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misc/cgo/testcarchive: avoid writing to GOROOT in tests
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Also add a -testwork flag to facilitate debugging the test itself.

Three of the tests of this package invoked 'go install -i
-buildmode=c-archive' in order to generate an archive as well as
multiple C header files.

Unfortunately, the behavior of the '-i' flag is inappropriately broad
for this use-case: it not only generates the library and header files
(as desired), but also attempts to install a number of (unnecessary)
archive files for transitive dependencies to
GOROOT/pkg/$GOOS_$GOARCH_shared, which may not be writable — for
example, if GOROOT is owned by the root user but the test is being run
by a non-root user.

Instead, for now we generate the header files for transitive dependencies
separately by running 'go tool cgo -exportheader'.

In the future, we should consider how to improve the ergonomics for
generating transitive header files without coupling that to
unnecessary library installation.

Updates #28387
Updates #30316
Updates #35715

Change-Id: I3d483f84e22058561efe740aa4885fc3f26137b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/208117
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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Bryan C. Mills committed Nov 22, 2019
1 parent ea18a1c commit c02f3b8
Showing 1 changed file with 157 additions and 82 deletions.
239 changes: 157 additions & 82 deletions misc/cgo/testcarchive/carchive_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,10 @@ var exeSuffix string
var GOOS, GOARCH, GOPATH string
var libgodir string

var testWork bool // If true, preserve temporary directories.

func TestMain(m *testing.M) {
flag.BoolVar(&testWork, "testwork", false, "if true, log and preserve the test's temporary working directory")
flag.Parse()
if testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
fmt.Printf("SKIP - short mode and $GO_BUILDER_NAME not set\n")
Expand All @@ -54,7 +57,11 @@ func testMain(m *testing.M) int {
if err != nil {
log.Panic(err)
}
defer os.RemoveAll(GOPATH)
if testWork {
log.Println(GOPATH)
} else {
defer os.RemoveAll(GOPATH)
}
os.Setenv("GOPATH", GOPATH)

// Copy testdata into GOPATH/src/testarchive, along with a go.mod file
Expand Down Expand Up @@ -164,6 +171,38 @@ func cmdToRun(name string) []string {
return []string{executor, name}
}

// genHeader writes a C header file for the C-exported declarations found in .go
// source files in dir.
//
// TODO(golang.org/issue/35715): This should be simpler.
func genHeader(t *testing.T, header, dir string) {
t.Helper()

// The 'cgo' command generates a number of additional artifacts,
// but we're only interested in the header.
// Shunt the rest of the outputs to a temporary directory.
objDir, err := ioutil.TempDir(GOPATH, "_obj")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(objDir)

files, err := filepath.Glob(filepath.Join(dir, "*.go"))
if err != nil {
t.Fatal(err)
}

cmd := exec.Command("go", "tool", "cgo",
"-objdir", objDir,
"-exportheader", header)
cmd.Args = append(cmd.Args, files...)
t.Log(cmd.Args)
if out, err := cmd.CombinedOutput(); err != nil {
t.Logf("%s", out)
t.Fatal(err)
}
}

func testInstall(t *testing.T, exe, libgoa, libgoh string, buildcmd ...string) {
t.Helper()
cmd := exec.Command(buildcmd[0], buildcmd[1:]...)
Expand All @@ -172,10 +211,12 @@ func testInstall(t *testing.T, exe, libgoa, libgoh string, buildcmd ...string) {
t.Logf("%s", out)
t.Fatal(err)
}
defer func() {
os.Remove(libgoa)
os.Remove(libgoh)
}()
if !testWork {
defer func() {
os.Remove(libgoa)
os.Remove(libgoh)
}()
}

ccArgs := append(cc, "-o", exe, "main.c")
if GOOS == "windows" {
Expand All @@ -191,7 +232,9 @@ func testInstall(t *testing.T, exe, libgoa, libgoh string, buildcmd ...string) {
t.Logf("%s", out)
t.Fatal(err)
}
defer os.Remove(exe)
if !testWork {
defer os.Remove(exe)
}

