debug/elf, debug/macho: add ImportedLibraries, ImportedSymbols
R=r, iant
CC=golang-dev
https://golang.org/cl/3470044
diff --git a/src/pkg/debug/elf/elf.go b/src/pkg/debug/elf/elf.go
index 46d618c..74e9799 100644
--- a/src/pkg/debug/elf/elf.go
+++ b/src/pkg/debug/elf/elf.go
@@ -1356,9 +1356,12 @@
const Sym32Size = 16
-func ST_BIND(info uint8) SymBind { return SymBind(info >> 4) }
-func ST_TYPE(bind SymBind, typ SymType) uint8 { return uint8(bind)<<4 | uint8(typ)&0xf }
-func ST_VISIBILITY(other uint8) SymVis { return SymVis(other & 3) }
+func ST_BIND(info uint8) SymBind { return SymBind(info >> 4) }
+func ST_TYPE(info uint8) SymType { return SymType(info & 0xF) }
+func ST_INFO(bind SymBind, typ SymType) uint8 {
+ return uint8(bind)<<4 | uint8(typ)&0xf
+}
+func ST_VISIBILITY(other uint8) SymVis { return SymVis(other & 3) }
/*
* ELF64
diff --git a/src/pkg/debug/elf/file.go b/src/pkg/debug/elf/file.go
index 568370b..e69317a 100644
--- a/src/pkg/debug/elf/file.go
+++ b/src/pkg/debug/elf/file.go
@@ -75,6 +75,15 @@
return dat[0:n], err
}
+// stringTable reads and returns the string table given by the
+// specified link value.
+func (f *File) stringTable(link uint32) ([]byte, os.Error) {
+ if link <= 0 || link >= uint32(len(f.Sections)) {
+ return nil, os.ErrorString("section has invalid string table link")
+ }
+ return f.Sections[link].Data()
+}
+
// Open returns a new ReadSeeker reading the ELF section.
func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
@@ -108,9 +117,9 @@
// A Symbol represents an entry in an ELF symbol table section.
type Symbol struct {
- Name uint32
+ Name string
Info, Other byte
- Section uint32
+ Section SectionIndex
Value, Size uint64
}
@@ -160,6 +169,17 @@
return err
}
+// SectionByType returns the first section in f with the
+// given type, or nil if there is no such section.
+func (f *File) SectionByType(typ SectionType) *Section {
+ for _, s := range f.Sections {
+ if s.Type == typ {
+ return s
+ }
+ }
+ return nil
+}
+
// NewFile creates a new File for accessing an ELF binary in an underlying reader.
// The ELF binary is expected to start at position 0 in the ReaderAt.
func NewFile(r io.ReaderAt) (*File, os.Error) {
@@ -293,9 +313,8 @@
}
// Load section header string table.
- s := f.Sections[shstrndx]
- shstrtab := make([]byte, s.Size)
- if _, err := r.ReadAt(shstrtab, int64(s.Offset)); err != nil {
+ shstrtab, err := f.Sections[shstrndx].Data()
+ if err != nil {
return nil, err
}
for i, s := range f.Sections {
@@ -309,25 +328,65 @@
return f, nil
}
-func (f *File) getSymbols() ([]Symbol, os.Error) {
+// getSymbols returns a slice of Symbols from parsing the symbol table
+// with the given type.
+func (f *File) getSymbols(typ SectionType) ([]Symbol, os.Error) {
switch f.Class {
case ELFCLASS64:
- return f.getSymbols64()
+ return f.getSymbols64(typ)
+
+ case ELFCLASS32:
+ return f.getSymbols32(typ)
}
return nil, os.ErrorString("not implemented")
}
-// GetSymbols returns a slice of Symbols from parsing the symbol table.
-func (f *File) getSymbols64() ([]Symbol, os.Error) {
- var symtabSection *Section
- for _, section := range f.Sections {
- if section.Type == SHT_SYMTAB {
- symtabSection = section
- break
- }
+func (f *File) getSymbols32(typ SectionType) ([]Symbol, os.Error) {
+ symtabSection := f.SectionByType(typ)
+ if symtabSection == nil {
+ return nil, os.ErrorString("no symbol section")
}
+ data, err := symtabSection.Data()
+ if err != nil {
+ return nil, os.ErrorString("cannot load symbol section")
+ }
+ symtab := bytes.NewBuffer(data)
+ if symtab.Len()%Sym32Size != 0 {
+ return nil, os.ErrorString("length of symbol section is not a multiple of SymSize")
+ }
+
+ strdata, err := f.stringTable(symtabSection.Link)
+ if err != nil {
+ return nil, os.ErrorString("cannot load string table section")
+ }
+
+ // The first entry is all zeros.
