diff --git a/Cargo.lock b/Cargo.lock
index 7f35b7344dfed..73605af7936f2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -910,6 +910,9 @@ dependencies = [
 [[package]]
 name = "fmt_macros"
 version = "0.0.0"
+dependencies = [
+ "syntax_pos 0.0.0",
+]
 
 [[package]]
 name = "fnv"
diff --git a/src/libfmt_macros/Cargo.toml b/src/libfmt_macros/Cargo.toml
index 50779a2d9ad08..fc32f21ec4e0a 100644
--- a/src/libfmt_macros/Cargo.toml
+++ b/src/libfmt_macros/Cargo.toml
@@ -8,3 +8,6 @@ edition = "2018"
 name = "fmt_macros"
 path = "lib.rs"
 crate-type = ["dylib"]
+
+[dependencies]
+syntax_pos = { path = "../libsyntax_pos" }
diff --git a/src/libfmt_macros/lib.rs b/src/libfmt_macros/lib.rs
index 6fed83021609d..b851183debfc5 100644
--- a/src/libfmt_macros/lib.rs
+++ b/src/libfmt_macros/lib.rs
@@ -24,6 +24,17 @@ use std::str;
 use std::string;
 use std::iter;
 
+use syntax_pos::{InnerSpan, Symbol};
+
+#[derive(Copy, Clone)]
+struct InnerOffset(usize);
+
+impl InnerOffset {
+    fn to(self, end: InnerOffset) -> InnerSpan {
+        InnerSpan::new(self.0, end.0)
+    }
+}
+
 /// A piece is a portion of the format string which represents the next part
 /// to emit. These are emitted as a stream by the `Parser` class.
 #[derive(Copy, Clone, PartialEq)]
@@ -39,7 +50,7 @@ pub enum Piece<'a> {
 #[derive(Copy, Clone, PartialEq)]
 pub struct Argument<'a> {
     /// Where to find this argument
-    pub position: Position<'a>,
+    pub position: Position,
     /// How to format the argument
     pub format: FormatSpec<'a>,
 }
@@ -54,9 +65,9 @@ pub struct FormatSpec<'a> {
     /// Packed version of various flags provided
     pub flags: u32,
     /// The integer precision to use
-    pub precision: Count<'a>,
+    pub precision: Count,
     /// The string width requested for the resulting format
-    pub width: Count<'a>,
+    pub width: Count,
     /// The descriptor string representing the name of the format desired for
     /// this argument, this can be empty or any number of characters, although
     /// it is required to be one word.
@@ -65,16 +76,16 @@ pub struct FormatSpec<'a> {
 
 /// Enum describing where an argument for a format can be located.
 #[derive(Copy, Clone, PartialEq)]
-pub enum Position<'a> {
+pub enum Position {
     /// The argument is implied to be located at an index
     ArgumentImplicitlyIs(usize),
     /// The argument is located at a specific index given in the format
     ArgumentIs(usize),
     /// The argument has a name.
-    ArgumentNamed(&'a str),
+    ArgumentNamed(Symbol),
 }
 
-impl Position<'_> {
+impl Position {
     pub fn index(&self) -> Option<usize> {
         match self {
             ArgumentIs(i) | ArgumentImplicitlyIs(i) => Some(*i),
@@ -119,11 +130,11 @@ pub enum Flag {
 /// A count is used for the precision and width parameters of an integer, and
 /// can reference either an argument or a literal integer.
 #[derive(Copy, Clone, PartialEq)]
-pub enum Count<'a> {
+pub enum Count {
     /// The count is specified explicitly.
     CountIs(usize),
     /// The count is specified by the argument with the given name.
-    CountIsName(&'a str),
+    CountIsName(Symbol),
     /// The count is specified by the argument at the given index.
     CountIsParam(usize),
     /// The count is implied and cannot be explicitly specified.
@@ -134,9 +145,8 @@ pub struct ParseError {
     pub description: string::String,
     pub note: Option<string::String>,
     pub label: string::String,
-    pub start: SpanIndex,
-    pub end: SpanIndex,
-    pub secondary_label: Option<(string::String, SpanIndex, SpanIndex)>,
+    pub span: InnerSpan,
+    pub secondary_label: Option<(string::String, InnerSpan)>,
 }
 
 /// The parser structure for interpreting the input format string. This is
@@ -155,24 +165,15 @@ pub struct Parser<'a> {
     /// `Some(raw count)` when the string is "raw", used to position spans correctly
     style: Option<usize>,
     /// Start and end byte offset of every successfully parsed argument
-    pub arg_places: Vec<(SpanIndex, SpanIndex)>,
+    pub arg_places: Vec<InnerSpan>,
     /// Characters that need to be shifted
     skips: Vec<usize>,
-    /// Span offset of the last opening brace seen, used for error reporting
-    last_opening_brace_pos: Option<SpanIndex>,
+    /// Span of the last opening brace seen, used for error reporting
+    last_opening_brace: Option<InnerSpan>,
     /// Wether the source string is comes from `println!` as opposed to `format!` or `print!`
     append_newline: bool,
 }
 
