Add a facility in the LanguageRuntime to provide a special
UnwindPlan based on the register values in a RegisterContext,
instead of using the return-pc to find a function and use its
normal UnwindPlans.
Needed when the runtime has special stack frames that we want
to show the user, but aren't actually on the real stack.
Specifically for Swift asynchronous functions.
With feedback from Greg Clayton, Jonas Devlieghere, Dave Lee
<rdar://problem/70398009>
Differential Revision: https://reviews.llvm.org/D96839
Add a new state for UnwindPlan::Row which indicates that any
register not listed is not defined, and should not be found in
stack frames newer than this one and passed up the stack. Mostly
intended for use with architectural default unwind plans that are
used for jitted stack frames, where we have no unwind information
or start address. lldb has no way to tell if registers were
spilled in the jitted frame & overwritten, so passing register
values up the stack is not safe to show the user.
Architectural default unwind plans are also used as a fast unwind
plan on x86_64 in particular, and are used as the fallback unwind
plans when lldb thinks it may be able to work around a problem
which causes the unwinder to stop walking the stack early.
For fast unwind plans, when we don't find a register location in
the arch default unwind plan, we fall back to computing & using
the full unwind plan. One small part of this patch is to know that
a register marked as Undefined in the fast unwind plan is a special
case, and we should continue on to the full unwind plan to find what
the real unwind rule is for this register.
Differential Revision: https://reviews.llvm.org/D96829
<rdar://problem/70398009>
Delete unused `EnableTracer()` and `SetTracer()` functions on `Thread`. By deleting
these, their `ThreadPlan` counterparts also become unused.
Then, by deleting `ThreadPlanStack::EnableTracer`, `EnableSingleStep` becomes unused.
With no more callers to `EnableSingleStep`, the value `m_single_step` is always true and
can be removed as well.
Differential Revision: https://reviews.llvm.org/D96666
Correct `RestoreThreadState` to a `void` return type. Also, update the signature of its
callee, `Thread::RestoreThreadStateFromCheckpoint`, by updating it to a `void` return
type, and making it non-`virtual`.
Differential Revision: https://reviews.llvm.org/D96688
The comment for ValueType claims that all values <1 are errors, but
not all switch statements take this into account. This patch
introduces an explicit Error case and deletes all default: cases, so
we get warned about incomplete switch coverage.
https://reviews.llvm.org/D96537
`QueueThreadPlanForStepInRange` accepts a `step_into_target`, but the constructor for
`ThreadPlanStepInRange` does not. Instead, a caller would optionally call
`SetStepInTarget()` in a separate statement.
This change adds `step_into_target` as a constructor argument. This simplifies
construction of `ThreadPlanSP`, by avoiding a subsequent downcast and conditional
assignment. This constructor is already used in downstream repos.
Differential Revision: https://reviews.llvm.org/D96539
While learning about ThreadPlan, I did a bit of cleanup:
* Remove unused code
* Move functions to protected where applicable
* Remove virtual for functions that are not overridden
Differential Revision: https://reviews.llvm.org/D96277
This patch refactors the current implementation of
`ProcessLaunchCommandOptions` to be generated by TableGen.
The patch also renames the class to `CommandOptionsProcessLaunch` to
align better with the rest of the codebase style and moves it to
separate files.
Differential Review: https://reviews.llvm.org/D95059
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Replace uses of GetModuleAtIndexUnlocked and
GetModulePointerAtIndexUnlocked with the ModuleIterable and
ModuleIterableNoLocking where applicable.
Differential revision: https://reviews.llvm.org/D94271
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
This is a speculative fix when looking at the finalization code in
Process. It tackles the following issues:
- Adds synchronization to prevent races between threads.
- Marks the process as finalized/invalid as soon as Finalize is called
rather than at the end.
- Simplifies the code by using only a single instance variable to track
finalization.
Differential revision: https://reviews.llvm.org/D93479
This reverts commit a01b26fb51, because it
breaks the "finish" command in some way -- the command does not
terminate after it steps out, but continues running the target. The
exact blast radius is not clear, but it at least affects the usage of
the "finish" command in TestGuiBasicDebug.py. The error is *not*
gui-related, as the same issue can be reproduced by running the same
steps outside of the gui.
