[NFC] As part of using inclusive language within the llvm project, this patch
renames master plan to controlling plan in lldb.
Reviewed By: jingham
Differential Revision: https://reviews.llvm.org/D113019
This adds a specific unwind plan for AArch64 Linux sigreturn frames.
Previously we assumed that the fp would be valid here but it is not.
https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
On Ubuntu Bionic it happened to point to an old frame info which meant
you got what looked like a correct backtrace. On Focal, the info is
completely invalid. (probably due to some code shuffling in libc)
This adds an UnwindPlan that knows that the sp in a sigreturn frame
points to an rt_sigframe from which we can offset to get saved
sp and pc values to backtrace correctly.
Based on LibUnwind's change: https://reviews.llvm.org/D90898
A new test is added that sets all compares the frames from the initial
signal catch to the handler break. Ensuring that the stack/frame pointer,
function name and register values match.
(this test is AArch64 Linux specific because it's the only one
with a specific unwind plan for this situation)
Fixes https://bugs.llvm.org/show_bug.cgi?id=52165
Reviewed By: omjavaid, labath
Differential Revision: https://reviews.llvm.org/D112069
This patch fixes an amusing bug where a Platform::Kill operation would
happily terminate a proces on a completely different platform, as long
as they have the same process ID. This was due to the fact that the
implementation was iterating through all known (debugged) processes in
order terminate them directly.
This patch just deletes that logic, and makes everything go through the
OS process termination APIs. While it would be possible to fix the logic
to check for a platform match, it seemed to me that the implementation
was being too smart for its own good -- accessing random Process
objects without knowing anything about their state is risky at best.
Going through the os ensures we avoid any races.
I also "upgrade" the termination signal to a SIGKILL to ensure the
process really dies after this operation.
Differential Revision: https://reviews.llvm.org/D113184
This reverts commit 5fbcf67734.
ProcessDebugger is used in ProcessWindows and NativeProcessWindows.
I thought I was simplifying things by renaming to DoGetMemoryRegionInfo
in ProcessDebugger but the Native process side expects "GetMemoryRegionInfo".
Follow the pattern that WriteMemory uses. So:
* ProcessWindows::DoGetMemoryRegioninfo calls ProcessDebugger::GetMemoryRegionInfo
* NativeProcessWindows::GetMemoryRegionInfo does the same
On AArch64 we have various things using the non address bits
of pointers. This means when you lookup their containing region
you won't find it if you don't remove them.
This changes Process GetMemoryRegionInfo to a non virtual method
that uses the current ABI plugin to remove those bits. Then it
calls DoGetMemoryRegionInfo.
That function does the actual work and is virtual to be overriden
by Process implementations.
A test case is added that runs on AArch64 Linux using the top
byte ignore feature.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D102757
The amount of roundtrips between StringRefs, ConstStrings and std::strings is
getting a bit out of hand, this patch avoid the unnecessary roundtrips.
Reviewed By: wallace, aprantl
Differential Revision: https://reviews.llvm.org/D112863
The key stored in the source map is a normalized path string with host's
path style, so it is also necessary to normalize the file path during
searching the map
Reviewed By: wallace, aprantl
Differential Revision: https://reviews.llvm.org/D112439
We weren't setting the listener back to the unhijacked one in this
case, so that a continue after the stop fails. It thinks the process
is still running. Also add tests for this behavior.
Differential Revision: https://reviews.llvm.org/D112747
Android and other platforms make wide use of signals when running applications and this can slow down debug sessions. Tracking this statistic can help us to determine why a debug session is slow.
The new data appears inside each target object and reports the signal hit counts:
"signals": [
{
"SIGSTOP": 1
},
{
"SIGUSR1": 1
}
],
Differential Revision: https://reviews.llvm.org/D112683
This patch adds breakpoints to each target's statistics so we can track how long it takes to resolve each breakpoint. It also includes the structured data for each breakpoint so the exact breakpoint details are logged to allow for reproduction of slow resolving breakpoints. Each target gets a new "breakpoints" array that contains breakpoint details. Each breakpoint has "details" which is the JSON representation of a serialized breakpoint resolver and filter, "id" which is the breakpoint ID, and "resolveTime" which is the time in seconds it took to resolve the breakpoint. A snippet of the new data is shown here:
"targets": [
{
"breakpoints": [
{
"details": {...},
"id": 1,
"resolveTime": 0.00039291599999999999
},
{
"details": {...},
"id": 2,
"resolveTime": 0.00022679199999999999
}
],
"totalBreakpointResolveTime": 0.00061970799999999996
}
]
This provides full details on exactly how breakpoints were set and how long it took to resolve them.
Differential Revision: https://reviews.llvm.org/D112587
The new key/value pairs that are added to each module's stats are:
"debugInfoByteSize": The size in bytes of debug info for each module.
"debugInfoIndexTime": The time in seconds that it took to index the debug info.
"debugInfoParseTime": The time in seconds that debug info had to be parsed.
At the top level we add up all of the debug info size, parse time and index time with the following keys:
"totalDebugInfoByteSize": The size in bytes of all debug info in all modules.
"totalDebugInfoIndexTime": The time in seconds that it took to index all debug info if it was indexed for all modules.
"totalDebugInfoParseTime": The time in seconds that debug info was parsed for all modules.
Differential Revision: https://reviews.llvm.org/D112501
Replace bool+by-ref argument with llvm::Optional, and move the common
implementation into HostInfoPOSIX. Based on my (simple) experiment,
the uname and the sysctl approach return the same value on MacOS, so
there's no need for a mac-specific implementation of this functionality.
Differential Revision: https://reviews.llvm.org/D112457
The new module stats adds the ability to measure the time it takes to parse and index the symbol tables for each module, and reports modules statistics in the output of "statistics dump" along with the path, UUID and triple of the module. The time it takes to parse and index the symbol tables are also aggregated into new top level key/value pairs at the target level.
Differential Revision: https://reviews.llvm.org/D112279
Now that AddRegister() is no longer used, remove it. While at it,
we can also make Finalize() protected as all supported API methods
call it internally.
Differential Revision: https://reviews.llvm.org/D111498
This patch is a smaller version of a previous patch https://reviews.llvm.org/D110804.
