github.com/x04/go/src@v0.0.0-20200202162449-3d481ceb3525/debug/macho/macho.go

// Copyright 2009 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.

// Mach-O header data structures
// Originally at:
// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html (since deleted by Apply)
// Archived copy at:
// https://web.archive.org/web/20090819232456/http://developer.apple.com/documentation/DeveloperTools/Conceptual/MachORuntime/index.html
// For cloned PDF see:
// https://github.com/aidansteele/osx-abi-macho-file-format-reference

package macho

import "github.com/x04/go/src/strconv"

// A FileHeader represents a Mach-O file header.
type FileHeader struct {
	Magic	uint32
	Cpu	Cpu
	SubCpu	uint32
	Type	Type
	Ncmd	uint32
	Cmdsz	uint32
	Flags	uint32
}

const (
	fileHeaderSize32	= 7 * 4
	fileHeaderSize64	= 8 * 4
)

const (
	Magic32		uint32	= 0xfeedface
	Magic64		uint32	= 0xfeedfacf
	MagicFat	uint32	= 0xcafebabe
)

// A Type is the Mach-O file type, e.g. an object file, executable, or dynamic library.
type Type uint32

const (
	TypeObj		Type	= 1
	TypeExec	Type	= 2
	TypeDylib	Type	= 6
	TypeBundle	Type	= 8
)

var typeStrings = []intName{
	{uint32(TypeObj), "Obj"},
	{uint32(TypeExec), "Exec"},
	{uint32(TypeDylib), "Dylib"},
	{uint32(TypeBundle), "Bundle"},
}

func (t Type) String() string	{ return stringName(uint32(t), typeStrings, false) }
func (t Type) GoString() string	{ return stringName(uint32(t), typeStrings, true) }

// A Cpu is a Mach-O cpu type.
type Cpu uint32

const cpuArch64 = 0x01000000

const (
	Cpu386		Cpu	= 7
	CpuAmd64	Cpu	= Cpu386 | cpuArch64
	CpuArm		Cpu	= 12
	CpuArm64	Cpu	= CpuArm | cpuArch64
	CpuPpc		Cpu	= 18
	CpuPpc64	Cpu	= CpuPpc | cpuArch64
)

var cpuStrings = []intName{
	{uint32(Cpu386), "Cpu386"},
	{uint32(CpuAmd64), "CpuAmd64"},
	{uint32(CpuArm), "CpuArm"},
	{uint32(CpuArm64), "CpuArm64"},
	{uint32(CpuPpc), "CpuPpc"},
	{uint32(CpuPpc64), "CpuPpc64"},
}

func (i Cpu) String() string	{ return stringName(uint32(i), cpuStrings, false) }
func (i Cpu) GoString() string	{ return stringName(uint32(i), cpuStrings, true) }

// A LoadCmd is a Mach-O load command.
type LoadCmd uint32

const (
	LoadCmdSegment		LoadCmd	= 0x1
	LoadCmdSymtab		LoadCmd	= 0x2
	LoadCmdThread		LoadCmd	= 0x4
	LoadCmdUnixThread	LoadCmd	= 0x5	// thread+stack
	LoadCmdDysymtab		LoadCmd	= 0xb
	LoadCmdDylib		LoadCmd	= 0xc	// load dylib command
	LoadCmdDylinker		LoadCmd	= 0xf	// id dylinker command (not load dylinker command)
	LoadCmdSegment64	LoadCmd	= 0x19
	LoadCmdRpath		LoadCmd	= 0x8000001c
)

var cmdStrings = []intName{
	{uint32(LoadCmdSegment), "LoadCmdSegment"},
	{uint32(LoadCmdThread), "LoadCmdThread"},
	{uint32(LoadCmdUnixThread), "LoadCmdUnixThread"},
	{uint32(LoadCmdDylib), "LoadCmdDylib"},
	{uint32(LoadCmdSegment64), "LoadCmdSegment64"},
	{uint32(LoadCmdRpath), "LoadCmdRpath"},
}

func (i LoadCmd) String() string	{ return stringName(uint32(i), cmdStrings, false) }
func (i LoadCmd) GoString() string	{ return stringName(uint32(i), cmdStrings, true) }

type (
	// A Segment32 is a 32-bit Mach-O segment load command.
	Segment32	struct {
		Cmd	LoadCmd
		Len	uint32
		Name	[16]byte
		Addr	uint32
		Memsz	uint32
		Offset	uint32
		Filesz	uint32
		Maxprot	uint32
		Prot	uint32
		Nsect	uint32
		Flag	uint32
	}

