Source file src/cmd/link/internal/ld/dwarf_test.go

     1  // Copyright 2017 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 ld
     6  
     7  import (
     8  	"debug/dwarf"
     9  	"debug/pe"
    10  	"fmt"
    11  	"internal/platform"
    12  	"internal/testenv"
    13  	"io"
    14  	"os"
    15  	"path/filepath"
    16  	"reflect"
    17  	"runtime"
    18  	"sort"
    19  	"strconv"
    20  	"strings"
    21  	"testing"
    22  
    23  	intdwarf "cmd/internal/dwarf"
    24  	objfilepkg "cmd/internal/objfile" // renamed to avoid conflict with objfile function
    25  	"cmd/link/internal/dwtest"
    26  )
    27  
    28  func mustHaveDWARF(t testing.TB) {
    29  	if !platform.ExecutableHasDWARF(runtime.GOOS, runtime.GOARCH) {
    30  		t.Helper()
    31  		t.Skipf("skipping on %s/%s: no DWARF symbol table in executables", runtime.GOOS, runtime.GOARCH)
    32  	}
    33  }
    34  
    35  const (
    36  	DefaultOpt = "-gcflags="
    37  	NoOpt      = "-gcflags=-l -N"
    38  	OptInl4    = "-gcflags=-l=4"
    39  	OptAllInl4 = "-gcflags=all=-l=4"
    40  )
    41  
    42  func TestRuntimeTypesPresent(t *testing.T) {
    43  	t.Parallel()
    44  	testenv.MustHaveGoBuild(t)
    45  
    46  	mustHaveDWARF(t)
    47  
    48  	dir := t.TempDir()
    49  
    50  	f := gobuild(t, dir, `package main; func main() { }`, NoOpt)
    51  	defer f.Close()
    52  
    53  	dwarf, err := f.DWARF()
    54  	if err != nil {
    55  		t.Fatalf("error reading DWARF: %v", err)
    56  	}
    57  
    58  	want := map[string]bool{
    59  		"internal/abi.Type":          true,
    60  		"internal/abi.ArrayType":     true,
    61  		"internal/abi.ChanType":      true,
    62  		"internal/abi.FuncType":      true,
    63  		"internal/abi.PtrType":       true,
    64  		"internal/abi.SliceType":     true,
    65  		"internal/abi.StructType":    true,
    66  		"internal/abi.InterfaceType": true,
    67  		"internal/abi.ITab":          true,
    68  	}
    69  
    70  	found := findTypes(t, dwarf, want)
    71  	if len(found) != len(want) {
    72  		t.Errorf("found %v, want %v", found, want)
    73  	}
    74  
    75  	// Must have one of OldMapType or SwissMapType.
    76  	want = map[string]bool{
    77  		"internal/abi.OldMapType":   true,
    78  		"internal/abi.SwissMapType": true,
    79  	}
    80  	found = findTypes(t, dwarf, want)
    81  	if len(found) != 1 {
    82  		t.Errorf("map type want one of %v found %v", want, found)
    83  	}
    84  }
    85  
    86  func findTypes(t *testing.T, dw *dwarf.Data, want map[string]bool) (found map[string]bool) {
    87  	found = make(map[string]bool)
    88  	rdr := dw.Reader()
    89  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
    90  		if err != nil {
    91  			t.Fatalf("error reading DWARF: %v", err)
    92  		}
    93  		switch entry.Tag {
    94  		case dwarf.TagTypedef:
    95  			if name, ok := entry.Val(dwarf.AttrName).(string); ok && want[name] {
    96  				found[name] = true
    97  			}
    98  		}
    99  	}
   100  	return
   101  }
   102  
   103  type builtFile struct {
   104  	*objfilepkg.File
   105  	path string
   106  }
   107  
   108  func gobuild(t *testing.T, dir string, testfile string, gcflags string) *builtFile {
   109  	src := filepath.Join(dir, "test.go")
   110  	dst := filepath.Join(dir, "out.exe")
   111  
   112  	if err := os.WriteFile(src, []byte(testfile), 0666); err != nil {
   113  		t.Fatal(err)
   114  	}
   115  
   116  	cmd := testenv.Command(t, testenv.GoToolPath(t), "build", gcflags, "-o", dst, src)
   117  	b, err := cmd.CombinedOutput()
   118  	if len(b) != 0 {
   119  		t.Logf("## build output:\n%s", b)
   120  	}
   121  	if err != nil {
   122  		t.Fatalf("build error: %v", err)
   123  	}
   124  
   125  	f, err := objfilepkg.Open(dst)
   126  	if err != nil {
   127  		t.Fatal(err)
   128  	}
   129  	return &builtFile{f, dst}
   130  }
   131  
   132  // Similar to gobuild() above, but uses a main package instead of a test.go file.
   133  
   134  func gobuildTestdata(t *testing.T, pkgDir string, gcflags string) *builtFile {
   135  	dst := filepath.Join(t.TempDir(), "out.exe")
   136  
   137  	// Run a build with an updated GOPATH
   138  	cmd := testenv.Command(t, testenv.GoToolPath(t), "build", gcflags, "-o", dst)
   139  	cmd.Dir = pkgDir
   140  	if b, err := cmd.CombinedOutput(); err != nil {
   141  		t.Logf("build: %s\n", b)
   142  		t.Fatalf("build error: %v", err)
   143  	}
   144  
   145  	f, err := objfilepkg.Open(dst)
   146  	if err != nil {
   147  		t.Fatal(err)
   148  	}
   149  	return &builtFile{f, dst}
   150  }
   151  
   152  // Helper to build a snippet of source for examination with dwtest.Examiner.
   153  func gobuildAndExamine(t *testing.T, source string, gcflags string) (*dwarf.Data, *dwtest.Examiner) {
   154  	dir := t.TempDir()
   155  
   156  	f := gobuild(t, dir, source, gcflags)
   157  	defer f.Close()
   158  
   159  	d, err := f.DWARF()
   160  	if err != nil {
   161  		t.Fatalf("error reading DWARF in program %q: %v", source, err)
   162  	}
   163  
   164  	rdr := d.Reader()
   165  	ex := &dwtest.Examiner{}
   166  	if err := ex.Populate(rdr); err != nil {
   167  		t.Fatalf("error populating DWARF examiner for program %q: %v", source, err)
   168  	}
   169  
   170  	return d, ex
   171  }
   172  
   173  func findSubprogramDIE(t *testing.T, ex *dwtest.Examiner, sym string) *dwarf.Entry {
   174  	dies := ex.Named(sym)
   175  	if len(dies) == 0 {
   176  		t.Fatalf("unable to locate DIE for %s", sym)
   177  	}
   178  	if len(dies) != 1 {
   179  		t.Fatalf("more than one %s DIE: %+v", sym, dies)
   180  	}
   181  	die := dies[0]
   182  
   183  	// Vet the DIE.
   184  	if die.Tag != dwarf.TagSubprogram {
   185  		t.Fatalf("unexpected tag %v on %s DIE", die.Tag, sym)
   186  	}
   187  
   188  	return die
   189  }
   190  
   191  func TestEmbeddedStructMarker(t *testing.T) {
   192  	t.Parallel()
   193  	testenv.MustHaveGoBuild(t)
   194  
   195  	mustHaveDWARF(t)
   196  
   197  	const prog = `
   198  package main
   199  
   200  import "fmt"
   201  
   202  type Foo struct { v int }
   203  type Bar struct {
   204  	Foo
   205  	name string
   206  }
   207  type Baz struct {
   208  	*Foo
   209  	name string
   210  }
   211  
   212  func main() {
   213  	bar := Bar{ Foo: Foo{v: 123}, name: "onetwothree"}
   214  	baz := Baz{ Foo: &bar.Foo, name: "123" }
   215  	fmt.Println(bar, baz)
   216  }`
   217  
   218  	want := map[string]map[string]bool{
   219  		"main.Foo": {"v": false},
   220  		"main.Bar": {"Foo": true, "name": false},
   221  		"main.Baz": {"Foo": true, "name": false},
   222  	}
   223  
   224  	dir := t.TempDir()
   225  
   226  	f := gobuild(t, dir, prog, NoOpt)
   227  
   228  	defer f.Close()
   229  
   230  	d, err := f.DWARF()
   231  	if err != nil {
   232  		t.Fatalf("error reading DWARF: %v", err)
   233  	}
   234  
   235  	rdr := d.Reader()
   236  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   237  		if err != nil {
   238  			t.Fatalf("error reading DWARF: %v", err)
   239  		}
   240  		switch entry.Tag {
   241  		case dwarf.TagStructType:
   242  			name, ok := entry.Val(dwarf.AttrName).(string)
   243  			if !ok {
   244  				continue
   245  			}
   246  			wantMembers := want[name]
   247  			if wantMembers == nil {
   248  				continue
   249  			}
   250  			gotMembers, err := findMembers(rdr)
   251  			if err != nil {
   252  				t.Fatalf("error reading DWARF: %v", err)
   253  			}
   254  
   255  			if !reflect.DeepEqual(gotMembers, wantMembers) {
   256  				t.Errorf("type %v: got map[member]embedded = %+v, want %+v", name, wantMembers, gotMembers)
   257  			}
   258  			delete(want, name)
   259  		}
   260  	}
   261  	if len(want) != 0 {
   262  		t.Errorf("failed to check all expected types: missing types = %+v", want)
   263  	}
   264  }
   265  
   266  func findMembers(rdr *dwarf.Reader) (map[string]bool, error) {
   267  	memberEmbedded := map[string]bool{}
   268  	// TODO(hyangah): define in debug/dwarf package
   269  	const goEmbeddedStruct = dwarf.Attr(intdwarf.DW_AT_go_embedded_field)
   270  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   271  		if err != nil {
   272  			return nil, err
   273  		}
   274  		switch entry.Tag {
   275  		case dwarf.TagMember:
   276  			name := entry.Val(dwarf.AttrName).(string)
   277  			embedded := entry.Val(goEmbeddedStruct).(bool)
   278  			memberEmbedded[name] = embedded
   279  		case 0:
   280  			return memberEmbedded, nil
   281  		}
   282  	}
   283  	return memberEmbedded, nil
   284  }
   285  
   286  func TestSizes(t *testing.T) {
   287  	mustHaveDWARF(t)
   288  
   289  	// External linking may bring in C symbols with unknown size. Skip.
