Add help for `#![feature(impl_trait_in_fn_trait_return)]`
This adds a new variant `ImplTraitContext::FeatureGated`, so we can
generalize the help for `return_position_impl_trait_in_trait` to also
work for `impl_trait_in_fn_trait_return`.
cc #99697
Stop passing -export-dynamic to wasm-ld.
-export-dynamic was a temporary hack added in the early days of the Rust wasm32 target when Rust didn't have a way to specify wasm exports in the source code. This flag causes all global symbols, and some compiler-internal symbols, to be exported, which is often more than needed.
Rust now does have a way to specify exports in the source code: `#[export_name = "..."]`.
So as the original comment suggests, -export-dynamic can now be removed, allowing users to have smaller binaries and better encapsulation in their wasm32-unknown-unknown modules.
It's possible that this change will require existing wasm32-unknown-unknown users will to add explicit `#[export_name = "..."]` directives to exporrt the symbols that their programs depend on having exported.
make retagging work even with 'unstable' places
This is based on top of https://github.com/rust-lang/rust/pull/105301. Only the last two commits are new.
While investigating https://github.com/rust-lang/unsafe-code-guidelines/issues/381 I realized that we would have caught this issue much earlier if the add_retag pass wouldn't bail out on assignments of the form `*ptr = ...`.
So this PR changes our retag strategy:
- When a new reference is created via `Rvalue::Ref` (or a raw ptr via `Rvalue::AddressOf`), we do the retagging as part of just executing that address-taking operation.
- For everything else, we still insert retags -- these retags basically serve to ensure that references stored in local variables (and their fields) are always freshly tagged, so skipping this for assignments like `*ptr = ...` is less egregious.
r? ```@oli-obk```
Detect long types in E0308 and write them to disk
On type error with long types, print an abridged type and write the full type to disk.
Print the widest possible short type while still fitting in the terminal.
Currently, LLVM profiling runtime counter relocation cannot be
used by rust during LTO because symbols are being internalized
before all symbol information is known.
This mode makes LLVM emit a __llvm_profile_counter_bias symbol
which is referenced by the profiling initialization, which itself
is pulled in by the rust driver here [1].
It is enabled with -Cllvm-args=-runtime-counter-relocation for
platforms which are opt-in to this mode like Linux. On these
platforms there will be no link error, rather just surprising
behavior for a user which request runtime counter relocation.
The profiling runtime will not see that symbol go on as if it
were never there. On Fuchsia, the profiling runtime must have
this symbol which will cause a hard link error.
As an aside, I don't have enough context as to why rust's LTO
model is how it is. AFAICT, the internalize pass is only safe
to run at link time when all symbol information is actually
known, this being an example as to why. I think special casing
this symbol as a known one that LLVM can emit which should not
have it's visbility de-escalated should be fine given how
seldom this pattern of defining an undefined symbol to get
initilization code pulled in is. From a quick grep,
__llvm_profile_runtime is the only symbol that rustc does this
for.
[1] 0265a3e93b/compiler/rustc_codegen_ssa/src/back/linker.rs (L598)
normalize before handling simple checks for evaluatability of `ty::Const`
`{{{{{{{ N }}}}}}}` is desugared into a `ConstKind::Unevaluated` for an anonymous `const` item so when calling `is_const_evaluatable` on it we skip the `ConstKind::Param(_) => Ok(())` arm which is incorrect.
Simplify attribute handling in rustc_ast_lowering
Given that attributes is stored in a separate BTreeMap, it's not necessary to pass it in when constructing `hir::Expr`. We can just construct `hir::Expr` and then call `self.lower_attrs` later if it needs attributes.
As most desugaring code don't use attributes, this allows some code cleanup.
Remove `{Early,Late}LintPassObjects`.
`EarlyContextAndPass` wraps a single early lint pass. We aggregate multiple passes into that single pass by using `EarlyLintPassObjects`.
This commit removes `EarlyLintPassObjects` by changing `EarlyContextAndPass` into `EarlyContextAndPasses`. I.e. it just removes a level of indirection. This makes the code simpler and slightly faster.
The commit does likewise for late lints.
r? `@cjgillot`
This adds a new variant `ImplTraitContext::FeatureGated`, so we can
generalize the help for `return_position_impl_trait_in_trait` to also
work for `impl_trait_in_fn_trait_return`.
-export-dynamic was a temporary hack added in the early days of the Rust
wasm32 target when Rust didn't have a way to specify wasm exports in the
source code. This flag causes all global symbols, and some compiler-internal
symbols, to be exported, which is often more than needed.
