Adding upstream version 1.20.14.upstream/1.20.14upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

20 files changed, 2603 insertions, 0 deletions

diff --git a/misc/cgo/testcarchive/carchive_test.go b/misc/cgo/testcarchive/carchive_test.go
new file mode 100644
index 0000000..30e12be
--- /dev/null
+++ b/misc/cgo/testcarchive/carchive_test.go
@@ -0,0 +1,1240 @@
+// Copyright 2016 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 carchive_test
+
+import (
+	"bufio"
+	"bytes"
+	"debug/elf"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"testing"
+	"time"
+	"unicode"
+)
+
+// Program to run.
+var bin []string
+
+// C compiler with args (from $(go env CC) $(go env GOGCCFLAGS)).
+var cc []string
+
+// ".exe" on Windows.
+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")
+		os.Exit(0)
+	}
+	if runtime.GOOS == "linux" {
+		if _, err := os.Stat("/etc/alpine-release"); err == nil {
+			fmt.Printf("SKIP - skipping failing test on alpine - go.dev/issue/19938\n")
+			os.Exit(0)
+		}
+	}
+
+	log.SetFlags(log.Lshortfile)
+	os.Exit(testMain(m))
+}
+
+func testMain(m *testing.M) int {
+	// We need a writable GOPATH in which to run the tests.
+	// Construct one in a temporary directory.
+	var err error
+	GOPATH, err = os.MkdirTemp("", "carchive_test")
+	if err != nil {
+		log.Panic(err)
+	}
+	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
+	// declaring the same path.
+	modRoot := filepath.Join(GOPATH, "src", "testcarchive")
+	if err := overlayDir(modRoot, "testdata"); err != nil {
+		log.Panic(err)
+	}
+	if err := os.Chdir(modRoot); err != nil {
+		log.Panic(err)
+	}
+	os.Setenv("PWD", modRoot)
+	if err := os.WriteFile("go.mod", []byte("module testcarchive\n"), 0666); err != nil {
+		log.Panic(err)
+	}
+
+	GOOS = goEnv("GOOS")
+	GOARCH = goEnv("GOARCH")
+	bin = cmdToRun("./testp")
+
+	ccOut := goEnv("CC")
+	cc = []string{string(ccOut)}
+
+	out := goEnv("GOGCCFLAGS")
+	quote := '\000'
+	start := 0
+	lastSpace := true
+	backslash := false
+	s := string(out)
+	for i, c := range s {
+		if quote == '\000' && unicode.IsSpace(c) {
+			if !lastSpace {
+				cc = append(cc, s[start:i])
+				lastSpace = true
+			}
+		} else {
+			if lastSpace {
+				start = i
+				lastSpace = false
+			}
+			if quote == '\000' && !backslash && (c == '"' || c == '\'') {
+				quote = c
+				backslash = false
+			} else if !backslash && quote == c {
+				quote = '\000'
+			} else if (quote == '\000' || quote == '"') && !backslash && c == '\\' {
+				backslash = true
+			} else {
+				backslash = false
+			}
+		}
+	}
+	if !lastSpace {
+		cc = append(cc, s[start:])
+	}
+
+	if GOOS == "aix" {
+		// -Wl,-bnoobjreorder is mandatory to keep the same layout
+		// in .text section.
+		cc = append(cc, "-Wl,-bnoobjreorder")
+	}
+	libbase := GOOS + "_" + GOARCH
+	if runtime.Compiler == "gccgo" {
+		libbase = "gccgo_" + libgodir + "_fPIC"
+	} else {
+		switch GOOS {
+		case "darwin", "ios":
+			if GOARCH == "arm64" {
+				libbase += "_shared"
+			}
+		case "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "solaris", "illumos":
+			libbase += "_shared"
+		}
+	}
+	libgodir = filepath.Join(GOPATH, "pkg", libbase, "testcarchive")
+	cc = append(cc, "-I", libgodir)
+
+	// Force reallocation (and avoid aliasing bugs) for parallel tests that append to cc.
+	cc = cc[:len(cc):len(cc)]
+
+	if GOOS == "windows" {
+		exeSuffix = ".exe"
+	}
+
+	return m.Run()
+}
+
+func goEnv(key string) string {
+	out, err := exec.Command("go", "env", key).Output()
+	if err != nil {
+		if ee, ok := err.(*exec.ExitError); ok {
+			fmt.Fprintf(os.Stderr, "%s", ee.Stderr)
+		}
+		log.Panicf("go env %s failed:\n%s\n", key, err)
+	}
+	return strings.TrimSpace(string(out))
+}
+
+func cmdToRun(name string) []string {
+	execScript := "go_" + goEnv("GOOS") + "_" + goEnv("GOARCH") + "_exec"
+	executor, err := exec.LookPath(execScript)
+	if err != nil {
+		return []string{name}
+	}
+	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 := os.MkdirTemp(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:]...)
+	cmd.Env = append(cmd.Environ(), "GO111MODULE=off") // 'go install' only works in GOPATH mode
+	t.Log(buildcmd)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	if !testWork {
+		defer func() {
+			os.Remove(libgoa)
+			os.Remove(libgoh)
+		}()
+	}
+
+	ccArgs := append(cc, "-o", exe, "main.c")
+	if GOOS == "windows" {
+		ccArgs = append(ccArgs, "main_windows.c", libgoa, "-lntdll", "-lws2_32", "-lwinmm")
+	} else {
+		ccArgs = append(ccArgs, "main_unix.c", libgoa)
+	}
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	t.Log(ccArgs)
+	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	if !testWork {
+		defer os.Remove(exe)
+	}
+
+	binArgs := append(cmdToRun(exe), "arg1", "arg2")
+	cmd = exec.Command(binArgs[0], binArgs[1:]...)
+	if runtime.Compiler == "gccgo" {
+		cmd.Env = append(cmd.Environ(), "GCCGO=1")
+	}
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	checkLineComments(t, libgoh)
+}
+
+var badLineRegexp = regexp.MustCompile(`(?m)^#line [0-9]+ "/.*$`)
+
+// checkLineComments checks that the export header generated by
+// -buildmode=c-archive doesn't have any absolute paths in the #line
+// comments. We don't want those paths because they are unhelpful for
+// the user and make the files change based on details of the location
+// of GOPATH.
+func checkLineComments(t *testing.T, hdrname string) {
+	hdr, err := os.ReadFile(hdrname)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			t.Error(err)
+		}
+		return
+	}
+	if line := badLineRegexp.Find(hdr); line != nil {
+		t.Errorf("bad #line directive with absolute path in %s: %q", hdrname, line)
+	}
+}
+
+// checkArchive verifies that the created library looks OK.
+// We just check a couple of things now, we can add more checks as needed.
+func checkArchive(t *testing.T, arname string) {
+	t.Helper()
+
+	switch GOOS {
+	case "aix", "darwin", "ios", "windows":
+		// We don't have any checks for non-ELF libraries yet.
+		if _, err := os.Stat(arname); err != nil {
+			t.Errorf("archive %s does not exist: %v", arname, err)
+		}
+	default:
+		checkELFArchive(t, arname)
+	}
+}
+
+// checkELFArchive checks an ELF archive.
+func checkELFArchive(t *testing.T, arname string) {
+	t.Helper()
+
+	f, err := os.Open(arname)
+	if err != nil {
+		t.Errorf("archive %s does not exist: %v", arname, err)
+		return
+	}
+	defer f.Close()
+
+	// TODO(iant): put these in a shared package?  But where?
