rustc: Obsolete the @ syntax entirely

This removes all remnants of `@` pointers from rustc. Additionally, this removes
the `GC` structure from the prelude as it seems odd exporting an experimental
type in the prelude by default.

Closes rust-lang#14193
[breaking-change]

src/libcollections/ringbuf.rs

@@ -419,6 +419,7 @@ impl<T: fmt::Show> fmt::Show for RingBuf<T> {
 mod tests {
     use std::fmt::Show;
     use std::prelude::*;
+    use std::gc::{GC, Gc};
     use test::Bencher;
     use test;
 
@@ -473,10 +474,10 @@ mod tests {
 
     #[test]
     fn test_boxes() {
-        let a: @int = @5;
-        let b: @int = @72;
-        let c: @int = @64;
-        let d: @int = @175;
+        let a: Gc<int> = box(GC) 5;
+        let b: Gc<int> = box(GC) 72;
+        let c: Gc<int> = box(GC) 64;
+        let d: Gc<int> = box(GC) 175;
 
         let mut deq = RingBuf::new();
         assert_eq!(deq.len(), 0);
@@ -621,7 +622,8 @@ mod tests {
 
     #[test]
     fn test_param_at_int() {
-        test_parameterized::<@int>(@5, @72, @64, @175);
+        test_parameterized::<Gc<int>>(box(GC) 5, box(GC) 72,
+                                      box(GC) 64, box(GC) 175);
     }
 
     #[test]

src/libcore/iter.rs

@@ -2345,6 +2345,7 @@ mod tests {
     use num;
     use realstd::vec::Vec;
     use realstd::slice::Vector;
+    use realstd::gc::GC;
 
     use cmp;
     use realstd::owned::Box;
@@ -2835,7 +2836,8 @@ mod tests {
     #[test]
     #[should_fail]
     fn test_rposition_fail() {
-        let v = [(box 0, @0), (box 0, @0), (box 0, @0), (box 0, @0)];
+        let v = [(box 0, box(GC) 0), (box 0, box(GC) 0),
+                 (box 0, box(GC) 0), (box 0, box(GC) 0)];
         let mut i = 0;
         v.iter().rposition(|_elt| {
             if i == 2 {

src/libdebug/reflect.rs

@@ -18,6 +18,7 @@ Runtime type reflection
 
 use std::intrinsics::{Disr, Opaque, TyDesc, TyVisitor};
 use std::mem;
+use std::gc::Gc;
 
 /**
  * Trait for visitor that wishes to reflect on data.
@@ -219,9 +220,9 @@ impl<V:TyVisitor + MovePtr> TyVisitor for MovePtrAdaptor<V> {
     }
 
     fn visit_box(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
-        self.align_to::<@u8>();
+        self.align_to::<Gc<u8>>();
         if ! self.inner.visit_box(mtbl, inner) { return false; }
-        self.bump_past::<@u8>();
+        self.bump_past::<Gc<u8>>();
         true
     }
 

src/libdebug/repr.rs

@@ -288,7 +288,7 @@ impl<'a> TyVisitor for ReprVisitor<'a> {
                         _align: uint) -> bool { fail!(); }
 
     fn visit_box(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
-        try!(self, self.writer.write(['@' as u8]));
+        try!(self, self.writer.write("box(GC) ".as_bytes()));
         self.write_mut_qualifier(mtbl);
         self.get::<&raw::Box<()>>(|this, b| {
             let p = &b.data as *() as *u8;
@@ -591,6 +591,7 @@ fn test_repr() {
     use std::io::stdio::println;
     use std::char::is_alphabetic;
     use std::mem::swap;
+    use std::gc::GC;
 
     fn exact_test<T>(t: &T, e:&str) {
         let mut m = io::MemWriter::new();
@@ -605,7 +606,7 @@ fn test_repr() {
     exact_test(&1.234, "1.234f64");
     exact_test(&("hello"), "\"hello\"");
 