There is some kind of a race going on, as the test fails only 20% of the
time on the buildbot.
Currently, the interpreter's context is not updated until a command is executed.
This has resulted in the behavior of SB-interface functions and some commands
depends on previous user actions. The interpreter's context can stay uninitialized,
point to a currently selected target, or point to one of previously selected targets.
This patch removes any usages of CommandInterpreter::UpdateExecutionContext.
CommandInterpreter::HandleCommand* functions still may override context temporarily,
but now they always restore it before exiting. CommandInterpreter saves overriden
contexts to the stack, that makes nesting commands possible.
Added test reproduces one of the issues. Without this fix, the last assertion fails
because interpreter's execution context is empty until running "target list", so,
the value of the global property was updated instead of process's local instance.
Differential Revision: https://reviews.llvm.org/D92164
TargetList::CreateTarget automatically adds created target to the list, however,
CommandObjectTargetCreate does some additional preparation after creating a target
and which can fail. The command should remove created target if it failed. Since
the function has many ways to return, scope guard does this work safely.
Changes to the TargetList make target adding and selection more transparent.
Other changes remove unnecessary SetSelectedTarget after CreateTarget.
Differential Revision: https://reviews.llvm.org/D93052
By now LLDB can import the 'std' C++ module to improve expression evaluation,
but there are still a few problems to solve before we can do this by default.
One is that importing the C++ module is slightly slower than normal expression
evaluation (mostly because the disk access and loading the initial lookup data
is quite slow in comparison to the barebone Clang setup the rest of the LLDB
expression evaluator is usually doing). Another problem is that some complicated
types in the standard library aren't fully supported yet by the ASTImporter, so
we end up types that fail to import (which usually appears to the user as if the
type is empty or there is just no result variable).
To still allow people to adopt this mode in their daily debugging, this patch
adds a setting that allows LLDB to automatically retry failed expression with a
loaded C++ module. All success expressions will behave exactly as they would do
before this patch. Failed expressions get a another parse attempt if we find a
usable C++ module in the current execution context. This way we shouldn't have
any performance/parsing regressions in normal debugging workflows, while the
debugging workflows involving STL containers benefit from the C++ module type
info.
This setting is off by default for now with the intention to enable it by
default on macOS soon-ish.
The implementation is mostly just extracting the existing parse logic into its
own function and then calling the parse function again if the first evaluation
failed and we have a C++ module to retry the parsing with.
Reviewed By: shafik, JDevlieghere, aprantl
Differential Revision: https://reviews.llvm.org/D92784
Add a 'can_connect' parameter to Process plugin initialization, and use
it to filter plugins to these capable of remote connections. This is
used to prevent 'process connect' from picking up a plugin that can only
be used locally, e.g. the legacy FreeBSD plugin.
Differential Revision: https://reviews.llvm.org/D91810
Update the help string for `target.source-map` to remove the use of the word
"duple" and to add examples. Additionally I rewrote parts with the goal of
making the description more concrete.
rdar://68736012
Differential Revision: https://reviews.llvm.org/D91742
This extends the "memory region" command to
show tagged regions on AArch64 Linux when the MTE
extension is enabled.
(lldb) memory region the_page
[0x0000fffff7ff8000-0x0000fffff7ff9000) rw-
memory tagging: enabled
This is done by adding an optional "flags" field to
the qMemoryRegion packet. The only supported flag is
"mt" but this can be extended.
This "mt" flag is read from /proc/{pid}/smaps on Linux,
other platforms will leave out the "flags" field.
Where this "mt" flag is received "memory region" will
show that it is enabled. If it is not or the target
doesn't support memory tagging, the line is not shown.
(since majority of the time tagging will not be enabled)
Testing is added for the existing /proc/{pid}/maps
parsing and the new smaps parsing.
Minidump parsing has been updated where needed,
though it only uses maps not smaps.
Target specific tests can be run with QEMU and I have
added MTE flags to the existing helper scripts.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D87442
Depends on D90490.
The stop command is simple and invokes the new method Trace::StopTracingThread(thread).
