Fix bug in bind thunks failing top drop unbound args; add test and adjust rustc to use bind again.

Author: graydon

src/Makefile

@@ -462,6 +462,7 @@ TEST_XFAILS_LLVM := $(TASK_XFAILS) \
                       deep.rs \
                       deref.rs \
                       destructor-ordering.rs \
+                      drop-bind-thunk-args.rs \
                       drop-on-empty-block-exit.rs \
                       export-non-interference.rs \
                       exterior.rs \

src/boot/me/trans.ml

@@ -1640,12 +1640,28 @@ let trans_visitor
         get_element_ptr closure_target_cell Abi.fn_field_code
       in
 
+      let self_args_cell =
+        get_element_ptr all_self_args_cell Abi.calltup_elt_args
+      in
+
+      let self_ty_params_cell =
+        get_element_ptr all_self_args_cell Abi.calltup_elt_ty_params
+      in
+
         merge_bound_args
           self_args_rty callee_args_rty
           arg_slots arg_bound_flags;
         iflog (fun _ -> annotate "call through to closure target fn");
 
         call_code (code_of_cell closure_target_code_cell);
+
+        (* Drop the args we were passed. *)
+        Array.iteri
+          (fun i slot ->
+             let cell = get_element_ptr self_args_cell i in
+               drop_slot self_ty_params_cell cell slot)
+          unbound_slots;
+
         trans_glue_frame_exit fix spill g
 
 

src/comp/middle/trans.rs

@@ -51,7 +51,7 @@ state type fn_ctxt = rec(ValueRef llfn,
 type terminator = fn(@fn_ctxt cx, builder build);
 
 tag cleanup {
-    clean(fn(@block_ctxt cx, ValueRef v), ValueRef);
+    clean(fn(@block_ctxt cx));
 }
 
 state type block_ctxt = rec(BasicBlockRef llbb,
@@ -303,8 +303,7 @@ fn trans_lit(@block_ctxt cx, &ast.lit lit) -> ValueRef {
                                   vec(p2i(C_str(cx.fcx.tcx, s)),
                                       C_int(len)));
             v = cx.build.IntToPtr(v, T_ptr(T_str()));
-            auto f = drop_str;
-            cx.cleanups += vec(clean(f, v));
+            cx.cleanups += vec(clean(bind drop_str(_, v)));
             ret v;
         }
     }
@@ -496,8 +495,8 @@ fn trans_block(@fn_ctxt cx, &ast.block b, terminator term) {
 
     for (cleanup c in bcx.cleanups) {
         alt (c) {
-            case (clean(?cfn, ?v)) {
-                cfn(bcx, v);
+            case (clean(?cfn)) {
+                cfn(bcx);
             }
         }
     }

src/rt/rust_builtin.cpp

@@ -338,6 +338,10 @@ debug_fn(rust_task *task, type_desc *t, rust_fn *fn)
     debug_tydesc_helper(task, t);
     task->log(rust_log::STDLIB, "  thunk at 0x%" PRIxPTR, fn->thunk);
     task->log(rust_log::STDLIB, "  closure at 0x%" PRIxPTR, fn->closure);
+    if (fn->closure) {
+        task->log(rust_log::STDLIB, "    refcount %" PRIdPTR,
+                  fn->closure->ref_count);
+    }
 }
 
 extern "C" CDECL void *

src/test/run-pass/drop-bind-thunk-args.rs

@@ -0,0 +1,8 @@
+fn f(@int x) { }
+
+fn main() {
+  auto x = @10;
+  auto ff = bind f(_);
+  ff(x);
+  ff(x);
+}