Source file src/runtime/runtime-gdb_test.go

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package runtime_test
     6  
     7  import (
     8  	"bytes"
     9  	"flag"
    10  	"fmt"
    11  	"internal/abi"
    12  	"internal/goexperiment"
    13  	"internal/testenv"
    14  	"os"
    15  	"os/exec"
    16  	"path/filepath"
    17  	"regexp"
    18  	"runtime"
    19  	"strconv"
    20  	"strings"
    21  	"testing"
    22  	"time"
    23  )
    24  
    25  // NOTE: In some configurations, GDB will segfault when sent a SIGWINCH signal.
    26  // Some runtime tests send SIGWINCH to the entire process group, so those tests
    27  // must never run in parallel with GDB tests.
    28  //
    29  // See issue 39021 and https://sourceware.org/bugzilla/show_bug.cgi?id=26056.
    30  
    31  func checkGdbEnvironment(t *testing.T) {
    32  	testenv.MustHaveGoBuild(t)
    33  	switch runtime.GOOS {
    34  	case "darwin":
    35  		t.Skip("gdb does not work on darwin")
    36  	case "netbsd":
    37  		t.Skip("gdb does not work with threads on NetBSD; see https://golang.org/issue/22893 and https://gnats.netbsd.org/52548")
    38  	case "linux":
    39  		if runtime.GOARCH == "ppc64" {
    40  			t.Skip("skipping gdb tests on linux/ppc64; see https://golang.org/issue/17366")
    41  		}
    42  		if runtime.GOARCH == "mips" {
    43  			t.Skip("skipping gdb tests on linux/mips; see https://golang.org/issue/25939")
    44  		}
    45  		// Disable GDB tests on alpine until issue #54352 resolved.
    46  		if strings.HasSuffix(testenv.Builder(), "-alpine") {
    47  			t.Skip("skipping gdb tests on alpine; see https://golang.org/issue/54352")
    48  		}
    49  	case "freebsd":
    50  		t.Skip("skipping gdb tests on FreeBSD; see https://golang.org/issue/29508")
    51  	case "aix":
    52  		if testing.Short() {
    53  			t.Skip("skipping gdb tests on AIX; see https://golang.org/issue/35710")
    54  		}
    55  	case "plan9":
    56  		t.Skip("there is no gdb on Plan 9")
    57  	}
    58  }
    59  
    60  func checkGdbVersion(t *testing.T) {
    61  	// Issue 11214 reports various failures with older versions of gdb.
    62  	out, err := exec.Command("gdb", "--version").CombinedOutput()
    63  	if err != nil {
    64  		t.Skipf("skipping: error executing gdb: %v", err)
    65  	}
    66  	re := regexp.MustCompile(`([0-9]+)\.([0-9]+)`)
    67  	matches := re.FindSubmatch(out)
    68  	if len(matches) < 3 {
    69  		t.Skipf("skipping: can't determine gdb version from\n%s\n", out)
    70  	}
    71  	major, err1 := strconv.Atoi(string(matches[1]))
    72  	minor, err2 := strconv.Atoi(string(matches[2]))
    73  	if err1 != nil || err2 != nil {
    74  		t.Skipf("skipping: can't determine gdb version: %v, %v", err1, err2)
    75  	}
    76  	// The Go toolchain now generates DWARF 5 by default, which needs
    77  	// a GDB version of 10 or above.
    78  	if major < 10 {
    79  		t.Skipf("skipping: gdb version %d.%d too old", major, minor)
    80  	}
    81  	t.Logf("gdb version %d.%d", major, minor)
    82  }
    83  
    84  func checkGdbPython(t *testing.T) {
    85  	if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
    86  		t.Skip("skipping gdb python tests on illumos and solaris; see golang.org/issue/20821")
    87  	}
    88  	args := []string{"-nx", "-q", "--batch", "-iex", "python import sys; print('go gdb python support')"}
    89  	gdbArgsFixup(args)
    90  	cmd := exec.Command("gdb", args...)
    91  	out, err := cmd.CombinedOutput()
    92  
    93  	if err != nil {
    94  		t.Skipf("skipping due to issue running gdb: %v", err)
    95  	}
    96  	if strings.TrimSpace(string(out)) != "go gdb python support" {
    97  		t.Skipf("skipping due to lack of python gdb support: %s", out)
    98  	}
    99  }
   100  
   101  // checkCleanBacktrace checks that the given backtrace is well formed and does
   102  // not contain any error messages from GDB.
