Auto merge of #51829 - petrochenkov:noideq, r=eddyb

Remove most of `PartialEq` and `Hash` impls from AST and HIR structures

Continuation of https://github.com/rust-lang/rust/pull/49326, prerequisite for removing `PartialEq` for `Ident`.

4 files changed, 16 insertions, 22 deletions

diff --git a/src/libsyntax_ext/deriving/generic/mod.rs b/src/libsyntax_ext/deriving/generic/mod.rs
index aad69c109f9..a9f60fd053c 100644
--- a/src/libsyntax_ext/deriving/generic/mod.rs
+++ b/src/libsyntax_ext/deriving/generic/mod.rs
@@ -188,7 +188,6 @@ pub use self::StaticFields::*;
 pub use self::SubstructureFields::*;
 
 use std::cell::RefCell;
-use std::collections::HashSet;
 use std::vec;
 
 use rustc_target::spec::abi::Abi;
@@ -617,7 +616,6 @@ impl<'a> TraitDef<'a> {
                     .map(|ty_param| ty_param.ident.name)
                     .collect();
 
-                let mut processed_field_types = HashSet::new();
                 for field_ty in field_tys {
                     let tys = find_type_parameters(&field_ty, &ty_param_names, self.span, cx);
 
@@ -625,11 +623,9 @@ impl<'a> TraitDef<'a> {
                         // if we have already handled this type, skip it
                         if let ast::TyKind::Path(_, ref p) = ty.node {
                             if p.segments.len() == 1 &&
-                            ty_param_names.contains(&p.segments[0].ident.name) ||
-                            processed_field_types.contains(&p.segments) {
+                               ty_param_names.contains(&p.segments[0].ident.name) {
                                 continue;
                             };
-                            processed_field_types.insert(p.segments.clone());
                         }
                         let mut bounds: Vec<_> = self.additional_bounds
                             .iter()
@@ -913,7 +909,7 @@ impl<'a> MethodDef<'a> {
                 Self_ if nonstatic => {
                     self_args.push(arg_expr);
                 }
-                Ptr(ref ty, _) if **ty == Self_ && nonstatic => {
+                Ptr(ref ty, _) if (if let Self_ = **ty { true } else { false }) && nonstatic => {
                     self_args.push(cx.expr_deref(trait_.span, arg_expr))
                 }
                 _ => {
diff --git a/src/libsyntax_ext/deriving/generic/ty.rs b/src/libsyntax_ext/deriving/generic/ty.rs
index 0b809ab585c..dcccb187bef 100644
--- a/src/libsyntax_ext/deriving/generic/ty.rs
+++ b/src/libsyntax_ext/deriving/generic/ty.rs
@@ -24,8 +24,7 @@ use syntax_pos::Span;
 use syntax_pos::symbol::keywords;
 
 /// The types of pointers
-#[derive(Clone, Eq, PartialEq)]
-#[allow(dead_code)]
+#[derive(Clone)]
 pub enum PtrTy<'a> {
     /// &'lifetime mut
     Borrowed(Option<&'a str>, ast::Mutability),
@@ -35,7 +34,7 @@ pub enum PtrTy<'a> {
 
 /// A path, e.g. `::std::option::Option::<i32>` (global). Has support
 /// for type parameters and a lifetime.
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone)]
 pub struct Path<'a> {
     path: Vec<&'a str>,
     lifetime: Option<&'a str>,
@@ -43,7 +42,7 @@ pub struct Path<'a> {
     kind: PathKind,
 }
 
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone)]
 pub enum PathKind {
     Local,
     Global,
@@ -107,7 +106,7 @@ impl<'a> Path<'a> {
 }
 
 /// A type. Supports pointers, Self, and literals
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone)]
 pub enum Ty<'a> {
     Self_,
     /// &/Box/ Ty
diff --git a/src/libsyntax_ext/format_foreign.rs b/src/libsyntax_ext/format_foreign.rs
index 2393af76c34..ff9663cdd3c 100644
--- a/src/libsyntax_ext/format_foreign.rs
+++ b/src/libsyntax_ext/format_foreign.rs
@@ -12,7 +12,7 @@ pub mod printf {
     use super::strcursor::StrCursor as Cur;
 
