Rollup merge of #77343 - varkor:rustc_args_required_const-validation, r=lcnr

Validate `rustc_args_required_const`

Fixes https://github.com/rust-lang/rust/issues/74608.

2 files changed, 74 insertions, 0 deletions

diff --git a/src/test/ui/invalid-rustc_args_required_const-arguments.rs b/src/test/ui/invalid-rustc_args_required_const-arguments.rs
new file mode 100644
index 00000000000..76c01c21301
--- /dev/null
+++ b/src/test/ui/invalid-rustc_args_required_const-arguments.rs
@@ -0,0 +1,26 @@
+#![feature(rustc_attrs)]
+
+#[rustc_args_required_const(0)] //~ ERROR index exceeds number of arguments
+fn foo1() {}
+
+#[rustc_args_required_const(1)] //~ ERROR index exceeds number of arguments
+fn foo2(_: u8) {}
+
+#[rustc_args_required_const(a)] //~ ERROR arguments should be non-negative integers
+fn foo4() {}
+
+#[rustc_args_required_const(1, a, 2, b)] //~ ERROR arguments should be non-negative integers
+fn foo5(_: u8, _: u8, _: u8) {}
+
+#[rustc_args_required_const(0)] //~ ERROR attribute should be applied to a function
+struct S;
+
+#[rustc_args_required_const(0usize)] //~ ERROR suffixed literals are not allowed in attributes
+fn foo6(_: u8) {}
+
+extern {
+    #[rustc_args_required_const(1)] //~ ERROR index exceeds number of arguments
+    fn foo7(_: u8);
+}
+
+fn main() {}
diff --git a/src/test/ui/invalid-rustc_args_required_const-arguments.stderr b/src/test/ui/invalid-rustc_args_required_const-arguments.stderr
new file mode 100644
index 00000000000..39d04626168
--- /dev/null
+++ b/src/test/ui/invalid-rustc_args_required_const-arguments.stderr
@@ -0,0 +1,48 @@
+error: suffixed literals are not allowed in attributes
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:18:29
+   |
+LL | #[rustc_args_required_const(0usize)]
+   |                             ^^^^^^
+   |
+   = help: instead of using a suffixed literal (`1u8`, `1.0f32`, etc.), use an unsuffixed version (`1`, `1.0`, etc.)
+
+error: index exceeds number of arguments
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:3:29
+   |
+LL | #[rustc_args_required_const(0)]
+   |                             ^ there are only 0 arguments
+
+error: index exceeds number of arguments
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:6:29
+   |
+LL | #[rustc_args_required_const(1)]
+   |                             ^ there is only 1 argument
+
+error: arguments should be non-negative integers
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:9:29
+   |
+LL | #[rustc_args_required_const(a)]
+   |                             ^
+
+error: arguments should be non-negative integers
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:12:32
+   |
+LL | #[rustc_args_required_const(1, a, 2, b)]
+   |                                ^     ^
+
+error: attribute should be applied to a function
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:15:1
+   |
+LL | #[rustc_args_required_const(0)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | struct S;
+   | --------- not a function
+
+error: index exceeds number of arguments
+  --> $DIR/invalid-rustc_args_required_const-arguments.rs:22:33
+   |
+LL |     #[rustc_args_required_const(1)]
+   |                                 ^ there is only 1 argument
+
+error: aborting due to 7 previous errors
+