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

Documentation: cmd/link/internal/ld

     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.MapType":       true,
    64  		"internal/abi.PtrType":       true,
    65  		"internal/abi.SliceType":     true,
    66  		"internal/abi.StructType":    true,
    67  		"internal/abi.InterfaceType": true,
    68  		"internal/abi.ITab":          true,
    69  	}
    70  
    71  	found := findTypes(t, dwarf, want)
    72  	if len(found) != len(want) {
    73  		t.Errorf("found %v, want %v", found, want)
    74  	}
    75  }
    76  
    77  func findTypes(t *testing.T, dw *dwarf.Data, want map[string]bool) (found map[string]bool) {
    78  	found = make(map[string]bool)
    79  	rdr := dw.Reader()
    80  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
    81  		if err != nil {
    82  			t.Fatalf("error reading DWARF: %v", err)
    83  		}
    84  		switch entry.Tag {
    85  		case dwarf.TagTypedef:
    86  			if name, ok := entry.Val(dwarf.AttrName).(string); ok && want[name] {
    87  				found[name] = true
    88  			}
    89  		}
    90  	}
    91  	return
    92  }
    93  
    94  type builtFile struct {
    95  	*objfilepkg.File
    96  	path string
    97  }
    98  
    99  func gobuild(t *testing.T, dir string, testfile string, gcflags string) *builtFile {
   100  	src := filepath.Join(dir, "test.go")
   101  	dst := filepath.Join(dir, "out.exe")
   102  
   103  	if err := os.WriteFile(src, []byte(testfile), 0666); err != nil {
   104  		t.Fatal(err)
   105  	}
   106  
   107  	cmd := testenv.Command(t, testenv.GoToolPath(t), "build", gcflags, "-o", dst, src)
   108  	b, err := cmd.CombinedOutput()
   109  	if len(b) != 0 {
   110  		t.Logf("## build output:\n%s", b)
   111  	}
   112  	if err != nil {
   113  		t.Fatalf("build error: %v", err)
   114  	}
   115  
   116  	f, err := objfilepkg.Open(dst)
   117  	if err != nil {
   118  		t.Fatal(err)
   119  	}
   120  	return &builtFile{f, dst}
   121  }
   122  
   123  // Similar to gobuild() above, but uses a main package instead of a test.go file.
   124  
   125  func gobuildTestdata(t *testing.T, tdir string, pkgDir string, gcflags string) *builtFile {
   126  	dst := filepath.Join(tdir, "out.exe")
   127  
   128  	// Run a build with an updated GOPATH
   129  	cmd := testenv.Command(t, testenv.GoToolPath(t), "build", gcflags, "-o", dst)
   130  	cmd.Dir = pkgDir
   131  	if b, err := cmd.CombinedOutput(); err != nil {
   132  		t.Logf("build: %s\n", b)
   133  		t.Fatalf("build error: %v", err)
   134  	}
   135  
   136  	f, err := objfilepkg.Open(dst)
   137  	if err != nil {
   138  		t.Fatal(err)
   139  	}
   140  	return &builtFile{f, dst}
   141  }
   142  
   143  // Helper to build a snippet of source for examination with dwtest.Examiner.
   144  func gobuildAndExamine(t *testing.T, source string, gcflags string) (*dwarf.Data, *dwtest.Examiner) {
   145  	dir := t.TempDir()
   146  
   147  	f := gobuild(t, dir, source, gcflags)
   148  	defer f.Close()
   149  
   150  	d, err := f.DWARF()
   151  	if err != nil {
   152  		t.Fatalf("error reading DWARF in program %q: %v", source, err)
   153  	}
   154  
   155  	rdr := d.Reader()
   156  	ex := &dwtest.Examiner{}
   157  	if err := ex.Populate(rdr); err != nil {
   158  		t.Fatalf("error populating DWARF examiner for program %q: %v", source, err)
   159  	}
   160  
   161  	return d, ex
   162  }
   163  
   164  func findSubprogramDIE(t *testing.T, ex *dwtest.Examiner, sym string) *dwarf.Entry {
   165  	dies := ex.Named(sym)
   166  	if len(dies) == 0 {
   167  		t.Fatalf("unable to locate DIE for %s", sym)
   168  	}
   169  	if len(dies) != 1 {
   170  		t.Fatalf("more than one %s DIE: %+v", sym, dies)
   171  	}
   172  	die := dies[0]
   173  
   174  	// Vet the DIE.
   175  	if die.Tag != dwarf.TagSubprogram {
   176  		t.Fatalf("unexpected tag %v on %s DIE", die.Tag, sym)
   177  	}
   178  
   179  	return die
   180  }
   181  
   182  func TestEmbeddedStructMarker(t *testing.T) {
   183  	t.Parallel()
   184  	testenv.MustHaveGoBuild(t)
   185  
   186  	mustHaveDWARF(t)
   187  
   188  	const prog = `
   189  package main
   190  
   191  import "fmt"
   192  
   193  type Foo struct { v int }
   194  type Bar struct {
   195  	Foo
   196  	name string
   197  }
   198  type Baz struct {
   199  	*Foo
   200  	name string
   201  }
   202  
   203  func main() {
   204  	bar := Bar{ Foo: Foo{v: 123}, name: "onetwothree"}
   205  	baz := Baz{ Foo: &bar.Foo, name: "123" }
   206  	fmt.Println(bar, baz)
   207  }`
   208  
   209  	want := map[string]map[string]bool{
   210  		"main.Foo": {"v": false},
   211  		"main.Bar": {"Foo": true, "name": false},
   212  		"main.Baz": {"Foo": true, "name": false},
   213  	}
   214  
   215  	dir := t.TempDir()
   216  
   217  	f := gobuild(t, dir, prog, NoOpt)
   218  
   219  	defer f.Close()
   220  
   221  	d, err := f.DWARF()
   222  	if err != nil {
   223  		t.Fatalf("error reading DWARF: %v", err)
   224  	}
   225  
   226  	rdr := d.Reader()
   227  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   228  		if err != nil {
   229  			t.Fatalf("error reading DWARF: %v", err)
   230  		}
   231  		switch entry.Tag {
   232  		case dwarf.TagStructType:
   233  			name, ok := entry.Val(dwarf.AttrName).(string)
   234  			if !ok {
   235  				continue
   236  			}
   237  			wantMembers := want[name]
   238  			if wantMembers == nil {
   239  				continue
   240  			}
   241  			gotMembers, err := findMembers(rdr)
   242  			if err != nil {
   243  				t.Fatalf("error reading DWARF: %v", err)
   244  			}
   245  
   246  			if !reflect.DeepEqual(gotMembers, wantMembers) {
   247  				t.Errorf("type %v: got map[member]embedded = %+v, want %+v", name, wantMembers, gotMembers)
   248  			}
   249  			delete(want, name)
   250  		}
   251  	}
   252  	if len(want) != 0 {
   253  		t.Errorf("failed to check all expected types: missing types = %+v", want)
   254  	}
   255  }
   256  
   257  func findMembers(rdr *dwarf.Reader) (map[string]bool, error) {
   258  	memberEmbedded := map[string]bool{}
   259  	// TODO(hyangah): define in debug/dwarf package
   260  	const goEmbeddedStruct = dwarf.Attr(intdwarf.DW_AT_go_embedded_field)
   261  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   262  		if err != nil {
   263  			return nil, err
   264  		}
   265  		switch entry.Tag {
   266  		case dwarf.TagMember:
   267  			name := entry.Val(dwarf.AttrName).(string)
   268  			embedded := entry.Val(goEmbeddedStruct).(bool)
   269  			memberEmbedded[name] = embedded
   270  		case 0:
   271  			return memberEmbedded, nil
   272  		}
   273  	}
   274  	return memberEmbedded, nil
   275  }
   276  
   277  func TestSizes(t *testing.T) {
   278  	mustHaveDWARF(t)
   279  
   280  	// External linking may bring in C symbols with unknown size. Skip.
   281  	testenv.MustInternalLink(t, false)
   282  
   283  	t.Parallel()
   284  
   285  	// DWARF sizes should never be -1.
   286  	// See issue #21097
   287  	const prog = `
   288  package main
   289  var x func()
   290  var y [4]func()
   291  func main() {
   292  	x = nil
   293  	y[0] = nil
   294  }
   295  `
   296  	dir := t.TempDir()
   297  
   298  	f := gobuild(t, dir, prog, NoOpt)
   299  	defer f.Close()
   300  	d, err := f.DWARF()
   301  	if err != nil {
   302  		t.Fatalf("error reading DWARF: %v", err)
   303  	}
   304  	rdr := d.Reader()
   305  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   306  		if err != nil {
   307  			t.Fatalf("error reading DWARF: %v", err)
   308  		}
   309  		switch entry.Tag {
   310  		case dwarf.TagArrayType, dwarf.TagPointerType, dwarf.TagStructType, dwarf.TagBaseType, dwarf.TagSubroutineType, dwarf.TagTypedef:
   311  		default:
   312  			continue
   313  		}
   314  		typ, err := d.Type(entry.Offset)
   315  		if err != nil {
   316  			t.Fatalf("can't read type: %v", err)
   317  		}
   318  		if typ.Size() < 0 {
   319  			t.Errorf("subzero size %s %s %T", typ, entry.Tag, typ)
   320  		}
   321  	}
   322  }
   323  
   324  func TestFieldOverlap(t *testing.T) {
   325  	mustHaveDWARF(t)
   326  	t.Parallel()
   327  
   328  	// This test grew out of issue 21094, where specific sudog<T> DWARF types
   329  	// had elem fields set to values instead of pointers.
