217 Commits

Author SHA1 Message Date
Felipe de Azevedo Piovezan
c416034374
[lldb][NFC] Address follow up comments in ExecutionContext (#153110)
The PR https://github.com/llvm/llvm-project/pull/152020 got merged by
accident. This commit addresses some follow up review comments.
2025-08-11 17:21:45 -07:00
Felipe de Azevedo Piovezan
f12e0380be
[lldb] Guard SBFrame/SBThread methods against running processes (#152020)
Prior to this patch, SBFrame/SBThread methods exhibit racy behavior if
called while the process is running, because they do not lock the
`Process::RetRunLock` mutex. If they did, they would fail, correctly
identifying that the process is not running.

Some methods _attempt_ to protect against this with the pattern:

```
ExecutionContext exe_ctx(m_opaque_sp.get(), lock); // this is a different lock
Process *process = exe_ctx.GetProcessPtr();
if (process) {
  Process::StopLocker stop_locker;
  if (stop_locker.TryLock(&process->GetRunLock()))
        .... do work ...
```

However, this is also racy: the constructor of `ExecutionContext` will
access the frame list, which is something that can only be done once the
process is stopped.

With this patch:

1. The constructor of `ExecutionContext` now expects a `ProcessRunLock`
as an argument. It attempts to lock the run lock, and only fills in
information about frames and threads if the lock can be acquired.
Callers of the constructor are expected to check the lock.
2. All uses of ExecutionContext are adjusted to conform to the above.
3. The SBThread.cpp-defined helper function ResumeNewPlan now expects a
locked ProcessRunLock as _proof_ that the execution is stopped. It will
unlock the mutex prior to resuming the process.

This commit exposes many opportunities for early-returns, but these
would increase the diff of this patch and distract from the important
changes, so we opt not to do it here.
2025-08-11 10:26:57 -07:00
Felipe de Azevedo Piovezan
849daa4aa0
[lldb][NFC] Move SBThread::ResumeNewPlan out of the header (#151988)
This *private* method is only defined as a member class of SBThread so
that it may be declared a `friend` of SBError and access a private
constructor of SBError that takes a `Status`, which is an `lldb_private`
object. In other words, the method does not use anything about the class
is belongs to, so it has no business being a member method.

A subsequent patch will need to add a new argument to this class, a
`Process::StopLocker`, which is also another `lldb_private` object. This
is another strong suggestion that this method does not belong on the
header file of a public API, even if at the private visibility level. We
can't forward declare nested types like `Process:StopLocker`, so this
problem is not easily solvable.

This commit moves the method out of the header and into an anon
namespace of the cpp file. It is also made to return a Status instead,
and the private `SBError` constructor is accessed by the SBThread
methods that call it.
2025-08-04 09:43:39 -07:00
Pavel Labath
1b237198dc
Reapply "[lldb] Implement basic support for reverse-continue (#125242)" (again) (#128156)
This reverts commit
87b7f63a11,
reapplying

7e66cf74fb
with a small (and probably temporary)
change to generate more debug info to help with diagnosing buildbot
issues.
2025-03-17 16:06:25 +01:00
Adrian Prantl
87b7f63a11 Revert "Reland "[lldb] Implement basic support for reverse-continue" (#125242)"
This reverts commit 7e66cf74fb4e6a103f923e34700a7b6f20ac2a9b.

Breaking green dragon:

https://green.lab.llvm.org/job/llvm.org/view/LLDB/job/as-lldb-cmake/19569/testReport/junit/lldb-api/functionalities_reverse-execution/TestReverseContinueWatchpoints_py/
2025-01-31 13:11:20 -08:00
David Spickett
7e66cf74fb
Reland "[lldb] Implement basic support for reverse-continue" (#125242)
This reverts commit a774de807e56c1147d4630bfec3110c11d41776e.

This is the same changes as last time, plus:
* We load the binary into the target object so that on Windows, we can
resolve the locations of the functions.
* We now assert that each required breakpoint has at least 1 location,
to prevent an issue like that in the future.
* We are less strict about the unsupported error message, because it
prints "error: windows" on Windows instead of "error: gdb-remote".
2025-01-31 15:56:33 +00:00
David Spickett
a774de807e
Revert "Reland "[lldb] Implement basic support for reverse-continue" (#123906)"" (#125091)
Reverts llvm/llvm-project#123945