	// A Segment64 is a 64-bit Mach-O segment load command.
	Segment64	struct {
		Cmd	LoadCmd
		Len	uint32
		Name	[16]byte
		Addr	uint64
		Memsz	uint64
		Offset	uint64
		Filesz	uint64
		Maxprot	uint32
		Prot	uint32
		Nsect	uint32
		Flag	uint32
	}

	// A SymtabCmd is a Mach-O symbol table command.
	SymtabCmd	struct {
		Cmd	LoadCmd
		Len	uint32
		Symoff	uint32
		Nsyms	uint32
		Stroff	uint32
		Strsize	uint32
	}

	// A DysymtabCmd is a Mach-O dynamic symbol table command.
	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
	}

	// A DylibCmd is a Mach-O load dynamic library command.
	DylibCmd	struct {
		Cmd		LoadCmd
		Len		uint32
		Name		uint32
		Time		uint32
		CurrentVersion	uint32
		CompatVersion	uint32
	}

	// A RpathCmd is a Mach-O rpath command.
	RpathCmd	struct {
		Cmd	LoadCmd
		Len	uint32
		Path	uint32
	}

	// A Thread is a Mach-O thread state command.
	Thread	struct {
		Cmd	LoadCmd
		Len	uint32
		Type	uint32
		Data	[]uint32
	}
)

const (
	FlagNoUndefs			uint32	= 0x1
	FlagIncrLink			uint32	= 0x2
	FlagDyldLink			uint32	= 0x4
	FlagBindAtLoad			uint32	= 0x8
	FlagPrebound			uint32	= 0x10
	FlagSplitSegs			uint32	= 0x20
	FlagLazyInit			uint32	= 0x40
	FlagTwoLevel			uint32	= 0x80
	FlagForceFlat			uint32	= 0x100
	FlagNoMultiDefs			uint32	= 0x200
	FlagNoFixPrebinding		uint32	= 0x400
	FlagPrebindable			uint32	= 0x800
	FlagAllModsBound		uint32	= 0x1000
	FlagSubsectionsViaSymbols	uint32	= 0x2000
	FlagCanonical			uint32	= 0x4000
	FlagWeakDefines			uint32	= 0x8000
	FlagBindsToWeak			uint32	= 0x10000
	FlagAllowStackExecution		uint32	= 0x20000
	FlagRootSafe			uint32	= 0x40000
	FlagSetuidSafe			uint32	= 0x80000
	FlagNoReexportedDylibs		uint32	= 0x100000
	FlagPIE				uint32	= 0x200000
	FlagDeadStrippableDylib		uint32	= 0x400000
	FlagHasTLVDescriptors		uint32	= 0x800000
	FlagNoHeapExecution		uint32	= 0x1000000
	FlagAppExtensionSafe		uint32	= 0x2000000
)

// A Section32 is a 32-bit Mach-O section header.
type Section32 struct {
	Name		[16]byte
	Seg		[16]byte
	Addr		uint32
	Size		uint32
	Offset		uint32
	Align		uint32
	Reloff		uint32
	Nreloc		uint32
	Flags		uint32
	Reserve1	uint32
	Reserve2	uint32
}

// A Section64 is a 64-bit Mach-O section header.
type Section64 struct {
	Name		[16]byte
	Seg		[16]byte
	Addr		uint64
	Size		uint64
	Offset		uint32
	Align		uint32
	Reloff		uint32
	Nreloc		uint32
	Flags		uint32
	Reserve1	uint32
	Reserve2	uint32
	Reserve3	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
}

// Regs386 is the Mach-O 386 register structure.
type Regs386 struct {
	AX	uint32
	BX	uint32
	CX	uint32
	DX	uint32
	DI	uint32
	SI	uint32
	BP	uint32
	SP	uint32
	SS	uint32
	FLAGS	uint32
	IP	uint32
	CS	uint32
	DS	uint32
	ES	uint32
	FS	uint32
	GS	uint32
}

// RegsAMD64 is the Mach-O AMD64 register structure.
type RegsAMD64 struct {
	AX	uint64
	BX	uint64
	CX	uint64
	DX	uint64
	DI	uint64
	SI	uint64
	BP	uint64
	SP	uint64
	R8	uint64
	R9	uint64
	R10	uint64
	R11	uint64
	R12	uint64
	R13	uint64
	R14	uint64
	R15	uint64
	IP	uint64
	FLAGS	uint64
	CS	uint64
	FS	uint64
	GS	uint64
}

type intName struct {
	i	uint32
	s	string
}

func stringName(i uint32, names []intName, goSyntax bool) string {
	for _, n := range names {
		if n.i == i {
			if goSyntax {
				return "macho." + n.s
			}
			return n.s
		}
	}
	return strconv.FormatUint(uint64(i), 10)
}