   330  	const prog = `
   331  package main
   332  
   333  var c chan string
   334  
   335  func main() {
   336  	c <- "foo"
   337  }
   338  `
   339  	dir := t.TempDir()
   340  
   341  	f := gobuild(t, dir, prog, NoOpt)
   342  	defer f.Close()
   343  
   344  	d, err := f.DWARF()
   345  	if err != nil {
   346  		t.Fatalf("error reading DWARF: %v", err)
   347  	}
   348  
   349  	rdr := d.Reader()
   350  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
   351  		if err != nil {
   352  			t.Fatalf("error reading DWARF: %v", err)
   353  		}
   354  		if entry.Tag != dwarf.TagStructType {
   355  			continue
   356  		}
   357  		typ, err := d.Type(entry.Offset)
   358  		if err != nil {
   359  			t.Fatalf("can't read type: %v", err)
   360  		}
   361  		s := typ.(*dwarf.StructType)
   362  		for i := 0; i < len(s.Field); i++ {
   363  			end := s.Field[i].ByteOffset + s.Field[i].Type.Size()
   364  			var limit int64
   365  			if i == len(s.Field)-1 {
   366  				limit = s.Size()
   367  			} else {
   368  				limit = s.Field[i+1].ByteOffset
   369  			}
   370  			if end > limit {
   371  				name := entry.Val(dwarf.AttrName).(string)
   372  				t.Fatalf("field %s.%s overlaps next field", name, s.Field[i].Name)
   373  			}
   374  		}
   375  	}
   376  }
   377  
   378  func TestSubprogramDeclFileLine(t *testing.T) {
   379  	testenv.MustHaveGoBuild(t)
   380  	t.Parallel()
   381  
   382  	mustHaveDWARF(t)
   383  
   384  	const prog = `package main
   385  %s
   386  func main() {}
   387  `
   388  	tests := []struct {
   389  		name string
   390  		prog string
   391  		file string
   392  		line int64
   393  	}{
   394  		{
   395  			name: "normal",
   396  			prog: fmt.Sprintf(prog, ""),
   397  			file: "test.go",
   398  			line: 3,
   399  		},
   400  		{
   401  			name: "line-directive",
   402  			prog: fmt.Sprintf(prog, "//line /foobar.go:200"),
   403  			file: "foobar.go",
   404  			line: 200,
   405  		},
   406  	}
   407  	for _, tc := range tests {
   408  		tc := tc
   409  		t.Run(tc.name, func(t *testing.T) {
   410  			t.Parallel()
   411  
   412  			d, ex := gobuildAndExamine(t, tc.prog, NoOpt)
   413  
   414  			maindie := findSubprogramDIE(t, ex, "main.main")
   415  
   416  			mainIdx := ex.IdxFromOffset(maindie.Offset)
   417  
   418  			fileIdx, fileIdxOK := maindie.Val(dwarf.AttrDeclFile).(int64)
   419  			if !fileIdxOK {
   420  				t.Errorf("missing or invalid DW_AT_decl_file for main")
   421  			}
   422  			file, err := ex.FileRef(d, mainIdx, fileIdx)
   423  			if err != nil {
   424  				t.Fatalf("FileRef: %v", err)
   425  			}
   426  			base := filepath.Base(file)
   427  			if base != tc.file {
   428  				t.Errorf("DW_AT_decl_file for main is %v, want %v", base, tc.file)
   429  			}
   430  
   431  			line, lineOK := maindie.Val(dwarf.AttrDeclLine).(int64)
   432  			if !lineOK {
   433  				t.Errorf("missing or invalid DW_AT_decl_line for main")
   434  			}
   435  			if line != tc.line {
   436  				t.Errorf("DW_AT_decl_line for main is %v, want %d", line, tc.line)
   437  			}
   438  		})
   439  	}
   440  }
   441  
   442  func TestVarDeclLine(t *testing.T) {
   443  	testenv.MustHaveGoBuild(t)
   444  	t.Parallel()
   445  
   446  	mustHaveDWARF(t)
   447  
   448  	const prog = `package main
   449  %s
   450  func main() {
   451  
   452  	var i int
   453  	i = i
   454  }
   455  `
   456  	tests := []struct {
   457  		name string
   458  		prog string
   459  		line int64
   460  	}{
   461  		{
   462  			name: "normal",
   463  			prog: fmt.Sprintf(prog, ""),
   464  			line: 5,
   465  		},
   466  		{
   467  			name: "line-directive",
   468  			prog: fmt.Sprintf(prog, "//line /foobar.go:200"),
   469  			line: 202,
   470  		},
   471  	}
   472  	for _, tc := range tests {
   473  		tc := tc
   474  		t.Run(tc.name, func(t *testing.T) {
   475  			t.Parallel()
   476  
   477  			_, ex := gobuildAndExamine(t, tc.prog, NoOpt)
   478  
   479  			maindie := findSubprogramDIE(t, ex, "main.main")
   480  
   481  			mainIdx := ex.IdxFromOffset(maindie.Offset)
   482  			childDies := ex.Children(mainIdx)
   483  			var iEntry *dwarf.Entry
   484  			for _, child := range childDies {
   485  				if child.Tag == dwarf.TagVariable && child.Val(dwarf.AttrName).(string) == "i" {
   486  					iEntry = child
   487  					break
   488  				}
   489  			}
   490  			if iEntry == nil {
   491  				t.Fatalf("didn't find DW_TAG_variable for i in main.main")
   492  			}
   493  
   494  			// Verify line/file attributes.
   495  			line, lineOK := iEntry.Val(dwarf.AttrDeclLine).(int64)
   496  			if !lineOK {
   497  				t.Errorf("missing or invalid DW_AT_decl_line for i")
   498  			}
   499  			if line != tc.line {
   500  				t.Errorf("DW_AT_decl_line for i is %v, want %d", line, tc.line)
   501  			}
   502  		})
   503  	}
   504  }
   505  
   506  // TestInlinedRoutineCallFileLine tests the call file and line records for an
   507  // inlined subroutine.
   508  func TestInlinedRoutineCallFileLine(t *testing.T) {
   509  	testenv.MustHaveGoBuild(t)
   510  
   511  	mustHaveDWARF(t)
   512  
   513  	t.Parallel()
   514  
   515  	const prog = `
   516  package main
   517  
   518  var G int
   519  
   520  //go:noinline
   521  func notinlined() int {
   522  	return 42
   523  }
   524  
   525  func inlined() int {
   526  	return notinlined()
   527  }
   528  
   529  %s
   530  func main() {
   531  	x := inlined()
   532  	G = x
   533  }
   534  `
   535  	tests := []struct {
   536  		name string
   537  		prog string
   538  		file string // basename
   539  		line int64
   540  	}{
   541  		{
   542  			name: "normal",
   543  			prog: fmt.Sprintf(prog, ""),
   544  			file: "test.go",
   545  			line: 17,
   546  		},
   547  		{
   548  			name: "line-directive",
   549  			prog: fmt.Sprintf(prog, "//line /foobar.go:200"),
   550  			file: "foobar.go",
   551  			line: 201,
   552  		},
   553  	}
   554  	for _, tc := range tests {
   555  		tc := tc
   556  		t.Run(tc.name, func(t *testing.T) {
   557  			t.Parallel()
   558  
   559  			// Note: this is a build with "-l=4", as opposed to "-l -N". The
   560  			// test is intended to verify DWARF that is only generated when
   561  			// the inliner is active. We're only going to look at the DWARF for
   562  			// main.main, however, hence we build with "-gcflags=-l=4" as opposed
   563  			// to "-gcflags=all=-l=4".
   564  			d, ex := gobuildAndExamine(t, tc.prog, OptInl4)
   565  
   566  			maindie := findSubprogramDIE(t, ex, "main.main")
   567  
   568  			// Walk main's children and pick out the inlined subroutines
   569  			mainIdx := ex.IdxFromOffset(maindie.Offset)
   570  			childDies := ex.Children(mainIdx)
   571  			found := false
   572  			for _, child := range childDies {
   573  				if child.Tag != dwarf.TagInlinedSubroutine {
   574  					continue
   575  				}
   576  
   577  				// Found an inlined subroutine.
   578  				if found {
   579  					t.Fatalf("Found multiple inlined subroutines, expect only one")
   580  				}
   581  				found = true
   582  
   583  				// Locate abstract origin.
   584  				ooff, originOK := child.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   585  				if !originOK {
   586  					t.Fatalf("no abstract origin attr for inlined subroutine at offset %v", child.Offset)
   587  				}
   588  				originDIE := ex.EntryFromOffset(ooff)
   589  				if originDIE == nil {
   590  					t.Fatalf("can't locate origin DIE at off %v", ooff)
   591  				}
   592  
   593  				// Name should check out.
   594  				name, ok := originDIE.Val(dwarf.AttrName).(string)
   595  				if !ok {
   596  					t.Fatalf("no name attr for inlined subroutine at offset %v", child.Offset)
   597  				}
   598  				if name != "main.inlined" {
   599  					t.Fatalf("expected inlined routine %s got %s", "main.cand", name)
   600  				}
   601  
   602  				// Verify that the call_file attribute for the inlined
   603  				// instance is ok. In this case it should match the file
   604  				// for the main routine. To do this we need to locate the
   605  				// compilation unit DIE that encloses what we're looking
   606  				// at; this can be done with the examiner.
