Commit Graph

195 Commits

Author SHA1 Message Date
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
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
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
Adrian Prantl
11084c5c49 [lldb] Convert DebuggerThread.cpp to new Status API (NFC) 2024-09-05 18:00:53 -07:00
Adrian Prantl
e0a93d3505 [lldb] Convert ProcessWindows.cpp to new Status API (NFC) 2024-09-05 16:12:17 -07:00
Adrian Prantl
67fb8d15c9 [lldb] Convert ProcessDebugger.cpp to new Status API (NFC) 2024-09-05 16:12:17 -07:00
Pavel Labath
04ed12ca3f [lldb] Support partial memory reads on windows (#106981)
ReadProcessMemory will not perform the read if part of the memory is
unreadable (and even though the API has a `number_of_bytes_read`
argument). To make this work, I explicitly inspect the memory region
being read and only read the accessible part.
2024-09-03 10:48:40 +02:00
Adrian Prantl
6ae657b08d [lldb] Adapt Plugins/Process/Windows to new Status API 2024-08-27 17:02:49 -07:00
Adrian Prantl
0642cd768b [lldb] Turn lldb_private::Status into a value type. (#106163)
This patch removes all of the Set.* methods from Status.

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

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

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

`    ResultTy DoFoo(Status& error)
`
to

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

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

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.
2024-08-27 10:59:31 -07:00
Alexandre Ganea
a819b0e55f [lldb] Silence warning
This fixes the following warning, when building with Clang ToT on
Windows:
```
[6668/7618] Building CXX object
tools\lldb\source\Plugins\Process\Windows\Common\CMakeFiles\lldbPluginProcessWindowsCommon.dir\TargetThreadWindows.cpp.obj
C:\src\git\llvm-project\lldb\source\Plugins\Process\Windows\Common\TargetThreadWindows.cpp(182,22):
warning: cast from 'FARPROC' (aka 'long long (*)()') to
'GetThreadDescriptionFunctionPtr' (aka 'long (*)(void *, wchar_t **)')
converts to incompatible function type [-Wcast-function-type-mismatch]
```

This is similar to: https://github.com/llvm/llvm-project/pull/97905
2024-08-11 19:01:12 -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
Alexandre Ganea
048815c22a Revert "[lldb] Silence function cast warning when building with Clang ToT targetting Windows"
This reverts commit cf1ded3ac2.
2024-07-06 12:00:13 -04:00
Alexandre Ganea
cf1ded3ac2 [lldb] Silence function cast warning when building with Clang ToT targetting Windows 2024-07-05 20:49:40 -04:00
Aleksandr Korepanov
00ed887454 [LLDB][Windows] Fix watchpoints for Windows (#95446)
Hello!

Currently, watchpoints don't work on Windows (this can be reproduced
with the existing tests). This patch fixes the related issues so that
the tests and watchpoints start working.

Here is the list of tests that are fixed by this patch (on Windows,
checked in **release/18.x** branch):
- commands/watchpoints/hello_watchpoint/TestMyFirstWatchpoint.py
- commands/watchpoints/multiple_hits/TestMultipleHits.py
- commands/watchpoints/multiple_threads/TestWatchpointMultipleThreads.py
- commands/watchpoints/step_over_watchpoint/TestStepOverWatchpoint.py
- commands/watchpoints/unaligned-watchpoint/TestUnalignedWatchpoint.py
- commands/watchpoints/watchpoint_commands/TestWatchpointCommands.py
-
commands/watchpoints/watchpoint_commands/command/TestWatchpointCommandLLDB.py
-
commands/watchpoints/watchpoint_commands/command/TestWatchpointCommandPython.py
-
commands/watchpoints/watchpoint_commands/condition/TestWatchpointConditionCmd.py
- commands/watchpoints/watchpoint_count/TestWatchpointCount.py
- commands/watchpoints/watchpoint_disable/TestWatchpointDisable.py
- commands/watchpoints/watchpoint_size/TestWatchpointSizes.py
- python_api/watchpoint/TestSetWatchpoint.py
- python_api/watchpoint/TestWatchpointIgnoreCount.py
- python_api/watchpoint/TestWatchpointIter.py
- python_api/watchpoint/condition/TestWatchpointConditionAPI.py
- python_api/watchpoint/watchlocation/TestTargetWatchAddress.py