binArgs := append(cmdToRun(exe), "arg1", "arg2")
cmd = exec.Command(binArgs[0], binArgs[1:]...)
Expand Down Expand Up @@ -227,17 +270,27 @@ func checkLineComments(t *testing.T, hdrname string) {
}

func TestInstall(t *testing.T) {
defer os.RemoveAll(filepath.Join(GOPATH, "pkg"))
if !testWork {
defer os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}

libgoa := "libgo.a"
if runtime.Compiler == "gccgo" {
libgoa = "liblibgo.a"
}

// Generate the p.h header file.
//
// 'go install -i -buildmode=c-archive ./libgo' would do that too, but that
// would also attempt to install transitive standard-library dependencies to
// GOROOT, and we cannot assume that GOROOT is writable. (A non-root user may
// be running this test in a GOROOT owned by root.)
genHeader(t, "p.h", "./p")

testInstall(t, "./testp1"+exeSuffix,
filepath.Join(libgodir, libgoa),
filepath.Join(libgodir, "libgo.h"),
"go", "install", "-i", "-buildmode=c-archive", "./libgo")
"go", "install", "-buildmode=c-archive", "./libgo")

// Test building libgo other than installing it.
// Header files are now present.
Expand All @@ -259,12 +312,14 @@ func TestEarlySignalHandler(t *testing.T) {
t.Skip("skipping signal test on Windows")
}

defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo2.a", "./libgo2")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down Expand Up @@ -297,12 +352,14 @@ func TestEarlySignalHandler(t *testing.T) {
func TestSignalForwarding(t *testing.T) {
checkSignalForwardingTest(t)

defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo2.a", "./libgo2")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down Expand Up @@ -345,12 +402,14 @@ func TestSignalForwardingExternal(t *testing.T) {
}
checkSignalForwardingTest(t)

defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo2.a", "./libgo2")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down Expand Up @@ -460,12 +519,14 @@ func TestOsSignal(t *testing.T) {
t.Skip("skipping signal test on Windows")
}

defer func() {
os.Remove("libgo3.a")
os.Remove("libgo3.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("libgo3.a")
os.Remove("libgo3.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo3.a", "./libgo3")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down Expand Up @@ -495,12 +556,14 @@ func TestSigaltstack(t *testing.T) {
t.Skip("skipping signal test on Windows")
}

defer func() {
os.Remove("libgo4.a")
os.Remove("libgo4.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("libgo4.a")
os.Remove("libgo4.h")
os.Remove("testp")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo4.a", "./libgo4")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down Expand Up @@ -544,13 +607,15 @@ func TestExtar(t *testing.T) {
t.Skip("shell scripts are not executable on iOS hosts")
}

defer func() {
os.Remove("libgo4.a")
os.Remove("libgo4.h")
os.Remove("testar")
os.Remove("testar.ran")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("libgo4.a")
os.Remove("libgo4.h")
os.Remove("testar")
os.Remove("testar.ran")
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

os.Remove("testar")
dir, err := os.Getwd()
Expand Down Expand Up @@ -584,12 +649,22 @@ func TestPIE(t *testing.T) {
t.Skipf("skipping PIE test on %s", GOOS)
}

defer func() {
os.Remove("testp" + exeSuffix)
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
if !testWork {
defer func() {
os.Remove("testp" + exeSuffix)
os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}()
}

