Avoid exponential behaviour when relating types
When equating bound types we check subtyping in both directions. Since closures are invariant in their substs, we end up comparing the two types an exponential number of times. If there are no bound variables this isn't needed.
Closes#68061
parser: syntactically allow `self` in all `fn` contexts
Part of https://github.com/rust-lang/rust/pull/68728.
`self` parameters are now *syntactically* allowed as the first parameter irrespective of item context (and in function pointers). Instead, semantic validation (`ast_validation`) is used.
r? @petrochenkov
Suggest path separator for single-colon typos
This commit adds guidance for when a user means to type a path, but ends
up typing a single colon, such as `<<Impl as T>:Ty>`.
This change seemed pertinent as the current error message is
particularly misleading, emitting `error: unmatched angle bracket`,
despite the angle bracket being matched later on, leaving the user to
track down the typo'd colon.
Slimmer syntax
High-level summary of changes:
- The `syntax::node_count` pass is moved into `rustc_ast_passes`. This works towards improving #65031 by making compiling `syntax` go faster.
- The `syntax::{GLOBALS, with_globals, ..}` business is consolidated into `syntax::attr` for cleaner code and future possible improvements.
- The pretty printer loses its dependency on `ParseSess`, opting to use `SourceMap` & friends directly instead.
- Some drive by cleanup of `syntax::attr::HasAttr` happens.
- Builtin attribute logic (`syntax::attr::builtin`) + `syntax::attr::allow_internal_unstable` is moved into a new `rustc_attr` crate. More logic from `syntax::attr` should be moved into that crate over time. This also means that `syntax` loses all mentions of `ParseSess`, which enables the next point.
- The pretty printer `syntax::print` is moved into a new crate `rustc_ast_pretty`.
- `rustc_session::node_id` is moved back as `syntax::node_id`. As a result, `syntax` gets to drop dependencies on `rustc_session` (and implicitly `rustc_target`), `rustc_error_codes`, and `rustc_errors`. Moreover `rustc_hir` gets to drop its dependency on `rustc_session` as well. At this point, these crates are mostly "pure data crates", which is approaching a desirable end state.
- We should consider renaming `syntax` to `rustc_ast` now.
Add support for Control Flow Guard on Windows.
LLVM now supports Windows Control Flow Guard (CFG): d157a9bc8b
This patch adds support for rustc to emit the required LLVM module flags to enable CFG metadata (cfguard=1) or metadata and checks (cfguard=2). The LLVM module flags are ignored on unsupported targets and operating systems.
Remove incorrect debug assertions from catch_unwind
Previously the debug assertions in the implementation of catch_unwind
used to verify consistency of the panic count by checking that the count
is zero just before leaving the function. This incorrectly assumed that
no panic was in progress when entering `catch_unwind`.
Fixes#68696.
Address inconsistency in using "is" with "declared here"
"is" was generally used for NLL diagnostics, but not other diagnostics. Using "is" makes the diagnostics sound more natural and readable, so it seems sensible to commit to them throughout.
r? @Centril
clarify "incorrect issue" error
Changes the message to be more precise, shrinks the span and adds a label specifying why the `issue` field is incorrect.
Change opt-level from 2 back to 3
In Cargo.toml, the opt-level for `release` and `bench` was overridden to be 2. This was to work around a problem with LLVM 7. However, rust no longer uses LLVM 7, so this is hopefully no longer needed?
I tried a little bit to replicate the original problem, and could not. I think running this through CI is the best way to smoke test this :) Even if things break dramatically, the comment should be updated to reflect that things are still broken with LLVM 9.
I'm just getting started playing with the compiler, so apologies if I've missed an obvious problem here.
fixes#52378
(possibly relevant is the [current update to LLVM 10](https://github.com/rust-lang/rust/pull/67759))
Previously the debug assertions in the implementation of catch_unwind
used to verify consistency of the panic count by checking that the count
is zero just before leaving the function. This incorrectly assumed that
no panic was in progress when entering `catch_unwind`.
