cmd/nm: handle cgo archive

This CL also make cmd/nm accept PE object file.

Fixes #21706

Change-Id: I4a528b7d53da1082e61523ebeba02c4c514a43a7
Reviewed-on: https://go-review.googlesource.com/64890
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/internal/goobj/read.go

@@ -133,7 +133,12 @@ type Package struct {
 	Syms       []*Sym          // symbols defined by this package
 	MaxVersion int             // maximum Version in any SymID in Syms
 	Arch       string          // architecture
-	Native     []io.ReaderAt // native object data (e.g. ELF)
+	Native     []*NativeReader // native object data (e.g. ELF)
+}
+
+type NativeReader struct {
+	Name string
+	io.ReaderAt
 }
 
 var (
@@ -439,7 +444,10 @@ func (r *objReader) parseArchive() error {
 					return fmt.Errorf("parsing archive member %q: %v", name, err)
 				}
 			} else {
-				r.p.Native = append(r.p.Native, io.NewSectionReader(r.f, r.offset, size))
+				r.p.Native = append(r.p.Native, &NativeReader{
+					Name:     name,
+					ReaderAt: io.NewSectionReader(r.f, r.offset, size),
+				})
 			}
 
 			r.skip(r.limit - r.offset)

src/cmd/internal/objfile/disasm.go

@@ -40,23 +40,23 @@ type Disasm struct {
 }
 
 // Disasm returns a disassembler for the file f.
-func (f *File) Disasm() (*Disasm, error) {
-	syms, err := f.Symbols()
+func (e *Entry) Disasm() (*Disasm, error) {
+	syms, err := e.Symbols()
 	if err != nil {
 		return nil, err
 	}
 
-	pcln, err := f.PCLineTable()
+	pcln, err := e.PCLineTable()
 	if err != nil {
 		return nil, err
 	}
 
-	textStart, textBytes, err := f.Text()
+	textStart, textBytes, err := e.Text()
 	if err != nil {
 		return nil, err
 	}
 
-	goarch := f.GOARCH()
+	goarch := e.GOARCH()
 	disasm := disasms[goarch]
 	byteOrder := byteOrders[goarch]
 	if disasm == nil || byteOrder == nil {

src/cmd/internal/objfile/elf.go

@@ -11,14 +11,14 @@ import (
 	"debug/elf"
 	"encoding/binary"
 	"fmt"
-	"os"
+	"io"
 )
 
 type elfFile struct {
 	elf *elf.File
 }
 
-func openElf(r *os.File) (rawFile, error) {
+func openElf(r io.ReaderAt) (rawFile, error) {
 	f, err := elf.NewFile(r)
 	if err != nil {
 		return nil, err

src/cmd/internal/objfile/goobj.go

@@ -22,12 +22,33 @@ type goobjFile struct {
 	f     *os.File // the underlying .o or .a file
 }
 
-func openGoobj(r *os.File) (rawFile, error) {
+func openGoFile(r *os.File) (*File, error) {
 	f, err := goobj.Parse(r, `""`)
 	if err != nil {
 		return nil, err
 	}
-	return &goobjFile{goobj: f, f: r}, nil
+	rf := &goobjFile{goobj: f, f: r}
+	if len(f.Native) == 0 {
+		return &File{r, []*Entry{&Entry{raw: rf}}}, nil
+	}
+	entries := make([]*Entry, len(f.Native)+1)
+	entries[0] = &Entry{
+		raw: rf,
+	}
+L:
+	for i, nr := range f.Native {
+		for _, try := range openers {
+			if raw, err := try(nr); err == nil {
+				entries[i+1] = &Entry{
+					name: nr.Name,
+					raw:  raw,
+				}
+				continue L
+			}
+		}
+		return nil, fmt.Errorf("open %s: unrecognized archive member %s", r.Name(), nr.Name)
+	}
+	return &File{r, entries}, nil
 }
 
 func goobjName(id goobj.SymID) string {

src/cmd/internal/objfile/macho.go

@@ -10,7 +10,7 @@ import (
 	"debug/dwarf"
 	"debug/macho"
 	"fmt"
-	"os"
+	"io"
 	"sort"
 )
 
@@ -20,7 +20,7 @@ type machoFile struct {
 	macho *macho.File
 }
 
-func openMacho(r *os.File) (rawFile, error) {
+func openMacho(r io.ReaderAt) (rawFile, error) {
 	f, err := macho.NewFile(r)
 	if err != nil {
 		return nil, err

src/cmd/internal/objfile/objfile.go

@@ -9,6 +9,7 @@ import (
 	"debug/dwarf"
 	"debug/gosym"
 	"fmt"
+	"io"
 	"os"
 	"sort"
 )
@@ -25,6 +26,11 @@ type rawFile interface {
 // A File is an opened executable file.
 type File struct {
 	r       *os.File
+	entries []*Entry
+}
+
+type Entry struct {
+	name string
 	raw  rawFile
 }
 
@@ -50,9 +56,8 @@ type RelocStringer interface {
 	String(insnOffset uint64) string
 }
 
