This removes the Cell from AdtDef. Also, moving destructor validity
checking to on-demand (forced during item-type checking) ensures that
invalid destructors can't cause ICEs.
Fixes#38868.
Fixes#40132.
Refactor the parser to consume token trees
This is groundwork for efficiently parsing attribute proc macro invocations, bang macro invocations, and `TokenStream`-based attributes and fragment matchers.
This improves parsing performance by 8-15% and expansion performance by 0-5% on a sampling of the compiler's crates.
r? @nrc
Cleanup refactoring around DefPath handling
This PR makes two big changes:
* All DefPaths of a crate are now stored in metadata in their own table (as opposed to `DefKey`s as part of metadata `Entry`s.
* The compiler will no longer allocate a pseudo-local DefId for inlined HIR nodes (because those are gross). Inlined HIR nodes will have a NodeId but they don't have there own DefId anymore. Turns out they were not needed anymore either. Hopefully HIR inlining will be gone completely one day but if until then we start needing to be able to map inlined NodeIds to original DefIds, we can add an additional table to metadata that allows for reconstructing this.
Overall this makes for some nice simplifications and removal of special cases.
r? @eddyb
cc @rust-lang/compiler
[9/n] rustc: move type information out of AdtDef and TraitDef.
_This is part of a series ([prev](https://github.com/rust-lang/rust/pull/37688) | [next]()) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well.
If any motivation is unclear, please ask for additional PR description clarifications or code comments._
<hr>
Both `AdtDef` and `TraitDef` contained type information (field types, generics and predicates) which was required to create them, preventing their use before that type information exists, or in the case of field types, *mutation* was required, leading to a variance-magicking implementation of `ivar`s.
This PR takes that information out and the resulting cleaner setup could even eventually end up merged with HIR, because, just like `AssociatedItem` before it, there's no dependency on types anymore.
(With one exception, variant discriminants should probably be moved into their own map later.)
This commit is an implementation of [RFC 1721] which adds a new target feature
to the compiler, `crt-static`, which can be used to select how the C runtime for
a target is linked. Most targets dynamically linke the C runtime by default with
the notable exception of some of the musl targets.
[RFC 1721]: https://github.com/rust-lang/rfcs/blob/master/text/1721-crt-static.md
This commit first adds the new target-feature, `crt-static`. If enabled, then
the `cfg(target_feature = "crt-static")` will be available. Targets like musl
will have this enabled by default. This feature can be controlled through the
standard target-feature interface, `-C target-feature=+crt-static` or
`-C target-feature=-crt-static`.
Next this adds an gated and unstable `#[link(cfg(..))]` feature to enable the
`crt-static` semantics we want with libc. The exact behavior of this attribute
is a little squishy, but it's intended to be a forever-unstable
implementation detail of the liblibc crate.
Specifically the `#[link(cfg(..))]` annotation means that the `#[link]`
directive is only active in a compilation unit if that `cfg` value is satisfied.
For example when compiling an rlib, these directives are just encoded and
ignored for dylibs, and all staticlibs are continued to be put into the rlib as
usual. When placing that rlib into a staticlib, executable, or dylib, however,
the `cfg` is evaluated *as if it were defined in the final artifact* and the
library is decided to be linked or not.
Essentially, what'll happen is:
* On MSVC with `-C target-feature=-crt-static`, the `msvcrt.lib` library will be
linked to.
* On MSVC with `-C target-feature=+crt-static`, the `libcmt.lib` library will be
linked to.
* On musl with `-C target-feature=-crt-static`, the object files in liblibc.rlib
are removed and `-lc` is passed instead.
* On musl with `-C target-feature=+crt-static`, the object files in liblibc.rlib
are used and `-lc` is not passed.
This commit does **not** include an update to the liblibc module to implement
these changes. I plan to do that just after the 1.14.0 beta release is cut to
ensure we get ample time to test this feature.
cc #37406
