sys

Documentation

Index

• Constants
• Variables
• type Arch
  • func (a *Arch) InFamily(xs ...ArchFamily) bool
• type ArchFamily

Constants

const ExecArgLengthLimit = (30 << 10)

ExecArgLengthLimit is the number of bytes we can safely pass as arguments to an exec.Command.

Windows has a limit of 32 KB. To be conservative and not worry about whether that includes spaces or not, just use 30 KB. Darwin's limit is less clear. The OS claims 256KB, but we've seen failures with arglen as small as 50KB.

Variables

var Arch386 = &Arch{
	Name:           "386",
	Family:         I386,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        4,
	RegSize:        4,
	MinLC:          1,
	Alignment:      1,
	CanMergeLoads:  true,
	HasLR:          false,
	FixedFrameSize: 0,
}

var ArchAMD64 = &Arch{
	Name:           "amd64",
	Family:         AMD64,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          1,
	Alignment:      1,
	CanMergeLoads:  true,
	CanJumpTable:   true,
	HasLR:          false,
	FixedFrameSize: 0,
}

var ArchARM = &Arch{
	Name:           "arm",
	Family:         ARM,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        4,
	RegSize:        4,
	MinLC:          4,
	Alignment:      4,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 4,
}

var ArchARM64 = &Arch{
	Name:           "arm64",
	Family:         ARM64,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          4,
	Alignment:      1,
	CanMergeLoads:  true,
	CanJumpTable:   true,
	HasLR:          true,
	FixedFrameSize: 8,
}

var ArchLoong64 = &Arch{
	Name:           "loong64",
	Family:         Loong64,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          4,
	Alignment:      8,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 8,
}

var ArchMIPS = &Arch{
	Name:           "mips",
	Family:         MIPS,
	ByteOrder:      binary.BigEndian,
	PtrSize:        4,
	RegSize:        4,
	MinLC:          4,
	Alignment:      4,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 4,
}

var ArchMIPS64 = &Arch{
	Name:           "mips64",
	Family:         MIPS64,
	ByteOrder:      binary.BigEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          4,
	Alignment:      8,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 8,
}

var ArchMIPS64LE = &Arch{
	Name:           "mips64le",
	Family:         MIPS64,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          4,
	Alignment:      8,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 8,
}

var ArchMIPSLE = &Arch{
	Name:           "mipsle",
	Family:         MIPS,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        4,
	RegSize:        4,
	MinLC:          4,
	Alignment:      4,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 4,
}

var ArchPPC64 = &Arch{
	Name:          "ppc64",
	Family:        PPC64,
	ByteOrder:     binary.BigEndian,
	PtrSize:       8,
	RegSize:       8,
	MinLC:         4,
	Alignment:     1,
	CanMergeLoads: false,
	HasLR:         true,

	FixedFrameSize: 4 * 8,
}

var ArchPPC64LE = &Arch{
	Name:           "ppc64le",
	Family:         PPC64,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          4,
	Alignment:      1,
	CanMergeLoads:  true,
	HasLR:          true,
	FixedFrameSize: 4 * 8,
}

var ArchRISCV64 = &Arch{
	Name:           "riscv64",
	Family:         RISCV64,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          4,
	Alignment:      8,
	CanMergeLoads:  false,
	HasLR:          true,
	FixedFrameSize: 8,
}

var ArchS390X = &Arch{
	Name:           "s390x",
	Family:         S390X,
	ByteOrder:      binary.BigEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          2,
	Alignment:      1,
	CanMergeLoads:  true,
	HasLR:          true,
	FixedFrameSize: 8,
}

var ArchWasm = &Arch{
	Name:           "wasm",
	Family:         Wasm,
	ByteOrder:      binary.LittleEndian,
	PtrSize:        8,
	RegSize:        8,
	MinLC:          1,
	Alignment:      1,
	CanMergeLoads:  false,
	HasLR:          false,
	FixedFrameSize: 0,
}

var Archs = [...]*Arch{
	Arch386,
	ArchAMD64,
	ArchARM,
	ArchARM64,
	ArchLoong64,
	ArchMIPS,
	ArchMIPSLE,
	ArchMIPS64,
	ArchMIPS64LE,
	ArchPPC64,
	ArchPPC64LE,
	ArchRISCV64,
	ArchS390X,
	ArchWasm,
}

Types

type Arch

type Arch struct {
	Name   string
	Family ArchFamily

	ByteOrder binary.ByteOrder

	// PtrSize is the size in bytes of pointers and the
	// predeclared "int", "uint", and "uintptr" types.
	PtrSize int

	// RegSize is the size in bytes of general purpose registers.
	RegSize int

	// MinLC is the minimum length of an instruction code.
	MinLC int

	// Alignment is maximum alignment required by the architecture
	// for any (compiler-generated) load or store instruction.
	// Loads or stores smaller than Alignment must be naturally aligned.
	// Loads or stores larger than Alignment need only be Alignment-aligned.
	Alignment int8

	// CanMergeLoads reports whether the backend optimization passes
	// can combine adjacent loads into a single larger, possibly unaligned, load.
	// Note that currently the optimizations must be able to handle little endian byte order.
	CanMergeLoads bool

	// CanJumpTable reports whether the backend can handle
	// compiling a jump table.
	CanJumpTable bool

	// HasLR indicates that this architecture uses a link register
	// for calls.
	HasLR bool

	// FixedFrameSize is the smallest possible offset from the
	// hardware stack pointer to a local variable on the stack.
	// Architectures that use a link register save its value on
	// the stack in the function prologue and so always have a
	// pointer between the hardware stack pointer and the local
	// variable area.
	FixedFrameSize int64
}

Arch represents an individual architecture.

func (*Arch) InFamily

func (a *Arch) InFamily(xs ...ArchFamily) bool

InFamily reports whether a is a member of any of the specified architecture families.

type ArchFamily

type ArchFamily byte

ArchFamily represents a family of one or more related architectures. For example, ppc64 and ppc64le are both members of the PPC64 family.

const (
	NoArch ArchFamily = iota
	AMD64
	ARM
	ARM64
	I386
	Loong64
	MIPS
	MIPS64
	PPC64
	RISCV64
	S390X
	Wasm
)