This PR ensures we correctly restore the cursor column after resizing
the statusline. To ensure we have space for the statusline, we have to
emit a newline to move up everything on screen. The newline causes the
cursor to move to the start of the next line, which needs to be undone.
Normally, we would use escape codes to save & restore the cursor
position, but that doesn't work here, as the cursor position may have
(purposely) changed. Instead, we move the cursor up one line using an
escape code, but we weren't restoring the column.
Interestingly, Editline was able to recover from this issue through the
LineInfo struct which contains the buffer and the cursor location, which
allows us to compute the column. This PR addresses the bug by having
Editline "refresh" the cursor position.
Fixes#134064
Rather than having one MCP server per debugger, make the MCP server
global and pass a debugger id along with tool invocations that require
one. This PR also adds a second tool to list the available debuggers
with their targets so the model can decide which debugger instance to
use.
This PR adds an MCP (Model Context Protocol ) server to LLDB. For
motivation and background, please refer to the corresponding RFC:
https://discourse.llvm.org/t/rfc-adding-mcp-support-to-lldb/86798
I implemented this as a new kind of plugin. The idea is that we could
support multiple protocol servers (e.g. if we want to support DAP from
within LLDB). This also introduces a corresponding top-level command
(`protocol-server`) with two subcommands to `start` and `stop` the
server.
```
(lldb) protocol-server start MCP tcp://localhost:1234
MCP server started with connection listeners: connection://[::1]:1234, connection://[127.0.0.1]:1234
```
The MCP sever supports one tool (`lldb_command`) which executes a
command, but can easily be extended with more commands.
This fixes a data race between the main thread and the default event
handler thread. The statusline format option value was protected by a
mutex, but it was returned as a pointer, allowing one thread to access
it while another was modifying it.
Avoid the data race by returning format values by value instead of by
pointer.
Something to do with control code handling in Windows terminals breaks
the statusline in various ways. It makes LLDB unusable and even if you
set the setting to disable statusline, it's too late, and the terminal
session is now in a weird state.
See https://github.com/llvm/llvm-project/issues/134846 for more details.
Until we figure this out, don't allow it to be used on Windows.
This patch is slightly different from other impl in that we dispatch
client-telemetry via a different helper method. This is to make it
easier for vendor to opt-out (simply by overriding the method to do
nothing). There is also a configuration option to disallow collecting
client telemetry.
---------
Co-authored-by: Pavel Labath <pavel@labath.sk>
Show assembly code when the source code for a frame is not available in
the debugger machine
Edit: this functionality will work only when using
`stop-disassembly-display = no-source` in the settings
Fix#136492
After the fix:
[Screencast From 2025-04-20
18-00-30.webm](https://github.com/user-attachments/assets/1ce41715-cf4f-42a1-8f5c-6196b9d685dc)
And use this functionality to replace the ASCII "|" with the same
full-geight line-drawing character used in diagnostics rendering on a
color terminal.
Fixes https://github.com/llvm/llvm-project/issues/22981
If `settings set use-color` is changed when lldb is running it does not take effect.
This is fixes that.
---------
Signed-off-by: Ebuka Ezike <yerimyah1@gmail.com>
Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>
Eliminate the potential for a race between the main thread, the default
event handler thread and the signal handling thread, when accessing the
m_statusline member.
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 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"
/>
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
Remove support for coalescing progress reports in LLDB. This
functionality was motivated by Xcode, which wanted to listen for less
frequent, aggregated progress events at the cost of losing some detail.
See the original RFC [1] for more details. Since then, they've
reevaluated this trade-off and opted to listen for the regular, full
fidelity progress events and do any post processing on their end.
rdar://146425487
This type of entry is used to collect data about the debugger
startup/exit
Also introduced a helper ScopedDispatcher
---------
Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>
Co-authored-by: Pavel Labath <pavel@labath.sk>
Make StreamAsynchronousIO an unique_ptr instead of a shared_ptr. I tried
passing the class by value, but the llvm::raw_ostream forwarder stored
in the Stream parent class isn't movable and I don't think it's worth
changing that. Additionally, there's a few places that expect a
StreamSP, which are easily created from a StreamUP.
This patch improves the synchronization of the debugger's output and error
streams using two new abstractions: `LockableStreamFile` and
`LockedStreamFile`.
- `LockableStreamFile` is a wrapper around a `StreamFile` and a mutex. Client
cannot use the `StreamFile` without calling `Lock`, which returns a
`LockedStreamFile`.
