Stabilize unsafe extern blocks (RFC 3484)

rust-lang · Jul 18, 2024 · 8e21e78 · 8e21e78
1 parent b01a977
commit 8e21e78
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Showing 40 changed files with 86 additions and 139 deletions.
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -447,11 +447,6 @@ impl<'a> AstValidator<'a> {
                             item_span: span,
                             block: Some(self.current_extern_span().shrink_to_lo()),
                         });
-                    } else if !self.features.unsafe_extern_blocks {
-                        self.dcx().emit_err(errors::InvalidSafetyOnExtern {
-                            item_span: span,
-                            block: None,
-                        });
                     }
                 }
             }
@@ -1048,32 +1043,19 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                         errors::VisibilityNotPermittedNote::IndividualForeignItems,
                     );
 
-                    if this.features.unsafe_extern_blocks {
-                        if &Safety::Default == safety {
-                            if item.span.at_least_rust_2024() {
-                                this.dcx()
-                                    .emit_err(errors::MissingUnsafeOnExtern { span: item.span });
-                            } else {
-                                this.lint_buffer.buffer_lint(
-                                    MISSING_UNSAFE_ON_EXTERN,
-                                    item.id,
-                                    item.span,
-                                    BuiltinLintDiag::MissingUnsafeOnExtern {
-                                        suggestion: item.span.shrink_to_lo(),
-                                    },
-                                );
-                            }
+                    if &Safety::Default == safety {
+                        if item.span.at_least_rust_2024() {
+                            this.dcx().emit_err(errors::MissingUnsafeOnExtern { span: item.span });
+                        } else {
+                            this.lint_buffer.buffer_lint(
+                                MISSING_UNSAFE_ON_EXTERN,
+                                item.id,
+                                item.span,
+                                BuiltinLintDiag::MissingUnsafeOnExtern {
+                                    suggestion: item.span.shrink_to_lo(),
+                                },
+                            );
                         }
-                    } else if let &Safety::Unsafe(span) = safety {
-                        let mut diag = this
-                            .dcx()
-                            .create_err(errors::UnsafeItem { span, kind: "extern block" });
-                        rustc_session::parse::add_feature_diagnostics(
-                            &mut diag,
-                            self.session,
-                            sym::unsafe_extern_blocks,
-                        );
-                        diag.emit();
                     }
 
                     if abi.is_none() {

diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -545,10 +545,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
     gate_all!(precise_capturing, "precise captures on `impl Trait` are experimental");
     gate_all!(global_registration, "global registration is experimental");
     gate_all!(unsafe_attributes, "`#[unsafe()]` markers for attributes are experimental");
-    gate_all!(
-        unsafe_extern_blocks,
-        "`unsafe extern {}` blocks and `safe` keyword are experimental"
-    );
     gate_all!(return_type_notation, "return type notation is experimental");
 
     if !visitor.features.never_patterns {

diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
@@ -387,6 +387,8 @@ declare_features! (
     (accepted, unrestricted_attribute_tokens, "1.34.0", Some(55208)),
     /// The `unsafe_op_in_unsafe_fn` lint (allowed by default): no longer treat an unsafe function as an unsafe block.
     (accepted, unsafe_block_in_unsafe_fn, "1.52.0", Some(71668)),
+    /// Allows unsafe on extern declarations and safety qualifiers over internal items.
+    (accepted, unsafe_extern_blocks, "CURRENT_RUSTC_VERSION", Some(123743)),
     /// Allows importing and reexporting macros with `use`,
     /// enables macro modularization in general.
     (accepted, use_extern_macros, "1.30.0", Some(35896)),

diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
@@ -628,8 +628,6 @@ declare_features! (
     (incomplete, unnamed_fields, "1.74.0", Some(49804)),
     /// Allows unsafe attributes.
     (unstable, unsafe_attributes, "1.80.0", Some(123757)),
-    /// Allows unsafe on extern declarations and safety qualifiers over internal items.
-    (unstable, unsafe_extern_blocks, "1.80.0", Some(123743)),
     /// Allows unsized fn parameters.
     (internal, unsized_fn_params, "1.49.0", Some(48055)),
     /// Allows unsized rvalues at arguments and parameters.

