This change makes the writer implementation more consistent with the way
fields are written down to avoid assumptions on bitfield order and
padding. We also fix an inconsistency between the type returned by the
`delta()` accessor to match the data member it's returning.
This is a follow-up to D51289 and D51210.
llvm-svn: 341230
Before this patch, the FDRTraceWriter would not take endianness into
account when writing data into the output stream.
This is a follow-up to D51289 and D51210.
llvm-svn: 341223
Summary:
This is the first step in the larger refactoring and reduction of
D50441.
This step in the process does the following:
- Introduces more granular types of `Record`s representing the many
kinds of records written/read by the Flight Data Recorder (FDR) mode
`Trace` loading function(s).
- Introduces an abstract `RecordVisitor` type meant to handle the
processing of the various `Record` derived types. This `RecordVisitor`
has two implementations in this patch: `RecordInitializer` and
`FDRTraceWriter`.
- We also introduce a convenience interface for building a collection of
`Record` instances called a `LogBuilder`. This allows us to generate
sequences of `Record` instances manually (used in unit tests but
useful otherwise).
- The`FDRTraceWriter` class implements the `RecordVisitor` interface and
handles the writing of metadata records to a `raw_ostream`. We
demonstrate that in the unit test, we can generate in-memory FDR mode
traces using the specific `Record` derived types, which we load
through the `loadTrace(...)` function yielding valid `Trace` objects.
This patch introduces the required types and concepts for us to start
replacing the logic implemented in the `loadFDRLog` function to use the
more granular types. In subsequent patches, we will introduce more
visitor implementations which isolate the verification, printing,
indexing, production/consumption, and finally the conversion of the FDR
mode logs.
The overarching goal of these changes is to make handling FDR mode logs
better tested, more understandable, more extensible, and more
systematic. This will also allow us to better represent the execution
trace, as we improve the fidelity of the events we represent in an XRay
`Trace` object, which we intend to do after FDR mode log processing is
in better shape.
Reviewers: eizan
Reviewed By: eizan
Subscribers: mgorny, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51210
llvm-svn: 341029
