Commit Graph

64 Commits

Author SHA1 Message Date
jimingham
04b443e778 Add the ability to define custom completers to the parsed_cmd template. (#109062)
If your arguments or option values are of a type that naturally uses one
of our common completion mechanisms, you will get completion for free.
But if you have your own custom values or if you want to do fancy things
like have `break set -s foo.dylib -n ba<TAB>` only complete on symbols
in foo.dylib, you can use this new mechanism to achieve that.
2024-09-24 10:00:00 -07:00
Med Ismail Bennani
f732157a9d [lldb/Interpreter] Introduce ScriptedStopHook{,Python}Interface & make use of it (#109498)
This patch re-lands #105449 and fixes the various test failures.

---------

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2024-09-20 16:55:47 -07:00
David Spickett
801046e330 Revert "[lldb] Fix SWIG wrapper compilation error"
...and "[lldb/Interpreter] Introduce `ScriptedStopHook{,Python}Interface` & make use of it (#105449)"

This reverts commit 76b827bb4d, and commit 1e131ddfa8
because the first commit caused the test command-stop-hook-output.test to fail.
2024-09-20 09:57:07 +00:00
Med Ismail Bennani
1e131ddfa8 [lldb/Interpreter] Introduce ScriptedStopHook{,Python}Interface & make use of it (#105449)
This patch introduces new `ScriptedStopHook{,Python}Interface` classes
that make use of the Scripted Interface infrastructure and makes use of
it in `StopHookScripted`.

It also relax the requirement on the number of argument for initializing
scripting extension if the size of the interface parameter pack contains
1 less element than the extension maximum number of positional arguments
for this initializer.
This addresses the cases where the embedded interpreter session
dictionary is passed to the extension initializer which is not used most
of the time.

---------

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2024-09-19 23:35:34 -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
ad75775242 Revert "Revert "[lldb][swig] Use the correct variable in the return statement""
This reverts commit 7323e7eee3.
2024-08-23 11:06:01 -07:00
Adrian Prantl
3c0fba4f24 Revert "Revert "[lldb] Extend frame recognizers to hide frames from backtraces (#104523)""
This reverts commit 547917aebd.
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 f01f80ce6c.

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
Dmitri Gribenko
7323e7eee3 Revert "[lldb][swig] Use the correct variable in the return statement"
This reverts commit 65281570af.

I'm reverting https://github.com/llvm/llvm-project/pull/104523
(f01f80ce6c)
and this fixup belongs to the same series of changes.
2024-08-22 13:14:30 +02:00
Dmitri Gribenko
65281570af [lldb][swig] Use the correct variable in the return statement
The issue was introduced in
https://github.com/llvm/llvm-project/pull/104523.

The code introduces the `ret_val` variable but does not use it. Instead
it returns a pointer, which gets implicitly converted to bool.
2024-08-21 15:29:03 +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
jimingham
77d131eddb Add the ability for Script based commands to specify their "repeat command" (#94823)
Among other things, returning an empty string as the repeat command
disables auto-repeat, which can be useful for state-changing commands.

There's one remaining refinement to this setup, which is that for parsed
script commands, it should be possible to change an option value, or add
a new option value that wasn't originally specified, then ask lldb "make
this back into a command string". That would make doing fancy things
with repeat commands easier.

That capability isn't present in the lldb_private side either, however.
So that's for a next iteration.

I haven't added this to the docs on adding commands yet. I wanted to
make sure this was an acceptable approach before I spend the time to do
that.
2024-07-03 10:39:34 -07:00
Med Ismail Bennani
9a9ec228cd [lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392) (#96868)
This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

This just re-lands #70392 after fixing test failures.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2024-06-27 01:45:30 -07:00
Chelsea Cassanova
3d86eebdf8 Reland "[lldb][api-test] Add API test for SBCommandInterpreter::Comm… (#95181)
…andOverrideCallback (#94518)"

