Auto merge of #90836 - matthiaskrgr:rollup-ou6yrlw, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #90589 (rustc_llvm: update PassWrapper for recent LLVM)
 - #90644 (Extend the const swap feature)
 - #90704 (Unix ExitStatus comments and a tiny docs fix)
 - #90761 (Shorten Span of unused macro lints)
 - #90795 (Add more comments to explain the code to generate the search index)
 - #90798 (Document `unreachable!` custom panic message)
 - #90826 (rustc_feature: Convert `BuiltinAttribute` from tuple to a struct)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

5 files changed, 42 insertions, 51 deletions

diff --git a/src/librustdoc/html/render/cache.rs b/src/librustdoc/html/render/cache.rs
index 896c2543608..7aa950d905d 100644
--- a/src/librustdoc/html/render/cache.rs
+++ b/src/librustdoc/html/render/cache.rs
@@ -244,8 +244,10 @@ fn get_index_type_name(clean_type: &clean::Type, accept_generic: bool) -> Option
 /// The point of this function is to replace bounds with types.
 ///
 /// i.e. `[T, U]` when you have the following bounds: `T: Display, U: Option<T>` will return
-/// `[Display, Option]` (we just returns the list of the types, we don't care about the
-/// wrapped types in here).
+/// `[Display, Option]`. If a type parameter has no trait bound, it is discarded.
+///
+/// Important note: It goes through generics recursively. So if you have
+/// `T: Option<Result<(), ()>>`, it'll go into `Option` and then into `Result`.
 crate fn get_real_types<'tcx>(
     generics: &Generics,
     arg: &Type,
@@ -329,7 +331,10 @@ crate fn get_real_types<'tcx>(
         return;
     }
 
+    // If this argument is a type parameter and not a trait bound or a type, we need to look
+    // for its bounds.
     if let Type::Generic(arg_s) = *arg {
+        // First we check if the bounds are in a `where` predicate...
         if let Some(where_pred) = generics.where_predicates.iter().find(|g| match g {
             WherePredicate::BoundPredicate { ty, .. } => {
                 ty.def_id_no_primitives() == arg.def_id_no_primitives()
@@ -352,6 +357,7 @@ crate fn get_real_types<'tcx>(
             }
             insert_ty(res, tcx, arg.clone(), ty_generics);
         }
+        // Otherwise we check if the trait bounds are "inlined" like `T: Option<u32>`...
         if let Some(bound) = generics.params.iter().find(|g| g.is_type() && g.name == arg_s) {
             let mut ty_generics = Vec::new();
             for bound in bound.get_bounds().unwrap_or(&[]) {
@@ -363,6 +369,11 @@ crate fn get_real_types<'tcx>(
             insert_ty(res, tcx, arg.clone(), ty_generics);
         }
     } else {
+        // This is not a type parameter. So for example if we have `T, U: Option<T>`, and we're
+        // looking at `Option`, we enter this "else" condition, otherwise if it's `T`, we don't.
+        //
+        // So in here, we can add it directly and look for its own type parameters (so for `Option`,
+        // we will look for them but not for `T`).
         let mut ty_generics = Vec::new();
         if let Some(arg_generics) = arg.generics() {
             for gen in arg_generics.iter() {
diff --git a/src/test/ui/lint/unused/issue-70041.stderr b/src/test/ui/lint/unused/issue-70041.stderr
index ecd618eae8b..b2e6d1aeb3f 100644
--- a/src/test/ui/lint/unused/issue-70041.stderr
+++ b/src/test/ui/lint/unused/issue-70041.stderr
@@ -1,11 +1,8 @@
-warning: unused macro definition
-  --> $DIR/issue-70041.rs:4:1
+warning: unused macro definition: `regex`
+  --> $DIR/issue-70041.rs:4:14
    |
-LL | / macro_rules! regex {
-LL | |
-LL | |     () => {};
-LL | | }
-   | |_^
+LL | macro_rules! regex {
+   |              ^^^^^
    |
    = note: `#[warn(unused_macros)]` on by default
 