This commit adds guidance for when a user means to type a path, but ends
up typing a single colon, such as `<<Impl as T>:Ty>`.
This change seemed pertinent as the current error message is
particularly misleading, emitting `error: unmatched angle bracket`,
despite the angle bracket being matched later on, leaving the user to
track down the typo'd colon.
In Cargo.toml, the opt-level for `release` and `bench` was
overridden to be 2. This was to work around a problem with LLVM
7. However, rust no longer uses LLVM 7, so this is no longer
needed.
This creates a small compile time regression in MIR constant eval,
so I've added a #[inline(always)] on the `step` function used in
const eval
Also creates a binary size increase in wasm-stringify-ints-small,
so I've bumped the limit there.
Move numeric consts to associated consts step1
A subset of #67913. Implements the first step of RFC https://github.com/rust-lang/rfcs/pull/2700
This PR adds the new constants as unstable constants and defines the old ones in terms of the new ones. Then fix a tiny bit of code that started having naming collisions because of the new assoc consts.
Removed a test that did not seem relevant any longer. Since doing just `u8::MIN` should now indeed be valid.
Rollup of 7 pull requests
Successful merges:
- #67722 (Minor: note how Any is an unsafe trait in SAFETY comments)
- #68586 (Make conflicting_repr_hints a deny-by-default c-future-compat lint)
- #68598 (Fix null synthetic_implementors error)
- #68603 (Changelog: Demonstrate final build-override syntax)
- #68609 (Set lld flavor for MSVC to link.exe)
- #68611 (Correct ICE caused by macros generating invalid spans.)
- #68627 (Document that write_all will not call write if given an empty buffer)
Failed merges:
r? @ghost
Detect use-after-scope bugs with AddressSanitizer
Enable use-after-scope checks by default when using AddressSanitizer.
They allow to detect incorrect use of stack objects after their scope
have already ended. The detection is based on LLVM lifetime intrinsics.
To facilitate the use of this functionality, the lifetime intrinsics are
now emitted regardless of optimization level if enabled sanitizer makes
use of them.
rustdoc: Fix re-exporting primitive types
* Generate links to the primitive type docs for re-exports.
* Don't ICE on cross crate primitive type re-exports.
* Make primitive type re-exports show up cross crate.
Fixes#67646Closes#67972
r? @GuillaumeGomez
Don't ICE on path-collision in dep-graph
Collisions in the dep-graph due to path-reuse are rare but can occur.
So, instead of ICE'ing, just fail to mark green in such cases (for `DepKind::{Hir, HirBody, CrateMetadata}`).
Fix#62649.
This patch enables rustc to emit the required LLVM module flags to enable Control Flow Guard metadata (cfguard=1) or metadata and checks (cfguard=2). The LLVM module flags are ignored on unsupported targets and operating systems.
Rename `Alloc` to `AllocRef`
The allocator-wg has decided to merge this change upstream in https://github.com/rust-lang/wg-allocators/issues/8#issuecomment-577122958.
This renames `Alloc` to `AllocRef` because types that implement `Alloc` are a reference, smart pointer, or ZSTs. It is not possible to have an allocator like `MyAlloc([u8; N])`, that owns the memory and also implements `Alloc`, since that would mean, that moving a `Vec<T, MyAlloc>` would need to correct the internal pointer, which is not possible as we don't have move constructors.
For further explanation please see https://github.com/rust-lang/wg-allocators/issues/8#issuecomment-489464843 and the comments after that one.
Additionally it clarifies the semantics of `Clone` on an allocator. In the case of `AllocRef`, it is clear that the cloned handle still points to the same allocator instance, and that you can free data allocated from one handle with another handle.
The initial proposal was to rename `Alloc` to `AllocHandle`, but `Ref` expresses the semantics better than `Handle`. Also, the only appearance of `Handle` in `std` are for windows specific resources, which might be confusing.
Blocked on https://github.com/rust-lang/miri/pull/1160
