os: drop the Wait function and the options to Process.Wait

They are portability problems and the options are almost always zero in practice anyway.

R=golang-dev, dsymonds, r, bradfitz
CC=golang-dev
https://golang.org/cl/5688046

2 files changed, 97 insertions, 0 deletions

diff --git a/src/cmd/fix/oswait.go b/src/cmd/fix/oswait.go
new file mode 100644
index 0000000000..fdc23f8537
--- /dev/null
+++ b/src/cmd/fix/oswait.go
@@ -0,0 +1,56 @@
+// Copyright 2011 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 (
+	"go/ast"
+)
+
+func init() {
+	register(oswaitFix)
+}
+
+var oswaitFix = fix{
+	"oswait",
+	"2012-02-20",
+	oswait,
+	`Delete options from os.Wait. If the option is the literal 0, rewrite the call.
+
+http://codereview.appspot.com/5688046
+`,
+}
+
+func oswait(f *ast.File) bool {
+	if !imports(f, "os") {
+		return false
+	}
+
+	fixed := false
+
+	walk(f, func(n interface{}) {
+		call, ok := n.(*ast.CallExpr)
+		if !ok {
+			return
+		}
+		if !isPkgDot(call.Fun, "os", "Wait") {
+			return
+		}
+		args := call.Args
+		const warning = "call to Process.Wait must be fixed manually"
+		if len(args) != 1 {
+			// Shouldn't happen, but check.
+			warn(call.Pos(), warning)
+			return
+		}
+		if basicLit, ok := args[0].(*ast.BasicLit); !ok || basicLit.Value != "0" {
+			warn(call.Pos(), warning)
+			return
+		}
+		call.Args = nil
+		fixed = true
+	})
+
+	return fixed
+}
diff --git a/src/cmd/fix/oswait_test.go b/src/cmd/fix/oswait_test.go
new file mode 100644
index 0000000000..baff017487
--- /dev/null
+++ b/src/cmd/fix/oswait_test.go
@@ -0,0 +1,41 @@
+// Copyright 2011 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
+
+func init() {
+	addTestCases(oswaitTests, oswait)
+}
+
+var oswaitTests = []testCase{
+	{
+		Name: "oswait.0",
+		In: `package main
+
+import (
+	"os"
+)
+
+func f() {
+	os.Wait()
+	os.Wait(0)
+	os.Wait(1)
+	os.Wait(A | B)
+}
+`,
+		Out: `package main
+
+import (
+	"os"
+)
+
+func f() {
+	os.Wait()
+	os.Wait()
+	os.Wait(1)
+	os.Wait(A | B)
+}
+`,
+	},
+}