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
@@ -4865,7 +4865,6 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust
-    /// #![feature(unsafe_extern_blocks)]
     /// #![warn(missing_unsafe_on_extern)]
     /// #![allow(dead_code)]
     ///

diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
@@ -1199,9 +1199,6 @@ impl<'a> Parser<'a> {
         if self.eat_keyword_case(kw::Unsafe, case) {
             Safety::Unsafe(self.prev_token.uninterpolated_span())
         } else if self.eat_keyword_case(kw::Safe, case) {
-            self.psess
-                .gated_spans
-                .gate(sym::unsafe_extern_blocks, self.prev_token.uninterpolated_span());
             Safety::Safe(self.prev_token.uninterpolated_span())
         } else {
             Safety::Default

diff --git a/tests/rustdoc/unsafe-extern-blocks.rs b/tests/rustdoc/unsafe-extern-blocks.rs
@@ -1,6 +1,5 @@
 // Test to ensure the feature is working as expected.
 
-#![feature(unsafe_extern_blocks)]
 #![crate_name = "foo"]
 
 // @has 'foo/index.html'
@@ -13,7 +12,7 @@
 // @count - '//ul[@class="item-table"]//sup[@title="unsafe function"]' 1
 // @has - '//ul[@class="item-table"]//sup[@title="unsafe function"]' '⚠'
 
-unsafe extern {
+unsafe extern "C" {
     // @has 'foo/static.FOO.html'
     // @has - '//pre[@class="rust item-decl"]' 'pub static FOO: i32'
     pub safe static FOO: i32;

diff --git a/tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.rs b/tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.rs
diff --git a/tests/ui/lint/unsafe_code/unsafe-extern-blocks.rs b/tests/ui/lint/unsafe_code/unsafe-extern-blocks.rs
@@ -1,4 +1,3 @@
-#![feature(unsafe_extern_blocks)]
 #![deny(unsafe_code)]
 
 #[allow(unsafe_code)]

diff --git a/tests/ui/lint/unsafe_code/unsafe-extern-blocks.stderr b/tests/ui/lint/unsafe_code/unsafe-extern-blocks.stderr
@@ -1,5 +1,5 @@
 error: usage of an `unsafe extern` block
-  --> $DIR/unsafe-extern-blocks.rs:9:1
+  --> $DIR/unsafe-extern-blocks.rs:8:1
    |
 LL | / unsafe extern "C" {
 LL | |
@@ -8,7 +8,7 @@ LL | | }
    | |_^
    |
 note: the lint level is defined here
-  --> $DIR/unsafe-extern-blocks.rs:2:9
+  --> $DIR/unsafe-extern-blocks.rs:1:9
    |
 LL | #![deny(unsafe_code)]
    |         ^^^^^^^^^^^

diff --git a/tests/ui/parser/unsafe-foreign-mod-2.rs b/tests/ui/parser/unsafe-foreign-mod-2.rs
@@ -1,8 +1,6 @@
 extern "C" unsafe {
     //~^ ERROR expected `{`, found keyword `unsafe`
-    //~| ERROR extern block cannot be declared unsafe
     unsafe fn foo();
-    //~^ ERROR items in unadorned `extern` blocks cannot have safety qualifiers
 }
 
 fn main() {}
diff --git a/tests/ui/parser/unsafe-foreign-mod-2.stderr b/tests/ui/parser/unsafe-foreign-mod-2.stderr
@@ -4,21 +4,5 @@ error: expected `{`, found keyword `unsafe`
 LL | extern "C" unsafe {
    |            ^^^^^^ expected `{`
 
-error: extern block cannot be declared unsafe
-  --> $DIR/unsafe-foreign-mod-2.rs:1:12
-   |
-LL | extern "C" unsafe {
-   |            ^^^^^^
-   |
-   = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
-   = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error: items in unadorned `extern` blocks cannot have safety qualifiers
-  --> $DIR/unsafe-foreign-mod-2.rs:4:5
-   |
-LL |     unsafe fn foo();
-   |     ^^^^^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/unsafe-foreign-mod.rs b/tests/ui/parser/unsafe-foreign-mod.rs
@@ -1,5 +1,5 @@
-unsafe extern "C" {
-    //~^ ERROR extern block cannot be declared unsafe
-}
+//@ check-pass
+
+unsafe extern "C" {}
 
