make unsafe_op_in_unsafe_fn MachineApplicable and add it to 2024 comp…

…atibility

compiler/rustc_lint_defs/src/builtin.rs

@@ -2755,6 +2755,11 @@ declare_lint! {
     pub UNSAFE_OP_IN_UNSAFE_FN,
     Allow,
     "unsafe operations in unsafe functions without an explicit unsafe block are deprecated",
+    @future_incompatible = FutureIncompatibleInfo {
+        reason: FutureIncompatibilityReason::EditionSemanticsChange(Edition::Edition2024),
+        reference: "issue #71668 <https://github.com/rust-lang/rust/issues/71668>",
+        explain_reason: false
+    };
     @edition Edition2024 => Warn;
 }
 

compiler/rustc_mir_build/src/errors.rs

@@ -430,7 +430,7 @@ impl AddToDiagnostic for UnsafeNotInheritedLintNote {
         diag.tool_only_multipart_suggestion(
             fluent::mir_build_wrap_suggestion,
             vec![(body_start, "{ unsafe ".into()), (body_end, "}".into())],
-            Applicability::MaybeIncorrect,
+            Applicability::MachineApplicable,
         );
     }
 }

tests/ui/rfcs/rfc-2396-target_feature-11/safe-calls.stderr

@@ -97,6 +97,7 @@ error: call to function `sse2` with `#[target_feature]` is unsafe and requires u
 LL |     sse2();
    |     ^^^^^^ call to function with `#[target_feature]`
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = help: in order for the call to be safe, the context requires the following additional target feature: sse2
    = note: the sse2 target feature being enabled in the build configuration does not remove the requirement to list it in `#[target_feature]`
 note: an unsafe function restricts its caller, but its body is safe by default

tests/ui/unsafe/edition-2024-unsafe_op_in_unsafe_fn.stderr

@@ -4,6 +4,7 @@ warning: call to unsafe function `unsf` is unsafe and requires unsafe block (err
 LL |     unsf();
    |     ^^^^^^ call to unsafe function
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: consult the function's documentation for information on how to avoid undefined behavior
 note: an unsafe function restricts its caller, but its body is safe by default
   --> $DIR/edition-2024-unsafe_op_in_unsafe_fn.rs:9:1

tests/ui/unsafe/unsafe_op_in_unsafe_fn/edition_2024_default.rs

@@ -0,0 +1,20 @@
+// edition: 2024
+// compile-flags: -Zunstable-options
+// check-pass
+
+// Tests that `unsafe_op_in_unsafe_fn` is warn-by-default in edition 2024 and that the
+// `unused_unsafe` lint does not consider the inner unsafe block to be unused.
+#![crate_type = "lib"]
+#![deny(unused_unsafe)]
+
+unsafe fn unsf() {}
+
+unsafe fn foo() {
+    unsf();
+    //~^ WARN
+
+    // no unused_unsafe
+    unsafe {
+        unsf();
+    }
+}

tests/ui/unsafe/unsafe_op_in_unsafe_fn/edition_2024_default.stderr

@@ -0,0 +1,17 @@
+warning: call to unsafe function `unsf` is unsafe and requires unsafe block (error E0133)
+  --> $DIR/edition_2024_default.rs:13:5
+   |
+LL |     unsf();
+   |     ^^^^^^ call to unsafe function
+   |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+note: an unsafe function restricts its caller, but its body is safe by default
+  --> $DIR/edition_2024_default.rs:12:1
+   |
+LL | unsafe fn foo() {
+   | ^^^^^^^^^^^^^^^
+   = note: `#[warn(unsafe_op_in_unsafe_fn)]` on by default
+
+warning: 1 warning emitted
+

tests/ui/unsafe/unsafe_op_in_unsafe_fn/in_2024_compatibility.rs

@@ -0,0 +1,9 @@
+#![deny(rust_2024_compatibility)]
+#![crate_type = "lib"]
+
+unsafe fn unsf() {}
+
+unsafe fn foo() {
+    unsf();
+    //~^ ERROR call to unsafe function `unsf` is unsafe and requires unsafe block
+}

