From 55ff380aff591663219dca76727bf65c7b4048a8 Mon Sep 17 00:00:00 2001
From: David Renshaw <dwrenshaw@gmail.com>
Date: Fri, 15 Nov 2024 11:50:03 -0500
Subject: [PATCH] when a struct has no pointer fields, we can elide lifetime in
 impl blocks

---
 capnp-rpc/src/rpc_capnp.rs          |  8 ++++----
 capnp-rpc/src/rpc_twoparty_capnp.rs | 10 +++++-----
 capnp/src/schema_capnp.rs           | 12 ++++++------
 capnpc/src/codegen.rs               | 20 +++++++++++++++++++-
 4 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/capnp-rpc/src/rpc_capnp.rs b/capnp-rpc/src/rpc_capnp.rs
index 92b604ccb..a1be17d70 100644
--- a/capnp-rpc/src/rpc_capnp.rs
+++ b/capnp-rpc/src/rpc_capnp.rs
@@ -3060,7 +3060,7 @@ pub mod finish {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
@@ -3815,7 +3815,7 @@ pub mod release {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
@@ -4450,7 +4450,7 @@ pub mod disembargo {
             }
         }
 
-        impl<'a> Reader<'a> {
+        impl Reader<'_> {
             pub fn reborrow(&self) -> Reader<'_> {
                 Self { ..*self }
             }
@@ -7511,7 +7511,7 @@ pub mod promised_answer {
             }
         }
 
-        impl<'a> Reader<'a> {
+        impl Reader<'_> {
             pub fn reborrow(&self) -> Reader<'_> {
                 Self { ..*self }
             }
diff --git a/capnp-rpc/src/rpc_twoparty_capnp.rs b/capnp-rpc/src/rpc_twoparty_capnp.rs
index c886ca62c..e30850d02 100644
--- a/capnp-rpc/src/rpc_twoparty_capnp.rs
+++ b/capnp-rpc/src/rpc_twoparty_capnp.rs
@@ -176,7 +176,7 @@ pub mod vat_id {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
@@ -457,7 +457,7 @@ pub mod provision_id {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
@@ -731,7 +731,7 @@ pub mod recipient_id {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
@@ -974,7 +974,7 @@ pub mod third_party_cap_id {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
@@ -1218,7 +1218,7 @@ pub mod join_key_part {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
diff --git a/capnp/src/schema_capnp.rs b/capnp/src/schema_capnp.rs
index 890a6fa9a..6bfc8a5be 100644
--- a/capnp/src/schema_capnp.rs
+++ b/capnp/src/schema_capnp.rs
@@ -5393,7 +5393,7 @@ pub mod field {
             }
         }
 
-        impl<'a> Reader<'a> {
+        impl Reader<'_> {
             pub fn reborrow(&self) -> Reader<'_> {
                 Self { ..*self }
             }
@@ -5668,7 +5668,7 @@ pub mod field {
             }
         }
 
-        impl<'a> Reader<'a> {
+        impl Reader<'_> {
             pub fn reborrow(&self) -> Reader<'_> {
                 Self { ..*self }
             }
@@ -9679,7 +9679,7 @@ pub mod type_ {
                 }
             }
 
-            impl<'a> Reader<'a> {
+            impl Reader<'_> {
                 pub fn reborrow(&self) -> Reader<'_> {
                     Self { ..*self }
                 }
@@ -10044,7 +10044,7 @@ pub mod type_ {
                 }
             }
 
-            impl<'a> Reader<'a> {
+            impl Reader<'_> {
                 pub fn reborrow(&self) -> Reader<'_> {
                     Self { ..*self }
                 }
@@ -10356,7 +10356,7 @@ pub mod type_ {
                 }
             }
 
-            impl<'a> Reader<'a> {
+            impl Reader<'_> {
                 pub fn reborrow(&self) -> Reader<'_> {
                     Self { ..*self }
                 }
@@ -13069,7 +13069,7 @@ pub mod capnp_version {
         }
     }
 
-    impl<'a> Reader<'a> {
+    impl Reader<'_> {
         pub fn reborrow(&self) -> Reader<'_> {
             Self { ..*self }
         }
diff --git a/capnpc/src/codegen.rs b/capnpc/src/codegen.rs
index 6d177b88e..c1d1c56e2 100644
--- a/capnpc/src/codegen.rs
+++ b/capnpc/src/codegen.rs
@@ -2052,6 +2052,7 @@ fn generate_node(
             private_mod_interior.push(generate_members_by_discriminant(*node_reader)?);
             private_mod_interior.push(generate_members_by_name(*node_reader)?);
 
+            let mut has_pointer_field = false;
             let fields = struct_reader.get_fields()?;
             for field in fields {
                 let name = get_field_name(field)?;
@@ -2060,6 +2061,19 @@ fn generate_node(
                 let discriminant_value = field.get_discriminant_value();
                 let is_union_field = discriminant_value != field::NO_DISCRIMINANT;
 
+                match field.which()? {
+                    field::Slot(s) => match s.get_type()?.which()? {
+                        type_::Text(())
+                        | type_::Data(())
+                        | type_::List(_)
+                        | type_::Struct(_)
+                        | type_::Interface(_)
+                        | type_::AnyPointer(_) => has_pointer_field = true,
+                        _ => (),
+                    },
+                    field::Group(_) => has_pointer_field = true,
+                }
+
                 if !is_union_field {
                     pipeline_impl_interior.push(generate_pipeline_getter(ctx, field)?);
                     let (ty, get, default_decl) = getter_text(ctx, &field, true, true)?;
@@ -2275,7 +2289,11 @@ fn generate_node(
                 ]),
                 line("}"),
                 BlankLine,
-                Line(format!("impl <'a,{0}> Reader<'a,{0}> {1} {{", params.params, params.where_clause)),
+                if has_pointer_field { // we do this to keep clippy happy
+                    Line(format!("impl <'a,{0}> Reader<'a,{0}> {1} {{", params.params, params.where_clause))
+                } else {
+                    Line(format!("impl <{0}> Reader<'_,{0}> {1} {{", params.params, params.where_clause))
+                },
                 indent(vec![
                         Line(format!("pub fn reborrow(&self) -> Reader<'_,{}> {{",params.params)),
                         indent(line("Self { .. *self }")),