Has failed on the Windows on Arm buildbot:
https://lab.llvm.org/buildbot/#/builders/141/builds/5865
```
********************
Unresolved Tests (2):
  lldb-api :: functionalities/reverse-execution/TestReverseContinueBreakpoints.py
  lldb-api :: functionalities/reverse-execution/TestReverseContinueWatchpoints.py
********************
Failed Tests (1):
  lldb-api :: functionalities/reverse-execution/TestReverseContinueNotSupported.py
```
Reverting while I reproduce locally.
2025-01-30 16:45:36 +00:00
David Spickett
0caba6c8dc
Reland "[lldb] Implement basic support for reverse-continue" (#123906)" (#123945)
This reverts commit 22561cfb443267905d4190f0e2a738e6b412457f and fixes
b7b9ccf44988edf49886743ae5c3cf4184db211f (#112079).

The problem is that x86_64 and Arm 32-bit have memory regions above the
stack that are readable but not writeable. First Arm:
```
(lldb) memory region --all
<...>
[0x00000000fffcf000-0x00000000ffff0000) rw- [stack]
[0x00000000ffff0000-0x00000000ffff1000) r-x [vectors]
[0x00000000ffff1000-0xffffffffffffffff) ---
```
Then x86_64:
```
$ cat /proc/self/maps
<...>
7ffdcd148000-7ffdcd16a000 rw-p 00000000 00:00 0                          [stack]
7ffdcd193000-7ffdcd196000 r--p 00000000 00:00 0                          [vvar]
7ffdcd196000-7ffdcd197000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]
```
Compare this to AArch64 where the test did pass:
```
$ cat /proc/self/maps
<...>
ffffb87dc000-ffffb87dd000 r--p 00000000 00:00 0                          [vvar]
ffffb87dd000-ffffb87de000 r-xp 00000000 00:00 0                          [vdso]
ffffb87de000-ffffb87e0000 r--p 0002a000 00:3c 76927217                   /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
ffffb87e0000-ffffb87e2000 rw-p 0002c000 00:3c 76927217                   /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
fffff4216000-fffff4237000 rw-p 00000000 00:00 0                          [stack]
```
To solve this, look up the memory region of the stack pointer (using
https://lldb.llvm.org/resources/lldbgdbremote.html#qmemoryregioninfo-addr)
and constrain the read to within that region. Since we know the stack is
all readable and writeable.

I have also added skipIfRemote to the tests, since getting them working
in that context is too complex to be worth it.

Memory write failures now display the range they tried to write, and
register write errors will show the name of the register where possible.

The patch also includes a workaround for a an issue where the test code
could mistake an `x` response that happens to begin with an `O` for an
output packet (stdout). This workaround will not be necessary one we
start using the [new
implementation](https://discourse.llvm.org/t/rfc-fixing-incompatibilties-of-the-x-packet-w-r-t-gdb/84288)
of the `x` packet.

---------

Co-authored-by: Pavel Labath <pavel@labath.sk>
2025-01-30 14:03:01 +00:00
Pavel Labath
22561cfb44
Revert "[lldb] Implement basic support for reverse-continue" (#123906)
Reverts llvm/llvm-project#112079 due to failures on the arm bot.
2025-01-22 09:43:11 +01:00
Robert O'Callahan
b7b9ccf449
[lldb] Implement basic support for reverse-continue (#112079)
This commit adds support for a
`SBProcess::ContinueInDirection()` API. A user-accessible command for
this will follow in a later commit.

This feature depends on a gdbserver implementation (e.g. `rr`) providing
support for the `bc` and `bs` packets. `lldb-server` does not support
those packets, and there is no plan to change that. For testing
purposes, this commit adds a Python implementation of *very limited*
record-and-reverse-execute functionality, implemented as a proxy between
lldb and lldb-server in `lldbreverse.py`. This should not (and in
practice cannot) be used for anything except testing.

The tests here are quite minimal but we test that simple breakpoints and
watchpoints work as expected during reverse execution, and that
conditional breakpoints and watchpoints work when the condition calls a
function that must be executed in the forward direction.
2025-01-22 08:37:17 +01:00
Pavel Labath
f66a5e220c
[lldb] Fix SBThread::StepOverUntil for discontinuous functions (#123046)
I think the only issue here was that we would erroneously consider
functions which are "in the middle" of the function were stepping to as
a part of the function, and would try to step into them (likely stepping
out of the function instead) instead of giving up early.
2025-01-17 12:13:30 +01:00
Jonas Devlieghere
b852fb1ec5
[lldb] Move ValueObject into its own library (NFC) (#113393)
ValueObject is part of lldbCore for historical reasons, but conceptually
it deserves to be its own library. This does introduce a (link-time) circular
dependency between lldbCore and lldbValueObject, which is unfortunate
but probably unavoidable because so many things in LLDB rely on
ValueObject. We already have cycles and these libraries are never built
as dylibs so while this doesn't improve the situation, it also doesn't
make things worse.