This reverts commit 7cff05ada0. The API
test that was added erroneously imports a module that isn't needed and
wouldn't be found which causes a test failures. This reversion removes
that import.
2024-06-11 16:41:31 -07:00
Chelsea Cassanova
7cff05ada0 Revert "[lldb][api-test] Add API test for SBCommandInterpreter::CommandOverrideCallback (#94518)"
This reverts commit 6fb6eba930.
This test breaks due to an incorrect import in the test.
2024-06-11 15:27:10 -07:00
Chelsea Cassanova
6fb6eba930 [lldb][api-test] Add API test for SBCommandInterpreter::CommandOverrideCallback (#94518)
`SBCommandInterpreter::CommandOverrideCallback` was not being exposed to
the Python API and has no coverage in the
API test suite, so this commits exposes and adds a test for it. Doing
this involves also adding a typemap for the callback used for this
function so that it matches the functionality of other callback
functions that are exposed to Python.
2024-06-11 15:20:35 -07:00
Med Ismail Bennani
ae3f68066c Revert "[lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (Reland #70392)" (#93153)
Reverts llvm/llvm-project#93149 since it breaks
https://lab.llvm.org/buildbot/#/builders/68/builds/74799
2024-05-23 01:46:29 -07:00
Med Ismail Bennani
4cc6d0f4df [lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (Reland #70392) (#93149)
This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

This just re-lands #70392 after fixing test failures.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2024-05-23 01:25:48 -07:00
jimingham
a69ecb2420 Add the ability to define a Python based command that uses CommandObjectParsed (#70734)
This allows you to specify options and arguments and their definitions
and then have lldb handle the completions, help, etc. in the same way
that lldb does for its parsed commands internally.

This feature has some design considerations as well as the code, so I've
also set up an RFC, but I did this one first and will put the RFC
address in here once I've pushed it...

Note, the lldb "ParsedCommand interface" doesn't actually do all the
work that it should. For instance, saying the type of an option that has
a completer doesn't automatically hook up the completer, and ditto for
argument values. We also do almost no work to verify that the arguments
match their definition, or do auto-completion for them. This patch
allows you to make a command that's bug-for-bug compatible with built-in
ones, but I didn't want to stall it on getting the auto-command checking
to work all the way correctly.

As an overall design note, my primary goal here was to make an interface
that worked well in the script language. For that I needed, for
instance, to have a property-based way to get all the option values that
were specified. It was much more convenient to do that by making a
fairly bare-bones C interface to define the options and arguments of a
command, and set their values, and then wrap that in a Python class
(installed along with the other bits of the lldb python module) which
you can then derive from to make your new command. This approach will
also make it easier to experiment.

See the file test_commands.py in the test case for examples of how this
works.
2024-02-13 11:09:47 -08:00
Jason Molenda
61384850c5 Revert "[lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)"
Temporarily revert to unblock the CI bots, this is breaking the -DLLVM_ENABLE_MODULES=On
modules style build.  I've notified Ismail.

This reverts commit 888501bc63.
2024-01-29 10:43:33 -08:00
Med Ismail Bennani
888501bc63 [lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)
This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2024-01-29 03:17:33 -08:00
Med Ismail Bennani
6eafe2cb7a Revert "[lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)"
This reverts commit 4b3cd379cc since it
introduces some test failures:

https://lab.llvm.org/buildbot/#/builders/68/builds/62556
2023-10-30 17:40:11 -07:00
Med Ismail Bennani
4b3cd379cc [lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)
This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2023-10-30 16:52:17 -07:00
Med Ismail Bennani
f22d82cef2 [lldb/Interpreter] Make ScriptedInterface Object creation more generic (#68052)
This patch changes the way plugin objects used with Scripted Interfaces
are created.

Instead of implementing a different SWIG method to create the object for
every scripted interface, this patch makes the creation more generic by
re-using some of the ScriptedPythonInterface templated Dispatch code.

This patch also improves error handling of the object creation by
returning an `llvm::Expected`.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>
2023-10-25 10:05:54 -07:00
Sterling Augustine
28c33805d4 Remove unnecessary std::moves [NFC]
These trigger the following error:

error: moving a temporary object prevents copy elision [-Werror,-Wpessimizing-move]
2023-07-13 19:24:01 -07:00
Kazuki Sakamoto
f03dbdb70a [lldb][LocateModuleCallback] Implement API, Python interface
RFC https://discourse.llvm.org/t/rfc-python-callback-for-target-get-module/71580

Use SWIG for the locate module callback the same as other Python callbacks.
TestLocateModuleCallback.py verifies the functionalities.