   607  				cf, cfOK := child.Val(dwarf.AttrCallFile).(int64)
   608  				if !cfOK {
   609  					t.Fatalf("no call_file attr for inlined subroutine at offset %v", child.Offset)
   610  				}
   611  				file, err := ex.FileRef(d, mainIdx, cf)
   612  				if err != nil {
   613  					t.Errorf("FileRef: %v", err)
   614  					continue
   615  				}
   616  				base := filepath.Base(file)
   617  				if base != tc.file {
   618  					t.Errorf("bad call_file attribute, found '%s', want '%s'",
   619  						file, tc.file)
   620  				}
   621  
   622  				// Verify that the call_line attribute for the inlined
   623  				// instance is ok.
   624  				cl, clOK := child.Val(dwarf.AttrCallLine).(int64)
   625  				if !clOK {
   626  					t.Fatalf("no call_line attr for inlined subroutine at offset %v", child.Offset)
   627  				}
   628  				if cl != tc.line {
   629  					t.Errorf("bad call_line attribute, found %d, want %d", cl, tc.line)
   630  				}
   631  			}
   632  			if !found {
   633  				t.Fatalf("not enough inlined subroutines found in main.main")
   634  			}
   635  		})
   636  	}
   637  }
   638  
   639  // TestInlinedRoutineArgsVars tests the argument and variable records for an inlined subroutine.
   640  func TestInlinedRoutineArgsVars(t *testing.T) {
   641  	testenv.MustHaveGoBuild(t)
   642  
   643  	mustHaveDWARF(t)
   644  
   645  	t.Parallel()
   646  
   647  	const prog = `
   648  package main
   649  
   650  var G int
   651  
   652  func noinline(x int) int {
   653  	defer func() { G += x }()
   654  	return x
   655  }
   656  
   657  func cand(x, y int) int {
   658  	return noinline(x+y) ^ (y - x)
   659  }
   660  
   661  func main() {
   662  	x := cand(G*G,G|7%G)
   663  	G = x
   664  }
   665  `
   666  	// Note: this is a build with "-l=4", as opposed to "-l -N". The
   667  	// test is intended to verify DWARF that is only generated when
   668  	// the inliner is active. We're only going to look at the DWARF for
   669  	// main.main, however, hence we build with "-gcflags=-l=4" as opposed
   670  	// to "-gcflags=all=-l=4".
   671  	_, ex := gobuildAndExamine(t, prog, OptInl4)
   672  
   673  	maindie := findSubprogramDIE(t, ex, "main.main")
   674  
   675  	// Walk main's children and pick out the inlined subroutines
   676  	mainIdx := ex.IdxFromOffset(maindie.Offset)
   677  	childDies := ex.Children(mainIdx)
   678  	found := false
   679  	for _, child := range childDies {
   680  		if child.Tag != dwarf.TagInlinedSubroutine {
   681  			continue
   682  		}
   683  
   684  		// Found an inlined subroutine.
   685  		if found {
   686  			t.Fatalf("Found multiple inlined subroutines, expect only one")
   687  		}
   688  		found = true
   689  
   690  		// Locate abstract origin.
   691  		ooff, originOK := child.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   692  		if !originOK {
   693  			t.Fatalf("no abstract origin attr for inlined subroutine at offset %v", child.Offset)
   694  		}
   695  		originDIE := ex.EntryFromOffset(ooff)
   696  		if originDIE == nil {
   697  			t.Fatalf("can't locate origin DIE at off %v", ooff)
   698  		}
   699  
   700  		// Name should check out.
   701  		name, ok := originDIE.Val(dwarf.AttrName).(string)
   702  		if !ok {
   703  			t.Fatalf("no name attr for inlined subroutine at offset %v", child.Offset)
   704  		}
   705  		if name != "main.cand" {
   706  			t.Fatalf("expected inlined routine %s got %s", "main.cand", name)
   707  		}
   708  
   709  		// Walk the children of the abstract subroutine. We expect
   710  		// to see child variables there, even if (perhaps due to
   711  		// optimization) there are no references to them from the
   712  		// inlined subroutine DIE.
   713  		absFcnIdx := ex.IdxFromOffset(ooff)
   714  		absFcnChildDies := ex.Children(absFcnIdx)
   715  		if len(absFcnChildDies) != 2 {
   716  			t.Fatalf("expected abstract function: expected 2 children, got %d children", len(absFcnChildDies))
   717  		}
   718  		formalCount := 0
   719  		for _, absChild := range absFcnChildDies {
   720  			if absChild.Tag == dwarf.TagFormalParameter {
   721  				formalCount += 1
   722  				continue
   723  			}
   724  			t.Fatalf("abstract function child DIE: expected formal, got %v", absChild.Tag)
   725  		}
   726  		if formalCount != 2 {
   727  			t.Fatalf("abstract function DIE: expected 2 formals, got %d", formalCount)
   728  		}
   729  
   730  		omap := make(map[dwarf.Offset]bool)
   731  
   732  		// Walk the child variables of the inlined routine. Each
   733  		// of them should have a distinct abstract origin-- if two
   734  		// vars point to the same origin things are definitely broken.
   735  		inlIdx := ex.IdxFromOffset(child.Offset)
   736  		inlChildDies := ex.Children(inlIdx)
   737  		for _, k := range inlChildDies {
   738  			ooff, originOK := k.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   739  			if !originOK {
   740  				t.Fatalf("no abstract origin attr for child of inlined subroutine at offset %v", k.Offset)
   741  			}
   742  			if _, found := omap[ooff]; found {
   743  				t.Fatalf("duplicate abstract origin at child of inlined subroutine at offset %v", k.Offset)
   744  			}
   745  			omap[ooff] = true
   746  		}
   747  	}
   748  	if !found {
   749  		t.Fatalf("not enough inlined subroutines found in main.main")
   750  	}
   751  }
   752  
   753  func abstractOriginSanity(t *testing.T, pkgDir string, flags string) {
   754  	t.Parallel()
   755  
   756  	dir := t.TempDir()
   757  
   758  	// Build with inlining, to exercise DWARF inlining support.
   759  	f := gobuildTestdata(t, dir, filepath.Join(pkgDir, "main"), flags)
   760  	defer f.Close()
   761  
   762  	d, err := f.DWARF()
   763  	if err != nil {
   764  		t.Fatalf("error reading DWARF: %v", err)
   765  	}
   766  	rdr := d.Reader()
   767  	ex := dwtest.Examiner{}
   768  	if err := ex.Populate(rdr); err != nil {
   769  		t.Fatalf("error reading DWARF: %v", err)
   770  	}
   771  
   772  	// Make a pass through all DIEs looking for abstract origin
   773  	// references.
   774  	abscount := 0
   775  	for i, die := range ex.DIEs() {
   776  		// Does it have an abstract origin?
   777  		ooff, originOK := die.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   778  		if !originOK {
   779  			continue
   780  		}
   781  
   782  		// All abstract origin references should be resolvable.
   783  		abscount += 1
   784  		originDIE := ex.EntryFromOffset(ooff)
   785  		if originDIE == nil {
   786  			ex.DumpEntry(i, false, 0)
   787  			t.Fatalf("unresolved abstract origin ref in DIE at offset 0x%x\n", die.Offset)
   788  		}
   789  
   790  		// Suppose that DIE X has parameter/variable children {K1,
   791  		// K2, ... KN}. If X has an abstract origin of A, then for
   792  		// each KJ, the abstract origin of KJ should be a child of A.
   793  		// Note that this same rule doesn't hold for non-variable DIEs.
   794  		pidx := ex.IdxFromOffset(die.Offset)
   795  		if pidx < 0 {
   796  			t.Fatalf("can't locate DIE id")
   797  		}
   798  		kids := ex.Children(pidx)
   799  		for _, kid := range kids {
   800  			if kid.Tag != dwarf.TagVariable &&
   801  				kid.Tag != dwarf.TagFormalParameter {
   802  				continue
   803  			}
   804  			kooff, originOK := kid.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
   805  			if !originOK {
   806  				continue
   807  			}
   808  			childOriginDIE := ex.EntryFromOffset(kooff)
   809  			if childOriginDIE == nil {
   810  				ex.DumpEntry(i, false, 0)
   811  				t.Fatalf("unresolved abstract origin ref in DIE at offset %x", kid.Offset)
   812  			}
   813  			coidx := ex.IdxFromOffset(childOriginDIE.Offset)
   814  			childOriginParent := ex.Parent(coidx)
   815  			if childOriginParent != originDIE {
   816  				ex.DumpEntry(i, false, 0)
   817  				t.Fatalf("unexpected parent of abstract origin DIE at offset %v", childOriginDIE.Offset)
   818  			}
   819  		}
   820  	}
   821  	if abscount == 0 {
   822  		t.Fatalf("no abstract origin refs found, something is wrong")
   823  	}
   824  }
   825  
   826  func TestAbstractOriginSanity(t *testing.T) {
   827  	testenv.MustHaveGoBuild(t)
   828  
   829  	if testing.Short() {
   830  		t.Skip("skipping test in short mode.")
