Deprecate the asm! macro

Author: Amanieu

src/libcore/macros/mod.rs

@@ -1316,9 +1316,13 @@ pub(crate) mod builtin {
         issue = "70173",
         reason = "inline assembly is not stable enough for use and is subject to change"
     )]
-    #[rustc_deprecated(
-        since = "1.44.0",
-        reason = "the syntax of asm! will change soon, use llvm_asm! to avoid breakage"
+    #[cfg_attr(
+        not(bootstrap),
+        rustc_deprecated(
+            since = "1.44.0",
+            reason = "the syntax of asm! will change soon, use llvm_asm! to avoid breakage",
+            suggestion = "llvm_asm",
+        )
     )]
     #[rustc_builtin_macro]
     #[macro_export]

src/libcore/prelude/v1.rs

@@ -54,6 +54,7 @@ pub use crate::fmt::macros::Debug;
 pub use crate::hash::macros::Hash;
 
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
+#[allow(deprecated)]
 #[doc(no_inline)]
 pub use crate::{
     asm, assert, cfg, column, compile_error, concat, concat_idents, env, file, format_args,

src/libstd/lib.rs

@@ -523,6 +523,7 @@ pub use core::{
 
 // Re-export built-in macros defined through libcore.
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
+#[allow(deprecated)]
 pub use core::{
     asm, assert, cfg, column, compile_error, concat, concat_idents, env, file, format_args,
     format_args_nl, global_asm, include, include_bytes, include_str, line, llvm_asm, log_syntax,

src/libstd/prelude/v1.rs

@@ -36,6 +36,7 @@ pub use crate::result::Result::{self, Err, Ok};
 
 // Re-exported built-in macros
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
+#[allow(deprecated)]
 #[doc(no_inline)]
 pub use core::prelude::v1::{
     asm, assert, cfg, column, compile_error, concat, concat_idents, env, file, format_args,

src/test/ui/feature-gates/feature-gate-asm.rs

@@ -3,6 +3,7 @@
 fn main() {
     unsafe {
         asm!(""); //~ ERROR inline assembly is not stable enough
+        //~^ WARN use of deprecated item 'asm'
         llvm_asm!(""); //~ ERROR inline assembly is not stable enough
     }
 }

src/test/ui/feature-gates/feature-gate-asm.stderr

@@ -8,14 +8,22 @@ LL |         asm!("");
    = help: add `#![feature(asm)]` to the crate attributes to enable
 
 error[E0658]: use of unstable library feature 'llvm_asm': inline assembly is not stable enough for use and is subject to change
-  --> $DIR/feature-gate-asm.rs:6:9
+  --> $DIR/feature-gate-asm.rs:7:9
    |
 LL |         llvm_asm!("");
    |         ^^^^^^^^
    |
    = note: see issue #70173 <https://github.com/rust-lang/rust/issues/70173> for more information
    = help: add `#![feature(llvm_asm)]` to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+warning: use of deprecated item 'asm': the syntax of asm! will change soon, use llvm_asm! to avoid breakage
+  --> $DIR/feature-gate-asm.rs:5:9
+   |
+LL |         asm!("");
+   |         ^^^ help: replace the use of the deprecated item: `llvm_asm`
+   |
+   = note: `#[warn(deprecated)]` on by default
+
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0658`.

src/test/ui/feature-gates/feature-gate-asm2.rs

@@ -3,6 +3,7 @@
 fn main() {
     unsafe {
         println!("{:?}", asm!("")); //~ ERROR inline assembly is not stable
+        //~^ WARN use of deprecated item 'asm'
         println!("{:?}", llvm_asm!("")); //~ ERROR inline assembly is not stable
     }
 }

src/test/ui/feature-gates/feature-gate-asm2.stderr

@@ -8,14 +8,22 @@ LL |         println!("{:?}", asm!(""));
    = help: add `#![feature(asm)]` to the crate attributes to enable
 
 error[E0658]: use of unstable library feature 'llvm_asm': inline assembly is not stable enough for use and is subject to change
-  --> $DIR/feature-gate-asm2.rs:6:26
+  --> $DIR/feature-gate-asm2.rs:7:26
    |
 LL |         println!("{:?}", llvm_asm!(""));
    |                          ^^^^^^^^
    |
    = note: see issue #70173 <https://github.com/rust-lang/rust/issues/70173> for more information
    = help: add `#![feature(llvm_asm)]` to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+warning: use of deprecated item 'asm': the syntax of asm! will change soon, use llvm_asm! to avoid breakage
+  --> $DIR/feature-gate-asm2.rs:5:26
+   |
+LL |         println!("{:?}", asm!(""));
+   |                          ^^^ help: replace the use of the deprecated item: `llvm_asm`
+   |
+   = note: `#[warn(deprecated)]` on by default
+
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0658`.