Make `$crate` a keyword

12 files changed, 139 insertions, 66 deletions

diff --git a/src/librustc/hir/print.rs b/src/librustc/hir/print.rs
index a78d5ce1c16..c6f4cd585d7 100644
--- a/src/librustc/hir/print.rs
+++ b/src/librustc/hir/print.rs
@@ -1527,7 +1527,8 @@ impl<'a> State<'a> {
             if i > 0 {
                 word(&mut self.s, "::")?
             }
-            if segment.name != keywords::CrateRoot.name() && segment.name != "$crate" {
+            if segment.name != keywords::CrateRoot.name() &&
+               segment.name != keywords::DollarCrate.name() {
                 self.print_name(segment.name)?;
                 self.print_path_parameters(&segment.parameters, colons_before_params)?;
             }
@@ -1554,7 +1555,8 @@ impl<'a> State<'a> {
                     if i > 0 {
                         word(&mut self.s, "::")?
                     }
-                    if segment.name != keywords::CrateRoot.name() && segment.name != "$crate" {
+                    if segment.name != keywords::CrateRoot.name() &&
+                       segment.name != keywords::DollarCrate.name() {
                         self.print_name(segment.name)?;
                         self.print_path_parameters(&segment.parameters, colons_before_params)?;
                     }
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index b97c08b5bde..4b6b754dca6 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -149,14 +149,15 @@ impl<'a> Resolver<'a> {
                             resolve_error(self,
                                           view_path.span,
                                           ResolutionError::SelfImportsOnlyAllowedWithin);
-                        } else if source_name == "$crate" && full_path.segments.len() == 1 {
+                        } else if source_name == keywords::DollarCrate.name() &&
+                                  full_path.segments.len() == 1 {
                             let crate_root = self.resolve_crate_root(source.ctxt);
                             let crate_name = match crate_root.kind {
                                 ModuleKind::Def(_, name) => name,
                                 ModuleKind::Block(..) => unreachable!(),
                             };
                             source.name = crate_name;
-                            if binding.name == "$crate" {
+                            if binding.name == keywords::DollarCrate.name() {
                                 binding.name = crate_name;
                             }
 
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 8c11aa7def8..4bfe4d25ded 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -2665,7 +2665,8 @@ impl<'a> Resolver<'a> {
         };
 
         if path.len() > 1 && !global_by_default && result.base_def() != Def::Err &&
-           path[0].name != keywords::CrateRoot.name() && path[0].name != "$crate" {
+           path[0].name != keywords::CrateRoot.name() &&
+           path[0].name != keywords::DollarCrate.name() {
             let unqualified_result = {
                 match self.resolve_path(&[*path.last().unwrap()], Some(ns), false, span) {
                     PathResult::NonModule(path_res) => path_res.base_def(),
@@ -2718,7 +2719,7 @@ impl<'a> Resolver<'a> {
             if i == 0 && ns == TypeNS && ident.name == keywords::CrateRoot.name() {
                 module = Some(self.resolve_crate_root(ident.ctxt.modern()));
                 continue
-            } else if i == 0 && ns == TypeNS && ident.name == "$crate" {
+            } else if i == 0 && ns == TypeNS && ident.name == keywords::DollarCrate.name() {
                 module = Some(self.resolve_crate_root(ident.ctxt));
                 continue
             }
diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs
index 60c07eda4d5..0fbc596f2e1 100644
--- a/src/librustc_resolve/macros.rs
+++ b/src/librustc_resolve/macros.rs
@@ -128,7 +128,7 @@ impl<'a> base::Resolver for Resolver<'a> {
         impl<'a, 'b> Folder for EliminateCrateVar<'a, 'b> {
             fn fold_path(&mut self, mut path: ast::Path) -> ast::Path {
                 let ident = path.segments[0].identifier;
-                if ident.name == "$crate" {
+                if ident.name == keywords::DollarCrate.name() {
                     path.segments[0].identifier.name = keywords::CrateRoot.name();
                     let module = self.0.resolve_crate_root(ident.ctxt);
                     if !module.is_local() {
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 8bd58ec7a52..ecab801d408 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -97,9 +97,8 @@ impl Path {
     }
 