tests/ui/unsafe/unsafe_op_in_unsafe_fn/in_2024_compatibility.stderr

@@ -0,0 +1,22 @@
+error: call to unsafe function `unsf` is unsafe and requires unsafe block (error E0133)
+  --> $DIR/in_2024_compatibility.rs:7:5
+   |
+LL |     unsf();
+   |     ^^^^^^ call to unsafe function
+   |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+note: an unsafe function restricts its caller, but its body is safe by default
+  --> $DIR/in_2024_compatibility.rs:6:1
+   |
+LL | unsafe fn foo() {
+   | ^^^^^^^^^^^^^^^
+note: the lint level is defined here
+  --> $DIR/in_2024_compatibility.rs:1:9
+   |
+LL | #![deny(rust_2024_compatibility)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^
+   = note: `#[deny(unsafe_op_in_unsafe_fn)]` implied by `#[deny(rust_2024_compatibility)]`
+
+error: aborting due to 1 previous error
+

tests/ui/unsafe/rfc-2585-unsafe_op_in_unsafe_fn.stderr → tests/ui/unsafe/unsafe_op_in_unsafe_fn/rfc-2585-unsafe_op_in_unsafe_fn.stderr

@@ -4,6 +4,7 @@ error: call to unsafe function `unsf` is unsafe and requires unsafe block (error
 LL |     unsf();
    |     ^^^^^^ call to unsafe function
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: consult the function's documentation for information on how to avoid undefined behavior
 note: an unsafe function restricts its caller, but its body is safe by default
   --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:8:1
@@ -22,6 +23,7 @@ error: dereference of raw pointer is unsafe and requires unsafe block (error E01
 LL |     *PTR;
    |     ^^^^ dereference of raw pointer
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: raw pointers may be null, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
 
 error: use of mutable static is unsafe and requires unsafe block (error E0133)
@@ -30,6 +32,7 @@ error: use of mutable static is unsafe and requires unsafe block (error E0133)
 LL |     VOID = ();
    |     ^^^^ use of mutable static
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: mutable statics can be mutated by multiple threads: aliasing violations or data races will cause undefined behavior
 
 error: unnecessary `unsafe` block
@@ -50,6 +53,7 @@ error: call to unsafe function `unsf` is unsafe and requires unsafe block (error
 LL |     unsf();
    |     ^^^^^^ call to unsafe function
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: consult the function's documentation for information on how to avoid undefined behavior
 note: an unsafe function restricts its caller, but its body is safe by default
   --> $DIR/rfc-2585-unsafe_op_in_unsafe_fn.rs:23:1
@@ -69,6 +73,7 @@ error: dereference of raw pointer is unsafe and requires unsafe block (error E01
 LL |     *PTR;
    |     ^^^^ dereference of raw pointer
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: raw pointers may be null, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
 
 error: use of mutable static is unsafe and requires unsafe block (error E0133)
@@ -77,6 +82,7 @@ error: use of mutable static is unsafe and requires unsafe block (error E0133)
 LL |     VOID = ();
    |     ^^^^ use of mutable static
    |
+   = note: for more information, see issue #71668 <https://github.com/rust-lang/rust/issues/71668>
    = note: mutable statics can be mutated by multiple threads: aliasing violations or data races will cause undefined behavior
 
 error: unnecessary `unsafe` block

tests/ui/unsafe/wrapping-unsafe-block-sugg.fixed → tests/ui/unsafe/unsafe_op_in_unsafe_fn/wrapping-unsafe-block-sugg.fixed

