Rollup merge of #96377 - compiler-errors:infer-rustfix, r=petrochenkov

make `fn() -> _ { .. }` suggestion MachineApplicable

This might not be valid, but it would be nice to promote this to `MachineApplicable` so people can use rustfix here.

Also de65fcf009d07019689cfad7f327667e390a325d is to [restore the suggestion for `issue-77179.rs`](de65fcf009 (diff-12e43fb5d6d12ec7cb5c6b48204a18d113cf5de0e12eb71a358b639bd9aadaf0R8)). (though in this case, the code in that issue still doesn't compile, so it's not marked with rustfix).
This commit is contained in:
Dylan DPC 2022-04-28 02:40:32 +02:00 committed by GitHub
commit 4a7483c905
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5 changed files with 46 additions and 35 deletions

View file

@ -3,8 +3,8 @@
use crate::ty::subst::{GenericArg, GenericArgKind};
use crate::ty::TyKind::*;
use crate::ty::{
ConstKind, ExistentialPredicate, ExistentialProjection, ExistentialTraitRef, InferTy,
ProjectionTy, Term, Ty, TyCtxt, TypeAndMut,
ConstKind, DefIdTree, ExistentialPredicate, ExistentialProjection, ExistentialTraitRef,
InferTy, ProjectionTy, Term, Ty, TyCtxt, TypeAndMut,
};
use rustc_data_structures::fx::FxHashMap;
@ -74,10 +74,10 @@ impl<'tcx> Ty<'tcx> {
}
/// Whether the type can be safely suggested during error recovery.
pub fn is_suggestable(self) -> bool {
fn generic_arg_is_suggestible(arg: GenericArg<'_>) -> bool {
pub fn is_suggestable(self, tcx: TyCtxt<'tcx>) -> bool {
fn generic_arg_is_suggestible<'tcx>(arg: GenericArg<'tcx>, tcx: TyCtxt<'tcx>) -> bool {
match arg.unpack() {
GenericArgKind::Type(ty) => ty.is_suggestable(),
GenericArgKind::Type(ty) => ty.is_suggestable(tcx),
GenericArgKind::Const(c) => const_is_suggestable(c.val()),
_ => true,
}
@ -99,8 +99,7 @@ impl<'tcx> Ty<'tcx> {
// temporary, so I'll leave this as a fixme.
match self.kind() {
Opaque(..)
| FnDef(..)
FnDef(..)
| Closure(..)
| Infer(..)
| Generator(..)
@ -108,27 +107,38 @@ impl<'tcx> Ty<'tcx> {
| Bound(_, _)
| Placeholder(_)
| Error(_) => false,
Opaque(did, substs) => {
let parent = tcx.parent(*did).expect("opaque types always have a parent");
if let hir::def::DefKind::TyAlias | hir::def::DefKind::AssocTy = tcx.def_kind(parent)
&& let Opaque(parent_did, _) = tcx.type_of(parent).kind()
&& parent_did == did
{
substs.iter().all(|a| generic_arg_is_suggestible(a, tcx))
} else {
false
}
}
Dynamic(dty, _) => dty.iter().all(|pred| match pred.skip_binder() {
ExistentialPredicate::Trait(ExistentialTraitRef { substs, .. }) => {
substs.iter().all(generic_arg_is_suggestible)
substs.iter().all(|a| generic_arg_is_suggestible(a, tcx))
}
ExistentialPredicate::Projection(ExistentialProjection {
substs, term, ..
}) => {
let term_is_suggestable = match term {
Term::Ty(ty) => ty.is_suggestable(),
Term::Ty(ty) => ty.is_suggestable(tcx),
Term::Const(c) => const_is_suggestable(c.val()),
};
term_is_suggestable && substs.iter().all(generic_arg_is_suggestible)
term_is_suggestable && substs.iter().all(|a| generic_arg_is_suggestible(a, tcx))
}
_ => true,
}),
Projection(ProjectionTy { substs: args, .. }) | Adt(_, args) => {
args.iter().all(generic_arg_is_suggestible)
args.iter().all(|a| generic_arg_is_suggestible(a, tcx))
}
Tuple(args) => args.iter().all(|ty| ty.is_suggestable()),
Slice(ty) | RawPtr(TypeAndMut { ty, .. }) | Ref(_, ty, _) => ty.is_suggestable(),
Array(ty, c) => ty.is_suggestable() && const_is_suggestable(c.val()),
Tuple(args) => args.iter().all(|ty| ty.is_suggestable(tcx)),
Slice(ty) | RawPtr(TypeAndMut { ty, .. }) | Ref(_, ty, _) => ty.is_suggestable(tcx),
Array(ty, c) => ty.is_suggestable(tcx) && const_is_suggestable(c.val()),
_ => true,
}
}