+ var skip [Sym32Size]byte
+ symtab.Read(skip[0:])
+
+ symbols := make([]Symbol, symtab.Len()/Sym32Size)
+
+ i := 0
+ var sym Sym32
+ for symtab.Len() > 0 {
+ binary.Read(symtab, f.ByteOrder, &sym)
+ str, _ := getString(strdata, int(sym.Name))
+ symbols[i].Name = str
+ symbols[i].Info = sym.Info
+ symbols[i].Other = sym.Other
+ symbols[i].Section = SectionIndex(sym.Shndx)
+ symbols[i].Value = uint64(sym.Value)
+ symbols[i].Size = uint64(sym.Size)
+ i++
+ }
+
+ return symbols, nil
+}
+
+func (f *File) getSymbols64(typ SectionType) ([]Symbol, os.Error) {
+ symtabSection := f.SectionByType(typ)
if symtabSection == nil {
return nil, os.ErrorString("no symbol section")
}
@@ -341,6 +400,11 @@
return nil, os.ErrorString("length of symbol section is not a multiple of Sym64Size")
}
+ strdata, err := f.stringTable(symtabSection.Link)
+ if err != nil {
+ return nil, os.ErrorString("cannot load string table section")
+ }
+
// The first entry is all zeros.
var skip [Sym64Size]byte
symtab.Read(skip[0:])
@@ -351,10 +415,11 @@
var sym Sym64
for symtab.Len() > 0 {
binary.Read(symtab, f.ByteOrder, &sym)
- symbols[i].Name = sym.Name
+ str, _ := getString(strdata, int(sym.Name))
+ symbols[i].Name = str
symbols[i].Info = sym.Info
symbols[i].Other = sym.Other
- symbols[i].Section = uint32(sym.Shndx)
+ symbols[i].Section = SectionIndex(sym.Shndx)
symbols[i].Value = sym.Value
symbols[i].Size = sym.Size
i++
@@ -403,7 +468,7 @@
return os.ErrorString("length of relocation section is not a multiple of Sym64Size")
}
- symbols, err := f.getSymbols()
+ symbols, err := f.getSymbols(SHT_SYMTAB)
if err != nil {
return err
}
@@ -478,3 +543,63 @@
abbrev, info, str := dat[0], dat[1], dat[2]
return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+// It does not return weak symbols.
+func (f *File) ImportedSymbols() ([]string, os.Error) {
+ sym, err := f.getSymbols(SHT_DYNSYM)
+ if err != nil {
+ return nil, err
+ }
+ var all []string
+ for _, s := range sym {
+ if ST_BIND(s.Info) == STB_GLOBAL && s.Section == SHN_UNDEF {
+ all = append(all, s.Name)
+ }
+ }
+ return all, nil
+}
+
+// ImportedLibraries returns the names of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, os.Error) {
+ ds := f.SectionByType(SHT_DYNAMIC)
+ if ds == nil {
+ // not dynamic, so no libraries
+ return nil, nil
+ }
+ d, err := ds.Data()
+ if err != nil {
+ return nil, err
+ }
+ str, err := f.stringTable(ds.Link)
+ if err != nil {
+ return nil, err
+ }
+ var all []string
+ for len(d) > 0 {
+ var tag DynTag
+ var value uint64
+ switch f.Class {
+ case ELFCLASS32:
+ tag = DynTag(f.ByteOrder.Uint32(d[0:4]))
+ value = uint64(f.ByteOrder.Uint32(d[4:8]))
+ d = d[8:]
+ case ELFCLASS64:
+ tag = DynTag(f.ByteOrder.Uint64(d[0:8]))
+ value = f.ByteOrder.Uint64(d[8:16])
+ d = d[16:]
+ }
+ if tag == DT_NEEDED {
+ s, ok := getString(str, int(value))
+ if ok {
+ all = append(all, s)
+ }
+ }
+ }
+
+ return all, nil
+}
diff --git a/src/pkg/debug/macho/file.go b/src/pkg/debug/macho/file.go
index d280226..fd8da94 100644
--- a/src/pkg/debug/macho/file.go
+++ b/src/pkg/debug/macho/file.go
@@ -24,6 +24,9 @@
Loads []Load
Sections []*Section
+ Symtab *Symtab
+ Dysymtab *Dysymtab
+
closer io.Closer
}
@@ -112,6 +115,28 @@
// Open returns a new ReadSeeker reading the Mach-O section.
func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+// A Dylib represents a Mach-O load dynamic library command.
+type Dylib struct {
+ LoadBytes
+ Name string
+ Time uint32
+ CurrentVersion uint32
+ CompatVersion uint32
+}
+
+// A Symtab represents a Mach-O symbol table command.
