When LLDB receives a SIGINT while running the embedded Python REPL it currently
just crashes in `ScriptInterpreterPythonImpl::Interrupt` with an error such as
the one below:
```
Fatal Python error: PyThreadState_Get: the function must be called with the GIL
held, but the GIL is released (the current Python thread state is NULL)
```
The faulty code that causes this error is this part of `ScriptInterpreterPythonImpl::Interrupt`:
```
PyThreadState *state = PyThreadState_GET();
if (!state)
state = GetThreadState();
if (state) {
long tid = state->thread_id;
PyThreadState_Swap(state);
int num_threads = PyThreadState_SetAsyncExc(tid, PyExc_KeyboardInterrupt);
```
The obvious fix I tried is to just acquire the GIL before this code is running
which fixes the crash but the `KeyboardInterrupt` we want to raise immediately
is actually just queued and would only be raised once the next line of input has
been parsed (which e.g. won't interrupt Python code that is currently waiting on
a timer or IO from what I can see). Also none of the functions we call here is
marked as safe to be called from a signal handler from what I can see, so we
might still end up crashing here with some bad timing.
Python 3.2 introduced `PyErr_SetInterrupt` to solve this and the function takes
care of all the details and avoids doing anything that isn't safe to do inside a
signal handler. The only thing we need to do is to manually setup our own fake
SIGINT handler that behaves the same way as the standalone Python REPL signal
handler (which raises a KeyboardInterrupt).
From what I understand the old code used to work with Python 2 so I kept the old
code around until we officially drop support for Python 2.
There is a small gap here with Python 3.0->3.1 where we might still be crashing,
but those versions have reached their EOL more than a decade ago so I think we
don't need to bother about them.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D104886
It is surprisingly difficult to write a simple python script that
can reliably `import lldb` without failing, or crashing. I'm
currently resorting to convolutions like this:
def find_lldb(may_reexec=False):
if prefix := os.environ.get('LLDB_PYTHON_PREFIX'):
if os.path.realpath(prefix) != os.path.realpath(sys.prefix):
raise Exception("cannot import lldb.\n"
f" sys.prefix should be: {prefix}\n"
f" but it is: {sys.prefix}")
else:
line1, line2 = subprocess.run(
['lldb', '-x', '-b', '-o', 'script print(sys.prefix)'],
encoding='utf8', stdout=subprocess.PIPE,
check=True).stdout.strip().splitlines()
assert line1.strip() == '(lldb) script print(sys.prefix)'
prefix = line2.strip()
os.environ['LLDB_PYTHON_PREFIX'] = prefix
if sys.prefix != prefix:
if not may_reexec:
raise Exception(
"cannot import lldb.\n" +
f" This python, at {sys.prefix}\n"
f" does not math LLDB's python at {prefix}")
os.environ['LLDB_PYTHON_PREFIX'] = prefix
python_exe = os.path.join(prefix, 'bin', 'python3')
os.execl(python_exe, python_exe, *sys.argv)
lldb_path = subprocess.run(['lldb', '-P'],
check=True, stdout=subprocess.PIPE,
encoding='utf8').stdout.strip()
sys.path = [lldb_path] + sys.path
This patch aims to replace all that with:
#!/usr/bin/env lldb-python
import lldb
...
... by adding the following features:
* new command line option: --print-script-interpreter-info. This
prints language-specific information about the script interpreter
in JSON format.
* new tool (unix only): lldb-python which finds python and exec's it.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D112973
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>
There is no reason why this function should be returning a ConstString.
While modifying these files, I also fixed several instances where
GetPluginName and GetPluginNameStatic were returning different strings.
I am not changing the return type of GetPluginNameStatic in this patch, as that
would necessitate additional changes, and this patch is big enough as it is.
Differential Revision: https://reviews.llvm.org/D111877
Due to CMake cache, find_package in FindLuaAndSwig.cmake
will be ignored. This commit adds EXACT and REQUIRED flags
to it and removes find_package in Lua ScriptInterpreter.
Signed-off-by: Siger Yang <sigeryeung@gmail.com>
Reviewed By: tammela, JDevlieghere
Differential Revision: https://reviews.llvm.org/D108515
This patch refactors Scripted Process and Scripted Thread related
classes to use LLVM_PRETTY_FUNCTION instead of the compiler macro.