The header includes were updated with the following command:

```
find . -type f -exec sed -i.bak "s%include \"lldb/Core/ValueObject%include \"lldb/ValueObject/ValueObject%" '{}' \;
```
2024-10-24 20:20:48 -07:00
Jason Molenda
3bef742559 Revert "[lldb] Implement basic support for reverse-continue (#99736)"
Reverting this again; I added a commit which added @skipIfDarwin
markers to the TestReverseContinueBreakpoints.py and
TestReverseContinueNotSupported.py API tests, which use lldb-server
in gdbserver mode which does not work on Darwin.  But the aarch64 ubuntu
bot reported a failure on TestReverseContinueBreakpoints.py,
https://lab.llvm.org/buildbot/#/builders/59/builds/6397

  File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/functionalities/reverse-execution/TestReverseContinueBreakpoints.py", line 63, in test_reverse_continue_skip_breakpoint
    self.reverse_continue_skip_breakpoint_internal(async_mode=False)
  File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/functionalities/reverse-execution/TestReverseContinueBreakpoints.py", line 81, in reverse_continue_skip_breakpoint_internal
    self.expect(
  File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2372, in expect
    self.runCmd(
  File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 1002, in runCmd
    self.assertTrue(self.res.Succeeded(), msg + output)
AssertionError: False is not true : Process should be stopped due to history boundary
Error output:
error: Process must be launched.

This reverts commit 4f297566b3150097de26c6a23a987d2bd5fc19c5.
2024-10-10 16:24:38 -07:00
Robert O'Callahan
4f297566b3 [lldb] Implement basic support for reverse-continue (#99736)
This commit only adds support for the
`SBProcess::ReverseContinue()` API. A user-accessible command for this
will follow in a later commit.

This feature depends on a gdbserver implementation (e.g. `rr`) providing
support for the `bc` and `bs` packets. `lldb-server` does not support
those packets, and there is no plan to change that. So, for testing
purposes, `lldbreverse.py` wraps `lldb-server` with a Python
implementation of *very limited* record-and-replay functionality for use
by *tests only*.

The majority of this PR is test infrastructure (about 700 of the 950
lines added).
2024-10-10 16:08:19 -07:00
Augusto Noronha
2ff4c25b7e Revert "[lldb] Implement basic support for reverse-continue (#99736)"
This reverts commit d5e1de6da96c1ab3b8cae68447e8ed3696a7006e.
2024-10-10 15:05:58 -07:00
Robert O'Callahan
d5e1de6da9
[lldb] Implement basic support for reverse-continue (#99736)
This commit only adds support for the
`SBProcess::ReverseContinue()` API. A user-accessible command for this
will follow in a later commit.

This feature depends on a gdbserver implementation (e.g. `rr`) providing
support for the `bc` and `bs` packets. `lldb-server` does not support
those packets, and there is no plan to change that. So, for testing
purposes, `lldbreverse.py` wraps `lldb-server` with a Python
implementation of *very limited* record-and-replay functionality for use
by *tests only*.

The majority of this PR is test infrastructure (about 700 of the 950
lines added).
2024-10-10 13:01:47 -07:00
AbdAlRahman Gad
6f2ebc435f
[lldb] Change SymbolContext::GetAddressRangeFromHereToEndLine to return Expected (NFC) (#110718)
Signed-off-by: AbdAlRahman Gad <abdobngad@gmail.com>
Co-authored-by: Adrian Prantl <adrian.prantl@gmail.com>
2024-10-08 10:04:52 -07:00
Adrian Prantl
b798f4bd50
[lldb] Make deep copies of Status explicit (NFC) (#107170) 2024-09-05 12:44:13 -07:00
Adrian Prantl
0642cd768b
[lldb] Turn lldb_private::Status into a value type. (#106163)
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.
2024-08-27 10:59:31 -07:00
Adrian Prantl
3c0fba4f24 Revert "Revert "[lldb] Extend frame recognizers to hide frames from backtraces (#104523)""
This reverts commit 547917aebd1e79a8929b53f0ddf3b5185ee4df74.
2024-08-23 11:06:01 -07:00
Dmitri Gribenko
547917aebd Revert "[lldb] Extend frame recognizers to hide frames from backtraces (#104523)"
This reverts commit f01f80ce6ca7640bb0e267b84b1ed0e89b57e2d9.