- `LockedStreamFile` is an RAII object that locks the stream for the duration
of its existence. As long as you hold on to the returned object you are
permitted to write to the stream. The destruction of the object
automatically flush the output stream.
A handful of minor improvements to StreamAsynchronousIO:
- Document the class.
- Use a named enum value to distinguishing between stdout and stderr.
- Add missing period to comment.
- Clear the string instead of assigning to it.
- Eliminate color argument.
This makes GetOutputStreamSP and GetErrorStreamSP protected members of
Debugger. Users who want to print to the debugger's stream should use
GetAsyncOutputStreamSP and GetAsyncErrorStreamSP instead and the few
remaining stragglers have been migrated.
Remove Debugger::GetOutputStream and Debugger::GetErrorStream in
preparation for replacing both with a new variant that needs to be
locked and hence can't be handed out like we do right now.
The patch replaces most uses with GetAsyncOutputStream and
GetAsyncErrorStream respectively. There methods return new StreamSP
objects that automatically get flushed on destruction.
See #126630 for more details.
Recently I've been working on a lot of internal Python tooling, and in
certain cases I want to report async to the script over DAP. Progress.h
already handles this, so I've exposed Progress via the SB API so Python
scripts can also update progress objects.
I actually have no idea how to test this, so I just wrote a [toy command
to test
it](https://gist.github.com/Jlalond/48d85e75a91f7a137e3142e6a13d0947)
I also copied the first section of the extensive Progress.h class
documentation to the docstrings.
Currently, we arbitrarily paginate editline completions to 40 elements.
On large terminals, that leaves some real-estate unused. On small
terminals, it's pretty annoying to not see the first completions. We can
address both issues by using the terminal height for pagination.
This builds on the improvements of #116456.
Summary of Changes:
Replaced the ineffective call to `substr` with a more efficient use of
`resize` to truncate the string.
Adjusted the code to use 'resize' instead of 'substr' for better
performance and readability.
Removed unwanted file from the previous commit.
Fixes: #91209
---------
Co-authored-by: aabhinavg <tiwariabhinavak@gmail.com>
This patch is a reworking of Pete Lawrence's (@PortalPete) proposal
for better expression evaluator error messages:
https://github.com/llvm/llvm-project/pull/80938
Before:
```
$ lldb -o "expr a+b"
(lldb) expr a+b
error: <user expression 0>:1:1: use of undeclared identifier 'a'
a+b
^
error: <user expression 0>:1:3: use of undeclared identifier 'b'
a+b
^
```
After:
```
(lldb) expr a+b
^ ^
│ ╰─ error: use of undeclared identifier 'b'
╰─ error: use of undeclared identifier 'a'
```
This eliminates the confusing `<user expression 0>:1:3` source
location and avoids echoing the expression to the console again, which
results in a cleaner presentation that makes it easier to grasp what's
going on. You can't see it here, bug the word "error" is now also in
color, if so desired.
Depends on https://github.com/llvm/llvm-project/pull/106442.
This patch is a reworking of Pete Lawrence's (@PortalPete) proposal
for better expression evaluator error messages:
https://github.com/llvm/llvm-project/pull/80938
Before:
```
$ lldb -o "expr a+b"
(lldb) expr a+b
error: <user expression 0>:1:1: use of undeclared identifier 'a'
a+b
^
error: <user expression 0>:1:3: use of undeclared identifier 'b'
a+b
^
```
After:
```
(lldb) expr a+b
^ ^
│ ╰─ error: use of undeclared identifier 'b'
╰─ error: use of undeclared identifier 'a'
```
This eliminates the confusing `<user expression 0>:1:3` source
location and avoids echoing the expression to the console again, which
results in a cleaner presentation that makes it easier to grasp what's
going on. You can't see it here, bug the word "error" is now also in
color, if so desired.
Depends on https://github.com/llvm/llvm-project/pull/106442.
This patch removes all of the Set.* methods from Status.
This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.
This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()
Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form
` ResultTy DoFoo(Status& error)
`
to
` llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?
The interesting changes are in Status.h and Status.cpp, all other
changes are mostly
` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.
Compilers and language runtimes often use helper functions that are
fundamentally uninteresting when debugging anything but the
compiler/runtime itself. This patch introduces a user-extensible
mechanism that allows for these frames to be hidden from backtraces and
automatically skipped over when navigating the stack with `up` and
`down`.
