librustc: Remove the concept of modes from the compiler.

This commit does not remove `ty::arg`, although that should be
possible to do now.

8 files changed, 52 insertions, 99 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 4137b3b8aa1..ba6fe1cda4f 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -198,7 +198,7 @@ pub enum def {
     def_mod(def_id),
     def_foreign_mod(def_id),
     def_const(def_id),
-    def_arg(node_id, mode, bool /* is_mutbl */),
+    def_arg(node_id, bool /* is_mutbl */),
     def_local(node_id, bool /* is_mutbl */),
     def_variant(def_id /* enum */, def_id /* variant */),
     def_ty(def_id),
@@ -417,43 +417,6 @@ pub enum unop {
     neg
 }
 
-// Generally, after typeck you can get the inferred value
-// using ty::resolved_T(...).
-#[auto_encode]
-#[auto_decode]
-#[deriving(Eq)]
-pub enum inferable<T> {
-    expl(T),
-    infer(node_id)
-}
-
-impl<T:to_bytes::IterBytes> to_bytes::IterBytes for inferable<T> {
-    fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) {
-        match *self {
-          expl(ref t) =>
-          to_bytes::iter_bytes_2(&0u8, t, lsb0, f),
-
-          infer(ref n) =>
-          to_bytes::iter_bytes_2(&1u8, n, lsb0, f),
-        }
-    }
-}
-
-// "resolved" mode: the real modes.
-#[auto_encode]
-#[auto_decode]
-#[deriving(Eq)]
-pub enum rmode { by_ref, by_copy }
-
-impl to_bytes::IterBytes for rmode {
-    fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) {
-        (*self as u8).iter_bytes(lsb0, f)
-    }
-}
-
-// inferable mode.
-pub type mode = inferable<rmode>;
-
 pub type stmt = spanned<stmt_>;
 
 #[auto_encode]
@@ -941,7 +904,6 @@ pub struct inline_asm {
 #[auto_decode]
 #[deriving(Eq)]
 pub struct arg {
-    mode: mode,
     is_mutbl: bool,
     ty: @Ty,
     pat: @pat,
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index c28d369e7f8..148b713a4f5 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -58,7 +58,7 @@ pub fn def_id_of_def(d: def) -> def_id {
       def_use(id) | def_struct(id) | def_trait(id) => {
         id
       }
-      def_arg(id, _, _) | def_local(id, _) | def_self(id, _) | def_self_ty(id)
+      def_arg(id, _) | def_local(id, _) | def_self(id, _) | def_self_ty(id)
       | def_upvar(id, _, _, _) | def_binding(id, _) | def_region(id)
       | def_typaram_binder(id) | def_label(id) => {
         local_def(id)
diff --git a/src/libsyntax/ext/auto_encode.rs b/src/libsyntax/ext/auto_encode.rs
index 0d451c66edb..da7b9570131 100644
--- a/src/libsyntax/ext/auto_encode.rs
+++ b/src/libsyntax/ext/auto_encode.rs
@@ -608,7 +608,6 @@ fn mk_ser_method(
     };
 
     let ser_inputs = ~[ast::arg {
-        mode: ast::infer(cx.next_id()),
         is_mutbl: false,
         ty: ty_s,
         pat: @ast::pat {
@@ -670,20 +669,22 @@ fn mk_deser_method(
         span: span,
     };
 
-    let deser_inputs = ~[ast::arg {
-        mode: ast::infer(cx.next_id()),
-        is_mutbl: false,
-        ty: ty_d,
-        pat: @ast::pat {
+    let deser_inputs = ~[
+        ast::arg {
+            is_mutbl: false,
+            ty: ty_d,
+            pat: @ast::pat {
+                id: cx.next_id(),
+                node: ast::pat_ident(ast::bind_by_copy,
+                                     ast_util::ident_to_path(span,
+                                                             cx.ident_of(
+                                                                ~"__d")),
+                                     None),
+                span: span,
+            },
             id: cx.next_id(),
-            node: ast::pat_ident(
-                ast::bind_by_copy,
-                ast_util::ident_to_path(span, cx.ident_of(~"__d")),
-                None),
-            span: span,
-        },
-        id: cx.next_id(),
-    }];
+        }
+    ];
 
     let deser_decl = ast::fn_decl {
         inputs: deser_inputs,
@@ -1120,7 +1121,6 @@ fn mk_enum_deser_body(
         ast::expr_fn_block(
             ast::fn_decl {
                 inputs: ~[ast::arg {
-                    mode: ast::infer(ext_cx.next_id()),
                     is_mutbl: false,
                     ty: @ast::Ty {
                         id: ext_cx.next_id(),
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index c4c2fed778f..4c876669f47 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -419,7 +419,6 @@ pub fn mk_arg(cx: @ext_ctxt,
            -> ast::arg {
     let arg_pat = mk_pat_ident(cx, span, ident);
     ast::arg {
-        mode: ast::infer(cx.next_id()),
         is_mutbl: false,
         ty: ty,
         pat: arg_pat,
diff --git a/src/libsyntax/ext/pipes/ast_builder.rs b/src/libsyntax/ext/pipes/ast_builder.rs
index ede3711b052..deaf1b1c754 100644
--- a/src/libsyntax/ext/pipes/ast_builder.rs
+++ b/src/libsyntax/ext/pipes/ast_builder.rs
@@ -196,7 +196,6 @@ impl ext_ctxt_ast_builder for @ext_ctxt {
 
