misc/cgo/testcshared: fix tests in module mode

Updates #30228

Change-Id: Ie9dca7c64be8dff729be98cb6190236287afd23e
Reviewed-on: https://go-review.googlesource.com/c/163213
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>

misc/cgo/testcshared/cshared_test.go

@@ -5,13 +5,13 @@
 package cshared_test
 
 import (
+	"bytes"
 	"debug/elf"
 	"fmt"
 	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
-	"path"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -22,9 +22,6 @@ import (
 // C compiler with args (from $(go env CC) $(go env GOGCCFLAGS)).
 var cc []string
 
-// An environment with GOPATH=$(pwd).
-var gopathEnv []string
-
 // ".exe" on Windows.
 var exeSuffix string
 
@@ -33,6 +30,12 @@ var installdir, androiddir string
 var libSuffix, libgoname string
 
 func TestMain(m *testing.M) {
+	os.Exit(testMain(m))
+}
+
+func testMain(m *testing.M) int {
+	log.SetFlags(log.Lshortfile)
+
 	GOOS = goEnv("GOOS")
 	GOARCH = goEnv("GOARCH")
 	GOROOT = goEnv("GOROOT")
@@ -41,19 +44,6 @@ func TestMain(m *testing.M) {
 		log.Fatalf("Unable able to find GOROOT at '%s'", GOROOT)
 	}
 
-	// Directory where cgo headers and outputs will be installed.
-	// The installation directory format varies depending on the platform.
-	installdir = path.Join("pkg", fmt.Sprintf("%s_%s_testcshared", GOOS, GOARCH))
-	switch GOOS {
-	case "darwin":
-		libSuffix = "dylib"
-	case "windows":
-		libSuffix = "dll"
-	default:
-		libSuffix = "so"
-		installdir = path.Join("pkg", fmt.Sprintf("%s_%s_testcshared_shared", GOOS, GOARCH))
-	}
-
 	androiddir = fmt.Sprintf("/data/local/tmp/testcshared-%d", os.Getpid())
 	if GOOS == "android" {
 		args := append(adbCmd(), "shell", "mkdir", "-p", androiddir)
@@ -62,10 +52,9 @@ func TestMain(m *testing.M) {
 		if err != nil {
 			log.Fatalf("setupAndroid failed: %v\n%s\n", err, out)
 		}
+		defer cleanupAndroid()
 	}
 
-	libgoname = "libgo." + libSuffix
-
 	cc = []string{goEnv("CC")}
 
 	out := goEnv("GOGCCFLAGS")
@@ -120,34 +109,56 @@ func TestMain(m *testing.M) {
 	}
 	cc = append(cc, "-I", filepath.Join("pkg", libgodir))
 
-	// Build an environment with GOPATH=$(pwd)
-	dir, err := os.Getwd()
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(2)
-	}
-	gopathEnv = append(os.Environ(), "GOPATH="+dir)
-
 	if GOOS == "windows" {
 		exeSuffix = ".exe"
 	}
 
-	st := m.Run()
+	// Copy testdata into GOPATH/src/testcshared, along with a go.mod file
+	// declaring the same path.
+
+	GOPATH, err := ioutil.TempDir("", "cshared_test")
+	if err != nil {
+		log.Panic(err)
+	}
+	defer os.RemoveAll(GOPATH)
+	os.Setenv("GOPATH", GOPATH)
+
+	// Copy testdata into GOPATH/src/testarchive, along with a go.mod file
+	// declaring the same path.
+	modRoot := filepath.Join(GOPATH, "src", "testcshared")
+	if err := overlayDir(modRoot, "testdata"); err != nil {
+		log.Panic(err)
+	}
+	if err := os.Chdir(modRoot); err != nil {
+		log.Panic(err)
+	}
+	if err := ioutil.WriteFile("go.mod", []byte("module testcshared\n"), 0666); err != nil {
+		log.Panic(err)
+	}
 
-	os.Remove(libgoname)
-	os.RemoveAll("pkg")
-	cleanupHeaders()
-	cleanupAndroid()
+	// Directory where cgo headers and outputs will be installed.
+	// The installation directory format varies depending on the platform.
+	output, err := exec.Command("go", "list",
+		"-buildmode=c-shared",
+		"-installsuffix", "testcshared",
+		"-f", "{{.Target}}",
+		"./libgo").CombinedOutput()
+	if err != nil {
+		log.Panicf("go list failed: %v\n%s", err, output)
+	}
+	target := string(bytes.TrimSpace(output))
+	libgoname = filepath.Base(target)
+	installdir = filepath.Dir(target)
+	libSuffix = strings.TrimPrefix(filepath.Ext(target), ".")
 
