Partial progress on #132735: Replace extern "rust-intrinsic" with #[rustc_intrinsic] across the codebase

compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs

@@ -1,4 +1,5 @@
 //! Codegen of intrinsics. This includes `extern "rust-intrinsic"`,
+//! functions marked with the `#[rustc_intrinsic]` attribute
 //! and LLVM intrinsics that have symbol names starting with `llvm.`.
 
 macro_rules! intrinsic_args {

src/tools/miri/tests/fail/intrinsics/copy_overlapping.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
-}
+#[rustc_intrinsic]
+unsafe fn copy_nonoverlapping<T>(_src: *const T, _dst: *mut T, _count: usize);
 
 fn main() {
     let mut data = [0u8; 16];

src/tools/miri/tests/fail/intrinsics/copy_unaligned.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
-}
+#[rustc_intrinsic]
+unsafe fn copy_nonoverlapping<T>(_src: *const T, _dst: *mut T, _count: usize);
 
 fn main() {
     let mut data = [0u16; 8];

src/tools/miri/tests/fail/intrinsics/ctlz_nonzero.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 mod rusti {
-    extern "rust-intrinsic" {
-        pub fn ctlz_nonzero<T>(x: T) -> u32;
-    }
+    #[rustc_intrinsic]
+    pub unsafe fn ctlz_nonzero<T>(_x: T) -> u32;
 }
 
 pub fn main() {

src/tools/miri/tests/fail/intrinsics/cttz_nonzero.rs

@@ -1,9 +1,9 @@
+
 #![feature(intrinsics)]
 
 mod rusti {
-    extern "rust-intrinsic" {
-        pub fn cttz_nonzero<T>(x: T) -> u32;
-    }
+    #[rustc_intrinsic]
+    pub unsafe fn cttz_nonzero<T>(_x: T) -> u32;
 }
 
 pub fn main() {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_inf1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_infneg1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_nan.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_nanneg.rs

@@ -1,9 +1,9 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
+
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_neg.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_too_big1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_too_big2.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_32_too_small1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_inf1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_infneg1.rs

@@ -1,9 +1,9 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
+
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_infneg2.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_nan.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_neg.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big2.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big3.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big4.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big5.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big6.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_big7.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_small1.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_small2.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/fail/intrinsics/float_to_int_64_too_small3.rs

@@ -1,9 +1,8 @@
 #![feature(intrinsics)]
 
 // Directly call intrinsic to avoid debug assertions in libstd
-extern "rust-intrinsic" {
-    fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int;
-}
+#[rustc_intrinsic]
+unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(_value: Float) -> Int;
 
 fn main() {
     unsafe {

src/tools/miri/tests/pass/intrinsics/portable-simd.rs

@@ -14,10 +14,9 @@ use std::ptr;
 use std::simd::StdFloat;
 use std::simd::prelude::*;
 
-extern "rust-intrinsic" {
-    #[rustc_nounwind]
-    pub fn simd_shuffle_generic<T, U, const IDX: &'static [u32]>(x: T, y: T) -> U;
-}
+#[rustc_intrinsic]
+#[rustc_nounwind]
+pub unsafe fn simd_shuffle_generic<T, U, const IDX: &'static [u32]>(_x: T, _y: T) -> U;
 
 fn simd_ops_f32() {
     let a = f32x4::splat(10.0);