This does not affect the numbering of frames, so `f <N>` will still
provide access to the hidden frames. The `bt` output will also print a
hint that frames have been hidden.
My primary motivation for this feature is to hide thunks in the Swift
programming language, but I'm including an example recognizer for
`std::function::operator()` that I wished for myself many times while
debugging LLDB.
rdar://126629381
Example output. (Yes, my proof-of-concept recognizer could hide even
more frames if we had a method that returned the function name without
the return type or I used something that isn't based off regex, but it's
really only meant as an example).
before:
```
(lldb) thread backtrace --filtered=false
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
* frame #0: 0x0000000100001f04 a.out`foo(x=1, y=1) at main.cpp:4:10
frame #1: 0x0000000100003a00 a.out`decltype(std::declval<int (*&)(int, int)>()(std::declval<int>(), std::declval<int>())) std::__1::__invoke[abi:se200000]<int (*&)(int, int), int, int>(__f=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:149:25
frame #2: 0x000000010000399c a.out`int std::__1::__invoke_void_return_wrapper<int, false>::__call[abi:se200000]<int (*&)(int, int), int, int>(__args=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:216:12
frame #3: 0x0000000100003968 a.out`std::__1::__function::__alloc_func<int (*)(int, int), std::__1::allocator<int (*)(int, int)>, int (int, int)>::operator()[abi:se200000](this=0x000000016fdff280, __arg=0x000000016fdff224, __arg=0x000000016fdff220) at function.h:171:12
frame #4: 0x00000001000026bc a.out`std::__1::__function::__func<int (*)(int, int), std::__1::allocator<int (*)(int, int)>, int (int, int)>::operator()(this=0x000000016fdff278, __arg=0x000000016fdff224, __arg=0x000000016fdff220) at function.h:313:10
frame #5: 0x0000000100003c38 a.out`std::__1::__function::__value_func<int (int, int)>::operator()[abi:se200000](this=0x000000016fdff278, __args=0x000000016fdff224, __args=0x000000016fdff220) const at function.h:430:12
frame #6: 0x0000000100002038 a.out`std::__1::function<int (int, int)>::operator()(this= Function = foo(int, int) , __arg=1, __arg=1) const at function.h:989:10
frame #7: 0x0000000100001f64 a.out`main(argc=1, argv=0x000000016fdff4f8) at main.cpp:9:10
frame #8: 0x0000000183cdf154 dyld`start + 2476
(lldb)
```
after
```
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
* frame #0: 0x0000000100001f04 a.out`foo(x=1, y=1) at main.cpp:4:10
frame #1: 0x0000000100003a00 a.out`decltype(std::declval<int (*&)(int, int)>()(std::declval<int>(), std::declval<int>())) std::__1::__invoke[abi:se200000]<int (*&)(int, int), int, int>(__f=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:149:25
frame #2: 0x000000010000399c a.out`int std::__1::__invoke_void_return_wrapper<int, false>::__call[abi:se200000]<int (*&)(int, int), int, int>(__args=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:216:12
frame #6: 0x0000000100002038 a.out`std::__1::function<int (int, int)>::operator()(this= Function = foo(int, int) , __arg=1, __arg=1) const at function.h:989:10
frame #7: 0x0000000100001f64 a.out`main(argc=1, argv=0x000000016fdff4f8) at main.cpp:9:10
frame #8: 0x0000000183cdf154 dyld`start + 2476
Note: Some frames were hidden by frame recognizers
```
# Motivation
Individual callers of `SBDebugger::SetDestroyCallback()` might think
that they have registered their callback and expect it to be called when
the debugger is destroyed. In reality, only the last caller survives,
and all previous callers are forgotten, which might be a surprise to
them. Worse, if this is called in a race condition, which callback
survives is less predictable, which may case confusing behavior
elsewhere.
# This PR
Allows multiple destroy callbacks to be registered and all called when
the debugger is destroyed.
**EDIT**: Adds two new APIs: `AddDestroyCallback()` and
`ClearDestroyCallback()`. `SetDestroyCallback()` will first clear then
add the given callback. Tests are added for the new APIs.
## Tests
```
bin/llvm-lit -sv ../external/llvm-project/lldb/test/API/python_api/debugger/TestDebuggerAPI.py
```
## (out-dated, see comments below) Semantic change to
`SetDestroyCallback()`
~~Currently, the method overwrites the old callback with the new one.
