The tests for the
[intel-pt](3483740289/lldb/docs/use/intel_pt.rst)
trace plugin were failing for multiple reasons.
On machines where tracing is supported many of the tests were crashing
because of a nullptr dereference. It looks like the `core_file`
parameter in `ProcessTrace::CreateInstance` was once ignored, but was
changed to always being dereferenced. This caused the tests to fail even
when tracing was supported.
On machines where tracing is not supported we would still run tests that
attempt to take a trace. These would obviously fail because the required
hardware is not present. Note that some of the tests simply read
serialized json as trace files which does not require any special
hardware.
This PR fixes these two issues by guarding the pointer dereference and
then skipping unsupported tests on machines. With these changes the
trace tests pass on both types of machines.
We also add a new unit test to validate that a process can be created
with a nullptr core_file through the generic process trace plugin path.
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
Update the Python tests (ie tests run via `lldb-dotest -p TestTrace`) to
handle new error introduced in D136610.
Test Plan:
`lldb-dotest -p TestTrace`
Differential Revision: https://reviews.llvm.org/D136801
These tests were being tested against a version of libipt from last
year. We just updated libipt to top of tree and many errors broke
because the new version of libipt emits more events than the older one,
which is fine.
`./bin/lldb-dotest -p TestTrace` passes
The JSON dumper is very minimalistic. It pretty much only shows the
delimiting instruction IDs of every segment, so that further queries to
the SBCursor can be used to make sense of the data. It's main purpose is
to be serialized somewhat cheaply.
I also renamed untracedSegment to untracedPrefixSegment, in case in the
future we add an untracedSuffixSegment. In any case, this new name is
more explicit, which I like.
Differential Revision: https://reviews.llvm.org/D136034
This diff implements the reconstruction algorithm for the call tree and
add tests.
See TraceDumper.h for documentation and explanations.
One important detail is that the tree objects are in TraceDumper, even
though Trace.h is a better home. I'm leaving that as future work.
Another detail is that this code is as slow as dumping the entire
symolicated trace, which is not that bad tbh. The reason is that we use
symbols throughout the algorithm and we are not being careful about
memory and speed. This is also another area for future improvement.
Lastly, I made sure that incomplete traces work, i.e. you start tracing
very deep in the stack or failures randomly appear in the trace.
Differential Revision: https://reviews.llvm.org/D135917
The command is thread trace dump function-calls and as minimum will
require printing to a file in json and non-json format
I added a test
Differential Revision: https://reviews.llvm.org/D135521
