Commit Graph

1568 Commits

Author SHA1 Message Date
Kazu Hirata
9173fd7739 [lldb] Avoid repeated map lookups (NFC) (#112655) 2024-10-17 07:45:50 -07:00
Jason Molenda
3bef742559 Revert "[lldb] Implement basic support for reverse-continue (#99736)"
Reverting this again; I added a commit which added @skipIfDarwin
markers to the TestReverseContinueBreakpoints.py and
TestReverseContinueNotSupported.py API tests, which use lldb-server
in gdbserver mode which does not work on Darwin.  But the aarch64 ubuntu
bot reported a failure on TestReverseContinueBreakpoints.py,
https://lab.llvm.org/buildbot/#/builders/59/builds/6397

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

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

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

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

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

The majority of this PR is test infrastructure (about 700 of the 950
lines added).
2024-10-10 13:01:47 -07:00
Dmitry Vasilyev
2e89312419 [lldb] Removed gdbserver ports map from lldb-server (#104238)
Listen to gdbserver-port, accept the connection and run `lldb-server gdbserver --fd` on all platforms.
Parameters --min-gdbserver-port and --max-gdbserver-port are deprecated now.

This is the part 2 of #101283.

Fixes #97537.
2024-10-03 21:00:47 +04:00
Youngsuk Kim
f35719ff67 [lldb] Don't flush llvm::raw_string_ostream (NFC) (#110128)
Don't call raw_string_ostream::flush(), which is essentially a no-op. As
specified in the docs, raw_string_ostream is always unbuffered. (
65b13610a5 for further reference )
2024-09-26 12:29:14 -04:00
dlav-sc
c93e29439b [lldb] fix vFile:open, vFile:unlink error codes (#106950)
This patch makes gdb-server sends only GDB RSP supported error codes
during vFile:open and vFile:unlink handling.
2024-09-25 10:13:40 +01:00
David Spickett
497759e872 [lldb][AArch64] Create Neon subregs when XML only includes SVE (#108365)
Fixes #107864

QEMU decided that when SVE is enabled it will only tell us about SVE
registers in the XML, and not include Neon registers. On the grounds
that the Neon V registers can be read from the bottom 128 bits of a SVE
Z register (SVE's vector length is always >= 128 bits).

To support this we create sub-registers just as we do for S and D
registers of the V registers. Except this time we use part of the Z
registers.

This change also updates our fallback for registers with unknown types
that are > 128 bit. This is detailed in
https://github.com/llvm/llvm-project/issues/87471, though that covers
more than this change fixes.

We'll now treat any register of unknown type that is >= 128 bit as a
vector of bytes. So that the user gets to see something
even if the order might be wrong.

And until lldb supports vector and union types for registers, this is
also the only way we can get a value to apply the sub-reg to, to make
the V registers.
2024-09-24 12:40:42 +01:00
Jason Molenda
6e6d5eae76 [lldb] Don't invalid register context after setting thread pc's (#109499)
Some gdb remote serial protocol stubs will send the thread IDs and PCs
for all threads in a process in the stop-reply packet. lldb often needs
to know the pc values for all threads while at a private stop, and that
results in <n-1> read-register packets for <n> threads, and can be a big
performance problem when this is a hot code path.

GDBRemoteRegisterContext tracks the StopID of when its values were set,
and when the thread's StopID has incremented, it marks all values it has
as Invalid, and knows to refetch them.

We have a code path that resulted in setting the PCs for all the
threads, and then `ProcessGDBRemote::CalculateThreadStopInfo` *forcing*
an invalidation of all the register contexts, forcing us to re-read the
pc values for all threads except the one that stopped.

There are times when it is valid to force an invalidation of the
regsiter cache - for instance, if the layout of the registers has
changed because the processor state is different, or we've sent a
write-all-registers packet to the inferior and we want to make sure we
stay in sync with the inferior. But there was no reason for this method
to be forcing the register context to be invalid.