With this PR, it will NOT overwrite. Instead, it will hold on to both.
Both callbacks get called during destroy.~~
~~**Risk**: Although the documentation of `SetDestroyCallback()` (see
[C++](https://lldb.llvm.org/cpp_reference/classlldb_1_1SBDebugger.html#afa1649d9453a376b5c95888b5a0cb4ec)
and
[python](https://lldb.llvm.org/python_api/lldb.SBDebugger.html#lldb.SBDebugger.SetDestroyCallback))
doesn't really specify the behavior, there is a risk: if existing call
sites rely on the "overwrite" behavior, they will be surprised because
now the old callback will get called. But as the above said, the current
behavior of "overwrite" itself might be unintended, so I don't
anticipate users to rely on this behavior. In short, this risk might be
less of a problem if we correct it sooner rather than later (which is
what this PR is trying to do).~~
## (out-dated, see comments below) Implementation
~~The implementation holds a `std::vector<std::pair<callback, baton>>`.
When `SetDestroyCallback()` is called, callbacks and batons are appended
to the `std::vector`. When destroy event happen, the `(callback, baton)`
pairs are invoked FIFO. Finally, the `std::vector` is cleared.~~
# (out-dated, see comments below) Alternatives considered
~~Instead of changing `SetDestroyCallback()`, a new method
`AddDestroyCallback()` can be added, which use the same
`std::vector<std::pair<>>` implementation. Together with
`ClearDestroyCallback()` (see below), they will replace and deprecate
`SetDestroyCallback()`. Meanwhile, in order to be backward compatible,
`SetDestroyCallback()` need to be updated to clear the `std::vector` and
then add the new callback. Pros: The end state is semantically more
correct. Cons: More steps to take; potentially maintaining an
"incorrect" behavior (of "overwrite").~~
~~A new method `ClearDestroyCallback()` can be added. Might be
unnecessary at this point, because workflows which need to set then
clear callbacks may exist but shouldn't be too common at least for now.
Such method can be added later when needed.~~
~~The `std::vector` may bring slight performance drawback if its
implementation doesn't handle small size efficiently. However, even if
that's the case, this path should be very cold (only used during init
and destroy). Such performance drawback should be negligible.~~
~~A different implementation was also considered. Instead of using
`std::vector`, the current `m_destroy_callback` field can be kept
unchanged. When `SetDestroyCallback()` is called, a lambda function can
be stored into `m_destroy_callback`. This lambda function will first
call the old callback, then the new one. This way, `std::vector` is
avoided. However, this implementation is more complex, thus less
readable, with not much perf to gain.~~
---------
Co-authored-by: Roy Shi <royshi@meta.com>
Removes the debugger broadcast bits from `Debugger.h` and instead uses
the enum from `lldb-enumerations.h` and adds the
`eBroadcastSymbolChange` bit to the enum in `lldb-enumerations.h`. This fixes a bug wherein the incorrect broadcast bit could be referenced due both of these enums previously existing and being out-of-sync with each other.
These are hardcoded strings that are already present in the data section
of the binary, no need to immediately place them in the ConstString
StringPools. Lots of code still calls `GetBroadcasterClass` and places
the return value into a ConstString. Changing that would be a good
follow-up.
Additionally, calls to these functions are still wrapped in ConstStrings
at the SBAPI layer. This is because we must guarantee the lifetime of
all strings handed out publicly.
Some languages may create artificial functions that have no real user
code, even though there is line table information for them. One such
case is with coroutine code that receives the CoroSplitter
transformation in LLVM IR. That code transformation creates many
different Functions, cloning one Instruction into many Instructions in
many different Functions and copying the associated debug locations.
It would be difficult to make that pass delete debug locations of cloned
instructions in a language agnostic way (is it even possible?), but LLDB
can ignore certain locations by querying its Language APIs and having it
decide based on, for example, mangling information.
llvm-project/lldb/source/Core/Debugger.cpp:107:14:
error: no type named 'DefaultThreadPoolThreadPool' in namespace 'llvm'
static llvm::DefaultThreadPoolThreadPool *g_thread_pool = nullptr;
~~~~~~^
1 error generated.
The base class llvm::ThreadPoolInterface will be renamed
llvm::ThreadPool in a subsequent commit.
This is a breaking change: clients who use to create a ThreadPool must
now create a DefaultThreadPool instead.