   103  func checkCleanBacktrace(t *testing.T, backtrace string) {
   104  	backtrace = strings.TrimSpace(backtrace)
   105  	lines := strings.Split(backtrace, "\n")
   106  	if len(lines) == 0 {
   107  		t.Fatalf("empty backtrace")
   108  	}
   109  	for i, l := range lines {
   110  		if !strings.HasPrefix(l, fmt.Sprintf("#%v  ", i)) {
   111  			t.Fatalf("malformed backtrace at line %v: %v", i, l)
   112  		}
   113  	}
   114  	// TODO(mundaym): check for unknown frames (e.g. "??").
   115  }
   116  
   117  // checkPtraceScope checks the value of the kernel parameter ptrace_scope,
   118  // skips the test when gdb cannot attach to the target process via ptrace.
   119  // See issue 69932
   120  //
   121  // 0 - Default attach security permissions.
   122  // 1 - Restricted attach. Only child processes plus normal permissions.
   123  // 2 - Admin-only attach. Only executables with CAP_SYS_PTRACE.
   124  // 3 - No attach. No process may call ptrace at all. Irrevocable.
   125  func checkPtraceScope(t *testing.T) {
   126  	if runtime.GOOS != "linux" {
   127  		return
   128  	}
   129  
   130  	// If the Linux kernel does not have the YAMA module enabled,
   131  	// there will be no ptrace_scope file, which does not affect the tests.
   132  	path := "/proc/sys/kernel/yama/ptrace_scope"
   133  	if _, err := os.Stat(path); os.IsNotExist(err) {
   134  		return
   135  	}
   136  
   137  	data, err := os.ReadFile(path)
   138  	if err != nil {
   139  		t.Fatalf("failed to read file: %v", err)
   140  	}
   141  	value, err := strconv.Atoi(strings.TrimSpace(string(data)))
   142  	if err != nil {
   143  		t.Fatalf("failed converting value to int: %v", err)
   144  	}
   145  	switch value {
   146  	case 3:
   147  		t.Skip("skipping ptrace: Operation not permitted")
   148  	case 2:
   149  		if os.Geteuid() != 0 {
   150  			t.Skip("skipping ptrace: Operation not permitted with non-root user")
   151  		}
   152  	}
   153  }
   154  
   155  // NOTE: the maps below are allocated larger than abi.MapBucketCount
   156  // to ensure that they are not "optimized out".
   157  
   158  var helloSource = `
   159  import "fmt"
   160  import "runtime"
   161  var gslice []string
   162  // TODO(prattmic): Stack allocated maps initialized inline appear "optimized out" in GDB.
   163  var smallmapvar map[string]string
   164  func main() {
   165  	smallmapvar = make(map[string]string)
   166  	mapvar := make(map[string]string, ` + strconv.FormatInt(abi.OldMapBucketCount+9, 10) + `)
   167  	slicemap := make(map[string][]string,` + strconv.FormatInt(abi.OldMapBucketCount+3, 10) + `)
   168      chanint := make(chan int, 10)
   169      chanstr := make(chan string, 10)
   170      chanint <- 99
   171  	chanint <- 11
   172      chanstr <- "spongepants"
   173      chanstr <- "squarebob"
   174  	smallmapvar["abc"] = "def"
   175  	mapvar["abc"] = "def"
   176  	mapvar["ghi"] = "jkl"
   177  	slicemap["a"] = []string{"b","c","d"}
   178      slicemap["e"] = []string{"f","g","h"}
   179  	strvar := "abc"
   180  	ptrvar := &strvar
   181  	slicevar := make([]string, 0, 16)
   182  	slicevar = append(slicevar, mapvar["abc"])
   183  	fmt.Println("hi")
   184  	runtime.KeepAlive(ptrvar)
   185  	_ = ptrvar // set breakpoint here
   186  	gslice = slicevar
   187  	fmt.Printf("%v, %v, %v\n", slicemap, <-chanint, <-chanstr)
   188  	runtime.KeepAlive(smallmapvar)
   189  	runtime.KeepAlive(mapvar)
   190  }  // END_OF_PROGRAM
   191  `
   192  
   193  func lastLine(src []byte) int {
   194  	eop := []byte("END_OF_PROGRAM")
   195  	for i, l := range bytes.Split(src, []byte("\n")) {
   196  		if bytes.Contains(l, eop) {
   197  			return i
   198  		}
   199  	}
   200  	return 0
   201  }
   202  
   203  func gdbArgsFixup(args []string) {
   204  	if runtime.GOOS != "windows" {
   205  		return
   206  	}
   207  	// On Windows, some gdb flavors expect -ex and -iex arguments
   208  	// containing spaces to be double quoted.
