cmd/link: skip TestBuildFortvOS if the SDK is missing

While we're here, move the test from dwarf_test.go to link_test.go;
it doesn't have anything to do with DWARF.

Should fix the macOS builders with only the Xcode command line tools
installed.

Change-Id: Iaaba1b589f4d778705f7b627f78c2b12388e2b3b
Reviewed-on: https://go-review.googlesource.com/c/go/+/168462
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

src/cmd/link/dwarf_test.go

@@ -171,54 +171,3 @@ func TestDWARFiOS(t *testing.T) {
 	testDWARF(t, "c-archive", true, cc, "CGO_ENABLED=1", "GOOS=darwin", "GOARCH=arm", "GOARM=7")
 	testDWARF(t, "c-archive", true, cc, "CGO_ENABLED=1", "GOOS=darwin", "GOARCH=arm64")
 }
-
-func TestBuildFortvOS(t *testing.T) {
-	testenv.MustHaveCGO(t)
-	testenv.MustHaveGoBuild(t)
-
-	// Only run this on darwin/amd64, where we can cross build for tvOS.
-	if runtime.GOARCH != "amd64" || runtime.GOOS != "darwin" {
-		t.Skip("skipping on non-darwin/amd64 platform")
-	}
-	if err := exec.Command("xcrun", "--help").Run(); err != nil {
-		t.Skipf("error running xcrun, required for iOS cross build: %v", err)
-	}
-
-	sdkPath, err := exec.Command("xcrun", "--sdk", "appletvos", "--show-sdk-path").Output()
-	if err != nil {
-		t.Fatalf("xcrun --sdk appletvos --show-sdk-path failed: %v", err)
-	}
-	CC := []string{
-		"clang",
-		"-arch",
-		"arm64",
-		"-isysroot", strings.TrimSpace(string(sdkPath)),
-		"-mtvos-version-min=12.0",
-		"-fembed-bitcode",
-		"-framework", "CoreFoundation",
-	}
-	lib := filepath.Join("testdata", "lib.go")
-	tmpDir, err := ioutil.TempDir("", "go-link-TestBuildFortvOS")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpDir)
-
-	ar := filepath.Join(tmpDir, "lib.a")
-	cmd := exec.Command(testenv.GoToolPath(t), "build", "-buildmode=c-archive", "-o", ar, lib)
-	cmd.Env = append(os.Environ(),
-		"CGO_ENABLED=1",
-		"GOOS=darwin",
-		"GOARCH=arm64",
-		"CC="+strings.Join(CC, " "),
-	)
-	if out, err := cmd.CombinedOutput(); err != nil {
-		t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)
-	}
-
-	link := exec.Command(CC[0], CC[1:]...)
-	link.Args = append(link.Args, ar, filepath.Join("testdata", "main.m"))
-	if out, err := link.CombinedOutput(); err != nil {
-		t.Fatalf("%v: %v:\n%s", link.Args, err, out)
-	}
-}

src/cmd/link/link_test.go

@@ -7,6 +7,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
+	"runtime"
 	"strings"
 	"testing"
 )
@@ -177,3 +178,54 @@ main.x: relocation target main.zero not defined
 		t.Fatalf("want:\n%sgot:\n%s", want, got)
 	}
 }
+
+func TestBuildFortvOS(t *testing.T) {
+	testenv.MustHaveCGO(t)
+	testenv.MustHaveGoBuild(t)
+
+	// Only run this on darwin/amd64, where we can cross build for tvOS.
+	if runtime.GOARCH != "amd64" || runtime.GOOS != "darwin" {
+		t.Skip("skipping on non-darwin/amd64 platform")
+	}
+	if err := exec.Command("xcrun", "--help").Run(); err != nil {
+		t.Skipf("error running xcrun, required for iOS cross build: %v", err)
+	}
+
+	sdkPath, err := exec.Command("xcrun", "--sdk", "appletvos", "--show-sdk-path").Output()
+	if err != nil {
+		t.Skip("failed to locate appletvos SDK, skipping")
+	}
+	CC := []string{
+		"clang",
+		"-arch",
+		"arm64",
+		"-isysroot", strings.TrimSpace(string(sdkPath)),
+		"-mtvos-version-min=12.0",
+		"-fembed-bitcode",
+		"-framework", "CoreFoundation",
+	}
+	lib := filepath.Join("testdata", "lib.go")
+	tmpDir, err := ioutil.TempDir("", "go-link-TestBuildFortvOS")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	ar := filepath.Join(tmpDir, "lib.a")
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-buildmode=c-archive", "-o", ar, lib)
+	cmd.Env = append(os.Environ(),
+		"CGO_ENABLED=1",
+		"GOOS=darwin",
+		"GOARCH=arm64",
+		"CC="+strings.Join(CC, " "),
+	)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)
+	}
+
+	link := exec.Command(CC[0], CC[1:]...)
+	link.Args = append(link.Args, ar, filepath.Join("testdata", "main.m"))
+	if out, err := link.CombinedOutput(); err != nil {
+		t.Fatalf("%v: %v:\n%s", link.Args, err, out)
+	}
+}