+type Symtab struct {
+ LoadBytes
+ SymtabCmd
+ Syms []Symbol
+}
+
+// A Dysymtab represents a Mach-O dynamic symbol table command.
+type Dysymtab struct {
+ LoadBytes
+ DysymtabCmd
+ IndirectSyms []uint32 // indices into Symtab.Syms
+}
/*
* Mach-O reader
@@ -217,6 +242,71 @@
default:
f.Loads[i] = LoadBytes(cmddat)
+ case LoadCmdDylib:
+ var hdr DylibCmd
+ b := bytes.NewBuffer(cmddat)
+ if err := binary.Read(b, bo, &hdr); err != nil {
+ return nil, err
+ }
+ l := new(Dylib)
+ if hdr.Name >= uint32(len(cmddat)) {
+ return nil, &FormatError{offset, "invalid name in dynamic library command", hdr.Name}
+ }
+ l.Name = cstring(cmddat[hdr.Name:])
+ l.Time = hdr.Time
+ l.CurrentVersion = hdr.CurrentVersion
+ l.CompatVersion = hdr.CompatVersion
+ l.LoadBytes = LoadBytes(cmddat)
+ f.Loads[i] = l
+
+ case LoadCmdSymtab:
+ var hdr SymtabCmd
+ b := bytes.NewBuffer(cmddat)
+ if err := binary.Read(b, bo, &hdr); err != nil {
+ return nil, err
+ }
+ strtab := make([]byte, hdr.Strsize)
+ if _, err := r.ReadAt(strtab, int64(hdr.Stroff)); err != nil {
+ return nil, err
+ }
+ var symsz int
+ if f.Magic == Magic64 {
+ symsz = 16
+ } else {
+ symsz = 12
+ }
+ symdat := make([]byte, int(hdr.Nsyms)*symsz)
+ if _, err := r.ReadAt(symdat, int64(hdr.Symoff)); err != nil {
+ return nil, err
+ }
+ st, err := f.parseSymtab(symdat, strtab, cmddat, &hdr, offset)
+ if err != nil {
+ return nil, err
+ }
+ f.Loads[i] = st
+ f.Symtab = st
+
+ case LoadCmdDysymtab:
+ var hdr DysymtabCmd
+ b := bytes.NewBuffer(cmddat)
+ if err := binary.Read(b, bo, &hdr); err != nil {
+ return nil, err
+ }
+ dat := make([]byte, hdr.Nindirectsyms*4)
+ if _, err := r.ReadAt(dat, int64(hdr.Indirectsymoff)); err != nil {
+ return nil, err
+ }
+ x := make([]uint32, hdr.Nindirectsyms)
+ if err := binary.Read(bytes.NewBuffer(dat), bo, x); err != nil {
+ return nil, err
+ }
+ st := new(Dysymtab)
+ st.LoadBytes = LoadBytes(cmddat)
+ st.DysymtabCmd = hdr
+ st.IndirectSyms = x
+ f.Loads[i] = st
+ f.Dysymtab = st
+
case LoadCmdSegment:
var seg32 Segment32
b := bytes.NewBuffer(cmddat)
@@ -301,6 +391,43 @@
return f, nil
}
+func (f *File) parseSymtab(symdat, strtab, cmddat []byte, hdr *SymtabCmd, offset int64) (*Symtab, os.Error) {
+ bo := f.ByteOrder
+ symtab := make([]Symbol, hdr.Nsyms)
+ b := bytes.NewBuffer(symdat)
+ for i := range symtab {
+ var n Nlist64
+ if f.Magic == Magic64 {
+ if err := binary.Read(b, bo, &n); err != nil {
+ return nil, err
+ }
+ } else {
+ var n32 Nlist32
+ if err := binary.Read(b, bo, &n32); err != nil {
+ return nil, err
+ }
+ n.Name = n32.Name
+ n.Type = n32.Type
+ n.Sect = n32.Sect
+ n.Desc = n32.Desc
+ n.Value = uint64(n32.Value)
+ }
+ sym := &symtab[i]
+ if n.Name >= uint32(len(strtab)) {
+ return nil, &FormatError{offset, "invalid name in symbol table", n.Name}
+ }
+ sym.Name = cstring(strtab[n.Name:])
+ sym.Type = n.Type
+ sym.Sect = n.Sect
+ sym.Desc = n.Desc
+ sym.Value = n.Value
+ }
+ st := new(Symtab)
+ st.LoadBytes = LoadBytes(cmddat)
+ st.Syms = symtab
+ return st, nil
+}
+
func (f *File) pushSection(sh *Section, r io.ReaderAt) {
f.Sections = append(f.Sections, sh)
sh.sr = io.NewSectionReader(r, int64(sh.Offset), int64(sh.Size))