This patch modifies the output of "statistics dump" to be able to get stats from the current target. It adds 3 new stats as well. The output of "statistics dump" is now emitted as JSON so that it can be used to track performance and statistics and the output could be used to populate a database that tracks performance. Sample output looks like:
(lldb) statistics dump
{
"expressionEvaluation": {
"failures": 0,
"successes": 0
},
"firstStopTime": 0.34164492800000001,
"frameVariable": {
"failures": 0,
"successes": 0
},
"launchOrAttachTime": 0.31969605400000001,
"targetCreateTime": 0.0040863039999999998
}
The top level keys are:
"expressionEvaluation" which replaces the previous stats that were emitted as plain text. This dictionary contains the success and fail counts.
"frameVariable" which replaces the previous stats for "frame variable" that were emitted as plain text. This dictionary contains the success and fail counts.
"targetCreateTime" contains the number of seconds it took to create the target and load dependent libraries (if they were enabled) and also will contain symbol preloading times if that setting is enabled.
"launchOrAttachTime" is the time it takes from when the launch/attach is initiated to when the first private stop occurs.
"firstStopTime" is the time in seconds that it takes to stop at the first stop that is presented to the user via the LLDB interface. This value will only have meaning if you set a known breakpoint or stop location in your code that you want to measure as a performance test.
This diff is also meant as a place to discuess what we want out of the "statistics dump" command before adding more funcionality. It is also meant to clean up the previous code that was storting statistics in a vector of numbers within the lldb_private::Target class.
Differential Revision: https://reviews.llvm.org/D111686
This patch deals with ObjectFile, ObjectContainer and OperatingSystem
plugins. I'll convert the other types in separate patches.
In order to enable piecemeal conversion, I am leaving some ConstStrings
in the lowest PluginManager layers. I'll convert those as the last step.
Differential Revision: https://reviews.llvm.org/D112061
gdbserver does not expose combined ymm* registers but rather XSAVE-style
split xmm* and ymm*h portions. Extend value_regs to support combining
multiple registers and use it to create user-friendly ymm* registers
that are combined from split xmm* and ymm*h portions.
Differential Revision: https://reviews.llvm.org/D108937
`Target::GetScratchTypeSystems` returns the list of scratch TypeSystems. The
current implementation is iterating over all LanguageType values and retrieves
the respective TypeSystem for each LanguageType.
All C/C++/Obj-C LanguageTypes are however mapped to the same
ScratchTypeSystemClang instance, so the current implementation adds this single
TypeSystem instance several times to the list of TypeSystems (once for every
LanguageType that we support).
The only observable effect of this is that `SBTarget.FindTypes` for builtin
types currently queries the ScratchTypeSystemClang several times (and also adds
the same result several times).
Reviewed By: bulbazord, labath
Differential Revision: https://reviews.llvm.org/D111931
gdbserver does not expose combined ymm* registers but rather XSAVE-style
split xmm* and ymm*h portions. Extend value_regs to support combining
multiple registers and use it to create user-friendly ymm* registers
that are combined from split xmm* and ymm*h portions.
Differential Revision: https://reviews.llvm.org/D108937
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
Support specifying an offset for value_regs[0], and add the offset
to the computed derived register offset. This makes it possible to
e.g. create the "ah" register on x86.
Differential Revision: https://reviews.llvm.org/D111489
Platform instances are stored in a function-local static list. However, the
logging code involves locking a function-local static mutex. This only works on
some implementations where the Log mutex is by accident destroyed *after* the
Platform list is destroyed.
This fixes randomly failing tests due to `recursive_mutex lock failed: Invalid
argument`.
Reviewed By: kastiglione
Differential Revision: https://reviews.llvm.org/D111816
Add an overload of DynamicRegisterInfo::SetRegisterInfo() that accepts
a std::vector<Register> as an argument. This moves the conversion
from DRI::Register to RegisterInfo directly into DynamicRegisterInfo,
and avoids the necessity of creating fully-compatible intermediate
RegisterInfo instances.
While the new method could technically reuse AddRegister(), the ultimate
goal is to replace AddRegister() with SetRegisterInfo() entirely.
Differential Revision: https://reviews.llvm.org/D111435
Move DynamicRegisterInfo::AddSupplementaryRegister() into a standalone
function working on std::vector<DynamicRegisterInfo::Register>.
Differential Revision: https://reviews.llvm.org/D111295
Call ABI::AugmentRegisterInfo() once with a vector of all defined
registers rather than calling it for every individual register. Move
and rename RemoteRegisterInfo from gdb-remote to
DynamicRegisterInfo::Register, and use this class when augmenting
registers.
Differential Revision: https://reviews.llvm.org/D111142
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
The previous version of the patch did not update the definitions in
conditionally compiled code. This patch includes changes to ARC and
windows targets.
Original commit message was:
These were added to support some mips registers on linux, but linux mips
support has now been removed due.
They are still referenced in the freebds mips implementation, but the
completeness of that implementation is also unknown. All other
architectures just set these fields to zero, which is a cause of
significant bloat in our register info definitions.
Arm also has registers with variable sizes, but they were implemented in
a more gdb-compatible fashion and don't use this feature.
Differential Revision: https://reviews.llvm.org/D110914
This reverts commit 00e704bf08.
This commit should should have updated
llvm/llvm-project/lldb/source/Plugins/ABI/ARC/ABISysV_arc.cpp like the other
architectures.
These were added to support some mips registers on linux, but linux mips
support has now been removed due.
They are still referenced in the freebds mips implementation, but the
completeness of that implementation is also unknown. All other
architectures just set these fields to zero, which is a cause of
significant bloat in our register info definitions.
Arm also has registers with variable sizes, but they were implemented in
a more gdb-compatible fashion and don't use this feature.
Differential Revision: https://reviews.llvm.org/D110914
Move DynamicRegisterInfo from the internal lldbPluginProcessUtility
library to the public lldbTarget library. This is a prerequisite
towards ABI plugin changes that are going to pass DynamicRegisterInfo
parameters.
Differential Revision: https://reviews.llvm.org/D110942
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
We added some support for this mode back in 2015, but the feature was
never productionized. It is completely untested, and there are known
major structural lldb issues that need to be resolved before this
feature can really be supported.
It also complicates making further changes to stop reply packet
handling, which is what I am about to do.
