x/lib: Move x/ref/lib/flags/buildinfo to x/lib/buildinfo
This reduces package nesting, and is also nicer since the
devtools/v23 tool uses this mechanism, and it's better for v23 to
have absolutely no dependencies on x/ref/...
MultiPart: 1/3
Change-Id: Ia65484a884793c721324e3169f23331a5e4fe298
diff --git a/buildinfo/buildinfo.go b/buildinfo/buildinfo.go
new file mode 100644
index 0000000..3960594
--- /dev/null
+++ b/buildinfo/buildinfo.go
@@ -0,0 +1,47 @@
+// Copyright 2015 The Vanadium 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 buildinfo defines a mechanism to inject build-time metadata into
+// binaries.
+package buildinfo
+
+import (
+ "encoding/json"
+ "runtime"
+)
+
+// These variables are filled in at link time, using:
+// -ldflags "-X v.io/x/lib/buildinfo.<varname> <value>"
+var timestamp, username, platform string
+
+// T describes binary metadata.
+type T struct {
+ GoVersion, BuildTimestamp, BuildUser, BuildPlatform string
+}
+
+var info T
+
+func init() {
+ info = T{
+ GoVersion: runtime.Version(),
+ BuildTimestamp: timestamp,
+ BuildUser: username,
+ BuildPlatform: platform,
+ }
+}
+
+// Info returns metadata about the current binary.
+func Info() *T {
+ return &info
+}
+
+// String returns the binary metadata as a JSON-encoded string, under the
+// expectation that clients may want to parse it for specific bits of metadata.
+func (t *T) String() string {
+ jsonT, err := json.Marshal(t)
+ if err != nil {
+ return ""
+ }
+ return string(jsonT)
+}