   290  	testenv.MustInternalLink(t, false)
   291  
   292  	t.Parallel()
   293  
   294  	// DWARF sizes should never be -1.
   295  	// See issue #21097
   296  	const prog = `
   297  package main
   298  var x func()
   299  var y [4]func()
   300  func main() {
   301  	x = nil
   302  	y[0] = nil
   303  }
   304  `
   305  	dir := t.TempDir()
   306  
   307  	f := gobuild(t, dir, prog, NoOpt)
   308  	defer f.Close()
   309  	d, err := f.DWARF()
   310  	if err != nil {
   311  		t.Fatalf("error reading DWARF: %v", err)
   312  	}
   313  	rdr := d.Reader()
   314  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   315  		if err != nil {
   316  			t.Fatalf("error reading DWARF: %v", err)
   317  		}
   318  		switch entry.Tag {
   319  		case dwarf.TagArrayType, dwarf.TagPointerType, dwarf.TagStructType, dwarf.TagBaseType, dwarf.TagSubroutineType, dwarf.TagTypedef:
   320  		default:
   321  			continue
   322  		}
   323  		typ, err := d.Type(entry.Offset)
   324  		if err != nil {
   325  			t.Fatalf("can't read type: %v", err)
   326  		}
   327  		if typ.Size() < 0 {
   328  			t.Errorf("subzero size %s %s %T", typ, entry.Tag, typ)
   329  		}
   330  	}
   331  }
   332  
   333  func TestFieldOverlap(t *testing.T) {
   334  	mustHaveDWARF(t)
   335  	t.Parallel()
   336  
   337  	// This test grew out of issue 21094, where specific sudog<T> DWARF types
   338  	// had elem fields set to values instead of pointers.
   339  	const prog = `
   340  package main
   341  
   342  var c chan string
   343  
   344  func main() {
   345  	c <- "foo"
   346  }
   347  `
   348  	dir := t.TempDir()
   349  
   350  	f := gobuild(t, dir, prog, NoOpt)
   351  	defer f.Close()
   352  
   353  	d, err := f.DWARF()
   354  	if err != nil {
   355  		t.Fatalf("error reading DWARF: %v", err)
   356  	}
   357  
   358  	rdr := d.Reader()
   359  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   360  		if err != nil {
   361  			t.Fatalf("error reading DWARF: %v", err)
   362  		}
   363  		if entry.Tag != dwarf.TagStructType {
   364  			continue
   365  		}
   366  		typ, err := d.Type(entry.Offset)
   367  		if err != nil {
   368  			t.Fatalf("can't read type: %v", err)
   369  		}
   370  		s := typ.(*dwarf.StructType)
   371  		for i := 0; i < len(s.Field); i++ {
   372  			end := s.Field[i].ByteOffset + s.Field[i].Type.Size()
   373  			var limit int64
   374  			if i == len(s.Field)-1 {
   375  				limit = s.Size()
   376  			} else {
   377  				limit = s.Field[i+1].ByteOffset
   378  			}
   379  			if end > limit {
   380  				name := entry.Val(dwarf.AttrName).(string)
   381  				t.Fatalf("field %s.%s overlaps next field", name, s.Field[i].Name)
   382  			}
   383  		}
   384  	}
   385  }
   386  
   387  func TestSubprogramDeclFileLine(t *testing.T) {
   388  	testenv.MustHaveGoBuild(t)
   389  	t.Parallel()
   390  
   391  	mustHaveDWARF(t)
   392  
   393  	const prog = `package main
   394  %s
   395  func main() {}
   396  `
   397  	tests := []struct {
   398  		name string
   399  		prog string
   400  		file string
   401  		line int64
   402  	}{
   403  		{
   404  			name: "normal",
   405  			prog: fmt.Sprintf(prog, ""),
   406  			file: "test.go",
   407  			line: 3,
   408  		},
   409  		{
   410  			name: "line-directive",
   411  			prog: fmt.Sprintf(prog, "//line /foobar.go:200"),
   412  			file: "foobar.go",
   413  			line: 200,
   414  		},
   415  	}
   416  	for _, tc := range tests {
   417  		tc := tc
   418  		t.Run(tc.name, func(t *testing.T) {
   419  			t.Parallel()
   420  
   421  			d, ex := gobuildAndExamine(t, tc.prog, NoOpt)
   422  
   423  			maindie := findSubprogramDIE(t, ex, "main.main")
   424  
   425  			mainIdx := ex.IdxFromOffset(maindie.Offset)
   426  
   427  			fileIdx, fileIdxOK := maindie.Val(dwarf.AttrDeclFile).(int64)
   428  			if !fileIdxOK {
   429  				t.Errorf("missing or invalid DW_AT_decl_file for main")
   430  			}
   431  			file, err := ex.FileRef(d, mainIdx, fileIdx)
   432  			if err != nil {
   433  				t.Fatalf("FileRef: %v", err)
   434  			}
   435  			base := filepath.Base(file)
   436  			if base != tc.file {
   437  				t.Errorf("DW_AT_decl_file for main is %v, want %v", base, tc.file)
   438  			}
   439  
   440  			line, lineOK := maindie.Val(dwarf.AttrDeclLine).(int64)
   441  			if !lineOK {
   442  				t.Errorf("missing or invalid DW_AT_decl_line for main")
   443  			}
   444  			if line != tc.line {
   445  				t.Errorf("DW_AT_decl_line for main is %v, want %d", line, tc.line)
   446  			}
   447  		})
   448  	}
   449  }
   450  
   451  func TestVarDeclLine(t *testing.T) {
   452  	testenv.MustHaveGoBuild(t)
   453  	t.Parallel()
   454  
   455  	mustHaveDWARF(t)
   456  
   457  	const prog = `package main
   458  %s
   459  func main() {
   460  
   461  	var i int
   462  	i = i
   463  }
   464  `
   465  	tests := []struct {
   466  		name string
   467  		prog string
   468  		line int64
   469  	}{
   470  		{
   471  			name: "normal",
   472  			prog: fmt.Sprintf(prog, ""),
   473  			line: 5,
   474  		},
   475  		{
   476  			name: "line-directive",
   477  			prog: fmt.Sprintf(prog, "//line /foobar.go:200"),
   478  			line: 202,
   479  		},
   480  	}
   481  	for _, tc := range tests {
   482  		tc := tc
   483  		t.Run(tc.name, func(t *testing.T) {
   484  			t.Parallel()
   485  
   486  			_, ex := gobuildAndExamine(t, tc.prog, NoOpt)
   487  
   488  			maindie := findSubprogramDIE(t, ex, "main.main")
   489  
   490  			mainIdx := ex.IdxFromOffset(maindie.Offset)
   491  			childDies := ex.Children(mainIdx)
   492  			var iEntry *dwarf.Entry
   493  			for _, child := range childDies {
   494  				if child.Tag == dwarf.TagVariable && child.Val(dwarf.AttrName).(string) == "i" {
   495  					iEntry = child
   496  					break
   497  				}
   498  			}
   499  			if iEntry == nil {
   500  				t.Fatalf("didn't find DW_TAG_variable for i in main.main")
   501  			}
   502  
   503  			// Verify line/file attributes.
   504  			line, lineOK := iEntry.Val(dwarf.AttrDeclLine).(int64)
   505  			if !lineOK {
   506  				t.Errorf("missing or invalid DW_AT_decl_line for i")
   507  			}
   508  			if line != tc.line {
   509  				t.Errorf("DW_AT_decl_line for i is %v, want %d", line, tc.line)
   510  			}
   511  		})
   512  	}
   513  }
   514  
   515  // TestInlinedRoutineCallFileLine tests the call file and line records for an
   516  // inlined subroutine.
   517  func TestInlinedRoutineCallFileLine(t *testing.T) {
   518  	testenv.MustHaveGoBuild(t)
   519  
   520  	mustHaveDWARF(t)
   521  
   522  	t.Parallel()
   523  
   524  	const prog = `
   525  package main
   526  
   527  var G int
   528  
   529  //go:noinline
   530  func notinlined() int {
   531  	return 42
   532  }
   533  
   534  func inlined() int {
   535  	return notinlined()
   536  }
   537  
   538  %s
   539  func main() {
   540  	x := inlined()
   541  	G = x
   542  }
   543  `
   544  	tests := []struct {
   545  		name string
   546  		prog string
   547  		file string // basename
   548  		line int64
   549  	}{
   550  		{
   551  			name: "normal",
   552  			prog: fmt.Sprintf(prog, ""),
   553  			file: "test.go",
   554  			line: 17,
   555  		},
   556  		{
   557  			name: "line-directive",
   558  			prog: fmt.Sprintf(prog, "//line /foobar.go:200"),
   559  			file: "foobar.go",
   560  			line: 201,
   561  		},
   562  	}
   563  	for _, tc := range tests {
   564  		tc := tc
   565  		t.Run(tc.name, func(t *testing.T) {
   566  			t.Parallel()
   567  
   568  			// Note: this is a build with "-l=4", as opposed to "-l -N". The
   569  			// test is intended to verify DWARF that is only generated when
   570  			// the inliner is active. We're only going to look at the DWARF for
   571  			// main.main, however, hence we build with "-gcflags=-l=4" as opposed
   572  			// to "-gcflags=all=-l=4".