Differential Revision: https://reviews.llvm.org/D110553
Replace misc. StringConvert uses with llvm::to_integer()
and llvm::to_float(), except for cases where further refactoring is
planned. The purpose of this change is to eliminate the StringConvert
API that is duplicate to LLVM, and less correct in behavior at the same
time.
Differential Revision: https://reviews.llvm.org/D110447
These have been here since r215992, guarding the calls to HostInfo, but
their purpose unclear -- HostInfoLinux provides these functions and they
work fine.
instead of a pointer. There are just two callers of this function, and
both of them have a valid target pointer, so there's no need for all
implementations to concern themselves with whether the pointer is null.
Update GetRegisterInfoByName() methods to support getting registers
by a generic name independently of alt_name entries in the register
context. This makes it possible to use generic names when interacting
with gdbserver (that does not supply alt_names). It also makes it
possible to remove some of the duplicated information from register
context declarations and/or use alt_names for another purpose.
Differential Revision: https://reviews.llvm.org/D108554
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
D101329 introduces the Process:SaveCore function returning a
`llvm::Expected<bool>`. That function causes that Clang with -fmodules crashes
while compiling LLDB's PythonDataObjects.cpp. With enabled asserts Clang fails
because of:
Assertion failed: (CachedFieldIndex && "failed to find field in parent")
Crash can be reproduced by building via -DLLVM_ENABLE_MODULES=On with Clang
12.0.1 and then building PythonDataObjects.cpp.o .
Clang bug is tracked at rdar://82901462
Implement a new target.process.follow-fork-mode setting to control
LLDB's behavior on fork. If set to 'parent', the forked child is
detached and parent continues being traced. If set to 'child',
the parent is detached and child becomes traced instead.
Differential Revision: https://reviews.llvm.org/D100503
It is easy to accidentally introduce a deadlock by having the callback
passed to Language::ForEach also attempt to acquire the same lock. It
is easy enough to disallow the callback from calling anything in
Language directly, but it may happen through a series of other
function/method calls.
The solution I am proposing is to tighten the lock in Language::ForEach
so that it is only held as we gather the currently loaded language
plugins. We store them in a vector and then iterate through them with
the callback so that the callback can't introduce a deadlock.
Differential Revision: https://reviews.llvm.org/D109013
Add a support for handling fork/vfork stops in LLGS client. At this
point, it only sends a detach packet for the newly forked child
(and implicitly resumes the parent).
Differential Revision: https://reviews.llvm.org/D100206
This patch adds a process launch form. Additionally, a LazyBoolean field
was implemented and numerous utility methods were added to various
fields to get the launch form working.
Differential Revision: https://reviews.llvm.org/D107869
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
Change `ThreadPlanStack::PopPlan` and `::DiscardPlan` to not do the following:
1. Move the last plan, leaving a moved `ThreadPlanSP` in the plans vector
2. Operate on the last plan
3. Pop the last plan off the plans vector
This leaves a period of time where the last element in the plans vector has been moved. I am not sure what, if any, guarantees there are when doing this, but it seems like it would/could leave a null `ThreadPlanSP` in the container. There are asserts in place to prevent empty/null `ThreadPlanSP` instances from being pushed on to the stack, and so this could break that invariant during multithreaded access to the thread plan stack.
An open question is whether this use of `std::move` was the result of a measure performance problem.
Differential Revision: https://reviews.llvm.org/D106171
Process::HandleStateChangedEvent, we check whether a thread stopped
for eStopReasonSignal is stopped for a signal that's currently set to
"no-stop". If it is, then we don't set that thread as the currently
selected thread.
But that only happens in the part of the algorithm that's handling the
case where the previously selected thread has no stop reason. Since we
want to keep on a thread as long as it is doing something interesting,
we always prefer the current thread. That's almost right, but we
forgot to check whether the previously selected thread stopped with an
eStopReasonSignal for a "no-stop" signal. If it did, then we shouldn't
select it.
This patch adds that check. I can't figure out a good way to test
this. This is the sort of thing that Ismail's scripted process plugin
will make easy once it is a real boy. But figuring out how to do this
in a real process is not trivial.
Differential Revision: https://reviews.llvm.org/D106712
This adds memory tag writing to Process and the
GDB remote code. Supporting work for the
"memory tag write" command. (to follow)
Process WriteMemoryTags is similair to ReadMemoryTags.
It will pack the tags then call DoWriteMemoryTags.
That function will send the QMemTags packet to the gdb-remote.
The QMemTags packet follows the GDB specification in:
https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html#General-Query-Packets
Note that lldb-server will be treating partial writes as
complete failures. So lldb doesn't need to handle the partial
write case in any special way.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D105181
Copying from the inline documentation:
```
Trace exporter plug-ins operate on traces, converting the trace data provided by an \a lldb_private::TraceCursor into a different format that can be digested by other tools, e.g. Chrome Trace Event Profiler.
Trace exporters are supposed to operate on an architecture-agnostic fashion, as a TraceCursor, which feeds the data, hides the actual trace technology being used.
```
I want to use this to make the code in https://reviews.llvm.org/D105741 a plug-in. I also imagine that there will be more and more exporters being implemented, as an exporter creates something useful out of trace data. And tbh I don't want to keep adding more stuff to the lldb/Target folder.
This is the minimal definition for a TraceExporter plugin. I plan to use this with the following commands:
- thread trace export <plug-in name> [plug-in specific args]
- This command would support autocompletion of plug-in names
- thread trace export list
- This command would list the available trace exporter plug-ins
I don't plan to create yet a "process trace export" because it's easier to start analyzing the trace of a given thread than of the entire process. When we need a process-level command, we can implement it.
I also don't plan to force each "export" command implementation to support multiple threads (for example, "thread trace start 1 2 3" or "thread trace start all" operate on many threads simultaneously). The reason is that the format used by the exporter might or might not support multiple threads, so I'm leaving this decision to each trace exporter plug-in.
Differential Revision: https://reviews.llvm.org/D106501
D104406 introduced an error in which, if there are multiple matchings rules for a given path, lldb was only checking for the validity in the filesystem of the first match instead of looking exhaustively one by one until a valid file is found.
Besides that, a call to consume_front was being done incorrectly, as it was modifying the input, which renders subsequent matches incorrect.
I added a test that checks for both cases.