This commit introduces an msan violation. See the discussion on https://github.com/llvm/llvm-project/pull/104523.
2024-08-22 13:24:57 +02:00
Adrian Prantl
f01f80ce6c
[lldb] Extend frame recognizers to hide frames from backtraces (#104523)
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
```
2024-08-20 16:01:22 -07:00
Jacob Lalonde
572943e790
[LLDB] Reapply #100443 SBSaveCore Thread list (#104497)
Reapply #100443 and #101770. These were originally reverted due to a
test failure and an MSAN failure. I changed the test attribute to
restrict to x86 (following the other existing tests). I could not
reproduce the test or the MSAN failure and no repo steps were provided.
2024-08-15 16:29:59 -07:00
jeffreytan81
f838fa820f
New ThreadPlanSingleThreadTimeout to resolve potential deadlock in single thread stepping (#90930)
This PR introduces a new `ThreadPlanSingleThreadTimeout` that will be
used to address potential deadlock during single-thread stepping.

While debugging a target with a non-trivial number of threads (around
5000 threads in one example target), we noticed that a simple step over
can take as long as 10 seconds. Enabling single-thread stepping mode
significantly reduces the stepping time to around 3 seconds. However,
this can introduce deadlock if we try to step over a method that depends
on other threads to release a lock.

To address this issue, we introduce a new
`ThreadPlanSingleThreadTimeout` that can be controlled by the
`target.process.thread.single-thread-plan-timeout` setting during
single-thread stepping mode. The concept involves counting the elapsed
time since the last internal stop to detect overall stepping progress.
Once a timeout occurs, we assume the target is not making progress due
to a potential deadlock, as mentioned above. We then send a new async
interrupt, resume all threads, and `ThreadPlanSingleThreadTimeout`
completes its task.

To support this design, the major changes made in this PR are:
1. `ThreadPlanSingleThreadTimeout` is popped during every internal stop
and reset (re-pushed) to the top of the stack (as a leaf node) during
resume. This is achieved by always returning `true` from
`ThreadPlanSingleThreadTimeout::DoPlanExplainsStop()` and
`ThreadPlanSingleThreadTimeout::MischiefManaged()`.
2. A new thread-specific async interrupt stop is introduced, which can
be detected/consumed by `ThreadPlanSingleThreadTimeout`.
3. The clearing of branch breakpoints in the range thread plan has been
moved from `DoPlanExplainsStop()` to `ShouldStop()`, as it is not
guaranteed that it will be called.

The detailed design is discussed in the RFC below:

[https://discourse.llvm.org/t/improve-single-thread-stepping/74599](https://discourse.llvm.org/t/improve-single-thread-stepping/74599)

---------

Co-authored-by: jeffreytan81 <jeffreytan@fb.com>
2024-08-05 17:26:39 -07:00
Jacob Lalonde
accf5c9bb3
Revert "[LLDB][SBSaveCore] Implement a selectable threadlist for Core… (#102018)
… Options.  (#100443)"

This reverts commit 3e4af616334eae532f308605b89ff158dd195180.

@adrian-prantl FYI

Reverts #100443
2024-08-05 10:17:25 -07:00
Jacob Lalonde
3e4af61633
[LLDB][SBSaveCore] Implement a selectable threadlist for Core Options. (#100443)
In #98403 I enabled the SBSaveCoreOptions object, which allows users via
the scripting API to define what they want saved into their core file.
As the first option I've added a threadlist, so users can scan and
identify which threads and corresponding stacks they want to save.

In order to support this, I had to add a new method to `Process.h` on
how we identify which threads are to be saved, and I had to change the
book keeping in minidump to ensure we don't double save the stacks.

Important to @jasonmolenda I also changed the MachO coredump to accept
these new APIs.
2024-08-02 13:35:05 -07:00
jimingham
845dee36ba
SBThread::StepInstruction shouldn't discard other plans (#97493)
This was just a typo, none of the external execution control functions
should discard other plans. In particular, it means if you stop in a
hand-called function and step an instruction, the function call thread
plan gets unshipped, popping all the function call frames.

I also added a test that asserts the correct behavior. I tested all the
stepping operations even though only StepInstruction was wrong.
2024-07-03 10:45:20 -07:00
Alex Langford
5779483527
[lldb][nfc] Move broadcaster class strings away from ConstString (#89690)
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.
2024-04-24 12:13:18 -07:00
Jonas Devlieghere
556fe5f290
[lldb] Reland: Store SupportFile in FileEntry (NFC) (#85892)
This is another step towards supporting DWARF5 checksums and inline
source code in LLDB. This is a reland of #85468 but without the
functional change of storing the support file from the line table (yet).
2024-03-21 08:40:08 -07:00
Jonas Devlieghere
a289f66efd
Revert "[lldb] Store SupportFile in FileEntry (NFC)" (#85885)
Reverts llvm/llvm-project#85468 because @slackito reports this broke
stepping in one of their tests [1] and this patch was meant to be NFC.

[1]
d5a277d309 (commitcomment-139991120)
2024-03-19 17:48:46 -07:00
Jonas Devlieghere
d5a277d309
[lldb] Store SupportFile in FileEntry (NFC) (#85468)
This is another step towards supporting DWARF5 checksums and inline
source code in LLDB.
2024-03-15 15:03:54 -07:00
Jason Molenda
c73a3f16f8 [lldb] [mostly NFC] Large WP foundation: WatchpointResources (#68845)
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.

This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.

There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.

This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.

This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.

To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.

I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.

There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).

"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.

I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.

I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.

https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
(cherry picked from commit fc6b72523f3d73b921690a713e97a433c96066c6)
2023-11-30 14:59:10 -08:00
David Spickett
b0af8a1ede Revert "[lldb] [mostly NFC] Large WP foundation: WatchpointResources (#68845)"
...and follow ups.

As it has caused test failures on Linux Arm and AArch64:
https://lab.llvm.org/buildbot/#/builders/96/builds/49126
https://lab.llvm.org/buildbot/#/builders/17/builds/45824

