wasm

Documentation

Index

• Variables
• func MemoryPagesToBytesNum(pages uint32) (bytesNum uint64)
• type Frame
• type Global
• type HostFunc
• type IndexSpace
• type Instance
  • func NewInstance(module *Module, externModules map[string]*Module) (*Instance, error)
  • func (ins *Instance) CallExportedFunc(name string, args ...uint64) (returns []uint64, returnTypes []types.ValueType, err error)
• type Memory
  • func (mem *Memory) Grow(newPages uint32) (result uint32)
  • func (m *Memory) PageSize() uint32
• type Module
  • func NewModule(config config.ModuleConfig, r *bytes.Reader) (*Module, error)
• type Table

Variables

var (
	ErrFuncInvalidInputType  = errors.New("invalid func input type")
	ErrFuncInvalidReturnType = errors.New("invalid func return type")
)

errors of func

var (
	ErrExportedFuncNotFound = errors.New("exported func is not found")
	ErrFuncIndexOutOfRange  = errors.New("function index out of range")
	ErrInvalidArgNum        = errors.New("invalid number of arguments")
)

errors on exec func

var (
	ErrUnreachable                 = errors.New("unreachable")
	ErrBlockNotInitialized         = errors.New("block not initialized")
	ErrBlockNotFound               = errors.New("block not found")
	ErrFuncSignMismatch            = errors.New("function signature mismatch")
	ErrLabelNotFound               = errors.New("label not found")
	ErrTableIndexOutOfRange        = errors.New("table index out of range")
	ErrTableInstanceNotInitialized = errors.New("table entry not initialized")
)

errors on control instr

var (
	ErrInvalidMagicNumber = errors.New("invalid magic number")
	ErrInvalidVersion     = errors.New("invalid version header")
)

errors on parsing module

var ErrPtrOutOfBounds = errors.New("pointer is out of bounds")

ErrPtrOutOfBounds will be throw when the pointer visiting a pos out of the range of memory

var ErrUndefined = errors.New("undefined")

ErrUndefined is a panic error

Functions

func MemoryPagesToBytesNum

func MemoryPagesToBytesNum(pages uint32) (bytesNum uint64)

MemoryPagesToBytesNum converts the given pages into the number of bytes contained in these pages.

Types

type Frame

type Frame struct {
	PC         uint64
	Func       *wasmFunc
	Locals     []uint64
	LabelStack *stacks.Stack[*stacks.Label]
}

Frame is the context data of one instance

type Global

type Global struct {
	*types.GlobalType
	Val interface{}
}

Global is an instance of the global value

type HostFunc

type HostFunc struct {
	Signature *types.FuncType // the shape of func (defined by inputs and outputs)

	// Generator is a func defined by other dev which acts as a Generator to the function
	// (generate when NewInstance's func initializing
	Generator func(ins *Instance) interface{}
	// contains filtered or unexported fields
}

HostFunc is an implement of wasm.Fn, which represents all the functions defined under host(golang) environment

type IndexSpace

type IndexSpace struct {
	Functions []fn
	Globals   []*Global
	Tables    []*Table
	Memories  []*Memory
}

IndexSpace is the indeices to the imports

type Instance

type Instance struct {
	*Module

	Active     *Frame
	FrameStack *stacks.Stack[*Frame]

	Functions []fn
	Memory    *Memory
	Globals   []uint64

	OperandStack *stacks.Stack[uint64]
}

Instance is an instantiated module

func NewInstance

func NewInstance(module *Module, externModules map[string]*Module) (*Instance, error)

NewInstance will instantiate the module with extern modules

func (*Instance) CallExportedFunc

func (ins *Instance) CallExportedFunc(name string, args ...uint64) (returns []uint64, returnTypes []types.ValueType, err error)

CallExportedFunc will call the func `name` with the args TODO: enhance this

type Memory

type Memory struct {
	types.MemoryType
	Value []byte
}

Memory is an instance of the memory value

func (*Memory) Grow

func (mem *Memory) Grow(newPages uint32) (result uint32)

func (*Memory) PageSize

func (m *Memory) PageSize() uint32

PageSize returns the current memory buffer size in pages.

type Module

type Module struct {
	config.ModuleConfig

	// sections
	TypeSection     []*types.FuncType
	ImportSection   []*segments.ImportSegment
	FunctionSection []uint32
	TableSection    []*types.TableType
	MemorySection   []*types.MemoryType
	GlobalSection   []*segments.GlobalSegment
	ExportSection   map[string]*segments.ExportSegment
	StartSection    []uint32
	ElementsSection []*segments.ElemSegment
	CodeSection     []*segments.CodeSegment
	DataSection     []*segments.DataSegment

	// index spaces
	IndexSpace *IndexSpace
}

Module is a standard wasm module implement according to wasm v1, https://www.w3.org/TR/wasm-core-1/#syntax-module%E2%91%A0

func NewModule

func NewModule(config config.ModuleConfig, r *bytes.Reader) (*Module, error)

NewModule reads bytes from the io.Reader and read all sections, finally return a wasman.Module entity if no error

type Table

type Table struct {
	types.TableType
	Value []*uint32 // vec of addr to func
}

Table is an instance of the table value