Fix all violations of stronger guarantees for mutable borrows

Fix all violations in the Rust source tree of the stronger guarantee
of a unique access path for mutable borrows as described in #12624.

5 files changed, 166 insertions, 88 deletions

diff --git a/src/libsyntax/ext/format.rs b/src/libsyntax/ext/format.rs
index cfce4b1e0fc..ca7596925a9 100644
--- a/src/libsyntax/ext/format.rs
+++ b/src/libsyntax/ext/format.rs
@@ -202,7 +202,8 @@ impl<'a, 'b> Context<'a, 'b> {
             }
             parse::CountIsNextParam => {
                 if self.check_positional_ok() {
-                    self.verify_arg_type(Exact(self.next_arg), Unsigned);
+                    let next_arg = self.next_arg;
+                    self.verify_arg_type(Exact(next_arg), Unsigned);
                     self.next_arg += 1;
                 }
             }
diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
index 112cdb26131..c9122e3ceaf 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/attr.rs
@@ -73,7 +73,8 @@ impl<'a> ParserAttr for Parser<'a> {
 
                 let style = if self.eat(&token::NOT) {
                     if !permit_inner {
-                        self.span_err(self.span,
+                        let span = self.span;
+                        self.span_err(span,
                                       "an inner attribute is not permitted in \
                                        this context");
                     }
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 459cb6d31ed..f7eac0b323f 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -368,7 +368,8 @@ impl<'a> StringReader<'a> {
                 } else {
                     "unterminated block comment"
                 };
-                self.fatal_span(start_bpos, self.last_pos, msg);
+                let last_bpos = self.last_pos;
+                self.fatal_span(start_bpos, last_bpos, msg);
             } else if self.curr_is('/') && self.nextch_is('*') {
                 level += 1;
                 self.bump();
@@ -419,7 +420,8 @@ impl<'a> StringReader<'a> {
                 rslt.push_str(exponent.as_slice());
                 return Some(rslt);
             } else {
-                self.err_span(start_bpos, self.last_pos, "scan_exponent: bad fp literal");
+                let last_bpos = self.last_pos;
+                self.err_span(start_bpos, last_bpos, "scan_exponent: bad fp literal");
                 rslt.push_str("1"); // arbitrary placeholder exponent
                 return Some(rslt);
             }
@@ -506,14 +508,16 @@ impl<'a> StringReader<'a> {
                           else { Unsigned(ast::TyU64) };
             }
             if num_str.len() == 0u {
-                self.err_span(start_bpos, self.last_pos, "no valid digits found for number");
+                let last_bpos = self.last_pos;
+                self.err_span(start_bpos, last_bpos, "no valid digits found for number");
                 num_str = "1".to_string();
             }
             let parsed = match from_str_radix::<u64>(num_str.as_slice(),
                                                      base as uint) {
                 Some(p) => p,
                 None => {
-                    self.err_span(start_bpos, self.last_pos, "int literal is too large");
+                    let last_bpos = self.last_pos;
+                    self.err_span(start_bpos, last_bpos, "int literal is too large");
                     1
                 }
             };
@@ -546,13 +550,15 @@ impl<'a> StringReader<'a> {
             if c == '3' && n == '2' {
                 self.bump();
                 self.bump();
-                self.check_float_base(start_bpos, self.last_pos, base);
+                let last_bpos = self.last_pos;
+                self.check_float_base(start_bpos, last_bpos, base);
                 return token::LIT_FLOAT(str_to_ident(num_str.as_slice()),
                                         ast::TyF32);
             } else if c == '6' && n == '4' {
                 self.bump();
                 self.bump();
-                self.check_float_base(start_bpos, self.last_pos, base);
+                let last_bpos = self.last_pos;
+                self.check_float_base(start_bpos, last_bpos, base);
                 return token::LIT_FLOAT(str_to_ident(num_str.as_slice()),
                                         ast::TyF64);
                 /* FIXME (#2252): if this is out of range for either a
@@ -562,25 +568,30 @@ impl<'a> StringReader<'a> {
                 self.bump();
                 self.bump();
                 self.bump();
-                self.check_float_base(start_bpos, self.last_pos, base);
+                let last_bpos = self.last_pos;
+                self.check_float_base(start_bpos, last_bpos, base);
                 return token::LIT_FLOAT(str_to_ident(num_str.as_slice()), ast::TyF128);
             }
-            self.err_span(start_bpos, self.last_pos, "expected `f32`, `f64` or `f128` suffix");
+            let last_bpos = self.last_pos;
+            self.err_span(start_bpos, last_bpos, "expected `f32`, `f64` or `f128` suffix");
         }
         if is_float {
-            self.check_float_base(start_bpos, self.last_pos, base);
+            let last_bpos = self.last_pos;
+            self.check_float_base(start_bpos, last_bpos, base);
             return token::LIT_FLOAT_UNSUFFIXED(str_to_ident(