-var openers = []func(*os.File) (rawFile, error){
+var openers = []func(io.ReaderAt) (rawFile, error){
 	openElf,
-	openGoobj,
 	openMacho,
 	openPE,
 	openPlan9,
@@ -65,9 +70,12 @@ func Open(name string) (*File, error) {
 	if err != nil {
 		return nil, err
 	}
+	if f, err := openGoFile(r); err == nil {
+		return f, nil
+	}
 	for _, try := range openers {
 		if raw, err := try(r); err == nil {
-			return &File{r, raw}, nil
+			return &File{r, []*Entry{&Entry{raw: raw}}}, nil
 		}
 	}
 	r.Close()
@@ -78,8 +86,44 @@ func (f *File) Close() error {
 	return f.r.Close()
 }
 
+func (f *File) Entries() []*Entry {
+	return f.entries
+}
+
 func (f *File) Symbols() ([]Sym, error) {
-	syms, err := f.raw.symbols()
+	return f.entries[0].Symbols()
+}
+
+func (f *File) PCLineTable() (Liner, error) {
+	return f.entries[0].PCLineTable()
+}
+
+func (f *File) Text() (uint64, []byte, error) {
+	return f.entries[0].Text()
+}
+
+func (f *File) GOARCH() string {
+	return f.entries[0].GOARCH()
+}
+
+func (f *File) LoadAddress() (uint64, error) {
+	return f.entries[0].LoadAddress()
+}
+
+func (f *File) DWARF() (*dwarf.Data, error) {
+	return f.entries[0].DWARF()
+}
+
+func (f *File) Disasm() (*Disasm, error) {
+	return f.entries[0].Disasm()
+}
+
+func (e *Entry) Name() string {
+	return e.name
+}
+
+func (e *Entry) Symbols() ([]Sym, error) {
+	syms, err := e.raw.symbols()
 	if err != nil {
 		return nil, err
 	}
@@ -93,37 +137,37 @@ func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr }
 func (x byAddr) Len() int           { return len(x) }
 func (x byAddr) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
 
-func (f *File) PCLineTable() (Liner, error) {
+func (e *Entry) PCLineTable() (Liner, error) {
 	// If the raw file implements Liner directly, use that.
 	// Currently, only Go intermediate objects and archives (goobj) use this path.
-	if pcln, ok := f.raw.(Liner); ok {
+	if pcln, ok := e.raw.(Liner); ok {
 		return pcln, nil
 	}
 	// Otherwise, read the pcln tables and build a Liner out of that.
-	textStart, symtab, pclntab, err := f.raw.pcln()
+	textStart, symtab, pclntab, err := e.raw.pcln()
 	if err != nil {
 		return nil, err
 	}
 	return gosym.NewTable(symtab, gosym.NewLineTable(pclntab, textStart))
 }
 
-func (f *File) Text() (uint64, []byte, error) {
-	return f.raw.text()
+func (e *Entry) Text() (uint64, []byte, error) {
+	return e.raw.text()
 }
 
-func (f *File) GOARCH() string {
-	return f.raw.goarch()
+func (e *Entry) GOARCH() string {
+	return e.raw.goarch()
 }
 
 // LoadAddress returns the expected load address of the file.
 // This differs from the actual load address for a position-independent
 // executable.
-func (f *File) LoadAddress() (uint64, error) {
-	return f.raw.loadAddress()
+func (e *Entry) LoadAddress() (uint64, error) {
+	return e.raw.loadAddress()
 }
 
 // DWARF returns DWARF debug data for the file, if any.
 // This is for cmd/pprof to locate cgo functions.
-func (f *File) DWARF() (*dwarf.Data, error) {
-	return f.raw.dwarf()
+func (e *Entry) DWARF() (*dwarf.Data, error) {
+	return e.raw.dwarf()
 }

src/cmd/internal/objfile/pe.go

@@ -10,7 +10,7 @@ import (
 	"debug/dwarf"
 	"debug/pe"
 	"fmt"
-	"os"
+	"io"
 	"sort"
 )
 
@@ -18,17 +18,11 @@ type peFile struct {
 	pe *pe.File
 }
 
-func openPE(r *os.File) (rawFile, error) {
+func openPE(r io.ReaderAt) (rawFile, error) {
 	f, err := pe.NewFile(r)
 	if err != nil {
 		return nil, err
 	}
-	switch f.OptionalHeader.(type) {
-	case *pe.OptionalHeader32, *pe.OptionalHeader64:
-		// ok
-	default:
-		return nil, fmt.Errorf("unrecognized PE format")
-	}
 	return &peFile{f}, nil
 }
 

src/cmd/internal/objfile/plan9obj.go

@@ -11,7 +11,7 @@ import (
 	"debug/plan9obj"
 	"errors"
 	"fmt"
-	"os"
+	"io"
 	"sort"
 )
 
@@ -28,7 +28,7 @@ type plan9File struct {
 	plan9 *plan9obj.File
 }
 
-func openPlan9(r *os.File) (rawFile, error) {
+func openPlan9(r io.ReaderAt) (rawFile, error) {
 	f, err := plan9obj.NewFile(r)
 	if err != nil {
 		return nil, err

src/cmd/nm/nm.go

@@ -106,7 +106,12 @@ func nm(file string) {
 	}
 	defer f.Close()
 