Differential Revision: https://reviews.llvm.org/D106723
Code was added to Target::RunStopHook to make sure that we don't run stop hooks when
you stop after an expression evaluation. But the way it was done was to check that we
hadn't run an expression since the last natural stop. That failed in the case where you
stopped for a breakpoint which had run an expression, because the stop-hooks get run
after the breakpoint actions, and so by the time we got to running the stop-hooks,
we had already run a user expression.
I fixed this by adding a target ivar tracking the last natural stop ID at which we had
run a stop-hook. Then we keep track of this and make sure we run the stop-hooks only
once per natural stop.
Differential Revision: https://reviews.llvm.org/D106514
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>
These two classes, TraceSessionFileParser and ThreadPostMortemTrace,
seem to be useful primarily for tracing. Currently it looks like
intel-pt is the sole user of these, but that other tracing plugins could
be written in the future that take advantage of these. Unfortunately
with them in Target, there is a dependency on PluginProcessUtility. I'd
like to sever that dependency, so I moved them into a `TraceCommon`
plugin.
Differential Revision: https://reviews.llvm.org/D105649
When we go to destroy the process, we first try to halt it, if
we succeeded and the target stopped, we want to clear out the
thread plans and breakpoints in case we still need to resume to complete
killing the process. If the target was exited or detached, it's
pointless but harmless to do this. But if the state is eStateInvalid -
for instance if we tried to interrupt the target to Halt it and that
fails - we don't want to keep trying to interact with the inferior,
so we shouldn't do this work.
This change explicitly checks eStateStopped, and only does the pre-resume
cleanup if we did manage to stop the process.
D104422 added the interface for TraceCursor, which is the main way to traverse instructions in a trace. This diff implements the corresponding cursor class for Intel PT and deletes the now obsolete code.
Besides that, the logic for the "thread trace dump instructions" was adapted to use this cursor (pretty much I ended up moving code from Trace.cpp to TraceCursor.cpp). The command by default traverses the instructions backwards, and if the user passes --forwards, then it's not forwards. More information about that is in the Options.td file.
Regarding the Intel PT cursor. All Intel PT cursors for the same thread share the same DecodedThread instance. I'm not yet implementing lazy decoding because we don't need it. That'll be for later. For the time being, the entire thread trace is decoded when the first cursor for that thread is requested.
Differential Revision: https://reviews.llvm.org/D105531
We've seen reports of crashes (none we've been able to reproduce
locally) that look like they are caused by concurrent access to a
thread plan stack. It looks like there are error paths when an
interrupt request to debugserver times out that cause this problem.
The thread plan stack access is never in a hot loop, and there
aren't enough of them for the extra data member to matter, so
there's really no good reason not to protect the access.
Adding the mutex revealed a couple of places where we were
using "auto" in an iteration when we should have been using
"auto &" - we didn't intend to copy the stack - and I fixed
those as well.
Except for preventing crashes this should be NFC.
Differential Revision: https\://reviews.llvm.org/D106122
Previously GetMemoryTagManager checked many things in one:
* architecture supports memory tagging
* process supports memory tagging
* memory range isn't inverted
* memory range is all tagged
Since writing follow up patches for tag writing (in review
at the moment) it has become clear that this gets unwieldy
once we add the features needed for that.
It also implies that the memory tag manager is tied to the
range you used to request it with but it is not. It's a per
process object.
Instead:
* GetMemoryTagManager just checks architecture and process.
* Then the MemoryTagManager can later be asked to check a
memory range.
This is better because:
* We don't imply that range and manager are tied together.
* A slightly diferent range calculation for tag writing
doesn't add more code to Process.
* Range checking code can now be unit tested.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D105630
Always destroy the process, regardless of its private state. This will
call the virtual function DoDestroy under the hood, giving our derived
class a chance to do the necessary tear down, including what to do when
the private state is eStateExited.
Differential revision: https://reviews.llvm.org/D106004
This reverts commit 82a3883715.
The original version had a copy-paste error: using the Interrupt timeout
for the ResumeSynchronous wait, which is clearly wrong. This error would
have been evident with real use, but the interrupt is long enough that it
only caused one testsuite failure (in the Swift fork).
Anyway, I found that mistake and fixed it and checked all the other places
where I had to plumb through a timeout, and added a test with a short
interrupt timeout stepping over a function that takes 3x the interrupt timeout
to complete, so that should detect a similar mistake in the future.
This patch fixes process event handling when the events are broadcasted
at launch. To do so, the patch introduces a new listener to fetch events
by hand off the event queue and then resending them ensure the event ordering.
Differental Revision: https://reviews.llvm.org/D105698
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
AArch64 architecture support virtual addresses with some of the top bits ignored.
These ignored bits can host memory tags or bit masks that can serve to check for
authentication of address integrity. We need to clear away the top ignored bits
from watchpoint address to reliably hit and set watchpoints on addresses
containing tags or masks in their top bits.
This patch adds support to watch tagged addresses on AArch64/Linux.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D101361
While on regular Linux system (Fedora 34 GA, not updated):
* thread #1, name = '1', stop reason = hit program assert
frame #0: 0x00007ffff7e242a2 libc.so.6`raise + 322
frame #1: 0x00007ffff7e0d8a4 libc.so.6`abort + 278
frame #2: 0x00007ffff7e0d789 libc.so.6`__assert_fail_base.cold + 15
frame #3: 0x00007ffff7e1ca16 libc.so.6`__assert_fail + 70
* frame #4: 0x00000000004011bd 1`main at assert.c:7:3
On Fedora 35 pre-release one gets:
* thread #1, name = '1', stop reason = signal SIGABRT
* frame #0: 0x00007ffff7e48ee3 libc.so.6`pthread_kill@GLIBC_2.2.5 + 67
frame #1: 0x00007ffff7dfb986 libc.so.6`raise + 22
frame #2: 0x00007ffff7de5806 libc.so.6`abort + 230
frame #3: 0x00007ffff7de571b libc.so.6`__assert_fail_base.cold + 15
frame #4: 0x00007ffff7df4646 libc.so.6`__assert_fail + 70
frame #5: 0x00000000004011bd 1`main at assert.c:7:3
I did not write a testcase as one needs the specific glibc. An
artificial test would just copy the changed source.