// Generate the p.h header file.
//
// 'go install -i -buildmode=c-archive ./libgo' would do that too, but that
// would also attempt to install transitive standard-library dependencies to
// GOROOT, and we cannot assume that GOROOT is writable. (A non-root user may
// be running this test in a GOROOT owned by root.)
genHeader(t, "p.h", "./p")

cmd := exec.Command("go", "install", "-i", "-buildmode=c-archive", "./libgo")
cmd := exec.Command("go", "install", "-buildmode=c-archive", "./libgo")
if out, err := cmd.CombinedOutput(); err != nil {
t.Logf("%s", out)
t.Fatal(err)
Expand Down Expand Up @@ -669,11 +744,13 @@ func TestSIGPROF(t *testing.T) {

t.Parallel()

defer func() {
os.Remove("testp6" + exeSuffix)
os.Remove("libgo6.a")
os.Remove("libgo6.h")
}()
if !testWork {
defer func() {
os.Remove("testp6" + exeSuffix)
os.Remove("libgo6.a")
os.Remove("libgo6.h")
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo6.a", "./libgo6")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down Expand Up @@ -709,10 +786,12 @@ func TestCompileWithoutShared(t *testing.T) {
// For simplicity, reuse the signal forwarding test.
checkSignalForwardingTest(t)

defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
}()
if !testWork {
defer func() {
os.Remove("libgo2.a")
os.Remove("libgo2.h")
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-gcflags=-shared=false", "-o", "libgo2.a", "./libgo2")
t.Log(cmd.Args)
Expand Down Expand Up @@ -751,7 +830,9 @@ func TestCompileWithoutShared(t *testing.T) {
if err != nil {
t.Fatal(err)
}
defer os.Remove(exe)
if !testWork {
defer os.Remove(exe)
}

binArgs := append(cmdToRun(exe), "1")
t.Log(binArgs)
Expand All @@ -769,14 +850,15 @@ func TestCompileWithoutShared(t *testing.T) {
}
}

// Test that installing a second time recreates the header files.
// Test that installing a second time recreates the header file.
func TestCachedInstall(t *testing.T) {
defer os.RemoveAll(filepath.Join(GOPATH, "pkg"))
if !testWork {
defer os.RemoveAll(filepath.Join(GOPATH, "pkg"))
}

h1 := filepath.Join(libgodir, "libgo.h")
h2 := filepath.Join(libgodir, "p.h")
h := filepath.Join(libgodir, "libgo.h")

buildcmd := []string{"go", "install", "-i", "-buildmode=c-archive", "./libgo"}
buildcmd := []string{"go", "install", "-buildmode=c-archive", "./libgo"}

cmd := exec.Command(buildcmd[0], buildcmd[1:]...)
t.Log(buildcmd)
Expand All @@ -785,17 +867,11 @@ func TestCachedInstall(t *testing.T) {
t.Fatal(err)
}

if _, err := os.Stat(h1); err != nil {
if _, err := os.Stat(h); err != nil {
t.Errorf("libgo.h not installed: %v", err)
}
if _, err := os.Stat(h2); err != nil {
t.Errorf("p.h not installed: %v", err)
}

if err := os.Remove(h1); err != nil {
t.Fatal(err)
}
if err := os.Remove(h2); err != nil {
if err := os.Remove(h); err != nil {
t.Fatal(err)
}

Expand All @@ -806,23 +882,22 @@ func TestCachedInstall(t *testing.T) {
t.Fatal(err)
}

if _, err := os.Stat(h1); err != nil {
if _, err := os.Stat(h); err != nil {
t.Errorf("libgo.h not installed in second run: %v", err)
}
if _, err := os.Stat(h2); err != nil {
t.Errorf("p.h not installed in second run: %v", err)
}
}

// Issue 35294.
func TestManyCalls(t *testing.T) {
t.Parallel()

defer func() {
os.Remove("testp7" + exeSuffix)
os.Remove("libgo7.a")
os.Remove("libgo7.h")
}()
if !testWork {
defer func() {
os.Remove("testp7" + exeSuffix)
os.Remove("libgo7.a")
os.Remove("libgo7.h")
}()
}

cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo7.a", "./libgo7")
if out, err := cmd.CombinedOutput(); err != nil {
Expand Down

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