   573  			d, ex := gobuildAndExamine(t, tc.prog, OptInl4)
   574  
   575  			maindie := findSubprogramDIE(t, ex, "main.main")
   576  
   577  			// Walk main's children and pick out the inlined subroutines
   578  			mainIdx := ex.IdxFromOffset(maindie.Offset)
   579  			childDies := ex.Children(mainIdx)
   580  			found := false
   581  			for _, child := range childDies {
   582  				if child.Tag != dwarf.TagInlinedSubroutine {
   583  					continue
   584  				}
   585  
   586  				// Found an inlined subroutine.
   587  				if found {
   588  					t.Fatalf("Found multiple inlined subroutines, expect only one")
   589  				}
   590  				found = true
   591  
   592  				// Locate abstract origin.
   593  				ooff, originOK := child.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   594  				if !originOK {
   595  					t.Fatalf("no abstract origin attr for inlined subroutine at offset %v", child.Offset)
   596  				}
   597  				originDIE := ex.EntryFromOffset(ooff)
   598  				if originDIE == nil {
   599  					t.Fatalf("can't locate origin DIE at off %v", ooff)
   600  				}
   601  
   602  				// Name should check out.
   603  				name, ok := originDIE.Val(dwarf.AttrName).(string)
   604  				if !ok {
   605  					t.Fatalf("no name attr for inlined subroutine at offset %v", child.Offset)
   606  				}
   607  				if name != "main.inlined" {
   608  					t.Fatalf("expected inlined routine %s got %s", "main.cand", name)
   609  				}
   610  
   611  				// Verify that the call_file attribute for the inlined
   612  				// instance is ok. In this case it should match the file
   613  				// for the main routine. To do this we need to locate the
   614  				// compilation unit DIE that encloses what we're looking
   615  				// at; this can be done with the examiner.
   616  				cf, cfOK := child.Val(dwarf.AttrCallFile).(int64)
   617  				if !cfOK {
   618  					t.Fatalf("no call_file attr for inlined subroutine at offset %v", child.Offset)
   619  				}
   620  				file, err := ex.FileRef(d, mainIdx, cf)
   621  				if err != nil {
   622  					t.Errorf("FileRef: %v", err)
   623  					continue
   624  				}
   625  				base := filepath.Base(file)
   626  				if base != tc.file {
   627  					t.Errorf("bad call_file attribute, found '%s', want '%s'",
   628  						file, tc.file)
   629  				}
   630  
   631  				// Verify that the call_line attribute for the inlined
   632  				// instance is ok.
   633  				cl, clOK := child.Val(dwarf.AttrCallLine).(int64)
   634  				if !clOK {
   635  					t.Fatalf("no call_line attr for inlined subroutine at offset %v", child.Offset)
   636  				}
   637  				if cl != tc.line {
   638  					t.Errorf("bad call_line attribute, found %d, want %d", cl, tc.line)
   639  				}
   640  			}
   641  			if !found {
   642  				t.Fatalf("not enough inlined subroutines found in main.main")
   643  			}
   644  		})
   645  	}
   646  }
   647  
   648  // TestInlinedRoutineArgsVars tests the argument and variable records for an inlined subroutine.
   649  func TestInlinedRoutineArgsVars(t *testing.T) {
   650  	testenv.MustHaveGoBuild(t)
   651  
   652  	mustHaveDWARF(t)
   653  
   654  	t.Parallel()
   655  
   656  	const prog = `
   657  package main
   658  
   659  var G int
   660  
   661  func noinline(x int) int {
   662  	defer func() { G += x }()
   663  	return x
   664  }
   665  
   666  func cand(x, y int) int {
   667  	return noinline(x+y) ^ (y - x)
   668  }
   669  
   670  func main() {
   671  	x := cand(G*G,G|7%G)
   672  	G = x
   673  }
   674  `
   675  	// Note: this is a build with "-l=4", as opposed to "-l -N". The
   676  	// test is intended to verify DWARF that is only generated when
   677  	// the inliner is active. We're only going to look at the DWARF for
   678  	// main.main, however, hence we build with "-gcflags=-l=4" as opposed
   679  	// to "-gcflags=all=-l=4".
   680  	_, ex := gobuildAndExamine(t, prog, OptInl4)
   681  
   682  	maindie := findSubprogramDIE(t, ex, "main.main")
   683  
   684  	// Walk main's children and pick out the inlined subroutines
   685  	mainIdx := ex.IdxFromOffset(maindie.Offset)
   686  	childDies := ex.Children(mainIdx)
   687  	found := false
   688  	for _, child := range childDies {
   689  		if child.Tag != dwarf.TagInlinedSubroutine {
   690  			continue
   691  		}
   692  
   693  		// Found an inlined subroutine.
   694  		if found {
   695  			t.Fatalf("Found multiple inlined subroutines, expect only one")
   696  		}
   697  		found = true
   698  
   699  		// Locate abstract origin.
   700  		ooff, originOK := child.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   701  		if !originOK {
   702  			t.Fatalf("no abstract origin attr for inlined subroutine at offset %v", child.Offset)
   703  		}
   704  		originDIE := ex.EntryFromOffset(ooff)
   705  		if originDIE == nil {
   706  			t.Fatalf("can't locate origin DIE at off %v", ooff)
   707  		}
   708  
   709  		// Name should check out.
   710  		name, ok := originDIE.Val(dwarf.AttrName).(string)
   711  		if !ok {
   712  			t.Fatalf("no name attr for inlined subroutine at offset %v", child.Offset)
   713  		}
   714  		if name != "main.cand" {
   715  			t.Fatalf("expected inlined routine %s got %s", "main.cand", name)
   716  		}
   717  
   718  		// Walk the children of the abstract subroutine. We expect
   719  		// to see child variables there, even if (perhaps due to
   720  		// optimization) there are no references to them from the
   721  		// inlined subroutine DIE.
   722  		absFcnIdx := ex.IdxFromOffset(ooff)
   723  		absFcnChildDies := ex.Children(absFcnIdx)
   724  		if len(absFcnChildDies) != 2 {
   725  			t.Fatalf("expected abstract function: expected 2 children, got %d children", len(absFcnChildDies))
   726  		}
   727  		formalCount := 0
   728  		for _, absChild := range absFcnChildDies {
   729  			if absChild.Tag == dwarf.TagFormalParameter {
   730  				formalCount += 1
   731  				continue
   732  			}
   733  			t.Fatalf("abstract function child DIE: expected formal, got %v", absChild.Tag)
   734  		}
   735  		if formalCount != 2 {
   736  			t.Fatalf("abstract function DIE: expected 2 formals, got %d", formalCount)
   737  		}
   738  
   739  		omap := make(map[dwarf.Offset]bool)
   740  
   741  		// Walk the child variables of the inlined routine. Each
   742  		// of them should have a distinct abstract origin-- if two
   743  		// vars point to the same origin things are definitely broken.
   744  		inlIdx := ex.IdxFromOffset(child.Offset)
   745  		inlChildDies := ex.Children(inlIdx)
   746  		for _, k := range inlChildDies {
   747  			ooff, originOK := k.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   748  			if !originOK {
   749  				t.Fatalf("no abstract origin attr for child of inlined subroutine at offset %v", k.Offset)
   750  			}
   751  			if _, found := omap[ooff]; found {
   752  				t.Fatalf("duplicate abstract origin at child of inlined subroutine at offset %v", k.Offset)
   753  			}
   754  			omap[ooff] = true
   755  		}
   756  	}
   757  	if !found {
   758  		t.Fatalf("not enough inlined subroutines found in main.main")
   759  	}
   760  }
   761  
   762  func abstractOriginSanity(t *testing.T, pkgDir string, flags string) {
   763  	t.Parallel()
   764  
   765  	// Build with inlining, to exercise DWARF inlining support.
   766  	f := gobuildTestdata(t, filepath.Join(pkgDir, "main"), flags)
   767  	defer f.Close()
   768  
   769  	d, err := f.DWARF()
   770  	if err != nil {
   771  		t.Fatalf("error reading DWARF: %v", err)
   772  	}
   773  	rdr := d.Reader()
   774  	ex := dwtest.Examiner{}
   775  	if err := ex.Populate(rdr); err != nil {
   776  		t.Fatalf("error reading DWARF: %v", err)
   777  	}
   778  
   779  	// Make a pass through all DIEs looking for abstract origin
   780  	// references.
   781  	abscount := 0
   782  	for i, die := range ex.DIEs() {
   783  		// Does it have an abstract origin?
   784  		ooff, originOK := die.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   785  		if !originOK {
   786  			continue
   787  		}
   788  
   789  		// All abstract origin references should be resolvable.
   790  		abscount += 1
   791  		originDIE := ex.EntryFromOffset(ooff)
   792  		if originDIE == nil {
   793  			ex.DumpEntry(i, false, 0)
   794  			t.Fatalf("unresolved abstract origin ref in DIE at offset 0x%x\n", die.Offset)
   795  		}
   796  
   797  		// Suppose that DIE X has parameter/variable children {K1,
   798  		// K2, ... KN}. If X has an abstract origin of A, then for
   799  		// each KJ, the abstract origin of KJ should be a child of A.
   800  		// Note that this same rule doesn't hold for non-variable DIEs.
