Fix merge conflicts

3 files changed, 169 insertions, 214 deletions

diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 4e4fe4256c9..49f714e4e46 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -83,28 +83,6 @@ impl<'a> StringReader<'a> {
         Ok(ret_val)
     }
 
-    /// Immutably extract string if found at current position with given delimiters
-    fn peek_delimited(&self, from_ch: char, to_ch: char) -> Option<String> {
-        let mut pos = self.pos;
-        let mut idx = self.src_index(pos);
-        let mut ch = char_at(&self.src, idx);
-        if ch != from_ch {
-            return None;
-        }
-        pos = pos + Pos::from_usize(ch.len_utf8());
-        let start_pos = pos;
-        idx = self.src_index(pos);
-        while idx < self.end_src_index {
-            ch = char_at(&self.src, idx);
-            if ch == to_ch {
-                return Some(self.src[self.src_index(start_pos)..self.src_index(pos)].to_string());
-            }
-            pos = pos + Pos::from_usize(ch.len_utf8());
-            idx = self.src_index(pos);
-        }
-        return None;
-    }
-
     fn try_real_token(&mut self) -> Result<Token, ()> {
         let mut t = self.try_next_token()?;
         loop {
diff --git a/src/libsyntax/parse/lexer/unicode_chars.rs b/src/libsyntax/parse/lexer/unicode_chars.rs
index 94ce6297fbe..6a870685938 100644
--- a/src/libsyntax/parse/lexer/unicode_chars.rs
+++ b/src/libsyntax/parse/lexer/unicode_chars.rs
@@ -1,10 +1,11 @@
 // Characters and their corresponding confusables were collected from
 // http://www.unicode.org/Public/security/10.0.0/confusables.txt
 
-use syntax_pos::{Span, Pos, NO_EXPANSION};
-use errors::{Applicability, DiagnosticBuilder};
 use super::StringReader;
+use errors::{Applicability, DiagnosticBuilder};
+use syntax_pos::{Pos, Span, NO_EXPANSION};
 
+#[rustfmt::skip] // for line breaks
 const UNICODE_ARRAY: &[(char, &str, char)] = &[
     ('
', "Line Separator", ' '),
     ('
', "Paragraph Separator", ' '),
@@ -293,8 +294,8 @@ const UNICODE_ARRAY: &[(char, &str, char)] = &[
     ('〉', "Right-Pointing Angle Bracket", '>'),
     ('〉', "Right Angle Bracket", '>'),
     ('》', "Right Double Angle Bracket", '>'),
-    ('＞', "Fullwidth Greater-Than Sign", '>'), ];
-
+    ('＞', "Fullwidth Greater-Than Sign", '>'),
+];
 
