Stabilize naked_functions

This stabilizes the feature described in RFC 2972,
which supersedes the earlier RFC 1201.

Closes rust-lang#32408
Closes rust-lang#90957

compiler/rustc_error_codes/src/error_codes/E0787.md

@@ -3,8 +3,6 @@ An unsupported naked function definition.
 Erroneous code example:
 
 ```compile_fail,E0787
-#![feature(naked_functions)]
-
 #[naked]
 pub extern "C" fn f() -> u32 {
     42

compiler/rustc_feature/src/accepted.rs

@@ -203,6 +203,8 @@ declare_features! (
     /// Allows patterns with concurrent by-move and by-ref bindings.
     /// For example, you can write `Foo(a, ref b)` where `a` is by-move and `b` is by-ref.
     (accepted, move_ref_pattern, "1.49.0", Some(68354), None),
+    /// Allows using `#[naked]` on functions.
+    (accepted, naked_functions, "1.60.0", Some(90957), None),
     /// Allows using `#![no_std]`.
     (accepted, no_std, "1.6.0", None, None),
     /// Allows defining identifiers beyond ASCII.

compiler/rustc_feature/src/active.rs

@@ -435,8 +435,6 @@ declare_features! (
     (active, more_qualified_paths, "1.54.0", Some(86935), None),
     /// Allows the `#[must_not_suspend]` attribute.
     (active, must_not_suspend, "1.57.0", Some(83310), None),
-    /// Allows using `#[naked]` on functions.
-    (active, naked_functions, "1.9.0", Some(32408), None),
     /// Allows specifying modifiers in the link attribute: `#[link(modifiers = "...")]`
     (active, native_link_modifiers, "1.53.0", Some(81490), None),
     /// Allows specifying the as-needed link modifier

compiler/rustc_feature/src/builtin_attrs.rs

@@ -360,6 +360,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // Code generation:
     ungated!(inline, Normal, template!(Word, List: "always|never"), FutureWarnFollowing),
     ungated!(cold, Normal, template!(Word), WarnFollowing),
+    ungated!(naked, Normal, template!(Word), WarnFollowing),
     ungated!(no_builtins, CrateLevel, template!(Word), WarnFollowing),
     ungated!(target_feature, Normal, template!(List: r#"enable = "name""#), DuplicatesOk),
     ungated!(track_caller, Normal, template!(Word), WarnFollowing),
@@ -379,7 +380,6 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // ==========================================================================
 
     // Linking:
-    gated!(naked, Normal, template!(Word), WarnFollowing, naked_functions, experimental!(naked)),
     gated!(
         link_ordinal, Normal, template!(List: "ordinal"), ErrorPreceding, raw_dylib,
         experimental!(link_ordinal)

compiler/rustc_lint_defs/src/builtin.rs

@@ -2745,8 +2745,6 @@ declare_lint! {
     /// ### Example
     ///
     /// ```rust
-    /// #![feature(naked_functions)]
-    ///
     /// use std::arch::asm;
     ///
     /// #[naked]

src/doc/unstable-book/src/compiler-flags/sanitizer.md

@@ -199,8 +199,6 @@ LLVM CFI can be enabled with -Zsanitizer=cfi and requires LTO (i.e., -Clto).
 ## Example
 
 ```text
-#![feature(naked_functions)]
-
 use std::arch::asm;
 use std::mem;
 

src/test/codegen/naked-functions.rs

@@ -3,7 +3,7 @@
 // only-x86_64
 
 #![crate_type = "lib"]
-#![feature(naked_functions)]
+
 use std::arch::asm;
 
 // CHECK: Function Attrs: naked

src/test/codegen/naked-noinline.rs

@@ -2,8 +2,8 @@
 // compile-flags: -O -Zmir-opt-level=3
 // needs-asm-support
 // ignore-wasm32
+
 #![crate_type = "lib"]
-#![feature(naked_functions)]
 
 use std::arch::asm;
 

src/test/ui/asm/naked-functions-ffi.rs

@@ -1,6 +1,6 @@
 // check-pass
 // needs-asm-support
-#![feature(naked_functions)]
+
 #![crate_type = "lib"]
 
 use std::arch::asm;

src/test/ui/asm/naked-functions-unused.rs

@@ -1,8 +1,8 @@
 // revisions: x86_64 aarch64
 //[x86_64] only-x86_64
 //[aarch64] only-aarch64
+
 #![deny(unused)]
-#![feature(naked_functions)]
 #![crate_type = "lib"]
 
 pub trait Trait {

src/test/ui/asm/naked-functions-unused.x86_64.stderr

@@ -5,7 +5,7 @@ LL |     pub extern "C" fn function(a: usize, b: usize) -> usize {
    |                                ^ help: if this is intentional, prefix it with an underscore: `_a`
    |
 note: the lint level is defined here
-  --> $DIR/naked-functions-unused.rs:4:9
+  --> $DIR/naked-functions-unused.rs:5:9
    |
 LL | #![deny(unused)]
    |         ^^^^^^

src/test/ui/asm/naked-functions.rs

@@ -3,7 +3,6 @@
 // ignore-spirv
 // ignore-wasm32
 
-#![feature(naked_functions)]
 #![feature(or_patterns)]
 #![feature(asm_const, asm_sym, asm_unwind)]
 #![crate_type = "lib"]
@@ -127,7 +126,7 @@ pub unsafe fn default_abi() {
 }
 