Rust now does have a way to specify exports in the source code:
`#[export_name = "..."]`.
So as the original comment suggests, -export-dynamic can now be removed,
allowing users to have smaller binaries and better encapsulation in
their wasm32-unknown-unknown modules.
It's possible that this change will require existing wasm32-unknown-unknown
users will to add explicit `#[export_name = "..."]` directives to
exporrt the symbols that their programs depend on having exported.
Rollup of 9 pull requests
Successful merges:
- #104898 (Put all cached values into a central struct instead of just the stable hash)
- #105004 (Fix `emit_unused_delims_expr` ICE)
- #105174 (Suggest removing struct field from destructive binding only in shorthand scenario)
- #105250 (Replace usage of `ResumeTy` in async lowering with `Context`)
- #105286 (Add -Z maximal-hir-to-mir-coverage flag)
- #105320 (rustdoc: simplify CSS selectors on top-doc and non-exhaustive toggles)
- #105349 (Point at args in associated const fn pointers)
- #105362 (Cleanup macro-expanded code in `rustc_type_ir`)
- #105370 (Remove outdated syntax from trait alias pretty printing)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove outdated syntax from trait alias pretty printing
Given the following program:
```rust
#![feature(trait_alias)]
trait A = ?Sized;
fn main() {}
```
Old output of `rustc +nightly ./t.rs -Zunpretty=normal`:
```rust
#![feature(trait_alias)]
trait A for ? Sized ;
fn main() {}
```
New output of `rustc +a ./t.rs -Zunpretty=normal`:
```rust
#![feature(trait_alias)]
trait A = ?Sized;
fn main() {}
```
cc `@durka` (you've written the `FIXME` in #45047, see https://github.com/rust-lang/rust/pull/45047#discussion_r144960751)
Cleanup macro-expanded code in `rustc_type_ir`
We could of course just leave this as-is, but every time I go-to-def to this file it's painful to see all this `(&A(ref __self_1_0),)` stuff.
Point at args in associated const fn pointers
Tiny follow-up to #105201, not so sure it's worth it but 🤷
The UI test example is a bit more compelling when it's `GlUniformScalar::FACTORY`
r? `@cjgillot`
Add -Z maximal-hir-to-mir-coverage flag
This PR adds a new unstable flag `-Z maximal-hir-to-mir-coverage` that changes the behavior of `maybe_lint_level_root_bounded`, pursuant to [a discussion on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Mapping.20MIR.20to.20HIR). When enabled, this function will not search upwards for a lint root, but rather immediately return the provided HIR node ID. This change increases the granularity of the mapping between MIR locations and HIR nodes inside the `SourceScopeLocalData` data structures. This increase in granularity is useful for rustc consumers like [Flowistry](https://github.com/willcrichton/flowistry) that rely on getting source-mapping information about the MIR CFG that is as precise as possible.
A test `maximal_mir_to_hir_coverage.rs` has been added to verify that this flag does not break anything.
r? `@cjgillot`
cc `@gavinleroy`
Replace usage of `ResumeTy` in async lowering with `Context`
Replaces using `ResumeTy` / `get_context` in favor of using `&'static mut Context<'_>`.
Usage of the `'static` lifetime here is technically "cheating", and replaces the raw pointer in `ResumeTy` and the `get_context` fn that pulls the correct lifetimes out of thin air.
fixes https://github.com/rust-lang/rust/issues/104828 and https://github.com/rust-lang/rust/pull/104321#issuecomment-1336363077
r? `@oli-obk`
Put all cached values into a central struct instead of just the stable hash
cc `@nnethercote`
this allows re-use of the type for Predicate without duplicating all the logic for the non-hash cached fields
Re-enable removal of ZST writes to unions
This was previously disabled because Miri was lazily allocating unsized locals. But we aren't doing that anymore since https://github.com/rust-lang/rust/pull/98831, so we can have this optimization back.
Make `note_obligation_cause_code` take a `impl ToPredicate` for predicate
The only usecase that wasn't `impl ToPredicate` was noting overflow errors while revealing opaque types, which passed in an `Obligation<'tcx, Ty<'tcx>>`... Since this only happens in a `RevealAll` environment, which is after typeck (and probably primarily within `normalize_erasing_regions`) we're unlikely to display anything useful while noting this code, evidenced by the lack of UI test changes.
support `ConstKind::Expr` in `is_const_evaluatable` and `WfPredicates::compute`
Fixes#105205
Currently we haven't implemented a way to evaluate `ConstKind::Expr(Expr::Binop(Add, 1, 2))` so I just left that with a `FIXME` and a `delay_span_bug` since I have no idea how to do that and it would make this a much larger (and more complicated) PR :P
Synthesize substitutions for bad auto traits in dyn types
Auto traits are stored as just `DefId`s inside a `dyn Trait`'s existential predicates list. This is usually fine, since auto traits are forbidden to have generics -- but this becomes a problem for an ill-formed auto trait.
