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// 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 runtime_test
import (
"bytes"
"flag"
"fmt"
"internal/testenv"
"os"
"os/exec"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"testing"
"time"
)
// NOTE: In some configurations, GDB will segfault when sent a SIGWINCH signal.
// Some runtime tests send SIGWINCH to the entire process group, so those tests
// must never run in parallel with GDB tests.
//
// See issue 39021 and https://sourceware.org/bugzilla/show_bug.cgi?id=26056.
func checkGdbEnvironment(t *testing.T) {
testenv.MustHaveGoBuild(t)
switch runtime.GOOS {
case "darwin":
t.Skip("gdb does not work on darwin")
case "netbsd":
t.Skip("gdb does not work with threads on NetBSD; see https://golang.org/issue/22893 and https://gnats.netbsd.org/52548")
case "windows":
t.Skip("gdb tests fail on Windows: https://golang.org/issue/22687")
case "linux":
if runtime.GOARCH == "ppc64" {
t.Skip("skipping gdb tests on linux/ppc64; see https://golang.org/issue/17366")
}
if runtime.GOARCH == "mips" {
t.Skip("skipping gdb tests on linux/mips; see https://golang.org/issue/25939")
}
// Disable GDB tests on alpine until issue #54352 resolved.
if strings.HasSuffix(testenv.Builder(), "-alpine") {
t.Skip("skipping gdb tests on alpine; see https://golang.org/issue/54352")
}
case "freebsd":
t.Skip("skipping gdb tests on FreeBSD; see https://golang.org/issue/29508")
case "aix":
if testing.Short() {
t.Skip("skipping gdb tests on AIX; see https://golang.org/issue/35710")
}
case "plan9":
t.Skip("there is no gdb on Plan 9")
}
if final := os.Getenv("GOROOT_FINAL"); final != "" && testenv.GOROOT(t) != final {
t.Skip("gdb test can fail with GOROOT_FINAL pending")
}
}
func checkGdbVersion(t *testing.T) {
// Issue 11214 reports various failures with older versions of gdb.
out, err := exec.Command("gdb", "--version").CombinedOutput()
if err != nil {
t.Skipf("skipping: error executing gdb: %v", err)
}
re := regexp.MustCompile(`([0-9]+)\.([0-9]+)`)
matches := re.FindSubmatch(out)
if len(matches) < 3 {
t.Skipf("skipping: can't determine gdb version from\n%s\n", out)
}
major, err1 := strconv.Atoi(string(matches[1]))
minor, err2 := strconv.Atoi(string(matches[2]))
if err1 != nil || err2 != nil {
t.Skipf("skipping: can't determine gdb version: %v, %v", err1, err2)
}
if major < 7 || (major == 7 && minor < 7) {
t.Skipf("skipping: gdb version %d.%d too old", major, minor)
}
t.Logf("gdb version %d.%d", major, minor)
}
func checkGdbPython(t *testing.T) {
if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
t.Skip("skipping gdb python tests on illumos and solaris; see golang.org/issue/20821")
}
cmd := exec.Command("gdb", "-nx", "-q", "--batch", "-iex", "python import sys; print('go gdb python support')")
out, err := cmd.CombinedOutput()
if err != nil {
t.Skipf("skipping due to issue running gdb: %v", err)
}
if strings.TrimSpace(string(out)) != "go gdb python support" {
t.Skipf("skipping due to lack of python gdb support: %s", out)
}
}
// checkCleanBacktrace checks that the given backtrace is well formed and does
// not contain any error messages from GDB.
func checkCleanBacktrace(t *testing.T, backtrace string) {
backtrace = strings.TrimSpace(backtrace)
lines := strings.Split(backtrace, "\n")
if len(lines) == 0 {
t.Fatalf("empty backtrace")
}
for i, l := range lines {
if !strings.HasPrefix(l, fmt.Sprintf("#%v ", i)) {
t.Fatalf("malformed backtrace at line %v: %v", i, l)
}
}
// TODO(mundaym): check for unknown frames (e.g. "??").
