Remove autoderef for calls

We were only using it in a single place, and there for no discernable reason
(probably as part of the bare-fn-vals-are-not-copyable plan). It seems more
surprising than useful.

Author: marijnh

src/comp/front/test.rs

@@ -10,7 +10,7 @@ import front::attr;
 
 export modify_for_testing;
 
-type node_id_gen = @fn() -> ast::node_id;
+type node_id_gen = fn() -> ast::node_id;
 
 type test = {path: [ast::ident], ignore: bool};
 
@@ -29,7 +29,7 @@ fn modify_for_testing(crate: @ast::crate) -> @ast::crate {
     // access to the real next node_id.
     let next_node_id = @mutable 200000;
     let next_node_id_fn =
-        @bind fn (next_node_id: @mutable ast::node_id) -> ast::node_id {
+        bind fn (next_node_id: @mutable ast::node_id) -> ast::node_id {
                   let this_node_id = *next_node_id;
                   *next_node_id += 1;
                   ret this_node_id;

src/comp/middle/alias.rs

@@ -222,7 +222,7 @@ fn cant_copy(cx: ctx, b: binding) -> bool {
 }
 
 fn check_call(cx: ctx, f: @ast::expr, args: [@ast::expr]) -> [binding] {
-    let fty = ty::type_autoderef(cx.tcx, ty::expr_ty(cx.tcx, f));
+    let fty = ty::expr_ty(cx.tcx, f);
     let by_ref = alt ty::ty_fn_ret_style(cx.tcx, fty) {
       ast::return_ref(_, arg_n) { arg_n } _ { 0u }
     };
@@ -685,7 +685,7 @@ fn expr_root(cx: ctx, ex: @ast::expr, autoderef: bool)
     if is_none(path_def_id(cx, base_root.ex)) {
         alt base_root.ex.node {
           ast::expr_call(f, args) {
-            let fty = ty::type_autoderef(cx.tcx, ty::expr_ty(cx.tcx, f));
+            let fty = ty::expr_ty(cx.tcx, f);
             alt ty::ty_fn_ret_style(cx.tcx, fty) {
               ast::return_ref(mut, arg_n) {
                 let arg = args[arg_n - 1u];

src/comp/middle/mut.rs

@@ -219,9 +219,7 @@ fn check_move_rhs(cx: @ctx, src: @expr) {
 }
 
 fn check_call(cx: @ctx, f: @expr, args: [@expr]) {
-    let arg_ts =
-        ty::ty_fn_args(cx.tcx,
-                       ty::type_autoderef(cx.tcx, ty::expr_ty(cx.tcx, f)));
+    let arg_ts = ty::ty_fn_args(cx.tcx, ty::expr_ty(cx.tcx, f));
     let i = 0u;
     for arg_t: ty::arg in arg_ts {
         if arg_t.mode != by_ref { check_lval(cx, args[i], msg_mut_ref); }

src/comp/middle/trans.rs

@@ -3676,9 +3676,8 @@ fn trans_call(in_cx: @block_ctxt, f: @ast::expr,
     // expression because of the hack that allows us to process self-calls
     // with trans_call.
     let fn_expr_ty = ty::expr_ty(bcx_tcx(in_cx), f);
-    let fn_ty = ty::type_autoderef(bcx_tcx(in_cx), fn_expr_ty);
     let by_ref = ast_util::ret_by_ref(ty::ty_fn_ret_style(bcx_tcx(in_cx),
-                                                          fn_ty));
+                                                          fn_expr_ty));
     let cx = new_scope_block_ctxt(in_cx, "call");
     let f_res = trans_lval_gen(cx, f);
     let bcx = f_res.res.bcx;
@@ -3694,10 +3693,7 @@ fn trans_call(in_cx: @block_ctxt, f: @ast::expr,
       none. {
         // It's a closure. We have to autoderef.
         if f_res.is_mem { faddr = load_if_immediate(bcx, faddr, fn_expr_ty); }
-        let res = autoderef(bcx, faddr, fn_expr_ty);
-        bcx = res.bcx;
-
-        let pair = res.val;
+        let pair = faddr;
         faddr = GEP(bcx, pair, [C_int(0), C_int(abi::fn_field_code)]);
         faddr = Load(bcx, faddr);
         let llclosure = GEP(bcx, pair, [C_int(0), C_int(abi::fn_field_box)]);
@@ -3707,7 +3703,8 @@ fn trans_call(in_cx: @block_ctxt, f: @ast::expr,
 
     let ret_ty = ty::node_id_to_type(bcx_tcx(cx), id);
     let args_res =
-        trans_args(bcx, in_cx, llenv, f_res.generic, lliterbody, args, fn_ty);
+        trans_args(bcx, in_cx, llenv, f_res.generic, lliterbody, args,
+                   fn_expr_ty);
     Br(args_res.outer_cx, cx.llbb);
     bcx = args_res.bcx;
     let llargs = args_res.args;

src/comp/middle/typeck.rs

@@ -1488,14 +1488,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt, expr: @ast::expr, unify: unifier,
         // Get the function type.
         let fty = expr_ty(fcx.ccx.tcx, f);
 
-        // We want to autoderef calls but not binds
-        let fty_stripped =
-            alt call_kind {
-              kind_call. { do_autoderef(fcx, sp, fty) }
-              _ { fty }
-            };
-
-        let sty = structure_of(fcx, sp, fty_stripped);
+        let sty = structure_of(fcx, sp, fty);
 
         // Check that we aren't confusing iter calls and fn calls
         alt sty {
@@ -1620,14 +1613,14 @@ fn check_expr_with_unifier(fcx: @fn_ctxt, expr: @ast::expr, unify: unifier,
 
         // Pull the return type out of the type of the function.
         let rt_1;
-        let fty = do_autoderef(fcx, sp, ty::expr_ty(fcx.ccx.tcx, f));
+        let fty = ty::expr_ty(fcx.ccx.tcx, f);
         alt structure_of(fcx, sp, fty) {
           ty::ty_fn(_, _, rt, cf, _) {
             bot |= cf == ast::noreturn;
             rt_1 = rt;
           }
           ty::ty_native_fn(_, _, rt) { rt_1 = rt; }
-          _ { fail "LHS of call expr didn't have a function type?!"; }
+          _ { fcx.ccx.tcx.sess.span_fatal(sp, "calling non-function"); }
         }
         write::ty_only_fixup(fcx, id, rt_1);
         ret bot;

src/test/compile-fail/occurs-check-2.rs

@@ -1,18 +1,18 @@
-fn fix_help<A, @B>(f: @fn(@fn(A) -> B, A) -> B, x: A) -> B {
-    ret f(@bind fix_help(f, _), x);
+fn fix_help<A, @B>(f: fn(fn(A) -> B, A) -> B, x: A) -> B {
+    ret f(bind fix_help(f, _), x);
 }
 
-fn fix<A, @B>(f: @fn(@fn(A) -> B, A) -> B) -> @fn(A) -> B {
-    ret @bind fix_help(f, _);
+fn fix<A, @B>(f: fn(fn(A) -> B, A) -> B) -> fn(A) -> B {
+    ret bind fix_help(f, _);
 }
 
-fn fact_(f: @fn(int) -> int, n: int) -> int {
+fn fact_(f: fn(int) -> int, n: int) -> int {
     // fun fact 0 = 1
     ret if n == 0 { 1 } else { n * f(n - 1) };
 }
 
 fn main() {
-    let fact = fix(@fact_);
+    let fact = fix(fact_);
     assert (fact(5) == 120);
     assert (fact(2) == 2);
 }