   801  		pidx := ex.IdxFromOffset(die.Offset)
   802  		if pidx < 0 {
   803  			t.Fatalf("can't locate DIE id")
   804  		}
   805  		kids := ex.Children(pidx)
   806  		for _, kid := range kids {
   807  			if kid.Tag != dwarf.TagVariable &&
   808  				kid.Tag != dwarf.TagFormalParameter {
   809  				continue
   810  			}
   811  			kooff, originOK := kid.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   812  			if !originOK {
   813  				continue
   814  			}
   815  			childOriginDIE := ex.EntryFromOffset(kooff)
   816  			if childOriginDIE == nil {
   817  				ex.DumpEntry(i, false, 0)
   818  				t.Fatalf("unresolved abstract origin ref in DIE at offset %x", kid.Offset)
   819  			}
   820  			coidx := ex.IdxFromOffset(childOriginDIE.Offset)
   821  			childOriginParent := ex.Parent(coidx)
   822  			if childOriginParent != originDIE {
   823  				ex.DumpEntry(i, false, 0)
   824  				t.Fatalf("unexpected parent of abstract origin DIE at offset %v", childOriginDIE.Offset)
   825  			}
   826  		}
   827  	}
   828  	if abscount == 0 {
   829  		t.Fatalf("no abstract origin refs found, something is wrong")
   830  	}
   831  }
   832  
   833  func TestAbstractOriginSanity(t *testing.T) {
   834  	testenv.MustHaveGoBuild(t)
   835  
   836  	if testing.Short() {
   837  		t.Skip("skipping test in short mode.")
   838  	}
   839  
   840  	mustHaveDWARF(t)
   841  	abstractOriginSanity(t, "testdata/httptest", OptAllInl4)
   842  }
   843  
   844  func TestAbstractOriginSanityIssue25459(t *testing.T) {
   845  	testenv.MustHaveGoBuild(t)
   846  
   847  	mustHaveDWARF(t)
   848  	if runtime.GOARCH != "amd64" && runtime.GOARCH != "386" {
   849  		t.Skip("skipping on not-amd64 not-386; location lists not supported")
   850  	}
   851  
   852  	abstractOriginSanity(t, "testdata/issue25459", DefaultOpt)
   853  }
   854  
   855  func TestAbstractOriginSanityIssue26237(t *testing.T) {
   856  	testenv.MustHaveGoBuild(t)
   857  
   858  	mustHaveDWARF(t)
   859  	abstractOriginSanity(t, "testdata/issue26237", DefaultOpt)
   860  }
   861  
   862  func TestRuntimeTypeAttrInternal(t *testing.T) {
   863  	testenv.MustHaveGoBuild(t)
   864  	testenv.MustInternalLink(t, false)
   865  
   866  	mustHaveDWARF(t)
   867  
   868  	testRuntimeTypeAttr(t, "-ldflags=-linkmode=internal")
   869  }
   870  
   871  // External linking requires a host linker (https://golang.org/src/cmd/cgo/doc.go l.732)
   872  func TestRuntimeTypeAttrExternal(t *testing.T) {
   873  	testenv.MustHaveGoBuild(t)
   874  	testenv.MustHaveCGO(t)
   875  
   876  	mustHaveDWARF(t)
   877  
   878  	// Explicitly test external linking, for dsymutil compatibility on Darwin.
   879  	if runtime.GOARCH == "ppc64" {
   880  		t.Skip("-linkmode=external not supported on ppc64")
   881  	}
   882  
   883  	testRuntimeTypeAttr(t, "-ldflags=-linkmode=external")
   884  }
   885  
   886  func testRuntimeTypeAttr(t *testing.T, flags string) {
   887  	t.Parallel()
   888  
   889  	const prog = `
   890  package main
   891  
   892  import "unsafe"
   893  
   894  type X struct{ _ int }
   895  
   896  func main() {
   897  	var x interface{} = &X{}
   898  	p := *(*uintptr)(unsafe.Pointer(&x))
   899  	print(p)
   900  }
   901  `
   902  	dir := t.TempDir()
   903  
   904  	f := gobuild(t, dir, prog, flags)
   905  	defer f.Close()
   906  
   907  	out, err := testenv.Command(t, f.path).CombinedOutput()
   908  	if err != nil {
   909  		t.Fatalf("could not run test program: %v", err)
   910  	}
   911  	addr, err := strconv.ParseUint(string(out), 10, 64)
   912  	if err != nil {
   913  		t.Fatalf("could not parse type address from program output %q: %v", out, err)
   914  	}
   915  
   916  	symbols, err := f.Symbols()
   917  	if err != nil {
   918  		t.Fatalf("error reading symbols: %v", err)
   919  	}
   920  	var types *objfilepkg.Sym
   921  	for _, sym := range symbols {
   922  		if sym.Name == "runtime.types" {
   923  			types = &sym
   924  			break
   925  		}
   926  	}
   927  	if types == nil {
   928  		t.Fatal("couldn't find runtime.types in symbols")
   929  	}
   930  
   931  	d, err := f.DWARF()
   932  	if err != nil {
   933  		t.Fatalf("error reading DWARF: %v", err)
   934  	}
   935  
   936  	rdr := d.Reader()
   937  	ex := dwtest.Examiner{}
   938  	if err := ex.Populate(rdr); err != nil {
   939  		t.Fatalf("error reading DWARF: %v", err)
   940  	}
   941  	dies := ex.Named("*main.X")
   942  	if len(dies) != 1 {
   943  		t.Fatalf("wanted 1 DIE named *main.X, found %v", len(dies))
   944  	}
   945  	rtAttr := dies[0].Val(intdwarf.DW_AT_go_runtime_type)
   946  	if rtAttr == nil {
   947  		t.Fatalf("*main.X DIE had no runtime type attr. DIE: %v", dies[0])
   948  	}
   949  
   950  	if platform.DefaultPIE(runtime.GOOS, runtime.GOARCH, false) {
   951  		return // everything is PIE, addresses are relocated
   952  	}
   953  	if rtAttr.(uint64)+types.Addr != addr {
   954  		t.Errorf("DWARF type offset was %#x+%#x, but test program said %#x", rtAttr.(uint64), types.Addr, addr)
   955  	}
   956  }
   957  
   958  func TestIssue27614(t *testing.T) {
   959  	// Type references in debug_info should always use the DW_TAG_typedef_type
   960  	// for the type, when that's generated.
   961  
   962  	testenv.MustHaveGoBuild(t)
   963  
   964  	mustHaveDWARF(t)
   965  
   966  	t.Parallel()
   967  
   968  	dir := t.TempDir()
   969  
   970  	const prog = `package main
   971  
   972  import "fmt"
   973  
   974  type astruct struct {
   975  	X int
   976  }
   977  
   978  type bstruct struct {
   979  	X float32
   980  }
   981  
   982  var globalptr *astruct
   983  var globalvar astruct
   984  var bvar0, bvar1, bvar2 bstruct
   985  
   986  func main() {
   987  	fmt.Println(globalptr, globalvar, bvar0, bvar1, bvar2)
   988  }
   989  `
   990  
   991  	f := gobuild(t, dir, prog, NoOpt)
   992  
   993  	defer f.Close()
   994  
   995  	data, err := f.DWARF()
   996  	if err != nil {
   997  		t.Fatal(err)
   998  	}
   999  
  1000  	rdr := data.Reader()
  1001  
  1002  	var astructTypeDIE, bstructTypeDIE, ptrastructTypeDIE *dwarf.Entry
  1003  	var globalptrDIE, globalvarDIE *dwarf.Entry
  1004  	var bvarDIE [3]*dwarf.Entry
  1005  
  1006  	for {
  1007  		e, err := rdr.Next()
  1008  		if err != nil {
  1009  			t.Fatal(err)
  1010  		}
  1011  		if e == nil {
  1012  			break
  1013  		}
  1014  
  1015  		name, _ := e.Val(dwarf.AttrName).(string)
  1016  
  1017  		switch e.Tag {
  1018  		case dwarf.TagTypedef:
  1019  			switch name {
  1020  			case "main.astruct":
  1021  				astructTypeDIE = e
  1022  			case "main.bstruct":
  1023  				bstructTypeDIE = e
  1024  			}
  1025  		case dwarf.TagPointerType:
  1026  			if name == "*main.astruct" {
  1027  				ptrastructTypeDIE = e
  1028  			}
  1029  		case dwarf.TagVariable:
  1030  			switch name {
  1031  			case "main.globalptr":
  1032  				globalptrDIE = e
  1033  			case "main.globalvar":
  1034  				globalvarDIE = e
  1035  			default:
  1036  				const bvarprefix = "main.bvar"
  1037  				if strings.HasPrefix(name, bvarprefix) {
  1038  					i, _ := strconv.Atoi(name[len(bvarprefix):])
  1039  					bvarDIE[i] = e
  1040  				}
  1041  			}
  1042  		}
  1043  	}
  1044  
  1045  	typedieof := func(e *dwarf.Entry) dwarf.Offset {
  1046  		return e.Val(dwarf.AttrType).(dwarf.Offset)
  1047  	}
  1048  
  1049  	if off := typedieof(ptrastructTypeDIE); off != astructTypeDIE.Offset {
  1050  		t.Errorf("type attribute of *main.astruct references %#x, not main.astruct DIE at %#x\n", off, astructTypeDIE.Offset)
  1051  	}
  1052  
  1053  	if off := typedieof(globalptrDIE); off != ptrastructTypeDIE.Offset {
  1054  		t.Errorf("type attribute of main.globalptr references %#x, not *main.astruct DIE at %#x\n", off, ptrastructTypeDIE.Offset)
  1055  	}
  1056  
  1057  	if off := typedieof(globalvarDIE); off != astructTypeDIE.Offset {
  1058  		t.Errorf("type attribute of main.globalvar1 references %#x, not main.astruct DIE at %#x\n", off, astructTypeDIE.Offset)
  1059  	}
  1060  
  1061  	for i := range bvarDIE {
  1062  		if off := typedieof(bvarDIE[i]); off != bstructTypeDIE.Offset {
  1063  			t.Errorf("type attribute of main.bvar%d references %#x, not main.bstruct DIE at %#x\n", i, off, bstructTypeDIE.Offset)
  1064  		}
  1065  	}
  1066  }
  1067  
  1068  func TestStaticTmp(t *testing.T) {
  1069  	// Checks that statictmp variables do not appear in debug_info or the
  1070  	// symbol table.