                     num_str.as_slice()));
         } else {
             if num_str.len() == 0u {
-                self.err_span(start_bpos, self.last_pos, "no valid digits found for number");
+                let last_bpos = self.last_pos;
+                self.err_span(start_bpos, last_bpos, "no valid digits found for number");
                 num_str = "1".to_string();
             }
             let parsed = match from_str_radix::<u64>(num_str.as_slice(),
                                                      base as uint) {
                 Some(p) => p,
                 None => {
-                    self.err_span(start_bpos, self.last_pos, "int literal is too large");
+                    let last_bpos = self.last_pos;
+                    self.err_span(start_bpos, last_bpos, "int literal is too large");
                     1
                 }
             };
@@ -597,10 +608,12 @@ impl<'a> StringReader<'a> {
         let start_bpos = self.last_pos;
         for _ in range(0, n_hex_digits) {
             if self.is_eof() {
-                self.fatal_span(start_bpos, self.last_pos, "unterminated numeric character escape");
+                let last_bpos = self.last_pos;
+                self.fatal_span(start_bpos, last_bpos, "unterminated numeric character escape");
             }
             if self.curr_is(delim) {
-                self.err_span(start_bpos, self.last_pos, "numeric character escape is too short");
+                let last_bpos = self.last_pos;
+                self.err_span(start_bpos, last_bpos, "numeric character escape is too short");
                 break;
             }
             let c = self.curr.unwrap_or('\x00');
@@ -616,7 +629,8 @@ impl<'a> StringReader<'a> {
         match char::from_u32(accum_int) {
             Some(x) => x,
             None => {
-                self.err_span(start_bpos, self.last_pos, "illegal numeric character escape");
+                let last_bpos = self.last_pos;
+                self.err_span(start_bpos, last_bpos, "illegal numeric character escape");
                 '?'
             }
         }
@@ -773,17 +787,18 @@ impl<'a> StringReader<'a> {
                     });
                 let keyword_checking_token =
                     &token::IDENT(keyword_checking_ident, false);
+                let last_bpos = self.last_pos;
                 if token::is_keyword(token::keywords::Self,
                                      keyword_checking_token) {
                     self.err_span(start,
-                                  self.last_pos,
+                                  last_bpos,
                                   "invalid lifetime name: 'self \
                                    is no longer a special lifetime");
                 } else if token::is_any_keyword(keyword_checking_token) &&
                     !token::is_keyword(token::keywords::Static,
                                        keyword_checking_token) {
                     self.err_span(start,
-                                  self.last_pos,
+                                  last_bpos,
                                   "invalid lifetime name");
                 }
                 return token::LIFETIME(ident);
@@ -811,7 +826,8 @@ impl<'a> StringReader<'a> {
                                 'u' => self.scan_numeric_escape(4u, '\''),
                                 'U' => self.scan_numeric_escape(8u, '\''),
                                 c2 => {
-                                    self.err_span_char(escaped_pos, self.last_pos,
+                                    let last_bpos = self.last_pos;
+                                    self.err_span_char(escaped_pos, last_bpos,
                                                          "unknown character escape", c2);
                                     c2
                                 }
@@ -820,17 +836,19 @@ impl<'a> StringReader<'a> {
                     }
                 }
                 '\t' | '\n' | '\r' | '\'' => {
-                    self.err_span_char( start, self.last_pos,
+                    let last_bpos = self.last_pos;
+                    self.err_span_char( start, last_bpos,
                         "character constant must be escaped", c2);
                 }
                 _ => {}
             }
             if !self.curr_is('\'') {
+                let last_bpos = self.last_pos;
                 self.fatal_span_verbose(
                                    // Byte offsetting here is okay because the
                                    // character before position `start` is an
                                    // ascii single quote.
-                                   start - BytePos(1), self.last_pos,
+                                   start - BytePos(1), last_bpos,
                                    "unterminated character constant".to_string());
             }
             self.bump(); // advance curr past token
@@ -842,7 +860,8 @@ impl<'a> StringReader<'a> {
             self.bump();
             while !self.curr_is('"') {
                 if self.is_eof() {
-                    self.fatal_span(start_bpos, self.last_pos, "unterminated double quote string");
+                    let last_bpos = self.last_pos;
+                    self.fatal_span(start_bpos, last_bpos, "unterminated double quote string");
                 }
 