}
const helloSource = `
import "fmt"
import "runtime"
var gslice []string
func main() {
mapvar := make(map[string]string, 13)
slicemap := make(map[string][]string,11)
chanint := make(chan int, 10)
chanstr := make(chan string, 10)
chanint <- 99
chanint <- 11
chanstr <- "spongepants"
chanstr <- "squarebob"
mapvar["abc"] = "def"
mapvar["ghi"] = "jkl"
slicemap["a"] = []string{"b","c","d"}
slicemap["e"] = []string{"f","g","h"}
strvar := "abc"
ptrvar := &strvar
slicevar := make([]string, 0, 16)
slicevar = append(slicevar, mapvar["abc"])
fmt.Println("hi")
runtime.KeepAlive(ptrvar)
_ = ptrvar // set breakpoint here
gslice = slicevar
fmt.Printf("%v, %v, %v\n", slicemap, <-chanint, <-chanstr)
runtime.KeepAlive(mapvar)
} // END_OF_PROGRAM
`
func lastLine(src []byte) int {
eop := []byte("END_OF_PROGRAM")
for i, l := range bytes.Split(src, []byte("\n")) {
if bytes.Contains(l, eop) {
return i
}
}
return 0
}
func TestGdbPython(t *testing.T) {
testGdbPython(t, false)
}
func TestGdbPythonCgo(t *testing.T) {
if strings.HasPrefix(runtime.GOARCH, "mips") {
testenv.SkipFlaky(t, 37794)
}
testGdbPython(t, true)
}
func testGdbPython(t *testing.T, cgo bool) {
if cgo {
testenv.MustHaveCGO(t)
}
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
checkGdbPython(t)
dir := t.TempDir()
var buf bytes.Buffer
buf.WriteString("package main\n")
if cgo {
buf.WriteString(`import "C"` + "\n")
}
buf.WriteString(helloSource)
src := buf.Bytes()
// Locate breakpoint line
var bp int
lines := bytes.Split(src, []byte("\n"))
for i, line := range lines {
if bytes.Contains(line, []byte("breakpoint")) {
bp = i
break
}
}
err := os.WriteFile(filepath.Join(dir, "main.go"), src, 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
nLines := lastLine(src)
cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
cmd.Dir = dir
out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
if err != nil {
t.Fatalf("building source %v\n%s", err, out)
}
args := []string{"-nx", "-q", "--batch",
"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
"-ex", "set startup-with-shell off",
"-ex", "set print thread-events off",
}
if cgo {
// When we build the cgo version of the program, the system's
// linker is used. Some external linkers, like GNU gold,
// compress the .debug_gdb_scripts into .zdebug_gdb_scripts.
// Until gold and gdb can work together, temporarily load the
// python script directly.
args = append(args,
"-ex", "source "+filepath.Join(testenv.GOROOT(t), "src", "runtime", "runtime-gdb.py"),
)
} else {
args = append(args,
"-ex", "info auto-load python-scripts",
)
}
args = append(args,
"-ex", "set python print-stack full",
"-ex", fmt.Sprintf("br main.go:%d", bp),
"-ex", "run",
"-ex", "echo BEGIN info goroutines\n",
"-ex", "info goroutines",
"-ex", "echo END\n",
"-ex", "echo BEGIN print mapvar\n",
"-ex", "print mapvar",
"-ex", "echo END\n",
"-ex", "echo BEGIN print slicemap\n",
"-ex", "print slicemap",
"-ex", "echo END\n",
"-ex", "echo BEGIN print strvar\n",
"-ex", "print strvar",
"-ex", "echo END\n",
"-ex", "echo BEGIN print chanint\n",
"-ex", "print chanint",
"-ex", "echo END\n",
"-ex", "echo BEGIN print chanstr\n",
"-ex", "print chanstr",
"-ex", "echo END\n",
"-ex", "echo BEGIN info locals\n",
"-ex", "info locals",
"-ex", "echo END\n",
"-ex", "echo BEGIN goroutine 1 bt\n",
"-ex", "goroutine 1 bt",
"-ex", "echo END\n",
"-ex", "echo BEGIN goroutine all bt\n",
"-ex", "goroutine all bt",
"-ex", "echo END\n",
"-ex", "clear main.go:15", // clear the previous break point
"-ex", fmt.Sprintf("br main.go:%d", nLines), // new break point at the end of main
"-ex", "c",
"-ex", "echo BEGIN goroutine 1 bt at the end\n",
"-ex", "goroutine 1 bt",
"-ex", "echo END\n",
filepath.Join(dir, "a.exe"),
)
got, err := exec.Command("gdb", args...).CombinedOutput()
t.Logf("gdb output:\n%s", got)
if err != nil {
t.Fatalf("gdb exited with error: %v", err)
}
firstLine, _, _ := bytes.Cut(got, []byte("\n"))
if string(firstLine) != "Loading Go Runtime support." {
// This can happen when using all.bash with
// GOROOT_FINAL set, because the tests are run before
// the final installation of the files.