 const ASCII_ARRAY: &[(char, &str)] = &[
     (' ', "Space"),
@@ -321,46 +322,72 @@ const ASCII_ARRAY: &[(char, &str)] = &[
     ('+', "Plus Sign"),
     ('<', "Less-Than Sign"),
     ('=', "Equals Sign"),
-    ('>', "Greater-Than Sign"), ];
-
-crate fn check_for_substitution<'a>(reader: &StringReader<'a>,
-                                  ch: char,
-                                  err: &mut DiagnosticBuilder<'a>) -> bool {
-    UNICODE_ARRAY
-    .iter()
-    .find(|&&(c, _, _)| c == ch)
-    .map(|&(_, u_name, ascii_char)| {
-        let span = Span::new(reader.pos, reader.next_pos, NO_EXPANSION);
-        match ASCII_ARRAY.iter().find(|&&(c, _)| c == ascii_char) {
-            Some(&(ascii_char, ascii_name)) => {
-                // special help suggestion for "directed" double quotes
-                if let Some(s) = reader.peek_delimited('“', '”') {
-                    let msg = format!("Unicode characters '“' (Left Double Quotation Mark) and \
-                        '”' (Right Double Quotation Mark) look like '{}' ({}), but are not",
-                                ascii_char, ascii_name);
-                    err.span_suggestion(
-                        Span::new(reader.pos, reader.next_pos + Pos::from_usize(s.len()) +
-                            Pos::from_usize('”'.len_utf8()), NO_EXPANSION),
-                        &msg,
-                        format!("\"{}\"", s),
-                        Applicability::MaybeIncorrect);
-                } else {
-                    let msg =
-                        format!("Unicode character '{}' ({}) looks like '{}' ({}), but it is not",
-                                ch, u_name, ascii_char, ascii_name);
-                    err.span_suggestion(
-                        span,
-                        &msg,
-                        ascii_char.to_string(),
-                        Applicability::MaybeIncorrect);
-                }
-                true
-            },
-            None => {
-                let msg = format!("substitution character not found for '{}'", ch);
-                reader.sess.span_diagnostic.span_bug_no_panic(span, &msg);
-                false
-            }
+    ('>', "Greater-Than Sign"),
+];
+
+crate fn check_for_substitution<'a>(
+    reader: &StringReader<'a>,
+    ch: char,
+    err: &mut DiagnosticBuilder<'a>,
+) -> bool {
+    let (u_name, ascii_char) = match UNICODE_ARRAY.iter().find(|&&(c, _, _)| c == ch) {
+        Some(&(_u_char, u_name, ascii_char)) => (u_name, ascii_char),
+        None => return false,
+    };
+
+    let span = Span::new(reader.pos, reader.next_pos, NO_EXPANSION);
+
+    let ascii_name = match ASCII_ARRAY.iter().find(|&&(c, _)| c == ascii_char) {
+        Some((_ascii_char, ascii_name)) => ascii_name,
+        None => {
+            let msg = format!("substitution character not found for '{}'", ch);
+            reader.sess.span_diagnostic.span_bug_no_panic(span, &msg);
+            return false
+        },
+    };
+
+    // special help suggestion for "directed" double quotes
+    if let Some(s) = reader.peek_delimited('“', '”') {
+        let msg = format!(
+            "Unicode characters '“' (Left Double Quotation Mark) and \
+             '”' (Right Double Quotation Mark) look like '{}' ({}), but are not",
+            ascii_char, ascii_name
+        );
+        err.span_suggestion(
+            Span::new(
+                reader.pos,
+                reader.next_pos + Pos::from_usize(s.len()) + Pos::from_usize('”'.len_utf8()),
+                NO_EXPANSION,
+            ),
+            &msg,
+            format!("\"{}\"", s),
+            Applicability::MaybeIncorrect,
+        );
+    } else {
+        let msg = format!(
+            "Unicode character '{}' ({}) looks like '{}' ({}), but it is not",
+            ch, u_name, ascii_char, ascii_name
+        );
+        err.span_suggestion(
+            span,
+            &msg,
+            ascii_char.to_string(),
+            Applicability::MaybeIncorrect,
+        );
+    }
+    true
+}
+
+impl StringReader<'_> {
+    /// Immutably extract string if found at current position with given delimiters
+    fn peek_delimited(&self, from_ch: char, to_ch: char) -> Option<&str> {
+        let tail = &self.src[self.src_index(self.pos)..];
+        let mut chars = tail.chars();
+        let first_char = chars.next()?;
+        if first_char != from_ch {
+            return None;
         }
-    }).unwrap_or(false)
+        let last_char_idx = chars.as_str().find(to_ch)?;
+        Some(&chars.as_str()[..last_char_idx])
+    }
 }
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index fc206580e38..9c179600093 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4324,51 +4324,49 @@ impl<'a> Parser<'a> {
     fn eat_macro_def(&mut self, attrs: &[Attribute], vis: &Visibility, lo: Span)
                      -> PResult<'a, Option<P<Item>>> {
         let token_lo = self.token.span;
-        let (ident, def) = match self.token.kind {
-            token::Ident(name, false) if name == kw::Macro => {
-                self.bump();
-                let ident = self.parse_ident()?;
-                let tokens = if self.check(&token::OpenDelim(token::Brace)) {
-                    match self.parse_token_tree() {
-                        TokenTree::Delimited(_, _, tts) => tts,
-                        _ => unreachable!(),
-                    }
-                } else if self.check(&token::OpenDelim(token::Paren)) {
-                    let args = self.parse_token_tree();
-                    let body = if self.check(&token::OpenDelim(token::Brace)) {
-                        self.parse_token_tree()
-                    } else {
-                        self.unexpected()?;
-                        unreachable!()
-                    };
-                    TokenStream::new(vec![
-                        args.into(),
-                        TokenTree::token(token::FatArrow, token_lo.to(self.prev_span)).into(),
-                        body.into(),
-                    ])
+        let (ident, def) = if self.eat_keyword(kw::Macro) {
+            let ident = self.parse_ident()?;
+            let tokens = if self.check(&token::OpenDelim(token::Brace)) {
+                match self.parse_token_tree() {
+                    TokenTree::Delimited(_, _, tts) => tts,
+                    _ => unreachable!(),
+                }
+            } else if self.check(&token::OpenDelim(token::Paren)) {
+                let args = self.parse_token_tree();
+                let body = if self.check(&token::OpenDelim(token::Brace)) {
+                    self.parse_token_tree()
                 } else {
                     self.unexpected()?;
                     unreachable!()
                 };
+                TokenStream::new(vec![
+                    args.into(),
+                    TokenTree::token(token::FatArrow, token_lo.to(self.prev_span)).into(),
+                    body.into(),
+                ])
+            } else {
+                self.unexpected()?;
+                unreachable!()
+            };
 
