build: add build comments to core packages
The go/build package already recognizes
system-specific file names like
mycode_darwin.go
mycode_darwin_386.go
mycode_386.s
However, it is also common to write files that
apply to multiple architectures, so a recent CL added
to go/build the ability to process comments
listing a set of conditions for building. For example:
// +build darwin freebsd openbsd/386
says that this file should be compiled only on
OS X, FreeBSD, or 32-bit x86 OpenBSD systems.
These conventions are not yet documented
(hence this long CL description).
This CL adds build comments to the multi-system
files in the core library, a step toward making it
possible to use go/build to build them.
With this change go/build can handle crypto/rand,
exec, net, path/filepath, os/user, and time.
os and syscall need additional adjustments.
R=golang-dev, r, gri, r, gustavo
CC=golang-dev
https://golang.org/cl/5011046
diff --git a/src/pkg/net/udpsock_posix.go b/src/pkg/net/udpsock_posix.go
index 1dc79f7..06298ee 100644
--- a/src/pkg/net/udpsock_posix.go
+++ b/src/pkg/net/udpsock_posix.go
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build darwin freebsd linux openbsd windows
+
// UDP sockets
package net