On the other hand, the start command works by delegating its implementation to a CommandObject provided by the Trace plugin. This is necessary because each trace plugin needs different options for this command. There's even the chance that a Trace plugin can't support live tracing, but instead supports offline decoding and analysis, which means that "thread trace dump instructions" works but "thread trace start" doest. Because of this and a few other reasons, it's better to have each plugin provide this implementation.
Besides, I'm using the GetSupportedTraceType method introduced in D90490 to quickly infer what's the trace plug-in that works for the current process.
As an implementation note, I moved CommandObjectIterateOverThreads to its header so that I can use it from the IntelPT plugin. Besides, the actual start and stop logic for intel-pt is not part of this diff.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D90729
I noticed that Process is inheriting from UserID to store its PID value. This patch
replaces this with a dedicated field in the Process class. This is NFC, but has some
small effects on the code using Process:
* `GetID()` now returns a `lldb::pid_t` like all other process code instead of `lldb::user_id_t`. Both are typedefs for `uint64_t`, so no change in behaviour.
* The equality operators defined for UserID no longer accept Process instances.
* Removes the inherited method `Process::Clear()` which didn't actually clear anything beside the PID value.
We maybe should also remove the getters/setters to `S/GetPID` or something like that. I can update all the code for that
in a follow-up NFC commit.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D91699
I only have a crash report for this. I could reproduce it with a slightly older
lldb by running an expression that called pthread_kill, but we started making modules
for our expression JIT code, so that no longer triggers the bug. I can't think of another
good way to test it but the fix is obvious.
Depends on D89408.
This diff finally implements trace decoding!
The current interface is
$ trace load /path/to/trace/session/file.json
$ thread trace dump instructions
thread #1: tid = 3842849, total instructions = 22
[ 0] 0x40052d
[ 1] 0x40052d
...
[19] 0x400521
$ # simply enter, which is a repeat command
[20] 0x40052d
[21] 0x400529
...
This doesn't do any disassembly, which will be done in the next diff.
Changes:
- Added an IntelPTDecoder class, that is a wrapper for libipt, which is the actual library that performs the decoding.
- Added TraceThreadDecoder class that decodes traces and memoizes the result to avoid repeating the decoding step.
- Added a DecodedThread class, which represents the output from decoding and that for the time being only stores the list of reconstructed instructions. Later it'll contain the function call hierarchy, which will enable reconstructing backtraces.
- Added basic APIs for accessing the trace in Trace.h:
- GetInstructionCount, which counts the number of instructions traced for a given thread
- IsTraceFailed, which returns an Error if decoding a thread failed
- ForEachInstruction, which iterates on the instructions traced for a given thread, concealing the internal storage of threads, as plug-ins can decide to generate the instructions on the fly or to store them all in a vector, like I do.
- DumpTraceInstructions was updated to print the instructions or show an error message if decoding was impossible.
- Tests included
Differential Revision: https://reviews.llvm.org/D89283
AFAICT, ~TargetList simply implements the default destructor, plus some
locking.
The history is murky, so I'm not sure why we do this locking. Perhaps,
at some point, it was possible to delete the same TargetList instance
from two different threads, setting up a race. If that were true, then
the locking would protect against the race.
Since TargetList is uniquely owned by Debugger (m_target_list), no such
race is possible today.
Testing: check-lldb
Differential Revision: https://reviews.llvm.org/D90895
Factor out dummy target creation from CreateTargetInternal.
This makes it impossible for dummy target creation to accidentally fail
due to too-strict checking in one of the CreateTargetInternal overloads.
Testing: check-lldb
rdar://70630655
Differential Revision: https://reviews.llvm.org/D90872
This class and it's surroundings contain a lot of shady code, but as far
as I can tell all of that code is unreachable (there is no code actually
setting the value to eValueTypeVector).
According to history this class was introduced in 2012 in
r167033/0665a0f09. At that time, the code seemed to serve some purpose,
and it had two entry points (in Value::SetContext and
ClangExpressionDeclMap::LookupDecl). The first entry point was deleted
in D17897 and the second one in r179842/44342735.
The stated purpose of the patch introducing this class was to fix
TestRegisters.py, and "expr $xmm0" in particular. Both of these things
function perfectly well these days without this class.