Reviewed By: mib
Differential Revision: https://reviews.llvm.org/D105133
This patch implements a slight improvement when debugging across
platforms and remapping source paths that are in a non-native
format. See the unit test for examples.
rdar://79205675
Differential Revision: https://reviews.llvm.org/D104407
NFC.
This patch replaces the function body FindFile() with a call to
RemapPath(), since the two functions implement the same functionality.
Differential Revision: https://reviews.llvm.org/D104406
This is an NFC modernization refactoring that replaces the combination
of a bool return + reference argument, with an Optional return value.
Differential Revision: https://reviews.llvm.org/D104405
This is an NFC modernization refactoring that replaces the combination
of a bool return + reference argument, with an Optional return value.
Differential Revision: https://reviews.llvm.org/D104404
This adds GDB client support for the qMemTags packet
which reads memory tags. Following the design
which was recently committed to GDB.
https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html#General-Query-Packets
(look for qMemTags)
lldb commands will use the new Process methods
GetMemoryTagManager and ReadMemoryTags.
The former takes a range and checks that:
* The current process architecture has an architecture plugin
* That plugin provides a MemoryTagManager
* That the range of memory requested lies in a tagged range
(it will expand it to granules for you)
If all that was true you get a MemoryTagManager you
can give to ReadMemoryTags.
This two step process is done to allow commands to get the
tag manager without having to read tags as well. For example
you might just want to remove a logical tag, or error early
if a range with tagged addresses is inverted.
Note that getting a MemoryTagManager doesn't mean that the process
or a specific memory range is tagged. Those are seperate checks.
Having a tag manager just means this architecture *could* have
a tagging feature enabled.
An architecture plugin has been added for AArch64 which
will return a MemoryTagManagerAArch64MTE, which was added in a
previous patch.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D95602
As a follow up of D103588, I'm reinitiating the discussion with a new proposal for traversing instructions in a trace which uses the feedback gotten in that diff.
See the embedded documentation in TraceCursor for more information. The idea is to offer an OOP way to traverse instructions exposing a minimal interface that makes no assumptions on:
- the number of instructions in the trace (i.e. having indices for instructions might be impractical for gigantic intel-pt traces, as it would require to decode the entire trace). This renders the use of indices to point to instructions impractical. Traces are big and expensive, and the consumer should try to do look linear lookups (forwards and/or backwards) and avoid random accesses (the API could be extended though, but for now I want to dicard that funcionality and leave the API extensible if needed).
- the way the instructions are represented internally by each Trace plug-in. They could be mmap'ed from a file, exist in plain vector or generated on the fly as the user requests the data.
- the actual data structure used internally for each plug-in. Ideas like having a struct TraceInstruction have been discarded because that would make the plug-in follow a certain data type, which might be costly. Instead, the user can ask the cursor for each independent property of the instruction it's pointing at.
The way to get a cursor is to ask Trace.h for the end or being cursor or a thread's trace.
There are some benefits of this approach:
- there's little cost to create a cursor, and this allows for lazily decoding a trace as the user requests data.
- each trace plug-in could decide how to cache the instructions it generates. For example, if a trace is small, it might decide to keep everything in memory, or if the trace is massive, it might decide to keep around the last thousands of instructions to speed up local searches.
- a cursor can outlive a stop point, which makes trace comparison for live processes feasible. An application of this is to compare profiling data of two runs of the same function, which should be doable with intel pt.
Differential Revision: https://reviews.llvm.org/D104422
This adds a basic SB API for creating and stopping traces.
Note: This doesn't add any APIs for inspecting individual instructions. That'd be a more complicated change and it might be better to enhande the dump functionality to output the data in binary format. I'll leave that for a later diff.
This also enhances the existing tests so that they test the same flow using both the command interface and the SB API.
I also did some cleanup of legacy code.
Differential Revision: https://reviews.llvm.org/D103500
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
Previously ignore counts were checked when we stopped to do the sync callback in Breakpoint::ShouldStop. That meant we would do all the ignore count work even when
there is also a condition says the breakpoint should not stop.
That's wrong, lldb treats breakpoint hits that fail the thread or condition checks as "not having hit the breakpoint". So the ignore count check should happen after
the condition and thread checks in StopInfoBreakpoint::PerformAction.
The one side-effect of doing this is that if you have a breakpoint with a synchronous callback, it will run the synchronous callback before checking the ignore count.
That is probably a good thing, since this was already true of the condition and thread checks, so this removes an odd asymmetry. And breakpoints with sync callbacks
are all internal lldb breakpoints and there's not a really good reason why you would want one of these to use an ignore count (but not a condition or thread check...)
Differential Revision https://reviews.llvm.org/D103217
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
More decoupling of plugins and non-plugins. Target doesn't need to
manage ClangModulesDeclVendor and ClangPersistentVariables is always available
in situations where you need ClangModulesDeclVendor.
Differential Revision: https://reviews.llvm.org/D102811
TestMultipleTargets is randomly failing on the bots. The reason for that is that
the test is calling `SBDebugger::CreateTarget` from multiple threads.
`TargetList::CreateTarget` is curiously missing the guard that all of its other
member functions have, so all the threads in the test end up changing the
internal TargetList state at the same time and end up corrupting it.
Reviewed By: vsk, JDevlieghere
Differential Revision: https://reviews.llvm.org/D103020
A long time ago LLDB wanted to start using StringRef instead of
C-Strings/ConstString but was blocked by the fact that the StringRef constructor
that takes a C-string was asserting that the C-string isn't a nullptr. To
workaround this, D24697 introduced a special function called `withNullAsEmpty`
and that's what LLDB (and only LLDB) started to use to build StringRefs from
C-strings.
A bit later it seems that `withNullAsEmpty` was declared too awkward to use and
instead the assert in the StringRef constructor got removed (see D24904). The
rest of LLDB was then converted to StringRef by just calling the now perfectly
usable implicit constructor.
However, all the calls to `withNullAsEmpty` just remained and are now just
strange artefacts in the code base that just look out of place. It's also
curiously a LLDB-exclusive function and no other project ever called it since
it's introduction half a decade ago.
This patch removes all uses of `withNullAsEmpty`. The follow up will be to
remove the function from StringRef.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D102597
This reverts commit bd5751f3d2.
This patch series is causing us to every so often miss switching
the state from eStateRunning to eStateStopped when we get the stop
packet from the debug server.