---------

Co-authored-by: Jason Molenda <jmolenda@apple.com>
2024-06-13 14:50:31 -07:00
Alexandre Ganea
935c652d07 [lldb] Silence warning when building with Clang ToT
Fixes:
```
C:\git\llvm-project\lldb\source\Plugins\Process\Windows\Common\x64\RegisterContextWindows_x64.cpp(195,5): warning: missing field 'flags_type' initializer [-Wmissing-field-initializers]
```
2024-01-17 07:23:56 -05:00
gmh
f3f4387e02 [lldb][NFC] Fix compilation issue on windows (#76453) 2024-01-04 08:39:50 +00:00
Nico Weber
54378a7c2f [lldb][Windows] Fix -Wmissing-field-initializers warnings after 54981bb75d (#76255) 2024-01-03 10:12:30 +00:00
oltolm
95e5839e06 [lldb] add support for thread names on Windows (#74731)
This PR adds support for thread names in lldb on Windows.

```
(lldb) thr list
Process 2960 stopped
  thread #53: tid = 0x03a0, 0x00007ff84582db34 ntdll.dll`NtWaitForMultipleObjects + 20
  thread #29: tid = 0x04ec, 0x00007ff845830a14 ntdll.dll`NtWaitForAlertByThreadId + 20, name = 'SPUW.6'
  thread #89: tid = 0x057c, 0x00007ff845830a14 ntdll.dll`NtWaitForAlertByThreadId + 20, name = 'PPU[0x1000019] physics[main]'
  thread #3: tid = 0x0648, 0x00007ff843c2cafe combase.dll`InternalDoATClassCreate + 39518
  thread #93: tid = 0x0688, 0x00007ff845830a14 ntdll.dll`NtWaitForAlertByThreadId + 20, name = 'PPU[0x100501d] uMovie::StreamingThread'
  thread #1: tid = 0x087c, 0x00007ff842e7a104 win32u.dll`NtUserMsgWaitForMultipleObjectsEx + 20
  thread #96: tid = 0x0890, 0x00007ff845830a14 ntdll.dll`NtWaitForAlertByThreadId + 20, name = 'PPU[0x1002020] HLE Video Decoder'
<...>
```
2023-12-21 12:42:22 +00:00
Kazu Hirata
ee667db4b8 [lldb] Use StringRef::{starts,ends}_with (NFC)
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.

I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
2023-12-16 15:02:15 -08:00
Jason Molenda
c73a3f16f8 [lldb] [mostly NFC] Large WP foundation: WatchpointResources (#68845)
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.

This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.

There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.

This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.

This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.

To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.

I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.

There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).

"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.

I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.

I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.

https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
(cherry picked from commit fc6b72523f)
2023-11-30 14:59:10 -08:00
David Spickett
b0af8a1ede Revert "[lldb] [mostly NFC] Large WP foundation: WatchpointResources (#68845)"
...and follow ups.

As it has caused test failures on Linux Arm and AArch64:
https://lab.llvm.org/buildbot/#/builders/96/builds/49126
https://lab.llvm.org/buildbot/#/builders/17/builds/45824

```
  lldb-shell :: Subprocess/clone-follow-child-wp.test
  lldb-shell :: Subprocess/fork-follow-child-wp.test
  lldb-shell :: Subprocess/vfork-follow-child-wp.test
```

This reverts commit a6c62bf1a4,
commit a0a1ff3ab4 and commit
fc6b72523f.
2023-11-28 09:39:37 +00:00
Jason Molenda
fc6b72523f [lldb] [mostly NFC] Large WP foundation: WatchpointResources (#68845)
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.

This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.

There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.

This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.

This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.

To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.

I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.

There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).

"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.

I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.

I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.

https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
2023-11-27 13:28:59 -08:00
Jason Molenda
a3fe9221ab Remove hardware index from watchpoints and breakpoints (#72012)
The Watchpoint and Breakpoint objects try to track the hardware index
that was used for them, if they are hardware wp/bp's. The majority of
our debugging goes over the gdb remote serial protocol, and when we set
the watchpoint/breakpoint, there is no (standard) way for the remote
stub to communicate to lldb which hardware index was used. We have an
lldb-extension packet to query the total number of watchpoint registers.

When a watchpoint is hit, there is an lldb extension to the stop reply
packet (documented in lldb-gdb-remote.txt) to describe the watchpoint
including its actual hardware index,

<addr within wp range> <wp hw index> <actual accessed address>

(the third field is specifically needed for MIPS). At this point, if the
stub reported these three fields (the stub is only required to provide
the first), we can know the actual hardware index for this watchpoint.