-#[derive(Clone, Copy, Debug)]
-pub struct SpanIndex(pub usize);
-
-impl SpanIndex {
-    pub fn unwrap(self) -> usize {
-        self.0
-    }
-}
-
 impl<'a> Iterator for Parser<'a> {
     type Item = Piece<'a>;
 
@@ -180,19 +181,20 @@ impl<'a> Iterator for Parser<'a> {
         if let Some(&(pos, c)) = self.cur.peek() {
             match c {
                 '{' => {
-                    let curr_last_brace = self.last_opening_brace_pos;
-                    self.last_opening_brace_pos = Some(self.to_span_index(pos));
+                    let curr_last_brace = self.last_opening_brace;
+                    let byte_pos = self.to_span_index(pos);
+                    self.last_opening_brace = Some(byte_pos.to(InnerOffset(byte_pos.0 + 1)));
                     self.cur.next();
                     if self.consume('{') {
-                        self.last_opening_brace_pos = curr_last_brace;
+                        self.last_opening_brace = curr_last_brace;
 
                         Some(String(self.string(pos + 1)))
                     } else {
                         let arg = self.argument();
-                        if let Some(arg_pos) = self.must_consume('}').map(|end| {
-                            (self.to_span_index(pos), self.to_span_index(end + 1))
-                        }) {
-                            self.arg_places.push(arg_pos);
+                        if let Some(end) = self.must_consume('}') {
+                            let start = self.to_span_index(pos);
+                            let end = self.to_span_index(end + 1);
+                            self.arg_places.push(start.to(end));
                         }
                         Some(NextArgument(arg))
                     }
@@ -207,8 +209,7 @@ impl<'a> Iterator for Parser<'a> {
                             "unmatched `}` found",
                             "unmatched `}`",
                             "if you intended to print `}`, you can escape it using `}}`",
-                            err_pos,
-                            err_pos,
+                            err_pos.to(err_pos),
                         );
                         None
                     }
@@ -240,7 +241,7 @@ impl<'a> Parser<'a> {
             style,
             arg_places: vec![],
             skips,
-            last_opening_brace_pos: None,
+            last_opening_brace: None,
             append_newline,
         }
     }
@@ -252,15 +253,13 @@ impl<'a> Parser<'a> {
         &mut self,
         description: S1,
         label: S2,
-        start: SpanIndex,
-        end: SpanIndex,
+        span: InnerSpan,
     ) {
         self.errors.push(ParseError {
             description: description.into(),
             note: None,
             label: label.into(),
-            start,
-            end,
+            span,
             secondary_label: None,
         });
     }
@@ -273,15 +272,13 @@ impl<'a> Parser<'a> {
         description: S1,
         label: S2,
         note: S3,
-        start: SpanIndex,
-        end: SpanIndex,
+        span: InnerSpan,
     ) {
         self.errors.push(ParseError {
             description: description.into(),
             note: Some(note.into()),
             label: label.into(),
-            start,
-            end,
+            span,
             secondary_label: None,
         });
     }
@@ -302,22 +299,21 @@ impl<'a> Parser<'a> {
         }
     }
 
-    fn raw(&self) -> usize {
-        self.style.map(|raw| raw + 1).unwrap_or(0)
-    }
-
-    fn to_span_index(&self, pos: usize) -> SpanIndex {
+    fn to_span_index(&self, pos: usize) -> InnerOffset {
         let mut pos = pos;
+        // This handles the raw string case, the raw argument is the number of #
+        // in r###"..."### (we need to add one because of the `r`).
+        let raw = self.style.map(|raw| raw + 1).unwrap_or(0);
         for skip in &self.skips {
             if pos > *skip {
                 pos += 1;
-            } else if pos == *skip && self.raw() == 0 {
+            } else if pos == *skip && raw == 0 {
                 pos += 1;
             } else {
                 break;
             }
         }
-        SpanIndex(self.raw() + pos + 1)
+        InnerOffset(raw + pos + 1)
     }
 