 fn main() {}
diff --git a/tests/ui/parser/unsafe-foreign-mod.stderr b/tests/ui/parser/unsafe-foreign-mod.stderr
diff --git a/tests/ui/rust-2024/safe-outside-extern.rs b/tests/ui/rust-2024/safe-outside-extern.rs
@@ -1,28 +1,20 @@
-//@ revisions: gated ungated
-#![cfg_attr(gated, feature(unsafe_extern_blocks))]
-
 safe fn foo() {}
 //~^ ERROR: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
-//[ungated]~| ERROR: unsafe extern {}` blocks and `safe` keyword are experimental [E0658]
 
 safe static FOO: i32 = 1;
 //~^ ERROR: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
-//[ungated]~| ERROR: unsafe extern {}` blocks and `safe` keyword are experimental [E0658]
 
 trait Foo {
     safe fn foo();
     //~^ ERROR: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
-    //[ungated]~| ERROR: unsafe extern {}` blocks and `safe` keyword are experimental [E0658]
 }
 
 impl Foo for () {
     safe fn foo() {}
     //~^ ERROR: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
-    //[ungated]~| ERROR: unsafe extern {}` blocks and `safe` keyword are experimental [E0658]
 }
 
 type FnPtr = safe fn(i32, i32) -> i32;
 //~^ ERROR: function pointers cannot be declared with `safe` safety qualifier
-//[ungated]~| ERROR: unsafe extern {}` blocks and `safe` keyword are experimental [E0658]
 
 fn main() {}
diff --git a/tests/ui/rust-2024/safe-outside-extern.stderr b/tests/ui/rust-2024/safe-outside-extern.stderr
@@ -0,0 +1,32 @@
+error: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
+  --> $DIR/safe-outside-extern.rs:1:1
+   |
+LL | safe fn foo() {}
+   | ^^^^^^^^^^^^^^^^
+
+error: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
+  --> $DIR/safe-outside-extern.rs:4:1
+   |
+LL | safe static FOO: i32 = 1;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
+  --> $DIR/safe-outside-extern.rs:8:5
+   |
+LL |     safe fn foo();
+   |     ^^^^^^^^^^^^^^
+
+error: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier
+  --> $DIR/safe-outside-extern.rs:13:5
+   |
+LL |     safe fn foo() {}
+   |     ^^^^^^^^^^^^^^^^
+
+error: function pointers cannot be declared with `safe` safety qualifier
+  --> $DIR/safe-outside-extern.rs:17:14
+   |
+LL | type FnPtr = safe fn(i32, i32) -> i32;
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors
+
diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/extern-items-unsafe.edition2021.stderr b/tests/ui/rust-2024/unsafe-extern-blocks/extern-items-unsafe.edition2021.stderr
@@ -1,13 +1,13 @@
 error[E0133]: call to unsafe function `test1` is unsafe and requires unsafe function or block
-  --> $DIR/extern-items-unsafe.rs:14:5
+  --> $DIR/extern-items-unsafe.rs:12:5
    |
 LL |     test1(TEST1);
    |     ^^^^^^^^^^^^ call to unsafe function
    |
    = note: consult the function's documentation for information on how to avoid undefined behavior
 
 error[E0133]: use of extern static is unsafe and requires unsafe function or block
-  --> $DIR/extern-items-unsafe.rs:14:11
+  --> $DIR/extern-items-unsafe.rs:12:11
    |
 LL |     test1(TEST1);
    |           ^^^^^ use of extern static

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/extern-items-unsafe.edition2024.stderr b/tests/ui/rust-2024/unsafe-extern-blocks/extern-items-unsafe.edition2024.stderr
@@ -1,13 +1,13 @@
 error[E0133]: call to unsafe function `test1` is unsafe and requires unsafe block
-  --> $DIR/extern-items-unsafe.rs:14:5
+  --> $DIR/extern-items-unsafe.rs:12:5
    |
 LL |     test1(TEST1);
    |     ^^^^^^^^^^^^ call to unsafe function
    |
    = note: consult the function's documentation for information on how to avoid undefined behavior
 
 error[E0133]: use of extern static is unsafe and requires unsafe block
-  --> $DIR/extern-items-unsafe.rs:14:11
+  --> $DIR/extern-items-unsafe.rs:12:11
    |
 LL |     test1(TEST1);
    |           ^^^^^ use of extern static

