internal/xcoff: add big archive support
This commit adds support to read AIX big archive inside internal/xcoff
package.
Change-Id: I4317b40824b24312a69c918dfc6438dc3aff7be7
Reviewed-on: https://go-review.googlesource.com/c/153398
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/internal/xcoff/ar.go b/src/internal/xcoff/ar.go
new file mode 100644
index 0000000..0fb410f
--- /dev/null
+++ b/src/internal/xcoff/ar.go
@@ -0,0 +1,228 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xcoff
+
+import (
+ "encoding/binary"
+ "fmt"
+ "io"
+ "os"
+ "strconv"
+ "strings"
+)
+
+const (
+ SAIAMAG = 0x8
+ AIAFMAG = "`\n"
+ AIAMAG = "<aiaff>\n"
+ AIAMAGBIG = "<bigaf>\n"
+
+ // Sizeof
+ FL_HSZ_BIG = 0x80
+ AR_HSZ_BIG = 0x70
+)
+
+type bigarFileHeader struct {
+ Flmagic [SAIAMAG]byte // Archive magic string
+ Flmemoff [20]byte // Member table offset
+ Flgstoff [20]byte // 32-bits global symtab offset
+ Flgst64off [20]byte // 64-bits global symtab offset
+ Flfstmoff [20]byte // First member offset
+ Fllstmoff [20]byte // Last member offset
+ Flfreeoff [20]byte // First member on free list offset
+}
+
+type bigarMemberHeader struct {
+ Arsize [20]byte // File member size
+ Arnxtmem [20]byte // Next member pointer
+ Arprvmem [20]byte // Previous member pointer
+ Ardate [12]byte // File member date
+ Aruid [12]byte // File member uid
+ Argid [12]byte // File member gid
+ Armode [12]byte // File member mode (octal)
+ Arnamlen [4]byte // File member name length
+ // _ar_nam is removed because it's easier to get name without it.
+}
+
+// Archive represents an open AIX big archive.
+type Archive struct {
+ ArchiveHeader
+ Members []*Member
+
+ closer io.Closer
+}
+
+// MemberHeader holds information about a big archive file header
+type ArchiveHeader struct {
+ magic string
+}
+
+// Member represents a member of an AIX big archive.
+type Member struct {
+ MemberHeader
+ sr *io.SectionReader
+}
+
+// MemberHeader holds information about a big archive member
+type MemberHeader struct {
+ Name string
+ Size uint64
+}
+
+// OpenArchive opens the named archive using os.Open and prepares it for use
+// as an AIX big archive.
+func OpenArchive(name string) (*Archive, error) {
+ f, err := os.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ arch, err := NewArchive(f)
+ if err != nil {
+ f.Close()
+ return nil, err
+ }
+ arch.closer = f
+ return arch, nil
+}
+
+// Close closes the Archive.
+// If the Archive was created using NewArchive directly instead of OpenArchive,
+// Close has no effect.
+func (a *Archive) Close() error {
+ var err error
+ if a.closer != nil {
+ err = a.closer.Close()
+ a.closer = nil
+ }
+ return err
+}
+
+// NewArchive creates a new Archive for accessing an AIX big archive in an underlying reader.
+func NewArchive(r io.ReaderAt) (*Archive, error) {
+ parseDecimalBytes := func(b []byte) (int64, error) {
+ return strconv.ParseInt(strings.TrimSpace(string(b)), 10, 64)
+ }
+ sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+ // Read File Header
+ var magic [SAIAMAG]byte
+ if _, err := sr.ReadAt(magic[:], 0); err != nil {
+ return nil, err
+ }
+
+ arch := new(Archive)
+ switch string(magic[:]) {
+ case AIAMAGBIG:
+ arch.magic = string(magic[:])
+ case AIAMAG:
+ return nil, fmt.Errorf("small AIX archive not supported")
+ default:
+ return nil, fmt.Errorf("unrecognised archive magic: 0x%x", magic)
+ }
+
+ var fhdr bigarFileHeader
+ if _, err := sr.Seek(0, os.SEEK_SET); err != nil {
+ return nil, err
+ }
+ if err := binary.Read(sr, binary.BigEndian, &fhdr); err != nil {
+ return nil, err
+ }
+
+ off, err := parseDecimalBytes(fhdr.Flfstmoff[:])
+ if err != nil {
+ return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+ }
+
+ if off == 0 {
+ // Occurs if the archive is empty.
+ return arch, nil
+ }
+
+ lastoff, err := parseDecimalBytes(fhdr.Fllstmoff[:])
+ if err != nil {
+ return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+ }
+
+ // Read members
+ for {
+ // Read Member Header
+ // The member header is normally 2 bytes larger. But it's easier
+ // to read the name if the header is read without _ar_nam.
+ // However, AIAFMAG must be read afterward.