Differential Revision: https://reviews.llvm.org/D153735
2023-07-12 11:33:51 -07:00
Alex Langford
27b6a4e63a [lldb] Mark most SBAPI methods involving private types as protected or private
Many SB classes have public constructors or methods involving types that
are private. Some are more obvious (e.g. containing lldb_private in the
name) than others (lldb::FooSP is usually std::shared_pointer<lldb_private::Foo>).

This commit explicitly does not address FileSP, so I'm leaving that one
alone for now.

Some of these were for other SB classes to use and should have been made
protected/private with a friend class entry added. Some of these were
public for some of the swig python helpers to use. I put all of those
functions into a class and made them static methods. The relevant SB
classes mark that class as a friend so they can access those
private/protected members.

I've also removed an outdated SBStructuredData test (can you guess which
constructor it was using?) and updated the other relevant tests.

Differential Revision: https://reviews.llvm.org/D150157
2023-05-10 12:36:55 -07:00
Jim Ingham
c2be702104 Allow scripted thread plans to modify the thread stop description when
they are completed.
2023-05-03 10:52:12 -07:00
Med Ismail Bennani
e31d0c20e4 [lldb] Improve breakpoint management for interactive scripted process
This patch improves breakpoint management when doing interactive
scripted process debugging.

In other to know which process set a breakpoint, we need to do some book
keeping on the multiplexer scripted process. When initializing the
multiplexer, we will first copy breakpoints that are already set on the
driving target.

Everytime we launch or resume, we should copy breakpoints from the
multiplexer to the driving process.

When creating a breakpoint from a child process, it needs to be set both
on the multiplexer and on the driving process. We also tag the created
breakpoint with the name and pid of the originator process.

This patch also implements all the requirement to achieve proper
breakpoint management. That involves:

- Adding python interator for breakpoints and watchpoints in SBTarget
- Add a new `ScriptedProcess.create_breakpoint` python method

Differential Revision: https://reviews.llvm.org/D148548

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2023-04-25 15:03:15 -07:00
Jeffrey Tan
b461398f1c Add a new SBDebugger::SetDestroyCallback() API
Adding a new SBDebugger::SetDestroyCallback() API.
This API can be used by any client to query for statistics/metrics before
exiting debug sessions.

Differential Revision: https://reviews.llvm.org/D143520
2023-03-07 14:48:15 -08:00
Med Ismail Bennani
b9d4c94a60 [lldb/Plugins] Add Attach capabilities to ScriptedProcess
This patch adds process attach capabilities to the ScriptedProcess
plugin. This doesn't really expects a PID or process name, since the
process state is already script, however, this allows to create a
scripted process without requiring to have an executuble in the target.

In order to do so, this patch also turns the scripted process related
getters and setters from the `ProcessLaunchInfo` and
`ProcessAttachInfo` classes to a `ScriptedMetadata` instance and moves
it in the `ProcessInfo` class, so it can be accessed interchangeably.

This also adds the necessary SWIG wrappers to convert the internal
`Process{Attach,Launch}InfoSP` into a `SB{Attach,Launch}Info` to pass it
as argument the scripted process python implementation and convert it
back to the internal representation.

rdar://104577406

Differential Revision: https://reviews.llvm.org/D143104

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2023-03-03 19:33:02 -08:00
Med Ismail Bennani
bb4ccc6688 [lldb] Add ScriptedPlatform python implementation
This patch introduces both the Scripted Platform python base
implementation and an example for it.

The base implementation is embedded in lldb python module under
`lldb.plugins.scripted_platform`.

This patch also refactor the various SWIG methods to create scripted
objects into a single method, that is now shared between the Scripted
Platform, Process and Thread. It also replaces the target argument by a
execution context object.

Differential Revision: https://reviews.llvm.org/D139250

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2023-01-12 12:49:05 -08:00
Kazu Hirata
2fe8327406 [lldb] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to clean up the "using" declarations, #include
"llvm/ADT/Optional.h", etc.