Differential Revision: https://reviews.llvm.org/D111452
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
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>
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>
Refactor TerminalState to make the code simpler. Move 'struct termios'
to a PImpl-style subclass. Add an RAII interface to automatically store
and restore the state.
Differential revision: https://reviews.llvm.org/D110721
In all these years, we haven't found a use for this function (it has
zero callers). Lets just remove the boilerplate.
Differential Revision: https://reviews.llvm.org/D109600
This patch should fix the build failure that surfaced when build llvm
with GCC: https://lab.llvm.org/staging/#/builders/16/builds/10450
GCC complained that I explicitely specialized
`ScriptedPythonInterface::ExtractValueFromPythonObject` in a
in non-namespace scope, which is tolerated by Clang.
To solve this issue, the specialization were declared out of the class
and implemented in the source file.
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
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>
Due to CMake cache, find_package in FindLuaAndSwig.cmake
will be ignored. This commit adds EXACT and REQUIRED flags
to it and removes find_package in Lua ScriptInterpreter.
Signed-off-by: Siger Yang <sigeryeung@gmail.com>
Reviewed By: tammela, JDevlieghere
Differential Revision: https://reviews.llvm.org/D108515
Modify OpenOptions enum to open the future path into synchronizing
vFile:open bits with GDB. Currently, LLDB and GDB use different flag
models effectively making it impossible to match bits. Notably, LLDB
uses two bits to indicate read and write status, and uses union of both
for read/write. GDB uses a value of 0 for read-only, 1 for write-only
and 2 for read/write.
In order to future-proof the code for the GDB variant:
1. Add a distinct eOpenOptionReadWrite constant to be used instead
of (eOpenOptionRead | eOpenOptionWrite) when R/W access is required.
2. Rename eOpenOptionRead and eOpenOptionWrite to eOpenOptionReadOnly
and eOpenOptionWriteOnly respectively, to make it clear that they
do not mean to be combined and require update to all call sites.
3. Use the intersection of all three flags when matching against
the three possible values.
This commit does not change the actual bits used by LLDB.
Differential Revision: https://reviews.llvm.org/D106984
This patch updates the `ScriptedProcess::GetGenericInteger` return type
to `llvm::Optional<unsigned long long>` to match implementation.
Differential Revision: https://reviews.llvm.org/D105788
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This patch should address the compiler warnings due to mismatch type
comparaison.
Differential Revision: https://reviews.llvm.org/D105788
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This patch introduces Scripted Processes to lldb.
The goal, here, is to be able to attach in the debugger to fake processes
that are backed by script files (in Python, Lua, Swift, etc ...) and
inspect them statically.
Scripted Processes can be used in cooperative multithreading environments
like the XNU Kernel or other real-time operating systems, but it can
also help us improve the debugger testing infrastructure by writting
synthetic tests that simulates hard-to-reproduce process/thread states.
Although ScriptedProcess is not feature-complete at the moment, it has
basic execution capabilities and will improve in the following patches.
rdar://65508855
Differential Revision: https://reviews.llvm.org/D100384
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Add the ability to silence command script import. The motivation for
this change is being able to add command script import -s
lldb.macosx.crashlog to your ~/.lldbinit without it printing the
following message at the beginning of every debug session.
"malloc_info", "ptr_refs", "cstr_refs", "find_variable", and
"objc_refs" commands have been installed, use the "--help" options on
these commands for detailed help.
In addition to forwarding the silent option to LoadScriptingModule, this
also changes ScriptInterpreterPythonImpl::ExecuteOneLineWithReturn and
ScriptInterpreterPythonImpl::ExecuteMultipleLines to honor the enable IO
option in ExecuteScriptOptions, which until now was ignored.
Note that IO is only enabled (or disabled) at the start of a session,
and for this particular use case, that's done when taking the Python
lock in LoadScriptingModule, which means that the changes to these two
functions are not strictly necessary, but (IMO) desirable nonetheless.
Differential revision: https://reviews.llvm.org/D105327
This is an NFC cleanup.
Many of the API's that returned BreakpointOptions always returned valid ones.
Internally the BreakpointLocations usually have null BreakpointOptions, since they
use their owner's options until an option is set specifically on the location.
So the original code used pointers & unique_ptr everywhere for consistency.
But that made the code hard to reason about from the outside.
This patch changes the code so that everywhere an API is guaranteed to
return a non-null BreakpointOption, it returns it as a reference to make
that clear.
