3 files changed, 19 insertions, 9 deletions
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 448ff9676c9..96584a580f1 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -1831,10 +1831,10 @@ mod tests {
     use errors;
     use feature_gate::UnstableFeatures;
     use parse::token;
-    use std::collections::HashSet;
     use std::io;
     use std::path::PathBuf;
     use diagnostics::plugin::ErrorMap;
+    use rustc_data_structures::fx::FxHashSet;
     use rustc_data_structures::sync::Lock;
     use with_globals;
     fn mk_sess(cm: Lrc<SourceMap>) -> ParseSess {
@@ -1845,10 +1845,10 @@ mod tests {
         ParseSess {
             span_diagnostic: errors::Handler::with_emitter(true, false, Box::new(emitter)),
             unstable_features: UnstableFeatures::from_environment(),
-            config: CrateConfig::new(),
+            config: CrateConfig::default(),
             included_mod_stack: Lock::new(Vec::new()),
             code_map: cm,
-            missing_fragment_specifiers: Lock::new(HashSet::new()),
+            missing_fragment_specifiers: Lock::new(FxHashSet::default()),
             raw_identifier_spans: Lock::new(Vec::new()),
             registered_diagnostics: Lock::new(ErrorMap::new()),
             non_modrs_mods: Lock::new(vec![]),
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 1136cda5ee3..28d63399b44 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -24,8 +24,8 @@ use symbol::Symbol;
 use tokenstream::{TokenStream, TokenTree};
 use diagnostics::plugin::ErrorMap;
 
+use rustc_data_structures::fx::FxHashSet;
 use std::borrow::Cow;
-use std::collections::HashSet;
 use std::iter;
 use std::path::{Path, PathBuf};
 use std::str;
@@ -46,7 +46,7 @@ pub struct ParseSess {
     pub span_diagnostic: Handler,
     pub unstable_features: UnstableFeatures,
     pub config: CrateConfig,
-    pub missing_fragment_specifiers: Lock<HashSet<Span>>,
+    pub missing_fragment_specifiers: Lock<FxHashSet<Span>>,
     /// Places where raw identifiers were used. This is used for feature gating
     /// raw identifiers
     pub raw_identifier_spans: Lock<Vec<Span>>,
@@ -75,8 +75,8 @@ impl ParseSess {
         ParseSess {
             span_diagnostic: handler,
             unstable_features: UnstableFeatures::from_environment(),
-            config: HashSet::new(),
-            missing_fragment_specifiers: Lock::new(HashSet::new()),
+            config: FxHashSet::default(),
+            missing_fragment_specifiers: Lock::new(FxHashSet::default()),
             raw_identifier_spans: Lock::new(Vec::new()),
             registered_diagnostics: Lock::new(ErrorMap::new()),
             included_mod_stack: Lock::new(vec![]),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 1695d3a8f96..6c50b9c82f2 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -786,7 +786,12 @@ impl<'a> Parser<'a> {
         } else {
             err.span_label(self.span, "expected identifier");
             if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) {
-                err.span_suggestion(self.span, "remove this comma", String::new());
+                err.span_suggestion_with_applicability(
+                    self.span,
+                    "remove this comma",
+                    String::new(),
+                    Applicability::MachineApplicable,
+                );
             }
         }
         err
@@ -6083,7 +6088,12 @@ impl<'a> Parser<'a> {
                                                                 self.this_token_to_string()));
                 if self.token.is_ident() {
                     // This is likely another field; emit the diagnostic and keep going
-                    err.span_suggestion(sp, "try adding a comma", ",".into());
+                    err.span_suggestion_with_applicability(
+                        sp,
+                        "try adding a comma",
+                        ",".into(),
+                        Applicability::MachineApplicable,
+                    );
                     err.emit();
                 } else {
                     return Err(err)