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
2023-01-07 14:18:35 -08:00
Kazu Hirata
1d0ba311d8 [lldb] Use std::nullopt instead of llvm::None (NFC)
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
2022-12-05 22:43:53 -08:00
Jorge Gorbe Moya
d76566417e [lldb] Add matching based on Python callbacks for data formatters.
This patch adds a new matching method for data formatters, in addition
to the existing exact typename and regex-based matching. The new method
allows users to specify the name of a Python callback function that
takes a `SBType` object and decides whether the type is a match or not.

Here is an overview of the changes performed:

- Add a new `eFormatterMatchCallback` matching type, and logic to handle
  it in `TypeMatcher` and `SBTypeNameSpecifier`.

- Extend `FormattersMatchCandidate` instances with a pointer to the
  current `ScriptInterpreter` and the `TypeImpl` corresponding to the
  candidate type, so we can run registered callbacks and pass the type
  to them. All matcher search functions now receive a
  `FormattersMatchCandidate` instead of a type name.

- Add some glue code to ScriptInterpreterPython and the SWIG bindings to
  allow calling a formatter matching callback. Most of this code is
  modeled after the equivalent code for watchpoint callback functions.

- Add an API test for the new callback-based matching feature.

For more context, please check the RFC thread where this feature was
originally discussed:
https://discourse.llvm.org/t/rfc-python-callback-for-data-formatters-type-matching/64204/11

Differential Revision: https://reviews.llvm.org/D135648
2022-10-19 12:53:38 -07:00
Pavel Labath
c154f397ee [lldb/python] Use PythonObject in LLDBSwigPython functions
Return our PythonObject wrappers instead of raw PyObjects (obfuscated as
void *). This ensures that ownership (reference counts) of python
objects is automatically tracked.

Differential Revision: https://reviews.llvm.org/D117462
2022-01-18 10:28:58 +01:00
Pavel Labath
0a07c9662e [lldb/python] Fix dangling Event and CommandReturnObject references
Unlike the rest of our SB objects, SBEvent and SBCommandReturnObject
have the ability to hold non-owning pointers to their non-SB
counterparts. This makes it hard to ensure the SB objects do not become
dangling once their backing object goes away.

While we could make these two objects behave like others, that would
require plubming even more shared pointers through our internal code
(Event objects are mostly prepared for it, CommandReturnObject are not).
Doing so seems unnecessarily disruptive, given that (unlike for some of
the other objects) I don't see any good reason why would someone want to
hold onto these objects after the function terminates.

For that reason, this patch implements a different approach -- the SB
objects will still hold non-owning pointers, but they will be reset to
the empty/default state as soon as the function terminates. This python
code will not crash if the user decides to store these objects -- but
the objects themselves will be useless/empty.

Differential Revision: https://reviews.llvm.org/D116162
2022-01-04 14:49:00 +01:00
Pavel Labath
2efc6892d8 [lldb/python] Avoid more dangling pointers in python glue code 2021-12-22 13:47:06 +01:00
Pavel Labath
6c2bf01270 [lldb/python] Fix a compile error in 7406d236d8
cannot pass object of non-trivial type
'lldb_private::python::PythonObject' through variadic function
2021-12-20 09:57:29 +01:00
Pavel Labath
7406d236d8 [lldb/python] Fix (some) dangling pointers in our glue code
This starts to fix the other half of the lifetime problems in this code
-- dangling references. SB objects created on the stack will go away
when the function returns, which is a problem if the python code they
were meant for stashes a reference to them somewhere.  Most of the time
this goes by unnoticed, as the code rarely has a reason to store these,
but in case it does, we shouldn't respond by crashing.

This patch fixes the management for a couple of SB objects (Debugger,
Frame, Thread). The SB objects are now created on the heap, and
their ownership is immediately passed on to SWIG, which will ensure they
are destroyed when the last python reference goes away. I will handle
the other objects in separate patches.

I include one test which demonstrates the lifetime issue for SBDebugger.
Strictly speaking, one should create a test case for each of these
objects and each of the contexts they are being used. That would require
figuring out how to persist (and later access) each of these objects.
Some of those may involve a lot of hoop-jumping (we can run python code
from within a frame-format string). I don't think that is
necessary/worth it since the new wrapper functions make it very hard to
get this wrong.