  1071  	// Also checks that statictmp variables do not collide with user defined
  1072  	// variables (issue #25113)
  1073  
  1074  	testenv.MustHaveGoBuild(t)
  1075  
  1076  	mustHaveDWARF(t)
  1077  
  1078  	t.Parallel()
  1079  
  1080  	dir := t.TempDir()
  1081  
  1082  	const prog = `package main
  1083  
  1084  var stmp_0 string
  1085  var a []int
  1086  
  1087  func init() {
  1088  	a = []int{ 7 }
  1089  }
  1090  
  1091  func main() {
  1092  	println(a[0])
  1093  }
  1094  `
  1095  
  1096  	f := gobuild(t, dir, prog, NoOpt)
  1097  
  1098  	defer f.Close()
  1099  
  1100  	d, err := f.DWARF()
  1101  	if err != nil {
  1102  		t.Fatalf("error reading DWARF: %v", err)
  1103  	}
  1104  
  1105  	rdr := d.Reader()
  1106  	for {
  1107  		e, err := rdr.Next()
  1108  		if err != nil {
  1109  			t.Fatal(err)
  1110  		}
  1111  		if e == nil {
  1112  			break
  1113  		}
  1114  		if e.Tag != dwarf.TagVariable {
  1115  			continue
  1116  		}
  1117  		name, ok := e.Val(dwarf.AttrName).(string)
  1118  		if !ok {
  1119  			continue
  1120  		}
  1121  		if strings.Contains(name, "stmp") {
  1122  			t.Errorf("statictmp variable found in debug_info: %s at %x", name, e.Offset)
  1123  		}
  1124  	}
  1125  
  1126  	// When external linking, we put all symbols in the symbol table (so the
  1127  	// external linker can find them). Skip the symbol table check.
  1128  	// TODO: maybe there is some way to tell the external linker not to put
  1129  	// those symbols in the executable's symbol table? Prefix the symbol name
  1130  	// with "." or "L" to pretend it is a label?
  1131  	if !testenv.CanInternalLink(false) {
  1132  		return
  1133  	}
  1134  
  1135  	syms, err := f.Symbols()
  1136  	if err != nil {
  1137  		t.Fatalf("error reading symbols: %v", err)
  1138  	}
  1139  	for _, sym := range syms {
  1140  		if strings.Contains(sym.Name, "stmp") {
  1141  			t.Errorf("statictmp variable found in symbol table: %s", sym.Name)
  1142  		}
  1143  	}
  1144  }
  1145  
  1146  func TestPackageNameAttr(t *testing.T) {
  1147  	const dwarfAttrGoPackageName = dwarf.Attr(0x2905)
  1148  	const dwarfGoLanguage = 22
  1149  
  1150  	testenv.MustHaveGoBuild(t)
  1151  
  1152  	mustHaveDWARF(t)
  1153  
  1154  	t.Parallel()
  1155  
  1156  	dir := t.TempDir()
  1157  
  1158  	const prog = "package main\nfunc main() {\nprintln(\"hello world\")\n}\n"
  1159  
  1160  	f := gobuild(t, dir, prog, NoOpt)
  1161  
  1162  	defer f.Close()
  1163  
  1164  	d, err := f.DWARF()
  1165  	if err != nil {
  1166  		t.Fatalf("error reading DWARF: %v", err)
  1167  	}
  1168  
  1169  	rdr := d.Reader()
  1170  	runtimeUnitSeen := false
  1171  	for {
  1172  		e, err := rdr.Next()
  1173  		if err != nil {
  1174  			t.Fatal(err)
  1175  		}
  1176  		if e == nil {
  1177  			break
  1178  		}
  1179  		if e.Tag != dwarf.TagCompileUnit {
  1180  			continue
  1181  		}
  1182  		if lang, _ := e.Val(dwarf.AttrLanguage).(int64); lang != dwarfGoLanguage {
  1183  			continue
  1184  		}
  1185  
  1186  		pn, ok := e.Val(dwarfAttrGoPackageName).(string)
  1187  		if !ok {
  1188  			name, _ := e.Val(dwarf.AttrName).(string)
  1189  			t.Errorf("found compile unit without package name: %s", name)
  1190  
  1191  		}
  1192  		if pn == "" {
  1193  			name, _ := e.Val(dwarf.AttrName).(string)
  1194  			t.Errorf("found compile unit with empty package name: %s", name)
  1195  		} else {
  1196  			if pn == "runtime" {
  1197  				runtimeUnitSeen = true
  1198  			}
  1199  		}
  1200  	}
  1201  
  1202  	// Something is wrong if there's no runtime compilation unit.
  1203  	if !runtimeUnitSeen {
  1204  		t.Errorf("no package name for runtime unit")
  1205  	}
  1206  }
  1207  
  1208  func TestMachoIssue32233(t *testing.T) {
  1209  	testenv.MustHaveGoBuild(t)
  1210  	testenv.MustHaveCGO(t)
  1211  
  1212  	if runtime.GOOS != "darwin" {
  1213  		t.Skip("skipping; test only interesting on darwin")
  1214  	}
  1215  
  1216  	f := gobuildTestdata(t, "testdata/issue32233/main", DefaultOpt)
  1217  	f.Close()
  1218  }
  1219  
  1220  func TestWindowsIssue36495(t *testing.T) {
  1221  	testenv.MustHaveGoBuild(t)
  1222  	if runtime.GOOS != "windows" {
  1223  		t.Skip("skipping: test only on windows")
  1224  	}
  1225  
  1226  	dir := t.TempDir()
  1227  
  1228  	prog := `
  1229  package main
  1230  
  1231  import "fmt"
  1232  
  1233  func main() {
  1234    fmt.Println("Hello World")
  1235  }`
  1236  	f := gobuild(t, dir, prog, NoOpt)
  1237  	defer f.Close()
  1238  	exe, err := pe.Open(f.path)
  1239  	if err != nil {
  1240  		t.Fatalf("error opening pe file: %v", err)
  1241  	}
  1242  	defer exe.Close()
  1243  	dw, err := exe.DWARF()
  1244  	if err != nil {
  1245  		t.Fatalf("error parsing DWARF: %v", err)
  1246  	}
  1247  	rdr := dw.Reader()
  1248  	for {
  1249  		e, err := rdr.Next()
  1250  		if err != nil {
  1251  			t.Fatalf("error reading DWARF: %v", err)
  1252  		}
  1253  		if e == nil {
  1254  			break
  1255  		}
  1256  		if e.Tag != dwarf.TagCompileUnit {
  1257  			continue
  1258  		}
  1259  		lnrdr, err := dw.LineReader(e)
  1260  		if err != nil {
  1261  			t.Fatalf("error creating DWARF line reader: %v", err)
  1262  		}
  1263  		if lnrdr != nil {
  1264  			var lne dwarf.LineEntry
  1265  			for {
  1266  				err := lnrdr.Next(&lne)
  1267  				if err == io.EOF {
  1268  					break
  1269  				}
  1270  				if err != nil {
  1271  					t.Fatalf("error reading next DWARF line: %v", err)
  1272  				}
  1273  				if strings.Contains(lne.File.Name, `\`) {
  1274  					t.Errorf("filename should not contain backslash: %v", lne.File.Name)
  1275  				}
  1276  			}
  1277  		}
  1278  		rdr.SkipChildren()
  1279  	}
  1280  }
  1281  
  1282  func TestIssue38192(t *testing.T) {
  1283  	testenv.MustHaveGoBuild(t)
  1284  
  1285  	mustHaveDWARF(t)
  1286  
  1287  	t.Parallel()
  1288  
  1289  	// Build a test program that contains a translation unit whose
  1290  	// text (from am assembly source) contains only a single instruction.
  1291  	f := gobuildTestdata(t, "testdata/issue38192", DefaultOpt)
  1292  	defer f.Close()
  1293  
  1294  	// Open the resulting binary and examine the DWARF it contains.
  1295  	// Look for the function of interest ("main.singleInstruction")
  1296  	// and verify that the line table has an entry not just for the
  1297  	// single instruction but also a dummy instruction following it,
  1298  	// so as to test that whoever is emitting the DWARF doesn't
  1299  	// emit an end-sequence op immediately after the last instruction
  1300  	// in the translation unit.
  1301  	//
  1302  	// NB: another way to write this test would have been to run the
  1303  	// resulting executable under GDB, set a breakpoint in
  1304  	// "main.singleInstruction", then verify that GDB displays the
  1305  	// correct line/file information.  Given the headache and flakiness
  1306  	// associated with GDB-based tests these days, a direct read of
  1307  	// the line table seems more desirable.
  1308  	rows := []dwarf.LineEntry{}
  1309  	dw, err := f.DWARF()
  1310  	if err != nil {
  1311  		t.Fatalf("error parsing DWARF: %v", err)
  1312  	}
  1313  	rdr := dw.Reader()
  1314  	for {
  1315  		e, err := rdr.Next()
  1316  		if err != nil {
  1317  			t.Fatalf("error reading DWARF: %v", err)
  1318  		}
  1319  		if e == nil {
  1320  			break
  1321  		}
  1322  		if e.Tag != dwarf.TagCompileUnit {
  1323  			continue
  1324  		}
  1325  		// NB: there can be multiple compile units named "main".
