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stabilize const_extern_fn

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This commit is contained in:
Folkert de Vries 2024-08-29 15:33:34 +02:00
parent 02b1be16c6
commit a528f4ecd9
29 changed files with 186 additions and 235 deletions
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25
compiler/rustc_ast_passes/src/feature_gate.rs
View file

@ -75,22 +75,9 @@ struct PostExpansionVisitor<'a> {
impl<'a> PostExpansionVisitor<'a> {
#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
fn check_abi(&self, abi: ast::StrLit, constness: ast::Const) {
fn check_abi(&self, abi: ast::StrLit) {
let ast::StrLit { symbol_unescaped, span, .. } = abi;
if let ast::Const::Yes(_) = constness {
match symbol_unescaped {
// Stable
sym::Rust | sym::C => {}
abi => gate!(
&self,
const_extern_fn,
span,
format!("`{}` as a `const fn` ABI is unstable", abi)
),
}
}
match abi::is_enabled(self.features, span, symbol_unescaped.as_str()) {
Ok(()) => (),
Err(abi::AbiDisabled::Unstable { feature, explain }) => {
@ -110,9 +97,9 @@ impl<'a> PostExpansionVisitor<'a> {
}
}
fn check_extern(&self, ext: ast::Extern, constness: ast::Const) {
fn check_extern(&self, ext: ast::Extern) {
if let ast::Extern::Explicit(abi, _) = ext {
self.check_abi(abi, constness);
self.check_abi(abi);
}
}
@ -239,7 +226,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
match &i.kind {
ast::ItemKind::ForeignMod(foreign_module) => {
if let Some(abi) = foreign_module.abi {
self.check_abi(abi, ast::Const::No);
self.check_abi(abi);
}
}
@ -341,7 +328,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
match &ty.kind {
ast::TyKind::BareFn(bare_fn_ty) => {
// Function pointers cannot be `const`
self.check_extern(bare_fn_ty.ext, ast::Const::No);
self.check_extern(bare_fn_ty.ext);
self.check_late_bound_lifetime_defs(&bare_fn_ty.generic_params);
}
ast::TyKind::Never => {
@ -446,7 +433,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) {
if let Some(header) = fn_kind.header() {
// Stability of const fn methods are covered in `visit_assoc_item` below.
self.check_extern(header.ext, header.constness);
self.check_extern(header.ext);
}
if let FnKind::Closure(ast::ClosureBinder::For { generic_params, .. }, ..) = fn_kind {

2
compiler/rustc_feature/src/accepted.rs
View file

@ -115,6 +115,8 @@ declare_features! (
(accepted, conservative_impl_trait, "1.26.0", Some(34511)),
/// Allows calling constructor functions in `const fn`.
(accepted, const_constructor, "1.40.0", Some(61456)),
/// Allows the definition of `const extern fn` and `const unsafe extern fn`.
(accepted, const_extern_fn, "CURRENT_RUSTC_VERSION", Some(64926)),
/// Allows basic arithmetic on floating point types in a `const fn`.
(accepted, const_fn_floating_point_arithmetic, "1.82.0", Some(57241)),
/// Allows using and casting function pointers in a `const fn`.

2
compiler/rustc_feature/src/unstable.rs
View file

@ -401,8 +401,6 @@ declare_features! (
(unstable, const_async_blocks, "1.53.0", Some(85368)),
/// Allows `const || {}` closures in const contexts.
(incomplete, const_closures, "1.68.0", Some(106003)),
/// Allows the definition of `const extern fn` and `const unsafe extern fn`.
(unstable, const_extern_fn, "1.40.0", Some(64926)),
/// Allows `for _ in _` loops in const contexts.
(unstable, const_for, "1.56.0", Some(87575)),
/// Allows using `&mut` in constant functions.

3
compiler/rustc_parse/src/parser/ty.rs
View file

@ -607,9 +607,6 @@ impl<'a> Parser<'a> {
let decl = self.parse_fn_decl(|_| false, AllowPlus::No, recover_return_sign)?;
let whole_span = lo.to(self.prev_token.span);
if let ast::Const::Yes(span) = constness {
// If we ever start to allow `const fn()`, then update
// feature gating for `#![feature(const_extern_fn)]` to
// cover it.
self.dcx().emit_err(FnPointerCannotBeConst { span: whole_span, qualifier: span });
}
if let Some(ast::CoroutineKind::Async { span, .. }) = coroutine_kind {