                 let ch = self.curr.unwrap();
@@ -850,7 +869,8 @@ impl<'a> StringReader<'a> {
                 match ch {
                   '\\' => {
                     if self.is_eof() {
-                        self.fatal_span(start_bpos, self.last_pos,
+                        let last_bpos = self.last_pos;
+                        self.fatal_span(start_bpos, last_bpos,
                                "unterminated double quote string");
                     }
 
@@ -876,7 +896,8 @@ impl<'a> StringReader<'a> {
                         accum_str.push_char(self.scan_numeric_escape(8u, '"'));
                       }
                       c2 => {
-                        self.err_span_char(escaped_pos, self.last_pos,
+                        let last_bpos = self.last_pos;
+                        self.err_span_char(escaped_pos, last_bpos,
                                         "unknown string escape", c2);
                       }
                     }
@@ -897,19 +918,23 @@ impl<'a> StringReader<'a> {
             }
 
             if self.is_eof() {
-                self.fatal_span(start_bpos, self.last_pos, "unterminated raw string");
+                let last_bpos = self.last_pos;
+                self.fatal_span(start_bpos, last_bpos, "unterminated raw string");
             } else if !self.curr_is('"') {
-                self.fatal_span_char(start_bpos, self.last_pos,
+                let last_bpos = self.last_pos;
+                let curr_char = self.curr.unwrap();
+                self.fatal_span_char(start_bpos, last_bpos,
                                 "only `#` is allowed in raw string delimitation; \
                                  found illegal character",
-                                self.curr.unwrap());
+                                curr_char);
             }
             self.bump();
             let content_start_bpos = self.last_pos;
             let mut content_end_bpos;
             'outer: loop {
                 if self.is_eof() {
-                    self.fatal_span(start_bpos, self.last_pos, "unterminated raw string");
+                    let last_bpos = self.last_pos;
+                    self.fatal_span(start_bpos, last_bpos, "unterminated raw string");
                 }
                 if self.curr_is('"') {
                     content_end_bpos = self.last_pos;
@@ -956,8 +981,9 @@ impl<'a> StringReader<'a> {
           '^' => { return self.binop(token::CARET); }
           '%' => { return self.binop(token::PERCENT); }
           c => {
-              self.fatal_span_char(self.last_pos, self.pos,
-                              "unknown start of token", c);
+              let last_bpos = self.last_pos;
+              let bpos = self.pos;
+              self.fatal_span_char(last_bpos, bpos, "unknown start of token", c);
           }
         }
     }
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index d11d303059f..250ed4af571 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -146,10 +146,12 @@ macro_rules! maybe_whole_expr (
                         INTERPOLATED(token::NtPath(ref pt)) => (**pt).clone(),
                         _ => unreachable!()
                     };
-                    Some($p.mk_expr($p.span.lo, $p.span.hi, ExprPath(pt)))
+                    let span = $p.span;
+                    Some($p.mk_expr(span.lo, span.hi, ExprPath(pt)))
                 }
                 INTERPOLATED(token::NtBlock(b)) => {
-                    Some($p.mk_expr($p.span.lo, $p.span.hi, ExprBlock(b)))
+                    let span = $p.span;
+                    Some($p.mk_expr(span.lo, span.hi, ExprBlock(b)))
                 }
                 _ => None
             };
@@ -370,7 +372,8 @@ impl<'a> Parser<'a> {
 