  1326  		name := e.Val(dwarf.AttrName).(string)
  1327  		if name != "main" {
  1328  			continue
  1329  		}
  1330  		lnrdr, err := dw.LineReader(e)
  1331  		if err != nil {
  1332  			t.Fatalf("error creating DWARF line reader: %v", err)
  1333  		}
  1334  		if lnrdr != nil {
  1335  			var lne dwarf.LineEntry
  1336  			for {
  1337  				err := lnrdr.Next(&lne)
  1338  				if err == io.EOF {
  1339  					break
  1340  				}
  1341  				if err != nil {
  1342  					t.Fatalf("error reading next DWARF line: %v", err)
  1343  				}
  1344  				if !strings.HasSuffix(lne.File.Name, "ld/testdata/issue38192/oneline.s") {
  1345  					continue
  1346  				}
  1347  				rows = append(rows, lne)
  1348  			}
  1349  		}
  1350  		rdr.SkipChildren()
  1351  	}
  1352  	f.Close()
  1353  
  1354  	// Make sure that:
  1355  	// - main.singleInstruction appears in the line table
  1356  	// - more than one PC value appears the line table for
  1357  	//   that compilation unit.
  1358  	// - at least one row has the correct line number (8)
  1359  	pcs := make(map[uint64]bool)
  1360  	line8seen := false
  1361  	for _, r := range rows {
  1362  		pcs[r.Address] = true
  1363  		if r.Line == 8 {
  1364  			line8seen = true
  1365  		}
  1366  	}
  1367  	failed := false
  1368  	if len(pcs) < 2 {
  1369  		failed = true
  1370  		t.Errorf("not enough line table rows for main.singleInstruction (got %d, wanted > 1", len(pcs))
  1371  	}
  1372  	if !line8seen {
  1373  		failed = true
  1374  		t.Errorf("line table does not contain correct line for main.singleInstruction")
  1375  	}
  1376  	if !failed {
  1377  		return
  1378  	}
  1379  	for i, r := range rows {
  1380  		t.Logf("row %d: A=%x F=%s L=%d\n", i, r.Address, r.File.Name, r.Line)
  1381  	}
  1382  }
  1383  
  1384  func TestIssue39757(t *testing.T) {
  1385  	testenv.MustHaveGoBuild(t)
  1386  
  1387  	mustHaveDWARF(t)
  1388  
  1389  	t.Parallel()
  1390  
  1391  	// In this bug the DWARF line table contents for the last couple of
  1392  	// instructions in a function were incorrect (bad file/line). This
  1393  	// test verifies that all of the line table rows for a function
  1394  	// of interest have the same file (no "autogenerated").
  1395  	//
  1396  	// Note: the function in this test was written with an eye towards
  1397  	// ensuring that there are no inlined routines from other packages
  1398  	// (which could introduce other source files into the DWARF); it's
  1399  	// possible that at some point things could evolve in the
  1400  	// compiler/runtime in ways that aren't happening now, so this
  1401  	// might be something to check for if it does start failing.
  1402  
  1403  	f := gobuildTestdata(t, "testdata/issue39757", DefaultOpt)
  1404  	defer f.Close()
  1405  
  1406  	syms, err := f.Symbols()
  1407  	if err != nil {
  1408  		t.Fatal(err)
  1409  	}
  1410  
  1411  	var addr uint64
  1412  	for _, sym := range syms {
  1413  		if sym.Name == "main.main" {
  1414  			addr = sym.Addr
  1415  			break
  1416  		}
  1417  	}
  1418  	if addr == 0 {
  1419  		t.Fatal("cannot find main.main in symbols")
  1420  	}
  1421  
  1422  	// Open the resulting binary and examine the DWARF it contains.
  1423  	// Look for the function of interest ("main.main")
  1424  	// and verify that all line table entries show the same source
  1425  	// file.
  1426  	dw, err := f.DWARF()
  1427  	if err != nil {
  1428  		t.Fatalf("error parsing DWARF: %v", err)
  1429  	}
  1430  	rdr := dw.Reader()
  1431  	ex := &dwtest.Examiner{}
  1432  	if err := ex.Populate(rdr); err != nil {
  1433  		t.Fatalf("error reading DWARF: %v", err)
  1434  	}
  1435  
  1436  	maindie := findSubprogramDIE(t, ex, "main.main")
  1437  
  1438  	// Collect the start/end PC for main.main. The format/class of the
  1439  	// high PC attr may vary depending on which DWARF version we're generating;
  1440  	// invoke a helper to handle the various possibilities.
  1441  	// the low PC as opposed to an address; allow for both possibilities.
  1442  	lowpc, highpc, perr := dwtest.SubprogLoAndHighPc(maindie)
  1443  	if perr != nil {
  1444  		t.Fatalf("main.main DIE malformed: %v", perr)
  1445  	}
  1446  	t.Logf("lo=0x%x hi=0x%x\n", lowpc, highpc)
  1447  
  1448  	// Now read the line table for the 'main' compilation unit.
  1449  	mainIdx := ex.IdxFromOffset(maindie.Offset)
  1450  	cuentry := ex.Parent(mainIdx)
  1451  	if cuentry == nil {
  1452  		t.Fatalf("main.main DIE appears orphaned")
  1453  	}
  1454  	lnrdr, lerr := dw.LineReader(cuentry)
  1455  	if lerr != nil {
  1456  		t.Fatalf("error creating DWARF line reader: %v", err)
  1457  	}
  1458  	if lnrdr == nil {
  1459  		t.Fatalf("no line table for main.main compilation unit")
  1460  	}
  1461  	rows := []dwarf.LineEntry{}
  1462  	mainrows := 0
  1463  	var lne dwarf.LineEntry
  1464  	for {
  1465  		err := lnrdr.Next(&lne)
  1466  		if err == io.EOF {
  1467  			break
  1468  		}
  1469  		rows = append(rows, lne)
  1470  		if err != nil {
  1471  			t.Fatalf("error reading next DWARF line: %v", err)
  1472  		}
  1473  		if lne.Address < lowpc || lne.Address > highpc {
  1474  			continue
  1475  		}
  1476  		if !strings.HasSuffix(lne.File.Name, "issue39757main.go") {
  1477  			t.Errorf("found row with file=%s (not issue39757main.go)", lne.File.Name)
  1478  		}
  1479  		mainrows++
  1480  	}
  1481  	f.Close()
  1482  
  1483  	// Make sure we saw a few rows.
  1484  	if mainrows < 3 {
  1485  		t.Errorf("not enough line table rows for main.main (got %d, wanted > 3", mainrows)
  1486  		for i, r := range rows {
  1487  			t.Logf("row %d: A=%x F=%s L=%d\n", i, r.Address, r.File.Name, r.Line)
  1488  		}
  1489  	}
  1490  }
  1491  
  1492  func TestIssue42484(t *testing.T) {
  1493  	testenv.MustHaveGoBuild(t)
  1494  	testenv.MustInternalLink(t, false) // Avoid spurious failures from external linkers.
  1495  
  1496  	mustHaveDWARF(t)
  1497  
  1498  	t.Parallel()
  1499  
  1500  	f := gobuildTestdata(t, "testdata/issue42484", NoOpt)
  1501  
  1502  	var lastAddr uint64
  1503  	var lastFile string
  1504  	var lastLine int
  1505  
  1506  	dw, err := f.DWARF()
  1507  	if err != nil {
  1508  		t.Fatalf("error parsing DWARF: %v", err)
  1509  	}
  1510  	rdr := dw.Reader()
  1511  	for {
  1512  		e, err := rdr.Next()
  1513  		if err != nil {
  1514  			t.Fatalf("error reading DWARF: %v", err)
  1515  		}
  1516  		if e == nil {
  1517  			break
  1518  		}
  1519  		if e.Tag != dwarf.TagCompileUnit {
  1520  			continue
  1521  		}
  1522  		lnrdr, err := dw.LineReader(e)
  1523  		if err != nil {
  1524  			t.Fatalf("error creating DWARF line reader: %v", err)
  1525  		}
  1526  		if lnrdr != nil {
  1527  			var lne dwarf.LineEntry
  1528  			for {
  1529  				err := lnrdr.Next(&lne)
  1530  				if err == io.EOF {
  1531  					break
  1532  				}
  1533  				if err != nil {
  1534  					t.Fatalf("error reading next DWARF line: %v", err)
  1535  				}
  1536  				if lne.EndSequence {
  1537  					continue
  1538  				}
  1539  				if lne.Address == lastAddr && (lne.File.Name != lastFile || lne.Line != lastLine) {
  1540  					t.Errorf("address %#x is assigned to both %s:%d and %s:%d", lastAddr, lastFile, lastLine, lne.File.Name, lne.Line)
  1541  				}
  1542  				lastAddr = lne.Address
  1543  				lastFile = lne.File.Name
  1544  				lastLine = lne.Line
  1545  			}
  1546  		}
  1547  		rdr.SkipChildren()
  1548  	}
  1549  	f.Close()
  1550  }
  1551  
  1552  // processParams examines the formal parameter children of subprogram
  1553  // DIE "die" using the explorer "ex" and returns a string that
  1554  // captures the name, order, and classification of the subprogram's
  1555  // input and output parameters. For example, for the go function
  1556  //
  1557  //	func foo(i1 int, f1 float64) (string, bool) {
  1558  //
  1559  // this function would return a string something like
  1560  //
  1561  //	i1:0:1 f1:1:1 ~r0:2:2 ~r1:3:2
  1562  //
  1563  // where each chunk above is of the form NAME:ORDER:INOUTCLASSIFICATION
  1564  func processParams(die *dwarf.Entry, ex *dwtest.Examiner) string {
  1565  	// Values in the returned map are of the form <order>:<varparam>
  1566  	// where order is the order within the child DIE list of the
  1567  	// param, and <varparam> is an integer:
  1568  	//
  1569  	//  -1: varparm attr not found
  1570  	//   1: varparm found with value false
  1571  	//   2: varparm found with value true
  1572  	//
  1573  	foundParams := make(map[string]string)
  1574  
  1575  	// Walk the subprogram DIE's children looking for params.
