Download crosstool-ng from GitHub
Workaround the current problem where http://crosstool-ng.org was done, causing all non-x86 jobs to fail spuriously (cc #40474).
If http://crosstool-ng.org becomes online before this PR is merged, this PR should be closed and the tree should be reopened.
This is meant to ease development of multi-stage dataflow analyses
where the output from one analysis is used to initialize the state
for the next; in such a context, you cannot start with `bottom_value`
for all the bits.
Converting a `RegionElementIndex` to a `Location` is O(n) though could
trivially be O(log n), but we don't do it that much anyhow -- just on
error and debugging.
macros: hygienize use of `core`/`std` in builtin macros
Today, if a builtin macro wants to access an item from `core` or `std` (depending `#![no_std]`), it generates `::core::path::to::item` or `::std::path::to::item` respectively (c.f. `fn std_path()` in `libsyntax/ext/base.rs`).
This PR refactors the builtin macros to instead always emit `$crate::path::to::item` here. That is, the def site of builtin macros is taken to be in `extern crate core;` or `extern crate std;`. Since builtin macros are macros 1.0 (i.e. mostly unhygienic), changing the def site can only effect the resolution of `$crate`.
r? @nrc
Record all imports (`use`, `extern crate`) in the crate metadata
This PR adds non-`pub` `use` and `extern crate` imports in the crate metadata since hygienic macros invoked in other crates may use them. We already include all other non-`pub` items in the crate metadata. This improves import suggestions in some cases.
Fixes#42337.
r? @nrc
Having the HIR local id is useful for cases like understanding the
ReScope identifiers, which are now derived from the HIR local id, and
thus one can map an ReScope back to the HIR node, once one knows what
those local ids are.
Implement impl Trait lifetime elision
Fixes#43396.
There's one weird ICE in the interaction with argument-position `impl Trait`. I'm still debugging it-- I've left a test for it commented out with a FIXME.
Also included a FIXME to ensure that `impl Trait` traits are caught under the lint in https://github.com/rust-lang/rust/issues/45992.
r? @nikomatsakis
