rust/compiler/rustc_driver
Joshua Nelson 622c48e4f1 Allow making RUSTC_BOOTSTRAP conditional on the crate name
The main change is that `UnstableOptions::from_environment` now requires
an (optional) crate name. If the crate name is unknown (`None`), then the new feature is not available and you still have to use `RUSTC_BOOTSTRAP=1`. In practice this means the feature is only available for `--crate-name`, not for `#![crate_name]`; I'm interested in supporting the second but I'm not sure how.

Other major changes:

- Added `Session::is_nightly_build()`, which uses the `crate_name` of
the session
- Added `nightly_options::match_is_nightly_build`, a convenience method
for looking up `--crate-name` from CLI arguments.
`Session::is_nightly_build()`should be preferred where possible, since
it will take into account `#![crate_name]` (I think).
- Added `unstable_features` to `rustdoc::RenderOptions`

  There is a user-facing change here: things like `RUSTC_BOOTSTRAP=0` no
  longer active nightly features. In practice this shouldn't be a big
  deal, since `RUSTC_BOOTSTRAP` is the opposite of stable and everyone
  uses `RUSTC_BOOTSTRAP=1` anyway.

- Add tests

  Check against `Cheat`, not whether nightly features are allowed.
  Nightly features are always allowed on the nightly channel.

- Only call `is_nightly_build()` once within a function

- Use booleans consistently for rustc_incremental

  Sessions can't be passed through threads, so `read_file` couldn't take a
  session. To be consistent, also take a boolean in `write_file_header`.
2020-11-07 13:45:11 -05:00
..
src Allow making RUSTC_BOOTSTRAP conditional on the crate name 2020-11-07 13:45:11 -05:00
Cargo.toml Upgrade to tracing 0.2.13 2020-10-07 19:27:10 -04:00
README.md mv compiler to compiler/ 2020-08-30 18:45:07 +03:00

The driver crate is effectively the "main" function for the rust compiler. It orchestrates the compilation process and "knits together" the code from the other crates within rustc. This crate itself does not contain any of the "main logic" of the compiler (though it does have some code related to pretty printing or other minor compiler options).

For more information about how the driver works, see the rustc dev guide.