   209  	var quote bool
   210  	for i, arg := range args {
   211  		if arg == "-iex" || arg == "-ex" {
   212  			quote = true
   213  		} else if quote {
   214  			if strings.ContainsRune(arg, ' ') {
   215  				args[i] = `"` + arg + `"`
   216  			}
   217  			quote = false
   218  		}
   219  	}
   220  }
   221  
   222  func TestGdbPython(t *testing.T) {
   223  	testGdbPython(t, false)
   224  }
   225  
   226  func TestGdbPythonCgo(t *testing.T) {
   227  	if strings.HasPrefix(runtime.GOARCH, "mips") {
   228  		testenv.SkipFlaky(t, 37794)
   229  	}
   230  	testGdbPython(t, true)
   231  }
   232  
   233  func testGdbPython(t *testing.T, cgo bool) {
   234  	if cgo {
   235  		testenv.MustHaveCGO(t)
   236  	}
   237  
   238  	checkGdbEnvironment(t)
   239  	t.Parallel()
   240  	checkGdbVersion(t)
   241  	checkGdbPython(t)
   242  	checkPtraceScope(t)
   243  
   244  	dir := t.TempDir()
   245  
   246  	var buf bytes.Buffer
   247  	buf.WriteString("package main\n")
   248  	if cgo {
   249  		buf.WriteString(`import "C"` + "\n")
   250  	}
   251  	buf.WriteString(helloSource)
   252  
   253  	src := buf.Bytes()
   254  
   255  	// Locate breakpoint line
   256  	var bp int
   257  	lines := bytes.Split(src, []byte("\n"))
   258  	for i, line := range lines {
   259  		if bytes.Contains(line, []byte("breakpoint")) {
   260  			bp = i
   261  			break
   262  		}
   263  	}
   264  
   265  	err := os.WriteFile(filepath.Join(dir, "main.go"), src, 0644)
   266  	if err != nil {
   267  		t.Fatalf("failed to create file: %v", err)
   268  	}
   269  	nLines := lastLine(src)
   270  
   271  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   272  	cmd.Dir = dir
   273  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   274  	if err != nil {
   275  		t.Fatalf("building source %v\n%s", err, out)
   276  	}
   277  
   278  	args := []string{"-nx", "-q", "--batch",
   279  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   280  		"-ex", "set startup-with-shell off",
   281  		"-ex", "set print thread-events off",
   282  	}
   283  	if cgo {
   284  		// When we build the cgo version of the program, the system's
   285  		// linker is used. Some external linkers, like GNU gold,
   286  		// compress the .debug_gdb_scripts into .zdebug_gdb_scripts.
   287  		// Until gold and gdb can work together, temporarily load the
   288  		// python script directly.
   289  		args = append(args,
   290  			"-ex", "source "+filepath.Join(testenv.GOROOT(t), "src", "runtime", "runtime-gdb.py"),
   291  		)
   292  	} else {
   293  		args = append(args,
   294  			"-ex", "info auto-load python-scripts",
   295  		)
   296  	}
   297  	args = append(args,
   298  		"-ex", "set python print-stack full",
   299  		"-ex", fmt.Sprintf("br main.go:%d", bp),
   300  		"-ex", "run",
   301  		"-ex", "echo BEGIN info goroutines\n",
   302  		"-ex", "info goroutines",
   303  		"-ex", "echo END\n",
   304  		"-ex", "echo BEGIN print smallmapvar\n",
   305  		"-ex", "print smallmapvar",
   306  		"-ex", "echo END\n",
   307  		"-ex", "echo BEGIN print mapvar\n",
   308  		"-ex", "print mapvar",
   309  		"-ex", "echo END\n",
   310  		"-ex", "echo BEGIN print slicemap\n",
   311  		"-ex", "print slicemap",
   312  		"-ex", "echo END\n",
   313  		"-ex", "echo BEGIN print strvar\n",
   314  		"-ex", "print strvar",
   315  		"-ex", "echo END\n",
   316  		"-ex", "echo BEGIN print chanint\n",
   317  		"-ex", "print chanint",
   318  		"-ex", "echo END\n",
   319  		"-ex", "echo BEGIN print chanstr\n",
   320  		"-ex", "print chanstr",
   321  		"-ex", "echo END\n",
   322  		"-ex", "echo BEGIN info locals\n",
   323  		"-ex", "info locals",
   324  		"-ex", "echo END\n",
   325  		"-ex", "echo BEGIN goroutine 1 bt\n",
