Added Mach-O file format

src/compiler/Result.go

@@ -4,11 +4,13 @@ import (
 	"bufio"
 	"io"
 	"os"
+	"runtime"
 
 	"git.akyoto.dev/cli/q/src/arch/x64"
 	"git.akyoto.dev/cli/q/src/asm"
 	"git.akyoto.dev/cli/q/src/core"
 	"git.akyoto.dev/cli/q/src/elf"
+	"git.akyoto.dev/cli/q/src/macho"
 	"git.akyoto.dev/cli/q/src/os/linux"
 )
 
@@ -31,13 +33,22 @@ func (r *Result) finalize() ([]byte, []byte) {
 		Data:         make(map[string][]byte, r.DataCount),
 	}
 
+	sysExit := 0
+
+	switch runtime.GOOS {
+	case "linux":
+		sysExit = linux.Exit
+	case "darwin":
+		sysExit = 1 | 0x2000000
+	}
+
 	final.Call("main.main")
-	final.RegisterNumber(asm.MOVE, x64.SyscallInputRegisters[0], linux.Exit)
+	final.RegisterNumber(asm.MOVE, x64.SyscallInputRegisters[0], sysExit)
 	final.RegisterNumber(asm.MOVE, x64.SyscallInputRegisters[1], 0)
 	final.Syscall()
 
 	final.Label(asm.LABEL, "_crash")
-	final.RegisterNumber(asm.MOVE, x64.SyscallInputRegisters[0], linux.Exit)
+	final.RegisterNumber(asm.MOVE, x64.SyscallInputRegisters[0], sysExit)
 	final.RegisterNumber(asm.MOVE, x64.SyscallInputRegisters[1], 1)
 	final.Syscall()
 
@@ -117,7 +128,17 @@ func (r *Result) WriteFile(path string) error {
 // write writes an executable file to the given writer.
 func write(writer io.Writer, code []byte, data []byte) error {
 	buffer := bufio.NewWriter(writer)
-	executable := elf.New(code, data)
-	executable.Write(buffer)
+
+	switch runtime.GOOS {
+	case "darwin":
+		exe := macho.New(code, data)
+		exe.Write(buffer)
+	case "linux":
+		exe := elf.New(code, data)
+		exe.Write(buffer)
+	default:
+		panic("unsupported platform")
+	}
+
 	return buffer.Flush()
 }

src/macho/CPU.go

@@ -0,0 +1,10 @@
+package macho
+
+type CPU uint32
+
+const (
+	CPU_X86    CPU = 7
+	CPU_X86_64 CPU = CPU_X86 | 0x01000000
+	CPU_ARM    CPU = 12
+	CPU_ARM_64 CPU = CPU_ARM | 0x01000000
+)

src/macho/Header.go

@@ -0,0 +1,13 @@
+package macho
+
+// Header contains general information.
+type Header struct {
+	Magic             uint32
+	Architecture      CPU
+	MicroArchitecture uint32
+	Type              HeaderType
+	NumCommands       uint32
+	SizeCommands      uint32
+	Flags             HeaderFlags
+	Reserved          uint32
+}

src/macho/HeaderFlags.go

@@ -0,0 +1,32 @@
+package macho
+
+type HeaderFlags uint32
+
+const (
+	FlagNoUndefs              HeaderFlags = 0x1
+	FlagIncrLink              HeaderFlags = 0x2
+	FlagDyldLink              HeaderFlags = 0x4
+	FlagBindAtLoad            HeaderFlags = 0x8
+	FlagPrebound              HeaderFlags = 0x10
+	FlagSplitSegs             HeaderFlags = 0x20
+	FlagLazyInit              HeaderFlags = 0x40
+	FlagTwoLevel              HeaderFlags = 0x80
+	FlagForceFlat             HeaderFlags = 0x100
+	FlagNoMultiDefs           HeaderFlags = 0x200
+	FlagNoFixPrebinding       HeaderFlags = 0x400
+	FlagPrebindable           HeaderFlags = 0x800
+	FlagAllModsBound          HeaderFlags = 0x1000
+	FlagSubsectionsViaSymbols HeaderFlags = 0x2000
+	FlagCanonical             HeaderFlags = 0x4000
+	FlagWeakDefines           HeaderFlags = 0x8000
+	FlagBindsToWeak           HeaderFlags = 0x10000
+	FlagAllowStackExecution   HeaderFlags = 0x20000
+	FlagRootSafe              HeaderFlags = 0x40000
+	FlagSetuidSafe            HeaderFlags = 0x80000
+	FlagNoReexportedDylibs    HeaderFlags = 0x100000
+	FlagPIE                   HeaderFlags = 0x200000
+	FlagDeadStrippableDylib   HeaderFlags = 0x400000
+	FlagHasTLVDescriptors     HeaderFlags = 0x800000
+	FlagNoHeapExecution       HeaderFlags = 0x1000000
+	FlagAppExtensionSafe      HeaderFlags = 0x2000000
+)

src/macho/HeaderType.go

@@ -0,0 +1,12 @@
+package macho
+
+type HeaderType uint32
+
+const (
+	TypeObject  HeaderType = 0x1
+	TypeExecute HeaderType = 0x2
+	TypeCore    HeaderType = 0x4
+	TypeDylib   HeaderType = 0x6
+	TypeBundle  HeaderType = 0x8
+	TypeDsym    HeaderType = 0xA
+)

