syntax: Make `_` a reserved identifier
Why:
- Lexically `_` is an identifier.
- Internally it makes implementation of `use Trait as _;` (https://github.com/rust-lang/rust/issues/48216) and some other things cleaner.
- We prevent the externally observable effect of `_` being accepted by macros expecting `ident` by treating `_` specially in the `ident` matcher:
```rust
macro_rules! m {
($i: ident) => { let $i = 10; }
}
m!(_); // Still an error
```
Checks for unknown attributes before aborting due to unresolved macros
Fixes#49074
The ``attribute `...` is currently unknown to the compiler`` error was not shown if there are any unresolved macros, which might be caused by mistyped `macro_use`.
Faster submodule updating
For the common case when there are no submodules which need updating, this takes 0.48 seconds instead of 47 seconds.
r? @alexcrichton
Support extra-verbose builds
- The bootstrap crate currently passes -v to Cargo if itself invoked with -vv. But Cargo supports -vv (to show build script output), so make bootstrap pass that if itself invoked with -vvv. (More specifically, pass N '-v's to Cargo if invoked with N+1 of them.)
- bootstrap.py currently tries to pass on up to two '-v's to cargo when building bootstrap, but incorrectly ('-v' is marked as 'store_true', so argparse stores either False or True, ignoring multiple '-v's). Fix this, allow passing any number of '-v's, and make it consistent with bootstrap's invocation of Cargo (i.e. subtract one from the number of '-v's).
- Also improve bootstrap.py's config.toml 'parsing' to support arbitrary verbosity levels, + allow command line to override it.
incr.comp.: Make sanity check in try_mark_green() aware of error conditions.
Before this PR, `DepGraph::try_mark_green()` assumed that forcing a query would always set the color of the corresponding dep-node. However, it did not take into account that queries could also fail (e.g. with a cycle error). This PR makes the method handle that condition gracefully.
Fixes#49070.
r? @nikomatsakis
rustc: Enable embedding LLVM bitcode for iOS
This commit updates rustc to embed bitcode in each object file generated by
default when compiling for iOS. This was determined in #35968 as a step
towards better compatibility with the iOS toolchain, so let's give it a spin and
see how it turns out!
Note that this also updates the `cc` dependency which should propagate this
change of embedding bitcode for C dependencies as well.
Make `assert` a built-in procedural macro
Makes `assert` macro a built-in one without touching its functionality. This is a prerequisite for RFC 2011 (#44838).
check stability of macro invocations
I haven't implemented tests yet but this should be a pretty solid prototype. I think as-implemented it will also stability-check macro invocations in the same crate, dunno if we want that or not.
I don't know if we want this to go through `rustc::middle::stability` or not, considering the information there wouldn't be available at the time of macro expansion (even for external crates, right?).
r? @nrc
closes#34079
cc @petrochenkov @durka @jseyfried #38356
- The bootstrap crate currently passes -v to Cargo if itself invoked
with -vv. But Cargo supports -vv (to show build script output), so make
bootstrap pass that if itself invoked with -vvv. (More specifically,
pass N '-v's to Cargo if invoked with N+1 of them.)
- bootstrap.py currently tries to pass on up to two '-v's to cargo when
building bootstrap, but incorrectly ('-v' is marked as 'store_true', so
argparse stores either False or True, ignoring multiple '-v's). Fix
this, allow passing any number of '-v's, and make it consistent with
bootstrap's invocation of Cargo (i.e. subtract one from the number of
'-v's).
- Also improve bootstrap.py's config.toml 'parsing' to support arbitrary
verbosity levels, + allow command line to override it.
Unstabilize FusedIterator for Flatten since Flatten is unstable
PR #47463 made `impl<I, U> FusedIterator for Flatten<I>` stable but shouldn't have since `Flatten` is still unstable. This PR makes the impl unstable again.