-                (ident, ast::MacroDef { tokens: tokens.into(), legacy: false })
-            }
-            token::Ident(name, _) if name == sym::macro_rules &&
-                                     self.look_ahead(1, |t| *t == token::Not) => {
-                let prev_span = self.prev_span;
-                self.complain_if_pub_macro(&vis.node, prev_span);
-                self.bump();
-                self.bump();
-
-                let ident = self.parse_ident()?;
-                let (delim, tokens) = self.expect_delimited_token_tree()?;
-                if delim != MacDelimiter::Brace && !self.eat(&token::Semi) {
-                    self.report_invalid_macro_expansion_item();
-                }
+            (ident, ast::MacroDef { tokens: tokens.into(), legacy: false })
+        } else if self.check_keyword(sym::macro_rules) &&
+                  self.look_ahead(1, |t| *t == token::Not) &&
+                  self.look_ahead(2, |t| t.is_ident()) {
+            let prev_span = self.prev_span;
+            self.complain_if_pub_macro(&vis.node, prev_span);
+            self.bump();
+            self.bump();
 
-                (ident, ast::MacroDef { tokens, legacy: true })
+            let ident = self.parse_ident()?;
+            let (delim, tokens) = self.expect_delimited_token_tree()?;
+            if delim != MacDelimiter::Brace && !self.eat(&token::Semi) {
+                self.report_invalid_macro_expansion_item();
             }
-            _ => return Ok(None),
+
+            (ident, ast::MacroDef { tokens, legacy: true })
+        } else {
+            return Ok(None);
         };
 
         let span = lo.to(self.prev_span);
@@ -4412,14 +4410,14 @@ impl<'a> Parser<'a> {
                   !self.is_existential_type_decl() &&
                   !self.is_auto_trait_item() &&
                   !self.is_async_fn() {
-            let pth = self.parse_path(PathStyle::Expr)?;
+            let path = self.parse_path(PathStyle::Expr)?;
 
             if !self.eat(&token::Not) {
                 let expr = if self.check(&token::OpenDelim(token::Brace)) {
-                    self.parse_struct_expr(lo, pth, ThinVec::new())?
+                    self.parse_struct_expr(lo, path, ThinVec::new())?
                 } else {
                     let hi = self.prev_span;
-                    self.mk_expr(lo.to(hi), ExprKind::Path(None, pth), ThinVec::new())
+                    self.mk_expr(lo.to(hi), ExprKind::Path(None, path), ThinVec::new())
                 };
 
                 let expr = self.with_res(Restrictions::STMT_EXPR, |this| {
@@ -4434,34 +4432,6 @@ impl<'a> Parser<'a> {
                 }));
             }
 
-            // it's a macro invocation
-            let id = match self.token.kind {
-                token::OpenDelim(_) => Ident::invalid(), // no special identifier
-                _ => self.parse_ident()?,
-            };
-
-            // check that we're pointing at delimiters (need to check
-            // again after the `if`, because of `parse_ident`
-            // consuming more tokens).
-            match self.token.kind {
-                token::OpenDelim(_) => {}
-                _ => {
-                    // we only expect an ident if we didn't parse one
-                    // above.
-                    let ident_str = if id.name == kw::Invalid {
-                        "identifier, "
-                    } else {
-                        ""
-                    };
-                    let tok_str = self.this_token_descr();
-                    let mut err = self.fatal(&format!("expected {}`(` or `{{`, found {}",
-                                                      ident_str,
-                                                      tok_str));
-                    err.span_label(self.token.span, format!("expected {}`(` or `{{`", ident_str));
-                    return Err(err)
-                },
-            }
-
             let (delim, tts) = self.expect_delimited_token_tree()?;
             let hi = self.prev_span;
 
@@ -4471,59 +4441,38 @@ impl<'a> Parser<'a> {
                 MacStmtStyle::NoBraces
             };
 