```
  lldb-shell :: Subprocess/clone-follow-child-wp.test
  lldb-shell :: Subprocess/fork-follow-child-wp.test
  lldb-shell :: Subprocess/vfork-follow-child-wp.test
```

This reverts commit a6c62bf1a4717accc852463b664cd1012237d334,
commit a0a1ff3ab40e347589b4e27d8fd350c600526735 and commit
fc6b72523f3d73b921690a713e97a433c96066c6.
2023-11-28 09:39:37 +00:00
Jason Molenda
fc6b72523f
[lldb] [mostly NFC] Large WP foundation: WatchpointResources (#68845)
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.

This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.

There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.

This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.

This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.

To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.

I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.

There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).

"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.

I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.

I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.

https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
2023-11-27 13:28:59 -08:00
Walter Erquinigo
1654d7dc38
[lldb-dap] Add an option to provide a format for threads (#72196)
When this option gets enabled, descriptions of threads will be generated
using the format provided in the launch configuration instead of
generating it manually in the dap code. This allows lldb-dap to show an
output similar to the one in the CLI.
This is very similar to https://github.com/llvm/llvm-project/pull/71843
2023-11-14 13:23:55 -05:00
Alex Langford
f2d32ddcec [lldb] Sink StreamFile into lldbHost
StreamFile subclasses Stream (from lldbUtility) and is backed by a File
(from lldbHost). It does not depend on anything from lldbCore or any of its
sibling libraries, so I think it makes sense for this to live in
lldbHost instead.

Differential Revision: https://reviews.llvm.org/D157460
2023-08-09 17:17:18 -07:00
Alex Langford
7ee633a24b [lldb][NFCI] Remove unneeded temporary std::string allocations in SBAPI
This uses some friend class trickery to avoid some unneeded temporary
std::string allocations.

Differential Revision: https://reviews.llvm.org/D155035
2023-07-14 10:46:42 -07:00
Med Ismail Bennani
1370a1cb5b [lldb] Add support for negative integer to {SB,}StructuredData
This patch refactors the `StructuredData::Integer` class to make it
templated, makes it private and adds 2 public specialization for both
`int64_t` & `uint64_t` with a public type aliases, respectively
`SignedInteger` & `UnsignedInteger`.

It adds new getter for signed and unsigned interger values to the
`StructuredData::Object` base class and changes the implementation of
`StructuredData::Array::GetItemAtIndexAsInteger` and
`StructuredData::Dictionary::GetValueForKeyAsInteger` to support signed
and unsigned integers.

This patch also adds 2 new `Get{Signed,Unsigned}IntegerValue` to the
`SBStructuredData` class and marks `GetIntegerValue` as deprecated.

Finally, this patch audits all the caller of `StructuredData::Integer`
or `StructuredData::GetIntegerValue` to use the proper type as well the
various tests that uses `SBStructuredData.GetIntegerValue`.

rdar://105575764

Differential Revision: https://reviews.llvm.org/D150485

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2023-05-22 16:14:00 -07:00
Alex Langford
41714c959d [lldb] Guarantee the lifetimes of all strings returned from SBAPI
LLDB should guarantee that the strings returned by SBAPI methods
live forever. I went through every method that returns a string and made
sure that it was added to the ConstString StringPool before returning if
it wasn't obvious that it was already doing so.
I've also updated the docs to document this behavior.

Differential Revision: https://reviews.llvm.org/D150804
2023-05-18 15:13:36 -07:00
Alex Langford
e9eaf7b430 Re-land "[lldb] Expose a const iterator for SymbolContextList"
Re-lands 04aa943be8ed5c03092e2a90112ac638360ec253 with modifications
to fix tests.
I originally reverted this because it caused a test to fail on Linux.
The problem was that I inverted a condition on accident.
2023-05-05 11:19:21 -07:00
Alex Langford
3d6073a9c3 Revert "[lldb] Expose a const iterator for SymbolContextList"
This reverts commit 04aa943be8ed5c03092e2a90112ac638360ec253.

This broke the debian buildbot and I'm not sure why. Reverting so I can
investigate.
2023-05-04 16:49:30 -07:00
Alex Langford
04aa943be8 [lldb] Expose a const iterator for SymbolContextList
There are many situations where we'll iterate over a SymbolContextList
with the pattern:
```
SymbolContextList sc_list;
// Fill in sc_list here
for (auto i = 0; i < sc_list.GetSize(); i++) {
  SymbolContext sc;
  sc_list.GetSymbolAtContext(i, sc);