   831  	}
   832  
   833  	mustHaveDWARF(t)
   834  
   835  	if wd, err := os.Getwd(); err == nil {
   836  		gopathdir := filepath.Join(wd, "testdata", "httptest")
   837  		abstractOriginSanity(t, gopathdir, OptAllInl4)
   838  	} else {
   839  		t.Fatalf("os.Getwd() failed %v", err)
   840  	}
   841  }
   842  
   843  func TestAbstractOriginSanityIssue25459(t *testing.T) {
   844  	testenv.MustHaveGoBuild(t)
   845  
   846  	mustHaveDWARF(t)
   847  	if runtime.GOARCH != "amd64" && runtime.GOARCH != "386" {
   848  		t.Skip("skipping on not-amd64 not-386; location lists not supported")
   849  	}
   850  
   851  	if wd, err := os.Getwd(); err == nil {
   852  		gopathdir := filepath.Join(wd, "testdata", "issue25459")
   853  		abstractOriginSanity(t, gopathdir, DefaultOpt)
   854  	} else {
   855  		t.Fatalf("os.Getwd() failed %v", err)
   856  	}
   857  }
   858  
   859  func TestAbstractOriginSanityIssue26237(t *testing.T) {
   860  	testenv.MustHaveGoBuild(t)
   861  
   862  	mustHaveDWARF(t)
   863  	if wd, err := os.Getwd(); err == nil {
   864  		gopathdir := filepath.Join(wd, "testdata", "issue26237")
   865  		abstractOriginSanity(t, gopathdir, DefaultOpt)
   866  	} else {
   867  		t.Fatalf("os.Getwd() failed %v", err)
   868  	}
   869  }
   870  
   871  func TestRuntimeTypeAttrInternal(t *testing.T) {
   872  	testenv.MustHaveGoBuild(t)
   873  	testenv.MustInternalLink(t, false)
   874  
   875  	mustHaveDWARF(t)
   876  
   877  	testRuntimeTypeAttr(t, "-ldflags=-linkmode=internal")
   878  }
   879  
   880  // External linking requires a host linker (https://golang.org/src/cmd/cgo/doc.go l.732)
   881  func TestRuntimeTypeAttrExternal(t *testing.T) {
   882  	testenv.MustHaveGoBuild(t)
   883  	testenv.MustHaveCGO(t)
   884  
   885  	mustHaveDWARF(t)
   886  
   887  	// Explicitly test external linking, for dsymutil compatibility on Darwin.
   888  	if runtime.GOARCH == "ppc64" {
   889  		t.Skip("-linkmode=external not supported on ppc64")
   890  	}
   891  
   892  	testRuntimeTypeAttr(t, "-ldflags=-linkmode=external")
   893  }
   894  
   895  func testRuntimeTypeAttr(t *testing.T, flags string) {
   896  	t.Parallel()
   897  
   898  	const prog = `
   899  package main
   900  
   901  import "unsafe"
   902  
   903  type X struct{ _ int }
   904  
   905  func main() {
   906  	var x interface{} = &X{}
   907  	p := *(*uintptr)(unsafe.Pointer(&x))
   908  	print(p)
   909  }
   910  `
   911  	dir := t.TempDir()
   912  
   913  	f := gobuild(t, dir, prog, flags)
   914  	defer f.Close()
   915  
   916  	out, err := testenv.Command(t, f.path).CombinedOutput()
   917  	if err != nil {
   918  		t.Fatalf("could not run test program: %v", err)
   919  	}
   920  	addr, err := strconv.ParseUint(string(out), 10, 64)
   921  	if err != nil {
   922  		t.Fatalf("could not parse type address from program output %q: %v", out, err)
   923  	}
   924  
   925  	symbols, err := f.Symbols()
   926  	if err != nil {
   927  		t.Fatalf("error reading symbols: %v", err)
   928  	}
   929  	var types *objfilepkg.Sym
   930  	for _, sym := range symbols {
   931  		if sym.Name == "runtime.types" {
   932  			types = &sym
   933  			break
   934  		}
   935  	}
   936  	if types == nil {
   937  		t.Fatal("couldn't find runtime.types in symbols")
   938  	}
   939  
   940  	d, err := f.DWARF()
   941  	if err != nil {
   942  		t.Fatalf("error reading DWARF: %v", err)
   943  	}
   944  
   945  	rdr := d.Reader()
   946  	ex := dwtest.Examiner{}
   947  	if err := ex.Populate(rdr); err != nil {
   948  		t.Fatalf("error reading DWARF: %v", err)
   949  	}
   950  	dies := ex.Named("*main.X")
   951  	if len(dies) != 1 {
   952  		t.Fatalf("wanted 1 DIE named *main.X, found %v", len(dies))
   953  	}
   954  	rtAttr := dies[0].Val(intdwarf.DW_AT_go_runtime_type)
   955  	if rtAttr == nil {
   956  		t.Fatalf("*main.X DIE had no runtime type attr. DIE: %v", dies[0])
   957  	}
   958  
   959  	if platform.DefaultPIE(runtime.GOOS, runtime.GOARCH, false) {
   960  		return // everything is PIE, addresses are relocated
   961  	}
   962  	if rtAttr.(uint64)+types.Addr != addr {
   963  		t.Errorf("DWARF type offset was %#x+%#x, but test program said %#x", rtAttr.(uint64), types.Addr, addr)
   964  	}
   965  }
   966  
   967  func TestIssue27614(t *testing.T) {
   968  	// Type references in debug_info should always use the DW_TAG_typedef_type
   969  	// for the type, when that's generated.
   970  
   971  	testenv.MustHaveGoBuild(t)
   972  
   973  	mustHaveDWARF(t)
   974  
   975  	t.Parallel()
   976  
   977  	dir := t.TempDir()
   978  
   979  	const prog = `package main
   980  
   981  import "fmt"
   982  
   983  type astruct struct {
   984  	X int
   985  }
   986  
   987  type bstruct struct {
   988  	X float32
   989  }
   990  
   991  var globalptr *astruct
   992  var globalvar astruct
   993  var bvar0, bvar1, bvar2 bstruct
   994  
   995  func main() {
   996  	fmt.Println(globalptr, globalvar, bvar0, bvar1, bvar2)
   997  }
   998  `
   999  
  1000  	f := gobuild(t, dir, prog, NoOpt)
  1001  
  1002  	defer f.Close()
  1003  
  1004  	data, err := f.DWARF()
  1005  	if err != nil {
  1006  		t.Fatal(err)
  1007  	}
  1008  
  1009  	rdr := data.Reader()
  1010  
  1011  	var astructTypeDIE, bstructTypeDIE, ptrastructTypeDIE *dwarf.Entry
  1012  	var globalptrDIE, globalvarDIE *dwarf.Entry
  1013  	var bvarDIE [3]*dwarf.Entry
  1014  
  1015  	for {
  1016  		e, err := rdr.Next()
  1017  		if err != nil {
  1018  			t.Fatal(err)
  1019  		}
  1020  		if e == nil {
  1021  			break
  1022  		}
  1023  
  1024  		name, _ := e.Val(dwarf.AttrName).(string)
  1025  
  1026  		switch e.Tag {
  1027  		case dwarf.TagTypedef:
  1028  			switch name {
  1029  			case "main.astruct":
  1030  				astructTypeDIE = e
  1031  			case "main.bstruct":
  1032  				bstructTypeDIE = e
  1033  			}
  1034  		case dwarf.TagPointerType:
  1035  			if name == "*main.astruct" {
  1036  				ptrastructTypeDIE = e
  1037  			}
  1038  		case dwarf.TagVariable:
  1039  			switch name {
  1040  			case "main.globalptr":
  1041  				globalptrDIE = e
  1042  			case "main.globalvar":
  1043  				globalvarDIE = e
  1044  			default:
  1045  				const bvarprefix = "main.bvar"
  1046  				if strings.HasPrefix(name, bvarprefix) {
  1047  					i, _ := strconv.Atoi(name[len(bvarprefix):])
  1048  					bvarDIE[i] = e
  1049  				}
  1050  			}
  1051  		}
  1052  	}
  1053  
  1054  	typedieof := func(e *dwarf.Entry) dwarf.Offset {
  1055  		return e.Val(dwarf.AttrType).(dwarf.Offset)
  1056  	}
  1057  
  1058  	if off := typedieof(ptrastructTypeDIE); off != astructTypeDIE.Offset {
  1059  		t.Errorf("type attribute of *main.astruct references %#x, not main.astruct DIE at %#x\n", off, astructTypeDIE.Offset)
  1060  	}
  1061  
  1062  	if off := typedieof(globalptrDIE); off != ptrastructTypeDIE.Offset {
  1063  		t.Errorf("type attribute of main.globalptr references %#x, not *main.astruct DIE at %#x\n", off, ptrastructTypeDIE.Offset)
  1064  	}
  1065  
  1066  	if off := typedieof(globalvarDIE); off != astructTypeDIE.Offset {
  1067  		t.Errorf("type attribute of main.globalvar1 references %#x, not main.astruct DIE at %#x\n", off, astructTypeDIE.Offset)
  1068  	}
  1069  
  1070  	for i := range bvarDIE {
  1071  		if off := typedieof(bvarDIE[i]); off != bstructTypeDIE.Offset {
  1072  			t.Errorf("type attribute of main.bvar%d references %#x, not main.bstruct DIE at %#x\n", i, off, bstructTypeDIE.Offset)
  1073  		}
  1074  	}
  1075  }
  1076  
  1077  func TestStaticTmp(t *testing.T) {
  1078  	// Checks that statictmp variables do not appear in debug_info or the
  1079  	// symbol table.