+	const (
+		magic = "!<arch>\n"
+		fmag  = "`\n"
+
+		namelen = 16
+		datelen = 12
+		uidlen  = 6
+		gidlen  = 6
+		modelen = 8
+		sizelen = 10
+		fmaglen = 2
+		hdrlen  = namelen + datelen + uidlen + gidlen + modelen + sizelen + fmaglen
+	)
+
+	type arhdr struct {
+		name string
+		date string
+		uid  string
+		gid  string
+		mode string
+		size string
+		fmag string
+	}
+
+	var magbuf [len(magic)]byte
+	if _, err := io.ReadFull(f, magbuf[:]); err != nil {
+		t.Errorf("%s: archive too short", arname)
+		return
+	}
+	if string(magbuf[:]) != magic {
+		t.Errorf("%s: incorrect archive magic string %q", arname, magbuf)
+	}
+
+	off := int64(len(magic))
+	for {
+		if off&1 != 0 {
+			var b [1]byte
+			if _, err := f.Read(b[:]); err != nil {
+				if err == io.EOF {
+					break
+				}
+				t.Errorf("%s: error skipping alignment byte at %d: %v", arname, off, err)
+			}
+			off++
+		}
+
+		var hdrbuf [hdrlen]byte
+		if _, err := io.ReadFull(f, hdrbuf[:]); err != nil {
+			if err == io.EOF {
+				break
+			}
+			t.Errorf("%s: error reading archive header at %d: %v", arname, off, err)
+			return
+		}
+
+		var hdr arhdr
+		hdrslice := hdrbuf[:]
+		set := func(len int, ps *string) {
+			*ps = string(bytes.TrimSpace(hdrslice[:len]))
+			hdrslice = hdrslice[len:]
+		}
+		set(namelen, &hdr.name)
+		set(datelen, &hdr.date)
+		set(uidlen, &hdr.uid)
+		set(gidlen, &hdr.gid)
+		set(modelen, &hdr.mode)
+		set(sizelen, &hdr.size)
+		hdr.fmag = string(hdrslice[:fmaglen])
+		hdrslice = hdrslice[fmaglen:]
+		if len(hdrslice) != 0 {
+			t.Fatalf("internal error: len(hdrslice) == %d", len(hdrslice))
+		}
+
+		if hdr.fmag != fmag {
+			t.Errorf("%s: invalid fmagic value %q at %d", arname, hdr.fmag, off)
+			return
+		}
+
+		size, err := strconv.ParseInt(hdr.size, 10, 64)
+		if err != nil {
+			t.Errorf("%s: error parsing size %q at %d: %v", arname, hdr.size, off, err)
+			return
+		}
+
+		off += hdrlen
+
+		switch hdr.name {
+		case "__.SYMDEF", "/", "/SYM64/":
+			// The archive symbol map.
+		case "//", "ARFILENAMES/":
+			// The extended name table.
+		default:
+			// This should be an ELF object.
+			checkELFArchiveObject(t, arname, off, io.NewSectionReader(f, off, size))
+		}
+
+		off += size
+		if _, err := f.Seek(off, io.SeekStart); err != nil {
+			t.Errorf("%s: failed to seek to %d: %v", arname, off, err)
+		}
+	}
+}
+
+// checkELFArchiveObject checks an object in an ELF archive.
+func checkELFArchiveObject(t *testing.T, arname string, off int64, obj io.ReaderAt) {
+	t.Helper()
+
+	ef, err := elf.NewFile(obj)
+	if err != nil {
+		t.Errorf("%s: failed to open ELF file at %d: %v", arname, off, err)
+		return
+	}
+	defer ef.Close()
+
+	// Verify section types.
+	for _, sec := range ef.Sections {
+		want := elf.SHT_NULL
+		switch sec.Name {
+		case ".text", ".data":
+			want = elf.SHT_PROGBITS
+		case ".bss":
+			want = elf.SHT_NOBITS
+		case ".symtab":
+			want = elf.SHT_SYMTAB
+		case ".strtab":
+			want = elf.SHT_STRTAB
+		case ".init_array":
+			want = elf.SHT_INIT_ARRAY
+		case ".fini_array":
+			want = elf.SHT_FINI_ARRAY
+		case ".preinit_array":
+			want = elf.SHT_PREINIT_ARRAY
+		}
+		if want != elf.SHT_NULL && sec.Type != want {
+			t.Errorf("%s: incorrect section type in elf file at %d for section %q: got %v want %v", arname, off, sec.Name, sec.Type, want)
+		}
+	}
+}
+
+func TestInstall(t *testing.T) {
+	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", "-buildmode=c-archive", "./libgo")
+
+	// Test building libgo other than installing it.
+	// Header files are now present.
+	testInstall(t, "./testp2"+exeSuffix, "libgo.a", "libgo.h",
+		"go", "build", "-buildmode=c-archive", filepath.Join(".", "libgo", "libgo.go"))
+
+	testInstall(t, "./testp3"+exeSuffix, "libgo.a", "libgo.h",
+		"go", "build", "-buildmode=c-archive", "-o", "libgo.a", "./libgo")
+}
+
+func TestEarlySignalHandler(t *testing.T) {
+	switch GOOS {
+	case "darwin", "ios":
+		switch GOARCH {
+		case "arm64":
+			t.Skipf("skipping on %s/%s; see https://golang.org/issue/13701", GOOS, GOARCH)
+		}
+	case "windows":
+		t.Skip("skipping signal test on Windows")
+	}
+
+	if !testWork {
+		defer func() {
+			os.Remove("libgo2.a")
+			os.Remove("libgo2.h")
+			os.Remove("testp" + exeSuffix)
+			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 {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo2.h")
+	checkArchive(t, "libgo2.a")
+
+	ccArgs := append(cc, "-o", "testp"+exeSuffix, "main2.c", "libgo2.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	darwin := "0"
+	if runtime.GOOS == "darwin" {
+		darwin = "1"
+	}
+	cmd = exec.Command(bin[0], append(bin[1:], darwin)...)
+
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+}
+
+func TestSignalForwarding(t *testing.T) {
+	checkSignalForwardingTest(t)
+	buildSignalForwardingTest(t)
+
+	cmd := exec.Command(bin[0], append(bin[1:], "1")...)
+
+	out, err := cmd.CombinedOutput()
+	t.Logf("%v\n%s", cmd.Args, out)
+	expectSignal(t, err, syscall.SIGSEGV, 0)
+
+	// SIGPIPE is never forwarded on darwin. See golang.org/issue/33384.
+	if runtime.GOOS != "darwin" && runtime.GOOS != "ios" {
+		// Test SIGPIPE forwarding
+		cmd = exec.Command(bin[0], append(bin[1:], "3")...)
+
+		out, err = cmd.CombinedOutput()
+		if len(out) > 0 {
+			t.Logf("%s", out)
+		}
+		expectSignal(t, err, syscall.SIGPIPE, 0)
+	}
+}
+
+func TestSignalForwardingExternal(t *testing.T) {
+	if GOOS == "freebsd" || GOOS == "aix" {
+		t.Skipf("skipping on %s/%s; signal always goes to the Go runtime", GOOS, GOARCH)
+	} else if GOOS == "darwin" && GOARCH == "amd64" {
+		t.Skipf("skipping on %s/%s: runtime does not permit SI_USER SIGSEGV", GOOS, GOARCH)
+	}
+	checkSignalForwardingTest(t)
+	buildSignalForwardingTest(t)
+
+	// We want to send the process a signal and see if it dies.
+	// Normally the signal goes to the C thread, the Go signal
+	// handler picks it up, sees that it is running in a C thread,
+	// and the program dies. Unfortunately, occasionally the
+	// signal is delivered to a Go thread, which winds up
+	// discarding it because it was sent by another program and
+	// there is no Go handler for it. To avoid this, run the
+	// program several times in the hopes that it will eventually
+	// fail.
+	const tries = 20
+	for i := 0; i < tries; i++ {
+		err := runSignalForwardingTest(t, "2")
+		if err == nil {
+			continue
+		}
+
+		// If the signal is delivered to a C thread, as expected,
+		// the Go signal handler will disable itself and re-raise
+		// the signal, causing the program to die with SIGSEGV.
+		//
+		// It is also possible that the signal will be
+		// delivered to a Go thread, such as a GC thread.
+		// Currently when the Go runtime sees that a SIGSEGV was
+		// sent from a different program, it first tries to send
+		// the signal to the os/signal API. If nothing is looking
+		// for (or explicitly ignoring) SIGSEGV, then it crashes.
+		// Because the Go runtime is invoked via a c-archive,
+		// it treats this as GOTRACEBACK=crash, meaning that it
+		// dumps a stack trace for all goroutines, which it does
+		// by raising SIGQUIT. The effect is that we will see the
+		// program die with SIGQUIT in that case, not SIGSEGV.
+		if expectSignal(t, err, syscall.SIGSEGV, syscall.SIGQUIT) {
+			return
+		}
+	}
+
+	t.Errorf("program succeeded unexpectedly %d times", tries)
+}
+
+func TestSignalForwardingGo(t *testing.T) {
+	// This test fails on darwin-amd64 because of the special
+	// handling of user-generated SIGSEGV signals in fixsigcode in
+	// runtime/signal_darwin_amd64.go.