Differential Revision: https://reviews.llvm.org/D115925
2021-12-20 09:42:08 +01:00
Pavel Labath
9d5e37ed8c [lldb] (Semi-automatically) format .swig files
I've found my recent ventures into the swig land painful because
of the strange way they are formatted. This patch attempts to alleviate
future headaches by formatting these files into something resembling the
normal llvm style.

Unfortunately, completely formatting these files automatically does not
work because clang format gets confused by swigs % syntax, so I have
employed a hybrid approach where I formatted blocks of c++ code with
clang-format and then manually massaged the code until it looked
reasonable (and compiled).

I don't expect these files to remain perfectly formatted (although, if
one's editor is configured to configure the current line/block on
request, one can get pretty good results by using it judiciously), but
at least it will prevent the (mangled form of the) old lldb style being
proliferated endlessly.

Differential Revision: https://reviews.llvm.org/D115736
2021-12-16 13:58:37 +01:00
Pavel Labath
ebb6bb725e [lldb/python] Plug SBStructuredData leaks
This applies the from D114259 to the SBStructuredData class.
2021-12-14 17:02:24 +01:00
Pavel Labath
82de8df26f [lldb] Clarify StructuredDataImpl ownership
StructuredDataImpl ownership semantics is unclear at best. Various
structures were holding a non-owning pointer to it, with a comment that
the object is owned somewhere else. From what I was able to gather that
"somewhere else" was the SBStructuredData object, but I am not sure that
all created object eventually made its way there. (It wouldn't matter
even if they did, as we are leaking most of our SBStructuredData
objects.)

Since StructuredDataImpl is just a collection of two (shared) pointers,
there's really no point in elaborate lifetime management, so this patch
replaces all StructuredDataImpl pointers with actual objects or
unique_ptrs to it. This makes it much easier to resolve SBStructuredData
leaks in a follow-up patch.

Differential Revision: https://reviews.llvm.org/D114791
2021-12-13 21:04:51 +01:00
Pavel Labath
9a14adeae0 [lldb] Remove 'extern "C"' from the lldb-swig-python interface
The LLDBSWIGPython functions had (at least) two problems:
- There wasn't a single source of truth (a header file) for the
  prototypes of these functions. This meant that subtle differences
  in copies of function declarations could go by undetected. And
  not-so-subtle differences would result in strange runtime failures.
- All of the declarations had to have an extern "C" interface, because
  the function definitions were being placed inside and extert "C" block
  generated by swig.

This patch fixes both problems by moving the function definitions to the
%header block of the swig files. This block is not surrounded by extern
"C", and seems more appropriate anyway, as swig docs say it is meant for
"user-defined support code" (whereas the previous %wrapper code was for
automatically-generated wrappers).

It also puts the declarations into the SWIGPythonBridge header file
(which seems to have been created for this purpose), and ensures it is
included by all code wishing to define or use these functions. This
means that any differences in the declaration become a compiler error
instead of a runtime failure.

Differential Revision: https://reviews.llvm.org/D114369
2021-11-30 11:06:09 +01:00
Pavel Labath
7f09ab08de [lldb] Fix [some] leaks in python bindings
Using an lldb_private object in the bindings involves three steps
- wrapping the object in it's lldb::SB variant
- using swig to convert/wrap that to a PyObject
- wrapping *that* in a lldb_private::python::PythonObject

Our SBTypeToSWIGWrapper was only handling the middle part. This doesn't
just result in increased boilerplate in the callers, but is also a
functionality problem, as it's very hard to get the lifetime of of all
of these objects right. Most of the callers are creating the SB object
(step 1) on the stack, which means that we end up with dangling python
objects after the function terminates. Most of the time this isn't a
problem, because the python code does not need to persist the objects.
However, there are legitimate cases where they can do it (and even if
the use case is not completely legitimate, crashing is not the best
response to that).

For this reason, some of our code creates the SB object on the heap, but
it has another problem -- it never gets cleaned up.

This patch begins to add a new function (ToSWIGWrapper), which does all
of the three steps, while properly taking care of ownership. In the
first step, I have converted most of the leaky code (except for
SBStructuredData, which needs a bit more work).