     pub fn unexpected_last(&mut self, t: &token::Token) -> ! {
         let token_str = Parser::token_to_str(t);
-        self.span_fatal(self.last_span, format!("unexpected token: `{}`",
+        let last_span = self.last_span;
+        self.span_fatal(last_span, format!("unexpected token: `{}`",
                                                 token_str).as_slice());
     }
 
@@ -441,7 +444,8 @@ impl<'a> Parser<'a> {
             && expected.iter().all(|t| *t != token::LBRACE)
             && self.look_ahead(1, |t| *t == token::RBRACE) {
             // matched; signal non-fatal error and recover.
-            self.span_err(self.span,
+            let span = self.span;
+            self.span_err(span,
                           "unit-like struct construction is written with no trailing `{ }`");
             self.eat(&token::LBRACE);
             self.eat(&token::RBRACE);
@@ -560,7 +564,8 @@ impl<'a> Parser<'a> {
     pub fn check_strict_keywords(&mut self) {
         if token::is_strict_keyword(&self.token) {
             let token_str = self.this_token_to_str();
-            self.span_err(self.span,
+            let span = self.span;
+            self.span_err(span,
                           format!("found `{}` in ident position",
                                   token_str).as_slice());
         }
@@ -581,8 +586,9 @@ impl<'a> Parser<'a> {
         match self.token {
             token::BINOP(token::AND) => self.bump(),
             token::ANDAND => {
-                let lo = self.span.lo + BytePos(1);
-                self.replace_token(token::BINOP(token::AND), lo, self.span.hi)
+                let span = self.span;
+                let lo = span.lo + BytePos(1);
+                self.replace_token(token::BINOP(token::AND), lo, span.hi)
             }
             _ => {
                 let token_str = self.this_token_to_str();
@@ -601,8 +607,9 @@ impl<'a> Parser<'a> {
         match self.token {
             token::BINOP(token::OR) => self.bump(),
             token::OROR => {
-                let lo = self.span.lo + BytePos(1);
-                self.replace_token(token::BINOP(token::OR), lo, self.span.hi)
+                let span = self.span;
+                let lo = span.lo + BytePos(1);
+                self.replace_token(token::BINOP(token::OR), lo, span.hi)
             }
             _ => {
                 let found_token = self.this_token_to_str();
@@ -644,8 +651,9 @@ impl<'a> Parser<'a> {
                     _ => false,
                 });
                 if force || next_lifetime {
-                    let lo = self.span.lo + BytePos(1);
-                    self.replace_token(token::LT, lo, self.span.hi);
+                    let span = self.span;
+                    let lo = span.lo + BytePos(1);
+                    self.replace_token(token::LT, lo, span.hi);
                     true
                 } else {
                     false
@@ -693,8 +701,9 @@ impl<'a> Parser<'a> {
         match self.token {
             token::GT => self.bump(),
             token::BINOP(token::SHR) => {
-                let lo = self.span.lo + BytePos(1);
-                self.replace_token(token::GT, lo, self.span.hi)
+                let span = self.span;
+                let lo = span.lo + BytePos(1);
+                self.replace_token(token::GT, lo, span.hi)
             }
             _ => {
                 let gt_str = Parser::token_to_str(&token::GT);
@@ -805,7 +814,8 @@ impl<'a> Parser<'a> {
                                -> Vec<T> {
         let result = self.parse_unspanned_seq(bra, ket, sep, f);
         if result.is_empty() {
-            self.span_err(self.last_span,
+            let last_span = self.last_span;
