cmd/go: allow underscores in tool name

        Otherwise we can't invoke go_bootstrap directly.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5900061

diff --git a/src/cmd/go/tool.go b/src/cmd/go/tool.go
index 9776d3359e836a4384d84df76187ce564b11432f..cb463a2e7179e99897a1492a3b4ac599d500cdc0 100644 (file)
--- a/src/cmd/go/tool.go
+++ b/src/cmd/go/tool.go
@@ -59,10 +59,10 @@ func runTool(cmd *Command, args []string) {
                return
        }
        toolName := args[0]
-       // The tool name must be lower-case letters and numbers.
+       // The tool name must be lower-case letters, numbers or underscores.
        for _, c := range toolName {
                switch {
-               case 'a' <= c && c <= 'z', '0' <= c && c <= '9':
+               case 'a' <= c && c <= 'z', '0' <= c && c <= '9', c == '_':
                default:
                        fmt.Fprintf(os.Stderr, "go tool: bad tool name %q\n", toolName)
                        setExitStatus(2)