docs formatted stderr | nested-cfg-attrs.rs

Author: Kivooeo

tests/ui/cfg/nested-cfg-attr-conditional-compilation.rs

@@ -1,4 +1,18 @@
+//! Test that nested `cfg_attr` attributes work correctly for conditional compilation.
+//! This checks that `cfg_attr` can be arbitrarily deeply nested and that the
+//! expansion works from outside to inside, eventually applying the innermost
+//! conditional compilation directive.
+//!
+//! In this test, `cfg_attr(all(), cfg_attr(all(), cfg(false)))` should expand to:
+//! 1. `cfg_attr(all(), cfg(false))` (outer cfg_attr applied)
+//! 2. `cfg(false)` (inner cfg_attr applied)
+//! 3. Function `f` is excluded from compilation
+//!
+//! Regression test for <https://github.com/rust-lang/rust/pull/34216>.
+
 #[cfg_attr(all(), cfg_attr(all(), cfg(false)))]
 fn f() {}
 
-fn main() { f() } //~ ERROR cannot find function `f` in this scope
+fn main() {
+    f() //~ ERROR cannot find function `f` in this scope
+}

tests/ui/cfg/nested-cfg-attr-conditional-compilation.stderr

@@ -1,8 +1,8 @@
 error[E0425]: cannot find function `f` in this scope
-  --> $DIR/nested-cfg-attrs.rs:4:13
+  --> $DIR/nested-cfg-attr-conditional-compilation.rs:17:5
    |
-LL | fn main() { f() }
-   |             ^ not found in this scope
+LL |     f()
+   |     ^ not found in this scope
 
 error: aborting due to 1 previous error