+	if runtime.GOOS == "darwin" && runtime.GOARCH == "amd64" {
+		t.Skip("not supported on darwin-amd64")
+	}
+
+	checkSignalForwardingTest(t)
+	buildSignalForwardingTest(t)
+	err := runSignalForwardingTest(t, "4")
+
+	// Occasionally the signal will be delivered to a C thread,
+	// and the program will crash with SIGSEGV.
+	expectSignal(t, err, syscall.SIGQUIT, syscall.SIGSEGV)
+}
+
+// checkSignalForwardingTest calls t.Skip if the SignalForwarding test
+// doesn't work on this platform.
+func checkSignalForwardingTest(t *testing.T) {
+	switch GOOS {
+	case "darwin", "ios":
+		switch GOARCH {
+		case "arm64":
+			t.Skipf("skipping on %s/%s; see https://golang.org/issue/13701", GOOS, GOARCH)
+		}
+	case "windows":
+		t.Skip("skipping signal test on Windows")
+	}
+}
+
+// buildSignalForwardingTest builds the executable used by the various
+// signal forwarding tests.
+func buildSignalForwardingTest(t *testing.T) {
+	if !testWork {
+		t.Cleanup(func() {
+			os.Remove("libgo2.a")
+			os.Remove("libgo2.h")
+			os.Remove("testp" + exeSuffix)
+			os.RemoveAll(filepath.Join(GOPATH, "pkg"))
+		})
+	}
+
+	t.Log("go build -buildmode=c-archive -o libgo2.a ./libgo2")
+	cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo2.a", "./libgo2")
+	out, err := cmd.CombinedOutput()
+	if len(out) > 0 {
+		t.Logf("%s", out)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	checkLineComments(t, "libgo2.h")
+	checkArchive(t, "libgo2.a")
+
+	ccArgs := append(cc, "-o", "testp"+exeSuffix, "main5.c", "libgo2.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	t.Log(ccArgs)
+	out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+	if len(out) > 0 {
+		t.Logf("%s", out)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func runSignalForwardingTest(t *testing.T, arg string) error {
+	t.Logf("%v %s", bin, arg)
+	cmd := exec.Command(bin[0], append(bin[1:], arg)...)
+
+	var out strings.Builder
+	cmd.Stdout = &out
+
+	stderr, err := cmd.StderrPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer stderr.Close()
+
+	r := bufio.NewReader(stderr)
+
+	err = cmd.Start()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Wait for trigger to ensure that process is started.
+	ok, err := r.ReadString('\n')
+
+	// Verify trigger.
+	if err != nil || ok != "OK\n" {
+		t.Fatal("Did not receive OK signal")
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	var errsb strings.Builder
+	go func() {
+		defer wg.Done()
+		io.Copy(&errsb, r)
+	}()
+
+	// Give the program a chance to enter the function.
+	// If the program doesn't get there the test will still
+	// pass, although it doesn't quite test what we intended.
+	// This is fine as long as the program normally makes it.
+	time.Sleep(time.Millisecond)
+
+	cmd.Process.Signal(syscall.SIGSEGV)
+
+	err = cmd.Wait()
+
+	s := out.String()
+	if len(s) > 0 {
+		t.Log(s)
+	}
+	wg.Wait()
+	s = errsb.String()
+	if len(s) > 0 {
+		t.Log(s)
+	}
+
+	return err
+}
+
+// expectSignal checks that err, the exit status of a test program,
+// shows a failure due to a specific signal or two. Returns whether we
+// found an expected signal.
+func expectSignal(t *testing.T, err error, sig1, sig2 syscall.Signal) bool {
+	t.Helper()
+	if err == nil {
+		t.Error("test program succeeded unexpectedly")
+	} else if ee, ok := err.(*exec.ExitError); !ok {
+		t.Errorf("error (%v) has type %T; expected exec.ExitError", err, err)
+	} else if ws, ok := ee.Sys().(syscall.WaitStatus); !ok {
+		t.Errorf("error.Sys (%v) has type %T; expected syscall.WaitStatus", ee.Sys(), ee.Sys())
+	} else if !ws.Signaled() || (ws.Signal() != sig1 && ws.Signal() != sig2) {
+		if sig2 == 0 {
+			t.Errorf("got %q; expected signal %q", ee, sig1)
+		} else {
+			t.Errorf("got %q; expected signal %q or %q", ee, sig1, sig2)
+		}
+	} else {
+		return true
+	}
+	return false
+}
+
+func TestOsSignal(t *testing.T) {
+	switch GOOS {
+	case "windows":
+		t.Skip("skipping signal test on Windows")
+	}
+
+	if !testWork {
+		defer func() {
+			os.Remove("libgo3.a")
+			os.Remove("libgo3.h")
+			os.Remove("testp" + exeSuffix)
+			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 {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo3.h")
+	checkArchive(t, "libgo3.a")
+
+	ccArgs := append(cc, "-o", "testp"+exeSuffix, "main3.c", "libgo3.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	if out, err := exec.Command(bin[0], bin[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+}
+
+func TestSigaltstack(t *testing.T) {
+	switch GOOS {
+	case "windows":
+		t.Skip("skipping signal test on Windows")
+	}
+
+	if !testWork {
+		defer func() {
+			os.Remove("libgo4.a")
+			os.Remove("libgo4.h")
+			os.Remove("testp" + exeSuffix)
+			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 {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo4.h")
+	checkArchive(t, "libgo4.a")
+
+	ccArgs := append(cc, "-o", "testp"+exeSuffix, "main4.c", "libgo4.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	if out, err := exec.Command(bin[0], bin[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+}
+
+const testar = `#!/usr/bin/env bash
+while [[ $1 == -* ]] >/dev/null; do
+  shift
+done
+echo "testar" > $1
+echo "testar" > PWD/testar.ran
+`
+
+func TestExtar(t *testing.T) {
+	switch GOOS {
+	case "windows":
+		t.Skip("skipping signal test on Windows")
+	}
+	if runtime.Compiler == "gccgo" {
+		t.Skip("skipping -extar test when using gccgo")
+	}
+	if runtime.GOOS == "ios" {
+		t.Skip("shell scripts are not executable on iOS hosts")
+	}
+
+	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()
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := strings.Replace(testar, "PWD", dir, 1)
+	if err := os.WriteFile("testar", []byte(s), 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	cmd := exec.Command("go", "build", "-buildmode=c-archive", "-ldflags=-extar="+filepath.Join(dir, "testar"), "-o", "libgo4.a", "./libgo4")
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo4.h")
+
+	if _, err := os.Stat("testar.ran"); err != nil {
+		if os.IsNotExist(err) {
+			t.Error("testar does not exist after go build")
+		} else {
+			t.Errorf("error checking testar: %v", err)
+		}
+	}
+}
+
+func TestPIE(t *testing.T) {
+	switch GOOS {
+	case "windows", "darwin", "ios", "plan9":
+		t.Skipf("skipping PIE test on %s", GOOS)
+	}
+
+	libgoa := "libgo.a"
+	if runtime.Compiler == "gccgo" {
+		libgoa = "liblibgo.a"
+	}
+
+	if !testWork {
+		defer func() {
+			os.Remove("testp" + exeSuffix)
+			os.Remove(libgoa)
+			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", "build", "-buildmode=c-archive", "./libgo")
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	ccArgs := append(cc, "-fPIE", "-pie", "-o", "testp"+exeSuffix, "main.c", "main_unix.c", libgoa)
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	binArgs := append(bin, "arg1", "arg2")
+	cmd = exec.Command(binArgs[0], binArgs[1:]...)