     /// Forces consumption of the specified character. If the character is not
@@ -335,8 +331,8 @@ impl<'a> Parser<'a> {
                 let label = "expected `}`".to_owned();
                 let (note, secondary_label) = if c == '}' {
                     (Some("if you intended to print `{`, you can escape it using `{{`".to_owned()),
-                     self.last_opening_brace_pos.map(|pos| {
-                        ("because of this opening brace".to_owned(), pos, pos)
+                     self.last_opening_brace.map(|sp| {
+                        ("because of this opening brace".to_owned(), sp)
                      }))
                 } else {
                     (None, None)
@@ -345,8 +341,7 @@ impl<'a> Parser<'a> {
                     description,
                     note,
                     label,
-                    start: pos,
-                    end: pos,
+                    span: pos.to(pos),
                     secondary_label,
                 });
                 None
@@ -360,8 +355,8 @@ impl<'a> Parser<'a> {
                 let label = format!("expected `{:?}`", c);
                 let (note, secondary_label) = if c == '}' {
                     (Some("if you intended to print `{`, you can escape it using `{{`".to_owned()),
-                     self.last_opening_brace_pos.map(|pos| {
-                        ("because of this opening brace".to_owned(), pos, pos)
+                     self.last_opening_brace.map(|sp| {
+                        ("because of this opening brace".to_owned(), sp)
                      }))
                 } else {
                     (None, None)
@@ -370,12 +365,11 @@ impl<'a> Parser<'a> {
                     description,
                     note,
                     label,
-                    start: pos,
-                    end: pos,
+                    span: pos.to(pos),
                     secondary_label,
                 });
             } else {
-                self.err(description, format!("expected `{:?}`", c), pos, pos);
+                self.err(description, format!("expected `{:?}`", c), pos.to(pos));
             }
             None
         }
@@ -434,20 +428,24 @@ impl<'a> Parser<'a> {
     /// integer index of an argument, a named argument, or a blank string.
     /// Returns `Some(parsed_position)` if the position is not implicitly
     /// consuming a macro argument, `None` if it's the case.
-    fn position(&mut self) -> Option<Position<'a>> {
+    fn position(&mut self) -> Option<Position> {
         if let Some(i) = self.integer() {
             Some(ArgumentIs(i))
         } else {
             match self.cur.peek() {
-                Some(&(_, c)) if c.is_alphabetic() => Some(ArgumentNamed(self.word())),
+                Some(&(_, c)) if c.is_alphabetic() => {
+                    Some(ArgumentNamed(Symbol::intern(self.word())))
+                }
                 Some(&(pos, c)) if c == '_' => {
                     let invalid_name = self.string(pos);
                     self.err_with_note(format!("invalid argument name `{}`", invalid_name),
                                        "invalid argument name",
                                        "argument names cannot start with an underscore",
-                                       self.to_span_index(pos),
-                                       self.to_span_index(pos + invalid_name.len()));
-                    Some(ArgumentNamed(invalid_name))
+                                        self.to_span_index(pos).to(
+                                            self.to_span_index(pos + invalid_name.len())
+                                        ),
+                                        );
+                    Some(ArgumentNamed(Symbol::intern(invalid_name)))
                 },
 
                 // This is an `ArgumentNext`.
@@ -555,7 +553,7 @@ impl<'a> Parser<'a> {
     /// Parses a Count parameter at the current position. This does not check
     /// for 'CountIsNextParam' because that is only used in precision, not
     /// width.
-    fn count(&mut self) -> Count<'a> {
+    fn count(&mut self) -> Count {
         if let Some(i) = self.integer() {
             if self.consume('$') {
                 CountIsParam(i)
@@ -569,7 +567,7 @@ impl<'a> Parser<'a> {
                 self.cur = tmp;
                 CountImplied
             } else if self.consume('$') {
-                CountIsName(word)
+                CountIsName(Symbol::intern(word))
             } else {
                 self.cur = tmp;
                 CountImplied
@@ -759,6 +757,8 @@ mod tests {
     }
     #[test]
     fn format_counts() {
+        use syntax_pos::{GLOBALS, Globals, edition};
+        GLOBALS.set(&Globals::new(edition::DEFAULT_EDITION), || {
         same("{:10s}",
              &[NextArgument(Argument {
                    position: ArgumentImplicitlyIs(0),
@@ -814,11 +814,12 @@ mod tests {
                        fill: None,
                        align: AlignUnknown,
                        flags: 0,
-                       precision: CountIsName("b"),
-                       width: CountIsName("a"),
+                       precision: CountIsName(Symbol::intern("b")),
+                       width: CountIsName(Symbol::intern("a")),
                        ty: "s",
                    },
                })]);
+        });
     }
     #[test]
     fn format_flags() {
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index 490501bde73e5..50d2eeef421c1 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -353,7 +353,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             _ => {
                 // this is a "direct", user-specified, rather than derived,
                 // obligation.
-                flags.push(("direct".to_owned(), None));
+                flags.push((sym::direct, None));
             }
         }
 
@@ -365,27 +365,27 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             // Currently I'm leaving it for what I need for `try`.
             if self.tcx.trait_of_item(item) == Some(trait_ref.def_id) {
                 let method = self.tcx.item_name(item);
-                flags.push(("from_method".to_owned(), None));
-                flags.push(("from_method".to_owned(), Some(method.to_string())));
+                flags.push((sym::from_method, None));
+                flags.push((sym::from_method, Some(method.to_string())));
             }
         }
         if let Some(t) = self.get_parent_trait_ref(&obligation.cause.code) {
-            flags.push(("parent_trait".to_owned(), Some(t)));
+            flags.push((sym::parent_trait, Some(t)));
         }
 
         if let Some(k) = obligation.cause.span.compiler_desugaring_kind() {
-            flags.push(("from_desugaring".to_owned(), None));
-            flags.push(("from_desugaring".to_owned(), Some(k.name().to_string())));
+            flags.push((sym::from_desugaring, None));
+            flags.push((sym::from_desugaring, Some(k.name().to_string())));
         }
         let generics = self.tcx.generics_of(def_id);
         let self_ty = trait_ref.self_ty();
         // This is also included through the generics list as `Self`,
         // but the parser won't allow you to use it
-        flags.push(("_Self".to_owned(), Some(self_ty.to_string())));
+        flags.push((sym::_Self, Some(self_ty.to_string())));
         if let Some(def) = self_ty.ty_adt_def() {
             // We also want to be able to select self's original
             // signature with no type arguments resolved
-            flags.push(("_Self".to_owned(), Some(self.tcx.type_of(def.did).to_string())));
+            flags.push((sym::_Self, Some(self.tcx.type_of(def.did).to_string())));
         }
 