I added a test when running on Darwin systems, where debugserver always
sends the thread IDs and PCs, which turns on packet logging. The test
runs against an inferior which has 4 threads; it steps over a dlopen()
call, steps in to a user function with debug info, steps-over and
steps-in across source lines with multiple function calls, and then
examines the packet log and flags it as an error if lldb asked for the
pc value of any thread at any point in the debug session.

For this program and the operations we're doing, with debugserver that
provides thread IDs and PCs, we should never ask for the value of a pc
register.

rdar://136247381
2024-09-23 12:13:48 -07:00
Pavel Labath
1f8a3286e0 [lldb] Only send "posix" error codes through the gdb-remote protocol
The other side has no way of telling which namespace do these codes
belong to, so mashing them all together is not very helpful.

I'm mainly doing this to simplify some code in a pending patch
<https://github.com/llvm/llvm-project/pull/106774/files#r1752628604>,
and I've picked the posix error category semi-randomly. If we wanted to
be serious about assigning meaning to these error codes, we should
create a special error category for "gdb errors".
2024-09-19 10:07:13 -07:00
Adrian Prantl
6dcde731eb Revert "[lldb] Only send "posix" error codes through the gdb-remote protocol"
This reverts commit a7c174502a.
2024-09-18 17:28:10 -07:00
Pavel Labath
a7c174502a [lldb] Only send "posix" error codes through the gdb-remote protocol
The other side has no way of telling which namespace do these codes
belong to, so mashing them all together is not very helpful.

I'm mainly doing this to simplify some code in a pending patch
<https://github.com/llvm/llvm-project/pull/106774/files#r1752628604>,
and I've picked the posix error category semi-randomly. If we wanted to
be serious about assigning meaning to these error codes, we should
create a special error category for "gdb errors".
2024-09-18 14:53:42 -07:00
Youngsuk Kim
d7796855b8 [lldb] Nits on uses of llvm::raw_string_ostream (NFC) (#108745)
As specified in the docs,
1) raw_string_ostream is always unbuffered and
2) the underlying buffer may be used directly

( 65b13610a5 for further reference )

* Don't call raw_string_ostream::flush(), which is essentially a no-op.
* Avoid unneeded calls to raw_string_ostream::str(), to avoid excess
indirection.
2024-09-16 00:26:51 -04:00
Jason Molenda
65a4d11b1e [lldb] Set the stop reason when receiving swbreak/hwbreak (#108518)
xusheng added support for swbreak/hwbreak a month ago, and no special
support was needed in ProcessGDBRemote when they're received because
lldb already marks a thread as having hit a breakpoint when it stops at
a breakpoint site. However, with changes I am working on, we need to
know the real stop reason a thread stopped or the breakpoint hit will
not be recognized.

This is similar to how lldb processes the "watch/rwatch/awatch" keys in
a thread stop packet -- we set the `reason` to `watchpoint`, and these
set it to `breakpoint` so we set the stop reason correctly later in
these methods.
2024-09-13 09:04:28 -07:00
Daniil Fukalov
345cc47ba7 [NFC] Add explicit #include llvm-config.h where its macros are used, lldb part. (#107603)
(this is lldb part)

Without these explicit includes, removing other headers, who implicitly
include llvm-config.h, may have non-trivial side effects. For example,
`clangd` may report even `llvm-config.h` as "no used" in case it defines
a macro, that is explicitly used with #ifdef. It is actually amplified
with different build configs which use different set of macros.
2024-09-09 12:44:03 +02:00
Dmitry Vasilyev
5d2b337875 [lldb][NFC] Used shared_fd_t (#107553)
Replaced `int connection_fd = -1` with `shared_fd_t connection_fd =
SharedSocket::kInvalidFD`.