-            if id.name == kw::Invalid {
-                let mac = respan(lo.to(hi), Mac_ { path: pth, tts, delim });
-                let node = if delim == MacDelimiter::Brace ||
-                              self.token == token::Semi || self.token == token::Eof {
-                    StmtKind::Mac(P((mac, style, attrs.into())))
-                }
-                // We used to incorrectly stop parsing macro-expanded statements here.
-                // If the next token will be an error anyway but could have parsed with the
-                // earlier behavior, stop parsing here and emit a warning to avoid breakage.
-                else if macro_legacy_warnings &&
-                        self.token.can_begin_expr() &&
-                        match self.token.kind {
-                    // These can continue an expression, so we can't stop parsing and warn.
-                    token::OpenDelim(token::Paren) | token::OpenDelim(token::Bracket) |
-                    token::BinOp(token::Minus) | token::BinOp(token::Star) |
-                    token::BinOp(token::And) | token::BinOp(token::Or) |
-                    token::AndAnd | token::OrOr |
-                    token::DotDot | token::DotDotDot | token::DotDotEq => false,
-                    _ => true,
-                } {
-                    self.warn_missing_semicolon();
-                    StmtKind::Mac(P((mac, style, attrs.into())))
-                } else {
-                    let e = self.mk_expr(mac.span, ExprKind::Mac(mac), ThinVec::new());
-                    let e = self.maybe_recover_from_bad_qpath(e, true)?;
-                    let e = self.parse_dot_or_call_expr_with(e, lo, attrs.into())?;
-                    let e = self.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(e))?;
-                    StmtKind::Expr(e)
-                };
-                Stmt {
-                    id: ast::DUMMY_NODE_ID,
-                    span: lo.to(hi),
-                    node,
-                }
+            let mac = respan(lo.to(hi), Mac_ { path, tts, delim });
+            let node = if delim == MacDelimiter::Brace ||
+                          self.token == token::Semi || self.token == token::Eof {
+                StmtKind::Mac(P((mac, style, attrs.into())))
+            }
+            // We used to incorrectly stop parsing macro-expanded statements here.
+            // If the next token will be an error anyway but could have parsed with the
+            // earlier behavior, stop parsing here and emit a warning to avoid breakage.
+            else if macro_legacy_warnings &&
+                    self.token.can_begin_expr() &&
+                    match self.token.kind {
+                // These can continue an expression, so we can't stop parsing and warn.
+                token::OpenDelim(token::Paren) | token::OpenDelim(token::Bracket) |
+                token::BinOp(token::Minus) | token::BinOp(token::Star) |
+                token::BinOp(token::And) | token::BinOp(token::Or) |
+                token::AndAnd | token::OrOr |
+                token::DotDot | token::DotDotDot | token::DotDotEq => false,
+                _ => true,
+            } {
+                self.warn_missing_semicolon();
+                StmtKind::Mac(P((mac, style, attrs.into())))
             } else {
-                // if it has a special ident, it's definitely an item
-                //
-                // Require a semicolon or braces.
-                if style != MacStmtStyle::Braces && !self.eat(&token::Semi) {
-                    self.report_invalid_macro_expansion_item();
-                }
-                let span = lo.to(hi);
-                Stmt {
-                    id: ast::DUMMY_NODE_ID,
-                    span,
-                    node: StmtKind::Item({
-                        self.mk_item(
-                            span, id /*id is good here*/,
-                            ItemKind::Mac(respan(span, Mac_ { path: pth, tts, delim })),
-                            respan(lo, VisibilityKind::Inherited),
-                            attrs)
-                    }),
-                }
+                let e = self.mk_expr(mac.span, ExprKind::Mac(mac), ThinVec::new());
+                let e = self.maybe_recover_from_bad_qpath(e, true)?;
+                let e = self.parse_dot_or_call_expr_with(e, lo, attrs.into())?;
+                let e = self.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(e))?;
+                StmtKind::Expr(e)
+            };
+            Stmt {
+                id: ast::DUMMY_NODE_ID,
+                span: lo.to(hi),
+                node,
             }
         } else {
             // FIXME: Bad copy of attrs
@@ -5734,9 +5683,12 @@ impl<'a> Parser<'a> {
     {
         let is_const_fn = self.eat_keyword(kw::Const);
         let const_span = self.prev_span;
-        let unsafety = self.parse_unsafety();
         let asyncness = self.parse_asyncness();
+        if let IsAsync::Async { .. } = asyncness {
+            self.ban_async_in_2015(self.prev_span);
+        }
         let asyncness = respan(self.prev_span, asyncness);
+        let unsafety = self.parse_unsafety();
         let (constness, unsafety, abi) = if is_const_fn {
             (respan(const_span, Constness::Const), unsafety, Abi::Rust)
         } else {
@@ -7254,13 +7206,7 @@ impl<'a> Parser<'a> {
                                         item_,
                                         visibility,
                                         maybe_append(attrs, extra_attrs));
-                if self.token.span.rust_2015() {
-                    self.diagnostic().struct_span_err_with_code(
-                        async_span,
-                        "`async fn` is not permitted in the 2015 edition",
-                        DiagnosticId::Error("E0670".into())
-                    ).emit();
-                }
+                self.ban_async_in_2015(async_span);
                 return Ok(Some(item));
             }
         }
@@ -7534,6 +7480,19 @@ impl<'a> Parser<'a> {
         self.parse_macro_use_or_failure(attrs, macros_allowed, attributes_allowed, lo, visibility)
     }
 