Breakpoints are worse; there's never any way for us to be notified about
which hardware index was used. Breakpoints got this as a side effect of
inherting from StoppointSite with Watchpoints.

We expose the watchpoint hardware index through "watchpoint list -v" and
through SBWatchpoint::GetHardwareIndex.

With my large watchpoint support, there is no *single* hardware index
that may be used for a watchpoint, it may need multiple resources. Also
I don't see what a user is supposed to do with this information, or an
IDE. Knowing the total number of watchpoint registers on the target, and
knowing how many Watchpoint Resources are currently in use, is helpful.
Knowing how many Watchpoint Resources
a single user-specified watchpoint needed to be implemented is useful.
But knowing which registers were used is an implementation detail and
not available until we hit the watchpoint when using gdb remote serial
protocol.

So given all that, I'm removing watchpoint hardware index numbers. I'm
changing the SB API to always return -1.
2023-11-15 13:32:42 -08:00
David Spickett
57c8fee1b9 [lldb] Add dummy field to RegisterInfo for register flags use later
This structure is supposed to be trivial, so we cannot simply do
"= nullptr;" on the new member. Doing that means you are non trivial,
regardless of whether you emulate the previously implied constructor somehow.

The next option is to update every use of brace initialisation.

Given that this is some hundreds of lines, this change just adds a dummy
pointer that is set to nullptr. Subsequent changes will actually use that
to point to register flags information.

Note: This change is not clang-format-ted because it changes a bunch of
areas that are not themselves formatted. It would just add noise.

Reviewed By: jasonmolenda, JDevlieghere

Differential Revision: https://reviews.llvm.org/D145568
2023-04-13 11:30:00 +00:00
Pavel Labath
e64cc75681 [lldb-server/linux] Use waitpid(-1) to collect inferior events
This is a follow-up to D116372, which had a rather unfortunate side
effect of making the processing of a single SIGCHLD quadratic in the
number of threads -- which does not matter for simple applications, but
can get really bad for applications with thousands of threads.

This patch fixes the problem by implementing the other possibility
mentioned in the first patch -- doing waitpid(-1) centrally and then
routing the events to the correct process instance. The "uncollected"
threads are held in the process factory class -- which I've renamed to
Manager for this purpose, as it now does more than creating processes.

Differential Revision: https://reviews.llvm.org/D146977
2023-03-30 12:48:36 +02:00
Jason Molenda
eaeb8ddd4a [LLDB] add arch-specific watchpoint behavior defaults to lldb
lldb was originally designed to get the watchpoint exception behavior
from the gdb remote serial protocol stub -- exceptions are either
received before the instruction executes, or after the instruction
has executed.  This behavior was reported via two lldb extensions
to gdb RSP, so generic remote stubs like gdbserver or a JTAG stub,
would not tell lldb which behavior was correct, and it would default
to "exceptions are received after the instruction has executed".
Two architectures hard coded their correct "exceptions before
instruction" behavior, to work around this issue.

Most architectures have a fixed behavior of watchpoint exceptions,
and we can center that information in lldb.  We can allow a remote
stub to override the default behavior via our packet extensions
if it's needed on a specific target.

This patch also separates the fetching of the number of watchpoints
from whether exceptions are before/after the insn.  Currently if
lldb couldn't fetch the number of watchpoints (not really needed), it
also wouldn't get when exceptions are received, and watchpoint
handling would fail.  lldb doesn't actually use the number of
watchpoints for anything beyond printing it to the user.