  1080  	// Also checks that statictmp variables do not collide with user defined
  1081  	// variables (issue #25113)
  1082  
  1083  	testenv.MustHaveGoBuild(t)
  1084  
  1085  	mustHaveDWARF(t)
  1086  
  1087  	t.Parallel()
  1088  
  1089  	dir := t.TempDir()
  1090  
  1091  	const prog = `package main
  1092  
  1093  var stmp_0 string
  1094  var a []int
  1095  
  1096  func init() {
  1097  	a = []int{ 7 }
  1098  }
  1099  
  1100  func main() {
  1101  	println(a[0])
  1102  }
  1103  `
  1104  
  1105  	f := gobuild(t, dir, prog, NoOpt)
  1106  
  1107  	defer f.Close()
  1108  
  1109  	d, err := f.DWARF()
  1110  	if err != nil {
  1111  		t.Fatalf("error reading DWARF: %v", err)
  1112  	}
  1113  
  1114  	rdr := d.Reader()
  1115  	for {
  1116  		e, err := rdr.Next()
  1117  		if err != nil {
  1118  			t.Fatal(err)
  1119  		}
  1120  		if e == nil {
  1121  			break
  1122  		}
  1123  		if e.Tag != dwarf.TagVariable {
  1124  			continue
  1125  		}
  1126  		name, ok := e.Val(dwarf.AttrName).(string)
  1127  		if !ok {
  1128  			continue
  1129  		}
  1130  		if strings.Contains(name, "stmp") {
  1131  			t.Errorf("statictmp variable found in debug_info: %s at %x", name, e.Offset)
  1132  		}
  1133  	}
  1134  
  1135  	// When external linking, we put all symbols in the symbol table (so the
  1136  	// external linker can find them). Skip the symbol table check.
  1137  	// TODO: maybe there is some way to tell the external linker not to put
  1138  	// those symbols in the executable's symbol table? Prefix the symbol name
  1139  	// with "." or "L" to pretend it is a label?
  1140  	if !testenv.CanInternalLink(false) {
  1141  		return
  1142  	}
  1143  
  1144  	syms, err := f.Symbols()
  1145  	if err != nil {
  1146  		t.Fatalf("error reading symbols: %v", err)
  1147  	}
  1148  	for _, sym := range syms {
  1149  		if strings.Contains(sym.Name, "stmp") {
  1150  			t.Errorf("statictmp variable found in symbol table: %s", sym.Name)
  1151  		}
  1152  	}
  1153  }
  1154  
  1155  func TestPackageNameAttr(t *testing.T) {
  1156  	const dwarfAttrGoPackageName = dwarf.Attr(0x2905)
  1157  	const dwarfGoLanguage = 22
  1158  
  1159  	testenv.MustHaveGoBuild(t)
  1160  
  1161  	mustHaveDWARF(t)
  1162  
  1163  	t.Parallel()
  1164  
  1165  	dir := t.TempDir()
  1166  
  1167  	const prog = "package main\nfunc main() {\nprintln(\"hello world\")\n}\n"
  1168  
  1169  	f := gobuild(t, dir, prog, NoOpt)
  1170  
  1171  	defer f.Close()
  1172  
  1173  	d, err := f.DWARF()
  1174  	if err != nil {
  1175  		t.Fatalf("error reading DWARF: %v", err)
  1176  	}
  1177  
  1178  	rdr := d.Reader()
  1179  	runtimeUnitSeen := false
  1180  	for {
  1181  		e, err := rdr.Next()
  1182  		if err != nil {
  1183  			t.Fatal(err)
  1184  		}
  1185  		if e == nil {
  1186  			break
  1187  		}
  1188  		if e.Tag != dwarf.TagCompileUnit {
  1189  			continue
  1190  		}
  1191  		if lang, _ := e.Val(dwarf.AttrLanguage).(int64); lang != dwarfGoLanguage {
  1192  			continue
  1193  		}
  1194  
  1195  		pn, ok := e.Val(dwarfAttrGoPackageName).(string)
  1196  		if !ok {
  1197  			name, _ := e.Val(dwarf.AttrName).(string)
  1198  			t.Errorf("found compile unit without package name: %s", name)
  1199  
  1200  		}
  1201  		if pn == "" {
  1202  			name, _ := e.Val(dwarf.AttrName).(string)
  1203  			t.Errorf("found compile unit with empty package name: %s", name)
  1204  		} else {
  1205  			if pn == "runtime" {
  1206  				runtimeUnitSeen = true
  1207  			}
  1208  		}
  1209  	}
  1210  
  1211  	// Something is wrong if there's no runtime compilation unit.
  1212  	if !runtimeUnitSeen {
  1213  		t.Errorf("no package name for runtime unit")
  1214  	}
  1215  }
  1216  
  1217  func TestMachoIssue32233(t *testing.T) {
  1218  	testenv.MustHaveGoBuild(t)
  1219  	testenv.MustHaveCGO(t)
  1220  
  1221  	if runtime.GOOS != "darwin" {
  1222  		t.Skip("skipping; test only interesting on darwin")
  1223  	}
  1224  
  1225  	tmpdir := t.TempDir()
  1226  
  1227  	wd, err := os.Getwd()
  1228  	if err != nil {
  1229  		t.Fatalf("where am I? %v", err)
  1230  	}
  1231  	pdir := filepath.Join(wd, "testdata", "issue32233", "main")
  1232  	f := gobuildTestdata(t, tmpdir, pdir, DefaultOpt)
  1233  	f.Close()
  1234  }
  1235  
  1236  func TestWindowsIssue36495(t *testing.T) {
  1237  	testenv.MustHaveGoBuild(t)
  1238  	if runtime.GOOS != "windows" {
  1239  		t.Skip("skipping: test only on windows")
  1240  	}
  1241  
  1242  	dir := t.TempDir()
  1243  
  1244  	prog := `
  1245  package main
  1246  
  1247  import "fmt"
  1248  
  1249  func main() {
  1250    fmt.Println("Hello World")
  1251  }`
  1252  	f := gobuild(t, dir, prog, NoOpt)
  1253  	defer f.Close()
  1254  	exe, err := pe.Open(f.path)
  1255  	if err != nil {
  1256  		t.Fatalf("error opening pe file: %v", err)
  1257  	}
  1258  	defer exe.Close()
  1259  	dw, err := exe.DWARF()
  1260  	if err != nil {
  1261  		t.Fatalf("error parsing DWARF: %v", err)
  1262  	}
  1263  	rdr := dw.Reader()
  1264  	for {
  1265  		e, err := rdr.Next()
  1266  		if err != nil {
  1267  			t.Fatalf("error reading DWARF: %v", err)
  1268  		}
  1269  		if e == nil {
  1270  			break
  1271  		}
  1272  		if e.Tag != dwarf.TagCompileUnit {
  1273  			continue
  1274  		}
  1275  		lnrdr, err := dw.LineReader(e)
  1276  		if err != nil {
  1277  			t.Fatalf("error creating DWARF line reader: %v", err)
  1278  		}
  1279  		if lnrdr != nil {
  1280  			var lne dwarf.LineEntry
  1281  			for {
  1282  				err := lnrdr.Next(&lne)
  1283  				if err == io.EOF {
  1284  					break
  1285  				}
  1286  				if err != nil {
  1287  					t.Fatalf("error reading next DWARF line: %v", err)
  1288  				}
  1289  				if strings.Contains(lne.File.Name, `\`) {
  1290  					t.Errorf("filename should not contain backslash: %v", lne.File.Name)
  1291  				}
  1292  			}
  1293  		}
  1294  		rdr.SkipChildren()
  1295  	}
  1296  }
  1297  
  1298  func TestIssue38192(t *testing.T) {
  1299  	testenv.MustHaveGoBuild(t)
  1300  
  1301  	mustHaveDWARF(t)
  1302  
  1303  	t.Parallel()
  1304  
  1305  	// Build a test program that contains a translation unit whose
  1306  	// text (from am assembly source) contains only a single instruction.
  1307  	tmpdir := t.TempDir()
  1308  	wd, err := os.Getwd()
  1309  	if err != nil {
  1310  		t.Fatalf("where am I? %v", err)
  1311  	}
  1312  	pdir := filepath.Join(wd, "testdata", "issue38192")
  1313  	f := gobuildTestdata(t, tmpdir, pdir, DefaultOpt)
  1314  	defer f.Close()
  1315  
  1316  	// Open the resulting binary and examine the DWARF it contains.
  1317  	// Look for the function of interest ("main.singleInstruction")
  1318  	// and verify that the line table has an entry not just for the
  1319  	// single instruction but also a dummy instruction following it,
  1320  	// so as to test that whoever is emitting the DWARF doesn't
  1321  	// emit an end-sequence op immediately after the last instruction
  1322  	// in the translation unit.
  1323  	//
  1324  	// NB: another way to write this test would have been to run the
  1325  	// resulting executable under GDB, set a breakpoint in
  1326  	// "main.singleInstruction", then verify that GDB displays the
  1327  	// correct line/file information.  Given the headache and flakiness
  1328  	// associated with GDB-based tests these days, a direct read of
  1329  	// the line table seems more desirable.
  1330  	rows := []dwarf.LineEntry{}
  1331  	dw, err := f.DWARF()
  1332  	if err != nil {
  1333  		t.Fatalf("error parsing DWARF: %v", err)
  1334  	}
  1335  	rdr := dw.Reader()
  1336  	for {
  1337  		e, err := rdr.Next()
  1338  		if err != nil {
  1339  			t.Fatalf("error reading DWARF: %v", err)
  1340  		}
  1341  		if e == nil {
  1342  			break
  1343  		}
  1344  		if e.Tag != dwarf.TagCompileUnit {
  1345  			continue
  1346  		}
  1347  		// NB: there can be multiple compile units named "main".
