"crypto/sha1": {"crypto", "errors", "hash", "io", "math", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "strconv", "sync", "sync/atomic", "unicode/utf8"},
"debug/dwarf": {"encoding/binary", "errors", "fmt", "internal/syscall/windows", "internal/syscall/windows/registry", "io", "math", "os", "path", "reflect", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "time", "unicode", "unicode/utf16", "unicode/utf8"},
"debug/elf": {"bytes", "debug/dwarf", "encoding/binary", "errors", "fmt", "internal/syscall/windows", "internal/syscall/windows/registry", "io", "math", "os", "path", "reflect", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "time", "unicode", "unicode/utf16", "unicode/utf8"},
+ "debug/macho": {"bytes", "debug/dwarf", "encoding/binary", "errors", "fmt", "internal/syscall/windows", "internal/syscall/windows/registry", "io", "math", "os", "path", "reflect", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "time", "unicode", "unicode/utf16", "unicode/utf8"},
"encoding": {"runtime", "runtime/internal/atomic", "runtime/internal/sys"},
"encoding/base64": {"errors", "io", "math", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "strconv", "sync", "sync/atomic", "unicode/utf8"},
"encoding/binary": {"errors", "io", "math", "reflect", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "strconv", "sync", "sync/atomic", "unicode/utf8"},
"unicode": {"runtime", "runtime/internal/atomic", "runtime/internal/sys"},
"unicode/utf16": {"runtime", "runtime/internal/atomic", "runtime/internal/sys"},
"unicode/utf8": {"runtime", "runtime/internal/atomic", "runtime/internal/sys"},
- "cmd/go": {"bufio", "bytes", "container/heap", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "encoding", "encoding/base64", "encoding/binary", "encoding/json", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "internal/singleflight", "internal/syscall/windows", "internal/syscall/windows/registry", "io", "io/ioutil", "log", "math", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
+ "cmd/go": {"bufio", "bytes", "container/heap", "crypto", "crypto/sha1", "debug/dwarf", "debug/elf", "debug/macho", "encoding", "encoding/base64", "encoding/binary", "encoding/json", "errors", "flag", "fmt", "go/ast", "go/build", "go/doc", "go/parser", "go/scanner", "go/token", "hash", "internal/singleflight", "internal/syscall/windows", "internal/syscall/windows/registry", "io", "io/ioutil", "log", "math", "net/url", "os", "os/exec", "os/signal", "path", "path/filepath", "reflect", "regexp", "regexp/syntax", "runtime", "runtime/internal/atomic", "runtime/internal/sys", "sort", "strconv", "strings", "sync", "sync/atomic", "syscall", "text/template", "text/template/parse", "time", "unicode", "unicode/utf16", "unicode/utf8"},
}
import (
"bytes"
"debug/elf"
+ "debug/macho"
"encoding/binary"
"fmt"
"io"
// No note. Treat as successful but build ID empty.
return "", nil
}
+
+// The Go build ID is stored at the beginning of the Mach-O __text segment.
+// The caller has already opened filename, to get f, and read a few kB out, in data.
+// Sadly, that's not guaranteed to hold the note, because there is an arbitrary amount
+// of other junk placed in the file ahead of the main text.
+func readMachoGoBuildID(filename string, f *os.File, data []byte) (buildid string, err error) {
+ // If the data we want has already been read, don't worry about Mach-O parsing.
+ // This is both an optimization and a hedge against the Mach-O parsing failing
+ // in the future due to, for example, the name of the __text section changing.
+ if b, err := readRawGoBuildID(filename, data); b != "" && err == nil {
+ return b, err
+ }
+
+ mf, err := macho.NewFile(f)
+ if err != nil {
+ return "", &os.PathError{Path: filename, Op: "parse", Err: err}
+ }
+
+ sect := mf.Section("__text")
+ if sect == nil {
+ // Every binary has a __text section. Something is wrong.
+ return "", &os.PathError{Path: filename, Op: "parse", Err: fmt.Errorf("cannot find __text section")}
+ }
+
+ // It should be in the first few bytes, but read a lot just in case,
+ // especially given our past problems on OS X with the build ID moving.
+ // There shouldn't be much difference between reading 4kB and 32kB:
+ // the hard part is getting to the data, not transferring it.
+ n := sect.Size
+ if n > uint64(BuildIDReadSize) {
+ n = uint64(BuildIDReadSize)
+ }
+ buf := make([]byte, n)
+ if _, err := f.ReadAt(buf, int64(sect.Offset)); err != nil {
+ return "", err
+ }
+
+ return readRawGoBuildID(filename, buf)
+}
goBuildEnd = []byte("\"\n \xff")
elfPrefix = []byte("\x7fELF")
+
+ machoPrefixes = [][]byte{
+ {0xfe, 0xed, 0xfa, 0xce},
+ {0xfe, 0xed, 0xfa, 0xcf},
+ {0xce, 0xfa, 0xed, 0xfe},
+ {0xcf, 0xfa, 0xed, 0xfe},
+ }
)
+var BuildIDReadSize = 32 * 1024 // changed for testing
+
// ReadBuildIDFromBinary reads the build ID from a binary.
//
// ELF binaries store the build ID in a proper PT_NOTE section.
return "", &os.PathError{Op: "parse", Path: filename, Err: errBuildIDUnknown}
}
- // Read the first 16 kB of the binary file.
+ // Read the first 32 kB of the binary file.
// That should be enough to find the build ID.
// In ELF files, the build ID is in the leading headers,
- // which are typically less than 4 kB, not to mention 16 kB.
+ // which are typically less than 4 kB, not to mention 32 kB.
+ // In Mach-O files, there's no limit, so we have to parse the file.
// On other systems, we're trying to read enough that
// we get the beginning of the text segment in the read.
// The offset where the text segment begins in a hello
//
// Plan 9: 0x20
// Windows: 0x600
- // Mach-O: 0x2000
//
f, err := os.Open(filename)
if err != nil {
}
defer f.Close()
- data := make([]byte, 16*1024)
+ data := make([]byte, BuildIDReadSize)
_, err = io.ReadFull(f, data)
if err == io.ErrUnexpectedEOF {
err = nil
if bytes.HasPrefix(data, elfPrefix) {
return readELFGoBuildID(filename, f, data)
}
+ for _, m := range machoPrefixes {
+ if bytes.HasPrefix(data, m) {
+ return readMachoGoBuildID(filename, f, data)
+ }
+ }
+
+ return readRawGoBuildID(filename, data)
+}
+// readRawGoBuildID finds the raw build ID stored in text segment data.
+func readRawGoBuildID(filename string, data []byte) (id string, err error) {
i := bytes.Index(data, goBuildPrefix)
if i < 0 {
// Missing. Treat as successful but build ID empty.