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/extern-items-unsafe.rs b/tests/ui/rust-2024/unsafe-extern-blocks/extern-items-unsafe.rs
@@ -3,8 +3,6 @@
 //@[edition2024] edition:2024
 //@[edition2024] compile-flags: -Zunstable-options
 
-#![feature(unsafe_extern_blocks)]
-
 unsafe extern "C" {
     static TEST1: i32;
     fn test1(i: i32);

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/extern-items.edition2024.stderr b/tests/ui/rust-2024/unsafe-extern-blocks/extern-items.edition2024.stderr
@@ -1,5 +1,5 @@
 error: extern blocks must be unsafe
-  --> $DIR/extern-items.rs:9:1
+  --> $DIR/extern-items.rs:7:1
    |
 LL | / extern "C" {
 LL | |

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/extern-items.rs b/tests/ui/rust-2024/unsafe-extern-blocks/extern-items.rs
@@ -4,8 +4,6 @@
 //@[edition2024] edition:2024
 //@[edition2024] compile-flags: -Zunstable-options
 
-#![feature(unsafe_extern_blocks)]
-
 extern "C" {
     //[edition2024]~^ ERROR extern blocks must be unsafe
     static TEST1: i32;

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/safe-impl-trait.rs b/tests/ui/rust-2024/unsafe-extern-blocks/safe-impl-trait.rs
@@ -1,6 +1,3 @@
-//@ revisions: gated ungated
-#![cfg_attr(gated, feature(unsafe_extern_blocks))]
-
 trait Bar {}
 safe impl Bar for () { }
 //~^ ERROR expected one of `!` or `::`, found keyword `impl`

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/safe-impl-trait.stderr b/tests/ui/rust-2024/unsafe-extern-blocks/safe-impl-trait.stderr
@@ -0,0 +1,8 @@
+error: expected one of `!` or `::`, found keyword `impl`
+  --> $DIR/safe-impl-trait.rs:2:6
+   |
+LL | safe impl Bar for () { }
+   |      ^^^^ expected one of `!` or `::`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/safe-items.rs b/tests/ui/rust-2024/unsafe-extern-blocks/safe-items.rs
@@ -4,8 +4,6 @@
 //@[edition2024] compile-flags: -Zunstable-options
 //@ check-pass
 
-#![feature(unsafe_extern_blocks)]
-
 unsafe extern "C" {
     safe static TEST1: i32;
     safe fn test1(i: i32);

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/safe-trait.rs b/tests/ui/rust-2024/unsafe-extern-blocks/safe-trait.rs
@@ -1,6 +1,3 @@
-//@ revisions: gated ungated
-#![cfg_attr(gated, feature(unsafe_extern_blocks))]
-
 safe trait Foo {}
 //~^ ERROR expected one of `!` or `::`, found keyword `trait`
 

diff --git a/tests/ui/rust-2024/unsafe-extern-blocks/safe-trait.stderr b/tests/ui/rust-2024/unsafe-extern-blocks/safe-trait.stderr
@@ -0,0 +1,8 @@
+error: expected one of `!` or `::`, found keyword `trait`
+  --> $DIR/safe-trait.rs:1:6
+   |
+LL | safe trait Foo {}
+   |      ^^^^^ expected one of `!` or `::`
+
+error: aborting due to 1 previous error
+
diff --git a/...i/rust-2024/unsafe-extern-blocks/safe-unsafe-on-unadorned-extern-block.edition2021.stderr b/...i/rust-2024/unsafe-extern-blocks/safe-unsafe-on-unadorned-extern-block.edition2021.stderr
@@ -1,5 +1,5 @@
 error: items in unadorned `extern` blocks cannot have safety qualifiers
-  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:10:5
+  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:8:5
    |
 LL |     safe static TEST1: i32;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
@@ -10,7 +10,7 @@ LL | unsafe extern "C" {
    | ++++++
 
 error: items in unadorned `extern` blocks cannot have safety qualifiers
-  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:12:5
+  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:10:5
    |
 LL |     safe fn test1(i: i32);
    |     ^^^^^^^^^^^^^^^^^^^^^^