From 7aeb71d3a9220a8f4709bce550f652976703fe09 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Mon, 23 Jun 2025 15:36:23 -0700
Subject: [PATCH 1/3] Move the panic_handler example to the intro and an
 example block

---
 src/panic.md | 70 ++++++++++++++++++++++++++--------------------------
 1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/src/panic.md b/src/panic.md
index 2be7e42fb2..2d167af23d 100644
--- a/src/panic.md
+++ b/src/panic.md
@@ -22,48 +22,48 @@ r[panic.panic_handler]
 r[panic.panic_handler.intro]
 The *`panic_handler` attribute* can be applied to a function to define the behavior of panics.
 
-r[panic.panic_handler.allowed-positions]
-The `panic_handler` attribute can only be applied to a function with signature `fn(&PanicInfo) -> !`.
+> [!EXAMPLE]
+> Below is shown a `panic_handler` function that logs the panic message and then halts the thread.
+> <!-- ignore: test infrastructure can't handle no_std -->
+> ```rust,ignore
+> #![no_std]
+>
+> use core::fmt::{self, Write};
+> use core::panic::PanicInfo;
+>
+> struct Sink {
+>     // ..
+> #    _0: (),
+> }
+> #
+> # impl Sink {
+> #     fn new() -> Sink { Sink { _0: () }}
+> # }
+> #
+> # impl fmt::Write for Sink {
+> #     fn write_str(&mut self, _: &str) -> fmt::Result { Ok(()) }
+> # }
+>
+> #[panic_handler]
+> fn panic(info: &PanicInfo) -> ! {
+>     let mut sink = Sink::new();
+>
+>     // logs "panicked at '$reason', src/main.rs:27:4" to some `sink`
+>     let _ = writeln!(sink, "{}", info);
+>
+>     loop {}
+> }
+> ```
 
 > [!NOTE]
 > The [`PanicInfo`] struct contains information about the location of the panic.
 
+r[panic.panic_handler.allowed-positions]
+The `panic_handler` attribute can only be applied to a function with signature `fn(&PanicInfo) -> !`.
+
 r[panic.panic_handler.unique]
 There must be a single `panic_handler` function in the dependency graph.
 
-Below is shown a `panic_handler` function that logs the panic message and then halts the thread.
-
-<!-- ignore: test infrastructure can't handle no_std -->
-```rust,ignore
-#![no_std]
-
-use core::fmt::{self, Write};
-use core::panic::PanicInfo;
-
-struct Sink {
-    // ..
-#    _0: (),
-}
-#
-# impl Sink {
-#     fn new() -> Sink { Sink { _0: () }}
-# }
-#
-# impl fmt::Write for Sink {
-#     fn write_str(&mut self, _: &str) -> fmt::Result { Ok(()) }
-# }
-
-#[panic_handler]
-fn panic(info: &PanicInfo) -> ! {
-    let mut sink = Sink::new();
-
-    // logs "panicked at '$reason', src/main.rs:27:4" to some `sink`
-    let _ = writeln!(sink, "{}", info);
-
-    loop {}
-}
-```
-
 r[panic.panic_handler.std]
 ### Standard behavior
 

From 731d62a0f468807d5d3965626de986203707c6ef Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Mon, 23 Jun 2025 15:44:19 -0700
Subject: [PATCH 2/3] Update panic_handler to use the attribute template

---
 src/panic.md | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/panic.md b/src/panic.md
index 2d167af23d..49b7c77512 100644
--- a/src/panic.md
+++ b/src/panic.md
@@ -20,7 +20,7 @@ r[panic.panic_handler]
 ## The `panic_handler` attribute
 
 r[panic.panic_handler.intro]
-The *`panic_handler` attribute* can be applied to a function to define the behavior of panics.
+The *`panic_handler` [attribute][attributes]* can be applied to a function to define the behavior of panics.
 
 > [!EXAMPLE]
 > Below is shown a `panic_handler` function that logs the panic message and then halts the thread.
@@ -58,8 +58,17 @@ The *`panic_handler` attribute* can be applied to a function to define the behav
 > [!NOTE]
 > The [`PanicInfo`] struct contains information about the location of the panic.
 
+r[panic.panic_handler.syntax]
+The `panic_handler` attribute uses the [MetaWord] syntax and thus does not take any inputs.
+
 r[panic.panic_handler.allowed-positions]
-The `panic_handler` attribute can only be applied to a function with signature `fn(&PanicInfo) -> !`.
+The `panic_handler` attribute may only be applied to a function with signature `fn(&PanicInfo) -> !`.
+
+r[panic.panic_handler.duplicates]
+Duplicate instances of the `panic_handler` attribute on a function are ignored.
+
+> [!NOTE]
+> `rustc` currently warns about unused duplicate `panic_handler` attributes.
 
 r[panic.panic_handler.unique]
 There must be a single `panic_handler` function in the dependency graph.

From d8e8071526d44b7ebf474473c1422b9dbb41d9db Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Mon, 22 Sep 2025 13:31:09 -0700
Subject: [PATCH 3/3] Minor update of `panic_hanlder`

More closely align with the template, and some minor word tweaks.
---
 src/panic.md | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/panic.md b/src/panic.md
index 49b7c77512..3240627bf0 100644
--- a/src/panic.md
+++ b/src/panic.md
@@ -16,6 +16,7 @@ There are also language features that provide a level of control over panic beha
 > [!NOTE]
 > The standard library provides the capability to explicitly panic via the [`panic!` macro][panic!].
 
+<!-- template:attributes -->
 r[panic.panic_handler]
 ## The `panic_handler` attribute
 
@@ -59,16 +60,16 @@ The *`panic_handler` [attribute][attributes]* can be applied to a function to de
 > The [`PanicInfo`] struct contains information about the location of the panic.
 
 r[panic.panic_handler.syntax]
-The `panic_handler` attribute uses the [MetaWord] syntax and thus does not take any inputs.
+The `panic_handler` attribute uses the [MetaWord] syntax.
 
 r[panic.panic_handler.allowed-positions]
 The `panic_handler` attribute may only be applied to a function with signature `fn(&PanicInfo) -> !`.
 
 r[panic.panic_handler.duplicates]
-Duplicate instances of the `panic_handler` attribute on a function are ignored.
+The `panic_handler` attribute may be used any number of times on a function.
 
 > [!NOTE]
-> `rustc` currently warns about unused duplicate `panic_handler` attributes.
+> `rustc` lints against any use following the first.
 
 r[panic.panic_handler.unique]
 There must be a single `panic_handler` function in the dependency graph.