Collect and use `#[doc(test(attr(..)))]` at every level

3 files changed, 285 insertions, 34 deletions

diff --git a/src/librustdoc/doctest/rust.rs b/src/librustdoc/doctest/rust.rs
index 4e9b1ee36f3..96975105ac5 100644
--- a/src/librustdoc/doctest/rust.rs
+++ b/src/librustdoc/doctest/rust.rs
@@ -127,6 +127,26 @@ impl HirCollector<'_> {
             return;
         }
 
+        // Try collecting `#[doc(test(attr(...)))]`
+        let old_global_crate_attrs_len = self.collector.global_crate_attrs.len();
+        for doc_test_attrs in ast_attrs
+            .iter()
+            .filter(|a| a.has_name(sym::doc))
+            .flat_map(|a| a.meta_item_list().unwrap_or_default())
+            .filter(|a| a.has_name(sym::test))
+        {
+            let Some(doc_test_attrs) = doc_test_attrs.meta_item_list() else { continue };
+            for attr in doc_test_attrs
+                .iter()
+                .filter(|a| a.has_name(sym::attr))
+                .flat_map(|a| a.meta_item_list().unwrap_or_default())
+                .map(|i| pprust::meta_list_item_to_string(i))
+            {
+                // Add the additional attributes to the global_crate_attrs vector
+                self.collector.global_crate_attrs.push(attr);
+            }
+        }
+
         let mut has_name = false;
         if let Some(name) = name {
             self.collector.cur_path.push(name);
@@ -161,6 +181,9 @@ impl HirCollector<'_> {
 
         nested(self);
 
+        // Restore global_crate_attrs to it's previous size/content
+        self.collector.global_crate_attrs.truncate(old_global_crate_attrs_len);
+
         if has_name {
             self.collector.cur_path.pop();
         }
@@ -174,40 +197,6 @@ impl<'tcx> intravisit::Visitor<'tcx> for HirCollector<'tcx> {
         self.tcx
     }
 