But since this will always result in an error, just synthesize some dummy (error) substitutions which are used at least to keep trait selection code happy about the number of substs in a trait ref.
Fixes#104808
propagate the error from parsing enum variant to the parser and emit out
While parsing enum variant, the error message always disappear
Because the error message that emit out is from main error of parser
The information of enum variant disappears while parsing enum variant with error
We only check the syntax of expecting token, i.e, in case https://github.com/rust-lang/rust/issues/103869
It will error it without telling the message that this error is from pasring enum variant.
Propagate the sub-error from parsing enum variant to the main error of parser by chaining it with map_err
Check the sub-error before emitting the main error of parser and attach it.
Fix https://github.com/rust-lang/rust/issues/103869
This makes both variants closer together in size (previously they were
different by 208 bytes -- 16 vs 224). This may make things worse, but
it's worth a try.
Add StableOrd trait as proposed in MCP 533.
The `StableOrd` trait can be used to mark types as having a stable sort order across compilation sessions. Collections that sort their items in a stable way can safely implement HashStable by hashing items in sort order.
See https://github.com/rust-lang/compiler-team/issues/533 for more information.
Replaces using `ResumeTy` / `get_context` in favor of using `&'static mut Context<'_>`.
Usage of the `'static` lifetime here is technically "cheating", and replaces
the raw pointer in `ResumeTy` and the `get_context` fn that pulls the
correct lifetimes out of thin air.
Tweak "the following other types implement trait"
When *any* of the suggested impls is an exact match, *only* show the exact matches. This is particularly relevant for integer types.
r? `@compiler-errors`
interpret: clobber return place when calling function
Makes sure the callee cannot observe the previous contents of the return place, and the caller cannot read any of the old return place contents even if the function unwinds.
I don't think we can test for this though, that would require some strange hand-written MIR.
r? `````@oli-obk`````
feed resolver_for_lowering instead of storing it in a field
r? `@cjgillot`
opening this as
* a discussion for `no_hash` + `feedable` queries. I think we'll want those, but I don't quite understand why they are rejected beyond a double check of the stable hashes for situations where the query is fed but also read from incremental caches.
* and a discussion on removing all untracked fields from TyCtxt and setting it up so that they are fed queries instead
Given that attributes is stored in a separate BTreeMap, it's not necessary
to pass it in when constructing `hir::Expr`. We can just construct
`hir::Expr` and then call `self.lower_attrs` later if it needs attributes.
As most desugaring code don't use attributes, this allows some code cleanup.
Disable top down MIR inlining
The current MIR inliner has exponential behavior in some cases: <https://godbolt.org/z/7jnWah4fE>. The cause of this is top-down inlining, where we repeatedly do inlining like `call_a() => { call_b(); call_b(); }`. Each decision on its own seems to make sense, but the result is exponential.
Disabling top-down inlining fundamentally prevents this. Each call site in the original, unoptimized source code is now considered for inlining exactly one time, which means that the total growth in MIR size is limited to number of call sites * inlining threshold.
Top down inlining may be worth re-introducing at some point, but it needs to be accompanied with a principled way to prevent this kind of behavior.
This ensures that the error is printed even for unused variables,
as well as unifying the handling between the LLVM and GCC backends.
This also fixes unusual behavior around exported Rust-defined variables
with linkage attributes. With the previous behavior, it appears to be
impossible to define such a variable such that it can actually be imported
and used by another crate. This is because on the importing side, the
variable is required to be a pointer, but on the exporting side, the
type checker rejects static variables of pointer type because they do
not implement `Sync`. Even if it were possible to import such a type, it
appears that code generation on the importing side would add an unexpected
additional level of pointer indirection, which would break type safety.
This highlighted that the semantics of linkage on Rust-defined variables
is different to linkage on foreign items. As such, we now model the
difference with two different codegen attributes: linkage for Rust-defined
variables, and import_linkage for foreign items.
This change gives semantics to the test
src/test/ui/linkage-attr/auxiliary/def_illtyped_external.rs which was
previously expected to fail to compile. Therefore, convert it into a
test that is expected to successfully compile.
The update to the GCC backend is speculative and untested.