   326  		"-ex", "goroutine 1 bt",
   327  		"-ex", "echo END\n",
   328  		"-ex", "echo BEGIN goroutine all bt\n",
   329  		"-ex", "goroutine all bt",
   330  		"-ex", "echo END\n",
   331  		"-ex", "clear main.go:15", // clear the previous break point
   332  		"-ex", fmt.Sprintf("br main.go:%d", nLines), // new break point at the end of main
   333  		"-ex", "c",
   334  		"-ex", "echo BEGIN goroutine 1 bt at the end\n",
   335  		"-ex", "goroutine 1 bt",
   336  		"-ex", "echo END\n",
   337  		filepath.Join(dir, "a.exe"),
   338  	)
   339  	gdbArgsFixup(args)
   340  	got, err := exec.Command("gdb", args...).CombinedOutput()
   341  	t.Logf("gdb output:\n%s", got)
   342  	if err != nil {
   343  		t.Fatalf("gdb exited with error: %v", err)
   344  	}
   345  
   346  	got = bytes.ReplaceAll(got, []byte("\r\n"), []byte("\n")) // normalize line endings
   347  	// Extract named BEGIN...END blocks from output
   348  	partRe := regexp.MustCompile(`(?ms)^BEGIN ([^\n]*)\n(.*?)\nEND`)
   349  	blocks := map[string]string{}
   350  	for _, subs := range partRe.FindAllSubmatch(got, -1) {
   351  		blocks[string(subs[1])] = string(subs[2])
   352  	}
   353  
   354  	infoGoroutinesRe := regexp.MustCompile(`\*\s+\d+\s+running\s+`)
   355  	if bl := blocks["info goroutines"]; !infoGoroutinesRe.MatchString(bl) {
   356  		t.Fatalf("info goroutines failed: %s", bl)
   357  	}
   358  
   359  	printSmallMapvarRe := regexp.MustCompile(`^\$[0-9]+ = map\[string\]string = {\[(0x[0-9a-f]+\s+)?"abc"\] = (0x[0-9a-f]+\s+)?"def"}$`)
   360  	if bl := blocks["print smallmapvar"]; !printSmallMapvarRe.MatchString(bl) {
   361  		t.Fatalf("print smallmapvar failed: %s", bl)
   362  	}
   363  
   364  	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"}$`)
   365  	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"}$`)
   366  	if bl := blocks["print mapvar"]; !printMapvarRe1.MatchString(bl) &&
   367  		!printMapvarRe2.MatchString(bl) {
   368  		t.Fatalf("print mapvar failed: %s", bl)
   369  	}
   370  
   371  	// 2 orders, and possible differences in spacing.
   372  	sliceMapSfx1 := `map[string][]string = {["e"] = []string = {"f", "g", "h"}, ["a"] = []string = {"b", "c", "d"}}`
   373  	sliceMapSfx2 := `map[string][]string = {["a"] = []string = {"b", "c", "d"}, ["e"] = []string = {"f", "g", "h"}}`
   374  	if bl := strings.ReplaceAll(blocks["print slicemap"], "  ", " "); !strings.HasSuffix(bl, sliceMapSfx1) && !strings.HasSuffix(bl, sliceMapSfx2) {
   375  		t.Fatalf("print slicemap failed: %s", bl)
   376  	}
   377  
   378  	chanIntSfx := `chan int = {99, 11}`
   379  	if bl := strings.ReplaceAll(blocks["print chanint"], "  ", " "); !strings.HasSuffix(bl, chanIntSfx) {
   380  		t.Fatalf("print chanint failed: %s", bl)
   381  	}
   382  
   383  	chanStrSfx := `chan string = {"spongepants", "squarebob"}`
   384  	if bl := strings.ReplaceAll(blocks["print chanstr"], "  ", " "); !strings.HasSuffix(bl, chanStrSfx) {
   385  		t.Fatalf("print chanstr failed: %s", bl)
   386  	}
   387  
   388  	strVarRe := regexp.MustCompile(`^\$[0-9]+ = (0x[0-9a-f]+\s+)?"abc"$`)
   389  	if bl := blocks["print strvar"]; !strVarRe.MatchString(bl) {
   390  		t.Fatalf("print strvar failed: %s", bl)
   391  	}
   392  
   393  	// The exact format of composite values has changed over time.
   394  	// For issue 16338: ssa decompose phase split a slice into
   395  	// a collection of scalar vars holding its fields. In such cases
   396  	// the DWARF variable location expression should be of the
   397  	// form "var.field" and not just "field".
   398  	// However, the newer dwarf location list code reconstituted
   399  	// aggregates from their fields and reverted their printing
   400  	// back to its original form.
