From fcc3cb03f0481884c455159627f665f4082c252a Mon Sep 17 00:00:00 2001
From: Martin Habovstiak <martin.habovstiak@gmail.com>
Date: Sun, 11 Aug 2024 14:57:47 +0200
Subject: [PATCH] Support non-doc attrs in extension trait macro

The `define_extension_trait` macro originally didn't support `#[inline]`
or other attributes for simplicity. We still want them so this commit
adds basic support for it. It adds the `doc` attributes to trait
*definition* only and adds all other attributes to the *implementation*
only. This should support `#[inline]` and other attributes. The downside
is it doesn't support adding non-doc attributes to trait *definition*
but I can't think of any relevant ones that we would want and we can
find a solution later if we do.
---
 bitcoin/src/internal_macros.rs | 47 +++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/bitcoin/src/internal_macros.rs b/bitcoin/src/internal_macros.rs
index 72819f103..32cc7e766 100644
--- a/bitcoin/src/internal_macros.rs
+++ b/bitcoin/src/internal_macros.rs
@@ -214,6 +214,38 @@ macro_rules! impl_asref_push_bytes {
 }
 pub(crate) use impl_asref_push_bytes;
 
+macro_rules! only_doc_attrs {
+    ({}, {$($fun:tt)*}) => {
+        $($fun)*
+    };
+    ({#[doc = $($doc:tt)*] $($all_attrs:tt)*}, {$($fun:tt)*}) => {
+        $crate::internal_macros::only_doc_attrs!({ $($all_attrs)* }, { #[doc = $($doc)*] $($fun)* });
+    };
+    ({#[doc($($doc:tt)*)] $($all_attrs:tt)*}, {$($fun:tt)*}) => {
+        $crate::internal_macros::only_doc_attrs!({ $($all_attrs)* }, { #[doc($($doc)*)] $($fun)* });
+    };
+    ({#[$($other:tt)*] $($all_attrs:tt)*}, {$($fun:tt)*}) => {
+        $crate::internal_macros::only_doc_attrs!({ $($all_attrs)* }, { $($fun)* });
+    };
+}
+pub(crate) use only_doc_attrs;
+
+macro_rules! only_non_doc_attrs {
+    ({}, {$($fun:tt)*}) => {
+        $($fun)*
+    };
+    ({#[doc = $($doc:tt)*] $($all_attrs:tt)*}, {$($fun:tt)*}) => {
+        $crate::internal_macros::only_doc_attrs!({ $($all_attrs)* }, { #[doc = $($doc)*] $($fun)* });
+    };
+    ({#[doc($($doc:tt)*)] $($all_attrs:tt)*}, {$($fun:tt)*}) => {
+        $crate::internal_macros::only_doc_attrs!({ $($all_attrs)* }, { $($fun)* });
+    };
+    ({#[$($other:tt)*] $($all_attrs:tt)*}, {$($fun:tt)*}) => {
+        $crate::internal_macros::only_doc_attrs!({ $($all_attrs)* }, { #[$(other)*] $($fun)* });
+    };
+}
+pub(crate) use only_non_doc_attrs;
+
 /// Defines an trait `$trait_name` and implements it for `ty`, used to define extension traits.
 macro_rules! define_extension_trait {
     ($(#[$($trait_attrs:tt)*])* $trait_vis:vis trait $trait_name:ident impl for $ty:ident {
@@ -224,14 +256,23 @@ macro_rules! define_extension_trait {
     }) => {
         $(#[$($trait_attrs)*])* $trait_vis trait $trait_name {
             $(
-                $(#[$($fn_attrs)*])*
-                fn $fn$(<$($gen: $gent),*>)?($($param_name: $param_type),*) $( -> $ret )?;
+                $crate::internal_macros::only_doc_attrs! {
+                    { $(#[$($fn_attrs)*])* },
+                    {
+                        fn $fn$(<$($gen: $gent),*>)?($($param_name: $param_type),*) $( -> $ret )?;
+                    }
+                }
             )*
         }
 
         impl $trait_name for $ty {
             $(
-                fn $fn$(<$($gen: $gent),*>)?($($param_name: $param_type),*) $( -> $ret )? $body
+                $crate::internal_macros::only_non_doc_attrs! {
+                    { $(#[$($fn_attrs)*])* },
+                    {
+                        fn $fn$(<$($gen: $gent),*>)?($($param_name: $param_type),*) $( -> $ret )? $body
+                    }
+                }
             )*
         }
     };