+            self.span_err(last_span,
             "nullary enum variants are written with no trailing `( )`");
         }
         result
@@ -1336,10 +1346,11 @@ impl<'a> Parser<'a> {
         } else if self.token == token::TILDE {
             // OWNED POINTER
             self.bump();
+            let last_span = self.last_span;
             match self.token {
                 token::LBRACKET =>
-                    self.obsolete(self.last_span, ObsoleteOwnedVector),
-                _ => self.obsolete(self.last_span, ObsoleteOwnedType),
+                    self.obsolete(last_span, ObsoleteOwnedVector),
+                _ => self.obsolete(last_span, ObsoleteOwnedType),
             };
             TyUniq(self.parse_ty(true))
         } else if self.token == token::BINOP(token::STAR) {
@@ -2375,17 +2386,18 @@ impl<'a> Parser<'a> {
             let e = self.parse_prefix_expr();
             hi = e.span.hi;
             // HACK: turn ~[...] into a ~-vec
+            let last_span = self.last_span;
             ex = match e.node {
               ExprVec(..) | ExprRepeat(..) => {
-                  self.obsolete(self.last_span, ObsoleteOwnedVector);
+                  self.obsolete(last_span, ObsoleteOwnedVector);
                   ExprVstore(e, ExprVstoreUniq)
               }
               ExprLit(lit) if lit_is_str(lit) => {
-                  self.obsolete(self.last_span, ObsoleteOwnedExpr);
+                  self.obsolete(last_span, ObsoleteOwnedExpr);
                   ExprVstore(e, ExprVstoreUniq)
               }
               _ => {
-                  self.obsolete(self.last_span, ObsoleteOwnedExpr);
+                  self.obsolete(last_span, ObsoleteOwnedExpr);
                   self.mk_unary(UnUniq, e)
               }
             };
@@ -2412,7 +2424,8 @@ impl<'a> Parser<'a> {
             // HACK: turn `box [...]` into a boxed-vec
             ex = match subexpression.node {
                 ExprVec(..) | ExprRepeat(..) => {
-                    self.obsolete(self.last_span, ObsoleteOwnedVector);
+                    let last_span = self.last_span;
+                    self.obsolete(last_span, ObsoleteOwnedVector);
                     ExprVstore(subexpression, ExprVstoreUniq)
                 }
                 ExprLit(lit) if lit_is_str(lit) => {
@@ -2843,8 +2856,9 @@ impl<'a> Parser<'a> {
             self.bump();
             let sub = self.parse_pat();
             pat = PatBox(sub);
-            hi = self.last_span.hi;
-            self.obsolete(self.last_span, ObsoleteOwnedPattern);
+            let last_span = self.last_span;
+            hi = last_span.hi;
+            self.obsolete(last_span, ObsoleteOwnedPattern);
             return box(GC) ast::Pat {
                 id: ast::DUMMY_NODE_ID,
                 node: pat,
@@ -3061,7 +3075,8 @@ impl<'a> Parser<'a> {
                        binding_mode: ast::BindingMode)
                        -> ast::Pat_ {
         if !is_plain_ident(&self.token) {
-            self.span_fatal(self.last_span,
+            let last_span = self.last_span;
+            self.span_fatal(last_span,
                             "expected identifier, found path");
         }
         // why a path here, and not just an identifier?
@@ -3079,8 +3094,9 @@ impl<'a> Parser<'a> {
         // binding mode then we do not end up here, because the lookahead
         // will direct us over to parse_enum_variant()
         if self.token == token::LPAREN {
+            let last_span = self.last_span;
             self.span_fatal(
-                self.last_span,
+                last_span,
                 "expected identifier, found enum pattern");
         }
 