  1348  		name := e.Val(dwarf.AttrName).(string)
  1349  		if name != "main" {
  1350  			continue
  1351  		}
  1352  		lnrdr, err := dw.LineReader(e)
  1353  		if err != nil {
  1354  			t.Fatalf("error creating DWARF line reader: %v", err)
  1355  		}
  1356  		if lnrdr != nil {
  1357  			var lne dwarf.LineEntry
  1358  			for {
  1359  				err := lnrdr.Next(&lne)
  1360  				if err == io.EOF {
  1361  					break
  1362  				}
  1363  				if err != nil {
  1364  					t.Fatalf("error reading next DWARF line: %v", err)
  1365  				}
  1366  				if !strings.HasSuffix(lne.File.Name, "ld/testdata/issue38192/oneline.s") {
  1367  					continue
  1368  				}
  1369  				rows = append(rows, lne)
  1370  			}
  1371  		}
  1372  		rdr.SkipChildren()
  1373  	}
  1374  	f.Close()
  1375  
  1376  	// Make sure that:
  1377  	// - main.singleInstruction appears in the line table
  1378  	// - more than one PC value appears the line table for
  1379  	//   that compilation unit.
  1380  	// - at least one row has the correct line number (8)
  1381  	pcs := make(map[uint64]bool)
  1382  	line8seen := false
  1383  	for _, r := range rows {
  1384  		pcs[r.Address] = true
  1385  		if r.Line == 8 {
  1386  			line8seen = true
  1387  		}
  1388  	}
  1389  	failed := false
  1390  	if len(pcs) < 2 {
  1391  		failed = true
  1392  		t.Errorf("not enough line table rows for main.singleInstruction (got %d, wanted > 1", len(pcs))
  1393  	}
  1394  	if !line8seen {
  1395  		failed = true
  1396  		t.Errorf("line table does not contain correct line for main.singleInstruction")
  1397  	}
  1398  	if !failed {
  1399  		return
  1400  	}
  1401  	for i, r := range rows {
  1402  		t.Logf("row %d: A=%x F=%s L=%d\n", i, r.Address, r.File.Name, r.Line)
  1403  	}
  1404  }
  1405  
  1406  func TestIssue39757(t *testing.T) {
  1407  	testenv.MustHaveGoBuild(t)
  1408  
  1409  	mustHaveDWARF(t)
  1410  
  1411  	t.Parallel()
  1412  
  1413  	// In this bug the DWARF line table contents for the last couple of
  1414  	// instructions in a function were incorrect (bad file/line). This
  1415  	// test verifies that all of the line table rows for a function
  1416  	// of interest have the same file (no "autogenerated").
  1417  	//
  1418  	// Note: the function in this test was written with an eye towards
  1419  	// ensuring that there are no inlined routines from other packages
  1420  	// (which could introduce other source files into the DWARF); it's
  1421  	// possible that at some point things could evolve in the
  1422  	// compiler/runtime in ways that aren't happening now, so this
  1423  	// might be something to check for if it does start failing.
  1424  
  1425  	tmpdir := t.TempDir()
  1426  
  1427  	wd, err := os.Getwd()
  1428  	if err != nil {
  1429  		t.Fatalf("where am I? %v", err)
  1430  	}
  1431  	pdir := filepath.Join(wd, "testdata", "issue39757")
  1432  	f := gobuildTestdata(t, tmpdir, pdir, DefaultOpt)
  1433  	defer f.Close()
  1434  
  1435  	syms, err := f.Symbols()
  1436  	if err != nil {
  1437  		t.Fatal(err)
  1438  	}
  1439  
  1440  	var addr uint64
  1441  	for _, sym := range syms {
  1442  		if sym.Name == "main.main" {
  1443  			addr = sym.Addr
  1444  			break
  1445  		}
  1446  	}
  1447  	if addr == 0 {
  1448  		t.Fatal("cannot find main.main in symbols")
  1449  	}
  1450  
  1451  	// Open the resulting binary and examine the DWARF it contains.
  1452  	// Look for the function of interest ("main.main")
  1453  	// and verify that all line table entries show the same source
  1454  	// file.
  1455  	dw, err := f.DWARF()
  1456  	if err != nil {
  1457  		t.Fatalf("error parsing DWARF: %v", err)
  1458  	}
  1459  	rdr := dw.Reader()
  1460  	ex := &dwtest.Examiner{}
  1461  	if err := ex.Populate(rdr); err != nil {
  1462  		t.Fatalf("error reading DWARF: %v", err)
  1463  	}
  1464  
  1465  	maindie := findSubprogramDIE(t, ex, "main.main")
  1466  
  1467  	// Collect the start/end PC for main.main
  1468  	lowpc := maindie.Val(dwarf.AttrLowpc).(uint64)
  1469  	highpc := maindie.Val(dwarf.AttrHighpc).(uint64)
  1470  
  1471  	// Now read the line table for the 'main' compilation unit.
  1472  	mainIdx := ex.IdxFromOffset(maindie.Offset)
  1473  	cuentry := ex.Parent(mainIdx)
  1474  	if cuentry == nil {
  1475  		t.Fatalf("main.main DIE appears orphaned")
  1476  	}
  1477  	lnrdr, lerr := dw.LineReader(cuentry)
  1478  	if lerr != nil {
  1479  		t.Fatalf("error creating DWARF line reader: %v", err)
  1480  	}
  1481  	if lnrdr == nil {
  1482  		t.Fatalf("no line table for main.main compilation unit")
  1483  	}
  1484  	rows := []dwarf.LineEntry{}
  1485  	mainrows := 0
  1486  	var lne dwarf.LineEntry
  1487  	for {
  1488  		err := lnrdr.Next(&lne)
  1489  		if err == io.EOF {
  1490  			break
  1491  		}
  1492  		rows = append(rows, lne)
  1493  		if err != nil {
  1494  			t.Fatalf("error reading next DWARF line: %v", err)
  1495  		}
  1496  		if lne.Address < lowpc || lne.Address > highpc {
  1497  			continue
  1498  		}
  1499  		if !strings.HasSuffix(lne.File.Name, "issue39757main.go") {
  1500  			t.Errorf("found row with file=%s (not issue39757main.go)", lne.File.Name)
  1501  		}
  1502  		mainrows++
  1503  	}
  1504  	f.Close()
  1505  
  1506  	// Make sure we saw a few rows.
  1507  	if mainrows < 3 {
  1508  		t.Errorf("not enough line table rows for main.main (got %d, wanted > 3", mainrows)
  1509  		for i, r := range rows {
  1510  			t.Logf("row %d: A=%x F=%s L=%d\n", i, r.Address, r.File.Name, r.Line)
  1511  		}
  1512  	}
  1513  }
  1514  
  1515  func TestIssue42484(t *testing.T) {
  1516  	testenv.MustHaveGoBuild(t)
  1517  	testenv.MustInternalLink(t, false) // Avoid spurious failures from external linkers.
  1518  
  1519  	mustHaveDWARF(t)
  1520  
  1521  	t.Parallel()
  1522  
  1523  	tmpdir, err := os.MkdirTemp("", "TestIssue42484")
  1524  	if err != nil {
  1525  		t.Fatalf("could not create directory: %v", err)
  1526  	}
  1527  	defer os.RemoveAll(tmpdir)
  1528  	wd, err := os.Getwd()
  1529  	if err != nil {
  1530  		t.Fatalf("where am I? %v", err)
  1531  	}
  1532  	pdir := filepath.Join(wd, "testdata", "issue42484")
  1533  	f := gobuildTestdata(t, tmpdir, pdir, NoOpt)
  1534  
  1535  	var lastAddr uint64
  1536  	var lastFile string
  1537  	var lastLine int
  1538  
  1539  	dw, err := f.DWARF()
  1540  	if err != nil {
  1541  		t.Fatalf("error parsing DWARF: %v", err)
  1542  	}
  1543  	rdr := dw.Reader()
  1544  	for {
  1545  		e, err := rdr.Next()
  1546  		if err != nil {
  1547  			t.Fatalf("error reading DWARF: %v", err)
  1548  		}
  1549  		if e == nil {
  1550  			break
  1551  		}
  1552  		if e.Tag != dwarf.TagCompileUnit {
  1553  			continue
  1554  		}
  1555  		lnrdr, err := dw.LineReader(e)
  1556  		if err != nil {
  1557  			t.Fatalf("error creating DWARF line reader: %v", err)
  1558  		}
  1559  		if lnrdr != nil {
  1560  			var lne dwarf.LineEntry
  1561  			for {
  1562  				err := lnrdr.Next(&lne)
  1563  				if err == io.EOF {
  1564  					break
  1565  				}
  1566  				if err != nil {
  1567  					t.Fatalf("error reading next DWARF line: %v", err)
  1568  				}
  1569  				if lne.EndSequence {
  1570  					continue
  1571  				}
  1572  				if lne.Address == lastAddr && (lne.File.Name != lastFile || lne.Line != lastLine) {
  1573  					t.Errorf("address %#x is assigned to both %s:%d and %s:%d", lastAddr, lastFile, lastLine, lne.File.Name, lne.Line)
  1574  				}
  1575  				lastAddr = lne.Address
  1576  				lastFile = lne.File.Name
  1577  				lastLine = lne.Line
  1578  			}
  1579  		}
  1580  		rdr.SkipChildren()
  1581  	}
  1582  	f.Close()
  1583  }
  1584  
  1585  // processParams examines the formal parameter children of subprogram
  1586  // DIE "die" using the explorer "ex" and returns a string that
  1587  // captures the name, order, and classification of the subprogram's
  1588  // input and output parameters. For example, for the go function
  1589  //
  1590  //	func foo(i1 int, f1 float64) (string, bool) {
  1591  //
  1592  // this function would return a string something like
  1593  //
  1594  //	i1:0:1 f1:1:1 ~r0:2:2 ~r1:3:2
  1595  //
  1596  // where each chunk above is of the form NAME:ORDER:INOUTCLASSIFICATION
  1597  func processParams(die *dwarf.Entry, ex *dwtest.Examiner) string {
  1598  	// Values in the returned map are of the form <order>:<varparam>
  1599  	// where order is the order within the child DIE list of the
  1600  	// param, and <varparam> is an integer:
  1601  	//
  1602  	//  -1: varparm attr not found
  1603  	//   1: varparm found with value false
  1604  	//   2: varparm found with value true
  1605  	//
  1606  	foundParams := make(map[string]string)
  1607  
  1608  	// Walk the subprogram DIE's children looking for params.
