bjoernager/rust
bjoernager/rust
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Rework precise capturing syntax

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This commit is contained in:
Michael Goulet 2024-06-05 16:18:52 -04:00
parent 68bd001c00
commit b1efe1ab5d
54 changed files with 406 additions and 350 deletions
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182
compiler/rustc_ast_passes/src/ast_validation.rs
View file

@ -751,7 +751,7 @@ impl<'a> AstValidator<'a> {
}
}
}
TyKind::ImplTrait(_, bounds, _) => {
TyKind::ImplTrait(_, bounds) => {
if self.is_impl_trait_banned {
self.dcx().emit_err(errors::ImplTraitPath { span: ty.span });
}
@ -1304,6 +1304,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
}
}
GenericBound::Outlives(_) => {}
GenericBound::Use(..) => {}
}
}
}
@ -1322,95 +1323,110 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
}
fn visit_param_bound(&mut self, bound: &'a GenericBound, ctxt: BoundKind) {
if let GenericBound::Trait(poly, modifiers) = bound {
match (ctxt, modifiers.constness, modifiers.polarity) {
(BoundKind::SuperTraits, BoundConstness::Never, BoundPolarity::Maybe(_)) => {
self.dcx().emit_err(errors::OptionalTraitSupertrait {
span: poly.span,
path_str: pprust::path_to_string(&poly.trait_ref.path),
});
match bound {
GenericBound::Trait(trait_ref, modifiers) => {
match (ctxt, modifiers.constness, modifiers.polarity) {
(BoundKind::SuperTraits, BoundConstness::Never, BoundPolarity::Maybe(_)) => {
self.dcx().emit_err(errors::OptionalTraitSupertrait {
span: trait_ref.span,
path_str: pprust::path_to_string(&trait_ref.trait_ref.path),
});
}
(BoundKind::TraitObject, BoundConstness::Never, BoundPolarity::Maybe(_)) => {
self.dcx().emit_err(errors::OptionalTraitObject { span: trait_ref.span });
}
(
BoundKind::TraitObject,
BoundConstness::Always(_),
BoundPolarity::Positive,
) => {
self.dcx().emit_err(errors::ConstBoundTraitObject { span: trait_ref.span });
}
(_, BoundConstness::Maybe(span), BoundPolarity::Positive)
if let Some(reason) = &self.disallow_tilde_const =>
{
let reason = match reason {
DisallowTildeConstContext::Fn(FnKind::Closure(..)) => {
errors::TildeConstReason::Closure
}
DisallowTildeConstContext::Fn(FnKind::Fn(_, ident, ..)) => {
errors::TildeConstReason::Function { ident: ident.span }
}
&DisallowTildeConstContext::Trait(span) => {
errors::TildeConstReason::Trait { span }
}
&DisallowTildeConstContext::TraitImpl(span) => {
errors::TildeConstReason::TraitImpl { span }
}
&DisallowTildeConstContext::Impl(span) => {
// FIXME(effects): Consider providing a help message or even a structured
// suggestion for moving such bounds to the assoc const fns if available.
errors::TildeConstReason::Impl { span }
}
&DisallowTildeConstContext::TraitAssocTy(span) => {
errors::TildeConstReason::TraitAssocTy { span }
}
&DisallowTildeConstContext::TraitImplAssocTy(span) => {
errors::TildeConstReason::TraitImplAssocTy { span }
}
&DisallowTildeConstContext::InherentAssocTy(span) => {
errors::TildeConstReason::InherentAssocTy { span }
}
DisallowTildeConstContext::TraitObject => {
errors::TildeConstReason::TraitObject
}
DisallowTildeConstContext::Item => errors::TildeConstReason::Item,
};
self.dcx().emit_err(errors::TildeConstDisallowed { span, reason });
}
(
_,
BoundConstness::Always(_) | BoundConstness::Maybe(_),
BoundPolarity::Negative(_) | BoundPolarity::Maybe(_),
) => {
self.dcx().emit_err(errors::IncompatibleTraitBoundModifiers {
span: bound.span(),
left: modifiers.constness.as_str(),
right: modifiers.polarity.as_str(),
});
}
_ => {}
}
(BoundKind::TraitObject, BoundConstness::Never, BoundPolarity::Maybe(_)) => {
self.dcx().emit_err(errors::OptionalTraitObject { span: poly.span });
}
(BoundKind::TraitObject, BoundConstness::Always(_), BoundPolarity::Positive) => {
