diff --git a/Cargo.lock b/Cargo.lock
index 05c7a3cfdc7..25d7e40e8ac 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -807,19 +807,18 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_arena"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d1c93a754d8026d90ac78a6cbbe9ea96bc914c3b7279e2c28b6e3a7f972f370a"
+checksum = "d77be159a7d411e02ddf51a97cc2f98e88b93bf2856ac203dea737b8041ed23c"
 dependencies = [
- "rustc-ap-rustc_data_structures",
  "smallvec 1.4.0",
 ]
 
 [[package]]
 name = "rustc-ap-rustc_ast"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "680fc977e0138606169d9df563d80bf891dbaad5ea31f2dbc027b88d4379526d"
+checksum = "584ac06879fc46441feb444b6b6f55bf71489e3dc10a6a94222513f118468526"
 dependencies = [
  "bitflags",
  "rustc-ap-rustc_data_structures",
@@ -834,9 +833,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_ast_passes"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "568484d3a1f27629d248859083148794cf510a56703033d6bfc8a99dc25061d8"
+checksum = "155c1e648133f0df2848d899564aade8bd58ce2c82b03727e8437ec2523f420b"
 dependencies = [
  "itertools 0.9.0",
  "rustc-ap-rustc_ast",
@@ -853,9 +852,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_ast_pretty"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e9bca9174b96ca0d43da37e99554cc92a23891c67d61aea28941f271802d952"
+checksum = "f3786235c5f1466ffd0f00cb1851e7cd8637f07d12efdeb206de3aa8cc285cf7"
 dependencies = [
  "rustc-ap-rustc_ast",
  "rustc-ap-rustc_span",
@@ -865,9 +864,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_attr"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a55e4a48ddb8681350bacfc2a0528aab92cb949d1319a37516f3a4a0887065f"
+checksum = "6e02580ccbaf8d417c59d97a946b446b2a5332d68a0cf1eab74bb5dd33100e99"
 dependencies = [
  "rustc-ap-rustc_ast",
  "rustc-ap-rustc_ast_pretty",
@@ -884,9 +883,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_data_structures"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d9ab43857012b05d21469faacbf264a260cb195234685217235ac9fc0aef4b9"
+checksum = "be2a1c1a22021daef8354fb7504da4ed6df6e0aaf345af32c51e4ccf8afc07c0"
 dependencies = [
  "arrayvec",
  "bitflags",
@@ -915,9 +914,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_errors"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fae07ec2982336cbb24ffa9372bcb99e53bc11349ea4c18e277e26c6e335b004"
+checksum = "f81730d3ab322d96265163f9ab2ced6815d336a0441a85641d134c30d69d6660"
 dependencies = [
  "annotate-snippets",
  "atty",
@@ -934,9 +933,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_expand"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "467da6ff9ae25cc5d42c550d05139b66a9d233ded99ba075d603d2d81b6833e9"
+checksum = "325f40a43586a4fbd1d3837c3bb024db3729193146201d13f59b637d28e73ffe"
 dependencies = [
  "rustc-ap-rustc_ast",
  "rustc-ap-rustc_ast_passes",
@@ -957,9 +956,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_feature"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1c8d97da0b8c738e5d81fd87ec09c24fd7629a7d09c2fbaaa5cc65ee88cc02df"
+checksum = "e53e214c56bd3db863bf87e23a68cc9c7b2ccf1796dc63b5c795f75e1457654b"
 dependencies = [
  "rustc-ap-rustc_data_structures",
  "rustc-ap-rustc_span",
@@ -967,21 +966,21 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_fs_util"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f48e05e2d6f70ca7b3060cae874d7bff3bfb746459b30167a72851eb3315acb0"
+checksum = "9783efc336cdb51ca8ed281040bf72bcb178a2a29867aade35893e4335f7ac01"
 
