This is to make debugging rust-analyzer easier.
The idea is that `dbg!(krate.debug(db))` will print the actual, fuzzy
crate name, instead of precise ID. Debug printing infra is a separate
thing, to make sure that the actual hir doesn't have access to global
information.
Do not use `.debug` for `log::` logging: debugging executes queries,
and might introduce unneded dependencies to the crate graph
This wasn't a right decision in the first place, the feature flag was
broken in the last rustfmt release, and syntax highlighting of imports
is more important anyway
Can be used like this:
```
$ cargo run --release -p ra_cli -- \
analysis-bench ../chalk/ \
--complete ../chalk/chalk-engine/src/logic.rs:94:0
loading: 225.970093ms
from scratch: 8.492373325s
no change: 445.265µs
trivial change: 95.631242ms
```
Or like this:
```
$ cargo run --release -p ra_cli -- \
analysis-bench ../chalk/ \
--highlight ../chalk/chalk-engine/src/logic.rs
loading: 209.873484ms
from scratch: 9.504916942s
no change: 7.731119ms
trivial change: 124.984039ms
```
"from scratch" includes initial analysis of the relevant bits of the
project
"no change" just asks the same question for the second time. It
measures overhead on assembling the answer outside of salsa.
"trivial change" doesn't do an actual salsa change, it just advances
the revision. This test how fast is salsa at validating things.
`ProjectWorkspace::to_roots` now returns a new `ProjectRoot` which contains
information regarding whether or not the given path is part of the current
workspace or an external dependency. This information can then be used in
`ra_batch` and `ra_lsp_server` to implement more advanced filtering. This allows
us to filter some unnecessary folders from external dependencies such as tests,
examples and benches.