+	if runtime.Compiler == "gccgo" {
+		cmd.Env = append(os.Environ(), "GCCGO=1")
+	}
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	if GOOS != "aix" {
+		f, err := elf.Open("testp" + exeSuffix)
+		if err != nil {
+			t.Fatal("elf.Open failed: ", err)
+		}
+		defer f.Close()
+		if hasDynTag(t, f, elf.DT_TEXTREL) {
+			t.Errorf("%s has DT_TEXTREL flag", "testp"+exeSuffix)
+		}
+	}
+}
+
+func hasDynTag(t *testing.T, f *elf.File, tag elf.DynTag) bool {
+	ds := f.SectionByType(elf.SHT_DYNAMIC)
+	if ds == nil {
+		t.Error("no SHT_DYNAMIC section")
+		return false
+	}
+	d, err := ds.Data()
+	if err != nil {
+		t.Errorf("can't read SHT_DYNAMIC contents: %v", err)
+		return false
+	}
+	for len(d) > 0 {
+		var t elf.DynTag
+		switch f.Class {
+		case elf.ELFCLASS32:
+			t = elf.DynTag(f.ByteOrder.Uint32(d[:4]))
+			d = d[8:]
+		case elf.ELFCLASS64:
+			t = elf.DynTag(f.ByteOrder.Uint64(d[:8]))
+			d = d[16:]
+		}
+		if t == tag {
+			return true
+		}
+	}
+	return false
+}
+
+func TestSIGPROF(t *testing.T) {
+	switch GOOS {
+	case "windows", "plan9":
+		t.Skipf("skipping SIGPROF test on %s", GOOS)
+	case "darwin", "ios":
+		t.Skipf("skipping SIGPROF test on %s; see https://golang.org/issue/19320", GOOS)
+	}
+
+	t.Parallel()
+
+	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")
+	out, err := cmd.CombinedOutput()
+	t.Logf("%v\n%s", cmd.Args, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo6.h")
+	checkArchive(t, "libgo6.a")
+
+	ccArgs := append(cc, "-o", "testp6"+exeSuffix, "main6.c", "libgo6.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+	t.Logf("%v\n%s", ccArgs, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	argv := cmdToRun("./testp6")
+	cmd = exec.Command(argv[0], argv[1:]...)
+	out, err = cmd.CombinedOutput()
+	t.Logf("%v\n%s", argv, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+// TestCompileWithoutShared tests that if we compile code without the
+// -shared option, we can put it into an archive. When we use the go
+// tool with -buildmode=c-archive, it passes -shared to the compiler,
+// so we override that. The go tool doesn't work this way, but Bazel
+// will likely do it in the future. And it ought to work. This test
+// was added because at one time it did not work on PPC Linux.
+func TestCompileWithoutShared(t *testing.T) {
+	// For simplicity, reuse the signal forwarding test.
+	checkSignalForwardingTest(t)
+
+	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")
+	out, err := cmd.CombinedOutput()
+	t.Logf("%v\n%s", cmd.Args, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo2.h")
+	checkArchive(t, "libgo2.a")
+
+	exe := "./testnoshared" + exeSuffix
+
+	// In some cases, -no-pie is needed here, but not accepted everywhere. First try
+	// if -no-pie is accepted. See #22126.
+	ccArgs := append(cc, "-o", exe, "-no-pie", "main5.c", "libgo2.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+	t.Logf("%v\n%s", ccArgs, out)
+
+	// If -no-pie unrecognized, try -nopie if this is possibly clang
+	if err != nil && bytes.Contains(out, []byte("unknown")) && !strings.Contains(cc[0], "gcc") {
+		ccArgs = append(cc, "-o", exe, "-nopie", "main5.c", "libgo2.a")
+		out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+		t.Logf("%v\n%s", ccArgs, out)
+	}
+
+	// Don't use either -no-pie or -nopie
+	if err != nil && bytes.Contains(out, []byte("unrecognized")) {
+		ccArgs = append(cc, "-o", exe, "main5.c", "libgo2.a")
+		out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+		t.Logf("%v\n%s", ccArgs, out)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !testWork {
+		defer os.Remove(exe)
+	}
+
+	binArgs := append(cmdToRun(exe), "1")
+	out, err = exec.Command(binArgs[0], binArgs[1:]...).CombinedOutput()
+	t.Logf("%v\n%s", binArgs, out)
+	expectSignal(t, err, syscall.SIGSEGV, 0)
+
+	// SIGPIPE is never forwarded on darwin. See golang.org/issue/33384.
+	if runtime.GOOS != "darwin" && runtime.GOOS != "ios" {
+		binArgs := append(cmdToRun(exe), "3")
+		out, err = exec.Command(binArgs[0], binArgs[1:]...).CombinedOutput()
+		t.Logf("%v\n%s", binArgs, out)
+		expectSignal(t, err, syscall.SIGPIPE, 0)
+	}
+}
+
+// Test that installing a second time recreates the header file.
+func TestCachedInstall(t *testing.T) {
+	if !testWork {
+		defer os.RemoveAll(filepath.Join(GOPATH, "pkg"))
+	}
+
+	h := filepath.Join(libgodir, "libgo.h")
+
+	buildcmd := []string{"go", "install", "-buildmode=c-archive", "./libgo"}
+
+	cmd := exec.Command(buildcmd[0], buildcmd[1:]...)
+	cmd.Env = append(cmd.Environ(), "GO111MODULE=off") // 'go install' only works in GOPATH mode
+	t.Log(buildcmd)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	if _, err := os.Stat(h); err != nil {
+		t.Errorf("libgo.h not installed: %v", err)
+	}
+
+	if err := os.Remove(h); err != nil {
+		t.Fatal(err)
+	}
+
+	cmd = exec.Command(buildcmd[0], buildcmd[1:]...)
+	cmd.Env = append(cmd.Environ(), "GO111MODULE=off")
+	t.Log(buildcmd)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	if _, err := os.Stat(h); err != nil {
+		t.Errorf("libgo.h not installed in second run: %v", err)
+	}
+}
+
+// Issue 35294.
+func TestManyCalls(t *testing.T) {
+	t.Parallel()
+
+	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")
+	out, err := cmd.CombinedOutput()
+	t.Logf("%v\n%s", cmd.Args, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo7.h")
+	checkArchive(t, "libgo7.a")
+
+	ccArgs := append(cc, "-o", "testp7"+exeSuffix, "main7.c", "libgo7.a")
+	if runtime.Compiler == "gccgo" {
+		ccArgs = append(ccArgs, "-lgo")
+	}
+	out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+	t.Logf("%v\n%s", ccArgs, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	argv := cmdToRun("./testp7")
+	cmd = exec.Command(argv[0], argv[1:]...)
+	sb := new(strings.Builder)
+	cmd.Stdout = sb
+	cmd.Stderr = sb
+	if err := cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+
+	timer := time.AfterFunc(time.Minute,
+		func() {
+			t.Error("test program timed out")
+			cmd.Process.Kill()
+		},
+	)
+	defer timer.Stop()
+
+	err = cmd.Wait()
+	t.Logf("%v\n%s", cmd.Args, sb)
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+// Issue 49288.
+func TestPreemption(t *testing.T) {
+	if runtime.Compiler == "gccgo" {
+		t.Skip("skipping asynchronous preemption test with gccgo")
+	}
+
+	t.Parallel()
+
+	if !testWork {
+		defer func() {
+			os.Remove("testp8" + exeSuffix)
+			os.Remove("libgo8.a")
+			os.Remove("libgo8.h")
+		}()
+	}
+
+	cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo8.a", "./libgo8")
+	out, err := cmd.CombinedOutput()
+	t.Logf("%v\n%s", cmd.Args, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo8.h")
+	checkArchive(t, "libgo8.a")
+
+	ccArgs := append(cc, "-o", "testp8"+exeSuffix, "main8.c", "libgo8.a")
+	out, err = exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput()
+	t.Logf("%v\n%s", ccArgs, out)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	argv := cmdToRun("./testp8")
+	cmd = exec.Command(argv[0], argv[1:]...)
+	sb := new(strings.Builder)
+	cmd.Stdout = sb
+	cmd.Stderr = sb
+	if err := cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+
+	timer := time.AfterFunc(time.Minute,
+		func() {
+			t.Error("test program timed out")
+			cmd.Process.Kill()
+		},
+	)
+	defer timer.Stop()
+
+	err = cmd.Wait()
+	t.Logf("%v\n%s", cmd.Args, sb)
+	if err != nil {
+		t.Error(err)
+	}
+}
diff --git a/misc/cgo/testcarchive/overlaydir_test.go b/misc/cgo/testcarchive/overlaydir_test.go
new file mode 100644
index 0000000..67974c5
--- /dev/null
+++ b/misc/cgo/testcarchive/overlaydir_test.go
@@ -0,0 +1,78 @@
+// 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 carchive_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
+	}
+
+	srcRoot, 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.MkdirAll(dstPath, perm|0200)
+		}
+
+		// If the OS supports symlinks, use them instead of copying bytes.