Differential Revision: https://reviews.llvm.org/D143215
rdar://101426626
2023-02-14 11:35:39 -08:00
serge-sans-paille
984b800a03 Move from llvm::makeArrayRef to ArrayRef deduction guides - last part
This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141298
2023-01-10 11:47:43 +01:00
Kazu Hirata
2fe8327406 [lldb] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to clean up the "using" declarations, #include
"llvm/ADT/Optional.h", etc.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 14:18:35 -08:00
Kazu Hirata
f190ce625a [lldb] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 13:43:00 -08:00
Kazu Hirata
529ca5ad07 [lldb] Use std::nullopt instead of llvm::None (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-05 23:18:15 -08:00
Alvin Wong
fe17e02695 [lldb][Windows] Always call SetExecutableModule on debugger connected
In `ProcessWindows::OnDebuggerConnected` (triggered from
`CREATE_PROCESS_DEBUG_EVENT`), we should always call
`Target::SetExecutableModule` regardless of whether LLDB has already
preloaded the executable modules. `SetExecutableModule` has the side
effect of clearing the module list of the Target, which help make sure
that module #0 is the executable module and the rest of the modules are
listed according to the DLL load order in the process (technically this
has no real consequences but it seems to make more sense anyway.) It
also fixes an issue where the modules preloaded by LLDB will be
duplicated when the debuggee process actually loads the DLL.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D134636
2022-09-30 13:51:56 +03:00
Joe Loser
47b76631e7 [lldb] Use std::size instead of llvm::array_lengthof
LLVM contains a helpful function for getting the size of a C-style
array: `llvm::array_lengthof`. This is useful prior to C++17, but not as
helpful for C++17 or later: `std::size` already has support for C-style
arrays.

Change call sites to use `std::size` instead.

Differential Revision: https://reviews.llvm.org/D133501
2022-09-08 14:21:55 -06:00
Fangrui Song
59d2495fe2 [lldb] LLVM_FALLTHROUGH => [[fallthrough]]. NFC 2022-08-08 11:31:49 -07:00
Michał Górny
9b031d5e3a [lldb] Make Process and subclass constructors protected
Make constructors of the Process and its subclasses class protected,
to prevent accidentally constructing Process on stack when it could be
afterwards accessed via a shared_ptr (since it uses
std::enable_shared_from_this<>).

The only place where a stack allocation was used were unittests,
and fixing them via declaring an explicit public constructor
in the respective mock classes is trivial.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D131275
2022-08-08 17:34:27 +02:00
Greg Clayton
529a3d87a7 [NFC] Improve FileSpec internal APIs and usage in preparation for adding caching of resolved/absolute.
Resubmission of https://reviews.llvm.org/D130309 with the 2 patches that fixed the linux buildbot, and new windows fixes.

The FileSpec APIs allow users to modify instance variables directly by getting a non const reference to the directory and filename instance variables. This makes it impossible to control all of the times the FileSpec object is modified so we can clear cached member variables like m_resolved and with an upcoming patch caching if the file is relative or absolute. This patch modifies the APIs of FileSpec so no one can modify the directory or filename instance variables directly by adding set accessors and by removing the get accessors that are non const.

Many clients were using FileSpec::GetCString(...) which returned a unique C string from a ConstString'ified version of the result of GetPath() which returned a std::string. This caused many locations to use this convenient function incorrectly and could cause many strings to be added to the constant string pool that didn't need to. Most clients were converted to using FileSpec::GetPath().c_str() when possible. Other clients were modified to use the newly renamed version of this function which returns an actualy ConstString:

ConstString FileSpec::GetPathAsConstString(bool denormalize = true) const;

This avoids the issue where people were getting an already uniqued "const char *" that came from a ConstString only to put the "const char *" back into a "ConstString" object. By returning the ConstString instead of a "const char *" clients can be more efficient with the result.

The patch:
- Removes the non const GetDirectory() and GetFilename() get accessors
- Adds set accessors to replace the above functions: SetDirectory() and SetFilename().
- Adds ClearDirectory() and ClearFilename() to replace usage of the FileSpec::GetDirectory().Clear()/FileSpec::GetFilename().Clear() call sites
- Fixed all incorrect usage of FileSpec::GetCString() to use FileSpec::GetPath().c_str() where appropriate, and updated other call sites that wanted a ConstString to use the newly returned ConstString appropriately and efficiently.

Differential Revision: https://reviews.llvm.org/D130549
2022-07-28 13:28:26 -07:00
David Spickett
1ca8a97802 [lldb][Windows] Fix memory region base addresses when a range is split
Previously we recorded AllocationBase as the base address of the region
we get from VirtualQueryEx. However, this is the base of the allocation,
which can later be split into more regions.

So you got stuff like:
[0x00007fff377c0000-0x00007fff377c1000) r-- PECOFF header
[0x00007fff377c0000-0x00007fff37840000) r-x .text
[0x00007fff377c0000-0x00007fff37870000) r-- .rdata

Where all the base addresses were the same.