  1576  	pIdx := ex.IdxFromOffset(die.Offset)
  1577  	childDies := ex.Children(pIdx)
  1578  	idx := 0
  1579  	for _, child := range childDies {
  1580  		if child.Tag == dwarf.TagFormalParameter {
  1581  			// NB: a setting of DW_AT_variable_parameter indicates
  1582  			// that the param in question is an output parameter; we
  1583  			// want to see this attribute set to TRUE for all Go
  1584  			// return params. It would be OK to have it missing for
  1585  			// input parameters, but for the moment we verify that the
  1586  			// attr is present but set to false.
  1587  			st := -1
  1588  			if vp, ok := child.Val(dwarf.AttrVarParam).(bool); ok {
  1589  				if vp {
  1590  					st = 2
  1591  				} else {
  1592  					st = 1
  1593  				}
  1594  			}
  1595  			if name, ok := child.Val(dwarf.AttrName).(string); ok {
  1596  				foundParams[name] = fmt.Sprintf("%d:%d", idx, st)
  1597  				idx++
  1598  			}
  1599  		}
  1600  	}
  1601  
  1602  	found := make([]string, 0, len(foundParams))
  1603  	for k, v := range foundParams {
  1604  		found = append(found, fmt.Sprintf("%s:%s", k, v))
  1605  	}
  1606  	sort.Strings(found)
  1607  
  1608  	return fmt.Sprintf("%+v", found)
  1609  }
  1610  
  1611  func TestOutputParamAbbrevAndAttr(t *testing.T) {
  1612  	testenv.MustHaveGoBuild(t)
  1613  
  1614  	mustHaveDWARF(t)
  1615  	t.Parallel()
  1616  
  1617  	// This test verifies that the compiler is selecting the correct
  1618  	// DWARF abbreviation for output parameters, and that the
  1619  	// variable parameter attribute is correct for in-params and
  1620  	// out-params.
  1621  
  1622  	const prog = `
  1623  package main
  1624  
  1625  //go:noinline
  1626  func ABC(c1, c2, c3 int, d1, d2, d3, d4 string, f1, f2, f3 float32, g1 [1024]int) (r1 int, r2 int, r3 [1024]int, r4 byte, r5 string, r6 float32) {
  1627  	g1[0] = 6
  1628  	r1, r2, r3, r4, r5, r6 = c3, c2+c1, g1, 'a', d1+d2+d3+d4, f1+f2+f3
  1629  	return
  1630  }
  1631  
  1632  func main() {
  1633  	a := [1024]int{}
  1634  	v1, v2, v3, v4, v5, v6 := ABC(1, 2, 3, "a", "b", "c", "d", 1.0, 2.0, 1.0, a)
  1635  	println(v1, v2, v3[0], v4, v5, v6)
  1636  }
  1637  `
  1638  	_, ex := gobuildAndExamine(t, prog, NoOpt)
  1639  
  1640  	abcdie := findSubprogramDIE(t, ex, "main.ABC")
  1641  
  1642  	// Call a helper to collect param info.
  1643  	found := processParams(abcdie, ex)
  1644  
  1645  	// Make sure we see all of the expected params in the proper
  1646  	// order, that they have the varparam attr, and the varparam is
  1647  	// set for the returns.
  1648  	expected := "[c1:0:1 c2:1:1 c3:2:1 d1:3:1 d2:4:1 d3:5:1 d4:6:1 f1:7:1 f2:8:1 f3:9:1 g1:10:1 r1:11:2 r2:12:2 r3:13:2 r4:14:2 r5:15:2 r6:16:2]"
  1649  	if found != expected {
  1650  		t.Errorf("param check failed, wanted:\n%s\ngot:\n%s\n",
  1651  			expected, found)
  1652  	}
  1653  }
  1654  
  1655  func TestDictIndex(t *testing.T) {
  1656  	// Check that variables with a parametric type have a dictionary index
  1657  	// attribute and that types that are only referenced through dictionaries
  1658  	// have DIEs.
  1659  	testenv.MustHaveGoBuild(t)
  1660  
  1661  	mustHaveDWARF(t)
  1662  	t.Parallel()
  1663  
  1664  	const prog = `
  1665  package main
  1666  
  1667  import "fmt"
  1668  
  1669  type CustomInt int
  1670  
  1671  func testfn[T any](arg T) {
  1672  	var mapvar = make(map[int]T)
  1673  	mapvar[0] = arg
  1674  	fmt.Println(arg, mapvar)
  1675  }
  1676  
  1677  func main() {
  1678  	testfn(CustomInt(3))
  1679  }
  1680  `
  1681  
  1682  	dir := t.TempDir()
  1683  	f := gobuild(t, dir, prog, NoOpt)
  1684  	defer f.Close()
  1685  
  1686  	d, err := f.DWARF()
  1687  	if err != nil {
  1688  		t.Fatalf("error reading DWARF: %v", err)
  1689  	}
  1690  
  1691  	rdr := d.Reader()
  1692  	found := false
  1693  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
  1694  		if err != nil {
  1695  			t.Fatalf("error reading DWARF: %v", err)
  1696  		}
  1697  		name, _ := entry.Val(dwarf.AttrName).(string)
  1698  		if strings.HasPrefix(name, "main.testfn") {
  1699  			found = true
  1700  			break
  1701  		}
  1702  	}
  1703  
  1704  	if !found {
  1705  		t.Fatalf("could not find main.testfn")
  1706  	}
  1707  
  1708  	offs := []dwarf.Offset{}
  1709  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
  1710  		if err != nil {
  1711  			t.Fatalf("error reading DWARF: %v", err)
  1712  		}
  1713  		if entry.Tag == 0 {
  1714  			break
  1715  		}
  1716  		name, _ := entry.Val(dwarf.AttrName).(string)
  1717  		switch name {
  1718  		case "arg", "mapvar":
  1719  			offs = append(offs, entry.Val(dwarf.AttrType).(dwarf.Offset))
  1720  		}
  1721  	}
  1722  	if len(offs) != 2 {
  1723  		t.Errorf("wrong number of variables found in main.testfn %d", len(offs))
  1724  	}
  1725  	for _, off := range offs {
  1726  		rdr.Seek(off)
  1727  		entry, err := rdr.Next()
  1728  		if err != nil {
  1729  			t.Fatalf("error reading DWARF: %v", err)
  1730  		}
  1731  		if _, ok := entry.Val(intdwarf.DW_AT_go_dict_index).(int64); !ok {
  1732  			t.Errorf("could not find DW_AT_go_dict_index attribute offset %#x (%T)", off, entry.Val(intdwarf.DW_AT_go_dict_index))
  1733  		}
  1734  	}
  1735  
  1736  	rdr.Seek(0)
  1737  	ex := dwtest.Examiner{}
  1738  	if err := ex.Populate(rdr); err != nil {
  1739  		t.Fatalf("error reading DWARF: %v", err)
  1740  	}
  1741  	for _, typeName := range []string{"main.CustomInt", "map[int]main.CustomInt"} {
  1742  		dies := ex.Named(typeName)
  1743  		if len(dies) != 1 {
  1744  			t.Errorf("wanted 1 DIE named %s, found %v", typeName, len(dies))
  1745  		}
  1746  		if dies[0].Val(intdwarf.DW_AT_go_runtime_type).(uint64) == 0 {
  1747  			t.Errorf("type %s does not have DW_AT_go_runtime_type", typeName)
  1748  		}
  1749  	}
  1750  }
  1751  
  1752  func TestOptimizedOutParamHandling(t *testing.T) {
  1753  	testenv.MustHaveGoBuild(t)
  1754  
  1755  	mustHaveDWARF(t)
  1756  	t.Parallel()
  1757  
  1758  	// This test is intended to verify that the compiler emits DWARF
  1759  	// DIE entries for all input and output parameters, and that:
  1760  	//
  1761  	//   - attributes are set correctly for output params,
  1762  	//   - things appear in the proper order
  1763  	//   - things work properly for both register-resident
  1764  	//     params and params passed on the stack
  1765  	//   - things work for both referenced and unreferenced params
  1766  	//   - things work for named return values un-named return vals
  1767  	//
  1768  	// The scenarios below don't cover all possible permutations and
  1769  	// combinations, but they hit a bunch of the high points.
  1770  
  1771  	const prog = `
  1772  package main
  1773  
  1774  // First testcase. All input params in registers, all params used.
  1775  
  1776  //go:noinline
  1777  func tc1(p1, p2 int, p3 string) (int, string) {
  1778  	return p1 + p2, p3 + "foo"
  1779  }
  1780  
  1781  // Second testcase. Some params in registers, some on stack.
  1782  
  1783  //go:noinline
  1784  func tc2(p1 int, p2 [128]int, p3 string) (int, string, [128]int) {
  1785  	return p1 + p2[p1], p3 + "foo", [128]int{p1}
  1786  }
  1787  
  1788  // Third testcase. Named return params.
  1789  
  1790  //go:noinline
  1791  func tc3(p1 int, p2 [128]int, p3 string) (r1 int, r2 bool, r3 string, r4 [128]int) {
  1792  	if p1 == 101 {
  1793  		r1 = p1 + p2[p1]
  1794  		r2 = p3 == "foo"
  1795  		r4 = [128]int{p1}
  1796  		return
  1797  	} else {
  1798  		return p1 - p2[p1+3], false, "bar", [128]int{p1 + 2}
  1799  	}
  1800  }
  1801  
  1802  // Fourth testcase. Some thing are used, some are unused.
