code review 4515167: gc: elide call to runtime.closure for function literals...

src/cmd/gc/walk.c

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include        "go.h"
 
 static  Node*   walkprint(Node*, NodeList**, int);
 static  Node*   conv(Node*, Type*);
 static  Node*   mapfn(char*, Type*);
 static  Node*   makenewvar(Type*, NodeList**, Node**);
@@ skipping 752 matching lines @@
                 walkexpr(&n->left, init);
                 walkexprlist(n->list, init);
                 ll = ascompatte(n->op, n->isddd, getinarg(t), n->list, 0, init);
                 n->list = reorder1(ll);
                 goto ret;
 
         case OCALLFUNC:
                 t = n->left->type;
                 if(n->list && n->list->n->op == OAS)
                         goto ret;
-                walkexpr(&n->left, init);
+
+                if(n->left->op == OCLOSURE) {
+                        walkcallclosure(n, init);
+                        t = n->left->type;
+                } else
+                        walkexpr(&n->left, init);
+
                 walkexprlist(n->list, init);
+
                 ll = ascompatte(n->op, n->isddd, getinarg(t), n->list, 0, init);
                 n->list = reorder1(ll);
                 if(isselect(n)) {
                         // special prob with selectsend and selectrecv:
                         // if chan is nil, they don't know big the channel
                         // element is and therefore don't know how to find
                         // the output bool, so we clear it before the call.
                         Node *b;
                         b = nodbool(0);
                         typecheck(&b, Erv);
@@ skipping 1656 matching lines @@
                 l = list(l, nod(OAS, nx, a->n));        // s[n] = arg
                 if (a->next != nil)
                         l = list(l, nod(OAS, nn, nod(OADD, nn, nodintconst(1))));  // n = n + 1
         }
 
         typechecklist(l, Etop);
         walkstmtlist(l);
         *init = concat(*init, l);
         return ns;
 }