[gcc/devel/rust/master] Avoid parsing const unsafe/extern functions as async

[gcc/devel/rust/master] Avoid parsing const unsafe/extern functions as async

[Thomas Schwinge]

https://gcc.gnu.org/g:01092b83913733d26f2c4d9bfdc22ff2eb0b0bbb

commit 01092b83913733d26f2c4d9bfdc22ff2eb0b0bbb
Author: Owen Avery <powerboat9.gamer@gmail.com>
Date:   Tue Mar 26 15:58:48 2024 -0400

    Avoid parsing const unsafe/extern functions as async
    
    gcc/rust/ChangeLog:
    
            * parse/rust-parse-impl.h
            (Parser::parse_vis_item):
            Call parse_function instead of parse_async_item when finding
            UNSAFE or EXTERN_KW during lookahead.
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/func-const-unsafe.rs: New test.
    
    Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>

Diff:
---
 gcc/rust/parse/rust-parse-impl.h                | 4 ++--
 gcc/testsuite/rust/compile/func-const-unsafe.rs | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index b6c2ca3fc0c9..263ca634ea5c 100644
--- a/gcc/rust/parse/rust-parse-impl.h
+++ b/gcc/rust/parse/rust-parse-impl.h
@@ -1382,10 +1382,10 @@ Parser<ManagedTokenSource>::parse_vis_item (AST::AttrVec outer_attrs)
 	case IDENTIFIER:
 	case UNDERSCORE:
 	  return parse_const_item (std::move (vis), std::move (outer_attrs));
-	case UNSAFE:
-	case EXTERN_KW:
 	case ASYNC:
 	  return parse_async_item (std::move (vis), std::move (outer_attrs));
+	case UNSAFE:
+	case EXTERN_KW:
 	case FN_KW:
 	  return parse_function (std::move (vis), std::move (outer_attrs));
 	default:
diff --git a/gcc/testsuite/rust/compile/func-const-unsafe.rs b/gcc/testsuite/rust/compile/func-const-unsafe.rs
new file mode 100644
index 000000000000..9c932bd1cb54
--- /dev/null
+++ b/gcc/testsuite/rust/compile/func-const-unsafe.rs
@@ -0,0 +1 @@
+pub const unsafe fn foo() {}