From 97cab903afbc887c70d6efdd4d382ab0427267bd Mon Sep 17 00:00:00 2001
From: Ken Thompson <ken@golang.org>
Date: Sun, 13 Jul 2008 16:20:27 -0700
Subject: [PATCH] chan

SVN=126959
---
 src/cmd/gc/subr.c  |  1 +
 src/cmd/gc/walk.c  | 64 +++++++++++++++++++++++++++++++++++++++++++---
 src/runtime/chan.c | 28 ++++++++++++++++++++
 3 files changed, 89 insertions(+), 4 deletions(-)

diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index 7816b45d05..7ee6314e2e 100644
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -1364,6 +1364,7 @@ deep(Type *t)
 
 	case TPTR32:
 	case TPTR64:
+	case TCHAN:
 		nt = shallow(t);
 		nt->type = deep(t->type);
 		break;
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 5d39554758..c293568c54 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -1700,12 +1700,16 @@ chanop(Node *n, int top)
 		break;
 
 	case OAS:
-		// chansend(hchan *chan any, elem any);
+		cl = listcount(n->left);
+		cr = listcount(n->right);
 
-//dump("assign1", n);
-		if(n->left->op != OSEND)
+		if(cl == 2 && cr == 1 && n->right->op == ORECV)
+			goto recv2;
+		if(cl != 1 || cr != 1 || n->left->op != OSEND)
 			goto shape;
 
+		// chansend(hchan *chan any, elem any);
+
 		t = fixchan(n->left->left->type);
 		if(t == T)
 			break;
@@ -1716,14 +1720,54 @@ chanop(Node *n, int top)
 		r = nod(OLIST, a, r);
 
 		on = syslook("chansend", 1);
-
+print("type=%lT\n", t);
+print("on=%lT\n", on->type);
 		argtype(on, t->type);	// any-1
+print("on=%lT\n", on->type);
 		argtype(on, t->type);	// any-2
+print("on=%lT\n", on->type);
 
 		r = nod(OCALL, on, r);
 		walktype(r, Erv);
 		break;
 
+	case ORECV:
+		// chanrecv1(hchan *chan any) (elem any);
+
+		t = fixchan(n->left->type);
+		if(t == T)
+			break;
+
+		a = n->left;			// chan
+		r = a;
+
+		on = syslook("chanrecv1", 1);
+
+		argtype(on, t->type);	// any-1
+		argtype(on, t->type);	// any-2
+		r = nod(OCALL, on, r);
+		walktype(r, Erv);
+		break;
+
+	recv2:
+		// chanrecv2(hchan *chan any) (elem any, pres bool);
+
+		t = fixchan(n->right->left->type);
+		if(t == T)
+			break;
+
+		a = n->right->left;			// chan
+		r = a;
+
+		on = syslook("chanrecv2", 1);
+
+		argtype(on, t->type);	// any-1
+		argtype(on, t->type);	// any-2
+		r = nod(OCALL, on, r);
+		n->right = r;
+		r = n;
+		walktype(r, Etop);
+		break;
 	}
 	return r;
 
@@ -1950,6 +1994,18 @@ multi:
 		a = old2new(nl->right, types[TBOOL]);
 		n = nod(OLIST, n, a);
 		break;
+
+	case ORECV:
+		if(cl != 2)
+			goto badt;
+		walktype(nr->left, Erv);
+		t = nr->left->type;
+		if(!isptrto(t, TCHAN))
+			goto badt;
+		a = old2new(nl->left, t->type->type);
+		n = a;
+		a = old2new(nl->right, types[TBOOL]);
+		n = nod(OLIST, n, a);
 	}
 	n = rev(n);
 	return n;
diff --git a/src/runtime/chan.c b/src/runtime/chan.c
index b491bbda32..7014ebc657 100644
--- a/src/runtime/chan.c
+++ b/src/runtime/chan.c
@@ -73,3 +73,31 @@ sys·chansend(Hchan* c, ...)
 		prints("\n");
 	}
 }
+
+// chanrecv1(hchan *chan any) (elem any);
+void
+sys·chanrecv1(Hchan* c, ...)
+{
+	byte *ae;
+
+	ae = (byte*)&c + c->eo;
+	if(debug) {
+		prints("chanrecv1: chan=");
+		sys·printpointer(c);
+		prints("\n");
+	}
+}
+
+// chanrecv2(hchan *chan any) (elem any, pres bool);
+void
+sys·chanrecv2(Hchan* c, ...)
+{
+	byte *ae;
+
+	ae = (byte*)&c + c->eo;
+	if(debug) {
+		prints("chanrecv2: chan=");
+		sys·printpointer(c);
+		prints("\n");
+	}
+}
-- 
2.48.1