cmd := exec.Command(testenv.GoToolPath(t), "env", "GOROOT")
cmd.Env = []string{}
out, err := cmd.CombinedOutput()
if err != nil && bytes.Contains(out, []byte("cannot find GOROOT")) {
t.Skipf("skipping because GOROOT=%s does not exist", testenv.GOROOT(t))
}
_, file, _, _ := runtime.Caller(1)
t.Logf("package testing source file: %s", file)
t.Fatalf("failed to load Go runtime support: %s\n%s", firstLine, got)
}
// Extract named BEGIN...END blocks from output
partRe := regexp.MustCompile(`(?ms)^BEGIN ([^\n]*)\n(.*?)\nEND`)
blocks := map[string]string{}
for _, subs := range partRe.FindAllSubmatch(got, -1) {
blocks[string(subs[1])] = string(subs[2])
}
infoGoroutinesRe := regexp.MustCompile(`\*\s+\d+\s+running\s+`)
if bl := blocks["info goroutines"]; !infoGoroutinesRe.MatchString(bl) {
t.Fatalf("info goroutines failed: %s", bl)
}
printMapvarRe1 := regexp.MustCompile(`^\$[0-9]+ = map\[string\]string = {\[(0x[0-9a-f]+\s+)?"abc"\] = (0x[0-9a-f]+\s+)?"def", \[(0x[0-9a-f]+\s+)?"ghi"\] = (0x[0-9a-f]+\s+)?"jkl"}$`)
printMapvarRe2 := regexp.MustCompile(`^\$[0-9]+ = map\[string\]string = {\[(0x[0-9a-f]+\s+)?"ghi"\] = (0x[0-9a-f]+\s+)?"jkl", \[(0x[0-9a-f]+\s+)?"abc"\] = (0x[0-9a-f]+\s+)?"def"}$`)
if bl := blocks["print mapvar"]; !printMapvarRe1.MatchString(bl) &&
!printMapvarRe2.MatchString(bl) {
t.Fatalf("print mapvar failed: %s", bl)
}
// 2 orders, and possible differences in spacing.
sliceMapSfx1 := `map[string][]string = {["e"] = []string = {"f", "g", "h"}, ["a"] = []string = {"b", "c", "d"}}`
sliceMapSfx2 := `map[string][]string = {["a"] = []string = {"b", "c", "d"}, ["e"] = []string = {"f", "g", "h"}}`
if bl := strings.ReplaceAll(blocks["print slicemap"], " ", " "); !strings.HasSuffix(bl, sliceMapSfx1) && !strings.HasSuffix(bl, sliceMapSfx2) {
t.Fatalf("print slicemap failed: %s", bl)
}
chanIntSfx := `chan int = {99, 11}`
if bl := strings.ReplaceAll(blocks["print chanint"], " ", " "); !strings.HasSuffix(bl, chanIntSfx) {
t.Fatalf("print chanint failed: %s", bl)
}
chanStrSfx := `chan string = {"spongepants", "squarebob"}`
if bl := strings.ReplaceAll(blocks["print chanstr"], " ", " "); !strings.HasSuffix(bl, chanStrSfx) {
t.Fatalf("print chanstr failed: %s", bl)
}
strVarRe := regexp.MustCompile(`^\$[0-9]+ = (0x[0-9a-f]+\s+)?"abc"$`)
if bl := blocks["print strvar"]; !strVarRe.MatchString(bl) {
t.Fatalf("print strvar failed: %s", bl)
}
// The exact format of composite values has changed over time.
