There's currently a bug with empty files, in that it initializes SourceBuffer with an invalid StringRef that results in a crash. That got me looking at the std::optional TODO, but the issue is that there are really three states:
- Buffered
- mmapped (not buffered)
- Moved out of (no longer initialized)
Technically an optional could work if we initialize the buffer on move out, indicating the mmap is gone. But the mode setup felt better to me.
And then this also adds the size check. Which is really how I started looking at this.
This gets us to a nearly clean state across the toolchain. A couple of
these are checks that I don't think we want to try to rigidly use and
I've disabled them completely. Others I've added relevant `NOLINT` style
suppressions or applied the automatic fix suggested by `clang-tidy`.
The implicit conversions that are allowed here with `NOLINT` are
probably worth at least a tiny bit of scrutiny to see if we could
replace the construct with something more direct without undue effort
and no longer need the implicit conversion. But until then, it seemed
fine to suppress.
This should clean up our top level directory and the build patterns.
No non-mechanical edits here. Just injecting `toolchain/` and
`TOOLCHAIN_` and then running formatting tools.
Jon Meow
