriptorFactory` returns `undefined`.
In order to facilitate this, I had to add two new properties to the
launch configuration that are used by the
`DebugAdapterDescriptorFactory` to tell VS Code how to launch the debug
adapter:
- `debugAdapterHostname` - the hostname for an existing lldb-dap server
- `debugAdapterPort` - the port for an existing lldb-dap server
I've also removed the check for the `executable` argument in
`LLDBDapDescriptorFactory.createDebugAdapterDescriptor()`. This argument
is only set by VS Code when the debug adapter executable properties are
set in the `package.json`. The LLDB DAP extension does not currently do
this (and I don't think it ever will). So, this makes the debug adapter
descriptor factory a little easier to read.
The check for whether or not `lldb-dap` exists has been moved into the
new `DebugConfigurationProvider` as well. This way the extension won't
get in the user's way unless they actually try to start a debugging
session. The error will show up as a modal which will also make it more
obvious when something goes wrong, rather than popping up as a warning
at the bottom right of the screen.
Emit progress events from SymbolFileDWARFDebugMap. Because we know the
number of OSOs, we can show determinate progress. This is based on a
patch from Adrian, and part of what prompted me to look into improving
how LLDB shows progress events. Before the statusline, all these
progress events would get shadowed and never displayed on the command
line.
The main change here is that we're now able to correctly look up plans
for these functions. Previously, due to caching, we could end up with
one entry covering most of the address space (because part of the
function was at the beginning and one at the end). Now, we can correctly
recognise that the part in between does not belong to that function, and
we can create a different FuncUnwinders instance for it. It doesn't help
the discontinuous function much (its plan will still be garbled), but
we can at least properly unwind out of the simple functions in between.
Fixing the unwind plans for discontinuous functions requires handling
each unwind source specially, and this setup allows us to make the
transition incrementally.
Using argv[0] for this was incorrect. I'm ignoring LaunchInfo::SetArg0,
as that's what darwin and windows launchers do (they use the first
element of the args vector instead).
I picked up the funny unit test re-exec method from the llvm unit tests.
The surrounding code doesn't use them anymore. This removes the internal
usages.
This patch makes the Rows actual values. An alternative would be to make
them unique_ptrs. That would make vector resizes faster at the cost of
more pointer chasing and heap fragmentation. I don't know which one is
better so I picked the simpler option.
When redrawing the statusline, the current implementation would clear
the current line before drawing the new content. Since we always
overwrite the whole statusline from beginning to end, there's no need to
clear it and we can avoid the potential for flickering.
There's no need to call RedrawStatusline from HandleProgressEvent. The
statusline gets redraw after handling all events, including progress
events, in the default event handler loop.
Add a statusline to command-line LLDB to display information about the
current state of the debugger. The statusline is a dedicated area
displayed at the bottom of the screen. The information displayed is
configurable through a setting consisting of LLDB’s format strings.
Enablement
----------
The statusline is enabled by default, but can be disabled with the
following setting:
```
(lldb) settings set show-statusline false
```
Configuration
-------------
The statusline is configurable through the `statusline-format` setting.
The default configuration shows the target name, the current file, the
stop reason and any ongoing progress events.
```
(lldb) settings show statusline-format
statusline-format (format-string) = "${ansi.bg.blue}${ansi.fg.black}{${target.file.basename}}{ | ${line.file.basename}:${line.number}:${line.column}}{ | ${thread.stop-reason}}{ | {${progress.count} }${progress.message}}"
```
The statusline supersedes the current progress reporting implementation.
Consequently, the following settings no longer have any effect (but
continue to exist to not break anyone's `.lldbinit`):
```
show-progress -- Whether to show progress or not if the debugger's output is an interactive color-enabled terminal.
show-progress-ansi-prefix -- When displaying progress in a color-enabled terminal, use the ANSI terminal code specified in this format immediately before the progress message.
show-progress-ansi-suffix -- When displaying progress in a color-enabled terminal, use the ANSI terminal code specified in this format immediately after the progress message.
```
Format Strings
--------------
LLDB's format strings are documented in the LLDB documentation and on
the website: https://lldb.llvm.org/use/formatting.html#format-strings.
The current implementation is relatively limited but various
improvements have been discussed in the RFC.
One such improvement is being to display a string when a format string
is empty. Right now, when launching LLDB without a target, the
statusline will be empty, which is expected, but looks rather odd.
RFC
---
The full RFC can be found on Discourse:
https://discourse.llvm.org/t/rfc-lldb-statusline/83948