 [[package]]
 name = "rustc-ap-rustc_graphviz"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aba5fc553fb1aa193946f1d549535dd3260a2a27d2a3e1bb87927f8a5721e3d4"
+checksum = "bb71e52620bcba8695271b90cb1d294ed16f1dcc81e85327e6dc67e6b5c3ef1d"
 
 [[package]]
 name = "rustc-ap-rustc_index"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d1f0eae2b583705f5e8fac5cefb5b44eb6c60804371d351652584d945752f69b"
+checksum = "c1e73d13c4839873924d0c04fb885a4e3980b5c8416f8a96f925a8e5a4eb9c8e"
 dependencies = [
  "arrayvec",
  "rustc-ap-rustc_macros",
@@ -990,18 +989,18 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_lexer"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0c9a47e24d4b7d74ec583d8813803b36985ee082fe7debe55f257df92d5fe50"
+checksum = "de5fb086575a381760a993126795222a49f3bab9faeb91dc67268dd19eab5c13"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "rustc-ap-rustc_macros"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33c94c1dbab188f380c4b1291616231d39ebb89d0d51d29c93be72825aeff0ff"
+checksum = "1cb3c133f618b5296c2ba57f05ee7b4c3fbec09d2779922083c2d16c5674f57c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1011,9 +1010,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_parse"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e923400798f2213b6be951ba0c9905eb66ad58fe665fc843513496cd567142d9"
+checksum = "9cc8e42993c1ff89f56e2e00240a186c6eaaad6839a271ee3d534240a624ea5a"
 dependencies = [
  "bitflags",
  "rustc-ap-rustc_ast",
@@ -1031,9 +1030,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_serialize"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc0c8a49f60cc2805f07213c7442a8be42225c2a7cfaf40bda751433fa51c52f"
+checksum = "1bb88c78d4551e0243518d05ea3ab16388af97ec839e60de71c39147154a0303"
 dependencies = [
  "indexmap",
  "smallvec 1.4.0",
@@ -1041,9 +1040,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_session"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b87138ef05f3069fdce0e759809cc8e9c9db6c183f15523b9ec0b843b48cdaed"
+checksum = "f1362a5e57049bc7d722b06f5a8886fbf169e3a892ac793aedd8529ef60a8750"
 dependencies = [
  "bitflags",
  "getopts",
@@ -1062,9 +1061,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_span"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b8eb89541600fb44f79db273167a59eade2e4faebe828bbba7e1906784a943e"
+checksum = "b67a086e3f81d54cb9d83974b11961ca8c4111a0955173124314e1ae99a1c2ad"
 dependencies = [
  "cfg-if",
  "md-5",
@@ -1081,9 +1080,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_target"
-version = "683.0.0"
+version = "684.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1ef97b8a6a40d5324975ce48de1fe86e60d67b42950b33cd4e33624ccaee7e8"
+checksum = "574c6a3e4495dfc522918103bd2cc77148a4716a58583ebed1a764963769151f"
 dependencies = [
  "bitflags",
  "rustc-ap-rustc_data_structures",
diff --git a/Cargo.toml b/Cargo.toml
index 6b01061370b..7bd99b89268 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -107,32 +107,32 @@ lazy_static = "1.0.0"
 
 [dependencies.rustc_ast]
 package = "rustc-ap-rustc_ast"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_ast_pretty]
 package = "rustc-ap-rustc_ast_pretty"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_data_structures]
 package = "rustc-ap-rustc_data_structures"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_errors]
 package = "rustc-ap-rustc_errors"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_expand]
 package = "rustc-ap-rustc_expand"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_parse]
 package = "rustc-ap-rustc_parse"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_session]
 package = "rustc-ap-rustc_session"
-version = "683.0.0"
+version = "684.0.0"
 
