Let Cargo track CLIPPY_ARGS
This PR makes `clippy-driver` emit `CLIPPY_ARGS` in its `dep-info` output.
Just like #6441, this allows this workflow to work:
```shell
cargo clippy # warning: empty `loop {}` wastes CPU cycles
cargo clippy -- -A clippy::empty_loop # no warnings emitted
```
But without rebuilding all dependencies.
cc https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/CLIPPY_ARGS.20is.20not.20tracked.20by.20Cargo/near/228599088
changelog: Cargo now re-runs Clippy if arguments after `--` provided to `cargo clippy` are changed.
Adds checks for:
* `no_core` attribute
* explicitly-enabled `legacy` symbol mangling
* mir_opt_level > 1 (which enables inlining)
I removed code from the `Inline` MIR pass that forcibly disabled
inlining if `-Zinstrument-coverage` was set. The default `mir_opt_level`
does not enable inlining anyway. But if the level is explicitly set and
is greater than 1, I issue a warning.
The new warnings show up in tests, which is much better for diagnosing
potential option conflicts in these cases.
RunCompiler::new takes non-optional params, and optional
params can be set using set_*field_name* method.
finally `run` will forward all fields to `run_compiler`.
Add option to pass a custom codegen backend from a driver
This allows the driver to pass information to the codegen backend. For example the headcrab debugger may in the future want to use cg_clif to JIT code to be injected in the debuggee. This would PR make it possible to tell cg_clif which symbol can be found at which address and to tell it to inject the JITed code into the right process.
This PR may also help with https://github.com/rust-lang/miri/pull/1540 by allowing miri to provide a codegen backend that only emits metadata and doesn't perform any codegen.
cc @nbaksalyar (headcrab)
cc @RalfJung (miri)
Update Clippy, RLS, and rustfmt
r? @Dylan-DPC
This makes Clippy test-pass again: 3089c3b
Otherwise this includes bugfixes and a few new lints.
Fixes#72231Fixes#72232
rustc_driver: factor out computing the exit code
In a recent Miri PR I [added a convenience wrapper](https://github.com/rust-lang/miri/pull/1405/files#diff-c3d602c5c8035a16699ce9c015bfeceaR125) around `catch_fatal_errors` and `run_compiler` that @oli-obk suggested I could upstream. However, after seeing what could be shared between `rustc_driver::main`, clippy and Miri, really the only thing I found is computing the exit code -- so that's what this PR does.
What prevents using the Miri convenience function in `rustc_driver::main` and clippy is that they do extra work inside `catch_fatal_errors`, and while I could abstract that away, clippy actually *computes the callbacks* inside there, and I fond no good way to abstract that and thus gave up. Maybe the clippy thing could be moved out, I am not sure if it ever can actually raise a `FatalErrorMarker` -- someone more knowledgeable in clippy would have to do that.
New lint `match_vec_item`
Added new lint to warn a match on index item which can panic. It's always better to use `get(..)` instead.
Closes#5500
changelog: New lint `match_on_vec_items`