The various GetSharedModule methods have an optional out parameter for
the old module when a file has changed or been replaced, which the
Target uses to keep its module list current/correct. We've been using
a single ModuleSP to track "the" old module, and this change switches
to using a SmallVector of ModuleSP, which has a couple benefits:
- There are multiple codepaths which may discover an old module, and
this centralizes the code for how to handle multiples in one place,
in the Target code. With the single ModuleSP, each place that may
discover an old module is responsible for how it handles multiples,
and the current code is inconsistent (some code paths drop the first
old module, others drop the second).
- The API will be more natural for identifying old modules in routines
that work on sets, like ModuleList::ReplaceEquivalent (which I plan
on updating to report old module(s) in a subsequent change to fix a
bug).
I'm not convinced we can ever actually run into the case that multiple
old modules are found in the same GetOrCreateModule call, but I think
this change makes sense regardless, in light of the above.
When an old module is reported, Target::GetOrCreateModule calls
m_images.ReplaceModule, which doesn't allow multiple "old" modules; the
new code calls ReplaceModule for the first "old" module, and for any
subsequent old modules it logs the event and calls m_images.Remove.
Reviewed By: jingham
Differential Revision: https://reviews.llvm.org/D89156
The intention is not to allow stop-hook commands to query the
user, so this is correct. It also works around a deadlock in
switching to the Python Session to execute python based commands
in the stop hook when the Debugger stdin is backed by a FILE *.
Differential Revision: https://reviews.llvm.org/D90332
The number of resumes should always be positive to let's make this an
unsigned everywhere. Also remove the unused 'localhost' parameter from
ConvertArgumentsForLaunchingInShell.
This patch redesigns the Target::GetUtilityFunctionForLanguage API:
- Use a unique_ptr instead of a raw pointer for the return type.
- Wrap the result in an llvm::Expected instead of using a Status object as an I/O parameter.
- Combine the action of "getting" and "installing" the UtilityFunction as they always get called together.
- Pass std::strings instead of const char* and std::move them where appropriate.
There's more room for improvement but I think this tackles the most
prevalent issues with the current API.
Differential revision: https://reviews.llvm.org/D90011
In a new Range class was introduced to simplify and the Disassembler API
and reduce duplication. It unintentionally broke the
SBFrame::Disassemble functionality because it unconditionally converts
the number of instructions to a Range{Limit::Instructions,
num_instructions}. This is subtly different from the previous behavior,
where now we're passing a Range and assume it's valid in the callee, the
original code would propagate num_instructions and the callee would
compare the value and decided between disassembling instructions or
bytes.
Unfortunately the existing tests was not particularly strict:
disassembly = frame.Disassemble()
self.assertNotEqual(len(disassembly), 0, "Disassembly was empty.")
This would pass because without this patch we'd disassemble zero
instructions, resulting in an error:
(lldb) script print(lldb.frame.Disassemble())
error: error reading data from section __text
Differential revision: https://reviews.llvm.org/D89925
Renamed ThreadIntelPT to TreaceThread, making it a top-level class. I noticed that this class can and shuld work for any trace plugin and there's nothing intel-pt specific in it.
With that TraceThread change, I was able to move most of the json file parsing logic to the base class TraceSessionFileParser, which makes adding new plug-ins easier.
This originally was part of https://reviews.llvm.org/D89283
Differential Revision: https://reviews.llvm.org/D89408
While debugging another bug I found out that we currently don't set any limit
for the number of diagnostics Clang emits. If a user does something that
generates a lot of errors (like including some long header file from within the
expression function), then we currently spam the LLDB output with potentially
thousands of Clang error diagnostics.
Clang sets a default limit of 20 errors, but given that LLDB is often used
interactively for small expressions I would say a limit of 5 is enough. The
limit is implemented as a setting, so if a user cares about seeing having a
million errors printed to their terminal then they can just increase the
settings value.
Reviewed By: shafik, mib
Differential Revision: https://reviews.llvm.org/D88889
RegisterInfo's `reg_name`/`reg_alt_name` fields are C-Strings and are supposed
to only be generated from a ConstString. The reason for that is that
`DynamicRegisterInfo::GetRegisterInfo` and
`RegInfoBasedABI::GetRegisterInfoByName` try to optimise finding registers by
name by only comparing the C string pointer values instead of the underlying
strings. This only works if both C strings involved in the comparison come from
a ConstString. If one of the two C strings doesn't come from a ConstString the
comparison won't work (and most likely will silently fail).
