1 files changed, 63 insertions, 0 deletions
diff --git a/src/cmd/go/discovery.go b/src/cmd/go/discovery.go
new file mode 100644
index 000000000..d9f930867
--- /dev/null
+++ b/src/cmd/go/discovery.go
@@ -0,0 +1,63 @@
+// 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.
+
+// +build !cmd_go_bootstrap
+
+// This code is compiled into the real 'go' binary, but it is not
+// compiled into the binary that is built during all.bash, so as
+// to avoid needing to build net (and thus use cgo) during the
+// bootstrap process.
+
+package main
+
+import (
+	"encoding/xml"
+	"io"
+	"strings"
+)
+
+// parseMetaGoImports returns meta imports from the HTML in r.
+// Parsing ends at the end of the <head> section or the beginning of the <body>.
+func parseMetaGoImports(r io.Reader) (imports []metaImport) {
+	d := xml.NewDecoder(r)
+	d.Strict = false
+	for {
+		t, err := d.Token()
+		if err != nil {
+			return
+		}
+		if e, ok := t.(xml.StartElement); ok && strings.EqualFold(e.Name.Local, "body") {
+			return
+		}
+		if e, ok := t.(xml.EndElement); ok && strings.EqualFold(e.Name.Local, "head") {
+			return
+		}
+		e, ok := t.(xml.StartElement)
+		if !ok || !strings.EqualFold(e.Name.Local, "meta") {
+			continue
+		}
+		if attrValue(e.Attr, "name") != "go-import" {
+			continue
+		}
+		if f := strings.Fields(attrValue(e.Attr, "content")); len(f) == 3 {
+			imports = append(imports, metaImport{
+				Prefix:   f[0],
+				VCS:      f[1],
+				RepoRoot: f[2],
+			})
+		}
+	}
+	return
+}
+
+// attrValue returns the attribute value for the case-insensitive key
+// `name', or the empty string if nothing is found.
+func attrValue(attrs []xml.Attr, name string) string {
+	for _, a := range attrs {
+		if strings.EqualFold(a.Name.Local, name) {
+			return a.Value
+		}
+	}
+	return ""
+}