cmd/go: break after terminal loop condition

After the first time needCostly is set to true, there is no need to
continue checking the remaining args.

Change-Id: I07171ce50d20e2a917117a0f84c442fe978cb274
GitHub-Last-Rev: 6d0c19341b7a85d507c3ec4967bab5f83b0fad8d
GitHub-Pull-Request: golang/go#41859
Reviewed-on: https://go-review.googlesource.com/c/go/+/260638
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Go Bot <gobot@golang.org>

diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index b5a48558fa54fd7e08af043b703b919b9f1c79d9..557e41892135a512a7e1f775fe596cb0a9575744 100644 (file)
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -217,6 +217,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
                needCostly = true
        } else {
                needCostly = false
+       checkCostly:
                for _, arg := range args {
                        switch argKey(arg) {
                        case "CGO_CFLAGS",
@@ -227,6 +228,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
                                "PKG_CONFIG",
                                "GOGCCFLAGS":
                                needCostly = true
+                               break checkCostly
                        }
                }
        }