Reverting till I can figure out how that could be happening.
The Mips in DW_LANG_Mips_Assembler is a vendor name not an
architecture name and in lack of a proper generic DW_LANG_assembler,
some assemblers emit DWARF using this tag. Due to a warning I recently
introduced users will now be greeted with
This version of LLDB has no plugin for the mipsassem language. Inspection of frame variables will be limited.
By renaming this to just "Assembler" this error message will make more sense.
Differential Revision: https://reviews.llvm.org/D101406
rdar://77214764
ProcessGDBRemote plugin layers.
Also fix a bug where if we tried to interrupt, but the ReadPacket
wakeup timer woke us up just after the timeout, we would break out
the switch, but then since we immediately check if the response is
empty & fail if it is, we could end up actually only giving a
small interval to the interrupt.
Differential Revision: https://reviews.llvm.org/D102085
This change ensures that if for whatever reason we read less bytes than expected (for example, when trying to read memory that spans multiple sections), we try reading from the live process as well.
Reviewed By: jasonmolenda
Differential Revision: https://reviews.llvm.org/D101390
When dumping the traced instructions in a for loop, like this one
4: for (int a = 0; a < n; a++)
5: do something;
there might be multiple LineEntry objects for line 4, but with different address ranges. This was causing the dump command to dump something like this:
```
a.out`main + 11 at main.cpp:4
[1] 0x0000000000400518 movl $0x0, -0x8(%rbp)
[2] 0x000000000040051f jmp 0x400529 ; <+28> at main.cpp:4
a.out`main + 28 at main.cpp:4
[3] 0x0000000000400529 cmpl $0x3, -0x8(%rbp)
[4] 0x000000000040052d jle 0x400521 ; <+20> at main.cpp:5
```
which is confusing, as main.cpp:4 appears twice consecutively.
This diff fixes that issue by making the line entry comparison strictly about the line, column and file name. Before it was also comparing the address ranges, which we don't need because our output is strictly about what the user sees in the source.
Besides, I've noticed that the logic that traverses instructions and calculates symbols and disassemblies had too much coupling, and made my changes harder to implement, so I decided to decouple it. Now there are two methods for iterating over the instruction of a trace. The existing one does it on raw load addresses, but the one provides a SymbolContext and an InstructionSP, and does the calculations efficiently (not as efficient as possible for now though), so the caller doesn't need to care about these details. I think I'll be using that iterator to reconstruct the call stacks.
I was able to fix a test with this change.
Differential Revision: https://reviews.llvm.org/D100740
This patch refactors a good part of the code base turning the usual
FileSpec, Line, Column, CheckInlines, ExactMatch arguments into a
SourceLocationSpec object.
This change is required for a following patch that will add handling of the
column line information when doing symbol resolution.
Differential Revision: https://reviews.llvm.org/D100965
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Introduce three new stop reasons for fork, vfork and vforkdone events.
This includes server support for serializing fork/vfork events into
gdb-remote protocol. The stop infos for the two base events take a pair
of PID and TID for the newly forked process.
Differential Revision: https://reviews.llvm.org/D100196
Landing this fix for Augusto Noronha. The code is getting the
Section from 'addr' passed in, but it may have been expressed as
a load address when it was created and Target::ReadMemory tries to
convert it to a Section+offset if that's now possible; use the
Section found from that cleanup if it exists.
Differential Revision: https://reviews.llvm.org/D100850
Commiting this patch for Augusto Noronha who is getting set
up still.
This patch changes Target::ReadMemory so the default behavior
when a read is in a Section that is read-only is to fetch the
data from the local binary image, instead of reading it from
memory. Update all callers to use their old preferences
(the old prefer_file_cache bool) using the new API; we should
revisit these calls and see if they really intend to read
live memory, or if reading from a read-only Section would be
equivalent and important for performance-sensitive cases.
rdar://30634422
Differential revision: https://reviews.llvm.org/D100338
Implement FixCodeAddress and FixDataAddress for ABIMacOSX_arm64 and
ABISysV_arm64 and add missing calls to RegisterContextUnwind. We need
this to unwind on Apple Silicon where libraries like libSystem are
arm64e even when the program being debugged is arm64.
Differential revision: https://reviews.llvm.org/D100521
Add a code and data address mask to Process with respective getters and
setters and a setting that allows the user to specify the mast as a
number of addressable bits. The masks will be used by FixCodeAddress and
FixDataAddress respectively in the ABI classes.
Differential revision: https://reviews.llvm.org/D100515
It looks like the goal of this code is to provide a more precise
architecture definition for the target when attaching to a process. When
attaching to a foreign debugserver, you might get into a situation where
the active (host) platform will give you bogus information on the target
process.
This change allows the platform to override the target arch only with a
compatible architecture. This fixes TestTargetXMLArch.py on Apple
Silicon. Another alternative would be to just fail in this scenario and
update the test(s).
That code is unused since it's check-in in 2010 (and I believe it would leak
memory when called as it releases the passed unique_ptr), so let's delete it.
Reviewed By: vsk
Differential Revision: https://reviews.llvm.org/D100212
When debugging LanguageRuntime unwindplans, it can be
helpful to disable their use and see the normal
stack walk. Add a setting for this.
Differential Revision: https://reviews.llvm.org/D99828
Inline callstacks were being incorrectly displayed in the results of "image lookup --address". The deepest frame wasn't displaying the line table line entry, it was always showing the inline information's call file and line on the previous frame. This is now fixed and has tests to make sure it doesn't regress.
Differential Revision: https://reviews.llvm.org/D98761
This implements the interactive trace start and stop methods.
This diff ended up being much larger than I anticipated because, by doing it, I found that I had implemented in the beginning many things in a non optimal way. In any case, the code is much better now.
There's a lot of boilerplate code due to the gdb-remote protocol, but the main changes are:
- New tracing packets: jLLDBTraceStop, jLLDBTraceStart, jLLDBTraceGetBinaryData. The gdb-remote packet definitions are quite comprehensive.
- Implementation of the "process trace start|stop" and "thread trace start|stop" commands.
- Implementaiton of an API in Trace.h to interact with live traces.
- Created an IntelPTDecoder for live threads, that use the debugger's stop id as checkpoint for its internal cache.