-	os.Exit(st)
+	return m.Run()
 }
 
 func goEnv(key string) string {
 	out, err := exec.Command("go", "env", key).Output()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "go env %s failed:\n%s", key, err)
-		fmt.Fprintf(os.Stderr, "%s", err.(*exec.ExitError).Stderr)
-		os.Exit(2)
+		log.Printf("go env %s failed:\n%s", key, err)
+		log.Panicf("%s", err.(*exec.ExitError).Stderr)
 	}
 	return strings.TrimSpace(string(out))
 }
@@ -197,10 +208,12 @@ func adbRun(t *testing.T, env []string, adbargs ...string) string {
 	return strings.Replace(string(out), "\r", "", -1)
 }
 
-func run(t *testing.T, env []string, args ...string) string {
+func run(t *testing.T, extraEnv []string, args ...string) string {
 	t.Helper()
 	cmd := exec.Command(args[0], args[1:]...)
-	cmd.Env = env
+	if len(extraEnv) > 0 {
+		cmd.Env = append(os.Environ(), extraEnv...)
+	}
 
 	if GOOS != "windows" {
 		// TestUnexportedSymbols relies on file descriptor 30
@@ -220,12 +233,12 @@ func run(t *testing.T, env []string, args ...string) string {
 	return string(out)
 }
 
-func runExe(t *testing.T, env []string, args ...string) string {
+func runExe(t *testing.T, extraEnv []string, args ...string) string {
 	t.Helper()
 	if GOOS == "android" {
-		return adbRun(t, env, args...)
+		return adbRun(t, append(os.Environ(), extraEnv...), args...)
 	}
-	return run(t, env, args...)
+	return run(t, extraEnv, args...)
 }
 
 func runCC(t *testing.T, args ...string) string {
@@ -237,9 +250,8 @@ func runCC(t *testing.T, args ...string) string {
 
 func createHeaders() error {
 	args := []string{"go", "install", "-i", "-buildmode=c-shared",
-		"-installsuffix", "testcshared", "libgo"}
+		"-installsuffix", "testcshared", "./libgo"}
 	cmd := exec.Command(args[0], args[1:]...)
-	cmd.Env = gopathEnv
 	out, err := cmd.CombinedOutput()
 	if err != nil {
 		return fmt.Errorf("command failed: %v\n%v\n%s\n", args, err, out)
@@ -248,9 +260,8 @@ func createHeaders() error {
 	args = []string{"go", "build", "-buildmode=c-shared",
 		"-installsuffix", "testcshared",
 		"-o", libgoname,
-		filepath.Join("src", "libgo", "libgo.go")}
+		filepath.Join(".", "libgo", "libgo.go")}
 	cmd = exec.Command(args[0], args[1:]...)
-	cmd.Env = gopathEnv
 	out, err = cmd.CombinedOutput()
 	if err != nil {
 		return fmt.Errorf("command failed: %v\n%v\n%s\n", args, err, out)
@@ -282,10 +293,6 @@ func createHeadersOnce(t *testing.T) {
 	}
 }
 
-func cleanupHeaders() {
-	os.Remove("libgo.h")
-}
-
 func cleanupAndroid() {
 	if GOOS != "android" {
 		return
@@ -294,7 +301,7 @@ func cleanupAndroid() {
 	cmd := exec.Command(args[0], args[1:]...)
 	out, err := cmd.CombinedOutput()
 	if err != nil {
-		log.Fatalf("cleanupAndroid failed: %v\n%s\n", err, out)
+		log.Panicf("cleanupAndroid failed: %v\n%s\n", err, out)
 	}
 }
 
@@ -312,7 +319,7 @@ func TestExportedSymbols(t *testing.T) {
 
 	defer os.Remove(bin)
 
-	out := runExe(t, append(gopathEnv, "LD_LIBRARY_PATH=."), bin)
+	out := runExe(t, []string{"LD_LIBRARY_PATH=."}, bin)
 	if strings.TrimSpace(out) != "PASS" {
 		t.Error(out)
 	}
@@ -361,11 +368,11 @@ func TestUnexportedSymbols(t *testing.T) {
 	libname := "libgo2." + libSuffix
 
 	run(t,
-		gopathEnv,
+		nil,
 		"go", "build",
 		"-buildmode=c-shared",
 		"-installsuffix", "testcshared",
-		"-o", libname, "libgo2",
+		"-o", libname, "./libgo2",
 	)
 	adbPush(t, libname)
 