`EarlyContextAndPass` wraps a single early lint pass. We aggregate
multiple passes into that single pass by using `EarlyLintPassObjects`.
This commit removes `EarlyLintPassObjects` by changing
`EarlyContextAndPass` into `EarlyContextAndPasses`. I.e. it just removes
a level of indirection. This makes the code simpler and slightly faster.
The commit does likewise for late lints.
It has a single call site in the HIR pretty printer, where the resulting
token lit is immediately converted to a string.
This commit replaces `LitKind::synthesize_token_lit` with a `Display`
impl for `LitKind`, which can be used by the HIR pretty printer.
These two methods both produce a `MetaItemLit`, and then some of the
call sites convert the `MetaItemLit` to a `token::Lit` with
`as_token_lit`.
This commit parameterises these two methods with a `mk_lit_char`
closure, which can be used to produce either `MetaItemLit` or
`token::Lit` directly as necessary.
Avoid some `InferCtxt::build` calls
Either because we're inside of an `InferCtxt` already, or because we're not in a place where we'd ever see inference vars.
r? types
There are better ways to create the meta items.
- In the rustdoc tests, the commit adds `dummy_meta_item_name_value`,
which matches the existing `dummy_meta_item_word` function and
`dummy_meta_item_list` macro.
- In `types.rs` the commit clones the existing meta item and then
modifies the clone.
Make sure async constructs do not `impl Generator`
Async lowering turns async functions and blocks into generators internally.
Though these special kinds of generators should not `impl Generator` themselves.
The other way around, normal generators should not `impl Future`.
This was discovered in https://github.com/rust-lang/rust/pull/105082#issuecomment-1332210907 and is a regression from https://github.com/rust-lang/rust/pull/104321.
r? `@compiler-errors`
rustc_codegen_ssa: Fix for codegen_get_discr
When doing the optimized implementation of getting the discriminant, the arithmetic needs to be done in the tag type so wrapping behavior works correctly.
Fixes#104519
Rollup of 6 pull requests
Successful merges:
- #101975 (Suggest to use . instead of :: when accessing a method of an object)
- #105141 (Fix ICE on invalid variable declarations in macro calls)
- #105224 (Properly substitute inherent associated types.)
- #105236 (Add regression test for #47814)
- #105247 (Use parent function WfCheckingContext to check RPITIT.)
- #105253 (Update a couple of rustbuild deps)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix ICE on invalid variable declarations in macro calls
This fixes ICE that happens with invalid variable declarations in macro calls like:
```rust
macro_rules! m { ($s:stmt) => {} }
m! { var x }
m! { auto x }
m! { mut x }
```
Found this is because of not collecting tokens on recovery, so I changed to force collect them.
Fixes https://github.com/rust-lang/rust/issues/103529.
Remove drop order twist of && and || and make them associative
Previously a short circuiting binop chain (chain of && or ||s) would drop the temporaries created by the first element after all the other elements, and otherwise follow evaluation order. So `f(1).g() && f(2).g() && f(3).g() && f(4).g()` would drop the temporaries in the order `2,3,4,1`. This made `&&` and `||` non-associative regarding drop order. In other words, adding ()'s to the expression would change drop order: `f(1).g() && (f(2).g() && f(3).g()) && f(4).g()` for example would drop in the order `3,2,4,1`.
As, except for the bool result, there is no data returned by the sub-expressions of the short circuiting binops, we can safely discard of any temporaries created by the sub-expr. Previously, code was already putting the rhs's into terminating scopes, but missed it for the lhs's.
This commit addresses this "twist". We now also put the lhs into a terminating scope. The drop order of the above expressions becomes `1,2,3,4`.
There might be code relying on the current order, and therefore I'd recommend doing a crater run to gauge the impact. I'd argue that such code is already quite wonky as it is one `foo() &&` addition away from breaking. ~~For the impact, I don't expect any *build* failures, as the compiler gets strictly more tolerant: shortening the lifetime of temporaries only expands the list of programs the compiler accepts as valid. There might be *runtime* failures caused by this change however.~~ Edit: both build and runtime failures are possible, e.g. see the example provided by dtolnay [below](https://github.com/rust-lang/rust/pull/103293#issuecomment-1285341113). Edit2: the crater run has finished and [results](https://github.com/rust-lang/rust/pull/103293#issuecomment-1292275203) are that there is only one build failure which is easy to fix with a +/- 1 line diff.
I've included a testcase that now compiles thanks to this patch.