   401  	// Only test that all variables are listed in 'info locals' since
   402  	// different versions of gdb print variables in different
   403  	// order and with differing amount of information and formats.
   404  
   405  	if bl := blocks["info locals"]; !strings.Contains(bl, "slicevar") ||
   406  		!strings.Contains(bl, "mapvar") ||
   407  		!strings.Contains(bl, "strvar") {
   408  		t.Fatalf("info locals failed: %s", bl)
   409  	}
   410  
   411  	// Check that the backtraces are well formed.
   412  	checkCleanBacktrace(t, blocks["goroutine 1 bt"])
   413  	checkCleanBacktrace(t, blocks["goroutine 1 bt at the end"])
   414  
   415  	btGoroutine1Re := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
   416  	if bl := blocks["goroutine 1 bt"]; !btGoroutine1Re.MatchString(bl) {
   417  		t.Fatalf("goroutine 1 bt failed: %s", bl)
   418  	}
   419  
   420  	if bl := blocks["goroutine all bt"]; !btGoroutine1Re.MatchString(bl) {
   421  		t.Fatalf("goroutine all bt failed: %s", bl)
   422  	}
   423  
   424  	btGoroutine1AtTheEndRe := regexp.MustCompile(`(?m)^#0\s+(0x[0-9a-f]+\s+in\s+)?main\.main.+at`)
   425  	if bl := blocks["goroutine 1 bt at the end"]; !btGoroutine1AtTheEndRe.MatchString(bl) {
   426  		t.Fatalf("goroutine 1 bt at the end failed: %s", bl)
   427  	}
   428  }
   429  
   430  const backtraceSource = `
   431  package main
   432  
   433  //go:noinline
   434  func aaa() bool { return bbb() }
   435  
   436  //go:noinline
   437  func bbb() bool { return ccc() }
   438  
   439  //go:noinline
   440  func ccc() bool { return ddd() }
   441  
   442  //go:noinline
   443  func ddd() bool { return f() }
   444  
   445  //go:noinline
   446  func eee() bool { return true }
   447  
   448  var f = eee
   449  
   450  func main() {
   451  	_ = aaa()
   452  }
   453  `
   454  
   455  // TestGdbBacktrace tests that gdb can unwind the stack correctly
   456  // using only the DWARF debug info.
   457  func TestGdbBacktrace(t *testing.T) {
   458  	if runtime.GOOS == "netbsd" {
   459  		testenv.SkipFlaky(t, 15603)
   460  	}
   461  	if flag.Lookup("test.parallel").Value.(flag.Getter).Get().(int) < 2 {
   462  		// It is possible that this test will hang for a long time due to an
   463  		// apparent GDB bug reported in https://go.dev/issue/37405.
   464  		// If test parallelism is high enough, that might be ok: the other parallel
   465  		// tests will finish, and then this test will finish right before it would
   466  		// time out. However, if test are running sequentially, a hang in this test
   467  		// would likely cause the remaining tests to run out of time.
   468  		testenv.SkipFlaky(t, 37405)
   469  	}
   470  
   471  	checkGdbEnvironment(t)
   472  	t.Parallel()
   473  	checkGdbVersion(t)
   474  	checkPtraceScope(t)
   475  
   476  	dir := t.TempDir()
   477  
   478  	// Build the source code.
   479  	src := filepath.Join(dir, "main.go")
   480  	err := os.WriteFile(src, []byte(backtraceSource), 0644)
   481  	if err != nil {
   482  		t.Fatalf("failed to create file: %v", err)
   483  	}
   484  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   485  	cmd.Dir = dir
   486  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   487  	if err != nil {
   488  		t.Fatalf("building source %v\n%s", err, out)
   489  	}
   490  
   491  	// Execute gdb commands.
   492  	start := time.Now()
   493  	args := []string{"-nx", "-batch",
   494  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   495  		"-ex", "set startup-with-shell off",
   496  		"-ex", "break main.eee",
   497  		"-ex", "run",
   498  		"-ex", "backtrace",
   499  		"-ex", "continue",
   500  		filepath.Join(dir, "a.exe"),
   501  	}
   502  	gdbArgsFixup(args)
   503  	cmd = testenv.Command(t, "gdb", args...)
   504  
   505  	// Work around the GDB hang reported in https://go.dev/issue/37405.
   506  	// Sometimes (rarely), the GDB process hangs completely when the Go program
   507  	// exits, and we suspect that the bug is on the GDB side.
   508  	//
   509  	// The default Cancel function added by testenv.Command will mark the test as
   510  	// failed if it is in danger of timing out, but we want to instead mark it as
   511  	// skipped. Change the Cancel function to kill the process and merely log
   512  	// instead of failing the test.