This is prerequisite for #104238.
2024-09-06 16:03:11 +04:00
Dmitry Vasilyev
b11a70392c [lldb] Fixed a typo in #107388 2024-09-06 14:42:28 +04:00
Christian Sigg
d4e320e6f4 [lldb][NFC] Fix -Wparentheses warning.
Fix `using the result of an assignment as a condition without parentheses` warning.
2024-09-06 11:55:24 +02:00
Dmitry Vasilyev
725fab987d [lldb][NFC] Separated GDBRemoteCommunication::GetDebugserverPath() (#107388)
This is the prerequisite for #104238.
2024-09-06 12:38:55 +04:00
Adrian Prantl
a0dd90eb7d [lldb] Make conversions from llvm::Error explicit with Status::FromEr… (#107163)
…ror() [NFC]
2024-09-05 12:19:31 -07:00
Felipe de Azevedo Piovezan
1b0a802493 [GDBRemote] Handle 'heap' memory region info type (#105883)
This should cause the memory region info "is stack" field to be set to
"no".
2024-09-04 07:02:55 -07:00
Pavel Labath
181cc75ea8 [lldb/linux] Make truncated reads work (#106532)
Previously, we were returning an error if we couldn't read the whole
region. This doesn't matter most of the time, because lldb caches memory
reads, and in that process it aligns them to cache line boundaries. As
(LLDB) cache lines are smaller than pages, the reads are unlikely to
cross page boundaries.

Nonetheless, this can cause a problem for large reads (which bypass the
cache), where we're unable to read anything even if just a single byte
of the memory is unreadable. This patch fixes the lldb-server to do
that, and also changes the linux implementation, to reuse any partial
results it got from the process_vm_readv call (to avoid having to
re-read everything again using ptrace, only to find that it stopped at
the same place).

This matches debugserver behavior. It is also consistent with the gdb
remote protocol documentation, but -- notably -- not with actual
gdbserver behavior (which returns errors instead of partial results). We
filed a
[clarification
bug](https://sourceware.org/bugzilla/show_bug.cgi?id=24751) several
years ago. Though we did not really reach a conclusion there, I think
this is the most logical behavior.

The associated test does not currently pass on windows, because the
windows memory read APIs don't support partial reads (I have a WIP patch
to work around that).
2024-09-02 14:44:18 +02:00
Adrian Prantl
0642cd768b [lldb] Turn lldb_private::Status into a value type. (#106163)
This patch removes all of the Set.* methods from Status.

This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.

This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()

Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form

`    ResultTy DoFoo(Status& error)
`
to

`    llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?

The interesting changes are in Status.h and Status.cpp, all other
changes are mostly

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.
2024-08-27 10:59:31 -07:00
Felipe de Azevedo Piovezan
8b4147d14c [GDBRemote] Fix processing of comma-separated memory region entries (#105873)
The existing algorithm was performing the following comparisons for an
`aaa,bbb,ccc,ddd`:

aaa\0bbb,ccc,ddd == "stack"
aaa\0bbb\0ccc,ddd == "stack"
aaa\0bbb\0ccc\0ddd == "stack"

Which wouldn't work. This commit just dispatches to a known algorithm
implementation.
2024-08-23 13:09:31 -07:00
Dhruv Srivastava
b804516dc5 [lldb][AIX] 1. Avoid namespace collision on other platforms (#104679)
This PR is in reference to porting LLDB on AIX.

Link to discussions on llvm discourse and github:
1.  https://discourse.llvm.org/t/port-lldb-to-ibm-aix/80640
2.  #101657 

The complete changes for porting are present in this draft PR:
https://github.com/llvm/llvm-project/pull/102601

The changes on this PR are intended to avoid namespace collision for
certain typedefs between lldb and other platforms:
1. tid_t --> lldb::tid_t
2. offset_t --> lldb::offset_t
2024-08-20 10:19:32 +01:00
xusheng
5dbec8c6ce [lldb] Claim to support swbreak and hwbreak packets when debugging a gdbremote (#102873)
This fixes https://github.com/llvm/llvm-project/issues/56125 and
https://github.com/vadimcn/codelldb/issues/666, as well as the
downstream issue in our binary ninja debugger:
https://github.com/Vector35/debugger/issues/535

Basically, lldb does not claim to support the `swbreak` packet so the
gdbserver would not use it. As a result, the gdbserver always sends the
unmodified program counter value which, on systems like x86, causes the
program counter to be off-by-one (or otherwise wrong). For reference,
the lldb-server always sends the modified program counter value so it
works perfectly with lldb.

https://sourceware.org/gdb/current/onlinedocs/gdb.html/Stop-Reply-Packets.html#swbreak-stop-reason

No new code is added to add support `swbreak`, since the way lldb works
already expects the remote to have adjusted the program counter. The
change just lets the gdbserver know that lldb supports it, so that it
will send the adjusted program counter.

