Auto merge of #129076 - matthiaskrgr:rollup-rg8mi2x, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #128410 (Migrate `remap-path-prefix-dwarf` `run-make` test to rmake)
 - #128759 (alloc: add ToString specialization for `&&str`)
 - #128873 (Add windows-targets crate to std's sysroot)
 - #129001 (chore(lib): Enhance documentation for core::fmt::Formatter's write_fm…)
 - #129061 (Use `is_lang_item` more)
 - #129062 (Remove a no-longer-true assert)

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

1 files changed, 47 insertions, 7 deletions

diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs
index 124230812df..e628be1546f 100644
--- a/library/alloc/src/string.rs
+++ b/library/alloc/src/string.rs
@@ -2643,14 +2643,54 @@ impl ToString for i8 {
     }
 }
 
-#[doc(hidden)]
+// Generic/generated code can sometimes have multiple, nested references
+// for strings, including `&&&str`s that would never be written
+// by hand. This macro generates twelve layers of nested `&`-impl
+// for primitive strings.
 #[cfg(not(no_global_oom_handling))]
-#[stable(feature = "str_to_string_specialization", since = "1.9.0")]
-impl ToString for str {
-    #[inline]
-    fn to_string(&self) -> String {
-        String::from(self)
-    }
+macro_rules! to_string_str_wrap_in_ref {
+    {x $($x:ident)*} => {
+        &to_string_str_wrap_in_ref! { $($x)* }
+    };
+    {} => { str };
+}
+#[cfg(not(no_global_oom_handling))]
+macro_rules! to_string_expr_wrap_in_deref {
+    {$self:expr ; x $($x:ident)*} => {
+        *(to_string_expr_wrap_in_deref! { $self ; $($x)* })
+    };
+    {$self:expr ;} => { $self };
+}
+#[cfg(not(no_global_oom_handling))]
+macro_rules! to_string_str {
+    {$($($x:ident)*),+} => {
+        $(
+            #[doc(hidden)]
+            #[stable(feature = "str_to_string_specialization", since = "1.9.0")]
+            impl ToString for to_string_str_wrap_in_ref!($($x)*) {
+                #[inline]
+                fn to_string(&self) -> String {
+                    String::from(to_string_expr_wrap_in_deref!(self ; $($x)*))
+                }
+            }
+        )+
+    };
+}
+
+#[cfg(not(no_global_oom_handling))]
+to_string_str! {
+    x x x x x x x x x x x x,
+    x x x x x x x x x x x,
+    x x x x x x x x x x,
+    x x x x x x x x x,
+    x x x x x x x x,
+    x x x x x x x,
+    x x x x x x,
+    x x x x x,
+    x x x x,
+    x x x,
+    x x,
+    x,
 }
 
 #[doc(hidden)]