     fn arg(&self, name: ident, ty: @ast::Ty) -> ast::arg {
         ast::arg {
-            mode: ast::infer(self.next_id()),
             is_mutbl: false,
             ty: ty,
             pat: @ast::pat {
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index da6d0e8bf7b..cee1f531176 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -105,7 +105,6 @@ fn fold_attribute_(at: attribute, fld: @ast_fold) -> attribute {
 //used in noop_fold_foreign_item and noop_fold_fn_decl
 fn fold_arg_(a: arg, fld: @ast_fold) -> arg {
     ast::arg {
-        mode: a.mode,
         is_mutbl: a.is_mutbl,
         ty: fld.fold_ty(a.ty),
         pat: fld.fold_pat(a.pat),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 30275436c06..ae374808270 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -17,10 +17,10 @@ use ast::{RegionTyParamBound, TraitTyParamBound};
 use ast::{provided, public, purity};
 use ast::{_mod, add, arg, arm, attribute, bind_by_ref, bind_infer};
 use ast::{bind_by_copy, bitand, bitor, bitxor, blk};
-use ast::{blk_check_mode, box, by_copy, by_ref};
+use ast::{blk_check_mode, box};
 use ast::{crate, crate_cfg, decl, decl_item};
 use ast::{decl_local, default_blk, deref, quot, enum_def};
-use ast::{expl, expr, expr_, expr_addr_of, expr_match, expr_again};
+use ast::{expr, expr_, expr_addr_of, expr_match, expr_again};
 use ast::{expr_assign, expr_assign_op, expr_binary, expr_block};
 use ast::{expr_break, expr_call, expr_cast, expr_copy, expr_do_body};
 use ast::{expr_field, expr_fn_block, expr_if, expr_index};
@@ -32,13 +32,13 @@ use ast::{expr_vstore_slice, expr_vstore_box};
 use ast::{expr_vstore_mut_slice, expr_while, extern_fn, field, fn_decl};
 use ast::{expr_vstore_uniq, TyClosure, TyBareFn, Onceness, Once, Many};
 use ast::{foreign_item, foreign_item_const, foreign_item_fn, foreign_mod};
-use ast::{ident, impure_fn, infer, inherited, item, item_, item_const};
+use ast::{ident, impure_fn, inherited, item, item_, item_const};
 use ast::{item_const, item_enum, item_fn, item_foreign_mod, item_impl};
 use ast::{item_mac, item_mod, item_struct, item_trait, item_ty, lit, lit_};
 use ast::{lit_bool, lit_float, lit_float_unsuffixed, lit_int};
 use ast::{lit_int_unsuffixed, lit_nil, lit_str, lit_uint, local, m_const};
 use ast::{m_imm, m_mutbl, mac_, mac_invoc_tt, matcher, match_nonterminal};
-use ast::{match_seq, match_tok, method, mode, mt, mul, mutability};
+use ast::{match_seq, match_tok, method, mt, mul, mutability};
 use ast::{named_field, neg, node_id, noreturn, not, pat, pat_box, pat_enum};
 use ast::{pat_ident, pat_lit, pat_range, pat_region, pat_struct};
 use ast::{pat_tup, pat_uniq, pat_wild, private};
@@ -765,22 +765,22 @@ pub impl Parser {
     }
 
     // parse an optional mode.
-    fn parse_arg_mode(&self) -> mode {
+    // XXX: Remove after snapshot.
+    fn parse_arg_mode(&self) {
         if self.eat(&token::BINOP(token::MINUS)) {
             self.obsolete(*self.span, ObsoleteMode);
-            expl(by_copy)
         } else if self.eat(&token::ANDAND) {
-            expl(by_ref)
+            // Ignore.
         } else if self.eat(&token::BINOP(token::PLUS)) {
             if self.eat(&token::BINOP(token::PLUS)) {
                 // ++ mode is obsolete, but we need a snapshot
                 // to stop parsing it.
-                expl(by_copy)
+                // Ignore.
             } else {
-                expl(by_copy)
+                // Ignore.
             }
         } else {
-            infer(self.get_id())
+            // Ignore.
         }
     }
 