To test this PR, you can use lldb to connect to a gdbserver running on
e.g., Ubuntu 22.04, and see the program counter is off-by-one without
the patch. With the patch, things work as expected
2024-08-13 15:28:35 +01:00
jeffreytan81
f838fa820f New ThreadPlanSingleThreadTimeout to resolve potential deadlock in single thread stepping (#90930)
This PR introduces a new `ThreadPlanSingleThreadTimeout` that will be
used to address potential deadlock during single-thread stepping.

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

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

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

The detailed design is discussed in the RFC below:

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

---------

Co-authored-by: jeffreytan81 <jeffreytan@fb.com>
2024-08-05 17:26:39 -07:00
Dmitry Vasilyev
f083764ba1 [lldb] Optimized lldb-server memory usage (#100666)
MAX_PATH is definitely larger than 6 bytes we are expecting for this
message, and could be rather large depending on the target OS (4K for
some Linux OSs).

Since the buffer gets allocated on the stack we better be conservative
and allocate what we actually need.
2024-07-26 19:12:05 +04:00
Jason Molenda
52c08d7ffd Revert "[lldb] Change lldb's breakpoint handling behavior (#96260)"
This reverts commit 05f0e86cc8.

The debuginfo dexter tests are failing, probably because the way
stepping over breakpoints has changed with my patches.  And there
are two API tests fails on the ubuntu-arm (32-bit) bot. I'll need
to investigate both of these, neither has an obvious failure reason.
2024-07-19 18:43:53 -07:00
Jason Molenda
05f0e86cc8 [lldb] Change lldb's breakpoint handling behavior (#96260)
lldb today has two rules: When a thread stops at a BreakpointSite, we
set the thread's StopReason to be "breakpoint hit" (regardless if we've
actually hit the breakpoint, or if we've merely stopped *at* the
breakpoint instruction/point and haven't tripped it yet). And second,
when resuming a process, any thread sitting at a BreakpointSite is
silently stepped over the BreakpointSite -- because we've already
flagged the breakpoint hit when we stopped there originally.

In this patch, I change lldb to only set a thread's stop reason to
breakpoint-hit when we've actually executed the instruction/triggered
the breakpoint. When we resume, we only silently step past a
BreakpointSite that we've registered as hit. We preserve this state
across inferior function calls that the user may do while stopped, etc.

Also, when a user adds a new breakpoint at $pc while stopped, or changes
$pc to be the address of a BreakpointSite, we will silently step past
that breakpoint when the process resumes. This is purely a UX call, I
don't think there's any person who wants to set a breakpoint at $pc and
then hit it immediately on resuming.

One non-intuitive UX from this change, but I'm convinced it is
necessary: If you're stopped at a BreakpointSite that has not yet
executed, you `stepi`, you will hit the breakpoint and the pc will not
yet advance. This thread has not completed its stepi, and the thread
plan is still on the stack. If you then `continue` the thread, lldb will
now stop and say, "instruction step completed", one instruction past the
BreakpointSite. You can continue a second time to resume execution. I
discussed this with Jim, and trying to paper over this behavior will
lead to more complicated scenarios behaving non-intuitively. And mostly
it's the testsuite that was trying to instruction step past a breakpoint
and getting thrown off -- and I changed those tests to expect the new
behavior.

The bugs driving this change are all from lldb dropping the real stop
reason for a thread and setting it to breakpoint-hit when that was not
the case. Jim hit one where we have an aarch64 watchpoint that triggers
one instruction before a BreakpointSite. On this arch we are notified of
the watchpoint hit after the instruction has been unrolled -- we disable
the watchpoint, instruction step, re-enable the watchpoint and collect
the new value. But now we're on a BreakpointSite so the watchpoint-hit
stop reason is lost.

Another was reported by ZequanWu in
https://discourse.llvm.org/t/lldb-unable-to-break-at-start/78282 we
attach to/launch a process with the pc at a BreakpointSite and
misbehave. Caroline Tice mentioned it is also a problem they've had with
putting a breakpoint on _dl_debug_state.