src/macho/LoadCommand.go

@@ -0,0 +1,34 @@
+package macho
+
+type LoadCommand uint32
+
+const (
+	LcSegment            LoadCommand = 0x1
+	LcSymtab             LoadCommand = 0x2
+	LcThread             LoadCommand = 0x4
+	LcUnixthread         LoadCommand = 0x5
+	LcDysymtab           LoadCommand = 0xB
+	LcDylib              LoadCommand = 0xC
+	LcIdDylib            LoadCommand = 0xD
+	LcLoadDylinker       LoadCommand = 0xE
+	LcIdDylinker         LoadCommand = 0xF
+	LcSegment64          LoadCommand = 0x19
+	LcUuid               LoadCommand = 0x1B
+	LcCodeSignature      LoadCommand = 0x1D
+	LcSegmentSplitInfo   LoadCommand = 0x1E
+	LcRpath              LoadCommand = 0x8000001C
+	LcEncryptionInfo     LoadCommand = 0x21
+	LcDyldInfo           LoadCommand = 0x22
+	LcDyldInfoOnly       LoadCommand = 0x80000022
+	LcVersionMinMacosx   LoadCommand = 0x24
+	LcVersionMinIphoneos LoadCommand = 0x25
+	LcFunctionStarts     LoadCommand = 0x26
+	LcDyldEnvironment    LoadCommand = 0x27
+	LcMain               LoadCommand = 0x80000028
+	LcDataInCode         LoadCommand = 0x29
+	LcSourceVersion      LoadCommand = 0x2A
+	LcDylibCodeSignDrs   LoadCommand = 0x2B
+	LcEncryptionInfo64   LoadCommand = 0x2C
+	LcVersionMinTvos     LoadCommand = 0x2F
+	LcVersionMinWatchos  LoadCommand = 0x30
+)

src/macho/MachO.go

@@ -0,0 +1,107 @@
+package macho
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+
+	"git.akyoto.dev/cli/q/src/config"
+)
+
+// MachO is the executable format used on MacOS.
+type MachO struct {
+	Header
+	Code []byte
+	Data []byte
+}
+
+// New creates a new Mach-O binary.
+func New(code []byte, data []byte) *MachO {
+	return &MachO{
+		Header: Header{
+			Magic:             0xFEEDFACF,
+			Architecture:      CPU_X86_64,
+			MicroArchitecture: 0x80000003,
+			Type:              TypeExecute,
+			NumCommands:       3,
+			SizeCommands:      0x48*2 + 184,
+			Flags:             FlagNoUndefs,
+			Reserved:          0,
+		},
+		Code: code,
+		Data: data,
+	}
+}
+
+// Write writes the Mach-O format to the given writer.
+func (m *MachO) Write(writer io.Writer) {
+	binary.Write(writer, binary.LittleEndian, &m.Header)
+
+	binary.Write(writer, binary.LittleEndian, &Segment64{
+		LoadCommand:  LcSegment64,
+		Length:       0x48,
+		Name:         [16]byte{'_', '_', 'P', 'A', 'G', 'E', 'Z', 'E', 'R', 'O'},
+		Address:      0,
+		SizeInMemory: config.BaseAddress,
+		Offset:       0,
+		SizeInFile:   0,
+		NumSections:  0,
+		Flag:         0,
+		MaxProt:      0,
+		InitProt:     0,
+	})
+
+	codeStart := 32 + m.Header.SizeCommands
+	totalSize := uint64(codeStart) + uint64(len(m.Code))
+
+	binary.Write(writer, binary.LittleEndian, &Segment64{
+		LoadCommand:  LcSegment64,
+		Length:       0x48,
+		Name:         [16]byte{'_', '_', 'T', 'E', 'X', 'T'},
+		Address:      config.BaseAddress,
+		SizeInMemory: totalSize,
+		Offset:       0,
+		SizeInFile:   totalSize,
+		NumSections:  0,
+		Flag:         0,
+		MaxProt:      ProtReadable | ProtWritable | ProtExecutable,
+		InitProt:     ProtReadable | ProtExecutable,
+	})
+
+	binary.Write(writer, binary.LittleEndian, &Thread{
+		LoadCommand: LcUnixthread,
+		Len:         184,
+		Type:        0x4,
+	})
+
+	binary.Write(writer, binary.LittleEndian, []uint32{
+		42,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		config.BaseAddress + uint32(codeStart), 0,
+		0, 0,
+		0, 0,
+		0, 0,
+		0, 0,
+	})
+
+	writer.Write(m.Code)
+
+	if totalSize < 4096 {
+		writer.Write(bytes.Repeat([]byte{0}, 4096-int(totalSize)))
+	}
+}

src/macho/Prot.go

@@ -0,0 +1,9 @@
+package macho
+
+type Prot uint32
+
+const (
+	ProtReadable   Prot = 0x1
+	ProtWritable   Prot = 0x2
+	ProtExecutable Prot = 0x4
+)

src/macho/Segment64.go

@@ -0,0 +1,16 @@
+package macho
+
+// Segment64 is a segment load command.
+type Segment64 struct {
+	LoadCommand
+	Length       uint32
+	Name         [16]byte
+	Address      uint64
+	SizeInMemory uint64
+	Offset       uint64
+	SizeInFile   uint64
+	MaxProt      Prot
+	InitProt     Prot
+	NumSections  uint32
+	Flag         uint32
+}

src/macho/Thread.go

@@ -0,0 +1,8 @@
+package macho
+
+// Thread is a thread state load command.
+type Thread struct {
+	LoadCommand
+	Len  uint32
+	Type uint32
+}