Revert "[lldb] Change lldb's breakpoint handling behavior (#96260)"

This reverts commit 05f0e86cc895181b3d2210458c78938f83353002.

The debuginfo dexter tests are failing, probably because the way
st

Revert "[lldb] Change lldb's breakpoint handling behavior (#96260)"

This reverts commit 05f0e86cc895181b3d2210458c78938f83353002.

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.

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[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

[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

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[lldb][test] Modernize asserts (#82503)

This uses [teyit](https://pypi.org/project/teyit/) to modernize asserts,
as recommended by the [unittest release
notes](https://docs.python.org/3.12/whatsne

[lldb][test] Modernize asserts (#82503)

This uses [teyit](https://pypi.org/project/teyit/) to modernize asserts,
as recommended by the [unittest release
notes](https://docs.python.org/3.12/whatsnew/3.12.html#id3).

For example, `assertTrue(a == b)` is replaced with `assertEqual(a, b)`.
This produces better error messages, e.g. `error: unexpectedly found 1
and 2 to be different` instead of `error: False`.

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[lldb] Replace assertEquals with assertEqual (NFC) (#82073)

assertEquals is a deprecated alias for assertEqual and has been removed
in Python 3.12. This wasn't an issue previously because we used a

[lldb] Replace assertEquals with assertEqual (NFC) (#82073)

assertEquals is a deprecated alias for assertEqual and has been removed
in Python 3.12. This wasn't an issue previously because we used a
vendored version of the unittest module. Now that we use the built-in
version this gets updated together with the Python version used to run
the test suite.

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[NFC][Py Reformat] Reformat python files in lldb

This is an ongoing series of commits that are reformatting our Python
code. Reformatting is done with `black` (23.1.0).

If you end up having problem

[NFC][Py Reformat] Reformat python files in lldb

This is an ongoing series of commits that are reformatting our Python
code. Reformatting is done with `black` (23.1.0).

If you end up having problems merging this commit because you have made
changes to a python file, the best way to handle that is to run `git
checkout --ours <yourfile>` and then reformat it with black.

RFC: https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style

Differential revision: https://reviews.llvm.org/D151460

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[lldb] Remove unused "import unittest2" statements

[lldb] Add assertStopReason helper function

Add a function to make it easier to debug a test failure caused by an
unexpected stop reason. This is similar to the assertState helper that
was added in

[lldb] Add assertStopReason helper function

Add a function to make it easier to debug a test failure caused by an
unexpected stop reason. This is similar to the assertState helper that
was added in ce825e46743b.

Before:

self.assertEqual(stop_reason, lldb.eStopReasonInstrumentation)
AssertionError: 5 != 10

After:

self.assertStopReason(stop_reason, lldb.eStopReasonInstrumentation)
AssertionError: signal (5) != instrumentation (10)

Differential revision: https://reviews.llvm.org/D131083

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[lldb][tests] Automatically call compute_mydir (NFC)

Eliminate boilerplate of having each test manually assign to `mydir` by calling
`compute_mydir` in lldbtest.py.

Differential Revision: https://r

[lldb][tests] Automatically call compute_mydir (NFC)

Eliminate boilerplate of having each test manually assign to `mydir` by calling
`compute_mydir` in lldbtest.py.

Differential Revision: https://reviews.llvm.org/D128077

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[lldb] Add assertState function to the API test suite

Add a function to make it easier to debug a test failure caused by an
unexpected state.

Currently, tests are using assertEqual which results in

[lldb] Add assertState function to the API test suite

Add a function to make it easier to debug a test failure caused by an
unexpected state.

Currently, tests are using assertEqual which results in a cryptic error
message: "AssertionError: 5 != 10". Even when a test provides a message
to make it clear why a particular state is expected, you still have to
figure out which of the two was the expected state, and what the other
value corresponds to.

We have a function in lldbutil that helps you convert the state number
into a user readable string. This patch adds a wrapper around
assertEqual specifically for comparing states and reporting better error
messages.

The aforementioned error message now looks like this: "AssertionError:
stopped (5) != exited (10)". If the user provided a message, that
continues to get printed as well.

Differential revision: https://reviews.llvm.org/D127355

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[lldb] Remove support for replaying the test suite from a reproducer

This patch removes the infrastructure to replay the test suite from a
reproducer, as well as the modifications made to the indivi

[lldb] Remove support for replaying the test suite from a reproducer

This patch removes the infrastructure to replay the test suite from a
reproducer, as well as the modifications made to the individual tests.

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[lldb/Reproducers] Add skipIfReproducer to more tests

Mark more tests as unsupported with reproducers.

[lldb] NFC: Fix trivial typo in comments, documents, and messages

Differential Revision: https://reviews.llvm.org/D77460

[lldb][testsuite] Create a SBDebugger instance for each test

Some tests set settings and don't clean them up, this leads to side effects in other tests.
The patch removes a global debugger instance

[lldb][testsuite] Create a SBDebugger instance for each test

Some tests set settings and don't clean them up, this leads to side effects in other tests.
The patch removes a global debugger instance with a per-test debugger to avoid such effects.

From what I see, lldb.DBG was needed to determine the platform before a test is run,
lldb.selected_platform is used for this purpose now. Though, this required adding a new function
to the SBPlatform interface.

Differential Revision: https://reviews.llvm.org/D74903

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[lldb][test] Remove symlink for API tests.

Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdi

[lldb][test] Remove symlink for API tests.

Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdir -p lldb/test/API/{test_runner/test,tools/lldb-{server,vscode}}
mv lldb/packages/Python/lldbsuite/test/test_runner/test lldb/test/API/test_runner
for d in $(find lldb/packages/Python/lldbsuite/test/* -maxdepth 0 -type d | egrep -v "make|plugins|test_runner|tools"); do mv $d lldb/test/API; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-vscode -maxdepth 1 -mindepth 1 | grep -v ".py"); do mv $d lldb/test/API/tools/lldb-vscode; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-server -maxdepth 1 -mindepth 1 | egrep -v "gdbremote_testcase.py|lldbgdbserverutils.py|socket_packet_pump.py"); do mv $d lldb/test/API/tools/lldb-server; done
```

lldb/packages/Python/lldbsuite/__init__.py and lldb/test/API/lit.cfg.py were also updated with the new directory structure.

Reviewers: labath, JDevlieghere

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71151

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