View file

@ -86,7 +86,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
let param_type = tcx.infer_ctxt().enter(|infcx| {
infcx.resolve_numeric_literals_with_default(tcx.type_of(param.def_id))
});
if param_type.is_suggestable() {
if param_type.is_suggestable(tcx) {
err.span_suggestion(
tcx.def_span(src_def_id),
"consider changing this type parameter to be a `const` generic",

View file

@ -2466,7 +2466,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
span,
ty,
opt_sugg: Some((span, Applicability::MachineApplicable))
.filter(|_| ty.is_suggestable()),
.filter(|_| ty.is_suggestable(tcx)),
});
ty

View file

@ -525,7 +525,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
self.resolve_numeric_literals_with_default(self.resolve_vars_if_possible(found));
// Only suggest changing the return type for methods that
// haven't set a return type at all (and aren't `fn main()` or an impl).
match (&fn_decl.output, found.is_suggestable(), can_suggest, expected.is_unit()) {
match (&fn_decl.output, found.is_suggestable(self.tcx), can_suggest, expected.is_unit()) {
(&hir::FnRetTy::DefaultReturn(span), true, true, true) => {
err.span_suggestion(
span,

View file

@ -41,7 +41,7 @@ use rustc_middle::ty::subst::InternalSubsts;
use rustc_middle::ty::util::Discr;
use rustc_middle::ty::util::IntTypeExt;
use rustc_middle::ty::{self, AdtKind, Const, DefIdTree, Ty, TyCtxt};
use rustc_middle::ty::{ReprOptions, ToPredicate, TypeFoldable};
use rustc_middle::ty::{ReprOptions, ToPredicate};
use rustc_session::lint;
use rustc_session::parse::feature_err;
use rustc_span::symbol::{kw, sym, Ident, Symbol};
@ -2004,28 +2004,29 @@ fn infer_return_ty_for_fn_sig<'tcx>(
visitor.visit_ty(ty);
let mut diag = bad_placeholder(tcx, visitor.0, "return type");
let ret_ty = fn_sig.skip_binder().output();
if !ret_ty.references_error() {
if !ret_ty.is_closure() {
let ret_ty_str = match ret_ty.kind() {
// Suggest a function pointer return type instead of a unique function definition
// (e.g. `fn() -> i32` instead of `fn() -> i32 { f }`, the latter of which is invalid
// syntax)
ty::FnDef(..) => ret_ty.fn_sig(tcx).to_string(),
_ => ret_ty.to_string(),
};
if ret_ty.is_suggestable(tcx) {
diag.span_suggestion(
ty.span,
"replace with the correct return type",
ret_ty.to_string(),
Applicability::MachineApplicable,
);
} else if matches!(ret_ty.kind(), ty::FnDef(..)) {
let fn_sig = ret_ty.fn_sig(tcx);
if fn_sig.skip_binder().inputs_and_output.iter().all(|t| t.is_suggestable(tcx)) {
diag.span_suggestion(
ty.span,
"replace with the correct return type",
ret_ty_str,
Applicability::MaybeIncorrect,
fn_sig.to_string(),
Applicability::MachineApplicable,
);
} else {
// We're dealing with a closure, so we should suggest using `impl Fn` or trait bounds
// to prevent the user from getting a papercut while trying to use the unique closure
// syntax (e.g. `[closure@src/lib.rs:2:5: 2:9]`).
diag.help("consider using an `Fn`, `FnMut`, or `FnOnce` trait bound");
diag.note("for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html");
}
} else if ret_ty.is_closure() {
// We're dealing with a closure, so we should suggest using `impl Fn` or trait bounds
// to prevent the user from getting a papercut while trying to use the unique closure
// syntax (e.g. `[closure@src/lib.rs:2:5: 2:9]`).
diag.help("consider using an `Fn`, `FnMut`, or `FnOnce` trait bound");
diag.note("for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html");
}
diag.emit();