Re-implement proc-macro feature decoupling.
This is essentially a rewrite of #8003. Instead of adding proc-macro to the index, it uses a strategy of downloading all packages before doing feature resolution. Then the package can be inspected for the proc-macro field.
This is a fairly major change. A brief overview:
- `PackageSet` now has a `download_accessible` method which tries to download a minimal set of every accessible package. This isn't very smart right now, and errs on downloading too much. In most cases it should be the same (or nearly the same) as before. It downloads extra in the following cases:
- The check for `[target]` dependencies checks both host and target for every dependency. I could tighten that up a little so build dependencies only check for the host, but it would add some complexity and I wanted to get feedback first.
- Optional dependencies disabled by the new feature resolver will get downloaded.
- Removed the loop in computing unit dependencies where downloading used to reside.
- When downloading starts, it should now show a more accurate count of how many crates are to be downloaded. Previously the count would fluctuate while the graph is being built.
Add proc-macro to index, and new feature resolver.
This adds the "pm" field to the index so that Cargo can detect which packages contain a proc-macro without downloading the package.
The second commit builds on that to support proc-macros in the new "de-unification" of the new feature resolver. This prevents dependencies shared between proc-macros and other dependency kinds from having features unified.
cc #7915
Generalized `clippy_is_available` and renamed as `command_is_available`.
No checks in `ignores_failure_to_format_source`, it's not supposed to
use `rustfmt` even if it's available
The `anyhow` crate interoperates with the `std::error::Error` trait
rather than a custom `Fail` trait, and this is the general trend of
error handling in Rust as well.
Note that this is mostly mechanical (sed) and intended to get the test
suite passing. As usual there's still more idiomatic cleanup that can
happen, but that's left to later commits.
Refactor `Kind` to carry target name in `Target`
This commit is an internal refactoring of Cargo's compilation backend to
eventually support compiling multiple target simultaneously. The
original motivation for this came up in discussion of #7297 and this has
long been something I've intended to update Cargo for. Nothing in the
backend currently exposes the ability to actually build multiple target
simultaneously, but this should have no function change with respect to
all current consumers. Eventually we'll need to refactor APIs of how you
enter the compilation backend to compile for multiple targets.
This commit is an internal refactoring of Cargo's compilation backend to
eventually support compiling multiple target simultaneously. The
original motivation for this came up in discussion of #7297 and this has
long been something I've intended to update Cargo for. Nothing in the
backend currently exposes the ability to actually build multiple target
simultaneously, but this should have no function change with respect to
all current consumers. Eventually we'll need to refactor APIs of how you
enter the compilation backend to compile for multiple targets.
Remove all `CARGO_*` env vars in tests
Usage of `CARGO_PROFILE_*` is generating unexpected warnings in tests in
rust-lang/rust#64316 so let's just blanket remove every env var that has
a `CARGO_*` prefix which generally means Cargo-specific env vars. Tests
practically all assume that they have blank configs right now.
Usage of `CARGO_PROFILE_*` is generating unexpected warnings in tests in
rust-lang/rust#64316 so let's just blanket remove every env var that has
a `CARGO_*` prefix which generally means Cargo-specific env vars. Tests
practically all assume that they have blank configs right now.
Only run these tests on one CI builder (not all platforms) though. This
is extremely resource intensive since it rebuilds libstd. Currently this
does not share a build directly like before because the number of tests
are supposed to be small, but if necessary we can add that in later too.