  // Do work with sc
}
```
Adding an iterator to iterate over the instances directly means we don't
have to do bounds checking or create a copy of every element of the
SymbolContextList.

Differential Revision: https://reviews.llvm.org/D149900
2023-05-04 16:36:44 -07:00
Jim Ingham
076341d108 Make sure SelectMostRelevantFrame happens only when returning to the user.
This is a user facing action, it is meant to focus the user's attention on
something other than the 0th frame when you stop somewhere where that's
helpful. For instance, stopping in pthread_kill after an assert will select
the assert frame.

This is not something you want to have happen internally in lldb, both
because internally you really don't want the selected frame changing out
from under you, and because the recognizers can do arbitrary work, and that
can cause deadlocks or other unexpected behavior.

However, it's not something that the current code does
explicitly after a stop has been delivered, it's expected to happen implicitly
as part of stopping. I changing this to call SMRF explicitly after a user
stop, but that got pretty ugly quickly.

So I added a bool to control whether to run this and audited all the current
uses to determine whether we're returning to the user or not.

Differential Revision: https://reviews.llvm.org/D148863
2023-04-21 14:21:25 -07:00
Kazu Hirata
343523d040 [lldb] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-04 16:51:25 -08:00
Michał Górny
ac666d1799 [lldb] [gdb-remote] Support getting siginfo via API
Add Thread::GetSiginfo() and SBThread::GetSiginfo() methods to retrieve
the siginfo value from server.

Differential Revision: https://reviews.llvm.org/D118055
2022-01-28 17:47:47 +01:00
Michał Górny
59a3f65f5e Revert "[lldb] [gdb-remote] Support getting siginfo via API"
This reverts commit 1a8f60f5f5b8638a3e8e7fb31ba7ae9e17a7ff2d.
The API requires further work.
2022-01-28 10:15:52 +01:00
Michał Górny
1a8f60f5f5 [lldb] [gdb-remote] Support getting siginfo via API
Add Thread::GetSiginfo() and SBThread::GetSiginfo() methods to retrieve
the siginfo value from server.

Differential Revision: https://reviews.llvm.org/D118055
2022-01-27 13:33:47 +01:00
Jonas Devlieghere
1755f5b1d7 [lldb] Decouple instrumentation from the reproducers
Remove the last remaining references to the reproducers from the
instrumentation. This patch renames the relevant files and macros.

Differential revision: https://reviews.llvm.org/D117712
2022-01-20 18:06:14 -08:00
Jonas Devlieghere
69c55d6362 [lldb] Remove LLDB_RECORD_CHAR_PTR_* macros 2022-01-10 11:57:20 -08:00
Jonas Devlieghere
d232abc33b [lldb] Remove LLDB_RECORD_RESULT macro 2022-01-09 22:54:17 -08:00