@@ -3144,7 +3160,8 @@ impl<'a> Parser<'a> {
         fn check_expected_item(p: &mut Parser, found_attrs: bool) {
             // If we have attributes then we should have an item
             if found_attrs {
-                p.span_err(p.last_span, "expected item after attributes");
+                let last_span = p.last_span;
+                p.span_err(last_span, "expected item after attributes");
             }
         }
 
@@ -3333,7 +3350,8 @@ impl<'a> Parser<'a> {
             match self.token {
                 token::SEMI => {
                     if !attributes_box.is_empty() {
-                        self.span_err(self.last_span, "expected item after attributes");
+                        let last_span = self.last_span;
+                        self.span_err(last_span, "expected item after attributes");
                         attributes_box = Vec::new();
                     }
                     self.bump(); // empty
@@ -3409,7 +3427,8 @@ impl<'a> Parser<'a> {
         }
 
         if !attributes_box.is_empty() {
-            self.span_err(self.last_span, "expected item after attributes");
+            let last_span = self.last_span;
+            self.span_err(last_span, "expected item after attributes");
         }
 
         let hi = self.span.hi;
@@ -3566,7 +3585,8 @@ impl<'a> Parser<'a> {
                 if ty_param.default.is_some() {
                     seen_default = true;
                 } else if seen_default {
-                    p.span_err(p.last_span,
+                    let last_span = p.last_span;
+                    p.span_err(last_span,
                                "type parameters with a default must be trailing");
                 }
                 ty_param
@@ -3591,7 +3611,8 @@ impl<'a> Parser<'a> {
 
     fn forbid_lifetime(&mut self) {
         if Parser::token_is_lifetime(&self.token) {
-            self.span_fatal(self.span, "lifetime parameters must be declared \
+            let span = self.span;
+            self.span_fatal(span, "lifetime parameters must be declared \
                                         prior to type parameters");
         }
     }
@@ -3609,11 +3630,13 @@ impl<'a> Parser<'a> {
                         p.bump();
                         if allow_variadic {
                             if p.token != token::RPAREN {
-                                p.span_fatal(p.span,
+                                let span = p.span;
+                                p.span_fatal(span,
                                     "`...` must be last in argument list for variadic function");
                             }
                         } else {
-                            p.span_fatal(p.span,
+                            let span = p.span;
+                            p.span_fatal(span,
                                          "only foreign functions are allowed to be variadic");
                         }
                         None
@@ -3756,7 +3779,8 @@ impl<'a> Parser<'a> {
                     self.parse_mutability()
                 } else { MutImmutable };
                 if self.is_self_ident() {
-                    self.span_err(self.span, "cannot pass self by unsafe pointer");
+                    let span = self.span;
+                    self.span_err(span, "cannot pass self by unsafe pointer");
                     self.bump();
                 }
                 SelfValue
@@ -4128,15 +4152,17 @@ impl<'a> Parser<'a> {
             token::RBRACE => {}
             #[cfg(stage0)]
             _ => {
+                let span = self.span;
                 let token_str = self.this_token_to_str();
-                self.span_fatal(self.span,
+                self.span_fatal(span,
                                 format!("expected `,`, or `\\}` but found `{}`",
                                         token_str).as_slice())
             }
             #[cfg(not(stage0))]
             _ => {
+                let span = self.span;
                 let token_str = self.this_token_to_str();
-                self.span_fatal(self.span,
+                self.span_fatal(span,
                                 format!("expected `,`, or `}}` but found `{}`",
                                         token_str).as_slice())
             }
@@ -4170,7 +4196,8 @@ impl<'a> Parser<'a> {
     fn parse_for_sized(&mut self) -> Sized {
         if self.eat_keyword(keywords::For) {
             if !self.eat_keyword(keywords::Type) {
-                self.span_err(self.last_span,
+                let last_span = self.last_span;
+                self.span_err(last_span,
                     "expected 'type' after for in trait item");
             }
             DynSize
@@ -4226,7 +4253,8 @@ impl<'a> Parser<'a> {
 
