Manually fix a part of the remaining clippy warnings in capnp

Summary of fixed clippy errors and warnings:
error: this public function might dereference a raw pointer but is not marked `unsafe`
error: this `if` has identical blocks
warning: match expression looks like `matches!` macro
warning: very complex type used. Consider factoring parts into `type` definitions
warning: this function has too many arguments (10/7)
warning: methods called `into_*` usually take `self` by value
warning: struct `FieldList` has a public `len` method, but no `is_empty` method
warning: this lifetime isn't used in the impl

$ cargo clippy
    Checking capnp v0.17.2 (/home/amiculas/work/capnproto-rust/capnp)
warning: match expression looks like `matches!` macro
   --> capnp/src/introspect.rs:99:13
    |
99  | /             match self.base {
100 | |                 BaseType::Text
101 | |                 | BaseType::Data
102 | |                 | BaseType::AnyPointer
...   |
105 | |                 _ => false,
106 | |             }
    | |_____________^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro
    = note: `#[warn(clippy::match_like_matches_macro)]` on by default
help: try this
    |
99  ~             matches!(self.base, BaseType::Text
100 +                 | BaseType::Data
101 +                 | BaseType::AnyPointer
102 +                 | BaseType::Struct(_)
103 +                 | BaseType::Capability)
    |

warning: very complex type used. Consider factoring parts into `type` definitions
  --> capnp/src/private/capability.rs:40:10
   |
40 |       ) -> Option<(
   |  __________^
41 | |         u32,
42 | |         crate::capability::Promise<(), crate::Error>,
43 | |         Box<dyn PipelineHook>,
44 | |     )>;
   | |______^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
   = note: `#[warn(clippy::type_complexity)]` on by default

error: this public function might dereference a raw pointer but is not marked `unsafe`
   --> capnp/src/private/layout.rs:164:48
    |
164 |         unsafe { this_addr.offset(8 * (1 + (((*ptr).offset_and_kind.get() as i32) >> 2)) as isize) }
    |                                                ^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#not_unsafe_ptr_arg_deref
    = note: `#[deny(clippy::not_unsafe_ptr_arg_deref)]` on by default

warning: this function has too many arguments (10/7)
    --> capnp/src/private/layout.rs:2187:5
     |
2187 | /     pub unsafe fn copy_pointer(
2188 | |         dst_arena: &mut dyn BuilderArena,
2189 | |         dst_segment_id: u32,
2190 | |         #[cfg(feature = "alloc")] dst_cap_table: CapTableBuilder,
...    |
2197 | |         canonicalize: bool,
2198 | |     ) -> Result<SegmentAnd<*mut u8>> {
     | |____________________________________^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_many_arguments
     = note: `#[warn(clippy::too_many_arguments)]` on by default

warning: methods called `into_*` usually take `self` by value
    --> capnp/src/private/layout.rs:4170:34
     |
4170 |     pub(crate) fn into_raw_bytes(&self) -> &'a m�[Iut [u8] {
     |                                  ^^^^^
     |
     = help: consider choosing a less ambiguous name
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wrong_self_convention
     = note: `#[warn(clippy::wrong_self_convention)]` on by default

warning: struct `FieldList` has a public `len` method, but no `is_empty` method
   --> capnp/src/schema.rs:160:5
    |
160 |     pub fn len(&self) -> u16 {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_without_is_empty
    = note: `#[warn(clippy::len_without_is_empty)]` on by default

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:177:6
    |
177 | impl<'a> IndexMove<u16, Field> for FieldList {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes
    = note: `#[warn(clippy::extra_unused_lifetimes)]` on by default

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:183:6
    |
183 | impl<'a> ::core::iter::IntoIterator for FieldList {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:223:6
    |
223 | impl<'a> IndexMove<u16, Field> for FieldSubset {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:229:6
    |
229 | impl<'a> ::core::iter::IntoIterator for FieldSubset {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:344:6
    |
344 | impl<'a> IndexMove<u16, Enumerant> for EnumerantList {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:350:6
    |
350 | impl<'a> ::core::iter::IntoIterator for EnumerantList {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:417:6
    |
417 | impl<'a> IndexMove<u32, Annotation> for AnnotationList {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

warning: this lifetime isn't used in the impl
   --> capnp/src/schema.rs:423:6
    |
423 | impl<'a> ::core::iter::IntoIterator for AnnotationList {
    |      ^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes

error: this `if` has identical blocks
   --> capnp/src/serialize.rs:355:46
    |
355 |       if segment_count >= SEGMENTS_COUNT_LIMIT {
    |  ______________________________________________^
356 | |         return Err(Error::from_kind(ErrorKind::InvalidNumberOfSegments(
357 | |             segment_count,
358 | |         )));
359 | |     } else if segment_count == 0 {
    | |_____^
    |
note: same as this
   --> capnp/src/serialize.rs:359:34
    |
359 |       } else if segment_count == 0 {
    |  __________________________________^
360 | |         return Err(Error::from_kind(ErrorKind::InvalidNumberOfSegments(
361 | |             segment_count,
362 | |         )));
363 | |     }
    | |_____^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#if_same_then_else
    = note: `#[deny(clippy::if_same_then_else)]` on by default

warning: `capnp` (lib) generated 16 warnings
error: could not compile `capnp` (lib) due to 2 previous errors; 16 warnings emitted

