cmd/go: run the real test binary if the test link was cached

Fixes #23150

Change-Id: Ia82c2d482a8dc53cabb3f173e4301fee66288821
Reviewed-on: https://go-review.googlesource.com/84376
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/go/go_test.go

@@ -5590,3 +5590,24 @@ func init() {}
 	tg.run("build", "-o", tg.path("a.exe"), "a")
 	tg.run("test", "a")
 }
+
+// Issue 23150.
+func TestCpuprofileTwice(t *testing.T) {
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.parallel()
+	tg.tempFile("prof/src/x/x_test.go", `
+		package x_test
+		import (
+			"testing"
+			"time"
+		)
+		func TestSleep(t *testing.T) { time.Sleep(10 * time.Millisecond) }`)
+	tg.setenv("GOPATH", tg.path("prof"))
+	bin := tg.path("x.test")
+	out := tg.path("cpu.out")
+	tg.run("test", "-o="+bin, "-cpuprofile="+out, "x")
+	tg.must(os.Remove(out))
+	tg.run("test", "-o="+bin, "-cpuprofile="+out, "x")
+	tg.mustExist(out)
+}

src/cmd/go/internal/test/test.go

@@ -1321,7 +1321,7 @@ func (c *runCache) builderRunTest(b *work.Builder, a *work.Action) error {
 	if !c.disableCache && len(execCmd) == 0 {
 		testlogArg = []string{"-test.testlogfile=" + a.Objdir + "testlog.txt"}
 	}
-	args := str.StringList(execCmd, a.Deps[0].Target, testlogArg, testArgs)
+	args := str.StringList(execCmd, a.Deps[0].BuiltTarget(), testlogArg, testArgs)
 
 	if testCoverProfile != "" {
 		// Write coverage to temporary profile, for merging later.

src/cmd/go/internal/work/action.go

@@ -98,6 +98,10 @@ func (a *Action) BuildContentID() string { return contentID(a.buildID) }
 // BuildID returns a's build ID.
 func (a *Action) BuildID() string { return a.buildID }
 
+// BuiltTarget returns the actual file that was built. This differs
+// from Target when the result was cached.
+func (a *Action) BuiltTarget() string { return a.built }
+
 // An actionQueue is a priority queue of actions.
 type actionQueue []*Action