diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
index 74e0f74294613..d218040847704 100644
--- a/compiler/rustc_errors/src/diagnostic_builder.rs
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -255,19 +255,6 @@ impl EmissionGuarantee for ! {
 /// instead of a `&DiagnosticBuilder<'a>`. This `forward!` macro makes
 /// it easy to declare such methods on the builder.
 macro_rules! forward {
-    // Forward pattern for &self -> &Self
-    (
-        $(#[$attrs:meta])*
-        pub fn $n:ident(&self, $($name:ident: $ty:ty),* $(,)?) -> &Self
-    ) => {
-        $(#[$attrs])*
-        #[doc = concat!("See [`Diagnostic::", stringify!($n), "()`].")]
-        pub fn $n(&self, $($name: $ty),*) -> &Self {
-            self.diagnostic.$n($($name),*);
-            self
-        }
-    };
-
     // Forward pattern for &mut self -> &mut Self
     (
         $(#[$attrs:meta])*
diff --git a/compiler/rustc_middle/src/ty/codec.rs b/compiler/rustc_middle/src/ty/codec.rs
index 7fcc46cc7c206..23c377651cc6c 100644
--- a/compiler/rustc_middle/src/ty/codec.rs
+++ b/compiler/rustc_middle/src/ty/codec.rs
@@ -453,9 +453,6 @@ macro_rules! impl_arena_allocatable_decoder {
             }
         }
     };
-    ([$ignore:ident $(, $attrs:ident)*]$args:tt) => {
-        impl_arena_allocatable_decoder!([$($attrs),*]$args);
-    };
 }
 
 macro_rules! impl_arena_allocatable_decoders {
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
index d5053034ed882..7d6b8c760ff6a 100644
--- a/compiler/rustc_serialize/src/serialize.rs
+++ b/compiler/rustc_serialize/src/serialize.rs
@@ -498,7 +498,6 @@ macro_rules! peel {
 /// Therefore, the recursion depth is the binary logarithm of the number of
 /// tokens to count, and the expanded tree is likewise very small.
 macro_rules! count {
-    ()                     => (0usize);
     ($one:tt)              => (1usize);
     ($($pairs:tt $_p:tt)*) => (count!($($pairs)*) << 1usize);
     ($odd:tt $($rest:tt)*) => (count!($($rest)*) | 1usize);
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index bd5b712c143c5..965a3c109832b 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -2249,10 +2249,6 @@ impl ToJson for Target {
                 let name = (stringify!($attr)).replace("_", "-");
                 d.insert(name, self.$attr.to_json());
             }};
-            ($attr:ident, $key_name:expr) => {{
-                let name = $key_name;
-                d.insert(name.into(), self.$attr.to_json());
-            }};
         }
 
         macro_rules! target_option_val {
diff --git a/library/core/src/internal_macros.rs b/library/core/src/internal_macros.rs
index 417ed51c6b6a2..7ef78e0b48af1 100644
--- a/library/core/src/internal_macros.rs
+++ b/library/core/src/internal_macros.rs
@@ -1,10 +1,6 @@
 // implements the unary operator "op &T"
 // based on "op T" where T is expected to be `Copy`able
 macro_rules! forward_ref_unop {
-    (impl $imp:ident, $method:ident for $t:ty) => {
-        forward_ref_unop!(impl $imp, $method for $t,
-                #[stable(feature = "rust1", since = "1.0.0")]);
-    };
     (impl const $imp:ident, $method:ident for $t:ty) => {
         forward_ref_unop!(impl const $imp, $method for $t,
                 #[stable(feature = "rust1", since = "1.0.0")]);
@@ -38,10 +34,6 @@ macro_rules! forward_ref_unop {
 // implements binary operators "&T op U", "T op &U", "&T op &U"
 // based on "T op U" where T and U are expected to be `Copy`able
 macro_rules! forward_ref_binop {
-    (impl $imp:ident, $method:ident for $t:ty, $u:ty) => {
-        forward_ref_binop!(impl $imp, $method for $t, $u,
-                #[stable(feature = "rust1", since = "1.0.0")]);
-    };
     (impl const $imp:ident, $method:ident for $t:ty, $u:ty) => {
         forward_ref_binop!(impl const $imp, $method for $t, $u,
                 #[stable(feature = "rust1", since = "1.0.0")]);
@@ -230,22 +222,6 @@ macro_rules! cfg_if {
         }
     };
 
-    // match if/else chains lacking a final `else`
-    (
-        if #[cfg( $i_meta:meta )] { $( $i_tokens:tt )* }
-        $(
-            else if #[cfg( $e_meta:meta )] { $( $e_tokens:tt )* }
-        )*
-    ) => {
-        cfg_if! {
-            @__items () ;
-            (( $i_meta ) ( $( $i_tokens )* )) ,
-            $(
-                (( $e_meta ) ( $( $e_tokens )* )) ,
-            )*
-        }
-    };
-
     // Internal and recursive macro to emit all the items
     //
     // Collects all the previous cfgs in a list at the beginning, so they can be
diff --git a/library/core/tests/num/ops.rs b/library/core/tests/num/ops.rs
index 9979cc8fde434..ae8b938250ec9 100644
--- a/library/core/tests/num/ops.rs
+++ b/library/core/tests/num/ops.rs
@@ -43,18 +43,6 @@ macro_rules! impls_defined {
 }
 
 macro_rules! test_op {
-    ($fn_name:ident, $op:ident::$method:ident($lhs:literal, $rhs:literal), $result:literal, $($t:ty),+) => {
-        #[test]
-        fn $fn_name() {
-            impls_defined!($op, $method($lhs, $rhs), $result, $($t),+);
-        }
-    };
-    ($fn_name:ident, $op:ident::$method:ident(&mut $lhs:literal, $rhs:literal), $result:literal, $($t:ty),+) => {
-        #[test]
-        fn $fn_name() {
-            impls_defined!($op, $method(&mut $lhs, $rhs), $result, $($t),+);
-        }
-    };
     ($fn_name:ident, $op:ident::$method:ident($lhs:literal), $result:literal, $($t:ty),+) => {
         #[test]
         fn $fn_name() {
diff --git a/library/proc_macro/src/quote.rs b/library/proc_macro/src/quote.rs
index 1fd59889709b2..04fa696d5e6be 100644
--- a/library/proc_macro/src/quote.rs
+++ b/library/proc_macro/src/quote.rs
@@ -12,7 +12,6 @@ macro_rules! quote_tt {
     ({$($t:tt)*}) => { Group::new(Delimiter::Brace, quote!($($t)*)) };
     (,) => { Punct::new(',', Spacing::Alone) };
     (.) => { Punct::new('.', Spacing::Alone) };
-    (:) => { Punct::new(':', Spacing::Alone) };
     (;) => { Punct::new(';', Spacing::Alone) };
     (!) => { Punct::new('!', Spacing::Alone) };
     (<) => { Punct::new('<', Spacing::Alone) };