  1609  	pIdx := ex.IdxFromOffset(die.Offset)
  1610  	childDies := ex.Children(pIdx)
  1611  	idx := 0
  1612  	for _, child := range childDies {
  1613  		if child.Tag == dwarf.TagFormalParameter {
  1614  			// NB: a setting of DW_AT_variable_parameter indicates
  1615  			// that the param in question is an output parameter; we
  1616  			// want to see this attribute set to TRUE for all Go
  1617  			// return params. It would be OK to have it missing for
  1618  			// input parameters, but for the moment we verify that the
  1619  			// attr is present but set to false.
  1620  			st := -1
  1621  			if vp, ok := child.Val(dwarf.AttrVarParam).(bool); ok {
  1622  				if vp {
  1623  					st = 2
  1624  				} else {
  1625  					st = 1
  1626  				}
  1627  			}
  1628  			if name, ok := child.Val(dwarf.AttrName).(string); ok {
  1629  				foundParams[name] = fmt.Sprintf("%d:%d", idx, st)
  1630  				idx++
  1631  			}
  1632  		}
  1633  	}
  1634  
  1635  	found := make([]string, 0, len(foundParams))
  1636  	for k, v := range foundParams {
  1637  		found = append(found, fmt.Sprintf("%s:%s", k, v))
  1638  	}
  1639  	sort.Strings(found)
  1640  
  1641  	return fmt.Sprintf("%+v", found)
  1642  }
  1643  
  1644  func TestOutputParamAbbrevAndAttr(t *testing.T) {
  1645  	testenv.MustHaveGoBuild(t)
  1646  
  1647  	mustHaveDWARF(t)
  1648  	t.Parallel()
  1649  
  1650  	// This test verifies that the compiler is selecting the correct
  1651  	// DWARF abbreviation for output parameters, and that the
  1652  	// variable parameter attribute is correct for in-params and
  1653  	// out-params.
  1654  
  1655  	const prog = `
  1656  package main
  1657  
  1658  //go:noinline
  1659  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) {
  1660  	g1[0] = 6
  1661  	r1, r2, r3, r4, r5, r6 = c3, c2+c1, g1, 'a', d1+d2+d3+d4, f1+f2+f3
  1662  	return
  1663  }
  1664  
  1665  func main() {
  1666  	a := [1024]int{}
  1667  	v1, v2, v3, v4, v5, v6 := ABC(1, 2, 3, "a", "b", "c", "d", 1.0, 2.0, 1.0, a)
  1668  	println(v1, v2, v3[0], v4, v5, v6)
  1669  }
  1670  `
  1671  	_, ex := gobuildAndExamine(t, prog, NoOpt)
  1672  
  1673  	abcdie := findSubprogramDIE(t, ex, "main.ABC")
  1674  
  1675  	// Call a helper to collect param info.
  1676  	found := processParams(abcdie, ex)
  1677  
  1678  	// Make sure we see all of the expected params in the proper
  1679  	// order, that they have the varparam attr, and the varparam is
  1680  	// set for the returns.
  1681  	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]"
  1682  	if found != expected {
  1683  		t.Errorf("param check failed, wanted:\n%s\ngot:\n%s\n",
  1684  			expected, found)
  1685  	}
  1686  }
  1687  
  1688  func TestDictIndex(t *testing.T) {
  1689  	// Check that variables with a parametric type have a dictionary index
  1690  	// attribute and that types that are only referenced through dictionaries
  1691  	// have DIEs.
  1692  	testenv.MustHaveGoBuild(t)
  1693  
  1694  	mustHaveDWARF(t)
  1695  	t.Parallel()
  1696  
  1697  	const prog = `
  1698  package main
  1699  
  1700  import "fmt"
  1701  
  1702  type CustomInt int
  1703  
  1704  func testfn[T any](arg T) {
  1705  	var mapvar = make(map[int]T)
  1706  	mapvar[0] = arg
  1707  	fmt.Println(arg, mapvar)
  1708  }
  1709  
  1710  func main() {
  1711  	testfn(CustomInt(3))
  1712  }
  1713  `
  1714  
  1715  	dir := t.TempDir()
  1716  	f := gobuild(t, dir, prog, NoOpt)
  1717  	defer f.Close()
  1718  
  1719  	d, err := f.DWARF()
  1720  	if err != nil {
  1721  		t.Fatalf("error reading DWARF: %v", err)
  1722  	}
  1723  
  1724  	rdr := d.Reader()
  1725  	found := false
  1726  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
  1727  		if err != nil {
  1728  			t.Fatalf("error reading DWARF: %v", err)
  1729  		}
  1730  		name, _ := entry.Val(dwarf.AttrName).(string)
  1731  		if strings.HasPrefix(name, "main.testfn") {
  1732  			found = true
  1733  			break
  1734  		}
  1735  	}
  1736  
  1737  	if !found {
  1738  		t.Fatalf("could not find main.testfn")
  1739  	}
  1740  
  1741  	offs := []dwarf.Offset{}
  1742  	for entry, err := rdr.Next(); entry != nil; entry, err = rdr.Next() {
  1743  		if err != nil {
  1744  			t.Fatalf("error reading DWARF: %v", err)
  1745  		}
  1746  		if entry.Tag == 0 {
  1747  			break
  1748  		}
  1749  		name, _ := entry.Val(dwarf.AttrName).(string)
  1750  		switch name {
  1751  		case "arg", "mapvar":
  1752  			offs = append(offs, entry.Val(dwarf.AttrType).(dwarf.Offset))
  1753  		}
  1754  	}
  1755  	if len(offs) != 2 {
  1756  		t.Errorf("wrong number of variables found in main.testfn %d", len(offs))
  1757  	}
  1758  	for _, off := range offs {
  1759  		rdr.Seek(off)
  1760  		entry, err := rdr.Next()
  1761  		if err != nil {
  1762  			t.Fatalf("error reading DWARF: %v", err)
  1763  		}
  1764  		if _, ok := entry.Val(intdwarf.DW_AT_go_dict_index).(int64); !ok {
  1765  			t.Errorf("could not find DW_AT_go_dict_index attribute offset %#x (%T)", off, entry.Val(intdwarf.DW_AT_go_dict_index))
  1766  		}
  1767  	}
  1768  
  1769  	rdr.Seek(0)
  1770  	ex := dwtest.Examiner{}
  1771  	if err := ex.Populate(rdr); err != nil {
  1772  		t.Fatalf("error reading DWARF: %v", err)
  1773  	}
  1774  	for _, typeName := range []string{"main.CustomInt", "map[int]main.CustomInt"} {
  1775  		dies := ex.Named(typeName)
  1776  		if len(dies) != 1 {
  1777  			t.Errorf("wanted 1 DIE named %s, found %v", typeName, len(dies))
  1778  		}
  1779  		if dies[0].Val(intdwarf.DW_AT_go_runtime_type).(uint64) == 0 {
  1780  			t.Errorf("type %s does not have DW_AT_go_runtime_type", typeName)
  1781  		}
  1782  	}
  1783  }
  1784  
  1785  func TestOptimizedOutParamHandling(t *testing.T) {
  1786  	testenv.MustHaveGoBuild(t)
  1787  
  1788  	mustHaveDWARF(t)
  1789  	t.Parallel()
  1790  
  1791  	// This test is intended to verify that the compiler emits DWARF
  1792  	// DIE entries for all input and output parameters, and that:
  1793  	//
  1794  	//   - attributes are set correctly for output params,
  1795  	//   - things appear in the proper order
  1796  	//   - things work properly for both register-resident
  1797  	//     params and params passed on the stack
  1798  	//   - things work for both referenced and unreferenced params
  1799  	//   - things work for named return values un-named return vals
  1800  	//
  1801  	// The scenarios below don't cover all possible permutations and
  1802  	// combinations, but they hit a bunch of the high points.
  1803  
  1804  	const prog = `
  1805  package main
  1806  
  1807  // First testcase. All input params in registers, all params used.
  1808  
  1809  //go:noinline
  1810  func tc1(p1, p2 int, p3 string) (int, string) {
  1811  	return p1 + p2, p3 + "foo"
  1812  }
  1813  
  1814  // Second testcase. Some params in registers, some on stack.
  1815  
  1816  //go:noinline
  1817  func tc2(p1 int, p2 [128]int, p3 string) (int, string, [128]int) {
  1818  	return p1 + p2[p1], p3 + "foo", [128]int{p1}
  1819  }
  1820  
  1821  // Third testcase. Named return params.
  1822  
  1823  //go:noinline
  1824  func tc3(p1 int, p2 [128]int, p3 string) (r1 int, r2 bool, r3 string, r4 [128]int) {
  1825  	if p1 == 101 {
  1826  		r1 = p1 + p2[p1]
  1827  		r2 = p3 == "foo"
  1828  		r4 = [128]int{p1}
  1829  		return
  1830  	} else {
  1831  		return p1 - p2[p1+3], false, "bar", [128]int{p1 + 2}
  1832  	}
  1833  }
  1834  
  1835  // Fourth testcase. Some thing are used, some are unused.