     /// Represents a single `printf`-style substitution.
-    #[derive(Clone, Eq, PartialEq, Debug)]
+    #[derive(Clone, PartialEq, Debug)]
     pub enum Substitution<'a> {
         /// A formatted output substitution.
         Format(Format<'a>),
@@ -40,7 +40,7 @@ pub mod printf {
         }
     }
 
-    #[derive(Clone, Eq, PartialEq, Debug)]
+    #[derive(Clone, PartialEq, Debug)]
     /// A single `printf`-style formatting directive.
     pub struct Format<'a> {
         /// The entire original formatting directive.
@@ -213,7 +213,7 @@ pub mod printf {
     }
 
     /// A general number used in a `printf` formatting directive.
-    #[derive(Copy, Clone, Eq, PartialEq, Debug)]
+    #[derive(Copy, Clone, PartialEq, Debug)]
     pub enum Num {
         // The range of these values is technically bounded by `NL_ARGMAX`... but, at least for GNU
         // libc, it apparently has no real fixed limit.  A `u16` is used here on the basis that it
@@ -739,7 +739,7 @@ pub mod printf {
 pub mod shell {
     use super::strcursor::StrCursor as Cur;
 
-    #[derive(Clone, Eq, PartialEq, Debug)]
+    #[derive(Clone, PartialEq, Debug)]
     pub enum Substitution<'a> {
         Ordinal(u8),
         Name(&'a str),
diff --git a/src/libsyntax_ext/proc_macro_registrar.rs b/src/libsyntax_ext/proc_macro_registrar.rs
index ab2bb446631..2522fa769c5 100644
--- a/src/libsyntax_ext/proc_macro_registrar.rs
+++ b/src/libsyntax_ext/proc_macro_registrar.rs
@@ -101,9 +101,7 @@ fn is_proc_macro_attr(attr: &ast::Attribute) -> bool {
 
 impl<'a> CollectProcMacros<'a> {
     fn check_not_pub_in_root(&self, vis: &ast::Visibility, sp: Span) {
-        if self.is_proc_macro_crate &&
-           self.in_root &&
-           vis.node == ast::VisibilityKind::Public {
+        if self.is_proc_macro_crate && self.in_root && vis.node.is_pub() {
             self.handler.span_err(sp,
                                   "`proc-macro` crate types cannot \
                                    export any items other than functions \
@@ -181,7 +179,7 @@ impl<'a> CollectProcMacros<'a> {
             Vec::new()
         };
 
-        if self.in_root && item.vis.node == ast::VisibilityKind::Public {
+        if self.in_root && item.vis.node.is_pub() {
             self.derives.push(ProcMacroDerive {
                 span: item.span,
                 trait_name,
@@ -206,7 +204,7 @@ impl<'a> CollectProcMacros<'a> {
             return;
         }
 
-        if self.in_root && item.vis.node == ast::VisibilityKind::Public {
+        if self.in_root && item.vis.node.is_pub() {
             self.attr_macros.push(ProcMacroDef {
                 span: item.span,
                 function_name: item.ident,
@@ -229,7 +227,7 @@ impl<'a> CollectProcMacros<'a> {
             return;
         }
 
-        if self.in_root && item.vis.node == ast::VisibilityKind::Public {
+        if self.in_root && item.vis.node.is_pub() {
             self.bang_macros.push(ProcMacroDef {
                 span: item.span,
                 function_name: item.ident,
@@ -271,7 +269,8 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
         for attr in &item.attrs {
             if is_proc_macro_attr(&attr) {
                 if let Some(prev_attr) = found_attr {
-                    let msg = if attr.path == prev_attr.path {
+                    let msg = if attr.path.segments[0].ident.name ==
+                                 prev_attr.path.segments[0].ident.name {
                         format!("Only one `#[{}]` attribute is allowed on any given function",
                                 attr.path)
                     } else {