         if first && attrs_remaining_len > 0u {
             // We parsed attributes for the first item but didn't find it
-            self.span_err(self.last_span, "expected item after attributes");
+            let last_span = self.last_span;
+            self.span_err(last_span, "expected item after attributes");
         }
 
         ast::Mod {
@@ -4458,7 +4486,8 @@ impl<'a> Parser<'a> {
             foreign_items: foreign_items
         } = self.parse_foreign_items(first_item_attrs, true);
         if ! attrs_remaining.is_empty() {
-            self.span_err(self.last_span,
+            let last_span = self.last_span;
+            self.span_err(last_span,
                           "expected item after attributes");
         }
         assert!(self.token == token::RBRACE);
@@ -4494,8 +4523,9 @@ impl<'a> Parser<'a> {
                 (path, the_ident)
             }
             _ => {
+                let span = self.span;
                 let token_str = self.this_token_to_str();
-                self.span_fatal(self.span,
+                self.span_fatal(span,
                                 format!("expected extern crate name but \
                                          found `{}`",
                                         token_str).as_slice());
@@ -4535,8 +4565,9 @@ impl<'a> Parser<'a> {
         let m = self.parse_foreign_mod_items(abi, next);
         self.expect(&token::RBRACE);
 
+        let last_span = self.last_span;
         let item = self.mk_item(lo,
-                                self.last_span.hi,
+                                last_span.hi,
                                 special_idents::invalid,
                                 ItemForeignMod(m),
                                 visibility,
@@ -4663,8 +4694,9 @@ impl<'a> Parser<'a> {
                 match abi::lookup(the_string) {
                     Some(abi) => Some(abi),
                     None => {
+                        let last_span = self.last_span;
                         self.span_err(
-                            self.last_span,
+                            last_span,
                             format!("illegal ABI: expected one of [{}], \
                                      found `{}`",
                                     abi::all_names().connect(", "),
@@ -4720,7 +4752,8 @@ impl<'a> Parser<'a> {
 
             if next_is_mod || self.eat_keyword(keywords::Crate) {
                 if next_is_mod {
-                   self.span_err(mk_sp(lo, self.last_span.hi),
+                    let last_span = self.last_span;
+                    self.span_err(mk_sp(lo, last_span.hi),
                                  format!("`extern mod` is obsolete, use \
                                           `extern crate` instead \
                                           to refer to external \
@@ -4736,8 +4769,9 @@ impl<'a> Parser<'a> {
                 let abi = opt_abi.unwrap_or(abi::C);
                 let (ident, item_, extra_attrs) =
                     self.parse_item_fn(NormalFn, abi);
+                let last_span = self.last_span;
                 let item = self.mk_item(lo,
-                                        self.last_span.hi,
+                                        last_span.hi,
                                         ident,
                                         item_,
                                         visibility,
@@ -4747,15 +4781,17 @@ impl<'a> Parser<'a> {
                 return self.parse_item_foreign_mod(lo, opt_abi, visibility, attrs);
             }
 
+            let span = self.span;
             let token_str = self.this_token_to_str();
-            self.span_fatal(self.span,
+            self.span_fatal(span,
                             format!("expected `{}` or `fn` but found `{}`", "{",
                                     token_str).as_slice());
         }
 
         let is_virtual = self.eat_keyword(keywords::Virtual);
         if is_virtual && !self.is_keyword(keywords::Struct) {
-            self.span_err(self.span,
+            let span = self.span;
+            self.span_err(span,
                           "`virtual` keyword may only be used with `struct`");
         }
 