  1836  
  1837  //go:noinline
  1838  func tc4(p1, p1un int, p2, p2un [128]int, p3, p3un string) (r1 int, r1un int, r2 bool, r3 string, r4, r4un [128]int) {
  1839  	if p1 == 101 {
  1840  		r1 = p1 + p2[p2[0]]
  1841  		r2 = p3 == "foo"
  1842  		r4 = [128]int{p1}
  1843  		return
  1844  	} else {
  1845  		return p1, -1, true, "plex", [128]int{p1 + 2}, [128]int{-1}
  1846  	}
  1847  }
  1848  
  1849  func main() {
  1850  	{
  1851  		r1, r2 := tc1(3, 4, "five")
  1852  		println(r1, r2)
  1853  	}
  1854  	{
  1855  		x := [128]int{9}
  1856  		r1, r2, r3 := tc2(3, x, "five")
  1857  		println(r1, r2, r3[0])
  1858  	}
  1859  	{
  1860  		x := [128]int{9}
  1861  		r1, r2, r3, r4 := tc3(3, x, "five")
  1862  		println(r1, r2, r3, r4[0])
  1863  	}
  1864  	{
  1865  		x := [128]int{3}
  1866  		y := [128]int{7}
  1867  		r1, r1u, r2, r3, r4, r4u := tc4(0, 1, x, y, "a", "b")
  1868  		println(r1, r1u, r2, r3, r4[0], r4u[1])
  1869  	}
  1870  
  1871  }
  1872  `
  1873  	_, ex := gobuildAndExamine(t, prog, DefaultOpt)
  1874  
  1875  	testcases := []struct {
  1876  		tag      string
  1877  		expected string
  1878  	}{
  1879  		{
  1880  			tag:      "tc1",
  1881  			expected: "[p1:0:1 p2:1:1 p3:2:1 ~r0:3:2 ~r1:4:2]",
  1882  		},
  1883  		{
  1884  			tag:      "tc2",
  1885  			expected: "[p1:0:1 p2:1:1 p3:2:1 ~r0:3:2 ~r1:4:2 ~r2:5:2]",
  1886  		},
  1887  		{
  1888  			tag:      "tc3",
  1889  			expected: "[p1:0:1 p2:1:1 p3:2:1 r1:3:2 r2:4:2 r3:5:2 r4:6:2]",
  1890  		},
  1891  		{
  1892  			tag:      "tc4",
  1893  			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]",
  1894  		},
  1895  	}
  1896  
  1897  	for _, tc := range testcases {
  1898  		// Locate the proper DIE
  1899  		which := fmt.Sprintf("main.%s", tc.tag)
  1900  		die := findSubprogramDIE(t, ex, which)
  1901  
  1902  		// Examine params for this subprogram.
  1903  		foundParams := processParams(die, ex)
  1904  		if foundParams != tc.expected {
  1905  			t.Errorf("check failed for testcase %s -- wanted:\n%s\ngot:%s\n",
  1906  				tc.tag, tc.expected, foundParams)
  1907  		}
  1908  	}
  1909  }
  1910  func TestIssue54320(t *testing.T) {
  1911  	// Check that when trampolines are used, the DWARF LPT is correctly
  1912  	// emitted in the final binary
  1913  	testenv.MustHaveGoBuild(t)
  1914  
  1915  	mustHaveDWARF(t)
  1916  
  1917  	t.Parallel()
  1918  
  1919  	const prog = `
  1920  package main
  1921  
  1922  import "fmt"
  1923  
  1924  func main() {
  1925  	fmt.Printf("Hello world\n");
  1926  }
  1927  `
  1928  
  1929  	dir := t.TempDir()
  1930  	f := gobuild(t, dir, prog, "-ldflags=-debugtramp=2")
  1931  	defer f.Close()
  1932  
  1933  	d, err := f.DWARF()
  1934  	if err != nil {
  1935  		t.Fatalf("error reading DWARF: %v", err)
  1936  	}
  1937  
  1938  	rdr := d.Reader()
  1939  	found := false
  1940  	var entry *dwarf.Entry
  1941  	for entry, err = rdr.Next(); entry != nil; entry, err = rdr.Next() {
  1942  		if err != nil {
  1943  			t.Fatalf("error reading DWARF: %v", err)
  1944  		}
  1945  		if entry.Tag != dwarf.TagCompileUnit {
  1946  			continue
  1947  		}
  1948  		name, _ := entry.Val(dwarf.AttrName).(string)
  1949  		if name == "main" {
  1950  			found = true
  1951  			break
  1952  		}
  1953  		rdr.SkipChildren()
  1954  	}
  1955  
  1956  	if !found {
  1957  		t.Fatalf("could not find main compile unit")
  1958  	}
  1959  	lr, err := d.LineReader(entry)
  1960  	if err != nil {
  1961  		t.Fatalf("error obtaining linereader: %v", err)
  1962  	}
  1963  
  1964  	var le dwarf.LineEntry
  1965  	found = false
  1966  	for {
  1967  		if err := lr.Next(&le); err != nil {
  1968  			if err == io.EOF {
  1969  				break
  1970  			}
  1971  			t.Fatalf("error reading linentry: %v", err)
  1972  		}
  1973  		// check LE contains an entry to test.go
  1974  		if le.File == nil {
  1975  			continue
  1976  		}
  1977  		file := filepath.Base(le.File.Name)
  1978  		if file == "test.go" {
  1979  			found = true
  1980  			break
  1981  		}
  1982  	}
  1983  	if !found {
  1984  		t.Errorf("no LPT entries for test.go")
  1985  	}
  1986  }
  1987  
  1988  const zeroSizedVarProg = `
  1989  package main
  1990  
  1991  import (
  1992  	"fmt"
  1993  )
  1994  
  1995  func main() {
  1996  	zeroSizedVariable := struct{}{}
  1997  	fmt.Println(zeroSizedVariable)
  1998  }
  1999  `
  2000  
  2001  func TestZeroSizedVariable(t *testing.T) {
  2002  	testenv.MustHaveGoBuild(t)
  2003  
  2004  	mustHaveDWARF(t)
  2005  	t.Parallel()
  2006  
  2007  	if testing.Short() {
  2008  		t.Skip("skipping test in short mode.")
  2009  	}
  2010  
  2011  	// This test verifies that the compiler emits DIEs for zero sized variables
  2012  	// (for example variables of type 'struct {}').
  2013  	// See go.dev/issues/54615.
  2014  
  2015  	for _, opt := range []string{NoOpt, DefaultOpt} {
  2016  		opt := opt
  2017  		t.Run(opt, func(t *testing.T) {
  2018  			_, ex := gobuildAndExamine(t, zeroSizedVarProg, opt)
  2019  
  2020  			// Locate the main.zeroSizedVariable DIE
  2021  			abcs := ex.Named("zeroSizedVariable")
  2022  			if len(abcs) == 0 {
  2023  				t.Fatalf("unable to locate DIE for zeroSizedVariable")
  2024  			}
  2025  			if len(abcs) != 1 {
  2026  				t.Fatalf("more than one zeroSizedVariable DIE")
  2027  			}
  2028  		})
  2029  	}
  2030  }
  2031  
  2032  func TestConsistentGoKindAndRuntimeType(t *testing.T) {
  2033  	testenv.MustHaveGoBuild(t)
  2034  
  2035  	mustHaveDWARF(t)
  2036  	t.Parallel()
  2037  
  2038  	if testing.Short() {
  2039  		t.Skip("skipping test in short mode.")
  2040  	}
  2041  
  2042  	// Ensure that if we emit a "go runtime type" attr on a type DIE,
  2043  	// we also include the "go kind" attribute. See issue #64231.
  2044  	_, ex := gobuildAndExamine(t, zeroSizedVarProg, DefaultOpt)
  2045  
  2046  	// Walk all dies.
  2047  	typesChecked := 0
  2048  	failures := 0
  2049  	for _, die := range ex.DIEs() {
  2050  		// For any type DIE with DW_AT_go_runtime_type set...
  2051  		rtt, hasRT := die.Val(intdwarf.DW_AT_go_runtime_type).(uint64)
  2052  		if !hasRT || rtt == 0 {
  2053  			continue
  2054  		}
  2055  		// ... except unsafe.Pointer...
  2056  		if name, _ := die.Val(intdwarf.DW_AT_name).(string); name == "unsafe.Pointer" {
  2057  			continue
  2058  		}
  2059  		typesChecked++
  2060  		// ... we want to see a meaningful DW_AT_go_kind value.
  2061  		if val, ok := die.Val(intdwarf.DW_AT_go_kind).(int64); !ok || val == 0 {
  2062  			failures++
  2063  			// dump DIEs for first 10 failures.
  2064  			if failures <= 10 {
  2065  				idx := ex.IdxFromOffset(die.Offset)
  2066  				t.Logf("type DIE has DW_AT_go_runtime_type but invalid DW_AT_go_kind:\n")
  2067  				ex.DumpEntry(idx, false, 0)
  2068  			}
  2069  			t.Errorf("bad type DIE at offset %d\n", die.Offset)
  2070  		}
  2071  	}
  2072  	if typesChecked == 0 {
  2073  		t.Fatalf("something went wrong, 0 types checked")
  2074  	} else {
  2075  		t.Logf("%d types checked\n", typesChecked)
  2076  	}
  2077  }
  2078  

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