   513  	//
   514  	// (This approach does not scale: if the test parallelism is less than or
   515  	// equal to the number of tests that run right up to the deadline, then the
   516  	// remaining parallel tests are likely to time out. But as long as it's just
   517  	// this one flaky test, it's probably fine..?)
   518  	//
   519  	// If there is no deadline set on the test at all, relying on the timeout set
   520  	// by testenv.Command will cause the test to hang indefinitely, but that's
   521  	// what “no deadline” means, after all — and it's probably the right behavior
   522  	// anyway if someone is trying to investigate and fix the GDB bug.
   523  	cmd.Cancel = func() error {
   524  		t.Logf("GDB command timed out after %v: %v", time.Since(start), cmd)
   525  		return cmd.Process.Kill()
   526  	}
   527  
   528  	got, err := cmd.CombinedOutput()
   529  	t.Logf("gdb output:\n%s", got)
   530  	if err != nil {
   531  		switch {
   532  		case bytes.Contains(got, []byte("internal-error: wait returned unexpected status 0x0")):
   533  			// GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28551
   534  			testenv.SkipFlaky(t, 43068)
   535  		case bytes.Contains(got, []byte("Couldn't get registers: No such process.")),
   536  			bytes.Contains(got, []byte("Unable to fetch general registers.: No such process.")),
   537  			bytes.Contains(got, []byte("reading register pc (#64): No such process.")):
   538  			// GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=9086
   539  			testenv.SkipFlaky(t, 50838)
   540  		case bytes.Contains(got, []byte("waiting for new child: No child processes.")):
   541  			// GDB bug: Sometimes it fails to wait for a clone child.
   542  			testenv.SkipFlaky(t, 60553)
   543  		case bytes.Contains(got, []byte(" exited normally]\n")):
   544  			// GDB bug: Sometimes the inferior exits fine,
   545  			// but then GDB hangs.
   546  			testenv.SkipFlaky(t, 37405)
   547  		}
   548  		t.Fatalf("gdb exited with error: %v", err)
   549  	}
   550  
   551  	// Check that the backtrace matches the source code.
   552  	bt := []string{
   553  		"eee",
   554  		"ddd",
   555  		"ccc",
   556  		"bbb",
   557  		"aaa",
   558  		"main",
   559  	}
   560  	for i, name := range bt {
   561  		s := fmt.Sprintf("#%v.*main\\.%v", i, name)
   562  		re := regexp.MustCompile(s)
   563  		if found := re.Find(got) != nil; !found {
   564  			t.Fatalf("could not find '%v' in backtrace", s)
   565  		}
   566  	}
   567  }
   568  
   569  const autotmpTypeSource = `
   570  package main
   571  
   572  type astruct struct {
   573  	a, b int
   574  }
   575  
   576  func main() {
   577  	var iface interface{} = map[string]astruct{}
   578  	var iface2 interface{} = []astruct{}
   579  	println(iface, iface2)
   580  }
   581  `
   582  
   583  // TestGdbAutotmpTypes ensures that types of autotmp variables appear in .debug_info
   584  // See bug #17830.
   585  func TestGdbAutotmpTypes(t *testing.T) {
   586  	checkGdbEnvironment(t)
   587  	t.Parallel()
   588  	checkGdbVersion(t)
   589  	checkPtraceScope(t)
   590  
   591  	if runtime.GOOS == "aix" && testing.Short() {
   592  		t.Skip("TestGdbAutotmpTypes is too slow on aix/ppc64")
   593  	}
   594  
   595  	dir := t.TempDir()
   596  
   597  	// Build the source code.
   598  	src := filepath.Join(dir, "main.go")
   599  	err := os.WriteFile(src, []byte(autotmpTypeSource), 0644)
   600  	if err != nil {
   601  		t.Fatalf("failed to create file: %v", err)
   602  	}
   603  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe", "main.go")
   604  	cmd.Dir = dir
   605  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   606  	if err != nil {
   607  		t.Fatalf("building source %v\n%s", err, out)
   608  	}
   609  
   610  	// Execute gdb commands.
   611  	args := []string{"-nx", "-batch",
   612  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   613  		"-ex", "set startup-with-shell off",
   614  		// Some gdb may set scheduling-locking as "step" by default. This prevents background tasks
   615  		// (e.g GC) from completing which may result in a hang when executing the step command.
   616  		// See #49852.