  1803  
  1804  //go:noinline
  1805  func tc4(p1, p1un int, p2, p2un [128]int, p3, p3un string) (r1 int, r1un int, r2 bool, r3 string, r4, r4un [128]int) {
  1806  	if p1 == 101 {
  1807  		r1 = p1 + p2[p2[0]]
  1808  		r2 = p3 == "foo"
  1809  		r4 = [128]int{p1}
  1810  		return
  1811  	} else {
  1812  		return p1, -1, true, "plex", [128]int{p1 + 2}, [128]int{-1}
  1813  	}
  1814  }
  1815  
  1816  func main() {
  1817  	{
  1818  		r1, r2 := tc1(3, 4, "five")
  1819  		println(r1, r2)
  1820  	}
  1821  	{
  1822  		x := [128]int{9}
  1823  		r1, r2, r3 := tc2(3, x, "five")
  1824  		println(r1, r2, r3[0])
  1825  	}
  1826  	{
  1827  		x := [128]int{9}
  1828  		r1, r2, r3, r4 := tc3(3, x, "five")
  1829  		println(r1, r2, r3, r4[0])
  1830  	}
  1831  	{
  1832  		x := [128]int{3}
  1833  		y := [128]int{7}
  1834  		r1, r1u, r2, r3, r4, r4u := tc4(0, 1, x, y, "a", "b")
  1835  		println(r1, r1u, r2, r3, r4[0], r4u[1])
  1836  	}
  1837  
  1838  }
  1839  `
  1840  	_, ex := gobuildAndExamine(t, prog, DefaultOpt)
  1841  
  1842  	testcases := []struct {
  1843  		tag      string
  1844  		expected string
  1845  	}{
  1846  		{
  1847  			tag:      "tc1",
  1848  			expected: "[p1:0:1 p2:1:1 p3:2:1 ~r0:3:2 ~r1:4:2]",
  1849  		},
  1850  		{
  1851  			tag:      "tc2",
  1852  			expected: "[p1:0:1 p2:1:1 p3:2:1 ~r0:3:2 ~r1:4:2 ~r2:5:2]",
  1853  		},
  1854  		{
  1855  			tag:      "tc3",
  1856  			expected: "[p1:0:1 p2:1:1 p3:2:1 r1:3:2 r2:4:2 r3:5:2 r4:6:2]",
  1857  		},
  1858  		{
  1859  			tag:      "tc4",
  1860  			expected: "[p1:0:1 p1un:1:1 p2:2:1 p2un:3:1 p3:4:1 p3un:5:1 r1:6:2 r1un:7:2 r2:8:2 r3:9:2 r4:10:2 r4un:11:2]",
  1861  		},
  1862  	}
  1863  
  1864  	for _, tc := range testcases {
  1865  		// Locate the proper DIE
  1866  		which := fmt.Sprintf("main.%s", tc.tag)
  1867  		die := findSubprogramDIE(t, ex, which)
  1868  
  1869  		// Examine params for this subprogram.
  1870  		foundParams := processParams(die, ex)
  1871  		if foundParams != tc.expected {
  1872  			t.Errorf("check failed for testcase %s -- wanted:\n%s\ngot:%s\n",
  1873  				tc.tag, tc.expected, foundParams)
  1874  		}
  1875  	}
  1876  }
  1877  func TestIssue54320(t *testing.T) {
  1878  	// Check that when trampolines are used, the DWARF LPT is correctly
  1879  	// emitted in the final binary
  1880  	testenv.MustHaveGoBuild(t)
  1881  
  1882  	mustHaveDWARF(t)
  1883  
  1884  	t.Parallel()
  1885  
  1886  	const prog = `
  1887  package main
  1888  
  1889  import "fmt"
  1890  
  1891  func main() {
  1892  	fmt.Printf("Hello world\n");
  1893  }
  1894  `
  1895  
  1896  	dir := t.TempDir()
  1897  	f := gobuild(t, dir, prog, "-ldflags=-debugtramp=2")
  1898  	defer f.Close()
  1899  
  1900  	d, err := f.DWARF()
  1901  	if err != nil {
  1902  		t.Fatalf("error reading DWARF: %v", err)
  1903  	}
  1904  
  1905  	rdr := d.Reader()
  1906  	found := false
  1907  	var entry *dwarf.Entry
  1908  	for entry, err = rdr.Next(); entry != nil; entry, err = rdr.Next() {
  1909  		if err != nil {
  1910  			t.Fatalf("error reading DWARF: %v", err)
  1911  		}
  1912  		if entry.Tag != dwarf.TagCompileUnit {
  1913  			continue
  1914  		}
  1915  		name, _ := entry.Val(dwarf.AttrName).(string)
  1916  		if name == "main" {
  1917  			found = true
  1918  			break
  1919  		}
  1920  		rdr.SkipChildren()
  1921  	}
  1922  
  1923  	if !found {
  1924  		t.Fatalf("could not find main compile unit")
  1925  	}
  1926  	lr, err := d.LineReader(entry)
  1927  	if err != nil {
  1928  		t.Fatalf("error obtaining linereader: %v", err)
  1929  	}
  1930  
  1931  	var le dwarf.LineEntry
  1932  	found = false
  1933  	for {
  1934  		if err := lr.Next(&le); err != nil {
  1935  			if err == io.EOF {
  1936  				break
  1937  			}
  1938  			t.Fatalf("error reading linentry: %v", err)
  1939  		}
  1940  		// check LE contains an entry to test.go
  1941  		if le.File == nil {
  1942  			continue
  1943  		}
  1944  		file := filepath.Base(le.File.Name)
  1945  		if file == "test.go" {
  1946  			found = true
  1947  			break
  1948  		}
  1949  	}
  1950  	if !found {
  1951  		t.Errorf("no LPT entries for test.go")
  1952  	}
  1953  }
  1954  
  1955  const zeroSizedVarProg = `
  1956  package main
  1957  
  1958  import (
  1959  	"fmt"
  1960  )
  1961  
  1962  func main() {
  1963  	zeroSizedVariable := struct{}{}
  1964  	fmt.Println(zeroSizedVariable)
  1965  }
  1966  `
  1967  
  1968  func TestZeroSizedVariable(t *testing.T) {
  1969  	testenv.MustHaveGoBuild(t)
  1970  
  1971  	mustHaveDWARF(t)
  1972  	t.Parallel()
  1973  
  1974  	if testing.Short() {
  1975  		t.Skip("skipping test in short mode.")
  1976  	}
  1977  
  1978  	// This test verifies that the compiler emits DIEs for zero sized variables
  1979  	// (for example variables of type 'struct {}').
  1980  	// See go.dev/issues/54615.
  1981  
  1982  	for _, opt := range []string{NoOpt, DefaultOpt} {
  1983  		opt := opt
  1984  		t.Run(opt, func(t *testing.T) {
  1985  			_, ex := gobuildAndExamine(t, zeroSizedVarProg, opt)
  1986  
  1987  			// Locate the main.zeroSizedVariable DIE
  1988  			abcs := ex.Named("zeroSizedVariable")
  1989  			if len(abcs) == 0 {
  1990  				t.Fatalf("unable to locate DIE for zeroSizedVariable")
  1991  			}
  1992  			if len(abcs) != 1 {
  1993  				t.Fatalf("more than one zeroSizedVariable DIE")
  1994  			}
  1995  		})
  1996  	}
  1997  }
  1998  
  1999  func TestConsistentGoKindAndRuntimeType(t *testing.T) {
  2000  	testenv.MustHaveGoBuild(t)
  2001  
  2002  	mustHaveDWARF(t)
  2003  	t.Parallel()
  2004  
  2005  	if testing.Short() {
  2006  		t.Skip("skipping test in short mode.")
  2007  	}
  2008  
  2009  	// Ensure that if we emit a "go runtime type" attr on a type DIE,
  2010  	// we also include the "go kind" attribute. See issue #64231.
  2011  	_, ex := gobuildAndExamine(t, zeroSizedVarProg, DefaultOpt)
  2012  
  2013  	// Walk all dies.
  2014  	typesChecked := 0
  2015  	failures := 0
  2016  	for _, die := range ex.DIEs() {
  2017  		// For any type DIE with DW_AT_go_runtime_type set...
  2018  		rtt, hasRT := die.Val(intdwarf.DW_AT_go_runtime_type).(uint64)
  2019  		if !hasRT || rtt == 0 {
  2020  			continue
  2021  		}
  2022  		// ... except unsafe.Pointer...
  2023  		if name, _ := die.Val(intdwarf.DW_AT_name).(string); name == "unsafe.Pointer" {
  2024  			continue
  2025  		}
  2026  		typesChecked++
  2027  		// ... we want to see a meaningful DW_AT_go_kind value.
  2028  		if val, ok := die.Val(intdwarf.DW_AT_go_kind).(int64); !ok || val == 0 {
  2029  			failures++
  2030  			// dump DIEs for first 10 failures.
  2031  			if failures <= 10 {
  2032  				idx := ex.IdxFromOffset(die.Offset)
  2033  				t.Logf("type DIE has DW_AT_go_runtime_type but invalid DW_AT_go_kind:\n")
  2034  				ex.DumpEntry(idx, false, 0)
  2035  			}
  2036  			t.Errorf("bad type DIE at offset %d\n", die.Offset)
  2037  		}
  2038  	}
  2039  	if typesChecked == 0 {
  2040  		t.Fatalf("something went wrong, 0 types checked")
  2041  	} else {
  2042  		t.Logf("%d types checked\n", typesChecked)
  2043  	}
  2044  }
  2045  

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