The change to each Process plugin that does execution control is that

1. If we've stopped at a BreakpointSite that has not been executed yet,
we will call Thread::SetThreadStoppedAtUnexecutedBP(pc) to record
that.  When the thread resumes, if the pc is still at the same site, we
will continue, hit the breakpoint, and stop again.

2. When we've actually hit a breakpoint (enabled for this thread or not),
the Process plugin should call Thread::SetThreadHitBreakpointSite().
When we go to resume the thread, we will push a step-over-breakpoint
ThreadPlan before resuming.

The biggest set of changes is to StopInfoMachException where we
translate a Mach Exception into a stop reason. The Mach exception codes
differ in a few places depending on the target (unambiguously), and I
didn't want to duplicate the new code for each target so I've tested
what mach exceptions we get for each action on each target, and
reorganized StopInfoMachException::CreateStopReasonWithMachException to
document these possible values, and handle them without specializing
based on the target arch.

rdar://123942164
2024-07-19 17:26:13 -07:00
Dmitry Vasilyev
d097f430a1 [lldb] Fixed the error unable to launch a GDB server in API tests (#98833)
TestPlatformLaunchGDBServer.py runs `ldb-server` w/o parameters
`--min-gdbserver-port`, `--max-gdbserver-port` or `--gdbserver-port`. So
`gdbserver_portmap` is empty and
`gdbserver_portmap.GetNextAvailablePort()` will return 0. Do not call
`portmap_for_child.AllowPort(0)` in this case. Otherwise
`portmap_for_child.GetNextAvailablePort()` will allocate and never free
the port 0 and next call `portmap_for_child.GetNextAvailablePort()` will
fail.

Added few asserts in `GDBRemoteCommunicationServerPlatform::PortMap` to
avoid such issue in the future.

This patch fixes a bug added in #88845. The behaviour is very close to
#97537 w/o parameters `--min-gdbserver-port`, `--max-gdbserver-port` and
`--gdbserver-port`.
2024-07-18 10:04:49 +01:00
David Spickett
b77e734e4e [lldb][AArch64] Add register field enum information (#96887)
This enables XML output for enums and adds enums for 2 fields on AArch64
Linux:
* mte_ctrl.tcf, which controls how tag faults are delivered.
* fpcr.rmode, which sets the rounding mode for floating point
operations.

The other one we could do is cpsr.btype, but it is not clear what would
be useful here so I'm not including it in this change.
2024-07-03 08:43:29 +01:00
David Spickett
208a08c3b7 Reland "[lldb] Parse and display register field enums" (#97258)" (#97270)
This reverts commit d9e659c538.

I could not reproduce the Mac OS ASAN failure locally but I narrowed it
down to the test `test_many_fields_same_enum`. This test shares an enum
between x0, which is 64 bit, and cpsr, which is 32 bit.

My theory is that when it does `register read x0`, an enum type is
created where the undlerying enumerators are 64 bit, matching the
register size.

Then it does `register read cpsr` which used the cached enum type, but
this register is 32 bit. This caused lldb to try to read an 8 byte value
out of a 4 byte allocation:
READ of size 8 at 0x60200014b874 thread T0
<...>
=>0x60200014b800: fa fa fd fa fa fa fd fa fa fa fd fa fa fa[04]fa

To fix this I've added the register's size in bytes to the constructed
enum type's name. This means that x0 uses:
__lldb_register_fields_enum_some_enum_8
And cpsr uses:
__lldb_register_fields_enum_some_enum_4

If any other registers use this enum and are read, they will use the
cached type as long as their size matches, otherwise we make a new type.
2024-07-01 10:45:56 +01:00
David Spickett
d9e659c538 Revert "[lldb] Parse and display register field enums" (#97258)
Reverts llvm/llvm-project#95768 due to a test failure on macOS with
ASAN:

https://green.lab.llvm.org/job/llvm.org/view/LLDB/job/lldb-cmake-sanitized/425/console
2024-07-01 07:46:19 +01:00
David Spickett
8a7730fb88 [lldb] Don't call AddRemoteRegisters if the target XML did not include any registers (#96907)
Fixes #92541

When e69a3d18f4 added fallback register
layouts, it assumed that the choices were target XML with registers, or
no target XML at all.

