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This reverts commit 9d98acb196a40fee5229afeb08f95fd36d41c10a.
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Line ending policies were changed in the parent, dccebddb3b80. To make
it easier to resolve downstream merge conflicts after line-ending
policies are adjusted this is a separate whitespace-only commit. If you
have merge conflicts as a result, you can simply `git add --renormalize
-u && git merge --continue` or `git add --renormalize -u && git rebase
--continue` - depending on your workflow.
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This test is currently flaky on a local Windows amd64 build. The reason
is that it relies on the order of `process.threads` but this order is
nondeterministic:
If we print lldb's inputs and outputs while running, we can see that the
breakpoints are always being set correctly, and always being hit:
```sh
runCmd: breakpoint set -f "main.c" -l 2
output: Breakpoint 1: where = a.out`func_inner + 1 at main.c:2:9, address = 0x0000000140001001
runCmd: breakpoint set -f "main.c" -l 7
output: Breakpoint 2: where = a.out`main + 17 at main.c:7:5, address = 0x0000000140001021
runCmd: run
output: Process 52328 launched: 'C:\workspace\llvm-project\llvm\build\lldb-test-build.noindex\functionalities\unwind\zeroth_frame\TestZerothFrame.test_dwarf\a.out' (x86_64)
Process 52328 stopped
* thread #1, stop reason = breakpoint 1.1
frame #0: 0x00007ff68f6b1001 a.out`func_inner at main.c:2:9
1 void func_inner() {
-> 2 int a = 1; // Set breakpoint 1 here
^
3 }
4
5 int main() {
6 func_inner();
7 return 0; // Set breakpoint 2 here
```
However, sometimes the backtrace printed in this test shows that the
process is stopped inside NtWaitForWorkViaWorkerFactory from
`ntdll.dll`:
```sh
Backtrace at the first breakpoint:
frame #0: 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
frame #1: 0x00007ffecc74585e ntdll.dll`RtlClearThreadWorkOnBehalfTicket + 862
frame #2: 0x00007ffecc3e257d kernel32.dll`BaseThreadInitThunk + 29
frame #3: 0x00007ffecc76af28 ntdll.dll`RtlUserThreadStart + 40
```
When this happens, the test fails with an assertion error that the
stopped thread's zeroth frame's current line number does not match the
expected line number. This is because the test is looking at the wrong
thread: `process.threads[0]`.
If we print the list of threads each time the test is run, we notice
that threads are sometimes in a different order, within
`process.threads`:
```sh
Thread 0: thread #4: tid = 0x9c38, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 1: thread #2: tid = 0xa950, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 2: thread #1: tid = 0xab18, 0x00007ff64bc81001 a.out`func_inner at main.c:2:9, stop reason = breakpoint 1.1
Thread 3: thread #3: tid = 0xc514, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 0: thread #3: tid = 0x018c, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 1: thread #1: tid = 0x85c8, 0x00007ff7130c1001 a.out`func_inner at main.c:2:9, stop reason = breakpoint 1.1
Thread 2: thread #2: tid = 0xf344, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 3: thread #4: tid = 0x6a50, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
```
Use `self.thread()` to consistently select the correct thread, instead.
Co-authored-by: kendal <kendal@thebrowser.company>
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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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Not needed now that we require python 3.
Reviewed By: kastiglione, JDevlieghere
Differential Revision: https://reviews.llvm.org/D131761
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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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Fix to code from https://reviews.llvm.org/D64993.
Field StackFrame::m_behaves_like_zeroth_frame was introduced in commit
[1], however that commit hasn't added a copying of the field to
UpdatePreviousFrameFromCurrentFrame, therefore the value wouldn't change
when updating frames to reflect the current situation.
The particular scenario, where this matters is following. Assume we have
function main that invokes function func1. We set breakpoint at
func1 entry and in main after the func1 call, and do not stop at
the main entry. Therefore, when debugger stops for the first time,
func1 is frame#0, while main is frame#1, thus
m_behaves_like_zeroth_frame is set to 0 for main frame. Execution is
resumed, and stops now in main, where it is now frame#0. However while
updating the frame object, m_behaves_like_zeroth_frame remains false.
This field plays an important role when calculating line information for
backtrace: for frame#0, PC is the current line, therefore line
information is retrieved for PC, however for all other frames this is
not the case - calculated PC is a return-PC, i.e. instruction after the
function call line, therefore for those frames LLDB needs to step back
by one instruction. Initial implementation did this strictly for frames
that have index != 0 (and index is updated properly in
UpdatePreviousFrameFromCurrentFrame), but m_behaves_like_zeroth_frame
added a capability for middle-of-stack frames to behave in a similar
manner. But because current code now doesn't check frame idx,
m_behaves_like_zeroth_frame must be set to true for frames with 0 index,
not only for frame that behave like one. In the described test case,
after stopping in main, LLDB would still consider frame#0 as
non-zeroth, and would subtract instruction from the PC, and would report
previous like as current line.
The error doesn't manifest itself in LLDB interpreter though - it can be
reproduced through LLDB-MI and when using SB API, but not when we
interpreter command "continue" is executed. Honestly, I didn't fully
understand why it works in interpreter, I did found that bug "fixes"
itself if I enable DEBUG_STACK_FRAMES in StackFrameList.cpp, because
that calls StackFrame::Dump and that calls
GetSymbolContext(eSymbolContextEverything), which fills the context of
frame on the first breakpoint, therefore it doesn't have to be
recalculated (improperly) on a second frame. However, on first
breakpoint symbol context is calculated for the "call" line, not the
next one, therefore it should be recalculated anyway on a second
breakpoint, and it is done correctly, even though
m_behaves_like_zeroth_frame is still incorrect, as long as
GetSymbolContext(eSymbolContextEverything) has been called.
[1] 31e6dbe1c6a6 Fix PC adjustment in StackFrame::GetSymbolContext
Differential Revision: https://reviews.llvm.org/D75975
Patch by Anton Kolesov <Anton.Kolesov@synopsys.com>
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