Remove `DropArena`.
Most arena-allocate types that impl `Drop` get their own `TypedArena`, but a
few infrequently used ones share a `DropArena`. This sharing adds complexity
but doesn't help performance or memory usage. Perhaps it was more effective in
the past prior to some other improvements to arenas.
This commit removes `DropArena` and the sharing of arenas via the `few`
attribute of the `arena_types` macro. This change removes over 100 lines of
code and nine uses of `unsafe` (one of which affects the parallel compiler) and
makes the remaining code easier to read.
Rollup of 8 pull requests
Successful merges:
- #86455 (check where-clause for explicit `Sized` before suggesting `?Sized`)
- #90801 (Normalize both arguments of `equate_normalized_input_or_output`)
- #90803 (Suggest `&str.chars()` on attempt to `&str.iter()`)
- #90819 (Fixes incorrect handling of TraitRefs when emitting suggestions.)
- #90910 (fix getting the discriminant of a zero-variant enum)
- #90925 (rustc_mir_build: reorder bindings)
- #90928 (Use a different server for checking clock drift)
- #90936 (Add a regression test for #80772)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
rustc_mir_build: reorder bindings
No functional changes intended.
I'm playing around with building compiler components using nightly rust
(2021-11-02) in a non-standard way. I encountered the following error while
trying to build rustc_mir_build:
```
error[E0597]: `wildcard` does not live long enough
--> rust/src/nightly/compiler/rustc_mir_build/src/build/matches/mod.rs:1767:82
|
1767 | let mut otherwise_candidate = Candidate::new(expr_place_builder.clone(), &wildcard, false);
| ^^^^^^^^^ borrowed value does not live long enough
...
1799 | }
| -
| |
| `wildcard` dropped here while still borrowed
| borrow might be used here, when `guard_candidate` is dropped and runs the destructor for type `Candidate<'_, '_>`
|
= note: values in a scope are dropped in the opposite order they are defined
```
I believe this flags an issue that may become an error in the future.
Swapping the order of `wildcard` and `guard_candidate` resolves it.
Fixes incorrect handling of TraitRefs when emitting suggestions.
Closes#90804 , although there were more issues here that were hidden by the thing that caused this ICE.
Underlying problem was that substitutions were being thrown out, which not only leads to an ICE but also incorrect diagnostics. On top of that, in some cases the self types from the root obligations were being mixed in with those from derived obligations.
This makes a couple diagnostics arguable worse ("`B<C>` does not implement `Copy`" instead of "`C` does not implement `Copy`") but the worse diagnostics are at least still correct and that downside is in my opinion clearly outweighed by the benefits of fixing the ICE and unambiguously wrong diagnostics.
check where-clause for explicit `Sized` before suggesting `?Sized`
Fixes#85945.
Based on #86454.
``@rustbot`` label +A-diagnostics +A-traits +A-typesystem +D-papercut +T-compiler
Address performance regression introduced by #90218
As part of the changes in #90218 , the `adt_drop_tys` and friends code stopped recursing through the query system, meaning that intermediate computations did not get cached. This change adds the recursions back in without re-introducing any of the old issues.
On local benchmarks this fixes the 5% regressions in #90504 ; the wg-grammar regressions didn't seem to move too much. I may take some time later to look into those.
Not sure who to request for review here, so will leave it up to whoever gets it.
Android is not GNU
For a long time, the Android targets had `target_env=""`, but this changed to `"gnu"` in Rust 1.49.0. I tracked this down to #77729 which started setting `"gnu"` in the `linux_base` target options, and this was inherited by `android_base`. Then #78929 split the env into `linux_gnu_base`, but `android_base` was also changed to follow that. Android was not specifically mentioned in either pull request, so I believe this was an accident. Moving it back to `linux_base` will use an empty `env` again.
r? ````@Mark-Simulacrum````
cc ````@petrochenkov````
Assoc item cleanup Part 2
- Remove `AssocItem` from `RegionVariableOrigin::AutoRef`
- Use the `associated_item_def_ids` query instead of the `associated_items` query when possible
The change to `ObligationCauseCode` from #90639 is omitted because it caused a perf regression.
r? `@cjgillot`
stabilize format args capture
Works as expected, and there are widespread reports of success with it, as well as interest in it.
RFC: rust-lang/rfcs#2795
Tracking issue: https://github.com/rust-lang/rust/issues/67984
Addressing items from the tracking issue:
- We don't support capturing arguments from a non-literal format string like `format_args!(concat!(...))`. We could add that in a future enhancement, or we can decide that it isn't supported (as suggested in https://github.com/rust-lang/rust/issues/67984#issuecomment-801394736 ).
- I've updated the documentation.
- `panic!` now supports capture as well.
- There are potentially opportunities to further improve diagnostics for invalid usage, such as if it looks like the user tried to use an expression rather than a variable. However, such cases are all already caught and provide reasonable syntax errors now, and we can always provided even friendlier diagnostics in the future.
No functional changes intended.
I'm playing around with building compiler components using nightly rust
(2021-11-02) in a non-standard way. I encountered the following error while
trying to build rustc_mir_build:
```
error[E0597]: `wildcard` does not live long enough
--> rust/src/nightly/compiler/rustc_mir_build/src/build/matches/mod.rs:1767:82
|
1767 | let mut otherwise_candidate = Candidate::new(expr_place_builder.clone(), &wildcard, false);
| ^^^^^^^^^ borrowed value does not live long enough
...