In the linked issue, a user has a debug stub that does have target XML,
but it's missing register information.

This caused us to finalize the register information using an empty set
of registers got from target XML, then fail an assert when we attempted
to add the fallback set. Since we think we've already completed the
register information.

This change adds a check to prevent that first call and expands the
existing tests to check each architecture without target XML and with
target XML missing register information.
2024-06-27 16:00:07 +01:00
David Spickett
ba60d8a11a [lldb] Parse and display register field enums (#95768)
This teaches lldb to parse the enum XML elements sent by lldb-server,
and make use of the information in `register read` and `register info`.

The format is described in

https://sourceware.org/gdb/current/onlinedocs/gdb.html/Enum-Target-Types.html.

The target XML parser will drop any invalid enum or evalue. If we find
multiple evalue for the same value, we will use the last one we find.

The order of evalues from the XML is preserved as there may be good
reason they are not in numerical order.
2024-06-27 10:03:06 +01:00
David Spickett
906316eaba [lldb] More descriptive name for register flags logging functions
This was requested on a review for enum code that added new log
functions.
2024-06-21 10:05:48 +00:00
Shivam Gupta
0af2e75f8c [lldb] Fix redundant condition in compression type check (NFC) (#94841)
The `else if` condition for checking `m_compression_type` is redundant
as it matches with a previous `if` condition, making the expression
always false. Reported by cppcheck as a possible cut-and-paste error.

Caught by cppcheck -

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp:543:35:
style: Expression is always false because 'else if' condition matches
previous condition at line 535. [multiCondition]

Fix #91222
2024-06-10 13:53:39 +05:30
Kazu Hirata
c33922666c [lldb] Use operator==(StringRef, StringRef) instead of StringRef::equals (NFC) (#92476)
Note that StringRef::equals has been deprecated in favor of
operator==(StringRef, StringRef).
2024-05-16 20:47:12 -07:00
Anthony Ha
95f208f97e [lldb] Unify CalculateMD5 return types (#91029)
This is a retake of https://github.com/llvm/llvm-project/pull/90921
which got reverted because I forgot to modify the CalculateMD5 unit test
I had added in https://github.com/llvm/llvm-project/pull/88812

The prior failing build is here:
https://lab.llvm.org/buildbot/#/builders/68/builds/73622
To make sure this error doesn't happen, I ran `ninja
ProcessGdbRemoteTests` and then executed the resulting test binary and
observed the `CalculateMD5` test passed.

# Overview
In my previous PR: https://github.com/llvm/llvm-project/pull/88812,
@JDevlieghere suggested to match return types of the various calculate
md5 functions.

This PR achieves that by changing the various calculate md5 functions to
return `llvm::ErrorOr<llvm::MD5::MD5Result>`.
 
The suggestion was to go for `std::optional<>` but I opted for
`llvm::ErrorOr<>` because local calculate md5 was already possibly
returning `ErrorOr`.

To make sure I didn't break the md5 calculation functionality, I ran
some tests for the gdb remote client, and things seem to work.

# Testing
1. Remote file doesn't exist

![image](https://github.com/llvm/llvm-project/assets/1326275/b26859e2-18c3-4685-be8f-c6b6a5a4bc77)

1. Remote file differs

![image](https://github.com/llvm/llvm-project/assets/1326275/cbdb3c58-555a-401b-9444-c5ff4c04c491)

1. Remote file matches

![image](https://github.com/llvm/llvm-project/assets/1326275/07561572-22d1-4e0a-988f-bc91b5c2ffce)

## Test gaps
Unfortunately, I had to modify
`lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp` and I
can't test the changes there. Hopefully, the existing test suite / code
review from whomever is reading this will catch any issues.
2024-05-09 15:57:46 -07:00
Jonas Devlieghere
ca8b064973 Revert "[lldb] Unify CalculateMD5 return types" (#90998)
Reverts llvm/llvm-project#90921
2024-05-03 12:14:45 -07:00
Anthony Ha
2f58b9aae2 [lldb] Unify CalculateMD5 return types (#90921)
# Overview
In my previous PR: https://github.com/llvm/llvm-project/pull/88812,
@JDevlieghere suggested to match return types of the various calculate
md5 functions.