   617  		"-ex", "set scheduler-locking off",
   618  		"-ex", "break main.main",
   619  		"-ex", "run",
   620  		"-ex", "step",
   621  		"-ex", "info types astruct",
   622  		filepath.Join(dir, "a.exe"),
   623  	}
   624  	gdbArgsFixup(args)
   625  	got, err := exec.Command("gdb", args...).CombinedOutput()
   626  	t.Logf("gdb output:\n%s", got)
   627  	if err != nil {
   628  		t.Fatalf("gdb exited with error: %v", err)
   629  	}
   630  
   631  	sgot := string(got)
   632  
   633  	// Check that the backtrace matches the source code.
   634  	types := []string{
   635  		"[]main.astruct",
   636  		"main.astruct",
   637  	}
   638  	if goexperiment.SwissMap {
   639  		types = append(types, []string{
   640  			"groupReference<string,main.astruct>",
   641  			"table<string,main.astruct>",
   642  			"map<string,main.astruct>",
   643  			"map<string,main.astruct> * map[string]main.astruct",
   644  		}...)
   645  	} else {
   646  		types = append(types, []string{
   647  			"bucket<string,main.astruct>",
   648  			"hash<string,main.astruct>",
   649  			"hash<string,main.astruct> * map[string]main.astruct",
   650  		}...)
   651  	}
   652  	for _, name := range types {
   653  		if !strings.Contains(sgot, name) {
   654  			t.Fatalf("could not find %q in 'info typrs astruct' output", name)
   655  		}
   656  	}
   657  }
   658  
   659  const constsSource = `
   660  package main
   661  
   662  const aConstant int = 42
   663  const largeConstant uint64 = ^uint64(0)
   664  const minusOne int64 = -1
   665  
   666  func main() {
   667  	println("hello world")
   668  }
   669  `
   670  
   671  func TestGdbConst(t *testing.T) {
   672  	checkGdbEnvironment(t)
   673  	t.Parallel()
   674  	checkGdbVersion(t)
   675  	checkPtraceScope(t)
   676  
   677  	dir := t.TempDir()
   678  
   679  	// Build the source code.
   680  	src := filepath.Join(dir, "main.go")
   681  	err := os.WriteFile(src, []byte(constsSource), 0644)
   682  	if err != nil {
   683  		t.Fatalf("failed to create file: %v", err)
   684  	}
   685  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-gcflags=all=-N -l", "-o", "a.exe", "main.go")
   686  	cmd.Dir = dir
   687  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   688  	if err != nil {
   689  		t.Fatalf("building source %v\n%s", err, out)
   690  	}
   691  
   692  	// Execute gdb commands.
   693  	args := []string{"-nx", "-batch",
   694  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   695  		"-ex", "set startup-with-shell off",
   696  		"-ex", "break main.main",
   697  		"-ex", "run",
   698  		"-ex", "print main.aConstant",
   699  		"-ex", "print main.largeConstant",
   700  		"-ex", "print main.minusOne",
   701  		"-ex", "print 'runtime.mSpanInUse'",
   702  		"-ex", "print 'runtime._PageSize'",
   703  		filepath.Join(dir, "a.exe"),
   704  	}
   705  	gdbArgsFixup(args)
   706  	got, err := exec.Command("gdb", args...).CombinedOutput()
   707  	t.Logf("gdb output:\n%s", got)
   708  	if err != nil {
   709  		t.Fatalf("gdb exited with error: %v", err)
   710  	}
   711  
   712  	sgot := strings.ReplaceAll(string(got), "\r\n", "\n")
   713  
   714  	if !strings.Contains(sgot, "\n$1 = 42\n$2 = 18446744073709551615\n$3 = -1\n$4 = 1 '\\001'\n$5 = 8192") {
   715  		t.Fatalf("output mismatch")
   716  	}
   717  }
   718  
   719  const panicSource = `
   720  package main
   721  
   722  import "runtime/debug"
   723  
   724  func main() {
   725  	debug.SetTraceback("crash")
   726  	crash()
   727  }
   728  
   729  func crash() {
   730  	panic("panic!")
   731  }
   732  `
   733  
   734  // TestGdbPanic tests that gdb can unwind the stack correctly
   735  // from SIGABRTs from Go panics.
   736  func TestGdbPanic(t *testing.T) {
   737  	checkGdbEnvironment(t)
   738  	t.Parallel()
   739  	checkGdbVersion(t)
   740  	checkPtraceScope(t)
   741  
   742  	if runtime.GOOS == "windows" {
   743  		t.Skip("no signals on windows")
   744  	}
   745  
   746  	dir := t.TempDir()
   747  
   748  	// Build the source code.