@@ -380,7 +387,7 @@ func TestUnexportedSymbols(t *testing.T) {
 	defer os.Remove(libname)
 	defer os.Remove(bin)
 
-	out := runExe(t, append(gopathEnv, "LD_LIBRARY_PATH=."), bin)
+	out := runExe(t, []string{"LD_LIBRARY_PATH=."}, bin)
 
 	if strings.TrimSpace(out) != "PASS" {
 		t.Error(out)
@@ -418,7 +425,7 @@ func TestMainExportedOnAndroid(t *testing.T) {
 func testSignalHandlers(t *testing.T, pkgname, cfile, cmd string) {
 	libname := pkgname + "." + libSuffix
 	run(t,
-		gopathEnv,
+		nil,
 		"go", "build",
 		"-buildmode=c-shared",
 		"-installsuffix", "testcshared",
@@ -451,7 +458,7 @@ func TestSignalHandlers(t *testing.T) {
 		t.Logf("Skipping on %s", GOOS)
 		return
 	}
-	testSignalHandlers(t, "libgo4", "main4.c", "testp4")
+	testSignalHandlers(t, "./libgo4", "main4.c", "testp4")
 }
 
 // test5: test signal handlers with os/signal.Notify
@@ -461,7 +468,7 @@ func TestSignalHandlersWithNotify(t *testing.T) {
 		t.Logf("Skipping on %s", GOOS)
 		return
 	}
-	testSignalHandlers(t, "libgo5", "main5.c", "testp5")
+	testSignalHandlers(t, "./libgo5", "main5.c", "testp5")
 }
 
 func TestPIE(t *testing.T) {
@@ -515,14 +522,16 @@ func TestCachedInstall(t *testing.T) {
 	}
 	// defer os.RemoveAll(tmpdir)
 
-	copyFile(t, filepath.Join(tmpdir, "src", "libgo", "libgo.go"), filepath.Join("src", "libgo", "libgo.go"))
-	copyFile(t, filepath.Join(tmpdir, "src", "p", "p.go"), filepath.Join("src", "p", "p.go"))
+	copyFile(t, filepath.Join(tmpdir, "src", "testcshared", "go.mod"), "go.mod")
+	copyFile(t, filepath.Join(tmpdir, "src", "testcshared", "libgo", "libgo.go"), filepath.Join("libgo", "libgo.go"))
+	copyFile(t, filepath.Join(tmpdir, "src", "testcshared", "p", "p.go"), filepath.Join("p", "p.go"))
 
-	env := append(os.Environ(), "GOPATH="+tmpdir)
+	env := append(os.Environ(), "GOPATH="+tmpdir, "GOBIN="+filepath.Join(tmpdir, "bin"))
 
-	buildcmd := []string{"go", "install", "-x", "-i", "-buildmode=c-shared", "-installsuffix", "testcshared", "libgo"}
+	buildcmd := []string{"go", "install", "-x", "-i", "-buildmode=c-shared", "-installsuffix", "testcshared", "./libgo"}
 
 	cmd := exec.Command(buildcmd[0], buildcmd[1:]...)
+	cmd.Dir = filepath.Join(tmpdir, "src", "testcshared")
 	cmd.Env = env
 	t.Log(buildcmd)
 	out, err := cmd.CombinedOutput()
@@ -572,6 +581,7 @@ func TestCachedInstall(t *testing.T) {
 	}
 
 	cmd = exec.Command(buildcmd[0], buildcmd[1:]...)
+	cmd.Dir = filepath.Join(tmpdir, "src", "testcshared")
 	cmd.Env = env
 	t.Log(buildcmd)
 	out, err = cmd.CombinedOutput()
@@ -621,8 +631,8 @@ func TestGo2C2Go(t *testing.T) {
 	}
 	defer os.RemoveAll(tmpdir)
 
-	shlib := filepath.Join(tmpdir, "libtestgo2c2go."+libSuffix)
-	run(t, gopathEnv, "go", "build", "-buildmode=c-shared", "-o", shlib, "go2c2go/go")
+	lib := filepath.Join(tmpdir, "libtestgo2c2go."+libSuffix)
+	run(t, nil, "go", "build", "-buildmode=c-shared", "-o", lib, "./go2c2go/go")
 
 	cgoCflags := os.Getenv("CGO_CFLAGS")
 	if cgoCflags != "" {
@@ -636,7 +646,7 @@ func TestGo2C2Go(t *testing.T) {
 	}
 	cgoLdflags += "-L" + tmpdir + " -ltestgo2c2go"
 