The breakage is also limited to drop order relative to conditionals in the && chain: that is, in code like this:
```Rust
let hello = foo().hi() && bar().world();
println!("hi");
```
we already drop the temporaries of `foo().hi()` before we reach "hi".
I'd ideally have this PR merged before let chains are stabilized. If this PR is taking too long, I'd love to have a more restricted version of this change limited to `&&`'s in let chains: the `&&`'s of such chains are quite special anyways as they accept `let` bindings, in there the `&&` is therefore more a part of the "if let chain" construct than a construct of its own.
Fixes#103107
Status: waiting on [this accepted FCP](https://github.com/rust-lang/rust/pull/103293#issuecomment-1293411354) finishing.
Fix passing MACOSX_DEPLOYMENT_TARGET to the linker
I messed up in https://github.com/rust-lang/rust/pull/103929 when merging the two base files together and as a result, started ignoring `MACOSX_DEPLOYMENT_TARGET` at the linker level. This ended up being the cause of nighty builds not running on older macOS versions.
My original hope with the previous PR was that CI would have caught something like that but there were only tests checking the compiler target definitions in codegen tests. Because of how badly this sucks to break, I put together a new test via `run-make` that actually confirms the deployment target set makes it to the linker instead of just LLVM.
Closes https://github.com/rust-lang/rust/issues/104570 (for real this time)
This avoids creation of a terminating scope in
chains that contain both && and ||, because
also there we know that a terminating scope is
not neccessary: all the chain members are already
in such terminating scopes.
Also add a mixed && / || test.
Previously a short circuiting && chain would drop the
first element after all the other elements, and otherwise
follow evaluation order, so code like:
f(1).g() && f(2).g() && f(3).g() && f(4).g()
would drop the temporaries in the order 2,3,4,1. This made
&& and || non-associative regarding drop order, so
adding ()'s to the expression would change drop order:
f(1).g() && (f(2).g() && f(3).g()) && f(4).g()
for example would drop in the order 3,2,4,1.
As, except for the bool result, there is no data returned
by the sub-expressions of the short circuiting binops,
we can safely discard of any temporaries created by the
sub-expr. Previously, code was already putting the rhs's
into terminating scopes, but missed it for the lhs's.
This commit addresses this "twist". In the expression,
we now also put the lhs into a terminating scope.
The drop order for the above expressions is 1,2,3,4
now.
Rollup of 9 pull requests
Successful merges:
- #104199 (Keep track of the start of the argument block of a closure)
- #105050 (Remove useless borrows and derefs)
- #105153 (Create a hacky fail-fast mode that stops tests at the first failure)
- #105164 (Restore `use` suggestion for `dyn` method call requiring `Sized`)
- #105193 (Disable coverage instrumentation for naked functions)
- #105200 (Remove useless filter in unused extern crate check.)
- #105201 (Do not call fn_sig on non-functions.)
- #105208 (Add AmbiguityError for inconsistent resolution for an import)
- #105214 (update Miri)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Restore `use` suggestion for `dyn` method call requiring `Sized`
Add the suggestion back that I accidentally removed in 88f2140d87 because I didn't understand that suggestion was actually useful...
Fixes#105159
Remove useless borrows and derefs
They are nothing more than noise.
<sub>These are not all of them, but my clippy started crashing (stack overflow), so rip :(</sub>
Previously, the `recover_local_after_let` function was called from the
body of the `recover_stmt_local` function. Unifying these two functions
make it more simple and more readable.
Don't elide type information when printing E0308 with `-Zverbose`
When we pass `-Zverbose`, we kinda expect for all `_` to be replaced with more descriptive information, for example --
```
= note: expected fn pointer `fn(_, u32)`
found fn item `fn(_, i32) {foo}`
```
Where `_` is the "identical" part of the fn signatures, now gets rendered as:
```
= note: expected fn pointer `fn(i32, u32)`
found fn item `fn(i32, i32) {foo}`
```
Check lifetime param count in `collect_trait_impl_trait_tys`
We checked the type and const generics count, but not the lifetimes, which were handled in a different function.
Fixes#105154
The StableOrd trait can be used to mark types as having a stable
sort order across compilation sessions. Collections that sort their
items in a stable way can safely implement HashStable by
hashing items in sort order.
Add `type_ascribe!` macro as placeholder syntax for type ascription
This makes it still possible to test the internal semantics of type ascription even once the `:`-syntax is removed from the parser. The macro now gets used in a bunch of UI tests that test the semantics and not syntax of type ascription.
I might have forgotten a few tests but this should hopefully be most of them. The remaining ones will certainly be found once type ascription is removed from the parser altogether.
Part of #101728