+		if err := os.Symlink(srcPath, 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
+	})
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo/libgo.go b/misc/cgo/testcarchive/testdata/libgo/libgo.go
new file mode 100644
index 0000000..37b30c1
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo/libgo.go
@@ -0,0 +1,53 @@
+// Copyright 2015 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 main
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+
+	_ "testcarchive/p"
+)
+
+import "C"
+
+var initCh = make(chan int, 1)
+var ranMain bool
+
+func init() {
+	// emulate an exceedingly slow package initialization function
+	time.Sleep(100 * time.Millisecond)
+	initCh <- 42
+}
+
+func main() { ranMain = true }
+
+//export DidInitRun
+func DidInitRun() bool {
+	select {
+	case x := <-initCh:
+		if x != 42 {
+			// Just in case initCh was not correctly made.
+			println("want init value of 42, got: ", x)
+			syscall.Exit(2)
+		}
+		return true
+	default:
+		return false
+	}
+}
+
+//export DidMainRun
+func DidMainRun() bool { return ranMain }
+
+//export CheckArgs
+func CheckArgs() {
+	if len(os.Args) != 3 || os.Args[1] != "arg1" || os.Args[2] != "arg2" {
+		fmt.Printf("CheckArgs: want [_, arg1, arg2], got: %v\n", os.Args)
+		os.Exit(2)
+	}
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo2/libgo2.go b/misc/cgo/testcarchive/testdata/libgo2/libgo2.go
new file mode 100644
index 0000000..35c89ae
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo2/libgo2.go
@@ -0,0 +1,86 @@
+// Copyright 2015 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 main
+
+/*
+#include <signal.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+// Raise SIGPIPE.
+static void CRaiseSIGPIPE() {
+	int fds[2];
+
+	if (pipe(fds) == -1) {
+		perror("pipe");
+		exit(EXIT_FAILURE);
+	}
+	// Close the reader end
+	close(fds[0]);
+	// Write to the writer end to provoke a SIGPIPE
+	if (write(fds[1], "some data", 9) != -1) {
+		fprintf(stderr, "write to a closed pipe succeeded\n");
+		exit(EXIT_FAILURE);
+	}
+	close(fds[1]);
+}
+*/
+import "C"
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+)
+
+// RunGoroutines starts some goroutines that don't do anything.
+// The idea is to get some threads going, so that a signal will be delivered
+// to a thread started by Go.
+//export RunGoroutines
+func RunGoroutines() {
+	for i := 0; i < 4; i++ {
+		go func() {
+			runtime.LockOSThread()
+			select {}
+		}()
+	}
+}
+
+// Block blocks the current thread while running Go code.
+//export Block
+func Block() {
+	select {}
+}
+
+var P *byte
+
+// TestSEGV makes sure that an invalid address turns into a run-time Go panic.
+//export TestSEGV
+func TestSEGV() {
+	defer func() {
+		if recover() == nil {
+			fmt.Fprintln(os.Stderr, "no panic from segv")
+			os.Exit(1)
+		}
+	}()
+	*P = 0
+	fmt.Fprintln(os.Stderr, "continued after segv")
+	os.Exit(1)
+}
+
+// Noop ensures that the Go runtime is initialized.
+//export Noop
+func Noop() {
+}
+
+// Raise SIGPIPE.
+//export GoRaiseSIGPIPE
+func GoRaiseSIGPIPE() {
+	C.CRaiseSIGPIPE()
+}
+
+func main() {
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo3/libgo3.go b/misc/cgo/testcarchive/testdata/libgo3/libgo3.go
new file mode 100644
index 0000000..3725f7a
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo3/libgo3.go
@@ -0,0 +1,56 @@
+// Copyright 2015 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 main
+
+import "C"
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+)
+
+// The channel used to read SIGIO signals.
+var sigioChan chan os.Signal
+
+// CatchSIGIO starts catching SIGIO signals.
+//export CatchSIGIO
+func CatchSIGIO() {
+	sigioChan = make(chan os.Signal, 1)
+	signal.Notify(sigioChan, syscall.SIGIO)
+}
+
+// ResetSIGIO stops catching SIGIO signals.
+//export ResetSIGIO
+func ResetSIGIO() {
+	signal.Reset(syscall.SIGIO)
+}
+
+// SawSIGIO reports whether we saw a SIGIO.
+//export SawSIGIO
+func SawSIGIO() C.int {
+	select {
+	case <-sigioChan:
+		return 1
+	case <-time.After(5 * time.Second):
+		return 0
+	}
+}
+
+// ProvokeSIGPIPE provokes a kernel-initiated SIGPIPE.
+//export ProvokeSIGPIPE
+func ProvokeSIGPIPE() {
+	r, w, err := os.Pipe()
+	if err != nil {
+		panic(err)
+	}
+	r.Close()
+	defer w.Close()
+	w.Write([]byte("some data"))
+}
+
+func main() {
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo4/libgo4.go b/misc/cgo/testcarchive/testdata/libgo4/libgo4.go
new file mode 100644
index 0000000..8cc1895
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo4/libgo4.go
@@ -0,0 +1,52 @@
+// Copyright 2015 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 main
+
+/*
+#include <signal.h>
+#include <pthread.h>
+
+// Raise SIGIO.
+static void CRaiseSIGIO(pthread_t* p) {
+	pthread_kill(*p, SIGIO);
+}
+*/
+import "C"
+
+import (
+	"os"
+	"os/signal"
+	"sync/atomic"
+	"syscall"
+)
+
+var sigioCount int32
+
+// Catch SIGIO.
+//export GoCatchSIGIO
+func GoCatchSIGIO() {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGIO)
+	go func() {
+		for range c {
+			atomic.AddInt32(&sigioCount, 1)
+		}
+	}()
+}
+
+// Raise SIGIO.
+//export GoRaiseSIGIO
+func GoRaiseSIGIO(p *C.pthread_t) {
+	C.CRaiseSIGIO(p)
+}
+
+// Return the number of SIGIO signals seen.
+//export SIGIOCount
+func SIGIOCount() C.int {
+	return C.int(atomic.LoadInt32(&sigioCount))
+}
+
+func main() {
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo6/sigprof.go b/misc/cgo/testcarchive/testdata/libgo6/sigprof.go
new file mode 100644
index 0000000..31527c5
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo6/sigprof.go
@@ -0,0 +1,25 @@
+// Copyright 2016 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 main
+
+import (
+	"io"
+	"runtime/pprof"
+)
+
+import "C"
+
+//export go_start_profile
+func go_start_profile() {
+	pprof.StartCPUProfile(io.Discard)
+}
+
+//export go_stop_profile
+func go_stop_profile() {
+	pprof.StopCPUProfile()
+}
+
+func main() {
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo7/sink.go b/misc/cgo/testcarchive/testdata/libgo7/sink.go
new file mode 100644
index 0000000..d61638b
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo7/sink.go
@@ -0,0 +1,17 @@
+// 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 main
+
+import "C"
+
+var sink []byte
+
+//export GoFunction7
+func GoFunction7() {
+	sink = make([]byte, 4096)
+}
+
+func main() {
+}
diff --git a/misc/cgo/testcarchive/testdata/libgo8/a.go b/misc/cgo/testcarchive/testdata/libgo8/a.go
new file mode 100644
index 0000000..718418e
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/libgo8/a.go
@@ -0,0 +1,36 @@
+// Copyright 2021 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 main
+
+import "C"
+
+import (
+	"os"
+	"runtime"
+	"sync/atomic"
+)
+
+var started int32
+
+// Start a goroutine that loops forever.
+func init() {
+	runtime.GOMAXPROCS(1)
+	go func() {
+		for {
+			atomic.StoreInt32(&started, 1)
+		}
+	}()
+}
+
+//export GoFunction8
+func GoFunction8() {
+	for atomic.LoadInt32(&started) == 0 {
+		runtime.Gosched()
+	}
+	os.Exit(0)
+}
+
+func main() {
+}
diff --git a/misc/cgo/testcarchive/testdata/main.c b/misc/cgo/testcarchive/testdata/main.c
new file mode 100644
index 0000000..163b539
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main.c
@@ -0,0 +1,48 @@
+// Copyright 2015 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.