-    fn visit_mod(&mut self, m: &'tcx hir::Mod<'tcx>, _s: Span, hir_id: hir::HirId) {
-        let attrs = self.tcx.hir_attrs(hir_id);
-
-        if !attrs.is_empty() {
-            // Try collecting `#![doc(test(attr(...)))]` from the attribute module
-            let old_len = self.collector.global_crate_attrs.len();
-            for doc_test_attrs in attrs
-                .iter()
-                .filter(|a| a.has_name(sym::doc))
-                .flat_map(|a| a.meta_item_list().unwrap_or_default())
-                .filter(|a| a.has_name(sym::test))
-            {
-                let Some(doc_test_attrs) = doc_test_attrs.meta_item_list() else { continue };
-                for attr in doc_test_attrs
-                    .iter()
-                    .filter(|a| a.has_name(sym::attr))
-                    .flat_map(|a| a.meta_item_list().unwrap_or_default())
-                    .map(|i| pprust::meta_list_item_to_string(i))
-                {
-                    // Add the additional attributes to the global_crate_attrs vector
-                    self.collector.global_crate_attrs.push(attr);
-                }
-            }
-
-            let r = intravisit::walk_mod(self, m);
-
-            // Restore global_crate_attrs to it's previous size/content
-            self.collector.global_crate_attrs.truncate(old_len);
-            r
-        } else {
-            intravisit::walk_mod(self, m)
-        }
-    }
-
     fn visit_item(&mut self, item: &'tcx hir::Item<'_>) {
         let name = match &item.kind {
             hir::ItemKind::Impl(impl_) => {
diff --git a/tests/rustdoc-ui/doctest/dead-code-items.rs b/tests/rustdoc-ui/doctest/dead-code-items.rs
new file mode 100644
index 00000000000..015504cbced
--- /dev/null
+++ b/tests/rustdoc-ui/doctest/dead-code-items.rs
@@ -0,0 +1,116 @@
+// Same test as dead-code-module but with 2 doc(test(attr())) at different levels.
+
+//@ edition: 2024
+//@ compile-flags:--test --test-args=--test-threads=1
+//@ normalize-stdout: "tests/rustdoc-ui/doctest" -> "$$DIR"
+//@ normalize-stdout: "finished in \d+\.\d+s" -> "finished in $$TIME"
+//@ failure-status: 101
+
+#![doc(test(attr(deny(warnings))))]
+
+#[doc(test(attr(allow(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// trait OnlyWarning { fn no_deny_warnings(); }
+/// ```
+static S: u32 = 5;
+
+#[doc(test(attr(allow(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// let unused_error = 5;
+///
+/// fn dead_code_but_no_error() {}
+/// ```
+const C: u32 = 5;
+
+#[doc(test(attr(allow(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// trait OnlyWarningAtA { fn no_deny_warnings(); }
+/// ```
+struct A {
+    #[doc(test(attr(deny(dead_code))))]
+    /// Example
+    ///
+    /// ```rust,no_run
+    /// trait DeadCodeInField {}
+    /// ```
+    field: u32
+}
+
+#[doc(test(attr(allow(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// trait OnlyWarningAtU { fn no_deny_warnings(); }
+/// ```
+union U {
+    #[doc(test(attr(deny(dead_code))))]
+    /// Example
+    ///
+    /// ```rust,no_run
+    /// trait DeadCodeInUnionField {}
+    /// ```
+    field: u32,
+    /// Example
+    ///
+    /// ```rust,no_run
+    /// trait NotDeadCodeInUnionField {}
+    /// ```
+    field2: u64,
+}
+
+#[doc(test(attr(deny(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// let not_dead_code_but_unused = 5;
+/// ```
+enum Enum {
+    #[doc(test(attr(allow(dead_code))))]
+    /// Example
+    ///
+    /// ```rust,no_run
+    /// trait NotDeadCodeInVariant {}
+    ///
+    /// fn main() { let unused_in_variant = 5; }
+    /// ```
+    Variant1,
+}
+
+#[doc(test(attr(allow(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// trait OnlyWarningAtImplA { fn no_deny_warnings(); }
+/// ```
+impl A {
+    /// Example
+    ///
+    /// ```rust,no_run
+    /// trait NotDeadCodeInImplMethod {}
+    /// ```
+    fn method() {}
+}
+
+#[doc(test(attr(deny(dead_code))))]
+/// Example
+///
+/// ```rust,no_run
+/// trait StillDeadCodeAtMyTrait { }
+/// ```
+trait MyTrait {
+    #[doc(test(attr(allow(dead_code))))]
+    /// Example
+    ///
+    /// ```rust,no_run
+    /// trait NotDeadCodeAtImplFn {}
+    ///
+    /// fn main() { let unused_in_impl = 5; }
+    /// ```
+    fn my_trait_fn();
+}
diff --git a/tests/rustdoc-ui/doctest/dead-code-items.stdout b/tests/rustdoc-ui/doctest/dead-code-items.stdout
new file mode 100644
index 00000000000..4b9d8be94dd
--- /dev/null
+++ b/tests/rustdoc-ui/doctest/dead-code-items.stdout