Differential Revision: https://reviews.llvm.org/D114259
2021-11-22 15:14:52 +01:00
Pavel Labath
f1127914d3 [lldb] Deobfuscate python-swigsafecast.swig
This file was way more complicated than it needed to be.

This patch removes the automagic reference-to-pointer delegation and
replaces the template specializations with regular free functions
(taking reference arguments).

The reason I chose references is twofold:
- there are more arguments being passed by reference than by pointer
- the reference arguments make it more obvious that there is a lot of
  leaking going on in there.

Currently, the code was assuming that the pointer arguments have some
kind of a special meaning and that pointer functions take ownership of
their arguments, which isn't true (it's possible it was true at some
point in the past, I haven't done the archeology).

This makes it easier to implement proper lifetime management in
follow-up patches.

Differential Revision: https://reviews.llvm.org/D114150
2021-11-18 19:27:09 +01:00
Med Ismail Bennani
738621d047 [lldb/bindings] Change ScriptedThread initializer parameters
This patch changes the `ScriptedThread` initializer in couple of ways:
- It replaces the `SBTarget` parameter by a `SBProcess` (pointing to the
  `ScriptedProcess` that "owns" the `ScriptedThread`).
- It adds a reference to the `ScriptedProcessInfo` Dictionary, to pass
  arbitrary user-input to the `ScriptedThread`.

This patch also fixes the SWIG bindings methods that call the
`ScriptedProcess` and `ScriptedThread` initializers by passing all the
arguments to the appropriate `PythonCallable` object.

Differential Revision: https://reviews.llvm.org/D112046

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-11-10 17:43:28 +01:00
Med Ismail Bennani
a758c9f720 [lldb/Plugins] Add memory region support in ScriptedProcess
This patch adds support for memory regions in Scripted Processes.
This is necessary to read the stack memory region in order to
reconstruct each stackframe of the program.

In order to do so, this patch makes some changes to the SBAPI, namely:
- Add a new constructor for `SBMemoryRegionInfo` that takes arguments
  such as the memory region name, address range, permissions ...
  This is used when reading memory at some address to compute the offset
  in the binary blob provided by the user.
- Add a `GetMemoryRegionContainingAddress` method to `SBMemoryRegionInfoList`
  to simplify the access to a specific memory region.

With these changes, lldb is now able to unwind the stack and reconstruct
each frame. On top of that, reloading the target module at offset 0 allows
lldb to symbolicate the `ScriptedProcess` using debug info, similarly to an
ordinary Process.

To test this, I wrote a simple program with multiple function calls, ran it in
lldb, stopped at a leaf function and read the registers values and copied
the stack memory into a binary file. These are then used in the python script.

Differential Revision: https://reviews.llvm.org/D108953

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-10-08 14:54:07 +02:00
Med Ismail Bennani
59d8dd79e1 [lldb/Plugins] Add support for ScriptedThread in ScriptedProcess
This patch introduces the `ScriptedThread` class with its python
interface.

When used with `ScriptedProcess`, `ScriptedThreaad` can provide various
information such as the thread state, stop reason or even its register
context.

This can be used to reconstruct the program stack frames using lldb's unwinder.

rdar://74503836

Differential Revision: https://reviews.llvm.org/D107585

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-10-08 14:54:07 +02:00
Med Ismail Bennani
3925204c1f [lldb/Plugins] Introduce Scripted Interface Factory
This patch splits the previous `ScriptedProcessPythonInterface` into
multiple specific classes:

1. The `ScriptedInterface` abstract class that carries the interface
   instance object and its virtual pure abstract creation method.

2. The `ScriptedPythonInterface` that holds a generic `Dispatch` method that
   can be used by various interfaces to call python methods and also keeps a
   reference to the Python Script Interpreter instance.

3. The `ScriptedProcessInterface` that describes the base Scripted
   Process model with all the methods used in the underlying script.

All these components are used to refactor the `ScriptedProcessPythonInterface`
class, making it more modular.

This patch is also a requirement for the upcoming work on `ScriptedThread`.

Differential Revision: https://reviews.llvm.org/D107521

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-09-03 19:37:25 +02:00