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "p.h"
+#include "libgo.h"
+
+extern int install_handler();
+extern int check_handler();
+
+int main(void) {
+	int32_t res;
+
+	int r1 = install_handler();
+	if (r1!=0) {
+		return r1;
+	}
+
+	if (!DidInitRun()) {
+		fprintf(stderr, "ERROR: buildmode=c-archive init should run\n");
+		return 2;
+	}
+
+	if (DidMainRun()) {
+		fprintf(stderr, "ERROR: buildmode=c-archive should not run main\n");
+		return 2;
+	}
+
+	int r2 = check_handler();
+	if (r2!=0) {
+		return r2;
+	}
+
+	res = FromPkg();
+	if (res != 1024) {
+		fprintf(stderr, "ERROR: FromPkg()=%d, want 1024\n", res);
+		return 2;
+	}
+
+	CheckArgs();
+
+	fprintf(stderr, "PASS\n");
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main2.c b/misc/cgo/testcarchive/testdata/main2.c
new file mode 100644
index 0000000..da35673
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main2.c
@@ -0,0 +1,239 @@
+// Copyright 2015 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.
+
+// Test installing a signal handler before the Go code starts.
+// This is a lot like misc/cgo/testcshared/main4.c.
+
+#include <setjmp.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sched.h>
+#include <time.h>
+#include <errno.h>
+
+#include "libgo2.h"
+
+static void die(const char* msg) {
+	perror(msg);
+	exit(EXIT_FAILURE);
+}
+
+static volatile sig_atomic_t sigioSeen;
+static volatile sig_atomic_t sigpipeSeen;
+
+// Use up some stack space.
+static void recur(int i, char *p) {
+	char a[1024];
+
+	*p = '\0';
+	if (i > 0) {
+		recur(i - 1, a);
+	}
+}
+
+static void pipeHandler(int signo, siginfo_t* info, void* ctxt) {
+	sigpipeSeen = 1;
+}
+
+// Signal handler that uses up more stack space than a goroutine will have.
+static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
+	char a[1024];
+
+	recur(4, a);
+	sigioSeen = 1;
+}
+
+static jmp_buf jmp;
+static char* nullPointer;
+
+// An arbitrary function which requires proper stack alignment; see
+// http://golang.org/issue/17641.
+static void callWithVarargs(void* dummy, ...) {
+	va_list args;
+	va_start(args, dummy);
+	va_end(args);
+}
+
+// Signal handler for SIGSEGV on a C thread.
+static void segvHandler(int signo, siginfo_t* info, void* ctxt) {
+	sigset_t mask;
+	int i;
+
+	// Call an arbitrary function that requires the stack to be properly aligned.
+	callWithVarargs("dummy arg", 3.1415);
+
+	if (sigemptyset(&mask) < 0) {
+		die("sigemptyset");
+	}
+	if (sigaddset(&mask, SIGSEGV) < 0) {
+		die("sigaddset");
+	}
+	i = sigprocmask(SIG_UNBLOCK, &mask, NULL);
+	if (i != 0) {
+		fprintf(stderr, "sigprocmask: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	// Don't try this at home.
+	longjmp(jmp, signo);
+
+	// We should never get here.
+	abort();
+}
+
+// Set up the signal handlers in a high priority constructor,
+// so that they are installed before the Go code starts.
+
+static void init(void) __attribute__ ((constructor (200)));
+
+static void init() {
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof sa);
+	sa.sa_sigaction = ioHandler;
+	if (sigemptyset(&sa.sa_mask) < 0) {
+		die("sigemptyset");
+	}
+	sa.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGIO, &sa, NULL) < 0) {
+		die("sigaction");
+	}
+
+	sa.sa_sigaction = segvHandler;
+	if (sigaction(SIGSEGV, &sa, NULL) < 0 || sigaction(SIGBUS, &sa, NULL) < 0) {
+		die("sigaction");
+	}
+
+	sa.sa_sigaction = pipeHandler;
+	if (sigaction(SIGPIPE, &sa, NULL) < 0) {
+		die("sigaction");
+	}
+}
+
+int main(int argc, char** argv) {
+	int verbose;
+	sigset_t mask;
+	int i;
+	struct timespec ts;
+	int darwin;
+
+	darwin = atoi(argv[1]);
+
+	verbose = argc > 2;
+
+	setvbuf(stdout, NULL, _IONBF, 0);
+
+	// Call setsid so that we can use kill(0, SIGIO) below.
+	// Don't check the return value so that this works both from
+	// a job control shell and from a shell script.
+	setsid();
+
+	if (verbose) {
+		printf("calling RunGoroutines\n");
+	}
+
+	RunGoroutines();
+
+	// Block SIGIO in this thread to make it more likely that it
+	// will be delivered to a goroutine.
+
+	if (verbose) {
+		printf("calling pthread_sigmask\n");
+	}
+
+	if (sigemptyset(&mask) < 0) {
+		die("sigemptyset");
+	}
+	if (sigaddset(&mask, SIGIO) < 0) {
+		die("sigaddset");
+	}
+	i = pthread_sigmask(SIG_BLOCK, &mask, NULL);
+	if (i != 0) {
+		fprintf(stderr, "pthread_sigmask: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	if (verbose) {
+		printf("calling kill\n");
+	}
+
+	if (kill(0, SIGIO) < 0) {
+		die("kill");
+	}
+
+	if (verbose) {
+		printf("waiting for sigioSeen\n");
+	}
+
+	// Wait until the signal has been delivered.
+	i = 0;
+	while (!sigioSeen) {
+		ts.tv_sec = 0;
+		ts.tv_nsec = 1000000;
+		nanosleep(&ts, NULL);
+		i++;
+		if (i > 5000) {
+			fprintf(stderr, "looping too long waiting for SIGIO\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	if (verbose) {
+		printf("provoking SIGPIPE\n");
+	}
+
+	// SIGPIPE is never forwarded on Darwin, see golang.org/issue/33384.
+	if (!darwin) {
+		GoRaiseSIGPIPE();
+
+		if (verbose) {
+			printf("waiting for sigpipeSeen\n");
+		}
+
+		// Wait until the signal has been delivered.
+		i = 0;
+		while (!sigpipeSeen) {
+			ts.tv_sec = 0;
+			ts.tv_nsec = 1000000;
+			nanosleep(&ts, NULL);
+			i++;
+			if (i > 5000) {
+				fprintf(stderr, "looping too long waiting for SIGPIPE\n");
+				exit(EXIT_FAILURE);
+			}
+		}
+	}
+
+	if (verbose) {
+		printf("calling setjmp\n");
+	}
+
+	// Test that a SIGSEGV on this thread is delivered to us.
+	if (setjmp(jmp) == 0) {
+		if (verbose) {
+			printf("triggering SIGSEGV\n");
+		}
+
+		*nullPointer = '\0';
+
+		fprintf(stderr, "continued after address error\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (verbose) {
+		printf("calling TestSEGV\n");
+	}
+
+	TestSEGV();
+
+	printf("PASS\n");
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main3.c b/misc/cgo/testcarchive/testdata/main3.c
new file mode 100644
index 0000000..4d11d9c
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main3.c
@@ -0,0 +1,210 @@
+// Copyright 2015 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.
+
+// Test os/signal.Notify and os/signal.Reset.
+// This is a lot like misc/cgo/testcshared/main5.c.
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <sched.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include "libgo3.h"
+
+static void die(const char* msg) {
+	perror(msg);
+	exit(EXIT_FAILURE);
+}
+
+static volatile sig_atomic_t sigioSeen;
+
+static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
+	sigioSeen = 1;
+}
+
+// Set up the SIGPIPE signal handler in a high priority constructor, so
+// that it is installed before the Go code starts.
+
+static void pipeHandler(int signo, siginfo_t* info, void* ctxt) {
+	const char *s = "unexpected SIGPIPE\n";
+	write(2, s, strlen(s));
+	exit(EXIT_FAILURE);
+}
+
+static void init(void) __attribute__ ((constructor (200)));
+
+static void init() {
+    struct sigaction sa;
+
+	memset(&sa, 0, sizeof sa);
+	sa.sa_sigaction = pipeHandler;
+	if (sigemptyset(&sa.sa_mask) < 0) {
+		die("sigemptyset");
+	}
+	sa.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGPIPE, &sa, NULL) < 0) {
+		die("sigaction");
+	}
+}
+
+static void *provokeSIGPIPE(void *arg) {
+	ProvokeSIGPIPE();
+	return NULL;
+}
+
+int main(int argc, char** argv) {
+	int verbose;
+	struct sigaction sa;
+	int i;
+	struct timespec ts;
+	int res;
+	pthread_t tid;
+
+	verbose = argc > 2;
+	setvbuf(stdout, NULL, _IONBF, 0);
+
+	if (verbose) {
+		printf("raising SIGPIPE\n");
+	}
+
+	// Test that the Go runtime handles SIGPIPE, even if we installed
+	// a non-default SIGPIPE handler before the runtime initializes.