@@ -0,0 +1,146 @@
+
+running 13 tests
+test $DIR/dead-code-items.rs - A (line 32) - compile ... ok
+test $DIR/dead-code-items.rs - A (line 88) - compile ... ok
+test $DIR/dead-code-items.rs - A::field (line 39) - compile ... FAILED
+test $DIR/dead-code-items.rs - A::method (line 94) - compile ... ok
+test $DIR/dead-code-items.rs - C (line 22) - compile ... FAILED
+test $DIR/dead-code-items.rs - Enum (line 70) - compile ... FAILED
+test $DIR/dead-code-items.rs - Enum::Variant1 (line 77) - compile ... FAILED
+test $DIR/dead-code-items.rs - MyTrait (line 103) - compile ... FAILED
+test $DIR/dead-code-items.rs - MyTrait::my_trait_fn (line 110) - compile ... FAILED
+test $DIR/dead-code-items.rs - S (line 14) - compile ... ok
+test $DIR/dead-code-items.rs - U (line 48) - compile ... ok
+test $DIR/dead-code-items.rs - U::field (line 55) - compile ... FAILED
+test $DIR/dead-code-items.rs - U::field2 (line 61) - compile ... ok
+
+failures:
+
+---- $DIR/dead-code-items.rs - A::field (line 39) stdout ----
+error: trait `DeadCodeInField` is never used
+  --> $DIR/dead-code-items.rs:40:7
+   |
+LL | trait DeadCodeInField {}
+   |       ^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:38:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+---- $DIR/dead-code-items.rs - C (line 22) stdout ----
+error: unused variable: `unused_error`
+  --> $DIR/dead-code-items.rs:23:5
+   |
+LL | let unused_error = 5;
+   |     ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_error`
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:20:9
+   |
+LL | #![deny(warnings)]
+   |         ^^^^^^^^
+   = note: `#[deny(unused_variables)]` implied by `#[deny(warnings)]`
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+---- $DIR/dead-code-items.rs - Enum (line 70) stdout ----
+error: unused variable: `not_dead_code_but_unused`
+  --> $DIR/dead-code-items.rs:71:5
+   |
+LL | let not_dead_code_but_unused = 5;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_not_dead_code_but_unused`
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:68:9
+   |
+LL | #![deny(warnings)]
+   |         ^^^^^^^^
+   = note: `#[deny(unused_variables)]` implied by `#[deny(warnings)]`
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+---- $DIR/dead-code-items.rs - Enum::Variant1 (line 77) stdout ----
+error: unused variable: `unused_in_variant`
+  --> $DIR/dead-code-items.rs:80:17
+   |
+LL | fn main() { let unused_in_variant = 5; }
+   |                 ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_in_variant`
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:75:9
+   |
+LL | #![deny(warnings)]
+   |         ^^^^^^^^
+   = note: `#[deny(unused_variables)]` implied by `#[deny(warnings)]`
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+---- $DIR/dead-code-items.rs - MyTrait (line 103) stdout ----
+error: trait `StillDeadCodeAtMyTrait` is never used
+  --> $DIR/dead-code-items.rs:104:7
+   |
+LL | trait StillDeadCodeAtMyTrait { }
+   |       ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:102:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+---- $DIR/dead-code-items.rs - MyTrait::my_trait_fn (line 110) stdout ----
+error: unused variable: `unused_in_impl`
+  --> $DIR/dead-code-items.rs:113:17
+   |
+LL | fn main() { let unused_in_impl = 5; }
+   |                 ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_in_impl`
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:108:9
+   |
+LL | #![deny(warnings)]
+   |         ^^^^^^^^
+   = note: `#[deny(unused_variables)]` implied by `#[deny(warnings)]`
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+---- $DIR/dead-code-items.rs - U::field (line 55) stdout ----
+error: trait `DeadCodeInUnionField` is never used
+  --> $DIR/dead-code-items.rs:56:7
+   |
+LL | trait DeadCodeInUnionField {}
+   |       ^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/dead-code-items.rs:54:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+Couldn't compile the test.
+
+failures:
+    $DIR/dead-code-items.rs - A::field (line 39)
+    $DIR/dead-code-items.rs - C (line 22)
+    $DIR/dead-code-items.rs - Enum (line 70)
+    $DIR/dead-code-items.rs - Enum::Variant1 (line 77)
+    $DIR/dead-code-items.rs - MyTrait (line 103)
+    $DIR/dead-code-items.rs - MyTrait::my_trait_fn (line 110)
+    $DIR/dead-code-items.rs - U::field (line 55)
+
+test result: FAILED. 6 passed; 7 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+