diff --git a/src/test/ui/lint/unused/unused-macro-rules.stderr b/src/test/ui/lint/unused/unused-macro-rules.stderr
index 6812a1d8f63..59db35b4111 100644
--- a/src/test/ui/lint/unused/unused-macro-rules.stderr
+++ b/src/test/ui/lint/unused/unused-macro-rules.stderr
@@ -1,10 +1,8 @@
-error: unused macro definition
-  --> $DIR/unused-macro-rules.rs:4:1
+error: unused macro definition: `unused`
+  --> $DIR/unused-macro-rules.rs:4:14
    |
-LL | / macro_rules! unused {
-LL | |     () => {};
-LL | | }
-   | |_^
+LL | macro_rules! unused {
+   |              ^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/unused-macro-rules.rs:1:9
@@ -12,26 +10,17 @@ note: the lint level is defined here
 LL | #![deny(unused_macros)]
    |         ^^^^^^^^^^^^^
 
-error: unused macro definition
-  --> $DIR/unused-macro-rules.rs:11:9
+error: unused macro definition: `m`
+  --> $DIR/unused-macro-rules.rs:11:22
    |
-LL | /         macro_rules! m {
-LL | |             () => {};
-LL | |         }
-   | |_________^
-...
-LL |   create_macro!();
-   |   --------------- in this macro invocation
-   |
-   = note: this error originates in the macro `create_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
+LL |         macro_rules! m {
+   |                      ^
 
-error: unused macro definition
-  --> $DIR/unused-macro-rules.rs:24:5
+error: unused macro definition: `unused`
+  --> $DIR/unused-macro-rules.rs:24:18
    |
-LL | /     macro_rules! unused {
-LL | |         () => {};
-LL | |     }
-   | |_____^
+LL |     macro_rules! unused {
+   |                  ^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/unused-macro-rules.rs:23:12
diff --git a/src/test/ui/lint/unused/unused-macro.stderr b/src/test/ui/lint/unused/unused-macro.stderr
index f5eb76179bf..1a73279ed6d 100644
--- a/src/test/ui/lint/unused/unused-macro.stderr
+++ b/src/test/ui/lint/unused/unused-macro.stderr
@@ -1,10 +1,8 @@
-error: unused macro definition
-  --> $DIR/unused-macro.rs:5:1
+error: unused macro definition: `unused`
+  --> $DIR/unused-macro.rs:5:7
    |
-LL | / macro unused {
-LL | |     () => {}
-LL | | }
-   | |_^
+LL | macro unused {
+   |       ^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/unused-macro.rs:2:9
@@ -12,13 +10,11 @@ note: the lint level is defined here
 LL | #![deny(unused_macros)]
    |         ^^^^^^^^^^^^^
 
-error: unused macro definition
-  --> $DIR/unused-macro.rs:15:5
+error: unused macro definition: `unused`
+  --> $DIR/unused-macro.rs:15:11
    |
-LL | /     macro unused {
-LL | |         () => {}
-LL | |     }
-   | |_____^
+LL |     macro unused {
+   |           ^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/unused-macro.rs:14:12
@@ -26,13 +22,11 @@ note: the lint level is defined here
 LL |     #[deny(unused_macros)]
    |            ^^^^^^^^^^^^^
 
-error: unused macro definition
-  --> $DIR/unused-macro.rs:21:5
+error: unused macro definition: `unused`
+  --> $DIR/unused-macro.rs:21:22
    |
-LL | /     pub(crate) macro unused {
-LL | |         () => {}
-LL | |     }
-   | |_____^
+LL |     pub(crate) macro unused {
+   |                      ^^^^^^
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/proc-macro/issue-39889.rs b/src/test/ui/proc-macro/issue-39889.rs
index ada125a215a..69bfb4f3cbf 100644
--- a/src/test/ui/proc-macro/issue-39889.rs
+++ b/src/test/ui/proc-macro/issue-39889.rs
@@ -1,6 +1,6 @@
 // run-pass
 
-#![allow(dead_code)]
+#![allow(dead_code, unused_macros)]
 // aux-build:issue-39889.rs
 
 extern crate issue_39889;