+	ProvokeSIGPIPE();
+
+	// Test that SIGPIPE on a non-main thread is also handled by Go.
+	res = pthread_create(&tid, NULL, provokeSIGPIPE, NULL);
+	if (res != 0) {
+		fprintf(stderr, "pthread_create: %s\n", strerror(res));
+		exit(EXIT_FAILURE);
+	}
+
+	res = pthread_join(tid, NULL);
+	if (res != 0) {
+		fprintf(stderr, "pthread_join: %s\n", strerror(res));
+		exit(EXIT_FAILURE);
+	}
+
+	if (verbose) {
+		printf("calling sigaction\n");
+	}
+
+	memset(&sa, 0, sizeof sa);
+	sa.sa_sigaction = ioHandler;
+	if (sigemptyset(&sa.sa_mask) < 0) {
+		die("sigemptyset");
+	}
+	sa.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGIO, &sa, NULL) < 0) {
+		die("sigaction");
+	}
+
+	// At this point there should not be a Go signal handler
+	// installed for SIGIO.
+
+	if (verbose) {
+		printf("raising SIGIO\n");
+	}
+
+	if (raise(SIGIO) < 0) {
+		die("raise");
+	}
+
+	if (verbose) {
+		printf("waiting for sigioSeen\n");
+	}
+
+	// Wait until the signal has been delivered.
+	i = 0;
+	while (!sigioSeen) {
+		ts.tv_sec = 0;
+		ts.tv_nsec = 1000000;
+		nanosleep(&ts, NULL);
+		i++;
+		if (i > 5000) {
+			fprintf(stderr, "looping too long waiting for signal\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	sigioSeen = 0;
+
+	// Tell the Go code to catch SIGIO.
+
+	if (verbose) {
+		printf("calling CatchSIGIO\n");
+	}
+
+	CatchSIGIO();
+
+	if (verbose) {
+		printf("raising SIGIO\n");
+	}
+
+	if (raise(SIGIO) < 0) {
+		die("raise");
+	}
+
+	if (verbose) {
+		printf("calling SawSIGIO\n");
+	}
+
+	if (!SawSIGIO()) {
+		fprintf(stderr, "Go handler did not see SIGIO\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (sigioSeen != 0) {
+		fprintf(stderr, "C handler saw SIGIO when only Go handler should have\n");
+		exit(EXIT_FAILURE);
+	}
+
+	// Tell the Go code to stop catching SIGIO.
+
+	if (verbose) {
+		printf("calling ResetSIGIO\n");
+	}
+
+	ResetSIGIO();
+
+	if (verbose) {
+		printf("raising SIGIO\n");
+	}
+
+	if (raise(SIGIO) < 0) {
+		die("raise");
+	}
+
+	if (verbose) {
+		printf("calling SawSIGIO\n");
+	}
+
+	if (SawSIGIO()) {
+		fprintf(stderr, "Go handler saw SIGIO after Reset\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (verbose) {
+		printf("waiting for sigioSeen\n");
+	}
+
+	// Wait until the signal has been delivered.
+	i = 0;
+	while (!sigioSeen) {
+		ts.tv_sec = 0;
+		ts.tv_nsec = 1000000;
+		nanosleep(&ts, NULL);
+		i++;
+		if (i > 5000) {
+			fprintf(stderr, "looping too long waiting for signal\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	printf("PASS\n");
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main4.c b/misc/cgo/testcarchive/testdata/main4.c
new file mode 100644
index 0000000..04f7740
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main4.c
@@ -0,0 +1,204 @@
+// Copyright 2015 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.
+
+// Test a C thread that calls sigaltstack and then calls Go code.
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <sched.h>
+#include <pthread.h>
+
+#include "libgo4.h"
+
+#ifdef _AIX
+// On AIX, CSIGSTKSZ is too small to handle Go sighandler.
+#define CSIGSTKSZ 0x4000
+#else
+#define CSIGSTKSZ SIGSTKSZ
+#endif
+
+static void die(const char* msg) {
+	perror(msg);
+	exit(EXIT_FAILURE);
+}
+
+static int ok = 1;
+
+static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
+}
+
+// Set up the SIGIO signal handler in a high priority constructor, so
+// that it is installed before the Go code starts.
+
+static void init(void) __attribute__ ((constructor (200)));
+
+static void init() {
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof sa);
+	sa.sa_sigaction = ioHandler;
+	if (sigemptyset(&sa.sa_mask) < 0) {
+		die("sigemptyset");
+	}
+	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
+	if (sigaction(SIGIO, &sa, NULL) < 0) {
+		die("sigaction");
+	}
+}
+
+// Test raising SIGIO on a C thread with an alternate signal stack
+// when there is a Go signal handler for SIGIO.
+static void* thread1(void* arg __attribute__ ((unused))) {
+	stack_t ss;
+	int i;
+	stack_t nss;
+	struct timespec ts;
+
+	// Set up an alternate signal stack for this thread.
+	memset(&ss, 0, sizeof ss);
+	ss.ss_sp = malloc(CSIGSTKSZ);
+	if (ss.ss_sp == NULL) {
+		die("malloc");
+	}
+	ss.ss_flags = 0;
+	ss.ss_size = CSIGSTKSZ;
+	if (sigaltstack(&ss, NULL) < 0) {
+		die("sigaltstack");
+	}
+
+	// Send ourselves a SIGIO.  This will be caught by the Go
+	// signal handler which should forward to the C signal
+	// handler.
+	i = pthread_kill(pthread_self(), SIGIO);
+	if (i != 0) {
+		fprintf(stderr, "pthread_kill: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	// Wait until the signal has been delivered.
+	i = 0;
+	while (SIGIOCount() == 0) {
+		ts.tv_sec = 0;
+		ts.tv_nsec = 1000000;
+		nanosleep(&ts, NULL);
+		i++;
+		if (i > 5000) {
+			fprintf(stderr, "looping too long waiting for signal\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	// We should still be on the same signal stack.
+	if (sigaltstack(NULL, &nss) < 0) {
+		die("sigaltstack check");
+	}
+	if ((nss.ss_flags & SS_DISABLE) != 0) {
+		fprintf(stderr, "sigaltstack disabled on return from Go\n");
+		ok = 0;
+	} else if (nss.ss_sp != ss.ss_sp) {
+		fprintf(stderr, "sigaltstack changed on return from Go\n");
+		ok = 0;
+	}
+
+	return NULL;
+}
+
+// Test calling a Go function to raise SIGIO on a C thread with an
+// alternate signal stack when there is a Go signal handler for SIGIO.
+static void* thread2(void* arg __attribute__ ((unused))) {
+	stack_t ss;
+	int i;
+	int oldcount;
+	pthread_t tid;
+	struct timespec ts;
+	stack_t nss;
+
+	// Set up an alternate signal stack for this thread.
+	memset(&ss, 0, sizeof ss);
+	ss.ss_sp = malloc(CSIGSTKSZ);
+	if (ss.ss_sp == NULL) {
+		die("malloc");
+	}
+	ss.ss_flags = 0;
+	ss.ss_size = CSIGSTKSZ;
+	if (sigaltstack(&ss, NULL) < 0) {
+		die("sigaltstack");
+	}
+
+	oldcount = SIGIOCount();
+
+	// Call a Go function that will call a C function to send us a
+	// SIGIO.
+	tid = pthread_self();
+	GoRaiseSIGIO(&tid);
+
+	// Wait until the signal has been delivered.
+	i = 0;
+	while (SIGIOCount() == oldcount) {
+		ts.tv_sec = 0;
+		ts.tv_nsec = 1000000;
+		nanosleep(&ts, NULL);
+		i++;
+		if (i > 5000) {
+			fprintf(stderr, "looping too long waiting for signal\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	// We should still be on the same signal stack.