+ if _, err := sr.Seek(off, os.SEEK_SET); err != nil {
+ return nil, err
+ }
+
+ var mhdr bigarMemberHeader
+ if err := binary.Read(sr, binary.BigEndian, &mhdr); err != nil {
+ return nil, err
+ }
+
+ member := new(Member)
+ arch.Members = append(arch.Members, member)
+
+ size, err := parseDecimalBytes(mhdr.Arsize[:])
+ if err != nil {
+ return nil, fmt.Errorf("error parsing size in member header(%q); %v", mhdr, err)
+ }
+ member.Size = uint64(size)
+
+ // Read name
+ namlen, err := parseDecimalBytes(mhdr.Arnamlen[:])
+ if err != nil {
+ return nil, fmt.Errorf("error parsing name length in member header(%q); %v", mhdr, err)
+ }
+ name := make([]byte, namlen)
+ if err := binary.Read(sr, binary.BigEndian, name); err != nil {
+ return nil, err
+ }
+ member.Name = string(name)
+
+ fileoff := off + AR_HSZ_BIG + namlen
+ if fileoff&1 != 0 {
+ fileoff++
+ if _, err := sr.Seek(1, os.SEEK_CUR); err != nil {
+ return nil, err
+ }
+ }
+
+ // Read AIAFMAG string
+ var fmag [2]byte
+ if err := binary.Read(sr, binary.BigEndian, &fmag); err != nil {
+ return nil, err
+ }
+ if string(fmag[:]) != AIAFMAG {
+ return nil, fmt.Errorf("AIAFMAG not found after member header")
+ }
+
+ fileoff += 2 // Add the two bytes of AIAFMAG
+ member.sr = io.NewSectionReader(sr, fileoff, size)
+
+ if off == lastoff {
+ break
+ }
+ off, err = parseDecimalBytes(mhdr.Arnxtmem[:])
+ if err != nil {
+ return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+ }
+
+ }
+
+ return arch, nil
+
+}
+
+// GetFile returns the XCOFF file defined by member name.
+// FIXME: This doesn't work if an archive has two members with the same
+// name which can occur if a archive has both 32-bits and 64-bits files.
+func (arch *Archive) GetFile(name string) (*File, error) {
+ for _, mem := range arch.Members {
+ if mem.Name == name {
+ return NewFile(mem.sr)
+ }
+ }
+ return nil, fmt.Errorf("unknown member %s in archive", name)
+
+}
diff --git a/src/internal/xcoff/ar_test.go b/src/internal/xcoff/ar_test.go
new file mode 100644
index 0000000..03c2fd1
--- /dev/null
+++ b/src/internal/xcoff/ar_test.go
@@ -0,0 +1,79 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xcoff
+
+import (
+ "reflect"
+ "testing"
+)
+
+type archiveTest struct {
+ file string
+ hdr ArchiveHeader
+ members []*MemberHeader
+ membersFileHeader []FileHeader
+}
+
+var archTest = []archiveTest{
+ {
+ "testdata/bigar-ppc64",
+ ArchiveHeader{AIAMAGBIG},
+ []*MemberHeader{
+ {"printbye.o", 836},
+ {"printhello.o", 860},
+ },
+ []FileHeader{
+ FileHeader{U64_TOCMAGIC},
+ FileHeader{U64_TOCMAGIC},
+ },
+ },
+ {
+ "testdata/bigar-empty",
+ ArchiveHeader{AIAMAGBIG},
+ []*MemberHeader{},
+ []FileHeader{},
+ },
+}
+
+func TestOpenArchive(t *testing.T) {
+ for i := range archTest {
+ tt := &archTest[i]
+ arch, err := OpenArchive(tt.file)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+ if !reflect.DeepEqual(arch.ArchiveHeader, tt.hdr) {
+ t.Errorf("open archive %s:\n\thave %#v\n\twant %#v\n", tt.file, arch.ArchiveHeader, tt.hdr)
+ continue
+ }
+
+ for i, mem := range arch.Members {
+ if i >= len(tt.members) {
+ break
+ }
+ have := &mem.MemberHeader
+ want := tt.members[i]
+ if !reflect.DeepEqual(have, want) {
+ t.Errorf("open %s, member %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+ }
+
+ f, err := arch.GetFile(mem.Name)
+ if err != nil {
+ t.Error(err)
+ continue
+ }
+ if !reflect.DeepEqual(f.FileHeader, tt.membersFileHeader[i]) {
+ t.Errorf("open %s, member file header %d:\n\thave %#v\n\twant %#v\n", tt.file, i, f.FileHeader, tt.membersFileHeader[i])
+ }
+ }
+ tn := len(tt.members)
+ an := len(arch.Members)
+ if tn != an {
+ t.Errorf("open %s: len(Members) = %d, want %d", tt.file, an, tn)
+ }
+
+ }
+}
diff --git a/src/internal/xcoff/testdata/bigar-empty b/src/internal/xcoff/testdata/bigar-empty
new file mode 100644
index 0000000..851ccc5
--- /dev/null
+++ b/src/internal/xcoff/testdata/bigar-empty
@@ -0,0 +1,2 @@
+<bigaf>
+0 0 0 0 0 0
\ No newline at end of file
diff --git a/src/internal/xcoff/testdata/bigar-ppc64 b/src/internal/xcoff/testdata/bigar-ppc64
new file mode 100644
index 0000000..a8d4979
--- /dev/null
+++ b/src/internal/xcoff/testdata/bigar-ppc64
Binary files differ
diff --git a/src/internal/xcoff/testdata/printbye.c b/src/internal/xcoff/testdata/printbye.c
new file mode 100644
index 0000000..9045079
--- /dev/null
+++ b/src/internal/xcoff/testdata/printbye.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+void printbye(){
+ printf("Goodbye\n");
+}
diff --git a/src/internal/xcoff/testdata/printhello.c b/src/internal/xcoff/testdata/printhello.c
new file mode 100644
index 0000000..182aa09
--- /dev/null
+++ b/src/internal/xcoff/testdata/printhello.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+void printhello(){
+ printf("Helloworld\n");
+}