Author: ariel-miculas

capnp-rpc/src/broken.rs

@@ -21,7 +21,7 @@
 
 use capnp::any_pointer;
 use capnp::private::capability::{
-    ClientHook, ParamsHook, PipelineHook, PipelineOp, RequestHook, ResultsHook,
+    ClientHook, ParamsHook, PipelineHook, PipelineOp, RequestHook, ResultsHook, TailSendReturnType,
 };
 use capnp::Error;
 
@@ -81,7 +81,7 @@ impl RequestHook for Request {
             pipeline: any_pointer::Pipeline::new(Box::new(pipeline)),
         }
     }
-    fn tail_send(self: Box<Self>) -> Option<(u32, Promise<(), Error>, Box<dyn PipelineHook>)> {
+    fn tail_send(self: Box<Self>) -> TailSendReturnType {
         None
     }
 }

capnp-rpc/src/local.rs

@@ -21,6 +21,7 @@
 use capnp::capability::{self, Promise};
 use capnp::private::capability::{
     ClientHook, ParamsHook, PipelineHook, PipelineOp, RequestHook, ResponseHook, ResultsHook,
+    TailSendReturnType,
 };
 use capnp::traits::{Imbue, ImbueMut};
 use capnp::Error;
@@ -250,7 +251,7 @@ impl RequestHook for Request {
             pipeline,
         }
     }
-    fn tail_send(self: Box<Self>) -> Option<(u32, Promise<(), Error>, Box<dyn PipelineHook>)> {
+    fn tail_send(self: Box<Self>) -> TailSendReturnType {
         unimplemented!()
     }
 }

capnp-rpc/src/reconnect.rs

@@ -3,7 +3,7 @@ use std::marker::PhantomData;
 use std::rc::Rc;
 
 use capnp::capability::{FromClientHook, Promise};
-use capnp::private::capability::{ClientHook, RequestHook};
+use capnp::private::capability::{ClientHook, RequestHook, TailSendReturnType};
 use futures::TryFutureExt;
 
 pub trait SetTarget<C> {
@@ -203,13 +203,7 @@ where
         result
     }
 
-    fn tail_send(
-        self: Box<Self>,
-    ) -> Option<(
-        u32,
-        Promise<(), capnp::Error>,
-        Box<dyn capnp::private::capability::PipelineHook>,
-    )> {
+    fn tail_send(self: Box<Self>) -> TailSendReturnType {
         todo!()
     }
 }

capnp-rpc/src/rpc.rs

@@ -26,6 +26,7 @@ use capnp::any_pointer;
 use capnp::capability::Promise;
 use capnp::private::capability::{
     ClientHook, ParamsHook, PipelineHook, PipelineOp, RequestHook, ResponseHook, ResultsHook,
+    TailSendReturnType,
 };
 use capnp::Error;
 
@@ -1909,7 +1910,7 @@ impl<VatId> RequestHook for Request<VatId> {
             }
         }
     }
-    fn tail_send(self: Box<Self>) -> Option<(u32, Promise<(), Error>, Box<dyn PipelineHook>)> {
+    fn tail_send(self: Box<Self>) -> TailSendReturnType {
         let tmp = *self;
         let Self {
             connection_state,

capnp/src/introspect.rs

@@ -96,14 +96,14 @@ impl Type {
         if self.list_count > 0 {
             true
         } else {
-            match self.base {
+            matches!(
+                self.base,
                 BaseType::Text
-                | BaseType::Data
-                | BaseType::AnyPointer
-                | BaseType::Struct(_)
-                | BaseType::Capability => true,
-                _ => false,
-            }
+                    | BaseType::Data
+                    | BaseType::AnyPointer
+                    | BaseType::Struct(_)
+                    | BaseType::Capability
+            )
         }
     }
 }

capnp/src/primitive_list.rs

@@ -116,7 +116,7 @@ impl<'a, T: PrimitiveElement> Reader<'a, T> {
     /// Returns something if the slice is as expected in memory.
     pub fn as_slice(&self) -> Option<&[T]> {
         if self.reader.get_element_size() == T::element_size() {
-            let bytes = self.reader.into_raw_bytes();
+            let bytes = self.reader.as_raw_bytes();
             Some(unsafe {
                 use core::slice;
                 slice::from_raw_parts(
@@ -174,7 +174,7 @@ where
     #[cfg(all(target_endian = "little"))]
     pub fn as_slice(&mut self) -> Option<&mut [T]> {
         if self.builder.get_element_size() == T::element_size() {
-            let bytes = self.builder.into_raw_bytes();
+            let bytes = self.builder.as_raw_bytes();
             Some(unsafe {
                 core::slice::from_raw_parts_mut(
                     bytes.as_mut_ptr() as *mut T,

capnp/src/private/capability.rs

@@ -31,17 +31,17 @@ pub trait ResponseHook {
     fn get(&self) -> crate::Result<any_pointer::Reader<'_>>;
 }
 