         for param in generics.params.iter() {
@@ -396,38 +396,38 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 },
                 GenericParamDefKind::Lifetime => continue,
             };
-            let name = param.name.to_string();
+            let name = param.name.as_symbol();
             flags.push((name, Some(value)));
         }
 
         if let Some(true) = self_ty.ty_adt_def().map(|def| def.did.is_local()) {
-            flags.push(("crate_local".to_owned(), None));
+            flags.push((sym::crate_local, None));
         }
 
         // Allow targeting all integers using `{integral}`, even if the exact type was resolved
         if self_ty.is_integral() {
-            flags.push(("_Self".to_owned(), Some("{integral}".to_owned())));
+            flags.push((sym::_Self, Some("{integral}".to_owned())));
         }
 
         if let ty::Array(aty, len) = self_ty.sty {
-            flags.push(("_Self".to_owned(), Some("[]".to_owned())));
-            flags.push(("_Self".to_owned(), Some(format!("[{}]", aty))));
+            flags.push((sym::_Self, Some("[]".to_owned())));
+            flags.push((sym::_Self, Some(format!("[{}]", aty))));
             if let Some(def) = aty.ty_adt_def() {
                 // We also want to be able to select the array's type's original
                 // signature with no type arguments resolved
                 flags.push((
-                    "_Self".to_owned(),
+                    sym::_Self,
                     Some(format!("[{}]", self.tcx.type_of(def.did).to_string())),
                 ));
                 let tcx = self.tcx;
                 if let Some(len) = len.assert_usize(tcx) {
                     flags.push((
-                        "_Self".to_owned(),
+                        sym::_Self,
                         Some(format!("[{}; {}]", self.tcx.type_of(def.did).to_string(), len)),
                     ));
                 } else {
                     flags.push((
-                        "_Self".to_owned(),
+                        sym::_Self,
                         Some(format!("[{}; _]", self.tcx.type_of(def.did).to_string())),
                     ));
                 }
diff --git a/src/librustc/traits/on_unimplemented.rs b/src/librustc/traits/on_unimplemented.rs
index 1c17ace90c2fb..b78396c90dc65 100644
--- a/src/librustc/traits/on_unimplemented.rs
+++ b/src/librustc/traits/on_unimplemented.rs
@@ -7,7 +7,7 @@ use crate::util::nodemap::FxHashMap;
 
 use syntax::ast::{MetaItem, NestedMetaItem};
 use syntax::attr;
-use syntax::symbol::sym;
+use syntax::symbol::{Symbol, kw, sym};
 use syntax_pos::Span;
 use syntax_pos::symbol::LocalInternedString;
 
@@ -52,7 +52,7 @@ fn parse_error(tcx: TyCtxt<'_, '_, '_>, span: Span,
 }
 
 impl<'a, 'gcx, 'tcx> OnUnimplementedDirective {
-    pub fn parse(tcx: TyCtxt<'a, 'gcx, 'tcx>,
+    fn parse(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                  trait_def_id: DefId,
                  items: &[NestedMetaItem],
                  span: Span,
@@ -167,7 +167,7 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedDirective {
     pub fn evaluate(&self,
                     tcx: TyCtxt<'a, 'gcx, 'tcx>,
                     trait_ref: ty::TraitRef<'tcx>,
-                    options: &[(String, Option<String>)])
+                    options: &[(Symbol, Option<String>)])
                     -> OnUnimplementedNote
     {
         let mut message = None;
@@ -180,7 +180,7 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedDirective {
                 if !attr::eval_condition(condition, &tcx.sess.parse_sess, &mut |c| {
                     c.ident().map_or(false, |ident| {
                         options.contains(&(
-                            ident.to_string(),
+                            ident.name,
                             c.value_str().map(|s| s.as_str().to_string())
                         ))
                     })
@@ -203,8 +203,8 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedDirective {
             }
         }
 
-        let options: FxHashMap<String, String> = options.into_iter()
-            .filter_map(|(k, v)| v.as_ref().map(|v| (k.to_owned(), v.to_owned())))
+        let options: FxHashMap<Symbol, String> = options.into_iter()
+            .filter_map(|(k, v)| v.as_ref().map(|v| (*k, v.to_owned())))
             .collect();
         OnUnimplementedNote {
             label: label.map(|l| l.format(tcx, trait_ref, &options)),
@@ -215,7 +215,7 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedDirective {
 }
 
 impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
-    pub fn try_parse(tcx: TyCtxt<'a, 'gcx, 'tcx>,
+    fn try_parse(tcx: TyCtxt<'a, 'gcx, 'tcx>,
                      trait_def_id: DefId,
                      from: LocalInternedString,
                      err_sp: Span)
@@ -241,16 +241,16 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
                 Piece::String(_) => (), // Normal string, no need to check it
                 Piece::NextArgument(a) => match a.position {
                     // `{Self}` is allowed
-                    Position::ArgumentNamed(s) if s == "Self" => (),
+                    Position::ArgumentNamed(s) if s == kw::SelfUpper => (),
                     // `{ThisTraitsName}` is allowed
-                    Position::ArgumentNamed(s) if s == name.as_str() => (),
+                    Position::ArgumentNamed(s) if s == name => (),
                     // `{from_method}` is allowed
-                    Position::ArgumentNamed(s) if s == "from_method" => (),
+                    Position::ArgumentNamed(s) if s == sym::from_method => (),
                     // `{from_desugaring}` is allowed
-                    Position::ArgumentNamed(s) if s == "from_desugaring" => (),
+                    Position::ArgumentNamed(s) if s == sym::from_desugaring => (),
                     // So is `{A}` if A is a type parameter
                     Position::ArgumentNamed(s) => match generics.params.iter().find(|param| {
-                        param.name.as_str() == s
+                        param.name.as_symbol() == s
                     }) {
                         Some(_) => (),
                         None => {
@@ -276,7 +276,7 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
         &self,
         tcx: TyCtxt<'a, 'gcx, 'tcx>,
         trait_ref: ty::TraitRef<'tcx>,
-        options: &FxHashMap<String, String>,
+        options: &FxHashMap<Symbol, String>,
     ) -> String {
         let name = tcx.item_name(trait_ref.def_id);
         let trait_str = tcx.def_path_str(trait_ref.def_id);
@@ -289,9 +289,9 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
                 },
                 GenericParamDefKind::Lifetime => return None
             };
-            let name = param.name.to_string();
+            let name = param.name.as_symbol();
             Some((name, value))
-        }).collect::<FxHashMap<String, String>>();
+        }).collect::<FxHashMap<Symbol, String>>();
         let empty_string = String::new();
 
         let parser = Parser::new(&self.0, None, vec![], false);
@@ -299,15 +299,15 @@ impl<'a, 'gcx, 'tcx> OnUnimplementedFormatString {
             match p {
                 Piece::String(s) => s,
                 Piece::NextArgument(a) => match a.position {
-                    Position::ArgumentNamed(s) => match generic_map.get(s) {
+                    Position::ArgumentNamed(s) => match generic_map.get(&s) {
                         Some(val) => val,
-                        None if s == name.as_str() => {
+                        None if s == name => {
                             &trait_str
                         }
                         None => {
-                            if let Some(val) = options.get(s) {
+                            if let Some(val) = options.get(&s) {
                                 val
-                            } else if s == "from_desugaring" || s == "from_method" {
+                            } else if s == sym::from_desugaring || s == sym::from_method {
                                 // don't break messages using these two arguments incorrectly
                                 &empty_string
                             } else {
diff --git a/src/librustdoc/passes/check_code_block_syntax.rs b/src/librustdoc/passes/check_code_block_syntax.rs
index 694843ad7f71e..6d51278b4e5e8 100644
--- a/src/librustdoc/passes/check_code_block_syntax.rs
+++ b/src/librustdoc/passes/check_code_block_syntax.rs
@@ -2,7 +2,7 @@ use errors::Applicability;
 use syntax::parse::lexer::{StringReader as Lexer};
 use syntax::parse::{ParseSess, token};
 use syntax::source_map::FilePathMapping;
-use syntax_pos::FileName;
+use syntax_pos::{InnerSpan, FileName};
 
 use crate::clean;
 use crate::core::DocContext;
@@ -63,7 +63,7 @@ impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> {
                 }
 
                 if code_block.syntax.is_none() && code_block.is_fenced {
-                    let sp = sp.from_inner_byte_pos(0, 3);
+                    let sp = sp.from_inner(InnerSpan::new(0, 3));
                     diag.span_suggestion(
                         sp,
                         "mark blocks that do not contain Rust code as text",
diff --git a/src/librustdoc/passes/mod.rs b/src/librustdoc/passes/mod.rs
index 018ab5dea6081..8fc6b9fdbe6b9 100644
--- a/src/librustdoc/passes/mod.rs
+++ b/src/librustdoc/passes/mod.rs
@@ -6,7 +6,7 @@ use rustc::lint as lint;
 use rustc::middle::privacy::AccessLevels;
 use rustc::util::nodemap::DefIdSet;
 use std::mem;
-use syntax_pos::{DUMMY_SP, Span};
+use syntax_pos::{DUMMY_SP, InnerSpan, Span};
 use std::ops::Range;
 
 use crate::clean::{self, GetDefId, Item};
@@ -440,10 +440,10 @@ crate fn source_span_for_markdown_range(
         }
     }
 
-    let sp = span_of_attrs(attrs).from_inner_byte_pos(
+    let sp = span_of_attrs(attrs).from_inner(InnerSpan::new(
         md_range.start + start_bytes,
         md_range.end + start_bytes + end_bytes,
-    );
+    ));
 