It also changes the Breakpoint to hold a BreakpointOption
member where it previously had a UP. Since we were always filling the UP
in the Breakpoint constructor, having the UP wasn't helping anything.
Differential Revision: https://reviews.llvm.org/D104162
This converts a default constructor's member initializers into C++11
default member initializers. This patch was automatically generated with
clang-tidy and the modernize-use-default-member-init check.
$ run-clang-tidy.py -header-filter='lldb' -checks='-*,modernize-use-default-member-init' -fix
This is a mass-refactoring patch and this commit will be added to
.git-blame-ignore-revs.
Differential revision: https://reviews.llvm.org/D103483
The C headers are deprecated so as requested in D102845, this is replacing them
all with their (not deprecated) C++ equivalent.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D103084
This patch adds a ScriptedProcess interface to the ScriptInterpreter and
more specifically, to the ScriptInterpreterPython.
This interface will be used in the C++ `ScriptProcess` Process Plugin to
call the script methods.
At the moment, not all methods are implemented, they will upstreamed in
upcoming patches.
This patch also adds helper methods to the ScriptInterpreter to
convert `SBAPI` Types (SBData & SBError) to `lldb_private` types
(DataExtractor & Status).
rdar://65508855
Differential Revision: https://reviews.llvm.org/D95711
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This function would fail in debug builds, as the two usages of the
LLDB_PYTHON_RELATIVE_LIBDIR macro would expand to two distinct strings.
The path iterator macros don't support that.
Use a temporary variable to ensure everything points to a single string.
This patch adds a ScriptedProcess interface to the ScriptInterpreter and
more specifically, to the ScriptInterpreterPython.
This interface will be used in the C++ `ScriptProcess` Process Plugin to
call the script methods.
At the moment, not all methods are implemented, they will upstreamed in
upcoming patches.
This patch also adds helper methods to the ScriptInterpreter to
convert `SBAPI` Types (SBData & SBError) to `lldb_private` types
(DataExtractor & Status).
rdar://65508855
Differential Revision: https://reviews.llvm.org/D95711
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Our code for locating the shared library directory works via dladdr (or
the windows equivalent) to locate the path of an address known to reside
in liblldb. This works great for C++ programs, but there's a catch.
When (lib)lldb is used from python (like in our test suite), this dladdr
call will return a path to the _lldb.so (or such) file in the python
directory. To compensate for this, we have code which attempts to
resolve this symlink, to ensure we get the canonical location. However,
here's the second catch.
On windows, this file is not a symlink (but a copy), so this logic
fails. Since most of our other paths are derived from the liblldb
location, all of these paths will be wrong, when running the test suite.
One effect of this was the failure to find lldb-server in D96202.
To fix this issue, I add some windows-specific code to locate the
liblldb directory. Since it cannot rely on symlinks, it works by
manually walking the directory tree -- essentially doing the opposite of
what we do when computing the python directory.
To avoid python leaking back into the host code, I implement this with
the help of a callback which can be passed to HostInfo::Initialize in
order to assist with the directory location. The callback lives inside
the python plugin.
I also strenghten the existing path test to ensure the returned path is
the right one.
Differential Revision: https://reviews.llvm.org/D96779
LLDB does not like to import Python files with dashes or dots in their
name. While the former are technically allowed, it is discouraged. Dots
are allowed for subpackages but not in module names. This patch improves
the user experience by printing a useful error.
Before this patch:
error: module importing failed: SyntaxError('invalid syntax',
('<string>', 1, 11, 'import foo-bar\n'))
After this patch:
error: module importing failed: Python discourages dashes in module
names: foo-bar
rdar://74263511
[1] https://www.python.org/dev/peps/pep-0008/#package-and-module-names
Differential revision: https://reviews.llvm.org/D96833
Adds support for running a Lua function when a breakpoint is hit.
Example:
breakpoint command add -s lua -F abc
The above runs the Lua function 'abc' passing 2 arguments. 'frame', 'bp_loc' and 'extra_args'.
A third parameter 'extra_args' is only present when there is structured data
declared in the command line.
Example:
breakpoint command add -s lua -F abc -k foo -v bar
Differential Revision: https://reviews.llvm.org/D93649
1 - Partial Statements
The interpreter loop runs every line it receives, so partial
Lua statements are not being handled properly. This is a problem for
multiline breakpoint scripts since the interpreter loop, for this
particular case, is just an abstraction to a partially parsed function
body declaration.