 #[naked]
-pub unsafe fn rust_abi() {
+pub unsafe extern "Rust" fn rust_abi() {
     //~^ WARN Rust ABI is unsupported in naked functions
     asm!("", options(noreturn));
 }

src/test/ui/asm/naked-functions.stderr

@@ -1,43 +1,43 @@
 error: asm with the `pure` option must have at least one output
-  --> $DIR/naked-functions.rs:111:14
+  --> $DIR/naked-functions.rs:110:14
    |
 LL |     asm!("", options(readonly, nostack), options(pure));
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^
 
 error: patterns not allowed in naked function parameters
-  --> $DIR/naked-functions.rs:21:5
+  --> $DIR/naked-functions.rs:20:5
    |
 LL |     mut a: u32,
    |     ^^^^^
 
 error: patterns not allowed in naked function parameters
-  --> $DIR/naked-functions.rs:23:5
+  --> $DIR/naked-functions.rs:22:5
    |
 LL |     &b: &i32,
    |     ^^
 
 error: patterns not allowed in naked function parameters
-  --> $DIR/naked-functions.rs:25:6
+  --> $DIR/naked-functions.rs:24:6
    |
 LL |     (None | Some(_)): Option<std::ptr::NonNull<u8>>,
    |      ^^^^^^^^^^^^^^
 
 error: patterns not allowed in naked function parameters
-  --> $DIR/naked-functions.rs:27:5
+  --> $DIR/naked-functions.rs:26:5
    |
 LL |     P { x, y }: P,
    |     ^^^^^^^^^^
 
 error: referencing function parameters is not allowed in naked functions
-  --> $DIR/naked-functions.rs:36:5
+  --> $DIR/naked-functions.rs:35:5
    |
 LL |     a + 1
    |     ^
    |
    = help: follow the calling convention in asm block to use parameters
 
 error[E0787]: naked functions must contain a single asm block
-  --> $DIR/naked-functions.rs:34:1
+  --> $DIR/naked-functions.rs:33:1
    |
 LL | / pub unsafe extern "C" fn inc(a: u32) -> u32 {
 LL | |
@@ -48,21 +48,21 @@ LL | | }
    | |_^
 
 error: referencing function parameters is not allowed in naked functions
-  --> $DIR/naked-functions.rs:42:31
+  --> $DIR/naked-functions.rs:41:31
    |
 LL |     asm!("/* {0} */", in(reg) a, options(noreturn));
    |                               ^
    |
    = help: follow the calling convention in asm block to use parameters
 
 error[E0787]: only `const` and `sym` operands are supported in naked functions
-  --> $DIR/naked-functions.rs:42:23
+  --> $DIR/naked-functions.rs:41:23
    |
 LL |     asm!("/* {0} */", in(reg) a, options(noreturn));
    |                       ^^^^^^^^^
 
 error[E0787]: naked functions must contain a single asm block
-  --> $DIR/naked-functions.rs:48:1
+  --> $DIR/naked-functions.rs:47:1
    |
 LL | / pub unsafe extern "C" fn inc_closure(a: u32) -> u32 {
 LL | |
@@ -72,7 +72,7 @@ LL | | }
    | |_^
 
 error[E0787]: only `const` and `sym` operands are supported in naked functions
-  --> $DIR/naked-functions.rs:65:10
+  --> $DIR/naked-functions.rs:64:10
    |
 LL |          in(reg) a,
    |          ^^^^^^^^^
@@ -87,7 +87,7 @@ LL |          out(reg) e,
    |          ^^^^^^^^^^
 
 error[E0787]: asm in naked functions must use `noreturn` option
-  --> $DIR/naked-functions.rs:63:5
+  --> $DIR/naked-functions.rs:62:5
    |
 LL | /     asm!("/* {0} {1} {2} {3} {4} {5} {6} */",
 LL | |
@@ -99,7 +99,7 @@ LL | |     );
    | |_____^
 
 error[E0787]: naked functions must contain a single asm block
-  --> $DIR/naked-functions.rs:54:1
+  --> $DIR/naked-functions.rs:53:1
    |
 LL | / pub unsafe extern "C" fn unsupported_operands() {
 LL | |
@@ -119,33 +119,33 @@ LL | | }
    | |_^
 
 error[E0787]: naked functions must contain a single asm block
-  --> $DIR/naked-functions.rs:77:1
+  --> $DIR/naked-functions.rs:76:1
    |
 LL | / pub extern "C" fn missing_assembly() {
 LL | |
 LL | | }
    | |_^
 
 error[E0787]: asm in naked functions must use `noreturn` option
-  --> $DIR/naked-functions.rs:84:5
+  --> $DIR/naked-functions.rs:83:5
    |
 LL |     asm!("");
    |     ^^^^^^^^
 
