bjoernager/rust
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Stabilize arbitrary_enum_discriminant, take 2

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This commit is contained in:
Deadbeef 2022-04-06 11:21:10 +10:00
parent eecde5850c
commit 988e75bb65
22 changed files with 12 additions and 221 deletions
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62
compiler/rustc_ast_passes/src/feature_gate.rs
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@ -1,7 +1,7 @@
use rustc_ast as ast;
use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor};
use rustc_ast::{AssocConstraint, AssocConstraintKind, NodeId};
use rustc_ast::{PatKind, RangeEnd, VariantData};
use rustc_ast::{PatKind, RangeEnd};
use rustc_errors::{struct_span_err, Applicability, StashKey};
use rustc_feature::{AttributeGate, BuiltinAttribute, Features, GateIssue, BUILTIN_ATTRIBUTE_MAP};
use rustc_session::parse::{feature_err, feature_err_issue, feature_warn};
@ -116,46 +116,6 @@ impl<'a> PostExpansionVisitor<'a> {
}
}
fn maybe_report_invalid_custom_discriminants(&self, variants: &[ast::Variant]) {
let has_fields = variants.iter().any(|variant| match variant.data {
VariantData::Tuple(..) | VariantData::Struct(..) => true,
VariantData::Unit(..) => false,
});
let discriminant_spans = variants
.iter()
.filter(|variant| match variant.data {
VariantData::Tuple(..) | VariantData::Struct(..) => false,
VariantData::Unit(..) => true,
})
.filter_map(|variant| variant.disr_expr.as_ref().map(|c| c.value.span))
.collect::<Vec<_>>();
if !discriminant_spans.is_empty() && has_fields {
let mut err = feature_err(
&self.sess.parse_sess,
sym::arbitrary_enum_discriminant,
discriminant_spans.clone(),
"custom discriminant values are not allowed in enums with tuple or struct variants",
);
for sp in discriminant_spans {
err.span_label(sp, "disallowed custom discriminant");
}
for variant in variants.iter() {
match &variant.data {
VariantData::Struct(..) => {
err.span_label(variant.span, "struct variant defined here");
}
VariantData::Tuple(..) => {
err.span_label(variant.span, "tuple variant defined here");
}
VariantData::Unit(..) => {}
}
}
err.emit();
}
}
/// Feature gate `impl Trait` inside `type Alias = $type_expr;`.
fn check_impl_trait(&self, ty: &ast::Ty) {
struct ImplTraitVisitor<'a> {
@ -273,26 +233,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
}
}
ast::ItemKind::Enum(ast::EnumDef { ref variants, .. }, ..) => {
for variant in variants {
match (&variant.data, &variant.disr_expr) {
(ast::VariantData::Unit(..), _) => {}
(_, Some(disr_expr)) => gate_feature_post!(
&self,
arbitrary_enum_discriminant,
disr_expr.value.span,
"discriminants on non-unit variants are experimental"
),
_ => {}
}
}
let has_feature = self.features.arbitrary_enum_discriminant;
if !has_feature && !i.span.allows_unstable(sym::arbitrary_enum_discriminant) {
self.maybe_report_invalid_custom_discriminants(&variants);
}
}
ast::ItemKind::Impl(box ast::Impl { polarity, defaultness, ref of_trait, .. }) => {
if let ast::ImplPolarity::Negative(span) = polarity {
gate_feature_post!(