This PR achieves that by changing the various calculate md5 functions to
return `llvm::ErrorOr<llvm::MD5::MD5Result>`.
 
The suggestion was to go for `std::optional<>` but I opted for
`llvm::ErrorOr<>` because local calculate md5 was already possibly
returning `ErrorOr`.

To make sure I didn't break the md5 calculation functionality, I ran
some tests for the gdb remote client, and things seem to work.

# Testing
1. Remote file doesn't exist

![image](https://github.com/llvm/llvm-project/assets/1326275/b26859e2-18c3-4685-be8f-c6b6a5a4bc77)

1. Remote file differs

![image](https://github.com/llvm/llvm-project/assets/1326275/cbdb3c58-555a-401b-9444-c5ff4c04c491)

1. Remote file matches

![image](https://github.com/llvm/llvm-project/assets/1326275/07561572-22d1-4e0a-988f-bc91b5c2ffce)

## Test gaps
Unfortunately, I had to modify
`lldb/source/Plugins/Platform/MacOSX/PlatformDarwinDevice.cpp` and I
can't test the changes there. Hopefully, the existing test suite / code
review from whomever is reading this will catch any issues.

Co-authored-by: Anthony Ha <antha@microsoft.com>
2024-05-03 11:51:25 -07:00
Ayush Sahay
2db782047b [lldb] [llgs] Fix assertion in Handle_qfThreadInfo (#88301)
Currently, GDBRemoteCommunicationServerLLGS::Handle_qfThreadInfo asserts
if the number of processes under debug isn’t 1 and the multiprocess
feature isn’t supported. This is so that we don't string IDs of threads
belonging to different processes together without including the IDs of
the processes themselves in the response when there are multiple
processes under debug. However, it’s conceivable that we have no process
under debug and the multiprocess feature isn’t supported. So, have
GDBRemoteCommunicationServerLLGS::Handle_qfThreadInfo assert if the
number of processes under debug is greater than 1 and the multiprocess
feature isn’t supported.
2024-04-25 22:30:02 +05:30
Anthony Ha
22c26fa13d [lldb] Skip remote PutFile when MD5 hashes equal (#88812)
This PR adds a check within `PutFile` to exit early when both local and
destination files have matching MD5 hashes. If they differ, or there is
trouble getting the hashes, the regular code path to put the file is
run.

As I needed this to talk to an `lldb-server` which runs the gdb-remote
protocol, I enabled `CalculateMD5` within `Platform/gdb-server` and also
found and fixed a parsing bug within it as well. Before this PR, the
client is incorrectly parsing the response packet containing the
checksum; after this PR, hopefully this is fixed. There is a test for
the parsing behavior included in this PR.

---------

Co-authored-by: Anthony Ha <antha@microsoft.com>
2024-04-18 12:24:24 -07:00
Alex Langford
10b0e35537 [lldb] Invert relationship between Process and AddressableBits (#85858)
AddressableBits is in the Utility module of LLDB. It currently directly
refers to Process, which is from the Target LLDB module. This is a
layering violation which concretely means that it is impossible to link
anything that uses Utility without it also using Target as well. This is
generally not an issue for LLDB (since everything is built together) but
it may make it difficult to write unit tests for AddressableBits later
on.
2024-03-20 10:46:06 -07:00
jeffreytan81
8bdddcf0bb Fix lldb crash while handling concurrent vfork() (#81564)
We got user reporting lldb crash while the debuggee is calling vfork()
concurrently from multiple threads.
The crash happens because the current implementation can only handle
single vfork, vforkdone protocol transaction.

This diff fixes the crash by lldb-server storing forked debuggee's <pid,
tid> pair in jstopinfo which will be decoded by lldb client to create
StopInfoVFork for follow parent/child policy. Each StopInfoVFork will
later have a corresponding vforkdone packet. So the patch also changes
the `m_vfork_in_progress` to be reference counting based.

