t.Parallel()

	// srcPath is intentionally not clean so that the path passed to testcover
	// will not normalize the trailing / to a \ on Windows.
	srcPath := t.TempDir() + string(filepath.Separator) + "\npackage main\nfunc main() { panic(string([]rune{'u', 'h', '-', 'o', 'h'}))\n/*/main.go"
	mainSrc := ` package main

func main() {
	/* nothing here */
	println("ok")
}
`

	// we have instrumented functions.
	if counterStmt == nil && len(p.counterLengths) != 0 {
		panic("internal error: seen functions with regonly/testmain")
	}

	// Emit package name.
	fmt.Fprintf(w, "\npackage %s\n\n", pkgconfig.PkgName)

	// Emit package ID var.
	fmt.Fprintf(w, "\nvar %sP uint32\n", *varVar)

	// Emit all of the counter variables.
	for k := range p.counterLengths {

	case *File:
		file := n
		seenRewrite := make(map[[3]string]string)
		fmt.Fprintf(w, "// Code generated from _gen/%s%s.rules using 'go generate'; DO NOT EDIT.\n", n.Arch.name, n.Suffix)
		fmt.Fprintf(w, "\npackage ssa\n")
		for _, path := range append([]string{
			"fmt",
			"internal/buildcfg",
			"math",
			"cmd/internal/obj",
			"cmd/compile/internal/base",
			"cmd/compile/internal/types",

	}
	if action == "" {
		t.Fatalf("execution recipe not found in GOROOT/test/%s", t.goFileName())
	}

	// Check for build constraints only up to the actual code.
	header, _, ok := strings.Cut(src, "\npackage")
	if !ok {
		header = action // some files are intentionally malformed
	}
	if ok, why := shouldTest(header, goos, goarch); !ok {
		t.Skip(why)
	}

	var args, flags, runenv []string
	var tim int