@@ -358,3 +485,33 @@
abbrev, info, str := dat[0], dat[1], dat[2]
return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+func (f *File) ImportedSymbols() ([]string, os.Error) {
+ if f.Dysymtab == nil || f.Symtab == nil {
+ return nil, &FormatError{0, "missing symbol table", nil}
+ }
+
+ st := f.Symtab
+ dt := f.Dysymtab
+ var all []string
+ for _, s := range st.Syms[dt.Iundefsym : dt.Iundefsym+dt.Nundefsym] {
+ all = append(all, s.Name)
+ }
+ return all, nil
+}
+
+// ImportedLibraries returns the paths of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, os.Error) {
+ var all []string
+ for _, l := range f.Loads {
+ if lib, ok := l.(*Dylib); ok {
+ all = append(all, lib.Name)
+ }
+ }
+ return all, nil
+}
diff --git a/src/pkg/debug/macho/macho.go b/src/pkg/debug/macho/macho.go
index a45d782..1386f5a 100644
--- a/src/pkg/debug/macho/macho.go
+++ b/src/pkg/debug/macho/macho.go
@@ -59,16 +59,21 @@
const (
LoadCmdSegment LoadCmd = 1
- LoadCmdSegment64 LoadCmd = 25
+ LoadCmdSymtab LoadCmd = 2
LoadCmdThread LoadCmd = 4
LoadCmdUnixThread LoadCmd = 5 // thread+stack
+ LoadCmdDysymtab LoadCmd = 11
+ LoadCmdDylib LoadCmd = 12
+ LoadCmdDylinker LoadCmd = 15
+ LoadCmdSegment64 LoadCmd = 25
)
var cmdStrings = []intName{
{uint32(LoadCmdSegment), "LoadCmdSegment"},
- {uint32(LoadCmdSegment64), "LoadCmdSegment64"},
{uint32(LoadCmdThread), "LoadCmdThread"},
{uint32(LoadCmdUnixThread), "LoadCmdUnixThread"},
+ {uint32(LoadCmdDylib), "LoadCmdDylib"},
+ {uint32(LoadCmdSegment64), "LoadCmdSegment64"},
}
func (i LoadCmd) String() string { return stringName(uint32(i), cmdStrings, false) }
@@ -104,6 +109,16 @@
Flag uint32
}
+// A DylibCmd is a Mach-O load dynamic library command.
+type DylibCmd struct {
+ Cmd LoadCmd
+ Len uint32
+ Name uint32
+ Time uint32
+ CurrentVersion uint32
+ CompatVersion uint32
+}
+
// A Section32 is a 32-bit Mach-O section header.
type Section32 struct {
Name [16]byte
@@ -135,6 +150,67 @@
Reserve3 uint32
}
+// A SymtabCmd is a Mach-O symbol table command.
+type SymtabCmd struct {
+ Cmd LoadCmd
+ Len uint32
+ Symoff uint32
+ Nsyms uint32
+ Stroff uint32
+ Strsize uint32
+}
+
+// A DysymtabCmd is a Mach-O dynamic symbol table command.
+type DysymtabCmd struct {
+ Cmd LoadCmd
+ Len uint32
+ Ilocalsym uint32
+ Nlocalsym uint32
+ Iextdefsym uint32
+ Nextdefsym uint32
+ Iundefsym uint32
+ Nundefsym uint32
+ Tocoffset uint32
+ Ntoc uint32
+ Modtaboff uint32
+ Nmodtab uint32
+ Extrefsymoff uint32
+ Nextrefsyms uint32
+ Indirectsymoff uint32
+ Nindirectsyms uint32
+ Extreloff uint32
+ Nextrel uint32
+ Locreloff uint32
+ Nlocrel uint32
+}
+
+// An Nlist32 is a Mach-O 32-bit symbol table entry.
+type Nlist32 struct {
+ Name uint32
+ Type uint8
+ Sect uint8
+ Desc uint16
+ Value uint32
+}
+
+// An Nlist64 is a Mach-O 64-bit symbol table entry.
+type Nlist64 struct {
+ Name uint32
+ Type uint8
+ Sect uint8
+ Desc uint16
+ Value uint64
+}
+
+// A Symbol is a Mach-O 32-bit or 64-bit symbol table entry.
+type Symbol struct {
+ Name string
+ Type uint8
+ Sect uint8
+ Desc uint16
+ Value uint64
+}
+
// A Thread is a Mach-O thread state command.
type Thread struct {
Cmd LoadCmd