+	if (sigaltstack(NULL, &nss) < 0) {
+		die("sigaltstack check");
+	}
+	if ((nss.ss_flags & SS_DISABLE) != 0) {
+		fprintf(stderr, "sigaltstack disabled on return from Go\n");
+		ok = 0;
+	} else if (nss.ss_sp != ss.ss_sp) {
+		fprintf(stderr, "sigaltstack changed on return from Go\n");
+		ok = 0;
+	}
+
+	return NULL;
+}
+
+int main(int argc, char **argv) {
+	pthread_t tid;
+	int i;
+
+	// Tell the Go library to start looking for SIGIO.
+	GoCatchSIGIO();
+
+	i = pthread_create(&tid, NULL, thread1, NULL);
+	if (i != 0) {
+		fprintf(stderr, "pthread_create: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	i = pthread_join(tid, NULL);
+	if (i != 0) {
+		fprintf(stderr, "pthread_join: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	i = pthread_create(&tid, NULL, thread2, NULL);
+	if (i != 0) {
+		fprintf(stderr, "pthread_create: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	i = pthread_join(tid, NULL);
+	if (i != 0) {
+		fprintf(stderr, "pthread_join: %s\n", strerror(i));
+		exit(EXIT_FAILURE);
+	}
+
+	if (!ok) {
+		exit(EXIT_FAILURE);
+	}
+
+	printf("PASS\n");
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main5.c b/misc/cgo/testcarchive/testdata/main5.c
new file mode 100644
index 0000000..c64c246
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main5.c
@@ -0,0 +1,105 @@
+// Copyright 2015 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.
+
+// Test for verifying that the Go runtime properly forwards
+// signals when non-Go signals are raised.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/select.h>
+
+#include "libgo2.h"
+
+int *nilp;
+
+int main(int argc, char** argv) {
+	int verbose;
+	int test;
+
+	if (argc < 2) {
+		printf("Missing argument\n");
+		return 1;
+	}
+
+	test = atoi(argv[1]);
+
+	verbose = (argc > 2);
+
+	Noop();
+
+	switch (test) {
+		case 1: {
+			if (verbose) {
+				printf("attempting segfault\n");
+			}
+
+			*nilp = 0;
+			break;
+		}
+
+		case 2: {
+			struct timeval tv;
+
+			if (verbose) {
+				printf("attempting external signal test\n");
+			}
+
+			fprintf(stderr, "OK\n");
+			fflush(stderr);
+
+			// The program should be interrupted before
+			// this sleep finishes. We use select rather
+			// than sleep because in older versions of
+			// glibc the sleep function does some signal
+			// fiddling to handle SIGCHLD.  If this
+			// program is fiddling signals just when the
+			// test program sends the signal, the signal
+			// may be delivered to a Go thread which will
+			// break this test.
+			tv.tv_sec = 60;
+			tv.tv_usec = 0;
+			select(0, NULL, NULL, NULL, &tv);
+
+			break;
+		}
+		case 3: {
+			if (verbose) {
+				printf("attempting SIGPIPE\n");
+			}
+
+			int fd[2];
+			if (pipe(fd) != 0) {
+				printf("pipe(2) failed\n");
+				return 0;
+			}
+			// Close the reading end.
+			close(fd[0]);
+			// Expect that write(2) fails (EPIPE)
+			if (write(fd[1], "some data", 9) != -1) {
+				printf("write(2) unexpectedly succeeded\n");
+				return 0;
+			}
+			printf("did not receive SIGPIPE\n");
+			return 0;
+		}
+		case 4: {
+			fprintf(stderr, "OK\n");
+			fflush(stderr);
+
+			if (verbose) {
+				printf("calling Block\n");
+			}
+			Block();
+		}
+		default:
+			printf("Unknown test: %d\n", test);
+			return 0;
+	}
+
+	printf("FAIL\n");
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main6.c b/misc/cgo/testcarchive/testdata/main6.c
new file mode 100644
index 0000000..2745eb9
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main6.c
@@ -0,0 +1,34 @@
+// Copyright 2016 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.
+
+// Test that using the Go profiler in a C program does not crash.
+
+#include <stddef.h>
+#include <sys/time.h>
+
+#include "libgo6.h"
+
+int main(int argc, char **argv) {
+	struct timeval tvstart, tvnow;
+	int diff;
+
+	gettimeofday(&tvstart, NULL);
+
+	go_start_profile();
+
+	// Busy wait so we have something to profile.
+	// If we just sleep the profiling signal will never fire.
+	while (1) {
+		gettimeofday(&tvnow, NULL);
+		diff = (tvnow.tv_sec - tvstart.tv_sec) * 1000 * 1000 + (tvnow.tv_usec - tvstart.tv_usec);
+
+		// Profile frequency is 100Hz so we should definitely
+		// get a signal in 50 milliseconds.
+		if (diff > 50 * 1000)
+			break;
+	}
+
+	go_stop_profile();
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main7.c b/misc/cgo/testcarchive/testdata/main7.c
new file mode 100644
index 0000000..2c6d98d
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main7.c
@@ -0,0 +1,18 @@
+// 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.
+
+// Test that lots of calls don't deadlock.
+
+#include <stdio.h>
+
+#include "libgo7.h"
+
+int main() {
+	int i;
+
+	for (i = 0; i < 100000; i++) {
+		GoFunction7();
+	}
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/main8.c b/misc/cgo/testcarchive/testdata/main8.c
new file mode 100644
index 0000000..95fb7a3
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main8.c
@@ -0,0 +1,16 @@
+// Copyright 2021 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.
+
+// Test preemption.
+
+#include <stdlib.h>
+
+#include "libgo8.h"
+
+int main() {
+	GoFunction8();
+
+	// That should have exited the program.
+	abort();
+}
diff --git a/misc/cgo/testcarchive/testdata/main_unix.c b/misc/cgo/testcarchive/testdata/main_unix.c
new file mode 100644
index 0000000..bd00f9d
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main_unix.c
@@ -0,0 +1,59 @@
+// Copyright 2015 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.
+
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct sigaction sa;
+struct sigaction osa;
+
+static void (*oldHandler)(int, siginfo_t*, void*);
+
+static void handler(int signo, siginfo_t* info, void* ctxt) {
+	if (oldHandler) {
+		oldHandler(signo, info, ctxt);
+	}
+}
+
+int install_handler() {
+	// Install our own signal handler.
+	memset(&sa, 0, sizeof sa);
+	sa.sa_sigaction = handler;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_ONSTACK | SA_SIGINFO;
+	memset(&osa, 0, sizeof osa);
+	sigemptyset(&osa.sa_mask);
+	if (sigaction(SIGSEGV, &sa, &osa) < 0) {
+		perror("sigaction");
+		return 2;
+	}
+	if (osa.sa_handler == SIG_DFL) {
+		fprintf(stderr, "Go runtime did not install signal handler\n");
+		return 2;
+	}
+	// gccgo does not set SA_ONSTACK for SIGSEGV.
+	if (getenv("GCCGO") == NULL && (osa.sa_flags&SA_ONSTACK) == 0) {
+		fprintf(stderr, "Go runtime did not install signal handler\n");
+		return 2;
+	}
+	oldHandler = osa.sa_sigaction;
+
+	return 0;
+}
+
+int check_handler() {
+	if (sigaction(SIGSEGV, NULL, &sa) < 0) {
+		perror("sigaction check");
+		return 2;
+	}
+	if (sa.sa_sigaction != handler) {
+		fprintf(stderr, "ERROR: wrong signal handler: %p != %p\n", sa.sa_sigaction, handler);
+		return 2;
+	}
+	return 0;
+}
+
diff --git a/misc/cgo/testcarchive/testdata/main_windows.c b/misc/cgo/testcarchive/testdata/main_windows.c
new file mode 100644
index 0000000..eded8af
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/main_windows.c
@@ -0,0 +1,17 @@
+// Copyright 2015 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.
+
+/*
+ * Dummy implementations for Windows, because Windows doesn't
+ * support Unix-style signal handling.
+ */
+
+int install_handler() {
+	return 0;
+}
+
+
+int check_handler() {
+	return 0;
+}
diff --git a/misc/cgo/testcarchive/testdata/p/p.go b/misc/cgo/testcarchive/testdata/p/p.go
new file mode 100644
index 0000000..82b445c
--- /dev/null
+++ b/misc/cgo/testcarchive/testdata/p/p.go
@@ -0,0 +1,10 @@
+// Copyright 2015 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 p
+
+import "C"
+
+//export FromPkg
+func FromPkg() int32 { return 1024 }