-    exact_test(&(@10), "@10");
+    exact_test(&(box(GC) 10), "box(GC) 10");
     exact_test(&(box 10), "box 10");
     exact_test(&(&10), "&10");
     let mut x = 10;
@@ -619,8 +620,8 @@ fn test_repr() {
                "&[\"hi\", \"there\"]");
     exact_test(&(P{a:10, b:1.234}),
                "repr::P{a: 10, b: 1.234f64}");
-    exact_test(&(@P{a:10, b:1.234}),
-               "@repr::P{a: 10, b: 1.234f64}");
+    exact_test(&(box(GC) P{a:10, b:1.234}),
+               "box(GC) repr::P{a: 10, b: 1.234f64}");
     exact_test(&(box P{a:10, b:1.234}),
                "box repr::P{a: 10, b: 1.234f64}");
 

src/libfourcc/lib.rs

@@ -63,6 +63,8 @@ use syntax::parse::token;
 use syntax::parse::token::InternedString;
 use rustc::plugin::Registry;
 
+use std::gc::Gc;
+
 #[plugin_registrar]
 pub fn plugin_registrar(reg: &mut Registry) {
     reg.register_macro("fourcc", expand_syntax_ext);
@@ -130,7 +132,8 @@ struct Ident {
     span: Span
 }
 
-fn parse_tts(cx: &ExtCtxt, tts: &[ast::TokenTree]) -> (@ast::Expr, Option<Ident>) {
+fn parse_tts(cx: &ExtCtxt,
+             tts: &[ast::TokenTree]) -> (Gc<ast::Expr>, Option<Ident>) {
     let p = &mut parse::new_parser_from_tts(cx.parse_sess(),
                                             cx.cfg(),
                                             tts.iter()

src/libhexfloat/lib.rs

@@ -57,6 +57,8 @@ use syntax::parse;
 use syntax::parse::token;
 use rustc::plugin::Registry;
 
+use std::gc::Gc;
+
 #[plugin_registrar]
 pub fn plugin_registrar(reg: &mut Registry) {
     reg.register_macro("hexfloat", expand_syntax_ext);
@@ -163,7 +165,8 @@ struct Ident {
     span: Span
 }
 
-fn parse_tts(cx: &ExtCtxt, tts: &[ast::TokenTree]) -> (@ast::Expr, Option<Ident>) {
+fn parse_tts(cx: &ExtCtxt,
+             tts: &[ast::TokenTree]) -> (Gc<ast::Expr>, Option<Ident>) {
     let p = &mut parse::new_parser_from_tts(cx.parse_sess(),
                                             cx.cfg(),
                                             tts.iter()

src/libregex_macros/lib.rs

@@ -26,6 +26,7 @@ extern crate syntax;
 extern crate rustc;
 
 use std::rc::Rc;
+use std::gc::{Gc, GC};
 
 use syntax::ast;
 use syntax::codemap;
@@ -110,7 +111,7 @@ struct NfaGen<'a> {
 }
 
 impl<'a> NfaGen<'a> {
-    fn code(&mut self) -> @ast::Expr {
+    fn code(&mut self) -> Gc<ast::Expr> {
         // Most or all of the following things are used in the quasiquoted
         // expression returned.
         let num_cap_locs = 2 * self.prog.num_captures();
@@ -331,7 +332,7 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
 
     // Generates code for the `add` method, which is responsible for adding
     // zero-width states to the next queue of states to visit.
-    fn add_insts(&self) -> @ast::Expr {
+    fn add_insts(&self) -> Gc<ast::Expr> {
         let arms = self.prog.insts.iter().enumerate().map(|(pc, inst)| {
             let nextpc = pc + 1;
             let body = match *inst {
@@ -432,7 +433,7 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
 
     // Generates the code for the `step` method, which processes all states
     // in the current queue that consume a single character.
-    fn step_insts(&self) -> @ast::Expr {
+    fn step_insts(&self) -> Gc<ast::Expr> {
         let arms = self.prog.insts.iter().enumerate().map(|(pc, inst)| {
             let nextpc = pc + 1;
             let body = match *inst {
@@ -523,7 +524,7 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
     // Translates a character class into a match expression.
     // This avoids a binary search (and is hopefully replaced by a jump
     // table).
-    fn match_class(&self, casei: bool, ranges: &[(char, char)]) -> @ast::Expr {
+    fn match_class(&self, casei: bool, ranges: &[(char, char)]) -> Gc<ast::Expr> {
         let expr_true = quote_expr!(self.cx, true);
 