-	goenv := append(gopathEnv[:len(gopathEnv):len(gopathEnv)], "CGO_CFLAGS="+cgoCflags, "CGO_LDFLAGS="+cgoLdflags)
+	goenv := []string{"CGO_CFLAGS=" + cgoCflags, "CGO_LDFLAGS=" + cgoLdflags}
 
 	ldLibPath := os.Getenv("LD_LIBRARY_PATH")
 	if ldLibPath != "" {
@@ -644,13 +654,13 @@ func TestGo2C2Go(t *testing.T) {
 	}
 	ldLibPath += tmpdir
 
-	runenv := append(gopathEnv[:len(gopathEnv):len(gopathEnv)], "LD_LIBRARY_PATH="+ldLibPath)
+	runenv := []string{"LD_LIBRARY_PATH=" + ldLibPath}
 
 	bin := filepath.Join(tmpdir, "m1") + exeSuffix
-	run(t, goenv, "go", "build", "-o", bin, "go2c2go/m1")
+	run(t, goenv, "go", "build", "-o", bin, "./go2c2go/m1")
 	runExe(t, runenv, bin)
 
 	bin = filepath.Join(tmpdir, "m2") + exeSuffix
-	run(t, goenv, "go", "build", "-o", bin, "go2c2go/m2")
+	run(t, goenv, "go", "build", "-o", bin, "./go2c2go/m2")
 	runExe(t, runenv, bin)
 }

misc/cgo/testcshared/overlaydir_test.go

+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cshared_test
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// overlayDir makes a minimal-overhead copy of srcRoot in which new files may be added.
+//
+// TODO: Once we no longer need to support the misc module in GOPATH mode,
+// factor this function out into a package to reduce duplication.
+func overlayDir(dstRoot, srcRoot string) error {
+	dstRoot = filepath.Clean(dstRoot)
+	if err := os.MkdirAll(dstRoot, 0777); err != nil {
+		return err
+	}
+
+	symBase, err := filepath.Rel(srcRoot, dstRoot)
+	if err != nil {
+		symBase, err = filepath.Abs(srcRoot)
+		if err != nil {
+			return err
+		}
+	}
+
+	return filepath.Walk(srcRoot, func(srcPath string, info os.FileInfo, err error) error {
+		if err != nil || srcPath == srcRoot {
+			return err
+		}
+
+		suffix := strings.TrimPrefix(srcPath, srcRoot)
+		for len(suffix) > 0 && suffix[0] == filepath.Separator {
+			suffix = suffix[1:]
+		}
+		dstPath := filepath.Join(dstRoot, suffix)
+
+		perm := info.Mode() & os.ModePerm
+		if info.Mode()&os.ModeSymlink != 0 {
+			info, err = os.Stat(srcPath)
+			if err != nil {
+				return err
+			}
+			perm = info.Mode() & os.ModePerm
+		}
+
+		// Always copy directories (don't symlink them).
+		// If we add a file in the overlay, we don't want to add it in the original.
+		if info.IsDir() {
+			return os.Mkdir(dstPath, perm)
+		}
+
+		// If the OS supports symlinks, use them instead of copying bytes.
+		if err := os.Symlink(filepath.Join(symBase, suffix), dstPath); err == nil {
+			return nil
+		}
+
+		// Otherwise, copy the bytes.
+		src, err := os.Open(srcPath)
+		if err != nil {
+			return err
+		}
+		defer src.Close()
+
+		dst, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
+		if err != nil {
+			return err
+		}
+
+		_, err = io.Copy(dst, src)
+		if closeErr := dst.Close(); err == nil {
+			err = closeErr
+		}
+		return err
+	})
+}

misc/cgo/testcshared/src/libgo/libgo.go → misc/cgo/testcshared/testdata/libgo/libgo.go

@@ -5,8 +5,8 @@
 package main
 
 import (
-	_ "p"
 	"syscall"
+	_ "testcshared/p"
 	"time"
 )
 

src/cmd/dist/test.go

@@ -695,7 +695,7 @@ func (t *tester) registerTests() {
 			t.registerHostTest("testcarchive", "../misc/cgo/testcarchive", "misc/cgo/testcarchive", ".")
 		}
 		if t.supportedBuildmode("c-shared") {
-			t.registerHostTest("testcshared", "../misc/cgo/testcshared", "misc/cgo/testcshared", "cshared_test.go")
+			t.registerHostTest("testcshared", "../misc/cgo/testcshared", "misc/cgo/testcshared", ".")
 		}
 		if t.supportedBuildmode("shared") {
 			t.registerTest("testshared", "../misc/cgo/testshared", t.goTest(), t.timeout(600))