     pub fn default_to_global(mut self) -> Path {
-        let name = self.segments[0].identifier.name;
-        if !self.is_global() && name != "$crate" &&
-           name != keywords::SelfValue.name() && name != keywords::Super.name() {
+        if !self.is_global() &&
+           !::parse::token::Ident(self.segments[0].identifier).is_path_segment_keyword() {
             self.segments.insert(0, PathSegment::crate_root());
         }
         self
diff --git a/src/libsyntax/ext/tt/quoted.rs b/src/libsyntax/ext/tt/quoted.rs
index fa65e9501c2..c094a23cefc 100644
--- a/src/libsyntax/ext/tt/quoted.rs
+++ b/src/libsyntax/ext/tt/quoted.rs
@@ -12,7 +12,7 @@ use ast;
 use ext::tt::macro_parser;
 use parse::{ParseSess, token};
 use print::pprust;
-use symbol::{keywords, Symbol};
+use symbol::keywords;
 use syntax_pos::{DUMMY_SP, Span, BytePos};
 use tokenstream;
 
@@ -196,7 +196,7 @@ fn parse_tree<I>(tree: tokenstream::TokenTree,
             Some(tokenstream::TokenTree::Token(ident_span, token::Ident(ident))) => {
                 let span = Span { lo: span.lo, ..ident_span };
                 if ident.name == keywords::Crate.name() {
-                    let ident = ast::Ident { name: Symbol::intern("$crate"), ..ident };
+                    let ident = ast::Ident { name: keywords::DollarCrate.name(), ..ident };
                     TokenTree::Token(span, token::Ident(ident))
                 } else {
                     TokenTree::Token(span, token::SubstNt(ident))
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 77db604c56e..d6a4dc2ee96 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -327,7 +327,8 @@ impl Token {
         match self.ident() {
             Some(id) => id.name == keywords::Super.name() ||
                         id.name == keywords::SelfValue.name() ||
-                        id.name == keywords::SelfType.name(),
+                        id.name == keywords::SelfType.name() ||
+                        id.name == keywords::DollarCrate.name(),
             None => false,
         }
     }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 34cda433d52..6c00e0b9efd 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -761,7 +761,7 @@ pub trait PrintState<'a> {
                         word(self.writer(), "::")?
                     }
                     if segment.identifier.name != keywords::CrateRoot.name() &&
-                       segment.identifier.name != "$crate" {
+                       segment.identifier.name != keywords::DollarCrate.name() {
                         word(self.writer(), &segment.identifier.name.as_str())?;
                     }
                 }
@@ -2375,7 +2375,7 @@ impl<'a> State<'a> {
                           -> io::Result<()>
     {
         if segment.identifier.name != keywords::CrateRoot.name() &&
-           segment.identifier.name != "$crate" {
+           segment.identifier.name != keywords::DollarCrate.name() {
             self.print_ident(segment.identifier)?;
             if let Some(ref parameters) = segment.parameters {
                 self.print_path_parameters(parameters, colons_before_params)?;
diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 6b5caff27e8..5e2e448f741 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -250,63 +250,64 @@ declare_keywords! {
     (4,  Const,          "const")
     (5,  Continue,       "continue")
     (6,  Crate,          "crate")
-    (7,  Else,           "else")
-    (8,  Enum,           "enum")
-    (9,  Extern,         "extern")
-    (10, False,          "false")
-    (11, Fn,             "fn")
-    (12, For,            "for")
-    (13, If,             "if")
-    (14, Impl,           "impl")
-    (15, In,             "in")
-    (16, Let,            "let")
-    (17, Loop,           "loop")
-    (18, Match,          "match")
-    (19, Mod,            "mod")
-    (20, Move,           "move")
-    (21, Mut,            "mut")
-    (22, Pub,            "pub")
-    (23, Ref,            "ref")
-    (24, Return,         "return")
-    (25, SelfValue,      "self")
-    (26, SelfType,       "Self")
-    (27, Static,         "static")
-    (28, Struct,         "struct")
-    (29, Super,          "super")
-    (30, Trait,          "trait")
-    (31, True,           "true")
-    (32, Type,           "type")
-    (33, Unsafe,         "unsafe")
-    (34, Use,            "use")
-    (35, Where,          "where")
-    (36, While,          "while")
+    (7,  DollarCrate,    "$crate")
+    (8,  Else,           "else")
+    (9,  Enum,           "enum")
+    (10, Extern,         "extern")
+    (11, False,          "false")
+    (12, Fn,             "fn")
+    (13, For,            "for")
+    (14, If,             "if")
+    (15, Impl,           "impl")
+    (16, In,             "in")
+    (17, Let,            "let")
+    (18, Loop,           "loop")
+    (19, Match,          "match")
+    (20, Mod,            "mod")
+    (21, Move,           "move")
+    (22, Mut,            "mut")
+    (23, Pub,            "pub")
+    (24, Ref,            "ref")
+    (25, Return,         "return")
+    (26, SelfValue,      "self")
+    (27, SelfType,       "Self")
+    (28, Static,         "static")
+    (29, Struct,         "struct")
+    (30, Super,          "super")
+    (31, Trait,          "trait")
+    (32, True,           "true")
+    (33, Type,           "type")
+    (34, Unsafe,         "unsafe")
+    (35, Use,            "use")
+    (36, Where,          "where")
+    (37, While,          "while")
 
