dnrops
/
rust
mirror of https://github.com/rust-lang/rust.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Stablize `const_extern_fn` for "Rust" and "C" 

All other ABIs are left unstable for now.

cc #64926
This commit is contained in:
Aaron Hill 2022-03-26 18:23:32 -04:00
parent 1fca19c8ca
commit 8035796b9a
No known key found for this signature in database
GPG Key ID: B4087E510E98B164
4 changed files with 42 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
compiler/rustc_ast_passes/src/feature_gate.rs
View File

@ -58,9 +58,22 @@ struct PostExpansionVisitor<'a> {
}
impl<'a> PostExpansionVisitor<'a> {
fn check_abi(&self, abi: ast::StrLit) {
fn check_abi(&self, abi: ast::StrLit, constness: ast::Const) {
let ast::StrLit { symbol_unescaped, span, .. } = abi;
if let ast::Const::Yes(_) = constness {
match symbol_unescaped.as_str() {
// Stable
"Rust" | "C" => {}
abi => gate_feature_post!(
&self,
const_extern_fn,
span,
&format!("`{}` as a `const fn` ABI is unstable", abi)
),
}
}
match symbol_unescaped.as_str() {
// Stable
"Rust" | "C" | "cdecl" | "stdcall" | "fastcall" | "aapcs" | "win64" | "sysv64"
@ -261,9 +274,9 @@ impl<'a> PostExpansionVisitor<'a> {
}
}
fn check_extern(&self, ext: ast::Extern) {
fn check_extern(&self, ext: ast::Extern, constness: ast::Const) {
if let ast::Extern::Explicit(abi) = ext {
self.check_abi(abi);
self.check_abi(abi, constness);
}
}
@ -445,7 +458,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
match i.kind {
ast::ItemKind::ForeignMod(ref foreign_module) => {
if let Some(abi) = foreign_module.abi {
self.check_abi(abi);
self.check_abi(abi, ast::Const::No);
}
}
@ -568,7 +581,8 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
fn visit_ty(&mut self, ty: &'a ast::Ty) {
match ty.kind {
ast::TyKind::BareFn(ref bare_fn_ty) => {
self.check_extern(bare_fn_ty.ext);
// Function pointers cannot be `const`
self.check_extern(bare_fn_ty.ext, ast::Const::No);
}
ast::TyKind::Never => {
gate_feature_post!(&self, never_type, ty.span, "the `!` type is experimental");
@ -668,18 +682,7 @@ 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);
if let (ast::Const::Yes(_), ast::Extern::Implicit)
| (ast::Const::Yes(_), ast::Extern::Explicit(_)) = (header.constness, header.ext)
{
gate_feature_post!(
&self,
const_extern_fn,
span,
"`const extern fn` definitions are unstable"
);
}
self.check_extern(header.ext, header.constness);
}
if fn_kind.ctxt() != Some(FnCtxt::Foreign) && fn_kind.decl().c_variadic() {

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

@ -523,6 +523,9 @@ 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.error_fn_ptr_bad_qualifier(whole_span, span, "const");
}
if let ast::Async::Yes { span, .. } = asyncness {

17
src/test/ui/consts/const-extern-fn/feature-gate-const_extern_fn.rs
View File

@ -1,10 +1,13 @@
// Check that `const extern fn` and `const unsafe extern fn` are feature-gated.
// Check that `const extern fn` and `const unsafe extern fn` are feature-gated
// for certain ABIs.
const extern fn foo1() {} //~ ERROR `const extern fn` definitions are unstable
const extern "C" fn foo2() {} //~ ERROR `const extern fn` definitions are unstable
const extern "Rust" fn foo3() {} //~ ERROR `const extern fn` definitions are unstable
const unsafe extern fn bar1() {} //~ ERROR `const extern fn` definitions are unstable
const unsafe extern "C" fn bar2() {} //~ ERROR `const extern fn` definitions are unstable
const unsafe extern "Rust" fn bar3() {} //~ ERROR `const extern fn` definitions are unstable
const extern fn foo1() {}
const extern "C" fn foo2() {}
const extern "Rust" fn foo3() {}
const extern "cdecl" fn foo4() {} //~ ERROR `cdecl` as a `const fn` ABI is unstable
const unsafe extern fn bar1() {}
const unsafe extern "C" fn bar2() {}
const unsafe extern "Rust" fn bar3() {}
const unsafe extern "cdecl" fn bar4() {} //~ ERROR `cdecl` as a `const fn` ABI is unstable
fn main() {}

54
src/test/ui/consts/const-extern-fn/feature-gate-const_extern_fn.stderr
View File

@ -1,57 +1,21 @@
error[E0658]: `const extern fn` definitions are unstable
--> $DIR/feature-gate-const_extern_fn.rs:3:1
error[E0658]: `cdecl` as a `const fn` ABI is unstable
--> $DIR/feature-gate-const_extern_fn.rs:7:14
|
LL | const extern fn foo1() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^
LL | const extern "cdecl" fn foo4() {}
| ^^^^^^^
|
= note: see issue #64926 <https://github.com/rust-lang/rust/issues/64926> for more information
= help: add `#![feature(const_extern_fn)]` to the crate attributes to enable
error[E0658]: `const extern fn` definitions are unstable
--> $DIR/feature-gate-const_extern_fn.rs:4:1
error[E0658]: `cdecl` as a `const fn` ABI is unstable
--> $DIR/feature-gate-const_extern_fn.rs:11:21
|
LL | const extern "C" fn foo2() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | const unsafe extern "cdecl" fn bar4() {}
| ^^^^^^^
|
= note: see issue #64926 <https://github.com/rust-lang/rust/issues/64926> for more information
= help: add `#![feature(const_extern_fn)]` to the crate attributes to enable
error[E0658]: `const extern fn` definitions are unstable
--> $DIR/feature-gate-const_extern_fn.rs:5:1
|
LL | const extern "Rust" fn foo3() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #64926 <https://github.com/rust-lang/rust/issues/64926> for more information
= help: add `#![feature(const_extern_fn)]` to the crate attributes to enable
error[E0658]: `const extern fn` definitions are unstable
--> $DIR/feature-gate-const_extern_fn.rs:6:1
|
LL | const unsafe extern fn bar1() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #64926 <https://github.com/rust-lang/rust/issues/64926> for more information
= help: add `#![feature(const_extern_fn)]` to the crate attributes to enable
error[E0658]: `const extern fn` definitions are unstable
--> $DIR/feature-gate-const_extern_fn.rs:7:1
|
LL | const unsafe extern "C" fn bar2() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #64926 <https://github.com/rust-lang/rust/issues/64926> for more information
= help: add `#![feature(const_extern_fn)]` to the crate attributes to enable
error[E0658]: `const extern fn` definitions are unstable
--> $DIR/feature-gate-const_extern_fn.rs:8:1
|
LL | const unsafe extern "Rust" fn bar3() {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #64926 <https://github.com/rust-lang/rust/issues/64926> for more information
= help: add `#![feature(const_extern_fn)]` to the crate attributes to enable
error: aborting due to 6 previous errors
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0658`.