This patch addresses this issue and as a side effect improves the
general Lua interpreter loop as well. It's now possible to write partial
statements in the 'script' command.
Example:
(lldb) script
>>> do
..> local a = 123
..> print(a)
..> end
123
The technique implemented is the same as the one employed by Lua's own REPL implementation.
Partial statements always errors out with the '<eof>' tag in the error
message.
2 - CheckSyntax in Lua.h
In order to support (1), we need an API for just checking the syntax of string buffers.
3 - Multiline scripted breakpoints
Finally, with all the base features implemented this feature is
straightforward. The interpreter loop behaves exactly the same, the
difference is that it will aggregate all Lua statements into the body of
the breakpoint function. An explicit 'quit' statement is needed to exit the
interpreter loop.
Example:
(lldb) breakpoint command add -s lua
Enter your Lua command(s). Type 'quit' to end.
The commands are compiled as the body of the following Lua function
function (frame, bp_loc, ...) end
..> print(456)
..> a = 123
..> quit
Differential Revision: https://reviews.llvm.org/D93481
This patch introduces a LLDB_SCOPED_TIMER macro to hide the needlessly
repetitive creation of scoped timers in LLDB. It's similar to the
LLDB_LOG(F) macro.
Differential revision: https://reviews.llvm.org/D93663
The reproducers currently use a static variable to track the API
boundary. This is obviously incorrect when the SB API is used
concurrently. While I do not plan to support that use-case (right now),
I do want to avoid us crashing. As a first step, correctly track API
boundaries across multiple threads.
Before this patch SB API calls made by the embedded script interpreter
would be considered "behind the API boundary" and correctly ignored.
After this patch, we need to tell the reproducers to ignore the
scripting thread as a "private thread".
Differential revision: https://reviews.llvm.org/D92811
LLDB is ignoring compilation errors for one-line breakpoint scripts.
This patch fixes the issues and now the error message of the
ScriptInterpreter is shown to the user.
I had to remove a new-line character for the Lua interpreter since it
was duplicated.
Differential Revision: https://reviews.llvm.org/D92729
The code that gets the ScriptInterpreter was not considering the
case that it receives a Lua interpreter.
Differential Revision: https://reviews.llvm.org/D92249
These callbacks are set using the following:
breakpoint command add -s lua -o "print('hello world!')"
The user supplied script is executed as:
function (frame, bp_loc, ...)
<body>
end
So the local variables 'frame', 'bp_loc' and vararg are all accessible.
Any global variables declared will persist in the Lua interpreter.
A user should never hold 'frame' and 'bp_loc' in a global variable as
these userdatas are context dependent.
Differential Revision: https://reviews.llvm.org/D91508
This patch changes the implementation of Lua's `print()` function to
respect `io.stdout`.
The original implementation uses `lua_writestring()` internally, which is
hardcoded to `stdout`.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D90787
This patch is a minor suggestion to not rely on the fact
that the `LUA_OK` macro is 0.
This assumption could change in future versions of the C API.
Differential Revision: https://reviews.llvm.org/D90556
This patch calls `lua_close()` on Lua dtor.
This guarantees that the Lua GC finalizers are honored, aside from the
usual internal clean up.
It also guarantees a call to the `__close` metamethod of any active
to-be-closed variable in Lua 5.4.
Since the previous `luaL_openlibs()` was a noop, because the standard
library is cached internally, I've removed it.
Differential Revision: https://reviews.llvm.org/D90557
Make it possible to use a relative path in command script import to the
location of the file being sourced. This allows the user to put Python
scripts next to LLDB command files and importing them without having to
specify an absolute path.
To enable this behavior pass `-c` to `command script import`. The
argument can only be used when sourcing the command from a file.
rdar://68310384
Differential revision: https://reviews.llvm.org/D89334
Currently we only strip the Python extension when the file exists on
disk because we assumed that if it didn't exist it was a module.
However, with the change from D89334 this is no longer the case as we
want to be able to import a relative path to a .py as a module. Since we
always import a scripting module as a "python module" we should always
strip the extension if present.
Differential revision: https://reviews.llvm.org/D89352
This reverts commit f775fe5964.
I fixed a return type error in the original patch that was causing a test failure.
Also added a REQUIRES: python to the shell test so we'll skip this for
people who build lldb w/o Python.
Also added another test for the error printing.
Raphael Isemann