   749  	src := filepath.Join(dir, "main.go")
   750  	err := os.WriteFile(src, []byte(panicSource), 0644)
   751  	if err != nil {
   752  		t.Fatalf("failed to create file: %v", err)
   753  	}
   754  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   755  	cmd.Dir = dir
   756  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   757  	if err != nil {
   758  		t.Fatalf("building source %v\n%s", err, out)
   759  	}
   760  
   761  	// Execute gdb commands.
   762  	args := []string{"-nx", "-batch",
   763  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   764  		"-ex", "set startup-with-shell off",
   765  		"-ex", "run",
   766  		"-ex", "backtrace",
   767  		filepath.Join(dir, "a.exe"),
   768  	}
   769  	gdbArgsFixup(args)
   770  	got, err := exec.Command("gdb", args...).CombinedOutput()
   771  	t.Logf("gdb output:\n%s", got)
   772  	if err != nil {
   773  		t.Fatalf("gdb exited with error: %v", err)
   774  	}
   775  
   776  	// Check that the backtrace matches the source code.
   777  	bt := []string{
   778  		`crash`,
   779  		`main`,
   780  	}
   781  	for _, name := range bt {
   782  		s := fmt.Sprintf("(#.* .* in )?main\\.%v", name)
   783  		re := regexp.MustCompile(s)
   784  		if found := re.Find(got) != nil; !found {
   785  			t.Fatalf("could not find '%v' in backtrace", s)
   786  		}
   787  	}
   788  }
   789  
   790  const InfCallstackSource = `
   791  package main
   792  import "C"
   793  import "time"
   794  
   795  func loop() {
   796          for i := 0; i < 1000; i++ {
   797                  time.Sleep(time.Millisecond*5)
   798          }
   799  }
   800  
   801  func main() {
   802          go loop()
   803          time.Sleep(time.Second * 1)
   804  }
   805  `
   806  
   807  // TestGdbInfCallstack tests that gdb can unwind the callstack of cgo programs
   808  // on arm64 platforms without endless frames of function 'crossfunc1'.
   809  // https://golang.org/issue/37238
   810  func TestGdbInfCallstack(t *testing.T) {
   811  	checkGdbEnvironment(t)
   812  
   813  	testenv.MustHaveCGO(t)
   814  	if runtime.GOARCH != "arm64" {
   815  		t.Skip("skipping infinite callstack test on non-arm64 arches")
   816  	}
   817  
   818  	t.Parallel()
   819  	checkGdbVersion(t)
   820  	checkPtraceScope(t)
   821  
   822  	dir := t.TempDir()
   823  
   824  	// Build the source code.
   825  	src := filepath.Join(dir, "main.go")
   826  	err := os.WriteFile(src, []byte(InfCallstackSource), 0644)
   827  	if err != nil {
   828  		t.Fatalf("failed to create file: %v", err)
   829  	}
   830  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "a.exe", "main.go")
   831  	cmd.Dir = dir
   832  	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
   833  	if err != nil {
   834  		t.Fatalf("building source %v\n%s", err, out)
   835  	}
   836  
   837  	// Execute gdb commands.
   838  	// 'setg_gcc' is the first point where we can reproduce the issue with just one 'run' command.
   839  	args := []string{"-nx", "-batch",
   840  		"-iex", "add-auto-load-safe-path " + filepath.Join(testenv.GOROOT(t), "src", "runtime"),
   841  		"-ex", "set startup-with-shell off",
   842  		"-ex", "break setg_gcc",
   843  		"-ex", "run",
   844  		"-ex", "backtrace 3",
   845  		"-ex", "disable 1",
   846  		"-ex", "continue",
   847  		filepath.Join(dir, "a.exe"),
   848  	}
   849  	gdbArgsFixup(args)
   850  	got, err := exec.Command("gdb", args...).CombinedOutput()
   851  	t.Logf("gdb output:\n%s", got)
   852  	if err != nil {
   853  		t.Fatalf("gdb exited with error: %v", err)
   854  	}
   855  
   856  	// Check that the backtrace matches
   857  	// We check the 3 inner most frames only as they are present certainly, according to gcc_<OS>_arm64.c
   858  	bt := []string{
   859  		`setg_gcc`,
   860  		`crosscall1`,
   861  		`threadentry`,
   862  	}
   863  	for i, name := range bt {
   864  		s := fmt.Sprintf("#%v.*%v", i, name)
   865  		re := regexp.MustCompile(s)
   866  		if found := re.Find(got) != nil; !found {
   867  			t.Fatalf("could not find '%v' in backtrace", s)
   868  		}
   869  	}
   870  }
   871  

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