code review 48870044: cmd/link: intial skeleton of linker written in Go

src/cmd/link/link_test.go

+// Copyright 2014 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.
+
+package main
+
+import (
+        "bytes"
+        "debug/goobj"
+        "testing"
+)
+
+func TestLinkHello(t *testing.T) {
+        p := &Prog{
+                GOOS:   "darwin",
+                GOARCH: "amd64",
+                Error:  func(s string) { t.Error(s) },
+        }
+        var buf bytes.Buffer
+        p.link(&buf, "testdata/hello.6")
+        if p.NumError > 0 {
+                return
+        }
+        if len(p.Syms) != 2 || p.Syms[goobj.SymID{"_rt0_go", 0}] == nil || p.Syms[goobj.SymID{"hello", 1}] == nil {
+                t.Errorf("Syms = %v, want [_rt0_go hello<1>]", p.Syms)
+        }
+
+        checkGolden(t, buf.Bytes(), "testdata/link.hello.darwin.amd64")
+
+        // uncomment to leave file behind for execution:
+        // ioutil.WriteFile("a.out", buf.Bytes(), 0777)
+}