self.dcx().emit_err(errors::ConstBoundTraitObject { span: poly.span });
}
(_, BoundConstness::Maybe(span), BoundPolarity::Positive)
if let Some(reason) = &self.disallow_tilde_const =>
{
let reason = match reason {
DisallowTildeConstContext::Fn(FnKind::Closure(..)) => {
errors::TildeConstReason::Closure
}
DisallowTildeConstContext::Fn(FnKind::Fn(_, ident, ..)) => {
errors::TildeConstReason::Function { ident: ident.span }
}
&DisallowTildeConstContext::Trait(span) => {
errors::TildeConstReason::Trait { span }
}
&DisallowTildeConstContext::TraitImpl(span) => {
errors::TildeConstReason::TraitImpl { span }
}
&DisallowTildeConstContext::Impl(span) => {
// FIXME(effects): Consider providing a help message or even a structured
// suggestion for moving such bounds to the assoc const fns if available.
errors::TildeConstReason::Impl { span }
}
&DisallowTildeConstContext::TraitAssocTy(span) => {
errors::TildeConstReason::TraitAssocTy { span }
}
&DisallowTildeConstContext::TraitImplAssocTy(span) => {
errors::TildeConstReason::TraitImplAssocTy { span }
}
&DisallowTildeConstContext::InherentAssocTy(span) => {
errors::TildeConstReason::InherentAssocTy { span }
}
DisallowTildeConstContext::TraitObject => {
errors::TildeConstReason::TraitObject
}
DisallowTildeConstContext::Item => errors::TildeConstReason::Item,
};
self.dcx().emit_err(errors::TildeConstDisallowed { span, reason });
}
(
_,
BoundConstness::Always(_) | BoundConstness::Maybe(_),
BoundPolarity::Negative(_) | BoundPolarity::Maybe(_),
) => {
self.dcx().emit_err(errors::IncompatibleTraitBoundModifiers {
span: bound.span(),
left: modifiers.constness.as_str(),
right: modifiers.polarity.as_str(),
});
}
_ => {}
}
}
// Negative trait bounds are not allowed to have associated constraints
if let GenericBound::Trait(trait_ref, modifiers) = bound
&& let BoundPolarity::Negative(_) = modifiers.polarity
&& let Some(segment) = trait_ref.trait_ref.path.segments.last()
{
match segment.args.as_deref() {
Some(ast::GenericArgs::AngleBracketed(args)) => {
for arg in &args.args {
if let ast::AngleBracketedArg::Constraint(constraint) = arg {
self.dcx().emit_err(errors::ConstraintOnNegativeBound {
span: constraint.span,
// Negative trait bounds are not allowed to have associated constraints
if let BoundPolarity::Negative(_) = modifiers.polarity
&& let Some(segment) = trait_ref.trait_ref.path.segments.last()
{
match segment.args.as_deref() {
Some(ast::GenericArgs::AngleBracketed(args)) => {
for arg in &args.args {
if let ast::AngleBracketedArg::Constraint(constraint) = arg {
self.dcx().emit_err(errors::ConstraintOnNegativeBound {
span: constraint.span,
});
}
}
}
// The lowered form of parenthesized generic args contains an associated type binding.
Some(ast::GenericArgs::Parenthesized(args)) => {
self.dcx().emit_err(errors::NegativeBoundWithParentheticalNotation {
span: args.span,
});
}
None => {}
}
}
// The lowered form of parenthesized generic args contains an associated type binding.
Some(ast::GenericArgs::Parenthesized(args)) => {
self.dcx().emit_err(errors::NegativeBoundWithParentheticalNotation {
span: args.span,
});
}
None => {}
}
GenericBound::Outlives(_) => {}
GenericBound::Use(_, span) => match ctxt {
BoundKind::Impl => {}
BoundKind::Bound | BoundKind::TraitObject | BoundKind::SuperTraits => {
self.dcx().emit_err(errors::PreciseCapturingNotAllowedHere {
loc: ctxt.descr(),
span: *span,
})
}
},
}
visit::walk_param_bound(self, bound)

8
compiler/rustc_ast_passes/src/errors.rs
View file

@ -844,3 +844,11 @@ pub struct MatchArmWithNoBody {
#[suggestion(code = " => todo!(),", applicability = "has-placeholders")]
pub suggestion: Span,
}
#[derive(Diagnostic)]
#[diag(ast_passes_precise_capturing_not_allowed_here)]
pub struct PreciseCapturingNotAllowedHere {
#[primary_span]
pub span: Span,
pub loc: &'static str,
}