@@ -4764,8 +4800,9 @@ impl<'a> Parser<'a> {
             // STATIC ITEM
             self.bump();
             let (ident, item_, extra_attrs) = self.parse_item_const();
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4778,8 +4815,9 @@ impl<'a> Parser<'a> {
             self.bump();
             let (ident, item_, extra_attrs) =
                 self.parse_item_fn(NormalFn, abi::Rust);
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4798,8 +4836,9 @@ impl<'a> Parser<'a> {
             self.expect_keyword(keywords::Fn);
             let (ident, item_, extra_attrs) =
                 self.parse_item_fn(UnsafeFn, abi);
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4810,8 +4849,9 @@ impl<'a> Parser<'a> {
             // MODULE ITEM
             let (ident, item_, extra_attrs) =
                 self.parse_item_mod(attrs.as_slice());
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4821,8 +4861,9 @@ impl<'a> Parser<'a> {
         if self.eat_keyword(keywords::Type) {
             // TYPE ITEM
             let (ident, item_, extra_attrs) = self.parse_item_type();
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4832,8 +4873,9 @@ impl<'a> Parser<'a> {
         if self.eat_keyword(keywords::Enum) {
             // ENUM ITEM
             let (ident, item_, extra_attrs) = self.parse_item_enum();
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4843,8 +4885,9 @@ impl<'a> Parser<'a> {
         if self.eat_keyword(keywords::Trait) {
             // TRAIT ITEM
             let (ident, item_, extra_attrs) = self.parse_item_trait();
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4854,8 +4897,9 @@ impl<'a> Parser<'a> {
         if self.eat_keyword(keywords::Impl) {
             // IMPL ITEM
             let (ident, item_, extra_attrs) = self.parse_item_impl();
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4865,8 +4909,9 @@ impl<'a> Parser<'a> {
         if self.eat_keyword(keywords::Struct) {
             // STRUCT ITEM
             let (ident, item_, extra_attrs) = self.parse_item_struct(is_virtual);
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     ident,
                                     item_,
                                     visibility,
@@ -4942,8 +4987,9 @@ impl<'a> Parser<'a> {
                                              span: mk_sp(self.span.lo,
                                                          self.span.hi) };
             let item_ = ItemMac(m);
+            let last_span = self.last_span;
             let item = self.mk_item(lo,
-                                    self.last_span.hi,
+                                    last_span.hi,
                                     id,
                                     item_,
                                     visibility,
@@ -4960,7 +5006,8 @@ impl<'a> Parser<'a> {
                 s.push_str("priv")
             }
             s.push_char('`');
-            self.span_fatal(self.last_span, s.as_slice());
+            let last_span = self.last_span;
+            self.span_fatal(last_span, s.as_slice());
         }
         return IoviNone(attrs);
     }
diff --git a/src/libsyntax/print/pp.rs b/src/libsyntax/print/pp.rs
index 4fefa1f1d3d..672e08af2d8 100644
--- a/src/libsyntax/print/pp.rs
+++ b/src/libsyntax/print/pp.rs
@@ -322,7 +322,8 @@ impl Printer {
                    b.offset, self.left, self.right);
             *self.token.get_mut(self.right) = t;
             *self.size.get_mut(self.right) = -self.right_total;
-            self.scan_push(self.right);
+            let right = self.right;
+            self.scan_push(right);
             Ok(())
           }
           End => {
@@ -334,7 +335,8 @@ impl Printer {
                 self.advance_right();
                 *self.token.get_mut(self.right) = t;
                 *self.size.get_mut(self.right) = -1;
-                self.scan_push(self.right);
+                let right = self.right;
+                self.scan_push(right);
                 Ok(())
             }
           }
@@ -348,7 +350,8 @@ impl Printer {
             debug!("pp Break({})/buffer ~[{},{}]",
                    b.offset, self.left, self.right);
             self.check_stack(0);
-            self.scan_push(self.right);
+            let right = self.right;
+            self.scan_push(right);
             *self.token.get_mut(self.right) = t;
             *self.size.get_mut(self.right) = -self.right_total;
             self.right_total += b.blank_space;