Auto merge of #126900 - matthiaskrgr:rollup-24ah97b, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #125241 (Add `rust_analyzer` as a predefined tool)
 - #126213 (Update docs for AtomicBool/U8/I8 with regard to alignment)
 - #126414 (Tier 2 std support must always be known)
 - #126882 (Special case when a code line only has multiline span starts)

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

8 files changed, 76 insertions, 38 deletions

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 7405705dd33..45118bcc58a 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -902,7 +902,7 @@ impl HumanEmitter {
         //      <EMPTY LINE>
         //
         let mut annotations_position = vec![];
-        let mut line_len = 0;
+        let mut line_len: usize = 0;
         let mut p = 0;
         for (i, annotation) in annotations.iter().enumerate() {
             for (j, next) in annotations.iter().enumerate() {
@@ -973,6 +973,31 @@ impl HumanEmitter {
             return vec![];
         }
 
+        if annotations_position
+            .iter()
+            .all(|(_, ann)| matches!(ann.annotation_type, AnnotationType::MultilineStart(_)))
+            && let Some(max_pos) = annotations_position.iter().map(|(pos, _)| *pos).max()
+        {
+            // Special case the following, so that we minimize overlapping multiline spans.
+            //
+            // 3 │       X0 Y0 Z0
+            //   │ ┏━━━━━┛  │  │     < We are writing these lines
+            //   │ ┃┌───────┘  │     < by reverting the "depth" of
+            //   │ ┃│┌─────────┘     < their multilne spans.
+            // 4 │ ┃││   X1 Y1 Z1
+            // 5 │ ┃││   X2 Y2 Z2
+            //   │ ┃│└────╿──│──┘ `Z` label
+            //   │ ┃└─────│──┤
+            //   │ ┗━━━━━━┥  `Y` is a good letter too
+            //   ╰╴       `X` is a good letter
+            for (pos, _) in &mut annotations_position {
+                *pos = max_pos - *pos;
+            }
+            // We know then that we don't need an additional line for the span label, saving us
+            // one line of vertical space.
+            line_len = line_len.saturating_sub(1);
+        }
+
         // Write the column separator.
         //
         // After this we will have:
diff --git a/compiler/rustc_parse/src/parser/tests.rs b/compiler/rustc_parse/src/parser/tests.rs
index 3a4690670af..42392ad2163 100644
--- a/compiler/rustc_parse/src/parser/tests.rs
+++ b/compiler/rustc_parse/src/parser/tests.rs
@@ -322,9 +322,8 @@ error: foo
  --> test.rs:3:3
   |
 3 |      X0 Y0
-  |   ___^__-
-  |  |___|
-  | ||
+  |  ____^  -
+  | | ______|
 4 | ||   X1 Y1
 5 | ||   X2 Y2
   | ||____^__- `Y` is a good letter too
@@ -361,9 +360,8 @@ error: foo
  --> test.rs:3:3
   |
 3 |      X0 Y0
-  |   ___^__-
-  |  |___|
-  | ||
+  |  ____^  -
+  | | ______|
 4 | ||   Y1 X1
   | ||____-__^ `X` is a good letter
   |  |____|
@@ -445,10 +443,9 @@ error: foo
  --> test.rs:3:3
   |
 3 |       X0 Y0 Z0
-  |    ___^__-__-
-  |   |___|__|
-  |  ||___|
-  | |||
+  |  _____^  -  -
+  | | _______|  |
+  | || _________|
 4 | |||   X1 Y1 Z1
 5 | |||   X2 Y2 Z2
   | |||____^__-__- `Z` label
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index 87794d11cea..8763e7aec43 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -140,9 +140,10 @@ pub(crate) fn registered_tools(tcx: TyCtxt<'_>, (): ()) -> RegisteredTools {
             }
         }
     }
-    // We implicitly add `rustfmt`, `clippy`, `diagnostic` to known tools,
-    // but it's not an error to register them explicitly.
-    let predefined_tools = [sym::clippy, sym::rustfmt, sym::diagnostic, sym::miri];
+    // We implicitly add `rustfmt`, `clippy`, `diagnostic`, `miri` and `rust_analyzer` to known
+    // tools, but it's not an error to register them explicitly.
+    let predefined_tools =
+        [sym::clippy, sym::rustfmt, sym::diagnostic, sym::miri, sym::rust_analyzer];
     registered_tools.extend(predefined_tools.iter().cloned().map(Ident::with_dummy_span));
     registered_tools
 }
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 8d8f4927e99..ab0538ff282 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1559,6 +1559,7 @@ symbols! {
         rust_2018_preview,
         rust_2021,
         rust_2024,
+        rust_analyzer,
         rust_begin_unwind,
         rust_cold_cc,
         rust_eh_catch_typeinfo,
diff --git a/library/core/src/sync/atomic.rs b/library/core/src/sync/atomic.rs
index c709ea2a15d..1d19c985f23 100644
--- a/library/core/src/sync/atomic.rs
+++ b/library/core/src/sync/atomic.rs
@@ -443,8 +443,8 @@ impl AtomicBool {
     ///
     /// # Safety
     ///
-    /// * `ptr` must be aligned to `align_of::<AtomicBool>()` (note that on some platforms this can
-    ///   be bigger than `align_of::<bool>()`).
+    /// * `ptr` must be aligned to `align_of::<AtomicBool>()` (note that this is always true, since
+    ///   `align_of::<AtomicBool>() == 1`).
     /// * `ptr` must be [valid] for both reads and writes for the whole lifetime `'a`.
     /// * You must adhere to the [Memory model for atomic accesses]. In particular, it is not
     ///   allowed to mix atomic and non-atomic accesses, or atomic accesses of different sizes,
@@ -2091,10 +2091,10 @@ impl<T> From<*mut T> for AtomicPtr<T> {
 }
 
