cmd/gc: fix initialization order involving method calls.

They were previously ignored when deciding order and
detecting dependency loops.
Fixes #3824.

R=rsc, golang-dev
CC=golang-dev, remy
https://golang.org/cl/6455055

src/cmd/gc/reflect.c

@@ -130,7 +130,12 @@ methodfunc(Type *f, Type *receiver)
 		out = list(out, d);
 	}
 
-	return functype(N, in, out);
+	t = functype(N, in, out);
+	if(f->nname) {
+		// Link to name of original method function.
+		t->nname = f->nname;
+	}
+	return t;
 }
 
 /*

src/cmd/gc/sinit.c

@@ -36,6 +36,10 @@ init1(Node *n, NodeList **out)
 	init1(n->right, out);
 	for(l=n->list; l; l=l->next)
 		init1(l->n, out);
+	if(n->left && n->type && n->left->op == OTYPE && n->class == PFUNC) {
+		// Definitions for method expressions are stored in type->nname.
+		init1(n->type->nname, out);
+	}
 
 	if(n->op != ONAME)
 		return;
@@ -170,6 +174,8 @@ init2(Node *n, NodeList **out)
 	
 	if(n->op == OCLOSURE)
 		init2list(n->closure->nbody, out);
+	if(n->op == ODOTMETH)
+		init2(n->type->nname, out);
 }
 
 static void

test/fixedbugs/bug446.go

@@ -0,0 +1,36 @@
+// run
+
+// Copyright 2012 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.
+
+// Issue 3824.
+// Method calls are ignored when deciding initialization
+// order.
+
+package main
+
+type T int
+
+func (r T) Method1() int { return a }
+func (r T) Method2() int { return b }
+
+// dummy1 and dummy2 must be initialized after a and b.
+var dummy1 = T(0).Method1()
+var dummy2 = T.Method2(0)
+
+// Use a function call to force generating code.
+var a = identity(1)
+var b = identity(2)
+
+func identity(a int) int { return a }
+
+func main() {
+	if dummy1 != 1 {
+		panic("dummy1 != 1")
+	}
+	if dummy2 != 2 {
+		panic("dummy2 != 2")
+	}
+}
+