Fix bad replacement for unsafe extern block suggestion

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -464,7 +464,7 @@ impl<'a> AstValidator<'a> {
  {
  self.dcx().emit_err(errors::InvalidSafetyOnExtern {
  item_span: span,
- block: self.current_extern_span(),
+ block: self.current_extern_span().shrink_to_lo(),
  });
  }
  }

compiler/rustc_ast_passes/src/errors.rs

@@ -221,7 +221,7 @@ pub enum ExternBlockSuggestion {
 pub struct InvalidSafetyOnExtern {
  #[primary_span]
  pub item_span: Span,
- #[suggestion(code = "", applicability = "maybe-incorrect")]
+ #[suggestion(code = "unsafe ", applicability = "machine-applicable", style = "verbose")]
  pub block: Span,
 }
 

tests/ui/parser/fn-header-semantic-fail.stderr

@@ -81,11 +81,13 @@ LL | async fn fe1();
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/fn-header-semantic-fail.rs:47:9
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-LL | async fn fe1();
 LL | unsafe fn fe2();
  | ^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: functions in `extern` blocks cannot have qualifiers
  --> $DIR/fn-header-semantic-fail.rs:48:9
@@ -135,11 +137,13 @@ LL | const async unsafe extern "C" fn fe5();
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/fn-header-semantic-fail.rs:50:9
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-...
 LL | const async unsafe extern "C" fn fe5();
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: functions cannot be both `const` and `async`
  --> $DIR/fn-header-semantic-fail.rs:50:9

tests/ui/parser/no-const-fn-in-extern-block.stderr

@@ -18,11 +18,13 @@ LL | const unsafe fn bar();
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/no-const-fn-in-extern-block.rs:4:5
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-...
 LL | const unsafe fn bar();
  | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: aborting due to 3 previous errors
 

tests/ui/parser/unsafe-foreign-mod-2.stderr

@@ -13,11 +13,13 @@ LL | extern "C" unsafe {
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/unsafe-foreign-mod-2.rs:4:5
  |
-LL | extern "C" unsafe {
- | ----------------- help: add unsafe to this `extern` block
-...
 LL | unsafe fn foo();
  | ^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" unsafe {
+ | ++++++
 
 error: aborting due to 3 previous errors
 

tests/ui/rust-2024/unsafe-extern-blocks/safe-unsafe-on-unadorned-extern-block.edition2021.stderr

@@ -1,20 +1,24 @@
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:10:5
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-LL |
 LL | safe static TEST1: i32;
  | ^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:12:5
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-...
 LL | safe fn test1(i: i32);
  | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: aborting due to 2 previous errors
 

tests/ui/rust-2024/unsafe-extern-blocks/safe-unsafe-on-unadorned-extern-block.edition2024.stderr

@@ -13,20 +13,24 @@ LL | | }
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:10:5
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-LL |
 LL | safe static TEST1: i32;
  | ^^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: items in unadorned `extern` blocks cannot have safety qualifiers
  --> $DIR/safe-unsafe-on-unadorned-extern-block.rs:12:5
  |
-LL | extern "C" {
- | ---------- help: add unsafe to this `extern` block
-...
 LL | safe fn test1(i: i32);
  | ^^^^^^^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
 
 error: aborting due to 3 previous errors
 

tests/ui/rust-2024/unsafe-extern-blocks/unsafe-on-extern-block-issue-126756.fixed

@@ -0,0 +1,10 @@
+//@ run-rustfix
+
+#![feature(unsafe_extern_blocks)]
+#![allow(dead_code)]
+
+unsafe extern "C" {
+ unsafe fn foo(); //~ ERROR items in unadorned `extern` blocks cannot have safety qualifiers
+}
+
+fn main() {}

tests/ui/rust-2024/unsafe-extern-blocks/unsafe-on-extern-block-issue-126756.rs

@@ -0,0 +1,10 @@
+//@ run-rustfix
+
+#![feature(unsafe_extern_blocks)]
+#![allow(dead_code)]
+
+extern "C" {
+ unsafe fn foo(); //~ ERROR items in unadorned `extern` blocks cannot have safety qualifiers
+}
+
+fn main() {}

tests/ui/rust-2024/unsafe-extern-blocks/unsafe-on-extern-block-issue-126756.stderr

@@ -0,0 +1,13 @@
+error: items in unadorned `extern` blocks cannot have safety qualifiers
+ --> $DIR/unsafe-on-extern-block-issue-126756.rs:7:5
+ |
+LL | unsafe fn foo();
+ | ^^^^^^^^^^^^^^^^
+ |
+help: add unsafe to this `extern` block
+ |
+LL | unsafe extern "C" {
+ | ++++++
+
+error: aborting due to 1 previous error
+