@@ -810,16 +810,14 @@ pub impl Parser {
     // This version of parse arg doesn't necessarily require
     // identifier names.
     fn parse_arg_general(&self, require_name: bool) -> arg {
-        let m;
         let mut is_mutbl = false;
         let pat = if require_name || self.is_named_argument() {
-            m = self.parse_arg_mode();
+            self.parse_arg_mode();
             is_mutbl = self.eat_keyword(&~"mut");
             let pat = self.parse_pat(false);
             self.expect(&token::COLON);
             pat
         } else {
-            m = infer(self.get_id());
             ast_util::ident_to_pat(self.get_id(),
                                    *self.last_span,
                                    special_idents::invalid)
@@ -827,8 +825,12 @@ pub impl Parser {
 
         let t = self.parse_ty(false);
 
-        ast::arg { mode: m, is_mutbl: is_mutbl,
-                  ty: t, pat: pat, id: self.get_id() }
+        ast::arg {
+            is_mutbl: is_mutbl,
+            ty: t,
+            pat: pat,
+            id: self.get_id(),
+        }
     }
 
     // parse a single function argument
@@ -838,7 +840,7 @@ pub impl Parser {
 
     // parse an argument in a lambda header e.g. |arg, arg|
     fn parse_fn_block_arg(&self) -> arg_or_capture_item {
-        let m = self.parse_arg_mode();
+        self.parse_arg_mode();
         let is_mutbl = self.eat_keyword(&~"mut");
         let pat = self.parse_pat(false);
         let t = if self.eat(&token::COLON) {
@@ -851,7 +853,6 @@ pub impl Parser {
             }
         };
         either::Left(ast::arg {
-            mode: m,
             is_mutbl: is_mutbl,
             ty: t,
             pat: pat,
@@ -2440,18 +2441,21 @@ pub impl Parser {
 
     // used by the copy foo and ref foo patterns to give a good
     // error message when parsing mistakes like ref foo(a,b)
-    fn parse_pat_ident(&self, refutable: bool,
-                       binding_mode: ast::binding_mode) -> ast::pat_ {
+    fn parse_pat_ident(&self,
+                       refutable: bool,
+                       binding_mode: ast::binding_mode)
+                       -> ast::pat_ {
         if !is_plain_ident(&*self.token) {
-            self.span_fatal(
-                *self.last_span,
-                ~"expected identifier, found path");
+            self.span_fatal(*self.last_span,
+                            ~"expected identifier, found path");
         }
         // why a path here, and not just an identifier?
         let name = self.parse_path_without_tps();
         let sub = if self.eat(&token::AT) {
             Some(self.parse_pat(refutable))
-        } else { None };
+        } else {
+            None
+        };
 
         // just to be friendly, if they write something like
         //   ref Some(i)
@@ -4406,10 +4410,11 @@ pub impl Parser {
     // text that can't be parsed as an item
     // - mod_items uses extern_mod_allowed = true
     // - block_tail_ uses extern_mod_allowed = false
-    fn parse_items_and_view_items(&self, first_item_attrs: ~[attribute],
+    fn parse_items_and_view_items(&self,
+                                  first_item_attrs: ~[attribute],
                                   mut extern_mod_allowed: bool,
                                   macros_allowed: bool)
-                                -> ParsedItemsAndViewItems {
+                                  -> ParsedItemsAndViewItems {
         let mut attrs = vec::append(first_item_attrs,
                                     self.parse_outer_attributes());
         // First, parse view items.
@@ -4539,8 +4544,11 @@ pub impl Parser {
 
     fn parse_str(&self) -> @~str {
         match *self.token {
-          token::LIT_STR(s) => { self.bump(); self.id_to_str(s) }
-          _ =>  self.fatal(~"expected string literal")
+            token::LIT_STR(s) => {
+                self.bump();
+                self.id_to_str(s)
+            }
+            _ =>  self.fatal(~"expected string literal")
         }
     }
 }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 918fc805194..337355304d4 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1718,19 +1718,6 @@ pub fn print_fn_block_args(s: @ps, decl: &ast::fn_decl) {
     maybe_print_comment(s, decl.output.span.lo);
 }
 
-pub fn mode_to_str(m: ast::mode) -> ~str {
-    match m {
-      ast::expl(ast::by_ref) => ~"&&",
-      ast::expl(ast::by_copy) => ~"+",
-      ast::infer(_) => ~""
-    }
-}
-
-pub fn print_arg_mode(s: @ps, m: ast::mode) {
-    let ms = mode_to_str(m);
-    if ms != ~"" { word(s.s, ms); }
-}
-
 pub fn print_bounds(s: @ps, bounds: @OptVec<ast::TyParamBound>) {
     if !bounds.is_empty() {
         word(s.s, ~":");
@@ -1879,7 +1866,6 @@ pub fn print_mt(s: @ps, mt: &ast::mt) {
 
 pub fn print_arg(s: @ps, input: ast::arg) {
     ibox(s, indent_unit);
-    print_arg_mode(s, input.mode);
     if input.is_mutbl {
         word_space(s, ~"mut");
     }