Two new test cases are added which crash/assert without the changes in
this patch.

---------

Co-authored-by: jeffreytan81 <jeffreytan@fb.com>
2024-03-06 10:50:32 -08:00
jimingham
2d704f4bf2 Start to clean up the process of defining command arguments. (#83097)
Partly, there's just a lot of unnecessary boiler plate. It's also
possible to define combinations of arguments that make no sense (e.g.
eArgRepeatPlus followed by eArgRepeatPlain...) but these are never
checked since we just push_back directly into the argument definitions.

This commit is step 1 of this cleanup - do the obvious stuff. In it, all
the simple homogenous argument lists and the breakpoint/watchpoint
ID/Range types, are set with common functions. This is an NFC change, it
just centralizes boiler plate. There's no checking yet because you can't
get a single argument wrong.

The end goal is that all argument definition goes through functions and
m_arguments is hidden so that you can't define inconsistent argument
sets.
2024-02-27 10:34:01 -08:00
Adrian Prantl
8a87f763a6 Aim debugserver workaround more precisely. (#83099) 2024-02-27 08:14:46 -08:00
Jason Molenda
87fadb3929 [lldb] Correctly annotate threads at a bp site as hitting it (#82709)
This is next in my series of "fix the racey tests that fail on
greendragon" addressing the failure of TestConcurrentManyBreakpoints.py
where we set a breakpoint in a function that 100 threads execute, and we
check that we hit the breakpoint 100 times. But sometimes it is only hit
99 times, and the test fails.

When we hit a software breakpoint, the pc value for the thread is the
address of the breakpoint instruction - as if it had not been hit yet.
And because a user might ADD a breakpoint for the current pc from the
commandline, when we go to resume execution, any thread that is sitting
at a breakpoint site will be silently advanced past the breakpoint
instruction (disable bp, instruction step that thread, re-enable bp)
before resuming -- whether that thread has hit its breakpoint or not.

What this test is exposing is that there is another corner case, a
thread that is sitting at a breakpoint site but has not yet executed the
breakpoint instruction. The thread will have no stop reason, no mach
exception, so it will not be recorded as having hit the breakpoint
(because it hasn't yet). But when we resume execution, because it is
sitting at a breakpoint site, we advance past it and miss the breakpoint
hit.

In 2016 Abhishek Aggarwal handled a similar issue with a patch in
`ProcessGDBRemote::SetThreadStopInfo()`, adding a breakpoint StopInfo
for a thread sitting at a breakpoint site that has no stop reason.
debugserver's `jThreadsInfo` would not correctly execute Abhishek's code
though because it would respond with `"reason":"none"` for a thread with
no stop reason, and `SetThreadStopInfo()` expected an empty reason here.
The first part of my patch is to clear the `reason` if it is `"none"` so
we flow through the code correctly.

On Darwin, though, our stop reply packet (Txx...) includes the
`threads`, `thread-pcs`, and `jstopinfo` keys, which give us the tids
for all current threads, the pc values for those threads, and
`jstopinfo` has a JSON dictionary with the mach exceptions for all
threads that have a mach exception. In
`ProcessGDBRemote::CalculateThreadStopInfo()` we set the StopInfo for
each thread for a private stop and if we have `jstopinfo` it is the
source of all the StopInfos. I have to add the same logic here, to give
the thread a breakpoint StopInfo even though it hasn't executed the
breakpoint yet. In this case we are very early in thread construction
and I only have the information in the Txx stop reply packet -- tids,
pcs, and jstopinfo, so I can't use the normal general mechanisms of
going through the RegisterContext to get the pc, it's a bit different.

If I hack debugserver to not issue `jstopinfo`,
`CalculateThreadStopInfo` will fall back to sending `qThreadStopInfo`
for each thread and going through
`ProcessGDBRemote::SetThreadStopInfo()` to set the stop infos (and with
the `reason:none` fix, use Abhishek's code).

rdar://110549165
2024-02-23 14:45:22 -08:00