 error[E0787]: asm in naked functions must use `noreturn` option
-  --> $DIR/naked-functions.rs:86:5
+  --> $DIR/naked-functions.rs:85:5
    |
 LL |     asm!("");
    |     ^^^^^^^^
 
 error[E0787]: asm in naked functions must use `noreturn` option
-  --> $DIR/naked-functions.rs:88:5
+  --> $DIR/naked-functions.rs:87:5
    |
 LL |     asm!("");
    |     ^^^^^^^^
 
 error[E0787]: naked functions must contain a single asm block
-  --> $DIR/naked-functions.rs:82:1
+  --> $DIR/naked-functions.rs:81:1
    |
 LL | / pub extern "C" fn too_many_asm_blocks() {
 LL | |
@@ -163,15 +163,15 @@ LL | | }
    | |_^
 
 error: referencing function parameters is not allowed in naked functions
-  --> $DIR/naked-functions.rs:97:11
+  --> $DIR/naked-functions.rs:96:11
    |
 LL |         *&y
    |           ^
    |
    = help: follow the calling convention in asm block to use parameters
 
 error[E0787]: naked functions must contain a single asm block
-  --> $DIR/naked-functions.rs:95:5
+  --> $DIR/naked-functions.rs:94:5
    |
 LL | /     pub extern "C" fn inner(y: usize) -> usize {
 LL | |
@@ -182,75 +182,75 @@ LL | |     }
    | |_____^
 
 error[E0787]: asm options unsupported in naked functions: `nomem`, `preserves_flags`
-  --> $DIR/naked-functions.rs:105:5
+  --> $DIR/naked-functions.rs:104:5
    |
 LL |     asm!("", options(nomem, preserves_flags, noreturn));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0787]: asm options unsupported in naked functions: `nostack`, `pure`, `readonly`
-  --> $DIR/naked-functions.rs:111:5
+  --> $DIR/naked-functions.rs:110:5
    |
 LL |     asm!("", options(readonly, nostack), options(pure));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0787]: asm in naked functions must use `noreturn` option
-  --> $DIR/naked-functions.rs:111:5
+  --> $DIR/naked-functions.rs:110:5
    |
 LL |     asm!("", options(readonly, nostack), options(pure));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0787]: asm options unsupported in naked functions: `may_unwind`
-  --> $DIR/naked-functions.rs:119:5
+  --> $DIR/naked-functions.rs:118:5
    |
 LL |     asm!("", options(noreturn, may_unwind));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: Rust ABI is unsupported in naked functions
-  --> $DIR/naked-functions.rs:124:15
+  --> $DIR/naked-functions.rs:123:15
    |
 LL | pub unsafe fn default_abi() {
    |               ^^^^^^^^^^^
    |
    = note: `#[warn(undefined_naked_function_abi)]` on by default
 
 warning: Rust ABI is unsupported in naked functions
-  --> $DIR/naked-functions.rs:130:15
+  --> $DIR/naked-functions.rs:129:29
    |
-LL | pub unsafe fn rust_abi() {
-   |               ^^^^^^^^
+LL | pub unsafe extern "Rust" fn rust_abi() {
+   |                             ^^^^^^^^
 
 error: naked functions cannot be inlined
-  --> $DIR/naked-functions.rs:170:1
+  --> $DIR/naked-functions.rs:169:1
    |
 LL | #[inline]
    | ^^^^^^^^^
 
 error: naked functions cannot be inlined
-  --> $DIR/naked-functions.rs:177:1
+  --> $DIR/naked-functions.rs:176:1
    |
 LL | #[inline(always)]
    | ^^^^^^^^^^^^^^^^^
 
 error: naked functions cannot be inlined
-  --> $DIR/naked-functions.rs:184:1
+  --> $DIR/naked-functions.rs:183:1
    |
 LL | #[inline(never)]
    | ^^^^^^^^^^^^^^^^
 
 error: naked functions cannot be inlined
-  --> $DIR/naked-functions.rs:191:1
+  --> $DIR/naked-functions.rs:190:1
    |
 LL | #[inline]
    | ^^^^^^^^^
 
 error: naked functions cannot be inlined
-  --> $DIR/naked-functions.rs:193:1
+  --> $DIR/naked-functions.rs:192:1
    |
 LL | #[inline(always)]
    | ^^^^^^^^^^^^^^^^^
 
 error: naked functions cannot be inlined
-  --> $DIR/naked-functions.rs:195:1
+  --> $DIR/naked-functions.rs:194:1
    |
 LL | #[inline(never)]
    | ^^^^^^^^^^^^^^^^

src/test/ui/asm/naked-invalid-attr.rs

@@ -1,7 +1,7 @@
 // Checks that #[naked] attribute can be placed on function definitions only.
 //
 // needs-asm-support
-#![feature(naked_functions)]
+
 #![naked] //~ ERROR should be applied to a function definition
 
 use std::arch::asm;

src/test/ui/asm/named-asm-labels.rs

@@ -11,7 +11,7 @@
 // which causes less readable LLVM errors and in the worst cases causes ICEs
 // or segfaults based on system dependent behavior and codegen flags.
 
-#![feature(naked_functions, asm_const)]
+#![feature(asm_const)]
 
 use std::arch::{asm, global_asm};