// For issue 16338: ssa decompose phase split a slice into
// a collection of scalar vars holding its fields. In such cases
// the DWARF variable location expression should be of the
// form "var.field" and not just "field".
// However, the newer dwarf location list code reconstituted
// aggregates from their fields and reverted their printing
// back to its original form.
// Only test that all variables are listed in 'info locals' since
// different versions of gdb print variables in different
// order and with differing amount of information and formats.
if bl := blocks["info locals"]; !strings.Contains(bl, "slicevar") ||
!strings.Contains(bl, "mapvar") ||
!strings.Contains(bl, "strvar") {
t.Fatalf("info locals failed: %s", bl)
}
// Check that the backtraces are well formed.
checkCleanBacktrace(t, blocks["goroutine 1 bt"])
checkCleanBacktrace(t, blocks["goroutine 1 bt at the end"])
btGoroutine1Re := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
if bl := blocks["goroutine 1 bt"]; !btGoroutine1Re.MatchString(bl) {
t.Fatalf("goroutine 1 bt failed: %s", bl)
}
if bl := blocks["goroutine all bt"]; !btGoroutine1Re.MatchString(bl) {
t.Fatalf("goroutine all bt failed: %s", bl)
}
btGoroutine1AtTheEndRe := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
if bl := blocks["goroutine 1 bt at the end"]; !btGoroutine1AtTheEndRe.MatchString(bl) {
t.Fatalf("goroutine 1 bt at the end failed: %s", bl)
}
}
const backtraceSource = `
package main
//go:noinline
func aaa() bool { return bbb() }
//go:noinline
func bbb() bool { return ccc() }
//go:noinline
func ccc() bool { return ddd() }
//go:noinline
func ddd() bool { return f() }
//go:noinline
func eee() bool { return true }
var f = eee
func main() {
_ = aaa()
}
`
// TestGdbBacktrace tests that gdb can unwind the stack correctly
// using only the DWARF debug info.
func TestGdbBacktrace(t *testing.T) {
if runtime.GOOS == "netbsd" {
testenv.SkipFlaky(t, 15603)
}
if flag.Lookup("test.parallel").Value.(flag.Getter).Get().(int) < 2 {
// It is possible that this test will hang for a long time due to an
// apparent GDB bug reported in https://go.dev/issue/37405.
// If test parallelism is high enough, that might be ok: the other parallel
// tests will finish, and then this test will finish right before it would
// time out. However, if test are running sequentially, a hang in this test
// would likely cause the remaining tests to run out of time.
testenv.SkipFlaky(t, 37405)
}
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
dir := t.TempDir()
// Build the source code.
src := filepath.Join(dir, "main.go")
err := os.WriteFile(src, []byte(backtraceSource), 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
cmd.Dir = dir
out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
if err != nil {
t.Fatalf("building source %v\n%s", err, out)
}
// Execute gdb commands.
start := time.Now()
args := []string{"-nx", "-batch",
"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
"-ex", "set startup-with-shell off",
"-ex", "break main.eee",
"-ex", "run",
"-ex", "backtrace",
"-ex", "continue",
filepath.Join(dir, "a.exe"),
}
cmd = testenv.Command(t, "gdb", args...)
// Work around the GDB hang reported in https://go.dev/issue/37405.
// Sometimes (rarely), the GDB process hangs completely when the Go program
// exits, and we suspect that the bug is on the GDB side.
//
// The default Cancel function added by testenv.Command will mark the test as
// failed if it is in danger of timing out, but we want to instead mark it as
// skipped. Change the Cancel function to kill the process and merely log
// instead of failing the test.
//
// (This approach does not scale: if the test parallelism is less than or
// equal to the number of tests that run right up to the deadline, then the
// remaining parallel tests are likely to time out. But as long as it's just
// this one flaky test, it's probably fine..?)