1799 | }
| -
| |
| `wildcard` dropped here while still borrowed
| borrow might be used here, when `guard_candidate` is dropped and runs the destructor for type `Candidate<'_, '_>`
|
= note: values in a scope are dropped in the opposite order they are defined
```
I believe this flags an issue that may become an error in the future.
Swapping the order of `wildcard` and `guard_candidate` resolves it.
Fix ld64 flags
- The `-exported_symbols_list` argument appears to be malformed for `ld64` (if you are not going through `clang`).
- The `-dynamiclib` argument isn't support for `ld64`. It should be guarded behind a compiler flag.
These problems are fixed by these changes. I have also refactored the way linker arguments are generated to be ld/compiler agnostic and therefore less error prone.
These changes are necessary to support cross-compilation to darwin targets.
Leave -Z strip available temporarily as an alias, to avoid breaking
cargo until cargo transitions to using -C strip. (If the user passes
both, the -C version wins.)
Tweak the `options!` macro to allow for -Z and -C options with the same
name without generating conflicting internal parsing functions.
Split out of the commit stabilizing -Z strip as -C strip.
Most arena-allocate types that impl `Drop` get their own `TypedArena`, but a
few infrequently used ones share a `DropArena`. This sharing adds complexity
but doesn't help performance or memory usage. Perhaps it was more effective in
the past prior to some other improvements to arenas.
This commit removes `DropArena` and the sharing of arenas via the `few`
attribute of the `arena_types` macro. This change removes over 100 lines of
code and nine uses of `unsafe` (one of which affects the parallel compiler) and
makes the remaining code easier to read.
Implement diagnostic for String conversion
This is my first real contribution to rustc, any feedback is highly appreciated.
This should fix https://github.com/rust-lang/rust/issues/89856
Thanks to `@estebank` for guiding me.
check if `String` or `&String` or `&str`
Update compiler/rustc_typeck/src/check/method/suggest.rs
Co-authored-by: Esteban Kuber <estebank@users.noreply.github.com>
remove some trailing whitespace
Generate documentation in rustc `rustc_index::newtype_index` macro
The macro now documents all generated items. Documentation notes possible panics and unsafety.
This commit refactors linker argument generation to leverage a helper
function that abstracts away details governing how these arguments are
transformed and provided to the linker.
This fixes the misuse of the `-exported_symbols_list` when an ld-like
linker is used rather than a compiler. A compiler would expect
`-Wl,-exported_symbols_list,path` but ld would expect
`-exported_symbols_list` and `path` as two seperate arguments. Prior
to this change, an ld-like linker was given
`-exported_symbols_list,path`.
Linker arguments must transformed when Rust is interacting with the
linker through a compiler. This commit introduces a helper function
that abstracts away details of this transformation.
Fix trait object error code
closes#90768
I `grep`:d and changed the occurrences that seemed relevant. Please let me know what you think and if anything is missing!
When suggesting references, substitutions were being forgotten and some types were misused. This led to at
least one ICE and other incorrectly emitted diagnostics. This has been fixed; in some cases this leads to
diagnostics changing, and tests have been adjusted.
Stabilize `const_raw_ptr_deref` for `*const T`
This stabilizes dereferencing immutable raw pointers in const contexts.
It does not stabilize `*mut T` dereferencing. This is behind the
same feature gate as mutable references.
closes https://github.com/rust-lang/rust/issues/51911
proc_macro: Add an expand_expr method to TokenStream
This feature is aimed at giving proc macros access to powers similar to those used by builtin macros such as `format_args!` or `concat!`. These macros are able to accept macros in place of string literal parameters, such as the format string, as they perform recursive macro expansion while being expanded.
This can be especially useful in many cases thanks to helper macros like `concat!`, `stringify!` and `include_str!` which are often used to construct string literals at compile-time in user code.
For now, this method only allows expanding macros which produce literals, although more expressions will be supported before the method is stabilized.
In earlier versions of this PR, this method exclusively returned `Literal`, and spans on returned literals were stripped of expansion context before being returned to be as conservative as possible about permission leakage. The method's naming has been generalized to eventually support arbitrary expressions, and the context stripping has been removed (https://github.com/rust-lang/rust/pull/87264#discussion_r674863279), which should allow for more general APIs like "format_args_implicits" (https://github.com/rust-lang/rust/issues/67984) to be supported as well.
## API Surface
```rust
impl TokenStream {
pub fn expand_expr(&self) -> Result<TokenStream, ExpandError>;
}
#[non_exhaustive]
pub struct ExpandError;
impl Debug for ExpandError { ... }
impl Display for ExpandError { ... }
impl Error for ExpandError {}
impl !Send for ExpandError {}
impl !Sync for ExpandError {}
```
This feature is aimed at giving proc macros access to powers similar to
those used by builtin macros such as `format_args!` or `concat!`. These
macros are able to accept macros in place of string literal parameters,
such as the format string, as they perform recursive macro expansion
while being expanded.
This can be especially useful in many cases thanks to helper macros like
`concat!`, `stringify!` and `include_str!` which are often used to
construct string literals at compile-time in user code.
For now, this method only allows expanding macros which produce
literals, although more expresisons will be supported before the method
is stabilized.
Shorten Span of unused macro lints
The span has been reduced to the actual ident of the macro, instead of linting the
*whole* macro.
Closes#90745
r? ``@estebank``