+    /// We are parsing `async fn`. If we are on Rust 2015, emit an error.
+    fn ban_async_in_2015(&self, async_span: Span) {
+        if async_span.rust_2015() {
+            self.diagnostic()
+                .struct_span_err_with_code(
+                    async_span,
+                    "`async fn` is not permitted in the 2015 edition",
+                    DiagnosticId::Error("E0670".into())
+                )
+                .emit();
+        }
+    }
+
     /// Parses a foreign item.
     crate fn parse_foreign_item(&mut self) -> PResult<'a, ForeignItem> {
         maybe_whole!(self, NtForeignItem, |ni| ni);
@@ -7609,26 +7568,17 @@ impl<'a> Parser<'a> {
             let mac_lo = self.token.span;
 
             // item macro.
-            let pth = self.parse_path(PathStyle::Mod)?;
+            let path = self.parse_path(PathStyle::Mod)?;
             self.expect(&token::Not)?;
-
-            // a 'special' identifier (like what `macro_rules!` uses)
-            // is optional. We should eventually unify invoc syntax
-            // and remove this.
-            let id = if self.token.is_ident() {
-                self.parse_ident()?
-            } else {
-                Ident::invalid() // no special identifier
-            };
-            // eat a matched-delimiter token tree:
             let (delim, tts) = self.expect_delimited_token_tree()?;
             if delim != MacDelimiter::Brace && !self.eat(&token::Semi) {
                 self.report_invalid_macro_expansion_item();
             }
 
             let hi = self.prev_span;
-            let mac = respan(mac_lo.to(hi), Mac_ { path: pth, tts, delim });
-            let item = self.mk_item(lo.to(hi), id, ItemKind::Mac(mac), visibility, attrs);
+            let mac = respan(mac_lo.to(hi), Mac_ { path, tts, delim });
+            let item =
+                self.mk_item(lo.to(hi), Ident::invalid(), ItemKind::Mac(mac), visibility, attrs);
             return Ok(Some(item));
         }
 
@@ -7654,9 +7604,9 @@ impl<'a> Parser<'a> {
                 !(self.is_async_fn() && self.token.span.rust_2015()) {
             let prev_span = self.prev_span;
             let lo = self.token.span;
-            let pth = self.parse_path(PathStyle::Mod)?;
+            let path = self.parse_path(PathStyle::Mod)?;
 
-            if pth.segments.len() == 1 {
+            if path.segments.len() == 1 {
                 if !self.eat(&token::Not) {
                     return Err(self.missing_assoc_item_kind_err(item_kind, prev_span));
                 }
@@ -7676,7 +7626,7 @@ impl<'a> Parser<'a> {
                 self.expect(&token::Semi)?;
             }
 
-            Ok(Some(respan(lo.to(self.prev_span), Mac_ { path: pth, tts, delim })))
+            Ok(Some(respan(lo.to(self.prev_span), Mac_ { path, tts, delim })))
         } else {
             Ok(None)
         }
@@ -7689,7 +7639,7 @@ impl<'a> Parser<'a> {
         let mut tokens = Vec::new();
         let prev_collecting = match self.token_cursor.frame.last_token {
             LastToken::Collecting(ref mut list) => {
-                Some(mem::replace(list, Vec::new()))
+                Some(mem::take(list))
             }
             LastToken::Was(ref mut last) => {
                 tokens.extend(last.take());
@@ -7707,7 +7657,7 @@ impl<'a> Parser<'a> {
 
         // Pull out the tokens that we've collected from the call to `f` above.
         let mut collected_tokens = match *last_token {
-            LastToken::Collecting(ref mut v) => mem::replace(v, Vec::new()),
+            LastToken::Collecting(ref mut v) => mem::take(v),
             LastToken::Was(_) => panic!("our vector went away?"),
         };