+pub type TailSendReturnType = Option<(
+    u32,
+    crate::capability::Promise<(), crate::Error>,
+    Box<dyn PipelineHook>,
+)>;
+
 pub trait RequestHook {
     fn get(&mut self) -> any_pointer::Builder<'_>;
     fn get_brand(&self) -> usize;
     fn send(self: Box<Self>) -> RemotePromise<any_pointer::Owned>;
-    fn tail_send(
-        self: Box<Self>,
-    ) -> Option<(
-        u32,
-        crate::capability::Promise<(), crate::Error>,
-        Box<dyn PipelineHook>,
-    )>;
+    fn tail_send(self: Box<Self>) -> TailSendReturnType;
 }
 
 pub trait ClientHook {

capnp/src/private/layout.rs

@@ -159,7 +159,7 @@ impl WirePointer {
     }
 
     #[inline]
-    pub fn target(ptr: *const Self) -> *const u8 {
+    pub unsafe fn target(ptr: *const Self) -> *const u8 {
         let this_addr: *const u8 = ptr as *const _;
         unsafe { this_addr.offset(8 * (1 + (((*ptr).offset_and_kind.get() as i32) >> 2)) as isize) }
     }
@@ -2184,6 +2184,7 @@ mod wire_helpers {
         }
     }
 
+    #[allow(clippy::too_many_arguments)]
     pub unsafe fn copy_pointer(
         dst_arena: &mut dyn BuilderArena,
         dst_segment_id: u32,
@@ -3904,7 +3905,7 @@ impl<'a> ListReader<'a> {
         self.element_size
     }
 
-    pub(crate) fn into_raw_bytes(self) -> &'a [u8] {
+    pub(crate) fn as_raw_bytes(self) -> &'a [u8] {
         if self.element_count == 0 {
             // Explictly handle this case to avoid forming a slice to a null pointer,
             // which would be undefined behavior.
@@ -4167,7 +4168,7 @@ impl<'a> ListBuilder<'a> {
         }
     }
 
-    pub(crate) fn into_raw_bytes(&self) -> &'a mut [u8] {
+    pub(crate) fn as_raw_bytes(&self) -> &'a mut [u8] {
         if self.element_count == 0 {
             // Explictly handle this case to avoid forming a slice to a null pointer,
             // which would be undefined behavior.

capnp/src/raw.rs

@@ -65,5 +65,5 @@ pub fn get_list_bytes<'a, T>(value: T) -> &'a [u8]
 where
     T: IntoInternalListReader<'a>,
 {
-    value.into_internal_list_reader().into_raw_bytes()
+    value.into_internal_list_reader().as_raw_bytes()
 }

capnp/src/schema.rs

@@ -161,6 +161,10 @@ impl FieldList {
         self.fields.len() as u16
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     pub fn get(self, index: u16) -> Field {
         Field {
             proto: self.fields.get(index as u32),
@@ -174,13 +178,13 @@ impl FieldList {
     }
 }
 
-impl<'a> IndexMove<u16, Field> for FieldList {
+impl IndexMove<u16, Field> for FieldList {
     fn index_move(&self, index: u16) -> Field {
         self.get(index)
     }
 }
 
-impl<'a> ::core::iter::IntoIterator for FieldList {
+impl ::core::iter::IntoIterator for FieldList {
     type Item = Field;
     type IntoIter = ShortListIter<FieldList, Self::Item>;
 
@@ -220,13 +224,13 @@ impl FieldSubset {
     }
 }
 
-impl<'a> IndexMove<u16, Field> for FieldSubset {
+impl IndexMove<u16, Field> for FieldSubset {
     fn index_move(&self, index: u16) -> Field {
         self.get(index)
     }
 }
 
-impl<'a> ::core::iter::IntoIterator for FieldSubset {
+impl ::core::iter::IntoIterator for FieldSubset {
     type Item = Field;
     type IntoIter = ShortListIter<FieldSubset, Self::Item>;
 
@@ -341,13 +345,13 @@ impl EnumerantList {
     }
 }
 
-impl<'a> IndexMove<u16, Enumerant> for EnumerantList {
+impl IndexMove<u16, Enumerant> for EnumerantList {
     fn index_move(&self, index: u16) -> Enumerant {
         self.get(index)
     }
 }
 
-impl<'a> ::core::iter::IntoIterator for EnumerantList {
+impl ::core::iter::IntoIterator for EnumerantList {
     type Item = Enumerant;
     type IntoIter = ShortListIter<Self, Self::Item>;
 
@@ -414,13 +418,13 @@ impl AnnotationList {
     }
 }
 
-impl<'a> IndexMove<u32, Annotation> for AnnotationList {
+impl IndexMove<u32, Annotation> for AnnotationList {
     fn index_move(&self, index: u32) -> Annotation {
         self.get(index)
     }
 }
 
-impl<'a> ::core::iter::IntoIterator for AnnotationList {
+impl ::core::iter::IntoIterator for AnnotationList {
     type Item = Annotation;
     type IntoIter = ListIter<Self, Self::Item>;