//
// If there is no deadline set on the test at all, relying on the timeout set
// by testenv.Command will cause the test to hang indefinitely, but that's
// what “no deadline” means, after all — and it's probably the right behavior
// anyway if someone is trying to investigate and fix the GDB bug.
cmd.Cancel = func() error {
t.Logf("GDB command timed out after %v: %v", time.Since(start), cmd)
return cmd.Process.Kill()
}
got, err := cmd.CombinedOutput()
t.Logf("gdb output:\n%s", got)
if err != nil {
if bytes.Contains(got, []byte("internal-error: wait returned unexpected status 0x0")) {
// GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28551
testenv.SkipFlaky(t, 43068)
}
if bytes.Contains(got, []byte("Couldn't get registers: No such process.")) {
// GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=9086
testenv.SkipFlaky(t, 50838)
}
if bytes.Contains(got, []byte(" exited normally]\n")) {
// GDB bug: Sometimes the inferior exits fine,
// but then GDB hangs.
testenv.SkipFlaky(t, 37405)
}
t.Fatalf("gdb exited with error: %v", err)
}
// Check that the backtrace matches the source code.
bt := []string{
"eee",
"ddd",
"ccc",
"bbb",
"aaa",
"main",
}
for i, name := range bt {
s := fmt.Sprintf("#%v.*main\\.%v", i, name)
re := regexp.MustCompile(s)
if found := re.Find(got) != nil; !found {
t.Fatalf("could not find '%v' in backtrace", s)
}
}
}
const autotmpTypeSource = `
package main
type astruct struct {
a, b int
}
func main() {
var iface interface{} = map[string]astruct{}
var iface2 interface{} = []astruct{}
println(iface, iface2)
}
`
// TestGdbAutotmpTypes ensures that types of autotmp variables appear in .debug_info
// See bug #17830.
func TestGdbAutotmpTypes(t *testing.T) {
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
if runtime.GOOS == "aix" && testing.Short() {
t.Skip("TestGdbAutotmpTypes is too slow on aix/ppc64")
}
dir := t.TempDir()
// Build the source code.
src := filepath.Join(dir, "main.go")
err := os.WriteFile(src, []byte(autotmpTypeSource), 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe", "main.go")
cmd.Dir = dir
out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
if err != nil {
t.Fatalf("building source %v\n%s", err, out)
}
// Execute gdb commands.
args := []string{"-nx", "-batch",
"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
"-ex", "set startup-with-shell off",
// Some gdb may set scheduling-locking as "step" by default. This prevents background tasks
// (e.g GC) from completing which may result in a hang when executing the step command.
// See #49852.
"-ex", "set scheduler-locking off",
"-ex", "break main.main",
"-ex", "run",
"-ex", "step",
"-ex", "info types astruct",
filepath.Join(dir, "a.exe"),
}
got, err := exec.Command("gdb", args...).CombinedOutput()
t.Logf("gdb output:\n%s", got)
if err != nil {
t.Fatalf("gdb exited with error: %v", err)
}
sgot := string(got)
// Check that the backtrace matches the source code.
types := []string{
"[]main.astruct;",
"bucket<string,main.astruct>;",
"hash<string,main.astruct>;",
"main.astruct;",
"hash<string,main.astruct> * map[string]main.astruct;",
}
for _, name := range types {
if !strings.Contains(sgot, name) {
t.Fatalf("could not find %s in 'info typrs astruct' output", name)
}
}
}
const constsSource = `
package main
const aConstant int = 42
const largeConstant uint64 = ^uint64(0)
const minusOne int64 = -1
func main() {
println("hello world")
}
`
func TestGdbConst(t *testing.T) {
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
dir := t.TempDir()
// Build the source code.
src := filepath.Join(dir, "main.go")
err := os.WriteFile(src, []byte(constsSource), 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe", "main.go")
cmd.Dir = dir
out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
if err != nil {
t.Fatalf("building source %v\n%s", err, out)
}
// Execute gdb commands.