 #[allow(unused_macros)] // This macro ends up being unused on some architectures.
-macro_rules! if_not_8_bit {
-    (u8, $($tt:tt)*) => { "" };
-    (i8, $($tt:tt)*) => { "" };
-    ($_:ident, $($tt:tt)*) => { $($tt)* };
+macro_rules! if_8_bit {
+    (u8, $( yes = [$($yes:tt)*], )? $( no = [$($no:tt)*], )? ) => { concat!("", $($($yes)*)?) };
+    (i8, $( yes = [$($yes:tt)*], )? $( no = [$($no:tt)*], )? ) => { concat!("", $($($yes)*)?) };
+    ($_:ident, $( yes = [$($yes:tt)*], )? $( no = [$($no:tt)*], )? ) => { concat!("", $($($no)*)?) };
 }
 
 #[cfg(target_has_atomic_load_store)]
@@ -2116,18 +2116,24 @@ macro_rules! atomic_int {
      $int_type:ident $atomic_type:ident) => {
         /// An integer type which can be safely shared between threads.
         ///
-        /// This type has the same size and bit validity as the underlying
-        /// integer type, [`
+        /// This type has the same
+        #[doc = if_8_bit!(
+            $int_type,
+            yes = ["size, alignment, and bit validity"],
+            no = ["size and bit validity"],
+        )]
+        /// as the underlying integer type, [`
         #[doc = $s_int_type]
         /// `].
-        #[doc = if_not_8_bit! {
+        #[doc = if_8_bit! {
             $int_type,
-            concat!(
+            no = [
                 "However, the alignment of this type is always equal to its ",
                 "size, even on targets where [`", $s_int_type, "`] has a ",
                 "lesser alignment."
-            )
+            ],
         }]
+        ///
         /// For more about the differences between atomic types and
         /// non-atomic types as well as information about the portability of
         /// this type, please see the [module-level documentation].
@@ -2220,9 +2226,19 @@ macro_rules! atomic_int {
             ///
             /// # Safety
             ///
-            #[doc = concat!(" * `ptr` must be aligned to \
-                `align_of::<", stringify!($atomic_type), ">()` (note that on some platforms this \
-                can be bigger than `align_of::<", stringify!($int_type), ">()`).")]
+            /// * `ptr` must be aligned to
+            #[doc = concat!("  `align_of::<", stringify!($atomic_type), ">()`")]
+            #[doc = if_8_bit!{
+                $int_type,
+                yes = [
+                    "  (note that this is always true, since `align_of::<",
+                    stringify!($atomic_type), ">() == 1`)."
+                ],
+                no = [
+                    "  (note that on some platforms this can be bigger than `align_of::<",
+                    stringify!($int_type), ">()`)."
+                ],
+            }]
             /// * `ptr` must be [valid] for both reads and writes for the whole lifetime `'a`.
             /// * You must adhere to the [Memory model for atomic accesses]. In particular, it is not
             ///   allowed to mix atomic and non-atomic accesses, or atomic accesses of different sizes,
@@ -2261,12 +2277,12 @@ macro_rules! atomic_int {
 
             #[doc = concat!("Get atomic access to a `&mut ", stringify!($int_type), "`.")]
             ///
-            #[doc = if_not_8_bit! {
+            #[doc = if_8_bit! {
                 $int_type,
-                concat!(
+                no = [
                     "**Note:** This function is only available on targets where `",
                     stringify!($int_type), "` has an alignment of ", $align, " bytes."
-                )
+                ],
             }]
             ///
             /// # Examples
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 39659473f22..71dc8c4ca0f 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -119,7 +119,7 @@ The `std` column in the table below has the following meanings:
 
 * ✓ indicates the full standard library is available.
 * \* indicates the target only supports [`no_std`] development.
-* ? indicates the standard library support is unknown or a work-in-progress.
+* ? indicates the standard library support is a work-in-progress.
 
 [`no_std`]: https://rust-embedded.github.io/book/intro/no-std.html
 
diff --git a/tests/ui/async-await/async-is-unwindsafe.stderr b/tests/ui/async-await/async-is-unwindsafe.stderr
index 5d87fc74768..85fdcda3b8c 100644
--- a/tests/ui/async-await/async-is-unwindsafe.stderr
+++ b/tests/ui/async-await/async-is-unwindsafe.stderr
@@ -2,9 +2,8 @@ error[E0277]: the type `&mut Context<'_>` may not be safely transferred across a
   --> $DIR/async-is-unwindsafe.rs:12:5
    |
 LL |        is_unwindsafe(async {
-   |   _____^_____________-
-   |  |_____|
-   | ||
+   |  ______^             -
+   | | ___________________|
 LL | ||
 LL | ||         use std::ptr::null;
 LL | ||         use std::task::{Context, RawWaker, RawWakerVTable, Waker};
diff --git a/tests/ui/lint/suggestions.stderr b/tests/ui/lint/suggestions.stderr
index 4caee777a13..a4871ead74b 100644
--- a/tests/ui/lint/suggestions.stderr
+++ b/tests/ui/lint/suggestions.stderr
@@ -41,9 +41,8 @@ warning: variable does not need to be mutable
   --> $DIR/suggestions.rs:54:13
    |
 LL |            let mut
-   |  ______________^
-   | | _____________|
-   | ||
+   |   _____________^
+   |  |_____________|
 LL | ||             b = 1;
    | ||____________-^
    | |_____________|