- Added a functionality to stop the process in case "process tracing" is enabled and a new thread can't traced.
- Added tests
I have some ideas to unify the code paths for post mortem and live threads, but I'll do that in another diff.
Differential Revision: https://reviews.llvm.org/D91679
The StopInfoBreakpoint::PerformAction was overriding the synchronous
breakpoint's ShouldStop report. Fix that and add a test.
This fixes two bugs in the original submission:
1) Actually generate both dylibs by including the second one in the Makefile
2) Don't ask synchronous callbacks for their opinion on whether to stop
in the async context, that info is taken care of by recording the m_should_stop
on entry to PerformAction.
Differential Revision: https://reviews.llvm.org/D98914
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/D95713
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/D95713
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This patch adds a new command options to the CommandObjectProcessLaunch
for scripted processes.
Among the options, the user need to specify the class name managing the
scripted process. The user can also use a key-value dictionary holding
arbitrary data that will be passed to the managing class.
This patch also adds getters and setters to `SBLaunchInfo` for the
class name managing the scripted process and the dictionary.
rdar://65508855
Differential Review: https://reviews.llvm.org/D95710
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This reverts commit 9406d43138.
I messed up a test, and when I got it right it was failing. The changed logic
doesn't work quite right (now the async callback called at sync time is
forcing us to stop. I need to be a little more careful about that.
We weren't taking into account the "m_should_stop" setting that the
synchronous breakpoint callback had already set when we did PerformAction
in the StopInfoBreakpoint. So we didn't obey its instructions when it
told us to stop. Fixed that and added some tests both for when we
just have the setting, and when we have the setting AND other breakpoints
at the shared library load notification breakpoint address.
Differential Revision: https://reviews.llvm.org/D98914
The functionality is not posix specific. Also force the usage of the
gdb-remote process plugin in the gdb platform class.
This is not sufficient to make TestPlatformConnect pass on windows (it
seems it suffers from module loading issues, unrelated to this test),
but it at least makes it shut down correctly, so I change the skip to an
xfail.
Add calls into LanguageRuntime when finding the unwind method to
use out of the 0th (currently executing) stack frame.
Allow for the LanguageRuntimes to indicate if this stack frames
should be treated like a zeroth-frame -- symbolication should be
done based on the saved pc address, not decremented like normal ABI
function calls.
Add methods to RegisterContext and StackFrame to get a pc value
suitable for symbolication, to reduce the number of places in lldb
where we decrement the saved pc values before symbolication.
<rdar://problem/70398009>
Differential Revision: https://reviews.llvm.org/D97644
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/D95713
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Some implementations of the DeepCopy function called the copy constructor that copied m_parent member instead of setting a new parent. Others just leaved the base class's members (m_parent, m_callback, m_was_set) empty.
One more problem is that not all classes override this function, e.g. OptionValueArgs::DeepCopy produces OptionValueArray instance, and Target[Process/Thread]ValueProperty::DeepCopy produces OptionValueProperty. This makes downcasting via static_cast invalid.
The patch implements idiom "virtual constructor" to fix these issues.
Add a test that checks DeepCopy for correct copying/setting all data members of the base class.
Differential Revision: https://reviews.llvm.org/D96952
LLDB uses utility functions to run code in the inferior for its own
internal purposes, such as reading classes from the Objective-C runtime
for example. Because these expressions should be transparent to the
user, we ignore breakpoints and unwind the stack on errors, which
makes them hard to debug.
This patch adds a new setting target.debug-utility-expression that, when
enabled, changes these options to facilitate debugging. It enables
breakpoints, disables unwinding and writes out the utility function
source code to disk so it shows up in the source view.
Differential revision: https://reviews.llvm.org/D97249
Adjust `ShouldAutoContinue` to be available to any thread plan previous to the plan that
explains a stop, not limited to the parent to the plan that explains the stop.
Before this change, `Thread::ShouldStop` did the following:
1. find the plan that explains the stop
2. if it's not a master plan, continue processing previous (aka parent) plans
3. first, call `ShouldAutoContinue` on the immediate parent of the explaining plan
4. then loop over previous plans, calling `ShouldStop` and `MischiefManaged`
Of note, the iteration in step 4 does not call `ShouldAutoContinue`, so again only the
plan just prior to the explaining plan is given the opportunity to override whether to
continue or stop.
This commit changes the loop call `ShouldAutoContinue`, giving each plan the opportunity
to override `ShouldStop` of previous plans.
Why? This allows a plan to do the following:
1. mark itself done and be popped off the stack
2. allow parent plans to finish their work, and to also be popped off the stack
3. and finally, have the thread continue, not stop
This is useful for stepping into async functions. A plan will would step far enough
enough to set a breakpoint on the async target, and then use `ShouldAutoContinue` to
unwind the necessary stepping, and then have the calling thread continue.
Differential Revision: https://reviews.llvm.org/D97076
Rename `stop_vote` and `run_vote` to `report_stop_vote` and `report_run_vote`
respectively. These variables are limited to logic involving (event) reporting only.
This naming is intended to make their context more clear.
Differential Revision: https://reviews.llvm.org/D96917
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.
Recently https://reviews.llvm.org/D88103 introduced a nice API for
converting a JSON object into C++ types, which include nice error
messaging.
I'm using that new functioniality to perform the parsing in a much more
elegant way. As a result, the code looks simpler and more maintainable,
as we aren't parsing anymore individual fields manually.
I updated the test cases accordingly.
Differential Revision: https://reviews.llvm.org/D88264
When the various methods of locating the module in GetRemoteSharedModule
fail, make sure we pass the original module spec to the bail-out call to
the provided resolver function.
Also make sure we consistently use the resolved module spec from the
various success paths.
Thanks to what appears to have been an accidentally inverted condition
(commit 85967fa applied the new condition to a path where GetModuleSpec
returns false, but should have applied it when GetModuleSpec returns
true), without this fix we only pass the original module spec in the
fallback if the original spec has no uuid (or has a uuid that somehow
matches the resolved module's uuid despite the call to GetModuleSpec
failing). This manifested as a bug when processing a minidump file with
a user-provided sysroot, since in that case the resolver call was being
applied to resolved_module_spec (despite resolution failing), which did
not have the path of its file_spec set.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D88099
This is the first in a series of patches that will adds a new processor trace plug-in to LLDB.
