`description` has been documented as soft-deprecated since 1.27.0 (17
months ago). There is no longer any reason to call it or implement it.
This commit:
- adds #[rustc_deprecated(since = "1.41.0")] to Error::description;
- moves description (and cause, which is also deprecated) below the
source and backtrace methods in the Error trait;
- reduces documentation of description and cause to take up much less
vertical real estate in rustdocs, while preserving the example that
shows how to render errors without needing to call description;
- removes the description function of all *currently unstable* Error
impls in the standard library;
- marks #[allow(deprecated)] the description function of all *stable*
Error impls in the standard library;
- replaces miscellaneous uses of description in example code and the
compiler.
This commit builds on #65501 continue to simplify the build system and
compiler now that we no longer have multiple LLVM backends to ship by
default. Here this switches the compiler back to what it once was long
long ago, which is linking LLVM directly to the compiler rather than
dynamically loading it at runtime. The `codegen-backends` directory of
the sysroot no longer exists and all relevant support in the build
system is removed. Note that `rustc` still supports a dynamically loaded
codegen backend as it did previously, it just no longer supports
dynamically loaded codegen backends in its own sysroot.
Additionally as part of this the `librustc_codegen_llvm` crate now once
again explicitly depends on all of its crates instead of implicitly
loading them through the sysroot. This involved filling out its
`Cargo.toml` and deleting all the now-unnecessary `extern crate`
annotations in the header of the crate. (this in turn required adding a
number of imports for names of macros too).
The end results of this change are:
* Rustbuild's build process for the compiler as all the "oh don't forget
the codegen backend" checks can be easily removed.
* Building `rustc_codegen_llvm` is much simpler since it's simply
another compiler crate.
* Managing the dependencies of `rustc_codegen_llvm` is much simpler since
it's "just another `Cargo.toml` to edit"
* The build process should be a smidge faster because there's more
parallelism in the main rustc build step rather than splitting
`librustc_codegen_llvm` out to its own step.
* The compiler is expected to be slightly faster by default because the
codegen backend does not need to be dynamically loaded.
* Disabling LLVM as part of rustbuild is still supported, supporting
multiple codegen backends is still supported, and dynamic loading of a
codegen backend is still supported.
Feature gating *declarations* => new crate `rustc_feature`
This PR moves the data-oriented parts of feature gating into its own crate, `rustc_feature`.
The parts consist of some data types as well as `accepted`, `active`, `removed`, and `builtin_attrs`.
Feature gate checking itself remains in `syntax::feature_gate::check`. The parts which define how to emit feature gate errors could probably be moved to `rustc_errors` or to the new `rustc_session` crate introduced in #66878. The visitor itself could probably be moved as a pass in `rustc_passes` depending on how the dependency edges work out.
The PR also contains some drive-by cleanup of feature gate checking. As such, the PR probably best read commit-by-commit.
r? @oli-obk
cc @petrochenkov
cc @Mark-Simulacrum
Remove pretty printing of specific nodes in AST
The ability to print a specific item as identified by NodeId or path
seems not particularly useful, and certainly carries quite a bit of
complexity with it.
This is intended to simplify our CLI parsing a bit and remove a
non-uncomplicated piece of it; I largely did this to remove the
dependency on NodeId from librustc/session but it's not really
necessary to do so in this invasive a way. The alternative is
moving it to librustc_interface or driver, probably.
The ability to print a specific item as identified by NodeId or path
seems not particularly useful, and certainly carries quite a bit of
complexity with it.
Function source_name declared in file
src/librustc_driver/lib.rs
is a duplicate of a function by the same name declared in file
src/librustc/session/config.rs
Add a callback that allows compiler consumers to override queries.
This pull request adds an additional callback that allows compiler consumers such as Prusti and MIRAI to override queries. My hope is that in this way it will be possible to get access to the internal compiler information (e.g. borrow checker) without major changes to the compiler.
This pull request is work in progress because I am still testing if I can get the information which I need.
cc @nikomatsakis
r? @oli-obk