         let mut arms = ranges.iter().map(|&(mut start, mut end)| {
@@ -545,7 +546,7 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
     // Generates code for checking a literal prefix of the search string.
     // The code is only generated if the regex *has* a literal prefix.
     // Otherwise, a no-op is returned.
-    fn check_prefix(&self) -> @ast::Expr {
+    fn check_prefix(&self) -> Gc<ast::Expr> {
         if self.prog.prefix.len() == 0 {
             self.empty_block()
         } else {
@@ -569,28 +570,28 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
     // A wild-card arm is automatically added that executes a no-op. It will
     // never be used, but is added to satisfy the compiler complaining about
     // non-exhaustive patterns.
-    fn match_insts(&self, mut arms: Vec<ast::Arm>) -> @ast::Expr {
+    fn match_insts(&self, mut arms: Vec<ast::Arm>) -> Gc<ast::Expr> {
         arms.push(self.wild_arm_expr(self.empty_block()));
         self.cx.expr_match(self.sp, quote_expr!(self.cx, pc), arms)
     }
 
-    fn empty_block(&self) -> @ast::Expr {
+    fn empty_block(&self) -> Gc<ast::Expr> {
         quote_expr!(self.cx, {})
     }
 
     // Creates a match arm for the instruction at `pc` with the expression
     // `body`.
-    fn arm_inst(&self, pc: uint, body: @ast::Expr) -> ast::Arm {
+    fn arm_inst(&self, pc: uint, body: Gc<ast::Expr>) -> ast::Arm {
         let pc_pat = self.cx.pat_lit(self.sp, quote_expr!(self.cx, $pc));
 
         self.cx.arm(self.sp, vec!(pc_pat), body)
     }
 
     // Creates a wild-card match arm with the expression `body`.
-    fn wild_arm_expr(&self, body: @ast::Expr) -> ast::Arm {
+    fn wild_arm_expr(&self, body: Gc<ast::Expr>) -> ast::Arm {
         ast::Arm {
             attrs: vec!(),
-            pats: vec!(@ast::Pat{
+            pats: vec!(box(GC) ast::Pat{
                 id: ast::DUMMY_NODE_ID,
                 span: self.sp,
                 node: ast::PatWild,
@@ -603,8 +604,9 @@ fn exec<'t>(which: ::regex::native::MatchKind, input: &'t str,
 
     // Converts `xs` to a `[x1, x2, .., xN]` expression by calling `to_expr`
     // on each element in `xs`.
-    fn vec_expr<T, It: Iterator<T>>(&self, xs: It, to_expr: |&ExtCtxt, T| -> @ast::Expr)
-                  -> @ast::Expr {
+    fn vec_expr<T, It: Iterator<T>>(&self, xs: It,
+                                    to_expr: |&ExtCtxt, T| -> Gc<ast::Expr>)
+                  -> Gc<ast::Expr> {
         let exprs = xs.map(|x| to_expr(self.cx, x)).collect();
         self.cx.expr_vec(self.sp, exprs)
     }

src/librustc/front/config.rs

@@ -12,7 +12,7 @@ use syntax::fold::Folder;
 use syntax::{ast, fold, attr};
 use syntax::codemap;
 
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 
 struct Context<'a> {
     in_cfg: |attrs: &[ast::Attribute]|: 'a -> bool,

src/librustc/front/std_inject.rs

@@ -23,7 +23,7 @@ use syntax::parse::token;
 use syntax::util::small_vector::SmallVector;
 
 use std::mem;
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 
 pub static VERSION: &'static str = "0.11.0-pre";
 

src/librustc/front/test.rs

@@ -18,7 +18,7 @@ use front::config;
 use front::std_inject::with_version;
 
 use std::cell::RefCell;
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 use std::slice;
 use std::vec;
 use syntax::ast_util::*;

src/librustc/middle/astencode.rs

@@ -40,7 +40,7 @@ use libc;
 use std::io::Seek;
 use std::io::MemWriter;
 use std::mem;
-use std::string::String;
+use std::gc::GC;
 
 use serialize::ebml::reader;
 use serialize::ebml;

src/librustc/middle/borrowck/mod.rs

@@ -23,6 +23,7 @@ use util::ppaux::{note_and_explain_region, Repr, UserString};
 use std::cell::{Cell};
 use std::ops::{BitOr, BitAnd};
 use std::rc::Rc;
+use std::gc::{Gc, GC};
 use std::string::String;
 use syntax::ast;
 use syntax::ast_map;
@@ -70,7 +71,7 @@ pub fn check_crate(tcx: &ty::ctxt,
                    krate: &ast::Crate) {
     let mut bccx = BorrowckCtxt {
         tcx: tcx,
-        stats: @BorrowStats {
+        stats: box(GC) BorrowStats {
             loaned_paths_same: Cell::new(0),
             loaned_paths_imm: Cell::new(0),
             stable_paths: Cell::new(0),
@@ -155,7 +156,7 @@ pub struct BorrowckCtxt<'a> {
     tcx: &'a ty::ctxt,
 