     Some(sp)
 }
diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index 377164728f42a..85b524786b2f5 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -28,7 +28,7 @@ enum ArgumentType {
 
 enum Position {
     Exact(usize),
-    Named(String),
+    Named(Symbol),
 }
 
 struct Context<'a, 'b: 'a> {
@@ -57,7 +57,7 @@ struct Context<'a, 'b: 'a> {
     /// Unique format specs seen for each argument.
     arg_unique_types: Vec<Vec<ArgumentType>>,
     /// Map from named arguments to their resolved indices.
-    names: FxHashMap<String, usize>,
+    names: FxHashMap<Symbol, usize>,
 
     /// The latest consecutive literal strings, or empty if there weren't any.
     literal: String,
@@ -127,9 +127,9 @@ fn parse_args<'a>(
     ecx: &mut ExtCtxt<'a>,
     sp: Span,
     tts: &[tokenstream::TokenTree]
-) -> Result<(P<ast::Expr>, Vec<P<ast::Expr>>, FxHashMap<String, usize>), DiagnosticBuilder<'a>> {
+) -> Result<(P<ast::Expr>, Vec<P<ast::Expr>>, FxHashMap<Symbol, usize>), DiagnosticBuilder<'a>> {
     let mut args = Vec::<P<ast::Expr>>::new();
-    let mut names = FxHashMap::<String, usize>::default();
+    let mut names = FxHashMap::<Symbol, usize>::default();
 
     let mut p = ecx.new_parser_from_tts(tts);
 
@@ -158,11 +158,10 @@ fn parse_args<'a>(
                     "expected ident, positional arguments cannot follow named arguments",
                 ));
             };
-            let name: &str = &name.as_str();
 
             p.expect(&token::Eq)?;
             let e = p.parse_expr()?;
-            if let Some(prev) = names.get(name) {
+            if let Some(prev) = names.get(&name) {
                 ecx.struct_span_err(e.span, &format!("duplicate argument named `{}`", name))
                     .span_note(args[*prev].span, "previously here")
                     .emit();
@@ -174,7 +173,7 @@ fn parse_args<'a>(
             // if the input is valid, we can simply append to the positional
             // args. And remember the names.
             let slot = args.len();
-            names.insert(name.to_string(), slot);
+            names.insert(name, slot);
             args.push(e);
         } else {
             let e = p.parse_expr()?;
@@ -188,7 +187,7 @@ impl<'a, 'b> Context<'a, 'b> {
     fn resolve_name_inplace(&self, p: &mut parse::Piece<'_>) {
         // NOTE: the `unwrap_or` branch is needed in case of invalid format
         // arguments, e.g., `format_args!("{foo}")`.
-        let lookup = |s| *self.names.get(s).unwrap_or(&0);
+        let lookup = |s: Symbol| *self.names.get(&s).unwrap_or(&0);
 
         match *p {
             parse::String(_) => {}
@@ -222,7 +221,7 @@ impl<'a, 'b> Context<'a, 'b> {
                 // it's written second, so it should come after width/precision.
                 let pos = match arg.position {
                     parse::ArgumentIs(i) | parse::ArgumentImplicitlyIs(i) => Exact(i),
-                    parse::ArgumentNamed(s) => Named(s.to_string()),
+                    parse::ArgumentNamed(s) => Named(s),
                 };
 
                 let ty = Placeholder(arg.format.ty.to_string());
@@ -232,7 +231,7 @@ impl<'a, 'b> Context<'a, 'b> {
         }
     }
 
-    fn verify_count(&mut self, c: parse::Count<'_>) {
+    fn verify_count(&mut self, c: parse::Count) {
         match c {
             parse::CountImplied |
             parse::CountIs(..) => {}
@@ -240,7 +239,7 @@ impl<'a, 'b> Context<'a, 'b> {
                 self.verify_arg_type(Exact(i), Count);
             }
             parse::CountIsName(s) => {
-                self.verify_arg_type(Named(s.to_string()), Count);
+                self.verify_arg_type(Named(s), Count);
             }
         }
     }
@@ -390,7 +389,7 @@ impl<'a, 'b> Context<'a, 'b> {
         ecx.std_path(&[sym::fmt, sym::rt, sym::v1, Symbol::intern(s)])
     }
 
-    fn build_count(&self, c: parse::Count<'_>) -> P<ast::Expr> {
+    fn build_count(&self, c: parse::Count) -> P<ast::Expr> {
         let sp = self.macsp;
         let count = |c, arg| {
             let mut path = Context::rtpath(self.ecx, "Count");
@@ -739,7 +738,7 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
                                     sp: Span,
                                     efmt: P<ast::Expr>,
                                     args: Vec<P<ast::Expr>>,
-                                    names: FxHashMap<String, usize>,
+                                    names: FxHashMap<Symbol, usize>,
                                     append_newline: bool)
                                     -> P<ast::Expr> {
     // NOTE: this verbose way of initializing `Vec<Vec<ArgumentType>>` is because
@@ -901,15 +900,15 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
 