 [dependencies.rustc_span]
 package = "rustc-ap-rustc_span"
-version = "683.0.0"
+version = "684.0.0"
diff --git a/src/formatting/expr.rs b/src/formatting/expr.rs
index b53496affa8..61937aeee3f 100644
--- a/src/formatting/expr.rs
+++ b/src/formatting/expr.rs
@@ -124,6 +124,9 @@ pub(crate) fn format_expr(
         | ast::ExprKind::Loop(..)
         | ast::ExprKind::While(..) => to_control_flow(expr, expr_type)
             .and_then(|control_flow| control_flow.rewrite(context, shape)),
+        ast::ExprKind::ConstBlock(ref anon_const) => {
+            Some(format!("const {}", anon_const.rewrite(context, shape)?))
+        }
         ast::ExprKind::Block(ref block, opt_label) => {
             match expr_type {
                 ExprType::Statement => {
diff --git a/src/formatting/macros.rs b/src/formatting/macros.rs
index 726ff964a53..0a1ee3e6e09 100644
--- a/src/formatting/macros.rs
+++ b/src/formatting/macros.rs
@@ -16,7 +16,8 @@ use rustc_ast::token::{BinOpToken, DelimToken, Token, TokenKind};
 use rustc_ast::tokenstream::{Cursor, TokenStream, TokenTree};
 use rustc_ast::{ast, ptr};
 use rustc_ast_pretty::pprust;
-use rustc_parse::{new_parser_from_tts, parser::Parser};
+use rustc_parse::parser::Parser;
+use rustc_parse::{stream_to_parser, MACRO_ARGUMENTS};
 use rustc_span::{
     symbol::{self, kw},
     BytePos, Span, Symbol, DUMMY_SP,
@@ -88,6 +89,14 @@ impl Rewrite for MacroArg {
     }
 }
 
+fn build_parser<'a>(context: &RewriteContext<'a>, cursor: Cursor) -> Parser<'a> {
+    stream_to_parser(
+        context.parse_sess.inner(),
+        cursor.collect(),
+        MACRO_ARGUMENTS,
+    )
+}
+
 fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
     macro_rules! parse_macro_arg {
         ($macro_arg:ident, $parser:expr, $f:expr) => {
@@ -297,7 +306,7 @@ fn rewrite_macro_inner(
         }
     }
 
-    let mut parser = new_parser_from_tts(context.parse_sess.inner(), ts.trees().collect());
+    let mut parser = build_parser(context, ts.trees());
     let mut arg_vec = Vec::new();
     let mut vec_with_semi = false;
     let mut trailing_comma = false;
@@ -1204,7 +1213,7 @@ pub(crate) fn convert_try_mac(
     let path = &pprust::path_to_string(&mac.path);
     if path == "try" || path == "r#try" {
         let ts = mac.args.inner_tokens();
-        let mut parser = new_parser_from_tts(context.parse_sess.inner(), ts.trees().collect());
+        let mut parser = build_parser(context, ts.trees());
 
         let mut kind = parser.parse_expr().ok()?;
         // take the end pos of mac so that the Try expression includes the closing parenthesis of
@@ -1445,7 +1454,7 @@ fn format_lazy_static(
     ts: &TokenStream,
 ) -> Option<String> {
     let mut result = String::with_capacity(1024);
-    let mut parser = new_parser_from_tts(context.parse_sess.inner(), ts.trees().collect());
+    let mut parser = build_parser(context, ts.trees());
     let nested_shape = shape
         .block_indent(context.config.tab_spaces())
         .with_max_width(context.config);
diff --git a/src/formatting/utils.rs b/src/formatting/utils.rs
index f3484020b05..01d4c4b202f 100644
--- a/src/formatting/utils.rs
+++ b/src/formatting/utils.rs
@@ -482,6 +482,7 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         | ast::ExprKind::While(..)
         | ast::ExprKind::If(..)
         | ast::ExprKind::Block(..)
+        | ast::ExprKind::ConstBlock(..)
         | ast::ExprKind::Async(..)
         | ast::ExprKind::Loop(..)
         | ast::ExprKind::ForLoop(..)