The idea for this first patch to to add the plug-in interface with simple commands for the trace files that can "load" and "dump" the trace information. We can test the functionality and ensure people are happy with the way things are done and how things are organized before moving on to adding more functionality.
Processor trace information can be view in a few different ways:
- post mortem where a trace is saved off that can be viewed later in the debugger
- gathered while a process is running and allow the user to step back in time (with no variables, memory or registers) to see how each thread arrived at where it is currently stopped.
This patch attempts to start with the first solution of loading a trace file after the fact. The idea is that we will use a JSON file to load the trace information. JSON allows us to specify information about the trace like:
- plug-in name in LLDB
- path to trace file
- shared library load information so we can re-create a target and symbolicate the information in the trace
- any other info that the trace plug-in will need to be able to successfully parse the trace information
- cpu type
- version info
- ???
A new "trace" command was added at the top level of the LLDB commmands:
- "trace load"
- "trace dump"
I did this because if we load trace information we don't need to have a process and we might end up creating a new target for the trace information that will become active. If anyone has any input on where this would be better suited, please let me know. Walter Erquinigo will end up filling in the Intel PT specific plug-in so that it works and is tested once we can agree that the direction of this patch is the correct one, so please feel free to chime in with ideas on comments!
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D85705
This patch adds the ability to use a custom interpreter with the
`platform shell` command. If the user set the `-s|--shell` option
with the path to a binary, lldb passes it down to the platform's
`RunShellProcess` method and set it as the shell to use in
`ProcessLaunchInfo to run commands.
Note that not all the Platforms support running shell commands with
custom interpreters (i.e. RemoteGDBServer is only expected to use the
default shell).
This patch also makes some refactoring and cleanups, like swapping
CString for StringRef when possible and updating `SBPlatformShellCommand`
with new methods and a new constructor.
rdar://67759256
Differential Revision: https://reviews.llvm.org/D86667
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
When `Target::GetEntryPointAddress()` calls `exe_module->GetObjectFile()->GetEntryPointAddress()`, and the returned
`entry_addr` is valid, it can immediately be returned.
However, just before that, an `llvm::Error` value has been setup, but in this case it is not consumed before returning, like is done further below in the function.
In https://bugs.freebsd.org/248745 we got a bug report for this, where a very simple test case aborts and dumps core:
```
* thread #1, name = 'testcase', stop reason = breakpoint 1.1
frame #0: 0x00000000002018d4 testcase`main(argc=1, argv=0x00007fffffffea18) at testcase.c:3:5
1 int main(int argc, char *argv[])
2 {
-> 3 return 0;
4 }
(lldb) p argc
Program aborted due to an unhandled Error:
Error value was Success. (Note: Success values must still be checked prior to being destroyed).
Thread 1 received signal SIGABRT, Aborted.
thr_kill () at thr_kill.S:3
3 thr_kill.S: No such file or directory.
(gdb) bt
#0 thr_kill () at thr_kill.S:3
#1 0x00000008049a0004 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52
#2 0x0000000804916229 in abort () at /usr/src/lib/libc/stdlib/abort.c:67
#3 0x000000000451b5f5 in fatalUncheckedError () at /usr/src/contrib/llvm-project/llvm/lib/Support/Error.cpp:112
#4 0x00000000019cf008 in GetEntryPointAddress () at /usr/src/contrib/llvm-project/llvm/include/llvm/Support/Error.h:267
#5 0x0000000001bccbd8 in ConstructorSetup () at /usr/src/contrib/llvm-project/lldb/source/Target/ThreadPlanCallFunction.cpp:67
#6 0x0000000001bcd2c0 in ThreadPlanCallFunction () at /usr/src/contrib/llvm-project/lldb/source/Target/ThreadPlanCallFunction.cpp:114
#7 0x00000000020076d4 in InferiorCallMmap () at /usr/src/contrib/llvm-project/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp:97
#8 0x0000000001f4be33 in DoAllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSD/ProcessFreeBSD.cpp:604
#9 0x0000000001fe51b9 in AllocatePage () at /usr/src/contrib/llvm-project/lldb/source/Target/Memory.cpp:347
#10 0x0000000001fe5385 in AllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Target/Memory.cpp:383
#11 0x0000000001974da2 in AllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Target/Process.cpp:2301
#12 CanJIT () at /usr/src/contrib/llvm-project/lldb/source/Target/Process.cpp:2331
#13 0x0000000001a1bf3d in Evaluate () at /usr/src/contrib/llvm-project/lldb/source/Expression/UserExpression.cpp:190
#14 0x00000000019ce7a2 in EvaluateExpression () at /usr/src/contrib/llvm-project/lldb/source/Target/Target.cpp:2372
#15 0x0000000001ad784c in EvaluateExpression () at /usr/src/contrib/llvm-project/lldb/source/Commands/CommandObjectExpression.cpp:414
#16 0x0000000001ad86ae in DoExecute () at /usr/src/contrib/llvm-project/lldb/source/Commands/CommandObjectExpression.cpp:646
#17 0x0000000001a5e3ed in Execute () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandObject.cpp:1003
#18 0x0000000001a6c4a3 in HandleCommand () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:1762
#19 0x0000000001a6f98c in IOHandlerInputComplete () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:2760
#20 0x0000000001a90b08 in Run () at /usr/src/contrib/llvm-project/lldb/source/Core/IOHandler.cpp:548
#21 0x00000000019a6c6a in ExecuteIOHandlers () at /usr/src/contrib/llvm-project/lldb/source/Core/Debugger.cpp:903
#22 0x0000000001a70337 in RunCommandInterpreter () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:2946
#23 0x0000000001d9d812 in RunCommandInterpreter () at /usr/src/contrib/llvm-project/lldb/source/API/SBDebugger.cpp:1169
#24 0x0000000001918be8 in MainLoop () at /usr/src/contrib/llvm-project/lldb/tools/driver/Driver.cpp:675
#25 0x000000000191a114 in main () at /usr/src/contrib/llvm-project/lldb/tools/driver/Driver.cpp:890```
Fix the incorrect error catch by only instantiating an `Error` object if it is necessary.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D86355
Provider a wrapper around llvm::sys::path::home_directory in the
FileSystem class. This will make it possible for the reproducers to
intercept the call in a central place.