args := []string{"-nx", "-batch",
"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
"-ex", "set startup-with-shell off",
"-ex", "break main.main",
"-ex", "run",
"-ex", "print main.aConstant",
"-ex", "print main.largeConstant",
"-ex", "print main.minusOne",
"-ex", "print 'runtime.mSpanInUse'",
"-ex", "print 'runtime._PageSize'",
filepath.Join(dir, "a.exe"),
}
got, err := exec.Command("gdb", args...).CombinedOutput()
t.Logf("gdb output:\n%s", got)
if err != nil {
t.Fatalf("gdb exited with error: %v", err)
}
sgot := strings.ReplaceAll(string(got), "\r\n", "\n")
if !strings.Contains(sgot, "\n$1 = 42\n$2 = 18446744073709551615\n$3 = -1\n$4 = 1 '\\001'\n$5 = 8192") {
t.Fatalf("output mismatch")
}
}
const panicSource = `
package main
import "runtime/debug"
func main() {
debug.SetTraceback("crash")
crash()
}
func crash() {
panic("panic!")
}
`
// TestGdbPanic tests that gdb can unwind the stack correctly
// from SIGABRTs from Go panics.
func TestGdbPanic(t *testing.T) {
checkGdbEnvironment(t)
t.Parallel()
checkGdbVersion(t)
dir := t.TempDir()
// Build the source code.
src := filepath.Join(dir, "main.go")
err := os.WriteFile(src, []byte(panicSource), 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
cmd.Dir = dir
out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
if err != nil {
t.Fatalf("building source %v\n%s", err, out)
}
// Execute gdb commands.
args := []string{"-nx", "-batch",
"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
"-ex", "set startup-with-shell off",
"-ex", "run",
"-ex", "backtrace",
filepath.Join(dir, "a.exe"),
}
got, err := exec.Command("gdb", args...).CombinedOutput()
t.Logf("gdb output:\n%s", got)
if err != nil {
t.Fatalf("gdb exited with error: %v", err)
}
// Check that the backtrace matches the source code.
bt := []string{
`crash`,
`main`,
}
for _, name := range bt {
s := fmt.Sprintf("(#.* .* in )?main\\.%v", name)
re := regexp.MustCompile(s)
if found := re.Find(got) != nil; !found {
t.Fatalf("could not find '%v' in backtrace", s)
}
}
}
const InfCallstackSource = `
package main
import "C"
import "time"
func loop() {
for i := 0; i < 1000; i++ {
time.Sleep(time.Millisecond*5)
}
}
func main() {
go loop()
time.Sleep(time.Second * 1)
}
`
// TestGdbInfCallstack tests that gdb can unwind the callstack of cgo programs
// on arm64 platforms without endless frames of function 'crossfunc1'.
// https://golang.org/issue/37238
func TestGdbInfCallstack(t *testing.T) {
checkGdbEnvironment(t)
testenv.MustHaveCGO(t)
if runtime.GOARCH != "arm64" {
t.Skip("skipping infinite callstack test on non-arm64 arches")
}
t.Parallel()
checkGdbVersion(t)
dir := t.TempDir()
// Build the source code.
src := filepath.Join(dir, "main.go")
err := os.WriteFile(src, []byte(InfCallstackSource), 0644)
if err != nil {
t.Fatalf("failed to create file: %v", err)
}
cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
cmd.Dir = dir
out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
if err != nil {
t.Fatalf("building source %v\n%s", err, out)
}
// Execute gdb commands.
// 'setg_gcc' is the first point where we can reproduce the issue with just one 'run' command.
args := []string{"-nx", "-batch",
"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
"-ex", "set startup-with-shell off",
"-ex", "break setg_gcc",
"-ex", "run",
"-ex", "backtrace 3",
"-ex", "disable 1",
"-ex", "continue",
filepath.Join(dir, "a.exe"),
}
got, err := exec.Command("gdb", args...).CombinedOutput()
t.Logf("gdb output:\n%s", got)
if err != nil {
t.Fatalf("gdb exited with error: %v", err)
}
// Check that the backtrace matches
// We check the 3 inner most frames only as they are present certainly, according to gcc_<OS>_arm64.c
bt := []string{
`setg_gcc`,
`crosscall1`,
`threadentry`,
}
for i, name := range bt {
s := fmt.Sprintf("#%v.*%v", i, name)
re := regexp.MustCompile(s)
if found := re.Find(got) != nil; !found {
t.Fatalf("could not find '%v' in backtrace", s)
}
}
}