     if !parser.errors.is_empty() {
         let err = parser.errors.remove(0);
-        let sp = fmt.span.from_inner_byte_pos(err.start.unwrap(), err.end.unwrap());
+        let sp = fmt.span.from_inner(err.span);
         let mut e = ecx.struct_span_err(sp, &format!("invalid format string: {}",
                                                      err.description));
         e.span_label(sp, err.label + " in format string");
         if let Some(note) = err.note {
             e.note(&note);
         }
-        if let Some((label, start, end)) = err.secondary_label {
-            let sp = fmt.span.from_inner_byte_pos(start.unwrap(), end.unwrap());
+        if let Some((label, span)) = err.secondary_label {
+            let sp = fmt.span.from_inner(span);
             e.span_label(sp, label);
         }
         e.emit();
@@ -917,9 +916,7 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
     }
 
     let arg_spans = parser.arg_places.iter()
-        .map(|&(parse::SpanIndex(start), parse::SpanIndex(end))| {
-            fmt.span.from_inner_byte_pos(start, end)
-        })
+        .map(|span| fmt.span.from_inner(*span))
         .collect();
 
     let mut cx = Context {
@@ -1044,7 +1041,9 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
                     let mut show_doc_note = false;
 
                     let mut suggestions = vec![];
-                    for sub in foreign::$kind::iter_subs(fmt_str) {
+                    // account for `"` and account for raw strings `r#`
+                    let padding = str_style.map(|i| i + 2).unwrap_or(1);
+                    for sub in foreign::$kind::iter_subs(fmt_str, padding) {
                         let trn = match sub.translate() {
                             Some(trn) => trn,
 
@@ -1064,10 +1063,8 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
                             show_doc_note = true;
                         }
 
-                        if let Some((start, end)) = pos {
-                            // account for `"` and account for raw strings `r#`
-                            let padding = str_style.map(|i| i + 2).unwrap_or(1);
-                            let sp = fmt_sp.from_inner_byte_pos(start + padding, end + padding);
+                        if let Some(inner_sp) = pos {
+                            let sp = fmt_sp.from_inner(inner_sp);
                             suggestions.push((sp, trn));
                         } else {
                             diag.help(&format!("`{}` should be written as `{}`", sub, trn));
diff --git a/src/libsyntax_ext/format_foreign.rs b/src/libsyntax_ext/format_foreign.rs
index 261b2f373cefd..7ad5997bf2c09 100644
--- a/src/libsyntax_ext/format_foreign.rs
+++ b/src/libsyntax_ext/format_foreign.rs
@@ -1,5 +1,6 @@
 pub mod printf {
     use super::strcursor::StrCursor as Cur;
+    use syntax_pos::InnerSpan;
 
     /// Represents a single `printf`-style substitution.
     #[derive(Clone, PartialEq, Debug)]
@@ -18,7 +19,7 @@ pub mod printf {
             }
         }
 
-        pub fn position(&self) -> Option<(usize, usize)> {
+        pub fn position(&self) -> Option<InnerSpan> {
             match *self {
                 Substitution::Format(ref fmt) => Some(fmt.position),
                 _ => None,
@@ -28,7 +29,7 @@ pub mod printf {
         pub fn set_position(&mut self, start: usize, end: usize) {
             match self {
                 Substitution::Format(ref mut fmt) => {
-                    fmt.position = (start, end);
+                    fmt.position = InnerSpan::new(start, end);
                 }
                 _ => {}
             }
@@ -65,7 +66,7 @@ pub mod printf {
         /// Type of parameter being converted.
         pub type_: &'a str,
         /// Byte offset for the start and end of this formatting directive.
-        pub position: (usize, usize),
+        pub position: InnerSpan,
     }
 
     impl Format<'_> {
@@ -263,10 +264,10 @@ pub mod printf {
     }
 
     /// Returns an iterator over all substitutions in a given string.
-    pub fn iter_subs(s: &str) -> Substitutions<'_> {
+    pub fn iter_subs(s: &str, start_pos: usize) -> Substitutions<'_> {
         Substitutions {
             s,
-            pos: 0,
+            pos: start_pos,
         }
     }
 
@@ -282,9 +283,9 @@ pub mod printf {
             let (mut sub, tail) = parse_next_substitution(self.s)?;
             self.s = tail;
             match sub {
-                Substitution::Format(_) => if let Some((start, end)) = sub.position() {
-                    sub.set_position(start + self.pos, end + self.pos);
-                    self.pos += end;
+                Substitution::Format(_) => if let Some(inner_span) = sub.position() {
+                    sub.set_position(inner_span.start + self.pos, inner_span.end + self.pos);
+                    self.pos += inner_span.end;
                 }
                 Substitution::Escape => self.pos += 2,
             }
@@ -373,7 +374,7 @@ pub mod printf {
                     precision: None,
                     length: None,
                     type_: at.slice_between(next).unwrap(),
-                    position: (start.at, next.at),
+                    position: InnerSpan::new(start.at, next.at),
                 }),
                 next.slice_after()
             ));
@@ -560,7 +561,7 @@ pub mod printf {
         drop(next);
 
         end = at;
-        let position = (start.at, end.at);
+        let position = InnerSpan::new(start.at, end.at);
 