     // Statistics:
-    stats: @BorrowStats
+    stats: Gc<BorrowStats>,
 }
 
 pub struct BorrowStats {

src/librustc/middle/check_match.rs

@@ -19,7 +19,7 @@ use middle::ty;
 use util::ppaux::ty_to_str;
 
 use std::cmp;
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 use std::iter;
 use syntax::ast::*;
 use syntax::ast_util::{is_unguarded, walk_pat};

src/librustc/middle/check_static.rs

@@ -123,7 +123,7 @@ impl<'a> Visitor<bool> for CheckStaticVisitor<'a> {
             ast::ExprUnary(ast::UnUniq, _) |
             ast::ExprVstore(_, ast::ExprVstoreUniq) => {
                 self.tcx.sess.span_err(e.span,
-                                   "static items are not allowed to have owned pointers");
+                                   "static items are not allowed to have custom pointers");
             }
             _ => {
                 let node_ty = ty::node_id_to_type(self.tcx, e.id);

src/librustc/middle/kind.rs

@@ -245,9 +245,12 @@ pub fn check_expr(cx: &mut Context, e: &Expr) {
     check_bounds_on_type_parameters(cx, e);
 
     match e.node {
-        ExprUnary(UnBox, ref interior) => {
-            let interior_type = ty::expr_ty(cx.tcx, &**interior);
-            let _ = check_static(cx.tcx, interior_type, interior.span);
+        ExprBox(ref loc, ref interior) => {
+            let def = ty::resolve_expr(cx.tcx, &**loc);
+            if Some(def.def_id()) == cx.tcx.lang_items.managed_heap() {
+                let interior_type = ty::expr_ty(cx.tcx, &**interior);
+                let _ = check_static(cx.tcx, interior_type, interior.span);
+            }
         }
         ExprCast(ref source, _) => {
             let source_ty = ty::expr_ty(cx.tcx, &**source);

src/librustc/middle/resolve.rs

@@ -35,7 +35,7 @@ use syntax::visit::Visitor;
 
 use std::collections::{HashMap, HashSet};
 use std::cell::{Cell, RefCell};
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 use std::mem::replace;
 use std::rc::{Rc, Weak};
 use std::uint;

src/librustc/middle/trans/_match.rs

@@ -226,7 +226,7 @@ use util::ppaux::{Repr, vec_map_to_str};
 use std::collections::HashMap;
 use std::cell::Cell;
 use std::rc::Rc;
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 use syntax::ast;
 use syntax::ast::Ident;
 use syntax::ast_util::path_to_ident;

src/librustc/middle/typeck/infer/error_reporting.rs

@@ -60,6 +60,7 @@ time of error detection.
 */
 
 use std::collections::HashSet;
+use std::gc::GC;
 use middle::def;
 use middle::subst;
 use middle::ty;

src/librustdoc/clean/mod.rs

@@ -32,7 +32,7 @@ use rustc::middle::ty;
 
 use std::rc::Rc;
 use std::u32;
-use std::gc::Gc;
+use std::gc::{Gc, GC};
 
 use core;
 use doctree;

src/librustdoc/core.rs

@@ -18,6 +18,7 @@ use syntax::parse::token;
 use syntax;
 
 use std::cell::RefCell;
+use std::gc::GC;
 use std::os;
 use std::collections::{HashMap, HashSet};
 

src/librustdoc/test.rs

@@ -10,12 +10,13 @@
 
 use std::cell::RefCell;
 use std::char;
-use std::io;
+use std::dynamic_lib::DynamicLibrary;
+use std::gc::GC;
 use std::io::{Command, TempDir};
+use std::io;
 use std::os;
 use std::str;
 use std::string::String;
-use std::dynamic_lib::DynamicLibrary;
 
 use std::collections::{HashSet, HashMap};
 use testing;