@@ -11,50 +11,60 @@ unsafe fn unsf() {}
 pub unsafe fn foo() { unsafe {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     unsf(); //~ ERROR call to unsafe function `unsf` is unsafe
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE call to unsafe function
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE consult the function's documentation
     unsf(); //~ ERROR call to unsafe function `unsf` is unsafe
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE call to unsafe function
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE consult the function's documentation
 }}
 
 pub unsafe fn bar(x: *const i32) -> i32 { unsafe {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     let y = *x; //~ ERROR dereference of raw pointer is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE dereference of raw pointer
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE raw pointers may be null
     y + *x //~ ERROR dereference of raw pointer is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE dereference of raw pointer
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE raw pointers may be null
 }}
 
 static mut BAZ: i32 = 0;
 pub unsafe fn baz() -> i32 { unsafe {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     let y = BAZ; //~ ERROR use of mutable static is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE use of mutable static
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE mutable statics can be mutated by multiple threads
     y + BAZ //~ ERROR use of mutable static is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE use of mutable static
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE mutable statics can be mutated by multiple threads
 }}
 
 macro_rules! unsafe_macro { () => (unsf()) }
 //~^ ERROR call to unsafe function `unsf` is unsafe
-//~| NOTE
-//~| NOTE
+//~| NOTE call to unsafe function
+//~| NOTE for more information, see issue #71668
+//~| NOTE consult the function's documentation
 //~| ERROR call to unsafe function `unsf` is unsafe
-//~| NOTE
-//~| NOTE
+//~| NOTE call to unsafe function
+//~| NOTE for more information, see issue #71668
+//~| NOTE consult the function's documentation
 
 pub unsafe fn unsafe_in_macro() { unsafe {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     unsafe_macro!();
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE in this expansion
+    //~| NOTE in this expansion
+    //~| NOTE in this expansion
     unsafe_macro!();
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE in this expansion
+    //~| NOTE in this expansion
+    //~| NOTE in this expansion
 }}
 
 pub unsafe fn unsafe_in_external_macro() {

tests/ui/unsafe/wrapping-unsafe-block-sugg.rs → tests/ui/unsafe/unsafe_op_in_unsafe_fn/wrapping-unsafe-block-sugg.rs

@@ -11,50 +11,60 @@ unsafe fn unsf() {}
 pub unsafe fn foo() {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     unsf(); //~ ERROR call to unsafe function `unsf` is unsafe
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE call to unsafe function
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE consult the function's documentation
     unsf(); //~ ERROR call to unsafe function `unsf` is unsafe
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE call to unsafe function
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE consult the function's documentation
 }
 
 pub unsafe fn bar(x: *const i32) -> i32 {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     let y = *x; //~ ERROR dereference of raw pointer is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE dereference of raw pointer
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE raw pointers may be null
     y + *x //~ ERROR dereference of raw pointer is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE dereference of raw pointer
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE raw pointers may be null
 }
 
 static mut BAZ: i32 = 0;
 pub unsafe fn baz() -> i32 {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     let y = BAZ; //~ ERROR use of mutable static is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE use of mutable static
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE mutable statics can be mutated by multiple threads
     y + BAZ //~ ERROR use of mutable static is unsafe and requires unsafe block
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE use of mutable static
+    //~| NOTE for more information, see issue #71668
+    //~| NOTE mutable statics can be mutated by multiple threads
 }
 
 macro_rules! unsafe_macro { () => (unsf()) }
 //~^ ERROR call to unsafe function `unsf` is unsafe
-//~| NOTE
-//~| NOTE
+//~| NOTE call to unsafe function
+//~| NOTE for more information, see issue #71668
+//~| NOTE consult the function's documentation
 //~| ERROR call to unsafe function `unsf` is unsafe
-//~| NOTE
-//~| NOTE
+//~| NOTE call to unsafe function
+//~| NOTE for more information, see issue #71668
+//~| NOTE consult the function's documentation
 
 pub unsafe fn unsafe_in_macro() {
     //~^ NOTE an unsafe function restricts its caller, but its body is safe by default
     unsafe_macro!();
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE in this expansion
+    //~| NOTE in this expansion
+    //~| NOTE in this expansion
     unsafe_macro!();
-    //~^ NOTE
-    //~| NOTE
+    //~^ NOTE in this expansion
+    //~| NOTE in this expansion
+    //~| NOTE in this expansion
 }
 
 pub unsafe fn unsafe_in_external_macro() {