-	syms, err := f.Symbols()
+	w := bufio.NewWriter(os.Stdout)
+
+	entries := f.Entries()
+
+	for _, e := range entries {
+		syms, err := e.Symbols()
 		if err != nil {
 			errorf("reading %s: %v", file, err)
 		}
@@ -123,9 +128,15 @@ func nm(file string) {
 			sort.Slice(syms, func(i, j int) bool { return syms[i].Size > syms[j].Size })
 		}
 
-	w := bufio.NewWriter(os.Stdout)
 		for _, sym := range syms {
-		if filePrefix {
+			if len(entries) > 1 {
+				name := e.Name()
+				if name == "" {
+					fmt.Fprintf(w, "%s(%s):\t", file, "_go_.o")
+				} else {
+					fmt.Fprintf(w, "%s(%s):\t", file, name)
+				}
+			} else if filePrefix {
 				fmt.Fprintf(w, "%s:\t", file)
 			}
 			if sym.Code == 'U' {
@@ -142,5 +153,7 @@ func nm(file string) {
 			}
 			fmt.Fprintf(w, "\n")
 		}
+	}
+
 	w.Flush()
 }

src/cmd/nm/nm_cgo_test.go

@@ -34,3 +34,14 @@ func TestInternalLinkerCgoExec(t *testing.T) {
 func TestExternalLinkerCgoExec(t *testing.T) {
 	testGoExec(t, true, true)
 }
+
+func TestCgoLib(t *testing.T) {
+	if runtime.GOARCH == "arm" {
+		switch runtime.GOOS {
+		case "darwin", "android", "nacl":
+		default:
+			t.Skip("skip test due to #19811")
+		}
+	}
+	testGoLib(t, true)
+}

src/cmd/nm/nm_test.go

@@ -161,7 +161,7 @@ func TestGoExec(t *testing.T) {
 	testGoExec(t, false, false)
 }
 
-func testGoLib(t *testing.T) {
+func testGoLib(t *testing.T, iscgo bool) {
 	tmpdir, err := ioutil.TempDir("", "TestGoLib")
 	if err != nil {
 		t.Fatal(err)
@@ -180,7 +180,7 @@ func testGoLib(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = template.Must(template.New("mylib").Parse(testlib)).Execute(file, nil)
+	err = template.Must(template.New("mylib").Parse(testlib)).Execute(file, iscgo)
 	if e := file.Close(); err == nil {
 		err = e
 	}
@@ -212,23 +212,46 @@ func testGoLib(t *testing.T) {
 	type symType struct {
 		Type  string
 		Name  string
+		CSym  bool
 		Found bool
 	}
 	var syms = []symType{
-		{"B", "%22%22.Testdata", false},
-		{"T", "%22%22.Testfunc", false},
+		{"B", "%22%22.Testdata", false, false},
+		{"T", "%22%22.Testfunc", false, false},
+	}
+	if iscgo {
+		syms = append(syms, symType{"B", "%22%22.TestCgodata", false, false})
+		syms = append(syms, symType{"T", "%22%22.TestCgofunc", false, false})
+		if runtime.GOOS == "darwin" || (runtime.GOOS == "windows" && runtime.GOARCH == "386") {
+			syms = append(syms, symType{"D", "_cgodata", true, false})
+			syms = append(syms, symType{"T", "_cgofunc", true, false})
+		} else {
+			syms = append(syms, symType{"D", "cgodata", true, false})
+			syms = append(syms, symType{"T", "cgofunc", true, false})
+		}
 	}
 	scanner := bufio.NewScanner(bytes.NewBuffer(out))
 	for scanner.Scan() {
 		f := strings.Fields(scanner.Text())
+		var typ, name string
+		var csym bool
+		if iscgo {
+			if len(f) < 4 {
+				continue
+			}
+			csym = !strings.Contains(f[0], "_go_.o")
+			typ = f[2]
+			name = f[3]
+		} else {
 			if len(f) < 3 {
 				continue
 			}
-		typ := f[1]
-		name := f[2]
+			typ = f[1]
+			name = f[2]
+		}
 		for i := range syms {
 			sym := &syms[i]
-			if sym.Type == typ && sym.Name == name {
+			if sym.Type == typ && sym.Name == name && sym.CSym == csym {
 				if sym.Found {
 					t.Fatalf("duplicate symbol %s %s", sym.Type, sym.Name)
 				}
@@ -248,7 +271,7 @@ func testGoLib(t *testing.T) {
 }
 
 func TestGoLib(t *testing.T) {
-	testGoLib(t)
+	testGoLib(t, false)
 }
 
 const testexec = `
@@ -274,6 +297,18 @@ func testfunc() {
 const testlib = `
 package mylib
 
+{{if .}}
+// int cgodata = 5;
+// void cgofunc(void) {}
+import "C"
+
+var TestCgodata = C.cgodata
+
+func TestCgofunc() {
+	C.cgofunc()
+}
+{{end}}
+
 var Testdata uint32
 
 func Testfunc() {}