Instead, use BaseAddress as the base of the region. So we get:
[0x00007fff377c0000-0x00007fff377c1000) r-- PECOFF header
[0x00007fff377c1000-0x00007fff37840000) r-x .text
[0x00007fff37840000-0x00007fff37870000) r-- .rdata

https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-memory_basic_information

The added test checks for any overlapping regions which means
if we get the base or size wrong it'll fail. This logic
applies to any OS so the test isn't restricted to Windows.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D129272
2022-07-07 13:55:48 +00:00
Michał Górny
b4f2d7cde5 [lldb] [llgs] Support "t" vCont action
Implement support for the "t" action that is used to stop a thread.
Normally this action is used only in non-stop mode.  However, there's
no technical reason why it couldn't be also used in all-stop mode,
e.g. to express "resume all threads except ..." (`t:...;c`).

While at it, add a more complete test for vCont correctly resuming
a subset of program's threads.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D126983
2022-06-27 17:33:59 +02:00
Alvin Wong
4d12378395 [lldb][windows] Fix crash on getting nested exception
LLDB tries to follow `EXCEPTION_RECORD::ExceptionRecord` to follow the
nested exception chain. In practice this code just causes Access
Violation whenever there is a nested exception. Since there does not
appear to be any code in LLDB that is actually using the nested
exceptions, this change just removes the crashing code and adds a
comment for future reference.

Fixes https://github.com/mstorsjo/llvm-mingw/issues/292

Reviewed By: DavidSpickett

Differential Revision: https://reviews.llvm.org/D128201
2022-06-22 17:16:06 +03:00
Martin Storsjö
9846a1f2d4 [lldb] Remove an outdated comment. NFC.
This comment became outdated in 053eb35651
(but was moved along); that commit moved the code and the comment
to a separate function, with a separate local variable
`num_of_bytes_read`. On error, the possibly garbage value is never
copied back to the caller's reference, thus the comment is no longer
relevant (and slightly confusing as is).

Differential Revision: https://reviews.llvm.org/D128226
2022-06-22 16:11:59 +03:00
Michał Górny
d6b3de7256 [lldb] [llgs] Fix signo sent with fork/vfork/vforkdone events
Fix ThreadStopInfo struct to include the signal number for all events.
Since signo was not included in the details for fork, vfork
and vforkdone stops, the code incidentally referenced the wrong union
member, resulting in wrong signo being sent.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127193
2022-06-21 19:47:30 +02:00
Alvin Wong
87a2dba14e [lldb] Fix loading DLL from some ramdisk on Windows
The WinAPI `GetFinalPathNameByHandle` is used to retrieve the DLL file
name from the HANDLE provided to `LOAD_DLL_DEBUG_EVENT` in the debug
loop. When this API fails, lldb will simply ignore that module.

Certain ramdisk (e.g. ImDisk) does not work with this API, which means
it is impossible to use lldb to debug a process which loads DLLs located
on this type of ramdisk. In order to make this work, we need to use a
fallback routine which involves creating a file mapping, using
`GetMappedFileName` to get a device path, then substitutes the device
path with its drive letter.

References:
* https://developercommunity.visualstudio.com/t/cannot-debug-program-when-compiled-to-ram-drive/43004#T-N109926
* https://github.com/jrfonseca/drmingw/issues/65
* https://docs.microsoft.com/en-us/windows/win32/memory/obtaining-a-file-name-from-a-file-handle

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D126657
2022-06-15 17:02:33 +03:00
Jonas Devlieghere
70984dd40a [lldb] Update ReadAllRegisterValues in RegisterContextWindows 2022-04-05 15:15:48 -07:00
Jonas Devlieghere
c2f6460145 [lldb] Update the NativeRegisterContext to take a WritableMemoryBuffer 2022-04-05 14:19:01 -07:00
Jonas Devlieghere
a6eeffa106 [lldb] Include lldb/Host/HostInfo.h in ProcessWindows.cpp 2022-03-11 12:34:41 -08:00
Jonas Devlieghere
530bc61901 [lldb] Fix typo in ProcessWindows.h 2022-03-11 11:33:16 -08:00
Jonas Devlieghere
68099b1d5c [lldb] Add a getter for the process' system architecture
This patch adds a getter for the process' system architecture. I went
with Process::GetSystemArchitecture to match
Platform::GetSystemArchitecture.

Differential revision: https://reviews.llvm.org/D121443
2022-03-11 10:58:04 -08:00