     // Keywords reserved for future use.
-    (37, Abstract,       "abstract")
-    (38, Alignof,        "alignof")
-    (39, Become,         "become")
-    (40, Do,             "do")
-    (41, Final,          "final")
-    (42, Macro,          "macro")
-    (43, Offsetof,       "offsetof")
-    (44, Override,       "override")
-    (45, Priv,           "priv")
-    (46, Proc,           "proc")
-    (47, Pure,           "pure")
-    (48, Sizeof,         "sizeof")
-    (49, Typeof,         "typeof")
-    (50, Unsized,        "unsized")
-    (51, Virtual,        "virtual")
-    (52, Yield,          "yield")
+    (38, Abstract,       "abstract")
+    (39, Alignof,        "alignof")
+    (40, Become,         "become")
+    (41, Do,             "do")
+    (42, Final,          "final")
+    (43, Macro,          "macro")
+    (44, Offsetof,       "offsetof")
+    (45, Override,       "override")
+    (46, Priv,           "priv")
+    (47, Proc,           "proc")
+    (48, Pure,           "pure")
+    (49, Sizeof,         "sizeof")
+    (50, Typeof,         "typeof")
+    (51, Unsized,        "unsized")
+    (52, Virtual,        "virtual")
+    (53, Yield,          "yield")
 
     // Weak keywords, have special meaning only in specific contexts.
-    (53, Default,        "default")
-    (54, StaticLifetime, "'static")
-    (55, Union,          "union")
-    (56, Catch,          "catch")
+    (54, Default,        "default")
+    (55, StaticLifetime, "'static")
+    (56, Union,          "union")
+    (57, Catch,          "catch")
 
     // A virtual keyword that resolves to the crate root when used in a lexical scope.
-    (57, CrateRoot, "{{root}}")
+    (58, CrateRoot,      "{{root}}")
 }
 
 // If an interner exists in TLS, return it. Otherwise, prepare a fresh one.
diff --git a/src/test/compile-fail/dollar-crate-is-keyword-2.rs b/src/test/compile-fail/dollar-crate-is-keyword-2.rs
new file mode 100644
index 00000000000..e221fc6e9e0
--- /dev/null
+++ b/src/test/compile-fail/dollar-crate-is-keyword-2.rs
@@ -0,0 +1,23 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+mod a {}
+
+macro_rules! m {
+    () => {
+        use a::$crate; //~ ERROR unresolved import `a::$crate`
+        use a::$crate::b; //~ ERROR unresolved import `a::$crate::b`
+        type A = a::$crate; //~ ERROR cannot find type `$crate` in module `a`
+    }
+}
+
+m!();
+
+fn main() {}
diff --git a/src/test/compile-fail/dollar-crate-is-keyword.rs b/src/test/compile-fail/dollar-crate-is-keyword.rs
new file mode 100644
index 00000000000..0bd47a0e11a
--- /dev/null
+++ b/src/test/compile-fail/dollar-crate-is-keyword.rs
@@ -0,0 +1,24 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+macro_rules! m {
+    () => {
+        struct $crate {} //~ ERROR expected identifier, found keyword `$crate`
+
+        use $crate; // OK
+                    //~^ WARN `$crate` may not be imported
+        use $crate as $crate; //~ ERROR expected identifier, found keyword `$crate`
+                              //~^ WARN `$crate` may not be imported
+    }
+}
+
+m!();
+
+fn main() {}
diff --git a/src/test/compile-fail/use-self-type.rs b/src/test/compile-fail/use-self-type.rs
new file mode 100644
index 00000000000..6b5286bf0a7
--- /dev/null
+++ b/src/test/compile-fail/use-self-type.rs
@@ -0,0 +1,21 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+struct S;
+
+impl S {
+    fn f() {}
+    fn g() {
+        use Self::f; //~ ERROR unresolved import
+        pub(in Self::f) struct Z; //~ ERROR Use of undeclared type or module `Self`
+    }
+}
+
+fn main() {}