From 38ab20dbf7469aa5a3cb0d7bfd3700281aa46467 Mon Sep 17 00:00:00 2001
From: V1shvesh <22243137+V1shvesh@users.noreply.github.com>
Date: Sun, 8 Sep 2019 14:57:03 +0530
Subject: [PATCH 1/4] Add pluralise macro

Adress issue #64238. Create a macro to be used for pluralisation check
throughout rustc codebase.
---
 src/librustc_errors/lib.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 6585633e00a..b5341a2b727 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -845,3 +845,11 @@ pub fn is_failure_note(&self) -> bool {
         }
     }
 }
+
+#[macro_export]
+macro_rules! pluralise {
+            ($x:expr) => {
+                if $x != 1 { "s" } else { "" }
+            };
+}
+

From c2552065819288a91a7e2646d95bf53765304b4f Mon Sep 17 00:00:00 2001
From: V1shvesh <22243137+V1shvesh@users.noreply.github.com>
Date: Sun, 8 Sep 2019 15:00:08 +0530
Subject: [PATCH 2/4] Refactor Pluralisation

Modify files performing pluralisation checks to incorporate the
dedicated macro located in `syntax::errors`.
---
 src/librustc/ty/error.rs                    | 7 +------
 src/librustc_typeck/astconv.rs              | 3 ++-
 src/librustc_typeck/check/compare_method.rs | 9 +++++----
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/src/librustc/ty/error.rs b/src/librustc/ty/error.rs
index f67526ea4a1..62910ec3204 100644
--- a/src/librustc/ty/error.rs
+++ b/src/librustc/ty/error.rs
@@ -4,6 +4,7 @@
 use std::fmt;
 use rustc_target::spec::abi;
 use syntax::ast;
+use syntax::errors::pluralise;
 use errors::{Applicability, DiagnosticBuilder};
 use syntax_pos::Span;
 
@@ -82,12 +83,6 @@ fn report_maybe_different(f: &mut fmt::Formatter<'_>,
             }
         };
 
-        macro_rules! pluralise {
-            ($x:expr) => {
-                if $x != 1 { "s" } else { "" }
-            };
-        }
-
         match *self {
             CyclicTy(_) => write!(f, "cyclic type of infinite size"),
             Mismatch => write!(f, "types differ"),
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
index 9e52eae88ef..e9ca0f3d978 100644
--- a/src/librustc_typeck/astconv.rs
+++ b/src/librustc_typeck/astconv.rs
@@ -23,6 +23,7 @@
 use crate::require_c_abi_if_c_variadic;
 use smallvec::SmallVec;
 use syntax::ast;
+use syntax::errors::pluralise;
 use syntax::feature_gate::{GateIssue, emit_feature_err};
 use syntax::util::lev_distance::find_best_match_for_name;
 use syntax::symbol::sym;
@@ -377,7 +378,7 @@ fn check_generic_arg_count(
                     quantifier,
                     bound,
                     kind,
-                    if bound != 1 { "s" } else { "" },
+                    pluralise!(bound),
                 ))
             };
 
diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs
index 8e187b7e05b..f22499f5472 100644
--- a/src/librustc_typeck/check/compare_method.rs
+++ b/src/librustc_typeck/check/compare_method.rs
@@ -10,6 +10,7 @@
 use errors::{Applicability, DiagnosticId};
 
 use syntax_pos::Span;
+use syntax::errors::pluralise;
 
 use super::{Inherited, FnCtxt, potentially_plural_count};
 
@@ -648,9 +649,9 @@ fn compare_number_of_generics<'tcx>(
                      declaration has {} {kind} parameter{}",
                     trait_.ident,
                     impl_count,
-                    if impl_count != 1 { "s" } else { "" },
+                    pluralise!(impl_count),
                     trait_count,
-                    if trait_count != 1 { "s" } else { "" },
+                    pluralise!(trait_count),
                     kind = kind,
                 ),
                 DiagnosticId::Error("E0049".into()),
@@ -665,7 +666,7 @@ fn compare_number_of_generics<'tcx>(
                         "expected {} {} parameter{}",
                         trait_count,
                         kind,
-                        if trait_count != 1 { "s" } else { "" },
+                        pluralise!(trait_count),
                     ));
                 }
                 for span in spans {
@@ -680,7 +681,7 @@ fn compare_number_of_generics<'tcx>(
                     "found {} {} parameter{}{}",
                     impl_count,
                     kind,
-                    if impl_count != 1 { "s" } else { "" },
+                    pluralise!(impl_count),
                     suffix.unwrap_or_else(|| String::new()),
                 ));
             }

From fc4375a895c899e937892c5666372cf14d35c6df Mon Sep 17 00:00:00 2001
From: V1shvesh <22243137+V1shvesh@users.noreply.github.com>
Date: Sun, 8 Sep 2019 22:58:28 +0530
Subject: [PATCH 3/4] Remove extra trailing newline

---
 src/librustc_errors/lib.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index b5341a2b727..20338a33ef6 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -852,4 +852,3 @@ macro_rules! pluralise {
                 if $x != 1 { "s" } else { "" }
             };
 }
-

From 7457ef858026d1858e9a36c7fad7a95773d0632d Mon Sep 17 00:00:00 2001
From: V1shvesh <22243137+V1shvesh@users.noreply.github.com>
Date: Sun, 8 Sep 2019 23:01:43 +0530
Subject: [PATCH 4/4] Dedent macro definition

---
 src/librustc_errors/lib.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 20338a33ef6..c1fba416d64 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -848,7 +848,7 @@ pub fn is_failure_note(&self) -> bool {
 
 #[macro_export]
 macro_rules! pluralise {
-            ($x:expr) => {
-                if $x != 1 { "s" } else { "" }
-            };
+    ($x:expr) => {
+        if $x != 1 { "s" } else { "" }
+    };
 }