         let f = Format {
             span: start.slice_between(end).unwrap(),
@@ -650,7 +651,7 @@ pub mod printf {
                                 precision: $prec,
                                 length: $len,
                                 type_: $type_,
-                                position: $pos,
+                                position: syntax_pos::InnerSpan::new($pos.0, $pos.1),
                             }),
                             "!"
                         ))
@@ -711,7 +712,7 @@ pub mod printf {
         #[test]
         fn test_iter() {
             let s = "The %d'th word %% is: `%.*s` %!\n";
-            let subs: Vec<_> = iter_subs(s).map(|sub| sub.translate()).collect();
+            let subs: Vec<_> = iter_subs(s, 0).map(|sub| sub.translate()).collect();
             assert_eq!(
                 subs.iter().map(|ms| ms.as_ref().map(|s| &s[..])).collect::<Vec<_>>(),
                 vec![Some("{}"), None, Some("{:.*}"), None]
@@ -761,6 +762,7 @@ pub mod printf {
 
 pub mod shell {
     use super::strcursor::StrCursor as Cur;
+    use syntax_pos::InnerSpan;
 
     #[derive(Clone, PartialEq, Debug)]
     pub enum Substitution<'a> {
@@ -778,11 +780,11 @@ pub mod shell {
             }
         }
 
-        pub fn position(&self) -> Option<(usize, usize)> {
+        pub fn position(&self) -> Option<InnerSpan> {
             match self {
                 Substitution::Ordinal(_, pos) |
                 Substitution::Name(_, pos) |
-                Substitution::Escape(pos) => Some(*pos),
+                Substitution::Escape(pos) => Some(InnerSpan::new(pos.0, pos.1)),
             }
         }
 
@@ -804,10 +806,10 @@ pub mod shell {
     }
 
     /// Returns an iterator over all substitutions in a given string.
-    pub fn iter_subs(s: &str) -> Substitutions<'_> {
+    pub fn iter_subs(s: &str, start_pos: usize) -> Substitutions<'_> {
         Substitutions {
             s,
-            pos: 0,
+            pos: start_pos,
         }
     }
 
@@ -823,7 +825,7 @@ pub mod shell {
             match parse_next_substitution(self.s) {
                 Some((mut sub, tail)) => {
                     self.s = tail;
-                    if let Some((start, end)) = sub.position() {
+                    if let Some(InnerSpan { start, end }) = sub.position() {
                         sub.set_position(start + self.pos, end + self.pos);
                         self.pos += end;
                     }
@@ -940,7 +942,7 @@ pub mod shell {
         fn test_iter() {
             use super::iter_subs;
             let s = "The $0'th word $$ is: `$WORD` $!\n";
-            let subs: Vec<_> = iter_subs(s).map(|sub| sub.translate()).collect();
+            let subs: Vec<_> = iter_subs(s, 0).map(|sub| sub.translate()).collect();
             assert_eq!(
                 subs.iter().map(|ms| ms.as_ref().map(|s| &s[..])).collect::<Vec<_>>(),
                 vec![Some("{0}"), None, Some("{WORD}")]
diff --git a/src/libsyntax_pos/lib.rs b/src/libsyntax_pos/lib.rs
index 8f5595968a738..bf0ab5fae4e87 100644
--- a/src/libsyntax_pos/lib.rs
+++ b/src/libsyntax_pos/lib.rs
@@ -504,10 +504,10 @@ impl Span {
         )
     }
 
-    pub fn from_inner_byte_pos(self, start: usize, end: usize) -> Span {
+    pub fn from_inner(self, inner: InnerSpan) -> Span {
         let span = self.data();
-        Span::new(span.lo + BytePos::from_usize(start),
-                  span.lo + BytePos::from_usize(end),
+        Span::new(span.lo + BytePos::from_usize(inner.start),
+                  span.lo + BytePos::from_usize(inner.end),
                   span.ctxt)
     }
 
@@ -1395,6 +1395,18 @@ pub struct MalformedSourceMapPositions {
     pub end_pos: BytePos
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub struct InnerSpan {
+    pub start: usize,
+    pub end: usize,
+}
+
+impl InnerSpan {
+    pub fn new(start: usize, end: usize) -> InnerSpan {
+        InnerSpan { start, end }
+    }
+}
+
 // Given a slice of line start positions and a position, returns the index of
 // the line the position is on. Returns -1 if the position is located before
 // the first line.
diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 302b3c75263cf..95d74ce054ef9 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -203,6 +203,7 @@ symbols! {
         core_intrinsics,
         crate_id,
         crate_in_paths,
+        crate_local,
         crate_name,
         crate_type,
         crate_visibility_modifier,
@@ -221,6 +222,7 @@ symbols! {
         deref,
         deref_mut,
         derive,
+        direct,
         doc,
         doc_alias,
         doc_cfg,
@@ -278,8 +280,10 @@ symbols! {
         format_args_nl,
         from,
         From,
+        from_desugaring,
         from_error,
         from_generator,
+        from_method,
         from_ok,
         from_usize,
         fundamental,
@@ -443,6 +447,7 @@ symbols! {
         panic_impl,
         panic_implementation,
         panic_runtime,
+        parent_trait,
         partial_cmp,
         PartialOrd,
         passes,
@@ -569,6 +574,7 @@ symbols! {
         __rust_unstable_column,
         rvalue_static_promotion,
         sanitizer_runtime,
+        _Self,
         self_in_typedefs,
         self_struct_ctor,
         Send,