I added an assert in b0060c3a78 which checks that
both strings come from a ConstString. Apparently not all ABI plugins are
generating their register names via ConstString, so this code is now not just
silently failing but also asserting.
In D88375 we did a shady fix for the MIPS plugins by just copying the
ConstString setup code to that plugin, but we still need to fix ABISysV_arc,
ABISysV_ppc and ABISysV_ppc64 plugins.
I would say we just fix the remaining plugins by removing the whole requirement
to have the register names coming from ConstStrings. I really doubt that we
actually save any time with the whole ConstString search trick (searching ~50
strings that have <4 characters doesn't sound more expensive than calling the
really expensive ConstString constructor + comparing the same amount of pointer
values). Also whatever small percentage of LLDB's runtime is actually spend in
this function is anyway not worth the complexity of this approach.
This patch just removes all this and just does a normal string comparison.
Reviewed By: JDevlieghere, labath
Differential Revision: https://reviews.llvm.org/D88490
Depends on D88841
As per the discussion in the RFC, we'll implement both
thread trace dump [instructions | functions]
This is the first step in implementing the "instructions" dumping command.
It includes:
- A minimal ProcessTrace plugin for representing processes from a trace file. I noticed that it was a required step to mimic how core-based processes are initialized, e.g. ProcessElfCore and ProcessMinidump. I haven't had the need to create ThreadTrace yet, though. So far HistoryThread seems good enough.
- The command handling itself in CommandObjectThread, which outputs a placeholder text instead of the actual instructions. I'll do that part in the next diff.
- Tests
{F13132325}
Differential Revision: https://reviews.llvm.org/D88769
With the feedback I was getting in different diffs, I realized that splitting the parsing logic into two classes was not easy to deal with. I do see value in doing that, but I'd rather leave that as a refactor after most of the intel-pt logic is in place. Thus, I'm merging the common parser into the intel pt one, having thus only one that is fully aware of Intel PT during parsing and object creation.
Besides, based on the feedback in https://reviews.llvm.org/D88769, I'm creating a ThreadIntelPT class that will be able to orchestrate decoding of its own trace and can handle the stop events correctly.
This leaves the TraceIntelPT class as an initialization class that glues together different components. Right now it can initialize a trace session from a json file, and in the future will be able to initialize a trace session from a live process.
Besides, I'm renaming SettingsParser to SessionParser, which I think is a better name, as the json object represents a trace session of possibly many processes.
With the current set of targets, we have the following
- Trace: main interface for dealing with trace sessions
- TraceIntelPT: plugin Trace for dealing with intel pt sessions
- TraceIntelPTSessionParser: a parser of a json trace session file that can create a corresponding TraceIntelPT instance along with Targets, ProcessTraces (to be created in https://reviews.llvm.org/D88769), and ThreadIntelPT threads.
- ProcessTrace: (to be created in https://reviews.llvm.org/D88769) can handle the correct state of the traces as the user traverses the trace. I don't think there'll be a need an intel-pt specific implementation of this class.
- ThreadIntelPT: a thread implementation that can handle the decoding of its own trace file, along with keeping track of the current position the user is looking at when doing reverse debugging.
Differential Revision: https://reviews.llvm.org/D88841
This is a polymorphic class, copying it is a bad idea.
This was not a problem because most classes inheriting from it were
deleting their copy operations themselves. However, this enables us to
delete those explicit deletions, and ensure noone forgets to add them in
the future.
Except for the few people actually debugging shells, stopping on a
SIGCONT doesn't add any value. And for people trying to run tests
under the debugger, stopping here is actively inconvenient. So this
patch switches the default behavior to not stop.
Differential Revision: https://reviews.llvm.org/D89019
This was looking at the privateState, but it's possible that
the actual process has started up and then stopped again by the
time we get to the check, which would lead us to get out of running
the stop hooks too early.
Instead we need to track the intention of the stop hooks directly.
Differential Revision: https://reviews.llvm.org/D88753
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.
